Control system applied to Doppler velocity measurement system

Abstract

The invention provides a control system applied to a Doppler velocity measurement system, which is convenient for use of a product. Comprising a receiving board, a transmitting board, a control board and a signal processing board which are connected in sequence. The receiving plate comprises an isolation transformer, a front-end amplification circuit, a high-frequency band-pass filter circuit, a frequency mixing circuit, a low-pass filter circuit, a phase shift circuit, a signal operation circuit and a gain control circuit; wherein the isolation transformer determines output current according to a conductance value of the transducer and determines inductance of the transformer according to a susceptance value of the transducer; a primary winding of the isolation transformer is connected with the transducer to form a single path, one path of a secondary winding is connected to the receiving circuit, and the other path of the secondary winding is connected to the transmitting circuit.

Description

Technical Field

[0001] The invention belongs to the field of Doppler speed measurement, and in particular relates to a control system applied to a Doppler speed measurement system. Background Art

[0002] Doppler velocity measurement system (DVL) is widely used in ships. Its main function is to measure the ship's sailing speed. Its circuit composition mainly includes a transmitting board, an isolation board, a receiving board and a main control board.

[0003] Among them, the transmitting board is used to transmit sound wave signals, the isolation board is used to isolate the signals of the receiving board and the transmitting board, the receiving board receives the signal returned by the sound wave, and the main control board calculates the sailing speed of the ship.

[0004] The existing Doppler velocity measurement system is relatively large in size and is not suitable for small equipment. The present invention is small in size and light in weight and is suitable for places where the system accuracy requirement is not high and the space is limited. Summary of the invention

[0005] The invention provides a control system applied to a Doppler speed measurement system, which facilitates the use of the product.

[0006] The present invention is achieved through the following technical solutions.

[0007] A control system applied to a Doppler speed measurement system, characterized in that it comprises: a receiving board, a transmitting board, a control board and a signal processing board, wherein the receiving board, the transmitting board, the control board and the signal processing board are connected in sequence.

[0008] The receiving board includes an isolation transformer, a front-end amplifier circuit, a high-frequency bandpass filter circuit, a mixing circuit, a low-pass filter circuit, a phase shift circuit, a signal operation circuit, and a gain control circuit; wherein:

[0009] The isolation transformer determines the output current according to the conductance value of the transducer, and determines the inductance of the transformer according to the susceptance value of the transducer; the primary winding of the isolation transformer is connected to the transducer in a single path, one path of the secondary winding is connected to the receiving circuit, and the other path is connected to the transmitting circuit;

[0010] The front-end amplifier circuit converts the received signal into a signal amplitude range that satisfies the requirements of the receiving circuit for processing the signal;

[0011] The high-frequency bandpass filter circuit is used to filter out high-frequency noise and DC signals in the signal to obtain a signal whose center frequency is the transmitter frequency;

[0012] The mixing circuit is used to reduce the sampling rate of the signal;

[0013] The low-pass filter circuit is a processing circuit after mixing, which is used to filter out the high-frequency signal after mixing to obtain an effective low-frequency signal;

[0014] The phase shift circuit generates three signals from the received low-frequency signal, namely the original signal, the positive 45° signal and the negative 45° signal, and then enters the signal operation circuit;

[0015] The signal operation circuit is used to operate on four signal channels, wherein the four signals are front, rear, left and right signals respectively;

[0016] The gain signal of the gain control circuit is provided by the control board and the signal processing board circuit, and is converted by the DA chip to obtain a gain analog signal, so that the amplitudes of the four-channel waveforms remain consistent.

[0017] Beneficial effects of the present invention:

[0018] 1. The present invention combines the isolation circuit with the receiving circuit so that the transmission and reception do not conflict with each other. At the same time, a mixing circuit is added to complete the downsampling in hardware.

[0019] 2. The receiving circuit is shielded and isolated from other circuit boards;

[0020] 3. Combine the isolation circuit with the receiving circuit and use a transformer. The primary winding of the transformer is a dual-channel signal, one for the output signal of the transmitting circuit and the other for the input signal of the receiving circuit. The secondary winding is a single-channel signal, and the transmitting and receiving share the same set of coil windings.

