Design, Modeling and Manufacturing a New Robotic Gripper with High Load Bearing Capability and Robust Control of its Mechanical Arm

In this paper, a new robotic gripper is proposed and modeled which is able to bear a high amount of load and it can be used as the claws of climbing robots. As the climbing robots are usually heavy and their configuration should be kept in height against the gravity, firm grippers with no slippage possibility should be designed in order to guarantee the stability. The proposed new gripper is essentially required for the grip-based climbing robots which are heavy and are supposed to accomplish a specific operational task while they are grasping the pipe-shaped structures. The kinematic and quasi-static modeling of the proposed gripper is extracted and its related parameters are optimized to provide the maximum gripping force and the minimum slippage probability. Since these robust grippers are usually actuated by high torque motors, the reaction effect of the actuators force on the arm of the robot model is investigated here as a new study. Hence, the corresponding mechanical arm is also controlled, using a robust nonlinear controller to neutralize the destructive effect of extreme reaction forces or torques from the gripper motors to the robot arm during its mission. Thus, a robust controller is designed and implemented on the arm joint to cover the required positioning accuracy of the arm movement during the climbing motion. Afterward, the applicability of the proposed gripper and also the efficiency of the designed controller is verified by the aid of some analytic and comparative simulation scenarios performed in MATLAB-SIMULINK and MSC-ADAMS simulation. It is shown that the proposed gripper together with its related controlling algorithm for the arm can successfully provide a proper climbing mechanism for these kinds of robots which are supposed to climb through the structures and perform a special manipulating task.  

Keywords:

Climbing Robot , Gripper Mechanism , Optimal Design , Robust controller , sliding mode control