JP3845205B2 - Stabilizer control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a stabilizer control device for changing the apparent torsional rigidity of a stabilizer provided between left and right wheels by an actuator.
[0002]
[Prior art]
A device that controls the change in the posture of the vehicle body during turning by changing the apparent torsional rigidity of a stabilizer including a torsion bar using an electromagnetic actuator is known (Japanese Patent Laid-Open No. 4-191114). reference). In such a device, the output of the actuator is generally controlled mainly based on the lateral acceleration value.
[0003]
In the above-described conventional technology, the actuator is extended and contracted in a direction to cancel the roll angle generated while the vehicle is turning. Specifically, an actuator is attached to one end or both ends of a normal stabilizer, and a force that opposes a load applied to the outer ring during turning is generated in the actuator according to the traveling speed. This reduces the roll angle at high speeds and improves the tire contact feeling by increasing the rigidity, while increasing the ride comfort by slightly reducing the rigidity at low speeds.
[0004]
[Problems to be solved by the invention]
However, regardless of the vehicle speed, it is desirable to stabilize the vehicle behavior when a large turn and a large lateral acceleration or yaw rate occur, and conversely, when the lateral acceleration or yaw rate is small even at high speeds, That is, it is desirable to place an emphasis on ride comfort when stable running is being performed.
[0005]
The present invention is intended to solve such problems of the prior art, and an object of the present invention is to provide an effect control device for a stabilizer that can improve the running stability of the vehicle body during turning and also improve the riding comfort. It is to provide.
[0006]
[Means for Solving the Problems]
In order to achieve such an object, in the present invention, the actuator 1 for changing the apparent torsional rigidity of the stabilizer R provided between the left and right wheels, and control means for controlling the output of the actuator (for example, in the embodiment) the electronic control unit E) and potency control unit of the stabilizer having a having a means for detecting the swirling degree during turning of the vehicle (e.g., the lateral acceleration sensor 31 in the embodiment), the swirling degree to the extent that Accordingly, the actuator output is divided into three regions, low, medium, and high, and the output of the actuator is reduced so that the apparent torsional rigidity of the stabilizer R in the low and high regions is lower than the apparent torsional rigidity in the intermediate region. Control is performed (for example, steps 51 to 55 in the embodiment). According to this, in a region where the turning strength is relatively small, the change in the posture of the vehicle body is suppressed in the same manner as when a rigid stabilizer is used by expansion and contraction of the actuator 1, and in a region where the turning strength is medium, The characteristics of emphasis on ride comfort are the same as when using a soft stabilizer, and in the region where the turning strength is relatively large, the actuator 1 with a narrow movable range is bottomed out and the running stability is stabilized by the inherent rigidity of the stabilizer R. It is possible to control the posture change of the vehicle body so as to achieve the characteristic with emphasis on sex.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to specific embodiments shown in the accompanying drawings.
[0008]
FIG. 1 shows an electromagnetic linear actuator (hereinafter referred to as an actuator) to which the present invention is applied. The actuator 1 has a bottomed cylindrical shape, a case 3 provided with a joint 2 made of a ball stud on the top surface thereof, and a number of solenoids having an annular shape laminated on the inner peripheral surface of the case 3 in the axial direction. A stator 5 composed of a piece 4, a rod 7 that extends on the central axis of the case 3 and that has a joint 6 composed of a ball stud at one end protruding from the opening of the case 3, and is laminated on the outer periphery of the rod 7. The armature 9 is composed of a large number of pole pieces 8.
[0009]
The opening of the case 3 is sealed with a cap 10 in which the rod 7 is inserted into the center hole 10a. The cap 10 has an O-ring 11 interposed at the opening end of the case 3 so that the seal 12 is hermetically fitted, and is screwed into a female screw 13 formed inside the opening. The space between the inner periphery of the center hole 10 a of the cap 10 and the outer periphery of the rod 7 is hermetically sealed with a seal member 14.
[0010]
Here, the case 3 is described as being opened downward for convenience, but it goes without saying that the direction is not restricted in practice.
