JP6614481B2 - Vehicle rollover risk judgment system - Google Patents

Description

The present invention relates to a vehicle rollover risk determination system .

  In Patent Document 1, a threshold value line is set on a two-dimensional map using the roll angle and roll angular velocity of a vehicle as parameters, and the actual roll angle and roll angular velocity history line of the vehicle is set on the origin side. A rollover determination method is described in which it is determined that a vehicle may roll over when it crosses from a non-rollover region to a rollover region on the opposite origin side.

  Further, Patent Document 2 discloses a start assist device that uses an air spring as a drive shaft of the rear two shafts to increase the ground pressure of the drive shaft at the start of the vehicle, thereby increasing the traction at the start. Has been described.

JP 2001-071845 A Japanese Patent Laid-Open No. 08-113023

  In a vehicle equipped with a start assist device as in Patent Document 2, the motion characteristics of the vehicle change between a start assist state in which the start assist device operates and a normal state in which the start assist device does not operate. For this reason, if the rollover determination method of Patent Document 1 is applied as it is to a vehicle equipped with a start assist device, there is a possibility that an appropriate determination result cannot be obtained.

Therefore, an object of the present disclosure is to provide a vehicle rollover risk determination system capable of obtaining an appropriate determination result even in the start assist state.

To achieve the above object, a first aspect of the present invention is a vehicle equipped with a start assisting device having a fluid spring to increase the contact pressure of the drive shaft is mounted on the drive shaft of the two axes after including a drive shaft Yes, the fluid spring is a left and right suspension having the same load-displacement characteristics and load-internal pressure characteristics, and the risk of rollover is mounted on the vehicle where the vehicle height is adjusted by supplying and exhausting pressurized air to the left and right suspensions. The degree determination system includes a detection unit, a storage unit, and a determination unit.

Detecting means detects a roll angular velocity of the vehicle and valid roll angle, as rollover danger level determination information for determining the rollover risk of a vehicle. The storage means stores in advance a normal threshold used in a normal state where the start assist device is not operating and a start assist threshold used in a start assist state where the start assist device is operating. The determination means determines the rollover risk of the vehicle using the rollover risk determination information detected by the detection means and the normal threshold stored in the storage means in the normal state, and the detection means detects in the start assist state. The rollover risk degree of the vehicle is determined using the rollover risk degree judgment information and the starting assistance threshold value stored in the storage means.
The detection unit includes a roll angle estimation device that outputs an effective roll angle based on the roll angle detected by the roll angle detection unit to the determination unit. The roll angle estimation device uses the measured values of the displacement of the left and right suspensions and the internal pressure as the correction roll angle for correcting the roll angle detected by the roll angle detector to the roll angle when the vehicle height adjustment is not performed. The correction roll angle calculation storage unit that stores the calculated correction roll angle and the roll angle detected by the roll angle detection unit is corrected using the correction roll angle stored in the correction roll angle calculation storage unit. The post-correction roll angle calculation unit that calculates the rear roll angle, the adjustment determination unit that determines whether or not the vehicle height adjustment is properly executed, and the adjustment determination unit that the vehicle height adjustment is properly executed In this case, the corrected roll angle calculated by the corrected roll angle calculation unit is output as an effective roll angle, and if the adjustment determination unit determines that the vehicle height adjustment is not properly performed, Comprises a roll angle output section roll angle detecting unit outputs a roll angle of value equal to the roll angle detected as a valid roll angle, a.

  In the above configuration, the rollover risk is determined using the normal threshold in the normal state where the start assist device does not operate, and the start assist threshold different from the normal threshold is used in the start assist state where the start assist device is operating. Therefore, the risk of rollover in the start assist state (when the start assist device is operating) can be appropriately determined.

A second aspect of the present invention is the first aspect rollover danger level determination system, memorize means is set roll angle and roll angular velocity on a two-dimensional map as parameters, non-rollover home side The first and second threshold lines that define the boundary between the region and the rollover region on the opposite origin side are stored as a normal threshold and a start assist threshold, respectively. The first threshold line defines the boundary between the normal non-rollover region and the rollover region. The second threshold line defines a boundary between the non-rollover region for starting assistance and the rollover region. In the normal state, the determination means determines that the risk of rollover is low when a point on the two-dimensional map specified by the roll angle and roll angular velocity detected by the detection means exists in the normal non-rollover region. In the normal rollover area, it is determined that the risk of rollover is high. In the start assist state, a point on the two-dimensional map specified by the roll angle and the roll angular velocity detected by the detection means is the start assist. It is determined that the risk of rollover is low when it exists in the non-rollover area for use, and it is determined that the risk of rollover is high when it exists in the rollover area for starting assistance.

  In the above configuration, the rollover risk degree is determined based on the roll angle and roll angular velocity of the vehicle, so that the determination accuracy of the rollover risk degree can be increased.

A third aspect of the present invention is a rollover danger level determination system of the first or second aspect, the roll angle estimating apparatus includes a mode storage unit. Mode storage unit stores which one of the modes of the roll angle estimating apparatus correction valid mode and corrective disabled mode. Roll angle output unit, Ri Oh mode stored in the mode storage unit is in the correction valid mode, and the case where the adjustment determination unit car height adjustment is properly executed is determined, the correction roll angle calculation unit calculating When the adjusted roll angle is output as an effective roll angle and the mode stored in the mode storage unit is the correction invalid mode , or when the adjustment determination unit determines that the vehicle height adjustment is not properly executed. The roll angle having a value equal to the roll angle detected by the roll angle detection unit is output as an effective roll angle.

  When the correction invalid mode is stored in the mode storage unit, the post-correction roll angle calculation unit may calculate the post-correction roll angle with the correction roll angle set to zero, and the roll angle output unit is stored in the mode storage unit. Regardless of which mode is stored, the corrected roll angle calculated by the corrected roll angle calculation unit may be output as an effective roll angle.

  The roll angle output unit may output the roll angle detected by the roll angle detection unit as an effective roll when the correction invalidation mode is stored in the mode storage unit.

  In the above configuration, by storing the correction invalid mode in the mode storage unit, a roll angle having a value equal to the roll angle (detected roll angle) detected by the roll angle detection unit can be reliably output to the determination unit.

  Therefore, after manufacturing a vehicle (reference vehicle) in which the configuration including the roll angle estimation device is made common among different vehicle types, in the manufacturing process of mounting a structure corresponding to the vehicle type on the rear part of the body frame of the reference vehicle, When manufacturing a vehicle (for example, a tank truck, an in-vehicle vehicle, a mixer vehicle, etc.) that is less likely to be unevenly distributed in the vehicle width direction, the mode invalidation mode is stored in the mode storage unit during or after the structure is mounted. Accordingly, a roll angle having a value equal to the detected roll angle can be reliably output to the determination means.

  The correction roll angle calculation storage unit calculates the correction roll angle even when the correction invalid mode is stored in the mode storage unit, and the above calculation is performed even when any mode is stored in the mode storage unit. The corrected roll angle may be accumulated and stored as history data.

  In the above configuration, the correction roll angle that is not used in the correction invalid mode is calculated and accumulated and stored as history data in the same manner as in the correction invalid mode. Thus, the occurrence state of unbalance can be estimated afterwards.

  The roll angle estimation apparatus may include a mode input unit and a mode setting unit. A mode setting instruction is input to the mode input unit. The mode setting unit stores the correction valid mode in the mode storage unit when the correction valid mode setting instruction is input to the mode input unit, and sets the correction invalid mode when the correction invalid mode setting command is input. Store in the mode storage.

  In the above configuration, the mode stored in the mode storage unit can be changed by input to the mode input unit without using an external setting device or the like.

According to a fourth aspect of the present invention , there is provided a vehicle including a start assisting device having a fluid spring that is mounted on a drive shaft among the two rear shafts including the drive shaft and increases a ground pressure of the drive shaft , and the fluid springs are the same. A left-right suspension having the following load-displacement characteristics and load-internal pressure characteristics, and a rollover risk determination system mounted on the vehicle in which automobile height adjustment is performed by supply and exhaust of pressurized air to the left and right suspensions , A detection unit, a storage unit, and a determination unit are provided.

The detection means is configured in the same manner as in the first aspect. The storage means stores in advance a normal threshold used in a normal state where the start assist device is not operating. In the normal state, the determination means determines the rollover risk degree of the vehicle using the rollover risk degree determination information detected by the detection means and the normal threshold value stored in the storage means, and in the start assist state, the rollover risk degree of the vehicle Do not judge.

  In the above configuration, the rollover risk is determined using the normal threshold in the normal state where the start assist device does not operate, and the rollover risk is not determined in the start assist state where the start assist device is operating. However, it is possible to prevent an erroneous determination that the risk of rollover is high in a start assist state that is significantly lower than that in the normal state.

  According to the rollover risk determination device of the present invention, an appropriate determination result can be obtained even in the start assist state.

It is the block diagram which showed one Embodiment of this invention. It is the block diagram which showed the rear-wheel side of FIG. It is the block diagram which showed the functional structure of the process part of FIG. It is the flowchart figure which showed the operation example of the starting assistance determination part and vehicle height adjustment apparatus of FIG. It is the flowchart figure which showed the example of interaction between the process part of FIG. 1, and a rollover risk determination apparatus. FIG. 2 is a graph showing a two-dimensional map used in the rollover risk determination device of FIG. 1 when the vehicle shown in FIG. 1 is in a normal state. FIG. 2 is a graph showing a two-dimensional map used in the rollover risk degree judging device of FIG. 1 when the vehicle shown in FIG. 1 is in a start assisting state. It is the figure which showed an example of the roll moment which arises in the vehicle of FIG. It is the graph which showed the example of the load-displacement characteristic of a suspension. It is the figure which showed the example of the load-internal pressure characteristic of a suspension. It is the graph which showed the relationship between the internal pressure of a suspension, and a displacement characteristic coefficient. It is the flowchart figure which showed the roll angle correction process example [1] of the process part used for one Embodiment of this invention. It is the flowchart which showed the filter process of FIG. It is the flowchart figure which showed the key ON mode process of FIG. It is a schematic sectional side view of the vehicle for demonstrating full rebound and a full bump. It is the graph which showed the example of the spring characteristic of the suspension in case load is constant. It is the flowchart which showed the flag setting process of FIG. 13 is a flowchart showing a vehicle height adjustment mode of FIG. It is the flowchart which showed the roll angle calculation process after correction | amendment of FIG. It is the flowchart which showed the vehicle height adjustment mode process of the roll angle correction process example [2] of the process part used for one Embodiment of this invention. It is the flowchart which showed the vehicle height adjustment mode process of the roll angle correction process example [2] of the process part used for one Embodiment of this invention. It is the flowchart which showed the roll angle calculation process after correction | amendment of the roll angle correction process example [3] of the process part used for one Embodiment of this invention.

<Configuration example: FIG. 1>
As shown in FIG. 1, a roll angle estimation device 10, a rollover risk determination device 20, a vehicle height adjustment device 30, and a start assist determination unit 31 are mounted on the vehicle 1 according to the present embodiment. 10 includes displacement detection units 11L and 11R (hereinafter may be collectively referred to as reference numeral 11), pressure measurement units 12L and 12R (hereinafter may be collectively referred to as reference numeral 12), and a processing unit 13. The rollover risk determination device 20 includes a roll angle / roll angular velocity detection unit (roll angle detection unit) 21, a rollover risk determination unit 22, a brake controller 23, a determination map storage unit 24, and a start assist flag storage. Part 25.

Displacement detectors 11L and 11R are suspensions 3L and 3R provided respectively near the left rear wheel 2L and the right rear wheel 2R of the vehicle 1 (hereinafter sometimes collectively referred to as reference numeral 3 and also referred to as air springs). The displacements Z _L and Z _R (the frame height with respect to the axle) are detected. Pressure measuring unit 12L and 12R measure the internal pressure _{P L} and _{P R} of the suspension 3L and 3R.

  The processing unit 13 of the roll angle estimation device 10, the rollover risk determination unit 22 of the rollover risk determination device 20, and the start assistance determination unit 31 store a predetermined program and data acquired and calculated in advance. Configured by an ECU (Electronic Central Unit) equipped with a storage unit such as a ROM (Read Only Memory) and a RAM (Random Access Memory) and a CPU (Central Processing Unit) that executes processing according to a program read from the storage unit Is done. The storage unit of the ECU is provided with a start assist flag storage unit 25 as a storage area for a start assist mode flag which is binary data described later.

