High-reliability low-time-drift Stirling cryocooler driving controller and method

Abstract

The invention discloses a high-reliability low-time-drift Stirling cryocooler driving controller and method. The high-reliability low-time-drift Stirling cryocooler driving controller comprises a signal processing circuit unit and a driving circuit unit. The signal processing circuit unit is used for acquiring the refrigeration temperature in the Stirling cryocooler, comparing the refrigeration temperature with a preset temperature value to obtain a temperature deviation, and generating a PWM signal by adopting a PID control algorithm; a first input end of the driving circuit unit is used for acquiring three paths of Hall signals corresponding to three phases of the three-phase brushless direct current motor, a second input end of the driving circuit unit is connected with the signal processing circuit unit and receives a PWM signal, and the driving circuit unit generates a motor driving signal for controlling the three-phase brushless direct current motor based on the three paths of Hall signals and the PWM signal; a calibration array is arranged in the signal processing circuit unit, temperature values and calibration coefficients are stored in the calibration array, and the calibration array is used for correcting temperature drift parameters and time drift parameters of the Stirling cryocooler driving controller according to the temperature. According to the invention, the time drift characteristic of the Stirling refrigeration machine driving controller can be improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of driving control of Stirling refrigerators, and particularly relates to a high-reliability low-time-drift Stirling refrigerator driving controller and method. BACKGROUND

[0002] The Stirling refrigerator driving controller is the core driving circuit of the Stirling refrigerator, and its reliability is particularly important. In some key equipment, the service life of the Stirling refrigerator driving controller reaches more than 100,000 hours, and the storage life requirement reaches more than 28 years, so a higher requirement is put forward for the time drift performance of the Stirling refrigerator driving controller. Since the standard embedded Stirling refrigerator driving controller has no communication interface, the current industry solution mainly selects high-quality and low-aging-rate components and good thermal design for theoretical estimation, but this scheme is an open-loop design, cannot evaluate the actual performance degradation of the product after many years, and cannot calibrate and correct the performance-degraded Stirling refrigerator driving controller. SUMMARY

[0003] In view of the above problems, the application provides a high-reliability low-time-drift Stirling refrigerator driving controller and method, which can improve the time drift characteristics of the Stirling refrigerator driving controller.

[0004] In order to achieve the above technical purposes and achieve the above technical effects, the application realizes the following technical solutions:

[0005] In a first aspect, the application provides a high-reliability low-time-drift Stirling refrigerator driving controller, comprising a signal processing circuit unit and a driving circuit unit.

[0006] The signal processing circuit unit is connected with a temperature measuring diode inside the Stirling refrigerator, acquires the refrigeration temperature inside the Stirling refrigerator, compares the refrigeration temperature with a pre-set temperature value to obtain a temperature deviation, and generates a PWM signal by using a PID control algorithm.

[0007] The first input end of the driving circuit unit is used to acquire three-way Hall signals corresponding to three phases of a three-phase brushless DC motor, the second input end thereof is connected with the output end of the signal processing circuit unit to receive the PWM signal, and the driving circuit unit generates a motor driving signal for controlling the three-phase brushless DC motor based on the three-way Hall signals and the PWM signal; the signal processing unit is internally provided with a calibration array, and the calibration array stores temperature values and calibration coefficients, and is used to correct the temperature drift parameters and time drift parameters of the Stirling refrigerator driving controller according to the temperature.

[0008] With the first aspect, optionally, the signal processing circuit unit comprises a processor, an ADC converter, a reference source and a constant current source.

[0009] The reference source provides a reference voltage for the constant current source and the ADC converter.

[0010] The constant current source is used to provide an external current to stabilize the operation of a temperature measuring diode inside the refrigerator.

[0011] The ADC converter collects temperature values output by the temperature measuring diode inside the refrigerator in real time.

[0012] The processor is connected to the ADC converter, obtains temperature values from the ADC converter, compares the temperature values with preset temperature values, obtains temperature deviation, and obtains a PWM signal required for driving a three-phase brushless DC motor through a PID control algorithm.

[0013] With the first aspect, optionally, the Stirling refrigerator driving controller further comprises a DB9 connector, the DB9 connector comprises a standby / serial receiving multiplexing pin and a refrigeration indication / serial sending multiplexing pin, the standby / serial receiving multiplexing pin is set to multiplex a standby signal and a serial receiving signal, and the refrigeration indication / serial sending multiplexing pin is set to multiplex a refrigeration indication signal and a serial sending signal.

[0014] After power-on, the processor first performs working mode judgment.

[0015] If it is determined that the Stirling refrigerator driving controller enters a calibration mode, the standby / serial receiving pin is set to a serial receiving pin, and the refrigeration indication / serial sending pin is set to a serial sending pin.

