Change-and-wait controller

A multi-purpose controller for modulating the flow rate of solid, liquid, or gaseous material being transported in a suitable conduit means wherein the measurement point of said material flow rate is located some distance downstream of a flow rate actuator and for maintaining a correspondence between said material flow rate and a reference or desired flow rate, comprising:

• means for inputting a desired flow rate reference signal into the controller;
• means for receiving a signal from a material flow rate measurement sensor;
• means for waiting a user-specified first time period, after the elapse of which said time period operating on said measured flow rate signal commences;
• means for quantifiably interpreting said signal in terms of said flow rate occurring in said conduit;
• means for determining a first index of said measured flow rate signal spanning a user-specified second time period;
• means for calculating the excess or deficiency of said first flow rate index relative to the said reference flow rate, also commonly referred to as the set point in the control industry, thereby creating an internal flow rate error;
• means for determining a needed change in controller output based on said created internal flow rate error;
• means for increasing or decreasing an earlier-determined controller output that is the input to a source flow rate actuator, thereby creating an updated controller output and changing said flow rate in accordance with and in response to said updated signal from said flow rate controller;
• means for repeating the cycle of receiving said flow rate signal, waiting said first time period, quantifiably interpreting, index determining, and controller output changing operations, thereby creating a repetitive Change-and-Wait control strategy applicable to a wide variety of applications where material is in transit in a suitable conduit.

A multi-purpose controller for controlling a process variable property of interest in a flowing system, comprising:

• means for inputting a desired process variable property reference signal into said controller;
• means for receiving a signal from a process variable property measurement sensor;
• means for waiting a user-specified first time period, after the elapse of which said time period operating on said measured process variable property signal commences;
• means for quantifiably interpreting said signal in terms of said process variable property occurring in said process variable;
• means for determining a first index of said measured process variable property signal spanning a user-specified second time period;
• means for calculating the excess or deficiency of said first index relative to said process variable property reference signal, also commonly referred to as a set point in the control industry, thereby creating an internal process variable property error;
• means for determining a needed change in controller output based on said created internal process variable property error;
• means for increasing or decreasing an earlier-determined controller output that is the input to one or the other of a pair of process variable property actuators, thereby creating an updated controller output and changing said process variable property in accordance with and in response to said updated signal from said controller;
• means for repeating the cycle of receiving said process variable property signal, waiting said first time period, quantifiably interpreting, index determining, and controller output changing operations, thereby creating a repetitive Change-and-Wait control strategy applicable to a wide variety of applications where a property of a flowing material is being controlled.