Tenreiro Machado, J. A.2019-04-092019-04-091995-09-20http://hdl.handle.net/10400.22/13492This article studies the variable strucutre control of robot manipulators with joints having flexibility and backlash. A second order reference model and a smooth control law eliminate the reaching phase problems and the chattering usually present in the sliding mode. The results show a remarkable improvement of the stability over conventional variable structure controllers, while the algorithm maintains a low computational load that makes it suited for microcomputer implementation.engconference object