[0016] If the Stirling refrigerator driving controller enters a normal working mode, the standby / serial receiving pin is set to a standby pin, and the refrigeration indication / serial sending pin is set to a refrigeration indication pin.

[0017] With the first aspect, optionally, the working mode judgment specifically comprises:

[0018] It is determined whether the timer exceeds a set time threshold, if the timer exceeds the set time threshold, the mode register is set to a normal working mode, if the timer does not exceed the set time threshold, it is further determined whether a frequency of a signal received by the standby / serial receiving multiplexing pin is a set frequency, if the frequency of the received signal is the set frequency, the mode register is set to a calibration mode, and if the frequency of the received signal is not the set frequency, the mode register is set to a normal working mode.

[0019] With the first aspect, optionally, the processor starts a self-calibration process, and first sends an offset calibration command to the ADC converter.

[0020] The multiplexer integrated inside the ADC converter is configured to connect the input port of the ADC converter to the GND inside the ADC converter;

[0021] The code value output by the ADC converter is compared with the theoretical code value to determine the offset error;

[0022] The offset correction coefficient is calculated based on the offset error, and is written into the FLASH inside the ADC converter;

[0023] The processor sends a gain calibration command to the ADC converter;

[0024] The multiplexer integrated inside the ADC converter is configured to connect the input port of the ADC converter to the VREF reference voltage terminal inside the ADC converter;

[0025] The code value output by the ADC converter is compared with the theoretical code value to determine the gain error;

[0026] The gain correction coefficient is calculated based on the gain error, and is written into the FLASH inside the ADC converter;

[0027] After the self-calibration process, the ADC output value = (original value + offset correction coefficient) * gain correction coefficient.

[0028] In combination with the first aspect, optionally, the PID control algorithm training process is divided into offline design and online debugging;

[0029] In the offline design, the PID control parameters are obtained by trial and error through experiments;

[0030] For online debugging, specifically includes:

[0031] The processor determines whether the Stirling cryogenic drive controller enters the calibration mode based on the mode register value;

[0032] If it is determined that the Stirling cryogenic drive controller enters the calibration mode, it is determined whether the command sent by the host computer is in a learning state or a calibration state;

[0033] If the Stirling cryogenic drive controller enters the learning state, the following steps are repeated until the temperature control precision and temperature control adjustment time parameters are qualified:

[0034] The host computer determines whether the temperature control precision parameter is qualified, and if not, the host computer sends the optimized PID control parameters to the processor, and after the configuration is completed, the three-temperature test of the Stirling cryogenic drive controller and the cryogenic machine is repeated until the temperature control precision parameter test is qualified;

[0035] After the temperature control precision parameter is qualified, it is judged whether the temperature control adjustment time parameter is qualified, if not, the host computer sends the optimized PID control parameter to the processor, after the configuration is completed, the three-temperature test on the Stirling cryocooler drive controller and the cryocooler is repeated;

[0036] The PID control parameter meeting the temperature control precision and the temperature control adjustment time parameter is written into the parameter storage area of the processor, and the self-learning state is exited.

[0037] In combination with the first aspect, optionally, the calibration array is a three-dimensional array, and the three-dimensional array stores temperature values, factory calibration coefficients and user calibration coefficients, and is used for correcting temperature drift parameters and time drift parameters of the Stirling cryocooler drive controller according to the temperature.

[0038] In combination with the first aspect, optionally, the three-dimensional array is generated by the processor by performing the following steps:

[0039] When the Stirling cryocooler drive controller enters the calibration mode, the processor performs the following steps:

[0040] Read the factory calibration register to determine whether factory calibration has been performed;

[0041] If factory calibration has not been performed, enter the factory calibration process;

[0042] Read the temperature value output by the environment temperature sensor of the Stirling cryocooler drive controller;

[0043] Read the value of the external voltage source connected thereto;

[0044] Compare the read voltage value with the standard value of the external voltage source;

[0045] Calculate the factory calibration coefficient based on the comparison result;

[0046] Store the temperature value output by the environment temperature sensor in the [x] column of the three-dimensional array arry[x][y][z];

[0047] Store the factory calibration coefficient in the [y] column of the three-dimensional array arry[x][y][z];

[0048] The Stirling cryocooler drive controller sets the factory calibration register, and completes the factory calibration

[0049] After entering the calibration mode, the factory calibration register is read, and if factory calibration has been performed, the customer calibration process is entered;

[0050] Read the temperature value output by the environment temperature sensor of the Stirling cryocooler drive controller;

[0051] reading a value of an external voltage source connected thereto;

[0052] comparing the read voltage value with a standard value of the external voltage source;

[0053] calculating a user calibration calibration coefficient based on a comparison result;

[0054] storing the user calibration calibration coefficient in a three-dimensional array arry[x][y][z] according to a temperature value output by an ambient temperature sensor;

[0055] ending the user calibration calibration process.

