JP4000664B2 - Vehicle constant speed traveling system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of fine vibration at the time of carrying out constant speed traveling and stop motion of only a constant speed traveling system at the time when abnormality occurs only in the constant speed traveling system. SOLUTION: A torque command value to carry out constant speed traveling is computed once per 96 ms in a constant speed traveling command value computing part 12 in a main microcomputer 10 of a vehicle controller 4 to control a motor 1 for traveling of an electric vehicle. In a variation smoothing part 13, the torque command value output immediately before is changed little by little per 8 ms and it is made to approach the torque command value output from the constant speed traveling command value computing part 12. As there is no extensive change in the torque command value to be input to a motor controller 3, no fine vibration is generated. Additionally, in the case when outputs of the constant speed traveling command value computing parts 12 and 22 are not roughly the same, constant speed traveling abnormality judgement parts 16 and 26 output abnormality detection signals, and a constant speed traveling fail safe part 7 stops motion of a constant speed traveling system, changes change-over parts 14 and 24 over to each other and carries out normal traveling.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle constant speed traveling system that causes a vehicle to travel at a constant speed at a set speed.
[0002]
[Prior art]
In recent years, a constant speed running system that automatically runs a vehicle at a constant speed at a speed set by a driver is mounted on many vehicles. Also, along with the electronic control of the vehicle control unit, a microcomputer in which a constant speed traveling system is built in a microcomputer mounted on the vehicle controller is being developed.
Also, as shown in FIG. 4, in order to improve safety, a main microcomputer 30 and a sub-microcomputer 40 are provided in parallel in the vehicle controller 9, and abnormality determination units 15 and 25 are provided respectively for monitoring abnormal operations. There is something that is.
[0003]
This constant speed traveling system is applied to an electric vehicle. During normal traveling, the normal traveling command value calculation unit 11 mounted on the main microcomputer 30 detects the accelerator opening detected by the accelerator opening detection unit 31 and Based on the shift position detected by the shift position detector 32, a torque command value for controlling the output torque of the traveling motor 1 is calculated and output to the motor controller 3 via the switching unit 14. In the motor controller 3, the torque command value is replaced with a current command value corresponding to the number of revolutions of the motor 1, and the inverter 2 converts the direct current from the battery 5 into a high frequency of a predetermined voltage to control the motor 1. Yes.
At this time, the normal travel command value calculation unit 21 mounted in the sub-microcomputer 40 also calculates the torque command value in the same manner as the normal travel command value calculation unit 11.
[0004]
When the constant speed travel switch 34 is turned on, the constant speed travel command value calculation unit 12 mounted in the main microcomputer 30 first determines the input values of the brake switch 35, the shift position detection unit 32, and the vehicle speed sensor 33. Then, it is determined whether or not constant speed travel is performed. If constant speed travel is performed, the travel speed when the constant speed travel switch 34 is turned on is set to the target vehicle speed, and a torque command value corresponding to the target vehicle speed is set. Calculate and output to the motor controller 3 via the switching unit 14.
At this time, the constant speed travel command value calculation unit 22 mounted on the sub-microcomputer 40 also calculates the torque command value in the same manner as the constant speed travel command value calculation unit 12.
[0005]
In the main microcomputer 30 and the sub-microcomputer 40, abnormality determination units 15 and 25 for determining whether an abnormality has occurred by comparing the torque command value calculated on its own side with the torque command value calculated on the other side, respectively. Is provided.
The abnormality determination units 15 and 25 output an abnormality detection signal to the fail safe unit 6 when the difference between the two torque command values is equal to or greater than the predetermined value b.
The fail safe unit 6 performs a fail safe operation such as system down when an abnormality detection signal is sent from the abnormality determination unit 15 or 25.
[0006]
[Problems to be solved by the invention]
In recent years, there has been an increasing demand for lower prices of vehicles, and in order to suppress an increase in manufacturing cost, a generally used two-pulse magnetic sensor is used as the vehicle speed sensor 33. When is 40 km / h, it takes about 70 ms to calculate the vehicle speed.
