Split temperature control system and method for modem used in ground testing of rotor system

Abstract

The present invention provides a split temperature control system and method for a modem used for ground testing of a rotor system, wherein the temperature control system includes a thermostat and a semiconductor refrigeration control box, wherein a semiconductor refrigeration device is arranged in the thermostat, and the hot end of the semiconductor refrigeration device is in contact with a supercooled water pipe; a fiber grating temperature sensor connected to a fiber grating demodulator is arranged outside the thermostat; a temperature sensor is also arranged in the inner cavity of the thermostat; a control system is arranged in the semiconductor refrigeration control box; the control system adjusts the circulation temperature of the semiconductor refrigeration and supercooled oil to stabilize the temperature in the thermostat according to the difference between the internal and external temperature sensors and the target temperature. The present invention can actively adjust the temperature according to the internal and external environment, especially before the internal temperature changes, and ensure that the internal temperature is within a reasonable working range when the external environment changes drastically, and ensure that the temperature fluctuation during temperature adjustment is always within the required range of the demodulator.

Description

Technical Field

[0001] The invention belongs to the technical field of temperature control of electronically controlled test equipment, and in particular to a split temperature control system and method for a modem used for ground testing of a rotor system. Background Art

[0002] The rotor is the core component that provides power and control for the helicopter. Dynamic monitoring of blade structural loads is the main basis for dynamic characteristics analysis and blade design verification of rotor blades, which directly affects the strength, performance and flight characteristics of the helicopter. The dynamic load test of rotor blades has the characteristics of complex distribution, large range, dense measurement points, sensitivity to additional mass, high dynamic response, and is in a complex environment such as rotation and vibration. How to monitor the dynamic load of the blades in flight and analyze and evaluate their operating status in real time is the focus of helicopter measurement technology. The blade bending moment is an important parameter for identifying the blade structural load. It is very important to measure the dynamic bending moment of the rotor blades in real time during operation and realize the dynamic monitoring of the blade structural load.

[0003] Traditional rotor load tests use electrical sensors to obtain measurement data, which has a low signal-to-noise ratio and seriously affects the accuracy of rotor load identification. A large number of strain gauges need to be pasted to access a large number of transmission wires. When measuring multiple points on the surface of composite blades, the smoothness and structure of the blade surface will be destroyed, resulting in a large additional mass, which will affect the aerodynamic flight characteristics of the blade. Fiber Bragg grating sensors have the advantages of small size, light weight, electrical insulation, anti-electromagnetic interference, high precision, high reliability, high sensitivity of fiber Bragg gratings, and easy to achieve high efficiency of distributed measurement. They break through the limitations of traditional electrical sensor-based measurement methods, and fiber Bragg grating sensors can directly measure multiple physical quantities such as strain, velocity, and vibration, reduce the complexity of the system, simplify the system structure, and facilitate the maintenance characteristics of the monitoring system itself.

[0004] However, due to the process limitations and principle characteristics of existing optoelectronic devices, the operating temperature range of optical devices or optoelectronic devices is relatively narrow. The operating temperature range of the demodulator in the fiber Bragg grating demodulation system is usually -20℃~60℃, while the service condition of the rotor is -40℃~70℃. The demodulator cannot work at low or high temperatures. Therefore, a device is needed to improve the operating temperature range of the demodulator. Some electronic components in the fiber Bragg grating demodulator are sensitive to temperature. Its working environment should be kept in a suitable temperature range, and the temperature should not fluctuate violently. The existing constant temperature device controls the internal temperature by receiving the temperature signal from the internal temperature sensor and controlling the heating and cooling system. When the external environment temperature changes violently, the control system cannot respond in time. During the temperature adjustment process, the internal temperature may temporarily exceed the working temperature range of the demodulator. The traditional temperature adjustment algorithm will generate a large amount of cold or heat in a short time, causing violent fluctuations in the temperature environment inside the constant temperature box. The violent temperature change will cause the equipment to fail or even be damaged.

[0005] Aiming at the problem of reduced efficiency caused by heat generated during the currently used semiconductor refrigeration, and combining with the actual service environment of the demodulator, a split temperature control system and method for a modem for ground testing of a rotor system are disclosed, which are mainly used. Summary of the invention

[0006] The purpose of the present invention is to overcome the problems existing in the above-mentioned prior art. In view of the application environment of the modem in the helicopter cabin, a split temperature control system and method for a modem for ground testing of a rotor system is provided. The system is a split constant temperature device with a simple structure and convenient for improving the operating temperature range of the fiber optic Bragg grating demodulator, the main equipment of the fiber optic Bragg grating demodulation system. The system can actively adjust the temperature according to the internal and external environment, especially before the internal temperature changes. In the case of drastic changes in the external environment, the system can ensure that the internal temperature is within a reasonable working range, and ensure that the temperature fluctuation during temperature adjustment is always within the required range of the demodulator.

