Interface conversion device and method of a propeller type wind sensor

Abstract

The application discloses an interface conversion device and method of a propeller type wind sensor, and the device comprises a filter circuit, a shaping circuit, a single-chip microcomputer, a signal conditioning circuit, a power supply unit and a relay; the single-chip microcomputer comprises a CPU, a program memory, a data memory, an interrupt system, an I / O port, a clock circuit, a timing / counter, a D / A converter, an SPI bus and a serial port, and the single-chip microcomputer is used for processing the filtered wind speed signal or the shaped wind direction signal; the signal conditioning circuit comprises a pulse signal conditioning circuit, a voltage signal conditioning circuit, a current signal conditioning circuit and a digital signal conditioning circuit, and is used for outputting the pulse signal, the voltage signal, the current signal or the digital signal after conditioning. The device and the method disclosed by the application can convert the output signal type into an existing general signal type, facilitate the compatibility of the wind sensor and a processing system, facilitate signal processing, and improve work efficiency.

Description

Technical Field

[0001] This invention relates to the field of wind sensors, and in particular to an interface conversion device and method for a propeller-type wind sensor. Background Technology

[0002] Wind sensors are widely used in ships, ocean buoys, weather stations, and oceanographic stations. The wind speed and direction information they provide plays a crucial role in safe navigation, typhoon and storm protection, and emergency rescue.

[0003] Existing wind sensors come in a variety of types and have different wind measurement principles. Some use electromagnetic induction to measure wind speed and contact potentiometers to measure wind direction; others use photoelectric switches to measure wind speed and non-contact photoelectric conversion devices to measure wind direction and azimuth. Therefore, their output signal types are also different. Wind speed signals have frequency output types, as well as current and RS485 output types, while wind direction signals mainly have voltage, current, and RS485 output types.

[0004] The propeller-type anemometer is a high-performance anemometer designed for marine environments. It employs a photoelectric switch principle, effectively improving anti-interference capabilities and electromagnetic compatibility. Using a non-contact photoelectric conversion device to measure azimuth angles avoids contact wear and measurement blind spots, contributing to extended service life. Furthermore, it boasts stronger anti-electromagnetic interference capabilities, making it a more ideal marine anemometer. The propeller-type anemometer senses wind speed through a propeller, and its working principle differs significantly from other existing anemometers. The propeller's rotational speed is converted into an electrical signal via a photoelectric switch, outputting a positive pulse signal proportional to the wind speed; wind direction is represented by a Gray code output through the photoelectric conversion device. Therefore, its output signal type differs from other existing anemometers, and current general-purpose processing systems cannot directly match it during post-processing. Thus, an interface conversion device needs to be designed to convert the wind speed and direction signals from the propeller-type anemometer into a commonly used signal type. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides an interface conversion device and method for a propeller-type wind sensor, which can convert the output signal type into an existing universal signal type, facilitating compatibility between the wind sensor and the processing system, simplifying signal processing, and improving work efficiency.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] An interface conversion device for a propeller-type wind sensor includes a filter circuit, a shaping circuit, a microcontroller, a signal conditioning circuit, a power supply unit, and a relay.

[0008] The filtering circuit and shaping circuit are used to filter and shape the received wind speed pulse signal and wind direction signal respectively before sending them to the microcontroller.

[0009] The microcontroller includes a CPU, program memory, data memory, interrupt system, I / O ports, clock circuit, timer / counter, D / A converter, SPI bus, and serial port. The microcontroller is used to process the filtered wind speed signal or the shaped wind direction signal and convert it into a pulse signal, voltage signal, current signal, or digital signal. The microcontroller controls the power supply unit to power on or off the signal conditioning circuit through a relay, thereby enabling the selection of the output form of the wind speed and wind direction signals.

[0010] The signal conditioning circuit includes a pulse signal conditioning circuit, a voltage signal conditioning circuit, a current signal conditioning circuit, and a digital signal conditioning circuit, used to condition and output pulse signals, voltage signals, current signals, or digital signals.

[0011] In the above scheme, the pulse signal conditioning circuit includes a three-stage operational amplifier circuit and a DC / DC converter. The three-stage operational amplifier circuit is used to adjust the polarity of the signal, and the DC / DC converter is used to provide positive and negative power supplies to power the three-stage operational amplifier circuit.

