Method and system for controlling an electric heater using energy control

Abstract

A method for controlling a heating process of an electric heater includes obtaining a setpoint variable indicating a target temperature of the heater. The method includes identifying an energy profile for the heater based on the setpoint variable. The energy profile provides a defined magnitude of initial electrical energy to be applied to the heater to cause the temperature of the heating process to reach the target temperature. The method includes obtaining a process variable indicative of a performance characteristic of the heating process. The method includes supplying electrical energy to the heater based on at least one of the energy profile and the process variable.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and the benefit of U.S. Patent Application No. 63 / 074,520, filed September 4, 2020, the disclosure of which is incorporated herein by reference. [Technical Field]

[0002] The present disclosure relates to a method for controlling the thermal performance of an electric heater. [Background technology]

[0003] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

[0004] Thermal systems for industrial processes typically include a heater system and a control system for monitoring and controlling the operation of the heater system. The control system may be a temperature proportional-integral-derivative (PID) control system configured to control the temperature of the heater system to a target temperature. However, when a temperature sensor detects a change in the measured temperature, the temperature PID controller responds to the change in the thermal system. Therefore, it may be difficult for the temperature PID controller to respond quickly and in a timely manner to changes in the thermal system, such as changes in heat load. Summary of the Invention

[0005] This section provides a general summary of the disclosure and is not an all-inclusive disclosure of its entire scope or features.

[0006] The present disclosure provides a method for controlling a heating process of a heater. The method includes obtaining a setpoint variable indicating a target temperature of the heater. The method includes identifying an energy profile for the heater based on the setpoint variable, where the energy profile provides a defined magnitude of initial electrical energy to be applied to the heater to cause the temperature of the heating process to reach the target temperature. The method includes obtaining a process variable indicative of a performance characteristic of the heating process. The method includes supplying electrical energy to the heater based on at least one of the energy profile and the process variable.

[0007] In some embodiments, supplying electrical energy to the heater further includes supplying an initial electrical energy of a defined magnitude to the heater. In some embodiments, supplying electrical energy to the heater further includes reducing the electrical energy to the heater in response to the process variable indicating that the temperature of the heater is within a temperature approach band of the target temperature of the heater, where the performance characteristic includes the temperature of the heater. In some embodiments, the electrical energy is reduced to steady-state power based on a natural time constant. In some embodiments, the electrical energy is reduced to steady-state power based on proportional-integral control.

[0008] In some embodiments, the method further includes determining whether the temperature of the heater is less than a setpoint variable. In response to the temperature of the heater being less than the setpoint variable, the electrical energy supplied to the heater is based on the identified energy profile and is equal to a defined magnitude of the initial electrical energy. In response to the temperature of the heater being greater than the setpoint variable, the method further includes turning off the electrical energy to the heater and acquiring a process variable indicative of a performance characteristic of the heater, where the performance characteristic includes the temperature of the heater. In some embodiments, in response to the temperature of the heater being greater than the setpoint variable, the method further includes increasing the electrical energy to the heater to a steady-state power in response to the temperature of the heater approaching the setpoint variable. In some embodiments, the electrical energy is increased from zero to the steady-state power based on a natural time constant. In some embodiments, the electrical energy is increased from zero to the steady-state power based on proportional-integral control.

[0009] In some embodiments, the method further includes determining whether a temperature of the heater is equal to a setpoint variable. In some embodiments, the method further includes controlling electrical energy to the heater based on a temperature control model to maintain the temperature of the heater at the setpoint variable. In some embodiments, the performance characteristic includes at least one of a heater voltage, a heater current, and a heater temperature.

[0010] The present disclosure provides a system for controlling a heater. The system includes a processor configured to execute a plurality of instructions stored on a non-transitory computer-readable medium. The instructions include obtaining a target temperature for the heater and a temperature of the heater, controlling the heater in one of an energy-based control mode and a temperature control mode based on the target temperature and the temperature, and specifying, during the energy-based control mode, an energy profile for the heater based on the target temperature, the energy profile providing a defined magnitude of initial electrical energy to be applied to the heater to cause the temperature to reach the target temperature. The method includes, during the energy-based control mode, supplying electrical energy to the heater based on the energy profile, and, during the temperature control mode, selectively supplying electrical energy to the heater based on the temperature.

[0011] In one embodiment, during the energy-based control mode, the instructions for supplying electrical energy to the heater based on the energy profile further include supplying an initial electrical energy of a defined magnitude to the heater, determining whether the temperature of the heater is within a temperature approach band of the heater's target temperature, and reducing the electrical energy supplied to the heater to a steady-state power in response to the temperature of the heater being within the temperature approach band of the heater's target temperature. In one embodiment, during the temperature control mode, the instructions for selectively providing electrical energy to the heater based on the temperature further include turning off the electrical energy to the heater, determining whether the temperature of the heater is within a temperature approach band of the heater's target temperature, and increasing the electrical energy supplied to the heater to a steady-state power in response to the temperature of the heater being within the temperature approach band of the heater's target temperature.

[0012] In one form, the instructions further include determining whether the temperature of the heater is equal to the target temperature, and, in response to the temperature of the heater being equal to the target temperature, controlling the electrical energy supplied to the heater based on the temperature control model to maintain the temperature of the heater.

