High-precision space remote sensor temperature resolving system and method

Abstract

The invention discloses a temperature resolving system and method for a high-precision space remote sensor, and the method comprises the steps: simulating a load through a precision resistor, and setting a resistance value; the main processor of the temperature controller is used for controlling the temperature measurement and control module to carry out temperature acquisition; receiving a temperature measurement data voltage code sent by the temperature measurement and control module; correcting the voltage code, and sending the corrected temperature measurement voltage code to ground equipment; according to the corrected temperature measurement voltage code and the set temperature, a PID temperature control method is adopted to obtain temperature control data; the ground equipment transmits the corrected voltage code to the calibration fitting module; calculating a resistance value R according to a fitting result in combination with the corrected voltage code; calculating a temperature value T according to the resistance value R; and the calibration fitting module performs data fitting on the resistance value R of the precision resistance simulation load and the corresponding corrected voltage code sent by the ground equipment by using a nonlinear least square fitting method to obtain a fitting result, and the fitting result is stored in the ground equipment. The system performance and the system expansion capability are improved.

Description

Technical Field

[0001] The invention relates to a high-precision space remote sensor temperature solution system and method, belonging to the technical field of space remote sensor temperature controllers. Background Art

[0002] The performance of the temperature control system of space remote sensors mainly depends on the system structure, temperature calculation accuracy and temperature control strategy. The temperature calculation accuracy is affected not only by thermistor accuracy, but also by circuit characteristics, calibration method and fitting method. The calibration fitting method widely used in space remote sensor temperature controllers is based on linear polynomial fitting of large data volumes of temperature measurement points. This method requires a lot of time and labor costs and is difficult to adapt to large-scale temperature measurement needs.

[0003] In addition to temperature measurement and temperature control, the space remote sensor temperature controller processor also needs to perform bus communication, process processing and other tasks, so temperature measurement and temperature control should minimize the use of the main processor. The space remote sensor temperature controller uses the voltage code collected by AD to directly calculate the corresponding temperature by the temperature controller processor, and uses the data for temperature control operations. This method requires a large number of floating-point operations, which occupies more main processor time.

[0004] At present, with the increasing demand for high-resolution and ultra-high-resolution detection, the demand for temperature measurement and control circuits of space remote sensor temperature controllers is increasing. Now the number of common temperature measurement and control circuits has reached hundreds or even more. The traditional temperature solution method can no longer adapt to the existing scale of temperature measurement and control. Summary of the invention

[0005] The technical problem solved by the present invention is: to overcome the deficiencies of the prior art, to provide a high-precision space remote sensor temperature solution system and method, and to improve system performance.

[0006] The technical solution of the present invention is:

[0007] The invention discloses a high-precision space remote sensor temperature solution system, comprising: a precision resistor simulation load, a temperature controller, ground equipment and a calibration fitting module; wherein:

[0008] The temperature controller includes a main processor and a temperature measurement and control module;

[0009] The precision resistor simulates the load, sets the resistance value, and outputs the resistance value to the temperature measurement and control module and the calibration fitting module;

[0010] The main processor obtains the set temperature according to the temperature measurement and control instruction sent by the ground equipment; receives the temperature measurement data voltage code sent by the temperature measurement and control module; corrects the temperature measurement data voltage code and sends the corrected temperature measurement voltage code to the ground equipment; uses the PID temperature control method according to the corrected temperature measurement voltage code and the set temperature to obtain the duty cycle and outputs it to the temperature measurement and control module; sends a collection instruction to the temperature measurement and control module;

[0011] The temperature measurement and control module controls the temperature of the external device according to the duty cycle; collects the temperature measurement data voltage code of the external device according to the acquisition instruction and sends it to the main processor;

[0012] The ground equipment sends a temperature measurement and control instruction to the main processor; transmits the corrected temperature measurement voltage code received from the temperature controller to the calibration fitting module; calculates the resistance value R according to the offset value sent by the calibration fitting module and the corrected temperature measurement voltage code; calculates the temperature value T according to the resistance value R;

[0013] The calibration fitting module uses the nonlinear least square fitting method to fit the resistance value R of the precision resistor simulation load and the corresponding calibrated temperature measurement voltage code sent by the ground equipment, obtains the offset value, and stores it in the ground equipment.

[0014] Furthermore, in the above-mentioned solution system, the calculated resistance value R is specifically:

[0015] R = (10000 + b) U / (4095 - U)

[0016] Among them, b is the offset value, U is the voltage code, and R is the resistance value.

