Ultrasonic transceiver circuit for measuring wind speed and wind direction

Abstract

The utility model discloses an ultrasonic wave transmit-receive circuit for measuring wind speed and wind direction, comprising an ultrasonic wave emitter and an ultrasonic wave receiver, the ultrasonic wave emitter is connected with a driving unit, and the driving unit drives the ultrasonic wave emitter to emit an ultrasonic wave signal; the ultrasonic receiver is used for receiving the ultrasonic signal transmitted by the ultrasonic transmitter, the ultrasonic receiver is connected with the amplifying unit, and the amplifying unit is used for amplifying the received ultrasonic signal. And the wind speed and direction measurement precision is improved.

Description

Technical Field

[0001] The utility model relates to a sensor, in particular to an ultrasonic transceiver circuit for measuring wind speed and direction. Background Art

[0002] Ultrasonic wind speed and direction meters are currently widely used. The basic principle of ultrasonic wind speed and direction measurement is to use the transmission of sound wave pulses and measure the time or frequency (Doppler shift) difference at the receiving end to calculate wind speed and direction.

[0003] Existing ultrasonic wind speed and direction meters typically feature four ultrasonic probes, each consisting of four transmitters and four corresponding receivers. These four transmitters are directly driven by four transformers, which can cause interference between the four transformers and affect sampling in subsequent circuits. Furthermore, because ultrasonic waves are high-frequency signals, directly comparing the waveforms can differ by one or several cycles, leading to errors in ultrasonic accuracy and inaccurate wind speed and direction measurements. Utility Model Content

[0004] In view of the defects of the existing technology, the present invention provides an ultrasonic transceiver circuit for measuring wind speed and direction.

[0005] An ultrasonic transceiver circuit for measuring wind speed and direction, comprising an ultrasonic transmitter and an ultrasonic receiver, wherein the ultrasonic transmitter is connected to a driving unit, and the driving unit drives the ultrasonic transmitter to emit an ultrasonic signal; the ultrasonic receiver is used to receive the ultrasonic signal emitted by the ultrasonic transmitter, and the ultrasonic receiver is connected to an amplifying unit, and the amplifying unit is used to amplify the received ultrasonic signal; the amplifying unit is connected to a detection unit, and the amplified ultrasonic signal is converted into an ultrasonic envelope signal by the detection unit; the detection unit is connected to a waveform conversion unit, and the ultrasonic envelope signal is converted into a square wave signal by the waveform conversion unit; the waveform conversion unit is connected to a timing unit, and the timing unit counts the The square wave signal is used for time measurement to calculate the wind speed and direction; the driving unit includes an analog switching circuit and a driving transformer connected to each other; the analog switching circuit has four PWM inputs and four PWM outputs, and the four PWM outputs are respectively connected to the driving transformers of the four ultrasonic transmitters; the input end of the driving transformer is respectively connected to an input resistor and an isolation diode, the input resistor is connected to the gate of a first MOS transistor, the drain of the first MOS transistor is connected to the primary side of the driving transformer, and the source of the first MOS transistor is grounded; the isolation diode is connected to the gate of a second MOS transistor, the drain of the second MOS transistor is respectively connected to an output capacitor and an output inductor, the output capacitor is connected to the secondary side of the driving transformer, and the source of the second MOS transistor is grounded.

[0006] Optionally, the amplifying unit includes an amplifier, the reverse input end of the amplifier is grounded through a resistor R15 and a capacitor C24, the positive input end of the amplifier is connected to the ultrasonic receiver, and a resistor R11 is connected between the reverse input end and the output end of the amplifier; a filtering circuit is also connected to the positive input end of the amplifier, in which a capacitor C30 and a resistor R19 are connected in parallel, one end of which is grounded, and the other end is connected to the positive input end of the amplifier, a resistor R38 and a capacitor C86 are connected in series, one end of which is grounded, and the other end is connected to the positive input end of the amplifier; the detection unit includes a BH4126FV chip, the IFIN pin of which is connected to the output of the amplifying unit, and the DIS pin is connected to the output of the amplifying unit through a resistor R13 and a capacitor C 31, C32, and C33 are grounded, and the RSSI pin serves as an output pin; the waveform conversion unit includes a first comparator U11B and a second comparator U12, which are connected in series to form an amplification and comparison circuit; one path of the inverting input of the first comparator U11B is grounded through a resistor R77, and the other path is connected to the output of the first comparator U11B through a resistor R52; the positive input of the first comparator U11B is connected to the output of the detection unit through a capacitor C60; the output of the first comparator U11B is connected to the positive input of the second comparator U12, and the direction input of the second comparator U12 is connected to the PWM input signal through an RC filtering network.

