Adaptive control of the SCORBOT-ER 4PC manipulator

The problem of the manipulator tracking control is not trivial because the manipulator is a nonlinear object, whose parameters may be unknown and variable. The control law should enable the manipulator to behave correctly even when operational conditions are changeable. The adaptive control system meets this requirement. In this paper, both kinematic and dynamic equations of motion for the Scorbot-ER 4pc are presented. The adaptive control algorithm was derived for this manipulator. The presented control and adaptive laws guarantee practical Lyapunov stability. The results of verification of theoretical investigations are presented. Experiments were carried out on a work station which consists of the Scorbot-ER 4pc robotic manipulator, a computer with Matlab and dSPACE ControlDesk software and a DS1006 digital signal processing board. In the experiments, the specified point of the manipulator has moved on a desired circular path and the gripper of the manipulator was loaded in variable ways. The operation of adaptive control system was compared with the computed moment method. From the result of the comparison we can see that, in practice, the adaptive control gives better results.

Full text (pdf)

1. Canudas de Wit C., Siciliano B., Bastin G.: Theory of Robot Control. Springer-Verlag, London 1996.
2. Spong M.W., Vidyasagar M.: Dynamika i sterowanie robotów. WNT, Warszawa 1997.
3. Tchoń K. i in.: Manipulatory i roboty mobilne: modele, planowanie ruchu i sterowanie. Akademicka Oficyna Wydawnicza PLJ, Warszawa 2000.
4. Cazilla J., Vallés M., Mata V., Díaz-Rodríguez M., Valera A.: Adaptive control of a 3-DOF parallel manipulator considering payload handling and relevant parameter models. Robot. Computer-Integrated Manuf., 30 (2014), 468-477.
5. Giergiel M.J., Hendzel Z., Żylski W.: Modelowanie i sterowanie mobilnych robotów kołowych. PWN, Warszawa 2002.
6. Isidori A.: Nonlinear Control Systems: An Introduction. Springer-Verlag, Berlin 1985.
7. Slotine J.J., Li W.: Applied Nonlinear Control. Prentice Hall, New Jersey 1991.
8. Zeinali M., Notash L.: Adaptive sliding mode control with uncertainty estimator for robot manipulators. Mech. Machine Theory, 45 (2010), 80-90.
9. Żylski W., Gierlak P.: Modelowanie ruchu wybranego manipulatora. Acta Mech. Automatica, 4 (2010), 112-119.
10. Lewis F.L., Yesildirek A., Liu K.: Multilayer Neural-Net Robot Controller with Guaranteed Tracking Performance. IEEE Trans. Neural Networks, 7 (1996), 388-399.