Calculation method and device for road slope based on lag filter

Abstract

The present invention discloses a method and device for calculating road slope based on hysteresis filtering, including: (a) calculating the average value of the longitudinal acceleration within the sampling period T; calculating the average value of the vehicle's own acceleration within the sampling period T; (b) Subtract the average value of the vehicle's own acceleration within the sampling period T from the average value of the longitudinal acceleration in the sampling period T to obtain the measured value of the longitudinal component of the vehicle's gravitational acceleration; (c) subtract the measured value of the longitudinal component of the vehicle's gravitational acceleration from the longitudinal acceleration sensor The zero point deviation of the vehicle's gravitational acceleration is obtained to obtain the true value of the longitudinal component of the vehicle's gravitational acceleration; (d) the real value of the vehicle's gravitational acceleration is subjected to lag filtering processing to obtain the vehicle's longitudinal component of the gravitational acceleration; (e) Calculate the slope value of the road surface, and the slope value is equal to The ratio of the longitudinal component of the vehicle's gravitational acceleration to the gravitational acceleration. The slope value obtained by using the invention is more accurate, the fluctuation is small, and the cost is low.

Description

technical field [0001] The invention belongs to the technical field of automobile intelligent control, and in particular relates to a calculation method and a device for calculating road slope based on hysteresis filtering. Background technique [0002] At present, the driving conditions of automobiles are very complicated, and the functions of intelligent control are becoming more and more abundant. If you don’t know the exact slope of the road where the car is now, there may be problems such as sliding slope, forward rush, engine speed overshoot, and inaccurate control of uphill and downhill speeds when starting. In the vehicle controller, ESP (body electronic stability system), EPB (electronic parking brake system), TCU (automatic transmission control unit), EMS (engine management system), intelligent driving system ACC (adaptive cruise control system), AEB (automatic emergency braking system), APA (automatic Parking assistance) and other functions require accurate slope...

AI Technical Summary

Problems solved by technology

[0003] At present, the vehicle slope calculation scheme on the market is replaced by the original longitudinal acceleration output signal of the ordinary vehicle acceleration sensor, but the signal fluctuates greatly during the constant speed driving, acceleration and braking stages and cannot truly reflect the slope state of the road, and the detection accuracy cannot meet APA accuracy. Control needs; while the cost of inertial navigation IMU is high (more than 10,000 yuan), the performance is not good, and the product has not been mass-produced, so it cannot be popularized and applied in batches

Use vehicle acceleration and vehicle speed information to estimate, which only uses weighted average algorithm, without considering the characteristics of sensor signal fluctuation and its own zero point deviation, the estimation result is unstable, and there is no practical engineering application for now

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