[0007] The beneficial effects of the present invention are as follows: the present invention adds an anti-interference circuit in the driving unit, so that the driving transformer (T1, T2, T3, T4) will not generate abnormal interference signals to the subsequent receiving waveform after transmitting the ultrasonic signal; the high-frequency ultrasonic signal is effectively converted into an ultrasonic envelope signal through the amplification unit and the detection unit, which effectively avoids the situation where the subsequent stage compares different peaks when comparing the threshold values, thereby improving the product accuracy; the ultrasonic envelope signal is further converted into a square wave signal through the waveform conversion unit, and the time difference of the square wave signal can be effectively timed in conjunction with the high-precision timing unit, so that the wind speed and direction can be accurately calculated. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a structural diagram of the ultrasonic drive circuit;

[0009] Figure 2 It is an analog switching circuit;

[0010] Figure 3A 、 Figure 3B 、 Figure 3C 、 Figure 3D This is the circuit diagram of the drive transformer;

[0011] Figure 4AThis is the circuit diagram of the amplification unit;

[0012] Figure 4B It is the amplified ultrasonic signal diagram;

[0013] Figure 5A This is the circuit diagram of the detection unit;

[0014] Figure 5B It is the ultrasonic envelope signal diagram;

[0015] Figure 6 is a circuit diagram of a waveform conversion unit;

[0016] Figure 7 This is the circuit structure diagram of the timing unit. DETAILED DESCRIPTION

[0017] To make the above-mentioned objects, features, and advantages of the present invention more readily apparent, the following detailed description of specific embodiments of the present invention is provided in conjunction with the accompanying drawings, so that the above-mentioned and other objects, features, and advantages of the present invention will become more apparent. Like reference numerals denote like parts throughout the drawings. The drawings are not drawn to scale; emphasis is placed on illustrating the subject matter of the present invention.

[0018] See Figure 1 The new ultrasonic driving circuit for measuring wind speed and direction includes an ultrasonic transmitter and an ultrasonic receiver. The transmitter and the receiver can be set up in four groups accordingly, wherein the transmitter is connected to the driving unit, and the driving unit drives the transmitter to emit an ultrasonic signal; the receiver is used to receive the ultrasonic signal emitted by the transmitter, and the receiver is connected to the amplifying unit, and the amplifying unit is used to amplify and process the received ultrasonic signal; the amplifying unit is connected to the detection unit, and the amplified high-frequency ultrasonic signal is converted into an ultrasonic envelope signal through the detection unit; the detection unit is connected to the waveform conversion unit, and the waveform conversion unit is used to convert the ultrasonic envelope signal into a square wave signal; the waveform conversion unit is connected to the timing unit, and the timing unit performs high-precision time measurement on the square wave signal, thereby measuring the time from emitting the ultrasonic wave to receiving the ultrasonic echo signal, thereby accurately calculating the wind speed and direction.

[0019] The driving unit includes an analog switch circuit and a driving transformer for 4 ultrasonic transmitters, such as Figure 2 As shown, the analog switch circuit has 4 PWM inputs and 4 PWM outputs. The analog switch circuit can respectively conduct the 4 PWM inputs and 4 PWM outputs. The 4 PWM outputs are connected to the driving transformers of the 4 ultrasonic transmitters, and the 4 transmitters are powered by the driving transformers of the 4 ultrasonic transmitters.

[0020] like Figure 3A 、 Figure 3B 、 Figure 3C 、 Figure 3D As shown, the driving transformers of the four ultrasonic transmitters have the same circuit structure, wherein the input ends thereof are respectively connected to the input resistors (R17, R56, R81, R85) and the isolation diodes (D4, D7, D23, D26), the input resistors are connected to the gates of the first MOS transistors (Q1, Q3, Q13, Q15), the drains of the first MOS transistors (Q1, Q3, Q13, Q15) are connected to the primary sides of the driving transformers (T1, T2, T3, T4), and the sources of the first MOS transistors (Q1, Q3, Q13, Q15) are grounded; the isolation diodes (D4, D7, D23, D26) are connected to the gate of the second MOS transistor (Q2, Q4, Q14, Q16), the drain of the second MOS transistor (Q2, Q4, Q14, Q16) is respectively connected to the output capacitor (C23, C47, C69, C75) and the output inductor (FB1, FB3, FB6, FB7), the output capacitor (C23, C47, C69, C75) is connected to the secondary side of the drive transformer (T1, T2, T3, T4), and the source of the second MOS transistor (Q2, Q4, Q14, Q16) is grounded.