[0012] In the above scheme, the voltage signal conditioning circuit includes a voltage follower and a precision reference voltage source connected to the microcontroller's D / A converter. The voltage follower is used to isolate the influence of the external sampling circuit on the sensor's internal circuit, ensure the lossless output of the wind direction voltage signal, and reduce the measurement error of the external sampling circuit. The precision reference voltage source is used to provide a reference voltage.

[0013] In the above scheme, the current signal conditioning circuit includes an optocoupler and a current transmitter. The optocoupler is used to isolate the communication between the microcontroller and the current transmitter to ensure reliable signal transmission. The current transmitter is powered by a current loop and is used to input the digital signal of the microcontroller in a serial manner and convert it into a 4-20mA current output.

[0014] In the above scheme, the digital signal conditioning circuit includes an RS485 interface chip, a CAN controller, and a CAN transceiver. The RS485 interface chip is used to convert the TTL level of the microcontroller to the RS-485 level. The CAN controller is used to receive instruction data from the microcontroller and then send it to the CAN transceiver. It is also used to receive data from the CAN transceiver, parse it, and then send it to the microcontroller. The CAN transceiver is used to connect the CAN controller to the CAN bus and convert the logic level output by the CAN controller into a differential signal and output it to the CAN bus.

[0015] An interface conversion method for a propeller-type wind sensor, employing the aforementioned conversion device, includes a pulse signal conditioning method, a voltage signal conditioning method, a current signal conditioning method, and a digital signal conditioning method. The pulse signal conditioning method comprises the following steps: the wind speed pulse signal is filtered by a filter circuit and then enters a microcontroller. An external interrupt service routine is introduced by the microcontroller's interrupt system. The external interrupt service routine performs frequency conversion according to a set conversion method, controlling the microcontroller's I / O port to output a pulse signal of the corresponding frequency. Then, the positive pulse sequence is converted into a negative pulse sequence by an inverting proportional operational amplifier circuit built from a first-stage operational amplifier circuit. The signal is then voltage-shifted by an inverting summation operational amplifier circuit built from a second-stage operational amplifier circuit, adjusting it into an alternating positive and negative pulse signal. Finally, the wind speed frequency pulse signal is output by a voltage follower built from a third-stage operational amplifier circuit.

[0016] Specifically, the frequency conversion method is as follows:

[0017] Under the same wind conditions, the wind speed is denoted as v (m / s), the rotational speed of the propeller-type anemometer shaft is denoted as n (r / s), the number of pulses output per revolution is denoted as p, and the rotational speed of the target anemometer shaft is denoted as n0. ′ The unit is r / s, and the number of pulses output per revolution is denoted as p. ′ Let F1 and F2 be the number of pulses per second added by the propeller-type anemometer and the target anemometer to be converted, respectively, for every 1 m / s increase in wind speed. Then we have:

[0018] F1=n×p÷v

[0019] F2=n ′ ×p ′ ÷v

[0020] Simplify the fractions F1 / F2 to obtain the simplest fraction:

[0021]

[0022] Where f1 and f2 are positive integers after removing their common divisors;

[0023] The above formula is used to achieve frequency conversion between wind sensors with different rotational speeds and different numbers of output pulses per unit time. The following is an explanation of different cases:

[0024] ① When f1 = f2, for every input pulse signal, one pulse signal is output synchronously;

[0025] ② When f1 > f2, take the integer part of the quotient obtained by f1 / f2 and denote it as N. N is a natural number greater than 1. Whenever the external interrupt receives N pulse signals, output 1 pulse signal at the microcontroller I / O port. Such a process is called process A, and assume this process needs to be repeated x times; whenever the external interrupt receives N + 1 pulse signals, output 1 pulse signal at the microcontroller I / O port. Such a process is called process B, and assume this process needs to be repeated y times; then x and y satisfy the system of equations (1):

[0026]

[0027] By solving the above system of equations, obtain the values of x and y;

