JPH10207540A - Automated guided vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To construct an automated guided vehicle capable of eliminating the necessity of highly accurate detection and complicated operation processing by providing a means capable of detecting the angle of a vehicle body by using non-contract magnetic markers instead of conventional correcting triangular markers and correcting the time drift of a gyro sensor. SOLUTION: Correcting magnetic markers 12a(c), 12b(d) are stuck to positions on a floor surface 15 which are symmetrical about a traveling route 11 by adhesives stuck to the rear side faces of these markers 12a(c), 12(b). Magnetic sensors 14a, 14b are attached to positions on the rear side face of the vehicle body which correspond to the magnetic markers 12a(c), 12b(d) in a non-contact state when an automated guided vehicle 13 is traveling on the route 11. A main control device 16 receives signals from the magnetic sensors 14a, 14b, generates correction data corresponding to a deviation between the right and left sides, corrects a gyro sensor signal and controls driving wheels to control the travel of the vehicle 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic guided vehicle that automatically travels on a predetermined traveling path and loads or unloads at each station.

[0002]

2. Description of the Related Art An automatic guided vehicle is a vehicle body that automatically travels along a conductor laid on a traveling path to a target station and performs loading or unloading work, and is in great demand particularly in the field of logistics. Information on the destination station and the like for the automatic guided vehicle is instructed wirelessly from the central control unit located outside the traveling path.

In the automatic guided vehicle described above, the angle and angular velocity of the vehicle body are mainly detected using a gyro sensor, and the traveling direction is controlled using the signals. However, since the gyro sensor has a time-domain signal drift, it is necessary to perform a signal correction process periodically during traveling. Conventionally, a gyro sensor signal is periodically corrected using a sensor or a corresponding circuit logic separately from the gyro sensor for this correction.

FIG. 3 shows a conventional example. In the figure, (a) is a plan view of the automatic guided vehicle, (b) is a side view, and (c) is a block diagram showing an internal configuration. In each case, only a relevant portion for detecting a vehicle body angle is extracted. Is shown. As can be seen, a triangular marker 3
When the vehicle passes through the vehicle body 33, the proximity marker or photoelectric sensor 34 mounted at a symmetrical position on the lower surface of the vehicle body detects the triangular marker position passage time. If the vehicle route angle deviates from the center of the travel route, a difference occurs in the operation time of the left and right marker detection sensor 34, and the main control device 35 performs an arithmetic process based on the amount of the deviation to recognize the vehicle body travel angle. Things.

[0005]

However, according to the above-mentioned prior art, the correction triangular marker has a large size and is disadvantageous in that it is made of metal, so that it is difficult to attach it to the floor and that it is easily peeled off. . Also, the corrected triangular marker becomes a road surface step when the automatic guided vehicle is traveling, and the sensor may malfunction due to the impact or the like,
It was not always reliable.

The present invention has been made in view of the above circumstances, and provides a means for correcting a time drift of a gyro sensor by detecting a vehicle body angle using a non-contact magnetic marker instead of a conventional correction triangle marker. By doing
It is an object of the present invention to provide an automatic guided vehicle that does not require highly accurate detection and complicated arithmetic processing.

[0007]

SUMMARY OF THE INVENTION The present invention relates to an automatic guided vehicle that detects the angle and angular velocity of a vehicle body using a gyro sensor and automatically controls the traveling direction based on the detected signals. A magnetic marker attached to a floor surface position that is symmetrical with respect to the traveling route,
When the automatic guided vehicle is traveling, a magnetic sensor mounted at the lower part of the vehicle body so as to face the magnetic marker in a non-contact manner when passing the magnetic marker position, and a left and right magnetic sensor at each arbitrary passing point of the traveling route And a control device that calculates the vehicle body angle by comparing signals obtained through the control unit, corrects the output of the gyro sensor, controls the drive wheels, and controls the vehicle body.

According to the present invention, the correction marker is small, it can be easily mounted on the floor, no complicated arithmetic processing is required, and high reliability can be obtained.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to FIGS.

