JPS60248481A - Rear wheel steering angle control device of car - Google Patents

Abstract

PURPOSE:To improve the responsiveness of turn movement and the stability of straight running by controlling the steering angle direction of a rear wheel in response to the steering speed of a handle. CONSTITUTION:A judgment circuit 22 judges the size of the angular frequency of a handle, i.e., steering speed, based on the steering quantity signal inputted from a detection means 20. A control circuit 24 allows a rear wheel to generate the steering angle in the opposite direction to that of a front wheel and outputs the control signal generating the steering angle in response to the steering quantity signal when the steering speed of the handle is high based on the judged result of the judgment circuit 22 and the steering signal. On the other hand, when the steering speed is low, it allows the rear wheel to generate the steering angle in the same direction as that of the front wheel and outputs the control signal generating the steering angle in response to the steering quantity signal.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a rear wheel steering angle control device of a vehicle, and in particular to a device for controlling an operating mechanism that produces a steering angle on the rear wheels to produce a steering angle on the front wheels. The present invention relates to a rear wheel steering angle control device for a vehicle (hereinafter referred to as a four-wheel steering vehicle) that automatically controls the steering angle of the rear wheels in accordance with the steering of a steering wheel.

A conventional rear wheel steering angle control device for a four-wheel steered vehicle (Japanese Patent Application Laid-Open No. 57-44568), which is the basis of the present invention, will be explained with reference to FIG.

The shaft 2 rotates as the handle 1 is rotated, and this rotation is transmitted to the gear box 3 and converted into linear motion of the linkage 4. The linear motion of the linkage 4 rotates the knuckle arm 5 around the fulcrum 5a, steers the front wheel 6, and causes the front wheel 6 to produce a steering angle δf (where t is time). The mounted sensor 15 detects the rotational steering angle δ^(1) of the nondle 1, and the sensor 7 detects the lateral acceleration V generated in the vehicle according to the rotational steering angle δ+1(1) of the handle 1.Computer 8 is actuator 9 based on the detection signal from sensor 7.15.
and linkage 14 via gearbox 10.
gives linear motion to. The linear movement of the linkage 14 rotates the knuckle arm 13 at rotation 9 around the fulcrum 13a, and the rear wheel 1
2 to cause the rear wheels 12 to produce a steering angle δ, , (1). The steering angle of this rear wheel is determined by the computer 8 as δX1.(t)- which is proportional to the lateral acceleration chamber.
・・・・・・・・・(1) or h −al, which is the front wheel steering angle δft(t) multiplied by the proportionality constant
Adding l'(t) to the right-hand side of equation (1) above, we get δ-,(t)-h-a z(riten-s...
...(2) is set and controlled.

However, such conventional rear wheel steering angle control devices are not configured to take into account the steering speed of the steering wheel, and the signal proportional to the rotational steering angle of the steering wheel may be used even when the rotational steering angle of the steering wheel is small. Rotation of the Steering Wheel Even when the steering angle is large, the rear wheels are steered in the same direction as the front wheels, which has the advantage of improving the running stability of the vehicle when driving straight and making it easier to correct the steering wheel. The response is not good and the structure does not allow for turning movement with a small turning radius.

In addition to the device shown in Fig. 2, conventionally, in a four-wheel steering vehicle in which a steering device for steering the front wheels and a steering device for steering the rear wheels are mechanically connected, a rotational steering angle of the I/N wheel has been proposed. When the steering angle of the front wheels is small, the rear wheels are steered in the same direction as the front wheel steering angle, and when the non-driving steering angle is large, the rear wheels are steered in the opposite direction to the front wheel steering angle. Controlling devices have also been proposed.

However, in such a device, the rear wheels are steered in the same direction or in the opposite direction as the front wheels depending on the magnitude of the rotational steering angle of the steering wheel, and the driver steers the steering wheel. For example, when the driver is responding to an emergency maneuver that requires a rapid turning movement such as to avoid an obstacle or changing lanes, and when the driver is responding to a normal steering operation such as when driving straight or slowly turning. Even if you change the steering speed of the steering wheel in anticipation of different motion characteristics depending on the situation, if the rotational steering angle of the steering wheel is constant, the steering angle of the rear wheels will remain constant in the specified direction. The structure is such that the size is controlled.

Therefore, in the above-mentioned conventional four-wheel steering vehicle, if the driver's expected motion is equally controlled according to the steering speed, the rear wheel steering angle control always steers the rear wheels in the same direction as the front wheels. As a result of comparing and examining the dynamic characteristics of a four-wheel steered vehicle equipped with this device and a four-wheel steered vehicle equipped with a rear wheel steering angle control device that always steers the rear wheels in the opposite direction to the front wheels, we found that The present invention was developed based on the need to develop a rear wheel steering angle control device that controls the direction of the rear wheel steering angle according to the steering speed, that is, the angular frequency.

[Purpose of the invention]

In consideration of the above points, and in order to eliminate the conventional delay point, the present invention focuses on the steering speed of the nondle and improves the responsiveness of the turning movement in situations where rapid turning movement is required. However, it is an object of the present invention to provide a rear wheel steering angle control device for a vehicle that improves straight running stability under conditions where slow and rapid turning movements are required.

[Summary of the invention]

In an automatically controlled rear wheel steering angle control device of a vehicle, a detection means detects a steering amount of a steering wheel and outputs a steering amount signal, and a determining means determines steering speed of the steering wheel based on the steering amount signal. Based on the judgment result of the judgment means, when the steering speed of the steering wheel is fast, the rear wheels are caused to produce a steering angle in the opposite direction to the front wheels, and when the steering speed is slow, the rear wheels are caused to produce a steering angle in the same direction as the front wheels. The present invention is characterized in that it includes a control means for controlling the actuation mechanism so as to produce a steering angle.

According to the present invention, the detection means detects the rotational steering angle a b (t) of the steering wheel or the displacement of the steering wheel corresponding to the straight-ahead direction of the vehicle and based on the position of the steering wheel, that is, the amount that changes to the steering angle of the front wheels. Detected as the amount of steering. If the rotational steering angle of the steering wheel is detected, the angular frequency ω of the steering wheel is calculated by differentiating the rotational steering angle with respect to time Bc.
is determined, and when the displacement of the handle is detected, the displacement is calculated using the angular frequency ω of the handle as X−f(ωt
). Therefore, the determination means can determine the steering speed of the steering wheel based on the steering amount signal output from the detection means. When the steering speed of the non-driver, that is, the angular frequency, is high, the control means controls the operating mechanism so that the rear wheels are steered in the opposite direction to the front wheels, and the front wheels and rear wheels are steered almost simultaneously. This causes a force to be generated on the tire, and these forces become a yawing moment that rotates in the same direction, which equivalently increases the ratio of the steering angle of the steering wheel to the rotational steering angle of the steering wheel, so-called steering gain. , the steering angle of the steering wheel is equivalently the sum of the steering angle of the front wheels and the steering angle of the rear wheels), and the responsiveness of the turning motion of the vehicle is improved. On the other hand, when the steering speed of the steering wheel, that is, the angular frequency, is small, the control means controls the operating mechanism so that the rear wheels have a steering angle in the same direction as the front wheels, so that the steering angle of the steered wheels is equivalently The steering gain decreases due to the difference between the front wheel steering angle and the rear wheel steering angle, improving the straight-line stability of the vehicle.