[0011]
As shown in FIG. 2, the solenoid piece 4 constituting the stator 5 includes a coil 17 in which a conductive wire is wound around a thin bobbin 16 made of a magnetic soft iron material provided with a recess 15 on the inner peripheral side. The stator 5 is screwed into a female screw 13 formed on the inner peripheral surface of the opening end side of the case 3 with both end portions in the axial direction where a large number of solenoid pieces 4 are stacked sandwiched between end collars 18a and 18b. The hollow nut 19 is tightened. In addition, each set of three coils 17 in the order of lamination is connected to the power supply lead S after being delta-connected.
[0012]
As shown in FIG. 2, the armature 9 is composed of an annular permanent magnet 20, a pair of annular yokes 21 made of a magnetic soft iron material sandwiching the magnets from above and below, and a stainless steel material sandwiched between the outer peripheral sides of the pair of annular yokes 21. A large number of pole pieces 8 composed of a magnetic shield ring 22 are stacked on the rod 7, both ends thereof are sandwiched between end collars 23 a and 23 b, and a nut 24 screwed to the top end side of the rod 7 is tightened. The rod 7 is integrally connected.
[0013]
The pole pieces 8 adjacent to each other are arranged such that the S poles and the N poles are alternately inverted.
[0014]
The armature 9 is slidably supported by oil-impregnated slide bushes 25 a and 25 b made of sintered alloy fitted to end collars 18 a and 18 b that hold both ends of the stator 5, and is movable in the axial direction together with the rod 7. . Here, in order to reduce frictional resistance against the slide bushes 25a and 25b and to prevent wear, the outer peripheral surface of the armature 1 is polished and a hard coating 26 such as hard chrome is formed. The hard coating 26 may be formed at least on the surface that slides with the slide bushes 25a and 25b, but may be applied to the entire surface in view of the effect of preventing rust.
[0015]
As described above, the rod 7 is linearly driven by the axial force generated in the armature 9 by sequentially exciting the solenoid pieces 4 in synchronism with the output of the pole piece position detecting means 27 using the Hall element. The linear motor type actuator 1 is configured. Since the principle of the linear motor is already known, further explanation is omitted here.
[0016]
The case 3 encloses the armature 9 together with the rod 7, and vacant spaces 28 a and 28 b are formed between the top surface of the case 3 and the inner surface of the cap 10, and both axial end surfaces of the armature 9. Yes. Since the volume of both the vacant chambers 28a and 28b changes with the movement of the armature 9, in order to balance the internal pressure of both the vacant chambers 28a and 28b, an air passage 29 that communicates between the vacant chambers 28a and 28b is provided. It is provided at the center of the rod 7.
[0017]
FIG. 3 shows one side of a suspension device in which each end of a stabilizer R composed of a torsion bar is connected to the left and right suspension arms A by the actuator 1 described above. As is well known, the stabilizer R has substantially no effect when the left and right wheels W move up and down in the same phase, but when the left and right wheels W move up and down in the opposite phase, the torsional rigidity causes the wheels W to move up and down. The higher the torsional rigidity, the less the change in posture during turning, and the lower the torsional rigidity, the higher the ride comfort on a flat road. That is, it can be said that the torsional rigidity of the stabilizer R is determined by a compromise between the turning stability and the ride quality on a flat road.
[0018]
For example, when one wheel W rides on a protrusion while traveling on a flat road, the rider's comfort is hindered because a force that prevents the wheel W from being lifted by the action of the stabilizer R works in a normal vehicle. If 1 is provided on one wheel W side, for example, and shortened, the force of the stabilizer R is absorbed and the wheel W moves up smoothly and the vibration is not transmitted to the vehicle body. Conversely, when one wheel W falls into the recess, the force of the stabilizer R can be absorbed by extending the actuator 1. That is, the apparent torsional rigidity of the stabilizer R can be continuously changed by providing the actuator 1 on at least one of the left and right ends of the stabilizer R, appropriately expanding and contracting it, and controlling the thrust. It becomes. That is, according to the device of the present invention, it is possible to increase the ride comfort on a flat road by setting the characteristics of the stabilizer R itself to a firm setting that emphasizes, for example, turning stability, and operating the actuator 1 as necessary. .