FIG. 1 is a diagram showing an embodiment of the present invention.
(A) is a plan view, (b) is a side view, and (c) shows an internal configuration of the automatic guided vehicle. In each case, only relevant portions for detecting the vehicle body angle are extracted and shown.

In the figure, 11 is a traveling route, 12a-
12d is a magnetic marker for correction, 13 is an automatic guided vehicle, 14
a and 14b are magnetic sensors, and 15 is a floor surface. The correction magnetic markers 12a (c) and 12b (d)
The back surface is adhered to the floor surface 15 symmetrical with respect to 1 with adhesive glue. The magnetic sensors 14a and 14b are attached to the back of the vehicle body in a non-contact manner with the magnetic markers 12a and 12b when the automatic guided vehicle 13 passes the magnetic marker position while traveling on the traveling route 11. As the magnetic sensors 14a and 14b, for example, a Hall element, a magnetoresistive element, or the like is used. Suitable for digital processing due to saturation.

Main controller 16 has a built-in CPU as a control center, processes signals input through various sensors connected to input / output ports based on contents programmed in a memory in advance, and controls driving wheels. By controlling it, automatic traveling as an automatic guided vehicle is realized. As will be described in detail below, the role of main controller 16 is to detect the vehicle body angle and to periodically correct the gyro sensor signal based on this signal.

FIG. 2 is a diagram showing output characteristics of the magnetic sensor 14 when a magnetic marker is detected.

The magnetic sensors 14a and 14b have a characteristic that the output changes in the width direction of the magnetic markers 12a and 12b.
Further, it may be a digital type. The magnetic sensors 14a and 14b used in the embodiment of the present invention generate 0V at the center of the magnetic markers 12a (c) and 12b (d), and generate a voltage of + V (-V) when the center is shifted in the horizontal direction. I do. Main controller 16 receives the +,-or 0 level voltage from magnetic sensors 14a and 14b, generates correction data corresponding to the amount of left and right deviation, and corrects the gyro sensor signal. And drive control by controlling the drive wheels.

As described above, according to the present invention, instead of installing the correction triangle mark on the floor, a magnetic marker is attached to the floor, and when the vehicle travels on the floor, the magnetic marker is placed at a position opposite to the vehicle. A vehicle angle is detected by mounting a sensor. Since the magnetic sensor that detects the magnetic marker has the characteristic of changing the output in the width direction of the magnetic marker, the main controller compares the left and right sensor output values to easily determine the deviation between the center of the traveling route and the vehicle body. It can be grasped.

[0016]

As described above, according to the present invention, the occupied area is smaller than that of the conventional triangular mark for correction, the mounting is easy, and the displacement of the vehicle body can be detected without contact. As a result, malfunctions due to impacts are eliminated and reliability is improved. Further, the detection can be easily recognized by analog or digital, and a complicated calculation process is not required as compared with the related art. Therefore, the logic for correction is simple, and an inexpensive guided vehicle can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing output characteristics of a magnetic sensor used in the present invention.

FIG. 3 is a diagram showing a configuration of a conventional example.

[Explanation of symbols]

11: travel route, 12a to 12d: magnetic marker for correction, 13: automatic guided vehicle, 14a, 14b: magnetic sensor,
15: floor surface, 16: main controller.

Claims (1)

[Claims] 1. An automatic guided vehicle that detects an angle and an angular velocity of a vehicle body using a gyro sensor and automatically controls a traveling direction based on a signal thereof. A magnetic marker attached to a symmetrical floor surface position, and a magnetic sensor mounted on a lower part of the vehicle body so as to face the magnetic marker without contact when passing through the magnetic marker position while the automatic guided vehicle is traveling. The vehicle body angle is calculated by comparing the signals obtained through the left and right magnetic sensors at each arbitrary passing point of the travel route, the output from the gyro sensor is corrected, and the drive wheels are controlled to control the vehicle body. An automatic guided vehicle, comprising: a control device.