A safety monitoring system of an air speed tube heating plate and an air speed tube

Abstract

The utility model discloses a kind of safety monitoring system and air speed tube of air speed tube heating plate, including MCU circuit, input power on-off control circuit, input power voltage acquisition circuit, input power current acquisition circuit, heating plate temperature acquisition circuit and fault protection circuit;MCU circuit connects input power on-off control circuit, input power voltage acquisition circuit, input power current acquisition circuit, heating plate temperature acquisition circuit and fault protection circuit;Input power on-off control circuit input total power supply and air speed tube heating plate;Input power voltage acquisition circuit and input power current acquisition circuit connect input total power supply;Heating plate temperature acquisition circuit connects air speed tube heating plate;Fault protection circuit is arranged between input power on-off control circuit and air speed tube heating plate.The utility model realizes the circuit protection of air speed tube heating plate, power monitoring and environmental temperature monitoring, effectively improve the security and stability of air speed tube heating plate.

Description

Technical Field

[0001] This utility model relates to the field of airspeed tube control technology, and in particular to a safety monitoring system for an airspeed tube heating plate and an airspeed tube. 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 acquires pressure data by sensing the total and static pressure of the airflow, and then calculates the aircraft's airspeed. Because pitot tubes often operate in high-altitude, low-temperature environments, the tube inlet can freeze, leading to malfunctions and decreased measurement accuracy. Therefore, heating plates are needed around the pitot tube to raise its temperature when necessary. However, current control schemes for pitot tube heating plates suffer from three major flaws: lack of circuit protection, inadequate power monitoring, and insufficient environmental adaptability. These flaws cause distorted heating plate data, potentially leading to overheating, short circuits, and even safety accidents, resulting in economic losses. Utility Model Content

[0003] The purpose of this utility model is to overcome the shortcomings of the prior art. This utility model provides a safety monitoring system for the airspeed tube heating plate and an airspeed tube, which realizes circuit protection, power monitoring and ambient temperature monitoring of the airspeed tube heating plate, effectively improving the safety and stability of the airspeed tube heating plate.

[0004] This utility model provides a safety monitoring system for a pitot tube heating plate. The system includes an MCU circuit, an input power supply on / off control circuit, an input power supply voltage acquisition circuit, an input power supply current acquisition circuit, and a heating plate temperature acquisition circuit. The MCU circuit is connected to the input power supply on / off control circuit, the input power supply voltage acquisition circuit, the input power supply current acquisition circuit, the heating plate temperature acquisition circuit, and the fault protection circuit. The input terminal of the input power supply on / off control circuit is connected to the main input power supply, and the output terminal of the input power supply on / off control circuit is connected to the airspeed tube heating plate. The input power voltage acquisition circuit and the input power current acquisition circuit are connected to the main input power supply; The heating plate temperature acquisition circuit is connected to the airspeed tube heating plate; The fault protection circuit is located between the input power supply on / off control circuit and the airspeed tube heating plate.

[0005] Furthermore, the MCU circuit includes an MCU chip U1, resistors R5, R7, and R14, capacitors C15 and C16, an inductor L2, a crystal oscillator Y1, and a light-emitting diode LED2. Pin 1 of the MCU chip U1 is connected to the first end of the resistor R5, and the second end of the resistor R5 is grounded. Pin 2 of the MCU chip U1 is connected to pin 3 of the crystal oscillator Y1, and is also connected to the first end of the capacitor C16; Pin 3 of the MCU chip U1 is connected to pin 1 of the crystal oscillator Y1, and is also connected to the first end of the capacitor C15; Pins 2 and 4 of the crystal oscillator Y1, the second terminal of capacitor C16, and the second terminal of capacitor C15 are grounded; Pin 4 of the MCU chip U1 is connected to the first end of the resistor R7; Pin 5 of the MCU chip U1 is connected to the first end of the inductor L2; Pin 16 of the MCU chip U1, the second end of the resistor R7, and the second end of the inductor L2 are connected to the MCU circuit input power supply. Pin 7 of the MCU chip U1 is connected to the first end of the resistor R14, and the second end of the resistor R14 is connected to the light-emitting diode LED2; Pin 10 of the MCU chip U1 is connected to the input power supply on / off control circuit; Pin 11 of the MCU chip U1 is connected to the input power supply voltage acquisition circuit; Pin 12 of the MCU chip U1 is connected to the input power current acquisition circuit; Pins 13 and 14 of the MCU chip U1 are connected to the heating plate temperature acquisition circuit.

[0006] Furthermore, the MCU chip U1 is model STM32F030F4P6TR.