[0007] The technical solution of the present invention is: a split temperature control system for a modem for ground testing of a rotor system, comprising a constant temperature box and a semiconductor refrigeration control box, wherein a semiconductor refrigeration device and a supercooling water pipe are arranged in the constant temperature box, the cold end of the semiconductor refrigeration device faces the inner cavity of the constant temperature box, and the hot end of the semiconductor refrigeration device is in contact with the supercooling water pipe; a fiber grating temperature sensor connected to a fiber grating demodulator is arranged outside the constant temperature box; the inner cavity of the constant temperature box is used to store the fiber grating demodulator and is provided with a resistance temperature sensor; a control system, a cooling water tank and a chiller are arranged in the semiconductor refrigeration control box; the semiconductor refrigeration device and the temperature sensor in the constant temperature box are connected to the control system in the control box; the control system adjusts the circulation temperature of the semiconductor refrigeration and the supercooling oil according to the temperature data measured by the resistance temperature sensor and the fiber grating temperature sensor to stabilize the temperature in the constant temperature box.

[0008] The control system comprises a control circuit and a control panel. The control circuit comprises a PIC controller. The control panel is provided with a temperature alarm indicator light. The semiconductor refrigeration device and the resistive temperature sensor in the thermostatic box are connected to the control system in the control box through signal lines.

[0009] Four fixing clamps are welded on the inner wall of the thermostatic box cover and the inner wall of the bottom of the thermostatic box, and the fixing clamps are used to fix the fiber grating demodulator.

[0010] A temperature control method for a split temperature control system of a modem for ground testing of a rotor system comprises the following steps:

[0011] 1) Detecting the temperature data of each area according to the agreed period, wherein the area includes the temperature of the outer wall area of ​​the thermostat corresponding to each fiber Bragg grating temperature sensor string and the temperature of the internal area corresponding to the resistance temperature sensor; wherein the resistance temperature sensor corresponds to the temperature value A of the interior of the thermostat, wherein A is the temperature collected at each time node; the temperature sensor inside the thermostat transmits the collected temperature value to the control system according to the agreed period; the temperature information collected by the fiber Bragg grating temperature sensor is analyzed and processed by the fiber Bragg grating demodulator to obtain the temperature value B of the external surface of the thermostat N , the temperature value is a collection of values ​​collected by multiple sensors B N , where N = 1, 2, ..., 20, N is the number of gratings in the fiber Bragg grating temperature sensor;

[0012] 2) Every time the signal from the resistance temperature sensor is received, the PIC controller in the control system determines the internal temperature value A of the thermostat. When A>60℃ or A<-20℃, an alarm is sounded and the alarm indicator light is on;

[0013] 3) Obtain the heat transfer coefficient C of the corresponding outer surface of the constant temperature box in each grating temperature sensor to the environment inside the equipment N; To obtain this heat transfer coefficient, when the temperatures inside and outside the thermostat are the same, heat or cool the side wall of the outer surface of the thermostat, measure the surface temperatures of the same part inside and outside the thermostat, and take the absolute value of the subtraction of the inside and outside temperatures. This absolute value is the heat transfer coefficient, and this heat transfer coefficient C N used to quantify the influence of the external temperature environment of the incubator on the inside;

[0014] 4) Determine the target temperature value S to be maintained inside the thermostat. This target temperature is determined according to the operating temperature of the fiber grating demodulator, that is, -20°C < S < 60°C. This target temperature value S is input into the control system through the control box;

[0015] 5) Determine the first difference function e(t) = S - A between the temperature inside the thermostat and the target temperature. This function is the function of the difference between the temperature value A inside the thermostat and the target temperature value S changing with time; Determine the second difference function between the temperature outside the thermostat and the target temperature Among them, for the calculation method of the second difference function, first obtain the temperature value B of each grating temperature sensor N multiplied by the corresponding heat transfer coefficient C N The average value of the product is the function of the difference between this average value and the target temperature with respect to time, which is the second difference function, and N is the number of grating of the external temperature sensor;

[0016] 6) Determine the first output function from the first difference function; this process is determined by the PID algorithm, that is, the first output function is obtained by the accumulation of proportional integral calculation, integral calculation and differential calculation; Among them, K p e(t) is the proportional integral calculation, that is, the temperature difference function e(t) inside the thermostat at time t is multiplied by the proportional gain K p , K p = 0.65K c , K c is the PID when the steady-state error of the control system reaches the minimum as much as possible under the condition of only using the proportional link control e(t) = K c The K in e(t) c value; By adjusting K p control the speed at which the thermostat reaches the target temperature. The larger K p is, the faster the approach to the target temperature; is the integral calculation link, that is, considering the past error, integrate the first difference function from the start to the current moment and multiply it by the integral gain K i to reduce the adjustment error, t is the PID control sampling calculation period, and T i is the integral time of the control system; It is the differential calculation link, that is, taking into account the upcoming error, the first derivative of the first difference function is calculated and the positive constant K d Multiply, t is the differential time of the control system; the three parameters are all adaptive parameters and are greater than 0, and are adjusted according to the ambient temperature range of the outer wall of the incubator;

[0017] 7) Determine the second output function by the second difference function; this process is determined by the PID algorithm, that is, the second output function is obtained by the accumulation of proportional calculation, integral calculation and differential calculation Among them, the proportional calculation, integral calculation and differential calculation are all based on the second difference function f(t), and the meaning and method are the same as the first output function. The three calculation links and parameter functions are the same as the first output function, but K p , K i , K d The specific values ​​are different;

