JPH0811483B2 - Vehicle characteristic control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention detects a steering angle of a steering wheel of a vehicle by a steering angle sensor, and based on the detected steering angle, roll rigidity and power steering of a suspension device. The present invention relates to an improvement in a vehicle characteristic control device that controls at least one vehicle characteristic among the assist force of the device and a rear wheel steering angle of a four-wheel steering device, and more specifically, a steering angle detected by a steering angle sensor, The present invention relates to a vehicle characteristic control device that controls those vehicle characteristics in consideration of the accuracy of the steering neutral position.

[Prior Art] As a steering angle sensor for detecting a steering angle of a steered wheel in a conventional vehicle, a potentiometer type sensor for detecting a rotation position as a voltage signal is used to detect a rotation accuracy of a steering wheel with respect to a steering column. Also, a photoelectric type is known in which the rotation operation is detected as two voltage pulse signals having a phase shift.

However, in these steering angle sensors, the steering angle sensor itself and the steering wheel and other components have errors and variations in manufacturing and mounting,
When mounting the steering angle sensor, the components and their mounting relationship may be deformed during use, and the mounting angle may be incorrect when disassembling and assembling during vehicle maintenance. It is difficult to accurately set the steering neutral position of the steered wheels to the detected value.

Therefore, when using the above steering angle sensor, the steering neutral position is detected or calculated separately from the detected value of the steering angle sensor or based on the detected value, and the detected value of the steering angle sensor and its steering are calculated. It is necessary to obtain the direction and magnitude of the steering absolute angle of the steered wheels from the difference from the neutral position.

As a conventional method for obtaining the neutral position of the detected values of these steering angle sensors, for example, the one disclosed in Japanese Patent Laid-Open No. 59-26341 is known.

In this method, the steering angle detection value of the steering angle sensor is used as the steering neutral position when the vehicle continues stable straight traveling, and the steering neutral position has a long stable straight traveling distance. It will be updated every time.

Another conventional method for obtaining the steering neutral position is disclosed in Japanese Patent Application No. 59-31872, which is a prior application of the present applicant.

In this method, the steering angle detection value of the operation angle sensor is sampled for each constant traveling distance of the vehicle, a predetermined number of sample values are stored, and the oldest steering angle detection value is discarded for each sampling and the latest steering angle is stored. The detected value is stored, and the steering neutral position is determined by the average value of the predetermined number of updated steering angle detection values, that is, the moving average value of the detected steering angle values.

[Problems to be solved by the invention]

However, in such a method, in which the steering neutral position is obtained, and the steering absolute position is calculated by calculating the difference between the steering angle detection value of the steering angle sensor and the steering neutral position, the ignition switch is turned on, While the steering neutral position computing device is not running for a long distance after being powered on, it is calculated, for example, when the steering wheel is largely cut off when the power is turned on. There is a problem that the value of the steering neutral position temporarily has a large error and does not accurately represent the steering neutral position.

Therefore, the steering absolute angle is obtained from the difference between the detected steering angle value and the steering neutral position, and based on this steering absolute angle,
For controlling vehicle characteristics such as the roll rigidity of the suspension device, the assist force of the power steering device, or the rear wheel steering angle of the four-wheel steering device, steering is performed while the mileage is not long after the power is turned on. There is a problem that control of vehicle characteristics may become unstable while the neutral position is not accurately obtained.

The present invention has been made in view of such a conventional problem, and mainly when the value of the steering neutral position is inaccurate while the mileage after the power is turned on is not long, the vehicle characteristic An object of the present invention is to provide a vehicle characteristic control device capable of stably controlling the vehicle.

