JPH09286346A - Control method for steering wheel of coupled vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suitably steer the wheels of a four-wheel drive tractor or a multi- coupled vehicle in a control method for steering wheels of coupled vehicles which is suitable for utilizing it to the multi-coupled vehicle consist of the tractor and a plurality of traitors. SOLUTION: This method can steer all wheels of a tractor 1 and all wheels of a plurality of tractors 2, 2,... which are sequentially connected to the tractor 1; the wheels of the tractor are steered such that the direction of the tractors 2, 2,... agrees or nearly agrees with the direction of speed vector of the just precedent vehicle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wheel steering control for a vehicle combined with a tractor and a plurality of trailers, which is suitable for appropriately steering each wheel while improving steering stability. Regarding the method.

[0002]

2. Description of the Related Art In recent years, the demand for transportation by automobiles (trucks) has been increasing. However, since a connected vehicle in which a tractor is connected with a detachable trailer has a large amount of transportation and a high transportation efficiency, the use of such vehicles is increasing. are doing. However, although such a combined vehicle has a great advantage in mass transportation, on the other hand, in terms of traveling performance, there are problems such as deterioration of stability and a problem of rutting during turning.

That is, since the articulated vehicle is provided with a joint point that allows relative rotation between the trailer and the tractor, it is inferior in steering stability and has a meandering motion as compared with a single vehicle such as a passenger vehicle. And the like, and a large rut difference (that is, inner ring difference) is likely to occur. Therefore, Japanese Patent Laid-Open No. 7-
As disclosed in Japanese Patent No. 17428, the present applicant has proposed a steering control method and apparatus for steering a front wheel of a tractor and a wheel of a trailer in a combined vehicle in which one trailer is connected to a tractor.

Such a technique controls the wheels of the trailer so that the direction of the vehicle of the trailer matches the direction of the velocity vector of the tractor. Then, the direction of the velocity vector of the tractor, that is, the angle βh formed between the velocity vector of the tractor and the center line of the tractor can be expressed as follows. βh = (v _TC −lh · γ _TC ) / u _TC However, the lateral velocity of the tractor is v _TC , the distance between the tractor-trailer joint point (hitch point) and the tractor center of gravity point is 1 h, and the tractor is The yaw rate of the tractor around the center of gravity is γ _TC , and the longitudinal velocity of the tractor is u _TC .

The distance lh between the hitch point and the center of gravity of the tractor is
Since it is a constant, the lateral velocity v of the tractor_TC， Center of gravity
Rino Tractor Yaw Rate γ_TC， Tractor forward / backward speed
Degree u _TCThe angle βh can be obtained by detecting
Also, the direction of the trailer can be expressed by the relative yaw angle ψ.
Wear. Then, in this technique, the angle βh of the velocity vector
The trailer wheels so that the relative yaw angle ψ matches.
Rudder angle δ_FiveIs controlled. For example, for angles βh and ψ
If the counterclockwise direction is the positive direction, the angle βh is greater than the angle ψ.
If smaller, trailer wheel steering angle δ_FiveCounterclockwise
If the angle βh is larger than the angle ψ, the trailer
Wheel steering angle δ_FiveIs decreased counterclockwise, and the angle βh becomes
If it matches the degree ψ, the trailer is facing the vehicle center line.
Will be towed straight toward
Improves stability.

In order to control the wheel steering angle of the trailer in this way, the wheel steering of the trailer is controlled while setting the target trailer wheel steering angle. The setting of this target trailer wheel steering angle is as follows. I am doing it. That is,
In a mathematical model in which the wheels of the trailer are steerably connected, from the equations of motion for the lateral speed of the tractor, yaw rate of the tractor, relative yaw angle of the tractor and trailer, front wheel steering angle of the tractor, and wheel steering angle of the trailer, A transfer function representing the relationship between the wheel steering angle δ _{5 of the} trailer and the relative yaw angle ψ is derived. Then, the target trailer wheel steering angle is determined from the detected relative yaw angle ψ and the above transfer function while detecting the relative yaw angle ψ while the connected vehicle is traveling. Further, the steering of the trailer wheels is controlled so that the trailer wheel steering angle δ ₅ becomes the target trailer wheel steering angle.

