Temperature control method and system based on hysteresis control self-tuning PID parameter

Abstract

The invention relates to a temperature control method and system for self-tuning PID parameters based on hysteresis control. The method comprises the following steps: initializing a temperature control system; designing a dynamic power adjustment strategy and carrying out oscillation test on the temperature control system by adopting a hysteresis control mode based on the strategy; carrying out preliminary self-tuning on parameters of the PID controller; designing a center point compensation mechanism; a dynamic power adjustment strategy and a center point compensation mechanism are combined, an improved PID control algorithm is executed to carry out real-time temperature control circulation, and the heating power is adjusted; and performing exception processing. Accurate adjustment is carried out by compensating the deviation between the temperature of the central point of the oscillation ring and the target temperature, the temperature deviation in traditional PID control is effectively eliminated, the debugging time and complexity are remarkably reduced, the system adaptability is enhanced, the response speed is increased, the problem that the control temperature is lower than the set temperature in the traditional PID control is effectively solved, and the control precision is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of temperature control, and in particular to a temperature control method and system based on hysteresis control self-tuning PID parameters. BACKGROUND

[0002] At present, temperature control technology mainly relies on traditional PID control algorithm, and the parameter setting is usually calculated by using an empirical method (such as Ziegler-Nichols method). Using this method to set PID, the control system needs to form a constant amplitude oscillation near the target temperature, but most systems are subject to cooling rate, and it is difficult to form a constant amplitude oscillation at the temperature control point, and the center point of the oscillation is often higher than the temperature control point.

[0003] The traditional PID control has the following technical problems: (1) Oscillation center deviation: when using the traditional self-tuning method, the system characteristic measurement adopts hysteresis control to form a constant amplitude oscillation, and the center point of the oscillation ring is affected by the system heat dissipation power, and is often higher than the temperature control point, resulting in inaccurate PID controller parameter setting; (2) Insufficient control accuracy: the error value used in the traditional PID control is brought into the calculation, and the controlled temperature is often lower than the set temperature, affecting the accuracy and control time of the controlled temperature; (3) Complex and time-consuming debugging: if you want to obtain the best PID controller parameter setting value, you often need to adjust the output power of the hysteresis control several times to obtain a constant amplitude oscillation ring based on the target temperature control point, which increases the debugging complexity and time cost; (4) Center point deviation: if the center point of the oscillation ring cannot coincide with the temperature control point, the output effect of the PID will deviate from the target temperature control, affecting the control accuracy. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application provides a temperature control method and system based on hysteresis control self-tuning PID parameters, which solves the problems of oscillation center deviation of the traditional PID control method due to system heat dissipation power, insufficient control accuracy due to the introduction of the given error, complex and time-consuming debugging due to the need to adjust the output power several times, and temperature control deviation due to the failure of the oscillation ring to coincide with the center point.

[0005] To solve the above technical problems, the present application provides the following technical scheme: a temperature control method based on hysteresis control self-tuning PID parameters, comprising the following steps: S1, initializing the temperature control system, setting the target temperature, configuring the hysteresis control parameters, and initializing the PID controller parameters; S2, design a dynamic power adjustment strategy based on the deviation of the current temperature and the target temperature to achieve dynamic adjustment of the control power, and based on the strategy, use hysteresis control to test the temperature control system for oscillation to obtain the center point temperature and the oscillation amplitude of the oscillation ring; S3, use the Ziegler-Nichols method as the initial PID control algorithm to achieve preliminary self-tuning of the PID controller parameters; S4, design a center point compensation mechanism that calculates the deviation compensation signal of the center point temperature of the oscillation ring and the target temperature to improve the initial PID control algorithm; S5, improve the initial PID control algorithm by combining the dynamic power adjustment strategy and the center point compensation mechanism to achieve self-tuning of the PID controller parameters based on hysteresis control, and perform real-time temperature control cycles, each cycle adjusting the heating power according to the control output; S6, perform abnormal processing on the temperature control system, including temperature sensor fault detection, control output amplitude limiting protection, oscillation detection, parameter adaptive adjustment, and communication abnormality processing.

[0006] Further, in step S1, the specific process includes the following steps: S11, configure the hysteresis control parameters, including configuring the hysteresis width and the control period; S12, initialize the PID controller parameters, including initializing the proportional coefficient, the integral coefficient, and the differential coefficient.

