Patent ID: 9684292
Date: 2017-06-20
CPC Classifications: G05B

Claim:
1. A conditional switched rate low pass filter for reducing noise in a closed-loop control system comprising: a first low pass digital filter, the input of which is coupled to an output of the control system, wherein the first digital filter removes noise, in the signal from the output of the control system, higher in frequency than the characteristic response of the control system; a second low pass digital filter, the input of which is coupled to the output of the first digital filter, and the output of which is coupled back into the control system; wherein the second digital filter removes noise which is at essentially the same frequency as the closed-loop system response; buffer memory for storing an output signal from the first digital filter; a signal stability monitor module, coupled to the buffer memory, configured to detect changes in the output signal from the first digital filter; and a computer implementing the first digital filter, the second digital filter, and the signal stability monitor module, coupled to the buffer memory, for controlling the operation of the switched rate low pass filter; wherein the signal stability monitor determines the response time of the second digital filter based on monitoring of the output signal from the first digital filter, as stored in the buffer memory, and wherein: