应用二维激光雷达的地形识别系统设计

动力型下肢假肢的主要功能是帮助截肢患者实现独立自如的行走，为了使假肢能够配合用户的运动，需要对用户的运动意图进行识别。通过提前获知用户前方环境信息，将其作为运动意图识别的先验知识，可以提高运动意图的识别精度。为了给动力型下肢假肢提供前方环境信息，设计了一种可穿戴的地形识别系统。首先通过安装在人体腰部的二维激光雷达收集前方地形数据，然后利用凝聚分层聚类算法对采集的数据进行线性特征提取，最后利用有限状态自动机对前方地形进行识别。实验中，对平地过渡到上/下斜坡、上/下楼梯四种地形进行了测试。结果表明，该系统不仅对四种地形的识别精度达到了95.8%，还可以计算出传统的运动意图识别方法无法得到的地形参数信息，包括斜坡的坡度、楼梯的阶数和台阶的高度与宽度。这证明了将该系统应用于动力型下肢假肢的有效性和可行性。

Design of terrain recognition system using 2D lidar

The main function of powered lower limb prosthesis is to help the amputees to achieve independent and comfortable walking. In order to make the powered lower limb prosthesis coordinate with the user, it is necessary to recognize the motion intention of the user. By knowing the environment information in front of the user, and taking it as a prior knowledge of motion intention recognition, the recognition accuracy of motion intention will be improved. In order to provide environment information in advance for the powered lower limb prosthesis, a wearable terrain recognition system was designed. The 2D lidar installed in the waist were used to collect the terrain data in front, then extract linear feature of the collected data using agglomerative hierarchical clustering algorithm, finally the terrain was recognized using finite automaton. In the experiment, four terrains were tested, including level ground to up/down stair and up/down slope. Results show that the recognition accuracy of the system to four terrains reaches to 95.8%, and it can obtain the information of terrain parameter including angle of slope, number of steps, stair height and stair depth which can't be obtained from the traditional motion intention recognition methods. It proves that the system is effective and feasible for powered lower limb prosthesis.