[0013] The present disclosure provides a method for learning an energy profile of a heater. The method includes obtaining a setpoint variable indicative of a target temperature of the heater and supplying electrical energy to the heater, where the electrical energy has a calibrated magnitude. The method includes obtaining a process variable indicative of a temperature of the heater. When the process variable indicates that the temperature of the heater is equal to the target temperature, the method includes determining a response time of the heater, selectively adjusting a plurality of gain values ​​based on the response time, and generating an energy profile based on the plurality of gain values ​​of the controller and the setpoint variable, where the energy profile correlates the setpoint variable to a predetermined value of the electrical energy.

[0014] In one embodiment, the energy profile further defines a steady-state power applied to the heater in response to the heater temperature being within a temperature approach band of the target temperature. In one embodiment, the method further includes defining the temperature approach band of the target temperature based on a mathematical model. In one embodiment, the energy profile further defines a duration for supplying a predetermined amount of electrical energy to the heater to cause the heater temperature to reach the target temperature. In one embodiment, selectively adjusting the plurality of gain values ​​based on the response time further includes adjusting the plurality of gain values ​​based on a Ziegler-Nichols tuning routine in response to the response time being less than a threshold response time. In one embodiment, the energy profile is further based on a calibration magnitude. In one embodiment, the method further includes selectively adjusting the calibration magnitude when the process variable indicates that the heater temperature is equal to the target temperature.

[0015] Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. [Brief explanation of the drawings]

[0016] In order that the present disclosure may be more fully understood, various forms thereof will now be described, given by way of example, with reference to the accompanying drawings, in which:

[0017] [Figure 1] FIG. 1 is a block diagram of a thermal system having an energy control system and a heater system according to the present disclosure.

[0018] [Figure 2] FIG. 2 is a block diagram of an operation control module of an energy control system according to the present disclosure.

[0019] [Figure 3]FIG. 3 is a block diagram of a learning module of an energy control system according to the present disclosure.

[0020] [Figure 4] FIG. 4 is a flowchart for controlling the temperature of the heater in the first embodiment according to the present disclosure.

[0021] [Figure 5] FIG. 5 is another flowchart for controlling the temperature of the heater in the second embodiment according to the present disclosure.

[0022] [Figure 6] FIG. 6 is a flow chart for learning the energy profile of a thermal system according to the present disclosure.

[0023] The drawings described herein are for illustrative purposes only and are not intended to limit the scope of the present disclosure in any way. DETAILED DESCRIPTION OF THE INVENTION

[0024] The following description is merely exemplary in nature and is not intended to limit the present disclosure, its application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

[0025] 1, a thermal system 10 is shown including a heater system 20 having a heater 22 and a control system 30 configured to provide a desired thermal response. In one form, the control system 30 is configured to control the operation of the heater system 20, and more specifically, the heater 22.

[0026] The thermal system 10 can be part of various types of industrial processes for controlling the thermal characteristics of a load being heated. For example, the thermal system 10 can be part of a semiconductor process in which the heater system 20 includes a pedestal heater for heating a wafer (e.g., a load). In this example, the control system 30 can be configured to control the energy profile of the pedestal heater, which can vary based on different controls. For example, the controls can include, but are not limited to, the power supplied to the pedestal heater, the operating mode of the thermal system 10 (e.g., a manual mode that controls power to the heater based on input from a user, a cold start mode that gradually increases the temperature of the pedestal heater, a steady state mode that maintains the pedestal heater at a target temperature, or other defined operating modes for controlling the heater system 20), and / or the operating conditions of different zones of the pedestal heater when the pedestal heater is a multi-zone heater, among other parameters controllable by the thermal system 10. Additionally, control may include other factors such as, but not limited to, the type of wafer being heated, the gas blown into the process chamber with the pedestal heater, and / or the pressure differential within the chamber to secure the wafer to the pedestal heater.

[0027] In another example, the thermal system 10 may be used in a semiconductor process abatement system to heat fluids flowing through a network of conduits. In one form, the heater system 20 may include multiple flexible heaters that wrap around the conduits and heat the fluid therein. In yet another example, the thermal system 10 may use cartridge heaters as part of the heater system 20 to directly heat fluids (e.g., gases and / or liquids) flowing through the conduits or provided within a vessel.

[0028] Although specific application examples of thermal system 10 are provided herein, the present disclosure may be applicable to other industrial processes having a thermal system for heating a load. Furthermore, heater 22 of heater system 20 should not be limited to the examples provided herein; heater 22 may include layered heaters, cartridge heaters, tubular heaters, polymer heaters, flexible heaters, and other heaters having resistive heating elements.

[0029] The heater system 20 may include one or more sensors 24 for measuring performance characteristics (i.e., process variables) of the heater 22, such as, but not limited to, the temperature, voltage, current, power, and / or resistance of the heater 22. Accordingly, the one or more sensors 24 may include thermocouples, resistance temperature detectors, infrared cameras, current sensors, and / or voltage sensors, among others.