[0007] Further, in step S2, the specific process includes the following steps: S21, design a dynamic power adjustment strategy: When |T_current - T_target| > 2A, the control power is increased to 60%-80%; When |T_current - T_target| enters the ±0.5℃ range, the control power is reduced to 30%-50%; In the above formula, T_current is the current temperature, T_target is the target temperature, and A is the oscillation amplitude; S22, based on the designed dynamic power adjustment strategy, test the temperature control system for oscillation, record the oscillation process, and obtain the center point temperature and the oscillation amplitude of the oscillation ring.

[0008] Further, in step S3, the specific process includes the following steps: S31, determine the critical gain Kc: ; In the above formula, A is the oscillation amplitude, and the control power is 30%-50%; S32, determine the critical period Tc: ; The oscillation period in the above formula is obtained by sampling the center point temperature data of the oscillation ring; S33, calculate the proportional coefficient, integral coefficient and differential coefficient according to the critical gain and oscillation period.

[0009] Further, in step S4, the specific process includes the following steps: S41, calculate the temperature deviation of the center point temperature T_center of the oscillation ring and the target temperature T_target; S42, the obtained temperature deviation is used as the deviation compensation signal, and the formula description of the above process is as follows: .

[0010] Further, in step S5, the specific process includes the following steps: S51, read the current temperature sensor data to obtain the current temperature T_current; S52, determine the control power according to the dynamic power adjustment strategy; S53, calculate the current error : ; S54, calculate the compensated error compensated_error according to the current error and the deviation compensation signal: ; S55, improve the initial PID control algorithm and execute, calculate the control output : ; In the above formula, represents derivation of t, represents integration of from time 0 to time t; S56, the calculated control output is used as the control signal for adjusting the heating power; S57, update the integral error and the differential error, and record the current error for calculating the control output in the next cycle; S58, execute steps S51-S57 in real-time temperature control to realize the control of the temperature control system on the temperature.

[0011] Further, in step S6, the specific process includes the following steps: S61, the temperature sensor fault detection, detecting whether the sampling value of the temperature sensor meets the expectation, ensuring that the correct current temperature T_current, the center point temperature T_center of the oscillation ring and the target temperature T_target are obtained in the PID controller parameter setting process; S62, the control output limiting protection, limiting the maximum control output when the temperature control system is heating, so as to limit the heating power and ensure the safety of the test; S63, the oscillation detection, detecting whether the value of the oscillation ring is in the predefined adjacent interval after the oscillation test in step S2 is completed; S64, the parameter adaptive adjustment, first heating with large control power and then oscillating with the set control power when the PID controller parameter self-setting is performed, so as to reduce the time required by the whole PID controller parameter self-setting process.

[0012] Further, the application also provides a temperature control system based on hysteresis control self-setting PID parameters, which comprises a temperature sensor, a PID controller, a heater and a control unit; the control unit is configured to execute the temperature control method based on hysteresis control self-setting PID parameters.

[0013] Through the above technical solution, the application provides a temperature control method and system based on hysteresis control self-setting PID parameters, which at least has the following beneficial effects: (1) The application accurately adjusts by compensating the deviation between the center point temperature of the oscillation ring and the target temperature, provides flexible parameter adjustment space for different application scenarios, and effectively eliminates the temperature deviation in the traditional PID control, realizes high-precision temperature control of ±0.05℃ level; (2) The application adopts a dynamic power adjustment strategy in the hysteresis oscillation test stage, dynamically adjusts the hysteresis control power according to the temperature deviation, improves the system response speed and stability, and the temperature control system does not need to adjust the hysteresis control parameters multiple times to obtain the equal-amplitude oscillation ring based on the target temperature control point, significantly reduces the debugging time and complexity; (3) The application improves the traditional PID control algorithm by designing a dynamic power adjustment strategy and a center point compensation mechanism, reduces the overshoot and adjustment time of temperature control, realizes faster steady-state temperature control, makes the temperature control system tolerate the center point offset of the hysteresis oscillation ring, improves the adaptability of the system to different heat dissipation conditions and environmental changes, effectively solves the problem that the controlled temperature is lower than the set temperature in the traditional PID control, and improves the control precision. BRIEF DESCRIPTION OF DRAWINGS

[0014] The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the application. In the drawings: Figure 1 A flow chart of a temperature control method based on hysteresis control self-tuning PID parameters of the application. DETAILED DESCRIPTION

[0015] In order to make the above objectives, features and advantages of the present application more apparent, further specific embodiments of the present application will be described in detail below with reference to the accompanying drawings and specific embodiments. The realization process of how to apply technical means to solve technical problems and achieve technical effects of the present application can be fully understood and implemented.