[0028] At this time, the frequency conversion method is as follows: Define a counting variable, start counting the external pulses from zero, and for each received external pulse, increment the counting variable by 1. According to the conditions, perform process A or process B. Whenever process A is completed x times and process B needs to be completed y times, the value of the counting variable is f1 at this time; then clear the counting variable and start counting again, repeating the above processing process and continuing in this way;

[0029] ③ When f1 < f2, take the integer part of the quotient obtained by f2 / f1 and denote it as N ′ , N ′ is a natural number greater than 1. Whenever the external interrupt receives 1 pulse signal, output N ′ pulse signals at the microcontroller I / O port. Such a process is called process A, and assume this process needs to be repeated x times; whenever the external interrupt receives 1 pulse signal, output N ′ +1 pulse signals at the microcontroller I / O port. Such a process is called process B, and assume this process needs to be repeated y times; then x and y satisfy the system of equations (2):

[0030]

[0031] By solving the above system of equations, obtain the values of x and y;

[0032] At this time, the frequency conversion method is as follows: Define a counting variable, start counting the external pulses from zero, and for each received external pulse, increment the counting variable by 1. According to the conditions, perform process A or process B. Whenever process A is completed x times and process B needs to be completed y times, the value of the counting variable is f1 at this time; then clear the counting variable and start counting again, repeating the above processing process and continuing in this way.

[0033] Furthermore, the voltage signal conditioning method includes the following process: after the wind direction signal is shaped by the shaping circuit, it is input from the I / O port of the microcontroller. The microcontroller converts it into the corresponding wind direction angle through the CPU, and then converts it into the corresponding digital quantity according to the linear proportional relationship, and drives the D / A converter to output the corresponding analog voltage. After passing through the voltage follower, the wind direction voltage signal is output to the outside.

[0034] Furthermore, the current signal conditioning method includes the following process: the wind speed signal is filtered by a filtering circuit and then enters the microcontroller. The microcontroller's CPU converts the wind speed pulse signal into a wind speed value through a counter, and then converts it into a digital wind speed value corresponding to the current transmitter according to a linear proportional relationship. The wind direction signal is shaped by a shaping circuit and then input from the microcontroller's I / O port. The microcontroller converts it into a corresponding wind direction angle through the CPU, and then converts it into a digital wind direction value corresponding to the current transmitter according to a linear proportional relationship. The digital wind speed value and the digital wind direction value drive the current transmitter to output the corresponding current signal through the microcontroller's SPI bus and optocoupler, respectively.

[0035] Furthermore, the digital signal conditioning method includes the following processes:

[0036] The wind speed signal is filtered by the filtering circuit and then enters the microcontroller. The microcontroller's CPU converts the wind speed pulse signal into a wind speed value through a counter. The wind direction signal is shaped by the shaping circuit and then input from the microcontroller's I / O port. The microcontroller converts it into the corresponding wind direction angle through the CPU, and then converts it into the corresponding serial port instruction data according to the serial communication protocol, or into the corresponding CAN instruction data according to the CAN communication protocol.

[0037] Serial port command data is output to the RS485 interface chip via the microcontroller's serial port, outputting signals conforming to the RS485 serial communication standard; CAN command data is output to the CAN controller and CAN transceiver via the microcontroller's SPI bus, ultimately outputting signals conforming to the CAN bus standard.

[0038] Through the above technical solution, the interface conversion device and method for the propeller-type wind sensor provided by the present invention have the following characteristics:

[0039] Beneficial effects:

[0040] The interface conversion device of this invention can convert the wind speed pulse signal output by the propeller-type anemometer into frequency pulse signal, current, digital and other output forms as needed, and convert the output wind direction signal into voltage, current, digital and other output forms as needed. This invention realizes real-time dynamic conversion and output of wind speed and wind direction signals of the propeller-type anemometer within the same time period through a quantitative corresponding conversion method combined with hardware interrupt response. It can adapt to the interface requirements of shipborne meteorological equipment, marine buoys, weather stations, etc., and the installation and disassembly methods are simple. Therefore, it has broad prospects for promotion and application. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0042] Figure 1 This is a schematic diagram of an interface conversion device for a propeller-type wind sensor disclosed in an embodiment of the present invention;

[0043] Figure 2 This is a schematic diagram of the pulse signal conditioning process;

[0044] Figure 3 Here is the flowchart for the interrupt service routine;

[0045] Figure 4 This is a schematic diagram of the voltage signal conditioning process;

[0046] Figure 5 This is a schematic diagram of the current signal conditioning process;

[0047] Figure 6 This is a schematic diagram of the digital signal conditioning process. Detailed Implementation

[0048] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0049] This invention provides an interface conversion device for a propeller-type wind sensor, such as... Figure 1 As shown, it includes a filter circuit, a shaping circuit, a microcontroller, a signal conditioning circuit, a power supply unit, and a relay.

