JPH01273770A - Steering angle ratio control device - Google Patents

Abstract

PURPOSE:To enable execution of smooth running without bringing a car body into contact with a side wall, by a method wherein at a car speed lower than a given value, a steering angle ratio responding to a car speed is determined by a distance between a vehicle and a side wall and a yaw angle, and is regulated to a minimum value at which the car body is prevented from making contact with the side wall. CONSTITUTION:An arcuate groove 29 formed around a pin 27 is formed in a control lever 30 of a steering ratio control mechanism A, and a coupling pin 28 slidable along the groove 29 is engaged therewith. In order to slide the coupling pin 28, an arcuate partial gear 22 is formed integrally with the end part of an output link 27, and a gear 17 geared therewith is driven with the aid of a steering ratio control motor 18. A distance sensor 62a to detect a distance S by means of a reflection wave of an ultrasonic wave disposed adjacently to the front and rear wheels of a vehicle and a yaw angle detecting means formed with a pair of distance sensors 62a and 62b disposed adjacently to the front and rear wheels of a vehicle are provided. Based on signals from the tow sensors, the revolving radius of a vehicle and a distance between the vehicle and a side wall are determined, a minimum steering angle ratio k1 in which the car body is prevented from making contact with the side wall is determined, and based on the minimum steering angle ratio, rear wheels are steered.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention is applicable to a steering angle ratio control device for a four-wheel steering vehicle.

[Prior art 1] In a four-wheel steered vehicle, if the rear wheels are steered in a phase F' opposite to the front wheels, the turning V diameter becomes smaller, and the turning ability is adversely affected. In this case, compared to a conventional front-wheel steering vehicle, the range of movement of the vehicle is expanded by -7. ] When changing direction, there is a risk that the rear corner of the vehicle may come into contact with the side wall.

In the four-wheel steering vehicle disclosed in Japanese Unexamined Patent Publication No. 27767, in order to solve the above problem, when the steering wheel is turned sharply, the rear wheel steering The invention solves the problem when the angle gradually approaches the target steering angle by 1° every predetermined travel distance.
In a four-wheel steering vehicle with ε-, the rear wheel steering angle (T3-
・Since the angle (the side wall 1, the inclination angle of the front body axis 1 of the pair of vehicles) also changes in stages t'', the movement of the vehicle becomes unnatural and the driver (,' lli!!!The Japanese feeling is t-
jλru, 1 The object of the present invention is above) Problem 41 (,': In view of this, if the steering angle ratio corresponding to the vehicle speed (:, 2) is
Distance from the side wall of the vehicle m! 3 J: IIIfE-11
3hu 3) Request J, 4) A steering angle ratio control device that allows smooth turning without any discomfort due to the minimum steering angle ratio that does not contact the side wall and does not cause discomfort. provide. L
There is a binding.

In order to achieve the above object, the structure of the present invention is as follows. Detecting the inclination of the vehicle relative to this: ]-Angle detection-4
- The signals from the front and rear wheel steering angle sensors 2 are input manually and 1'8 U.
4j To'4 ゛F diameter failure f. The turning cliff diameter obtained from the stage is the distance between the turning center and the side wall of the vehicle calculated from the distance Renly/Kinra. , below the predetermined 1st speed, the low-speed steering angle ratio setting lower stage signal > i ((Ko-S steering angle ratio ai control) 1 It is something.

[Effect (Be careful when the vehicle speed ■ comes into contact with the side wall 4- Requires vehicle speed ■1 (e.g. 2 km/h or less) e), read the distance S from the initial coring angle ψ relative to the side wall (4), and calculate the distance S. From = f (ψ, S), find the value of the limit steering angle ratio that does not touch the left and right side walls (-2 minimum steering angle ratio, 1 and 8 separately, and when the steering wheel is turned to the left side wall) The minimum steering angle ratio is ζ-, and when the knife is turned, 1. is the value of C1 on the right side wall. Distance with @J, rim is also small, J, sea urchin decided, -'5
Do 1.

The turning radius of the vehicle is determined from the steering angle of the front and rear wheels on the turning IJ17':l]IA side and the -angle. With these seven wheels, the turning radius is not a precise longitudinal trajectory, but a distance between the rear corner that protrudes outward from the vehicle during turning and the center of turning <'(J').