When performing the constant speed travel, the vehicle speed is once measured, the torque command value is calculated, and as a result of considering the response time in which the vehicle speed is changed by the calculated torque command value, the constant speed travel command value calculation unit 12 Torque command values are calculated and output every 96 ms. On the other hand, the normal travel command value calculation unit 11 considers the response time when the accelerator pedal is operated, and outputs a torque command value corresponding to the depression amount of the accelerator pedal detected by the accelerator opening detection unit 31 every 8 ms. Calculated and output.
[0007]
Therefore, when performing normal traveling, the torque command value output every 8 ms is output every 96 ms when performing constant speed traveling, and the torque change that is changed at one time. The amount increases, and fine vibrations may occur in the vehicle, and the performance may decrease in terms of vehicle operability and riding comfort.
In addition, when the constant speed running command value calculation unit 12 or 22 is abnormal when performing constant speed running, an abnormality occurs only in the constant speed running command value calculation unit 12 or 22, Even when the travel command value calculation unit 11 or 12 can operate normally, an abnormality detection signal is sent from the abnormality determination unit 15 or 25, and a fail-safe operation such as shutting down the entire vehicle controller 9 is performed.
[0008]
In view of such conventional problems, the present invention prevents the occurrence of minute vibrations, improves the operability and ride comfort of the vehicle, and is stable when an abnormality occurs only in the constant speed traveling system. It is an object of the present invention to provide a constant speed traveling system for a vehicle that can continue traveling in a normal traveling state by stopping only the high speed traveling system.
[0009]
[Means for Solving the Problems]
For this reason, in the present invention, in a vehicle constant speed traveling system that causes a vehicle having traveling control means for controlling the traveling speed of the vehicle to travel at a selected speed at a constant speed, the traveling speed of the vehicle is set to a first predetermined time interval. Based on the vehicle speed detection unit detected by the vehicle speed, the traveling vehicle speed detected by the vehicle speed detection unit and the selected speed, a command value for driving the vehicle at a constant speed is set at a second predetermined time interval longer than the first predetermined time interval. A constant speed travel command value calculation unit to calculate, and a change amount smoothing unit that outputs a command value calculated by performing smoothing processing based on the command value calculated by the constant speed travel command value calculation unit to the travel control means, In the change amount smoothing unit, when the command value calculated by the constant speed travel command value calculation unit is input, the constant speed travel command value calculation unit is generated at every third predetermined time interval shorter than the second predetermined time interval. Command value input from Command value input from the constant speed travel command value calculation unit The command value output from the change amount smoothing unit immediately before is compared, and the difference between the command value input from the constant speed travel command value calculation unit and the command value output from the change amount smoothing unit immediately before is the first predetermined value. If smaller, the command value input from the constant speed travel command value calculation unit is output to the travel control means, and the command value input from the constant speed travel command value calculation unit is the command value output from the change amount smoothing unit immediately before. If it is larger than the first predetermined value, the command value that is sequentially increased by the first predetermined value from the command value output from the change amount smoothing unit to the travel control unit immediately before is output to the travel control unit, and the constant speed travel is performed. If the command value input from the command value calculation unit is smaller than the command value output from the change amount smoothing unit immediately before the first predetermined value, the command value output from the change amount smoothing unit to the travel control means immediately before Traveling control of command value sequentially decreased by the first predetermined value And outputs it to the stage.
[0010]
When the abnormality detection signal is input from the constant speed traveling abnormality determination unit that determines abnormality of the command value calculated by the constant speed traveling command value calculation unit and outputs an abnormality detection signal, and the constant speed traveling abnormality determination unit It is preferable to provide a constant speed traveling stop unit that stops the operation of the vehicle constant speed traveling system.
The constant speed running abnormality determining unit determines that an abnormality has occurred when the amount of change in the command value output within a predetermined time is equal to or greater than a predetermined amount.
[0011]
And a sub-constant speed travel command value calculation unit that calculates a command value for causing the vehicle to travel at a constant speed based on the travel vehicle speed detected by the vehicle speed detection unit and the selected speed, at the second predetermined time interval, The constant speed running abnormality determining unit is configured when the difference between the command value calculated by the constant speed running command value calculating unit and the command value calculated by the sub constant speed running command value calculating unit is equal to or greater than a second predetermined value. May output an abnormality detection signal.
[0012]
The vehicle is an electric vehicle, the constant speed running control means is a motor controller that controls the output torque of the running motor, and the constant speed running command value calculation unit and the sub constant speed running command value calculation unit output torque command values. It is preferable to do.
