Compensation research on the friction characteristic of the DDVC flange-type rotary vane steering gear

Direct Drive Volume Control (DDVC) flange-type rotary vane steering gear is a greatly promising component to be applied in the controlling course and posture of vessel due to the superior advantages of compact structure, powerful vibration absorption, simple control and etc. However, the nonlinear friction is a main limit for DDVC flange-type rotary vane steering gear to meat the accuracy requirement of vessel. In this paper, we proposed a high gain PID methods to suppress the non-linear friction so as to control the rudder effectively and precisely. According to the principle of the DDVC flange-type rotary vane steering gear, we established the mathematical model, transfer function of the steering gear system and the mathematical model about the impact of nonlinear friction on rudder system. To suppress the nonlinear friction, a compensation method independent of friction model by high gain PID control strategy was proposed, studied theoretically and experimentally. Measured results by prototype testing reveal that both the two methods can compensate the nonlinear friction, while the performance increased up to 40 percent than no compensation state. The outcome of this research will contribute to the rapidity and stability of DDVC flange-type rotary vane steering gear system.