METHOD AND APPARATUS OF A SELF-CONFIGURED, MODEL-BASED ADAPTIVE, PREDICTIVE CONTROLLER FOR MULTI-ZONE REGULATION SYSTEMS
First Claim
1. A model-based adaptive, predictive process control system comprising:
- a multi-zoned regulated apparatus having in each zone at least one input field device that measures a controlled parameter and at least one output field device capable of influencing the controlled parameter;
a controller coupled to the respective field devices and performing the following operational steps in at least a plurality of the zones in real time;
periodically sampling the controlled parameter with the respective input field device and predictively modeling future sample readings thereof in a moving window prediction model horizon;
accumulating a plurality of the moving window prediction model horizons and periodically, in a moving window control horizon, predictively modeling future controlled apparatus response of the plurality of zones as a function of the accumulated prediction model horizons;
comparing the modeled response of the controlled apparatus in the control horizon to a desired response;
adjusting the system model based on past measurements;
adjusting the respective output field device in order to attempt to converge modeled and desired responses; and
periodically repeating the above controlled functions.
1 Assignment
0 Petitions
Accused Products
Abstract
A control system simultaneously controls a multi-zone process with a self-adaptive model predictive controller (MPC), such as temperature control within a plastic injection molding system. The controller is initialized with basic system information. A pre-identification procedure determines a suggested system sampling rate, delays or “dead times” for each zone and initial system model matrix coefficients necessary for operation of the control predictions. The recursive least squares based system model update, control variable predictions and calculations of the control horizon values are preferably executed in real time by using matrix calculation basic functions implemented and optimized for being used in a S7 environment by a Siemens PLC. The number of predictions and the horizon of the control steps required to achieve the setpoint are significantly high to achieve smooth and robust control. Several matrix calculations, including an inverse matrix procedure performed at each sample pulse and for each individual zone determine the MPC gain matrices needed to bring the system with minimum control effort and variations to the final setpoint. Corrective signals, based on the predictive model and the minimization criteria explained above, are issued to adjust system heating/cooling outputs at the next sample time occurrence, so as to bring the system to the desired set point. The process is repeated continuously at each sample pulse.
124 Citations
32 Claims
-
1. A model-based adaptive, predictive process control system comprising:
-
a multi-zoned regulated apparatus having in each zone at least one input field device that measures a controlled parameter and at least one output field device capable of influencing the controlled parameter; a controller coupled to the respective field devices and performing the following operational steps in at least a plurality of the zones in real time; periodically sampling the controlled parameter with the respective input field device and predictively modeling future sample readings thereof in a moving window prediction model horizon; accumulating a plurality of the moving window prediction model horizons and periodically, in a moving window control horizon, predictively modeling future controlled apparatus response of the plurality of zones as a function of the accumulated prediction model horizons; comparing the modeled response of the controlled apparatus in the control horizon to a desired response;
adjusting the system model based on past measurements;adjusting the respective output field device in order to attempt to converge modeled and desired responses; and periodically repeating the above controlled functions. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A model-based adaptive, predictive process controller capable of being coupled to at least one input field device that measures a controlled parameter and at least one output field device capable of influencing the controlled parameter for each respective zone of a multi-zoned regulated apparatus, the controller capable of performing the following operational steps in at least a plurality of the zones in real time:
-
periodically sampling the controlled parameter with the respective input field device and predictively modeling future sample readings thereof in a moving window prediction model horizon; accumulating a plurality of the moving window prediction model horizons and periodically, in a moving window control horizon, predictively modeling future controlled apparatus response of the plurality of zones as a function of the accumulated prediction model horizons; comparing the modeled response of the controlled apparatus in the control horizon to a desired response; adjusting the system model based on past measurements; adjusting the respective output field device in order to attempt to converge modeled and desired responses; and periodically repeating the above controlled functions. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
-
-
21. In a process control system including a multi-zoned regulated apparatus having in each zone at least one input field device that measures a controlled parameter and at least one output field device capable of influencing the controlled parameter, and a controller coupled to the respective field devices, a method for operating the controller in real time, comprising the steps of:
-
periodically sampling the controlled parameter with the respective input field device and predictively modeling future sample readings thereof in a moving window prediction model horizon; accumulating a plurality of the moving window prediction model horizons and periodically, in a moving window control horizon, predictively modeling future controlled apparatus response of the plurality of zones as a function of the accumulated prediction model horizons; comparing the modeled response of the controlled apparatus in the control horizon to a desired response; adjusting the system model based on past measurements; adjusting the respective output field device in order to attempt to converge modeled and desired responses; and periodically repeating the above controlled functions. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29, 30)
-
-
31. A storage medium comprising model-based adaptive, predictive process controller software capable of execution by a processor within a process controller, wherein the controller is in turn coupled to at least one input field device that measures a controlled parameter and at least one output field device capable of influencing the controlled parameter for each respective zone of a multi-zoned regulated apparatus, the software when executed by the processor causing the controller to perform the following operational steps in at least a plurality of the zones in real time:
-
periodically sampling the controlled parameter with the respective input field device and predictively modeling future sample readings thereof in a moving window prediction model horizon; accumulating a plurality of the moving window prediction model horizons and periodically, in a moving window control horizon, predictively modeling future controlled apparatus response of the plurality of zones as a function of the accumulated prediction model horizons; comparing the modeled response of the controlled apparatus in the control horizon to a desired response; adjusting the system model based on past measurements; adjusting the respective output field device in order to attempt to converge modeled and desired responses; and periodically repeating the above controlled functions.
-
-
32. A model-based adaptive, predictive process controller capable of being coupled to at least one input field device that measures a controlled parameter and at least one output field device capable of influencing the controlled parameter for each respective zone of a multi-zoned regulated apparatus, the controller having means for performing the following operational steps in at least a plurality of the zones in real time:
-
periodically sampling the controlled parameter with the respective input field device and predictively modeling future sample readings thereof in a moving window prediction model horizon; accumulating a plurality of the moving window prediction model horizons and periodically, in a moving window control horizon, predictively modeling future controlled apparatus response of the plurality of zones as a function of the accumulated prediction model horizons; comparing the modeled response of the controlled apparatus in the control horizon to a desired response; adjusting the system model based on past measurements; adjusting the respective output field device in order to attempt to converge modeled and desired responses; and periodically repeating the above controlled functions.
-
Specification