JPH0793029A - Running control unit for unmanned vehicle - Google Patents

Abstract

PURPOSE:To make the unamnned vehicle travel along a virtual travel path by easily detecting the relative position of the unmanned vehicle to the virtual travel path, specially, the tilt angle at a low cost. CONSTITUTION:Angle detection lines 400 are laid at specific intervals perpendicularly to the virtual locus 300 and a pair of sensors 14 mounted on the unmanned vehicle detect the angle detection line 400. Once the sensors 14 detect a angle detection line 400, detection signals from the sensors 14 are outputted to a CPU 18 as a control unit. The digital signal from an encoder 16 which detects the angle of rotation of a steering wheel is outputted to the CPU 18 as well. The attitude angle theta is calculqted from theta=tan-1(D/L), where L is the interval between the couple of sensors 14 and D is the distance by which the unmanned vehicle travels until the pair of sensors 14 detect the angle detection line 400.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an unmanned vehicle traveling control device,
In particular, it relates to relative position detection of an unmanned vehicle with respect to a virtual road.

[0002]

2. Description of the Related Art Conventionally, unmanned vehicles such as carrier vehicles have been widely used for assembling vehicles. A general unmanned vehicle supports the entire vehicle with three or more traveling wheels, and drives these wheels with a motor mounted on the vehicle to travel along predetermined guidelines. There are electromagnetic induction type, tape optical type, electrostatic capacitance type, etc. as the method of guiding the unmanned vehicle along the guideline.

On the other hand, there is also a system in which guide lines are intermittently provided or hardly provided, and the guide lines are allowed to travel on a virtual road. In the case of this unguided method, it is important to detect the relative position of the unmanned vehicle with respect to the virtual travel route. In order to specify the relative position, it is necessary to know the deviation amount with respect to the virtual traveling road and the posture angle with respect to the virtual traveling road. For example, JP-A-60-101
In the traveling control method of a moving body of Japanese Patent No. 613, a mark provided on a traveling road is input as an image signal by an imaging device, the obtained image is processed, and a deviation amount from a planned traveling road and an attitude angle are detected. A technique for steering control to solve these problems is disclosed.

[0004]

However, the technique of processing an image and detecting the position in this way requires an expensive image recognition device, which causes a problem of high cost.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to detect the relative position of an unmanned vehicle with respect to a virtual running path, particularly, the inclination angle, easily and inexpensively, and to detect the unmanned vehicle. An object of the present invention is to provide a travel control device for an unmanned vehicle that can drive the vehicle along a virtual travel path.

[0006]

In order to achieve the above object, a traveling control device for an unmanned vehicle according to the present invention is mounted perpendicularly to a longitudinal center line of the unmanned vehicle at a predetermined distance L, and is mounted in advance. A pair of detection means for detecting angle detection lines provided at predetermined intervals so as to be perpendicular to the virtual traveling path, and one of the pair of detection means detects the angle detection line and then the other is Distance detecting means for detecting a traveling distance D of the unmanned vehicle until the angle detection line is detected, and the distance L.
And an operation means for calculating an attitude angle of the unmanned guided vehicle with respect to the virtual travel path based on the traveling distance D, and a control means for controlling steering of the unmanned vehicle based on the calculated attitude angle.

[0007]

According to the present invention, the pair of detecting means are mounted perpendicularly to the longitudinal center line of the unmanned vehicle and separated from each other by the predetermined distance L, so that the detecting means make them perpendicular to the virtual traveling path. The angle detection line provided at every predetermined interval is detected. If an unmanned vehicle is traveling along a virtual driveway,
That is, when the attitude angle is zero, the pair of detecting means detect the angle detection lines almost at the same time, but when the unmanned vehicle deviates from the virtual road and the attitude angle is not zero, the time detected by the pair of detecting means. Will be different. Then, a simple geometrical relationship tan θ = D / L is established between the distance L of the pair of detection means and the distance D and the posture angle θ that the unmanned vehicle travels during the detection time difference. θ can be easily detected.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 shows a conceptual diagram of the traveling control system for the automatic guided vehicle in the present embodiment, and FIG. 1 shows the configuration of the automatic guided vehicle in the present embodiment. In FIG. 3, the automated guided vehicle 10 is on the guide wire 100, and a mark plate 200 for instructing the start of the non-guide is installed near the end of the guide wire 100. Automated guided vehicle 1
0 is provided with a sensor (for example, a magnetic sensor) for detecting the mark plate, and when the mark plate 200 is read by a well-known detecting means during the guide traveling, the control device mounted on the automatic guided vehicle 10 is provided. Keeps the steering wheel (leading wheel of the three wheels) 12 in a straight-ahead state and travels on a virtual trajectory 300 on which the guide wire 100 is not laid.

In an ideal state, the automated guided vehicle travels on the virtual trajectory 300 without guidance, but in reality, the swell of the road surface, the slip between the steering wheel 12 and the floor, and the rattling of the steering unit. Unmanned guided vehicle is a virtual trajectory 3 due to
It will deviate from 00. Among these deviations, particularly in the present embodiment, the inclination angle θ between the virtual locus 300 and the automated guided vehicle 10, that is, the angle θ between the virtual locus 300 and the vehicle front-rear centerline (see FIG. 3) is simply and accurately detected. It is characterized by doing.