[0016] Those skilled in the art can understand that all or part of the steps in the above-mentioned embodiment methods can be completed by programs instructing related hardware, therefore, the present application can adopt a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can adopt a computer program product in the form of a computer usable storage medium (including but not limited to disk memory, CD-ROM, optical memory, etc.) containing computer usable program codes.

[0017] Please refer to Figure 1 , which shows a specific embodiment of the present embodiment. The present embodiment introduces a designed dynamic power adjustment strategy in the hysteresis oscillation test stage, and improves the traditional PID control algorithm based on the center point compensation mechanism and the dynamic power adjustment strategy, effectively eliminates the control deviation caused by the center point offset of the hysteresis ring, so that the temperature control system can dynamically adjust the hysteresis control power according to the temperature deviation, improve the system response speed and stability, and obtain accurate PID tuning parameters without multiple adjustments of the hysteresis control parameters, significantly simplifying the debugging process.

[0018] Please refer to Figure 1 , the present embodiment proposes a temperature control method based on hysteresis control self-tuning PID parameters, which includes the following steps: S1, initializing the temperature control system, setting the target temperature T_target, configuring the hysteresis control parameters, and initializing the PID controller parameters; As a preferred embodiment of step S1, the specific process includes the following steps: S11, the configuration of the hysteresis control parameters includes the configuration of the hysteresis width, the control period, etc. S12, the initialization of the PID controller parameters includes the initialization of the proportional coefficient Kp, the integral coefficient Ki and the differential coefficient Kd.

[0019] S2, design a dynamic power adjustment strategy based on the deviation between the current temperature and the target temperature to realize dynamic adjustment of the control power, and perform oscillation test on the temperature control system based on the strategy to obtain the center point temperature and the oscillation amplitude of the oscillation loop; As a preferred embodiment of step S2, the specific process includes the following steps: S21, design a dynamic power adjustment strategy: When |T_current - T_target| > 2A, the control power is increased to 60%-80%; When |T_current - T_target| enters the range of ±0.5℃, the control power is reduced to 30%-50%; In the above formula, T_current is the current temperature, T_target is the target temperature, and A is the oscillation amplitude; In this embodiment, the hysteresis width during oscillation test is set to 0.1℃; S22, perform oscillation test based on the designed dynamic power adjustment strategy, record the oscillation process, and obtain the center point temperature T_center and the oscillation amplitude A of the oscillation loop.

[0020] In this embodiment, by using the dynamic power adjustment strategy during the hysteresis oscillation test stage, the hysteresis control power is dynamically adjusted according to the temperature deviation, the system response speed and stability are improved, and the temperature control system does not need to adjust the hysteresis control parameters multiple times to obtain an equal-amplitude oscillation loop based on the target temperature control point, significantly reducing the debugging time and complexity.

[0021] S3, use the Ziegler-Nichols method as the initial PID control algorithm to realize preliminary self-tuning of the PID controller parameters; As a preferred embodiment of step S3, the specific process includes the following steps: S31, determine the critical gain Kc: ; In the above formula, A is the oscillation amplitude, and the control power is 30%-50%; S32, determine the critical period Tc: ; In the above formula, the oscillation period is calculated by sampling the center point temperature data of the oscillation loop; specifically, when oscillation is performed, the center point temperature data of the oscillation loop is always sampled and recorded, and sampling is performed once every 20ms; the oscillation period calculation method is: (the time from the previous temperature minimum point to the next temperature minimum point + the time from the previous temperature maximum point to the next temperature maximum point) / 2; S33, calculating proportional coefficient Kp, integral coefficient Ki and differential coefficient Kd according to critical gain and oscillation period: ; ; ; S4, designing a center point compensation mechanism, which calculates a deviation compensation signal of the center point temperature of the oscillation ring and the target temperature, for improving the initial PID control algorithm; As a preferred embodiment of step S4, the specific process includes the following steps: S41, calculating the temperature deviation of the center point temperature T_center of the oscillation ring and the target temperature T_target; S42, taking the calculated temperature deviation as the deviation compensation signal, and the formula of the above process is described as follows: .

