JPH08272444A - Retreat controllable tractive vehicle - Google Patents

Abstract

PURPOSE: To provide the tractive vehicle capable of automatically and steadily controlling the direction of a vehicle to be towed when going backwards. CONSTITUTION: A tractor 1 consists of a self-travelling tractor 1, connection arm 3 which connects a vehicle 2 to be towed by the tractor 1 and it, actuator 8 provided between the arm 3 and the tractor 1, backward controller for the actuator 8, the 1st angle sensor 6 which detects the angle between the tractor 1 and the arm 3, and the 2nd angle sensor 7 which detects the angle between the arm 3 and the vehicle 2. When the vehicles go backwards, the backward controller which is operated according to the angle signals from the 1st and the 2nd angle sensors 6 and 7, the steering control amount and the radius of turn at the time of going backwards controls the actuator 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a towed vehicle, and more particularly to a towed vehicle capable of reverse control capable of automatically controlling the direction of a towed vehicle during reverse.

[0002]

2. Description of the Related Art A tow vehicle in which a towed vehicle is connected to a rear portion is known. Such towed vehicles include trailer trucks and electric vehicles for premises, but the backward stability of the towed vehicle is inferior in stability, so it requires skill to operate in reverse. There is.

Further, an automatically controlled vehicle that automatically travels on a predetermined running path is used for an automated guided vehicle in a factory, a durability running test, or the like. Such an autopiloted vehicle, for example, has a guide line laid on the track and performs steering, acceleration, and deceleration along the guide line while detecting the position of the guide line by a magnetic field sensor provided on the vehicle. Perform automatic driving. As such an autopilot vehicle, there is known a type of a passive vehicle that is being towed, that is, a type in which a vehicle that does not have power for self-driving and that travels depending on the power of the tow vehicle is connected to the rear. ing. However, when such a towed vehicle is used, only forward traveling can be performed automatically. In other words, reverse driving by automatic driving is impossible because the towed vehicle is pushed by the towed vehicle, and it is difficult to control the direction thereof.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a towing vehicle capable of stably and automatically controlling the direction of the towed vehicle during reverse travel in view of the above-mentioned prior art.

[0005]

SUMMARY OF THE INVENTION The present invention is directed to a self-propelled towing vehicle, a connecting arm for connecting the towed vehicle towed by the towing vehicle and the self-propelled towing vehicle, the connecting arm and the towing vehicle. An actuator provided between the towing vehicle, a reverse control device for the actuator, a first angle sensor for detecting an angle between the towing vehicle and the connecting arm, the connecting arm and the towed vehicle A tow vehicle including a second angle sensor for detecting an angle between the tow vehicle and the tow vehicle, the tow vehicle having a drive power source and a steering mechanism, the connecting arm including the tow vehicle and the towed vehicle. On each side of the towing vehicle, it is mounted rotatably in the horizontal direction, the actuator being capable of driving the connecting arm to the left and right in a horizontal plane, only when retracting, The first one Retraction controllable towing vehicle and controlling the actuator by the retraction control device which operates in accordance with the turning radius at the time of backward and beauty angle signal and the steering operation amount from the second angle sensor.

The vehicle that can be used as the towing vehicle according to the present invention is not particularly limited as long as it is a vehicle that can be driven by a general internal combustion engine, an electric vehicle, or the like and can move backward. Either unmanned driving or manned driving may be used. However, it is essential to have a controllable steering mechanism. Therefore, a vehicle that does not have a steering mechanism and simply travels on or in a predetermined track is not the subject of the present invention.

As the towed vehicle connected to the towing vehicle according to the present invention, one in which the front wheels connected to the towing vehicle are casters and the rear wheels have a fixed axle can be used. This towed vehicle does not require a self-propelled power source and drive. Further, although there is a mechanism for connecting the connecting arm in front of the towed vehicle, any mechanism may be used as long as it allows reliable mechanical connection.

The connecting arm may be of any type as long as it has sufficient rigidity to withstand the towing load of the towed vehicle. Further, it is generally preferable that the connecting arm has a structure that can be detached from both the tow vehicle and the towed vehicle, but it may be one that cannot be detached from the tow vehicle or the towed vehicle.

