Modeling and interactional control of the multifingered hand

Abstract

Object grasping by robot hands is challenging due to the hand and object modeling uncertainties, unknown contact type and object stiffness properties. To overcome these challenges, the essential purpose is to achieve the mathematical model of the robot hand, model the object and the contact between the object and the hand. In this paper, the mathematical model of a three fingered hand called The Barrett Hand is developed applying the Lagrangian method. Cartesian and Joint space motions are simulated on the basis of the PD computed torque algorithm. A hand-object contact model is developed for a coupled system assuming that the object properties are known. The performed simulation studies confirm the joint and Cartesian space motions along with the estimated contact force. The impedance control is considered in an existing system to regulate the interaction force during contact. This method controls the stiffness and damping of the interaction; force and position are regulated due to the compliance of the finger. The impedance based control is simulated in the Simulink/ SimMechanics environment and the results are presented under different environment stiffness. This certifies the implementation of the law in real hand soon.