An adaptive control method is proposed to resist disturb-ance while walking with given trajectory. The method con-tains two parts. The optimal control method of quadratic exponent of linear system is used to avoid random inter-ference caused by unpredicted motion. Considering that the center of gravity (COG) of user varies while walking with lower limb exoskeleton, an estimable systematic disturb-ance is introduced to the BWS system. And a feedforward control method based on error input is designed to avoid systematic interference. The systematic interference is modeled according to the structure of the leg in lower limb exoskeleton. The complete control approach is the combi-nation of two controllers. Finally, simulations of different control methods have been carried out to prove the effec-tiveness of the proposed method.
An Adaptive Control Approach of Body Weight Support System for Lower Limb Exoskeleton Based on Trajectory Feedforward Xingming Wu, Ziwen Xu, Jianhua Wang, Jianbin Zhang, Weihai Chen