[0018] 8) Determine the output function μ(t); the output function μ(t) is obtained by adding the first function and the second function; wherein the output function μ(t) is μ(t)=αPID e(t) +βPID f(t) , where α and β are the adaptation parameters of the first output function and the second output function respectively. 0<α<1, 0<β<1, α is the proportional parameter corresponding to the internal ambient temperature difference and the maximum temperature difference, e is the temperature difference between the current internal ambient temperature of the constant temperature box and the set target temperature when the PIC control system is sampling, when the internal ambient temperature range is below -40℃ or above 70℃, α is 1, when the internal ambient temperature is the same as the target temperature, α is 0; β is the proportional parameter corresponding to the external ambient temperature difference and the maximum temperature difference, f is the temperature difference between the current external ambient temperature and the set target temperature when the PIC control system is sampling, when the external ambient temperature range is below -20℃ and above 60℃, β is 1, when the external ambient temperature is the same as the target temperature, β is 0;

[0019] 9) Determine the semiconductor cooling and heating capacity; semiconductors will generate heat during cooling. In order to reduce the impact of heat accumulation on semiconductor cooling power, the accumulated heat is taken away by circulating fluid driven by a chiller;

[0020] 10) According to the output function and the semiconductor cooling and heating capacity, the semiconductor cooling or heating power is adjusted; when the output μ(t)>0, it is the semiconductor heating mode, and the control system adjusts the semiconductor voltage size and direction according to μ(t) to control the semiconductor heating power; when the output μ(t)<0, it is the semiconductor cooling mode, and the control system adjusts the semiconductor voltage direction and size according to μ(t) to control the cooling power, and at the same time the chiller is started to provide cooling water to ensure the normal operation of semiconductor refrigeration.

[0021] Beneficial effects of the invention: The invention discloses a split temperature control system and method for a modem used for ground testing of a rotor system.

[0022] The split temperature control system of the present invention has the following beneficial effects:

[0023] 1. The device integrates two temperature control technologies to ensure the realization of the constant temperature function. First, glass fiber is used as the heat insulation material to isolate the heat exchange between the inside and outside of the constant temperature box and reduce the temperature fluctuation in the box; second, semiconductor cooling / heating is used to maintain the constant temperature in the box. The semiconductor refrigeration device can stabilize the temperature balance in the box under high or low temperature service environment. Under the combined effect of the two measures, the applicable temperature range of the constant temperature box is effectively improved.

[0024] 2. The semiconductor refrigeration device of the device is installed in the filling material outside the inner cavity of the thermostat. The semiconductor is close to the inner wall of the thermostat, does not occupy the inner cavity space of the thermostat, and will not cause the local temperature to be too high or too low.

[0025] 3. The interior of the thermostat of the device uses stainless steel as the cavity wall, which is conducive to the semiconductor refrigeration device absorbing the heat of the environment inside the thermostat cavity, and can also conduct the heat of the semiconductor refrigeration device to the cavity.

[0026] 4. The device has cable holes on the thermostat box, which can leave space for cable connection of the equipment inside the box, which is conducive to the use and application expansion of internal equipment, can connect more signal lines, and improve the use efficiency. The device uses fiber grating sensors and demodulators, which can simultaneously monitor and output multiple temperature signals outside the incubator, and can also superimpose other sensors for measurement.

[0027] 5. The device adopts the cooling oil circulation cooling method to reduce the temperature of the heating end during semiconductor refrigeration, improve the efficiency of semiconductor refrigeration, and ensure the continuous normal operation of the constant temperature box in a high temperature environment.

[0028] The device uses a split box, and uses supercooled oil to cool the semiconductor refrigeration device, which reduces the impact of heat generation during semiconductor refrigeration, improves the refrigeration efficiency of the semiconductor, and also increases the working temperature range of the constant temperature box. The device uses a split box, and the semiconductor refrigeration control box is located in a normal temperature environment. There is no need for high and low temperature resistance design, and the structure is simple. The device adds a clamping device to fix the demodulator to prevent the demodulator from moving during operation, isolate the demodulator from contact with the inner wall of the insulation box, ensure the temperature balance of the demodulator surface, and prevent the local temperature from being too high or too low.

[0029] 6. The device uses fixing clamps on the bottom and upper and lower parts of the box cover to fix the demodulator. On the one hand, it prevents the demodulator from displacement during operation; on the other hand, the contact part between the fixing clamp and the demodulator is provided with a heat insulation pad, so that the demodulator does not contact the inner wall of the insulation box, preventing the overall temperature of the demodulator surface from being balanced, and preventing the local temperature from being too high or too low.

[0030] 7. The device uses fiber grating sensors and fiber grating demodulators as the main source of temperature signals. The fiber grating sensors are arranged in the external service environment of the incubator to accurately monitor the temperature changes inside and outside the incubator.

