JP2007161148A - Drive control device for rear vehicle in coupled vehicle - Google Patents

Abstract

[PROBLEMS] To improve running stability of a rear vehicle by controlling a difference in braking / driving force between left and right wheels of the rear vehicle so that a bending moment in a horizontal plane does not act on a connecting portion between vehicles.
(A) The left rear wheel forward drive force Tfl and the right rear wheel forward drive force Tfr of the front vehicle 1 are made the same, and the left wheel forward drive force Twl and the right wheel forward drive force Twr of the rear vehicle 2 are the same. The front straight drive state with the same is shown. From this state, as shown in (b), when the front vehicle 1 makes a left turn, when the rear vehicle 2 applies a clockwise bending moment Lm to the vehicle connecting portion 3, the sensor 11 that detects this Lm In response to this signal, the target forward drive force tTwr of the right wheel 9R in the rear vehicle 2 is made larger than the target forward drive force tTwl of the left wheel 9L. Such left and right wheel driving force difference control of the rear vehicle 2 causes the rear vehicle 2 to generate a counterclockwise yaw moment on (b), and this yaw moment attenuates the clockwise bending moment Lm of (b) to cause the rear vehicle The running stability of 2 can be improved.
[Selection] Figure 4

Description

  The present invention relates to a connected vehicle in which a plurality of vehicles are connected in tandem, and more particularly to a connected vehicle capable of individually controlling the braking / driving force of the connected plurality of vehicles, so that the rear vehicle is improved so that the running stability of the rear vehicle is improved. The present invention relates to a drive control technology.

As a technique for driving and controlling a rear vehicle (towed vehicle) in a connected vehicle such as a camper, a trailer truck, and a tandem bus, conventionally, for example, as described in Patent Document 1,
In a coupled vehicle that can individually control the driving force of a tow vehicle that is a front vehicle and a tow vehicle that is a rear vehicle,
The left and right steered wheels of the towed vehicle are attached to the vehicle body by a turning support member, and the left and right steered wheels can be steered by the difference in rotation between the two,
When moving forward, the left and right wheel rotation speed and left and right wheel driving force of the towed vehicle are controlled according to the steering angle and vehicle speed of the towed vehicle or the towed vehicle, and when towed, the towed vehicle pulls the towed vehicle. 2. Description of the Related Art A vehicle that controls the left and right wheel rotation speed and the left and right wheel driving force of a vehicle is known.
Japanese Translation of National Publication No. 07-500239

  However, as in the prior art, if left and right steered wheels are set on the towed vehicle and the left and right steered wheels are steered by the rotation difference between them, all the wheels of the towed vehicle are attached to the vehicle body in a non-steerable manner Needless to say, a wheel support structure is indispensable for setting left and right steered wheels and attaching them to the vehicle body by means of a turning support member that is steered to the vehicle body. Thus, there is a problem that the wheel support structure becomes complicated and causes a cost disadvantage.

  In addition, conventionally, the left and right steered wheels are steered by controlling the difference in rotation between the two so that the towed vehicle follows the towed vehicle. The above-mentioned purpose cannot be achieved, and it is necessary to rely on accurate and difficult control, and this also raises the problem of high cost.

  In view of the above circumstances, the present invention is disadvantageous in that all the wheels of the rear vehicle as the towed vehicle are attached to the vehicle body in a non-steerable manner, and thus the wheel support structure of the rear vehicle becomes complicated and the cost is increased. Without the need for accurate and difficult right / left wheel rotation difference control for wheel steering, and therefore without increasing the cost associated with this, the driving stability of the rear vehicle is improved. An object of the present invention is to propose a drive control device for a rear vehicle in a connected vehicle.

For this purpose, a drive control device for a connected vehicle rear vehicle according to the present invention, as described in claim 1,
The basic premise of the gist configuration is a connected vehicle in which multiple vehicles capable of individually controlling braking / driving force are connected in tandem.
A connecting portion that connects the front vehicle and the rear vehicle that are adjacent to each other of the connected vehicle is provided with a connecting portion load detecting means that detects a bending load in a horizontal plane applied to the connecting portion,
Left and right wheel braking / driving force control means for the rear vehicle for controlling the left and right wheel braking / driving force of the rear vehicle so as to give a braking / driving force difference between the left and right wheels of the rear vehicle so that the bending load in the horizontal plane detected by the means is eliminated. Characterized by the configuration provided.

According to the drive control device for the rear vehicle in the connected vehicle of the present invention,
The connecting portion load detecting means detects a bending load in the horizontal plane applied to the connecting portion connecting the front vehicle and the rear vehicle adjacent to each other,
In order to have a braking / driving force difference between the left and right wheels of the rear vehicle so that this detected horizontal plane bending load is eliminated, the left and right wheel braking / driving force control means for the rear vehicle controls the left and right wheel braking / driving force of the rear vehicle, Since the rear vehicle is made to travel stably in a manner in which the bending load in the horizontal plane is not generated,
Even if all the wheels of the rear vehicle are attached to the vehicle body so that they cannot be steered, there is no disadvantage that the wheel support structure of the rear vehicle is complicated and expensive, and it is accurate for wheel steering. Thus, it is possible to improve the running stability of the rear vehicle without requiring difficult left and right wheel rotation difference control, and thus without increasing the cost associated therewith.

Hereinafter, embodiments of the present invention will be described in detail based on examples shown in the drawings.
FIG. 1 is a plan view of a connected vehicle provided with a drive control device for a rear vehicle according to an embodiment of the present invention. The connected vehicle includes a tow vehicle 1 as a front vehicle and a towed vehicle 2 as a rear vehicle. Are connected in tandem (front-rear direction).

  When connecting the towed vehicle 1 and the towed vehicle 2, a towed vehicle side connecting shaft 3 that is integrally coupled to the rear end of the towed vehicle 1 and protrudes rearward from the towed vehicle 1 is provided, and is integrally coupled to the front end of the towed vehicle 2. A towed vehicle side connecting shaft 4 that protrudes forward from the vehicle is provided, and the ends of the shafts 3 and 4 are connected to each other by a pivot pin 5 so as to be swingable in the direction indicated by the arrow around the vertical axis.

The tow vehicle 1 is a four-wheel vehicle having left and right front wheels 6L and 6R and left and right rear wheels 7L and 7R. The left and right front wheels are driven forward and backward by separate reversible driving of the left and right rear wheels 7L and 7R by electric motors 8L and 8R. It shall be steered by 6L and 6R steering.
The towed vehicle 2 is a two-wheeled vehicle having only the left and right wheels 9L and 9R, and the left and right wheels 9L and 9R are individually reversibly driven by the electric motors 10L and 10R so as to follow the towed vehicle 1. It is assumed that the vehicle travels backward.
The tow vehicle 1 and the towed vehicle 2 can individually control the driving force.

Note that the electric motors 8L and 8R of the tow vehicle 1 and the electric motors 10L and 10R of the towed vehicle 2 not only perform the above-described reversible drive, but also reduce the rotation reduction energy when reducing the reversible rotation speed of the corresponding wheel. It also has a generator function for regenerative braking that converts the power into electric power and reduces the rotation (braking). Therefore, the driving force of the left and right rear wheels 7L, 7R (traction vehicle 1) by the electric motors 8L, 8R And the driving force of the left and right wheels 9L, 9R (towed vehicle 2) by the electric motors 10L, 10R respectively means braking / driving force.

  Further, the connecting vehicle of FIG. 1 has a connecting portion for connecting the towed vehicle 1 and the towed vehicle 2 (in the figure, the towed vehicle side connecting shaft 3 may be a towed vehicle side connecting shaft 4), A vehicle connection part load sensor (strain gauge, etc.) 11 as a connection part load detection means is provided on the lower surface, whereby a horizontal plane bending load (bending moment in the horizontal plane) Lm applied to the vehicle connection part (traction vehicle side connection shaft 3) Lm And the vehicle front-back direction (axial direction) load La is detected.