[0013]
[Action]
In the vehicle constant speed traveling system according to the present invention, a change amount smoothing unit is provided between the constant speed travel command value calculating unit and the travel control means, and the change amount smoothing unit has a relatively short third predetermined time interval. The command value input from the constant speed travel command value calculation unit Command value input from the constant speed travel command value calculation unit Compare the command value output from the change amount smoothing unit immediately before, and if the command value input from the constant speed travel command value calculation unit is greater than the command value output from the change amount smoothing unit immediately before the first predetermined value, From the command value output from the change amount smoothing unit immediately before, the command value is increased in small increments by the first predetermined value, and if it is smaller than the first predetermined value, the command value decreased in small increments by the first predetermined value is output.
[0014]
Also, the change amount smoothing unit receives the command value output from the change amount smoothing unit and the command input from the travel constant speed travel command value calculation unit before the next command value is input from the constant speed travel command value calculation unit. When the difference between the values becomes smaller than the first predetermined value or when the difference between the command values from the beginning is smaller than the first predetermined value, the command value is changed to the third value until the next command value is input. Are output at predetermined time intervals.
When the next command value is input from the constant speed travel command value calculation unit, the newly input command value is compared with the command value output from the change amount smoothing unit immediately before, and the same operation is repeated.
For this reason, a command value that changes in small increments at a relatively short third time interval is input to the traveling control means, and a command value that has changed significantly from the command value that was input immediately before is not input. The occurrence of minute vibrations in the vehicle is prevented.
[0015]
In addition, for example, when a constant speed running abnormality determination unit that monitors the change amount of the command value calculated by the constant speed running command value calculation unit is provided, and the change amount of the command value is so large that it cannot be a normal constant speed running state In this case, it is possible to continue traveling in the normal traveling state by stopping only the operation of the constant speed traveling system.
In addition, a sub-constant running command value calculation unit that calculates a command value for causing the vehicle to travel at a constant speed is provided, and the command values calculated by the constant-speed traveling command value calculation unit and the sub-constant running command value calculation unit are compared If the difference between the command values is greater than or equal to the second predetermined value, it is possible to continue running in the normal running state by stopping only the operation of the constant speed running system. You can also
[0016]
The above invention is applied to an electric vehicle, and the constant speed travel command value calculation unit outputs a torque command value for controlling the output torque of the travel motor, which is the travel control means, according to the selected speed. Then, the torque command value calculation unit of the constant speed traveling system can be incorporated in the vehicle controller.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
The embodiment of the present invention will be described with reference to examples.
FIG. 1 is a block diagram showing the configuration of the embodiment.
The motor 1 is a traveling motor mounted on an electric vehicle, and is an AC induction motor. A transaxle (not shown) is connected to the motor 1, and the driving force from the transaxle is transmitted to both front wheels (not shown) via the left and right front wheel shafts.
The motor 1 is connected to a vehicle controller 4 via an inverter 2 and a motor controller 3. The motor 1 is connected via an inverter 2 to a battery 5 that is a main power source for driving driving.
The vehicle controller 4 includes a main microcomputer 10 and a sub microcomputer 20.
[0018]
The main microcomputer 10 includes a normal travel command value calculation unit 11 that calculates a torque command value during normal travel, a constant speed travel command value calculation unit 12 that calculates a torque command value when performing constant speed travel, and a constant speed travel. A change amount smoothing unit 13 for smoothing the torque command value calculated by the command value calculation unit 12 and a torque command value calculated by the normal travel command value calculation unit 11 or a change calculated by the constant speed travel command value calculation unit 12 From the switching unit 14 that outputs one of the torque command values output via the quantity smoothing unit 13 to the motor controller 3, the torque command value output from the switching unit 14, and the switching unit 24 of the sub-microcomputer 20 described later. Torque command output from the abnormality determination unit 15 that compares the output torque command value to determine abnormal operation and outputs an abnormality detection signal to the fail safe unit 6 and the constant speed travel command value calculation unit 12 Is compared with a torque command value output from a constant speed travel command value calculation unit 22 of the sub-microcomputer 20 to be described later, an abnormal operation is determined, and an abnormal detection signal is output to the constant speed travel fail safe unit 7. An abnormality determination unit 16 is provided.
