关于超声波倒车雷达测距的，包含特征值与特征向量的提取、训练样本以及最后的识别，仿真图是速度、距离、幅度三维图像。- About ultrasonic parking radar ranging, Contains the eigenvalue and eigenvector extraction, the training sample, and the final recognition, FIG simulation speed, distance, amplitude three-dime