A pitot tube self-adaptive heating device and a pitot tube

Abstract

The utility model discloses a kind of air speed tube self-adapting heating device and air speed tube, the device includes control panel and heating plate, the control panel connects the heating plate;Microcontroller, MOSFET drive circuit, heating switch circuit are provided on the control panel, the microcontroller connects the MOSFET drive circuit, the MOSFET drive circuit connects the heating switch circuit, the heating switch circuit connects the heating plate;Heating resistance array is provided on the heating plate, the heating resistance array includes several heating resistances, series-parallel hybrid topology structure is connected between the several heating resistances.The utility model is based on microcontroller collocation MOSFET drive circuit and heating switch circuit, control heating resistance array of series-parallel hybrid topology structure arranged on heating plate carries out heating operation, control precision is higher, reliability is better, heating efficiency is higher, realize to air speed tube more optimal heating effect.

Description

Technical Field

[0001] This utility model relates to the field of heating control technology, and in particular to an airspeed tube adaptive heating device. Background Technology

[0002] A pitot tube is an aerodynamic sensor installed on an aircraft, primarily used to measure the aircraft's airspeed (i.e., the speed of the aircraft relative to the surrounding air). It senses the total and static pressure of the airflow, acquires pressure data, and sends it to the pitot tube control board to calculate the aircraft's airspeed. Because pitot tubes often operate in high-altitude, low-temperature environments, the tube opening can freeze, leading to pitot tube malfunctions and decreased measurement accuracy. Therefore, heating devices are needed around the pitot tube to warm it up when necessary.

[0003] Traditional methods for heating the pitot tube typically involve using a relay to control the on / off state of the heating resistor circuit. When the heating resistor circuit is energized, the heating resistors connected in series in the circuit generate Joule heat through direct heating. This direct heating method has certain drawbacks: the relay control of the heating resistor circuit relies on the electromagnetic engagement of the relay contacts, resulting in a relatively short service life and poor reliability; furthermore, the heat generated by the heating resistors connected in series in the circuit is relatively low, leading to poor heating efficiency and making it unsuitable for the actual heating requirements of the pitot tube. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of the prior art. This invention provides an adaptive heating device for the pitot tube and the pitot tube. Based on a microcontroller combined with a MOSFET driving circuit and a heating switch circuit, it controls the heating resistor array with a series-parallel hybrid topology set on the heating plate to perform heating operation. This results in higher control precision, better reliability, higher heating efficiency, and a better heating effect on the pitot tube.

[0005] This utility model provides an adaptive heating device for a pitot tube. The device includes a control board and a heating plate. The control board is connected to the heating plate, and the heating plate wraps around the pitot tube.

[0006] The control board is equipped with a microcontroller, a MOSFET driving circuit, and a heating switch circuit. The microcontroller is connected to the MOSFET driving circuit, the MOSFET driving circuit is connected to the heating switch circuit, and the heating switch circuit is connected to the heating plate.

[0007] The heating plate is provided with a heating resistor array, which includes a plurality of heating resistors connected in a series-parallel hybrid topology.

[0008] Furthermore, the heating resistor array includes several heating resistor subarrays, with heating resistors in any one heating resistor subarray connected in series and parallel, and adjacent heating resistor subarrays connected in series.

[0009] Furthermore, the microcontroller is model TMS320F28004x.

[0010] Furthermore, the MOSFET driving circuit includes transistors Q1, Q2, Q3, and Q4, resistors R1, R2, R3, R4, R5, and R6.

[0011] The first end of the resistor R1 is connected to the microcontroller;

[0012] The second end of the resistor R1 is connected to the emitter of transistor Q1 and the emitter of transistor Q2;

[0013] The base of transistor Q1 is connected to the base of transistor Q2, and is also connected to the first terminal of resistor R2, the first terminal of resistor R3, and the collector of transistor Q4.

