JPH03248010A - System for detecting present position, running speed and running direction of running vehicle - Google Patents

Abstract

PURPOSE:To detect a present position, a running speed and a running direction accurately by comparing the running speed based on the number of rotations of a tire per unit time and the running directions based on the signal from an azimuth detecting device with the running speed and the running direction which are measured with a radiowave-type position/ speed/direction measuring device, and operating the speed and the direction. CONSTITUTION:In a running vehicle 1, a rotation sensor 3 for detecting the number of rotations of a tire 2, an azimuth detecting device 4 and an operating device 5 are provided, and the running speed, the running direction and the present position are detected. A radiowave-type position/speed/direction measuring device 7 which receives the radiowave from a radiowave oscillating apparatus 6 and measures the present position, the running speed and the running direction is provided. The operated running speed and the measured running speed are compared, and the running speed whose error is estimated to be minimum is operated. The running direction based on the signal from the device 4 and the measured running direction are compared, and the running direction whose error is estimated to be minimum is operated. The operated present position based on the corrected running speed and the measured present position are compared, and the present position whose error is estimated to be minimum is operated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a system for detecting the current position, speed, and direction of a traveling vehicle.

[Conventional technology]

In order to automatically control the running of a running vehicle, it is necessary to detect the current position, running speed, and running direction of a running vehicle, and various detection systems have been proposed.

For example, the number of tire rotations per unit time of a running vehicle is measured, the running speed is calculated from the rotation number and the tire diameter, and the running direction is measured by an azimuth angle detection device installed on the running vehicle.
A system is known that calculates a current position based on a calculated running speed and a measured running direction.

[Problem to be solved by the invention]

Calculating the running speed in this way has poor accuracy because a calculation error occurs if the tire diameter changes due to tire wear, difference in loaded weight, etc., or if the tires spin on the road surface.

Furthermore, measurement of the running direction using existing azimuth angle detection devices such as a gyro compass or a geomagnetic sensor has bias, drift noise, etc., resulting in poor measurement accuracy.

Furthermore, since the current position is calculated based on the running speed calculated by an inaccurate calculation system and the running direction measured by an azimuth angle detection device with poor measurement accuracy, it is difficult to obtain practical accuracy.

As described above, the accuracy of detecting the current position, traveling speed, and traveling direction using the above-mentioned system is low, so that the vehicle cannot be driven accurately when automatically controlling the traveling vehicle.

Therefore, an object of the present invention is to provide a detection system that can accurately detect the current position, traveling speed, and traveling direction.

[Means and actions for solving the problem] The number of tire rotations per unit time, the running speed and running direction calculated from the signal of the azimuth angle detection device, and the running speed and running direction measured by a radio wave position, speed, and direction measurement device. The running speed and running direction that are estimated to have the smallest error are calculated by comparing them, and after calculating the current position based on the running speed and running direction, the current position is compared with the current position measured by the measuring device. This is a detection system that calculates the current position that is estimated to have the smallest error based on the current position, and can thereby accurately detect the traveling speed, traveling direction, and current position.

〔Example〕

As shown in FIG. 2, the running vehicle 1 is provided with a rotation sensor 3 for detecting the number of rotations per unit time of the tires 2, an azimuth angle detection device 4, and an arithmetic device 5. In addition to detecting the current position, the system receives radio waves emitted from a radio wave oscillator 6 attached to an artificial satellite fixed on the ground or lifted into orbit around the earth to determine the current position, traveling speed, and traveling direction. A radio wave position/velocity/direction measuring device 7 is provided to measure the position, speed, and direction, and this radio wave position/velocity/direction measurement bag M7 calculates the distance between the two from the arrival time of the radio waves emitted from the radio wave oscillator 6. The current position of the vehicle is determined, and the speed and direction of travel are calculated from the wavelength shift caused by the Doppler effect.

As shown in FIG. 1, the calculation device 5 includes a speed calculation circuit 8 that calculates the running speed based on the rotation speed detected by the rotation sensor 3 and a set tire diameter, and a direction calculation circuit that calculates the running direction based on the signal from the azimuth detection bag W14. The calculation circuit 9 calculates the calculated running speed v1 and the running speed v measured by the radio wave position/speed/direction measurement device 7.
A speed error correction circuit 10 that calculates a speed estimated to have the smallest error by comparing
A direction error correction circuit 1 that compares the measured running direction α2 and calculates the running direction in which the error is estimated to be the smallest.
1. A position calculation circuit 12 that calculates the current position from the corrected running speed vs and the corrected running direction α3. A position that compares the calculated current position and the measured current position and calculates the position where the error is estimated to be the smallest. An error correction circuit 13 is provided.

In this way, the traveling speed calculated based on the rotation speed detected by the rotation sensor 3 and the measured traveling speed are compared to calculate the traveling speed estimated to have the smallest error, and the traveling direction is determined based on the signal of the gyro compass 4. Since the measured running direction is compared with the running direction and the running direction estimated to have the smallest error is calculated, the running speed and running direction can be detected with high accuracy.

Furthermore, the current position calculated from the corrected running speed and the corrected running direction is compared with the measured current position to calculate the current position estimated to have the smallest error, so the current position can be detected with high accuracy.

〔Effect of the invention〕

It is estimated that the error is the smallest by comparing the running speed based on the number of tire revolutions per unit time, the running direction based on the signal from the azimuth angle detection device, and the running speed and direction measured by the radio wave position, speed, and direction measuring device. Since the running speed and running direction are calculated, the running speed and running direction can be detected with high accuracy.

The current position calculated based on the traveling speed and direction described above is compared with the current position measured by the measuring device to calculate the current position estimated to have the smallest error, so the current position can be detected with high accuracy.

[Brief explanation of drawings]

The drawing shows an example of a device implementing the system of the invention,
FIG. 1 is an overall system diagram of a traveling vehicle, and FIG. 2 is a diagrammatic diagram illustrating the configuration of an arithmetic unit. 1 is a running vehicle, 2 is a tire, 3 is a rotation sensor, 4 is an azimuth angle detection device, 5 is a calculation device, and 7 is a radio wave type position/speed/direction measuring device.

Claims (1)

[Claims] The running speed is calculated based on the number of tire rotations per unit time of the running vehicle, the running direction is calculated based on the signal from the azimuth angle detection device, and the current position/speed/direction measurement device is used to calculate the running speed. Measure the position, running speed and running direction, compare the measured running speed and running direction with the calculated running speed and running direction, calculate the running speed and running direction that are estimated to have the smallest error, and calculate the running speed and running direction that are estimated to have the smallest error. A running vehicle that calculates a current position based on a running speed and a running direction, and then compares the calculated current position with the measured current position to calculate a current position that is estimated to have the smallest error. Current position, running speed, and running direction detection system.