[0030] In some variations, the heater 22 may generate a performance characteristic instead of, or in addition to, one or more sensors 24 generating the performance characteristic. As an example, the heater system 20 may be a two-wire heater system in which the heater 22 is operable to generate heat and acts as a sensor to measure the performance characteristic of the heater 22. In particular, the heater 22 may include one or more resistive heating elements that act as sensors to measure the average temperature of the resistive heating element based on the resistance of the resistive heating element. An example of a two-wire heater system is disclosed in U.S. Pat. No. 7,196,295, which is commonly owned with this application and is incorporated herein by reference in its entirety. In a two-wire system, the thermal system is an adaptive thermal system that merges the heater design, with controls incorporating power, resistance, voltage, and current, into a customizable feedback control system to limit one or more of these parameters (i.e., power, resistance, voltage, and current) and control another. In one embodiment, the control system 30 is configured to monitor at least one of the current, voltage, and power supplied to the resistive heating element to determine the resistance, and therefore the temperature, of the resistive heating element.

[0031] In another variation, as a two-wire heater, the heater 22 is configured to include a temperature-sensing power pin for measuring the temperature of the heater 22. Measuring the temperature of a resistive heating element using a power pin as a thermocouple is disclosed in U.S. Patent No. 10,728,956, which is commonly owned with the present application and is incorporated herein by reference in its entirety. Generally, the resistive heating element of the heater 22 and the control system 30 are connected via first and second power pins that define first and second junctions, respectively. The first and second power pins function as thermocouple-sensing pins for measuring the temperature of the resistive heating element of the heater 22. The control system 30, in communication with the first and second power pins, can be configured to measure the change in voltage at the first and second junctions. More specifically, the control system 30 can measure the millivolt (mV) change at the junctions and use these voltage changes to calculate the temperature of the resistive heating element.

[0032] Control system 30 is configured to control heater system 20 based on an energy profile that defines a power output control for controlling heater system 20. The power output control may be provided in a variety of suitable forms, such as a percentage of input power (e.g., 75% of input voltage) and / or an actual voltage level. Further, control system 30 is configured to define one or more energy profiles utilized to control heater system 20.

[0033] In one form, control system 30 includes a heater control process database 38, a mode control module 40, an operation control module 50, a learning module 60, an energy profile database 70, and a power module 80. To perform the functions described herein, control system 30 may be implemented by a microcontroller including one or more processor circuits configured to execute machine-readable instructions stored on one or more non-transitory computer-readable media, such as random access memory (RAM) circuitry and / or read-only memory (ROM) circuitry. While heater control process database 38, mode control module 40, operation control module 50, learning module 60, energy profile database 70, and power module 80 are shown as part of control system 30, it should be understood that any of these components may be located on separate controller(s) communicatively coupled to control system 30.

[0034] In some forms, control system 30 includes one or more defined control processes stored in heater control process database 38 that, when executed by control system 30, control the thermal performance of heater 22. A given control process may define, among other parameters, one or more target temperatures for heater 22, a process timeline indicating the time and duration of the target temperature(s), and / or a control mode for control system 30. In some forms, a user may select the control process to be executed via an external device, such as a human-machine interface (HMI).

[0035] In some embodiments, the mode control module 40 is configured to obtain the target temperature and set the control mode of the control system 30. As an example, the mode control module 40 is configured to set the energy control mode to an energy profile learning mode provided by the learning module 60 and / or an operational control mode provided by the operational control module 50. In one embodiment, the energy control mode is set by a user via an external device. For example, a user may operate the control system 30 in an energy profile learning mode that defines one or more energy profiles based on one or more parameters set by the user and / or defined in a pre-stored control process. In another embodiment, the energy control mode is automatically set based on a control process executed by the control system 30. For example, the control process is configured to specify a control mode, target temperature(s), and a timeline for controlling the heater at the target temperature(s). In another example, the energy control mode is automatically set to the operational control mode once the learning module 60 completes the energy profile learning routine. This is described in more detail below with reference to FIGS. 3 and 6.

[0036] In some forms, the operational control module 50 is configured to execute a control process(es) to determine output control based on a target temperature and a process variable (e.g., temperature measurements from one or more sensors 24) indicative of a measurable performance characteristic of the heater system 20. The functionality of the operational control module 50 is described in more detail below with reference to Figures 2, 4, and 5.

[0037] In some forms, the learning module 60 is configured to generate and store one or more energy profiles 72 in the energy profile database 70. In some forms, the energy profile 72 correlates a target temperature to a defined magnitude of initial power and / or energy to be applied to the heater 22 to cause the temperature of the heater 22 to reach the target temperature. The energy profile 72 may also define a steady-state voltage to be applied to the heater 22 in response to the temperature of the heater 22 being within a defined temperature approach band of the target temperature of the heater 22 to provide transient control of the heater 22 to the target temperature. This reduces or prevents overshoot of the target temperature. In some forms, the temperature approach band (e.g., deviation from the target temperature expressed as a temperature threshold tolerance) is unique among each of the energy profiles 72. In some variations, the temperature approach band is equal among each of the energy profiles. In some forms, the temperature approach band is defined by a user, a mathematical model, and / or a learning routine, among others. In another embodiment, the temperature approach bands of the energy profile 72 may be dynamically updated based on various conditions of the thermal system 10 .

[0038] In an application, both the operational control mode and the learning mode may be selected to execute a selected control process. In such an application, the operational control module 50 operates the heater 22 as described below to control the thermal performance of the heater 22, and the learning module 60 is configured to define an energy profile 72 for the executed control process. The defined energy profile 72 therefore takes into account known and unknown parameters of the industrial process having the thermal system 10. For example, in a semiconductor process, the known and unknown parameters may include the mass of a load (e.g., wafers), the insertion / removal of liquids / powder, and / or the opening / closing of valves / doors.