〔Effect of the invention〕

Therefore, according to the present invention, when the steering wheel is steered quickly, that is, when the angular frequency of the steering wheel is high, the steering gain is increased to improve the responsiveness of rapid turning movements of the vehicle, and when the angular frequency of the steering wheel is small, the steering gain is increased. It is possible to improve the running stability of the vehicle when driving straight by reducing the amount of head tilt of the vehicle, preventing wobbling, etc.
This effect can be obtained. - [Detailed Description of the Invention] Next, aspects of the present invention will be described. The present invention can adopt the following aspects. In a first aspect, the control means causes the rear wheels to produce a steering angle in the opposite direction to the front wheels when the speed of steering the steering wheel is high based on the determination result of the determination means and the steering amount signal, and controls the steering angle of the steering wheel in the opposite direction to that of the front wheels. When the speed is slow, the operating mechanism is controlled so that the rear wheels have a steering angle in the same direction as the front wheels, and the rear wheels have a steering angle of a magnitude corresponding to the steering amount signal.

According to this first aspect, the direction in which the steering angle of the rear wheels is generated is controlled according to the steering speed of the steering wheel, and the magnitude of the steering angle of the rear wheels is controlled according to the steering amount signal. It is possible to optimally determine the ratio between the front wheel steering angle and the rear wheel steering angle using the steering amount signal, and if necessary, the ratio between the front wheel steering angle and the rear wheel steering angle can be adjusted appropriately according to the driver's preference. It has the advantage of being configurable.

The second aspect is that the increase beak consumption-determination means has the following transfer function G
@), and the control means controls the actuating mechanism based on the result.

Ke G@) - Kd - □ + Ts - T8 , , , , Mountain (
3) However, Kd, Ke are O(, K d (K e
S is a complex frequency expressed as a+jω (where, T is an arbitrary real number unrelated to time t, J−n−), and T is a first-order lag time constant.

Note that, as is well known, the transmission amount e G (S) is 2 of the output
Glass transformation form, i.e., the image function δ obtained by Laplace transform of the steering angle δ-(1) of the rear wheels, 2-plus transformation form of the input St, for example, the image function Jet obtained by 2-plus transformation of the rotational steering angle JAI(t) of the steering wheel. It is divided by (to).

The actuating mechanism is controlled by a transmission characteristic that is equal to or less than 9 times.

The conventional transfer characteristic of this type of device is, for example, the following transfer function G @ expressed by the ratio of the proportional element and the first-order lag element.
There is.

However, Ke''')O.

This transfer function G (Q is G (S) −
At the limit of Ke, S→■, it becomes G(S)-o, so if the steering wheel is turned slowly, the rear wheels will have a steering angle in the same direction as the front wheels, and if the steering wheel is turned quickly, the rear wheels will have a steering angle in the same direction as the front wheels. The angle has a characteristic of being zero or a small value close to zero in the same direction as the front wheel. In other words, compared to conventional vehicles that do not control the steering angle of the rear wheels, when the steering wheel is turned slowly, the rear wheels are controlled in the same direction as the front wheels to improve straight-line stability. The difference is simply maintained at the same level as the conventional vehicle.

Therefore, the inventors have arrived at a rear wheel steering angle control device that is controlled by a transfer function that satisfies the following conditions.

(a) For fast steering, that is, for steering with a high non-driving angular frequency, the rear wheel steering angle is set to be opposite to the front wheel steering angle by minimizing the delay with respect to front wheel steering. In response to slow steering, the response level of the rear wheels is reduced to weaken the influence of the steering wheel on the steering. The transfer function G(8) that satisfies this condition is as follows, and is expressed by a proportional element, a -order lag element, and a differential element.

(0<Kd<Ke) (b) For steering with a slow steering wheel, that is, steering with a low angular frequency, the rear wheel steering angle is controlled in the same direction as the front wheel steering angle. In this case, the response level of the rear wheels is reduced to weaken the influence of the steering wheel on steering. The transfer function GO that satisfies this condition is given by It's like that.

In order to explain the characteristics of the above equation (7), consider a case where the steering wheel is steered extremely slowly and a case where the steering wheel is steered extremely quickly. When the steering wheel is turned extremely slowly, the complex frequency S becomes an extremely small value, and its limit S→
0, the above equation (7) becomes as follows.

Kd)Q, so if the input is the rotational steering angle of the steering wheel δ), the steering angle of the rear wheels δ-<1) and the rotational steering angle of the steering wheel δA(t) have the same sign, and the rotational steering angle of the rear wheels is The steering angle is controlled in the same direction as the steering angle of the front wheels.

- When the steering wheel is steered extremely quickly, the complex frequency S becomes an extremely large value, and at its limit S-+ω, the above equation (7) becomes as follows.

1m G(S)+a K d −K e −(9)S−
〇Ke > VL, dte exists, so KCd - -e < o, and if the input is the rotational steering angle δA(t) of the steering wheel, then the steering angle δ(1) of the rear wheels and the rotational steering angle δA(t
) has the opposite sign, and the steering angle of the rear wheels is controlled in the opposite direction to the steering angle of the front wheels.

In addition, in the above case, the steering angle δiri of the rear wheels is a constant K
d, Kd - Kce is proportional to the rotational steering angle δa) of the bolt, so the magnitude of the steering angle of the rear wheels is controlled in proportion to the magnitude of the rotational steering angle of the bolt.

Note that although the rotational steering angle of the steering wheel is used as an input in the above, the same control can be performed using the displacement of the steering wheel.

As described above, according to the second aspect, the direction and magnitude of the steering angle of the rear wheels are controlled according to the steering speed of the steering wheel, and the values of the constants Kd, Kke, and time constant T are optimally determined. This has the advantage that the magnitude and direction of the steering angle of the rear wheels can be optimally controlled in accordance with the steering speed of the steering wheel.

