This paper presents design of an self contained actuators unit in wide area damping control of power system in stabilizing system response for both nominal system condition and during actuator faults.First it is prese...This paper presents design of an self contained actuators unit in wide area damping control of power system in stabilizing system response for both nominal system condition and during actuator faults.First it is presented that use of multiple actuators in wide area control aid in improving damping in power system.A wide area damping controller feeding multiple actuators to satisfy multiple objectives in wide area damping control of power system is designed.Minimization of infinity norm of closed loop transfer function of power system with wide area controller in feedback path&closed loop poles placement techniques are used in controller synthesis.Second a reconfigurable control on the lines of fault hiding principle is added to the controller design to maintain system damping to pre-fault level in case of actuator faults.A reconfiguration component(RC)is activated on occurrence of actuator fault thereby reconfiguring system dynamics and redistributing wide area control signal among remaining active actuators.RC together with remaining active actuators and under same wide area damping controller maintains system damping to pre-fault level thereby preserving system dynamic response.In the reconfigurable control design presented here no new actuators outside the unit of actuators designed for wide area damping control is required.This makes for an self contained actuators unit in wide area damping control of power system both for nominal system condition and for system affected by actuator faults.A two area power system model is considered here for demonstrating effectiveness of designed robust damping controller with multiple outputs feeding multiple actuators in wide area control and illustrating the idea of self contained actuators unit for maintaining system damping in case of actuator faults.展开更多
Each joint of hydraulic drive quadruped robot is driven by the hydraulic drive unit（HDU）, and the contacting between the robot foot end and the ground is complex and variable, which increases the difficulty of force...Each joint of hydraulic drive quadruped robot is driven by the hydraulic drive unit（HDU）, and the contacting between the robot foot end and the ground is complex and variable, which increases the difficulty of force control inevitably. In the recent years, although many scholars researched some control methods such as disturbance rejection control, parameter self-adaptive control, impedance control and so on, to improve the force control performance of HDU, the robustness of the force control still needs improving. Therefore, how to simulate the complex and variable load characteristics of the environment structure and how to ensure HDU having excellent force control performance with the complex and variable load characteristics are key issues to be solved in this paper. The force control system mathematic model of HDU is established by the mechanism modeling method, and the theoretical models of a novel force control compensation method and a load characteristics simulation method under different environment structures are derived, considering the dynamic characteristics of the load stiffness and the load damping under different environment structures. Then, simulation effects of the variable load stiffness and load damping under the step and sinusoidal load force are analyzed experimentally on the HDU force control performance test platform, which provides the foundation for the force control compensation experiment research. In addition, the optimized PID control parameters are designed to make the HDU have better force control performance with suitable load stiffness and load damping, under which the force control compensation method is introduced, and the robustness of the force control system with several constant load characteristics and the variable load characteristics respectively are comparatively analyzed by experiment. The research results indicate that if the load characteristics are known, the force control compensation method presented in this paper has positive compensation effects on the loa展开更多
文摘This paper presents design of an self contained actuators unit in wide area damping control of power system in stabilizing system response for both nominal system condition and during actuator faults.First it is presented that use of multiple actuators in wide area control aid in improving damping in power system.A wide area damping controller feeding multiple actuators to satisfy multiple objectives in wide area damping control of power system is designed.Minimization of infinity norm of closed loop transfer function of power system with wide area controller in feedback path&closed loop poles placement techniques are used in controller synthesis.Second a reconfigurable control on the lines of fault hiding principle is added to the controller design to maintain system damping to pre-fault level in case of actuator faults.A reconfiguration component(RC)is activated on occurrence of actuator fault thereby reconfiguring system dynamics and redistributing wide area control signal among remaining active actuators.RC together with remaining active actuators and under same wide area damping controller maintains system damping to pre-fault level thereby preserving system dynamic response.In the reconfigurable control design presented here no new actuators outside the unit of actuators designed for wide area damping control is required.This makes for an self contained actuators unit in wide area damping control of power system both for nominal system condition and for system affected by actuator faults.A two area power system model is considered here for demonstrating effectiveness of designed robust damping controller with multiple outputs feeding multiple actuators in wide area control and illustrating the idea of self contained actuators unit for maintaining system damping in case of actuator faults.
基金Supported by National Key Basic Research Program of China(973 Program,Grant No.2014CB046405)State Key Laboratory of Fluid Power and Mechatronic Systems(Zhejiang University)Open Fund Project(Grant No.GZKF-201502)Hebei Military and Civilian Industry Development Funds Projects of China(Grant No.2015B060)
文摘Each joint of hydraulic drive quadruped robot is driven by the hydraulic drive unit（HDU）, and the contacting between the robot foot end and the ground is complex and variable, which increases the difficulty of force control inevitably. In the recent years, although many scholars researched some control methods such as disturbance rejection control, parameter self-adaptive control, impedance control and so on, to improve the force control performance of HDU, the robustness of the force control still needs improving. Therefore, how to simulate the complex and variable load characteristics of the environment structure and how to ensure HDU having excellent force control performance with the complex and variable load characteristics are key issues to be solved in this paper. The force control system mathematic model of HDU is established by the mechanism modeling method, and the theoretical models of a novel force control compensation method and a load characteristics simulation method under different environment structures are derived, considering the dynamic characteristics of the load stiffness and the load damping under different environment structures. Then, simulation effects of the variable load stiffness and load damping under the step and sinusoidal load force are analyzed experimentally on the HDU force control performance test platform, which provides the foundation for the force control compensation experiment research. In addition, the optimized PID control parameters are designed to make the HDU have better force control performance with suitable load stiffness and load damping, under which the force control compensation method is introduced, and the robustness of the force control system with several constant load characteristics and the variable load characteristics respectively are comparatively analyzed by experiment. The research results indicate that if the load characteristics are known, the force control compensation method presented in this paper has positive compensation effects on the loa