[0050] The filtering and shaping circuits are used to filter and shape the received wind speed pulse signal and wind direction signal respectively before sending them to the microcontroller.

[0051] A microcontroller includes a CPU, program memory, data memory, interrupt system, I / O ports, clock circuit, timer / counter, D / A converter, SPI bus, and serial port. The microcontroller is used to process the filtered wind speed signal or the shaped wind direction signal and convert it into a pulse signal, voltage signal, current signal, or digital signal. The microcontroller controls the power supply unit through a relay to power or de-power the signal conditioning circuit, thereby enabling the selection of the output form of the wind speed and wind direction signals.

[0052] Signal conditioning circuits include pulse signal conditioning circuits, voltage signal conditioning circuits, current signal conditioning circuits, and digital signal conditioning circuits, used to condition pulse signals, voltage signals, current signals, or digital signals before outputting them.

[0053] Specifically, the pulse signal conditioning circuit includes a three-stage operational amplifier circuit and a DC / DC converter. The three-stage operational amplifier circuit is used to adjust the polarity of the signal, and the DC / DC converter is used to provide positive and negative power supplies to power the three-stage operational amplifier circuit.

[0054] The voltage signal conditioning circuit includes a voltage follower connected to the microcontroller's D / A converter and a precision reference voltage source. The voltage follower is used to isolate the influence of the external sampling circuit on the sensor's internal circuitry, ensuring lossless output of the wind direction voltage signal and reducing the measurement error of the external sampling circuit. The precision reference voltage source is used to provide a reference voltage.

[0055] The current signal conditioning circuit includes an optocoupler and a current transmitter. The optocoupler is used to isolate the communication between the microcontroller and the current transmitter to ensure reliable signal transmission. The current transmitter is powered by a current loop and is used to input the digital signal from the microcontroller in a serial manner and convert it into a 4-20mA current output.

[0056] The digital signal conditioning circuit includes an RS485 interface chip, a CAN controller, and a CAN transceiver. The RS485 interface chip is used to convert the TTL level of the microcontroller to the RS-485 level. The CAN controller is used to receive instruction data from the microcontroller and then send it to the CAN transceiver. It is also used to receive data from the CAN transceiver, parse it, and then send it to the microcontroller. The CAN transceiver is used to connect the CAN controller to the CAN bus and convert the logic level output by the CAN controller into a differential signal output to the CAN bus.

[0057] An interface conversion method for a propeller-type wind sensor, employing the aforementioned conversion device, includes a pulse signal conditioning method, a voltage signal conditioning method, a current signal conditioning method, and a digital signal conditioning method.

[0058] Specifically, such as Figure 2As shown, the pulse signal conditioning method includes the following process: After the wind speed pulse signal is filtered by a filtering circuit, it enters the microcontroller. An external interrupt service routine is introduced by the microcontroller's interrupt system. The external interrupt service routine performs frequency conversion according to a set conversion method, controlling the microcontroller's I / O port to output a pulse signal of the corresponding frequency. Then, the positive pulse sequence is converted into a negative pulse sequence by an inverting proportional operational amplifier circuit built from the first-stage operational amplifier circuit. Next, the voltage is shifted by an inverting summation operational amplifier circuit built from the second-stage operational amplifier circuit, adjusting it into an alternating positive and negative pulse signal. Finally, the wind speed frequency pulse signal is output by a voltage follower circuit built from the third-stage operational amplifier circuit. The conditioned output signal supports zero-crossing detection and can achieve compatible replacement for the alternating positive and negative electrical signals generated by existing wind speed sensors.