[0014] The collector of transistor Q1 is connected to the first terminal of resistor R4, the collector of transistor Q3, and is connected to the driving power supply.

[0015] The collector of transistor Q2 is connected to the base of transistor Q3;

[0016] The base of the transistor Q3 is connected to the first terminal of the resistor R5 and the first terminal of the resistor R6.

[0017] The second end of resistor R4 and the second end of resistor R5 are connected to the heating switch circuit.

[0018] The second end of the resistor R2 is connected to the driving power supply;

[0019] The emitter of transistor Q3, the emitter of transistor Q4, the second terminal of resistor R3, and the second terminal of resistor R6 are grounded.

[0020] Furthermore, the heating switch circuit includes a switching MOSFET Q5, a resistor R7, and a resistor R8;

[0021] The first end of the resistor R7 is connected to the output end of the MOSFET drive circuit.

[0022] The second end of the resistor R7 is connected to the gate of the switching MOSFET Q5;

[0023] The drain of the switching MOSFET Q5 is connected to one end of the resistor R8;

[0024] The source of the switching MOSFET Q5 is connected to the heating plate.

[0025] Furthermore, the heating plate is also equipped with a temperature sensing module, which is connected to the microcontroller.

[0026] Furthermore, the temperature sensing module includes a plurality of temperature-sensing resistors, which are arranged in the heating resistor array.

[0027] Furthermore, the heating plate is also equipped with an infrared icing sensor, which is connected to the controller.

[0028] Furthermore, the device is also equipped with a power module, which is connected to the control board and the heating plate.

[0029] This utility model also provides an airspeed tube, on which the above-mentioned airspeed tube adaptive heating device is provided.

[0030] This invention provides an adaptive heating device for the pitot tube and the pitot tube itself. Based on a microcontroller combined with a MOSFET driving circuit and a heating switch circuit, it controls a series-parallel hybrid topology array of heating resistors on the heating plate to perform heating operations. Compared with the traditional heating operation using relay control of a series-connected heating resistor circuit, it has higher control precision, better reliability, and higher heating efficiency, achieving a better heating effect for the pitot tube. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the airspeed tube adaptive heating device module architecture in Embodiment 1 of this utility model;

[0033] Figure 2 This is a schematic diagram of the heating resistor array structure in Embodiment 1 of this utility model;

[0034] Figure 3 This is a circuit diagram of the MOSFET driving circuit in Embodiment 1 of this utility model;

[0035] Figure 4 This is a circuit diagram of the heating switch circuit in Embodiment 1 of this utility model. Detailed Implementation

[0036] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0037] In this invention, it should be understood that terms such as “comprising” or “having” are intended to indicate the presence of features, figures, steps, actions, components, portions or combinations thereof disclosed in this specification, and are not intended to exclude the possibility of the presence or addition of one or more other features, figures, steps, actions, components, portions or combinations thereof.

[0038] It should also be noted that, where there is no conflict, the embodiments and features in the embodiments of this utility model can be combined with each other. The present utility model will now be described in detail with reference to the accompanying drawings and embodiments.

[0039] Example 1

[0040] This utility model provides an adaptive heating device for a pitot tube, characterized in that the device includes a control board and a heating plate, the control board is connected to the heating plate, and the heating plate wraps around the pitot tube;

[0041] The control board is equipped with a microcontroller, a MOSFET driving circuit, and a heating switch circuit. The microcontroller is connected to the MOSFET driving circuit, the MOSFET driving circuit is connected to the heating switch circuit, and the heating switch circuit is connected to the heating plate.

[0042] The heating plate is provided with a heating resistor array, which includes a plurality of heating resistors connected in a series-parallel hybrid topology.

[0043] In one optional implementation of this embodiment, such as Figure 1 As shown, Figure 1 A schematic diagram of the pitot tube adaptive heating device module architecture in Embodiment 1 of this utility model is shown. The device includes a control board and a heating plate. The control board is connected to the heating plate, and the heating plate wraps around the pitot tube.