[0017] Furthermore, in the above-mentioned solution system, the temperature value T is calculated according to the resistance value R, specifically:

[0018]

[0019] Among them, T is temperature, R is voltage, and A0, A1, and A2 are constants.

[0020] The present invention discloses a high-precision space remote sensor temperature calculation method using a high-precision space remote sensor temperature calculation system, comprising:

[0021] According to the temperature measurement range, select several calibrated resistance values;

[0022] Measure the voltage code corresponding to each resistance value;

[0023] Performing data fitting between the resistance value and the corresponding voltage code to obtain an offset value set;

[0024] Select any offset value from the offset value set as the initial offset value;

[0025] According to the initial offset value, a least squares fitting is performed on the resistance value and the corresponding voltage code to obtain an offset value of the temperature measurement loop;

[0026] According to the offset value of the temperature measurement circuit, a functional relationship between the resistance value and the corresponding voltage code is obtained;

[0027] According to the functional relationship, the theoretical resistance value corresponding to the calibration voltage code is obtained;

[0028] Calculating a calibration temperature value corresponding to the theoretical resistance value;

[0029] The calibrated temperature value is verified according to the actual resistance value.

[0030] Furthermore, in the above-mentioned method, the offset value set is specifically:

[0031]

[0032] Among them, b is the offset value, U is the voltage code, and R is the resistance value.

[0033] Furthermore, in the above method, the functional relationship between the resistance value and the corresponding voltage code is specifically:

[0034] U=4095R / (R+10000+b)

[0035] Among them, b is the offset value, U is the voltage code, and R is the resistance value.

[0036] Furthermore, in the above method, the calibration temperature value corresponding to the calculated theoretical resistance value is specifically:

[0037]

[0038] Where T is temperature, R is voltage, and A0, A1, and A2 are constants determined by the characteristics of the thermistor itself.

[0039] Furthermore, in the above method, the calibration temperature value is verified according to the actual resistance value, specifically:

[0040] Calculate the theoretical resistance value R1 corresponding to the calibration voltage code U;

[0041] Calculate the theoretical temperature T1 corresponding to the theoretical resistance value R1;

[0042] According to the actual resistance value R, calculate the corresponding actual temperature T;

[0043] Calculate the difference between the theoretical temperature T1 and the actual temperature T;

[0044] Determine whether the difference is within the error range. If so, the calibration temperature value meets the requirements; otherwise, it does not meet the requirements.

[0045] The beneficial effects of the present invention and the prior art are:

[0046] (1) Under the condition that the main processor, temperature control cycle and temperature control algorithm remain unchanged, the present invention adopts a temperature solution method based on nonlinear least squares fitting to reduce the fitting calibration workload and reduce the computing pressure of the main processor; it solves the problem that calibration fitting takes too much time and manpower and the computing pressure of the main processor is high.

[0047] (2) In the process of calibrating thermistor data, the present invention adopts a fixed resistance value calibration method, which eliminates the step of calculating the resistance value through temperature and reduces the calculation workload; in the process of fitting the resistance-voltage relationship of the calibration data, a nonlinear least squares fitting method is used to replace the traditional polynomial fitting, thereby reducing the amount of data required for fitting and the number of parameter storage.

[0048] (3) In the program processing of the present invention, the collected voltage code is used to represent the temperature data for temperature control calculation, and the calculation process of calculating the resistance value from the voltage code and the temperature value from the resistance value are handed over to the ground equipment, thereby reducing the floating-point operations of the main processor, which is beneficial to improving the system performance and enhancing the system expansion capability.

[0049] (4) The present invention can effectively reduce the workload and improve the scalability of the system. Its positive effects are directly brought about by the technical features. When the number of temperature measurement and control paths of the system remains unchanged, compared with the traditional temperature solution method, it can effectively shorten the software development cycle and the temperature control cycle, thereby improving the system performance and the system expansion capability. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is a logical composition block diagram of the present invention;

[0051] Figure 2 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0052] The present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0053] The invention discloses a high-precision space remote sensor temperature solution system, comprising: a precision resistor simulation load, a temperature controller, ground equipment and a calibration fitting module; wherein:

[0054] The temperature controller includes a main processor and a temperature measurement and control module;

[0055] The precision resistor simulates the load, sets the resistance value, and outputs the resistance value to the temperature measurement and control module and the calibration fitting module;