[0019]
Here, as shown in FIG. 3, the stroke range of the actuator 1, ie, the movable range L1, is narrower than the stroke range of the left and right wheels W, ie, the movable range L2 (L1 <L2). Therefore, when a force larger than the driving force of the actuator 1 is input, the actuator 1 bottoms out, and thereafter, a reaction force due to only the torsional rigidity of the stabilizer R is generated.
[0020]
Next, general drive control of the actuator 1 will be described with reference to FIG.
[0021]
The electronic control unit E that centrally controls the device captures the outputs of the lateral acceleration sensor 31, the left front wheel speed sensor 32, the right front wheel speed sensor 33, the yaw rate sensor 34, and the steering angle sensor 35. The estimated yaw rate calculator 36 calculates the estimated yaw rate from the speed difference, and the estimated lateral acceleration calculator 37 calculates the estimated lateral acceleration from the steering angle and the left and right wheel speed average values.
[0022]
For the lateral acceleration and yaw rate, the respective estimated values and detected values are input to the comparison circuits 38 and 39, and the larger value is input to the actuator thrust calculator 40. This is a measure for compensating for the delay in response of the sensor output, which cannot be avoided.
[0023]
In the thrust calculator 40, since the relationship of the thrust with respect to the added value of the lateral acceleration and the yaw rate is stored in the form of a map or a mathematical expression, a thrust value is calculated based on the lateral acceleration and the yaw rate, and this is used as a target current setting device. 41, and the thrust is converted into a current value.
[0024]
On the other hand, the steering angular velocity is calculated by, for example, differentiating the output of the steering angle sensor 35 by the steering angular velocity calculator 42, and this value is input to the correction current calculator 43 at the start of cutting and preset in the form of a map. From the relationship between the steering angular velocity and the current value, a target current value corresponding to the steering angular velocity at that time is output.
[0025]
This is input to the comparison circuit 44 together with the output of the target current setter 41, and the larger one is output to the PID control circuit 45. This is control focusing on the fact that the steered steering has a higher steering angular velocity at the start of turning, and during sudden steering, measures are taken to increase the effectiveness of the stabilizer R by setting a larger target current at the beginning of turning. It is. Then, an excitation current is supplied to the stator 5 composed of the laminated body of the coils 17 that are three-phase delta-connected through the drive circuit 46 in accordance with the synchronization signal generated by the synchronization signal generation circuit 47 based on the output of the position detection means 27. At the same time, the actual current from the current detection circuit 48 is fed back, so that the actuator 1 is driven to extend and contract so as to optimize the torsional rigidity of the stabilizer R.
[0026]
On the other hand, the output from the stroke sensor 48 provided in the actuator 1 is input to the bottom determination circuit 49. When the actuator 1 reaches the end of its movable range, that is, when bottom is detected, it is driven. The energization of the actuator 1 from the circuit 48 is stopped.
[0027]
Next, a basic control flow of the present invention will be described with reference to FIG.
[0028]
When the ignition switch is turned on (step 1), the electronic control unit E performs self-diagnosis and performs initial setting (step 2). Next, the lateral acceleration, the vehicle speed, the steering angle, etc. are read (step 3), and it is determined whether or not the operating condition of the actuator 1 has been cleared (step 4). Such expansion / contraction control of the actuator 1 is performed. Then, in step 6, it is determined whether or not the actuator 1 has reached the end of its movable range, that is, the bottom is determined. That is, when the bottom is reached, the energization of the actuator 1 is stopped (step 7), and the process proceeds to step 8. On the other hand, if it has not bottomed out in step 6, the process proceeds to step 8 as it is. Then, step 3 to step 7 are repeated until it is determined in step 8 that the ignition switch is turned off.