[0019]
The normal travel command value calculation unit 11 is connected to an accelerator opening detection unit 31 that detects the depression amount of the accelerator pedal and a shift position detection unit 32 that detects a travel range from the position of the shift lever.
The constant speed traveling command value calculation unit 12 calculates the traveling vehicle speed from the shift position detection unit 32, the rotational speed of the wheel driven by the motor 1, and outputs it, and the constant speed traveling provided near the driver's seat. A constant speed travel switch 34 and a brake switch 35 are connected.
For example, when the vehicle speed is 40 km / h, the vehicle speed sensor 33 requires about 70 ms to calculate the vehicle speed.
The brake switch 35 is a switch that is attached to a brake pedal (not shown) and is turned on with a minute stroke at the start of depression of the brake pedal.
[0020]
As with the main microcomputer 10, the sub-microcomputer 20 includes a normal travel command value calculation unit 21 that calculates a torque command value during normal travel, and a constant speed travel command value calculation unit that calculates a torque command value during constant speed travel. 22, a change amount smoothing unit 23 that smoothes the torque command value calculated by the constant speed traveling command value calculation unit 22, a switching unit 24 that switches a torque command value to be output to an abnormality determination unit 25 described later, and a switching unit The abnormality determination unit that compares the torque command value output from 24 and the torque command value output from the switching unit 14 of the main microcomputer 10 to determine abnormal operation and outputs an abnormality detection signal to the fail safe unit 6. 25, the torque command value output from the constant speed travel command value calculation unit 22 and the torque command value output from the constant speed travel command value calculation unit 12 of the main microcomputer 10 are compared to determine abnormal operation, A constant speed running abnormality determination unit 26 that outputs a normal detection signal to the constant-speed running failsafe section 7 is provided.
The normal travel command value calculation unit 21 is connected to an accelerator opening detection unit 31 and a shift position detection unit 32.
A shift position detector 32, a vehicle speed sensor 33, a constant speed travel switch 34, and a brake switch 35 are connected to the constant speed travel command value calculation unit 22.
[0021]
The normal travel command value calculation units 11 and 21 are torque commands for controlling the output torque of the motor 1 based on the shift position detected by the shift position detection unit 32 and the accelerator opening detected by the accelerator opening detection unit 31. The value is calculated every 8 ms and output to the switching unit 14 or the switching unit 24.
When the constant speed travel switch 34 is turned on, the constant speed travel command value calculation units 12 and 22 first have the shift position detected by the shift position detection unit 32 as the drive range, and the traveling vehicle speed detected by the vehicle speed sensor 33 is It is within the range of 40 km / h to 110 km / h, and it is determined whether or not the brake switch 35 is in the OFF state. If these conditions are satisfied, the vehicle shifts to the constant speed running state.
When the constant speed travel state is entered, the constant speed travel command value calculation units 12 and 22 set the travel vehicle speed when the constant speed travel switch 34 is turned on as the constant speed travel speed, and a new vehicle speed sensor every 96 ms. The traveling vehicle speed input from 33 is compared with the set constant speed traveling speed to calculate a torque command value necessary for traveling at the constant speed traveling speed, and the variation smoothing unit 13 or 23 and the constant speed traveling abnormality are calculated. It outputs to the determination parts 16 and 26.
[0022]
In the change amount smoothing units 13 and 23, when the torque command value calculated by the constant speed travel command value calculation unit 12 or 22 is input, the torque command input from the constant speed travel command value calculation unit 12 every 8 ms. The difference S between the torque command value output from the change amount smoothing unit 13 or 23 immediately before the value is calculated, and the torque command value output from the change amount smoothing unit 13 or 23 immediately before is calculated according to the value of the difference S. A torque command value that increases or decreases the value by the change amount limit value a or does not change is output to the switching unit 14 or 24. Detailed operation will be described later.
[0023]
The switching unit 14 normally outputs the torque command value input from the normal travel command value calculation unit 11 to the motor controller 3 and the abnormality determination units 15 and 25. When the constant speed traveling command value calculation unit 12 determines that the constant speed traveling state can be shifted, the switching unit 14 switches and outputs the torque command value input from the variation smoothing unit 14.
The switching unit 24 normally outputs the torque command value input from the normal travel command value calculation unit 21 to the abnormality determination units 15 and 25. When it is determined by the constant speed travel command value calculation unit 22 that the transition to the constant speed travel state is possible, the torque command value input from the variation smoothing unit 23 is output.