[0031] 8. The temperature control method of the split temperature control system of the modem for ground testing of the rotor system of the present invention has the following technical advantages:

[0032] The temperature control method of the present invention calculates the heating / cooling power required to balance the fluctuations of the internal and external environments according to the two temperature sensors inside and outside the thermostat, and superimposes the two outputs, which can comprehensively output the influence of the internal and external environments, thereby reducing the reaction time of temperature regulation and the fluctuations of the internal environment temperature. The device takes into account the influence of the external cold and hot environment and the internal heat source on the internal temperature environment of the thermostat, and uses the detection results of the two internal and external sensors as independent inputs to obtain two output functions respectively. The overall cooling and heating output is obtained by integrating the two output functions. On the one hand, it can balance the internal temperature rise caused by the heating of the internal equipment of the thermostat, and on the other hand, it can balance the influence of the external temperature environment on the internal temperature environment of the thermostat. When the external environment fluctuates violently and the internal temperature of the equipment begins to change, the control system increases the heating / cooling power to balance the influence of the external environment in advance, which can effectively reduce the internal temperature fluctuations.

[0033] The temperature fluctuation in the constant temperature box is affected by three aspects. First, the self-heating generated by the demodulator when it is working will accumulate in the box and cause the temperature to rise; second, the external high temperature or low temperature conducts heat or cold to the inside through the wall of the constant temperature box, causing temperature fluctuations; finally, the cooling or heating of the semiconductor in the box wall affects the internal temperature. The present invention overcomes the defects of certain adjustment delays and drastic temperature fluctuations in the traditional temperature control method using a single input and a single output control method. The temperature control method of the present invention calculates the influence of internal and external environmental changes on the internal temperature respectively. First, for the influence of the self-heating of the demodulator on the internal temperature, the proportional, integral and differential methods are used to calculate the cooling power required for the self-heating of the balancing equipment; then for the influence of the external environment, according to the heat transfer coefficient of each sensor location, the proportional, integral and differential calculations are used to obtain the cooling or heating power required to balance the influence of the external environment. The influence of the external environment is offset in the wall of the constant temperature box and will not be conducted to the inside, so it will not cause fluctuations in the internal temperature environment; the cooling or heating capacity of the inside and outside is added and executed by a set of systems, which reduces energy loss. Therefore, this control method balances the influence of the internal heat source of the thermostat and multiple external heat sources or cold sources through a set of cooling and heating systems; when the surface temperature of the thermostat changes but the internal temperature does not change, the temperature control system intervenes to adjust, which has the characteristics of fast adjustment response and small temperature fluctuation. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Attached Figure 1 : Schematic diagram of the appearance of the thermostat of the device of the present invention;

[0035] Attached Figure 2 : Schematic diagram of the internal structure of the thermostat of the device of the present invention;

[0036] Attached Figure 3 : Schematic diagram of the structure of the thermostatic box cover of the device of the present invention;

[0037] Attached Figure 4 : Schematic diagram of the internal structure of the thermostat of the device of the present invention from top view;

[0038] Attached Figure 5 : A schematic diagram of the internal structure of the thermostat of the device of the present invention;

[0039] Attached Figure 6 : Schematic diagram of the semiconductor control box structure of the device of the present invention;

[0040] Attached Figure 7 : Temperature control process of the device of the present invention;

[0041] Attached Figure 8 : Schematic diagram of the control relationship of the temperature control system of the device of the present invention.

[0042] Explanation of the reference numerals: 1. Cable hole; 2. Grating signal line; 3. Network cable; 4. Demodulator power line; 5. Fiber Bragg grating demodulator; 6. Constant temperature box signal interface; 7. Water inlet; 8. Water outlet; 9. Constant temperature box power interface; 10. Stainless steel shell; 11. Glass fiber insulation layer; 12. Supercooling water pipe; 13. Semiconductor refrigeration device; 14. Resistive temperature sensor; 15. Insulation pad; 16. Handle; 17. Quick release buckle; 18. Box cover; 19. Constant temperature box controller; 20. Temperature alarm indicator; 21. Transformer; 22. Cooling water tank; 23. Chiller; 24. PIC controller; 25. Semiconductor refrigeration switch; 26. Cooling oil switch; 27. Cooling oil controller; 28. Fixing fixture; 29. ​​Fiber Bragg grating temperature sensor. DETAILED DESCRIPTION

[0043] A specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings, but it should be understood that the protection scope of the present invention is not limited by the specific implementation.

[0044] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the technical solutions of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0045] See also Figure 1-Figure 8 The embodiment of the present invention provides a split temperature control system and method for a modem for ground testing of a rotor system.

