Anti-folding control system for semi-trailer

Abstract

The invention provides an anti-folding control system for a semi-trailer; vehicle parameters are measured through a sensor, and the vehicle speed, the road adhesion coefficient and the ideal yaw velocity are estimated; an intervention threshold value is set, an anti-folding control program sets three folding angle threshold values and a folding angle speed threshold value to serve as the distinguishing basis of the active braking strategy, the size relation among the three folding angle threshold values is sequentially decreased, and the first folding angle threshold value is the maximum value in the three threshold values; the anti-folding control system architecture adopts electric and pneumatic double-loop control and has a redundancy function; and brake action control over corresponding wheel brake chambers is achieved through a tractor rear axle double-channel bridge control valve and a semitrailer double-channel bridge control valve, and the state of brake air pressure is controlled, namely pressure increasing, pressure maintaining and pressure reducing. By reducing the output torque of an engine and implementing combined intervention of active braking, the folding instability working condition of the semi-trailer is effectively prevented, and posture correction of the folding instability working condition of the semi-trailer is achieved.

Description

technical field [0001] The invention relates to a control system for a semi-trailer, in particular to an anti-folding control system for a semi-trailer. Background technique [0002] Semi-trailers have the advantages of high efficiency, economy, and large transportation volume. They are an important force in modern transportation, but the traffic safety problems caused by them are also extremely serious. The semi-trailer is articulated by the tractor through the fifth wheel. Compared with the two-axle single vehicle, the semi-trailer has mutual coupling of motion, and because of its unique structural factors, it will lead to high-speed driving and emergency steering. Under extreme working conditions such as obstacle avoidance and emergency braking, the tires will approach or reach the road adhesion limit faster, or even completely lose the lateral adhesion ability. As the load changes, the lateral force will also change accordingly. Therefore, the interference of the extern...

AI Technical Summary

Problems solved by technology

The semi-trailer is articulated by the tractor through the fifth wheel. Compared with the two-axle single vehicle, the semi-trailer has mutual coupling of motion, and because of its unique structural factors, it will lead to high-speed driving and emergency steering. Under extreme working conditions such as obstacle avoidance and emergency braking, the tires will approach or reach the road adhesion limit faster, or even completely lose the lateral adhesion ability. As the load changes, the lateral force will also change accordingly. Therefore, the interference of the external lateral force under the above working conditions will easily cause the tractor to deviate from the original driving direction and cause lateral movement. Because the rear semi-trailer will cause impact on the front tractor, It causes a yaw movement, causing it to quickly approach the semi-trailer around the fifth wheel. Because the folding angle of the two workshops is too large, the folding instability occurs and it is difficult to maneuver

[0003] The angle between the central axis of the tractor and the central axis of the semi-trailer is the folding angle. The folding angle increases to 90° or greater than 90°, which is a sign of folding phenomenon. When the speed of the vehicle is turned or the front of the car is turned, the folding angle will also increase. Under such working conditions, there is no hidden danger of instability, and it has no effect on driving safety and stability.

The existing semi-trailer control lacks a control system or method for anti-folding of the semi-trailer, and it is impossible to distinguish whether the increase in the folding angle of the semi-trailer is caused by the driver's active operation or the phenomenon of folding instability. Therefore, an effective control system is needed to identify And suppress the phenomenon of semi-trailer folding instability to improve the driving safety and stability of the semi-trailer

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