Extended active disturbance rejection controller

Abstract

Multiple designs, systems, methods and processes for controlling a system or plant using an extended active disturbance rejection control (ADRC) based controller are presented. The extended ADRC controller accepts sensor information from the plant. The sensor information is used in conjunction with an extended state observer in combination with a predictor that estimates and predicts the current state of the plant and a co-joined estimate of the system disturbances and system dynamics. The extended state observer estimates and predictions are used in conjunction with a control law that generates an input to the system based in part on the extended state observer estimates and predictions as well as a desired trajectory for the plant to follow.

What is claimed is: 
     
         1 . A system for controlling velocity of a plant, comprising:
 a first order state space model comprising a velocity value, v(t), where v(t) equals the sum of f(t) and b*u(t), f(t) represents the combined effects of internal dynamics and external disturbance of the plant, u(t) is a control signal, and b is a constant to an approximate value;   a linear extended state observer, which is a function of a single performance parameter, for estimating the value of f(t); and   a monitor adapted to cancel the effect of f(t) on the velocity value by an estimate from the linear extended state observer.   
     
     
         2 . The system of  claim 1 , where the plant is a web processing system. 
     
     
         3 . The system of  claim 2 , where the velocity value comprises at least one of a carriage roller velocity, an exit-side roller velocity, and a process-side roller velocity. 
     
     
         4 . The system of  claim 1 , where the linear extended state observer comprises a reduced order extended state observer. 
     
     
         5 . The system of  claim 2 , where the web processing system comprises a web handling machine for processing paper. 
     
     
         6 . The system of  claim 2 , where the web processing system comprises a web handling machine for processing plastic film. 
     
     
         7 . The system of  claim 2 , where the web processing system comprises a web handling machine for processing cloth fabrics. 
     
     
         8 . The system of  claim 2 , where the web processing system comprises a web handling machine for processing strip steel. 
     
     
         9 . The system of  claim 1 , where the velocity value v(t) comprises velocities of rollers at either end of a web span. 
     
     
         10 . The system of  claim 1 , where the combined effects of internal dynamics and external disturbance of the plant comprise effects of temperature and humidity. 
     
     
         11 . The system of  claim 1 , where the combined effects of internal dynamics and external disturbance of the plant comprise effects of machine wear and variations in raw material. 
     
     
         12 . A control system for a plant, comprising:
 a plurality of active disturbance rejection controllers; and   a high frequency gain matrix implemented in an electronic device for receiving at least one input signal from each of the plurality of active disturbance rejection controllers and for producing a plurality of control signals u,   where the plant receives the plurality of control signals u and produces a plurality of output signals y, each of said plurality of output signals further provided as an input to at least one of the plurality of active disturbance rejection controllers.   
     
     
         13 . The control system for the plant of  claim 12 , where the high-frequency gain matrix is a single gain matrix. 
     
     
         14 . The control system for the plant of  claim 12 , where the high-frequency gain matrix comprises a plurality of matrices with a one-to-one association between each input signal and each control signal. 
     
     
         15 . The control system for the plant of  claim 12 , where the plant is a turbofan. 
     
     
         16 . The control system for the plant of  claim 12 , where the plant is one of a chemical process, a mechanical process, or an electrical process. 
     
     
         17 . The control system for a plant of  claim 12 , where the plant is one of a chemical process, an airplane flight control, a missile flight control, a CNC machine control, a robotics control, a magnetic bearing, a satellite attitude control, or a process control.