A control method for parallel parking

Abstract

The invention discloses a control method for parallel parking. The control method for the parallel parking comprises the steps of obtaining a parking initial position and a parking target position, obtaining a first control point and a second control point according to the parking initial position and the parking target position, generating a planning parking track based on a three-stage bezier curve according to the parking initial position, the parking target position, the first control point and the second control point, and controlling parking of a vehicle with a trajectory tracking method and based on the planning parking track. According to the control method for the parallel parking, due to the fact that the three-stage bezier curve for forming the planning parking track is convenient to generate, small in occupancy of computing resources, and capable of solving the problem of curvature mutation, the process for parking is enabled to be smooth; due to the adoption of the trajectory tracking method, errors between an actual traveling track and the planning track, speed of a vehicle, and the distance between one side, close to an obstacle, of the vehicle and the obstacle are obtained in real time, steering angles of wheels of the vehicle are corrected in real time with a fuzzy control method, and therefore errors in the parking process can be reduced, and safety of the parking is improved.

Description

technical field [0001] The present invention relates to the technical field of automatic parking control, more specifically, to a control method for parallel parking. Background technique [0002] At present, the automatic parking assist system has become the most popular electronic equipment in the car. At present, it is generally used to park according to the parking trajectory path formed by two arcs determined by the initial parking position and the parking target position, or supplemented by a smooth curve. [0003] Such as figure 1 As shown, it is a schematic diagram of the trajectory path formed by the two-segment arc method. The entire parking trajectory is composed of two tangent arcs AC and CB, and the tangent point is point C. That is, when the vehicle is in the effective initial position area of ​​parallel parking, control the vehicle to turn the steering wheel to the right from point A (parking initial position) to the specified angle Drive to point C, contr...

AI Technical Summary

Problems solved by technology

[0004] The above-mentioned parking method based on the parking trajectory formed by two arcs has a defect that the sudden change of the steering wheel angle cannot be realized during the parking process due to the problem of a sudden change in curvature at the point C of the parking trajectory. And the parking is carried out according to the parking trajectory formed by two arcs. It is required that the speed of the vehicle is zero when the vehicle moves to point C, and the steering wheel is controlled by Hit in reverse The following vehicle continues to move according to the planned path, but it is difficult for the driver to achieve precise control of the vehicle speed

Therefore, the impact of vehicle speed will inevitably lead to a certain error between the actual parking trajectory of the vehicle and the planned ideal trajectory, which will easily cause the vehicle body to tilt after parking in the parking space, and even fail to avoid obstacles safely.

[0005] At present, another parking method is to use two circular arc segments and at least two smooth curve segments to jointly form the entire parking path trajectory with continuous curvature, which avoids the sudden change of curvature of the steering wheel angle during parking and reduces the parking time. The error between the actual running trajectory of the vehicle and the planned ideal trajectory during vehicle control, but the control method of the entire parking path trajectory with continuous curvature composed of two circular arc segments and at least two smooth curve segments has high requirements for system computing power , and the parking process is not smooth enough

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