  As shown in FIG. 3, the processing unit 13 of the roll angle estimation device 10 includes a corrected roll angle calculation storage unit 14, a post-correction roll angle calculation unit 15, a roll angle output unit 16, a mode storage unit 17, an adjustment determination unit 18, And it functions as the determination storage unit 19. Each flag (binary data) other than the start assistance mode flag is stored in a predetermined storage area of the processing unit 13 or the rollover risk determination device 20.

The correction roll angle calculation storage unit 14 includes internal pressures P _L and P _R (measured values of the internal pressure) measured by the pressure measurement units 12L and 12R, and displacements Z _L and Z _R (displacement values) detected by the displacement detection units 11L and 11R. Based on the measured value), the roll angle φ _2es when the vehicle height adjustment is not performed (hereinafter sometimes referred to as vehicle height adjustment non-execution) is estimated, and the roll angle / roll while the vehicle 1 is traveling The correction roll angle φ _2off for correcting the roll angle φ detected by the angular velocity detection unit 21 to the roll angle when the vehicle height adjustment is not executed is used as the estimated roll angle φ _2es when the vehicle height adjustment is not executed. The calculated correction roll angle φ _2off is stored in the storage unit. The post-correction roll angle calculation unit 15 corrects the roll angle φ detected by the roll angle / roll angular velocity detection unit 21 using the stored correction roll angle _φ2off , thereby correcting the roll angle (post-correction roll). Angle) φ _AMD is calculated. The roll angle output unit 16 outputs an effective roll angle to the rollover risk determination unit 22 of the rollover risk determination device 20.

  The roll angle estimation device 10 is selectively set to one of the correction valid mode and the correction invalid mode, and is set to the mode storage unit 17 (the storage unit of the processing unit 13) according to the mode change. The state of the correction invalid mode flag is switched. That is, the mode storage unit 17 stores which mode the roll angle estimation device 10 is in the correction valid mode and the correction invalid mode. The roll angle estimation device 10 is set to the correction valid mode (correction invalid mode flag: “0”) in the initial state, and receives a setting invalid mode invalidation instruction (correction invalid mode flag: correction invalid mode flag: When the setting is switched to “1”) and a setting instruction for the correction valid mode is received, the correction valid mode (correction invalid mode flag: “0”) is switched again. The roll angle estimation device 10 is connected to an external setting device 40 having a function of changing and setting a program in the processing unit 13 as necessary, and a mode setting instruction (rewriting of correction invalid mode flag data) is performed. This is performed by using a program setting function by the external setting device 40 connected to the roll angle estimation device 10.

The vehicle height adjusting device 30 is set to the vehicle height adjusting mode or the manual mode in accordance with an input instruction from a user (driver or the like). Displacement Z _L and Z _R detected by the displacement detector 11L and 11R is also input to the level control system 30, when the vehicle height adjusting mode is set, the level control system 30 of the vehicle 1 as the vehicle height becomes the predetermined standard vehicle height in the engine driving state (such that the displacement Z _L and Z _R are all reference displacement Z _ST), controls the supply and exhaust of pressurized air for suspension 3L and 3R . On the other hand, when the manual mode is set, the vehicle height adjusting device 30 controls the supply and exhaust of pressurized air to and from the suspensions 3L and 3R so as to achieve the vehicle height according to the input instruction from the user. Supply / exhaust of pressurized air to / from the suspensions 3L and 3R is controlled by opening / closing control valves (not shown) provided in air lines (not shown) to the suspensions 3L and 3R.

If the vehicle height adjusting mode is set, the vehicle height adjustment device 30, for example during turning, in order to suppress a variation from the standard vehicle height, one of the inner pressure of the displacement Z _L and Z based on the _R suspension 3L and 3R Is increased (injected with air AP) and the other internal pressure is decreased (discharged with air AP), thereby forcibly changing the load-displacement characteristics of the suspensions 3L and 3R, respectively, so Adjust (correct) (Z _L -Z _R ).

  That is, in the vehicle 1, only the suspensions 3L and 3R are subject to vehicle height adjustment, and the vehicle height adjustment (hereinafter sometimes simply referred to as vehicle height adjustment) is performed by supplying and exhausting pressurized air to and from the suspensions 3L and 3R. The vehicle height adjustment is not performed for the suspensions 5L and 5R provided near the left front wheel 4L and the right front wheel 4R, respectively. Therefore, in the following description, the load F and the internal pressure P are values for the suspensions 3L and 3R.

  As shown in FIG. 2, the vehicle 1 of the present embodiment is a rear two-shaft vehicle having two shafts (the rear front shaft 6F and the rear rear shaft 6B) as the rear axle 6, and the left and right rear wheels 2L and 2R are The rear front wheels 2LF and 2RF are supported by the rear front shaft 6F, and the rear rear wheels 2LB and 2RB are supported by the rear rear shaft 6B. The rear front shaft 6F is a drive shaft, the rear front wheels 2LF and 2RF are drive wheels, the rear rear shaft 6B is a driven shaft, and the rear rear wheels 2LB and 2RB are driven wheels.

  The left suspension 3L includes a pair of rear front suspensions 3LF disposed before and after the rear front shaft 6F and a pair of rear rear suspensions 3LB disposed before and after the rear rear shaft 6B. 3R includes a pair of rear front suspensions 3RF disposed before and after the rear front shaft 6F and a pair of rear rear suspensions 3RB disposed before and after the rear rear shaft 6B. The eight suspensions 3LF, 3LB, 3RF, and 3RB are the same suspension. In the present embodiment, the internal pressures of the left pair of rear rear suspensions 3LF, the internal pressures of the left pair of rear rear suspensions 3LB, the internal pressures of the right pair of rear front suspensions 3RF, and the right ones Each internal pressure of the rear rear suspension 3RB of the pair is controlled to the same internal pressure. The left pressure measurement unit 12L includes a pressure measurement unit 12LF that measures the internal pressure of the left rear rear suspension 3LF, and a pressure measurement unit 12LB that measures the internal pressure of the left rear rear suspension 3LB, and the right pressure measurement unit 12R includes a pressure measurement unit 12RF that measures the internal pressure of the right rear front suspension 3RF, and a pressure measurement unit 12RB that measures the internal pressure of the right rear rear suspension 3RB.

  The left and right rear front suspensions 3LF and 3RF are mounted on the drive shaft 6F among the rear two shafts 6F and 6B including the drive shaft 6F and function as fluid springs that increase the ground pressure of the drive shaft 6F (drive wheels 2LF and 2RF). To do. By injecting the pressurized air into the rear front suspensions 3LF and 3RF while stopping the supply and discharge of the pressurized air to the rear rear suspensions 3LB and 3RB, the ground pressure of the drive wheels 2LF and 2RF increases.

  In FIG. 1, for the sake of simplicity, the rear front wheels 2LF and 2RF and the rear rear wheels 2LB and 2RB are illustrated as one rear wheel 2L and 2R, and the left two rear front suspensions 3LF and two rear rear suspensions are illustrated. 3LB is illustrated as one suspension 3L on the left, the two rear rear suspensions 3RF on the right and the two rear rear suspensions 3RB are illustrated as one suspension 3R on the right, and the front and rear pressure measurement units 12LF and 12LB are illustrated. Is shown as one pressure measurement unit 12L on the left, and the pressure measurement units 12RF and 12RB on the right and the back are shown as one pressure measurement unit 12R on the right.

  In processes other than starting assistance (vehicle height adjustment process, etc.) described later, the left rear front suspension 3LF and the rear rear suspension 3LB are controlled to have the same internal pressure, and the right rear front suspension 3RF and the rear rear suspension 3RB have the same internal pressure. Controlled. Therefore, regarding the processing other than the start assistance, the left four suspensions 3LF and 3LB are regarded as one suspension 3L (the whole four suspensions 3LF and 3LB are replaced with one suspension 3L), and the right four The description will be made assuming that the three suspensions 3RF and 3RB are regarded as one suspension 3R (the whole of the four suspensions 3RF and 3RB is replaced with one suspension 3R).

  The start assist determination unit 31 determines that the condition for shifting to the start assist mode is when the vehicle 1 is starting from a stopped state and the vehicle 1 is empty (a load is lighter than a predetermined weight). It is determined that it has been established. Further, it is determined that the condition for canceling the start assist mode is satisfied when the vehicle shifts to the normal travel during the start assist mode. In the present embodiment, the period from when the vehicle speed detected by a vehicle speed sensor (not shown) increases from zero to reach a predetermined vehicle speed is determined as starting, and when the vehicle reaches the predetermined vehicle speed during the start assist mode, the vehicle travels normally. Judge that it has migrated. Further, when the internal pressure measured by the pressure measuring units 12L and 12R is less than a predetermined pressure, it is determined that the product is empty.

Start assisting determination unit 31, when the shift condition to start assisting mode is established, sends a start assist start signal SS _S relative vehicle height adjusting device 30, the start assist mode flag of start assisting flag storage unit 25 " Set to 1 ”. Further, when the release conditions of start assisting mode during start aid mode is established, sends a start assist completion signal SS _F relative vehicle height adjusting device 30, the start assist mode flag of start assisting flag storage section 25, "0 Set to "". Incidentally, without transmitting the start assist start assist start signal from the determination unit 31 to the vehicle height adjusting device 30 SS _S and start assist completion signal SS _F, in response to the start assisting mode flag is set to "1", rollover risk determining unit 20 or processing unit 13 may transmit the start assist start signal SS _S and start assist completion signal SS _F to the level control system 30.

Vehicle height adjusting device 30, by receiving a start assist start signal SS _S, it is changed from the vehicle height adjusting mode or the manual mode to the start assist mode, by receiving a start assist completion signal SS _F, from start assist mode Return to automobile height adjustment mode or manual mode. The rollover risk determination device 20 is set to the start assist mode by setting the start assist mode flag to “1”, and is set to the normal state (non-start by setting the start assist mode flag to “0”). Return to assist mode.

  When shifting to the start assist mode, the vehicle height adjusting device 30 injects pressurized air into the rear front suspensions 3LF and 3RF while stopping the supply and discharge of the pressurized air to the rear rear suspensions 3LB and 3RB. Thereby, the ground pressure of the drive wheels 2LF and 2RF increases. In this way, the vehicle height adjusting device 30 functions as a axle load moving device that increases the axial load of the drive shaft 6F during an unloading operation, and the start assist determination unit 31, the vehicle height adjusting device 30, the rear front suspensions 3LF, 3RF, Constitutes a starting assistance device. When the start assist mode is canceled, the vehicle height adjusting device 30 starts a vehicle height adjusting operation according to the set vehicle height adjusting mode or the manual mode.

The processing unit 13 and the vehicle height adjusting device 30 are interconnected, and the processing unit 13 starts vehicle height adjustment (vehicle height adjustment in both the vehicle height adjusting mode and the manual mode) from the vehicle height adjusting device 30. while receiving a signal SG _S and SG _F respectively timing and end timing, so as to be suspended vehicle height adjustment gives the vehicle height adjustment suspension command signal INS1 and restart instruction signal INS2 relative vehicle height adjusting device 30 Yes.

The adjustment determination unit 18 determines whether or not the vehicle height adjustment device 30 properly executes the vehicle height adjustment in the vehicle height adjustment mode, and determines that the vehicle height adjustment is properly executed. The correction validity determination flag set in the unit 19 (storage unit of the processing unit 13) is set to “1”. The correction valid determination flag is set to “1” only when the vehicle height adjustment is properly executed in the vehicle height adjustment mode, and when the vehicle height adjustment is not properly executed in the vehicle height adjustment mode or in the manual mode. In this case, it is set to “0”. When the vehicle height adjustment is not properly executed, for example, when the pressure measuring unit 12L or 12R is broken, when the control valve of the air line is broken, or when the vehicle is supplied to the suspension 3L or 3R This is the case when the amount of pressurized air to be used or the pressure is insufficient. Since height In any case is in a state of being deviated from the standard vehicle height, in the present embodiment, the automobile height adjustment mode, both the displacement Z _L and Z _R detected by the displacement detector 11L and 11R when _{(Z ST -α ≦ Z L ≦} Z ST + β, and _{Z ST -α ≦ Z R ≦ Z} ST + β) which is included in a predetermined reference range including the reference displacement _{Z ST,} properly car height adjustment It determined to be running, when at least one of the displacement _{Z L} or _{Z R} is not included in the reference range _{(Z L <Z ST -α,} Z ST + β <Z L, Z R <Z ST -α, Alternatively, it is determined that the vehicle height adjustment is not properly executed in Z _ST + β <Z _R ). Α and β defining the reference range may be the same value or different values. In addition, assuming that the displacement detection unit 11L or 11R is out of order, the failure detection of the displacement detection unit 11L and 11R is executed, and even when it is determined that the displacement detection unit 11L or 11R is out of order, You may determine with adjustment not being performed appropriately. Further, it may be determined whether or not the vehicle height adjustment is properly performed based on fluctuations in internal pressure and displacement with respect to the control valve opening / closing control. In other words, it is arbitrary how to determine whether or not the vehicle height adjustment is properly executed.