[0024]
The abnormality determination units 15 and 25 always compare the values of the torque command values output from the switching unit 14 and the switching unit 24. If the difference is equal to or greater than the predetermined value b, the abnormality determination signal is sent to the fail safe unit 6. Output.
The constant speed running abnormality determination units 16 and 26 always compare the values of the torque command values output from the constant speed running command value calculation unit 12 and the constant speed running command value calculation unit 22, and the difference is equal to or greater than a predetermined value c. In this case, an abnormality detection signal is output to the constant speed traveling fail safe unit 7.
[0025]
When an abnormality detection signal is input, the fail safe unit 6 performs a fail safe operation such as system down.
When the abnormality detection signal is input, the constant speed traveling fail safe unit 7 stops the operation of the constant speed traveling command value calculating units 12 and 22, and the switching unit 14 and the switching unit 24 are changed to the normal traveling command value calculating units 11 and 21. The torque command value input from is fixed to the output side.
In addition, a display unit (not shown) displays that an operation has stopped due to an abnormality in the constant speed traveling system.
The vehicle speed sensor 33 constitutes a vehicle speed detector of the invention, and the motor controller constitutes a travel control means. The constant speed travel failsafe unit 7 constitutes a constant speed travel stop unit of the invention, and the constant speed travel command value calculation unit 22 constitutes a sub constant speed travel command value calculation unit.
Further, the limit value a is a first predetermined value of the invention, and the predetermined value c is a second predetermined value.
[0026]
Next, the operation when performing constant speed running will be described.
First, the driver operates the shift lever to set the drive range before actually carrying out the constant speed travel, and when the vehicle speed becomes a desired value by the control of the accelerator pedal, the constant speed travel switch 34 is turned on. To do.
In the constant speed travel command value calculation unit 12, the travel range detected by the shift position detection unit 32 is the drive range, the vehicle speed detected by the vehicle speed sensor 33 is in the range of 40 km / h to 110 km / h, and the brake switch 35. If is in the off state, the state shifts to the constant speed traveling state.
If any of these conditions is not met, constant speed running is not performed.
[0027]
In the constant speed running state, first, the constant speed running command value calculation unit 12 sets the vehicle speed detected by the vehicle speed sensor 33 when the constant speed running switch 34 is turned on as the constant speed running vehicle speed, and once in 96 ms. The set vehicle speed and the latest traveling vehicle speed detected by the vehicle speed sensor 33 are compared, a torque command value necessary for traveling at the set vehicle speed is calculated, and the variation smoothing unit 13 and the constant speed traveling are calculated. It outputs to the abnormality determination parts 16 and 26.
[0028]
The operation of the variation smoothing unit 13 will be described with reference to the flowchart shown in FIG.
In step 101, the smoothed torque that is the torque command value output from the change amount smoothing unit 13 immediately before the smoothing torque command value A that is the torque command value input from the constant speed running command value calculation unit 12 A difference S obtained by subtracting the command value B is calculated.
In step 102, it is determined whether or not the difference S is greater than or equal to a predetermined change amount limit value a. If the difference S is greater than or equal to the limit value a, the process proceeds to step 103.
In step 103, a value obtained by adding the limit value a of the change amount to the smoothed torque command value B is set as a new smoothed torque command value B. Then, it progresses to step 106.
[0029]
In step 104, it is determined whether or not the difference S is equal to or less than a negative value of the predetermined change amount limit value a. If not, the process proceeds to step 105. If not, the process proceeds to step 106.
In step 105, a value obtained by subtracting the variation limit value a from the smoothed torque command value B is set as a new smoothed torque command value B. Then, it progresses to step 106.
In step 106, the smoothed torque command value B is output to the switching unit 14 and the process proceeds to step 107.
In step 107, the elapsed time is monitored, and it is determined whether or not 8 ms has passed since the torque command value output operation performed immediately before.
If not, step 107 is repeated until 8 ms elapses.
[0030]
That is, for example, as shown in FIG. 3A, at time a1, the values of the pre-smoothing torque command value A and the smoothed torque command value B output from the constant speed travel command value calculation unit 11 are b1. If they match, when a value of b3 greater than b1 is input as a new pre-smoothing torque command value A at time a2, first, in step 101, the pre-smoothing torque command value A and the smoothed torque command As the difference S of the value B, s1 shown in FIG.