[Embodiments of the invention]

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

FIG. 1 is a schematic diagram of a four-wheel steering vehicle connected to a basic circuit according to an embodiment of the present invention. A handle (steering wheel) 1 is connected to a gear box 3 via a shaft 2. Linkages 4 are connected to both ends of the gearbox 3, and a front wheel 6 is connected to each linkage 4 via a knuckle arm 5. The rear wheel 12 is connected to both ends of a steering link mechanism that includes a knuckle arm 13 and a linkage 14, similar to the front wheel 6.

A detection means 20 that continuously detects the amount of steering of the handle 1 is connected to the shaft 2, and this detection means 20 is connected to an actuation mechanism 28 via a control means 26 composed of a judgment circuit 22 and a control circuit 24. has been done.

The determination circuit 22 determines the magnitude of the angular frequency ω of the steering wheel, that is, the speed of steering, based on the steering amount signal output from the detection means 20. Based on the determination result of the determination circuit 22 and the steering amount signal, the control circuit 24 causes the rear wheels to produce a steering angle in the opposite direction to the front wheels when the steering speed of the steering wheel is high, and also controls the steering angle in accordance with the steering amount signal. On the other hand, when the steering speed is slow, the system outputs a control signal that causes a steering angle of the same magnitude as that of the front wheels. Outputs a control signal to generate the signal.

The actuation mechanism 28 controls the direction and magnitude of the steering angle of the rear wheels based on this control signal.

Next, specific examples of the present invention will be described.

In the following description, parts corresponding to those in FIG. 1 are designated by the same reference numerals.

FIG. 3 is a circuit diagram showing a first specific embodiment of the present invention. The rear wheel steering angle control device of the first specific embodiment includes a detection means 50 for detecting the rotational steering angle of the steering wheel 1, and a steering angle signal connected to the detection means 50 and outputted from the detection means. a determination circuit 201 that determines the steering speed, that is, the angular frequency of the steering wheel, based on the rate of change of the steering angle signal; and a control circuit 251 that outputs a control signal corresponding to the steering speed of the steering wheel based on the determination signal output by the determination circuit 201.
It is connected to the control circuit 251 and is installed in the vehicle body to generate force in response to a control signal, and this force is transmitted to the rear wheels when the steering wheel is slowly steered, that is, when the angular frequency is small. The rear E wheels are steered in the same direction as the front wheel steering angle, and if the steering wheel is steered quickly, that is, when the angular frequency is large, the rear wheels are steered in the opposite direction to the front wheel steering angle, and the rear wheels are steered. It is composed of an actuation mechanism 80 that generates. The determination circuit 201 and control circuit 251 described above constitute a signal processing circuit 200.

The detection means 50 is constituted by a rotary potentiometer RP, which is made up of an arc-shaped resistor 502 and a slider 504, and is fixed to the vehicle body B of the vehicle. One end of the slider 504 is locked to the tip of the shaft 2. If a predetermined voltage is applied to the rotary potentiometer RP in advance, the handle 1
The shaft 2 rotates according to the steering angle δA(t) of the handle 1, and the other end of the slider 504 slides along the resistor 502, and the voltage signal corresponding to the steering angle δA(t)K of the handle 1 is used for steering. The detection means outputs the angle signal as an angle signal. This steering angle signal is a running voltage signal that is proportional to the rotational steering angle δ-(1) of the steering wheel 1, and is the rotational steering angle δ^(t)- of the steering wheel.

(Steering angle δAt of the front wheels 6 with respect to the straight-ahead direction) -0 state) When the steering wheel 1 is rotated to the right (when it is 7, the polarity is positive) / When the steering wheel 1 is rotated to the left has a negative polarity.

The judgment circuit 201 is the first sample and hold circuit 100
, differential amplifier circuit 110, second sample and hold circuit 1
20, an absolute value circuit 130, an oscillator 213, a monostable multivibrator (hereinafter referred to as monomulti circuit) 214, and a comparison circuit 140. This judgment circuit 2
01 is based on K, which calculates the change value of the steering angle signal from the detection means 50 at fixed time intervals in order to judge the steering speed of the steering wheel 1 based on the steering angle signal output from the detection means 50. This circuit compares the absolute value of a voltage signal corresponding to a rate of change signal with a predetermined voltage level.

The steering angle signal output from the detection means 50 is supplied to the input terminal of the analog switch 202 of the first sample and hold circuit 100 and the resistor 207 of the differential amplifier circuit 110. The first sample and hold circuit 100 is composed of an analog switch 202 whose control terminal is connected to a mono multi circuit 214, a capacitor 203, and an operational amplifier 204. switch 202
The steering angle signal is sampled and the sampled signal is held in the capacitor 203.

Therefore, as shown in FIG. 4(6), the first sample and hold circuit 100 receives the steering angle signal X, which is a continuous signal.
is converted into discrete values by a pulse signal outputted from the monomulti circuit 214 at regular intervals, and a stepped voltage signal Vs is output. The differential amplifier circuit 110 consists of an operational amplifier 209 and resistors 205, 206, 207, and 208. One end of the resistor 205 is supplied with the stepped voltage signal VB output from the first sample-and-hold circuit 100, and the resistor 2
07 is supplied with the steering angle signal X from the detection means 50, and performs operational calculations on these two signals Vs and X.

Therefore, as shown in FIG. 4, the differential amplifier circuit 110 outputs the steering angle signal
A sawtooth voltage signal Vsa is output by subtracting the voltage signal v8 output from the voltage signal V8. This voltage signal Vsa is
This corresponds to a change value of the steering angle signal X every fixed time, that is, a change rate signal.

Similar to the first sample and hold circuit 100, the second sample and hold circuit 120 includes an analog switch 210
, a capacitor 211, and an operational amplifier 212.The input terminal of the analog switch 2100 is supplied with a sawtooth waveform voltage signal Via from the differential amplifier 110, and the control terminal of the analog switch 210 is supplied with a pulse signal from an oscillator 213. Supplied. This second sample and hold circuit 120 is connected to the voltage signal Vs output from the differential amplifier when the pulse signal output from the oscillator 213 and rising only for a short time is on.
a is sampled and held in the capacitor 211. The output pulse signal of the oscillator 213 is supplied to the analog switch 202 via a mono multi-circuit 214 that operates with a negative edge trigger (operates at the rising edge of the signal), and is also supplied to the analog switch 210. Immediately after the switch 210 changes from the on state to the off state, the analog switch 202 turns on. Therefore, the second sample and hold circuit 120 outputs the voltage signal Vd at fixed time intervals according to the rate of change signal output from the differential amplifier circuit, as shown in FIG. That is, the second sample and hold circuit 120 outputs a voltage signal Vd at fixed time intervals in accordance with the steering speed of the steering wheel at fixed time intervals based on the steering angle signal X from the detection means 50.

