JPS60124572A - Steering system for car - Google Patents

Abstract

PURPOSE:To prevent slippage of car when turning by obtaining a target angular speed to be produced on car when turning from the steering amount of front wheel and car speed then controlling the rear wheel rolling system in accordance to the rear wheel rolling amount corresponding with the difference between said target angular speed an actual speed. CONSTITUTION:A rolling detection sensor 2 for detecting rolling of front wheel 3 to be steered by steering wheel 1, car speed sensor 5 and angular speed sensor 6 for detecting the angular speed due to turning while travelling are provided to produce output signals to be fed to an operation control circuit 8. In the control circuit 8, target angular speed of car W1 is obtained from rolling amount S of front wheel 3 and car speed F and compared with actual angular speed W2 detected by said sensor 6. Consequently, rolling R of rear wheel 9 for matching the actual angular speed W2 with target angular speed W1 is operated to control rear wheel rolling means or servo-actuator 10 with correspondence to said rolling R thus to roll only rear wheel 9 by R through gear box 12.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a steering system for a vehicle, and more particularly to a steering system that steers the rear wheels of a vehicle to maintain a stable state when the vehicle turns.

[Prior art] A vehicle usually turns by turning the steering wheel and steering the front wheels, but depending on the vehicle's driving condition, the road surface, the tire condition, etc., it may cause skidding. This may result in the vehicle not making the intended turn. In such cases, conventional driving systems optimally steer the front wheels to return the vehicle to a stable state and make a turn. In addition to requiring sophisticated technology to rebuild, it also took a certain amount of time to return to a stable state. This goes against ensuring safe driving, especially when driving at high speeds, and the steering system is required to shift the vehicle when skidding occurs and return it to a stable state within σ time. It has been desired.

1. Purpose of the present invention] The object of the present invention is to detect an unstable condition such as skidding when the vehicle is turning, and to steer the rear wheels by an optimal amount () to steer the vehicle smoothly. An object of the present invention is to provide a steering device that restores a stable state.

[Component (14) of the Invention] The structure of the present invention, which has been made to achieve the above object, is as shown in FIG. steering amount detection means M1 for detecting the steering amount of
and vehicle speed detection means M2 of the vehicle, angular velocity detection means M3 that detects the angular velocity of the vehicle caused by turning, rear wheel steering means M4 that steers the rear wheels, and the turning amount detection means M1 when the vehicle turns. Determine the target angular velocity of the vehicle from the front wheel turning amount detected by and the vehicle speed detected by the vehicle speed detection means M2, and calculate the actual angular velocity of the vehicle detected by the angular velocity detection means M3 and the target angular velocity. The steering amount of the rear wheels is calculated so that the actual angular velocity n1 matches the target angular velocity.
an arithmetic control circuit M5 that controls the rear wheel steering means M4 according to
It is said that 1% of vehicles are characterized by having a rudder system.

[Embodiment] FIG. 2 is a schematic X1' view of the vehicle for explaining the steering device, and FIG. 3 is an explanatory diagram mainly covering the control system of the steering device.

In the figure, 1 is a steering wheel, 2 is a steering amount detection sensor that detects the amount of turning of the front wheels 3 by steering the steering wheel 1 and generates a two-phase pulse signal, and 5 is a pulse signal proportional to the vehicle speed. A vehicle speed sensor 6 generates a signal, and numeral 6 represents an angular velocity sensor that detects the angular velocity caused by turning while the vehicle is running. In addition, 8 is an arithmetic control circuit including a microcombi and nota, so
Front wheel turning amount S detected by steering amount detection sensor 2
From the vehicle speed F detected by the medium speed sensor 5 and the angular velocity W2 detected by the angular velocity sensor 6, the amount of steering R of the rear wheels 9 to be steered is determined, and according to the amount R of steering, C Tanabata, etc. A lift bore actuator 10 as a rear wheel steering means configured by the following is controlled 1i. The rev actuator 10 performs a motion direction changing function to steer the rear wheel 9 by 1 degree R through the right gear A7 box 12.