Since this s1 is larger than the change amount limit value a, the routine proceeds from step 102 to step 103, where b1 + a is set as a new smoothed torque value B and is output at step 106.
In step 107, it is determined whether or not 8 ms has elapsed from time a2, and when 8 ms has elapsed, the process returns to step 101 and the same steps are repeated.
[0031]
The above steps 101 to 107 are repeated 8 times. At time a3, the pre-smoothing torque command value A and the smoothed torque command value B coincide with b3. Therefore, steps 101 to 102, 104 are performed. , 106, and then until the time a4 when the new pre-smoothing torque command value A is output from the constant speed traveling command value calculation unit 12, the same value as the smoothed torque command value B output at time a3 is obtained. Is output.
At time a4 after 96 ms from time a2, a new pre-smoothing torque command value A is input, and s2 shown in FIG.
Since s2 is smaller than the minus value of the change amount limit value a, the process proceeds from step 101 to steps 102, 104, and 105, b3-a is set as a new smoothed torque value B, and is output in step 106. The
[0032]
In step 107, when 8 ms has passed, the process returns to step 101 and the same steps are repeated. At time a5, since the value of the torque command value A before smoothing processing and the value of the smoothed torque command value B coincide with b2, the time when the next torque command value is input from the constant speed travel command value calculation unit 12 Up to a6, b2 is output as the smoothed torque command value B. Thereafter, similarly, from time a6, the value increases within the range of the limit value a, and decreases from time a7.
Thus, the torque command value calculated by the change amount smoothing unit 13 is output to the motor controller 3 and the abnormality determination units 15 and 25 via the switching unit 14, and constant speed running is performed.
The change amount smoothing unit 23 similarly smoothes the torque command value and outputs the torque command value to the abnormality determination units 15 and 25.
For this reason, a torque command value that changes in small increments with the limit value a is input to the motor controller 3 every 8 ms, and a torque command value that has changed significantly from the torque command value that was input immediately before is input. Therefore, it is possible to prevent fine vibrations from occurring in the vehicle.
[0033]
Next, a description will be given of the fail-safe operation when an abnormality occurs during operation at a constant speed.
For example, as shown in FIG. 3 (b), as the value of the pre-smoothing torque command value A output at time a6, b5 is output if it is operating normally. The fail-safe operation when the operation of the value calculation unit 12 is abnormal and b3 ′ is output will be described.
[0034]
At this time, the constant speed travel command value calculation unit 22 operates normally, and b5 is output as the pre-smoothing torque command value A ′. The difference between b5 and b3 ′ is larger than the predetermined value b.
Until the time a6 is reached, values of the pre-smoothing torque command value A output from the constant speed travel command value calculation unit 12 and the pre-smoothing torque command value A ′ output from the constant speed travel command value calculation unit 22 Therefore, the constant speed running abnormality determining unit 16 and the constant speed running abnormality determining unit 26 do not output an abnormality detection signal.
[0035]
When b3 ′ is output from the constant speed travel command value calculation unit 12 and b5 is output from the constant speed travel command value calculation unit 22 at time a6, the constant speed travel abnormality determination unit 16 and the constant speed travel abnormality determination unit 26 Since the difference between the pre-smoothing torque command value A and the pre-smoothing torque command value A ′ is greater than the predetermined value b, it is determined that an abnormality has occurred and an abnormality detection signal is output. When the abnormality detection signal is input, the constant speed traveling fail safe unit 7 stops the operation of the constant speed traveling command value calculation units 12 and 22, and switches the switching units 14 and 24 to the normal traveling command value calculation units 11 and 21. Switch to the output side.
[0036]
Even if there is a difference between the pre-smoothing torque command value A output from the constant speed travel command value calculation unit 12 and the pre-smoothing torque command value A ′ output from the constant speed travel command value calculation unit 22 , Each of which is larger or smaller than the smoothed torque command value B output from the variation smoothing unit 13 and the smoothed torque command value B ′ output from the variation smoothing unit 23. If so, the smoothed torque command value B and the smoothed torque command value B ′ increase or decrease in the same way for a while, for example, from time a6 to time a6 ′ in FIG. Therefore, no abnormality detection signal is output from the abnormality determination units 15 and 25.