On the other hand, k=f(V)l;2 Find the steering angle ratio k in normal uphill running, and if the steering angle ratio l( is smaller than 1 to the minimum steering angle ratio, [ ] the steering angle ratio k() !(Set as 1.

If I↑rav is higher than \11 and lower than V2 (vehicle speed at -1- limit in start mode, e.g. 10km/It), the female small steering angle ratio at start is 1 (maintains 1). .

Even if the medium speed V is t times lower than v2, the steering angle ratio k is the minimum steering angle ratio 1.
If the value is greater than 1, set the start mode flag to 64'L.
FF and the target steering angle ratio kt for normal driving.

Car) When Song V becomes higher than V2J, start [-Turn off the tonneau lug and determine the target steering angle ratio k (for normal driving).

When driving in a low direction Lx, the turning radius will be smaller than the distance between the turning center and the side wall when the steering angle ratio or the minimum steering angle ratio is on the side of the road (if there is a side wall that is obstructive). Even if the front wheels are set at the maximum steering angle and start 12, it is similar to the case of J2, where the front wheels touch the side wall.Also, when driving, if the car turns all the way or turns (... Contact with the two side walls is avoided.

[Embodiment 1 of the Invention As shown in FIGS.
The small arm 3 is movably supported on the vehicle by a support shaft 3a, and is operatively connected by a rod 4. The arm of the right knuckle arm 3 is connected to the front wheel steering mechanism 7 via a drag link 10. When the front wheel steering mechanism 7 rotates the steering shaft 6 by 5, the output @7a is generated.
is rotated, the drop arm 8 connected thereto swings, and the drag link 10 moves back and forth. A rod 12 is connected to the intermediate portion of the drop arm 8 and connected to a pin 9, and the rear end of the rod 12 is connected by a pin 13 to a heel 14 of the steering angle ratio control mechanism Δ.

Input link 14 is in bin 151. :More control! , ・Connected to the end of the bar 30. The vehicle (FF111M1 collar 30, which is movably supported by a support shaft 23) is connected to an output link 27 by a connecting bin 28. Output link 2
7 moves back and forth by the turn 27a and is connected to the rad 31. Rod 311. Rear wheel steering system 34 Noriichi
The control valve 32 is coupled to one valve element of the control valve 32. .

The rear wheel steering mechanism 34 is integrally composed of a bullet piece 32, a seventh tip, and a clover.The actuator 1 is fitted with a cylinder 33L and a piston 35F. , the outer end of the rod is supported by the vehicle, the other valve elements of the servo-controlled valve 32 are integral with the cylinder 33, and the outer end of the rod is supported by the vehicle. Ru.

A rod 36 is connected to one end of the lever 37, supported by a support shaft 38V on the width 1, and a "-" rod 39 that moves back and forth is connected to the other end L. The guard is connected to an arm of a Y-tsuku small arm 41 that supports the rear wheel 40. The left and right buckle arms 41 are Quirods 42 CJ:
; The center of the bin 27a is located at the center of the arc-shaped ifl! 29 is provided and is slidable along this i corner (along J); two interlocking bins 28 are engaged. In order to drive the three coupling bins 28, An arc-shaped partial gear 22 is integrally formed with the gear 6-1, and a gear 1°t meshing with the gear 6-1 is driven by the steering angle ratio control motor 18. This second gear 17/ is coaxially connected to 2f, ``gear 16f,'': ``J-nohm shaft 21 of the steering angle ratio control motor 18 is engaged,'' (41, a). θ[;Angle 11. The control motor 18 and the gear 17 are integrally supported on a frame.
,,, - evening + 91 =:) Fffi! Ii is done.

Aku 5. ]-]J--ta 11 is connected to the cylinder by fitting a screw into the cylinder, and the screw 1 of J is connected to the rod with the frame of the steering angle ratio control l-1-ta 18. Usually the spring force i
, '' is biased toward the front b (tooth 117, !1m partial tooth depth 2? in the direction of disengagement).

The one-die i-shaft 23 of the control lever 30 has a groove connected to the groove 29 to the right. , υ1 rot 11. , brim ~ 3 (combined with 0, f, nilever 24 -) 1 Kudu 1 digit 25 (, -, then 1
When the control lever 30 is rotated in the direction t, the groove of the support shaft 23
llt :) Added from 9. Ak% -L iT
'---925vt cylinder L.