Therefore, in this embodiment, the virtual trajectory 300
The angle detection lines 400 are laid vertically at a predetermined interval,
The attitude angle θ is detected by detecting the angle detection line 400 with the pair of sensors 14 provided in the automatic guided vehicle 10. One of the sensors 14 also serves as the sensor for reading the mark plate 200 described above. Also, the angle detection line 40
0 is formed of the same material as the mark plate 200 (for example, metal), and the sensor 14 detects the mark plate 200 on the same principle (for example, magnetic change).
When the angle detection line 400 is detected by the sensor 14, the sensor 1
The detection signal from 4 is output to the CPU 18 as a control device. On the other hand, the CPU 18 also outputs a digital signal from the encoder 16 that detects the rotation angle of the steering wheel 12. Based on these signals, the CPU 18 calculates the traveling distance of the automated guided vehicle from when one of the sensors 14 detects the angle detection line 400 to when the other detects the angle detection line 400. Assuming that the distance between the pair of sensors 14 is L and the travel distance until the pair of sensors 14 detect the angle detection line 400 is D, there is a relationship of tan θ = D / L with the posture angle θ. Calculates the attitude angle θ by θ = tan−1 (D / L) (1) Then, the CPU 18 controls the steering motor 20 so that this θ becomes zero before detecting the next angle detection line 400, and controls the traveling of the automatic guided vehicle.

The traveling control of the automatic guided vehicle according to the present embodiment is performed as described above. The traveling control according to the present embodiment will be described in more detail below with reference to the flowchart of FIG.

When one of the sensors 14 of the automatic guided vehicle (hereinafter referred to as AGV) 10 detects the mark plate 200,
The detection signal is output to the CPU 18. The CPU 18 maintains the steering wheel 12 in a straight traveling state by inputting the detection signal and drives the motor 22 to start non-guided traveling (S101). When the unguided running is started, the CPU 18
Inputs the digital signal from the encoder 16 to the AGV
The traveling distance of 10 is calculated (S102). Then, it is determined whether or not the vehicle has traveled the predetermined set distance or more (S103). As described above, the angle detection lines 400 are laid at predetermined intervals on the virtual trajectory 300, and if the angle detection lines 400 cannot be detected even after traveling the set distance or more, it is determined that an abnormality has occurred and the motor is detected. The drive of 22 is stopped and abnormally stopped (S104). If the vehicle has not traveled the set distance or more, it is next determined whether or not the angle detection line 400 has been detected (S105). This determination is made based on whether the detection signal is input from the sensor 14 to the CPU 18 as described above. Angle detection line 40 with a pair of sensors 14
When 0 is detected, the CPU 18 executes AGV according to the equation (1).
The posture angle θ, that is, the angle formed by the vehicle front-rear centerline with respect to the virtual trajectory 300 is calculated (S106).

After the attitude angle θ of the AGV 10 is calculated, the process proceeds to the process of calculating the deviation amount of the AGV 10 with respect to the virtual trajectory 300. In this embodiment, as shown in FIG. 3, a position correction mark 500 is laid in advance at a predetermined position on the virtual trajectory 300, and the deviation amount d is calculated by detecting this position correction mark 500. The position correction mark 500 is provided immediately after the position near the angle detection line 400, and is detected by a sensor (not shown) separately provided in the AGV 10. The position correction mark 500 is attached to the angle detection line 400.
It is also possible to lay it with the same material as above, to provide a pair of sensors 14 and to detect the position correction mark by the sensor 14. When the position correction mark 500 is detected by the sensor (S107), a detection signal is supplied to the CPU 18, and the position correction mark 500 and the AGV 10 are detected from the detected position.
The shift amount d of is calculated (S108).

After the posture angle θ and the shift amount d are calculated, CP
U18 uses these to calculate the traveling locus of the AGV 10 up to the next mark (S109), and the posture angle θ and the deviation d
The steering motor 20 is driven to correct the steering angle so that is zero (S110). As a result, the AGV 10 can travel along the virtual locus even if there is swell on the road surface, slip between the steering wheel 12 and the floor surface, rattling of the steering unit, or the like.

As described above, this embodiment does not require an expensive image recognition device as in the prior art, but a pair of simple and inexpensive sensors such as a magnetic sensor are provided, and the attitude angle is determined based on the difference in detection time between these sensors. Therefore, the cost performance of the system can be improved.

[0017]

As described above, according to the running control apparatus for an unmanned vehicle of the present invention, it is possible to easily and inexpensively detect the relative position of the unmanned vehicle with respect to the virtual running path, particularly the tilt angle, and to detect the unmanned vehicle. Can be run along the virtual travel path.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an unmanned vehicle according to an embodiment of the present invention.

FIG. 2 is a processing flowchart of the embodiment.

FIG. 3 is a travel control explanatory diagram of the embodiment.

[Explanation of symbols]

 10 Automated guided vehicle (AGV) 12 Steering wheel 14 Sensor 16 Encoder 18 CPU 20 Steering motor 100 Guide line 200 Mark plate 300 Virtual locus 400 Angle detection line 500 Position correction mark

Claims (1)

[Claims] 1. A travel control device mounted on an unmanned vehicle for causing the unmanned vehicle to travel along a virtual travel path, wherein the unmanned vehicle is mounted perpendicular to a front-rear centerline of the unmanned vehicle and separated by a predetermined distance L. And a pair of detection means for detecting angle detection lines provided at predetermined intervals so as to be perpendicular to the virtual travel path in advance, and one of the pair of detection means detects the angle detection line. From the other to the detection of the angle detection line, distance detection means for detecting the travel distance D of the unmanned vehicle, and the attitude angle of the automatic guided vehicle with respect to the virtual travel path are calculated based on the distance L and the travel distance D. A travel control device for an unmanned vehicle, comprising: a computing means; and a control means for controlling steering of the unmanned vehicle based on the calculated attitude angle.