A temperature control method of a different heating rate adaptive control system

Abstract

The application provides a temperature control method of a different heating rate adaptive control system, which comprises a heat transfer body, a heating rod, a heated body, a temperature sensor A, a temperature sensor B, a heat preservation layer, a temperature control panel, a solid-state relay and a power supply; the heating rod and the heated body are arranged in the heat transfer body, the heat preservation layer wraps the heat transfer body, the temperature sensor A is used for acquiring a heating rod temperature increment change value, and the temperature sensor B is arranged close to the heated body; the solid-state relay and the temperature control panel are both arranged outside the heat preservation layer and are electrically connected, the solid-state relay heating body is electrically connected, the temperature sensor A and the temperature sensor B are both electrically connected with the temperature control panel, and the temperature control panel is provided with a PID control algorithm. The system can automatically match different heating modes and dynamically adjust PID parameters, so that the hysteresis of the temperature value of the heated body in the different gradient heating process in a cycle time is improved, and the temperature overshoot is prevented from being outside the gradient value increment range at a certain moment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of instrument temperature control, in particular to a temperature control method of a different heating rate adaptive control system. BACKGROUND

[0002] In some experimental environments, temperature conditions are usually considered. For example, water bath temperature control, in which a part of experiments that need to accurately control temperature parameters need to use instruments with high temperature control precision. The temperature control principle of such instruments is usually to set a corresponding control algorithm in the laboratory instrument, and the common control algorithm is the PID control algorithm. The PID control algorithm includes proportional, integral and derivative control, and its formula is as follows:

[0003]

[0004] In the formula, U(t) is the output of the algorithm; Kp is the proportional function; e(t) is the input of the algorithm; Ti is the integral time constant; Td is the derivative time constant. p I D

[0005] The PID control algorithm process mainly adds the output after proportional, integral and derivative operations to the input of the system to control the behavior of the system. The existing PID temperature controller and method (CN101017380A) can be applied to the measurement of the heat conduction efficiency of solid materials, control the temperature of the closed chamber of the measurement device, and keep it constant. It mainly includes a temperature sensor in the closed chamber, a heat source, and a computer board card and a computer outside the chamber. The temperature sensor is used to collect the temperature signal in the closed chamber, and then the signal is input to the analog input port of the computer board card. The computer control system performs digital filtering and operation processing on the input temperature signal data, and then uses the operation result as a control signal to send to the heat source through the computer board card to realize temperature control. A PID temperature control with anti-windup and fast adaptive tuning can be further designed. The temperature of the closed chamber can be quickly and effectively controlled and kept constant. However, in some temperature control application scenarios with different gradient values in the period of time, due to the time lag and heating inertia, and the constant parameter setting of the present application, temperature overshoot may occur at a gradient value increment outside the range at a certain moment. SUMMARY

[0006] The present application provides a temperature control method of a different heating rate adaptive control system, which aims to solve the problem of temperature overshoot in the temperature control scenario with different gradient values in the period of time.

[0007] ​​​The application provides a temperature control method of a different heating rate adaptive control system.

[0008] A different heating rate adaptive control system comprises a heat transfer body (1), a heating rod (2), a heated body (3), a temperature sensor A (4), a temperature sensor B (5), a heat preservation layer (6), a temperature control panel (7), a solid-state relay (8) and a power supply (9) electrically connected with the solid-state relay (8).

[0009] The heating rod (2) and the heated body (3) are arranged in the heat transfer body (1), the heat preservation layer (6) wraps the heat transfer body (1), the temperature sensor A (4) is used for acquiring a temperature increment change value of the heating rod (2), the temperature sensor B (5) is arranged close to the heated body (3), the solid-state relay (8) and the temperature control panel (7) are arranged outside the heat preservation layer (6) and electrically connected with each other, the solid-state relay (8) is electrically connected with the heating rod (2), the temperature sensor A (4) and the temperature sensor B (5) are electrically connected with the temperature control panel (7), and the temperature control panel (7) is provided with a PID control algorithm.