When it is determined that the correction valid mode is set (the correction invalid mode flag is “0”) and the vehicle height adjustment is properly executed (the correction valid judgment flag is “1”), the processing unit 13 performs the post-correction The roll angle φ _AMD is output to the rollover risk determination unit 22 as an effective roll angle. On the other hand, when the correction invalid mode is set (the correction invalid mode flag is “1”), or when it is determined that the vehicle height adjustment is not properly executed (the correction valid determination flag is “0”), the processing unit 13 outputs a roll angle having a value equal to the roll angle φ detected by the roll angle / roll angular velocity detection unit 21 to the rollover risk determination unit 22 as an effective roll angle. In the present embodiment, when the correction invalid mode flag is “1” or when the correction validity determination flag is “0”, the post-correction roll angle calculation unit 15 sets the correction roll angle _φ2off to zero and the post-correction roll angle φ. _{The AMD} is calculated, and the roll angle output unit 16 outputs the corrected roll angle φ _AMD calculated by the corrected roll angle calculation unit 15 to the rollover risk determination unit 22 as an effective roll angle.

<Starting assistance processing: FIG. 4>
Next, an example of the start assistance determination process executed by the start assistance determination unit 31 will be described with reference to FIG.

  As shown in FIG. 4, the start assist determination unit 31 determines whether or not the start assist mode flag in the start assist flag storage unit 25 is “1” (whether or not the start assist mode is in effect) (step S31). S151).

  If it is determined that the start assist mode flag is “0” (not in the start assist mode) (step S151: NO), it is determined whether a condition for shifting to the start assist mode is satisfied (step S152). Specifically, it is determined that the transition condition is satisfied when the vehicle 1 is at the start and is idle.

Shift condition to start assisting mode is determined to be satisfied (step S152: YES), it sends a start assist start signal SS _S relative vehicle height adjusting device 30, starting the auxiliary mode flag of start assisting flag storage section 25 Is set to “1” (step S153), and this process is terminated.

  If the start assist mode flag is “0” (step S151: NO) and it is determined that the conditions for shifting to the start assist mode are not satisfied (step S152: NO), the process of step S153 is not executed. The process ends.

  If it is determined that the start assist mode flag is “1” (in the start assist mode) (step S151: YES), it is determined whether or not the vehicle 1 has shifted to normal travel (step 154). Specifically, when the vehicle speed is equal to or higher than a predetermined vehicle speed, it is determined that the vehicle has shifted to normal travel.

When the vehicle 1 is determined to have shifted to the normal traveling (step 154: YES), sends a start assist completion signal SS _F relative vehicle height adjusting device 30, the start assist mode flag of start assisting flag storage unit 25 " It is set to “0” (step S155), and this process ends.

  If the start assist mode flag is “1” (step S151: YES) and it is determined that the vehicle 1 has not shifted to normal travel (step 154: NO), the process of step S155 is not executed, and the start assist mode is set. This processing is terminated while maintaining the above.

The level control system has received the start assist start signal SS _S 30, the process proceeds to start assisting mode, distant future suspension 3LB, before or after remains stopped pressurized air supply and discharge for 3RB suspension 3LF, pressurized air to 3RF To increase the ground pressure of the drive wheels 2LF and 2RF. Also, start assisting completion signal SS _F level control system has received the 30 cancels the start assist mode to start the vehicle height adjustment operation according to the pre-set has been car height adjustment mode or manual mode.

<Rolling risk determination processing: FIGS. 5 to 7>
Next, an example of the rollover risk determination / control process executed by the rollover risk determination device 20 will be described with reference to FIGS.

The rollover risk determination device 20 shown in FIG. 1 rolls over the vehicle 1 based on the roll angle φ and roll angular velocity ω (rollover risk determination information) of the vehicle 1 detected by the roll angle / roll angular velocity detection unit (detection means) 21. A rollover risk degree determination unit (determination means) 22 that calculates the target deceleration G _target from the rollover risk degree H and a brake controller 23 that performs brake control according to the target deceleration G _target while determining the risk degree H. A determination map storage unit (storage means) 24 for storing a two-dimensional map used in the rollover risk determination processing in each of the normal state (other than the start assist mode) and the start assist state (start assist mode); The start assist flag storage unit 25 stores a start assist mode flag indicating whether or not the assist mode is set.

  FIG. 5 shows the mutual operation of the rollover risk degree determination device 20 and the roll angle estimation device 10. This operation is executed in parallel with the vehicle height adjusting device 30 based on the starting assistance determination process of FIG. As shown in FIG. 5, the roll angle / roll angular velocity detection unit 21 detects the roll angle φ and the roll angular velocity ω of the vehicle 1, gives the roll angular velocity ω to the rollover risk determination unit 22, and processes the roll angle φ. To the unit 13 (step S101).

The processing unit 13 corrects the roll angle φ and gives the corrected roll angle φ _AMD to the rollover risk determination unit 22 as an effective roll angle (step S102). As described above, when the correction invalid mode is set, or when it is determined that the vehicle height adjustment is not properly executed, the roll angle φ detected by the roll angle / roll angular velocity detection unit 21 is determined. Is given to the rollover risk determination unit 22 as an effective roll angle.

  Next, the rollover risk determination unit 22 refers to the start assist mode flag stored in the start assist flag storage unit 25, and the roll angle φ and the roll angular velocity ω stored in advance in the determination map storage unit 24. Of the two types of two-dimensional maps (FIGS. 6 and 7) showing the relationship, the map to be used in the subsequent processing is selected (step S103).

  FIG. 6 is a two-dimensional map selected and used in the normal state (when the start assist mode flag = “0”), and FIG. 7 shows the start assist state (when the start assist mode flag = “1”). It is a two-dimensional map that is selected and used.

  As shown in FIGS. 6 and 7, each two-dimensional map is set with the roll angle φ and the roll angular velocity ω as parameters. In the normal two-dimensional map (FIG. 6), the boundary between the rollover area on the origin side (stable area R1) and the rollover area on the opposite side (left rollover risk area R2L and right rollover risk area R2R) is defined. The first threshold line (boundary lines T1 and T2) is stored (set) as a normal threshold. In addition, in the two-dimensional map for starting assistance (FIG. 7), the boundary between the rollover area on the origin side (stable area R1) and the rollover area on the opposite side (left rollover danger area R2L and right rollover danger area R2R). Is stored (set) as a threshold value for starting assistance.

  As shown in FIG. 7, the start assisting boundary lines T3 and T4 of the present embodiment are set at positions moved substantially parallel to the normal boundary lines T1 and T2 in a direction away from the origin. The start assisting stable region R1β extends (is widened) from the normal stable region R1α (see FIG. 6) so as to narrow both the left rollover risk region R2L and the right rollover risk region R2R. Note that the normal boundary line and the start assist boundary line are not limited to the above, and it is sufficient that the start assist line is set to expand the stable region rather than the normal line.

  The rollover risk determination unit 22 uses the two-dimensional map selected in step S103, and determines the roll angle φ and each of the two boundary lines (T1, T2 or T3, T4) provided in the two-dimensional map. The distances L1 and L2 to the point S specified by the roll angular velocity ω are calculated according to the following formulas (1) and (2) (step S104). As described above, the pair of boundary lines (T1, T2 and T3, T4) of each two-dimensional map has a stable region R1 indicating that there is no risk of the vehicle 1 rolling over, and the vehicle 1 rolls over to the left. A left rollover risk area R2L indicating that there is a risk and a right rollover risk area R2R indicating that there is a risk of rollover to the right are classified.

  In the normal state, as shown in FIG. 6, A1 and B1 in the above formula (1) are the φ axis intercept (A1α) and the ω axis intercept (B1α) of the boundary line T1, and the above formula ( A2 and B2 in 2) are the φ-axis intercept (A2α) and the ω-axis intercept (B2α) of the boundary line T2. In the start assist state, as shown in FIG. 7, A1 and B1 in the above equation (1) are the φ axis intercept (A1β) and the ω axis intercept (B1β) of the boundary T3, and the above equation A2 and B2 in (2) are the φ-axis intercept (A2β) and the ω-axis intercept (B2β) of the boundary line T4. Since A1α and A1β, A2α and A2β, B1α and B1β, and B2α and B2β are all set to different values, the position of the point S (roll angle φ and roll angular velocity ω) on each two-dimensional map is Even if they are the same, the distances L1 (L1α) and L2 (L2α) calculated in the normal state and the distances L1 (L1β) and L2 (L2β) calculated in the start assist state are different from each other. Become.

  Here, assuming that the left rollover risk area R2L side and the right rollover risk area R2R side are positive with respect to the boundary lines T1 and T2, and in each case, the stable area R1 side is defined as negative, the distances L1 and L2 The combinations are as follows.

  (A) When L1 ≦ 0 and L2 ≦ 0, there is no risk of rollover.

  (B) When L1> 0 and L2 ≦ 0, there is a risk of rollover to the left.

  (C) When L1 ≦ 0 and L2> 0, there is a risk of rollover to the right.

  (D) System error if L1> 0 and L2> 0.

  Therefore, when the above (A) is satisfied (step S105: YES), the rollover risk determination unit 22 determines that there is no risk of rollover (within the stable region R1) and does not perform any control (step S108). As described above, since the start assistance stable region R1β is wider than the normal stability region R1α, it is easier to determine that there is no danger in the start assistance state than in the normal state.

  On the other hand, when the above (B) is established (step S106: YES), the rollover risk determination unit 22 determines that there is a risk of left rollover (within the left rollover risk area R2L), and sets the distance L1 to the rollover risk H (Step S109).

  If (C) is satisfied (step S107: YES), the rollover risk determination unit 22 determines that there is a risk of right rollover (within the right rollover risk area R2R), and sets the distance L2 to the rollover risk H (Step S110).

  As described above, the distance L1 is adopted as the value of the risk of rollover H when there is a risk of rollover to the left and the distance L2 when there is a risk of rollover to the right.

Then, the rollover risk degree determination unit 22 calculates a target deceleration G _target necessary for preventing the vehicle 1 from rollover from the rollover risk degree H, and supplies the target deceleration G _target to the brake controller 23 (step S111). The target deceleration G _target is not limited to the one calculated by multiplying the rollover risk H by a coefficient K as shown in the figure, but may be any that changes according to the increase or decrease of the rollover risk H.

The brake controller 23 calculates the brake pressure necessary for each wheel so as to achieve the target deceleration G _target and performs brake control (step S113).

  If (D) is established, the rollover risk determination unit 22 determines a system error, and records an error flag inside the rollover risk determination device 20 (step S112).

  In this rollover risk determination device 20, the rollover risk determination unit 22 outputs a rollover risk H to the outside, and performs an alarm control according to the rollover risk H instead of the brake controller 23 described above. (Not shown). In this case as well, the above description applies in the same manner.

  In this manner, the rollover risk level is determined based on the roll angle and the roll angular velocity that continuously change according to the traveling state of the vehicle 1, and brake control, alarm control, and the like according to the rollover risk level can be performed. Thus, it is possible to prevent the vehicle 1 from overturning.

In addition, since the rollover risk determination device 20 calculates the distances L1 and L2 using the corrected roll angle φ _AMD obtained by the roll angle correction process, even if the vehicle height adjustment is performed, The rollover risk determination device 20 can accurately determine the rollover risk H of the vehicle 1.

  Furthermore, in the normal state where start assistance is not executed, the risk of rollover is determined using a normal two-dimensional map, and in the start assist state, the risk of rollover is determined using a two-dimensional map for starting assistance different from the normal one. Therefore, the risk of rollover in the start assist state can be properly determined.