[0044] In an optional implementation of this embodiment, the control board is provided with a microcontroller, a MOSFET driving circuit, and a heating switch circuit. The microcontroller is connected to the MOSFET driving circuit, the MOSFET driving circuit is connected to the heating switch circuit, and the heating switch circuit is connected to the heating plate.

[0045] Specifically, the microcontroller is used to further control the heating operation of the heating plate by controlling the operation of the MOSFET driving circuit and the heating switch circuit.

[0046] In an optional implementation of this embodiment, the heating plate is provided with a heating resistor array, which includes a plurality of heating resistors connected in a series-parallel hybrid topology.

[0047] The heating resistor array includes several heating resistor subarrays, with heating resistors in any one heating resistor subarray connected in series and parallel, and adjacent heating resistor subarrays connected in series.

[0048] Specifically, such as Figure 2 As shown, Figure 2 This diagram illustrates the heating resistor array structure according to Embodiment 1 of the present invention. In this embodiment, the heating plate is provided with z heating resistor sub-arrays, which are connected in series. Each heating resistor sub-array contains x*y heating resistors, where x is the number of heating resistors connected in series in each path, and y is the number of heating resistors connected in parallel in each path of series heating resistors. In this embodiment, as shown... Figure 2 As shown, the heating resistor array on the heating plate is provided with 3 heating resistor sub-arrays, and adjacent heating resistor sub-arrays are connected in series. Each heating resistor sub-array is provided with 3*2=6 heating resistors R connected in series and parallel in a 3*2 configuration.

[0049] Furthermore, in the heating mode of the heating plate, the maximum operating voltage of a single heating resistor subarray is U, and the rated power of a single heating resistor is P. Therefore, the maximum operating power Pmax of a single heating resistor subarray does not exceed the total power x*y*P of the heating resistors. Simplify to get The number of series and parallel heating resistors, i.e., the values ​​of x and y, should be selected reasonably according to the size of the airspeed tube, the magnitude of the power supply voltage, and the heating power. By changing the value of x or y, different power supply voltages or heating power requirements can be adapted. When the power supply voltage U increases, x is increased to reduce the working voltage of a single resistor through series voltage division. When the heating power needs to be increased, y is increased to increase the total current through parallel connection, while keeping the power of a single resistor within the limit.

[0050] This section considers the traditional heating resistor circuit where the heating resistors are connected in series. Under the same power conditions, the actual total heating power is less than that of heating resistors connected in parallel. In this embodiment, by setting the number of heating resistors connected in series and parallel in the heating resistor subarray, including x series * y parallel settings, different power supply voltages or heating power requirements can be adapted by changing the values ​​of x and y. When the power supply voltage U increases, x is increased to reduce the working voltage of a single resistor through series voltage division; when the heating power needs to be increased, y is increased to increase the total current through parallel connection, while keeping the power of a single resistor within the limit.

[0051] Furthermore, considering that in practical applications, the icing and cooling phenomenon at the pitot tube inlet is more severe than that in the tube body, using a single heating resistor array with uniformly controlled heating power would result in uneven heating. In this embodiment, multiple heating resistor arrays are considered. The heating resistor array at the pitot tube inlet uses higher heating power, while the heating resistor array in the pitot tube body uses lower heating power. This arrangement helps save energy and improves heating efficiency, achieving a better heating effect for the pitot tube.

[0052] Furthermore, the heating resistors on the heating plate are standardized resistors, avoiding the research and development costs of custom high-power resistors.

[0053] In an optional implementation of this embodiment, the microcontroller is a TMS320F28004x.

[0054] Specifically, the TMS320F28004x is a Texas Instruments C2000 series microcontroller chip with built-in hardware PID controller, high-resolution ePWM, ADC sampling, and analog-to-digital converter. It is suitable for high-frequency temperature closed-loop and PWM signal power regulation applications, and is preferably matched with the airspeed tube adaptive heating device used in this embodiment.

