| Mechanical systems involving relative motion are always under the influence of friction. Therefore, it is important to include the frictional effect for designing controllers when the precise regulation of the system is required. For a point-to-point control of flexible systems which is also under the influence of friction, vibratory motion of the system may cause undesirable behavior such as residual vibration and stick-slip. Finding a controller for such a system is a challenging problem because of the complex behavior of friction. In this thesis, various friction models and friction compensation techniques for frictional systems are discussed. New developments are proposed such as velocity constrained linear programming, time-optimal control, and pulse amplitude modulated control to handle the flexibility under the influence of frictional forces. The proposed techniques are illustrated on a frictional benchmark problem to demonstrate the effectiveness of the control. |