Close the screws with () and connect the piston and 1.・Ba~
ri) 4 are connected to rods i, T:, l. Usually Akbu 11. ．． 11: The lever 24 is pressed against the stopper 26 by the force of the spring of the lever 2!5, and the lever 24 is pressed against the stopper 26, and the groove 29 of the support shaft 23 is in a continuous state.

Now, if you turn the steering wheel 54 to the right, the front wheel steering structure 71)
1 Drag Lee, ・'Noro 0 Tsuno'; Move in the +Vi direction, knuckle i'-Z% 3 is the pivot 3 a small center and (
At 7, it rotates clockwise and the front wheel 2 is deflected to the right. At the same time, [-1tsu 1-2 also moves forward, Pli+IIH
The collar 30 rotates one turn in the counterclockwise cutting direction about the support shaft 23. 1. Pressure oil is supplied to the front chamber of the cylinder. Go 3
3 moves to ship 'B' and passes through L tube 37 to [] Tsurad 9.
moves backward, the knuckle arm 41 rotates 1-2 in the counterclockwise direction around the support shaft 41, and the rear wheel 40 rotates 7
It is deflected in the T'' direction (opposite phase to the front wheels).11L is
The turning radius of 11 cars has become smaller, and is it for low speed? "i"17
The booth will be occupied by Inno 1.

Vehicle speed (, 2-related steering angle jt Ril control () - E18
The teeth $17'8 rotate once, and the output links 27, 2, and 27a are rotated from the center L' counterclockwise 11i! 1-
Then, the connecting beam], ・281.1 The part of the support @ 23 moves to the side. ・When the rear width 40 is deflected to the same phase as the front wheel 2 (see Fig. 4); 1.11 The rA longitudinal stability when changing lanes at high speeds has been improved by -1.

The present invention [by vehicle origination] 1 (time and narrow roads 7.=J
When changing direction at any point, the steering angle ratio is set to the minimum steering angle to prevent the rear corners of the vehicle from protruding from the road and coming into contact with the side walls. In comparison! +11 limited. The minimum steering angle ratio is the distance between the vehicle and the side wall.]
= - angle, and the turning radius of the vehicle is set to a value that is not larger than the distance between the turning center and the side wall. The turning radius is the distance between the rear corner of the vehicle and the turning center.

The turning center is the front wheel steering angle 0f, the rear wheel steering angle θ1, and the ball 1-angle ψ.
Determined from.

If the front wheel steering angle is tθI and the steering angle ratio is 1×4, then the rear wheel steering angle θ1 is θ1・−k・θ 1, Fig. 2 143 JI4ft, wheel support shaft 41 a <Katsu@41
al, is at the center of the rear wheel 40, and the center of 46) is the origin 0 and 1. , the coordinates of the support shaft 3a of the front wheel 22 (the support shaft 3a is the center of the front wheel 1I7) 1), the forward tl of the front wheel 2: direction, 1 - the vertical direction (passes through the point [)] Straight line/
\However, which intersection point of the straight line 1-3 passing through the 'h'Mx t'j 7 direction of the rear wheel 40 and the vertical point O is defined as 0.

Also, the side! S! The yaw angle of the vehicle with 80tC is Φ,
Boil base (point G) and point 00 interval) are W, l:1''.

The slope of M line A is a, the slope of straight line 1 is i-b,! Putting two together, a=van(θf→φ) b-tan(θ1・tenΦ) The equation for the straight line is Y-aX+c (1) This 1-(7
, front wheel 2 support shaft 3a17) seat <vote P (X, V)
LtX---Wsinψ (2)y
-1\to/ COSψ
(3) (2), <3) Equation 8 (1) Equation (z' Substituting -', W cosψ-“a ・(-W si
nψ) 4CC-W<cosψ-+-asinψ) ,', Y -a X', -W (cosψ+asi
nψ) (4) Equation number of straight line 13, end 'y' -b X (5)
J, vehicle turning center (ν2) seat Pa (xo,
yo) is (71), to]) from the formula I, V
-ax-+-W (cosψ+a 5in(7x))
! -・[)V.