[0007] Furthermore, the input power supply on / off control circuit includes a switch driver U5, a field-effect transistor Q1, resistors R2, R3, and R1, and capacitors C1 and C4. Pin 1 of the switch driver U5 is connected to the first terminal of the capacitor C1 and is also connected to the input power supply of the switch driver. Pin 2 of the switch driver U5 is connected to the first end of the resistor R1; The second terminal of resistor R1, the second terminal of capacitor C1, and pin 3 of switch driver U5 are grounded; Pin 4 of the switch driver U5 is connected to the MCU circuit; Pin 5 of the switch driver U5 is connected to the first end of resistor R2 and the first end of resistor R3; The second terminal of resistor R3 is grounded; Pins 6 and 7 of the switch driver U5 are connected to the gate of the field-effect transistor Q1; Pin 8 of the switch driver U5 is connected to the first terminal of the capacitor C4, the source of the field-effect transistor Q1, and the power input of the heating plate. Pin 9 of the switch driver U5 is connected to the second terminal of the capacitor C4; Pin 11 of the switch driver U5 is grounded; The drain of the field-effect transistor Q1 is connected to the second terminal of the resistor R2 and then to the main power supply.

[0008] Furthermore, the input power supply voltage acquisition circuit includes resistors R9, R10, and R30, capacitor C70, Zener diode D1, and Zener diode D2; The first terminals of resistor R9, resistor R10, and resistor R30 are connected to the voltage sampling terminal of the input power supply. The second end of resistor R9 is connected to the main power supply, and the second end of resistor R10 is grounded. The second end of the resistor R30, the first end of the capacitor C70, the anode of the Zener diode D1, and the cathode of the Zener diode D2 are connected to the MCU circuit. The cathode of the Zener diode D1 is connected to the input power supply voltage acquisition circuit. The anode of the Zener diode D2 and the second terminal of the capacitor C70 are grounded.

[0009] Furthermore, the input power current acquisition circuit includes a current acquisition chip U19, a resistor R37, a capacitor C66, a capacitor C67, an electrostatic discharge protection diode ESD1, and a transient voltage suppression diode TVS1. Pins 1 and 2 of the current acquisition chip U19 are connected to the main power supply. Pins 3 and 4 of the current acquisition chip U19 are connected to the first terminal of the electrostatic discharge protection diode ESD1 and the first terminal of the transient voltage suppression diode TVS1, and the second terminal of the electrostatic discharge protection diode ESD1 and the second terminal of the transient voltage suppression diode TVS1 are grounded. Pin 5 of the current acquisition chip U19 is connected to the first terminal of the capacitor C67 and grounded; Pin 6 of the current acquisition chip U19 is connected to the second terminal of the capacitor C67; Pin 7 of the current acquisition chip U19 is connected to the first end of the resistor R37, and the second end of the resistor R37 is connected to the current sampling terminal of the input power supply. Pin 8 of the current acquisition chip U19 is connected to the first end of the capacitor C66 and to the input power supply current acquisition circuit. The second end of the capacitor C66 is grounded.

[0010] Furthermore, the heating plate temperature acquisition circuit includes resistor R8, capacitor C5, resistor R46, capacitor C72, Zener diode D3, Zener diode D4, resistor R11, capacitor C6, resistor R47, capacitor C73, Zener diode D5, and Zener diode D6. The first end of resistor R8, the first end of capacitor C5, and the first end of resistor R46 are connected to the first thermistor of the airspeed tube heating plate. The second end of the resistor R8 is connected to the power input of the heating plate temperature acquisition circuit, and the second end of the capacitor C5 is grounded. The second terminal of resistor R46, the first terminal of capacitor C72, the anode of Zener diode D3, and the cathode of Zener diode D4 are connected to the MCU circuit. The cathode of the Zener diode D3 is connected to the input power supply of the heating plate temperature acquisition circuit; The anode of the Zener diode D4 and the second terminal of the capacitor C72 are grounded; The first end of resistor R11, the first end of capacitor C6, and the first end of resistor R47 are connected to the second thermistor of the airspeed tube heating plate. The second end of the resistor R11 is connected to the input power of the heating plate temperature acquisition circuit, and the second end of the capacitor C6 is grounded. The second terminal of resistor R47, the first terminal of capacitor C73, the anode of Zener diode D5, and the cathode of Zener diode D6 are connected to the MCU circuit. The cathode of the Zener diode D5 is connected to the input power supply of the heating plate temperature acquisition circuit. The anode of the Zener diode D6 and the second terminal of the capacitor C73 are grounded.

[0011] Furthermore, the fault protection circuit includes a fuse F1, one end of which is connected to the heating plate input power supply, and the other end of which is connected to the heating plate power supply.

[0012] Furthermore, the system also includes a voltage conversion circuit, which is disposed between the main input power supply and the input power supply on / off control circuit.

[0013] This utility model also provides an airspeed tube, which includes the aforementioned safety monitoring system for the airspeed tube heating plate.