[0046] The temperature control system of the present invention comprises a thermostat and a semiconductor refrigeration control box; the thermostat comprises a box cover 18 and a box body; an insulation layer 11 is arranged in the thermostat, a semiconductor refrigeration device 13 and a supercooling water pipe 12 are arranged in the insulation layer, one side of the semiconductor refrigeration device is attached to the inner cavity wall, and one side is in contact with the supercooling water pipe; a water inlet 7, a water outlet 8, a signal interface 6, a power interface 8 and a cable hole 1 are arranged on the thermostat body; a fiber grating demodulator 5 and a resistance temperature sensor 14 are arranged in the inner cavity of the thermostat; the fiber grating demodulator comprises a power line 4, a signal line 2 and a network line 3; four fixing clamps 28 are welded on the inner wall of the thermostat cover, and four fixing clamps 28 are welded on the inner wall of the bottom of the thermostat; the thermostat cover and the box body are connected by a buckle 17; a temperature control system is arranged in the semiconductor refrigeration control box. system, cooling water tank 22 and chiller 23; the control system includes a control circuit and a control panel, the control circuit includes a transformer 21 and a PIC controller 24; the control panel includes a temperature alarm indicator light 20, a thermostat temperature controller 19, a cooling oil temperature controller 27, a power switch 26 and a semiconductor refrigeration switch 25; the surface of the semiconductor refrigeration control box is provided with a water inlet 7, a water outlet 8, a signal interface 6 and a power interface 9, and the water inlet, water outlet, signal interface and power interface are respectively connected to the interfaces on the thermostat; the semiconductor refrigeration device and the temperature sensor in the thermostat are connected to the control system in the control box through a signal line; the control system adjusts the circulation temperature of the semiconductor refrigeration and the supercooled oil according to the difference between the internal and external temperature sensors to stabilize the temperature in the thermostat.

[0047] Working principle: The split thermostatic device first isolates the heat transfer between the box and the environment outside the box through the insulation layer 11, reducing the temperature fluctuation inside the box; the insulation layer adopts the measure of built-in semiconductor refrigeration devices to detect the signals of the resistive temperature sensor 14 and the fiber grating sensor 29 outside the box (the fiber grating sensor is a grating, the temperature causes the wavelength to change, and the temperature is analyzed by the demodulator). When there is a difference between the internal and external temperatures and the target temperature, the refrigeration system and the heating system are started, and the power is adjusted at any time according to the difference; when the temperature inside the box is higher than the working temperature, the cooling mode is adopted to reduce the temperature inside the box; when the temperature inside the box is lower than the working temperature, the heating mode is adopted to increase the temperature inside the box. In order to further solve the problem of heat generation during the semiconductor refrigeration process leading to a decrease in refrigeration efficiency, the cooling oil circulation heat absorption method is adopted to absorb the heat on the semiconductor surface and improve the semiconductor refrigeration efficiency. The demodulator is fixed by the fixing fixtures at the box cover and the bottom to prevent the demodulator from moving. The fixing fixture is provided with a heat insulation pad so that the inner wall of the insulation box will not directly conduct heat to the demodulator.

[0048] Working process: before starting the machine, add enough cooling oil to the water tank; install the fiber Bragg grating demodulator into the fixing fixture in the thermostat, connect the power cord, fiber Bragg grating sensor cable and network cable of the demodulator, and pass them through the cable hole on the thermostat; cover the box cover, and fix the demodulator with the box cover fixture and the bottom fixture; connect the power cord, control signal line and cooling water pipe of the thermostat; turn on the chiller to cool the cooling oil first, and then turn on the semiconductor refrigeration after a while. At this time, the split thermostat enters the working state. The thermal insulation layer will first reduce the impact of the high and low temperature environment on the incubator. The resistive temperature sensor will always detect the temperature inside the incubator. The fiber grating demodulator analyzes the changes in the fiber grating and outputs the temperature signal, which is transmitted to the PIC control system through the signal line. The PIC control system continuously compares with the threshold. When there is a difference between the external environment temperature and the temperature inside the box, the heating and cooling systems are started; when the external environment temperature is higher than the set threshold, the PIC control system output controls the semiconductor refrigeration to start, and continuously cools the inner wall of the incubator until the temperature inside the box reaches the specified value. When the external environment temperature is lower than the set threshold, the PIC control system output controls the semiconductor heating to start, and continuously heats the inner wall of the incubator until the temperature inside the box reaches the specified value.

[0049] The temperature control process of this temperature control system Figure 7 As shown, the fiber Bragg grating demodulator detects temperature changes and inputs the target temperature that the semiconductor thermostat needs to maintain. The temperature sensors inside and outside the thermostat detect the ambient temperature. The fiber Bragg grating demodulator receives and processes the signal and inputs it to the control system. The control system determines whether the ambient temperature will alarm. If the temperature deviates from the target temperature, the semiconductor heating / cooling system will work and turn on the cooling or heating function.

[0050] The input and output control relationship of the temperature control system is as follows:

[0051] μ(t)=αPID e(t) +βPID f(t)

[0052]

[0053]

[0054] e(t)=SA

[0055]

[0056] Where: K p =0.65K c ;

[0057]

[0058] e: Temperature difference inside the incubator;

[0059] f: Temperature difference outside the incubator:

[0060] S: Temperature setting value:

[0061] A: The temperature of the temperature sensor inside the incubator;

[0062] B N : Temperature of the insulation box surface temperature sensor;

[0063] C N : Influencing parameters of sensors at different positions on the surface of the incubator;