[0056] In combination with the first aspect, optionally, the Stirling cryocooler drive controller further comprises a power supply filtering and converting unit, and the power supply filtering and converting unit comprises:

[0057] a power supply filtering subunit, configured to filter an external input power supply and filter a ripple interference signal generated by a drive circuit unit;

[0058] a power supply converting subunit, configured to convert the external input voltage into a voltage signal suitable for a signal processing unit and the drive circuit unit.

[0059] In the second aspect, the present application provides a Stirling cryocooler drive control method with high reliability and low time drift, comprising:

[0060] a signal processing circuit unit is connected to a temperature measurement diode inside the Stirling cryocooler to obtain a refrigeration temperature inside the Stirling cryocooler, and the refrigeration temperature is compared with a pre-set temperature value to obtain a temperature deviation, and a PID control algorithm is used to generate a PWM signal;

[0061] a first input end of a drive circuit unit is used to obtain three Hall signals corresponding to three phases of a three-phase brushless DC motor, and a second input end of the drive circuit unit is connected to an output end of the signal processing circuit unit to receive the PWM signal;

[0062] the drive circuit unit generates a motor drive signal for controlling the three-phase brushless DC motor based on the three Hall signals and the PWM signal; the signal processing unit is provided with a calibration array, and the calibration array stores temperature values and calibration coefficients, and is used to correct temperature drift parameters and time drift parameters of the Stirling cryocooler drive controller according to the temperature.

[0063] Compared with the prior art, the present application has the following beneficial effects:

[0064] The present application provides a Stirling cryocooler drive controller and method with high reliability and low time drift, and by setting a calibration array, the time drift characteristics of the Stirling cryocooler drive controller can be improved.

[0065] The ADC converter and the constant current source in the application have self-calibration function, which can effectively improve the robustness of the Stirling cryocooler driving controller with high reliability and low time drift.

[0066] The application has learning ability, provides adaptive PID control parameters according to different load conditions, and completes self-learning and configuration through the host computer software.

[0067] The application provides a serial communication interface compatible with standard interfaces, which can provide whole machine maintenance function after installation, and can test and calibrate the performance attenuation of the product after long time work, and further improve the time drift characteristics of the Stirling cryocooler driving controller. BRIEF DESCRIPTION OF DRAWINGS

[0068] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor under the premise of the drawings.

[0069] Figure 1 The design block diagram of the Stirling cryocooler driving controller with high reliability and low time drift provided by an embodiment of the application is provided;

[0070] Figure 2 The design block diagram of the signal processing unit provided by an embodiment of the application is provided;

[0071] Figure 3 The design block diagram of the serial interface multiplexing process provided by an embodiment of the application is provided;

[0072] Figure 4 The design block diagram of the ADC self-calibration process of the data acquisition circuit provided by an embodiment of the application is provided;

[0073] Figure 5 The design block diagram of the constant current source self-calibration process of the data acquisition circuit provided by an embodiment of the application is provided;

[0074] Figure 6 The working flow chart of the "self-learning state" in the "online work" provided by an embodiment of the application is provided;

[0075] Figure 7 The working flow chart of the factory calibration and customer calibration provided by an embodiment of the application is provided. DETAILED DESCRIPTION

[0076] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0077] In addition, if the present application embodiments involve the description of "first", "second", etc., the description of "first", "second", etc. is only for the purpose of description, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can be explicitly or implicitly included at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the fact that a person of ordinary skill in the art can realize it. When the combination of technical solutions contradicts each other or cannot be realized, it should be considered that the combination of technical solutions does not exist and is not within the protection scope of the present application.

[0078] Embodiment 1

[0079] The present application provides a high-reliability low-time-drift Stirling cryogenic engine driving controller, which comprises Figure 1 a signal processing circuit unit and a driving circuit unit as shown in the middle red box;

[0080] The signal processing circuit unit is connected with the temperature measuring diode inside the Stirling cryogenic engine to obtain the refrigeration temperature inside the Stirling cryogenic engine, and compare the refrigeration temperature with the pre-set temperature value to obtain the temperature deviation, and generate a PWM signal by using a PID control algorithm.

[0081] The first input end of the driving circuit unit is used to obtain three Hall signals corresponding to three phases of the three-phase brushless DC motor (i.e. HA, HB, HC in Figure 1 , which are used to feedback the motor rotor position), and the second input end thereof is connected with the output end of the signal processing circuit unit to receive the PWM signal. The driving circuit unit generates a motor driving signal for controlling the three-phase brushless DC motor based on the three Hall signals and the PWM signal. The motor driving signal is used to drive the three-phase brushless DC motor to run at a stable speed, and the three-phase brushless DC motor drives the Stirling cryogenic engine to work, compresses the inert gas working medium to perform inverse Stirling cycle, and realizes closed-loop control of the refrigeration temperature of the cryogenic engine. The signal processing unit is built-in calibration array, and the calibration array stores temperature values and calibration coefficients, which are used to correct the temperature drift parameters and time drift parameters of the Stirling cryogenic engine driving controller according to the temperature.