The actuator used in the present invention may be any actuator as long as it can apply a force in the horizontal direction to the connecting arm, and its specific structure and the nature of the power source are arbitrary depending on various conditions such as the characteristics of the towing vehicle. It can be determined according to, and is not particularly limited. As an example of the actuator, a type driven by a motor, or a type driven by air pressure or hydraulic pressure can be used. For example, if the ball screw is driven by an electric motor, the servo motor, or the towing vehicle has a pump serving as a hydraulic or pneumatic pressure source, a cylinder actuator can be used.

As the angle sensor which can be used in the present invention, for example, a potentiometer can be mentioned, but other suitable transducers other than the potentiometer can also be used. The angle sensor is preferably attached to the towing vehicle and the connecting arm. This angle sensor can be attached to the towed vehicle, but in that case, a mechanism for transmitting a signal from the angle sensor on the towed vehicle side to the towed vehicle is required.
The signal from the sensor on the articulated arm or towed vehicle is
It can be transmitted to a control circuit in the towing vehicle.

A general analog feedback control circuit (servo system) can be preferably used as the reverse control device. However, if necessary, it is possible to use a digital control circuit or a microcomputer.

[0012]

The towing vehicle of the present invention can be self-propelled by connecting the towed vehicle to the rear portion thereof. During normal forward traveling, the actuator is off and exerts no force on the connecting arm. Therefore, the towed vehicle moves forward together with the movement of the towed vehicle.

When attempting to move the towing vehicle backward,
The actuator and the reverse control that controls this actuator are turned on. The reverse control device receives the steering operation amount, the target value based on the turning radius, and the signals from the first angle sensor and the second angle sensor,
By operating the actuator so that the towed vehicle does not operate abnormally such as a jack knife-like,
Controls the state of the connecting arm. By controlling the connecting arm, the movement of the towed vehicle is automatically controlled. Therefore, it is possible to automatically avoid a situation in which the towed vehicle makes an abnormal movement during the backward movement, which makes the backward movement impossible or impairs safety.

[0014]

FIG. 1 is a perspective view of an overall image of a towing vehicle according to an embodiment of the present invention. Here, a case of an automatic driving vehicle for a premises will be described as an example. In the towing vehicle of this embodiment, the towing vehicle 1 and the towed vehicle (trailer) 2
There is a connecting arm 3. The connecting arm 3 is connected to both vehicles 1 and 2 by connecting portions 4 and 5 on the towing vehicle 1 side and the towed vehicle 2 side which are configured to be freely rotatable in the horizontal direction. The connection parts 4 and 5 are pin-bonded. Sensors 6 and 7 for detecting an angle α between the towing vehicle 1 and the connecting arm 3 and an angle β between the connecting arm 3 and the towed vehicle 3 are provided at the connecting portions 4 and 5.
Are provided respectively. That is, the sensor 6 is
The angle α between the towing vehicle 1 and the connecting arm 3 can be detected,
The sensor 7 can detect the angle β between the connecting arm 3 and the towed vehicle 2. The sensors 6 and 7 can be configured by using, for example, a potentiometer, and the sensor 6 can be an actuator 8 described below in which an operation amount detecting means is incorporated.

Further, an actuator 8 is provided between the connecting arm 3 and the towing vehicle 1. By driving the actuator 8, the horizontal angle α of the connecting arm 3 with respect to the towing vehicle 1 can be changed.

FIG. 1 further shows the angles α and β mentioned above.
Shows how is defined. The angle α is
The angle between the centerline of the towing vehicle 1 and the centerline of the connecting arm 3 is defined, and the angle β is defined as the angle between the centerline of the connecting arm 3 and the centerline of the towing vehicle 1.

FIG. 2 is a control block diagram of an actuator 8 for driving the connecting arm 3 left and right in the horizontal direction. A servo mechanism for the actuator 8 is configured by the control shown in this control block diagram. This control is performed only in reverse. When moving forward,
The actuator 8 is turned off and exerts no force on the connecting arm 3.

In FIG. 2, the target value is 0 in the case of backward straight travel, and in the case of a curve, the target value is determined according to the set turning radius. In addition, the gain adjuster, depending on the input steering operation angle,
It functions to adjust the feedback gain of the signal from the sensor 6. The controller can be designed so that optimum control can be performed according to various conditions such as the size and weight of the towed vehicle and the length of the connecting arm.

A specific control method will be described with reference to FIG.
FIG. 3 is a plan view of the towing vehicle 1 and the towed vehicle 2 as seen from directly above. The towed vehicle 2 is connected to the rear of the towed vehicle 1 (downward in the drawing).