[0059] The specific frequency conversion method is as follows:

[0060] For propeller-type sensors, the greater the wind speed, the faster the wind speed shaft rotates. That is, the rotation speed of the wind speed shaft is directly proportional to the wind speed. For the same type of sensor, the number of pulses output per revolution is also fixed. Therefore, the number of pulses output by the sensor is directly proportional to the wind speed.

[0061] Under the same wind conditions (wind speed denoted as v, unit m / s), the rotational speed of the propeller-type anemometer's shaft is denoted as n (unit r / s, representing revolutions per second), the number of pulses output per revolution is denoted as p, and the rotational speed of the target anemometer's shaft is denoted as n0. ′ (Unit: r / s), the number of pulses output per revolution is denoted as p. ′ Let F1 and F2 be the number of pulses per second added by the propeller-type anemometer and the target anemometer, respectively, for every 1 m / s increase in wind speed. Then:

[0062] F1=n×p÷v

[0063] F2=n ′ ×p ′ ÷v

[0064] Where, rotational speed n and n ′ The number of pulses p and p ′ The answer can be found or calculated from the wind tunnel test report or technical manual of the wind sensor.

[0065] Simplify the fractions F1 / F2 to obtain the simplest fraction:

[0066]

[0067] Where f1 and f2 are positive integers after removing their common divisors;

[0068] The frequency conversion between wind speed sensors with different rotational speeds and different output pulse numbers per unit time can be achieved through the above formula, which will be described in different cases below:

[0069] ① When f1 = f2, every time 1 pulse signal is input, 1 pulse signal is synchronously output;

[0070] ② When f1 > f2, the quotient obtained by f1 / f2 is rounded down and denoted as N, where N is a natural number greater than 1. Every time N pulse signals are received by an external interrupt, 1 pulse signal is output at the I / O port of the single-chip microcomputer. Such a process is called process A, and it is assumed that this process needs to be repeated x times; every time N + 1 pulse signals are received by an external interrupt, 1 pulse signal is output at the I / O port of the single-chip microcomputer. Such a process is called process B, and it is assumed that this process needs to be repeated y times; then x and y satisfy the system of equations (1):

[0071]

[0072] In the above system of equations, all quantities except x and y are known. Therefore, by solving this system of linear equations with two variables, the values of x and y can be obtained;

[0073] At this time, the method of frequency conversion is as follows: Define a counting variable, start counting the external pulses from zero, and add 1 to the counting variable every time an external pulse is received. According to the conditions, perform process A or process B. Every time process A is completed x times and process B needs to be completed y times, the value of the counting variable is f1 at this time; then the counting variable is cleared and starts counting again, repeating the above processing process, and so on continuously. It should be noted that it is not necessary to wait until process A is completed x times before starting process B. Process A and process B can also be interspersed, but it is necessary to ensure that when the total number of times process A is completed is x and the total number of times process B is completed is y, then enter the next pulse number counting process.

[0074] ③ When f1 < f2, the quotient obtained by f2 / f1 is rounded down and denoted as N ′ , N ′ is a natural number greater than 1. Every time 1 pulse signal is received by an external interrupt, N ′ pulse signals are output at the I / O port of the single-chip microcomputer. Such a process is called process A, and it is assumed that this process needs to be repeated x times; every time 1 pulse signal is received by an external interrupt, N ′ + 1 pulse signals are output at the I / O port of the single-chip microcomputer. Such a process is called process B, and it is assumed that this process needs to be repeated y times; then x and y satisfy the system of equations (2):

[0075]

[0076] In the above system of equations, all quantities except x and y are known. Therefore, by solving this system of two linear equations, the values ​​of x and y can be obtained.

[0077] At this point, the frequency conversion process is similar to that when f1>f2, that is: define a counter variable, start counting external pulses from zero, increment the counter variable by 1 for each external pulse received, and perform either process A or process B according to the conditions. Whenever process A is completed x times, process B needs to be completed y times. At this time, the counter variable value is f1; then the counter variable is cleared to zero and the counting starts again. Repeat the above process, and so on.

[0078] The following explanation uses F1 / F2 = 8 / 3 as an example. At this time, f1 = 8, f2 = 3, f1 > f2. Rounding 8 / 3 gives N = 2. Substituting this into the system of equations (1), we can obtain...

