JPH05108155A - Method for controlling attitude getting beneath wagon for unmanned wagon tracter - Google Patents

Abstract

PURPOSE:To obtain a method for controlling the attitude getting beneath the wagon for the unmanned wagon tractor capable of allowing the attitude of the unmanned tractor to follow up the attitude of the wagon which is located at an arrangement position and eliminating the need for a fixing facility on a traveling path such as a wagon guide without restraining the attitude of the wagon. CONSTITUTION:An unmanned tractor 20 is provided with a radio type right range finding sensor 30R and a radio type left range finding sensor 30L measuring the right and left distances in the direction of a vehicle width between the tractor and a wagon 101 and detects the deviated width of the distance in the right and left vehicles and the deviated angle of a vehicle attitude by inputting in sampling the output of both the measurement sensors. When the deviated amount exceeds an allowable value, a guiding control is switched over to a programmed control, a required correction operation angle is calculated and a staring control is executed while utilizing the calculation value as an aimed control value.

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 a retracting posture of an unmanned towing vehicle which is pulled under a hand cart (hereinafter referred to as a wagon vehicle) and tow the wagon vehicle.

[0002]

2. Description of the Related Art FIGS. 3 to 5 show an example of a wagon vehicle used for parts delivery in factories, serving in hospitals, etc. A wagon vehicle 10 of this type has four free wheels 11. As shown in FIG. 6, the bottom plate 12 is provided with a connecting portion 13 having a pin receiving hole 14 that opens toward the traveling road surface FL of the factory or hospital. Reference numeral 15 is a gripping portion.

Reference numeral 20 denotes an unmanned towing vehicle having a low vehicle height, having drive wheels 21 having front and rear steering shafts, and a guide wire (magnetic tape, optical tape, etc.) 22 stretched on the floor of a factory or hospital. Guide sensor 23 for detecting, this guide sensor 2
The 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 control sensor 3 and the output of a mark sensor (not shown) that reads various control marks on the traveling road surface FL.
4 is installed, a predetermined program is executed based on a command input, and traveling / stopping from destination to destination is repeated. As shown in FIG. 6, the unmanned towing vehicle 20 includes a protruding pin 26 capable of vertically protruding from a top plate 25 of a vehicle body cover, a pin for engaging with the protruding pin 26 and a rack and pinion, and vertically driving a predetermined distance. It has a drive unit 27. Reference numeral 28 denotes an optical position sensor, and when the unmanned towing vehicle 20 projects and the pin 26 travels up and down to face the pin receiving hole 14, the light reflecting plate adhered to the outer surface of the bottom plate 12 of the wagon vehicle 10. A signal is generated opposite to (not shown).

The wagon vehicle 10 is manually placed at a predetermined vehicle allocation position on the traveling road surface FL. Unmanned towing vehicle 2
0 automatically travels to the bottom of the wagon vehicle 10 parked at a predetermined vehicle allocation position and slips under the wagon vehicle 10. When the position sensor 28 outputs, the vehicle temporarily stops and the protruding pin 26 is raised. 6, as shown in FIG. 6, the wagon vehicle 10 is made to project into the pin receiving hole 14 of the connecting portion 13 of the wagon vehicle 10, and when this connecting operation is completed, traveling to the next destination is started and the wagon vehicle 10 is towed. ..

[0005]

The wagon vehicle 10 is manually stopped at a predetermined vehicle allocation position and, as described above, all the wheels are free wheels 11, so that the vehicle is in a correct posture. It is difficult to stop accurately. For example, when the outer diameter d ₂ of the protruding pin 26 is 30 mm and the inner diameter d ₁ of the pin receiving hole 14 is 40 mm, the unmanned towing vehicle 20
If the stopping accuracy in the advancing direction is ± 5 mm, the lateral deviation (lateral deviation) is only 0 mm, and if the stopping accuracy is ± 0 mm, the lateral deviation (lateral deviation) is plus. It will be -5 mm. That is, as understood from FIG. 7 and FIG. 8, the larger the stop error in the traveling direction of the unmanned towing vehicle, the smaller the deviation margin that is allowed in the lateral direction. Since it is difficult to stop the wagon vehicle 10 with, it is impossible to always automatically and automatically pin-connect the wagon vehicle 10 and the unmanned towing vehicle 20.