[0014] This utility model provides a safety monitoring system for a pitot tube heating plate and a pitot tube. It achieves circuit protection for the pitot tube heating plate by setting up a fault protection circuit, realizes power monitoring of the pitot tube heating plate by setting up an input power voltage acquisition circuit and an input power current acquisition circuit, realizes temperature monitoring of the pitot tube heating plate by setting up a heating plate temperature acquisition circuit, and realizes safety monitoring of the pitot tube heating plate by setting up an MCU circuit and an input power on / off control circuit, effectively improving the safety and stability of the pitot tube heating plate. Attached Figure Description

[0015] 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.

[0016] Figure 1 This is a module architecture diagram of the safety monitoring system for the airspeed tube heating plate in Embodiment 1 of this utility model; Figure 2 This is the electrical schematic diagram of the MCU circuit in Embodiment 1 of this utility model; Figure 3 This is the electrical schematic diagram of the input power supply on / off control circuit and fault protection circuit in Embodiment 1 of this utility model; Figure 4 This is the electrical schematic diagram of the input power supply voltage acquisition circuit in Embodiment 1 of this utility model; Figure 5 This is the electrical schematic diagram of the input power current acquisition circuit in Embodiment 1 of this utility model; Figure 6 This is the electrical schematic diagram of the heating plate temperature acquisition circuit in Embodiment 1 of this utility model. Detailed Implementation

[0017] 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.

[0018] 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.

[0019] 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.

[0020] Example 1 This utility model provides a safety monitoring system for a pitot tube heating plate, characterized in that the system includes an MCU circuit, an input power supply on / off control circuit, an input power supply voltage acquisition circuit, an input power supply current acquisition circuit, a heating plate temperature acquisition circuit, and a fault protection circuit. The MCU circuit is connected to the input power supply on / off control circuit, the input power supply voltage acquisition circuit, the input power supply current acquisition circuit, and the heating plate temperature acquisition circuit. The input terminal of the input power supply on / off control circuit is connected to the main input power supply, and the output terminal of the input power supply on / off control circuit is connected to the airspeed tube heating plate. The input power voltage acquisition circuit and the input power current acquisition circuit are connected to the main input power supply; The heating plate temperature acquisition circuit is connected to the airspeed tube heating plate; The fault protection circuit is located between the input power supply on / off control circuit and the airspeed tube heating plate.

[0021] In one optional implementation of this embodiment, such as Figure 1 As shown, Figure 1 This diagram illustrates the module architecture of a safety monitoring system for the pitot tube heating plate according to Embodiment 1 of this utility model. The safety monitoring system includes an MCU circuit, an input power supply on / off control circuit, an input power supply voltage acquisition circuit, an input power supply current acquisition circuit, a heating plate temperature acquisition circuit, and a fault protection circuit. The MCU circuit is connected to the input power supply on / off control circuit, the input power supply voltage acquisition circuit, the input power supply current acquisition circuit, and the heating plate temperature acquisition circuit. The input terminal of the input power supply on / off control circuit is connected to the main input power supply, and the output terminal of the input power supply on / off control circuit is connected to the pitot tube heating plate. The input power supply voltage acquisition circuit and the input power supply current acquisition circuit are connected to the main input power supply. The heating plate temperature acquisition circuit is connected to the pitot tube heating plate. The fault protection circuit is located between the input power supply on / off control circuit and the pitot tube heating plate.

[0022] In one optional implementation of this embodiment, such as Figure 2 As shown, Figure 2 The diagram shows the electrical schematic of the MCU circuit in Embodiment 1 of this utility model. The MCU circuit includes an MCU chip U1, resistors R5, R7, and R14, capacitors C15 and C16, inductor L2, crystal oscillator Y1, and light-emitting diode LED2. Pin 1 of the MCU chip U1 is connected to the first end of the resistor R5, and the second end of the resistor R5 is grounded. Pin 2 of the MCU chip U1 is connected to pin 3 of the crystal oscillator Y1, and is also connected to the first end of the capacitor C16; Pin 3 of the MCU chip U1 is connected to pin 1 of the crystal oscillator Y1, and is also connected to the first end of the capacitor C15; Pins 2 and 4 of the crystal oscillator Y1, the second terminal of capacitor C16, and the second terminal of capacitor C15 are grounded; Pin 4 of the MCU chip U1 is connected to the first end of the resistor R7; Pin 5 of the MCU chip U1 is connected to the first end of the inductor L2; Pin 16 of the MCU chip U1, the second end of the resistor R7, and the second end of the inductor L2 are connected to the MCU circuit input power supply VCC_3V3. Pin 7 of the MCU chip U1 is connected to the first end of the resistor R14, and the second end of the resistor R14 is connected to the light-emitting diode LED2; Pin 10 of the MCU chip U1 is connected to the input power supply on / off control circuit; Pin 11 of the MCU chip U1 is connected to the input power supply voltage acquisition circuit; Pin 12 of the MCU chip U1 is connected to the input power current acquisition circuit; Pins 13 and 14 of the MCU chip U1 are connected to the heating plate temperature acquisition circuit.