,',XO4' (cosψtena sinψ)
(('= )-a '1o-'v-W(costI)=-asInt)〈
7)-a As shown in FIG.
(Q mark is 0: distance from point 0 to rear corner R? tλ: front and back of small mountain @ line G to 4-ro, white 0 and rear corner 86
R,! - and the e-bow angle of line 1 connecting 4-, x-egin<ψ+-α) (9) y =
+UCO3(ψ→α> (1(j) and -(", Vehicle turning' - V7 diameter μQ+:λ !iii QR of the point F, (G), (7), iK and <9>,
From the <10> generation, ((1)R) 2 = (y+o −a sin (ψ
-+α)])J-[yo-e cos(ψ+-+x)1
2 (II) 1, the center of both Φ and the l of the side wall? li Since the tuna is XO, the condition that the rear corner of the vehicle does not touch the side wall (splash, QR
<XO+S (12) (3: Support @4
1a Any side wall 80 In any case of an 8-turn at any distance m, it can be found in the same way (, -shi).From the second thing, the steering angle jtk・-t (ψ, W)
The relationship will be successful.

For example, a distance 1: 18.τ is installed adjacent to the rear wheel of a vehicle, and distance S is detected from the reflected wave r of the ultrasonic wave 62a.
For example, IJ'! Yaw angle detection means (
32 is established, 11, based on the number of both names, find the radius of turning 1' of one vehicle and the distance from the side wall I38"], and find 1 for the minimum steering angle ratio without contact with the side wall. 5° direction, normal running (1, the steering angle ttL5 vehicle speed U2C is controlled according to (see Fig. 4). For example, the vehicle speed sensor 55 disposed opposite Based on the signal, the steering angle ratio is set to 1st stage to 94, vehicle speed [41 to r (5t, target no. 4 to 1), and based on this, the steering angle The actual steering angle ratio ks obtained by the ratio control gear 18 is driven. k
t, the r1 steering angle ratio control mode 18 is stopped 1°. In Figure 6, the 1ift control described in L is transferred to the microphone 1.
It is a flowchart of a print column performed by an electronic control device 551 consisting of a single coater. [, nog [-1 grams star 1-1 in pll), p 12”r initialization 1
2. Set the start mode flag to 0NII'' in p13.

p14ri speed,, Nsa551r:: r ReIN
Load the speed V, pls use the ship wheel steering angle sensor 591J,
Read the J-ri front wheel steering angle θ[. 1″N6 and 1F (determine whether the speed ＼/ is smaller than the value ＼12 that would prevent contact with the sidewall. If the 7 vehicle speed ■ is faster than the value ＼/2, then , OFF northward mo~tonoragu with ρ17
Doji, 1) Proceed to 25 1. If p+6-i' vehicle speed ■ is the value \12, 1, li) is small, determine whether the vehicle speed V is smaller than the low level value \/1. . , if the vehicle speed \/ is more crowded than the value \11, proceed to 1) 22, and if the vehicle speed \2 is smaller than the value V1, L, p + '' distance sensor (2a, 62b, Read the −1 − angle ψ1゛, ψ1 on the right and left that were found.

p20F distance 1. An (+6213 reads the distance from the rear of the vehicle to the left side wall $1', sl @. 8: Find the minimum steering angle ratio that does not exceed the distance of
Determine whether f is greater than 0 or C. Front wheel steering angle/7f
If is smaller than O (for stone cutting), 1) If 23 is the minimum steering angle ratio 1 (1 is kll, proceed to p25. l) If 22 is larger than front wheel steering angle θf7jto < 11-steering angle) is set to the minimum steering angle ratio by 1fklr in [)24.

p25? , ′-width \l versus l, ? 54 rudder angle ratio 1
Memorized in 4! I'm looking for sin. p2
Use G to judge whether the starter-1/5 is ON or not! 1-ru41
Starting 7 - If F Norag is OFF, [) 2/ starts one = - Tonorag is OF I'i',! l: l・,
1) At 28, the steering angle ratio 1 (is the target steering angle ratio kt, and ``) 3j
Proceed to.