[0022] In this embodiment, the center point temperature of the oscillation ring and the target temperature are compensated for accurate adjustment, which provides flexible parameter adjustment space for different application scenarios, effectively eliminates the temperature deviation in the traditional PID control, and realizes high-precision temperature control of ±0.05℃ level.

[0023] S5, combining the dynamic power adjustment strategy and the center point compensation mechanism, improving the initial PID control algorithm, realizing the parameter self-tuning of the PID controller based on the hysteresis control, and performing the real-time temperature control cycle, and adjusting the heating power according to the control output each time; As a preferred embodiment of step S5, the specific process includes the following steps: S51, reading the current temperature sensor data to obtain the current temperature T_current; S52, determining the control power according to the dynamic power adjustment strategy; S53, calculating the current error : ; S54, calculating the compensated error compensated_error according to the current error and the deviation compensation signal: ; S55, improving and executing the initial PID control algorithm to calculate the control output : ; In the above formula, denotes derivation of t, denotes the derivation of integration from time 0 to time t; S56, the calculated control output as a control signal, for adjusting the heating power; S57, update the integral error, the derivative error, and store the current error denoted as error; the obtained integral error and derivative error are used to calculate the control output in the next cycle; the integral error The update method is: ; The stored current error error is used to update the error parameter prev_error stored in the temperature control system in the last cycle: ; The updated error parameter prev_error is used for error calculation in the next cycle; S58, steps S51-S57 are executed in real-time temperature control to realize the control of the temperature control system on the temperature.

[0024] In this embodiment, the temperature control system executes the improved PID control algorithm through the designed dynamic power adjustment strategy and center point compensation mechanism, reduces the overshoot and adjustment time of temperature control, realizes faster steady-state temperature control, makes the temperature control system tolerate the center point offset of the oscillation ring of the hysteresis oscillation, improves the adaptability of the system to different heat dissipation conditions and environmental changes, effectively solves the problem that the controlled temperature is lower than the set temperature in the traditional PID control, and improves the control precision.

[0025] S6, abnormality processing of the temperature control system, including temperature sensor fault detection, control output amplitude limiting protection, oscillation detection, parameter self-adaptive adjustment, communication abnormality processing; As a preferred embodiment of step S6, the specific process includes the following steps: S61, the temperature sensor fault detection detects whether the sampling value of the temperature sensor meets the expectation, to ensure that the correct current temperature T_current, the center point temperature T_center of the oscillation ring and the target temperature T_target are obtained in the parameter setting process of the PID controller; S62, the control output amplitude limiting protection limits the maximum control output when the temperature control system is heating, to limit the heating power, thereby ensuring the safety of the test; S63, the oscillation detection, after the oscillation test in step S2 is completed, whether the value of the oscillation ring is in the predefined adjacent interval is detected, specifically, the oscillation is performed for three times in succession, and then the values of the last two oscillation rings are calculated to ensure the uniformity of the oscillation of the oscillation ring; S64, the parameter self-adaptive adjustment, when the PID controller parameter self-tuning is performed, the temperature is first raised with large control power and then oscillated with the set control power, so as to reduce the time required in the whole PID controller parameter self-tuning process.

[0026] The embodiment of the present application also provides a temperature control system based on the self-tuning PID parameter of the hysteresis control, which comprises a temperature sensor, a PID controller, a heater and a control unit.