[0055] In one optional implementation of this embodiment, such as Figure 3 As shown, Figure 3 The circuit diagram of the MOSFET driving circuit in Embodiment 1 of this utility model is shown. The MOSFET driving circuit includes transistors Q1, Q2, Q3, and Q4, resistors R1, R2, R3, R4, R5, and R6.

[0056] The first end of the resistor R1 is connected to the microcontroller;

[0057] The second end of the resistor R1 is connected to the emitter of transistor Q1 and the emitter of transistor Q2;

[0058] The base of transistor Q1 is connected to the base of transistor Q2, and is also connected to the first terminal of resistor R2, the first terminal of resistor R3, and the collector of transistor Q4.

[0059] The collector of transistor Q1 is connected to the first terminal of resistor R4, the collector of transistor Q3, and is connected to the driving power supply.

[0060] The collector of transistor Q2 is connected to the base of transistor Q3;

[0061] The base of the transistor Q3 is connected to the first terminal of the resistor R5 and the first terminal of the resistor R6.

[0062] The second end of resistor R4 and the second end of resistor R5 are connected to the heating switch circuit.

[0063] The second end of the resistor R2 is connected to the driving power supply;

[0064] The emitter of transistor Q3, the emitter of transistor Q4, the second terminal of resistor R3, and the second terminal of resistor R6 are grounded.

[0065] Specifically, transistors Q1, Q3, and Q4 are NPN transistors, and transistor Q2 is a PNP transistor.

[0066] Furthermore, the operating principle of the MOSFET driving circuit includes:

[0067] The PWM control signal of the microcontroller is input into the MOSFET drive circuit, converted into a MOSFET drive signal, and then input into the heating switch circuit to control the heating operation of the heating plate.

[0068] Resistor R1 performs preliminary filtering of the microcontroller's PWM control signal and limits the base current of transistor Q4. Transistors Q1 and Q2 form a totem-pole circuit structure to isolate the PWM control signal. Transistor Q4 is connected to the drive power supply to provide drive current. Resistors R2 and R3 provide the PWM signal voltage reference. Resistor R4 limits the gate current of the switching MOSFET in the heating switch circuit. Transistor Q3 outputs the drive signal. Resistors R5 and R6 are feedback resistors. By sampling the gate voltage of the switching MOSFET in the heating switch circuit, a negative feedback mechanism is formed to limit the gate voltage corresponding to the final drive signal output by the switching MOSFET in the heating switch circuit, thereby controlling the on / off state of the heating switch circuit and further controlling the heating operation on the heating plate.

[0069] By setting up a MOSFET drive circuit and combining it with a microcontroller, the heating operation of the heating plate is realized, resulting in higher control precision and better reliability.

[0070] In one optional implementation of this embodiment, such as Figure 4 As shown, Figure 4 The circuit diagram of the heating switch circuit in Embodiment 1 of this utility model is shown. The heating switch circuit includes a switching MOSFET Q5, a resistor R7, and a resistor R8.

[0071] The first end of the resistor R7 is connected to the output end of the MOSFET drive circuit.

[0072] The second end of the resistor R7 is connected to the gate of the switching MOSFET Q5;

[0073] The drain of the switching MOSFET Q5 is connected to one end of the resistor R8;

[0074] The source of the switching MOSFET Q5 is connected to the heating plate.

[0075] Furthermore, the working principle of the heating switch circuit includes:

[0076] The gate of the switching MOSFET Q5 receives the drive signal output from the MOSFET drive circuit, adjusts the gate-source voltage, and controls the conductive channel, thereby controlling the heating operation of the heating plate. Resistor R7 acts as a stabilizing resistor to isolate and reduce noise from the drive signal output from the MOSFET drive circuit, and resistor R8 acts as a pull-up resistor connected to the switching power supply.

