Focusing on the problem of the friction disturbances in direct current(DC)servo system

a scheme of friction compensation with genetic algorithm(GA)is proposed. A friction model is established according to the friction characteristics of a DC servo system; then

the friction compensation is introduced to the feedback control structure of DC servo system to calculate the position error of the servo motor. Genetic algorithm is adopted to identify the friction compensation model

and to make the quantity of friction compensation approximates to the practical friction disturbance unceasingly

so that the influence of friction on the servo system is eliminated. Moreover

the objective function of genetic algorithm is selected according to the control demands in the transition process and steady state of the system. The friction compensation model obtained from optimized parameters compensates the low dynamic and static performance of the previous DC servo systems due to friction disturbance

and ensures that the servo motor has higher track precision. Simulation results demonstrate that

compared to the case without friction compensation

the adjusting time of rotating speed response of the DC servo motor is decreased by 0.12 s

and the static error is lowered by 1%

meanwhile the system has better restraint ability against friction disturbance and parameter robustness.