JP3143802B2 - Posture control method for unmanned towing vehicle for wagon vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling the position of an unmanned towing vehicle which is driven under a hand truck (hereinafter referred to as a "wagon vehicle") to tow the wagon vehicle.

[0002]

2. Description of the Related Art FIGS. 3 to 5 show an example of a wagon truck used for delivering parts at a factory or serving food at a hospital. This type of wagon truck 10 has four free wheels 11. Then, as shown in FIG. 6, the bottom plate 12 is provided with a connecting portion 13 having a pin receiving hole 14 opening toward the traveling road surface FL of a factory or a hospital. Reference numeral 15 denotes a grip.

[0003] Reference numeral 20 denotes an unmanned towing vehicle having a low vehicle height, which has drive wheels 21 having steering shafts at the front and rear, and guide wires (magnetic tape, optical tape, etc.) 22 on the floor of a factory or hospital. Guide sensor 23 for detecting, this guide sensor 2
Control device 2 for controlling the steering angle and the rotation speed of the steering / driving wheels 21 by taking in the output of the motor 3 and the output of a mark sensor (not shown) for reading various control marks on the road surface FL.
4 is mounted, and a predetermined program is executed based on a command input to repeatedly run and stop from the destination to the destination. As shown in FIG. 6, the unmanned towing vehicle 20 has a pin 26 projecting vertically from the top plate 25 of the vehicle body cover and a pin which engages with the projecting pin 26 and a rack and pinion to drive up and down a predetermined distance. It has a drive unit 27. Reference numeral 28 denotes an optical position sensor. When the unmanned towing vehicle 20 travels to a position where the protruding pin 26 is vertically opposed to the pin receiving hole 14, the light reflected on the outer surface of the bottom plate 12 of the wagon vehicle 10 is reflected. A signal is generated facing a plate (not shown).

[0004] The wagon 10 is manually placed at a predetermined dispatch position on the traveling road surface FL. Unmanned towing vehicle 2
0 automatically travels under the wagon vehicle 10 parked at a predetermined vehicle allocation position, enters under the wagon vehicle 10, stops when the position sensor 28 outputs, temporarily raises the protrusion pin 26, As shown in FIG. 6, the wagon vehicle 10 is protruded into the pin receiving hole 14 of the connecting portion 13 of the wagon vehicle 10, and when this connecting operation is completed, the vehicle starts traveling to the next destination and tow the wagon vehicle 10. .

[0005]

The wagon 10 is manually stopped at a predetermined dispatch position, and all the wheels are free wheels 11 as described above. It is difficult to stop accurately. For example, if the outer diameter d ₂ is 30mm ejector pins 26, the inner diameter d ₁ of the pin receiving hole 14 is 40 mm, the unmanned tractor 20
When the stop accuracy in the traveling direction of the moving direction is ± 5 mm, the deviation (lateral deviation) allowed in the lateral direction is only 0 mm, and when the stopping accuracy is ± 0 mm, the deviation (lateral deviation) allowed in the lateral direction is plus. It becomes minus 5 mm. That is, as can be understood from FIGS. 7 and 8, as the stop error in the traveling direction of the unmanned tow vehicle increases, the deviation margin allowed in the lateral direction decreases. It is difficult to stop the wagon 10 with the vehicle, so it is impossible to always automatically and automatically connect the wagon 10 and the unmanned towing vehicle 20 with pins.

For this reason, there is an idea that a mechanical guide (a bar parallel at a predetermined interval) is provided at a vehicle allocation position to regulate the posture of the wagon vehicle 10, but the guide does not obstruct the passage of a person, and the guide does not interfere with the traffic. In order to avoid contact with the wagon vehicle, it is necessary to provide a narrow gap between the two, and it is necessary to suppress variations in the vehicle width accuracy of the wagon vehicle, causing a problem that the wagon vehicle becomes expensive.

The present invention has been made to solve this problem. Instead of restricting the position of the wagon vehicle, the unmanned towing vehicle is caused to follow the posture of the wagon vehicle at the dispatching position. It is an object of the present invention to provide a method for controlling a recessed attitude of an unmanned towing vehicle for a wagon vehicle, which can eliminate the need for a fixed facility such as a vehicle guide on a traveling path.

