The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 02, 1999
Filed:
Jul. 08, 1997
Kirk H Drees, Cedarburg, WI (US);
Nebil Ben-Aissa, Franklin, WI (US);
John E Seem, Shorewood, WI (US);
Johnson Services Company, Milwaukee, WI (US);
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.