[0056] The main processor obtains the set temperature according to the temperature measurement and control instruction sent by the ground equipment; receives the temperature measurement data voltage code sent by the temperature measurement and control module; corrects the temperature measurement data voltage code and sends the corrected temperature measurement voltage code to the ground equipment; uses the PID temperature control method according to the corrected temperature measurement voltage code and the set temperature to obtain the duty cycle and outputs it to the temperature measurement and control module; sends a collection instruction to the temperature measurement and control module;

[0057] The temperature measurement and control module controls the temperature of the external device according to the duty cycle; collects the temperature measurement data voltage code of the external device according to the acquisition instruction and sends it to the main processor;

[0058] The ground equipment sends a temperature measurement and control instruction to the main processor; transmits the corrected temperature measurement voltage code received from the temperature controller to the calibration fitting module; calculates the resistance value R according to the offset value sent by the calibration fitting module and the corrected temperature measurement voltage code; calculates the temperature value T according to the resistance value R;

[0059] The calibration fitting module uses the nonlinear least square fitting method to fit the resistance value R of the precision resistor simulation load and the corresponding calibrated temperature measurement voltage code sent by the ground equipment, obtains the offset value, and stores it in the ground equipment.

[0060] Preferably, the resistance value R is calculated as follows:

[0061] R = (10000 + b) U / (4095 - U)

[0062] Among them, b is the offset value, U is the voltage code, and R is the resistance value.

[0063] Preferably, the temperature value T is calculated according to the resistance value R, specifically:

[0064]

[0065] Among them, T is temperature, R is voltage, and A0, A1, and A2 are constants.

[0066] The present invention discloses a high-precision space remote sensor temperature calculation method using a high-precision space remote sensor temperature calculation system, comprising:

[0067] According to the temperature measurement range, select several calibrated resistance values;

[0068] Measure the voltage code corresponding to each resistance value;

[0069] Perform data fitting between the resistance value and the corresponding voltage code to obtain an offset value set;

[0070] Select any offset value from the offset value set as the initial offset value;

[0071] According to the initial offset value, the least squares fitting is performed on the resistance value and the corresponding voltage code to obtain the offset value of the temperature measurement loop;

[0072] According to the offset value of the temperature measurement circuit, a functional relationship between the resistance value and the corresponding voltage code is obtained;

[0073] According to the functional relationship, the theoretical resistance value corresponding to the calibration voltage code is obtained;

[0074] Calculate the calibration temperature value corresponding to the theoretical resistance value;

[0075] Verify the calibrated temperature value based on the actual resistance value.

[0076] Preferably, the offset value set is specifically:

[0077]

[0078] Among them, b is the offset value, U is the voltage code, and R is the resistance value.

[0079] Preferably, the functional relationship between the resistance value and the corresponding voltage code is specifically:

[0080] U=4095R / (R+10000+b)

[0081] Among them, b is the offset value, U is the voltage code, and R is the resistance value.

[0082] Preferably, the calibration temperature value corresponding to the theoretical resistance value is calculated as follows:

[0083]

[0084] Where T is temperature, R is voltage, and A0, A1, and A2 are constants determined by the characteristics of the thermistor itself.

[0085] Preferably, the calibration temperature value is verified according to the actual resistance value, specifically:

[0086] Calculate the theoretical resistance value R1 corresponding to the calibration voltage code U;

[0087] Calculate the theoretical temperature T1 corresponding to the theoretical resistance value R1;

[0088] According to the actual resistance value R, calculate the corresponding actual temperature T;

[0089] Calculate the difference between the theoretical temperature T1 and the actual temperature T;

[0090] Determine whether the difference is within the error range. If so, the calibration temperature value meets the requirements; otherwise, it does not meet the requirements.

[0091] Example

[0092] like Figure 1 As shown, this embodiment provides a high-precision space remote sensor temperature solution system, including a precision resistor simulation load, a temperature controller, ground equipment and a calibration fitting module, wherein the temperature controller includes a main processor and a temperature measurement and control module.

[0093] The precision resistor simulation load is responsible for providing multiple groups of precision resistor outputs. The output resistance value can be adjusted by setting. The resistance value serves as the input of the temperature measurement and control module and the calibration fitting module.

[0094] The main processor of the temperature controller controls the temperature measurement and control module to collect temperature. After receiving the temperature measurement data voltage code, it corrects the voltage code and transmits the corrected voltage code as temperature measurement data to the ground equipment. It receives the temperature measurement and control instructions sent by the ground equipment, calculates the temperature control data according to the temperature control algorithm, and performs temperature control output to the temperature measurement and control module.