[Means for solving problems]

Therefore, the vehicle characteristic control apparatus of this invention, as shown in FIG. 1, a steering angle sensor for detecting a steering angle theta, the steering neutral position detecting means for detecting a steering neutral position theta _C or steering neutral position theta _C The steering neutral position calculation means for calculating the difference between the steering angle θ and the steering neutral position θ _C is calculated, and the steering absolute angle (θ
Steering absolute angle calculation means for calculating −θ _C ), and based on the steering absolute angle (θ −θ _C ) the roll rigidity of the suspension device, the assist force of the power steering device, and the rear wheel steering angle of the four-wheel steering device. In a vehicle characteristic control device including at least one vehicle characteristic changing means for changing the vehicle characteristic, the steering neutral position when the state in which the fluctuation range of the steering angle θ is small after the power is turned on continues for a predetermined traveling distance or more. When the steering neutral position accuracy determining unit that determines that θ _C is accurate and the steering neutral position θ _C is incorrect as a result of the determination by the steering neutral position accuracy determining unit, the vehicle characteristic changing unit determines And a characteristic change prohibiting means for prohibiting a change operation of the vehicle characteristic.

[Action]

The operation of the vehicle characteristic control device of the present invention determines whether or not the value of the steering neutral position θC is accurate by the steering neutral position accuracy determining means, and the fluctuation range of the steering angle θ after the power is turned on is small. While the steering neutral position θ _C is inaccurate, for example, when the vehicle cannot be judged to be in a straight traveling state because the vehicle has not continued for a predetermined traveling distance or more, the characteristic change prohibiting means prohibits the operation of changing the vehicle characteristic by the vehicle characteristic changing means, The vehicle characteristics are changed after the control of unstable characteristics is not performed and the steering neutral position accuracy determining means determines that the steering neutral position θ _C is accurate.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

In the embodiment, the steering neutral position θ _C is calculated from the steering angle θ detected by the steering angle sensor, and the difference between the steering angle θ and the steering neutral position θ _C is calculated to calculate the steering absolute angle (θ
Seeking - [theta] _C), the steering absolute angle based on (θ-θ _C) to determine the roll of the vehicle body status, to change the damping force of the variable damping force shock absorber of a suspension device according to the determination result, vehicle characteristics The roll rigidity is controlled to suppress the roll of the vehicle body.

First, the configuration will be described. In FIG. 2, as the steering angle sensor 1, as described at the beginning, a potentiometer type or photoelectric type, which is difficult to set the steering neutral position θC at the time of mounting, is used.

Reference numeral 2 denotes a controller. The controller 2 includes a microcomputer 3 and a drive circuit 5 for driving an actuator for changing the damping force of the damping force variable shock absorbers 4a to 4d included in the vehicle suspension device. It is configured to include.

The microcomputer 3 is configured to include at least an interface circuit 6, an arithmetic processing unit 7, and a storage device 8 such as a RAM or a ROM. The steering angle sensor 1 and the drive circuit 5 are connected to the interface circuit 6.

The steering angle sensor 1 that outputs a digital amount detection signal like a photoelectric type is directly connected to the interface circuit 6, and the steering angle sensor 1 that outputs an analog amount detection signal like a potentiometer type is A / It is connected to the interface circuit 6 via a D converter (not shown).

The arithmetic processing unit 7 reads the steering angle θ detection signal from the steering angle sensor 1 via the interface circuit 6 and performs arithmetic processing and other processing described later based on the signal. Further, the storage device 8 stores a predetermined program necessary for executing the processing, and also stores the processing result of the arithmetic processing device 7 and the like.

FIG. 3 shows, as an example of the variable damping force shock absorbers 4a to 4d, one capable of changing the damping force in two steps, soft side and hard side.

In the figure, 10 is a piston rod formed by connecting an upper rod 11 and a lower rod 12, and the upper end thereof is fixed to the vehicle body side. 13 is a tube whose lower end is fixed to the wheel side, 14 is a piston which is fixed to the lower end of the lower rod 12 and slides along the inner peripheral surface of the tube 13, and 15 is the inner circumference of the tube 13 at the bottom side of the tube 13. A free piston that slides along a surface. Inside the tube 13, a piston upper chamber A is formed above the piston 14, a piston lower chamber B is formed between the piston 14 and the free piston 15, and a gas chamber C is formed below the free piston 15. The upper chamber A and the piston lower chamber B are filled with oil, and the gas chamber C is filled with high-pressure gas.