With such a technique, it is possible to precisely control the steering of the wheels of the trailer of the combined vehicle and enhance the steering stability of the combined vehicle.

[0008]

By the way, the prior art as described above is applied to a trailer vehicle in which the steering elements are two pairs of front and rear steering wheels of the tractor and a pair of left and right wheels of the trailer. I am thinking about steering control of wheels,
As an articulated vehicle, a vehicle that can steer a larger number of wheels can be considered.

That is, for example, it is conceivable that the tractor is of the four-wheel steering type in which the pair of left and right front wheels and the pair of left and right rear wheels are both driving wheels, and the trailer wheels can be steered. Further, as a connected vehicle with a large transport volume, a multiple connected vehicle that connects multiple trailers can be considered,
In such a multi-connection vehicle, one in which the wheels of each trailer can be steered can be considered.

As described above, in the case where a large number of wheels can be steered, if the respective wheels can be appropriately controlled, the steering stability of such a combined vehicle can be further enhanced. In the above-mentioned prior art, steering control combining four-wheel steering type steering of the wheels of the trailer and steering control of each wheel in a multiple articulated vehicle in which a plurality of trailers are connected is not particularly considered, and some control technique is used. Will be required.

On the other hand, if a large number of steered wheels are provided in this manner, the target steering angle to be set becomes large, so that the transfer function is derived from the equation of motion of the combined vehicle as in the above-mentioned prior art, and this transfer is performed. The method of determining the target trailer wheel steering angle based on a function cannot be applied. That is, if a motion equation for a four-wheel steering tractor or a multi-link vehicle is created, it becomes a multi-dimensional motion equation with many unknowns, and it is difficult to derive a transfer function like the above-mentioned conventional technique, and it is desired to develop a new method. Be done.

The present invention was devised in view of the above problems, and a wheel steering control method for a combined vehicle, which enables appropriate steering control of each wheel for a four-wheel steering tractor or multiple combined vehicles. The purpose is to provide.

[0013]

Therefore, in the wheel steering control method for an articulated vehicle according to the first aspect of the present invention, the wheel of the trailer is provided with a tractor and a plurality of trailers sequentially connected to the tractor. In the wheel steering control method for a combined vehicle configured to be able to steer, the direction of the host vehicle in each of the trailers described above matches or substantially matches the direction of the speed vector of the vehicle immediately before the host vehicle, It is characterized in that steering of the wheels of the trailer is controlled.

According to a second aspect of the present invention, there is provided a wheel steering control method for a combined vehicle comprising a tractor and a trailer or trailers sequentially connected to the tractor, and both front and rear wheels of the tractor can be steered. In a wheel steering control method for a combined vehicle configured so that the wheels of a trailer can also be steered, a rear wheel of the tractor and a wheel of the trailer set a center-of-gravity side slip angle of the tractor to 0, and a direction of the trailer. Is controlled so that the direction of the vehicle immediately before the trailer matches or substantially matches the direction of the speed vector of the vehicle.

In the method according to the first or second aspect of the present invention, for any vehicle, the direction of the vehicle is controlled so as to match the direction of the velocity vector of the vehicle immediately before, and, for example, in the order of proximity to the tractor. Assuming the first trailer, the second trailer, the third trailer, ..., the steering of the wheels of the first trailer is controlled so that the orientation of the vehicle of the first trailer matches the orientation of the velocity vector of the tractor,
Regarding the wheels of the second trailer, steering is controlled so that the orientation of the vehicle of the second trailer matches the orientation of the velocity vector of the first trailer, and the orientation of the vehicle of the third trailer is the orientation of the velocity vector of the second trailer. The steering is controlled so as to match with.

