Fuzzy logic based compensation of friction in low speed motion control

A fuzzy adaptive feedforward control scheme in conjunction with conventional linear feedback control is proposed for use in mechanical motion control systems where friction undermines performance. The proposed control scheme was realized in terms of three alternative control systems for low speed control of a DC motor driving a mechanical system having both dry and lubricated junctions. In experiments these alternative control systems achieved good tracking performance, i.e., without stick-slip type oscillations for reference speeds as low as 0.005 rad/sec, while conventional linear control without fuzzy adaptation exhibited large stick-slip type oscillations or poor tracking performance over the same range of reference speeds.