[0064] t: PID control sampling calculation cycle

[0065] T i : Integral time of the control system

[0066] T d : Derivative time of the control system

[0067] The temperature control algorithm of the present invention is based on the PID algorithm. After setting the target temperature, the internal resistance temperature sensor 14 detects the internal temperature, and the detection result A is input into the control system to calculate the difference function e(t) between the current internal ambient temperature and the target temperature. Substitute e(t) into the PID algorithm, and after superimposing the proportional algorithm, the integral algorithm and the differential algorithm, the output function required internally is obtained as PID. e(t) External temperature sensor 29 detects the external temperature, and the detection result B N Input to the control system, the control system adds the influence factor C according to the influence of each temperature sensor temperature on the interior of the constant temperature box N And calculate the temperature difference between the external and internal environments to obtain the temperature difference function f(t). Substitute f(t) into the PID algorithm to obtain the output function PIDf (t) , the total output of the heating and cooling system is μ(t) obtained by combining the influence of internal heat source and external heat source / cold source on the internal temperature environment and superimposing the two output functions; the device can adjust the cooling or heating power in real time according to the influence of the internal and external temperature environment to maintain the temperature environment of the thermostat box in balance near the target temperature; the PID algorithm of the internal temperature sensor can quickly control the internal temperature of the thermostat box to the target temperature, and the PID algorithm of the external temperature sensor can reduce the shock effect of the external temperature environment on the internal environment control. K p , K i , K d , α, β are adaptive parameters and can be determined through repeated experiments.

[0068] Specifically, the temperature control method of the split-type temperature control system of the modem for ground testing of the rotor system of the present invention includes the following steps:

[0069] 1) Detect the temperature data of each area at a predefined cycle. The areas include the temperature of the outer wall area of the constant temperature box corresponding to each fiber Bragg grating temperature sensor string and the temperature of the internal area corresponding to the resistive temperature sensor. Among them, the resistive temperature sensor corresponds to the internal temperature value A of the constant temperature box, where A is the temperature collected at each time node. The internal temperature sensor of the constant temperature box transmits the collected temperature value to the control system at a predefined cycle. The temperature information collected by the fiber Bragg grating temperature sensor is analyzed and processed by a fiber Bragg grating demodulator to obtain the external surface temperature value B of the constant temperature box N , and this temperature value is the set B of the values collected by multiple sensors N , where N = 1, 2,..., 20, and N is the number of gratings in the fiber Bragg grating temperature sensor;

[0070] 2) When receiving the signal of the resistive temperature sensor at each moment, the PIC controller in the control system judges the internal temperature value A of the constant temperature box. When A > 60°C or A < -20°C, an alarm is issued and the alarm indicator light is on;

[0071] 3) Obtain the heat transfer coefficient C of the corresponding part of the outer surface of the constant temperature box in each grating temperature sensor for the internal environment of the equipment N ; To obtain this heat transfer coefficient, when the temperatures inside and outside the constant temperature box are the same, by heating or cooling the side wall of the outer surface of the constant temperature box, measure the surface temperatures of the same part inside and outside the constant temperature box, and take the absolute value of the difference between the internal and external temperatures. This absolute value is the heat transfer coefficient, and this heat transfer coefficient C N is used to quantify the influence of the external temperature environment of the insulation box on the inside;

[0072] 4) Determine the target temperature value S to be maintained inside the constant temperature box. This target temperature is determined according to the operating temperature of the fiber Bragg grating demodulator, that is, -20°C < S < 60°C. This target temperature value S is input into the control system through the control box;

[0073] 5) Determine the first difference function e(t) = S - A between the temperature inside the constant temperature box and the target temperature. This function is the function of the difference between the temperature value A inside the constant temperature box and the target temperature value S changing with time; Determine the second difference function between the temperature outside the constant temperature box and the target temperature Among them, for the calculation method of the second difference function, first obtain the temperature value B of each grating temperature sensor N multiplied by the corresponding heat transfer coefficient C N The average value of the product is the function of the difference between this average value and the target temperature with respect to time, and N is the number of gratings of the external temperature sensor;

[0074] 6) Determine the first output function by the first difference function; this process is determined by the PID algorithm, that is, the first output function is obtained by accumulating proportional integral calculation, integral calculation and differential calculation; Among them, K p e(t) is the proportional integral calculation, that is, the temperature difference function e(t) inside the constant temperature box at time t multiplied by the proportional gain K p , K p =0.65K c ,K c It is a PID control system that minimizes the steady-state error of the control system under the condition of using only proportional control. e(t) =K c K in e(t) c By adjusting K p Control the speed at which the thermostat reaches the target temperature, K p The larger it is, the faster it approaches the target temperature. This is the integral calculation step, that is, taking into account the past errors, the first difference function is integrated from the beginning to the current moment and combined with the integral gain K i Multiplication can reduce the adjustment error. t is the PID control sampling calculation period, T i is the integration time of the control system; It is the differential calculation link, that is, taking into account the upcoming error, the first derivative of the first difference function is calculated and the positive constant K d Multiply, t is the differential time of the control system; the three parameters are all adaptive parameters and are greater than 0, and are adjusted according to the ambient temperature range of the outer wall of the incubator;