[0021] In the driving unit, PWM is output to the driving transformers (T1, T2, T3, T4) of the four ultrasonic probes through analog switches. After boosting, the ultrasonic transmitter is driven to transmit ultrasonic waves, and the ultrasonic receiver on the opposite side can receive the ultrasonic signals. The new invention adds a second MOS tube (Q2, Q4, Q14, Q16) after the output capacitor (C23, C47, C69, C75) of the ultrasonic transmitting end. When the PWM reaches the driving transformer (T1, T2, T3, T4), the second MOS tube (Q2, Q4, Q14, Q16) is turned on. This can effectively lower the voltage driving the ultrasonic transmitter, so that the driving transformer (T1, T2, T3, T4) will not generate abnormal interference signals on the subsequent received waveform after transmitting the ultrasonic signal.

[0022] Figure 4A This is the circuit diagram of the amplifier unit. Since the received ultrasonic signal is a very weak high-frequency oscillation wave, only tens of millivolts and will decrease as the wind speed increases, this amplifier unit can amplify the signal to the required voltage. The amplified signal is as follows: Figure 4B shown.

[0023] The amplification unit includes an amplifier (U11A), the reverse input terminal of the amplifier is grounded through a resistor R15 and a capacitor C24, the positive input terminal of the amplifier is connected to the ultrasonic receiver, a resistor R11 is connected between the reverse input terminal and the output terminal of the amplifier, and a filter circuit is also connected to the positive input terminal of the amplifier. In the filter circuit, the capacitor C30 is connected in parallel with the resistor R19, and one end is grounded, and the other end is connected to the positive input terminal of the amplifier; the resistor R38 is connected in series with the capacitor C86, and one end is grounded, and the other end is connected to the positive input terminal of the amplifier.

[0024] See Figure 5A and Figure 5B The detection unit is mainly used to convert the amplified high-frequency ultrasonic signal into an ultrasonic envelope signal (such as Figure 5B This step effectively prevents the subsequent stage from comparing different peaks during threshold comparison, improving product accuracy. The detection unit primarily uses the BH4126FV RF detector chip. Its IFIN pin is connected to the output of the amplification unit, the DIS pin is grounded via resistor R13 and capacitors C31, C32, and C33, and the RSSI pin serves as the output. Its operating principle is to truncate the lower half of the AM signal or perform full-wave rectification, then filter out the high-frequency components through a low-pass filter to ultimately obtain the desired modulated signal, thus extracting the modulated signal from the high-frequency modulated signal.

[0025] In order to facilitate the comparison of the ultrasonic envelope signal output by the detection unit, the envelope signal needs to be converted into a rectangular wave signal through the waveform conversion unit. The circuit structure of the waveform conversion unit is as follows: Figure 6 As shown, it has a first comparator U11B and a second comparator U12, which are connected in series to form an amplification and comparison circuit. One end of the inverting input of the first comparator U11B is grounded through a resistor R77, and the other end is connected to the output of the first comparator U11B through a resistor R52. The positive input of the first comparator U11B is connected to the output of the detection unit through a capacitor C60; the output of the first comparator U11B is connected to the positive input of the second comparator U12, and the direction input of the second comparator U12 is connected to the PWM input signal through an RC filter network. The RC filter network includes a resistor R54 and a resistor R55 connected in series, one end of the capacitor C55 is connected to the resistor R54, and the other end is grounded, and one end of the capacitor C56 is connected to the resistor R55, and the other end is grounded.

[0026] Figure 7This is the circuit structure of the timing unit, which uses the high-precision time measurement chip MS1030. The timing unit measures the time between ultrasonic emission and reception of ultrasonic echo signals, thereby accurately calculating wind speed and direction. A first crystal oscillator Y3 is connected between the XIN and XOUT pins of the MS1030. This first crystal oscillator Y3 is connected in parallel with resistor R62, with both ends of resistor R62 connected to ground via capacitors C64 and C65, respectively. A second crystal oscillator Y2 is connected between the CLK32IN and CLK32OUT pins of the MS1030. This second crystal oscillator Y2 is connected in parallel with resistor R65, with both ends of resistor R65 connected to ground via capacitors C15 and C18, respectively. The MS1030 features high precision, high stability, and high efficiency. Its measurement accuracy reaches up to 15 ps, and its measurement range extends from 500 nsec to 4 msec at 4 MHz. Its internal comparator offset is programmable to ±127 mV, with an additional ±64 mV comparator bias voltage. It can measure up to eight echo pulses in one direction, and includes a built-in automatic measurement mode for both forward and reverse current. After measurement, the eight echo pulse values for both the forward and reverse current directions, as well as the sum of the eight echo pulses, are stored in separate result registers. This mode improves accuracy while significantly reducing power consumption. The timing unit circuitry operates by integrating a timer / counter to generate a time base. The timer / counter operates through a prescaler and a counter. The prescaler reduces the system clock frequency to the appropriate counter clock frequency, while the counter calculates elapsed time.