Reference numeral 16 is an extension side valve, 17 is an extension side orifice, 18 is a contraction side valve, and 19 is a contraction side orifice. Also, 20 and
Reference numeral 21 is a through hole and a hollow portion formed in the upper rod 11, and 22 and 23 are bypass passages and a hollow portion formed in the lower rod 12.

A plunger 24 is arranged in the two cavities 21 and 23, the plunger 24 is constantly pressed upward in the drawing (direction D) by the restoring force of the return spring 25, and a solenoid 26 is arranged around the plunger 24. Solenoid 26
An actuator 27 is configured by the plunger 24 and the plunger 24. The solenoid 26 is connected to the drive circuit 5 via a lead wire 28 passing through the through hole 20 of the upper rod 11.

In the extension stroke, the damping force variable shock absorbers 4a to 4d open the extension side valve 16 so that the piston upper chamber A and the piston lower chamber B communicate with each other via the extension side orifice 17, and the compression side valve 18 The contraction side orifice 19 is closed. In the compression stroke, the compression valve 18 opens, the piston upper chamber A and the piston lower chamber B communicate with each other via the compression orifice 19, and the expansion valve 17 closes the expansion orifice 17. .

 Next, the operation of this embodiment will be described.

When the ignition switch is turned on, the controller 2 is powered on and the detection signal of the steering angle sensor 1 is supplied to the interface circuit 6 of the microcomputer 3.

FIG. 4 shows a procedure executed by the microcomputer 3 for obtaining the steering neutral position θC from the detection signal of the steering angle sensor 1. This processing is preferably performed every time a vehicle speed pulse is input from a vehicle speed sensor (not shown).
That is, it is executed as an interrupt every time the vehicle travels a predetermined distance Δl.

In the figure, in step, the steering angle sensor 1
The value of the steering angle θ is read from the detection signal of.

When the steering angle sensor 1 is a potentiometer type,
An analog amount detection signal of the steering angle sensor 1 is converted into a digital signal by the A / D converter, and the digital signal becomes the steering angle θ.

When the steering angle sensor 1 is of a photoelectric type, for example, as described in Japanese Patent Application No. 59-31872, two pulses with a phase difference input from the steering angle sensor 1 to the interface circuit 6 are input. For example, when the signal rises, the main program is interrupted, the steering direction is judged based on the phase shift, and a predetermined counter is counted up each time a pulse signal is input, for example, if it is right-turned, it is counted up and left-turned. If there is, the countdown is continued, and the count value is set as the steering angle θ.

Next, in step, the maximum value θ _M of the previous steering angle θ stored in the predetermined area of the storage device 8 is read out and compared with the steering angle θ, and if θ> θ _M , then θ in step Is stored as a maximum value θ _M , and θ ≦ θ _M
If so, do not update. Next, in step, the minimum value θ _m of the previous steering angle θ stored in a predetermined area of the storage device 8 is read and compared with the steering angle θ, and θ <θ
_{If m} , then θ is updated and stored as the minimum value θ _m in the step, and if θ ≧ θ _m, it is not updated.

Next, the process proceeds to step, and the absolute value of the difference between the maximum value θ _M of the steering angle θ and the minimum value θ _m of the steering angle θ that has been updated and stored as described above is obtained, and this value is determined by a predetermined value Δθ.
Compare with If | θ _M −θ _m | <Δθ, the process proceeds to the step, the value of the predetermined counter 1 for integrating the traveling distance 1 is incremented by Δ1, and the process proceeds to the step.