The arithmetic control circuit 8 is a known CPU 20. ROM21, R.A.
A microcomputer section 23 composed of M22, etc., and a steering amount detection sensor 2. Equipped with a pulse input port 1-24 for inputting pulse signals from the vehicle speed sensor 5 and an analog input port 25 for inputting pulse signals from the angular velocity sensor 6, and an analog input port 25 for inputting pulse signals from the angular velocity sensor 6. It is connected to a battery 31 as a battery.

The illll speed per second 4/5 is composed of a photoelectric conversion system, an electromagnetic pickup system, or a contact system, etc., and is installed in a transmission (not shown) to generate a pulse signal synchronized with the rotation of the gears, and it is possible to determine the vehicle speed from the frequency of the pulse signal. .

The steering amount detecting sensor 2 is constructed by a photoelectric steering system, an electromagnetic pickup system, a contact system, or the like, and is disposed on a steering shirt 1 (not shown) to generate a pulse signal in accordance with the steering amount of the front wheels. FIG. 4 shows the relationship between the steering amount detection sensor 2 which follows the photoelectric conversion method and the steering amount detection sensor 2 which is linked to the steering operation. are two sensors 2-1.2 fixedly arranged with a predetermined i◇ phase difference from each other.
-2 to the right, it is equipped with a rotating body 41 that rotates according to the rotation of the steering wheel 771-40, and the body 41 is sandwiched between the steering wheels 1 and 2-1.
(Light source (not shown) disposed at 9) The light sword light from IJst and others is received and blocked by the sensor 1-2-1.2-2 by the rotation of the rotating body 41. Therefore, the rotating body 41 When the rotating body 41 rotates clockwise, the output waveforms of the sensor 21iB and the sensor 2-2 are as shown in FIG. As shown in FIG. 1 in FIG.
You can know the direction of rotation of 0.

It is also possible to know the amount of steering from the number of output pulses.

By the way, the center of the steering wheel is required to know whether to turn or return the steering wheel. This station)
L ring rentals usually require rotation to set the accuracy due to variations in the parts that make up the 4i4 steering wheel, and variations in assembly time.

Therefore, when the car is going straight, the angle of movement of the steering wheel is small, so if the angle of movement of the steering wheel is continuously smaller than a certain value for a certain distance, it is assumed that the car is going straight, and the steering position at that time is is determined as a temporary center. The following formula is used to find the true center.

Sada center = ((AX previous Sada center) +13
×temporary center))/(A×B) Here, A>B, and for example, A=15/1.6 and B=1/16. It should be noted that the initial value of the previous true center in the above formula corresponds to the steering position at the time of key maintenance, and is valid for 5th shift.

Also, as an angular speed melon detection sensor, U.S. Patent No. 358732
A fluid type angular velocity sensor, a vibration type sensor, a spin motor type sensor υ', etc. disclosed in No. 8 are known. The fluid-type angular velocity sensor 1 includes a piezoelectric tire flamm pump and a fluid nozzle through which a suitable fluid, such as an inert gas, is directed toward a pair of temperature-sensitive resistive elements made of tungsten wire or the like. It is a 114-built building that is used for 111'5. When turning the vehicle, press J to turn, etc.
Because of the angular velocity that occurs, the two jets move 1FJJ within the sensitivity plane of the temperature-sensitive element, so the pair of temperature-sensitive resistance elements is differentially cooled and the element resistance changes, depending on the angular velocity. It generates a voltage (14).The signal is read in through the driver cover 25.
:You can know the angular velocity.

Next, the processing operation of this embodiment configured with the lens group 1 will be explained.

FIG. 6 shows the processing of this embodiment, and includes flowcharts 1 to C, including a microcomputer.) When the key switch 15 is turned on, the control circuit 8 starts the process shown in FIG. 6A. .