[0027] The present invention adds an anti-interference circuit in the driving unit, so that the driving transformer (T1, T2, T3, T4) will not generate abnormal interference signals to the subsequent receiving waveform after transmitting the ultrasonic signal; the high-frequency ultrasonic signal is effectively converted into an ultrasonic envelope signal through the amplification unit and the detection unit, which effectively avoids the situation where the subsequent stage compares different wave peaks when comparing the threshold values, thereby improving the product accuracy; the ultrasonic envelope signal is further converted into a square wave signal through the waveform conversion unit, and the time difference of the square wave signal can be effectively timed in conjunction with the high-precision timing unit, so that the wind speed and direction can be accurately calculated.

[0028] In the above description, many specific details are set forth in order to fully understand the present invention. However, the above description is only a preferred embodiment of the present invention. The present invention can be implemented in many other ways different from those described herein, so the present invention is not limited by the specific implementation disclosed above. At the same time, any person skilled in the art can use the above-disclosed methods and technical contents to make many possible changes and modifications to the present invention without departing from the scope of the present invention, or modify it into an equivalent embodiment of equivalent changes. Any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention without departing from the content of the present invention is still within the scope of protection of the present invention.

Claims

1. An ultrasonic transceiver circuit for measuring wind speed and direction, characterized in that: The ultrasonic transmitter comprises an ultrasonic transmitter and an ultrasonic receiver, wherein the ultrasonic transmitter is connected to a driving unit, and the driving unit drives the ultrasonic transmitter to emit an ultrasonic signal; the ultrasonic receiver is used to receive the ultrasonic signal emitted by the ultrasonic transmitter, and the ultrasonic receiver is connected to an amplifying unit, and the amplifying unit is used to amplify the received ultrasonic signal; the amplifying unit is connected to a detection unit, and the amplified ultrasonic signal is converted into an ultrasonic envelope signal through the detection unit; the detection unit is connected to a waveform conversion unit, and the ultrasonic envelope signal is converted into a square wave signal through the waveform conversion unit; the waveform conversion unit is connected to a timing unit, and the timing unit performs time measurement on the square wave signal. The wind speed and direction are calculated by measuring the wind speed and direction. The driving unit includes an analog switch circuit and a driving transformer connected to each other. The analog switch circuit has four PWM inputs and four PWM outputs, and the four PWM outputs are respectively connected to the driving transformers of the four ultrasonic transmitters. The input end of the driving transformer is respectively connected to an input resistor and an isolation diode, the input resistor is connected to the gate of a first MOS transistor, the drain of the first MOS transistor is connected to the primary side of the driving transformer, and the source of the first MOS transistor is grounded. The isolation diode is connected to the gate of a second MOS transistor, the drain of the second MOS transistor is respectively connected to an output capacitor and an output inductor, the output capacitor is connected to the secondary side of the driving transformer, and the source of the second MOS transistor is grounded.

2. The ultrasonic transceiver circuit according to claim 1, wherein: The amplifying unit includes an amplifier, the inverting input terminal of the amplifier is grounded via a resistor R15 and a capacitor C24, the positive input terminal of the amplifier is connected to the ultrasonic receiver, and a resistor R11 is connected between the inverting input terminal and the output terminal of the amplifier.

3. The ultrasonic transceiver circuit according to claim 2, wherein: A filter circuit is also connected to the positive input end of the amplifier. In the filter circuit, capacitor C30 and resistor R19 are connected in parallel, one end of which is grounded, and the other end is connected to the positive input end of the amplifier. Resistor R38 and capacitor C86 are connected in series, one end of which is grounded, and the other end is connected to the positive input end of the amplifier.

4. The ultrasonic transceiver circuit according to claim 1, wherein: The detection unit includes a BH4126FV chip, the IFIN pin of which is connected to the output of the amplification unit, the DIS pin is grounded through a resistor R13 and capacitors C31, C32, and C33, and the RSSI pin serves as an output pin.

5. The ultrasonic transceiver circuit according to claim 1, wherein: The waveform conversion unit includes a first comparator U11B and a second comparator U12, and the first comparator U11B and the second comparator U12 are connected in series to form an amplification and comparison circuit.

6. The ultrasonic transceiver circuit according to claim 5, characterized in that: One inverting input terminal of the first comparator U11B is grounded through a resistor R77, and the other is connected to the output of the first comparator U11B through a resistor R52. The positive input terminal of the first comparator U11B is connected to the output terminal of the detection unit through a capacitor C60.

7. The ultrasonic transceiver circuit according to claim 6, characterized in that: The output of the first comparator U11B is connected to the positive input terminal of the second comparator U12, and the direction input terminal of the second comparator U12 is connected to the PWM input signal through an RC filter network.

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