[0010] The formula of the PID control algorithm used in the temperature control panel (7) is as follows:

[0011]

[0012] Wherein, U(t) is the output of the algorithm, K P is a proportional time coefficient, e(t) is the input of the algorithm, e(t-1) is the deviation of the last sampling, e(t-2) is the deviation of the last but one sampling, K I is an integral time coefficient, and K D is a differential time coefficient.

[0013] Preferably, the temperature sensor A (4) and the temperature sensor B (5) are arranged between the heating rod (2) and the heated body (3), the temperature sensor A (4) is arranged on the side close to the heating rod (2), and the temperature sensor B (5) is arranged on the side close to the heated body (3).

[0014] A temperature control method based on the above different heating rate adaptive control system comprises the following steps.

[0015] S1: initial temperature control PID parameters, a target temperature T s , a heating gradient TK, a collection time at, a proportional time coefficient K P , an integral time coefficient K I , and a differential time coefficient K DAnd the PID control channel flag is set to 0, and the temperature sensor A(4) reads the real-time temperature T of the heating rod (2). cA The temperature control board (7) will set T cA As input to the PID control algorithm, it controls the solid-state relay (8) to supply power to the heating rod (2);

[0016] S2: Temperature sensor B(5) reads the real-time temperature T of the heated body (3). cB Temperature control board (7) calculates T cA and T s The difference dT cA T cB and T s The difference dT cB T cA and T cB The difference dT cX ;

[0017] S3: Temperature control board (7) determines whether the following conditions are met simultaneously: T cA Greater than T cB T cB Less than T s dT cX If the temperature is greater than 5℃, the system is determined to enter the rapid heating mode. The temperature control board (7) adjusts the PID parameters, the PID control channel switching flag is set to 0, and the temperature sensor A (4) reads the real-time temperature T of the heating rod (2). cA The temperature control board (7) will set T cA As the input to the PID control algorithm, the solid-state relay (8) supplies power to the heating rod (2), and step S2 is executed again;

[0018] S4: If the judgment result in S3 is negative, then the temperature control board (7) determines whether the following conditions are met simultaneously: T cA Greater than T S T cB Less than T s dT cB If the temperature is less than 0.5°C, the system is determined to enter the slow heating mode. The temperature control board (7) adjusts the PID parameters, and the PID control channel flag is set to 1. Then the temperature sensor B (5) reads the real-time temperature T of the heated body (3). cB The temperature control board (7) will set T cB As input to the PID control algorithm, the solid-state relay (8) supplies power to the heating rod (2), and the temperature sensor A (4) reads the real-time temperature T of the heating rod (2). cA Repeat step S2;

[0019] S5: If the result of S4 is no, the temperature control board (7) judges whether the following conditions are met simultaneously: T cA > T S , T cB > T s , dT cX < 0.2℃, if yes, the system is determined to enter the holding mode, the temperature control board (7) adjusts the PID parameters, the PID control channel switching flag is set to 1, then the temperature sensor B (5) reads the real-time temperature T cB of the heating body (3), the temperature control board (7) takes T cB as the input of the PID control algorithm, and controls the solid-state relay (8) to supply power to the heating rod (2), the temperature sensor A (4) reads the real-time temperature T cA of the heating rod (2), and the subsequent steps start from S2.

[0020] S6: If the result of S5 is no, the temperature control board (7) judges whether at is equal to 0, if no, the process starts from S2 again.

[0021] S7: If the result of S6 is yes, the temperature controller tests the real-time temperature T cA and the backup temperature T cA ' of the temperature sensor A (4) and the difference dT cA K therebetween, tests the real-time temperature T cB and the backup temperature T cB ' of the temperature sensor B (5) and the difference dT cB K therebetween, and the temperature control board (7) recalculates the collection time at, the temperature control board (7) judges whether dT cA K and dT cB K are both greater than TK, if yes, the temperature control board (7) adjusts the PID parameters according to the determination methods of the three different modes in S3-S5, dT cA K and dT cB K are reset to 0, if no, the step S2 is executed again.