[0039] The power module 80 is configured to control the electrical energy supplied to the heater system 20 based on the output control from one of the operation control module 50 and the learning module 60. In one form, the power module 80 may include a power regulator circuit (not shown) electrically coupled to a power source (not shown) and regulating power from the power source to a selected power level and applying the regulated power to the heater 22. Using predefined algorithms and / or tables, the power module 80 is configured to select a power level for the heater system 20 based on the output control.

[0040] Referring to FIG. 2 , an exemplary block diagram of the operational control module 50 is shown. In some embodiments, the operational control module 50 includes a control mode selection module 52, a temperature control loop module 54, and an energy-based control module 56. The control mode selection module 52 is configured to set the operational control mode as one of an energy-based operational control mode or a temperature control mode based on the target temperature and process variables from one or more sensors 24. In one embodiment, the control mode selection module 52 sets the operational control mode to the energy-based control mode, which is controlled by the energy-based control module 56 when the target temperature is higher than the measured temperature of the heater 22. On the other hand, when the target temperature is equal to or lower than the measured temperature of the heater 22, the control mode selection module 52 sets the operational control mode to the temperature control mode, which is controlled by the temperature control loop module 54. In one variation, the control mode selection module 52 sets the operational control mode to the energy-based control mode when the measured temperature is lower than the target temperature by a defined deviation (e.g., 10° C., 15° C., or other suitable value). Otherwise, if the measured temperature is above the target temperature by the defined offset, the temperature control mode is selected.

[0041] During the energy-based control mode, the energy-based control module 56 is configured to control the heater 22 based on a target temperature and an energy profile defined for the target temperature and / or control process. More specifically, when the temperature of the heater 22 is outside a temperature approach band of the target temperature, the energy-based control module 56 is configured to provide an initial power and / or energy of a defined magnitude to the heater 22 based on the target temperature.

[0042] As an example, energy-based control module 56 identifies an energy profile 72 from among energy profiles 72 stored in database 70 based on the ongoing control process, the target temperature (e.g., a target temperature of 200°C), and / or the measured temperature of the heater. The identified energy profile 72 provides a defined magnitude of initial electrical energy and / or power to be applied to heater 22 to bring the current temperature of heater 22 to the target temperature (e.g., identified energy profile 72 indicates that 12,500 watt-seconds (Ws) of electrical energy must be applied to heater 22 to bring the current measured temperature to the target temperature of 200°C). Energy-based control module 56 then provides output control to power module 80 to provide the defined magnitude of initial electrical energy and / or power to heater 22.

[0043] A defined magnitude of initial electrical energy and / or power is supplied to the heater 22 until the temperature of the heater 22 falls within the temperature approach band. As an example, the energy-based control module 56 monitors the temperature of the heater 22 to determine whether the temperature is within the temperature approach band. If the temperature of the heater 22 is within the temperature approach band, as indicated by the process variable, the energy-based control module 56 supplies power to the heater 22 at a steady-state magnitude associated with the specified energy profile 72 (e.g., the specified energy profile 72 indicates a steady-state magnitude of power of 1,500 watts at 200°C). The steady-state magnitude of power may be based on a natural time constant, magnitude of overshoot, response time, and / or steady-state error of the energy-based control module 56. In some forms, the steady-state magnitude of power may be based on a proportional-integral (PI) control routine implemented by the energy-based control module 56.

[0044] Once the temperature of the heater 22 reaches the target temperature, the operational control module 50 transitions to a temperature control mode. During the temperature control mode, the temperature control loop module 54 is configured to control the heater 22 based on the target temperature and a process variable, such as the temperature of the heater 22. For example, in one embodiment, the temperature control loop module 54 implements a PID control that monitors the temperature of the heater 22 and determines the difference between the actual temperature and the target temperature. The temperature control loop module 54 then determines, as an output control, the level of electrical energy required to reduce the difference between the actual temperature of the heater 22 and the target temperature.

[0045] By selectively specifying the operational control mode between an energy-based control mode (i.e., an open-loop control routine) and a temperature control mode (i.e., a closed-loop control routine), the control system 30 reduces the response time of the heater 22 to reaching a target temperature and transitioning between changing target temperatures. Additionally, in one form, the operational control module 50 is configured to select different operational control modes for different operational conditions. For example, when the temperature of the heater system 20 is stable, the operational control module 50 selects a temperature control mode to maintain the temperature at the target temperature. During dynamic conditions, the operational control module 50 selects energy-based control to optimize response while monitoring the temperature of the heater system 20.

[0046] 3, an exemplary block diagram of learning module 60 is shown. In some forms, learning module 60 includes a parameter module 62, a response time module 64, a temperature determination module 66, an energy profile generation module 68, and a parameter adjustment module 69. Learning module 60, which may be implemented by a PID control module, is configured to execute an energy profile learning routine when mode control module 40 sets control system 30 to an energy profile learning mode.

[0047] The learning module 60 may periodically execute an energy profile learning routine to define an energy profile. In some forms, the learning module 60 may execute the energy profile learning routine in conjunction with the operational control routine executed by the operational control module 50. This allows the control system 30 to identify various conditions of the thermal system 10, such as energy consumption, heater or sensor failure, changes in heat transfer, among other conditions of the thermal system 10.