[0082] In the scheme, the time drift characteristic of the Stirling refrigeration machine driving controller is improved by setting the calibration array. In the implementation process, the temperature measuring diode in the Stirling refrigeration machine is arranged in the refrigeration component Dewar cavity, and the refrigeration temperature exists in the form of a voltage signal.

[0083] In one specific embodiment of the embodiment of the application, as shown in Figure 2 The signal processing circuit unit includes a processor (i.e. Figure 2 MCU), an ADC converter, a reference source and a constant current source.

[0084] The reference source provides a reference voltage for the constant current source and the ADC converter.

[0085] The constant current source is used to provide an external current to stabilize the operation of the temperature measuring diode in the refrigeration machine.

[0086] The ADC converter collects the temperature value (the voltage across the temperature measuring diode is different at different temperatures) output by the temperature measuring diode in the refrigeration machine in real time.

[0087] The processor is connected with the ADC converter, obtains the temperature value from the ADC converter, compares the temperature value with a preset temperature value, obtains a temperature deviation, obtains a PWM signal required for driving the three-phase brushless DC motor through a PID control algorithm, and sends the PWM signal to the driving circuit unit to drive the refrigeration machine to stably operate at a user-required temperature control point. In the implementation process, the processor also performs filtering processing on the collected temperature value (voltage signal).

[0088] In the implementation process, the processor is a 32-bit ARM microprocessor, the ADC converter is a 24-bit ADC converter, and the constant current source provides an external 500 mu A current for the temperature measuring diode in the refrigeration machine to stably work.

[0089] The standard Stirling refrigerator (embedded Stirling refrigerator drive controller) has 8 signals of power supply, ground, standby / serial receiving interface, pause, refrigeration indication, temperature measurement diode signal (D+, D-), signal ground (GND) for external interface, which is connected with the upper computer by using DB9 connector. The standard Stirling refrigerator has no communication interface for external, and cannot realize communication or parameter change function after the whole machine (Stirling refrigerator + Stirling refrigerator drive controller) is assembled. In one specific embodiment of the embodiment of the application, the Stirling refrigerator drive controller further comprises a DB9 connector, the DB9 connector comprises a standby / serial receiving multiplexing pin (i.e. standby / serial receiving multiplexing interface) and a refrigeration indication / serial sending multiplexing pin (i.e. refrigeration indication / serial sending multiplexing interface), the standby / serial receiving multiplexing pin is set to multiplex standby signal and serial receiving signal, and the refrigeration indication / serial sending multiplexing pin is set to multiplex refrigeration indication signal and serial sending signal.

[0090] As shown in Figure 3 After power-on, the processor first judges the working mode;

[0091] If it is judged that the Stirling refrigerator drive controller enters the calibration mode, the standby / serial receiving pin is set to the serial receiving pin, and the refrigeration indication / serial sending pin is set to the serial sending pin (i.e. the refrigeration indication / serial sending interface is set to the serial sending interface).

[0092] If the Stirling refrigerator drive controller enters the normal working mode, the standby / serial receiving pin is set to the standby pin, and the refrigeration indication / serial sending pin is set to the refrigeration indication pin (i.e. the refrigeration indication / serial sending interface is set to the refrigeration indication interface).

[0093] The processor (MCU) completes the multiplexing interface setting, and realizes the multiplexing functions of standby signal and serial receiving signal, and refrigeration indication signal and serial receiving signal.

[0094] In one specific embodiment of the embodiment of the application, the working mode judgment specifically comprises:

[0095] It is judged whether the timer exceeds the set time threshold (such as 2s), if the set time threshold is exceeded, the mode register is set to the normal working mode; if the set time threshold is not exceeded, it is judged whether the frequency of the signal received by the standby / serial receiving multiplexing pin is the set frequency (such as 9600HZ), the set frequency can be set according to actual needs, if the frequency of the received signal is the set frequency, the mode register is set to the calibration mode, if the frequency of the received signal is not the set frequency, the mode register is set to the normal working mode.

[0096] The ADC converter and the constant current source in the embodiment of the application have a self-calibration function. Through self-calibration, it can be ensured that the Stirling cryocooler driving controller can enter a stable and reliable working state after long-time work. In one specific embodiment of the embodiment of the application, the specific self-calibration steps of the ADC converter are as shown in the following table: Figure 4

[0097] The processor starts the self-calibration process, and first sends an offset calibration command to the ADC converter.