[0008]

In order to achieve the above object, according to the present invention, an unmanned towing vehicle is provided with a wireless right distance measuring device for measuring a distance between a left and right vehicle in a vehicle width direction with respect to a wagon vehicle. It has a sensor and a left ranging sensor, and detects and inputs the output of both ranging sensors to detect the deviation width of the distance between the left and right vehicles .
After running one unit time, the distance information after sampling
The deviation angle of the vehicle body posture is calculated between the deviation width of the left-to-right vehicle distance and when the deviation amount exceeds the allowable value,
By switching to program control from the induction control, strike-slip at the time
Skew the front and rear wheels at the same steering angle,
In the case of a deviation, the steering angles of the front and rear wheels are equal to the deviation angle calculated above.
Steering in opposite directions and running in a direction to correct the body posture
The configuration was adopted.

According to a second aspect of the present invention, the left and right sides of the wagon vehicle are
With a side plate that can reflect sound waves or light waves from the distance measurement sensor
The configuration was covered .

[0010]

[0011]

[0012]

According to the present invention , when the unmanned tow vehicle starts moving into the wagon vehicle at the dispatch position, the vehicle travels while changing its posture so as to follow the posture of the wagon vehicle. Unlike the case of performing the above, the guide and the like described above become unnecessary.

[0013]

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numerals 30R and 30L denote a right distance measuring sensor and a left distance measuring sensor, respectively.
Right and left sides of the front of the vehicle (with the protruding pin 26 interposed)
It is provided in. Both distance measuring sensors 30R and 30L are wireless distance measuring sensors, and the outputs thereof are digitally converted and sampled and input to the arithmetic processing unit CPU of the control device 24. The two distance measuring sensors 30R and 30L are ultrasonic or photoelectric type distance measuring sensors. Of the left and right side plates of the wagon 10 of the present embodiment, the distance measuring sensors 30R and 30L are provided.
The portion facing 0L is formed of a material that can reflect the sound waves or light from both distance measuring sensors 30R and 30L.

When the unmanned towing vehicle 20 starts to move into the wagon vehicle 10, the right distance measuring sensor 30R is turned on by the wagon vehicle 10.
The left distance measurement sensor 30L measures and outputs the inter-vehicle distance L to the left side of the vehicle body of the wagon vehicle 10. Control processing unit CPU of the device 24 and the measured value R San bling input from the right distance measuring sensor 30R (the sampling values and R _1), the measured value L of the right distance measuring sensors 30L San Bring input (sampled value is referred to as _{L 1),} calculates the amount of lateral deviation ΔW ₁ = _{R 1} -L _1. Subsequently, when the unmanned towing vehicle 20 travels for a unit time (the traveling distance during this time is assumed to be a constant value a), the measurement value R _{2 of} the right distance measurement sensor 30R and the measurement value L ₂ of the right distance measurement sensor 30L.
To calculate the lateral shift amount ΔW ₂ = R ₂ −L ₂ . The arithmetic processing unit CPU determines whether (A) ΔW ₁ and ΔW ₂ are within a preset allowable range, and (B) if both ΔW ₁ and ΔW ₂ are within the allowable range, The vehicle 10 has its center line O as shown in FIG.
It is determined that the vehicle 1 is stopped in a posture on the guide line 22, and the unmanned towing vehicle 20 is caused to travel in the posture at the start of the undercut. (C) If _one of ΔW ₁ and ΔW ₂ exceeds the allowable range, the wagon vehicle 10 is displaced from the guide line 22, and the control of the unmanned towing vehicle 20 is switched from the guidance control to the program control. .

(1) If △ W ₁ = △ W ₂ , for example,
As shown in FIG. 2A, in the wagon 10 , it is determined that the center line 01 of the wagon 10 is shifted laterally by 誘導 W ₁ = △ W _{2 with} respect to the guide line 22, and Both the front and rear wheels are steered by an angle θ _{K and the} required traveling distance S
_K and the required traveling speed _VK are calculated, and the unmanned towing vehicle 20 is skewed as shown in FIG.

