The pneumatic rotary position system, in which an electro-pneumatic proportional flow valve controled a rotary cylinder, was studied, and its mathematical model was built. The model indicated that the controlled pneum...The pneumatic rotary position system, in which an electro-pneumatic proportional flow valve controled a rotary cylinder, was studied, and its mathematical model was built. The model indicated that the controlled pneumatic system had disadvantages such as inherent non-linearity and variations of system parameters with working points. In order to improve the dynamic performance of the system, feed forward compensation self-tuning pole-placement strategy was adopted to place the poles of the system in a desired position in real time, and a recursive least square method with fixed forgetting factors was also used in the parameter estimation. Experimental results show that the steady state error of the pneumatic rotary position system is within 3% and the identified system parameters can be converged in 5 s. Under different loads, the controlled system has an excellent tracking performance and robustness of anti-disturbance.展开更多
Positioning with high precision piezoelectric actuators is widely used.To overcome positioning inaccuracy caused by hysteresis and creep of actuators,a precise tracking method for piezoelectric actuators using active ...Positioning with high precision piezoelectric actuators is widely used.To overcome positioning inaccuracy caused by hysteresis and creep of actuators,a precise tracking method for piezoelectric actuators using active disturbance rejection control(ADRC) has been proposed in this paper.This method,in real-time,actively estimates and compensates parameter uncertainties,nonlinear factors such as hysteresis,and external disturbances in the tracking system.Precise tracking of the piezoelectric actuator can be achieved without any form of feedforward compensations.The experimental results demonstrate that the active disturbance rejection controller can reduce tracking errors by over90%comparing with those using the PID controller.Those features of the proposed control method are very suitable for applications in adaptive optics.展开更多
基金Project(50375034) supported by the National Natural Science Foundation of China
文摘The pneumatic rotary position system, in which an electro-pneumatic proportional flow valve controled a rotary cylinder, was studied, and its mathematical model was built. The model indicated that the controlled pneumatic system had disadvantages such as inherent non-linearity and variations of system parameters with working points. In order to improve the dynamic performance of the system, feed forward compensation self-tuning pole-placement strategy was adopted to place the poles of the system in a desired position in real time, and a recursive least square method with fixed forgetting factors was also used in the parameter estimation. Experimental results show that the steady state error of the pneumatic rotary position system is within 3% and the identified system parameters can be converged in 5 s. Under different loads, the controlled system has an excellent tracking performance and robustness of anti-disturbance.
基金Supported by the National Natural Science Foundation of China(No.11373048)
文摘Positioning with high precision piezoelectric actuators is widely used.To overcome positioning inaccuracy caused by hysteresis and creep of actuators,a precise tracking method for piezoelectric actuators using active disturbance rejection control(ADRC) has been proposed in this paper.This method,in real-time,actively estimates and compensates parameter uncertainties,nonlinear factors such as hysteresis,and external disturbances in the tracking system.Precise tracking of the piezoelectric actuator can be achieved without any form of feedforward compensations.The experimental results demonstrate that the active disturbance rejection controller can reduce tracking errors by over90%comparing with those using the PID controller.Those features of the proposed control method are very suitable for applications in adaptive optics.