[0077] In an optional implementation of this embodiment, the heating plate is further provided with a temperature sensing module, which is connected to the microcontroller.

[0078] Specifically, the temperature sensing module includes several temperature-sensing resistors, which are arranged in the heating resistor array.

[0079] Furthermore, such as Figure 2 As shown, the heating plate has a plurality of temperature measuring resistors (NTCs) arranged in its heating resistor array, and the temperature measuring resistors are NTC thermistors.

[0080] Specifically, one or more NTC thermistors are provided in each heating resistor subarray of the heating resistor array of the heating plate.

[0081] The temperature sensing module collects temperature information from the airspeed tube and heating plate based on the set NTC thermistor, and transmits the collected temperature information to the microcontroller on the control board.

[0082] Furthermore, the temperature sensing module can also use a thermocouple or an infrared temperature sensor, depending on actual needs.

[0083] In an optional implementation of this embodiment, an infrared icing sensor is further provided on the heating plate, and the infrared icing sensor is connected to the controller.

[0084] Specifically, the infrared icing sensor detects whether there is icing on the pitot tube body through non-contact infrared laser detection, and transmits the infrared icing detection data to the microcontroller on the control board. The microcontroller determines whether the heating power of the heating plate needs to be increased for a short time based on the infrared icing detection data.

[0085] In an optional implementation of this embodiment, the device is further provided with a power module, which is connected to the control board and the heating plate.

[0086] Specifically, the power module is used to provide power for the operation of the control board and the heating plate.

[0087] In an optional implementation of this embodiment, the working principle of the pitot tube adaptive heating device includes:

[0088] The microcontroller collects the temperature data of the airspeed tube through the temperature sensing module, calculates the heating power control data corresponding to the heating demand, and controls the output drive signal of the MOSFET drive circuit through the PWM signal to control the on and off state of the switching MOSFET in the heating switch circuit, thereby controlling the heating operation on the heating plate and realizing precise heating operation of the airspeed tube.

[0089] Specifically, the NTC thermistor collects the real-time temperature value of the airspeed tube and outputs an analog voltage signal to the microcontroller. The microcontroller performs analog-to-digital conversion on the analog voltage signal, calculates the actual temperature value Treal, and compares it with the preset threshold Tset. The microcontroller automatically modulates the duty cycle of the PWM signal through a built-in PID algorithm. When the detected actual temperature value Treal is lower than the preset threshold Tset, the PWM duty cycle is increased; when it approaches the upper limit of the preset threshold Tset, the PWM duty cycle is gradually decreased until heating stops.

[0090] Furthermore, the preset temperature threshold is 5℃~15℃ (which can be modified according to actual design requirements). When the detected temperature is lower than the lower threshold, the heating power is fully turned on; when it approaches the upper threshold, the PWM duty cycle is gradually reduced until heating stops.

[0091] In summary, Embodiment 1 of this utility model provides an adaptive heating device for the pitot tube. Based on a microcontroller combined with a MOSFET driving circuit and a heating switch circuit, it controls the heating resistor array with a series-parallel hybrid topology on the heating plate to perform heating operations. Compared with the traditional heating operation using a relay to control a series-connected heating resistor circuit, it has higher control precision, better reliability, and higher heating efficiency, achieving a better heating effect on the pitot tube.

[0092] Example 2

[0093] This utility model provides a pitot tube in embodiment two, wherein the pitot tube is provided with the pitot tube adaptive heating device described in embodiment one.

[0094] In an optional implementation of this embodiment, the heating plate of the pitot tube adaptive heating device described in Embodiment 1 is made using flexible printed circuit board (FPC) technology and can be folded to wrap around the pitot tube. Heat insulation adhesive is provided between the heating plate and the pitot tube to achieve uniform heating of the pitot tube.

