Meteorological sensor cold start heating device and control method thereof

Abstract

The invention belongs to the field of meteorological sensors, and relates to a meteorological sensor cold start heating device and a control method thereof, and the device comprises a controller MCU and a cold start heating circuit. The cold start heating circuit comprises a power supply VDD, a triode, a resistor and a voltage-controlled constant current source heating circuit. The power supply VDD is connected to the triode through a first connecting line after being subjected to resistor voltage division; the triode is connected to the voltage-controlled constant-current source heating circuit through a second connecting line after being subjected to voltage division by a resistor; the MCU is respectively connected with the first connecting line and the second connecting line; the heating device can start the cold start heating mode when the environment temperature is lower than the minimum working temperature of the controller, and the heating device is switched to the voltage-controlled constant-current source heating mode until the environment temperature is not lower than the minimum working temperature of the controller, namely when the controller is started, so that normal work of the meteorological sensor in the extremely cold environment is guaranteed.

Description

Technical Field

[0001] The invention belongs to the field of meteorological sensors and relates to a meteorological sensor cold start heating device and a control method thereof. Background Art

[0002] Meteorological sensors are electronic devices used to measure meteorological parameters. They are widely used in meteorological observation, environmental monitoring, aerospace and other fields. Meteorological sensors can obtain meteorological parameter data such as temperature, humidity, wind speed, wind direction, air pressure, rainfall, solar radiation, etc., which helps us better understand meteorological conditions and evaluate environmental quality. The working principles of meteorological sensors vary. Generally, they sense the corresponding meteorological parameters, convert physical quantities into electrical signals, and then process and transmit them.

[0003] However, the meteorological environment in different regions varies greatly. In extremely cold areas, the temperature can be lower than -40℃. Traditional meteorological sensors will be frozen in such extremely cold areas and cannot work normally. In order to ensure that the meteorological sensors are not frozen and can work normally, some meteorological sensors have added a resistor heating device inside. The working principle of this type of meteorological sensor heating device is as follows: after power-on, the meteorological sensor control system works, collects temperature data, and starts the heating device after determining that the external ambient temperature is lower than a certain value.

[0004] However, after the above-mentioned meteorological sensor is placed in an extremely cold environment for a period of time, the ambient temperature is lower than the minimum operating temperature of the control system during cold start, resulting in the control system being unable to start, and its heating device becomes ineffective, making the meteorological sensor unable to work normally. Summary of the invention

[0005] In order to solve the above-mentioned problems of the prior art, the present invention adopts a cold start heating device for a meteorological sensor, including: a controller MCU and a cold start heating circuit; the cold start heating circuit includes: a power supply VDD, a transistor, a resistor and a voltage-controlled constant current source heating circuit; the power supply VDD is connected to the transistor through a first connecting line after being divided by a resistor; the transistor is connected to the voltage-controlled constant current source heating circuit through a second connecting line after being divided by a resistor; the MCU is respectively connected to the first connecting line and the second connecting line.

[0006] The MCU includes: an IO port and a DAC pin. The IO port is connected to the first connecting line to control the opening and closing of the transistor; the DAC pin is connected to the second connecting line to control the current of the voltage-controlled constant current source heating circuit; wherein, the IO port is a general input and output port, and the DAC pin is a digital-to-analog converter pin.

[0007] The cold start heating device includes: a cold start heating mode and a voltage-controlled constant current source heating mode; when the MCU is not started, Q1 is turned on, and the cold start heating device is in the cold start heating mode; when the MCU is started, the IO port is pulled low, Q1 is disconnected, and the current of the voltage-controlled constant current source heating circuit is controlled by the DAC pin of the MCU, and the cold start heating device is in the voltage-controlled constant current source heating mode.

[0008] The resistors include: resistor R1, resistor R2, resistor R3 and resistor R4; the power supply VDD is connected to the transistor through the first connecting line after resistor voltage division, including: the power supply VDD is connected to one end of the resistor R1, the other end of the resistor R1 is respectively connected to one end of the resistor R2, one end of the resistor R3 and the source of the transistor, the other end of the resistor R2 is grounded, the other end of the resistor R3 is connected to one end of the resistor R4 through the first connecting line, and the other end of R4 is connected to the gate of the transistor.

[0009] The resistors also include: resistor R5 and resistor R6; the transistor is connected to the voltage-controlled constant current source heating circuit through the second connecting line after resistor voltage division, including: the drain of the transistor is connected to one end of the resistor R5, and the other end of the resistor R5 is connected to one end of the resistor R6 and the voltage-controlled constant current source heating circuit through the second connecting line; the other end of the resistor R6 is grounded.