Therefore, if the abnormality detection signals are output from the constant speed traveling abnormality determining unit 16 and the constant speed traveling abnormality determining unit 26 while the abnormality detecting signals are not output from the abnormality determining units 15 and 25, normal driving is performed from the constant speed traveling state. If the operation is switched to the state and there is no abnormality in the normal travel command value calculation units 11 and 21, normal travel is performed.
[0037]
If an abnormality has occurred in the main microcomputer 10 and the operation of the normal travel command value calculation unit 11 has also occurred, torque output from the normal travel command value calculation unit 11 and the normal travel command value calculation unit 21 Since a difference occurs in the command value, an abnormality detection signal is output from the abnormality determination unit 15 and the abnormality determination unit 25, and a fail safe operation such as system down is performed in the fail safe unit 6.
Therefore, when an abnormality occurs only in the constant speed traveling system, it is possible to continue traveling in the normal traveling state by stopping only the operation of the constant speed traveling system.
[0038]
As described above, in this embodiment, the occurrence of minute vibrations is prevented, the operability and ride comfort of the vehicle are improved, and when an abnormality occurs only in the constant speed traveling system, only the constant speed traveling system is provided. By stopping the operation, it is possible to continue traveling in the normal traveling state.
[0039]
In this embodiment, since the abnormality determination unit is built in the microcomputer, when an abnormality occurs in one of the microcomputers, both the microcomputer in which the abnormality has occurred and the abnormality determination unit in the microcomputer malfunction, and the abnormality is detected. The signal may not be output. Therefore, although an abnormality determination unit is provided in each microcomputer so that an abnormality can be determined by the abnormality determination unit of the other microcomputer even if an abnormality occurs in one microcomputer, the present invention is not limited to this. If it is mounted on another microcomputer or the like, only one abnormality determination unit is required, and the circuit is simplified.
[0040]
Furthermore, for example, a constant speed running abnormality determination unit is provided to monitor the change amount of the torque command value calculated by the constant speed running command value calculation unit, and the change amount of the torque command value is so large that it cannot be a normal constant speed running state. In such a case, if the operation of the constant speed traveling system is stopped, the sub constant speed traveling command value calculation unit becomes unnecessary, and the circuit can be further simplified.
In the present embodiment, the first predetermined time for detecting the vehicle speed in the invention is 70 ms, the second predetermined time for calculating the command value is 96 ms, and the third predetermined time for outputting the command value from the variation smoothing unit. Although 8 ms is set, the present invention is not limited to this, and the second predetermined time may be a value obtained by adding a response to the vehicle speed change to the first predetermined time, and the third predetermined time may be the second predetermined time. Any time interval smaller than the predetermined time may be used.
[0041]
【The invention's effect】
In the vehicle constant speed traveling system according to the present invention, a variation smoothing unit is provided between the constant speed traveling command value calculation unit and the traveling control means, and the variation smoothing unit is immediately before the relatively short third time interval. In order to output the command value that is changed in small increments from the command value output from the constant speed travel command value calculation unit so as to approach the command value input from the constant speed travel command value calculation unit, the travel control unit is input immediately before Since a command value that is significantly changed from the command value is not input, the occurrence of minute vibrations in the vehicle is prevented, and the operability and ride comfort of the vehicle are improved.
[0042]
In addition, for example, when a constant speed running abnormality determination unit that monitors the change amount of the command value calculated by the constant speed running command value calculation unit is provided, and the change amount of the command value is so large that it cannot be a normal constant speed running state In order to stop only the operation of the constant speed traveling system, or separately from the constant speed traveling command value calculation unit, a sub constant speed traveling command value calculation unit for calculating a command value for causing the vehicle to travel at a constant speed is provided. A constant speed running abnormality determination unit that compares the command values calculated in each of them is provided, and when the difference between the command values is equal to or larger than the second predetermined value, by stopping only the operation of the constant speed running system, When an abnormality occurs only in the constant speed traveling system, only the constant speed traveling system can be stopped, and the traveling in the normal traveling state can be continued.
[0043]
The above invention is applied to an electric vehicle, and the constant speed travel command value calculation unit outputs a torque command value for controlling the output torque of the travel motor, which is the travel control means, according to the selected speed. Then, the torque command value calculation unit of the constant speed traveling system can be incorporated in the vehicle controller.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention.