For this reason, there is a concept that a mechanical guide (bars parallel to each other at predetermined intervals) is provided at the vehicle dispatching position to regulate the posture of the wagon vehicle 10. However, the guide not only interferes with the passage of people but also serves as a guide. In order to avoid contact with the wagon vehicle, it is necessary to make a narrow gap between them, and variations in the vehicle width accuracy of the wagon vehicle must be suppressed, which causes a problem that the wagon vehicle becomes expensive.

The present invention has been made in order to solve this problem. Instead of restricting the attitude of the wagon vehicle, the unmanned tow vehicle's retracting attitude is made to follow the attitude of the wagon vehicle in the dispatch position, and the wagon An object of the present invention is to provide a method for controlling the retracting posture of an unmanned tow vehicle for a wagon that can eliminate the need for fixed equipment such as a vehicle guide on the traveling path.

[0008]

In order to achieve the above object, the present invention provides a wireless right distance measuring system according to claim 1, wherein an unmanned towing vehicle measures a distance between left and right vehicles in a vehicle width direction with a wagon vehicle. It has a sensor and a left distance measuring sensor, and outputs the outputs of both distance measuring sensors by sampling to detect the deviation width of the distance between the left and right vehicles and the deviation angle of the vehicle body posture, and when this deviation amount exceeds the allowable value, The guidance control is switched to the program control, the required corrected steering angle is calculated, and the steering control is performed using the calculated value as the control target value.

According to the second aspect of the invention, when the lateral deviation between the left and right vehicle distances exceeds the allowable value, the front and rear wheels are made to have the same steering angle and slanted.

According to a third aspect of the present invention, when the deviation angle of the vehicle body posture exceeds the allowable value, the required correction steering angle is calculated every unit time and the correction operation is repeated.

According to a fourth aspect of the present invention, the left and right side portions of the wagon are covered with side plates capable of reflecting sound waves or light waves from both distance measuring sensors.

[0012]

In the present invention, when the unmanned towing vehicle starts to sneak into the wagon vehicle at the dispatch position, it runs while changing its posture so as to follow the posture of the wagon vehicle. Therefore, the posture of the wagon vehicle is restrained. Unlike the above case, the guide and the like described above are unnecessary.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 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 side and left side of the front part of the vehicle (with the protruding pin 26 in between)
It is provided in. Both distance measuring sensors 30R and 30L are wireless distance measuring sensors, and their outputs are digitally converted and sampled and input to the arithmetic processing unit CPU of the control device 24. Both distance measuring sensors 30R, 30L are ultrasonic type or photoelectric type distance measuring sensors, and the distance measuring sensors 30R, 3R are included in the left and right side plates of the wagon vehicle 10 of this embodiment.
The portion facing 0L is formed of a material capable of reflecting sound waves or light from both distance measuring sensors 30R and 30L.

When the unmanned towing vehicle 20 starts to go into the wagon vehicle 10, the right distance measuring sensor 30R is moved to the wagon vehicle 10.
The inter-vehicle distance R to the right side of the vehicle body is measured and output, and the left distance measuring sensor 30L measures and outputs the inter-vehicle distance L to the left side of the vehicle body of the wagon vehicle 10. The arithmetic processing unit CPU of the control device 24 inputs the measured value R of the right distance measuring sensor 30R by sumbling (the sampling value is R ₁ ) and the measured value L of the right distance measuring sensor 30L by sumbling (the sampling value). Is set to L ₁ ) and both lateral deviations ΔW ₁ = R ₁ −L ₁ are calculated. Subsequently, when the unmanned towing vehicle 20 travels for a unit time (the traveling distance during this time is a constant value a), the measured value R _{2 of} the right distance measuring sensor 30R and the measured value L ₂ of the right distance measuring sensor 30L.
Is input and both lateral deviations ΔW ₂ = R ₂ −L ₂ are calculated. The arithmetic processing unit CPU (A) determines whether or not ΔW ₁ and ΔW ₂ are within a preset allowable range. (B) When both ΔW ₁ and ΔW ₂ are within the allowable range, the wagon is As shown in FIG. 1, the car 10 has its center line O
It is determined that the vehicle 1 is in a posture in which it is on the guide line 22, and the unmanned towing vehicle 20 is caused to travel in the posture at the time of starting the diving. (C) When either ΔW ₁ or ΔW ₂ exceeds the allowable range, the wagon vehicle 10 is out of alignment with the guide wire 22, so the control of the unmanned tow vehicle 20 is switched from the guide control to the program control. .