[0022] Preferably, when the system is in the fast heating mode, the following PID parameters are adjusted: the temperature control board (7) increases the value of K P , and reduces the values of K I and K D until they fall within the range values set in S1.

[0023] Preferably, when the system is in the slow heating mode, the following PID parameters are adjusted: the temperature control board (7) reduces the values of K P and K D , and increases the value of K I until they fall within the range values set in S1.

[0024] Preferably, when the system is in the temperature maintaining mode, the PID parameters of the temperature control board (7) are adjusted: the value of K P and K I is increased until it falls within the range value set by S1. D

[0025] Preferably, the formula for the temperature control board (7) to recalculate the collection time at in S7 is:

[0026]

[0027] wherein at is the collection time; dT cA K is the difference between the real-time temperature T cA and the backup temperature T cA ' of the temperature sensor A (4); dT cB K is the difference between the real-time temperature T cB and the backup temperature T cB ' of the temperature sensor B (5).

[0028] Compared with the prior art, the present application has the beneficial technical effects in that:

[0029] 1. The temperature control method of the different heating rate adaptive control system provided by the present application is characterized in that two groups of temperature sensors are arranged near the heating end and the heated body, respectively, the temperature sensor A and the temperature sensor B monitor the corresponding temperature change parameters after the heat conduction between the heating rod and the heated body in the heat transfer body and transmit them to the temperature control board, the temperature sensor A and B detect the temperature and the target temperature parameters, the temperature control board automatically switches the fast heating mode, the slow heating mode and the temperature maintaining mode through different judgment conditions, automatically matches and dynamically adjusts the PID parameters in different ways for temperature control in different heating modes, and adjusts the collection time at to improve the hysteresis of the temperature value of the heated body in the different gradient heating process within the cycle time and prevent the temperature overshoot from being outside the gradient value increment range at a certain moment.

[0030] 2. The temperature control method of the different heating rate adaptive control system provided by the present application is characterized in that the temperature sensor A is installed near the heating rod in the heat transfer body, which facilitates the rapid acquisition of the temperature increment change value, and the temperature sensor B is installed near the heated body in the heat transfer body, which facilitates the acquisition of the change value of the temperature hysteresis due to the different heat capacity ratios of the heat transfer body and the heated body. BRIEF DESCRIPTION OF DRAWINGS

[0031] Fig. 1 is the assembly drawing of the different heating rate adaptive control system provided by the present application; ​

[0032] Fig. 2 is a method flowchart of a different heating rate adaptive control system provided by the present application.

[0033] The figure mark: 1, heat transfer body; 2, heating rod; 3, heated body; 4, temperature sensor A; 5, temperature sensor B; 6, heat preservation layer; 7, temperature control board; 8, solid state relay; 9, power supply. DETAILED DESCRIPTION

[0034] The following will be combined with the Figs. 1-2 The present application is further described in detail.

[0035] The embodiment of the present application discloses a temperature control method of a different heating rate adaptive control system.

[0036] Embodiment 1:

[0037] A different heating rate adaptive control system, comprising: a heat transfer body 1, a heating rod 2, a heated body 3, a temperature sensor A 4, a temperature sensor B 5, a heat preservation layer 6, a temperature control board 7, a solid state relay 8 and a power supply 9 connected with the solid state relay 8;

[0038] The heating rod 2 and the heated body 3 are both arranged in the heat transfer body 1, the heat preservation layer 6 wraps the heat transfer body 1, the temperature sensor A 4 is used to obtain the temperature increment change value of the heating rod 2, and the temperature sensor B 5 is arranged close to the heated body 3;

[0039] The solid state relay 8 and the temperature control board 7 are both arranged outside the heat preservation layer 6 and electrically connected, the solid state relay 8 is electrically connected with the heating rod 2, the temperature sensor A 4 and the temperature sensor B 5 are both electrically connected with the temperature control board 7, and the temperature control board 7 is provided with a PID control algorithm.