In addition, in FIGS. 4(G) and (2), the rise intervals of the pulse signals, which are the outputs of the monomulti circuit 214 and the oscillator, are shown widened to simplify the explanation, but the oscillation of the pulse signals The frequency is desirably about 103 times or more the frequency of the steering angle signal, that is, the steering angle frequency of the steering wheel.

The absolute value circuit 130 includes resistors 215, 216°220.2
21 and 222, diodes 217 and 218, and operational amplifiers 219 and 223, and outputs the absolute value of the voltage signal Vd corresponding to the steering speed at fixed time intervals output from the second sample hold circuit 120. As shown in FIG. 5, this absolute value circuit 130 outputs a voltage with a positive slope in response to the speed of right steering, and outputs a voltage with a negative slope in response to the speed of left steering. Overall, only a positive polarity output voltage V is output.

Comparator 140 includes operational amplifiers 224, 225, 226, .
227 and a voltage source generating a positive voltage 228.229
The output voltage V from the absolute value circuit 130 is generated from the voltage source 2
28, 229 and a running voltage level el,
Compare with el (et < ex ). Operational amplifier 22
4 is a non-inverting input terminal (positive terminal) to which the output voltage from the absolute value circuit 130 is supplied, and a reversal input terminal (negative terminal).
As shown in FIG. 60, the output voltage V from the absolute value circuit 130 corresponding to the steering speed at each fixed time is the voltage A high level voltage signal v3 is output only when the voltage is greater than the positive voltage el from the source 228. The operational amplifiers 225 and 226 form a window comparator, and the negative terminal of the operational amplifier 225 and the positive terminal of the operational amplifier 226 are connected, and the output voltage V from the absolute value circuit 130 is supplied to the positive terminal of the operational amplifier 225. is supplied with a positive voltage e from a voltage source 228, and the negative terminal of the operational amplifier 226 is supplied with a positive voltage e1 from a voltage source 229 (el < ex
) is supplied. And operational amplifier 225,2
The 26 output terminals are connected to each other, and as shown in FIG. 6 0, the output voltage is output only when the output voltage V from the absolute value circuit 130 corresponding to the steering speed at fixed time intervals is e1≦V≦e2. A high level voltage signal v2 is output. Operational amplifier 22
7 consists of a comparator whose negative terminal is supplied with the output voltage V from the absolute value circuit 130 and whose positive terminal is supplied with the positive voltage el from the voltage source 229, as shown in FIG. 6 (5). , the voltage signal V1 is at a high level only when the output voltage V from the absolute value circuit 130 corresponding to the steering speed at fixed time intervals is smaller than the positive voltage el from the voltage source 229.
Output.

The operation of the judgment circuit 201 explained above will be explained. Based on the steering angle signal output from the detection means 50, the judgment circuit 201 converts the steering angle signal into a change rate signal by calculating the change value of the steering angle signal at fixed time intervals, and converts the steering angle signal into a change rate signal corresponding to the change rate signal. The absolute value of the voltage signal is compared to a predetermined voltage level.

Then, based on this comparison, the steering speed of the steering wheel 1 is determined, and when the steering speed of the steering wheel 1 is slow, the operational amplifier 227
A high level voltage signal is output from the operational amplifier 224, and when the steering speed of the steering wheel is slow, a high level voltage signal is output from the operational amplifier 224. Further, when the steering speed of the steering wheel is intermediate between the above two, a high level voltage signal is output from the operational amplifiers 225 and 226 which are connected to each other.

The control circuit 251 is composed of inverting amplifier circuits 150, 160 and analog switches 252, 253, 254,
The steering angle signal from the detection means 50 and the judgment circuit 20
1, the voltage signal V,,V,.

Based on VsK, nine control signals are output in accordance with the steering speed of the steering wheel 1.

A control terminal of the analog switch 252 is supplied with the voltage signal v3 from the operational amplifier 224 of the determination circuit 201, and an input terminal of the analog switch 252 is supplied with the output signal of the inverting amplifier circuit 150. Further, the control terminal of the analog switch 253 is connected to the judgment circuit 2.
The voltage signal v2 from the operational amplifiers 225 and 226 of 01 is supplied, and the input terminal of the analog switch 2530 is grounded. The voltage signal v1 from the operational amplifier 227 of the judgment circuit 201 is supplied to the control terminal of the analog switch 254, and the analog switch 2540
The output signal of the inverting amplifier circuit 160 is supplied to the input terminal. The above-mentioned inverting amplifier circuit 150 includes an operational amplifier 257
, an input resistor 255 and a feedback resistor 256,
The steering angle signal from the detection means 50 supplied to one end of the input resistor 255 is invertedly amplified (-KA times) by an amplification factor KA determined by the resistance ratio of the input resistor 255 and the feedback resistor 256, and is output. Further, the inverting amplifier circuit 160 is the inverting amplifier circuit 15
0, it is composed of an operational amplifier 2601, a human power resistor 258, and a feedback resistor 259, and the steering angle signal from the detection means 50 supplied to one end of the input resistor 258 is input to the input resistor 258.
The signal is inverted and amplified (-1 times) with an amplification factor of 1 determined by the resistance ratio between the signal and the feedback resistor 259 and is output.

The operation of the control circuit 251 configured as described above will be described below. If the steering speed of steering wheel 1 is fast,
Only the operational amplifier 224 of the determination circuit 201 outputs a high level voltage signal v3, turning the analog switch 252 on. On the other hand, the steering angle signal from the detection means 50 is
The signal is multiplied by -KA by the inverting amplifier circuit 150 and input to the analog switch 252. However, if the steering wheel is turned quickly, the control circuit 251 outputs a signal obtained by multiplying the steering angle signal by -^ as a control signal.

If the steering speed of the steering wheel 1 is slow, the judgment circuit 201
Only the operational amplifier 227 outputs a high level voltage signal v1, turning on the analog switch 254. On the other hand, the steering angle signal from the detection means 50 is multiplied by KA by two inverting amplifier circuits 150 and 160 and input to the analog switch 254. Therefore, when the steering speed of the steering wheel is slow, the control circuit 251 changes the steering angle signal to K.
The signal multiplied by A is output as a control signal. When the steering speed of the steering wheel 1 is between the above two, only the operational amplifiers 225 and 226 of the judgment circuit 201 output a high level voltage signal 2, and the analog switch 2
53 is turned on. On the other hand, the analog switch 253
Since the input terminal of the control circuit 251 is grounded, if the steering speed of the steering wheel is between the above two, the control circuit 251
outputs a signal with zero voltage as a control signal.

