Quarter Decay Ratio Tuning of Control Loops

4 Quarter Decay Ratio Tuning of Control Loops 

The height between the first peak and valley, that is, 50% plus 25%, is 75% of the height of the step change in setpoint. This response pattern can be recognized as being aggressive. There is a lot of control action in response to a disturbance to the control loop. 

3 Pattern Recognition Tuning of Self-Regulating Control Loops 

Robbins reported the development of a closed-loop tuning methodology that does not require any of the loops to be run with sustained cycling. The steps for the Robbins tuning method for self-regulating control loops are as follows  

Turn off the reset, or set the integral time constant at least four times the response time. 

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