[0010] The voltage-controlled constant current source heating circuit includes: an operational amplifier, a semiconductor heating device and a probe; the non-inverting input terminal of the operational amplifier is connected to the second connecting line, the output terminal of the operational amplifier is connected to the gate of the semiconductor heating device, the source of the semiconductor heating device is connected to one end of the probe, the drain is connected to the power supply VDD, and the other end of the probe is grounded and connected to the inverting input terminal of the operational amplifier.

[0011] The voltage-controlled constant current source heating circuit also includes: resistors R7, R8 and R9; the output end of the operational amplifier is connected to the gate of the semiconductor heating device through resistor R7; the probe is grounded through resistor R9 and connected to the inverting input end of the operational amplifier through resistor R8.

[0012] There is at least one semiconductor heating device; when there are more than one semiconductor heating device, the semiconductor heating devices are connected in either a serial manner or a parallel manner.

[0013] The cold start heating circuit also includes a capacitor, one end of which is grounded, and the other end of which is connected to the in-phase input terminal of the operational amplifier.

[0014] On the other hand, the present invention adopts a control method based on the above-mentioned meteorological sensor cold start heating device, comprising:

[0015] S1. Start the cold start heating mode by powering on the meteorological sensor;

[0016] S2, when the MCU starts, disconnect the cold start heating mode by controlling the IO port;

[0017] S3, using a meteorological sensor to collect the external temperature, and determining whether the collected temperature is lower than 0°C. If so, executing step S4 to start the voltage-controlled constant current source heating mode; otherwise, controlling the DAC pin voltage to close the voltage-controlled constant current source heating mode;

[0018] S4. Calculate the DAC pin voltage change using the PID control algorithm according to the collected temperature, set the DAC pin voltage according to the DAC pin voltage change, and return to step S3.

[0019] Beneficial effects of the present invention:

[0020] 1. The semiconductor heating device used in the heating device of the present invention has a small size, high heat generation and is easy to integrate; 2. The heating device of the present invention can start the cold start heating mode when the ambient temperature is lower than the minimum operating temperature of the controller, until the ambient temperature is not lower than the minimum operating temperature of the controller, that is, when the controller is started, it switches to the voltage-controlled constant current source heating mode to ensure the normal operation of the meteorological sensor in an extremely cold environment; 3. The voltage-controlled constant current source heating mode of the present invention adopts a voltage-controlled constant current source method for heating, which can accurately control the heating current, and the temperature control is more accurate and stable than that of traditional heating devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the installation position of the meteorological sensor cold start heating device provided by an embodiment of the present invention on the meteorological sensor housing;

[0022] Figure 2 is a schematic diagram of a single-point heating circuit for cold start provided by an embodiment of the present invention;

[0023] Figure 3 Schematic diagram of a cold start heating circuit with dual-channel heating in series provided by an embodiment of the present invention;

[0024] Figure 4 Schematic diagram of a three-channel heating circuit in series connected to a cold start heating circuit according to an embodiment of the present invention;

[0025] Figure 5 Schematic diagram of a cold start heating circuit with dual parallel channels for heating provided by an embodiment of the present invention;

[0026] Figure 6 Schematic diagram of a semiconductor heating device for a cold start heating circuit provided by an embodiment of the present invention;

[0027] Figure 7 It is a schematic diagram of a cold start heating circuit control strategy provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] In order to solve the problem that the existing meteorological sensor cannot be cold-started in an extremely cold environment, the present invention adopts a cold-start heating device installed on the meteorological sensor housing using a semiconductor power device.

[0030] The cold start heating device comprises: a controller MCU and a cold start heating circuit; the MCU comprises: an IO port and a DAC pin; a power supply VDD, a transistor, a resistor and a voltage-controlled constant current source heating circuit; the power supply VDD is connected to the transistor through a first connecting line after being divided by a resistor; the transistor is connected to the voltage-controlled constant current source heating circuit through a second connecting line after being divided by a resistor; wherein the IO port is a general input and output port, the DAC is a digital-to-analog converter, the first connecting line is a No. 23 connecting line, and the second connecting line is a No. 18 connecting line;

[0031] The voltage-controlled constant current source heating circuit includes: an operational amplifier, a semiconductor heating device, a probe and a resistor; the non-inverting input terminal of the operational amplifier is connected to the second connecting line, the output terminal of the operational amplifier is connected to the gate of the semiconductor heating device, the source of the semiconductor heating device is connected to one end of the probe, the drain is connected to the power supply VDD, and the other end of the probe is grounded and connected to the inverting input terminal of the operational amplifier.