  1 is based on the horizontal bending moment Lm and the axial load La applied to the towed vehicle side connecting shaft 3 detected by the sensor 11, so that the traveling stability of the towed vehicle 2 is increased. 2 includes a drive control device for a towed vehicle (rear vehicle) 2 as shown in a block diagram in FIG. 2 so as to control the braking / driving force of the left and right wheels (9L, 9R).

The drive control device includes a controller 21, and the controller 21 includes
In addition to signals related to the bending moment Lm in the horizontal plane detected by the sensor 11 and the axial load La,
A signal from a steering angle sensor 22 that detects a front wheel steering angle θ of a tow vehicle (front vehicle) 1;
A signal from the rear vehicle yaw rate sensor 23 for detecting the yaw rate φ generated in the towed vehicle (rear vehicle) 2,
A signal from the vehicle speed sensor 24 for detecting the vehicle speed VSP;
A signal from the accelerator opening sensor 25 that detects the amount of depression of the accelerator pedal (accelerator opening) APO that the driver steps on according to the driving force demand level,
A signal from the brake switch 26 that is turned on in response to braking when the brake pedal is depressed is input.

The controller 21 executes the control program shown in FIG. 3 on the basis of the above input information to obtain the target left wheel braking / driving force tTwl ′ (tTwl) and the target right wheel braking / driving force tTwr ′ (tTwr) of the towed vehicle 2 respectively. The left vehicle left wheel braking / driving force control unit 27 and the rear vehicle right wheel braking / driving force control unit corresponding to the target left wheel braking / driving force tTwl ′ (tTwl) and the target right wheel braking / driving force tTwr ′ (tTwr) Output to 28.
The rear vehicle left wheel braking / driving force control unit 27 controls the left wheel electric motor 10L so that the target left wheel braking / driving force tTwl '(tTwl) is achieved, and the rear vehicle right wheel braking / driving force control unit 28 is a target right wheel control. The right wheel electric motor 10R is controlled so that the driving force tTwr ′ (tTwr) is achieved.

3 will be described in detail. First, in step S11, whether the vehicle speed VSP is 0 (stopped), VSP> 0 (forward travel), or VSP <0 (reverse travel). Check.
If VSP = 0 (stopped), the drive control aimed by the present invention for improving the running stability of the rear vehicle 2 is unnecessary, and the control is terminated as it is.

If VSP> 0 (during forward travel), it is checked in step S12 whether or not the vehicle connecting portion bending moment Lm is generated. If it is generated, in step S13, the vehicle connecting portion bending moment Lm is checked. It is checked whether it is clockwise (clockwise) when viewed from above the vehicle, or conversely, it is counterclockwise (counterclockwise) when viewed from above the vehicle.
When it is determined in step S13 that a clockwise (clockwise) bending moment Lm is applied to the vehicle connecting portion, in step S14 corresponding to the left vehicle left and right wheel braking / driving force control means in the present invention, the rear vehicle 2 The forward drive force of the right wheel 9R is made larger than the forward drive force of the left wheel 9L.

According to the driving force difference control during the forward movement of the left and right wheels 9L and 9R, the forward traveling stability of the rear vehicle 2 can be improved as follows.
FIG. 4 (a) shows that the left wheel (left rear wheel) forward drive force Tfl and the right wheel (right rear wheel) forward drive force Tfr of the front vehicle 1 are the same, and the left vehicle forward drive force Twl and right wheel of the rear vehicle 2 are the same. The state at the time of forward straight drive with the same wheel forward drive force Twr is shown.
In the forward straight drive state, a horizontal plane bending moment does not act on the vehicle connecting portion, and the load sensor 11 provided on the vehicle connecting portion does not detect the horizontal bending moment Lm.

  From the front straight drive state of FIG. 4 (a), as a result of the front vehicle 1 turning left as shown in FIG. 4 (b), the rear vehicle 2 tries to follow the front vehicle 1 to the vehicle connecting portion from above the vehicle. When a clockwise horizontal bending moment Lm is applied, step S13 selects step S14 in response to the clockwise bending moment Lm, as described above, and as shown in FIG. 4 (b). The target forward drive force tTwr of the right wheel 9R in the rear vehicle 2 is made larger than the target forward drive force tTwl of the left wheel 9L.

The right wheel target forward driving force tTwr and the left wheel target forward driving force tTwl of the rear vehicle 2 are respectively commanded to the right wheel braking / driving force control unit 28 and the left wheel braking / driving force control unit 27 as shown in FIG. The unit controls the electric motors 10R and 10L for driving the wheels so that the driving force of the corresponding wheel of the rear vehicle 2 becomes the respective target value.
Such left and right wheel driving force difference control of the rear vehicle 2 generates a counterclockwise yaw moment on the rear vehicle 2 in FIG. 4 (b), and this yaw moment is opposite to the clockwise bending moment Lm in FIG. 4 (b). Due to the orientation, the clockwise bending moment Lm of FIG. 4 (b) acting on the vehicle connecting portion can be reduced, and the running stability of the rear vehicle 2 can be improved.

Note that when the right wheel target forward drive force tTwr of the rear vehicle 2 is made larger than the left wheel target forward drive force tTwl in step S14 in FIG. 3, the sum of the two is kept unchanged to give a drive force difference. Good to do.
In this case, the overall forward drive force of the rear vehicle 2 is kept unchanged, and the vehicle longitudinal load at the vehicle connecting portion does not change. Since the driving force of the rear vehicle 2 is determined based on the above relationship, the rear vehicle 2 can be made to travel while maintaining the vehicle longitudinal load at the vehicle connecting portion at 0 even during turning.

  If it is determined in step S13 of FIG. 3 that a counterclockwise bending moment Lm is applied to the vehicle connecting portion, in step S15 corresponding to the left and right wheel braking / driving force control means for the rear vehicle in the present invention. The forward drive force of the left wheel 9L in the rear vehicle 2 is made larger than the forward drive force of the right wheel 9R.

According to the driving force difference control during the forward movement of the left and right wheels 9L and 9R, the forward traveling stability of the rear vehicle 2 can be improved as follows.
FIG. 4 (a) shows that the left wheel (left rear wheel) forward drive force Tfl and the right wheel (right rear wheel) forward drive force Tfr of the front vehicle 1 are the same, and the left vehicle forward drive force Twl and right wheel of the rear vehicle 2 are the same. Shows the state of forward straight drive with the same wheel forward drive force Twr,
In this forward straight drive state, no bending moment in the horizontal plane acts on the vehicle connecting portion, and the load sensor 11 provided in this vehicle connecting portion does not detect the bending moment Lm in the horizontal plane.

  The forward vehicle 1 follows the forward vehicle 1 while the forward vehicle 1 is making a left turn as shown in FIG. When trying to apply a counterclockwise horizontal bending moment Lm as viewed from above the vehicle to the vehicle connecting portion, step S13 selects step S15 in response to the counterclockwise bending moment Lm, as described above. Then, as shown in FIG. 4 (c), the target forward drive force tTwl of the left wheel 9L in the rear vehicle 2 is made larger than the target forward drive force tTwr of the right wheel 9R.

The left wheel target advance driving force tTwl and the right wheel target forward drive force tTwr of the rear vehicle 2 are respectively commanded to the left wheel braking / driving force control unit 27 and the right wheel braking / driving force control unit 28 as shown in FIG. The unit controls the electric motors 10L and 10R for driving the wheels so that the driving force of the corresponding wheels of the rear vehicle 2 becomes the respective target values.
Such left and right wheel driving force difference control of the rear vehicle 2 causes the rear vehicle 2 to generate a clockwise yaw moment in FIG. 4 (c), and this yaw moment is opposite to the counterclockwise bending moment Lm in FIG. 4 (c). Since it is in the direction, the counterclockwise bending moment Lm of FIG. 4 (c) acting on the vehicle connecting portion can be reduced, and the running stability of the rear vehicle 2 can be improved.

