Biomimetic Control of Myoelectric Prosthetic Hand Based on a Lambda-type Muscle Model

Myoelectric prosthetic hands are intended to re-place the function of the amputee’s lost arm. Therefore, developing robotic prosthetics that can mimic not only the appearance and functionality of humans but also characteristics unique to human movements is paramount. This paper proposes a novel biomimetic control method for myoelectric prosthetic hands integrating the impedance model with the concept of the λ-type muscle model. According to the state of the muscle, the proposed method can dynamically control the joint equilibrium position, and can maintain the joint angle naturally during muscle relaxation. The experimental results, based on comparison with the actual human joint angles, suggest that the proposed method has a better correlation with the actual human motion than the conventional methods. Additionally, the control experiments showed that the proposed method could achieve a natural prosthetic hand movement similar to that of a human, thereby allowing voluntary hand movements.