First, as shown in FIG. 3 (A), it is assumed that the towing vehicle 1, the connecting arm 3 and the towed vehicle 2 are located on a straight line and are receding straight downwards in the figure. In this case, the angle signals of the sensors 6 and 7 show 0. The towing vehicle 1 and the towed vehicle move backward while the connecting arm 3 of the actuator 8 is fixed as it is while the linear state is maintained.

However, as shown in FIG. 3B, when the towed vehicle 2 is displaced to the right in the traveling direction for some reason, or the towed vehicle 1 is traveling in the traveling direction (backward). When the direction is changed to the left by changing the direction to the left, the angle β between the connecting arm 3 and the towed vehicle 2 measured by the sensor 7 changes from zero. The actuator 8 operates according to the angle value β1 from the sensor 7, and operates the connecting arm 3 in a direction in which the towed vehicle 2 deviates from the towing vehicle 1. This operation is performed until the signal of the sensor 7 becomes zero. That is, as shown in (C) of FIG. 3, the connecting arm 3 is moved by the actuator 8 until the connecting arm 3 and the towed vehicle 2 become a straight line. However, if left as it is, the towed vehicle 2 shifts to the right side with respect to the traveling direction (downward in the drawing), so that it is necessary to drive the connecting arm 3 further to the right. Therefore, the sensor 6
Angle α between the towing vehicle 1 and the connecting arm 3 detected by
The signal corresponding to is added to the target value shown in FIG.
As a result, the actuator 8 further operates and drives the connecting arm 3. As a result, the positional relationship between the towing vehicle 1 and the towed vehicle 2 is as shown in FIG. In this figure, the angle α needs to be larger than the angle β in order for the towed vehicle 2 to also travel in the traveling direction of the towed vehicle 1. The difference between the angle α and the angle β differs depending on whether the towing vehicle 1 is traveling straight ahead or is turning, and also depending on the traveling speed, and when the towing vehicle 1 is traveling or the traveling speed is high. Requires a larger angle difference. In order to control the angle difference, the signal from the sensor 6 may be amplified by the gain adjuster shown in FIG. 2 according to the steering operation amount (steering angle) of the towing vehicle and the traveling speed. Here, as the gain adjuster, one that acts as an amplifier can be used.

As described above, the towed vehicle 2 becomes the towed vehicle 1
The traveling direction is controlled according to the backward traveling direction of.

[0023]

As described in detail above, according to the present invention, the movement of the towed vehicle can be automatically controlled even when the towed vehicle coupled with the towed vehicle is moved backward.
The towing vehicle that is being automatically driven can be moved backward, and the movement of the towed vehicle can be automatically controlled when manned driving, so safe operation is possible without depending on the skill of the driver. Becomes Further, according to the present invention, it is possible to easily control using a general servo controller without using a microcomputer or the like.

[Brief description of drawings]

FIG. 1 is a perspective view showing a towing vehicle and a towed vehicle connected thereto according to an embodiment of the present invention.

FIG. 2 is a block diagram of a feedback backward control circuit according to an embodiment of the present invention.

FIG. 3 is a schematic plan view showing the positional relationship between the towing vehicle and the towed vehicle for showing the control status of the embodiment of the present invention.

[Explanation of symbols]

 1 Towing vehicle 2 Towed vehicle 3 Connection arm 4, 5 Connection part 6, 7 Sensor 8 Actuator

Claims (1)

[Claims] 1. A self-propelled towing vehicle, a connecting arm for connecting the towed vehicle towed by the towing vehicle and the self-propelled towing vehicle, and provided between the connecting arm and the towing vehicle. An actuator, a reverse control device for the actuator, a first angle sensor for detecting an angle between the towing vehicle and the connecting arm, and a first angle sensor for detecting an angle between the connecting arm and the towed vehicle. A towing vehicle comprising a two-angle sensor, the towing vehicle having a drive power source and a steering mechanism, wherein the connecting arm is provided on each side of the towing vehicle and the towed vehicle. The actuator is mounted so as to be rotatable in the horizontal direction, and the actuator is capable of driving the connecting arm to the left and right in a horizontal plane. Only when the actuator retracts, the first and second angle sensors are moved. from A reversing-controllable towing vehicle characterized in that the actuator is controlled by the reversing control device that operates according to an angle signal, a steering operation amount, and a turning radius when reversing.