[0029]
Here, the process of step 5 will be described in more detail with reference to FIG. 6. First, in step 51, it is determined whether or not the lateral acceleration as the turning strength of the vehicle is 0.2 G or more. If it is smaller than 2G, the reaction force becomes larger, that is, the reaction force is the same as that when a hard stabilizer is used (step 52). If the lateral acceleration is 0.2G or more, it is further determined whether or not the lateral acceleration is 0.6G or more (step 53). If the lateral acceleration is smaller than 0.6G, that is, the lateral acceleration is 0.2G. If it is between 0.6 G, the reaction force is set to be small, that is, the reaction force is the same as that when a soft stabilizer is used (step 54). If the lateral acceleration is 0.6 G or more, the actuator 1 is set to bottom (step 55), and the actuator 1 is actually driven and controlled (not shown).
[0030]
FIG. 7 shows the relationship between the roll angle of the vehicle and the lateral acceleration in the case of using a stabilizer to which the present invention is applied, a hard stabilizer consisting only of the stabilizer bar, and a soft stabilizer consisting only of the stabilizer bar. The roll angle change is constant regardless of the lateral acceleration of the hard stabilizer composed only of the stabilizer bar and the soft stabilizer composed only of the stabilizer bar.
[0031]
On the other hand, in the stabilizer to which the present invention is applied, first, in the range where the roll angle is small (from the origin to the point A (0.2 G)), the thrust of the actuator 1 is superior to the external force, and a hard stabilizer is used. Adjust the roll angle to be the same as the case. When the roll angle is slightly larger (from point A to point B (0.6 G)), the thrust of the actuator 1 is lost to the external force and gradually pushed back (pulled), and a soft stabilizer is used. Adjust so that the roll angle changes in the same way as Then, the actuator 1 is bottomed out at the point B, and after that (right side from the point B), only the mechanical reaction force of the relatively hard stabilizer R is used. Here, when the point A is reached from the point A side to the point B, the power supply to the actuator 1 is stopped, thereby suppressing the power consumption. Needless to say, when the roll angle is reduced again and the point B is reached from the right side of the graph, the energization is resumed and the above control is performed.
[0032]
In this embodiment, the actuator 1 is an electromagnetic linear actuator. However, a rotary electromagnetic actuator, a conventional hydraulic actuator, or the like may be used, and a separate link member or the like is interposed between the actuator and the stabilizer. Also good.
[0033]
In the above embodiment, the turning strength of the vehicle is determined by detecting the lateral acceleration. However, the yaw rate is detected, and the lateral acceleration and the yaw rate are estimated from the steering angle, the wheel speed, the vehicle speed, and the like. The turning strength may be determined.
[0034]
【The invention's effect】
As described above, according to the present invention, the actuator is driven and controlled according to the turning strength of the vehicle to change the apparent torsional rigidity of the stabilizer. Controls the posture change of the vehicle body so that it becomes a characteristic, bottoms out the actuator when the turning strength increases, and controls the posture change of the vehicle body to become a characteristic that emphasizes running stability by the inherent rigidity of the stabilizer, etc. Depending on the turning strength, it is possible to give fine and appropriate characteristics and improve both ride comfort and running stability.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an electromagnetic linear actuator of a stabilizer efficacy control device to which the present invention is applied. FIG. 2 is an enlarged sectional view of a solenoid piece and a pole piece. FIG. 3 is a suspension device to which the present invention is applied. Fig. 4 is a block diagram of the control system of the present invention. Fig. 5 is a basic control flow diagram of the present invention. Fig. 6 is a detailed control flow diagram of the main portion of Fig. 5. Is a graph to explain the operating characteristics of the stabilizer to which is applied
1 Actuator 31 Lateral acceleration sensor 32 Left front wheel speed sensor, 33 Right front wheel speed sensor (vehicle speed sensor)
35 Steering angle sensor 48 Stroke sensor, 49 Bottom determination circuit (bottom detection means)
R Stabilizer E Electronic control unit (control means)

Claims (1)

A stabilizer efficacy control device having an actuator for changing the apparent torsional rigidity of a stabilizer provided between the left and right wheels, and a control means for controlling the output of the actuator,
A means for detecting the turning strength when the vehicle turns,
The turning strength is divided into three regions of low, medium, and high according to the degree, and the apparent torsional rigidity in the middle region is higher than the apparent torsional rigidity of the stabilizer in the low region and the high region. A stabilizer control device for controlling the effect of controlling the output of the actuator to be low .

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