[0023] Specifically, pin 10 of the MCU chip U1 is connected to the input power supply on / off control circuit, and HEAT_PWM indicates that the output PWM control signal is sent to the input power supply on / off control circuit to control the on / off of the input power supply to the air tube heating plate; Pin 11 of the MCU chip U1 is connected to the input power supply voltage acquisition circuit, and VBAT_ADC indicates that the voltage data acquired by the input power supply voltage acquisition circuit is received. Pin 12 of the MCU chip U1 is connected to the input power current acquisition circuit, and BAT-CURENT indicates that the current data acquired by the input power current acquisition circuit is received. Pins 13 and 14 of the MCU chip U1 are connected to the heating plate temperature acquisition circuit. NTC1 of pin 13 indicates that the voltage data of the first thermistor on the airspeed tube heating plate is acquired by the heating plate temperature acquisition circuit, and NTC2 of pin 14 indicates that the voltage data of the second thermistor on the airspeed tube heating plate is acquired by the heating plate temperature acquisition circuit. The temperature data of the airspeed tube heating plate is obtained by processing the voltage data of the thermistors.

[0024] Furthermore, pins 17 and 18 of the MCU chip U1 can be used to receive ambient temperature and humidity data; Pins 8 and 9 of the MCU chip U1 are used to connect to the host computer (USART1_TX, USART1_RX), communicate with the host computer, provide feedback on the collected data, and execute manual heating commands.

[0025] In an optional implementation of this embodiment, the MCU chip U1 is an STM32F030F4P6TR. The STM32F030F4P6TR is a low-power, high-performance microcontroller that integrates a high-performance core, storage resources, and rich peripheral interfaces. In this embodiment, the MCU chip U1 can be programmed with specific control software to control the entire security monitoring system.

[0026] Furthermore, the value of resistor R5 is 100kΩ, the value of resistor R7 is 10kΩ, the value of resistor R14 is 2.7kΩ, the values ​​of capacitors C15 and C16 are 12pF, the value of inductor L2 is 600Ω@100MHz, and the value of crystal oscillator Y1 is 8MHz.

[0027] In one optional implementation of this embodiment, such as Figure 3 As shown, Figure 3 The electrical schematic diagram of the input power supply on / off control circuit and fault protection circuit in Embodiment 1 of this utility model is shown. The input power supply on / off control circuit includes a switch driver U5, a field-effect transistor Q1, a resistor R2, a resistor R3, a resistor R1, a capacitor C1, and a capacitor C4. Pin 1 of the switch driver U5 is connected to the first terminal of the capacitor C1 and is also connected to the switch driver input power supply VCC_5V. Pin 2 of the switch driver U5 is connected to the first end of the resistor R1; The second terminal of resistor R1, the second terminal of capacitor C1, and pin 3 of switch driver U5 are grounded; Pin 4 of the switch driver U5 is connected to the MCU circuit; Pin 5 of the switch driver U5 is connected to the first end of resistor R2 and the first end of resistor R3; The second terminal of resistor R3 is grounded; Pins 6 and 7 of the switch driver U5 are connected to the gate G of the field-effect transistor Q1; Pin 8 of the switch driver U5 is connected to the first terminal of the capacitor C4, the source S of the field-effect transistor Q1, and the heating plate input power supply VCC_HEAT. Pin 9 of the switch driver U5 is connected to the second terminal of the capacitor C4; Pin 11 of the switch driver U5 is grounded; The drain D of the field-effect transistor Q1 is connected to the second terminal of the resistor R2 and to the input power supply VBAT_50V.

[0028] Specifically, the switch driver U5 is model LTC7001 IMSE#PBF, which is a 150V high-voltage side fast NMOS static switch driver used to drive the switching of the field-effect transistor Q1. Pin 4 of the switch driver U5 is connected to pin 10 of the MCU chip U1 to receive the PWM signal (HEAT_PWM) from the MCU chip U1 and control the operation of the field-effect transistor Q1. The field-effect transistor Q1 is an N-channel field-effect transistor (NMOS), model WSP08N15, used to control the flow of current from the input total power supply to the airspeed tube heating plate.

[0029] Furthermore, the value of resistor R2 is 976kΩ, the value of resistor R3 is 10.5kΩ, the value of resistor R1 is 71.5kΩ, and the values ​​of capacitors C1 and C4 are 0.1uF.

[0030] In one optional implementation of this embodiment, such as Figure 4 As shown, Figure 4 The diagram shows the electrical schematic of the input power voltage acquisition circuit in Embodiment 1 of this utility model. The input power voltage acquisition circuit includes resistors R9, R10, and R30, capacitor C70, Zener diode D1, and Zener diode D2. The first terminals of resistor R9, resistor R10, and resistor R30 are connected to the voltage sampling terminal VBAT_ADC of the input power supply. The second end of resistor R9 is connected to the main input power supply VBAT_50V, and the second end of resistor R10 is grounded. The second end of the resistor R30, the first end of the capacitor C70, the anode of the Zener diode D1, and the cathode of the Zener diode D2 are connected to the MCU circuit. The cathode of the Zener diode D1 is connected to the input power supply voltage acquisition circuit input power supply VCC_3V3; The anode of the Zener diode D2 and the second terminal of the capacitor C70 are grounded.