[0032] The IO port is connected to the first connecting line to control the opening and closing of the transistor; the DAC pin is connected to the second connecting line to control the current of the cold start heating circuit.

[0033] There is at least one semiconductor heating device; when there are more than one semiconductor heating device, the semiconductor heating devices are connected in either a serial manner or a parallel manner.

[0034] In one embodiment, Figure 4 As shown, the number of semiconductor heating device groups of the semiconductor heating device group is 3, and the cold start heating circuit includes: a power supply VDD, a transistor Q1, an operational amplifier U1, semiconductor heating devices Q2-Q4, resistors R1-R12, a probe 1 and a capacitor C1;

[0035] After being divided by R1 and R2, VDD is connected to the gate of transistor Q1 through resistors R3, resistor R4 and connecting wire No. 23. After being divided by R1 and R2, VDD is directly connected to the source of transistor Q1; after being divided by R5 and R6, the drain of Q1 is connected to the non-inverting input terminal of operational amplifier U1, the output terminal of operational amplifier U1 is connected to the gate of semiconductor heating device Q2 through resistor R7, the source of semiconductor heating device Q2 is connected to one end of probe 1, the other end of probe 1 is grounded through resistor R9 and connected to the inverting input terminal of operational amplifier U1 through resistor R8; one end of capacitor C1 is grounded, and the other end is connected to the non-inverting input terminal of operational amplifier U1.

[0036] The drain of the semiconductor heating device Q2 is connected to the source of the semiconductor heating device Q3, the drain of the semiconductor heating device Q3 is connected to the source of the semiconductor heating device Q4, the drain of the semiconductor heating device Q4 is connected to the power supply VDD, and the power supply VDD is connected to the gate of the semiconductor heating device Q3 and the gate of the semiconductor heating device Q4 after being divided by resistors R11~R12.

[0037] The working principle is: the meteorological sensor is powered on, VDD is the external power supply, the No. 23 connecting wire is connected to the IO port in the MCU to control the opening and closing of the transistor Q1, and the No. 18 connecting wire is connected to the DAC pin in the MCU to control the heating current in the heating circuit.

[0038] Cold start heating mode: VDD is supplied to transistor Q1 after voltage division by R1 and R2. At this time, Q1 is turned on and connected to the common-phase input terminal of operational amplifier U1 after voltage division by R5 and R6. At this time, semiconductor heating devices Q2, Q3, and Q4 are turned on, and the heating current of the heating device flows into the ground plane through R9. After the MCU is powered on and started, the IO port connected to lead 23 is pulled low. At this time, Q1 is disconnected, the cold start heating mode is turned off, and the voltage-controlled constant current source heating mode is turned on.

[0039] Voltage-controlled constant current source heating mode: Q1 is disconnected, and the heating temperature of the entire heating circuit is controlled by connecting lead 18 to the DAC pin of the MCU; the heating temperature of the semiconductor heating devices Q2, Q3, and Q4 in this circuit is positively correlated with the current at probe 1, so it is only necessary to control the current flowing through R9 to accurately control the heating temperature. The current flowing through R9 is positively correlated with the voltage at lead 18. The collected temperature data is input into the MCU, and the MCU calculates the change in DAC pin voltage according to the PID algorithm. The DAC pin voltage of the MCU is set according to the change in DAC pin voltage to accurately control the heating temperature of the cold start heating device of the meteorological sensor.

[0040] The installation position of the cold start heating device in the meteorological sensor is as follows: Figure 1As shown, three positions are selected in the meteorological sensor to evenly distribute heating sources; among them, 4 is the meteorological sensor, 1 is the first semiconductor heating device of the cold start heating device of the meteorological sensor, 2 is the second semiconductor heating device of the cold start heating device of the meteorological sensor, and 3 is the third semiconductor heating device of the cold start heating device of the meteorological sensor.

[0041] In one embodiment, when the meteorological sensor is small in size, the semiconductor heating device group has only one or two semiconductor heating devices, and the following can be used: Figure 2 Single point heating device as shown or Figure 3 The series-connected dual-channel heating device shown.

[0042] In one embodiment, a semiconductor heating device such as Figure 6 shown.

[0043] According to the actual situation, multiple channel references need to be connected in series Figure 2 to Figure 4 The heating device circuit can be.

[0044] In one embodiment, for the complex and irregular structure of the meteorological sensor, when the serial heating method is not convenient for wiring, this embodiment also provides a parallel multi-channel cold start heating device such as Figure 5 As shown, the cold start heating circuit includes: a power supply VDD, a transistor Q1, operational amplifiers U1-U2, semiconductor heating devices Q2-Q3, resistors R1-R12, probes 1-2 and capacitors C1-C2;

[0045] After being divided by R1 and R2, VDD is connected to the gate of transistor Q1 through resistors R3, R4 and No. 23 connecting wire, and is directly connected to the source of transistor Q1 after being divided by R1 and R2; the drain of Q1 is connected to the in-phase input terminal of operational amplifiers U1 and U2 after being divided by R5 and R6.