[0079]

[0080] Solving the system of equations, we get x = 1 and y = 2.

[0081] The corresponding process A is: whenever an external interrupt receives N=2 pulse signals, the microcontroller outputs 1 pulse signal at the I / O port, and this process needs to be completed x=1 times; the corresponding process B is: whenever an external interrupt receives (N+1)=3 pulse signals, the microcontroller outputs 1 pulse signal at the I / O port, and this process needs to be completed y=2 times.

[0082] After the main program initializes, external interrupts are enabled, and then an infinite loop is entered. When an external pulse is triggered, the interrupt service routine immediately responds and completes the frequency conversion task, thus exhibiting good tracking and real-time performance. Here, one I / O port of the microcontroller is set to external interrupt mode, triggered by a rising edge, and a single high-low level change is equivalent to outputting a pulse signal. The designed external interrupt service routine flow is as follows: Figure 3 As shown, the program flow is as follows: The counter variable starts counting from zero. When the first external pulse is received, the output is set low; when the second external pulse is received, the output is set high, thus completing process A for the first time. When the third external pulse is received, the output is set low; when the fourth external pulse is received, the output remains low; when the fifth external pulse is received, the output is set high, thus completing process B for the first time. When the sixth external pulse is received, the output is set low; when the seventh external pulse is received, the output remains low; when the eighth external pulse is received, the output is set high, thus completing process B for the second time. At this point, process A has been completed x = 1 time, and process B has been completed y = 2 times, so the value of the counter variable is f1 = 8. Then the counter variable is reset to zero and the counting starts again, repeating the above process, and so on, continuing in this manner.

[0083] like Figure 4As shown, the voltage signal conditioning method includes the following process: The wind direction signal in Gray code form is shaped by a shaping circuit and then input from the microcontroller's I / O port. The microcontroller converts it into the corresponding wind direction angle through the CPU, then converts it into a corresponding digital quantity according to a linear proportional relationship, and drives the D / A converter to output the corresponding analog voltage. After passing through a voltage follower, the wind direction voltage signal is output externally. Because the voltage follower has the characteristics of high input impedance and low output impedance, it can effectively isolate the influence of the external sampling circuit on the internal circuit of the sensor, ensure the lossless output of the wind direction voltage signal, and reduce the measurement error of the external sampling circuit.

[0084] like Figure 5 As shown, the current signal conditioning method includes the following process: the wind speed signal is filtered by the filtering circuit and then enters the microcontroller. The microcontroller's CPU converts the wind speed pulse signal into a wind speed value through a counter, and then converts it into a digital wind speed value corresponding to the current transmitter according to a linear proportional relationship. The wind direction signal is shaped by the shaping circuit and then input from the microcontroller's I / O port. The microcontroller converts it into a corresponding wind direction angle through the CPU, and then converts it into a digital wind direction value corresponding to the current transmitter according to a linear proportional relationship. The digital wind speed value and the digital wind direction value drive the current transmitter to output the corresponding current signal through the microcontroller's SPI bus and optocoupler, respectively.

[0085] like Figure 6 As shown, the digital signal conditioning method includes the following process:

[0086] The wind speed signal is filtered by the filtering circuit and then enters the microcontroller. The microcontroller's CPU converts the wind speed pulse signal into a wind speed value through a counter. The wind direction signal is shaped by the shaping circuit and then input from the microcontroller's I / O port. The microcontroller converts it into the corresponding wind direction angle through the CPU, and then converts it into the corresponding serial port instruction data according to the serial communication protocol, or into the corresponding CAN instruction data according to the CAN communication protocol.

[0087] Serial port command data is output to the RS485 interface chip via the microcontroller's serial port, outputting signals conforming to the RS485 serial communication standard; CAN command data is output to the CAN controller and CAN transceiver via the microcontroller's SPI bus, ultimately outputting signals conforming to the CAN bus standard.

[0088] Therefore, the aforementioned interface conversion device can convert the wind speed and wind direction signals output by the propeller-type wind sensor into various forms of signals as needed, adapting to the interface requirements of shipborne meteorological equipment, marine buoys, weather stations, etc.

