Analysis of user's comfort of walker based on wrist point dexterity to improve physical human-robot interaction

A walker is a tool that uses the person's own remaining locomotion capability to provide support while walking. The user's operating comfort determines the utilization rate and auxiliary effect of the device. Users' different operating postures and different walking styles bring different operating feelings to users. However, few people have explored the visual analysis method of the user's operating comfort of the walker. The purpose of this study is to provide an intuitive method for analyzing the user comfort of walkers by using a motion capture system and upper limb motion dexterity, and to provide solutions for human-robot interaction strategies. Ten healthy male volunteers without upper limb diseases were tested with standard walker and front-wheel walker respectively. Based on the kinematic model proposed in this paper, the upper limb motion trajectory is measured by the VICON motion capture system, and the user's comfort in operating the walker is analyzed using the wrist point motion track tangent and manipulability ellipsoid. The wrist point motion track tangent and motion ability can intuitively analyze the user's operating comfort at any stage. The results show that there is a deviation between the wrist point motion track tangent and the optimal motion direction in the assisted gait, which is related to the structure and operation mode of the walker. The research method provided by this experiment can further understand the user's operation rules during the operation of the walker, and is of great significance to improve the user's operation comfort and control smoothness.