[0048] In some forms, the learning module 60 is configured to generate energy profiles 72 for a range of setpoint / target temperatures while executing the energy profile learning routine (e.g., the learning module 60 is configured to generate energy profiles 72 for multiple target temperatures between −10° C. and 250° C., including endpoints). In some forms, the energy profiles 72 correlate the target temperatures with a defined magnitude of initial electrical energy and / or power to be applied to the heater 22 and / or a duration for providing electrical energy to bring the temperature of the heater 22 to the target temperature. The energy profiles 72 may also define a steady-state voltage magnitude of electrical energy applied to the heater 22 in response to a process variable indicating that the temperature of the heater 22 is within a temperature approach band of the target temperature of the heater 22. In some forms, during the energy profile learning routine, the temperature approach band of each energy profile 72 is also defined, for example, by a user, a mathematical model, and / or the learning routine, among others.

[0049] During the energy profile learning routine, the parameter module 62 is configured to obtain a setpoint variable indicating a target temperature (e.g., 200°C) for the heater 22 and provide output control such that the power module 80 outputs electrical energy having a calibrated magnitude (e.g., 10,500 Ws) to the heater 22. Additionally, the parameter module 62 is configured to specify a set of gain values ​​for evaluating and controlling the heater 22 during the energy profile learning routine (i.e., the parameter module 62 defines at least one of a proportional gain value, an integral gain value, and / or a derivative gain value for the learning module 60). The set of gain values ​​may be determined using, for example, a Ziegler-Nichols tuning method.

[0050] While electrical energy is supplied to the heater 22, the temperature determination module 66 is configured to determine the temperature of the heater 22 based on the performance characteristics of the heater 22 as a process variable. Furthermore, while electrical energy is supplied to the heater 22, the response time module 64 is activated and configured to increase a corresponding value proportionally to the amount of time elapsed. When the temperature of the heater 22 equals the target temperature, the response time module 64 is configured to determine a response time of the heater 22. As used herein, "response time of the heater 22" refers to the amount of time required for the heater 22 to reach the target temperature after obtaining a setpoint variable. In some forms, the response time of the heater 22 may be based on gain values ​​(e.g., proportional gain value, integral gain value, and / or derivative gain value) of the learning module 60.

[0051] The energy profile generation module 68 is configured to generate an energy profile 72 based on the gain value, the target temperature, the calibration magnitude, and the response time of the heater 22. By way of example, if the response time of the heater 22 is determined to be sufficient to control the heater 22 (i.e., the response time is less than a threshold), the energy profile generation module 68 generates an energy profile 72 for the corresponding target temperature, where the energy profile 72 correlates the calibration magnitude and the gain value to the particular target temperature. Additionally, if the response time of the heater 22 is determined to be sufficient to control the heater 22, the energy profile generation module 68 may associate a steady-state magnitude with the particular target temperature, where the steady-state magnitude is based on the time constant indicated by the gain value.

[0052] As another example, if the response time of the heater 22 is determined to be insufficient to control the heater 22 (i.e., the response time is greater than a threshold), the parameter adjustment module 69 may adjust at least one of the calibration magnitude and the gain value to decrease the response time of the heater 22. In some embodiments, the parameter adjustment module 69 may selectively adjust the gain value based on a Ziegler-Nichols tuning method. In some embodiments, the parameter adjustment module 69 may increase the calibration magnitude to decrease the response time of the heater 22. The parameter adjustment module 69 iteratively adjusts at least one of the calibration magnitude and the gain value until the response time of the heater 22 is determined to be sufficient to control the heater 22.

[0053] In some forms, the learning module 60 of the present disclosure can improve the heater system 20's response to recurring dynamic conditions that may not necessarily require user input. For example, the learning module 60 can execute machine learning routines to predict the occurrence and severity of dynamic conditions and identify control modes and settings to improve the control system's response. Thus, the control system 30 can improve and / or maintain performance as the components of the thermal system 10 change over time. Additionally, data collected and determined by the control system 30 can be provided to a user for additional analysis.

[0054] Referring to FIG. 4, a flowchart illustrating an example routine 400 for controlling the temperature of the heater system 20 during an operational control mode is shown. At 404, the control system 30 obtains a setpoint variable indicating a target temperature of the heater 22. In one embodiment, the setpoint variable is provided in the control process being executed. In another embodiment, the setpoint variable is manually entered by a user. At 408, the control system 30 identifies an energy profile 72 for the heater 22 based on the setpoint variable. In addition to the setpoint variable, the energy profile 72 may be selected based on the control process and the current temperature of the heater 22. At 412, the control system 30 obtains a process variable indicative of performance characteristic(s) of the heater 22. At 416, the control system 30 provides electrical energy to the heater 22 based on at least one of the energy profile 72 and the performance characteristic.

[0055] 5, a flow chart illustrating another exemplary routine 500 for controlling the temperature of the heater system 20 during an operational control mode is shown. At 504, the control system 30 determines whether the setpoint variable indicates that the target temperature of the heater 22 is greater than the temperature of the heater 22. If so, the routine 500 proceeds to 508. Alternatively, if the target temperature of the heater 22 is less than the temperature of the heater 22, the routine 500 proceeds to 524.