According to a third aspect of the present invention, there is provided a wheel steering control method for a combined vehicle, comprising a tractor and one or more trailers sequentially connected to the tractor, and both front and rear wheels of the tractor can be steered. In a wheel steering control method for a combined vehicle configured to steer the wheels of a trailer as well, a lateral speed of the tractor, a yaw rate of the tractor, a connection angle of each trailer to a preceding vehicle, and the tractor are provided for each vehicle. Of the front wheel steering angle, the rear wheel steering angle of the tractor, and the wheel steering angle of each of the trailers described above are established, a state equation is derived from the equation of motion, and the center of gravity side slip angle of the tractor is added to the system relating to the state equation. Is set to 0 and the orientation of the trailer is matched with the orientation of the velocity vector of the vehicle immediately in front of the trailer. By constructing a servo control system in which _d is introduced, the feedback coefficient for the state amount of the state equation and the error amount of the servo control system is set as an optimal solution that minimizes the evaluation function of the following equation (1), and the following equation ( From the solution P of the Riccati equation in 2),

[0017]

[Equation 2]

Based on the feedback coefficient thus obtained, the rear wheel steering angle of the tractor and the wheel steering angle of each trailer are feedback-controlled.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS.
A wheel steering control method for a combined vehicle as an embodiment of the present invention will be described. First, the combination vehicle according to the present embodiment will be described. FIG. 2 is a vehicle side view showing the combination vehicle,
As shown in the figure, this combined vehicle comprises a tractor (full tractor) 1 having a luggage compartment 9 and a plurality of trailers 2 connected to the tractor 1. However, due to space limitations, only two trailers are shown in FIG.

Tractor 1, trailer 2 and trailer 2,
A coupling device 5 is interposed between the two. The coupling device 5 includes a coupler 3 provided on an upper surface of a chassis frame 6 at a rear portion of the tractor 1 or the trailer 2,
The trailer 2 includes a kingpin 4 projecting from the lower surface of the chassis frame 10 at the front portion thereof. The coupler 3 has a pair of jaws (not shown) that can be opened and closed. Engagement recesses are formed at opposite edges of the jaws. A kingpin 4 is inserted between the engagement recesses to close the pair of jaws. This allows the kingpin 4 to be locked between the engaging recesses. Further, the jaws can be fixed in the closed state by press-fitting a lock plunger (not shown) into the gap between the facing edges of the pair of closed jaws.

The front wheels 7 of the tractor 1 are steered in accordance with the operation of a steering handle (handle) (not shown), and the rear wheels 8 of the tractor 1 and the wheels 18 of each trailer 2 are also operated. It is designed to be steered according to. FIG. 3 shows wheels 18 of each trailer 2.
FIG. 2 is a schematic plan view showing a chassis frame portion provided with a rear wheel 8 of the tractor 1, and as shown in the drawing, the chassis frame 10 of the trailer 2 or the chassis frame 6 of the tractor 1 has left and right side rails 12, Both ends have a plurality of cross members fixed to the side rails 12. The left and right side frames 12 support the front and rear ends of the main leaf spring 20 via shackle links (not shown).

Reference numeral 16 is an axle housing that rotatably supports the wheels 18 of the trailer 2 or the rear wheel 8 of the tractor 1 (only the left wheel is shown in the drawing). The axle housing 16 is rotationally driven around the center in the vehicle width direction by a trailer wheel steering mechanism or a tractor rear wheel steering mechanism, which will be described later, whereby the wheels 18 or 8 are steered.

Axle housing 1 which rotates in this way
6, both ends of the main leaf spring 6 are supported by a main leaf spring 20 and a helper leaf spring 22 arranged above the main leaf spring 20 via rubber pad members (not shown).
The relative displacement of 6 is enabled, and the rotation of the axle housing 16 is allowed.

The trailer wheel steering mechanism and the tractor rear wheel steering mechanism include a hydraulic cylinder device 30 as a wheel steering actuator, and a V-shaped upper radius rod 40 having a V-shaped apex portion as a rotation center of the axle housing 16. And a mechanism for displacing the displacement of the piston shaft 32 of the hydraulic cylinder device 30 to the rotation of the axle housing 16.

