A novel bilateral haptic teleoperation approach for hexapod robot walking and manipulating with legs

Teleoperation control of the multiple degrees-of-freedom (DOF) robot requires a strategy for improving its controllability and adaptability. A novel bilateral haptic teleoperation approach (multi-master single slave) is proposed for a hexapod robot in which the first master control the primary task of the slave, e.g. the linear/steering motion; meanwhile, the second master can perform a minor task, e.g. to interact with the environment by leg. The designed teleoperation system consists of two parts: body-level and leg-level. In body-level subsystem, the linear/angular velocity of the slave body follow the first master's position, and the velocity loss caused by the system disturbances is fed back to the operator in the form of haptic force. In leg-level subsystem, a modified four-channel (4CH) teleoperation control architecture is proposed for the manipulable leg, which can be regarded as a manipulator, so as to guarantee the performance of the position/force tracking in the subsystem subject to parametric uncertainties, environmental perturbation and unmeasurable interaction force. Additionally, the stability of the multi-DOF bilateral haptic teleoperation system are verified via absolute stability criterion and Lyapunov theorem, respectively. Experiments of the proposed approach demonstrate that it can result in stable and transparent bilateral teleoperation with haptic force feedback. (C) 2018 Published by Elsevier B.V.