First, an initial 11 rice step 100 is executed to perform initial settings for subsequent processing, such as initializing registers and the like. Next, in step 110, the steering amount S of the front wheels is read by the pulse signal 241 from the steering amount detection sensor 2. Here, if S>0, the amount of steering is turned when turning left, and if S<O, the amount of turning is +1 when turning right
: Determine the procedure for detecting the amount of steering using two-phase pulses.j3
<. As a concrete method, when the steering amount detection sensor 2 is considered to be at the true center, the value of the counter is set to O, and the number of pulses detected by the sensor 4-2-1 is calculated. I [In the steering amount counter, the rising edge of the output pulse of sensor 2-1 (positive) -
If the output signal of sensor 2-2 is at a high level at the time of
-] If you have level C, go down to 1. At step 110, by reading this counter value, the amount of steering and its direction can be known.

t (M
30 te is [1 The angular velocity W1 is calculated by the following formula.

W+ =a XFXS-(1) In equation (1), a is a coefficient. The target angular velocity W1 refers to the angular velocity that should be generated in the vehicle if the vehicle speed is Ft'' and the front wheels are steered by S and the vehicle turns and skidding or the like does not occur.

In step 140, the actual angular velocity W2 actually generated in the vehicle is read from the angular velocity detection sensor 6. W2 is read as a positive value when turning left, and a negative value when turning right 114. In the following step 150, based on the target angular velocity W1 determined in step 130 and the actual angular velocity W2 read in step 140, the steering amount R4 of the rear wheels, R=k x (W+ - W2 )...・〈2)
This will lock you out. In equation (2), k is a coefficient for calculating the angular velocity A-minute J and the steering amount R. Here W +
> W 2 or W+<:Wz,
It can be determined that the vehicle is not making the turn that should be achieved by operating the steering wheels and is in an unstable state. In step 160, a signal corresponding to the rear wheel steering ff1R determined in step 150 is output to the servo actuator 10, and the rear wheel steering and control is performed via the gear box 12 by driving the servo actuator 10. Do the following.

After completing the execution of step 160, the process returns to step 110, and the series of steps J! 1!
Repeat.

FIG. 7 is an explanatory diagram showing an example of control in this embodiment.

In Fig. 7 (A), a vehicle traveling in direction f has its front wheels 8
The state in which the steering wheel is turned by 1 is shown by a solid line. At this time, the 7th
If the sideslip shown by b occurs in the figure (A>) and the vehicle turns as shown by the broken line, then W2'>W+ will cause the rear wheels to turn as shown by the broken line according to equation (2). The steering wheel is turned (), the turning of the vehicle is suppressed, and the vehicle travels in the direction shown by a in the figure.On the contrary, as shown in Figure 7 (13)
("As shown in the figure, when the vehicle does not start turning sufficiently even after steering the front wheels and travels as shown by d in the figure, W2<Wl, so the rear wheels are turned as indicated by the broken line C. As shown in Figure 7 (A), the vehicle was steered in the opposite direction as shown in Figure 7 (B).
Drive in the direction indicated by middle C.

Figure 8 (A) shows an example of the angular velocity and rear wheel turning amount while the vehicle is running.
, shown in (B). In Fig. 8 (△), the target angular velocity W1
When the angle changes as the vehicle turns as shown by the solid line, some skidding occurs and the actual angular velocity W2 of 4 becomes as shown by the broken line.As shown in Fig. 8(B), The rear wheels are steered by the amount of steering MR, and the vehicle quickly returns to a stable running condition.

In this embodiment, the angular velocity (target angular velocity W+) generated in the vehicle when turning is determined from the steering amount S of the front wheels and the vehicle speed [=, and is compared with the actual angular velocity (actual angular velocity W2). Accordingly, the rear wheels are steered so that both angular velocities match. Therefore, even if an unstable running state of the vehicle occurs, such as skidding or the like, this can be quickly resolved and safe running of the vehicle can be realized. Further, in this embodiment, a micro combicoater is used as a part of the drive means for steering the rear wheels by steering ff1R according to signals from the front wheel steering amount detection sensor 2, vehicle speed sensor 5, and angular velocity sensor 6. Using the arithmetic control circuit used, steering M f'? , it is possible to easily change the setting of the amount of steering of the rear wheels, and for example, the amount of steering can be corrected according to variations in turning characteristics of each vehicle or changes over time of the vehicle, especially the suspension. It is also possible to say that. Furthermore, it is possible to set the turning characteristics of the vehicle according to the user's requests.