[0095] The temperature measurement and control module of the temperature controller is controlled by the main processor to collect temperature and transmit the collected voltage code to the main processor; it receives the temperature control data of the main processor, and performs PWM output on the corresponding temperature control circuit according to the temperature control data to realize the temperature control function.

[0096] The ground equipment transmits the temperature measurement data received from the temperature controller to the calibration fitting module, calculates the resistance value R through the voltage code U according to the fitting result, and calculates the temperature value T through the resistance value R and the thermistor conversion formula.

[0097] The calibration fitting module uses the nonlinear least square fitting method to fit the resistance value R of the precision resistor simulation load and the corresponding voltage code U, and obtains the fitting result and stores it in the ground equipment.

[0098] like Figure 2 As shown, the method steps are as follows:

[0099] 1) Select the calibrated fixed resistance value

[0100] Due to the slight differences in the characteristics of circuits, devices and thermistors, the resistance-voltage conversion relationship cannot be simply expressed by the same formula when the accuracy requirement is high, and each temperature measurement loop has slight differences. The calibration process quantifies the characteristics of each temperature measurement loop. For the same resistance value, each temperature measurement loop will have a different voltage value output. First, it is necessary to determine the fixed resistance value used for calibration. The present invention uses 14 fixed resistance values, namely: 630Ω, 999.9Ω, 1999.9Ω, 3299.8Ω, 3599.7Ω, 3899.5Ω, 4699.7Ω, 5099.7Ω, 6199.3Ω, 7498.5Ω, 9998.9Ω, 19999Ω, 32997Ω, 61995Ω. This group of resistance values ​​can cover the temperature range of [-40℃, 60℃] and meet the temperature measurement range requirements.

[0101] 2) Data calibration

[0102] Each temperature measurement circuit is calibrated separately. A precision resistor is used to simulate the load and connected to the temperature measurement circuit. The voltage code U corresponding to each resistance value R is measured. Table 1 shows the calibration result of a certain temperature measurement circuit. Different temperature measurement circuits will obtain different voltage codes U.

[0103] Table 1 Temperature measurement circuit calibration results

[0104] Resistance value R 630 999.9 1999.9 3299.8 3599.7 3899.5 4699.7 Voltage code U 243 372 683 1017 1084 1149 1310 Resistance value R 5099.7 6199.3 7498.5 9998.9 19999 32997 61995 Voltage code U 1383 1567 1755 2047 2730 3142 3525

[0105] 3) Data fitting

[0106] Using the calibration data, the nonlinear least squares fitting function in MATLAB is used to process the data. The steps are as follows.

[0107] Determine the functional relationship between R and U. The temperature measurement circuit is to connect the thermistor Rx in series with a 10KΩ precision resistor for voltage division. The relationship function between U and R is determined as formula (1), where the maximum value is 4095 under the condition of 12-bit quantization of the collected measurement value; the 10KΩ thermistor is substituted into the formula as a fixed value of 10000, b is the offset value of the temperature measurement loop, which is different for each temperature measurement loop. Data fitting is performed to obtain the offset value b of each temperature measurement loop. The relationship function between R and U is formula (2), and the offset value b is calculated using formula (3);

[0108] U=4095R / (R+10000+b) (1)

[0109] R=(10000+b)U / (4095-U) (2)

[0110]

[0111] a. Determine the data set of the data R and U to be fitted, and calculate the offset value set under each set of data according to formula (3), and select any one of the offset values ​​as the initial offset value b0;

[0112] b. Use the lsqcurvefit function in MATLAB to perform nonlinear least squares fitting on R and U, [b, jm] = lsqcurvefit (@myfun, b0, U, R), where the myfun function uses formula (2) to obtain the offset value b = 3.8745 of the temperature measurement loop;

[0113] 4) Verification of fitting results

[0114] The theoretical resistance value R1 of the calibrated voltage code U is calculated according to formula (2), and the temperature T1 is calculated according to the relationship formula (4) between temperature T and resistance R. The temperature T is calculated according to the calibrated actual resistance value R and formula (4), and the difference between T1 and T, that is, the error of the temperature data, is calculated. The error range is [-0.035, 0.018]. The temperature difference meets the technical requirement of ±0.1°C, where A0=1.45275276E-03, A1=1.75534060E-04, and A2=6.57504952E-06. This parameter belongs to the fixed parameter of the thermistor and is determined by the characteristics of the thermistor itself.