[0089] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An interface conversion method for a propeller-type wind sensor, characterized in that, This includes pulse signal conditioning methods, voltage signal conditioning methods, current signal conditioning methods, and digital signal conditioning methods. The pulse signal conditioning method includes the following process: the wind speed signal is filtered by a filtering circuit and then enters the microcontroller. An external interrupt service routine is introduced by the microcontroller's interrupt system. The external interrupt service routine performs frequency conversion according to a set conversion method, controlling the microcontroller's I / O ports to output pulse signals of the corresponding frequency. Then, the signal is converted from a positive pulse sequence to a negative pulse sequence by an inverting proportional operational amplifier circuit built from a first-stage operational amplifier circuit. Next, the voltage is shifted by an inverting summation operational amplifier circuit built from a second-stage operational amplifier circuit, adjusting it into an alternating positive and negative pulse signal. Finally, the wind speed frequency pulse signal is output by a voltage follower circuit built from a third-stage operational amplifier circuit. The specific frequency conversion method is as follows: Under the same wind conditions, the wind speed is denoted as . ,unit The rotational speed of the wind speed axis of the propeller-type anemometer is denoted as... ,unit The number of pulses output per revolution is denoted as . The rotational speed of the wind speed axis of the target anemometer sensor to be converted is denoted as... ,unit The number of pulses output per revolution is denoted as . Assuming that for every 1 m / s increase in wind speed, the number of pulses per second added by the propeller-type anemometer and the target anemometer to be converted are respectively... and Then we have: ； ； bisection After simplification, we obtain the simplest fraction: ； in, , It is a positive integer after removing its common divisors; The above formula is used to achieve frequency conversion between wind sensors with different rotational speeds and different numbers of output pulses per unit time. The following is an explanation of different cases: ①When When a pulse signal is input, a pulse signal is output synchronously. ②When At that time, The quotient, rounded down, is denoted as N, where N is a natural number greater than 1. Whenever an external interrupt receives N pulse signals, the microcontroller outputs one pulse signal through its I / O port. This process is called process A. Assume this process needs to be repeated. Every time an external interrupt receives N+1 pulse signals, that is, when the microcontroller outputs 1 pulse signal at the I / O port, this process is called process B. Let this process need to be repeated y times; then x and y satisfy the system of equations (1): （1）； By solving the above system of equations, we can obtain the values ​​of x and y; At this point, the frequency conversion method is as follows: Define a counter variable to count external pulses starting from zero. For each received external pulse, the counter variable is incremented by 1. Process A or process B is performed based on conditions. Whenever process A completes x times, process B needs to complete y times. At this time, the counter variable value is... Then the counter variable is cleared to zero and the counting starts again. The above process is repeated, and so on. ③When At that time, The quotient, after being rounded down, is denoted as , For each natural number greater than 1, the microcontroller outputs a pulse signal whenever an external interrupt is received. A process is called process A, where each pulse signal is received by an external interrupt. Let x be the number of pulse signals that need to be repeated. Each time an external interrupt receives a pulse signal, it is output at the microcontroller's I / O port. +1 pulse signal, such a process is called process B, let such a process need to be repeated y times; then x and y satisfy the system of equations (2): （2）； By solving the above system of equations, we can obtain the values ​​of x and y; At this point, the frequency conversion method is as follows: Define a counter variable to count external pulses starting from zero. For each received external pulse, the counter variable is incremented by 1. Process A or process B is performed based on conditions. Whenever process A completes x times, process B needs to complete y times. At this time, the counter variable value is... Then the counter variable is cleared to zero and the counting starts again. The above process is repeated, and so on, until the process continues.

2. The conversion method according to claim 1, characterized in that, The voltage signal conditioning method includes the following process: after the wind direction signal is shaped by the shaping circuit, it is input from the I / O port of the microcontroller. The microcontroller converts it into the corresponding wind direction angle through the CPU, and then converts it into the corresponding digital quantity according to the linear proportional relationship, and drives the D / A converter to output the corresponding analog voltage. After passing through the voltage follower, the wind direction voltage signal is output to the outside.