[0040] The temperature sensor A 4 and the temperature sensor B 5 are both arranged between the heating rod 2 and the heated body 3, the temperature sensor A 4 is arranged on the side close to the heating rod 2, the temperature sensor B 5 is arranged on the side close to the heated body 3, and the temperature sensor A 4 and the temperature sensor B 5 do not contact each other. By installing the temperature sensor A 4 in the heat transfer body 1 close to the heating rod 2, the temperature increment change value in heating can be quickly obtained, since the heat capacity ratio of the heat transfer body 1 and the heated body 3 is different, the temperature sensor B 5 is installed in the heat transfer body 1 close to the heated body 3, so that the change value of temperature hysteresis can be obtained.

[0041] The formula of the PID control algorithm used in the temperature control board 7 is:

[0042]

[0043] Wherein, U(t) is the output of the algorithm, K Pis the proportional time coefficient, e(t) is the input of the algorithm, e(t-1) is the deviation of the last sampling, e(t-2) is the deviation of the last but one sampling, K I is the integral time coefficient, K D is the differential time coefficient.

[0044] A method based on the above-mentioned different heating rate adaptive control system, comprising the following steps:

[0045] S1: set the initial temperature control PID parameter target temperature T s , heating gradient TK, collection time at, proportional time coefficient K P , integral time coefficient K I , differential time coefficient K D on the temperature control panel 7, and set the PID control channel flag to 0, the temperature sensor A4 reads the real-time temperature T cA of the heating rod 2, and the temperature control panel 7 takes T cA as the input of the PID control algorithm to control the power supply of the solid-state relay 8 to the heating rod 2;

[0046] S2: the temperature sensor B5 reads the real-time temperature T cB of the heated body 3, and the temperature control panel 7 calculates the difference dT cA between T s and T cA , the difference dT cB between T s and T cB , and the difference dT cA between T cB and T cX ;

[0047] S3: the temperature control panel 7 judges whether T cA is greater than T cB , T cB is less than T s , and dT cX is greater than 5℃, if yes, it is determined that the system enters the fast heating mode, and the temperature control panel 7 adjusts the PID parameters as follows: increase the value of K P , and reduce the values of K I and K D until they fall within the range values set in S1, set the PID control channel switching flag to 0, the temperature sensor A4 reads the real-time temperature T cA of the heating rod 2, the temperature control panel 7 takes T cA as the input of the PID control algorithm to control the power supply of the solid-state relay 8 to the heating rod 2, and re-executes step S2;

[0048] S4: if the result of the judgment in S3 is no, the temperature control panel 7 judges whether TcA Greater than T S T cB Less than T s dT cB If the temperature is less than 0.5°C, the system is determined to have entered slow heating mode, and the temperature control board 7 adjusts the PID parameters as follows: reduce K... P and K D The value of K is increased. I The value will remain within the range set by S1 until it falls into the range of the heated body 3. The PID control channel flag will then be set to 1, and the temperature sensor B5 will read the real-time temperature T of the heated body 3. cB Temperature control board 7 will T cB The solid-state relay 8, acting as input to the PID control algorithm, supplies power to the heating rod 2. Temperature sensor A4 reads the real-time temperature T of the heating rod 2. cA Repeat step S2;

[0049] S5: If the result of the judgment in S4 is negative, then the temperature control board 7 determines whether T is satisfied simultaneously. cA Greater than T S T cB Greater than T s dT cX If the temperature is less than 0.2℃, the system is determined to enter the heat preservation mode, and the temperature control board 7 adjusts the PID parameters as follows: reduce K P and K I The value of K is increased. D The value falls within the range set by S1, and the PID control channel switching flag is set to 1. Then, temperature sensor B5 reads the real-time temperature T of the heated body 3. cB Temperature control board 7 will T cB The solid-state relay 8, acting as input to the PID control algorithm, supplies power to the heating rod 2. Temperature sensor A4 reads the real-time temperature T of the heating rod 2. cA Repeat step S2;

[0050] S6: If the judgment result in S5 is negative, the temperature control board 7 determines whether at is equal to 0. If not, step S2 is executed again.