In step, the traveling distance 1 which is the content of the counter 1
Is greater than or equal to a predetermined distance L, and l <
If L, return to the main program. In addition,
The predetermined distance L set in advance may be a value initially set by initialization, and then may be reset in a step described later.

If l ≧ L in the step, the average of the maximum value θ _M and the minimum value θ _m is taken in the next step, and this is set as the steering neutral position θ _C, and the predetermined distance L determined in advance is counted by the counter l. The travel distance 1 which is the content of is set and corrected again, and the process returns to the main program.

If | θ _M −θ _m | ≧ Δθ in step, the process proceeds to step to clear the maximum value θ _M , the minimum value θ _m, and the value of the traveling distance l, and return to the main program.

According to such processing shown in FIG. 4, the steering neutral position θ _C is obtained by the average value of the maximum value θ _M and the minimum value θ _m of the detected values of the steering angle θ by the steering angle sensor 1.
However, only when the straight running in which the difference between the maximum value θ _M and the minimum value θ _m is within a predetermined small range (−Δθ to Δθ) continues for a predetermined distance L or more. , The steering neutral position θ _C is calculated by the average value of the maximum value θ _M and the minimum value θ _m in the traveling distance. Then, the difference between the maximum value θ _M and the minimum value θ _m is within a predetermined range (−Δθ˜
The calculation of the steering neutral position θ _C is not executed while the traveling distance is not within Δθ) or when the difference is within a predetermined range and the traveling distance that is within is less than the predetermined distance L. Next, a case where the roll rigidity of the suspension device is controlled based on the steering neutral position θ _C thus obtained will be described with reference to FIG. This process is preferably executed as a timer interrupt every 20 ms, for example.

In FIG. 5, first, in a step, it is determined whether or not the value of the steering neutral position θ _C in the processing shown in FIG. 4 is accurate. This determination is made when the steering neutral position θ _C is calculated in the step of FIG. 4, that is, when the difference between the maximum value θ _M and the minimum value θ _m of the steering angle θ is within a predetermined range (−Δ.
When the straight traveling within the range of θ to Δθ continues for a predetermined distance L or more, the steering neutral obtained as an average value of the maximum value θ _M and the minimum value θ _m in the traveling distance. The value of the position θ _C is determined to be accurate.

Since the predetermined traveling distance L is reset by the traveling distance 1 of the counter 1 in step, the steering neutral position θ _C is not calculated thereafter unless the newly set predetermined traveling distance L is exceeded. Therefore, since it is not calculated unless the more accurate steering neutral position θ _C is required, a more accurate steering neutral position θ _C can be obtained as the vehicle travels.

Then, in the process in FIG. 4, the steering neutral position θ
_When the value of _C is not calculated, that is, while the difference between the maximum value θ _M and the minimum value θ _m does not fall within the predetermined range (−Δθ to Δθ), and even when the difference falls within the predetermined range, it does not fall. While the running distance is less than the predetermined distance L, it is determined that the value of the steering neutral position θ _C is not accurate even if it is calculated.

In the step, when it is determined that the value of the steering neutral position θ _C is accurate, the roll rigidity of the suspension device is controlled using the steering neutral position θ _C.
That is, the process proceeds to step and the difference between the value of the steering angle θ detected by the steering angle sensor 1 and the value of the steering neutral position θ _C calculated as described above is calculated to calculate the absolute steering angle (θ
-? _C ) is obtained, and it is checked whether or not this steering absolute angle (?-? _C ) is within a predetermined range (-a to a). That is, if | θ−θ _C | <a, it is determined that the vehicle body does not roll at all or so much, the damping forces of the variable damping force shock absorbers 4a to 4d are set to the soft side, and the roll rigidity of the vehicle body is set. Set to the soft side.