(1) If ΔW ₁ = ΔW ₂ , then, for example,
As shown in FIG. 2A, the wagon vehicle 10 determines that its center line O1 is laterally offset from the guide line 22 by ΔW ₁ = ΔW _2, and determines the front and rear wheels of the unmanned towing vehicle 20. And the required traveling distance S _K and the required traveling speed V _K are both steered by the angle θ _K , and as shown in FIG.
The unmanned towing vehicle 20 is slanted.

(2) ΔR = R ₂ −R ₁ , ΔL = L ₂ −L
_{When 1} is not 0, for example, as shown in FIG. 2C, it is determined that the wagon vehicle 10 is rotating with respect to the guide wire 22, and the shift angle θ ₁ is calculated, After the front and rear wheels of the unmanned tow vehicle 20 are both steered by an angle θ _{1 and} run for a unit time (the running distance is a ₂ ), the measured value R ₃ of the right distance measuring sensor 30R and the left distance measuring sensor Enter the measured value L _{3 of} 30 L and again Is calculated and both the front and rear wheels of the unmanned tow vehicle 20 are steered by an angle θ _{1 to} run for a unit time. This operation is R _n =
Repeat until L _n , θ _n = 0.

Thus, in this embodiment, the unmanned towing vehicle 2 is used.
When 0 starts slipping into the wagon vehicle 10, a deviation of the attitude of the wagon vehicle 10 with respect to the guide wire 22 is detected, and the attitude of the unmanned towing vehicle 20 is detected with respect to the guide wire 22.
Because it is controlled so that it is the same as
It is possible to stop 0 at the vehicle allocation position with its center line aligned with the center line O1 of the wagon vehicle 10, and it is possible to easily keep the lateral deviation amount within the above-mentioned allowable range.

[0019]

As described above, according to the present invention, the amount of deviation of the posture of the wagon vehicle with respect to the guide wire is measured on the unmanned towing vehicle side by the non-contact method after the start of the skimming, and the unmanned towing vehicle is used by using the measurement data. Since the posture of the wagon is made to follow the posture of the wagon car, it is not necessary to use mechanical means such as the above-mentioned guides that obstruct the passage of traffic, and the manufacturing accuracy of the wagon car can be relaxed, so the production cost is correspondingly reduced. It will be cheaper.

[Brief description of drawings]

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

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

FIG. 3 is a side view of a conventional wagon vehicle 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 view showing a pin connecting mechanism of a conventional wagon vehicle and an unmanned towing vehicle.

FIG. 7 is a diagram for explaining stop accuracy of a wagon vehicle and an unmanned towing vehicle.

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

[Explanation 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 Body cover top plate 26 Projection pin 27 Pin drive part 30R, 30L Ranging sensor

Claims (4)

[Claims] 1. An unmanned towing vehicle that is guided by a guidance control so that it can be pulled under a stopped wagon vehicle and is pin-connected to the wagon vehicle, and then tow the wagon vehicle. It has a wireless right distance sensor and a left distance sensor for measuring the distance between left and right vehicles in the width direction.The output of both distance sensors is sampled and input to determine the deviation width of the left and right vehicle distance and the deviation angle of the vehicle body posture. When the deviation amount is detected and exceeds the allowable value, the guide control is switched to the program control to calculate a required corrected steering angle, and the steering control is performed using the calculated value as a control target value. A method for controlling the attitude of an unmanned towing vehicle for a wagon. 2. The unmanned towing vehicle for a wagon according to claim 1, wherein, when the lateral deviation between the left and right vehicle distances exceeds a permissible value, the front and rear wheels are made to have the same steering angle and are slanted. Crawling posture control method. 3. The wagon vehicle according to claim 1, wherein when the deviation angle of the vehicle body posture exceeds an allowable value, a required correction steering angle is calculated every time a unit time elapses and the correction operation is repeated. Attitude control method for unmanned tow vehicles. 4. The wagon according to claim 1, wherein the left and right side portions of the wagon vehicle are covered with side plates capable of reflecting sound waves or light waves from both distance measuring sensors. Attitude control method for unmanned tow vehicles.