[0031] Specifically, the first ends of resistor R9, resistor R10, and resistor R30 are connected to the voltage sampling terminal VBAT_ADC of the input power supply. After sampling the input voltage of the input power supply, the collected voltage data is transmitted to the MCU chip U1 for processing through pin 11 connected to the MCU chip U1.

[0032] Furthermore, the value of resistor R9 is 330kΩ, the value of resistor R10 is 20kΩ, the value of resistor R30 is 47kΩ, the value of capacitor C70 is 1nF, and the model of Zener diodes D1 and D2 is BAV99.

[0033] In one optional implementation of this embodiment, such as Figure 5 As shown, Figure 5 The electrical schematic diagram of the input power current acquisition circuit in Embodiment 1 of this utility model is shown. The input power current acquisition circuit includes a current acquisition chip U19, a resistor R37, a capacitor C66, a capacitor C67, an electrostatic discharge protection diode ESD1, and a transient voltage suppression diode TVS1. Pins 1 and 2 of the current acquisition chip U19 are connected to the input main power supply VBAT_50V; Pins 3 and 4 of the current acquisition chip U19 are connected to the first terminal of the electrostatic discharge protection diode ESD1 and the first terminal of the transient voltage suppression diode TVS1, and the second terminal of the electrostatic discharge protection diode ESD1 and the second terminal of the transient voltage suppression diode TVS1 are grounded. Pin 5 of the current acquisition chip U19 is connected to the first terminal of the capacitor C67 and grounded; Pin 6 of the current acquisition chip U19 is connected to the second terminal of the capacitor C67; Pin 7 of the current acquisition chip U19 is connected to the first end of the resistor R37, and the second end of the resistor R37 is connected to the current sampling terminal BAT-CURRENT of the input power supply. Pin 8 of the current acquisition chip U19 is connected to the first end of the capacitor C66 and to the input power supply current acquisition circuit input power supply VCC_5V. The second end of the capacitor C66 is grounded.

[0034] Specifically, the current acquisition chip U19 is an ACS712ELCTR-05B-T ammeter, which is connected to the BAT-CURRENT current sampling terminal of the input power supply. After sampling the input current of the input power supply, the acquired current data is transmitted to the MCU chip U1 for processing through pin 12 connected to the MCU chip U1. The electrostatic discharge protection diode ESD1 is an electrostatic discharge protection device used to protect electronic components from electrostatic damage. The transient voltage suppressor diode TVS1 is a transient voltage suppressor diode that clamps overvoltage within a safe range by quickly responding to voltage spikes, thereby protecting circuit components from damage. The electrostatic discharge protection diode ESD1 and transient voltage suppression diode TVS1 are used here to effectively protect the input power current acquisition circuit.

[0035] Furthermore, the value of resistor R37 is 120, the value of capacitor C66 is 0.1uF, and the value of capacitor C67 is 1nF.

[0036] Furthermore, the current acquisition chip U19 can be replaced with a discrete current detection chip.

[0037] In one optional implementation of this embodiment, such as Figure 6 As shown, Figure 6 The diagram shows the electrical schematic of the heating plate temperature acquisition circuit in Embodiment 1 of this utility model. The heating plate temperature acquisition circuit includes resistor R8, capacitor C5, resistor R46, capacitor C72, Zener diode D3, Zener diode D4, resistor R11, capacitor C6, resistor R47, capacitor C73, Zener diode D5, and Zener diode D6. The first end of resistor R8, the first end of capacitor C5, and the first end of resistor R46 are connected to the first thermistor NTC1 of the airspeed tube heating plate. The second end of the resistor R8 is connected to the input power supply VCC_3V3 of the heating plate temperature acquisition circuit, and the second end of the capacitor C5 is grounded. The second terminal of resistor R46, the first terminal of capacitor C72, the anode of Zener diode D3, and the cathode of Zener diode D4 are connected to the MCU circuit. The cathode of the Zener diode D3 is connected to the input power supply VCC_3V3 of the heating plate temperature acquisition circuit; The anode of the Zener diode D4 and the second terminal of the capacitor C72 are grounded; The first end of resistor R11, the first end of capacitor C6, and the first end of resistor R47 are connected to the second thermistor NTC2 of the airspeed tube heating plate. The second end of the resistor R11 is connected to the input power supply VCC_3V3 of the heating plate temperature acquisition circuit, and the second end of the capacitor C6 is grounded. The second terminal of resistor R47, the first terminal of capacitor C73, the anode of Zener diode D5, and the cathode of Zener diode D6 are connected to the MCU circuit. The cathode of the Zener diode D5 is connected to the input power supply VCC_3V3 of the heating plate temperature acquisition circuit; The anode of the Zener diode D6 and the second terminal of the capacitor C73 are grounded.