<Other examples of rollover risk determination processing>
In the above example, the determination map storage unit 24 stores two types of two-dimensional maps (for normal use and for starting assistance) in advance, and the rollover risk determination unit 22 rolls over using the normal two-dimensional map in a normal state. The risk is determined, and in the start assist state, the risk of rollover is determined using the two-dimensional map for starting assistance. However, the determination map storage unit 24 stores only the normal two-dimensional map in advance and determines the risk of rollover. The unit 22 may determine the risk of rollover using the normal two-dimensional map only in the normal state without determining the risk of rollover in the start assist state.

  In this example, it is possible to prevent an erroneous determination that the risk of rollover is high in a start assist state in which the possibility of rollover is significantly lower than in the normal state.

<Description of roll stiffness coefficient K _φ13 >
Next, the definition of the roll stiffness coefficient _Kφ13 will be described below with reference to FIG. The calculation of the roll stiffness coefficient and the correction of the roll angle by the calculation are necessary for the rollover risk determination device 20 to perform an accurate operation, and will be described in detail below. Further, in the operations described below, several flags (binary data) such as a key ON mode flag, a control flag, a correction invalid flag, and a correction valid determination flag are used, all of which are processing units. 13 is stored and used internally, and is independent of the start assist mode flag stored in the start assist flag storage unit 25 described above.

As shown in FIG. 8, assuming that a roll moment M _x is generated in the vehicle 1 due to unbalanced load (or constant centrifugal acceleration), on the front wheel side of the vehicle 1 (the suspensions 5L and 5R side that are not subject to vehicle height adjustment). The roll moment balance equation can be expressed by the following equation (3).

K _φ1 , φ ₁ , K _φ12 , and φ ₂ in the above equation (3) are respectively known fixed roll stiffness coefficients common to the suspensions 5L and 5R determined by design conditions and the like, and suspensions 5L and 5R. Unknown (not measured) roll angle caused by the displacement difference, unknown torsional stiffness coefficient of the vehicle frame (not shown) that changes depending on the material of the load and its fixing condition, and the rear wheel subject to vehicle height adjustment This is a measurable roll angle caused by the displacement difference between the side suspensions 3L and 3R.

  Further, the equation of balance of roll moments on the suspensions 3L and 3R side can be expressed by the following equation (4).

M _x2 and K _φ2 in the above formula (4) are common to the suspensions 3L and 3R determined by the unknown roll moment generated by the suspensions 3L and 3R, the design conditions, etc. in accordance with the vehicle height adjustment, respectively. A known fixed roll stiffness coefficient.

When the above formula (3) is arranged for the roll angle φ ₁ , the following formula (5) is obtained.

When this formula (5) is updated to the above formula (4) and the roll moment M _x due to the load unbalance is arranged, the following formula (6) is obtained.

Here, as shown in the following equation (7), the roll stiffness coefficient K _.phi.1, to define the vehicle-specific roll stiffness coefficient K _Ø13 by K _.phi.2 and frame torsional rigidity coefficient K _.phi.12, in the above formula (6) Focusing on the fact that the expressed roll moment M _x is constant as long as the loading condition of the load does not change, any two time points at which vehicle height adjustment (at least a part from the adjustment start time to the end time) intervenes. , The roll moment M _x2a by the suspensions 3L and 3R at the first time point (for example, at the start of vehicle height adjustment) and the roll angle φ _2a generated by the displacement difference thereof, and the roll at the second time point (for example, at the end of vehicle height adjustment). The equality relationship shown in the following formula (8) is established between the moment M _x2b and the roll angle φ _2b .

When the above equation (8) is arranged for the roll stiffness coefficient _Kφ13 , the following equation (9) is obtained.

In other words, even frame torsional rigidity coefficient K _.phi.12 is any value, it is possible to determine the roll stiffness coefficient K _Ø13 knowing the roll moment M _x2a and M _x2b and roll angle phi _2a and phi _2b are.

Here, the loads F _La and F _Ra to the suspensions 3L and 3R are calculated from the internal pressures P _La and P _Ra at the first time point according to the following equation (10).

The above equation (10) is a linear approximation equation (k and m are coefficients determined by design conditions) indicating the load-internal pressure characteristics commonly exhibited by the suspensions 3L and 3R themselves. As shown in FIG. P _L and _P loads from _{R F L} and _{F R} are uniquely identified respectively.

Moreover, the load _{F Lb} and _{F Rb} for suspension 3L and 3R from the internal pressure _{P Lb} and _{P Rb} in the second time point is calculated according to the following equation (11).

The roll moment M _x2a by the suspensions 3L and 3R at the first time point is calculated using the loads F _La and F _Ra calculated by the above equation (10) according to the following equation (12). Similarly, the roll moment _{M x2b} by suspension 3L and 3R in the second time, in accordance with the following equation (12), is calculated using the load _{F Lb} and _{F Rb} calculated by the formula (11).

  In the above equation (12), trd is the distance (tread length) between the suspensions 3L and 3R and the roll center (not shown).

The roll angle φ _{2a at} the first time point is calculated using the displacements Z _La and Z _Ra at the first time point according to the following equation (13). Similarly, the roll angle φ _{2b at} the second time point is calculated using the displacements Z _Lb and Z _Rb at the second time point according to the following equation (13).

The roll stiffness coefficient K _φ13 is calculated using the above formula (9) using the roll moments M _x2a and M _x2b calculated by the above formula (12) and the roll angles φ _2a and φ _2b calculated by the above formula (13). ).

<First estimation method of roll angle φ _2es when vehicle height adjustment is not executed>
Next, a first method for estimating the roll angle φ _2es when the vehicle height adjustment is not executed using the roll stiffness coefficient K _φ13 will be described.

Since the roll moment M _x due to the unbalanced load shown in FIG. 8 is constant before and after the vehicle height adjustment, the roll moment M _x2b and the roll angle φ _2b at the end of the vehicle height adjustment and when the vehicle height adjustment is not executed. The equality relationship shown in the following formula (14) is established between the roll moment (trd (F _Les -F _Res )) and the roll angle φ _2es .

F _Les and F _Res in the above formula (14) are loads when the vehicle height adjustment is not executed on the suspensions 3L and 3R, respectively.

  The above formula (14) can be expressed by the following formula (16) using a linear approximation formula of load-displacement characteristics common to the suspensions 3L and 3R shown in the following formula (15).

Z _Les and Z _Res in the above equation (16) are the displacements of the suspensions 3L and 3R when the vehicle height adjustment is not executed, respectively. The constant b is deleted when the difference between the displacements Z _Les and Z _Res is taken.

Also, a plurality of first-order coefficients a and constants b in the above equation (15) are obtained in advance by experiments or the like as shown in FIG. That is, in the experimental stage, the internal pressure P when the reference length _{P 1,} P _2, and fixed to the _{··· P 7 (P 1 <P} 2 <··· <P 7) in a state of containment air The load F applied to the suspension 3L or 3R is sequentially changed, and the displacement Z at each time is measured. Thus, actual load-displacement characteristics CF1 to CF7 indicated by dotted lines in FIG.

  Thereafter, as shown in FIG. 1A, the displacement characteristics CF1 to CF7 are linearly approximated, and linear approximation expressions EXP1 (load F = primary coefficient a1 · displacement Z + constant b1), EXP2 (F = a2 · Z + b2). ), EXP3 (F = a3 * Z + b3), EXP4 (F = a4 * Z + b4), EXP5 (F = a5 * Z + b5), EXP6 (F = a6 * Z + b6), and EXP7 (F = a7 * Z + b7).

  The table shown in FIG. 2B shows the internal pressure P and the values of the first order coefficients a1 to a7 and the constants b1 to b7 in the linear approximation expressions EXP1 to EXP7 in association with each other. As shown in the figure, the primary coefficient a and the constant b are proportional to the internal pressure P. This is shown on the graph in FIGS. 11 (1) and 11 (2), and the primary coefficient a and the constant b are expressed by the following formula (17).

As described above, the vehicle height adjusting device 30 pressurizes one internal pressure of the suspensions 3L and 3R, and reduces the other internal pressure by the pressurization. Therefore, the average value between the internal pressure _{P Lb} and _{P Rb} (not shown) is equal to the internal pressure average value of the suspension 3L and 3R in the second time point, the mean value between the internal pressure _{P Lb} and _{P Rb} second The primary coefficient a at the time can be uniquely identified from the data table of FIG. 10 (2) or the graph of FIG. 10 (1).

Note that the primary coefficient a may be selected using the internal pressures P _La and P _Ra at the first time point.

On the other hand, the roll angle φ _2es can be expressed by the following formula (18).

  When this equation (18) is updated to the above equation (16), the following equation (19) is obtained.

When the above equation (19) is arranged with respect to the roll angle φ _2es , the following equation (20) is obtained.

Since the roll stiffness coefficient K _φ13 of the above equation (20) is calculated by the above equation (9), the roll angle φ _2es when the vehicle height adjustment is not executed is expressed by the following equation (21).

Thus, the roll angle φ _2es when the vehicle height adjustment is not executed is determined by the roll moments M _x2a and M _x2b by the suspensions 3L and 3R at the first time point and the second time point, and the first time point and the second time point. Is calculated according to the above equation (21) using the roll angles φ _2a , φ _2b , the tread length trd, and the primary coefficient a in the above equation (17).

<Second estimation method of roll angle φ _2es when vehicle height adjustment is not executed>
Next, a second method for estimating the roll angle _φ2es when the vehicle height adjustment is not executed using the roll stiffness coefficient _Kφ13 will be described.

In the first estimation method, the roll angle φ _2es when the vehicle height adjustment is not executed is estimated using the roll stiffness coefficient K _φ13 calculated according to the above equation (9), but the vehicle height adjustment starts from the start of the vehicle. Until it is started (period immediately after starting), the internal pressure P and the displacement Z at two points in time where the state of the suspension 3 is different cannot be detected, and the roll stiffness coefficient K _φ13 is set according to the above equation (9). It is not possible to _calculate and estimate the roll angle φ _2es when the vehicle height adjustment is not executed according to the above equation (21). In addition, a load in which the moment Mx changes due to a light load state with a light load, a middle load state in which the load center is approximately the center of the left or right, or a change in the load state of the load during load adjustment (load change, load collapse, etc.) In the moving state, the accuracy of the roll stiffness coefficient _Kφ13 calculated according to the above equation (9) is reduced, and the accuracy of the roll angle _φ2es calculated when the vehicle height adjustment is not executed is also reduced according to the above equation (21). To do. Further, the absolute value when the state change of the suspension 3 at two different time points is small (the denominator ((M _x2a −M _x2b ) + 2 × trd ² × a (φ _2b −φ _2a )) of the above equation (21). Is small), the accuracy of the roll angle φ _2es when the vehicle height adjustment is not executed, which is calculated according to the above equation (21), is reduced.

The second estimation method is a method for calculating the roll angle φ _2es with relatively high accuracy in each of the above cases where the disadvantage of the first estimation method occurs, and the roll stiffness coefficient according to the above equation (9). without calculating the K _Ø13, alternatively, preset stored default roll stiffness coefficient K _Fai13def, or using a roll stiffness coefficient K _Fai13new updated to stored from the default, the above equation (20) To calculate the roll angle φ _2es when vehicle height adjustment is not executed. That is, in the first estimation method, the roll angle φ _2es is calculated using the roll moments M _x2a and M _x2b and the roll angles φ _2a and φ _2b at two different time points (first and second time points). On the other hand, in the second estimation method, the roll moment M _x2 and the roll angle φ ₂ at any one time point and the roll stiffness coefficient K _φ13def or K _φ13new stored before obtaining these detected values _Is used to calculate the roll angle φ _2es . In the case of the second estimation method, the roll angle φ _2b at the second time point in the above equation (20) is the roll angle φ ₂ at any one time point. Thus, the corrected roll angle φ _2off of the second estimation method is not the roll moments M _x2a and M _x2b and the roll angles φ _2a and φ _2b at two different time points, but the roll moment M _x2 at one time point. And using the roll angle φ ₂ and a predetermined roll stiffness coefficient K _φ13def (or K _φ13new ), it is calculated according to the above equation (20). The default roll stiffness coefficient K _φ13def is obtained in advance by experiments, simulations, etc., and stored for each vehicle.

In the first estimation method, the difference in reliability of the calculated roll angle φ _2es is likely to occur due to the detection environment such as the fluctuation state of the air suspension 3 and the change in the state of the load. A highly reliable and highly accurate roll angle _φ2es can be obtained. On the other hand, in the second estimation method, the reliability under a suitable detection environment is lower than that in the first estimation method, but the difference in reliability due to the detection environment is less likely to occur than in the first estimation method. A roll angle φ _2es that is stable in _terms of _properties can be obtained.

