Virtual Model Control Algorithm Simulation for Lower Limb Assist Exoskeleton

In response to the problem of poor motion control models for lower limb heavy-duty exoskeleton robots, this paper proposes a lower limb assisted exoskeleton control method based on virtual model control algorithm (VMC). The dynamic model, human motion model, and human-exoskeleton interaction model of the exoskeleton robot are established. The virtual model applied by the overall control target is decomposed into each support leg according to certain principles, and the corresponding joint torque is calculated using the Jacobian matrix of both legs, And a virtual model of the swinging phase of both legs is constructed for VMC control of the swinging phase, and model switching is carried out based on gait rules and touchdown signals, thereby avoiding the derivation of complex global Jacobian matrices and reducing the disturbance introduced by model switching, improving the effect of exoskeleton following human motion. Through simulation modeling analysis, the virtual model control algorithm based lower limb assist exoskeleton control method has smaller human-exoskeleton interaction compared to sensitivity amplification control, which improves the control performance of lower limb heavy-duty assist exoskeleton robots.