The operating mechanism 80 is a hydraulic pressure generating device P1 accumulator AL.
, a flow rate control valve S■, an actuator AC1 connected to the flow rate control valve Sv through an oil sump T1 piping connected to the suction side of the hydraulic pressure generator P and returning unnecessary oil, and a knuckle arm 13 having a fulcrum 13a, and left and right knuckle arms 13. It consists of steering linkages SL, which connect knuckle arms 13, 13 via pin joints SLa, SLa.

The hydraulic pressure generator P is composed of a vane pump driven by the engine via a pulley, and stores a predetermined pressure in an accumulator AL in advance. In this bacon,
It is driven according to the rotation of the engine.

The accumulator AL is a metal container 3 having a predetermined capacity.
The inside of this metal container 30 is divided into two by a rubber diaphragm 32, and one chamber is filled with gas such as nitrogen at a predetermined pressure.1-1 The other chamber is connected via piping to constitute a hydraulic pressure generator P. It is configured to communicate with the discharge O of the vane pump.

This accumulator AL compensates for the inoperability of the rear wheel steering angle control device when the capacity of the vane pump is insufficient to meet the requirements of the rear wheel steering angle control device of the vehicle. Also,
By providing the accumulator AL, the vane pump can be made smaller and have a smaller capacity. Then, the accumulator AL is connected to the flow rate control valve SV via piping.
The hydraulic pressure accumulated in the accumulator AI is supplied to the actuator AC according to the opening degree of the flow control valve SV.

The flow rate control valve SV is composed of a spool valve consisting of a cylinder in which an inflow port and a discharge boat are arranged, and a spool that moves the cylinder in the axial direction. The discharge flow rate is controlled by changing the opening area of the throttle by changing the positional relationship with the boat.

The actuator AC is composed of a cylinder 34 connected to the discharge boat of the flow control valve SV via piping and a piston 36 that moves in the axial direction within the cylinder 34, and the cylinder 34 is locked to the vehicle body B of the vehicle. Both ends of the piston 36 are locked to left and right steering ring cages SL, SL.

The effects of the vehicle rear wheel steering angle control device of this embodiment configured as described above will be explained below.

In the following, to simplify the explanation, we will consider a case where the steering wheel 1 is steered to the right by an angle δ4(t).

When the handle 1 is rotated to the right, the shaft 2 is also rotated in accordance with the rotation of the handle. Along with this, the slider of the rotary potentiometer of the detection means 50 fixed to the tip of the shaft 2 is slid, and the detection means 50 outputs a steering angle signal X corresponding to the rotational steering angle δA(t) of the handle. Output. At this time, the front wheels 6 are steered to the right as in the conventional case, producing a steering angle δ/(1). This steering angle signal X is input to the determination circuit 201 and control circuit 251 of the signal processing circuit 200.

The judgment circuit 201 calculates the change value of the steering angle signal X at fixed time intervals to make the steering angle signal X a change rate signal, and compares the absolute value of the voltage signal corresponding to the change rate signal with a predetermined voltage level. In particular, the steering speed of the steering wheel at fixed time intervals is determined. The control circuit 251 operates according to the steering speed of the steering wheel 1 at fixed time intervals determined by the determination circuit 201.
When the steering speed of the steering wheel is slow, set the steering angle signal X to KA.
The multiplied control signal Y -KA -X is output, and when the steering speed of the steering wheel is fast, the control signal Y = - which is multiplied by the steering angle signal When the speed is intermediate between the above two speeds, a control signal y-0 with a voltage of zero is output.

The flow control valve SV of the actuating mechanism 80 is opened and closed by the control signal Y, and introduces the hydraulic pressure of the accumulator AL into the actuator AC. Therefore, the pressure inside the cylinder of actuator AC changes and the piston is moved. This piston moves the steering linkage SL, rotates the knuckle arm 13 about the fulcrum 13a, and steers the rear wheel 12 to produce a steering angle δ-(1). That is, rear wheel 1
2 is a steering angle δ, (1), which is caused by the actuation mechanism 80 to adjust the steering angle signal to the voltage multiplied by 2 in the same direction as the steering direction of the steering wheel 1, that is, to the right when the polarity of the control signal Y is positive. Be steered. On the other hand, when the polarity of the control signal Y is negative,
The rear wheels 12 are steered in the direction opposite to the steering direction of the non-driving lever 1, that is, to the left, by a steering angle δ(1) corresponding to a voltage multiplied by the steering angle signal.

Furthermore, when the control signal Y is zero, the rear wheels 12 are not steered and the steering angle δ(1) of the rear wheels remains zero.

As described above, according to this embodiment, when the steering speed of the steering wheel is slow, the rear wheels are steered in the same direction as the steering angle of the front wheels, and when the steering speed is fast, the steering angle of the front wheels is steered. If you steer the rear wheels in the opposite direction to generate a steering angle on the rear wheels that is proportional to the steering angle of the front wheels, and steer the nondle at a speed intermediate between the above two, the rear wheels will turn in the opposite direction. The steering angle of the rear wheels can be made zero without steering the wheels. In this way, in this embodiment, a force corresponding to the steering speed of the steering wheel is applied to the rear wheels.
Since the magnitude and direction of the rear wheel steering angle can be controlled according to the steering speed of the steering wheel, both the stability of the vehicle when traveling straight and the responsiveness of turning movements can be improved.
It has the advantage of Furthermore, in this embodiment, it is possible to detect the steering angle of the steering wheel, determine the steering speed of the steering wheel from one steering angle signal, and determine the direction of steering of the rear wheels and the magnitude of the steering angle. Therefore, it has the advantage that it is not necessary to have both a means for detecting the steering speed of the steering wheel and a means for detecting the rotational steering angle of the steering wheel, so that it is suitable for being mounted on a vehicle.

Although the above example uses a rotary potentiometer, it is also possible to use a so-called rotary encoder that generates pulses in response to the rotational steering of the steering wheel, and it is also possible to use a speed sensor to adjust the steering speed of the steering wheel. It is also possible to detect. Further, the steering speed of the steering wheel may be determined by differentiating the steering angle signal using a differentiator as a judgment circuit, or the steering speed of the steering wheel may be further divided by increasing the number of comparators of the comparator 140. Alternatively, the rear wheels may be controlled by determining the steering speed. Furthermore, as an operating mechanism, if necessary, a means for detecting the steering angle of the rear wheels is provided, and the control signal output from the control circuit is used as a target value signal, and the output from the means for detecting the steering angle of the rear wheels is set as a target value signal. Even if so-called feedback control is used, in which a deviation signal, which is the difference between the target value signal and the actual measurement value signal, is used as the actual measurement value signal, the flow control valve is controlled to steer the rear wheels so that the deviation signal becomes zero. good. In this case, if a large amount of electrical power is required, it is also possible to use means such as an amplifier for amplifying the deviation signal.