(2) ΔR = R ₂ −R ₁ , ΔL = L ₂ −L
If ₁ is not 0, for example, as shown in (C) of FIG. 2, it is determined that the wagon 10 is rotated relative to the guide wire 22, the deviation angle theta ₁ is calculated by the following equation Deviation angle θ ₁ = tan (a / (R ₂ −R ₁ )) = tan
(A / (L ₂ −L ₁ )) After the front and rear wheels of the unmanned towing vehicle 20 are driven in the opposite directions, and both are steered by the angle θ ₁ , and run for a unit time (the running distance between these is defined as a ₂ ) ), the measured value _{R 3} of the right distance-measuring sensors 30R, enter the measured value _{L 3} of the left distance measuring sensor 30L, again shift angle _{θ 2 = tan (a 2 /} (R 3 -R 2)) = ta
n (a ₂ / (L ₃ −L ₂ )) to calculate the unmanned towing vehicle 2
Reverse the front and rear wheels to each other 0, and allowed to travel by both the angle theta ₂ steering to unit time. This operation is called R _n = L _n ,
Repeat until θ _n = 0.

As described above, in this embodiment, the unmanned towing vehicle 2
When the vehicle starts moving into the wagon vehicle 10, the deviation of the posture of the wagon vehicle 10 with respect to the guide line 22 is detected, and the posture of the unmanned towing vehicle 20 is shifted with respect to the guide line 22.
Is controlled to be the same as
0 can be stopped at the vehicle allocation position with its center line coinciding with the center line O1 of the wagon vehicle 10, and the amount of lateral displacement can easily be within the allowable range described above.

[0019]

As described above, the present invention measures the amount of deviation of the attitude of the wagon vehicle with respect to the guide line by the non-contact method on the unmanned tow vehicle side after the start of digging, and uses the measured data to perform the measurement. Is made to follow the position of the wagon car, so that there is no need to use mechanical means such as the above-mentioned guides that obstruct the passage, and the manufacturing accuracy of the wagon car can be reduced, so that the manufacturing cost is accordingly reduced. Become cheap.

[Brief description of the drawings]

FIG. 1 is a partially broken plan view showing an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a relationship between an unmanned towing vehicle and a wagon vehicle for explaining the operation of the embodiment.

FIG. 3 is a side view of a conventional wagon and an unmanned towing vehicle.

FIG. 4 is a plan view of a conventional wagon vehicle and an unmanned towing vehicle.

FIG. 5 is a front view of a conventional wagon vehicle and an unmanned towing vehicle.

FIG. 6 is a diagram showing a conventional pin connection mechanism between a wagon vehicle and an unmanned towing vehicle.

FIG. 7 is a diagram for explaining the stopping accuracy of the wagon vehicle and the unmanned towing vehicle.

FIG. 8 is a diagram for explaining the relationship between the traveling direction stop accuracy of the unmanned towing vehicle and a lateral margin with respect to the wagon vehicle.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Wagon vehicle 11 Free wheel 12 Bottom plate 13 Pin connection part 14 Pin receiving hole 20 Unmanned towing vehicle 21 Steering / driving wheel 22 Guide wire 23 Guide sensor 24 Control device 25 Top plate of vehicle body cover 26 Protruding pin 27 Pin driving unit 30R, 30L Distance sensor

Claims (2)

(57) [Claims] 1. An unmanned towing vehicle that pulls under a stopped wagon vehicle by means of guidance control, connects the wagon vehicle with a pin, and then tow the wagon vehicle. It has a wireless right ranging sensor and a left ranging sensor for measuring the distance between the left and right vehicles in the width direction, samples and inputs the outputs of both ranging sensors, detects the width of deviation between the left and right vehicles, and outputs a unit time Run
The distance information after sampling is input.
The deviation angle of the vehicle body posture is calculated with respect to the deviation width, and when the deviation amount exceeds an allowable value, the guidance control is switched to the program control, and in the case of a lateral deviation, the steering angles of the front and rear wheels are changed.
Skewed in the same direction.
The steering angle is steered in the opposite direction by the deviation angle calculated above.
A method of controlling a recessed posture of an unmanned towing vehicle for a wagon vehicle, wherein the vehicle is steered in a direction to correct a vehicle body posture . 2. The left and right sides of the wagon are provided with two distance measuring sensors.
These sound waves or light waves are covered by side plates that can reflect
The unmanned traction for a wagon vehicle according to claim 1, wherein
A method for controlling the car's recessed posture.