That is, the upper radius rod 40 is disposed between the left and right side frames 12, its V-shaped apex is pivotally attached to the accelerator housing 16 via a ball joint, and its left and right free ends are via a ball joint. And is pivotally attached to each side frame 12. Further, the left and right lower radius rods 60, which form the main part of the conversion mechanism together with the L-shaped lever 50, have one ends pivotally attached to brackets provided at the lower ends of both ends of the accelerator housing 16 via ball joints. The end is pivotally attached to the tip of the lateral arm of the L-shaped lever 50 via a ball joint. The bent portion of the L-shaped lever 50 is pivotally supported by a bracket fixed to the side frame 12, and the end of the connecting rod 70 has a ball joint at the rear end of the vertical arm of the L-shaped lever 50. Is pivoted through.

Piston shaft 32 of hydraulic cylinder device 30
Is connected to the middle part of the vertical arm of the L-shaped lever 50 on the left side, for example, via a ball joint.
The zero cylinder 34 is supported by the bracket of the chassis frame 10 via a ball joint. As a result, the L-shaped lever 50 rotates according to the expansion and contraction of the hydraulic cylinder device 30, and the end portion of the accelerator housing 16 is driven back and forth via the lower radius rod 60 to rotate the axle housing 16. Has become.

In order to expand and contract the hydraulic cylinder device 30 as described above, a hydraulic pump 80 and a control valve 82 are provided as shown in FIG. By controlling the communication state with the hydraulic pump 80, the expansion and contraction of the hydraulic cylinder device 30 is adjusted. The expansion and contraction adjustment of the hydraulic cylinder device 30 is of course for steering the trailer wheels and the rear wheels of the tractor, and is provided with a control means (controller) 15 for controlling the control valve 82. A lateral G sensor 101 for detecting the lateral acceleration of the tractor 1, a longitudinal G sensor 102 for detecting the longitudinal acceleration of the tractor 1, and a tractor 1
Yaw rate sensor 103 for detecting the yaw rate of
A yaw angle sensor 104 for detecting a yaw angle between the tractor 1 and the trailer 2, a vehicle speed sensor 106 for detecting a vehicle speed of the tractor 1, and a steering angle sensor 107 for detecting a steering angle of the steering wheel of the tractor 1. Detection information is input.

Further, the processor of the controller 15 is
The controller 15 has a function of performing various calculations related to the wheel steering control method for the present combination vehicle, which will be described later. In the controller 15, the input detection data is calculated by the processor and each target steering angle is determined. Steering control of each wheel is performed based on the target steering angle. Here, the wheel steering control method of the present combined vehicle will be described. In the present method, first, for each vehicle,
The equations of motion for the lateral speed of the tractor, the yaw rate of the tractor, the connecting angle of each trailer to the front vehicle and the front wheel steering angle of the tractor, the rear wheel steering angle of the tractor, and the wheel steering angle of each trailer are established. Next, a state equation is derived from the equation of motion, and a servo control system in which a control matrix C _d set under a required condition is introduced into the system relating to the state equation is used to configure the state of the state equation. Amount and an error amount of the servo control system as an optimal solution that minimizes the evaluation function, is obtained from the solution of the Riccati equation, and based on the obtained feedback coefficient, the rear wheel steering angle of the tractor and the above The wheel steering angle of each trailer is feedback controlled.

Here, the method will be specifically described. First, when establishing the equation of motion in this method, each numerical value is set as shown in FIG. 1 and Tables 1 to 5 below. The first hitch point is a connection point between the tractor 1 and the first trailer 2 connected to the rear (hereinafter referred to as a hitch point), and the second hitch point is connected to the first trailer 2 and the rear. It is a hitch point with the second trailer, and hereinafter, the nth hitch point is a hitch point with the (n-1) th trailer 2 and the nth trailer connected to the rear.