When the damping force of the variable damping force shock absorbers 4a to 4d is set to the soft side, the interface circuit 6 of the microcomputer 3 sends a control signal of "L (low level or logical value" 0 ")" to the drive circuit 5. Supply. 2 and 3, the driving circuit 5 supplies no exciting current to the solenoid 26 of the actuator 27, the solenoid 26 is de-energized, and the plunger 24 is drawn by the restoring force of the return spring 25. Above (D direction)
The lower end of the plunger 24 is disengaged from the bypass passage 22 and the upper piston chamber A and the lower piston chamber B are in communication with each other via the bypass passage 22. Therefore, the damping force of the variable damping force shock absorbers 4a-4d is increased. Set on the software side. Therefore, the roll rigidity of the vehicle body is on the soft side.

Returning to FIG. 5, if | θ−θ _C | ≧ a in the step, it is determined that the vehicle body is largely rolled, and the damping force of the variable damping force shock absorbers 4a to 4d is switched to the hard side, The roll rigidity of the car is switched to the hard side to suppress the car body roll.

When the damping force of the variable damping force shock absorbers 4a to 4d is switched to the hardware side, the interface circuit 6 of the microcomputer 3 supplies the control signal of "H (high level or logical value" 1 ")" to the drive circuit 5. To do. 2 and 3, the driving circuit 5 supplies the exciting current of a predetermined value to the solenoid 26 of the actuator 27 to bring the solenoid 26 into the excited state, and the electromagnetic force of the solenoid 26 causes the plunger 24 to return. The lower end of the plunger 24 enters the bypass passage 22 against the restoring force of the spring 25, and the lower end of the plunger 24 enters the bypass passage 22 to cut off the communication between the upper piston chamber A and the lower piston chamber B. The damping force of the variable damping force shock absorbers 4a to 4d is set to the hard side. Therefore, the roll rigidity of the vehicle body is on the hard side, and the rolling of the vehicle body is suppressed.

Returning to FIG. 5, when it is determined in step that the value of the steering neutral position θ _C is inaccurate, control of the roll rigidity of the suspension device in steps 1 to 3 is prohibited, and the damping force variable shock absorber is suppressed in step. The damping force of 4a-4d is fixed to the soft side, and the roll rigidity is fixed to the soft side.

The operation of fixing the damping force of the damping force variable shock absorbers 4a to 4d to the soft side is the same as the above-mentioned setting of the damping force to the soft side, and maintains this state.

After the roll rigidity is controlled in steps 1 to 3, the control proceeds to step and other control not based on the detection value of the steering angle sensor 1, for example, a damping force variable shock for suppressing the nose dive of the vehicle body during braking. Absorber 4a
Performs anti-dive control that switches the damping force of ~ 4d to the hard side.

FIG. 6 shows a specific example of the roll rigidity control described above. At the time point t ₀ when the ignition switch is turned on, the steering wheel is greatly cut to the left and the vehicle is stopped, and the steering middle ratio position θ _C is large. The case where there is a deviation is shown.
The horizontal axis of the figure shows the travel distance after the start of travel.

In the figure, when the vehicle starts traveling at time t ₀ ,
The steering wheel returns to the neutral position and the steering angle θ
The detected value of changes to the right. During the traveling distance _1, the difference between the maximum value θ _M and the minimum value θ _m of the steering angle θ is within a predetermined range, that is, | θ _M −θ _m | <Δθ, and at the end of I ₁ , | θ _M −θ _m | ≧ Δθ, but since I ₁ is less than the predetermined distance L, the value of the steering neutral position θ _C is not calculated.
Similarly, during the traveling distance I ₂ , | θ _M −θ _m | ≧ Δθ, and I ₂
At the end time t ₁ of | θ _M −θ _m | ≧ Δθ,
Since I ₂ ≧ L, the value of the steering neutral position θ _C is calculated and accurate after the time point t ₁ . Therefore, in the present invention, the damping force is fixed to the soft side at the time points t _{0 to} t ₁ and the low rigidity control is prohibited, and after the time point t _1, the steering angle θ
The steering force absolute angle (θ−θ _C ) which is the difference between the detected value and the calculated steering neutral position θ _C is compared with a predetermined value a to control the damping force, that is, the roll rigidity.