<Calculation method of corrected roll angle φ _AMD >
Next, a method for calculating the corrected roll angle φ _AMD will be described.

The corrected roll angle φ _2off is determined according to the following equation (22), the roll angle φ _2es and the roll angle φ _2b at the second time point (in the case of the second estimation method, the roll angle φ ₂ at any one time point). Therefore, it is calculated from φ _2b = φ ₂ ). Note that “0” is set as the initial value of the correction roll angle _φ2off .

The corrected roll angle φ _AMD is calculated by adding the corrected roll angle φ _2off to the detected roll angle φ according to the following equation (23).

<Roll Angle Correction Processing Example [1]: FIGS. 12 to 19>
Next, an example of the roll angle correction process performed by the roll angle estimation apparatus 10 will be described with reference to FIGS. In the processing example [1], the roll angle φ _2es when the vehicle height adjustment is not executed is estimated only by the second estimation method.

As shown in FIG. 12, the roll angle correction process in the processing unit 13 includes (1) the result of removing noise from the output values (measured values) acquired from the displacement detecting unit 11 and the pressure measuring unit 12 (displacement Z _L , Z Filter processing (step S1) for constantly updating _R and internal pressures P _L , P _R ), and (2) key ON mode processing (step S2) for estimating the roll angle φ _2es immediately after the key ON (start of the vehicle 1). (3) Flag setting process (step S3) for setting a control flag, (4) Vehicle height adjustment mode process (step S4) for estimating the roll angle φ _2es in the vehicle height adjustment mode, (5) Estimated consisting calculates the post-correction roll angle phi _AMD based on the roll angle phi _2ES corrected roll angle calculation process (step S5).

  Hereinafter, these processes (1) to (5) will be described in order.

(1) Filter processing: FIG.
Each time the processing unit 13 inputs the internal pressures P _L and P _R measured by the pressure measurement unit 12 and the displacements Z _L and Z _R (detection data) detected by the displacement detection unit 11, the Butterworth shown in FIG. Perform filtering.

When this processing is started (step S10), the processing unit 13 acquires detection data (P _L , P _R , Z _L , Z _R ) (step S11), and performs Butterworth filter processing on these detection data. , the detected values of the filtered _{(P Lfilter, P Rfilter, Z} Lfilter, Z Rfilter) the key ON mode process pressure _P L to be used in (step S2) after the correction process, _{P R} and the displacement _Z L, _{Z R} Is updated and stored (step S12).

Note that the respective detected values of the filtered, and accumulates and stores a predetermined number of samples, and the average value was calculated every time to get the latest detection data, the internal pressure P _L using the calculated average value by the correction process , _{P R} and the displacement _Z L, may be stored as _{Z R.}

(2) Key ON mode processing: FIG.
After the process (1), the processing unit 13 executes a key ON mode process. The key ON mode is a mode set in the key ON phase from the start of the vehicle 1 to the start of vehicle height adjustment. Processing unit 13 sets the key ON mode flag to "1" upon detection of the engine start of the vehicle 1 (e.g., an ignition switch ON), the key ON mode flag when receiving the vehicle height adjustment start signal SG _S "0" Set to. In the key ON mode, before the vehicle height adjustment is started and the roll angle φ _2es when the vehicle height adjustment is not executed cannot be estimated by the first estimation method, the vehicle height adjustment is not executed by the second estimation method. Estimate the _current roll angle φ _2es .

  When starting this processing (step S20), the processing unit 13 determines whether or not the key ON phase is set (step S21). Specifically, when the key ON mode flag is “1”, it is determined that the key ON phase is set, and when it is “0”, it is determined that the key ON phase is not set. If it is determined that it is not the key ON phase (step S21: NO), this process is terminated.

If it is determined that the key ON phase (step S21: YES), the processing unit 13, the internal pressure _P L stored in the filtering process (step S1), _{P R} and the displacement _Z L, reads _{Z R} (step S22), and reads by using the internal pressure _P L, _{P R} and the displacement _Z L, _{Z R,} the above formula (10), to calculate the roll moment _{M x2} and roll angle phi ₂ according to equation (12) and (13). Next, select the primary coefficient a with the internal pressure P _L, P _R, the roll moment M _x2 and roll angle phi ₂ calculated above, the roll stiffness coefficient K _Ø13 stored, linear coefficient selected Using a, roll angle φ _2es when vehicle height adjustment is not executed is calculated according to the above equation (20) (step S23). As the roll stiffness coefficient _Kφ13 , the latest roll stiffness coefficient _Kφ13new updated and stored in step S43 described later is used. When the update process in steps S36 to S44 is omitted, a preset roll stiffness coefficient K _φ13def that is preset and stored is used.

The processing unit 13 that calculates the roll angle φ ₂ and the roll angle φ _2es when the vehicle height adjustment is not executed calculates the corrected roll angle φ _2off according to the above equation (22), and calculates the calculated corrected roll angle φ _2off . Update and store (step S24), and the process ends. When the processing unit 13 of the present embodiment updates and stores data such as the roll stiffness coefficient _Kφ13 and the corrected roll angle _φ2off , the data before update (the roll stiffness coefficient _Kφ13 and the corrected roll angle _φ2off ). Are stored as history data without being deleted.

(3) Flag setting process: FIGS.
After the process (2), the processing unit 13 performs a flag setting process. In the flag setting process, the processing unit 13 determines whether or not the vehicle height adjusting device 30 is executing the vehicle height adjustment, and whether or not the load-displacement characteristic (spring characteristic) of the suspension 3 is within a linear approximation range. (Whether or not it is within a range in which the relationship shown in FIG. 10 is established).

For example, as shown in FIG. 15 (1), in the full rebound in which the stroke of the air suspension 3 is maximized, the spring characteristics of the air suspension 3 deviate from the range in which linear approximation can be performed. Further, as shown in FIG. 15 (2), in the full bump where the stroke of the air suspension 3 is minimized, the bump rubber BR abuts on the axle AXL, and the sprung load F _Load is caused by the air suspension 3 and the bump rubber BR. It is shared and supported. For this reason, the spring characteristic of FIG. 10 set on the assumption that the sprung load F _Load is supported only by the air suspension 3 is not established, and the spring characteristic of the air suspension 3 deviates from the range in which linear approximation can be performed. Note that the maximum displacement Z _Max of the air suspension 3 at which the air suspension 3 becomes full rebound and the minimum displacement Z _{Min at} which the air suspension 3 becomes full bump can be obtained in advance from the design specifications of the vehicle.

  Further, for example, in the air suspension characteristic (spring characteristic) when the internal pressure is constant, as shown in FIG. 16, the load value with respect to the displacement Z is substantially constant near the reference length of the suspension 3, but the displacement Z greatly increases. Then, the load is not constant and deviates from the linear approximation range.

  Further, in the containment characteristic (spring characteristic in the state of containing air), as shown in FIG. 10 (1) (in the figure, the measured value is indicated by a broken line, and the linear approximation straight line is indicated by a solid line), the internal pressure (pressure ) Comparing the load error when P is high and the load error when internal pressure P is low, the magnitudes of the errors are almost equal to each other. Therefore, when the internal pressure P is low, the estimated load (estimated from the internal pressure) The ratio of the error inherent in (load) increases, and as a result, it deviates from the range in which linear approximation is possible. Even when the displacement Z is extremely small or the internal pressure P is extremely large, the deviation of the measured value from the linear approximation line is large and deviates from the range that can be linearly approximated.

As described above, when the displacement Z or the internal pressure P of the suspension 3 is too large or too small, the spring characteristics of the suspension 3 tend to deviate from the range that can be linearly approximated. Accordingly, the upper limit threshold Z _High and the lower limit threshold Z _Low of the displacement Z of the air suspension 3 that cannot be linearly approximated, and the upper limit threshold P _High and the lower limit threshold P _Low of the internal pressure P of the air suspension 3 are set in advance. When the displacement Z is greater than or equal to the predetermined upper limit threshold Z _High (Z ≧ Z _High ) or less than the predetermined lower limit threshold Z _Low (Z ≦ Z _Low ) (when the displacement Z is out of the predetermined displacement range), or the internal pressure P Is the predetermined upper threshold P _High or higher (P ≧ P _High ) or lower than the predetermined lower threshold P _Low (P ≦ P _Low ) (when the internal pressure P is out of the predetermined pressure range), the spring of the air suspension 3 It can be determined that the update prohibition state is outside the range in which the characteristic can be linearly approximated.

In both the first estimation method and the second estimation method, the roll stiffness coefficient K _φ13 and the roll angle φ when the vehicle height adjustment is not executed are performed on the assumption that the air suspension 3 is deformed within a linear approximation range. _{In order} to calculate _2es , if the spring characteristics of at least one of the left and right suspensions 3 are out of the range that can be linearly approximated, the accuracy of these calculated values decreases.

For this reason, when the spring characteristic is out of the range in which linear approximation is possible, the processing unit 13 determines that the update is prohibited, sets the control flag to “0”, and sets a roll stiffness coefficient K _φ13 described later. _Execution of update processing and update processing of the correction roll angle _φ2off is prohibited.

Further, during the non-execution of the vehicle height adjustment, by setting the control flag to "0", to prohibit the execution of the update processing of the update processing and the correction roll angle phi _2off roll stiffness coefficient K _Ø13 described later.

  As shown in FIG. 17, when the processing unit 13 starts this processing (step S90), it is determined whether or not the vehicle height adjustment device 30 is executing vehicle height adjustment (within a period from the start to the end of vehicle height adjustment). (Step S91).

  If it determines with vehicle height adjustment not being performed (step S91: NO), the process part 13 will set a control flag to "0" (step S92), and will complete | finish this process.

If it is determined that the vehicle height adjustment is being performed (step S91: YES), the processing unit 13 determines whether it is neither full rebound nor full bump (non-full rebound and non-full bump) (step S93). . Specifically, the displacements Z _L and Z _R stored in the filtering process (step S1) are read, and the read displacements Z _L and Z _R both exceed the minimum displacement Z _Min and are less than the maximum displacement Z _Max. When (Z _Min <Z _L , Z _R <Z _Max ), it is determined that neither full rebound nor full bump is present.

  If it is determined that it is either full rebound or full bump (step S93: NO), the processing unit 13 sets the control flag to “0” (step S92) and ends this process.

If it is determined that neither a full rebound and Furubanpu (step S93: YES), the processing unit 13, the internal pressure _P L stored in the filtering process (step S1), _{P R} and the displacement _Z L, reads _{Z R,} read pressure _P L, _{P R} Do are both within the range of less than the lower threshold P _Low beyond and upper threshold _{P High (P Low <P L} , P R <P High), and the read displacement _Z L, is _{Z R} Both are determined to be within the range of exceeding the lower limit threshold Z _Low and less than the upper limit threshold Z _High (Z _Low <Z _L , Z _R <Z _High ).

Pressure _P L, _{P R} and the displacement _Z L, the _{Z R} are both determined to be within the above range (step S94: YES), the processing unit 13 sets the control flag to "1" (step S95), This process ends.

Pressure _P L, _{P R} and the displacement _Z L, when at least one of _{Z R} is determined to be outside the above range (step S94: NO), the processing unit 13 sets the control flag to "0" (step S92 ), This process is terminated.

When the maximum displacement Z _Max is larger than the upper limit value Z _High or the minimum displacement Z _Min is smaller than the lower limit value Z _{Low in} the determination in step S93 and the determination in step S94, the displacement Z _L in step S93. It may be omitted compared with the Z _R and the maximum displacement Z _Max or minimum displacement Z _Min, on the contrary, the maximum displacement Z if _Max is less than the upper limit value Z _High or minimum displacement Z _Min is the lower limit value Z _Low If it is larger, the comparison between the displacements Z _L and Z _R and the upper limit value Z _High or the lower limit value Z _Low in step S94 may be omitted. Further, it may be determined whether or not the spring characteristic of the suspension 3 is in a range that can be linearly approximated by only one of Step S93 and Step S94.

(4) Vehicle height adjustment mode processing: FIG.
After the process (3), the processing unit 13 executes a vehicle height adjustment mode process.

  When starting the processing (step S30), the processing unit 13 determines whether or not the control flag is “1” (step S31).