[0046] The output end of the operational amplifier U1 is connected to the gate of the semiconductor heating device Q2 through the resistor R7, the source of the semiconductor heating device Q2 is connected to one end of the probe 1, the other end of the probe 1 is grounded through the resistor R9 and connected to the inverting input end of the operational amplifier U1 through the resistor R8; the output end of the operational amplifier U2 is connected to the gate of the semiconductor heating device Q3 through the resistor R11, the source of the semiconductor heating device Q3 is connected to one end of the probe 2, the other end of the probe 2 is grounded through the resistor R10 and connected to the inverting input end of the operational amplifier U2 through the resistor R12; the drains of the semiconductor heating devices Q2 and Q3 are connected to the power supply VDD.

[0047] One end of the capacitor C1 is grounded, and the other end is connected to the non-inverting input terminal of the operational amplifier U1; one end of the capacitor C2 is grounded, and the other end is connected to the non-inverting input terminal of the operational amplifier U2.

[0048] The working principle is: the meteorological sensor is powered on, and the meteorological sensor heating circuit Figure 5 VDD is the external power supply, wire No. 23 is connected to the IO port in the MCU to control the opening and closing of the transistor Q1, and wire No. 18 is connected to the DAC pin in the MCU to control the heating current in the heating circuit.

[0049] Cold start heating mode: VDD is supplied to transistor Q1 after being divided by R1 and R2. At this time, Q1 is turned on and connected to the in-phase input of operational amplifiers U1 and U2 after being divided by R5 and R6. Figure 5 The semiconductor heating devices Q2 and Q3 are turned on; the heating currents in the two parallel semiconductor heating devices flow into the ground plane through R9 and R10 respectively. After the MCU is powered on, the IO port connected to the 23rd lead is pulled low, at which time Q1 is disconnected, the cold start heating mode is turned off, and the voltage-controlled constant current source heating mode is turned on.

[0050] Voltage-controlled constant current source heating mode: The heating temperature of the entire heating circuit is controlled by the DAC pin of the MCU connected to the No. 18 lead. Figure 5 The heating temperature of the semiconductor heating devices Q2 and Q3 is positively correlated with the current at probe 1. Therefore, the heating temperature can be accurately controlled by controlling the current flowing through R9 and R10. The current flowing through R9 and R10 is positively correlated with the voltage at the leads of probes 1 and 2. The collected temperature data is input into the MCU. The MCU calculates the change in the DAC pin voltage according to the PID algorithm. The heating temperature of the meteorological sensor heating device can be accurately controlled by controlling the DAC pin voltage of the MCU.

[0051] According to the actual situation, a parallel multi-channel heating device can be used. Figure 2 and Figure 5 Just expand on it.

[0052] like Figure 7 As shown, the control strategy of the cold start heating device includes:

[0053] S1, turning on the cold start heating mode of the cold start heating device by powering on the meteorological sensor;

[0054] S2, when the MCU starts, pull the IO port low to disconnect the cold start heating mode;

[0055] S3. Use the temperature and humidity sensor on the meteorological sensor to collect the external temperature and determine whether the collected temperature is lower than 0°C. If so, turn on the voltage-controlled constant current source heating mode by executing step S4; otherwise, control the DAC pin voltage to be 0; since the heating circuit current is proportional to the DAC pin voltage, when the DAC pin voltage is 0, no current flows through the semiconductor heating device in the heating circuit and no heat is generated, so the voltage-controlled constant current source heating mode can be turned off.

[0056] S4. Calculate the voltage change of the DAC pin using the PID control algorithm according to the collected temperature, and set the DAC pin voltage according to the voltage change of the DAC pin. At this time, the voltage of lead 18 is also the voltage of the DAC pin, thereby controlling the heating temperature of the semiconductor heating devices Q2, Q3, and Q4. The heat generated by the semiconductor heating devices Q2, Q3, and Q4 is introduced into the meteorological sensor housing; return to step S3.

[0057] The difference between the heating device of the present invention and the traditional heating device is that: in an extremely cold environment, when the MCU in the meteorological sensor cannot start normally, the meteorological sensor is heated as a whole by the cold start heating device first, and after the MCU starts, the cold start heating mode is turned off and the voltage-controlled constant current source heating mode is switched. When the meteorological sensor housing is frozen, the above heating device can also melt the ice of the meteorological sensor housing.