[0056] At 508, control system 30 provides electrical energy having a defined magnitude of electrical energy and / or power as provided by energy profile 72 for the target temperature. At 512, control system 30 obtains the temperature of heater 22 as a process variable. At 516, control system 30 determines whether the temperature of heater 22 is within the temperature approach band, as indicated by energy profile 72. If so, routine 500 proceeds to 520. Alternatively, if the temperature of heater 22 is not within the temperature approach band, routine 500 proceeds to 508. At 520, control system 30 reduces the magnitude of power to a steady-state magnitude of power, as indicated by energy profile 72, and proceeds to 540.

[0057] In response to the setpoint variable indicating that the target temperature of the heater 22 is lower than the temperature of the heater 22 at 524 and at 508, the control system 30 stops supplying electrical energy to the heater 22. At 528, the control system 30 obtains the temperature of the heater 22 as a process variable. At 532, the control system 30 determines whether the temperature of the heater 22 is within the temperature approach band, as indicated by the energy profile 72. If so, the routine 500 proceeds to 536. Alternatively, if the temperature of the heater 22 is not within the temperature approach band, the routine 500 proceeds to 528. At 536, the control system 30 increases the magnitude of the power to the steady-state magnitude of the power, as indicated by the energy profile 72 (e.g., the magnitude of the power is increased from zero to the steady-state power based on proportional-integral control and / or a natural time constant), and proceeds to 540.

[0058] At 540, control system 30 performs closed-loop temperature control to control the temperature of the heater at the target temperature, as provided above. At 544, control system 30 determines whether a new target temperature is available. If so, routine 500 proceeds to 504. If not, routine 500 remains at 544 until a new target temperature is available.

[0059] 6, a flowchart of a learning routine 600 executed by control system 30 during the energy profile learning mode is shown. At 604, control system 30 obtains a setpoint variable indicating a target temperature of heater 22. At 606, control system 30 defines an initial set of gain values ​​and calibration magnitudes for a particular target temperature. At 608, control system 30 supplies electrical energy having the calibration magnitude to heater 22. At 612, control system 30 obtains the temperature of heater 22 as a process variable. At 616, control system 30 determines whether the temperature of heater 22 is equal to the target temperature. If so, routine 600 proceeds to 620. If the temperature of heater 22 is not equal to the target temperature at 616, routine 600 proceeds to 608.

[0060] At 620, the control system 30 determines the response time of the heater 22. At 624, the control system 30 determines whether the response time is less than a threshold response time. If so, the routine 600 proceeds to 632, where the control system 30 generates an energy profile 72 for a particular target temperature based on the gain value and the magnitude of the electrical energy. If, at 624, the response time of the heater 22 is greater than the threshold response time, the routine 600 proceeds to 628, where the control system 30 adjusts at least one of the gain value (e.g., using Ziegler-Nichols tuning) and the calibration magnitude, and then proceeds to 608.

[0061] It should be readily understood that routines 400, 500, and 600 are exemplary control routines and that other suitable control routines may be used to carry out the operations of the control system of the present disclosure.

[0062] Unless otherwise expressly indicated herein, all numerical values ​​expressing mechanical / thermal properties, composition percentages, dimensions and / or tolerances, or other characteristics should be understood as being modified by the word "about" or "approximately" when describing the scope of this disclosure. This modification may be desirable for a variety of reasons, including industry practices, materials, manufacturing, assembly tolerances, and testing capabilities.

[0063] Spatial and functional relationships between elements are described using a variety of terms, including "connected," "attached," "coupled," "adjacent," "next to," "on top of," "above," "under," and "disposed." Unless explicitly stated as "directly," when a relationship between a first element and a second element in this disclosure is described, the relationship can be a direct relationship, where no other intervening elements exist between the first and second elements, or an indirect relationship, where one or more intervening elements (spatial or functional) exist between the first and second elements. As used herein, the phrase "at least one of A, B, and C" should be interpreted to mean a non-exclusive logical OR (A OR B OR C), and not to mean "at least one A, at least one B, and at least one C."

[0064] In this application, the term “module” may be interchangeable with the term “circuitry.” The term “module” may refer to, be part of, or include an application-specific integrated circuit (ASIC), digital, analog, or mixed digital / analog discrete circuitry, a digital, analog, or mixed digital / analog integrated circuit, a combinational logic circuit, a field-programmable gate array (FPGA), a processor circuit (shared, dedicated, or group) that executes code, a memory circuit (shared, dedicated, or group) that stores code executed by the processor circuitry, other suitable hardware components that provide the described functionality, or a combination of some or all of the above, such as in a system-on-chip.

[0065] The term code may include software, firmware, and / or microcode, and may refer to programs, routines, functions, classes, data structures, and / or objects. The term memory circuit is a subset of the term computer-readable medium. As used herein, the term computer-readable medium does not include transitory electrical or electromagnetic signals propagating through a medium (such as a carrier wave). Thus, the term computer-readable medium may be considered tangible and non-transitory.