In step S15, when the left wheel target forward drive force tTwl of the rear vehicle 2 is made larger than the right wheel target forward drive force tTwr, the sum of the two is kept unchanged so as to have a drive force difference. good.
In this case, the overall forward drive force of the rear vehicle 2 is kept unchanged, and the vehicle longitudinal load at the vehicle connecting portion does not change. Since the driving force of the rear vehicle 2 is determined based on the above relationship, the rear vehicle 2 can be made to travel while maintaining the vehicle longitudinal load at the vehicle connecting portion at 0 even during turning.

  In the above description, the case where the front vehicle 1 makes a left turn has been described. Even when the front vehicle 1 makes a right turn, the same operation and effect can be achieved by the same left / right wheel driving force difference control of the rear vehicle 2.

  In the above description, the point of improving the running stability of the rear vehicle 2 during forward drive traveling of the connected vehicle has been described. The intended purpose can be achieved in the same manner as described in (1).

FIG. 5 (a) shows that the left wheel (left rear wheel) regenerative braking force Tfl ′ and the right wheel (right rear wheel) regenerative braking force Tfr ′ of the front vehicle 1 are the same during forward traveling, and the left wheel of the rear vehicle 2 The state at the time of forward straight braking where the regenerative braking force Twl ′ and the right wheel regenerative braking force Twr ′ are the same is shown.
In such a forward straight braking state, no bending moment in the horizontal plane acts on the vehicle connecting portion, and the load sensor 11 provided on this vehicle connecting portion does not detect the bending moment Lm in the horizontal plane.

  From the front straight braking state of FIG. 5 (a), as a result of the front vehicle 1 turning left as shown in FIG. 5 (b), the rear vehicle 2 is moved to the vehicle connecting portion from the relative position change with the front vehicle 1, When a counterclockwise horizontal bending moment Lm is applied as seen from FIG. 5, step S13 selects step S15 in response to the counterclockwise bending moment Lm, as described above, and as shown in FIG. 5 (b). Thus, the target forward drive force tTwl of the left wheel 9L in the rear vehicle 2 is made larger than the target forward drive force tTwr of the right wheel 9R.

The left wheel target advance driving force tTwl and the right wheel target forward drive force tTwr of the rear vehicle 2 are respectively commanded to the left wheel braking / driving force control unit 27 and the right wheel braking / driving force control unit 28 as shown in FIG. The unit controls the electric motors 10L and 10R for driving the wheels so that the driving force of the corresponding wheels of the rear vehicle 2 becomes the respective target values.
Such left and right wheel driving force difference control of the rear vehicle 2 causes the rear vehicle 2 to generate a clockwise yaw moment in FIG. 5 (b), and this yaw moment is opposite to the counterclockwise bending moment Lm in FIG. 5 (b). Since it is in the direction, the counterclockwise bending moment Lm of FIG. 5 (b) acting on the vehicle connecting portion can be reduced, and the running stability of the rear vehicle 2 can be improved.

  By the way, when the forward braking is applied, the counterclockwise horizontal bending moment Lm acting on the vehicle connecting portion as shown in FIG. 5 (b) is reduced by the left / right (regenerative) braking force difference of the rear vehicle 2. In step S15 selected in response to the bending moment Lm, as shown in FIG. 5 (c), the target braking force tTwr ′ of the right wheel 9R in the rear vehicle 2 is made larger than the target braking force tTwl ′ of the left wheel 9L.

The right wheel target braking force tTwr ′ and the left wheel target braking force tTwl ′ of the rear vehicle 2 are respectively commanded to the right wheel braking / driving force control unit 28 and the left wheel braking / driving force control unit 27 as shown in FIG. The unit controls the electric motors 10R and 10L for driving the wheels so that the braking force of the corresponding wheels of the rear vehicle 2 becomes the respective target values.
Such control of the left and right wheel braking force difference of the rear vehicle 2 causes the rear vehicle 2 to generate a clockwise yaw moment in FIG. 5 (c), and this yaw moment is opposite to the counterclockwise bending moment Lm in FIG. 5 (c). Since it is in the direction, the counterclockwise bending moment Lm of FIG. 5 (c) acting on the vehicle connecting portion can be reduced, and the running stability of the rear vehicle 2 can be improved.

Contrary to those shown in FIGS. 5 (b) and 5 (c), when a clockwise horizontal bending moment Lm as viewed from above the vehicle acts on the vehicle connecting portion, it is selected in response to the clockwise bending moment Lm. In step S14, contrary to FIG. 5 (b), the target forward drive force tTwr of the right wheel 9R in the rear vehicle 2 is made larger than the target forward drive force tTwl of the left wheel 9L, or
Contrary to FIG. 5 (c), the target braking force tTwl ′ of the left wheel 9L in the rear vehicle 2 is made larger than the target braking force tTwr ′ of the right wheel 9R.
Such left / right wheel driving force difference control or left / right wheel braking force difference control of the rear vehicle 2 generates a counterclockwise yaw moment on the rear vehicle 2 in FIGS. 5 (b), (c) reverse to the clockwise clockwise bending moment Lm opposite to that shown in FIG. 5 (b), the clockwise bending moment Lm acting on the vehicle connecting part can be reduced, and the rear vehicle The running stability of 2 can be improved.

By repeating the above loop including step S12 to step S15, when the connected vehicle moves forward,
The left and right wheels of the rear vehicle 2 have a braking / driving force difference between the left and right wheels 9L, 9R of the rear vehicle 2 so that the bending moment Lm in the horizontal plane applied to the connecting portion between the adjacent front vehicle 1 and the rear vehicle 2 is eliminated. To control the braking / driving force,
The rear vehicle 2 can be driven in a stable manner in a manner in which the horizontal plane bending moment Lm does not occur, and the running stability of the rear vehicle 2 can be improved.
Moreover, even if all the wheels 9L, 9R of the rear vehicle 2 are attached to the vehicle body so that they cannot be steered, the wheel support structure of the rear vehicle 2 is complicated and the cost is not increased. The above-described effect of improving the running stability of the rear vehicle 2 without the need for accurate and difficult left-right wheel rotation difference control for wheel steering, and thus without the associated high cost. Can be achieved.

  If the bending moment Lm in the horizontal plane does not act on the vehicle connecting portion by repeating the above loop including Step S12 to Step S15, Step S12 selects Step S16, where the vehicle connecting portion axial load is selected. It is checked whether or not La is generated. If it is not generated, the bending moment Lm is not generated and the control according to the present invention is unnecessary, so the control is terminated as it is.

  If it is determined in step S16 that the vehicle connecting portion axial load La is generated, in step S17, the vehicle connecting portion axial load La is a tensile load greater than 0 (the rear vehicle 2 is pulled by the front vehicle 1). On the other hand, or conversely, whether the vehicle connecting portion axial load La is a compressive load smaller than 0 (a state in which the rear vehicle 2 pushes the front vehicle 1) is checked.

When it is determined in step S17 that the vehicle connecting portion axial load La is a tensile load (a state in which the rear vehicle 2 is pulled by the front vehicle 1), the control is performed on the right and left wheel braking drive force control for the rear vehicle in the present invention. Proceeding to step S18 corresponding to the means, the target driving forces tTwl and Twr of the left and right wheels 9L and 9R in the rear vehicle 2 are increased by the same predetermined amount ΔTw.
By repeating such left and right wheel driving force increase control, the axial tensile load La acting on the vehicle connecting portion is gradually reduced and finally becomes 0, and the state in which the rear vehicle 2 is pulled by the front vehicle 1 is eliminated. As a result, the running stability of the rear vehicle 2 can be improved.
Since the increase in driving force for the left and right wheels 9L and 9R is set to the same ΔTw, the braking / driving force difference set for eliminating the bending moment Lm in steps S12 to S15 is maintained, and the driving force for the left and right wheels 9L and 9R is increased. The running stability of the rear vehicle 2 is not hindered by the control.