  If it is determined that the control flag is “1” (step S31: YES), the processing unit 13 determines whether or not the control flag is rising (set the control flag to “1” in the flag setting process in step S3). It is determined whether or not (step S32).

If it is determined that the time of rising of the control flag (step S32: YES), the processing unit 13, step S38 that the internal pressure _P L stored in the filtering process (step S1), _{P R} and the displacement _Z L, the _{Z R,} described later _Are stored as internal pressures P _La and P _Ra and displacements Z _La and Z _Ra (step S33). Then, regardless of whether or not the rising edge of the control flag, the internal pressure _P L stored in the filtering process (step S1), _{P R} and the displacement _Z L, _{Z R} of the internal pressure _{P Lb, P Rb} and displacement _{Z Lb} , Z _Rb (step S45), and using the read internal pressures P _Lb , P _Rb and displacements Z _Lb , Z _Rb , the roll moment M _x2b according to the above equations (11), (12), and (13). And roll angle (phi) _2b is calculated. Next, select the primary coefficient a with the internal pressure P _Lb, P _Rb, and the roll moment M _x2b and roll angle phi _2b calculated above, the roll stiffness coefficient K _Ø13 stored, linear coefficient selected Using a, roll angle φ _2es when vehicle height adjustment is not executed is calculated according to the above equation (20) (step S34). The roll stiffness coefficient _Kφ13 used at this time is the latest roll stiffness coefficient _Kφ13new updated and stored in step S43 described later. When the update process in steps S36 to S44 is omitted, a preset roll stiffness coefficient K _φ13def that is preset and stored is used.

The processing unit 13 that calculates the roll angle φ _2b and the roll angle φ _2es when the vehicle height adjustment is not executed calculates the corrected roll angle φ _2off according to the above equation (22), and calculates the calculated corrected roll angle φ _2off . Update and store (step S35), and the process ends.

  If it is determined that the control flag is not “1” (“0”) (step S31: NO), the processing unit 13 determines whether or not the control flag is falling (flag setting process in step S3). In step S36, it is determined whether or not it is immediately after the control flag is set to "0".

If it is determined that the control flag is falling (step S36: YES), the processing unit 13 _executes update processing (steps S37 to S44) of the roll stiffness coefficient _Kφ13 .

As shown in the above equation (9), the roll stiffness coefficient K _φ13 is obtained by changing the roll moment change ΔM (ΔM = M _x2a −M _x2b ) and the roll angle change Δφ (Δφ = φ) at two different _{times. 2a−} φ _2b ) is a value calculated by substituting K _φ13 = ΔM / Δφ.

For this reason, in an empty _vehicle state where the _product load is light, or in a medium load state where the _product load center is approximately in the middle of the left and right, both the values of ΔM and Δφ are small, and the calculated roll stiffness coefficient K _φ13 tends to diverge strongly. _Thus , the accuracy of the roll stiffness coefficient K _φ13 is lowered.

Also, in the load movement state in which the moment Mx changes due to load load change or load collapse during vehicle height adjustment, load movement is included in the factors that generate ΔM and Δφ, so the accuracy of the calculated roll stiffness coefficient K _φ13 Decreases.

Further, the absolute value when the state change of the suspension 3 at two different time points is small (the denominator ((M _x2a −M _x2b ) + 2 × trd ² × a (φ _2b −φ _2a )) of the above equation (21). The accuracy of the calculated roll stiffness coefficient K _φ13 also decreases.

Therefore, in order to maintain the reliability of the roll angle _φ2es when the vehicle height adjustment is not executed, which is calculated using the roll stiffness coefficient _Kφ13 in step S23 and step S35, in the case of an empty vehicle state, a middle load state, or a load movement state Alternatively, when the state change of the suspension 3 is small, it is determined that the update is prohibited, and the roll stiffness coefficient _Kφ13 is not updated, and the roll stiffness coefficient _Kφ13 is updated only in other cases.

In the determination of whether or not the vehicle is in an empty state (empty vehicle determination), the wheel loads acting on the left and right rear wheels according to the above equation (11) using the internal pressures P _Lb and P _Rb at the time of the main determination (at the end of vehicle height adjustment). F _Lb and F _Rb are calculated.

Next, the rear axle weight _FRr acting on the rear wheel axle is calculated according to the following equation (24).

When the rear axle weight F _Rr is less than a predetermined threshold B set in advance (F _Rr <B), it is determined that the vehicle is in an empty state, and the rear axle weight F _Rr is greater than or equal to the threshold B (F _Rr ≧ B). Determines that the vehicle is not in an empty state.

In the determination of whether or not the vehicle is in the middle load state (medium load determination / unbalanced state determination), the roll moment M _x2b according to the above equations (11) and (12) using the internal pressures P _Lb and P _Rb at the time of this determination. Is calculated.

Next, a roll moment M _xb due to unbalanced load is calculated according to the following equation (25). The roll stiffness coefficient _Kφ13 used in the equation (25) is the latest roll stiffness coefficient _Kφ13new updated and stored in step S43 described later. When the update process in steps S36 to S44 is omitted, a preset roll stiffness coefficient K _φ13def that is preset and stored is used.

When the roll moment M _xb is less than the preset threshold value C (M _xb <C), it is determined that there is a middle load state, and when the roll moment M _xb is equal to or greater than the threshold value C (M _xb ≧ C), It is determined that it is not in a loaded state.

The decision of whether the cargo moving state (load movement determination), height adjustment at the start of the internal pressure _{P La, P Ra} and the determination time of the internal pressure _{P Lb,} by using the _{P Rb,} the above equation (10) to According to the equation (12), roll moments M _x2a and M _x2b at _two time _points are respectively calculated.

Next, the difference between the roll moment M _xb due to the load unbalance at the end of the vehicle height adjustment and the roll moment M _xa due to the load unbalance at the start of the vehicle height adjustment is defined as the uneven moment difference ΔM _x , and the roll moment M _x2a and It calculates according to the following formula _| equation (26) using _Mx2b .

The partial moment difference ΔM _x in the above equation (26) depends on the roll moment change ΔM (ΔM = M _x2a −M _x2b ) and the roll angle change Δφ (Δφ = φ _2a −φ _2b ) as _follows : It is expressed as equation (27). The roll stiffness coefficient K _φ13 used in the equations (26) and (27) is the latest roll stiffness coefficient K _φ13new updated and stored in step S43 described later. When the update process in steps S36 to S44 is omitted, a preset roll stiffness coefficient K _φ13def that is preset and stored is used.

When the absolute value of the partial moment difference ΔM _x exceeds a preset threshold D (ΔM _x > D), it is determined that the load is moving, and the absolute value of the partial moment difference ΔM _x is the threshold D. In the following case (ΔM _x ≦ D), it is determined that the load is not in a moving state.

In the determination of whether the state change of the suspension 3 at two different time points is large (whether the state of the suspension 3 has changed _beyond a level at which a highly reliable roll stiffness coefficient K _φ13 can be calculated), The absolute value (| ΔM + 2 × trd ² × a × Δφ |) of the denominator of Equation (21) is calculated as a predetermined state value of the suspension 3, and whether the calculated value exceeds a predetermined threshold A Determine whether or not. When the absolute value of the denominator of the above equation (21) exceeds the threshold A, it is determined that the state of the suspension 3 has changed beyond a level where the highly reliable roll stiffness coefficient K _φ13 can be calculated. In the case of A or less, it is determined that the state change of the suspension 3 has not reached the above level.

When proceeding to the update process of the roll stiffness coefficient K _Ø13, processing unit 13, the internal pressure _P L stored in the filtering process (step S1), _{P R} and the displacement _Z L, _{Z R} of the internal pressure _{P Lb, P Rb} and displacement _{Z Lb} , Z _Rb (step S37), and using the read internal pressures P _Lb , P _Rb and displacements Z _Lb , Z _Rb , the roll moment M _x2b and the roll angle φ _2b according to the above formulas (10) to (13). Is calculated. Further, using the internal pressures P _La and P _Ra and the displacements Z _La and Z _Ra stored in the most recent step S33, the roll moment M _x2a and the roll angle φ _2a are set according to the above formulas (10) to (13). calculate. Then, using the calculated roll moments M _x2a and M _x2b and the roll angles φ _2a and φ _2b , the roll moment change ΔM (ΔM = M _x2a −M _x2b ) and the roll angle change Δφ (Δφ = φ _2a -.phi _2b) is calculated (step S38).

Next, the processing unit 13 determines whether or not the vehicle is in an empty state (step S39). When the processing unit 13 determines that the vehicle is not in an empty state (step S39: NO), the processing unit 13 determines whether or not the vehicle is in an intermediate state (step S39). S40) If it is determined that it is not in the middle load state (step S40: NO), it is determined whether it is in the load movement state (step S41), and if it is determined that it is not in the load movement state (step S41: NO), It is determined whether or not the state of the suspension 3 has changed to such an extent that the highly flexible roll stiffness coefficient _Kφ13 can be calculated (step S44).

If it is determined that the state of the suspension 3 has changed to a level that allows calculation of the highly reliable roll stiffness coefficient _Kφ13 , which is neither an empty state, a middle load state, or a load movement state (step S44: YES), the processing The unit 13 calculates the roll stiffness coefficient K _φ13 by substituting the roll moment change ΔM and the roll angle change Δφ calculated in step S38 into K _φ13 = ΔM / Δφ, and calculates the calculated K _{φ13. Is} updated and stored as the latest roll stiffness coefficient K _φ13new (step S43), and this process is terminated. In the initial state (when the vehicle is shipped), a default roll stiffness coefficient K _φ13def is stored, and this default value is the latest roll stiffness until the first update of the roll stiffness coefficient K _φ13 is executed. _Used as coefficient K _φ13new .

On the other hand, if it is determined that the suspension 3 is in an empty state, a middle load state, or a load movement state, or the state of the suspension 3 has not changed more than the level at which the highly reliable roll stiffness coefficient K _φ13 can be calculated (step) S39: YES, step S40: YES, step S41: YES, or step S44: NO), the roll stiffness coefficient _Kφ13 is not updated (step S42), and this process is terminated.

If it is determined that the control flag is not falling (step S36: NO), the processing unit 13 ends the process without executing the roll rigidity coefficient _Kφ13 update process (steps S37 to S44). To do.

The roll rigidity coefficient K _φ13 update process (steps S36 to S44) can be omitted. In this case, the roll stiffness coefficient K _Ø13, the default roll stiffness coefficient K _Fai13def is used at all times.

Further, instead of or in addition to the above update determination, when the absolute value (| φ _2a −φ _2b |) of the roll angle change amount Δφ is equal to or less than the first predetermined position, it is determined that the update is prohibited. Alternatively, when the absolute value (| M _x2a -M _x2b |) of the change amount ΔM of the roll moment is equal to or _smaller than the second predetermined value, it may be determined that the update is prohibited.

(5) Roll angle calculation process after correction: FIG.
After the above process (4), the processing unit 13 executes a corrected roll angle calculation process.

  When this processing is started (step S50), the processing unit 13 determines whether or not the correction valid mode is set (whether or not the correction invalid flag is “0”) (step S51).

  If it is determined that the correction valid mode is set (the correction invalid flag is “0”) (step S51: YES), whether or not the vehicle height adjustment device 30 is properly performing the vehicle height adjustment in the vehicle height adjustment mode. It is determined whether or not the correction validity determination flag is “1” (step S52).

When it is determined that the vehicle height adjustment is properly executed in the vehicle height adjustment mode (the correction validity determination flag is “1”) (step S52: YES), the updated updated correction roll angle _φ2off is detected. The corrected roll angle φ _AMD is calculated by adding to the roll angle φ (step S51), and this process is terminated.

The post-correction roll angle φ _AMD calculated in this way is provided to the rollover risk determination unit 22 (shown in FIG. 1). As the correction roll angle φ _2off , the latest correction roll angle φ _2off updated and stored in step S24 or step S35 is used.

On the other hand, if it is determined that the correction invalid mode is selected (the correction invalid flag is “1”) (step S51: NO), or the vehicle height adjustment mode is appropriate even if the vehicle height adjustment mode is not used. Is not executed (the correction validity determination flag is “0”) (step S52: NO), the value of the correction roll angle _φ2off is updated to zero and stored (step S54). The corrected roll angle φ _AMD is calculated by adding the roll angle φ _2off to the detected roll angle φ (step S53), and this process is terminated. That is, in the case of the correction invalid mode, the manual mode, or the vehicle height adjustment mode, even if the vehicle height adjustment is not properly executed, the roll angle correction is not substantially executed, and the detected roll The angle φ is provided to the rollover risk determination unit 22 (shown in FIG. 1) as the corrected roll angle φ _AMD .