Next, a second specific example of the present invention will be described. FIG. 7 is a circuit diagram of a second specific embodiment. The rear wheel steering angle control device of the second specific embodiment includes a detection means 60 for detecting the displacement of the steering wheel 1, and a steering speed of the steering wheel based on a displacement signal connected to the detection means 60 and outputted by the detection means. is determined based on the angular frequency of the nondle steering, and as the angular frequency of the nondle steering increases, the phase lags by up to 180 degrees with respect to the input displacement signal, and the amplification factor is constant regardless of the angular frequency of the nondle steering. a signal processing circuit 300 that outputs a control signal amplified by the signal processing circuit 300; In the region where the angular frequency of the steering wheel is small, the rear wheels are steered in the same direction as the steering angle of the front wheels, and the angular frequency of the steering wheel that corresponds to the case where the steering wheel is steered quickly. In the region where the steering angle is large, the operating mechanism 90 steers the rear wheels in the opposite direction to the steering angle of the front wheels to generate a steering angle in the rear wheels.
The rear wheel steering angle control device of the second specific embodiment comprises the above-mentioned first device.
The signal processing circuit 200 of the specific embodiment is modified so that the steering speed of the steering wheel is determined based on the angular frequency of the steering wheel, without relying on the rate of change signal from the output of the detection means. The main difference is that a control signal corresponding to the steering speed of the steering wheel is output by shifting the phase of the displacement signal. We will mainly explain the differences below,
Identical parts are given the same reference numerals to simplify the explanation.

The detection means 60 consists of a linear resistor 602 and a slider 604, and is constituted by a linear potentiometer SP fixed to the body B of the vehicle. One end of the slider 604 is locked to a gear built into the gear box 3. When the shaft 2 rotates according to the steering angle δA(t) of the handle 1, this rotational movement is transferred to the slider 604 by a motion converting mechanism such as a rack and pinion built in the gear box 3.
is converted into linear motion of the locked gear. Detection means 6
゜ detects this linear movement as a displacement corresponding to the steering angle δ of the handle 1 with a linear potentiometer SP,
A corresponding voltage signal is output as a displacement signal. Here, to simplify the explanation, if we assume that the steering wheel 1 is continuously steered in a sinusoidal manner at an angular frequency ω, then the rotational steering angle δ4t) of the steering wheel is expressed as ωt, so the rotation with respect to the straight-ahead direction The displacement of the steering wheel at steering angle ωt is δ
Persimmon sin ωt (where δ^0 is the amplitude of the handle), and the displacement signal output from the linear potentiometer SP accordingly has an angular frequency ω with an amplitude Do corresponding to the amplitude of the handle. A sinusoidal continuous voltage signal DD(, -tinωt) is obtained.

The signal processing circuit consists of a phase shift circuit 301 connected to the slider of the detection means 60 and a coefficient multiplier 351.

The resistance values of input resistor 302 and feedback resistor 303 are set to be equal. The above-mentioned resistor 304 and capacitor 305 correspond to the judgment circuit of the first specific embodiment, and the resistors 302 and 303, the operational amplifier 306, and the coefficient multiplier 35
1 corresponds to a control circuit.

In the phase shift circuit 301, when the angular frequency ω of the input displacement signal is small and close to zero, the reactance of the capacitor 305 becomes close to infinity, and the positive terminal of the operational amplifier 306 receives the displacement signal at one end. resistor 304 supplied with
A signal is input via. At the same time, a displacement signal is applied to the input resistor 302, and since the resistance ratio between the input resistor 302 and the feedback resistor 303 is 1, the signal input to the negative terminal of the operational amplifier 306 produces a signal with a gain of -1. Output. On the other hand, a signal with a gain of 2 is output from the signal input to the positive terminal of the operational amplifier 306, and the phase shift circuit 301 as a whole obtains an output with a gain of 2-1-1. Therefore,
When the angular frequency of the displacement signal is small and close to zero, an output signal equal to the input displacement signal is obtained.

On the other hand, when the angular frequency ω of the input displacement signal is large and close to infinity, the capacitor 305 is almost in a short-circuited state, which is equivalent to the case where the positive terminal of the operational amplifier 306 is grounded. At this time, since a signal is input only to the negative terminal of the operational amplifier 306, the phase shift circuit 301 functions only as an inverting amplifier itself. In this case, input resistance 3
Since the resistance ratio between 02 and feedback resistor 303 is 1, the gain is -
It becomes 1. Therefore, when the angular frequency ω of the displacement signal is large and close to infinity, the input displacement signal is inverted to obtain the running output signal. This output signal is the absolute value (
A signal whose amplitude D(1) is equal to the input signal and whose phase is delayed by 180° with respect to the input signal is obtained.

According to the operating principle described above, as the angular frequency of the displacement signal increases, the phase shift circuit 301 outputs an output signal whose phase is delayed from 06 degrees to a maximum of 180 degrees with respect to the displacement signal.

The coefficient multiplier 351 amplifies the output signal from the phase shift circuit 301 to a constant value and outputs a control signal Y.

The actuation mechanism 90 is a hydraulic generator P1 accumulator AL.
, a knuckle arm 13 having a fulcrum 13a and an actuator AC1 connected to the flow control valve Sv through an oil sump T1 pipe for returning unnecessary oil by communicating with the suction side of the flow control valve Sv1 hydraulic pressure generator P and left and right knuckle arms. The steering linkage SL connects the wheels 13 and 13 via bin joints SLa and SLa.

The hydraulic pressure generator P is composed of a vane pump driven by the engine via a pulley, and stores a predetermined pressure in an accumulator AL in advance. This vane pump is driven according to the rotation of the engine.

The accumulator AL is a metal container 3 having a predetermined capacity.
The interior of this metal container 30 is divided into two by a rubber diaphragm 32, one chamber is filled with gas such as nitrogen at a predetermined pressure, and the other chamber is connected to a hydraulic generator P via piping. It is configured to communicate with the discharge port of the constituent vane pump.

This accumulator AL is connected to the flow rate control valve S via piping.
v, and supplies the hydraulic pressure accumulated in the accumulator AL to the actuator AC according to the valve opening degree of the flow control valve SV.