On p26, ``Start King-1;'' In the case of ``Norag Thickness (I)N 1.
艮, p29 (``Is the minimum steering angle ratio k corresponding to the turning radius and the distance between the center of rotation and the side wall 1 (greater than 1) smaller than 1'!''? 5) Judgment question When the steering angle ratio k is less than the minimum steering angle ratio 1<1 (11: 6 is 1), proceed to 27.p
29r Rudder angle it: k h<Minimum h1'' If smaller than i angle 1tk1 L&, ρ30, minimum steering angle It kl is the target steering angle ratio kt, p3tr Fig. 7, J'<-”1 interrupt program Based on) steering angle ratio control tll-E-ta'1
8i ζ drive ゛4゛ru5゜Fig. 7 is also not shown.
1-1 Drive the steering angle ratio control T----ta 18 so that
p43T'' Detects the actual steering angle ratio ks, and determines whether p44T-actual steering angle ratio i<s is equal to [1 (large steering angle ratio ks). Large steering angle ratio ks or target steering angle ratio If it is not equal to kt (,42,E), return to 42. If the large steering angle ratio ks is [1
[mark steering angle ratio kt, etc.], 7, p45-r stop the steering angle ratio control motor 18 l/, L) 46 and return to Fig. 6 (, L' indicates -1[] 1, [below], the program 1-1 is executed for a predetermined period of time (repeatedly 1 every τ).

1 Advantages of the Invention 1 The present invention has the above-mentioned 5+, an 8-f-f'1 detection stage that detects the tilting of the 41 cars, and a 010 multi-wheel steering angle 1! scissor. Which signal is input as the turning radius numbing means? Low-speed steering angle ratio setting means No. 5, above a predetermined vehicle speed] is a low-speed steering angle ratio setting - 1 stage signal (: Based on the signal, the steering angle ratio control mechanism is driven (based on the steering angle ratio control device). When changing direction on a narrow road from L-, the turning center of the vehicle and the turning center are calculated from the distance from the side wall of the vehicle, the yaw angle relative to the side wall, and the steering angle of the front and rear wheels as soon as the vehicle starts. The distance between the turning side wall and the turning center is determined by the distance between the turning center and the turning center. The minimum steering angle ratio is smaller than 1, 1.
, the steering angle ratio is 1' above the predetermined p5 of the vehicle.
In order to maintain the minimum steering angle ratio related to the steering wheel (continuous 1r,
, ! Since the rear wheel steering angle is controlled continuously, the rear wheel steering angle also changes continuously (, -, and driving Bt-: smooth steering that does not feel strange at first glance. .No, y: If the vehicle is not more than a predetermined value, the driver should turn the steering wheel sharply in the same manner as in a conventional front-wheel steering vehicle to avoid collisions with the side walls of the vehicle. do.

[Brief explanation of the drawing]

FIG. 1 shows an outline of a four-wheel steering vehicle equipped with a steering angle ratio control device according to the present invention! The top view shows the configuration, and Figures 2 and 3 show the front and rear wheel steering angles and turning! 4 is a characteristic diagram of the steering angle ratio setting means, and FIG. 5 is a diagram showing the configuration of the steering angle ratio control device. This is a flowchart of the program that controls the steering angle ratio υ type 1 scissors. 6: Steering shaft 17; Gear 18: Steering angle ratio control
19,2! U: Actuator 22: Partial gear 1 wheel 2
3: Support shaft 27: Output link 2; 3: Connection bin 30
: Control lever 34: Wheel steering wheel 40: Rear wheel 5”l
: 15 child control device 55: Medium speed 12 sensor 56: Steering angle ratio sensor 59: Front wheel rudder μ4↑ sensor 60: Rear wheel steering angle sensor 62a, 62b: Distance sensor 62: E-angle detection means 5 I: ( × Compared to the sand mountain ○

Claims (1)

[Claims] The turning radius calculated by the turning radius calculation means which receives signals from the yaw angle detection means for detecting the inclination of the vehicle with respect to the side wall and the front and rear wheel steering angle sensors is determined from the distance between the vehicle turning center and the side wall calculated from the distance sensor. and a steering angle ratio control motor that drives the steering angle ratio control mechanism based on a signal from the low speed steering angle ratio setting means when the vehicle speed is below a predetermined vehicle speed. A steering angle ratio control device.