[0038] Specifically, two sets of heating plate temperature acquisition circuits are set up here to acquire the voltage data of two thermistors set on the pitot tube heating plate. After the acquisition is completed, they are connected to pins 13 and 14 of the MCU chip U1 respectively to transmit the voltage data of the thermistors to the MCU chip U1. The voltage data of the thermistors is then processed and converted into the temperature of the pitot tube heating plate.

[0039] Furthermore, the values ​​of resistors R8 and R9 are 249kΩ, the values ​​of resistors R46 and R47 are 47kΩ, the values ​​of capacitors C5 and C6 are 2.2nF, the values ​​of capacitors C72 and C73 are 1nF, and the model of Zener diodes D3, D4, D5, and D6 is BAV99.

[0040] In one optional implementation of this embodiment, such as Figure 3 As shown, the fault protection circuit includes a fuse F1, one end of which is connected to the heating plate input power supply, and the other end of which is connected to the heating plate power supply.

[0041] Specifically, the fuse F1 is a 63V 2A fuse, which is installed between the input power supply on / off control circuit and the pitot tube heating plate to ensure that the power supply to the heating plate can be cut off in time in the event of a short circuit or power failure, so as to prevent accidents such as deformation and fire caused by overheating of the pitot tube.

[0042] It should be noted that in this embodiment, a 63V 2A fuse is used when the total input power is 50V, and a 125V 1A fuse is used when the total input power is 100V.

[0043] Furthermore, the fuse F1 may be a resettable fuse.

[0044] In an optional implementation of this embodiment, the system further includes a voltage conversion circuit, which is disposed between the main input power supply and the input power supply on / off control circuit.

[0045] Specifically, in this embodiment, the input total power supply voltage is 50V. The voltage conversion circuit is used to convert the voltage to 5V and 3.3V. The 5V supplies power to the input power supply on / off control circuit and the input power supply current acquisition circuit, while the 3.3V supplies power to the MCU circuit, the input power supply voltage acquisition circuit, and the heating plate temperature acquisition circuit.

[0046] Working Principle: The existing control system for the pitot tube heating plate has the following drawbacks and shortcomings: 1. Lack of circuit protection mechanism: The heating plate power supply lacks a fuse, making it prone to fire in case of a short circuit (design flaw). 2. Lack of power monitoring: It cannot detect overload / underpower anomalies, leading to equipment damage (insufficient software monitoring). 3. Environmental perception blind spot: It does not collect heating plate temperature and ambient temperature and humidity, resulting in a rigid temperature control strategy under extreme conditions (weak system adaptability). Therefore, regarding the first point, a fault protection circuit composed of fuses is set up to protect the circuit; regarding the second point, an input power voltage acquisition circuit and an input power current acquisition circuit are set up to obtain the current power of the heating plate by acquiring voltage and current data, so as to monitor the working power in real time and stop heating in time when abnormal power is detected; regarding the third point, a heating plate temperature acquisition circuit, as well as an ambient temperature sensor and an ambient humidity sensor, are set up to acquire temperature and humidity data. In addition, the PID (proportional-integral-derivative) control algorithm is used on the MCU chip U1 to calculate the PWM control signal based on the collected data and transmit it to the input power on / off control circuit for control, so as to heat the pitot tube of small and medium-sized UAVs in an energy-saving, safe and precise way, and prevent the pitot tube from freezing and blocking in low temperature environment. Furthermore, when the ambient temperature is greater than or equal to 0℃, the target temperature of the PID control algorithm is 5℃. When the ambient temperature is less than 0℃, the target temperature of the PID control algorithm is 20℃.

[0047] Using a 50V main power supply, a voltage conversion circuit is connected to step down the voltage to 5V and 3.3V to power other circuits. The input power voltage acquisition circuit, input power current acquisition circuit, and heating plate temperature acquisition circuit collect data from the airspeed tube heating plate and transmit the collected data back to the MCU circuit. After processing the data, the MCU circuit generates a PWM signal and transmits it to the input power on / off control circuit. The PWM signal controls the on / off state of the field-effect transistor Q1 by controlling the fast high-voltage side NMOS static switch driver chip (switch driver U5). When the field-effect transistor Q1 is turned on, the heating plate is connected to the power supply and starts heating. When the field-effect transistor Q1 is turned off, the heating plate is disconnected from the power supply and heating stops.

[0048] Furthermore, the MCU chip U1 enables both manual and automatic heating modes. When a heating control command is received every 2 seconds from the aircraft control computer (host computer), the MCU chip U1 outputs a PWM wave according to the duty cycle of the control command to initiate heating. If no control command is received for more than 2 seconds, it enters automatic heating mode. In automatic heating mode, the target temperature of the heating plate is set to 20℃ when the ambient temperature is below 0℃, and to 5℃ when the ambient temperature is above or equal to 0℃. In automatic heating mode, the PWM duty cycle is calculated using a PID control algorithm based on the temperature collected by the temperature sensor in the heating zone.

