ABSTRACT
Objective:To design a multimodality wheelchair in order to meet many use requirements of the lower limbs dyskinesia patients. Methods:For some shortcomings of the existing multimodality wheelchair such as heavy structure and drive redundancy, the design of multimodality wheelchair based on double parallelogram mechanism is studied, and a simple and reliable multimodality wheelchair mechanism is presented. Rotary actuation drives the double parallelogram mechanism and makes parts of the wheelchair move, and three posture transformations are realized. The coupling movement of the back and leg rest realizes the transformation of sitting and supine posture, and the coupling movement of seat and back realizes the change of sitting and standing posture. The mechanical analysis of wheelchairs based on uniform load was carried out, and the rotation moment is calculated. Results:When the driving torque changed from sitting position to supine position, it increased with the increase of rotation angle and reached a peak value. When the driving torque changed from sitting position to standing position, it gradually decreased with the increase of rotation angle. Then the dynamics simulation is carried out in Adams software, the calculated results were basically consistent with the simulation results. Conclusion:The proposed mechanism is helpful to realize the lightweight design of multimodality wheelchair, and meets the design needs of intelligent multimodality wheelchair.