When it is determined in step S17 that the vehicle connecting portion axial load La is a compressive load (a state in which the rear vehicle 2 pushes the front vehicle 1), the control is performed on the left and right wheel braking / driving force control means for the rear vehicle in the present invention. Then, the process proceeds to step S19, in which the target braking forces tTwl ′ and Twr ′ of the left and right wheels 9L and 9R in the rear vehicle 2 are increased by the same predetermined amount ΔTw ′.
By repeating such left and right wheel braking force increase control, the axial compression load La acting on the vehicle connecting portion is gradually reduced and finally becomes 0, and the state where the rear vehicle 2 pushes the front vehicle 1 is eliminated. As a result, the running stability of the rear vehicle 2 can be improved.
Since the increase in the braking force of the left and right wheels 9L and 9R is set to the same ΔTw ′, the braking / driving force difference set for eliminating the bending moment Lm in steps S12 to S15 is maintained, and the braking force of the left and right wheels 9L and 9R is maintained. The running stability of the rear vehicle 2 is not hindered by the increase control.

If it is determined in step S11 of FIG. 3 that VSP <0 (during reverse travel), it is checked in step S21 whether or not the vehicle connecting portion bending moment Lm has occurred. In step S22, it is checked whether the vehicle connecting portion bending moment Lm is clockwise (clockwise) when viewed from above the vehicle, or conversely, is counterclockwise (counterclockwise) when viewed from above the vehicle.
When it is determined in step S22 that a clockwise (clockwise) bending moment Lm is applied to the vehicle connecting portion, in step S23 corresponding to the rear vehicle left and right wheel braking / driving force control means in the present invention, the rear vehicle 2 The reverse drive force of the left wheel 9L is made larger than the reverse drive force of the right wheel 9R.

According to the drive force difference control during the reverse travel of the left and right wheels 9L and 9R, the backward travel stability of the rear vehicle 2 can be improved as follows.
FIG. 6 (a) shows that the left wheel (left rear wheel) reverse drive force Tfl and the right wheel (right rear wheel) reverse drive force Tfr of the front vehicle 1 are the same, and the rear wheel 2 left wheel reverse drive force Twl and right vehicle 2 The state at the time of straight forward drive after making the wheel reverse drive force Twr the same is shown.
In such a straight forward drive state, no bending moment in the horizontal plane acts on the vehicle connecting portion, and the load sensor 11 provided in this vehicle connecting portion does not detect the bending moment Lm in the horizontal plane.

  From the rear straight drive state in FIG. 6 (a), as shown in FIG. 6 (b), the left vehicle of the front vehicle 1 steers the rear vehicle 2 to the vehicle connecting portion due to the relative rotational position change with the front vehicle 1. When applying a clockwise horizontal bending moment Lm as viewed from above the vehicle, step S23 selects step S23 in response to the clockwise bending moment Lm, as described above, and as shown in FIG. As shown, the target forward drive force tTwl of the left wheel 9L in the rear vehicle 2 is made larger than the target forward drive force tTwr of the right wheel 9R.

The left wheel target advance driving force tTwl and the right wheel target forward drive force tTwr of the rear vehicle 2 are respectively commanded to the left wheel braking / driving force control unit 27 and the right wheel braking / driving force control unit 28 as shown in FIG. The unit controls the electric motors 10L and 10R for driving the wheels so that the driving force of the corresponding wheels of the rear vehicle 2 becomes the respective target values.
Such left and right wheel reverse drive force difference control of the rear vehicle 2 generates a counterclockwise yaw moment on the rear vehicle 2 in FIG. 6 (b), and this yaw moment is the clockwise bending moment Lm of FIG. 6 (b). Since the direction is opposite, the clockwise bending moment Lm of FIG. 6 (b) acting on the vehicle connecting portion can be reduced, and the running stability of the rear vehicle 2 can be improved.

When the left wheel target reverse drive force tTwl of the rear vehicle 2 is made larger than the right wheel target reverse drive force tTwr in step S23 of FIG. 3, the sum of the two is kept unchanged so as to have a drive force difference. Good to do.
In this case, the overall backward driving force of the rear vehicle 2 is kept unchanged, and the vehicle longitudinal load at the vehicle connecting portion does not change. Since the driving force of the rear vehicle 2 is determined based on the above relationship, the rear vehicle 2 can be made to travel while maintaining the vehicle longitudinal load at the vehicle connecting portion at 0 even during turning.

  If it is determined in step S22 in FIG. 3 that a bending moment Lm counterclockwise (counterclockwise) is applied to the vehicle connecting portion, as opposed to FIG. In step S24 corresponding to the force control means, contrary to FIG. 6B, the target reverse drive force tTwr of the right wheel 9R in the rear vehicle 2 is made larger than the target reverse drive force tTwl of the left wheel 9L.

  The reverse drive force difference control during the reverse movement of the left and right wheels 9L and 9R causes the rear vehicle 2 to generate a clockwise yaw moment on FIG. 6 (b), and this yaw moment is opposite to that in FIG. 6 (b). Since it is in the opposite direction to the counterclockwise bending moment Lm, the counterclockwise bending moment Lm acting on the vehicle connecting part, which is opposite to that shown in FIG. 6 (b), can be reduced, and the running stability of the rear vehicle 2 is improved. Can be.

In step S24, when the right wheel target reverse drive force tTwr of the rear vehicle 2 is made larger than the left wheel target reverse drive force tTwl, the sum of the two is kept unchanged so as to have a reverse drive force difference. Is good.
In this case, the overall forward drive force of the rear vehicle 2 is kept unchanged, and the vehicle longitudinal load at the vehicle connecting portion does not change. Since the driving force of the rear vehicle 2 is determined based on the above relationship, the rear vehicle 2 can be made to travel while maintaining the vehicle longitudinal load at the vehicle connecting portion at 0 even during turning.

  In the above description, the case where the front vehicle 1 is steered to the left has been described. Even when the front vehicle 1 is steered to the right, the same operation and effect can be achieved by the left and right wheel reverse drive force difference control of the rear vehicle 2.

By repeating the above loop including step S21 to step S24, when the connected vehicle is traveling backward,
The left and right wheels of the rear vehicle 2 have a backward driving force difference between the left and right wheels 9L and 9R of the rear vehicle 2 so that the horizontal bending moment Lm applied to the connecting portion between the adjacent front vehicle 1 and the rear vehicle 2 is eliminated. To control the reverse drive force,
The rear vehicle 2 can travel backward in a stable manner in a manner in which the bending moment Lm in the horizontal plane does not occur, and the backward traveling stability of the rear vehicle 2 can be improved.
Moreover, even if all the wheels 9L, 9R of the rear vehicle 2 are attached to the vehicle body so that they cannot be steered, the wheel support structure of the rear vehicle 2 is complicated and the cost is not increased. The above-mentioned effect of improving the backward running stability of the rear vehicle 2 without requiring accurate and difficult left / right wheel rotation difference control for wheel steering, and thus without increasing the cost associated therewith. Can be achieved.

  If the bending moment Lm in the horizontal plane does not act on the vehicle connecting portion by repeating the loop including step S21 to step S24, step S21 selects step S25, where the vehicle connecting portion axial load is selected. It is checked whether or not La is generated. If it is not generated, the bending moment Lm is not generated and the control according to the present invention is unnecessary, so the control is terminated as it is.

  When it is determined in step S25 that the vehicle connecting portion axial load La is generated, in step S26, the vehicle connecting portion axial load La is a compression load smaller than 0 (the rear vehicle 2 is pushed by the front vehicle 1). The vehicle connecting portion axial load La is a tensile load greater than 0 (a state in which the rear vehicle 2 is pulling the front vehicle 1).