Note that, as a steering device, instead of the arithmetic control circuit 8 using a microcomputer shown in FIG. 3 of this embodiment, an analog arithmetic device 2 whose schematic configuration is shown in FIG.
There is no problem in constructing the configuration J using 00.

In FIG. 9, 201 and 202 are the steering detection sensors 2 and 2, respectively. Pulse human power buffer 7.203 that converts and outputs an analog signal according to the pulse signal from the vehicle speed detection sensor 5
is an input buffer for the angular velocity sensor 6, 204 is a four-phenomenon multiplication amplifier that multiplies the output signals of the pulse human power buffers 201 and 202, and 205 is an output signal of the input buffer 203 and an output signal of the four-phenomenon multiplication amplifier 204). 206 represents an output buffer 7 that amplifies the output signal of the differential amplifier 205 to drive the servo actuator 10. Even in a steering system using a multiplier calculation circuit, the same effect as in the above embodiment can be obtained by appropriately determining the sensitivity, amplification factor, etc. of each multiplier. .

[Effects of the Invention] As described in detail above, the steering device for medium objects of the present invention has the following characteristics: - From the steering h1 of the front wheels detected by the steering detection means and the medium speed detected by the vehicle speed detection means. Determine the target angular velocity that should occur in the vehicle when turning, compare the angular velocity with the actual angular velocity of the vehicle detected by the angular velocity detection means, determine the amount of steering of the rear wheels according to the difference, and calculate both angular velocities. The rear wheel steering device is configured to control the rear wheel steering means to steer the rear wheels so as to coincide with each other.

Therefore, even if an unstable state such as skidding or the like occurs in the vehicle, it is possible to promptly resolve the situation and return to a stable state, thereby achieving the excellent effect of realizing safe running of the vehicle. I can do it.

[Brief explanation of the drawing]

Figure 1 shows the basic system of the present invention; Figure 2 is a schematic plan view of a vehicle as an embodiment for explaining the steering system of the present invention;
The figure is also an explanatory diagram focusing on the control system of the steering system,
5 and 5 are explanatory diagrams for detecting the steering amount, FIG. 6 is an explanatory diagram showing an example of the processing operation of the embodiment, and FIG. 7 is an explanatory diagram showing an example of the control of the embodiment. The figure is an explanatory diagram showing an example of the angular velocity and the amount of rear wheel turning according to the embodiment, and FIG. 9 is an explanatory diagram of a control system using an analog calculation circuit as a part of the steering device. 1... Steered wheel 2... Steered amount detection sensor 5... Vehicle speed sensor 6... Angular velocity detection sensor 8... Arithmetic control circuit 10... Servo actuator 200... Analog computing circuit agent Patent attorney Tsutomu Sadatsu and 1 other person Fig. 1 5 Fig. 2 S4 Fig. 5 (A) Denwa 2″2 (B)

Claims (1)

[Scope of Claims] In a vehicle in which the front wheels and rear wheels are steered, there is provided a steering amount detecting means for detecting the amount of turning of the front wheels due to steering; a means for detecting vehicle speed of the vehicle; angular velocity detection means for detecting angular velocity; rear wheel steering means for steering the rear wheels; and a steering amount of the front wheels detected by the steering distance detection means and detected by the vehicle speed detection means when the vehicle is turning. The target angular velocity of the vehicle is determined from the vehicle speed determined, the actual angular velocity of the vehicle detected by the angular velocity detection means is compared with the target angular velocity, and the amount of steering of the rear wheels that makes the actual angle match the target angular velocity is determined as mJ Pi. -! A steering device for a J-vehicle, comprising: a steering control means for controlling a rear wheel steering means according to the amount of steering;