[0030]

[Table 1]

[0031]

[Table 2]

[0032]

[Table 3]

[0033]

[Table 4]

[0034]

[Table 5]

As shown in FIG. 1, when one tractor pulls a plurality of semi-trailers, not only the front wheels of the tractor but also the rear wheels of the tractor and the trailer wheels can be steered. Like
Here, the equation of motion is set up for each vehicle in consideration of the lateral force at each hitch point, and this lateral force is eliminated and rearranged to form an m × m matrix as shown in equation (3). Here, in the case of towing (n-1) trailers,
Consider a total of n vehicle groups. In this case m
= N + 1.

[0036]

(Equation 3)

From the above equation (3), the state equation (4) is derived, and this equation is simply described as the equation (5).

[0038]

(Equation 4)

[0039]

(Equation 5)

The state equation (5) is a multi-input system consisting of 2n + 2 state variables and having n + 2 inputs.
Therefore, based on this state equation (5), a servo control system that makes each vehicle follow a preset target value is configured. That is, the control amount y _d and the control matrix C _d are introduced into the system of equation (5), and the control amount y _d is set to the target value y _r.
Configure a servo control system that follows the error without error. The error e at this time is expressed by the following equation.

[0041]

(Equation 6)

Here, the respective target values y _ri are determined as follows for all vehicles. (A) The side slip angle of the center of gravity of the tractor is set to zero. This is represented by the following equation.

[0043]

(Equation 7)

(B) First trailer: The center line of the vehicle body is aligned with the direction of the velocity vector of the tractor at the hitch point. (See Fig. 6) (Hereinafter, this condition is called vector follow condition)

[0045]

(Equation 8)

(C) Second trailer: The vector follow condition is satisfied at the hitch point of the second trailer.

[0047]

[Equation 9]

(D) Third trailer: Consider the same in the following. When the above results are put together, a control matrix −C _d is obtained. Assuming δ _1f is the step input, (4)
Differentiate the expression and apply the following variable transformation.

[0049]

(Equation 10)

As a result, the equation (2) is transformed into the following equation.

[0051]

[Equation 11]

The output equation in this case is expressed by the following equation.

[0053]

(Equation 12)

Here, the manipulated variable v is created as follows by state feedback.

[0055]

(Equation 13)

This feedback coefficient F is (A ₀ ,
B ₀ ) exists if controllable, and the evaluation function of the following equation

[0057]

[Equation 14]

As an optimal solution that minimizes
It can be obtained from the solution P of the tti equation. In the above equation (1), Q is a gradient designating matrix and R is a transfer matrix. It is desirable to set Q large and R small in order to minimize the error e.

[0059]

(Equation 15)

When the initial value is 0, each wheel steering angle d is given by the following equation.

[0061]

(Equation 16)

FIG. 7 shows a feedback coefficient F that gives δ ₂ obtained by changing the vehicle speed when n = 2, where Q is 100 and R is 1. (See Table 6 for specifications.) As shown in FIG. 7, by setting the feedback coefficients F ₀₁ , F ₀₂ , F ₀₃ , F ₀₄ , F ₁₁ , and F ₁₂ according to the vehicle speed, the following equation (11) is obtained. ), Input values v ₁ , γ ₁ , ψ ₁₂ , ψ
The target steering angle δ ₂ of the first trailer can be obtained from ₁₂ ′ [“” represents time derivative], e ₁ and e ₂ .

Δ ₂ = F ₀₁ v ₁ + F ₀₂ γ ₁ + F ₀₃ ψ ₁₂ + F ₀₄ ψ ₁₂ ′ + F ₁₁ e ₁ + F ₁₂ e ₂ (11)

[0064]

[Table 6]

The wheel steering control method for the combined vehicle as one embodiment of the present invention is configured as described above. Therefore, by calculating the feedback coefficient F in advance as described above, Based on the detection information entered
By setting the target steering angle δ of each wheel, the center-of-gravity point side slip angle of the tractor is set to 0, and the direction of the host vehicle matches the direction of the speed vector of the vehicle immediately before the host vehicle (that is, the vector follow condition). The steering control of the tractor rear wheel and each trailer wheel can be performed while maintaining the above (1), and the steering stability of the multiple coupling vehicle can be improved.

