In order to avoid the shortcomings of external force sensors equipped on prosthetic hands in the grasping force control

a grasping force control method of prosthetic hands based on force estimation using motor current signals is proposed. Combining the prosthetic hand model

the contact force model and the direct current（ DC） motor model

a grasping force estimation model based on current signals is established. The force estimation model is applied to the proportional-integral-differential（ PID） force controller to achieve grasping control of prosthetic hands without external force sensors. Grasping control simulations and experiments show that the proposed methods of estimating and controlling the grasping force of prosthetic hands are effective.