Bidirectional Position Control of a Prismatic joint for Motorized Single Link Robotic Arm Using Adaptive Super- Twisting Sliding Mode Control

Design of the dual layer adaptive super-twisting sliding mode control (ASTSMC) strategy for position control of a motorized single link flexible robotic arm is presented in this article.The system comprises of a cantilever beam, the robotic arm whose horizontal sliding enables positioning at the required length. Prismatic joint at the fixed extremity of the flexure is positioned at the desired point (the set length) by a linear actuation system- the DC motor and the lead-screw. The parameters and hence the model of the DC motor is determined using the nonlinear least-square (NLS) parameter estimation method. The flexible manipulator is modeled using the lumped parameter model approach. The super twisting algorithm and adaptive law are designed in combination to control the position of the robotic arm; the performance of the adaptive SMC controller is compared with that of the classical PID controller and SMC. The simulated and experimental results show that positioning accuracy is ensured and the response time is improved by the ASTSMC controller. © 2023, The Institution of Engineers (India).