[0051] S7: If the determination result in S6 is yes, then the temperature controller will test the real-time temperature T of temperature sensor A4. cA and backup temperature T cA 'and the difference between the two dT cA K, the real-time temperature T of the test temperature sensor B5. cB and backup temperature T cB 'and the difference between the two dT cBK, the temperature control board 7 recalculates the collection time at, the formula of the temperature control board 7 recalculates the collection time aT is:

[0052]

[0053] Wherein, at is the collection time; dT cA K is the real-time temperature T of the temperature sensor A4 cA And the difference between the backup temperature T cA ' of dT cB K is the real-time temperature T of the temperature sensor B5 cB And the difference between the backup temperature T cB ' of dT.

[0054] The temperature control board 7 judges dT cA K and dT cB K are greater than TK, if so, the temperature control board 7 adjusts the PID parameters according to the determination method of three different modes in S3-S5, dT cA K and dT cB K reset to 0, if not, the subsequent steps all start from S2.

[0055] The implementation principle of the embodiment is that: by arranging two groups of temperature sensors near the heating end and the heated body 3 respectively, the temperature sensor A4 and the temperature sensor B5 monitor the corresponding temperature change parameters after the heat conduction between the heating rod 2 and the heated body 3 in the heat transfer body 1 and transmit them to the temperature control board 7, the temperature sensor A4 and B detect the temperature and the target temperature parameter, automatically switch the fast heating mode, the slow heating mode and the holding mode, the temperature control board 7 automatically matches different heating modes by different judgment conditions and automatically matches and dynamically adjusts the PID parameters in different ways for temperature control by the temperature control board 7, and adjusts the collection time at to improve the hysteresis of the temperature value of the heated body 3 in the different gradient heating process in the cycle time, prevent the temperature overshoot from being outside the gradient value increment range at a moment.

[0056] The above are the preferred embodiments of the present application, not limited to the protection scope of the present application, therefore: all equivalent changes made according to the structure, shape, principle of the present application should be covered in the protection scope of the present application.