[0098] The multiplexer integrated in the ADC converter is configured to connect the input port of the ADC converter to the GND inside the ADC converter.

[0099] The code value output by the ADC converter is compared with the theoretical code value to determine the offset error.

[0100] The offset correction coefficient is calculated based on the offset error, and is written into the FLASH inside the ADC converter.

[0101] The processor sends a gain calibration command to the ADC converter.

[0102] The multiplexer integrated in the ADC converter is configured to connect the input port of the ADC converter to the VREF reference voltage end inside the ADC converter.

[0103] The code value output by the ADC converter is compared with the theoretical code value to determine the gain error.

[0104] The gain correction coefficient is calculated based on the gain error, and is written into the FLASH inside the ADC converter.

[0105] After the self-calibration process, the ADC output value = (original value + offset correction coefficient) * gain correction coefficient.

[0106] In view of the inconsistent objective conditions of the Stirling cryocooler, in order to better adapt to the demand of high-precision controller under various load conditions, an adaptive PID control algorithm is adopted to improve the robustness of the system. In one specific embodiment of the embodiment of the application, the PID control algorithm training process is divided into offline design and online debugging.

[0107] In the offline design, the PID control parameters are obtained by trial and error through experiments; specifically: in the offline design, the basic proportional system K P , integral coefficient K i , and differential coefficient K d ​Adapt to the control coefficient under normal conditions. If the user is not satisfied with the performance of the Stirling refrigerator drive controller after it is matched with the refrigerator, "online debugging" is performed. During the debugging process, the three-temperature test (high temperature 100 degrees, normal temperature 25 degrees, low temperature-55 degrees) of the Stirling refrigerator drive controller after it is matched with the refrigerator is optimized by the host computer debugging tool. The optimized parameters are written into the user parameter configuration area of the controller, so that the product can adapt to more boundary condition refrigerators.

[0108] For online debugging, a self-learning state is included, which specifically includes:

[0109] The processor determines whether the Stirling refrigerator drive controller enters the calibration mode based on the mode register value;

[0110] If it is determined that the Stirling refrigerator drive controller enters the calibration mode, it is determined whether the command sent by the host computer is a learning state or a calibration state;

[0111] If the Stirling refrigerator drive controller enters the learning state, the following steps are repeated until the temperature control precision and temperature control adjustment time parameters are qualified:

[0112] The host computer determines whether the temperature control precision parameter is qualified. If it is not qualified, the host computer sends the optimized PID control parameters (K p_new1 ,K i_new1 ,K d_new1 ) to the processor through the serial port. After the configuration is completed, the three-temperature (high temperature 100 degrees, normal temperature 25 degrees, low temperature-55 degrees) test of the Stirling refrigerator drive controller and the refrigerator is repeated until the temperature control precision parameter test is qualified;

[0113] After the temperature control precision parameter is qualified, it is determined whether the temperature control adjustment time parameter is qualified. If it is not qualified, the host computer sends the optimized PID control parameters (K p_new2 ,K i_new2 ,K d_new2 ) to the processor through the serial port. After the configuration is completed, the three-temperature (high temperature 100 degrees, normal temperature 25 degrees, low temperature-55 degrees) test of the Stirling refrigerator drive controller and the refrigerator is repeated;

[0114] The PID control parameters (K p_newN ,K i_newN ,K d_newN ) that meet the temperature control precision and temperature control adjustment time parameters are written into the parameter storage area of the processor, and the self-learning state is exited.

[0115] In order to prolong the service life of the Stirling cryogenic engine driving controller, a three-dimensional array lookup table algorithm is designed in the Stirling cryogenic engine driving controller software, and the temperature drift parameters of the controller can be corrected according to the temperature in view of the aging and performance parameter attenuation of the components in the Stirling cryogenic engine driving controller. After long-term use of the user, the Stirling cryogenic engine driving controller can be recalibrated, and the calibration coefficient is stored in the calibration array, and the calibration array exists in the Flash of the processor. The Stirling cryogenic engine driving controller reads the calibration coefficient from the calibration array by using the lookup table method during normal operation, mainly corrects and fits the time drift parameters of the ADC converter, the reference source and the constant current source, so as to improve the system reliability and reduce the time drift. In one specific embodiment of the embodiment, the calibration array is a three-dimensional array, and the temperature value, the factory calibration coefficient and the user calibration coefficient are stored in the three-dimensional array, and the temperature drift parameters and the time drift parameters of the Stirling cryogenic engine driving controller are corrected according to the temperature.