[0049] In summary, Embodiment 1 of this utility model provides a safety monitoring system for the pitot tube heating plate. It achieves circuit protection for the pitot tube heating plate by setting up a fault protection circuit, monitors the power of the pitot tube heating plate by setting up an input power voltage acquisition circuit and an input power current acquisition circuit, monitors the temperature of the pitot tube heating plate by setting up a heating plate temperature acquisition circuit, and completes safety monitoring of the pitot tube heating plate by setting up an MCU circuit and an input power on / off control circuit. This effectively improves the safety and stability of the pitot tube heating plate.

[0050] Example 2 This utility model provides a pitot tube in embodiment two, wherein the pitot tube includes the safety monitoring system for the pitot tube heating plate in embodiment one.

[0051] In summary, Embodiment 2 of this utility model provides a pitot tube, including the safety monitoring system for the pitot tube heating plate in Embodiment 1. It achieves circuit protection for the pitot tube heating plate by setting a fault protection circuit, monitors the power of the pitot tube heating plate by setting an input power voltage acquisition circuit and an input power current acquisition circuit, monitors the temperature of the pitot tube heating plate by setting a heating plate temperature acquisition circuit, and completes safety monitoring of the pitot tube heating plate by setting an MCU circuit and an input power on / off control circuit, effectively improving the safety and stability of the pitot tube heating plate.

[0052] The above provides a detailed description of the safety monitoring system for the pitot tube heating plate and the pitot tube provided in 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 safety monitoring system for a pitot tube heating plate, characterized in that, The system includes an MCU circuit, an input power supply on / off control circuit, an input power supply voltage acquisition circuit, an input power supply current acquisition circuit, a heating plate temperature acquisition circuit, and a fault protection circuit. The MCU circuit is connected to the input power supply on / off control circuit, the input power supply voltage acquisition circuit, the input power supply current acquisition circuit, and the heating plate temperature acquisition circuit. The input terminal of the input power supply on / off control circuit is connected to the main input power supply, and the output terminal of the input power supply on / off control circuit is connected to the airspeed tube heating plate. The input power voltage acquisition circuit and the input power current acquisition circuit are connected to the main input power supply; The heating plate temperature acquisition circuit is connected to the airspeed tube heating plate; The fault protection circuit is located between the input power supply on / off control circuit and the airspeed tube heating plate.

2. The safety monitoring system for the airspeed tube heating plate as described in claim 1, characterized in that, The MCU circuit includes an MCU chip U1, resistors R5, R7, and R14, capacitors C15 and C16, an inductor L2, a crystal oscillator Y1, and a light-emitting diode LED2. Pin 1 of the MCU chip U1 is connected to the first end of the resistor R5, and the second end of the resistor R5 is grounded. Pin 2 of the MCU chip U1 is connected to pin 3 of the crystal oscillator Y1, and is also connected to the first end of the capacitor C16; Pin 3 of the MCU chip U1 is connected to pin 1 of the crystal oscillator Y1, and is also connected to the first end of the capacitor C15; Pins 2 and 4 of the crystal oscillator Y1, the second terminal of capacitor C16, and the second terminal of capacitor C15 are grounded; Pin 4 of the MCU chip U1 is connected to the first end of the resistor R7; Pin 5 of the MCU chip U1 is connected to the first end of the inductor L2; Pin 16 of the MCU chip U1, the second end of the resistor R7, and the second end of the inductor L2 are connected to the MCU circuit input power supply. Pin 7 of the MCU chip U1 is connected to the first end of the resistor R14, and the second end of the resistor R14 is connected to the light-emitting diode LED2; Pin 10 of the MCU chip U1 is connected to the input power supply on / off control circuit; Pin 11 of the MCU chip U1 is connected to the input power supply voltage acquisition circuit; Pin 12 of the MCU chip U1 is connected to the input power current acquisition circuit; Pins 13 and 14 of the MCU chip U1 are connected to the heating plate temperature acquisition circuit.

3. The safety monitoring system for the airspeed tube heating plate as described in claim 2, characterized in that, The MCU chip U1 is model STM32F030F4P6TR.