A simulation analysis was performed to examine the present method as described above, which will be described below. First, in order to simplify the study, we decided to pull a plurality of semi-trailers with the same specifications as shown in Table 5 above. As a typical example of the transient response to the tractor front wheel steering angle input, it was assumed that two types of steering inputs were used assuming lane change and circle entry, and a pulsed force acts as a disturbance input.

Further, since it would be convenient if the stability could be improved by additional steering of only some wheels, it was considered first. When two trailers were connected (n = 3), the following cases were examined. (A) Steer only the front wheels of the tractor. (B) Coordinate steering of the rear wheels of the tractor.

(The side slip angle of the center of gravity of the tractor is controlled to 0) (c) The second trailer is cooperatively steered. (The second trailer satisfies the vector follow condition) The simulation results for the above three cases are shown in FIG.
However, the effect is not so great.

Here, since additional steering of the rear wheels of the tractor lowers the yaw rate gain of the tractor, in this case, the yaw rate gain of the tractor front wheels is doubled to make the yaw rate gain substantially constant. Next, the response when all wheels are cooperatively steered will be described. As described above, "the rear wheels of the tractor control the sideslip angle of the center of gravity of the tractor to zero, and each trailer wheel controls each of them to the vector follow state."
The response was obtained when all the wheels were cooperatively steered so that the above conditions were simultaneously achieved. Here there are 3 trailers
FIG. 9 shows the results obtained when the units were connected (n = 4).
Shown in As shown in the figure, the yaw rate gain characteristics from the leading tractor to the trailing trailer are almost the same even when changing lanes and entering a circle, and the stability is remarkably improved. The error in this case is approximately 0, and the target is achieved.

Further, the stability against disturbance was examined.
In other words, a pulsed disturbance input was applied only to the trailer, but the driver of the tractor did not notice this and examined the stability when traveling straight ahead. FIG.
Is the simulation result when disturbance is applied to the last trailer when three trailers are being towed (n = 4). As shown in the figure, even in this case, additional steering slightly affects other vehicles. However, it is understood that the stability is remarkably improved.

By the way, although the above discussion has proceeded on the assumption that all the state quantities and errors can be detected, actually, the tractor lateral velocity v ₁ , the error e _1, etc. are not easy to measure. Therefore, it was considered to estimate all other state quantities including errors from a small number of state quantities that are relatively easy to measure, and to perform state feedback using this estimated value. Equation of state (4)
When state feedback is performed in the equation, the feedback coefficient F is included as shown in the following equation.

[0072]

[Equation 17]

Over time, x and e converge to constant values,
Equation (12) is as follows.

[0074]

(Equation 18)

Therefore, from the second line, 0 = -C_dx_s= 0-C_dx_s= Y_r-Y_ds And y_dIs y without deviation_rConverge to (= 0). this
A block diagram of the control system configured as shown in FIG.
Swell. As shown in FIG. 5, the controlled variable y_rAnd target value y_d
And the difference (y_r-Y_d) To K₁Laplace conversion with / s
Then, to this value, output x gain K₀Add the value multiplied by
And gain B_TwoMultiply by And this way
The steering wheel front wheel steering angle (the steering wheel angle
Correspondence) δ_1fGain B₁The value multiplied by and the output x
In A ₀Add the values multiplied by and add this value to K₁/
Laplace transform with s, and then C_dMultiply the gain according to
Target value y calculated_dGet. Of course, this target value is
And is used for the next control.

Some of the state variables in the equation (12) are output y.
Assuming that can be directly measured as, the output equation at that time is as follows.

[0077]

[Equation 19]

Regardless of the output matrix C, the controllability is determined by A'and B'in the equation (12 ').
Since observability is affected by C, the point is whether the remaining variables can be estimated even if the number of measured state variables is small. Focus on the case where two trailers are towed in order to proceed with specific studies. It is observable when the number of minimum measured values is two.