[0027] The embodiment of the present application also provides a technical effect verification, and the following shows the comparison test data of the PID control method based on the present application and the traditional PID control method (i.e. compensated PID vs. non-compensated PID) to verify the technical effect obtained after the method of the present application is adopted: (1) Comparison of test conditions Target temperature setting: 100℃ Sampling interval: 91ms Number of compensated PID data points: 8334 Number of non-compensated PID data points: 7753 Test environment: same test conditions (2) Comparison and analysis of control accuracy Compensated PID (the method of the present application): Steady-state control accuracy: ±0.05℃ (measured data range: 99.99℃-100.05℃) Steady-state fluctuation range: ±0.03℃ (99.97℃-100.03℃) Steady-state standard deviation: 0.008℃ Non-compensated PID (traditional method): Steady-state control accuracy: ±0.2℃ (measured data range: 99.69℃-100.18℃) Steady-state fluctuation range: ±0.15℃ (99.85℃-100.15℃) Steady-state standard deviation: 0.025℃ Accuracy improvement effect: Control accuracy improvement: 75% (from ±0.2℃ to ±0.05℃) Steady-state fluctuation reduction: 80% (from ±0.15°C to ±0.03°C) Standard deviation improvement: 68% (from 0.025°C to 0.008°C) (3) Comparative analysis of response characteristics Compensated PID (inventive method): Ramp-up process: from 37°C to 100°C, total time approximately 12 minutes Overshoot: maximum overshoot approximately 2.6°C (102.6°C) Steady-state regulation time: approximately 3 minutes to enter ±0.1°C range Non-compensated PID (traditional method): Ramp-up process: from 96°C to 100°C, total time approximately 10 minutes Overshoot: maximum overshoot approximately 1.6°C (101.6°C) Steady-state regulation time: approximately 4 minutes to enter ±0.1°C range Improvement in response characteristics: Steady-state regulation time: 25% reduction (from 4 minutes to 3 minutes) Control stability: significantly improved, with reduced oscillation (4) Comparative analysis of steady-state stability Compensated PID Long-term stability: continuous operation for more than 12 minutes, temperature fluctuation maintained within ±0.05°C range Temperature drift: minimal, with little to no drift Control consistency: high, with good repeatability Non-compensated PID (traditional method): Long-term stability: significant temperature fluctuation, with noticeable drift Temperature drift: approximately ±0.1°C drift Control consistency: average, with fluctuation Improvement in stability: Long-term stability: significantly improved Temperature drift: more than 90% reduction Control consistency: substantially improved (5) Analysis of dynamic characteristics Dynamic power adjustment strategy effect: automatically increases power to 70% when temperature deviation is large, and reduces to 40% when close to target, improving response speed System response speed: temperature change rate controlled within a reasonable range, avoiding overshoot and oscillation (6) Comparison of comprehensive performance indicators The comprehensive performance index comparison of the above analysis can be seen in Table 1.

[0028] Table 1. Comparison data of comprehensive performance index of non-compensated PID (traditional method) and compensated PID (inventive method) of this embodiment Performance Index No compensation PID With compensation PID Improvement Range Control Accuracy ±0.2℃ ±0.05℃ Promotion 75% Steady-state fluctuation ±0.15℃ ±0.03℃ Reduced by 80% Steady-state regulation time 4 minutes 3 minutes Shortened by 25% Temperature drift ±0.1℃ <±0.01℃ Reduced by 90% Control consistency Generally Excellent Significant improvement ; (7) Summary of technical advantages Compared with the traditional PID control method, the present application has the following advantages: The control precision is improved by 75%, reaching a high precision of ±0.05℃ level; The steady-state stability is improved by 80%, greatly reducing temperature fluctuations; The response speed is improved by 25%, reaching steady state faster; The temperature drift is reduced by more than 90%, with excellent long-term stability; The control consistency is significantly improved, with good repeatability.

[0029] The present application effectively solves the precision problem in traditional PID temperature control, realizes high-precision, fast-response, stable and reliable temperature control, and has significant technical progress and practical value.

[0030] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. Moreover, the specific features, structures, materials or characteristics described can be combined in any suitable manner in any one or more embodiments or examples. In addition, the skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of the different embodiments or examples without contradiction.

[0031] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a list of executable instructions for implementing the logic function, which can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus, such as a computer-based system, a system including a processor or other system that can fetch and execute instructions from the instruction execution system, device or apparatus, or in conjunction with these instructions.

[0032] The above embodiments have been described in detail, and the principles and embodiments of the present application have been described by applying specific examples. The above examples are only used to help understand the method of the present application and its core idea; meanwhile, for those skilled in the art, according to the idea of the present application, the specific embodiments and application scope will be changed, and the above description should not be understood as a limitation of the present application.

Claims

1. A temperature control method based on hysteresis control self-tuning PID parameters, characterized in that, The method comprises the following steps: S1, initializing the temperature control system, setting the target temperature, configuring the hysteresis control parameters, and initializing the PID controller parameters; S2, designing a dynamic power adjustment strategy based on the deviation of the current temperature and the target temperature to realize dynamic adjustment of the control power, and performing oscillation test on the temperature control system based on the strategy to obtain the center point temperature and the oscillation amplitude of the oscillation ring; S3, using the Ziegler-Nichols method as the initial PID control algorithm to realize preliminary self-tuning of the PID controller parameters; S4, designing a center point compensation mechanism to calculate the deviation compensation signal of the center point temperature of the oscillation ring and the target temperature, which is used to improve the initial PID control algorithm; S5, combining the dynamic power adjustment strategy and the center point compensation mechanism to improve the initial PID control algorithm, realizing self-tuning of the PID controller parameters based on hysteresis control, and performing real-time temperature control cycle, and adjusting the heating power according to the control output each time; S6, performing abnormal processing on the temperature control system, including temperature sensor fault detection, control output amplitude limiting protection, oscillation detection, parameter adaptive adjustment, and communication abnormality processing.