[0066] The description of the present disclosure is merely exemplary in nature and, thus, variations that do not depart from the content of the disclosure are intended to be within the scope of the disclosure. Such variations should not be considered a departure from the spirit and scope of the disclosure. [Appendix 1] 1. A method for controlling a heating process of a heater, comprising: obtaining a setpoint variable indicating a target temperature of the heater; identifying an energy profile for the heater based on the setpoint variable, the energy profile providing a defined magnitude of initial electrical energy to be applied to the heater to cause the temperature of the heating process to reach the target temperature; obtaining a process variable indicative of a performance characteristic of the heating process; and supplying electrical energy to the heater based on at least one of the energy profile and the process variable. method. [Appendix 2] Providing the electrical energy to the heater comprises: providing the heater with initial electrical energy of the defined magnitude; reducing the electrical energy to the heater in response to the process variable indicating that the temperature of the heater is within a temperature approach band of the target temperature of the heater, and the performance characteristic includes the temperature of the heater. Method in Appendix 1. [Appendix 3] 3. The method of claim 2, wherein the electrical energy is reduced to a steady-state power based on a natural time constant. [Appendix 4] 3. The method of claim 2, wherein the electrical energy is reduced to a steady-state power based on proportional-integral control. [Appendix 5] The method further comprises determining whether the temperature of the heater is less than the setpoint variable; in response to the temperature of the heater being less than the setpoint variable, the electrical energy supplied to the heater is based on the identified energy profile and equal to the defined magnitude of initial electrical energy; In response to the temperature of the heater being greater than the setpoint variable, the method comprises: turning off electrical energy to the heater; obtaining the process variable indicative of the performance characteristic of the heater, the performance characteristic including the temperature of the heater; and increasing the electrical energy to the heater to a steady state power in response to the temperature of the heater approaching the setpoint variable. Method in Appendix 1. [Appendix 6] 6. The method of claim 5, wherein the electrical energy is ramped from zero to the steady-state power based on a natural time constant. [Appendix 7] 6. The method of claim 5, wherein the electrical energy is increased from zero to the steady-state power based on proportional-integral control. [Appendix 8] determining whether the temperature of the heater is equal to the setpoint variable; controlling the electrical energy to the heater based on a temperature control model to maintain the temperature of the heater at the setpoint variable. Method in Appendix 1. [Appendix 9] 2. The method of claim 1, wherein the performance characteristics include at least one of a heater voltage, a heater current, and a heater temperature. [Appendix 10] 1. A system for controlling a heater, comprising: The system comprises: a processor configured to execute instructions stored on a non-transitory computer-readable medium; The plurality of instructions: obtaining a target temperature of the heater and a temperature of the heater; controlling the heater in one of an energy-based control mode and a temperature control mode based on the target temperature and the temperature; during the energy-based control mode, identifying an energy profile for the heater based on the target temperature, the energy profile providing an initial magnitude of electrical energy to be applied to the heater to cause the temperature to reach the target temperature; providing electrical energy to the heater based on the energy profile during the energy-based control mode; and selectively supplying the electrical energy to the heater based on the temperature during the temperature control mode. system. [Appendix 11] During the energy-based control mode, the instructions for supplying the electrical energy to the heater based on the energy profile include: providing the defined magnitude of initial electrical energy to the heater; determining whether the temperature of the heater is within a temperature approach band of the target temperature of the heater; and reducing the electrical energy supplied to the heater to a steady state power in response to the temperature of the heater being within the temperature approach band of the target temperature of the heater. Appendix 10 system. [Appendix 12] The instructions for selectively supplying the electrical energy to the heater based on the temperature during the temperature control mode include: turning off electrical energy to the heater; determining whether the temperature of the heater is within a temperature approach band of the target temperature of the heater; increasing the electrical energy supplied to the heater to a steady state power in response to the temperature of the heater being within the temperature approach band of the target temperature of the heater. Appendix 10 system. [Appendix 13] The plurality of instructions: determining whether the temperature of the heater is equal to the target temperature; and controlling the electrical energy supplied to the heater based on a temperature control model to maintain the temperature of the heater in response to the temperature of the heater being equal to the target temperature. Appendix 10 system. [Appendix 14] 1. A method for learning an energy profile of a heater, the method comprising: obtaining a setpoint variable indicating a target temperature of the heater; providing electrical energy to the heater, the electrical energy having a calibrated magnitude; obtaining a process variable indicative of a temperature of the heater; if the process variable indicates that the temperature of the heater is equal to the target temperature; determining a response time of the heater; Selectively adjusting a plurality of gain values ​​of a controller based on the response time; generating an energy profile based on the plurality of gain values ​​and the setpoint variable, the energy profile correlating the setpoint variable to a predetermined value of electrical energy. method. [Appendix 15] the energy profile further defines a steady-state power applied to the heater in response to the temperature of the heater being within a temperature approach band of the target temperature. Appendix 14 method. [Appendix 16] further comprising defining the temperature approach band of the target temperature based on a mathematical model. Method in Appendix 15. [Appendix 17] the energy profile further defines a duration for which the predetermined value of electrical energy is supplied to the heater to cause the temperature of the heater to reach the target temperature. Appendix 14 method. [Appendix 18] Selectively adjusting the plurality of gain values ​​based on the response time further comprises adjusting the plurality of gain values ​​based on a Ziegler-Nichols tuning routine in response to the response time being less than a threshold response time. Appendix 14 method. [Appendix 19] the energy profile is further based on the calibration magnitude; Appendix 14 method. [Appendix 20] selectively adjusting the calibration magnitude when the process variable indicates that the temperature of the heater is equal to the target temperature. Appendix 14 method.

