Abstract: In view of the shortcomings of the existing technology of electro-hydraulic servo edge and center position control system extensively used in the strip production line, such as low efficiency of energy utilization, easy heat generation, and production interruption caused by easy failure of core devices servo valve and deviation sensor, the hardware redundancy control principle using two servo valves for master-slave control and combined photoelectric sensor and capacitance sensor for detection of strip deviation is proposed. With this new technology, the probability of failure of deviation rectification system is reduced, and in turn the loss caused by production interruption is decreased. To improve the energy efficiency of the system, the constant flow pump with variable speed drive, cooperated with the energy accumulator, to work in the pressure control mode is proposed. During the research, a redundancy detection principle by using both serial and parallel sensors is formulated. The dynamic and static characteristics and control accuracy of photoelectric detection and capacitance detection are tested. The energy consumption and dynamic response performance in the deviation rectification process of hydraulic pump with variable speed drive and that with constant speed drive are compared; and the deviation rectification process of system under continuous disturbance is tested. The research results show that with the new control scheme, the requirements of dynamic and static performance during deviation rectification can be satisfied on the basis of reducing 70% of system energy consumption, thus reaching the expected goal.

Key words: Deviation control, Energy-saving, Redundancy control, Servo system