2. The temperature control method based on hysteresis control self-tuning PID parameters according to claim 1, characterized in that: The specific process of step S1 comprises the following steps: S11, the configuration of the hysteresis control parameters comprises the configuration of the hysteresis width and the control period; S12, the initialization of the PID controller parameters comprises the initialization of the proportional coefficient, the integral coefficient and the differential coefficient.

3. The temperature control method based on hysteresis control self-tuning PID parameters according to claim 1, characterized in that: The specific process of step S2 comprises the following steps: S21, designing a dynamic power adjustment strategy: When |T_current - T_target| > 2A, the control power is increased to 60%-80%; When |T_current - T_target| enters the range of ±0.5℃, the control power is reduced to 30%-50%; In the formula, T_current is the current temperature, T_target is the target temperature, and A is the oscillation amplitude; S22, performing oscillation test on the temperature control system based on the designed dynamic power adjustment strategy, recording the oscillation process, and obtaining the center point temperature and the oscillation amplitude of the oscillation ring.

4. The temperature control method based on hysteresis control self-tuning PID parameters according to claim 1, characterized in that: The specific process of step S3 comprises the following steps: S31, determining the critical gain Kc: ； In the formula, A is the oscillation amplitude, and the control power is 30%-50%; S32, determining the critical period Tc: ； In the formula, the oscillation period is calculated by sampling the center point temperature data of the oscillation ring; S33, calculating the proportional coefficient, the integral coefficient and the differential coefficient according to the critical gain and the oscillation period.

5. The temperature control method based on hysteresis control self-tuning PID parameters according to claim 1, characterized in that: The specific process of step S4 comprises the following steps: S41, calculating the temperature deviation of the center point temperature T_center of the oscillation ring and the target temperature T_target; S42, the obtained temperature deviation is used as the deviation compensation signal, and the formula of the above process is described as follows: 。 6. The temperature control method based on hysteresis control self-tuning PID parameters according to claim 5, characterized in that: The specific process of step S5 comprises the following steps: S51, reading the current temperature sensor data to obtain the current temperature T_current; S52, determining the control power according to the dynamic power adjustment strategy; S53, calculate a current error from the center point temperature T_center of the oscillation ring and the current temperature T_current : ； S54, according to the current error and the deviation compensation signal to calculate a compensated error compensated_error: ； S55, improve the initial PID control algorithm and execute, calculate the control output at time t : ； In the above formulae, denotes derivation with respect to t, denotes derivation with respect to integration from time 0 to time t; S56, the calculated control output as a control signal for adjusting the heating power; S57, update the integral error and the differential error, and record the current error for calculating the control output in the next cycle; S58, execute the steps S51-S57 in real-time temperature control to realize the temperature control of the temperature control system.

7. The temperature control method based on hysteresis control self-tuning PID parameters according to claim 1, characterized in that: The step S6 includes the following steps: S61, the temperature sensor fault detection, detect whether the sampling value of the temperature sensor meets the expectation, to ensure that the correct current temperature T_current, the center point temperature T_center of the oscillation ring and the target temperature T_target are obtained in the PID controller parameter setting process; S62, the control output limiting protection, limit the maximum control output when the temperature control system is heating, to limit the heating power, thereby ensuring the safety of the test; S63, the oscillation detection, after the oscillation test in the step S2 is completed, detect whether the value of the oscillation ring is in the predefined adjacent interval; S64, the parameter adaptive adjustment, when the PID controller parameter self-setting is performed, first warm up with large control power and then oscillate with the set control power, to reduce the time required by the whole PID controller parameter self-setting process.

8. A temperature control system based on hysteresis control self-tuning PID parameters, characterized in that, It includes: a temperature sensor, a PID controller, a heater and a control unit; the control unit is configured to execute the temperature control method based on the hysteresis control self-setting PID parameter according to any one of claims 1-7.

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