The flow rate control valve Sv controls the discharge flow rate by changing the opening area of the aperture according to the control signal Y from the signal processing circuit 300.

Actuator AC is different from the first specific embodiment,
The cylinder part 34 is locked to the vehicle body B, and the cylinder part 3
A rod 38 protruding from 4 is fixed to the piston part 36,
The tip of the rod 38 is locked to the knuckle arm 13. The cylinder portion 34 of the actuator AC is connected to the discharge boat of the flow control valve S■. In addition, the actuator AC is disposed approximately parallel to the steering linkage SL that connects the left and right knuckle arms 13. is locked to the knuckle arm 13 at a position intermediate between the fulcrum 13a of the knuckle arm 13 and the binge joint SLa.

The effects of the vehicle rear wheel steering angle control device of the second specific embodiment configured as described above will be described below.

When the nondle 1 is continuously steered in a sinusoidal manner with an imaging width δAQ and an angular frequency ω as described above, that is, the rotational steering angle δ
Consider the case where steering is performed by A(t)-δAO·sinωt. In response to this, the detection means 60 detects an amplitude.

A sinusoidal continuous displacement signal D with an angular frequency ω at
-D(, -5inωt are output. Then, the signal processing circuit 300 processes the displacement signal according to the angular frequency ω of the displacement signal and outputs the control signal Y.

The flow rate control valve Sv of the actuating mechanism 90 has its aperture opening area changed in accordance with the control signal Y, and introduces the hydraulic pressure of the accumulator AL into the actuator AC.

As a result, the pressure inside the cylinder of actuator AC is changed, the piston is moved, and the knuckle arm 13 is rotated around the fulcrum 13a. Since the left and right knuckle arms 13.13 are connected by the steering linkage SL, the left and right rear wheels 12.12 are steered by the rotation of the knuckle arms 13.13, and a steering angle δa) is generated. Of course, depending on the steering wheel 1, the front wheel 6
is steered, and a steering angle δ/(1) is generated at the front wheels 6. It goes without saying that the direction of steering of nondle 1 and the direction of steering of front wheel 6 are the same.

FIG. 8 (5) shows the relationship between the characteristics of the signal processing circuit and the steering angle δ-<1> of the rear wheels 12 when operated as described above.
, @, (C), (D) A detailed explanation will be given based on K.

FIG. 8(6) shows the characteristics of the signal processing circuit 300 of this embodiment. The signal processing circuit 300 generates a control signal Y whose gain is always constant KA and whose phase lags from θ° to a maximum of 180° as the angular frequency ω increases, with respect to the input displacement signal D=-D6-sinωt. Output. While the angular frequency ω of the displacement signal is in the small region ω1, depending on the characteristics of the signal processing circuit, the signal processing circuit outputs a signal obtained by multiplying the input signal by KA as the control signal Y-D. Therefore, the rear wheels are steered by the actuating mechanism according to the control signal Y, and the steering angle δ(1) of the rear wheels 12 is as shown in FIG.
As shown in , the steering angle δXt of the front wheels 6 is controlled in the same direction as the steering angle δXt>. The steering angle of the rear wheels at this time is proportional to the displacement of the steering wheel.

On the other hand, while the angular frequency of the displacement signal is in the large region ω3, due to the characteristics of the signal processing circuit, the signal processing circuit generates a signal whose phase is delayed by 180 degrees with respect to the input signal, that is, the displacement signal is multiplied by −KA. Control signal Y--KAIID
Output as . Therefore, the rear wheels are steered by the actuating mechanism in accordance with the control signal Y, and the steering angle δbeta of the rear wheels 12 is determined as the steering angle δ/<1 of the front wheels 6, as shown in FIG. ) and in the opposite direction, with a magnitude proportional to the displacement of the handle.

Furthermore, while the angular frequency ω of the displacement signal is in the region ω2 intermediate between the region ω1 and the region ω3, the signal processing circuit changes the phase from θ° to 18° with respect to the input signal due to the characteristics of the signal processing circuit.
A signal with a delay of up to 0° is output as a control signal Y. For example, if the signal processing circuit outputs a signal whose phase is delayed by 90' relative to the input signal as the control signal Y, the rear wheels are steered by the actuating mechanism with a delay in relation to the front wheels, and the rear wheels are steered with a delay in relation to the front wheels (Fig. 8C). As shown in FIG. 2, the steering angle δt) of the rear wheel 12 is controlled to become zero when the steering angle δbut) of one front wheel reaches the maximum.

In the above, the case where the steering wheel was continuously steered in a sinusoidal manner was explained as the effect of the second specific embodiment.
Below, we will discuss the operation of the second specific embodiment when changing lanes under the conditions of actually driving a vehicle.
This will be explained with reference to Figures (5), (B), and IC). Note that the effects shown in FIGS. 9(5), (c), and 0 are substantially the same not only in the second specific embodiment but also in the first specific embodiment, which indicates the feasibility of the present invention. It is.

Figures 9(5), (c), and 0 all show the rotational steering angle δA(t) of the steering wheel and the rear wheel angle when changing lanes in a vehicle using the device related to the second specific embodiment. This shows a waveform related to time with respect to the steering angle δbet). As shown in area a of Figure 9 (6), when the steering wheel is steered to the right by slowing down the steering speed, the rear wheels will move in the same direction as the steering wheel (in this case, from left to right). steered (in the rudder direction). On the other hand, if the steering speed of one steering wheel is increased and the steering is performed from right to left as shown in area C of Fig. 9, the rear wheels will move in the opposite direction to the steering direction of the steering wheel (in this case (from left to right steering direction). Furthermore, as shown in the area (c) of Figure 9(c), when the steering wheel is steered at a speed intermediate between the above two, the rear wheels are steered with a delay in response to the steering wheel steering, and as described above, If the phase delay is approximately 90', the steering angle of the rear wheels will be approximately zero when the steering angle of the steering wheel is at its maximum, as shown at point d in FIG. 90. Since the direction of steering of the steering wheel is the same as the direction of steering of the front wheels, the device of this embodiment adjusts the steering angle of the rear wheels relative to the steering angle of the front wheels according to the steering speed of the steering wheel, that is, the angular frequency of steering of the steering wheel. It is understood that the direction and magnitude of are controlled.