3. The conversion method according to claim 1, characterized in that, The current signal conditioning method includes the following process: the wind speed signal is filtered by a filtering circuit and then enters the microcontroller. The microcontroller's CPU converts the wind speed signal into a wind speed value through a counter, and then converts it into a digital wind speed value corresponding to the current transmitter according to a linear proportional relationship. The wind direction signal is shaped by a shaping circuit and then input from the microcontroller's I / O port. The microcontroller converts it into a corresponding wind direction angle through the CPU, and then converts it into a digital wind direction value corresponding to the current transmitter according to a linear proportional relationship. The digital wind speed value and the digital wind direction value drive the current transmitter to output the corresponding current signal through the microcontroller's SPI bus and optocoupler, respectively.

4. The conversion method according to claim 1, characterized in that, The digital signal conditioning method includes the following process: the wind speed signal is filtered by the filtering circuit and then enters the microcontroller. The CPU of the microcontroller converts the wind speed signal into a wind speed value through a counter. The wind direction signal is shaped by the shaping circuit and then input from the I / O port of the microcontroller. The microcontroller converts it into the corresponding wind direction angle through the CPU, and then converts it into the corresponding serial port instruction data according to the serial communication protocol, or into the corresponding CAN instruction data according to the CAN communication protocol. Serial port command data is output to the RS485 interface chip via the microcontroller's serial port, outputting signals conforming to the RS485 serial communication standard; CAN command data is output to the CAN controller and CAN transceiver via the microcontroller's SPI bus, ultimately outputting signals conforming to the CAN bus standard.

5. An interface conversion device for a propeller-type wind sensor, employing the method described in claim 1, characterized in that, It includes filter circuits, shaping circuits, microcontrollers, signal conditioning circuits, power supply units, and relays; The filtering circuit and shaping circuit are used to filter and shape the received wind speed and wind direction signals respectively before sending them to the microcontroller. The microcontroller includes a CPU, program memory, data memory, interrupt system, I / O ports, clock circuit, timer / counter, D / A converter, SPI bus, and serial port. The microcontroller is used to process the filtered wind speed signal or the shaped wind direction signal and convert it into a pulse signal, voltage signal, current signal, or digital signal. The microcontroller controls the power supply unit to power on or off the signal conditioning circuit through a relay, thereby enabling the selection of the output form of the wind speed and wind direction signals. The signal conditioning circuit includes a pulse signal conditioning circuit, a voltage signal conditioning circuit, a current signal conditioning circuit, and a digital signal conditioning circuit, used to condition and output pulse signals, voltage signals, current signals, or digital signals.

6. The interface conversion device for a propeller-type wind sensor according to claim 5, characterized in that, The pulse signal conditioning circuit includes a three-stage operational amplifier circuit and a DC / DC converter. The three-stage operational amplifier circuit is used to adjust the polarity of the signal, and the DC / DC converter is used to provide positive and negative power supplies to power the three-stage operational amplifier circuit.

7. The interface conversion device for a propeller-type wind sensor according to claim 5, characterized in that, The voltage signal conditioning circuit includes a voltage follower connected to the microcontroller's D / A converter and a precision reference voltage source. The voltage follower is used to isolate the influence of the external sampling circuit on the sensor's internal circuitry, ensure lossless output of the wind direction voltage signal, and reduce the measurement error of the external sampling circuit. The precision reference voltage source is used to provide a reference voltage.

8. The interface conversion device for a propeller-type wind sensor according to claim 5, characterized in that, The current signal conditioning circuit includes an optocoupler and a current transmitter. The optocoupler is used to isolate the communication between the microcontroller and the current transmitter to ensure reliable signal transmission. The current transmitter is powered by a current loop and is used to input the digital signal from the microcontroller in a serial manner and convert it into a 4-20mA current output.

9. The interface conversion device for a propeller-type wind sensor according to claim 5, characterized in that, The digital signal conditioning circuit includes an RS485 interface chip, a CAN controller, and a CAN transceiver. The RS485 interface chip is used to convert the TTL level of the microcontroller to the RS-485 level. The CAN controller is used to receive instruction data from the microcontroller and then send it to the CAN transceiver. It is also used to receive data from the CAN transceiver, parse it, and then send it to the microcontroller. The CAN transceiver is used to connect the CAN controller to the CAN bus and convert the logic level output by the CAN controller into a differential signal and output it to the CAN bus.

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