Conventionally, | θ−θ _C | ≧ a at the traveling distances I ₃ and I ₄ , so that the damping force is switched to the hard side and the roll rigidity is switched to the hard side unnecessarily at I ₃ and I ₄ . Therefore, the roll characteristics of the vehicle may become unstable during this period.

 FIG. 7 shows another embodiment of controlling the roll rigidity.

In this embodiment, the steering neutral position θ
_When it is determined that the value of _C is inaccurate, the process of fixing the damping force to the software side as shown in FIG. 5 is not performed,
Immediately after the step, the anti-dive control is executed.

In the embodiment described above, regarding the various means shown in FIG. 1, the processing shown in FIG. 4 is a concrete example of the steering neutral position calculating means, and the processing of the steps of FIGS. 5 and 7 is the steering absolute angle. A concrete example of the calculating means, a step of FIGS. 5 and 7 is a concrete example of the steering neutral position accuracy determining means, a process of steps of FIGS. 5 and 7 and a driving circuit 5 of FIG. The specific example of the characteristic changing means with the actuator 27 of FIG. 3 is the same as the specific example of the characteristic changing prohibiting means in the processing of the step of FIG. 5 and the processing of shifting to the step after the determination of NO in the step of FIG. Show.

Further, although the one configured by using the microcomputer as the controller is shown, instead of this, an electronic circuit such as a comparison circuit, an addition circuit, a subtraction circuit, an absolute value circuit, a command value setting circuit, a counting circuit, and a logic circuit. It is also possible to configure the controller by combining.

Further, the calculation method or the detection method of the steering neutral position θ _C is not particularly limited, and the difference between the maximum value θ _M and the minimum value θ _m of the detected values of the steering angle θ as described in the embodiment is predetermined. In addition to the steering neutral position θ _{C, which} is an average value of the maximum value θ _M and the minimum value θ _m when traveling within the range (−Δθ to Δθ) continues for a predetermined distance L or more, detection by the steering angle sensor 1 The steering neutral position θ _C may be a moving average of the values.

In this case, the means for determining whether the value of the steering neutral position θ _C is accurate is usually the steering neutral position θ _C calculated by the moving average until the vehicle travels a predetermined distance after the ignition switch is turned on. Since it is highly probable that the value is incorrect, the distance traveled by the vehicle after the ignition switch is turned on is detected, and the calculated steering neutral position θ is reached while this distance is less than the predetermined distance. _C
The value of is inaccurate, and it is preferable to determine that the value is accurate after the predetermined distance is exceeded.

In the case of the above-described embodiment as well, the value of the steering neutral position θ _C is not calculated unless the vehicle has traveled at least a predetermined distance L. Therefore, in the case of the embodiment as well, a kind of determination as to whether or not the vehicle has traveled the predetermined distance It can be said that it is a means.

Also, in order to perform roll control, the shock absorber damping force can be changed in two steps, soft side and hard side, but the number of change steps is not limited to two steps, and soft, medium, hard The present invention can be applied to a multi-step changeable in three steps or four or more steps, and in this case, the present invention can be applied to an appropriate two steps in the multi-step change step number. To do so.

Also, in order to control the roll rigidity, the case where the damping force of the shock absorber is changed has been illustrated, but the spring constant of the fluid suspension device is changed instead of the damping force of the shock absorber or together with the damping force of the shock absorber. The present invention also includes a case in which the roll rigidity is controlled by doing so.

Further, the present invention is not limited to the case of controlling the roll rigidity as the vehicle characteristic, and is applied to all the control of the vehicle characteristic using the detection value of the steering angle sensor. In addition to roll rigidity, for example, a power steering device that controls an assist force based on a steering angle θ detected by a steering angle sensor and a steering force,
The present invention can also be applied to a four-wheel steering device that controls the rear wheel steering angle to an angle proportional to the steering angle θ, for example.

