JP2000002536A - Vehicle posture detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect with high precision a deviation (a yaw angle) of a posture from a straight line set as a travel target before travel start by use of a real time kinematic GPS without being influenced by the external world when a vehicle travels autonomously and works automatically. SOLUTION: One mobile station real time kinematic GPS receiver is mounted on a traveling vehicle, and a GPS antenna is arranged in an upper part of this vehicle so as to move in a straight line to a front-and-rear direction or move rotatably, and a position is measured by ground coordinate systems in the front and rear parts in the moving range to the front-and-rear direction of this GPS antenna, thereby to acquire a straight line coupling two points to each other. Further, an angle made by this straight line and a straight line set as a travel target of the vehicle is acquired, and an initial value of a yaw angle sensor is set by the angle, and an autonomous travel and an automatic work of the vehicle are executed with high precision with a simple structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle equipped with one real-time kinematic GPS receiver, moving a GPS antenna installed on the vehicle back and forth, measuring the position at two front and rear positions, and calculating an initial value of the yaw angle. The present invention relates to a vehicle attitude detection device that is set.

[0002]

2. Description of the Related Art Conventionally, in order to detect the direction of a vehicle in the absolute direction, the direction is detected using a geomagnetic direction sensor, or a real-time kinematic GPS (RT) for a mobile station.
KGPS) To obtain the position coordinates of two points by using two receivers and two antennas, and to determine the attitude of the vehicle from this, or to travel straight a few meters, and then compare the running path with the straight line as the running target of the vehicle. And so on.

[0003]

When a vehicle performs autonomous traveling or automatic work, a deviation (yaw angle) of a posture from a straight line as a traveling target before starting traveling is detected with high accuracy without being affected by the outside world. There is a need to. With the conventional technology, the position of the vehicle cannot be accurately detected in a place where the external magnetic field changes, the cost is high because two or more antennas and receivers are required, and when traveling in an uneven place, There were problems such as insufficient accuracy. Therefore, it is necessary to develop a simple and inexpensive method and device capable of giving an initial value to the yaw angle sensor with high accuracy. The present invention has been made based on such circumstances.

[0004]

In order to achieve the above object, the present invention provides a self-propelled vehicle equipped with one real-time kinematic GPS receiver for a mobile station, and a GPS mounted on top of the vehicle.
The PS antenna is installed so as to be able to move linearly or rotationally in the front-rear direction, position is measured by a ground coordinate system at a front part and a rear part in a front-rear movement range of the GPS antenna, and a straight line connecting the two points is obtained. An angle between this straight line and a straight line as a travel target of the vehicle is determined, and the initial value of the yaw angle sensor is set based on the angle.

[0005]

With the above configuration, the vehicle attitude detecting apparatus of the present invention moves one GPS antenna in the upper part of the vehicle in the front-rear direction, and performs position measurement in the front part and the rear part by the ground coordinate system. Is obtained, and the angle between this straight line and the straight line as the travel target of the vehicle is obtained, and the initial value of the yaw angle sensor is set based on the angle, thereby obtaining one real-time kinematic GPS for mobile station. By using the receiver and one GPS antenna, a deviation (yaw angle) of a posture from a straight line as a traveling target of the vehicle can be detected with high accuracy without being affected by the outside world before the vehicle starts traveling. In addition, since one mobile station real-time kinematic GPS receiver and one GPS antenna are sufficient, the cost can be reduced.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a vehicle posture detecting apparatus using a real-time kinematic GPS according to the present invention will be specifically described with reference to the accompanying drawings.
1 and 2, reference numeral 1 denotes an autonomous traveling rice transplanter prototyped based on a commercially available rice transplanter. The rice transplanter 1 includes a real-time kinematic GPS (not shown) for mobile stations.
A receiver, an optical fiber gyro sensor 2 and a computer are mounted. An antenna slide 3 extending in the front-rear direction is provided at the center of the rice transplanter 1 in the body width direction, and one GPS antenna 4 is installed on the slide 3 so as to be linearly movable in the front-rear direction. ing. Note that this GPS
The antenna 4 may move linearly while rotating.

