Case Study on Energy-Aware Position Control for Flexible Link Mechatronic Systems

The paper studies how the concept of embedded energy-aware actuators (E2A2) can be applied for position control of flexible link robots, which are widely used for manipulation tasks. Quanser rotary flexible link mechatronic system is used as a testbed for research. At the first stage, a dynamic model of a system was obtained based on the Euler-Lagrange equations and the method of assumed modes. The resulting model has finite dimension and can be easily adopted for simulation in order to study the dynamic characteristics of the system and further for trajectories planning and motion control. Next, the algorithm for combined feedforward and PD feedback control for rest-to-rest motion in a horizontal plane is presented. After studying how E2A2 switching policy affects the deformation of the link we suggest a modified scheme for smoother torque profiles, which led to reduced residual flexible link oscillations caused by an instant jump in control. Simulation and experimental results demonstrate system behaviour for different trajectories.