[0115]

[0116] 5) Temperature treatment

[0117] Since the voltage code collected in the program can represent the current temperature value, the voltage code is used instead of the temperature value for calculation in the temperature control process, which reduces the process of the processor calculating the temperature from the voltage code. The RU formula and coefficient b, the TR formula and coefficients A0, A1, and A2 are written into the ground equipment, and the process of calculating the temperature from the voltage code is handed over to the ground equipment, which reduces the program scale and reduces the floating-point operation overhead of the main processor.

[0118] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

[0119] The contents not described in detail in the specification of the present invention belong to the common knowledge of the professionals in this field.

Claims

1. A high-precision space remote sensor temperature solution system, characterized in that: include: Precision resistor simulation load, temperature controller, ground equipment and calibration fitting module; among them, The temperature controller includes a main processor and a temperature measurement and control module; The precision resistor simulates the load, sets the resistance value, and outputs the resistance value to the temperature measurement and control module and the calibration fitting module; The main processor obtains the set temperature according to the temperature measurement and control instruction sent by the ground equipment; receives the temperature measurement data voltage code sent by the temperature measurement and control module; corrects the temperature measurement data voltage code and sends the corrected temperature measurement voltage code to the ground equipment; uses the PID temperature control method according to the corrected temperature measurement voltage code and the set temperature to obtain the duty cycle and outputs it to the temperature measurement and control module; sends a collection instruction to the temperature measurement and control module; The temperature measurement and control module controls the temperature of the external device according to the duty cycle; collects the temperature measurement data voltage code of the external device according to the acquisition instruction and sends it to the main processor; The ground equipment sends a temperature measurement and control instruction to the main processor; transmits the corrected temperature measurement voltage code received from the temperature controller to the calibration fitting module; calculates the resistance value R according to the offset value sent by the calibration fitting module and the corrected temperature measurement voltage code; calculates the temperature value T according to the resistance value R; The calibration fitting module uses the nonlinear least square fitting method to fit the resistance value R of the precision resistor simulation load and the corresponding calibrated temperature measurement voltage code sent by the ground equipment, obtains the offset value, and stores it in the ground equipment.

2. A high-precision space remote sensor temperature solution system according to claim 1, characterized in that: The calculated resistance value R is specifically: R = (10000 + b) U / (4095 - U) Among them, b is the offset value, U is the voltage code, and R is the resistance value.

3. A high-precision space remote sensor temperature solution system according to claim 1, characterized in that: The temperature value T is calculated according to the resistance value R, specifically: Among them, T is temperature, R is voltage, and A0, A1, and A2 are constants.

4. A high-precision space remote sensor temperature calculation method using a high-precision space remote sensor temperature calculation system as claimed in claim 1, characterized in that: include: According to the temperature measurement range, select several calibrated resistance values; Measure the voltage code corresponding to each resistance value; Performing data fitting between the resistance value and the corresponding voltage code to obtain an offset value set; Select any offset value from the offset value set as the initial offset value; According to the initial offset value, a least squares fitting is performed on the resistance value and the corresponding voltage code to obtain an offset value of the temperature measurement loop; According to the offset value of the temperature measurement circuit, a functional relationship between the resistance value and the corresponding voltage code is obtained; According to the functional relationship, the theoretical resistance value corresponding to the calibration voltage code is obtained; Calculating a calibration temperature value corresponding to the theoretical resistance value; The calibrated temperature value is verified according to the actual resistance value.

5. The high-precision space remote sensor temperature calculation method according to claim 4, characterized in that: The offset value set is specifically: Among them, b is the offset value, U is the voltage code, and R is the resistance value.

6. The high-precision space remote sensor temperature calculation method according to claim 4, characterized in that: The functional relationship between the resistance value and the corresponding voltage code is specifically: U=4095R / (R+10000+b) Among them, b is the offset value, U is the voltage code, and R is the resistance value.

7. The high-precision space remote sensor temperature calculation method according to claim 4, characterized in that: The calibration temperature value corresponding to the calculated theoretical resistance value is specifically: Where T is temperature, R is voltage, and A0, A1, and A2 are constants determined by the characteristics of the thermistor itself.

8. The high-precision space remote sensor temperature calculation method according to claim 4, characterized in that: The calibration temperature value is verified according to the actual resistance value, specifically: Calculate the theoretical resistance value R1 corresponding to the calibration voltage code U; Calculate the theoretical temperature T1 corresponding to the theoretical resistance value R1; According to the actual resistance value R, calculate the corresponding actual temperature T; Calculate the difference between the theoretical temperature T1 and the actual temperature T; Determine whether the difference is within the error range. If so, the calibration temperature value meets the requirements; otherwise, it does not meet the requirements.

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