[0116] In one specific embodiment of the embodiment, as shown in Figure 7 The three-dimensional array is generated by the processor by executing the following steps:

[0117] When the Stirling cryogenic engine driving controller enters the calibration mode, the processor executes the following steps:

[0118] Read the factory calibration register to determine whether the factory calibration has been performed;

[0119] If the factory calibration has not been performed, enter the factory calibration process;

[0120] Read the temperature value output by the environment temperature sensor of the Stirling cryogenic engine driving controller;

[0121] Read the value of the external voltage source connected thereto;

[0122] Compare the read voltage value with the standard value of the external voltage source;

[0123] Calculate the factory calibration coefficient based on the comparison result;

[0124] Store the temperature value output by the environment temperature sensor in the [x] column of the three-dimensional array arry[x][y][z];

[0125] Store the factory calibration coefficient in the [y] column of the three-dimensional array arry[x][y][z];

[0126] The Stirling cryogenic engine driving controller sets the factory calibration register, and completes the factory calibration

[0127] After entering the calibration mode, the factory calibration register is interpreted, and if factory calibration has been performed, the customer calibration process is entered;

[0128] reading the temperature value output by the environmental temperature sensor of the Stirling cryocooler drive controller;

[0129] reading the value of the external voltage source connected thereto;

[0130] comparing the read voltage value with the standard value of the external voltage source;

[0131] calculating the user calibration coefficient based on the comparison result;

[0132] storing the user calibration coefficient in the [z] column of the three-dimensional array arry[x][y][z] according to the temperature value output by the environmental temperature sensor;

[0133] the customer calibration process is ended.

[0134] After the Stirling cryocooler drive controller completes factory calibration and customer calibration, in normal operation, it can improve the key parameter indicators such as temperature control accuracy and temperature control adjustment time of the Stirling cryocooler drive controller, reduce the influence of temperature drift and time drift of electronic components on the Stirling cryocooler drive controller and the cryocooler, and meet the requirements of the Stirling cryocooler drive controller with a working life of more than 100,000 hours and a storage life of more than 28 years.

[0135] In one specific embodiment of the embodiment of the application, the Stirling cryocooler drive controller further comprises a power filtering and conversion unit, which comprises:

[0136] a power filtering subunit for filtering the power input from the outside and filtering the ripple interference signals generated by the drive circuit unit; specifically, the power filtering subunit mainly filters the current ripple generated by the high-frequency switching of the MOS tube of the three-phase brushless DC motor drive circuit, filters the voltage spikes generated by the commutation of the motor winding, and filters the EMI (electromagnetic interference) noise generated by the parasitic inductance and capacitance of the power circuit and the parasitic capacitance of the switching device under high-frequency switching;

[0137] a power conversion subunit for converting the external input voltage (such as 18V-32V) into a voltage signal suitable for the signal processing unit and the drive circuit unit, such as a 5.0V voltage signal suitable for the signal processing unit and a 3.3V voltage signal suitable for the drive circuit unit.

[0138] Example 2

[0139] The application provides a high-reliability low-time-drift Stirling cryogenic engine driving control method, comprising the following steps of:

[0140] The signal processing circuit unit is connected with a temperature measuring diode inside the Stirling cryogenic engine to obtain a refrigeration temperature inside the Stirling cryogenic engine, and the refrigeration temperature is compared with a preset temperature value to obtain a temperature deviation, and a PID control algorithm is used to generate a PWM signal;

[0141] The first input end of the driving circuit unit is used to obtain three paths of Hall signals corresponding to three phases of the three-phase brushless DC motor, and the second input end is connected with the output end of the signal processing circuit unit to receive the PWM signal;

[0142] The driving circuit unit is used to generate a motor driving signal for controlling the three-phase brushless DC motor based on the three paths of Hall signals and the PWM signal; the signal processing unit is internally provided with a calibration array, and the calibration array stores temperature values and calibration coefficients, and is used to correct temperature drift parameters and time drift parameters of the Stirling cryogenic engine driving controller according to the temperature.

[0143] The high-reliability low-time-drift Stirling cryogenic engine driving control method in the application can be realized based on the high-reliability low-time-drift Stirling cryogenic engine driving controller in the embodiment 1.

[0144] Those skilled in the art should understand that the embodiments of the application can be provided as a method, a system or a computer program product. Therefore, the application can be in the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware aspects. Moreover, the application can be in the form of a computer program product implemented on one or more computer usable storage media containing computer usable program codes (including but not limited to disk memory, CD-ROM, optical memory, etc.).

[0145] The application is described with reference to flowcharts and / or block diagrams according to the method, equipment (system) and computer program product of the embodiments of the application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of the flows and / or blocks in the flowcharts and / or block diagrams can be realized by computer program instructions. These computer program instructions can be provided to a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing devices to produce a machine, so that the instructions executed by the computer or other programmable data processing devices produce a device for implementing the functions specified in the flowcharts and / or block diagrams. Figure 1 The device for implementing the functions specified in one flow or multiple flows and / or blocks Figure 1 The device for implementing the functions specified in one flow or multiple flows and / or blocks

[0146] These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the Figure 1 function specified in the flow or flows and / or blocks Figure 1 of the block or blocks.