FIG. 2 is a flowchart for explaining a torque command value change amount smoothing method in the embodiment;
FIG. 3 is a diagram illustrating torque command values before and after smoothing in the embodiment.
FIG. 4 is a block diagram showing a configuration of a conventional example.
[Explanation of symbols]
1 Motor
2 Inverter
3 Motor controller
4,9 Vehicle controller
5 battery
6 Fail safe section
7 Constant-speed running fail-safe section
10, 30 Main microcomputer
11, 21 Normal travel command value calculation unit
12, 22 Constant speed running command value calculation unit
13, 23 Change amount smoothing part
14, 24 switching part
15, 25 Abnormality judgment part
16, 26 Constant speed running abnormality determination unit
20, 40 Sub-microcomputer
31 Accelerator position detector
32 Shift position detector
33 Vehicle speed sensor
34 Constant speed travel switch
35 Brake switch

Claims (5)

In a vehicle constant speed traveling system for causing a vehicle having traveling control means for controlling a traveling speed of the vehicle to travel at a constant speed at a selected speed,
A vehicle speed detection unit for detecting a traveling speed of the vehicle at a first predetermined time interval;
A constant speed travel command value for calculating a command value for causing the vehicle to travel at a constant speed based on the traveling vehicle speed detected by the vehicle speed detection unit and the selected speed at a second predetermined time interval longer than the first predetermined time interval. A calculation unit;
A change amount smoothing unit that outputs a command value calculated by performing a smoothing process based on the command value calculated by the constant speed travel command value calculation unit to the travel control unit;
In the change amount smoothing unit, when the command value calculated by the constant speed travel command value calculation unit is input, the constant speed travel is performed at every third predetermined time interval shorter than the second predetermined time interval. The command value input from the command value calculation unit is compared with the command value output from the variation smoothing unit immediately before the input of the command value from the constant speed travel command value calculation unit, and the constant speed travel command value calculation unit the running control means a command value inputted from difference the constant speed travel command value calculating portion is smaller than the first predetermined value of the command value output from the variation smoothing section to the immediately preceding the entered command value output, traveling from the greater the instruction to cruise control value command value input from the calculation section is equal to or more than the first predetermined value than the command value output from the change amount smoothing section to the immediately preceding, variation smoothing unit to the immediately preceding The command value output to the control means is sequentially increased by the first predetermined value. The command value is outputted to the traveling control means is, the smaller command value input from the constant-speed travel command value calculating unit said immediately preceding the change amount equal to or more than the first predetermined value from the output command value from the smoothing unit, the A constant speed traveling system for a vehicle, characterized in that a command value that is sequentially decreased by a first predetermined value from a command value output from a change amount smoothing unit to a travel control unit immediately before is output to the travel control unit. A constant speed running abnormality determination unit that determines abnormality of the command value calculated by the constant speed running command value calculation unit and outputs an abnormality detection signal;
2. The vehicle constant speed according to claim 1, further comprising a constant speed travel stop unit that stops the operation of the vehicle constant speed travel system when an abnormality detection signal is input from the constant speed travel abnormality determination unit. Traveling system. 3. The vehicle-use vehicle according to claim 2, wherein the constant speed running abnormality determination unit determines that an abnormality has occurred when a change amount of the command value output within a predetermined time is equal to or greater than a predetermined amount. Constant speed running system. A sub-constant speed travel command value calculation unit that calculates a command value for causing the vehicle to travel at a constant speed based on the travel vehicle speed detected by the vehicle speed detection unit and the selected speed, at the second predetermined time interval;
The constant speed running abnormality determining unit has a difference between the command value calculated by the constant speed running command value calculating unit and the command value calculated by the sub constant speed running command value calculating unit being a second predetermined value or more. 3. The vehicle constant speed traveling system according to claim 2, wherein an abnormality detection signal is output in such a case. The vehicle is an electric vehicle, the constant speed traveling control means is a motor controller that controls output torque of a traveling motor, and the constant speed traveling command value calculating unit and the sub constant speed traveling command value calculating unit are torque commands. The vehicle constant speed traveling system according to claim 1, 2, 3, or 4, wherein the vehicle outputs a value.

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