Dynamics and control of locomotion of one leg walking as self-impact double pendulum

Abstract

Despite some successful dynamic simulation of self-impact double pendulum - as humanoid robots legs or arms- studies, there limited information is available about the control of one leg locomotion. It is clear that the gait cycle, as a part of the lower-extremity motions, has a remarkable effect on the whole body movement and also behavior. The whole walking motion has been modeled into an inverted pendulum structure where the one leg locomotion is similar to Self-Impact Double Pendulum (SIDP) with a stopper at the lower-joint. The main goal of the research is to improve the reliability of the mammalians leg locomotion and building more elaborated models close to the natural movement, by modeling it as a SIDP. This paper also presents the control design of the SIDP where the stability analysis is a vital factor on the investigation of the whole body movement. The model is characterized by the impact that occurs at the pattelo-femoral joint (the lower joint of the model) in both dynamic and control design. Also the dynamic and control aspects of a different and new perspective of the role that impact plays on thigh locomotion while running fast will be expressed. Since the system is considered (as) nonlinear, MIMO Input-Output Feedback Linearization method will be employed for control purposes. Holding hand or leg in different positions will be regarded here by regulating a smooth arc length angle of each link. The simulation results are available to illustrate the system performance.