在月面环境下车轮滑转影响月球车的运动性能和定位精度,针对星球车车轮滑转率检测问题,提出一种基于车辙图像频域特征的滑转率估计方法。通过分析车轮与土壤相互作用过程与车辙形成机理,建立车辙的时域参数化解析模型。并在车辙构造时域解析模型基础上,通过对车辙图像进行频域分析,建立了基于车辙图像基频特征的车轮滑转率估计模型。此外,介绍了一种适用于该方法的车辙频域特征提取和图像处理技术。通过试验证明,该方法只需检测车辙图像基频便可以实现车轮滑转率非接触式精确估计。采用本方法估计车轮滑转率,相对精度可达3%。
The wheel slippage affects the rover mobility and localization accuracy in lunar terrains. In view of the rover slip ratio detection problem, this paper suggests a method for estimating the rover vehicle wheel slip ratio by detecting trace imprint image frequency feature. The defuse analysis model of trace imprint is built by analyzing the wheel-terrain- interaction process and trace imprint formation mechanism. The slip ratio estimation model based on the imprint image fundamental frequency characteristics is built by the defuse analysis model of trace imprint and the frequency domain analysis of trace imprint image. Further, the trace imprint image process and frequency domain feature extraction process for this method are also proposed. The slip ratio can be measured without contact only by detecting the fundamental frequency of the trace imprint image precisely. The test results show that the relative accuracy of the wheel slip ratio is 3% by using this method.