[0058] The above embodiments further illustrate the purpose, technical solutions and advantages of the present invention in detail. It should be understood that the above embodiments are only preferred implementation modes of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made to the present invention within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A cold start heating device for a meteorological sensor, characterized in that: include: Controller MCU and cold start heating circuit; The cold start heating circuit includes: a power supply VDD, a transistor, a resistor and a voltage-controlled constant current source heating circuit; The power source VDD is connected to the transistor through the first connection line after resistor voltage division; the transistor is connected to the voltage-controlled constant current source heating circuit through the second connection line after resistor voltage division; and the MCU is connected to the first connection line and the second connection line respectively.

2. A meteorological sensor cold start heating device according to claim 1, characterized in that: The MCU includes: an IO port and a DAC pin. The IO port is connected to the first connecting line to control the opening and closing of the transistor; the DAC pin is connected to the second connecting line to control the current of the voltage-controlled constant current source heating circuit; wherein, the IO port is a general input and output port, and the DAC pin is a digital-to-analog converter pin.

3. A meteorological sensor cold start heating device according to claim 2, characterized in that: The cold start heating device includes: a cold start heating mode and a voltage-controlled constant current source heating mode; when the MCU is not started, Q1 is turned on, and the cold start heating device is in the cold start heating mode; when the MCU is started, the IO port is pulled low, Q1 is disconnected, and the current of the voltage-controlled constant current source heating circuit is controlled by the DAC pin of the MCU, and the cold start heating device is in the voltage-controlled constant current source heating mode.

4. A meteorological sensor cold start heating device according to claim 1, characterized in that: The resistors include: resistor R1, resistor R2, resistor R3 and resistor R4; the power supply VDD is connected to the transistor through the first connecting line after resistor voltage division, including: the power supply VDD is connected to one end of the resistor R1, the other end of the resistor R1 is respectively connected to one end of the resistor R2, one end of the resistor R3 and the source of the transistor, the other end of the resistor R2 is grounded, the other end of the resistor R3 is connected to one end of the resistor R4 through the first connecting line, and the other end of R4 is connected to the gate of the transistor.

5. The cold start heating device for a meteorological sensor according to claim 1, characterized in that: The resistors also include: resistor R5 and resistor R6; the transistor is connected to the voltage-controlled constant current source heating circuit through the second connecting line after resistor voltage division, including: the drain of the transistor is connected to one end of the resistor R5, and the other end of the resistor R5 is connected to one end of the resistor R6 and the voltage-controlled constant current source heating circuit through the second connecting line; the other end of the resistor R6 is grounded.

6. A meteorological sensor cold start heating device according to claim 1, characterized in that: The voltage-controlled constant current source heating circuit includes: an operational amplifier, a semiconductor heating device and a probe; the non-inverting input terminal of the operational amplifier is connected to the second connecting line, the output terminal of the operational amplifier is connected to the gate of the semiconductor heating device, the source of the semiconductor heating device is connected to one end of the probe, the drain is connected to the power supply VDD, and the other end of the probe is grounded and connected to the inverting input terminal of the operational amplifier.

7. A meteorological sensor cold start heating device according to claim 6, characterized in that: The voltage-controlled constant current source heating circuit also includes: resistors R7, R8 and R9; the output end of the operational amplifier is connected to the gate of the semiconductor heating device through resistor R7; the probe is grounded through resistor R9 and connected to the inverting input end of the operational amplifier through resistor R8.

8. The cold start heating device for a meteorological sensor according to claim 6, characterized in that: There is at least one semiconductor heating device; when there are more than one semiconductor heating device, the semiconductor heating devices are connected in either a serial manner or a parallel manner.

9. A meteorological sensor cold start heating device according to claim 6, characterized in that: The cold start heating circuit also includes a capacitor, one end of which is grounded, and the other end of which is connected to the in-phase input end of the operational amplifier.

10. A control method for a cold start heating device of a meteorological sensor according to claims 1 to 9, characterized in that: include: S1. Start the cold start heating mode by powering on the meteorological sensor; S2, when the MCU starts, disconnect the cold start heating mode by controlling the IO port; S3, using a meteorological sensor to collect the external temperature, and determining whether the collected temperature is lower than 0°C. If so, the voltage-controlled constant current source heating mode is turned on by executing step S4; otherwise, the voltage-controlled constant current source heating mode is turned off by controlling the DAC pin voltage; S4. Calculate the DAC pin voltage change using the PID control algorithm according to the collected temperature, set the DAC pin voltage according to the DAC pin voltage change, and return to step S3.

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