Abstract: Gait event detection is an important part of exoskeleton robot motion control and performance evaluation.In order to improve the efficiency and accuracy of gait event detection of exoskeleton robots,a wearable gait time detection system based on infrared distance sensor was proposed. Firstly,an intelligent wearable device with infrared distance sensor was developed to obtain stable distance signal. The height of the rear heel and toe gap above the ground was used to detect all six gait events in a gait cycle and convert them into effective foot posture information.Secondly,an online detection algorithm using local search window and fixed threshold was proposed.By combining this algorithm with infrared distance sensor,the minimum time delay and reduced computational load can be achieved. Finally,the proposed method was integrated into the exoskeleton robot system for experiments to detect gait events of human-robot collaborative walking. The experimental results show that when the proposed method is applied to the lower limb exoskeleton robot,all gait events of human-robot synchronous walking can be successfully detected,with an average detection error of less than 34 ms and an average detection accuracy of 99.62 %,which has good real-time performance and high detection accuracy.

Key words: exoskeleton robot, infrared distance sensor, gait event detection, foot height from the ground