Robust deflection control and analysis of a fishing rod-type flexible robotic manipulator for collaborative robotics
Authors :- Prasenjit Sarkhel, Mithilesh K. Dikshit, Vimal Kumar, Pathak, Kuldeep K. Saxena, C. Prakash, Dharam Buddhi
Publication :- Robotics and Autonomous Systems, Volume 159, January 2023
Due to high-speed operation at low inertia, flexible manipulators are becoming more and more popular in today’s world. These manipulators produce excessive vibration, which must be reduced using an efficient control technique for the manipulator to function well. In the present study, a flexible manipulator model with a single link is built in such a manner that it can be considered as a flexible fishing rod. The free end of the flexible rod has a provision for applying a payload, which serves to give a deflection of the flexible rod. A lumped parameter method is adopted for modelling the flexible rod as well as the string using the Sim-Mechanics tool in MATLAB. Simulations were carried out for sudden and sinusoidal loading. It has been found that the flexible link produces excessive vibration under both sudden and sinusoidal loading. A proportional integral derivative (PID) controller is used to suppress the excessive vibration generated in the simulation model. Four different locations (Location 1: 15 cm; Location 2: 30 cm; Location 3: 45 cm; and Location 4: 60 cm) are selected for controller positioning. Simulation revealed that the minimum deflection was observed at location 4, i.e., at the tip for both sudden and sinusoidal loading. The developed model is validated using two loading conditions, viz., the beam’s self-weight and a point load of 30 N at the free end. It has been found that the simulation results resemble the analytical results with an error of 0.44% and 0.36% for both the loading conditions.