[0075] 7) Determine the second output function by the second difference function; this process is determined by the PID algorithm, that is, the second output function is obtained by the accumulation of proportional calculation, integral calculation and differential calculation Among them, the proportional calculation, integral calculation and differential calculation are all based on the second difference function f(t), and the meaning and method are the same as the first output function. The three calculation links and parameter functions are the same as the first output function, but K p , K i , K d The specific values ​​are different;

[0076] 8) Determine the output function μ(t); the output function μ(t) is obtained by adding the first function and the second function; wherein the output function μ(t) is μ(t)=αPID e(t) +βPID f(t) , where α and β are the adaptation parameters of the first output function and the second output function respectively. 0<α<1, 0<β<1, α is the proportional parameter corresponding to the internal ambient temperature difference and the maximum temperature difference, e is the temperature difference between the current internal ambient temperature of the constant temperature box and the set target temperature when the control system is sampled, when the internal ambient temperature range is below -40℃ or above 70℃, α is 1, when the internal ambient temperature is the same as the target temperature, α is 0; β is the proportional parameter corresponding to the external ambient temperature difference and the maximum temperature difference, f is the temperature difference between the current external ambient temperature and the set target temperature when the control system is sampled, when the external ambient temperature range is below -20℃ and above 60℃, β is 1, when the external ambient temperature is the same as the target temperature, β is 0;

[0077] 9) Determine the semiconductor cooling and heating capacity; semiconductors will generate heat during cooling. In order to reduce the impact of heat accumulation on semiconductor cooling power, the accumulated heat is taken away by circulating fluid driven by a chiller;

[0078] 10) According to the output function and the semiconductor cooling and heating capacity, the semiconductor cooling or heating power is adjusted; when the output μ(t)>0, it is the semiconductor heating mode, and the control system adjusts the semiconductor voltage size and direction according to μ(t) to control the semiconductor heating power; when the output μ(t)<0, it is the semiconductor cooling mode, and the control system adjusts the semiconductor voltage direction and size according to μ(t) to control the cooling power, and at the same time the chiller is started to provide cooling water to ensure the normal operation of semiconductor refrigeration.

[0079] The control relationship principle block diagram of the temperature control system of the present invention is as follows: Figure 8 As shown. The temperature control method of the present invention calculates the heating / cooling power required to balance the fluctuations of the internal and external environments based on the two temperature sensors inside and outside the thermostat, and superimposes the two outputs, which can comprehensively output the influence of the internal and external environments, thereby reducing the reaction time of temperature regulation and the internal environment temperature fluctuations. The device takes into account the influence of the external cold and hot environment and the internal heat source on the internal temperature environment of the thermostat, and uses the detection results of the two internal and external sensors as independent inputs to obtain two output functions respectively. The overall cooling and heating output is obtained by integrating the two output functions. On the one hand, it can balance the internal temperature rise caused by the heating of the internal equipment of the thermostat, and on the other hand, it can balance the influence of the external temperature environment on the internal temperature environment of the thermostat. When the external environment fluctuates violently and the temperature inside the equipment begins to change, the control system increases the heating / cooling power to balance the influence of the external environment in advance, which can effectively reduce the internal temperature fluctuations.