4. The safety monitoring system for the airspeed tube heating plate as described in claim 1, characterized in that, The input power supply on / off control circuit includes a switch driver U5, a field-effect transistor Q1, resistors R2, R3, and R1, and capacitors C1 and C4. Pin 1 of the switch driver U5 is connected to the first terminal of the capacitor C1 and is also connected to the input power supply of the switch driver. Pin 2 of the switch driver U5 is connected to the first end of the resistor R1; The second terminal of resistor R1, the second terminal of capacitor C1, and pin 3 of switch driver U5 are grounded; Pin 4 of the switch driver U5 is connected to the MCU circuit; Pin 5 of the switch driver U5 is connected to the first end of resistor R2 and the first end of resistor R3; The second terminal of resistor R3 is grounded; Pins 6 and 7 of the switch driver U5 are connected to the gate of the field-effect transistor Q1; Pin 8 of the switch driver U5 is connected to the first terminal of the capacitor C4, the source of the field-effect transistor Q1, and the power input of the heating plate. Pin 9 of the switch driver U5 is connected to the second terminal of the capacitor C4; Pin 11 of the switch driver U5 is grounded; The drain of the field-effect transistor Q1 is connected to the second terminal of the resistor R2 and then to the main power supply.

5. The safety monitoring system for the airspeed tube heating plate as described in claim 1, characterized in that, The input power supply voltage acquisition circuit includes resistors R9, R10, and R30, capacitor C70, Zener diode D1, and Zener diode D2. The first terminals of resistor R9, resistor R10, and resistor R30 are connected to the voltage sampling terminal of the input power supply. The second end of resistor R9 is connected to the main power supply, and the second end of resistor R10 is grounded. The second end of the resistor R30, the first end of the capacitor C70, the anode of the Zener diode D1, and the cathode of the Zener diode D2 are connected to the MCU circuit. The cathode of the Zener diode D1 is connected to the input power supply voltage acquisition circuit. The anode of the Zener diode D2 and the second terminal of the capacitor C70 are grounded.

6. The safety monitoring system for the airspeed tube heating plate as described in claim 1, characterized in that, The input power current acquisition circuit includes a current acquisition chip U19, a resistor R37, a capacitor C66, a capacitor C67, an electrostatic discharge protection diode ESD1, and a transient voltage suppression diode TVS1. Pins 1 and 2 of the current acquisition chip U19 are connected to the main power supply. Pins 3 and 4 of the current acquisition chip U19 are connected to the first terminal of the electrostatic discharge protection diode ESD1 and the first terminal of the transient voltage suppression diode TVS1, and the second terminal of the electrostatic discharge protection diode ESD1 and the second terminal of the transient voltage suppression diode TVS1 are grounded. Pin 5 of the current acquisition chip U19 is connected to the first terminal of the capacitor C67 and grounded; Pin 6 of the current acquisition chip U19 is connected to the second terminal of the capacitor C67; Pin 7 of the current acquisition chip U19 is connected to the first end of the resistor R37, and the second end of the resistor R37 is connected to the current sampling terminal of the input power supply. Pin 8 of the current acquisition chip U19 is connected to the first end of the capacitor C66 and to the input power supply current acquisition circuit. The second end of the capacitor C66 is grounded.

7. The safety monitoring system for the airspeed tube heating plate as described in claim 1, characterized in that, The heating plate temperature acquisition circuit includes resistor R8, capacitor C5, resistor R46, capacitor C72, Zener diode D3, Zener diode D4, resistor R11, capacitor C6, resistor R47, capacitor C73, Zener diode D5, and Zener diode D6. The first end of resistor R8, the first end of capacitor C5, and the first end of resistor R46 are connected to the first thermistor of the airspeed tube heating plate. The second end of the resistor R8 is connected to the power input of the heating plate temperature acquisition circuit, and the second end of the capacitor C5 is grounded. The second terminal of resistor R46, the first terminal of capacitor C72, the anode of Zener diode D3, and the cathode of Zener diode D4 are connected to the MCU circuit. The cathode of the Zener diode D3 is connected to the input power supply of the heating plate temperature acquisition circuit; The anode of the Zener diode D4 and the second terminal of the capacitor C72 are grounded; The first end of resistor R11, the first end of capacitor C6, and the first end of resistor R47 are connected to the second thermistor of the airspeed tube heating plate. The second end of the resistor R11 is connected to the input power of the heating plate temperature acquisition circuit, and the second end of the capacitor C6 is grounded. The second terminal of resistor R47, the first terminal of capacitor C73, the anode of Zener diode D5, and the cathode of Zener diode D6 are connected to the MCU circuit. The cathode of the Zener diode D5 is connected to the input power supply of the heating plate temperature acquisition circuit. The anode of the Zener diode D6 and the second terminal of the capacitor C73 are grounded.

8. The safety monitoring system for the airspeed tube heating plate as described in claim 1, characterized in that, The fault protection circuit includes a fuse F1, one end of which is connected to the heating plate input power supply, and the other end of which is connected to the heating plate power supply.

9. The safety monitoring system for the airspeed tube heating plate as described in claim 1, characterized in that, The system also includes a voltage conversion circuit, which is disposed between the main input power supply and the input power supply on / off control circuit.

10. A pitot tube, characterized in that, The airspeed tube includes the safety monitoring system for the airspeed tube heating plate as described in any one of claims 1-9.

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