As explained above, in the second specific embodiment, when the steering wheel is turned slowly, the rear wheels are steered in the same direction as the steering angle of the front wheels, and when the steering wheel is turned quickly, the rear wheels are steered in the same direction as the steering angle of the front wheels. Since the rear wheels are steered in the direction of , and the steering angle of the rear wheels is controlled, it has the advantage that both the running stability of the vehicle when traveling straight and the responsiveness of turning motion can be improved. In addition, in the second specific embodiment, the function of a determination circuit that determines the steering speed of the steering wheel by determining the steering speed of the steering wheel based on the angular frequency of steering of the steering wheel, and the By using a simple phase shift circuit and a coefficient multiplier that simultaneously performs both the control circuit function of outputting a control signal corresponding to the
It has the advantage of being suitable for in-vehicle use. Furthermore, the signal processing circuit of the second specific embodiment judges the steering speed of the steering wheel based on the angular frequency of steering the steering wheel, and as the angular frequency increases, the phase becomes maximum with respect to the input displacement signal. 1
It is characterized by outputting a control signal that is delayed up to 8 degrees and whose absolute value is amplified at a constant value regardless of the angular frequency of the steering wheel. The present invention is not limited to this, and any circuit can be applied as long as it determines the steering speed of the steering wheel based on the angular frequency of steering the steering wheel based on the control calculation principle of the second aspect of the present invention. Furthermore, as for the operating mechanism of the second specific embodiment, as described in the operating mechanism of the first specific embodiment, if necessary, means for appropriately detecting the steering angle of the rear wheels is provided, and this means The rear wheels may be steered by controlling the flow rate control valve by so-called feedback control, which uses a deviation signal between the output signal of the output signal and the control signal from the signal processing circuit. In the second specific embodiment, instead of detecting the rotational steering angle of the steering wheel, linear motion converted by a motion conversion mechanism such as a rack and pinion built into the gear box is detected as the steering displacement of the steering wheel. Although an example has been described, for example, an example in which a linear potentiometer or a rotary potentiometer is used for rotating the knuckle arm, the present invention is not limited to this, and the magnetic flux changes according to the steering angle or displacement of the handle. It is possible to use sensors such as electromagnetic sensors, optical sensors, and telemeters that detect the The control means of the present invention is not limited to what is illustrated in each specific embodiment, but may be one that determines the steering speed of the steering wheel and outputs a signal corresponding to the steering speed of the steering wheel based on this determination. If available, any circuitry can be used. Furthermore, although each specific embodiment has been shown as an example constructed using an analog circuit, the present invention is not limited thereto, and may also be constructed using a digital circuit using a microcomputer or the like. Further, the actuation mechanism of the present invention is not limited to those illustrated in each specific embodiment, but may be any mechanism as long as it generates force in response to a control signal output from the control means and controls the steering angle of the rear wheels. A hydraulic circuit, a pneumatic circuit, an air actuator, a hydraulic actuator, or an electromagnetic force or other force that applies force to the rear wheel other than those described in each specific embodiment may be used.

Although the first specific embodiment describes an example in which the steering angle of the rear wheels is controlled by detecting the rotational steering angle of the steering wheel, it is also possible to control the steering angle of the rear wheels by detecting the displacement of the steering wheel. In the second specific embodiment, an example has been described in which the steering angle of the rear wheels is controlled by detecting the displacement of the steering wheel, but it is also possible to control the steering angle of the rear wheels by detecting the rotational steering angle of the steering wheel. Therefore, it is also possible to use the detection means of the second embodiment in the specific embodiment of vXl, and to use the detection means of the first embodiment in the second embodiment. Also,
In each specific example, when the angular frequency ω is large, the amplifier is in the negative range, and when the angular frequency ω is small, the amplification factor is KA, so the transfer function G (corresponding to equation (3))
S) is shown below.

[Brief explanation of the drawing]

Figure 1 is a block diagram showing a basic embodiment of the present invention, Figure 2 is a block diagram showing a basic embodiment of the present invention.
The figure is a block diagram showing a conventional rear wheel steering angle control device for a four-wheel steering vehicle, FIG. 3 is a circuit diagram showing a first specific embodiment of the present invention, and FIGS. B) shows the first sample-and-hold circuit output, steering angle signal, mono multi-circuit output, differential amplifier circuit output, and second sample-and-hold circuit output in the first specific embodiment.
FIG. 5 is a diagram showing the waveform of the output of the sample-hold circuit and the oscillator output of the first specific embodiment. FIG. 6 is a diagram showing the waveform of the absolute value circuit output of the first concrete example. 0 is a diagram showing the waveform of the comparator circuit output of the first specific embodiment, FIG. 7 is a block diagram showing the second specific embodiment of the present invention,
Figure 8 (c) is a diagram showing the gain and phase of the signal processing circuit of the second specific embodiment, Figure 8 (b), Figure 8 0 and Figure 8 0 are diagrams showing the gain and phase of the signal processing circuit of the second specific embodiment. An explanatory diagram showing the steering angles of the front wheels and rear wheels corresponding to FIG. It is a diagram showing changes in the steering angle of the rear wheels. 1. Handle, 2. Shaft, 6. Front wheel, 12.
・Rear wheel, 20 ・Detection means, 22 ・Judgment circuit, 24
. . . control circuit, 26 . . control means, 28 . . . actuation mechanism. Figure 26 Figure 2 Figure 4 (A) Figure 4 (B) Figure 5 Figure 6 I: Output power 1v

Claims (1)

[Scope of Claims] (1) The rear of a vehicle that automatically controls the steering angle of the rear wheels in response to the steering of a steering wheel that controls the operating mechanism that causes the rear wheels to generate a steering angle and generates a steering angle of the front wheels. In the wheel steering angle control device,
a detecting means for detecting the steering amount of the non-rubber and outputting a steering amount signal; a determining means for determining the steering speed of the steering wheel based on the steering amount signal; The operating mechanism is configured to cause the rear wheels to produce a steering angle in the opposite direction to the front wheels when the steering speed is fast, and to cause the rear wheels to produce a steering angle in the same direction as the front wheels when the steering speed is slow. A rear wheel steering angle control device for a vehicle, comprising: a control means for controlling the rear wheel steering angle of a vehicle. ((2) The control means causes the rear wheels to produce a steering angle in the opposite direction to the front wheels when the steering speed is fast based on the judgment result of the judgment means and the front Hc2 steering amount signal. The rear wheel steering angle control device according to claim (1), which controls the operating mechanism so as to generate a steering angle of a magnitude corresponding to the steering amount signal at the rear wheels. ) constants Kd, Ke are 0(Kd(Ke
Then, the determining means determines that G)-Kd--! ! The rear wheel of a vehicle according to claim 1, wherein the determination is made based on a transfer function G(S) expressed by isolated -TS 1+ TS , and the control means controls the actuation mechanism based on the determination result. Rudder angle control device.