[0095] In summary, Embodiment 2 of this utility model provides a pitot tube, on which the pitot tube adaptive heating device described in Embodiment 1 is provided. Based on a microcontroller combined with a MOSFET driving circuit and a heating switch circuit, the heating resistor array with a series-parallel hybrid topology on the heating plate is controlled to perform heating operation. Compared with the traditional heating operation using a relay to control a series-connected heating resistor circuit, the control accuracy is higher, the reliability is better, the heating efficiency is higher, and a better heating effect is achieved for the pitot tube.

[0096] The above provides a detailed description of the pitot tube adaptive heating device and pitot tube provided by the embodiments of this utility model. Specific examples have been used to illustrate the principle and implementation of this utility model. The description of the above embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A pitot tube adaptive heating device, characterized in that, The device includes a control board and a heating plate, the control board being connected to the heating plate, and the heating plate enclosing the pitot tube; The control board is equipped with a microcontroller, a MOSFET driving circuit, and a heating switch circuit. The microcontroller is connected to the MOSFET driving circuit, the MOSFET driving circuit is connected to the heating switch circuit, and the heating switch circuit is connected to the heating plate. The heating plate is provided with a heating resistor array, which includes a plurality of heating resistors connected in a series-parallel hybrid topology.

2. The airspeed tube adaptive heating device as described in claim 1, characterized in that, The heating resistor array includes several heating resistor subarrays, with heating resistors in any one heating resistor subarray connected in series and parallel, and adjacent heating resistor subarrays connected in series.

3. The airspeed tube adaptive heating device as described in claim 1, characterized in that, The microcontroller is model TMS320F28004x.

4. The airspeed tube adaptive heating device as described in claim 1, characterized in that, The MOSFET driving circuit includes transistors Q1, Q2, Q3, and Q4, resistors R1, R2, R3, R4, R5, and R6. The first end of the resistor R1 is connected to the microcontroller; The second end of the resistor R1 is connected to the emitter of transistor Q1 and the emitter of transistor Q2; The base of transistor Q1 is connected to the base of transistor Q2, and is also connected to the first terminal of resistor R2, the first terminal of resistor R3, and the collector of transistor Q4. The collector of transistor Q1 is connected to the first terminal of resistor R4, the collector of transistor Q3, and is connected to the driving power supply. The collector of transistor Q2 is connected to the base of transistor Q3; The base of the transistor Q3 is connected to the first terminal of the resistor R5 and the first terminal of the resistor R6. The second end of resistor R4 and the second end of resistor R5 are connected to the heating switch circuit. The second end of the resistor R2 is connected to the driving power supply; The emitter of transistor Q3, the emitter of transistor Q4, the second terminal of resistor R3, and the second terminal of resistor R6 are grounded.

5. The pitot tube adaptive heating device as described in claim 1, characterized in that, The heating switch circuit includes a switching MOSFET Q5, a resistor R7, and a resistor R8. The first end of the resistor R7 is connected to the output end of the MOSFET drive circuit. The second end of the resistor R7 is connected to the gate of the switching MOSFET Q5; The drain of the switching MOSFET Q5 is connected to one end of the resistor R8; The source of the switching MOSFET Q5 is connected to the heating plate.

6. The pitot tube adaptive heating device as described in claim 1, characterized in that, The heating plate is also equipped with a temperature sensing module, which is connected to the microcontroller.

7. The pitot tube adaptive heating device as described in claim 6, characterized in that, The temperature sensing module includes several temperature-sensing resistors, which are arranged in the heating resistor array.

8. The pitot tube adaptive heating device as described in claim 1, characterized in that, The heating plate is also equipped with an infrared icing sensor, which is connected to the controller.

9. The airspeed tube adaptive heating device as described in claim 1, characterized in that, The device is also equipped with a power module, which is connected to the control board and the heating plate.

10. A pitot tube, characterized in that, The pitot tube is provided with a pitot tube adaptive heating device as described in any one of claims 1-9.

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