<Roll Angle Correction Processing Example [2]: FIGS. 20 and 21>
In the roll angle correction processing example [1], the roll angle φ _2es when the vehicle height adjustment is not executed is estimated only by the second estimation method. In this processing example [2], the first estimation method and the first estimation method are performed. In combination with the estimation method 2, the roll angle φ _2es when the vehicle height adjustment is not executed is estimated.

That is, when the state (detection environment) of the air suspension 3 when detecting the roll moment M _x2 and the roll angle φ ₂ is an ideal detection environment, and the reliability of the calculated roll angle φ _2es is high. When the roll angle φ _2es is calculated by the first estimation method and the roll angle φ _2es cannot be calculated by the first estimation method, or when the reliability of the calculated roll angle φ _2es decreases, the second The roll angle φ _2es is calculated by the following estimation method.

When the roll angle φ _2es cannot be calculated by the first estimation method, it corresponds to immediately after the key is _turned on (before the start of the vehicle height adjustment). In addition, when the reliability of the roll angle φ _2es calculated by the first estimation method is lowered, the state of the suspension 3 is changed at two different times in addition to the empty state, the middle load state, and the load movement state. The case where the absolute value of the denominator ((M _x2a −M _x2b ) + 2 × trd ² × a (φ _2b −φ _2a )) of the above formula (21) is small is applicable.

  The processing unit 13 executes the processes of steps S1 to S5 in FIG. 1 as in the process example [1]. Among these processes, the vehicle height adjustment mode process (step S4) is illustrated in FIG. Instead of (Steps S30 to S44), the following processing shown in FIGS. 20 and 21 is executed.

  When starting this process (step S60), the processing unit 13 determines whether or not the control flag is “1” (step S61).

  If it is determined that the control flag is “1” (step S61: YES), the processing unit 13 determines whether or not the control flag is rising (step S62).

If it is determined that the time of rising of the control flag (step S62: YES), the processing unit 13, as in the processing example [1], the internal pressure _P L stored in the filtering process (step S1), _{P R} and the displacement _{Z L} , Z _R are read as internal pressures P _La , P _Ra and displacements Z _La , Z _Ra (step S63), and using the read internal pressures P _La , P _Ra and displacements Z _La , Z _Ra , the above formula (10), The roll moment M _x2a and the roll angle φ _2a are calculated according to the equations (12) and (13), and the calculated roll moment M _x2a and roll angle φ _2a and the stored roll stiffness coefficient K _φ13new are used. The roll angle φ _2es when the vehicle height adjustment is not executed is calculated according to the equation (20) (by the second estimation method) (step S64). At this time, the calculated roll moment M _x2a and roll angle φ _2a are updated and stored.

The processing unit 13 that calculates the roll angle φ _2a and the roll angle φ _2es when the vehicle height adjustment is not executed calculates the corrected roll angle φ _2off according to the above equation (22), and calculates the calculated corrected roll angle φ _2off . Update and store (step S65), and the process ends.

On the other hand, if it is not determined that the time of rising of the control flag (step S62: NO), the processing unit 13, the internal pressure was stored in the filtering process (Step S1) _P L, _{P R} and the displacement _Z L, _{Z R} of the internal pressure _{P Lb} , _{P Rb} and displacement _{Z Lb,} read (step S66) as a _{Z Rb,} read pressure _{P Lb, P Rb} and displacement _{Z Lb,} using _{Z Rb,} roll moment according to the above equation (10) to (13) M _x2b and roll angle φ _2b are calculated, and using the calculated roll moment M _x2b and roll angle φ _2b and the roll moment M _x2a and roll angle φ _2a stored in the most recent step S64, the roll moment is calculated. Change amount ΔM (ΔM = M _x2a -M _x2b ) and roll angle change amount Δφ (Δφ = φ _2a -φ _2b ) are calculated (step S67).

Next, the processing unit 13 determines whether or not the state of the suspension 3 has changed between the time when the vehicle height adjustment starts and the time when the vehicle height adjustment ends _until the roll angle φ _2es can be calculated with high reliability. It is determined (whether the difference between the predetermined state values of the suspension 3 between the two time points exceeds a predetermined threshold value) (step S68). Specifically, the absolute value (| ΔM + 2 × trd ² × a × Δφ |) of the denominator of the above equation (21) is calculated, and whether or not the calculated value exceeds a predetermined threshold A set in advance. Determine.

  When the calculated value exceeds the threshold value A, the processing unit 13 determines whether or not the vehicle is in an empty state (step S69), and determines that the vehicle is not in an empty state (step S69: NO), the vehicle is in a middle load state. (Step S70), if it is determined that it is not in the middle load state (step S70: NO), it is further determined whether or not it is in the load movement state (step S71). Note that the empty vehicle determination, medium load determination, and load movement determination are performed in the same manner as steps S39 to S41 of the processing example [1], and thus detailed description thereof is omitted.

If it is determined that the absolute value (| ΔM + 2 × trd ² × a × Δφ |) of the denominator of Expression (21) exceeds the threshold value A and is not any of the empty state, the middle load state, and the load movement state (step S71). : NO), the processing unit 13 calculates the roll angle φ _2es when the vehicle height adjustment is not executed by the first estimation method (step S72). Specifically, the read pressure _P Lb in step _S66, the select primary coefficient a with _{P Rb,} 1 and primary coefficient a selected roll moment _{M x2b} calculated in step S67, the roll angle phi _2b, The roll angle φ _2es is calculated according to the above equation (21) using the roll moment change ΔM, the roll angle change Δφ, and the primary coefficient a.

The processing unit 13 that calculates the roll angle φ _2b and the roll angle φ _2es when the vehicle height adjustment is not executed calculates the corrected roll angle φ _2off according to the above equation (22), and calculates the calculated corrected roll angle φ _2off . Update and store (step S74), and the process ends.

On the other hand, when it is determined that the absolute value (| ΔM + 2 × trd ² × a × Δφ |) of the denominator of Expression (21) is equal to or less than the threshold value A, or the vehicle is in an empty state, a middle load state, or a load movement state. (Step S68: NO, Step S69: YES, Step S70: YES, Step S71: YES), the processing unit 13 calculates the roll angle φ _2es when the vehicle height adjustment is not executed by the second estimation method (Step S73). ). Specifically, the roll moment M _x2b and the roll angle φ _2b are calculated according to the above equations (11) to (13) using the internal pressures P _Lb and P _Rb and the displacements Z _Lb and Z _Rb read in step S66. To do. Then, the internal pressure P _Lb, select a primary coefficient a with P _Rb, and the roll moment M _x2b and roll angle phi _2b calculated above, and the roll stiffness coefficient K _Fai13new stored, selected linear coefficient Using a, the roll angle φ _2es when the vehicle height adjustment is not executed is calculated according to the above equation (20).

The processing unit 13 that calculates the roll angle φ _2b and the roll angle φ _2es when the vehicle height adjustment is not executed calculates the corrected roll angle φ _2off according to the above equation (22), and calculates the calculated corrected roll angle φ _2off . Update and store (step S74), and the process ends.

  If it is determined that the control flag is not “1” (step S61: NO), the processing unit 13 determines whether or not the control flag is falling (step S36).

If it is determined that the control flag is falling (step S36: YES), the processing unit 13 _executes update processing (steps S37 to S44) of the roll stiffness coefficient _Kφ13 . The roll rigidity coefficient _Kφ13 update process (steps S37 to S44) is the same as the process example [1], and thus detailed description thereof is omitted.

Even when it is determined that the control flag is not falling (step S36: NO), the processing unit 13 updates the roll stiffness coefficient _Kφ13 (steps S37 to S44) as in the processing example [1]. This process is terminated without executing.

<Roll Angle Correction Processing Example [3]: FIG. 22>
In the roll angle correction processing examples [1] and [2] described above, the corrected roll angle φ _2off (the corrected roll angle φ _{updated in} steps S24, S35, S65, or S74) in the post-correction roll angle calculation processing (step S5). _2off ) is added to the detected roll angle φ to calculate the corrected roll angle φ _AMD (step S51).

However, in an empty vehicle state or a medium load state, the influence of the load on the roll angle φ is small, and there is little need to correct the detected roll angle φ. For this reason, in the processing example [3], in the case of an empty vehicle state or a middle load state, in the case of the correction invalid mode, the manual mode, or the case where the vehicle height adjustment is not properly executed in the vehicle height adjustment mode. Similarly, the correction roll angle φ _2off is set to zero so that the roll angle correction is not substantially executed (so that the detected roll angle φ is output as the corrected roll angle φ _AMD as it is).

  The processing unit 13 executes the processes in steps S1 to S5 in FIG. 1 as in the process example [1] or the process example [2]. Among these processes, the corrected roll angle calculation process (step S5) is performed. Performs the following processing shown in FIG. 22 instead of the processing shown in FIG. 19 (steps S50 to S54).

  When this processing is started (step S80), the processing unit 13 determines whether or not the correction valid mode is set (whether or not the correction invalid flag is “0”) (step S81).

  If it is determined that the correction valid mode is set (the correction invalid flag is “0”) (step S81: YES), whether or not the vehicle height adjustment device 30 is appropriately performing the vehicle height adjustment in the vehicle height adjustment mode. It is determined (whether or not the correction validity determination flag is “1”) (step S82).

If it is determined that the vehicle height adjustment is properly executed in the vehicle height adjustment mode (the correction validity determination flag is “1”) (step S82: YES), it is determined whether the vehicle is in an empty state (step S82). S83) If it is determined that the vehicle is not empty (step S83: NO),
When it is determined whether or not it is in the middle load state (step S84), and it is determined that it is not in the middle load state (step S84: NO), the correction roll angle φ _2off ( The corrected roll angle φ _AMD is calculated by adding the corrected roll angle φ _2off ) updated in step S24, S35, S65, or S74 to the detected roll angle φ (step S86), and this process ends.

On the other hand, if it is determined that the correction invalid mode is set (the correction invalid flag is “1”) (step S81: NO), the vehicle height adjustment is appropriately performed even if the vehicle height adjustment mode is not used or the vehicle height adjustment mode is set. When it is determined that it is not executed (the correction validity determination flag is “0”) (step S82: NO), when it is determined that the vehicle is in an empty state (step S83: YES), or in the middle load state If it is determined that there is (step S84: YES), the value of the corrected roll angle φ _2off is updated to zero and stored (step S85), and the corrected roll angle φ _2off is added to the detected roll angle φ to correct the corrected roll. The angle φ _AMD is calculated (step S86), and this process is terminated. That is, in the correction invalid mode, in the manual mode, in the vehicle height adjustment mode, when the vehicle height adjustment is not properly executed, or when the vehicle is empty or in the middle load state, the roll angle correction is substantially performed. The detected roll angle φ is provided to the rollover risk determination unit 22 (shown in FIG. 1) as the corrected roll angle φ _AMD .

Note that when the process example [3] is applied to the process example [2], steps S69 and S70 of the process example [2] may be omitted. Further, in the processing example [2], when it is determined that the vehicle is in the empty state in step S69 (step S69: YES) and when it is determined that the vehicle is in the middle state in step S70 (step S70: YES), the process does not proceed to step S73. As in step S85 of the processing example [3], the value of the correction roll angle _φ2off may be updated to zero and stored. Further, in the processing example [2], immediately after the start of the vehicle adjustment mode processing (between step S60 and step S61), the empty vehicle determination and the intermediate load determination are executed, and in the case of the empty vehicle state and the intermediate load state, the correction roll The value of the angle φ _2off may be updated to zero and stored.

  According to this embodiment, in the normal state where the start assistance is not executed, the risk of rollover is determined using the normal two-dimensional map, and in the start assistance state, using the two-dimensional map for starting assistance different from the normal use. Since the rollover risk is determined (or the rollover risk is not determined), it is possible to appropriately determine the rollover risk in the start assist state.

  If the vehicle height adjustment is not functioning normally due to a system failure or the like, the adjustment determination unit 18 determines that the vehicle height adjustment device 30 is not properly executing the vehicle height adjustment and sets a correction validity determination flag. Set to “0”, the roll angle output unit 16 outputs a roll angle having a value equal to the detected roll angle φ to the rollover risk determination device 20 as an effective roll angle. Therefore, it is possible to eliminate the possibility that a roll angle including an excessive estimation error is output, and to suppress a decrease in the reliability of the roll angle output from the roll angle estimation device 10 to the rollover risk determination device 20. can do.