In this case, the output in the case of the combination of (ψ ₁₂ ′, ψ ₂₃ ′) is expressed by the following equation. Note that ψ ₁₂ ′, ψ ₂₃ ′
"'" Indicates the time derivative.

[0080]

(Equation 20)

From equations (12) and (14), Gopit
The following observer was created by the method of ATH.

[0082]

(Equation 21)

Since the steering angle d of each wheel is determined by the estimated state quantity Z ^* , it is given by the following equation.

[0084]

(Equation 22)

FIG. 11 shows a simulation result when other state quantities are estimated and fed back assuming that only the measured values of (ψ ₁₂ ′, ψ ₂₃ ′) are obtained. As shown in the figure, in the case of a circle approach, a steady deviation remains, but a fairly accurate result is obtained. In this way, this method, that is, when one tractor pulls several semi-trailers, all wheels are cooperatively steered and the stability is improved. The following results were obtained. (1) Based on the state equation, a method of constructing a servo control system for making each vehicle follow a predetermined target and constructing a state feedback system for optimally steering each wheel was shown. (2) A series of simulations using the above system was used to study the movements when entering a circle, when changing lanes, and when side wind disturbances were applied, and clarified the effect of all-wheel steering on improving stability. (3) An observer that measures only the relative yaw angle of the trailer and estimates other state quantities is configured, and the effect is confirmed by simulation.

[0086]

As described in detail above, according to the wheel steering control method for a combined vehicle of the first aspect of the present invention, the wheel of the trailer is provided with a tractor and a plurality of trailers connected in sequence to the tractor. In the wheel steering control method for a combined vehicle configured so that both can be steered, the direction of the own vehicle in each of the above trailers is set to match or substantially match the direction of the speed vector of the vehicle immediately before the own vehicle. In addition, by controlling the steering of the wheels of the trailer, it becomes possible to appropriately steer the multiple-connection vehicle, and it is possible to improve the steering stability of the multiple-connection vehicle.

According to the wheel steering control method for the combined vehicle of the second aspect of the present invention, the front and rear wheels of the tractor can be steered, including the tractor and the trailer or trailers sequentially connected to the tractor. With the wheel steering control method for a combined vehicle configured to be able to steer the wheels of the trailer together, the rear wheels of the tractor and the wheels of the trailer are:
The front and rear wheel steering type tractor is controlled by setting the lateral slip angle of the center of gravity of the tractor to 0 and controlling the steering so that the direction of the trailer matches or substantially matches the direction of the velocity vector of the vehicle immediately before the trailer. In addition, when the trailer connected to this is steerable, the steering can be appropriately performed, and the steering stability of the combined vehicle can be improved.

According to the wheel steering control method for a combined vehicle of the third aspect of the present invention, the front and rear wheels of the tractor can be steered with the tractor and the trailer or trailers sequentially connected to the tractor. In addition, in the wheel steering control method for a combined vehicle configured to be able to steer the wheels of the trailer, the lateral speed of the tractor, the yaw rate of the tractor, the connection angle of each of the trailers to the preceding vehicle, and The equation of motion for the front wheel rudder angle of the tractor, the rear wheel rudder angle of the tractor, and the wheel rudder angle of each trailer is established, the state equation is derived from the equation of motion, and the center of gravity of the tractor is added to the system relating to the state equation. A control matrix set under conditions such that the sideslip angle is zero and the orientation of the trailer matches the orientation of the velocity vector of the vehicle immediately preceding the trailer. Constitute a servo control system which was introduced scan C _d, the feedback coefficients for the error amount of the state quantity and the servo control system of the state equation as the optimal solution that minimizes the evaluation function of the following equation (1), the following Obtained from the solution P of the Riccati equation of equation (2),

[0089]

(Equation 23)

Based on the feedback coefficient thus obtained, the rear wheel steering angle of the tractor and the wheel steering angles of the trailers are feedback-controlled to control the steering of each wheel of the four-wheel steering tractor and the multiple articulated vehicle. It is possible to properly and surely set the target value for the above, and it is possible to surely improve the steering stability of the combined vehicle.

