Simulation of interaction tasks for pneumatic soft robots using SimMechanics

Soft robot arms, driven by novel pneumatic actuators with Rotary Elastic Chambers (REC), are well suitable for assistive and service tasks. However, the control of such robots is quite difficult because of high nonlinearities in actuators dynamics in addition to robot arm models. In this paper the recently developed Simulink-based program library “SoftRob” for simulation of the soft robots with REC actuators is described. A new adaptive admittance control scheme for pneumatic soft robots is proposed. The approach imitates the human force control capacity to regulate the contact force by adapting the arm stiffness. The algorithm is assumed to be realized without explicit force measurement, i.e. without the use of expensive external force sensors. The proposed control scheme is tested in simulation on example of a planar 2DOF model.