When it is determined in step S26 that the vehicle connecting portion axial load La is a compressive load smaller than 0 (a state in which the rear vehicle 2 is pushed by the front vehicle 1), the control is performed on the left and right wheel control for the rear vehicle in the present invention. Proceeding to step S27 corresponding to the driving force control means, the target backward driving forces tTwl and Twr of the left and right wheels 9L and 9R in the rear vehicle 2 are increased by the same predetermined amount ΔTw.
By repeating such left and right wheel reverse drive force increase control, the axial compressive load La acting on the vehicle connecting portion is gradually reduced and finally becomes 0, and the rear vehicle 2 is pushed by the front vehicle 1. The traveling stability of the rear vehicle 2 can be improved by eliminating the state.
Since the amount of increase in the reverse drive force of the left and right wheels 9L, 9R is set to the same ΔTw, the reverse drive force difference set for eliminating the bending moment Lm in steps S21 to S24 is maintained, and the reverse drive of the left and right wheels 9L, 9R is maintained. The running stability of the rear vehicle 2 is not hindered by the force increase control.

If it is determined in step S26 that the vehicle connecting portion axial load La is a tensile load greater than 0 (a state in which the rear vehicle 2 is pulling the front vehicle 1), the control is performed on the left and right wheel control for the rear vehicle in the present invention. Proceeding to step S28 corresponding to the driving force control means, the target reverse braking force (regenerative braking force) tTwl ′, Twr ′ of the left and right wheels 9L, 9R in the rear vehicle 2 is increased by the same predetermined amount ΔTw ′.
When the left and right wheel reverse braking force increase control is repeated, the axial tensile load La acting on the vehicle connecting portion is gradually decreased and finally becomes 0, and the rear vehicle 2 is pulling the front vehicle 1. By eliminating the above, the running stability of the rear vehicle 2 can be improved.
Since the amount of increase in the reverse braking force of the left and right wheels 9L and 9R is set to the same ΔTw ′, the reverse drive force difference set for eliminating the bending moment Lm in steps S21 to S24 is maintained, and the reverse drive of the left and right wheels 9L and 9R is reversed. The running stability of the rear vehicle 2 is not hindered by the braking force increase control.

In the above description, as shown in FIG. 1, the case where the connected vehicle is configured by tandemly connecting the towed vehicle 1 and the towed vehicle 2 has been described.
Even a connected vehicle in which a number of towed vehicles are sequentially connected to the first towed vehicle 1, between the next towed vehicle 1 and the next towed vehicle, or between the towed vehicles adjacent to each other However, it is needless to say that the same operation and effect as described above can be achieved by performing the same drive control as described above for the rear vehicle.

Further, as described above, as shown in FIG. 1, the case where the towed vehicle 2 is a two-wheeled vehicle having only a pair of left and right wheels 9L, 9R has been described, but the towed vehicle 2 is a four-wheeled vehicle, It goes without saying that the idea of the present invention can be applied in the same way when driving two wheels as well as when driving four wheels.
Further, in the above-described left and right wheel braking / driving force difference control, the target yaw rate of the rear vehicle 2 to be canceled is calculated from the magnitude of the vehicle connecting portion bending moment Lm, and this and the rear vehicle 2 detected by the sensor 23 are calculated. On the basis of the deviation from the actual yaw rate φ, the magnitude of the left / right wheel braking / driving force difference per calculation cycle can be determined to make the control gain variable.

FIGS. 7 (a) and 7 (b) show a drive control device for a rear vehicle 2 according to another embodiment of the present invention. In this embodiment, in addition to performing the same drive control as described above, the rear vehicle 2 The left and right wheels 9L, 9R can be steered and suspended on the vehicle.
That is, the knuckles 12L and 12R that rotatably support the left and right wheels 9L and 9R can be swung about the kingpin axis extending in the vertical direction of the vehicle body via the suspension devices 13L and 13R, and suspended on the vehicle body. Thus, the left and right wheels 9L and 9R are supported so that the toe angle can be changed, that is, can be steered.

The knuckles 12L and 12R are connected to each other by a tie rod 14 at a position offset from the kingpin axis, whereby the knuckles 12L and 12R, and thus the left and right wheels 9L and 9R can be linked to each other to change the toe angle in the same direction. Do it like this.
In addition, a pair of springs 15L and 15R acting on the tie rod 14 in both longitudinal directions are stretched to elastically support the tie rod 14 in the neutral position in the vehicle width direction, whereby the left and right wheels 9L and 9R are normally shown in FIG. Hold in the non-steering position shown in a).

  Furthermore, the left and right wheels 9L and 9R change toe angles in the toe-out direction due to the driving reaction force accompanying the driving forces tTwl and tTwr of the left and right wheels 9L and 9R shown in FIG. The geometry of the suspension devices 13L and 13R is set so that a scrub offset is provided so that the left and right wheels 9L and 9R change the toe angle in the toe-in direction by the braking reaction force accompanying the powers tTwl 'and tTwr'.

According to the configuration of this embodiment, the relationship between tTwl> tTwr between the driving forces tTwl and tTwr of the left and right wheels 9L and 9R as shown in FIG. 4 (c) and FIG. When the toe angle changing force of the left wheel 9L with a large driving force is larger than the toe angle changing force of the right wheel 9R with a small driving force, the left and right wheels 9L, 9R are shown in the figure. Turn left as shown in 7 (b).
This left-turning further promotes the clockwise yaw rate due to the difference between the left and right wheel drive forces (tTwl> tTwr) in Fig. 4 (c) and Fig. 5 (b), and quickly eliminates the counterclockwise bending moment Lm. Thus, the effect of improving the running stability of the rear vehicle 2 can be quickly achieved.

In addition, as shown in FIG. 4 (b), when the left and right wheel driving force difference control has a relationship of tTwl <tTwr between the driving forces tTwl and tTwr of the left and right wheels 9L and 9R, the right wheel 9R having a large driving force The toe-out direction toe angle changing force is larger than the toe-out direction toe angle changing force of the left wheel 9L having a small driving force, and the left and right wheels 9L and 9R are steered to the right, contrary to FIG. 7 (b).
This right turning further promotes the counterclockwise yaw rate due to the left / right wheel driving force difference (tTwl <tTwr) in FIG. 4 (b), and quickly eliminates the clockwise bending moment Lm. The effect of improving running stability can be achieved quickly.

Further, when the relationship between the braking forces tTwl ′ and tTwr ′ of the left and right wheels 9L and 9R is given by the above-described left and right wheel braking force difference control as shown in FIG. 5C, the braking force is large. The toe-in direction toe angle changing force of the right wheel 9R is larger than the toe-in direction toe angle changing force of the left wheel 9L having a small braking force, and the left and right wheels 9L and 9R are steered to the left.
This left-turning further promotes the clockwise yaw rate due to the left / right wheel braking force difference (tTwl '<tTwr') in Fig. 5 (c), and quickly eliminates the counterclockwise bending moment Lm. The effect of improving the running stability of 2 can be quickly achieved.

In addition, as shown in FIG. 6 (b), when the left and right wheels 9L and 9R have the reverse drive force tTwl and tTwr with a relationship of tTwl> tTwr as shown in FIG. The toe-in direction toe angle changing force of 9L is larger than the toe-in direction toe angle changing force of the right wheel 9R having a small reverse driving force, and the left and right wheels 9L, 9R are steered to the right.
This right turning further promotes the counterclockwise yaw rate due to the difference between the left and right wheel reverse driving force (tTwl> tTwr) in FIG. 6 (b), and quickly eliminates the clockwise bending moment Lm. The effect of improving the running stability of the vehicle can be achieved quickly.