Claims

1. 1. A method for controlling a heating process of a heater, comprising: obtaining a setpoint variable indicating a target temperature of the heater; identifying an energy profile for the heater based on the setpoint variable, wherein the energy profile correlates the target temperature of the heater to a defined magnitude of initial electrical energy applied to the heater to cause the temperature of the heating process to reach the target temperature of the heater; obtaining a process variable indicative of a performance characteristic of the heating process; and supplying electrical energy to the heater based on an operational control mode and based on one of the energy profile and the process variable. method.

2. Providing the electrical energy to the heater comprises: providing the heater with initial electrical energy of the defined magnitude; reducing the electrical energy to the heater in response to the process variable indicating that the temperature of the heater is within a temperature approach band of the target temperature of the heater, and the performance characteristic includes the temperature of the heater.

10. The method of claim 1.

3. The method of claim 2 , wherein the electrical energy is reduced to a steady-state power based on a natural time constant, or the electrical energy is reduced to a steady-state power based on proportional-integral control.

4. The performance characteristic includes the temperature of the heater, the method further comprising determining whether the temperature of the heater is less than the setpoint variable; in response to the temperature of the heater being less than the setpoint variable, the electrical energy supplied to the heater is based on the identified energy profile and equal to the defined magnitude of initial electrical energy; In response to the temperature of the heater being greater than the setpoint variable, the method comprises: turning off electrical energy to the heater; obtaining the process variable indicative of the temperature of the heater; increasing the electrical energy to the heater to a steady state power in response to the temperature of the heater approaching the setpoint variable.

10. The method of claim 1.

5. The method of claim 4 , wherein the electrical energy is increased from zero to the steady-state power based on a natural time constant, or the electrical energy is increased from zero to the steady-state power based on proportional-integral control.

6. determining whether the temperature of the heater is equal to the setpoint variable; controlling the electrical energy to the heater based on a temperature control model to maintain the temperature of the heater at the setpoint variable.

10. The method of claim 1.

7. The method of claim 1 , wherein the performance characteristics include at least one of the heater voltage, the heater current, and the heater temperature.

8. 1. A system for controlling a heater, comprising: The system comprises: a processor configured to execute instructions stored on a non-transitory computer-readable medium; The plurality of instructions: obtaining a target temperature of the heater and a temperature of the heater; controlling the heater in one of an energy-based control mode and a temperature control mode based on the target temperature and the temperature of the heater; determining an energy profile for the heater during the energy-based control mode based on the target temperature of the heater, the energy profile correlating the target temperature of the heater to a defined magnitude of initial electrical energy to be applied to the heater to cause the temperature to reach the target temperature of the heater; providing electrical energy to the heater based on the energy profile during the energy-based control mode; and selectively supplying the electrical energy to the heater based on the temperature during the temperature control mode. system.

9. During the energy-based control mode, the instructions for supplying the electrical energy to the heater based on the energy profile include: providing the defined magnitude of initial electrical energy to the heater; determining whether the temperature of the heater is within a temperature approach band of the target temperature of the heater; and reducing the electrical energy supplied to the heater to a steady state power in response to the temperature of the heater being within the temperature approach band of the target temperature of the heater. The system of claim 8.

10. The instructions for selectively supplying the electrical energy to the heater based on the temperature during the temperature control mode include: turning off electrical energy to the heater; determining whether the temperature of the heater is within a temperature approach band of the target temperature of the heater; increasing the electrical energy supplied to the heater to a steady state power in response to the temperature of the heater being within the temperature approach band of the target temperature of the heater. The system of claim 8.

11. The plurality of instructions: determining whether the temperature of the heater is equal to the target temperature of the heater; and controlling the electrical energy supplied to the heater based on a temperature control model to maintain the temperature of the heater in response to the temperature of the heater being equal to the target temperature of the heater. The system of claim 8.

12. 1. A method for learning an energy profile of a heater, the method comprising: obtaining a setpoint variable indicating a target temperature of the heater; providing electrical energy to the heater, the electrical energy having a calibrated magnitude; obtaining a process variable indicative of a temperature of the heater; if the process variable indicates that the temperature of the heater is equal to the target temperature; determining a response time of the heater; Selectively adjusting a plurality of gain values ​​of a controller based on the response time; generating an energy profile based on the plurality of gain values ​​and the setpoint variable, the energy profile correlating the setpoint variable to a predetermined value of electrical energy. method.

13. the energy profile further defines a steady-state power applied to the heater in response to the temperature of the heater being within a temperature approach band of the target temperature, the energy profile further defines a duration for supplying the predetermined value of electrical energy to the heater to cause the temperature of the heater to reach the target temperature, or the energy profile is further based on the calibration magnitude.

13. The method of claim 12.

14. further comprising defining the temperature approach band of the target temperature based on a mathematical model, or further comprising selectively adjusting the calibration magnitude when the process variable indicates that the temperature of the heater is equal to the target temperature.

14. The method of claim 13.

15. Selectively adjusting the plurality of gain values ​​based on the response time further comprises adjusting the plurality of gain values ​​based on a Ziegler-Nichols tuning routine in response to the response time being less than a threshold response time.

13. The method of claim 12.

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