Their controller designs usually base on the models which consider manipulators as series of rigid links. In the applications of high precision positioning control, however, there is a level of tolerance such that the flexibility in the links must be considered in the controller design. Another difficulty in robot control is friction.
Friction exists in most of physical manipulators and mechanical control systems.
Friction can cause steady state errors, undesired stick-slip motion or even unstability. It consists of a flexible drive train, a flexible link, and adjustable friction and backlash mechanisms. Although this test bed has capability to add backlash into the system, this talk will focus on modelling and control of the test bed under the influence of friction only. The model of the test bed was developed using Kane's method together with assumed-mode method. Several analytical mode shapes were investigated.