FIG. 8 shows a drive control device for a rear vehicle 2 according to still another embodiment of the present invention. In this embodiment,
Whereas in the above embodiment, one vehicle connecting portion load sensor 11 is provided on the upper surface (or lower surface) of the connecting shaft 3 to detect the horizontal plane bending moment Lm and the axial load La,
Vehicle connecting portion load sensors 11L and 11R (strain gauges, etc.) are provided on the left and right sides of the connecting shaft 3 (or connecting shaft 4) as viewed from above the vehicle, respectively, and the vehicle front and rear detected by the pair of sensors 11L and 11R. The bending moment in the horizontal plane is detected based on the difference in direction (axial direction) load.

  In this embodiment, the controller 21 in FIG. 2 determines whether the vehicle travels forward or backward based on the vehicle speed VSP. If the vehicle travels forward, the left and right wheels 9L, 9R in the rear vehicle 2 are determined based on the logical map shown in FIG. The forward braking / driving force is controlled, and if the vehicle is traveling backward, the backward braking / driving force of the left and right wheels 9L, 9R in the rear vehicle 2 is controlled based on the logical map shown in FIG.

The braking / driving force control during forward movement shown in FIG. 9 will be described below.
When the left load sensor 11L detects a compressive load and the right load sensor 11R also detects a compressive load, the vehicle is in a braking state. In this case, the following cases 1 to 3 exist.
case 1:
If the compressive load detected by the left load sensor 11L is the same as the compressive load detected by the right load sensor 11R, it can be regarded as a forward braking state in a straight line. In this case, the left and right wheels 9L of the rear vehicle 2 , Command the same braking force to 9R.
Case 2:
If the compressive load detected by the left load sensor 11L is larger than the compressive load detected by the right load sensor 11R, it can be regarded as a turning forward braking state in which a clockwise bending moment acts on the vehicle connection part. By commanding the left wheel braking force of the rear vehicle 2 to be greater than the right wheel braking force, thereby generating a counterclockwise yaw rate in the rear vehicle 2 and reducing the clockwise bending moment of the vehicle connecting portion, The running stability of the vehicle 2 can be improved.
Case 3:
If the compression load detected by the left load sensor 11L is smaller than the compression load detected by the right load sensor 11R, it can be regarded as a turning forward braking state in which a counterclockwise bending moment acts on the vehicle connection part. By instructing the right wheel braking force of the rear vehicle 2 to be greater than the left wheel braking force, thereby generating a clockwise yaw rate in the rear vehicle 2 and reducing the counterclockwise bending moment of the vehicle connecting portion, The running stability of the vehicle 2 can be improved.

When the left load sensor 11L detects a tensile load and the right load sensor 11R also detects a tensile load, the vehicle is in a driving state. In this case, the following cases 1 to 3 exist.
case 1:
If the tensile load detected by the left load sensor 11L and the tensile load detected by the right load sensor 11R are the same, it can be regarded as a forward drive state in a straight drive. In this case, the left and right wheels 9L of the rear vehicle 2 , Command the same driving force to 9R.
Case 2:
If the tensile load detected by the left load sensor 11L is larger than the tensile load detected by the right load sensor 11R, it can be regarded as a turning forward drive state in which a counterclockwise bending moment acts on the vehicle connection part. By commanding the left wheel driving force of the rear vehicle 2 to be greater than the right wheel driving force, this causes the rear vehicle 2 to generate a clockwise yaw rate, thereby reducing the counterclockwise bending moment of the vehicle connecting portion, The running stability of the vehicle 2 can be improved.
Case 3:
If the tensile load detected by the right load sensor 11R is larger than the tensile load detected by the left load sensor 11L, it can be regarded as a turning forward drive state in which a clockwise bending moment acts on the vehicle connection part. By instructing the right wheel driving force of the rear vehicle 2 to be larger than the left wheel driving force, thereby generating a counterclockwise yaw rate in the rear vehicle 2 and reducing the clockwise bending moment of the vehicle connecting portion, The running stability of the vehicle 2 can be improved.

  When the left side load sensor 11L detects a compressive load and the right side load sensor 11R detects a tensile load, it is a forward turning drive state of the vehicle in which a clockwise bending moment acts on the vehicle connecting portion. Command to make the right wheel driving force of 2 larger than the left wheel driving force, thereby generating a counterclockwise yaw rate in the rear vehicle 2 and reducing the clockwise bending moment of the vehicle connecting portion, thereby reducing the rear vehicle 2 The running stability of the vehicle can be improved.

  When the left load sensor 11L detects a tensile load and the right load sensor 11R detects a compressive load, it is a forward turning drive state of the vehicle in which a counterclockwise bending moment acts on the vehicle connecting portion. Command to make the left wheel driving force of 2 greater than the right wheel driving force, thereby generating a clockwise yaw rate in the rear vehicle 2 and reducing the counterclockwise bending moment of the vehicle connecting portion, thereby reducing the rear vehicle 2 The running stability of the vehicle can be improved.

Next, the braking / driving force control during reverse travel shown in FIG. 10 will be described below.
When the left load sensor 11L detects a compressive load and the right load sensor 11R also detects a compressive load, the vehicle is in a driving state. In this case, the following cases 1 to 3 exist.
case 1:
If the compressive load detected by the left load sensor 11L and the compressive load detected by the right load sensor 11R are the same, it can be regarded as a straight drive reverse drive state. In this case, the left and right wheels 9L of the rear vehicle 2 , Command the same driving force to 9R.
Case 2:
If the compressive load detected by the left load sensor 11L is larger than the compressive load detected by the right load sensor 11R, it can be regarded as a reverse turning drive state in which a clockwise bending moment acts on the vehicle connection part. By commanding the rear wheel 2 backward driving force to be greater than the right wheel backward driving force, this causes the backward vehicle 2 to generate a counterclockwise yaw rate, thereby reducing the clockwise bending moment of the vehicle connection part. In addition, the running stability of the rear vehicle 2 can be improved.
Case 3:
If the compressive load detected by the left load sensor 11L is smaller than the compressive load detected by the right load sensor 11R, it can be regarded as a reverse turning drive state in which a counterclockwise bending moment acts on the vehicle connection part. By commanding the right wheel backward drive force of the rear vehicle 2 to be larger than the left wheel reverse drive force, this causes the backward vehicle 2 to generate a clockwise yaw rate, thereby reducing the counterclockwise bending moment of the vehicle connecting portion. In addition, the running stability of the rear vehicle 2 can be improved.

If the left load sensor 11L detects a tensile load and the right load sensor 11R also detects a tensile load, the vehicle is in a reverse braking state. In this case, the following cases 1 to 3 exist.
case 1:
If the tensile load detected by the left-side load sensor 11L is the same as the tensile load detected by the right-side load sensor 11R, it can be regarded as a straight reverse drive braking state. In this case, the left and right wheels 9L of the rear vehicle 2 , Command the same braking force to 9R.
Case 2:
If the tensile load detected by the left load sensor 11L is larger than the tensile load detected by the right load sensor 11R, it can be regarded as a reverse turning braking state in which a counterclockwise bending moment acts on the vehicle connection part. By instructing the backward braking force of the rear vehicle 2 to be greater than the backward braking force of the left wheel, this causes the backward vehicle 2 to generate a clockwise yaw rate, thereby reducing the counterclockwise bending moment of the vehicle connection part. In addition, the running stability of the rear vehicle 2 can be improved.
Case 3:
If the tensile load detected by the right load sensor 11R is greater than the tensile load detected by the left load sensor 11L, it can be regarded as a reverse-turning braking state in which a clockwise bending moment acts on the vehicle connection part. By commanding the backward braking force of the rear wheel 2 to be greater than the backward braking force of the right wheel, this causes the backward vehicle 2 to generate a counterclockwise yaw rate, thereby reducing the clockwise bending moment of the vehicle connection part. In addition, the running stability of the rear vehicle 2 can be improved.