The GPS antenna 4 is moved back and forth in response to a digital signal from a computer.
The stop position is controlled by the three limit switches 5 to 7. The front position (position of the limit switch 5) and the rear position (position of the limit switch 7) in the movement range of the antenna 4
In the position), the position is measured using the ground coordinate system, a straight line A connecting the two points is obtained, and this straight line A and a straight line B as a travel target of the rice transplanter 1 (predetermined before the rice transplanter 1 starts traveling). When the rice transplanter 1 travels along a straight line path, the steering is controlled so as to travel along the straight line), and the initial angle of the yaw angle sensor of the optical fiber gyro sensor 2 is determined based on the angle θ. The value is set. In addition,
The limit switch 6 is used when the rice transplanter 1
This is the stop position of the S antenna 4.

[0008] In the rice transplanter 1 of autonomous running having such a configuration, the vehicle is stopped before starting running (work).
As shown in FIGS. 1 and 2 (a) to 2 (c), the GPS antenna 4 is moved along the antenna slide 3 and the position is determined by the ground coordinate system at two points, a front position and a rear position. The intersection angle θ between the straight line A connecting the two points and the straight line B as the traveling target of the rice transplanter 1 was obtained. Then, the initial value of the yaw angle sensor of the optical fiber gyro sensor 2 is set based on the angle θ, the traveling (work) is started, and the rice transplanting work is continuously performed.

Table 1 shows a comparison between yaw angles obtained by the gyro sensor, yaw angles calculated by the GPS antenna of the vehicle attitude detecting apparatus using the real-time kinematic GPS according to the present invention, and errors. As is clear from the comparison of the measured values, the difference is at most 0.8 degree, which indicates sufficient accuracy for the rice transplanter 1 to perform autonomous traveling.

[Table 1]

[0010]

As described above, according to the vehicle attitude detecting apparatus of the present invention, one real-time kinematic GPS receiver for a mobile station is mounted on a self-propelled vehicle, and a GPS antenna is mounted above the vehicle. The GPS antenna is installed so as to be able to move linearly or rotationally in the direction, and the position is measured by the ground coordinate system at the front part and the rear part in the front and rear movement range of the GPS antenna, and a straight line connecting the two points is obtained. Since the angle formed with the straight line as the travel target is obtained and the initial value of the yaw angle sensor is set based on this angle, one mobile station real-time kinematic GPS is used.
Position deviation (Yaw angle) from the target straight line before the vehicle starts traveling by the receiver and one GPS antenna
Can be detected with high accuracy without being affected by the outside world. In addition, since one mobile station real-time kinematic GPS receiver and one GPS antenna are sufficient, the cost can be reduced.

[Brief description of the drawings]

FIGS. 1A to 1C are plan views illustrating the principle of a vehicle attitude detecting device using a real-time kinematic GPS according to the present invention.

FIGS. 2A to 2C are side views of a measurement example by moving a GPS antenna.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Autonomous traveling rice transplanter (vehicle) 2 Optical fiber gyro sensor 3 Antenna slide 4 GPS antenna 5-7 Limit switch A Straight line connecting two measurement points before and after B Straight line as a running target of the vehicle

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2F029 AA08 AB01 AB07 AB11 AC04 5H301 AA03 BB01 CC08 CC09 DD05 DD17 FF11 GG17 5J062 AA02 AA11 BB01 CC07 DD21 GG02

Claims (1)

[Claims] 1. A self-propelled vehicle equipped with one real-time kinematic GPS receiver for a mobile station, and a G
The PS antenna is installed so as to be able to move linearly or rotationally in the front-rear direction, position is measured by a ground coordinate system at a front part and a rear part in a front-rear movement range of the GPS antenna, and a straight line connecting the two points is obtained. A vehicle attitude detecting device, wherein an angle between the straight line and a straight line as a travel target of the vehicle is determined, and an initial value of a yaw angle sensor is set based on the angle.