Calibration method for vehicle speed measuring instrument

Abstract

A method for calibrating vehicle speed measurer includes receiving GPS positioning data by GPS receiver and obtaining instrument data by said speed measurer, judging whether GPS positioning data and instrument data are in accordance to speed calibration model or not, revising speed factor originally set in said speed measurer to obtain new speed factor and storing it then using product of this new speed factor and instrument data as true speed of vehicle if it is or otherwise re-receiving GPS positioning data and instrument data.

Description

Technical field [0001] The invention relates to a method for calibrating a vehicle-mounted speed measuring instrument in dead reckoning for vehicle satellite positioning and navigation. Background technique [0002] Due to the increasing maturity of satellite positioning technology, more and more satellite positioning and navigation technologies are used by various vehicles. However, in practical applications, due to metropolitan viaducts, tunnels, overpasses, etc., satellite signals in many areas are poorly received, and due to urban The multi-channel effect of radio waves brought by large buildings greatly reduces the positioning accuracy of satellites. In severe cases, satellites cannot be positioned. The consequence is that they cannot provide continuous and accurate vehicle positioning, which affects the use of satellite navigation systems; in order to solve this problem In current vehicle navigation systems, combined positioning technology is commonly used, that is, in addi...

AI Technical Summary

Problems solved by technology

[0002] Due to the increasingly mature satellite positioning technology, more and more satellite positioning and navigation technologies are used by various vehicles. The multi-path effect of radio waves brought by large buildings greatly reduces the positioning accuracy of satellites, and in severe cases, satellites cannot be positioned. The consequence is that continuous and accurate vehicle positioning cannot be provided, which affects the use of satellite navigation systems; in order to solve this problem , in the current vehicle navigation system, the combined positioning technology is widely used, that is, in addition to the use of satellite positioning, the dead reckoning algorithm is also used to measure the heading change of the vehicle according to the angular velocity sensor, the vehicle speed value measured by the speed sensor and GPS or other positioning systems. The reference position provided can be calculated with high accuracy when the satellite positioning is not good, and the continuous positioning signal

[0003] The dead reckoning algorithm can use GPS or other positioning systems to eliminate the cumulative error of dead reckoning, so as to achieve continuous and accurate vehicle positioning and measurement of speed and heading; usually the angular velocity measurement component is a gyroscope, and the vehicle speed measurement component is a vehicle mileage signal , ABS differential signal, engine speed signal and other vehicle speed sensors, due to different circuits, gyro characteristics, vehicle types and vehicle tire wear, in order to meet the accuracy of positioning, it is necessary to carry out the gyroscope and vehicle speed sensor. Calibration; at present, there is no good method to accurately calibrate the errors of the gyroscope and vehicle speed sensor installed on the vehicle site, that is, the values ​​​​obtained by the gyroscope and vehicle speed sensor are not accurate enough

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