  When the left side load sensor 11L detects a compressive load and the right side load sensor 11R detects a tensile load, the vehicle is in a reverse turning drive state in which a clockwise bending moment acts on the vehicle connecting portion. Command to make the left wheel reverse drive force of 2 greater than the right wheel reverse drive force, thereby generating a counterclockwise yaw rate in the rear vehicle 2 and reducing the clockwise bending moment of the vehicle connecting portion, thereby The running stability of the vehicle 2 can be improved.

  When the left side load sensor 11L detects a tensile load and the right side load sensor 11R detects a compressive load, the vehicle is in a reverse turning drive state in which a counterclockwise bending moment acts on the vehicle connecting portion. Command to make the right wheel reverse drive force of 2 larger than the left wheel reverse drive force, thereby generating a clockwise yaw rate in the rear vehicle 2 and reducing the counterclockwise bending moment of the vehicle connecting part, The running stability of the vehicle 2 can be improved.

As is clear from the above description, also in the embodiments shown in FIGS. 8 to 10, when the connected vehicle moves forward and backward,
The left and right wheels of the rear vehicle 2 are controlled so that there is a braking / driving force difference between the left and right wheels 9L and 9R of the rear vehicle 2 so that the bending moment in the horizontal plane applied to the connecting portion between the adjacent front vehicle 1 and the rear vehicle 2 is eliminated. To control the driving force,
The rear vehicle 2 can be driven in a stable manner in a manner in which no bending moment in the horizontal plane is generated, and the running stability of the rear vehicle 2 can be improved.
Moreover, even if all the wheels 9L, 9R of the rear vehicle 2 are attached to the vehicle body so that they cannot be steered, the wheel support structure of the rear vehicle 2 is complicated and the cost is not increased. The above-described effect of improving the running stability of the rear vehicle 2 without the need for accurate and difficult left-right wheel rotation difference control for wheel steering, and thus without the associated high cost. Can be achieved.

In each of the above embodiments, the straight traveling stability of the rear vehicle 2 is improved by the left / right wheel braking / driving force difference control of the rear vehicle 2, but the right / left wheel braking / driving force difference control of the rear vehicle 2 and the front The straight running stability of the rear vehicle 2 can be improved by combining with the left / right wheel braking / driving force difference control of the vehicle 1.
In addition, since the left and right wheel braking / driving force difference control of the front vehicle 1 is not necessarily required, it is not always necessary to be able to individually control the braking / driving force of the left and right wheels of the front vehicle 1 as in the above embodiments.

11 (a) and 11 (b), as described above with reference to FIGS. 7 (a) and 7 (b), the left and right wheels 9L and 9R of the rear vehicle 2 can be steered and suspended on the vehicle. A scrub offset opposite to that in the cases of a) and (b) is given.
In other words, the knuckles 12L and 12R that rotatably support the left and right wheels 9L and 9R of the rear vehicle 2 can be swung about the kingpin axis extending in the vertical direction of the vehicle body via the suspension devices 13L and 13R and suspended on the vehicle body. Thus, the left and right wheels 9L and 9R are supported so that the toe angle can be changed, that is, the vehicle can be steered.

The knuckles 12L and 12R are connected to each other by a tie rod 14 at a position offset from the kingpin axis, whereby the knuckles 12L and 12R, and thus the left and right wheels 9L and 9R can be linked to each other to change the toe angle in the same direction. Do it like this.
In addition, a pair of springs 15L, 15R acting in both the longitudinal directions of the tie rod 14 are stretched to elastically support the tie rod 14 at the neutral position in the vehicle width direction, whereby the left and right wheels 9L, 9R are normally shown in FIG. Hold in the non-steering position shown in a).

  Further, the left and right wheels 9L and 9R change toe-in in the toe-in direction due to the drive reaction force accompanying the forward drive forces Twl and Twr of the left and right wheels 9L and 9R shown in FIGS. 11 (a) and 11 (b). A scrub offset is applied so that the left and right wheels 9L and 9R change toe angles in the toe-out direction by the braking reaction force accompanying the forward braking forces tTwl 'and tTwr' of the left and right wheels 9L and 9R shown in (a) and (b). Therefore, the geometry of the suspension devices 13L and 13R is set.

According to the left and right wheel suspension devices 13L and 13R of the rear vehicle 2, the following operational effects can be obtained.
FIG. 11 (a) shows a state in which the left and right wheels 9L, 9R of the rear vehicle 2 are driven forward on the road surface having the same friction coefficient μ, and in this case, since the road surface μ is the same, The left and right wheels 9L and 9R generate the same forward driving force Twl and Twr.
Therefore, the toe-in direction toe angle changing force of the left and right wheels 9L and 9R due to the driving reaction force associated with the forward driving force Twl and Twr is the same, and the left and right wheels 9L and 9R are caused by the mutually opposite spring forces of the springs 15L and 15R, respectively. The non-steering neutral position shown in FIG. 11 (a) is maintained.

By the way, as shown in FIG. 12 (a), the left wheel 9L rides on a low μ road such as an icy road with a relatively low friction coefficient, so that the left and right wheels 9L, 9R are on the road surface with different friction coefficients μ. If the vehicle is to be driven forward (during left / right split μ), the left wheel forward drive as shown in FIGS. 11 (b) and 12 (a) due to the left wheel road surface μ <the right wheel road surface μ. Force Twl <right wheel forward drive force Twr.
This difference between the left and right wheel forward drive forces causes the rear vehicle 2 traveling straight ahead to try to yaw in the same direction by a counterclockwise yaw moment indicated by α in FIG. 12A when viewed from above the vehicle.
This yaw movement impairs the straight running stability of the rear vehicle 2 and should be avoided as much as possible.

Therefore, according to the configuration of FIG. 11 (a), during the left-right split μ traveling, the toe-in toe angle of the right wheel 9R having a large forward driving force because the left wheel forward driving force Twl <the right wheel forward driving force Twr. The changing force is larger than the toe-in direction toe angle changing force of the left wheel 9L having a small forward driving force, and the left and right wheels 9L and 9R are steered to the left as shown in FIG. 12 (b).
The left turning shown in FIG. 12 (b) of the left and right wheels 9L, 9R generates a clockwise yaw moment as indicated by β in the rear vehicle 2, and this yaw moment β is the above-mentioned counterclockwise yaw moment α. To prevent the rear vehicle 2 from yawing in the same direction due to the counterclockwise yaw moment α, and to improve the straight traveling stability of the rear vehicle 2 during forward drive in the left-right split μ. it can.

  On the contrary, the right wheel 9R rides on a low μ road such as an icy road with a relatively low friction coefficient, so the left and right wheels 9L and 9R are driven forward with the friction coefficient μ on the road surface. Even during forward drive traveling in the left and right split μ, the rightward traveling stability of the rear vehicle 2 can be improved by the right turning of the left and right wheels 9L and 9R based on the same principle as described above.

FIGS. 13 (a) and 13 (b) show a state in which the vehicle is performing forward braking on the left and right split μ road, and the left wheel 9L is low μ like a frozen road with a relatively low friction coefficient as shown in the figure. If the left and right wheels 9L and 9R are to be braked forward while riding on the road surface with different friction coefficients μ because they are on the road, the left wheel road surface μ <the right wheel road surface μ As shown in a) and (b), the left wheel forward braking force Twl '<the right wheel forward braking force Twr.
The left and right wheel forward braking force difference causes the rear vehicle 2 traveling straight ahead to try to yaw in the same direction by a clockwise yaw moment indicated by γ in FIG. 13 (a) when viewed from above the vehicle.