Claims

1. A different ramp rate adaptive control system, characterized by, Include: Heat transfer body (1), heating rod (2), heated body (3), temperature sensor A (4), temperature sensor B (5), heat preservation layer (6), temperature control board (7), solid state relay (8) and power supply (9) electrically connected with solid state relay (8); The heating rod (2) and heated body (3) are arranged in the heat transfer body (1), the heat preservation layer (6) wraps the heat transfer body (1), the temperature sensor A (4) is used for acquiring the temperature increment change value of the heating rod (2), the temperature sensor B (5) is arranged close to the heated body (3), the solid state relay (8) and the temperature control board (7) are arranged outside the heat preservation layer (6) and electrically connected, the solid state relay (8) is electrically connected with the heating rod (2), the temperature sensor A (4) and the temperature sensor B (5) are electrically connected with the temperature control board (7), and the temperature control board (7) is provided with PID control algorithm; The formula of the PID control algorithm used in the temperature control board (7) is: wherein, is the output of the algorithm, is the proportional time coefficient, is the input of the algorithm, is the deviation of the last sample, is the deviation of the sample before the last sample, is the integral time coefficient, is the derivative time coefficient; The temperature sensor A (4) and the temperature sensor B (5) are arranged between the heating rod (2) and the heated body (3), the temperature sensor A (4) is arranged on the side close to the heating rod (2), and the temperature sensor B (5) is arranged on the side close to the heated body (3); The temperature control method of the different heating rate adaptive control system comprises the following steps: S1: Set the initial temperature control PID parameter target temperature T on the temperature control board (7) s , temperature gradient TK, collection time aT, proportional time coefficient K P , integral time coefficient K I , differential time coefficient K D , and set the PID control channel flag to 0. The temperature sensor A (4) reads the real-time temperature T of the heating rod (2) cA . The temperature control board (7) takes T cA as the input of the PID control algorithm and controls the solid-state relay (8) to supply power to the heating rod (2). S2: Temperature sensor B (5) reads the real-time temperature T of the heated body (3). cB Temperature control board (7) calculates T cA and T s The difference dT cA T cB and T s The difference dT cB T cA and T cB The difference dT cX ; S3: The temperature control board (7) determines whether the following conditions are met simultaneously: T cA > T cB , T cB < T s , dT cX > 5℃. If so, it is determined that the system enters a fast heating mode, the temperature control board (7) adjusts the PID parameters, the PID control channel switching flag is set to 0, the temperature sensor A (4) reads the real-time temperature T cA of the heating rod (2), and the temperature control board (7) takes T cA as the input of the PID control algorithm to control the solid-state relay (8) to supply power to the heating rod (2), and step S2 is re-executed. S4: If the judgment result in S3 is negative, then the temperature control board (7) determines whether the following conditions are met simultaneously: T cA Greater than T S T cB Less than T s dT cB If the temperature is less than 0.5°C, the system is determined to enter the slow heating mode. The temperature control board (7) adjusts the PID parameters, and the PID control channel flag is set to 1. Then the temperature sensor B (5) reads the real-time temperature T of the heated body (3). cB， Temperature control board (7) will T cB As the input to the PID control algorithm, the solid-state relay (8) supplies power to the heating rod (2), and the temperature sensor A (4) reads the real-time temperature T of the heating rod (2). cA Repeat step S2; S5: If the result of the judgment in S4 is no, the temperature control board (7) judges whether the following conditions are met simultaneously: T cA > T S , T cB > T s , dT cX < 0.2℃, if yes, it is determined that the system enters the holding mode, the temperature control board (7) adjusts the PID parameters, the PID control channel switching flag is set to 1, and the temperature sensor B (5) reads the real-time temperature T cB， of the heated body (3); the temperature control board (7) takes T cB as the input of the PID control algorithm, and the solid-state relay (8) supplies power to the heating rod (2); the temperature sensor A (4) reads the real-time temperature T cA of the heating rod (2); and the subsequent steps start from S2. S6: if the determination result in S5 is no, the temperature control board (7) judges whether aT is equal to 0, if no, the process starts from S2 step again; S7: If the result of the determination in S6 is yes, the temperature controller tests the real-time temperature T cA and the backup temperature T cA of temperature sensor A (4) respectively, and the difference dT cA K between them, tests the real-time temperature T cB and the backup temperature T cB of temperature sensor B (5) respectively, and the difference dT cB K between them, and the temperature control board (7) recalculates the collection time aT, and the temperature control board (7) determines whether dT cA K and dT cB K are both greater than TK, if yes, the temperature control board (7) adjusts the PID parameters according to the determination method of the three different modes in S3-S5, dT cA K and dT cB K are reset to 0, if not, step S2 is executed again.

2. The system of claim 1, wherein the system is configured to: When the system is in fast heating mode, adjust the following PID parameters: increase the value of K P of the temperature control board (7), and decrease the values of K I and K D until they fall within the range values set in step S1.

3. The system of claim 1, wherein the system is configured to: When the system is in slow warming mode, adjust the following PID parameters: decrease the value of K P and K D and increase the value of K I until it falls within the range set in S1.

4. The variable ramp rate adaptive control system of claim 1, wherein, When the system is in the holding mode, adjust the following PID parameters: decrease the value of K P and K I , and increase the value of K D until it falls within the range of values set in S1.

5. The variable ramp rate adaptive control system of claim 1, wherein, The formula for recalculating the collection time aT of the temperature control board (7) in S7 is: wherein, T is the acquisition time; is the difference between the real-time temperature T cA and the backup temperature T cA of the temperature sensor A (4); is the difference between the real-time temperature T cB and the backup temperature T cB of the temperature sensor B (5).

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