[0147] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions that are executed on the computer or other programmable apparatus provide steps for implementing the Figure 1 function specified in the flow or flows and / or blocks Figure 1 of the block or blocks.

[0148] The embodiments of the present application described above are merely intended to illustrate the principles and main features of the present application. It should be understood by those skilled in the art that the present application is not limited to the above-described embodiments, and the above-described embodiments are merely illustrative, but not restrictive. Those skilled in the art can make many modifications and improvements to the present application without departing from the spirit and scope of the present application, and these modifications and improvements all fall within the scope of the present application. The scope of the present application is defined by the appended claims and their equivalents.

[0149] The basic principles and main features of the present application and the advantages of the present application are shown and described above. It should be understood by those skilled in the art that the present application is not limited to the above-described embodiments, and the above-described embodiments and descriptions in the specification are merely illustrative of the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the present application. The scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A highly reliable, low-time-drift Stirling refrigerator drive controller, characterized in that, Includes signal processing circuit units and drive circuit units; The signal processing circuit unit is connected to the temperature sensing diode inside the Stirling refrigerator to obtain the cooling temperature inside the Stirling refrigerator, compare the cooling temperature with the preset temperature value to obtain the temperature deviation, and generate a PWM signal using a PID control algorithm. The first input terminal of the drive circuit unit is used to acquire three Hall signals corresponding to the three phases of the three-phase brushless DC motor. Its second input terminal is connected to the output terminal of the signal processing circuit unit to receive PWM signals. The drive circuit unit generates motor drive signals for controlling the three-phase brushless DC motor based on the three Hall signals and the PWM signals. The signal processing unit has a built-in calibration array, which stores temperature values ​​and calibration coefficients, and is used to correct the temperature drift parameters and time drift parameters of the Stirling refrigerator drive controller according to the temperature.

2. The highly reliable, low-time-drift Stirling refrigerator drive controller according to claim 1, characterized in that, The signal processing circuit unit includes: a processor, an ADC converter, a reference source, and a constant current source; The reference source provides a reference voltage for the constant current source and the ADC converter; The constant current source is used to provide current to the outside so that the temperature sensing diode inside the refrigerator can work stably. The ADC converter acquires the temperature value output by the temperature-sensing diode inside the refrigerator in real time. The processor is connected to an ADC converter, obtains the temperature value from the ADC converter, compares it with a preset temperature value to obtain the temperature deviation, and obtains the PWM signal required to drive the three-phase brushless DC motor through a PID control algorithm.

3. A highly reliable, low-time-drift Stirling refrigerator drive controller according to claim 2, characterized in that: The Stirling refrigerator drive controller also includes a DB9 connector, which includes a standby / serial receive multiplexed pin and a cooling indication / serial transmit multiplexed pin. The standby / serial receive multiplexed pin is configured to multiplex the standby signal and the serial receive signal, and the cooling indication / serial transmit multiplexed pin is configured to multiplex the cooling indication signal and the serial transmit signal. After power-on, the processor first determines the operating mode; If it is determined that the Stirling refrigerator drive controller has entered the calibration mode, then the standby / serial receive pin is set to the serial receive pin, and the cooling indication / serial transmit pin is set to the serial transmit pin. If the Stirling chiller drive controller enters normal operating mode, the standby / serial receive pin is set to standby, and the chiller indication / serial transmit pin is set to chiller indication.

4. A highly reliable, low-time-drift Stirling refrigerator drive controller according to claim 3, characterized in that: The working mode determination specifically includes: Determine if the timer exceeds the set time threshold. If it does, set the mode register to normal working mode. If it does not exceed the set time threshold, determine if the frequency of the signal received by the standby / serial receive multiplexed pin is the set frequency. If the frequency of the received signal is the set frequency, set the mode register to calibration mode. If the frequency of the received signal is not the set frequency, set the mode register to normal working mode.

5. A highly reliable, low-time-drift Stirling refrigerator drive controller according to claim 2, characterized in that: The processor initiates a self-calibration process by first sending an offset calibration command to the ADC converter. Configure the multiplexer integrated inside the ADC converter to connect the input port of the ADC converter to the internal GND of the ADC converter; The offset error is determined by comparing the code value output by the ADC converter with the theoretical code value. The offset correction coefficient is calculated based on the offset error and written into the internal FLASH of the ADC converter; The processor sends a gain calibration command to the ADC converter; Configure the multiplexer integrated inside the ADC converter to connect the input port of the ADC converter to the VREF reference voltage terminal inside the ADC converter. The gain error is determined by comparing the code value output by the ADC converter with the theoretical code value. The gain correction coefficient is calculated based on the gain error and written into the internal FLASH of the ADC converter; After the self-calibration process, the ADC output value = (original value + offset correction coefficient) * gain correction coefficient.