〔The invention's effect〕

As described above, according to the vehicle characteristic control device of the present invention, it is determined whether the steering neutral position detected or calculated based on the steering angle detection value by the steering angle sensor is accurate, and the steering neutral position is determined. When it is determined that the value of is inaccurate, the roll rigidity of the suspension device, the assist force of the power steering device, and the change operation of at least one vehicle characteristic among the rear wheel steering angles of the four-wheel steering device are prohibited. Therefore, after the power is turned on, the fluctuation range of the steering angle θ does not continue for a predetermined period of time or more, and it cannot be determined that the vehicle is in a straight traveling state.While the detected or calculated steering neutral position value is inaccurate, steering neutral It is possible to obtain an effect that an unstable control operation of the vehicle characteristic based on an inaccurate value of the position can be prevented and the vehicle characteristic can be stably controlled.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of a vehicle characteristic control device of the present invention, FIG. 2 is a block diagram showing a configuration of an embodiment of the present invention, and FIG. 3 is a longitudinal section showing an example of a damping force variable shock absorber. FIG. 4 is a flow chart showing a processing procedure of an embodiment for obtaining a steering neutral position based on a detection value of a steering angle sensor, which is executed by a microcomputer, and FIG. 5 is based on the processing result of FIG. FIG. 6 is a flow chart showing a processing procedure of an embodiment of roll rigidity control of the suspension device, FIG. 6 is a view for explaining a specific example of the processing operation of FIG. 5, and FIG. 7 is roll rigidity control. 5 is a flowchart showing a processing procedure of another embodiment of FIG. 1 ... Steering angle sensor, 2 ... Controller, 3 ... Microcomputer, 4a-4d ... Damping force variable shock absorber, 5 ... Drive circuit, 6 ... Interface circuit,
7 ... Arithmetic processing device, 8 ... Storage device, 10 ... Piston rod, 13 ... Tube, 14 ... Piston, 22 ... Bypass passage, 24 ... Plunger, 25 ... Return spring, 26 ... Solenoid , 27 …… Actuator, A ……
Piston upper chamber, B …… Piston lower chamber, θ …… Steering angle, θ
_{C ......} steering neutral position, θ-θ _{C ......} steering absolute angle.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location B62D 137: 00 (72) Inventor Kazunobu Kawabata 2 Takaracho, Kanagawa-ku, Kanagawa Prefecture (56) Reference JP-A-60-176804 (JP, A) JP-A-56-25031 (JP, A) JP-A-58-49507 (JP, A) JP-A-60-248479 (JP, A) Actual Development Sho 60-34907 (JP, U)

Claims (1)

[Claims] 1. A steering angle sensor for detecting a steering angle theta, the steering neutral position calculating means for calculating a steering neutral position detecting means or steering neutral device theta _C for detecting a steering neutral position theta _C, and the steering angle theta Steering absolute angle calculating means for calculating a steering absolute angle (θ−θ _C ) by obtaining a difference from the steering neutral position θ _C ,
Vehicle characteristic changing means for changing at least one vehicle characteristic among the roll rigidity of the suspension device, the assist force of the power steering device, and the rear wheel steering angle of the four-wheel steering device based on the steering absolute angle (?-? _C ). In a vehicle characteristic control device including: a steering neutral position accuracy for determining that the steering neutral position θ _C is accurate when a state in which the fluctuation range of the steering angle θ is small after the power is turned on continues for a predetermined traveling distance or more. And a characteristic change prohibiting means for prohibiting the vehicle characteristic changing operation by the vehicle characteristic changing means when the value of the steering neutral position θ _C is inaccurate as a result of the judgment by the judging means and the steering neutral position accuracy judging means. A vehicle characteristic control device comprising: