Feedback controller
First Claim
1. A control system comprising:
- a process regulator that adjusts the value of a process variable in response to a setpoint associated therewith;
a sensor associated with the process regulator that senses the process variable and that outputs a process variable signal corresponding thereto; and
a controller connected to both the process regulator and the sensor in a closed loop, the controller being programmed with PID logic to control operation of the process regulator in response to the process variable signal received from the sensor, and to generate a control signal, including proportional, integral and derivative function contributions, that controls the process regulator based on a non-uniform two-point sampling of the process variable signal.
2 Assignments
0 Petitions
Accused Products
Abstract
A closed loop feedback control system that operates to maintain a process variable at or near a process variable setpoint. The system includes a setpoint regulator that adjusts the value of a process variable in response to a setpoint associated therewith. A sensor associated with the setpoint regulator senses the process variable and outputs a process variable signal corresponding thereto. A controller connected to both the setpoint regulator and the sensor in a closed loop is programmed with PID logic to control operation of the setpoint regulator in response to the process variable signal received from the sensor. The controller generates a control signal that controls the setpoint regulator based on a non-uniform two-point sampling of the process variable signal. The controller delivers smooth, bump-free, control in spite of changes in the setpoint controller gains or system parameters. A digital filter is also implemented with the controller of the present invention to filter the process variable signal input into the controller. The filter includes both an amplitude to clip signal spikes and glitches and a low pass frequency filter to remove higher order noise-related frequencies from the signal, thereby reducing system memory requirements and increasing system computational speed.
-
Citations
26 Claims
-
1. A control system comprising:
-
a process regulator that adjusts the value of a process variable in response to a setpoint associated therewith; a sensor associated with the process regulator that senses the process variable and that outputs a process variable signal corresponding thereto; and a controller connected to both the process regulator and the sensor in a closed loop, the controller being programmed with PID logic to control operation of the process regulator in response to the process variable signal received from the sensor, and to generate a control signal, including proportional, integral and derivative function contributions, that controls the process regulator based on a non-uniform two-point sampling of the process variable signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
-
-
19. A feedback control method, comprising the steps of:
-
setting a process setpoint at a desired value; determining deviation of a process variable from the process setpoint via a non-uniform sampling of the process variable; and controlling the process variable in response to said step of determining deviation of a process variable to reduce the deviation in a manner that minimizes setpoint overshoot and undershoot wherein said controlling is accomplished via digital Proportional integral derivative (PID) logic that produces a control signal having a proportional function contribution, an integral function contribution and a derivative function contribution. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26)
-
Specification