[0080] The above disclosures are only several specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto. Any changes that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A split temperature control system for a modem used for ground testing of a rotor system, characterized in that: The invention comprises a thermostat and a semiconductor refrigeration control box, wherein a semiconductor refrigeration device (13) and a supercooling water pipe (12) are arranged in the thermostat, the cold end of the semiconductor refrigeration device (13) faces the inner cavity of the thermostat, and the hot end of the semiconductor refrigeration device (13) contacts the supercooling water pipe (12); a fiber grating temperature sensor (29) connected to a fiber grating demodulator (5) is arranged outside the thermostat; the inner cavity of the thermostat is used to store the fiber grating demodulator (5) and is provided with a resistance temperature sensor (14); a control system, a cooling water tank (22) and a chiller (23) are arranged in the semiconductor refrigeration control box; the semiconductor refrigeration device and the resistance temperature sensor (14) in the thermostat are connected to the control system in the control box; the control system adjusts the circulation temperature of the semiconductor refrigeration and the supercooling oil according to the temperature data measured by the resistance temperature sensor (14) and the fiber grating temperature sensor (29) to stabilize the temperature in the thermostat; The temperature control method of the split temperature control system of the modem for ground testing of the rotor system comprises the following steps: 1) Detecting the temperature data of each area according to the agreed period, wherein the area includes the temperature of the outer wall area of ​​the thermostat corresponding to each fiber Bragg grating temperature sensor string and the temperature of the internal area corresponding to the resistance temperature sensor; wherein the resistance temperature sensor corresponds to the temperature value A of the interior of the thermostat, wherein A is the temperature collected at each time node; the temperature sensor inside the thermostat transmits the collected temperature value to the control system according to the agreed period; the temperature information collected by the fiber Bragg grating temperature sensor is analyzed and processed by the fiber Bragg grating demodulator to obtain the temperature value B of the external surface of the thermostat N , the temperature value is a collection of values ​​collected by multiple sensors B N , where N = 1, 2, ..., 20, N is the number of gratings in the fiber Bragg grating temperature sensor; 2) Every moment when the signal from the resistance temperature sensor is received, the control system determines the temperature value A inside the thermostat. When A>60℃ or A<-20℃, an alarm is sounded and the alarm indicator lights up; 3) Obtain the heat transfer coefficient C of the corresponding outer surface of the constant temperature box in each grating temperature sensor to the environment inside the equipment N To obtain the heat transfer coefficient, it is necessary to heat or cool the side wall of the outer surface of the thermostat when the temperature inside and outside the thermostat is the same, measure the surface temperature of the same part inside and outside the thermostat, and take the absolute value after subtracting the inner and outer temperatures. This absolute value is the heat transfer coefficient. 4) Determine the target temperature value S to be maintained in the constant temperature box. The target temperature is determined according to the working temperature of the fiber Bragg grating demodulator, that is, -20℃ <S<60℃; 5) Determine the first difference function e(t)=SA between the temperature in the thermostat and the target temperature, which is a function of the difference between the temperature value A in the thermostat and the target temperature value S over time; determine the second difference function between the temperature outside the thermostat and the target temperature Among them, for the calculation method of the second difference function, first obtain the temperature value B of each grating temperature sensor N And the corresponding heat transfer coefficient C N The average value after multiplication, the difference between the average value and the target temperature as a function of time is the second difference function, and N is the number of external temperature sensor gratings; 6) Determining the first output function by the first difference function; that is, obtaining the first output function by accumulating proportional integral calculation, integral calculation and differential calculation; Among them, K p e(t) is the proportional integral calculation, that is, the temperature difference function e(t) inside the constant temperature box at time t multiplied by the proportional gain K p , K p =0.65K c ,K c It is a PID control system that minimizes the steady-state error of the control system under the condition of using only proportional control. e(t) =K c K in e(t) c value; by adjusting K p Control the speed at which the thermostat reaches the target temperature, K p The larger it is, the faster it approaches the target temperature. This is the integral calculation step, that is, taking into account the past errors, the first difference function is integrated from the beginning to the current moment and combined with the integral gain K i Multiplication can reduce the adjustment error. t is the PID control sampling calculation period, T i is the integration time of the control system; It is the differential calculation link, that is, taking into account the upcoming error, the first derivative of the first difference function is calculated and the positive constant K d Multiply, is the differential time of the control system; the three parameters are all adaptive parameters and are greater than 0, and are adjusted according to the ambient temperature range of the outer wall of the incubator; 7) Determine the second output function by the second difference function; this process is determined by the PID algorithm, that is, the second output function is obtained by the accumulation of proportional calculation, integral calculation and differential calculation Among them, the proportional calculation, integral calculation and differential calculation are all obtained based on the second difference function f(t), and the meaning and method are the same as the first output function. The three calculation links and parameter functions are the same as the first output function; 8) Determine the output function μ(t); the output function μ(t) is obtained by adding the first function and the second function; wherein the output function μ(t) is μ(t)=αPID e(t) +βPID f(t) , where α and β are the adaptation parameters of the first output function and the second output function respectively. 0<α<1, 0<β<1, α is the proportional parameter corresponding to the internal ambient temperature difference and the maximum temperature difference, e is the temperature difference between the current internal ambient temperature of the constant temperature box and the set target temperature when the control system is sampled, when the internal ambient temperature range is below -40℃ or above 70℃, α is 1, when the internal ambient temperature is the same as the target temperature, α is 0; β is the proportional parameter corresponding to the external ambient temperature difference and the maximum temperature difference, f is the temperature difference between the current external ambient temperature and the set target temperature when the control system is sampled, when the external ambient temperature range is below -20℃ and above 60℃, β is 1, when the external ambient temperature is the same as the target temperature, β is 0; 9) Determine the semiconductor cooling and heating capacity; semiconductors will generate heat during cooling. In order to reduce the impact of heat accumulation on semiconductor cooling power, the accumulated heat is taken away by circulating fluid driven by a chiller; 10) According to the output function and the semiconductor cooling and heating capacity, the semiconductor cooling or heating power is adjusted; when the output μ(t)>0, it is the semiconductor heating mode, and the control system adjusts the semiconductor voltage size and direction according to μ(t) to control the semiconductor heating power; when the output μ(t)<0, it is the semiconductor cooling mode, and the control system adjusts the semiconductor voltage direction and size according to μ(t) to control the cooling power, and at the same time the chiller is started to provide cooling water to ensure the normal operation of semiconductor refrigeration.

2. The split temperature control system for the modem for ground testing of a rotor system according to claim 1, characterized in that: The control system comprises a control circuit and a control panel, wherein the control circuit comprises a PIC controller (24) and the control panel is provided with a temperature alarm indicator light (20); the semiconductor refrigeration device (13) and the resistance temperature sensor (14) in the constant temperature box are connected to the control system in the control box via a signal line.

3. The split temperature control system of the modem for ground testing of a rotor system according to claim 1, characterized in that: Four fixing clamps (28) are welded on the inner wall of the thermostatic box cover and the inner wall of the bottom of the thermostatic box. The fixing clamps (28) are used to fix the optical fiber grating demodulator (5).

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