Also, roll stiffness coefficient K _φ13 and correction roll angle φ _2off , which are not used when the vehicle height adjustment is not properly executed or in the correction invalid mode, can be used when the vehicle height adjustment is properly executed or the correction is effective. As in the case of the mode, calculation is performed and accumulated and stored as history data, so even if the vehicle height adjustment is not properly performed or vehicles that are unlikely to be unbalanced are generated, The state can be inferred afterwards.

  Further, by setting the correction invalid mode flag in the mode storage unit 17 to “1”, a roll angle having a value equal to the detected roll angle φ is set as an effective roll angle from the roll angle estimation device 10 to the rollover risk determination device 20. Can be output reliably.

  Therefore, after manufacturing a reference vehicle having a configuration including the roll angle estimation device 10 shared among different vehicle types, in a manufacturing process in which a structure corresponding to the vehicle type is mounted on the rear part of the body frame of the reference vehicle, When manufacturing a vehicle (for example, a tank lorry vehicle, an on-vehicle vehicle, a mixer vehicle, etc.) that is less likely to be unevenly distributed in the width direction, the correction invalid mode flag should be set to “1” when or after the structure is mounted. Thus, a roll angle having a value equal to the detected roll angle can be reliably output.

  As mentioned above, although the embodiment to which the invention made by the present inventor is applied has been described, the present invention is not limited by the discussion and the drawings that form part of the disclosure of the present invention according to this embodiment. That is, it is needless to say that other embodiments, examples, operation techniques, and the like made by those skilled in the art based on this embodiment are all included in the scope of the present invention.

For example, in the above processing example [1], in the vehicle height adjustment mode processing, the roll angle φ _2es is calculated only at the start of the vehicle height adjustment, but at other points in time during the vehicle height adjustment (for example, predetermined from the start of the vehicle height adjustment). The roll angle φ _2es may be calculated at a later time).

  The combination of the two time points in the processing example [2] is not limited to the time when the vehicle height adjustment is started and the time when the vehicle height adjustment is finished. The time point may be after the start of the vehicle height adjustment (including during adjustment, at the end and after the end, but not at the start), and the first time point is being adjusted in the vehicle height (including the start time but not at the end) The second time point may be after the first time point (including during adjustment and after completion).

  In process example [1], one or more of steps S39 to S41 may be omitted. In process example [2], one or more of steps S68 to S71 may be omitted. Further, in the processing example [3], one of step S83 or step S84 may be omitted.

Whether or not the spring characteristic is within the linear approximation range is not included in the control flag setting process, and in the vehicle height adjustment mode setting process (step S4), before the roll rigidity coefficient _Kφ13 is updated or the corrected roll angle φ The update process may be performed at an arbitrary timing before the _2off update process, and the update process may be prohibited when the spring characteristics are out of the linear approximation range.

The roll angle estimation device 10 may _{notify the} driver of the calculated roll angle φ _2es in a state that is visible to the driver every time the roll angle φ _2es when the vehicle height adjustment is not executed is calculated. For example, a display unit may be provided in front of the driver's seat in the passenger compartment, and the calculated roll angle _φ2es may be displayed on the display unit in a predetermined display mode. Preset display mode may be a numerical display of the roll angle phi _2ES, state changes in accordance with the value of the roll angle phi _2ES (e.g. stretching, moving, discoloration, etc.), or the like to the indicator.

When a roll angle having a value equal to the detected roll angle φ is output to the rollover risk determination device 20 as an effective roll angle, the corrected roll angle φ _AMD is calculated with the corrected roll angle φ _2off being zero, and the calculated post-correction The roll angle φ _AMD is output, but instead, the detected roll angle φ may be output as it is to the rollover risk determination device 20 as an effective roll angle.

  When the vehicle height adjusting device 30 has a function of self-diagnosis of a system failure related to the vehicle height adjustment, the adjustment determination unit 18 determines whether or not the vehicle height adjustment is properly executed. You may determine according to.

  The roll angle estimation apparatus 10 may be provided with a mode input unit 41 and a mode setting unit 42 (indicated by a two-dot chain line in FIG. 3). A mode setting instruction is input to the mode input unit 41. The mode setting unit 42 sets the correction invalid mode flag to “0” when the correction valid mode setting instruction is input to the mode input unit 41, and corrects when the correction invalid mode setting instruction is input. Set the invalid mode flag to “1”.

  By providing the mode input unit 41 and the mode setting unit 42, the state of the correction invalid mode flag can be changed by input to the mode input unit 41 without using the external setting device 40.

  The present invention is widely applicable to vehicles equipped with an air suspension.

1: Vehicles 3L, 3R, 5L, 5R: Suspension 3LF, 3RF: Suspension (fluid spring, start assist device)
10: Roll angle estimation device 11L, 11R: Displacement detection unit 12L, 12R: Pressure measurement unit 13: Processing unit 14: Corrected roll angle calculation storage unit 15: Corrected roll angle calculation unit 16: Roll angle output unit 17: Mode storage Unit 18: Adjustment determination unit 20: Rollover risk determination device 21: Roll angle / roll angular velocity detection unit (detection means)
22: Roll-over risk determination unit (determination means)
24: Determination map storage unit (storage means)
25: Start assist flag storage unit 30: Vehicle height adjusting device (start assist device)
31: Start assist determination unit (start assist device)
40: external setting device 41: mode input unit 42: mode setting unit _{Z, Z L, Z La,} Z Lb, Z R, Z Ra, Z Rb: air spring displacement _{P, P L, P La,} P Lb, P R _{, P} Ra, _{P Rb:} air spring pressure phi: detecting the roll angle phi _2a: roll angle (vehicle height adjustment start)
φ _2b : Roll angle (during vehicle height adjustment or at the end of vehicle height adjustment)
phi _2ES: vehicle height control is not executed when the roll angle phi _2off: correction roll angle phi _AMD: corrected roll angle _{K φ1, K φ2, K φ13} , K φ13new: roll stiffness coefficient K _.phi.12: frame torsional rigidity coefficient M _x2 : Roll moment by suspension M _x2a : Roll moment by suspension at the start of vehicle height adjustment M _x2b : Roll moment by suspension at the end of vehicle height adjustment M _x : Roll moments by load unloading CF1-CF7: Load-displacement characteristics EXP1 EXP7: Linear approximation formula a: Linear coefficient b: Constant SG _S : Vehicle height adjustment start signal SG _F : Vehicle height adjustment end signal SS _S : Starting assistance start signal SS _F : Starting assistance end signal AP: Air

Claims (4)

A vehicle including a starting assisting device having a fluid spring that is mounted on the drive shaft and increases the ground pressure of the drive shaft among the two rear shafts including the drive shaft , and the fluid spring has the same load-displacement characteristics and A left-right suspension having a load-internal pressure characteristic, and a rollover risk determination system mounted on the vehicle in which vehicle height adjustment is performed by supply and exhaust of pressurized air to the left and right suspensions ,
Detecting means for detecting the roll angular velocity and the effective roll angle of the vehicle as rollover risk determination information for determining the rollover risk of the vehicle;
Storage means for preliminarily storing a normal threshold value used in a normal state where the start assist device is not operating and a start assist threshold value used in a start assist state where the start assist device is operating;
In the normal state, the rollover risk degree determination information detected by the detection means and the normal threshold value stored in the storage means are used to determine the rollover risk degree of the vehicle. In the start assist state, the detection means Determining means for determining the risk of rollover of the vehicle using the rollover risk determination information detected by the storage means and the start assist threshold stored in the storage means ,
The detection means includes a roll angle estimation device that outputs the effective roll angle based on the roll angle detected by the roll angle detection unit to the determination means,
The roll angle estimation device is:
A correction roll angle for correcting the roll angle detected by the roll angle detection unit to a roll angle when the vehicle height adjustment is not performed is calculated using measured values of the displacement and internal pressure of the left and right suspensions. A correction roll angle calculation storage unit for storing the calculated correction roll angle;
A post-correction roll angle calculation unit that calculates a post-correction roll angle by correcting the roll angle detected by the roll angle detection unit using the correction roll angle stored in the correction roll angle calculation storage unit;
An adjustment determination unit for determining whether or not the vehicle height adjustment is properly executed;
When the adjustment determination unit determines that the vehicle height adjustment is properly executed, the corrected roll angle calculated by the corrected roll angle calculation unit is output as the effective roll angle, and the vehicle height adjustment is performed. Roll angle output unit that outputs a roll angle having a value equal to the roll angle detected by the roll angle detection unit as the effective roll angle. vehicle rollover danger level determination system, characterized in that it comprises. A vehicle including a starting assisting device having a fluid spring that is mounted on the drive shaft and increases the ground pressure of the drive shaft among the two rear shafts including the drive shaft , and the fluid spring has the same load-displacement characteristics and A left-right suspension having a load-internal pressure characteristic, and a rollover risk determination system mounted on the vehicle in which vehicle height adjustment is performed by supply and exhaust of pressurized air to the left and right suspensions ,
Detecting means for detecting the roll angular velocity and the effective roll angle of the vehicle as rollover risk determination information for determining the rollover risk of the vehicle;
Storage means for storing in advance a normal threshold value used in a normal state in which the start assist device is not operating;
In the normal state, the rollover risk degree of the vehicle is determined using the rollover risk degree determination information detected by the detection means and the normal threshold value stored in the storage means, and in the start assist state, A determination means that does not determine the risk of rollover ,
The detection means includes a roll angle estimation device that outputs the effective roll angle based on the roll angle detected by the roll angle detection unit to the determination means,
The roll angle estimation device is:
A correction roll angle for correcting the roll angle detected by the roll angle detection unit to a roll angle when the vehicle height adjustment is not performed is calculated using measured values of the displacement and internal pressure of the left and right suspensions. A correction roll angle calculation storage unit for storing the calculated correction roll angle;
A post-correction roll angle calculation unit that calculates a post-correction roll angle by correcting the roll angle detected by the roll angle detection unit using the correction roll angle stored in the correction roll angle calculation storage unit;
An adjustment determination unit for determining whether or not the vehicle height adjustment is properly executed;
When the adjustment determination unit determines that the vehicle height adjustment is properly executed, the corrected roll angle calculated by the corrected roll angle calculation unit is output as the effective roll angle, and the vehicle height adjustment is performed. Roll angle output unit that outputs a roll angle having a value equal to the roll angle detected by the roll angle detection unit as the effective roll angle. vehicle rollover danger level determination system, characterized in that it comprises. The rollover risk determination system according to claim 1 ,
Before SL storage means is set roll angle and roll angular velocity on a two-dimensional map as a parameter, the first and second threshold line defining the boundary between the non-rollover region and opposite home side rollover region of origin side Are stored as the normal threshold and the start assist threshold,
The first threshold line defines a boundary between a normal non-rollover region and a rollover region;
The second threshold line defines a boundary between a non-rollover region and a rollover region for starting assistance,
In the normal state, the determination means is a risk of rollover when a point on the two-dimensional map specified by the roll angle and roll angular velocity detected by the detection means exists in the normal non-rollover area. Is determined to be low, it is determined that the risk of rollover is high when it is in the normal rollover region, and in the start assist state, the roll is detected by the roll angle and roll angular velocity detected by the detection means. When a point on the two-dimensional map exists in the start assistance non-rollover area, it is determined that the rollover risk is low, and when it exists in the start assistance rollover area, it is determined that the rollover risk is high. A vehicle rollover risk determination system characterized by: A rollover danger level determination system according to any one of claims 1 to 3,
Before SL roll angle estimating apparatus includes a mode storage unit that pre-Symbol roll angle estimation device stores which one of the modes of the correction valid mode and corrective disabled mode,
The roll angle output unit, said mode Ri storage unit in the stored mode is Ah in the correction enabled mode, the and the when the vehicle height adjustment determines said adjustment determining unit to have been properly performed, the correction The corrected roll angle calculated by the roll angle calculation unit is output as the effective roll angle, and the mode stored in the mode storage unit is the correction invalid mode , or the vehicle height adjustment is properly executed. If the adjustment determination unit determines that no you output roll angle equal to the roll angle which the roll angle detecting unit has detected as a valid roll angle wherein
Rollover risk assessment system of the vehicle, wherein a call.

Images