Thus, according to the configuration of FIG. 11 (a), during left / right split μ travel, the toe-out direction toe of the right wheel 9R having a large forward braking force is satisfied because the left wheel forward braking force Twl ′ <the right wheel forward driving force Twr ′. The angle change force is larger than the toe-out direction toe angle change force of the left wheel 9L with a small forward braking force, and the left and right wheels 9L, 9R are steered to the right as shown in FIG. 13 (b).
The right steering shown in FIG. 13 (b) of the left and right wheels 9L and 9R generates a counterclockwise yaw moment as indicated by δ in the rear vehicle 2, and this yaw moment δ is the clockwise yaw moment γ described above. To prevent the rear vehicle 2 from yawing in the same direction due to the clockwise yaw moment γ, and to improve the straight traveling stability of the rear vehicle 2 during forward braking traveling in the left-right split μ. it can.

  On the contrary, the right wheel 9R rides on a low μ road such as an icy road with a relatively low friction coefficient, so the left and right wheels 9L and 9R are driven forward with the friction coefficient μ on the road surface. Even during forward braking traveling in the left-right split μ, the left-side steering of the left and right wheels 9L and 9R based on the same principle as described above can improve the straight traveling stability of the rear vehicle 2.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic plan view showing an outline of a connected vehicle provided with a rear vehicle drive control device according to an embodiment of the present invention when viewed from above the vehicle. It is a block diagram which shows the drive control apparatus of the back vehicle provided in the connection vehicle. It is a flowchart which shows the drive control program of the back vehicle which the controller in a drive control apparatus performs. FIG. 2 is a diagrammatic plan view showing a state in which the coupled vehicle of FIG. 1 is traveling forward, (a) is a diagrammatic plan view when the coupled vehicle is traveling straight, and (b) is a coupled plan view. (C) is a diagrammatic plan view when the vehicle is turning counterclockwise and a clockwise bending moment is applied to the vehicle connection part. (C) is a left-hand bending of the vehicle connection part when the connected vehicle is turning left. It is a diagrammatic plan view when a moment acts. FIG. 2 is a diagrammatic plan view showing a state in which the coupled vehicle of FIG. 1 is traveling forwardly, (a) is a diagrammatic plan view when the coupled vehicle is traveling straight, and (b) is a coupled plan view. (C) is a diagrammatic plan view when the vehicle is turning counterclockwise and a clockwise bending moment is applied to the vehicle connection part. (C) is a left-hand bending of the vehicle connection part when the connected vehicle is turning left. It is a diagrammatic plan view when a moment acts. FIG. 2 is a diagrammatic plan view showing a state in which the coupled vehicle of FIG. 1 is driven in reverse drive, in which (a) is a diagrammatic plan view when the coupled vehicle is traveling straight, and (b) is a coupled plan view. FIG. 5 is a diagrammatic plan view when the vehicle is turning left and a clockwise bending moment acts on the vehicle connecting portion. FIG. 6 is a schematic plan view showing an outline of a rear vehicle provided with a drive control device according to another embodiment of the present invention when viewed from above the vehicle, in which (a) is a case where the vehicle is driven to drive straight forward. (B) is a diagrammatic plan view when the vehicle is driven to turn forward. FIG. 6 is a schematic plan view showing an outline of a connected vehicle including a rear vehicle drive control device according to still another embodiment of the present invention when viewed from above the vehicle. It is a control logic diagram of the left and right wheel braking / driving force difference control of the rear vehicle executed by the controller of the rear vehicle drive control device in the same embodiment during forward traveling. It is a control logic diagram of the left and right wheel braking / driving force difference control of the rear vehicle, which is executed by the controller of the rear vehicle drive control device in the same embodiment during reverse travel. FIG. 9 is a diagrammatic plan view showing another example of the configuration of a rear vehicle that forms a connected vehicle, as viewed from above the vehicle; (a) shows the rear vehicle moving forward when the left and right wheels are on the road surface having the same coefficient of friction. (B) is a diagrammatic plan view showing a rear vehicle in a forward drive state when the left and right wheels are riding on road surfaces having different friction coefficients. FIG. 11 is a diagrammatic plan view of the rear vehicle in FIG. 11 when the left wheel is on a road surface with a low coefficient of friction during straight forward driving. (B) shows the difference between the left and right wheel forward drive force generated when the left wheel of the rear vehicle rides on the road surface with a low coefficient of friction. It is a diagrammatic top view showing the steering state of the accompanying left and right wheels. FIG. 11 is a diagrammatic plan view of the rear vehicle in FIG. 11 in a state where the left wheel rides on a road surface with a low friction coefficient during front straight braking, and (a) shows the left wheel of the rear vehicle on a road surface with a low friction coefficient. (B) shows the difference between left and right wheel forward braking force generated when the left wheel of the rear vehicle rides on a road surface with a low friction coefficient. It is a diagrammatic top view showing the steering state of the accompanying left and right wheels.

Explanation of symbols

1 Towing vehicle (front vehicle)
2 Towed vehicle (rear vehicle)
3 Towing vehicle side connecting shaft (vehicle connecting part)
4 Towed vehicle side connecting shaft (vehicle connecting part)
5 Pivot pin
6L front left wheel
6R front right wheel
7L left rear wheel
7R Right rear wheel
8L electric motor
8R electric motor
9L, 9R Left and right wheels for towed vehicles
10L, 10R electric motor
11 Vehicle connection load sensor (connection load detection means)
11L, 11R Vehicle connection load sensor (connection load detection means)
12L, 12R knuckle
13L, 13R suspension system
14 Tie rod
15L, 15R Spring

Claims (5)

In a connected vehicle formed by connecting a plurality of vehicles capable of individually controlling braking / driving force in tandem,
A connecting portion that connects the front vehicle and the rear vehicle that are adjacent to each other of the connected vehicle is provided with a connecting portion load detecting means that detects a bending load in a horizontal plane applied to the connecting portion,
Left and right wheel braking / driving force control means for the rear vehicle for controlling the left and right wheel braking / driving force of the rear vehicle so as to give a braking / driving force difference between the left and right wheels of the rear vehicle so that the bending load in the horizontal plane detected by the means is eliminated. A drive control device for a rear vehicle in a connected vehicle, characterized in that it is provided. The driving force control device for a rear vehicle in the coupled vehicle according to claim 1,
The connecting portion load detecting means includes a pair of vehicle longitudinal load detection sensors provided on both sides in the vehicle width direction of the connecting portion as viewed from above the vehicle, and the vehicle longitudinal load detected by the pair of sensors. A drive control device for a rear vehicle in a connected vehicle, wherein the horizontal bending load is detected based on a difference. The driving force control device for a rear vehicle in a connected vehicle according to claim 1 or 2,
The left and right wheel braking / driving force control means for the rear vehicle keeps the sum of the left and right wheel braking / driving forces unchanged when providing a braking / driving force difference between the left and right wheels of the rear vehicle so as to eliminate the bending load in the horizontal plane. The drive control device for the rear vehicle in the connected vehicle is characterized in that the left and right wheel braking / driving force of the rear vehicle is controlled so as to give the difference between the left and right wheel braking / driving force. In the driving force control device for the rear vehicle in the connected vehicle according to any one of claims 1 to 3,
The connecting portion load detecting means detects a vehicle longitudinal load in addition to the horizontal plane bending load,
The rear vehicle left / right wheel braking / driving force control means is configured to increase / decrease the left / right wheel braking / driving force of the rear vehicle equally so that the vehicle longitudinal load is eliminated. apparatus. In the driving force control device for the rear vehicle in the connected vehicle according to any one of claims 1 to 4,
The left and right wheels of the rear vehicle can be steered and suspended on the vehicle, and the left and right wheels are linked to each other so as to be steered in the same direction and elastically supported at a non-steer position.
A rear vehicle in a connected vehicle, wherein the left and right wheels of the rear vehicle are steered in a direction to eliminate the bending load in the horizontal plane in response to the braking / driving force difference. Drive control device.

Images