6. A highly reliable, low-time-drift Stirling refrigerator drive controller according to claim 2, characterized in that: The training process of the PID control algorithm is divided into offline design and online debugging. In offline design, PID control parameters are obtained through trial and error in experiments. For online debugging, the specific components include: The processor determines whether the Stirling refrigerator drive controller has entered calibration mode based on the mode register value; If it is determined that the Stirling refrigerator drive controller has entered calibration mode, then determine whether the command sent by the host computer is in learning mode or calibration mode. If the Stirling refrigerator drive controller enters the learning state, repeat the following steps until the temperature control accuracy and temperature control adjustment time parameters are both qualified: The host computer determines whether the temperature control accuracy parameters are qualified. If they are not qualified, the host computer sends the optimized PID control parameters to the processor. After the configuration is completed, the three-temperature test is repeated on the Stirling refrigerator drive controller and the refrigerator until the temperature control accuracy parameters are qualified. After the temperature control accuracy parameter is qualified, it is determined whether the temperature control adjustment time parameter is qualified. If it is not qualified, the host computer will send the optimized PID control parameters to the processor. After the configuration is completed, the three-temperature test is repeated on the Stirling refrigerator drive controller and the refrigerator. Write the PID control parameters that meet the temperature control accuracy and temperature control adjustment time parameters into the processor's parameter storage area, and exit the self-learning state.

7. A highly reliable, low-time-drift Stirling refrigerator drive controller according to claim 6, characterized in that: The calibration array is a three-dimensional array that stores temperature values, factory calibration coefficients, and user calibration coefficients. It is used to correct the temperature drift and time drift parameters of the Stirling refrigerator drive controller based on the temperature.

8. A highly reliable, low-time-drift Stirling refrigerator drive controller according to claim 7, characterized in that: The three-dimensional array is generated by the processor performing the following steps: When the Stirling refrigerator drive controller enters calibration mode, the processor executes the following steps: Read the factory calibration register to determine whether factory calibration has been performed; If factory calibration has not been performed, proceed with the factory calibration process. Read the temperature value output by the ambient temperature sensor of the Stirling refrigerator drive controller; Read the value of the external voltage source connected to it; The read voltage value is compared with the standard value of the external voltage source; The factory calibration coefficients were calculated based on the comparison results. Store the temperature value output by the ambient temperature sensor into the [x] column of the three-dimensional array arry[x][y][z]; Store the factory calibration coefficients into the [y] column of the three-dimensional array arry[x][y][z]; The Stirling refrigeration engine drive controller sets the factory calibration register to complete the factory calibration. After entering the calibration mode, the factory calibration register is read. If the factory calibration has been performed, the customer calibration process will begin. Read the temperature value output by the ambient temperature sensor of the Stirling refrigerator drive controller; Read the value of the external voltage source connected to it; The read voltage value is compared with the standard value of the external voltage source; The user calibration coefficients are calculated based on the comparison results; Based on the temperature value output by the ambient temperature sensor, the user calibration coefficients are stored in the [z] column of the three-dimensional array arry[x][y][z]. The customer calibration process is complete.

9. A highly reliable, low-time-drift Stirling refrigerator drive controller according to claim 1, characterized in that: The Stirling refrigerator drive controller further includes a power filtering and conversion unit, which includes: The power supply filtering subunit is used to filter the external power input and to filter the ripple interference signal generated by the drive circuit unit. The power conversion subunit is used to convert external input voltage into a voltage signal that is compatible with the signal processing unit and the drive circuit unit.

10. A highly reliable, low-time-drift Stirling refrigerator drive control method, characterized in that, include: The signal processing circuit unit is connected to the temperature sensing diode inside the Stirling refrigerator to obtain the cooling temperature inside the Stirling refrigerator. The cooling temperature is compared with the preset temperature value to obtain the temperature deviation. A PID control algorithm is used to generate a PWM signal. The first input terminal of the drive circuit unit is used to obtain three Hall signals corresponding to the three phases of the three-phase brushless DC motor, and its second input terminal is connected to the output terminal of the signal processing circuit unit to receive PWM signals. The drive circuit unit generates a motor drive signal for controlling the three-phase brushless DC motor based on the three Hall signals and the PWM signal; the signal processing unit has a built-in calibration array, which stores temperature values ​​and calibration coefficients, and is used to correct the temperature drift parameters and time drift parameters of the Stirling refrigerator drive controller according to the temperature.

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