Direct adaptive control of a plane flexible arm

Based on a general dynamic model of flexible structures, the authors propose an adaptive computed torque scheme for the control of a plane flexible arm. From one unique input, the torque actuator, trajectory tracking is achieved for the joint angle (the rigid variable), while elastic variables are tuned to zero. A parallel use of the dynamics error equation and the coupling equations between elastic and rigid variables allows one to establish the stability of the control scheme. The adaptation law is derived from the Lyapunov direct method. Simulation results show the performances of the proposed scheme. Robustness is tested by varying the nominal payload mass, and the model parameters.<>