[Brief description of drawings]

FIG. 1 is a diagram illustrating parameters and the like related to a wheel steering control method for a combined vehicle as an embodiment of the present invention.

FIG. 2 is a schematic side view illustrating the configuration of the combination vehicle according to the embodiment of the present invention.

FIG. 3 is a schematic plan view showing a steered wheel portion of a trailer or the like according to an embodiment of the present invention.

FIG. 4 is a schematic diagram showing a wheel steering control system of a trailer or the like according to an embodiment of the present invention.

FIG. 5 is a block diagram of wheel steering of a trailer and the like according to an embodiment of the present invention.

FIG. 6 is a diagram illustrating vector follow according to the embodiment of the present invention.

FIG. 7 is a diagram showing an example of setting a feedback coefficient according to the embodiment of the present invention.

FIG. 8 is a diagram showing a simulation result according to the embodiment of the present invention.

FIG. 9 is a diagram showing a simulation result according to the embodiment of the present invention.

FIG. 10 is a diagram showing a simulation result according to an embodiment of the present invention.

FIG. 11 is a diagram showing a simulation result according to the embodiment of the present invention.

[Explanation of Codes] 1 tractor (full tractor) 2 trailer 3 coupler 4 kingpin 5 coupling device 6 chassis frame 7 front wheel of tractor 1 8 rear wheel of tractor 1 9 luggage compartment 10 chassis frame 18 wheels of trailer 2 12 siderails 20 main Leaf spring 16 Axle housing 22 Helper leaf spring 30 Hydraulic cylinder device 32 Piston shaft of hydraulic cylinder device 30 Upper radius rod 50 L-shaped lever 60 Lower radius rod 70 Connecting rod 34 Cylinder of hydraulic cylinder device 80 Hydraulic pump 82 Control valve 15 Control Means (controller) 101 Lateral G sensor 102 Front-rear G sensor 103 Yaw rate sensor 104 Yaw angle sensor 106 Vehicle speed sensor 107 Steering angle sensor

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location B62D 137: 00

Claims (3)

[Claims] 1. A wheel steering control method for a combined vehicle, comprising: a tractor and a plurality of trailers connected in sequence to the tractor, wherein the wheels of the trailer are all steerable. A wheel steering control method for a combined vehicle, wherein steering of wheels of the trailer is controlled so that a direction of the vehicle coincides or substantially coincides with a direction of a velocity vector of the vehicle immediately before the own vehicle. 2. A combined vehicle comprising a tractor and a trailer or trailers sequentially connected to the tractor, wherein the front and rear wheels of the tractor are both steerable and the wheels of the trailer are steerable. In the wheel steering control method, the rear wheels of the tractor and the wheels of the trailer set the lateral slip angle of the center of gravity of the tractor to 0, and the direction of the trailer matches the direction of the velocity vector of the vehicle immediately before the trailer, or A wheel steering control method for a combined vehicle, wherein steering control is performed so that they substantially match. 3. A combined vehicle having a tractor and a trailer or trailers sequentially connected to the tractor, wherein front and rear wheels of the tractor can be steered and wheels of the trailer can be steered. In the wheel steering control method, for each vehicle, the lateral speed of the tractor, the yaw rate of the tractor, the connection angle of each trailer to the preceding vehicle, the front wheel steering angle of the tractor, the rear wheel steering angle of the tractor, and the above A motion equation for the wheel steering angle of each trailer is established, and a state equation is derived from the motion equation. Of the state equation by constructing a servo control system in which a control matrix C _d set under the condition of matching the direction of the velocity vector of Is obtained from the solution P of the Riccati equation of the following equation (2) as an optimal solution that minimizes the evaluation function of the following equation (1), and the feedback coefficient for the error amount of the servo control system is ] A wheel steering control method for a combined vehicle, comprising feedback-controlling a rear wheel steering angle of the tractor and a wheel steering angle of each trailer based on the feedback coefficient thus obtained.