Apparatus and methods for non-invasive closed loop step testing with controllable optimization relaxation

A computer system for increasing performance in conducting step testing of an industrial process, the system comprising:

• a user interface configured to enable a user to define a giveaway tolerance for each of one or more process variables;
• a MPC controller configured to control an industrial process at a plant or refinery, the MPC controller having an objective function and the industrial process having one or more process variables, the MPC controller implementing:
• a target optimizer, for each of the one or more process variables, the target optimizer configured to:
• (i) receive, from the user interface, a defined giveaway tolerance for the process variable, the defined giveaway tolerance defining an allowable difference between a current value of the process variable and a target value for the process variable, the target value determined by the target optimizer, and
• (ii) determine if the current value of the process variable meets the received giveaway tolerance;
• the target optimizer further configured to:
• in response to at least one of the process variables not meeting the received giveaway tolerance, adjust the configuration of the MPC controller in a manner that moves the at least one process variables not meeting the received giveaway tolerance towards the received giveaway tolerance, wherein the adjusting creates room for the at least one process variables not meeting the received giveaway tolerance to optimize by modifying high and low limits on at least one process variable already within the respective received giveaway tolerance, wherein the adjusting comprises, for each of the one or more process variables:
• calculating an optimal target value for the process variable using the objective function;
• determining to optimize the process variable if the current value is not within the giveaway tolerance with respect to the calculated optimal target value;
• in response to determining not to optimize the process variable:
• adjusting the configuration with respect to the process variable by modifying at least one of high and low limits on the process variable;
• and
• adjusting the objective function by removing the process variable from the calculation performed by the objective function;
• and
• using the adjusted configuration, calculate new target values for the one or more process variables;
• and
• a dynamic controller configured to:
• generate a dynamic move plan from the calculated new target values;
• and
• add to the dynamic move plan perturbation signals calculated based on the adjusted configuration.

A non-transitory computer-readable storage medium having computer-readable code stored thereon, which, when loaded and executed by a computer processor, causes the computer processor to increase performance in conducting step testing of an industrial process by:

• configuring a MPC controller that controls an industrial process at a plant or refinery, the MPC controller having an objective function and the industrial process having one or more process variables;
• for each of the one or more process variables:
• receiving a giveaway tolerance defining an allowable difference between a current value of the process variable and a target value for the process variable, the target value determined by the MPC controller;
• determining that at least one of the process variables does not meet the received giveaway tolerance and adjusting the configuration of the MPC controller in a manner that moves the at least one process variables not meeting the received giveaway tolerance towards the received giveaway tolerance, wherein the adjusting creates room for the at least one process variables not meeting the received giveaway tolerance to optimize by modifying high and low limits on at least one process variable already within the respective received giveaway tolerance, the adjusting comprising, for each of the one or more process variables:
• calculating an optimal target value for the process variable using the objective function;
• in response to the current value not being within the giveaway tolerance with respect to the calculated optimal target values, determining to optimize the process variable;
• in response to determining not to optimize the process variable:
• adjusting the configuration with respect to the process variable by modifying at least one of high and low limits on the process variable;
• and
• adjusting the objective function by removing the process variable from the calculation performed by the objective function;
• using the adjusted configuration, calculating new target values for the one or more process variables;
• generating a dynamic move plan from the calculated new target values;
• and
• adding to the dynamic move plan perturbation signals calculated based on the adjusted configuration.