[0021] 4. The received input signal passes through the front-end amplifier circuit, bandpass filter circuit, mixer circuit, low-pass filter circuit, phase shift circuit and gain control circuit in sequence, and finally the collected signal is output to the control board. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A control system composition diagram for a Doppler speed measurement system according to the present invention;

[0023] Figure 2 It is a block diagram of the receiving board of the present invention;

[0024] Figure 3 It is a working schematic diagram of the control panel of the present invention. DETAILED DESCRIPTION

[0025] The exemplary embodiments of the present invention are described in detail below with reference to the accompanying drawings. It should be understood that the embodiments shown and described in the accompanying drawings are only exemplary and are intended to illustrate the principles and spirit of the present invention, rather than to limit the scope of the present invention.

[0026] like Figure 1As shown, a control system applied to a Doppler speed measurement system of the present invention specifically comprises: a receiving board, a transmitting board, a control board and a signal processing board, wherein the receiving board, the transmitting board, the control board and the signal processing board are connected in sequence.

[0027] like Figure 2 As shown, the receiving board includes an isolation transformer, a front-end amplifier circuit, a high-frequency bandpass filter circuit, a mixing circuit, a low-pass filter circuit, a phase shift circuit, a signal operation circuit, and a gain control circuit; wherein:

[0028] The isolation transformer determines the output current according to the conductance value of the transducer, and determines the inductance of the transformer according to the susceptance value of the transducer; the primary winding of the isolation transformer is connected to the transducer in a single path, one path of the secondary winding is connected to the receiving circuit, and the other path is connected to the transmitting circuit; in specific implementation, the specific parameters of the isolation transformer design are related to the measured parameters of the transducer.

[0029] The front-end amplifier circuit converts the received signal into a signal that satisfies the signal amplitude range requirements of the receiving circuit. In this embodiment, the gain resistor of the front-end amplifier circuit is a high-precision resistor;

[0030] The high-frequency bandpass filter circuit is used to filter out high-frequency noise and DC signals in the signal to obtain a signal whose center frequency is the transmitter frequency;

[0031] The mixing circuit is used to reduce the sampling rate of the signal; in this embodiment, the sampling rate of the signal is reduced by the following method: the square wave signal output by the signal processing board circuit is passed through the square wave bandpass filter circuit to obtain a sine wave signal, and the signal is mixed with the output signal of the previous high-frequency bandpass filter circuit through a mixer and then sent to the low-pass filter circuit;

[0032] The low-pass filter circuit is a processing circuit after mixing, which is used to filter out the high-frequency signal after mixing to obtain an effective low-frequency signal;

[0033] The phase shift circuit generates three signals from the received low-frequency signal, namely the original signal, the positive 45° signal and the negative 45° signal, and then enters the signal operation circuit;

[0034] The signal operation circuit is used to operate on four signal channels, and the four signals are front, rear, left and right signals respectively; the operation is specifically: subtracting the positive 45° signal and the negative 45° signal of the forward channel, and then adding the signal of the rear channel to obtain the signal and then performing gain control; subtracting the positive 45° signal and the negative 45° signal of the rear channel, and then adding the signal of the front channel to obtain the signal and then performing gain control; similarly, the processing method of the left and right channels is consistent with the processing method of the front and rear channels;

[0035] The gain signal of the gain control circuit is provided by the control board and the signal processing board circuit, and is converted by the DA chip to obtain a gain analog signal, so that the amplitudes of the four-channel waveforms remain consistent.

[0036] like Figure 3 As shown, 4-channel AD acquisition signals are converted into digital signals and then output to the signal processing board. The signal processing board outputs a gain control signal and a square wave signal required for mixing to the receiving board, and outputs a PWM signal to the transmitting board. In specific implementation, the external interface circuit of the control board is a serial port or a network port.

[0037] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

[0038] It is obvious to those skilled in the art that the embodiments of the present invention are not limited to the details of the above exemplary embodiments, and that the embodiments of the present invention can be implemented in other specific forms without departing from the spirit or basic features of the embodiments of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the embodiments of the present invention is limited by the attached claims rather than the above description, so it is intended to include all changes that fall within the meaning and scope of the equivalent elements of the claims in the embodiments of the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved. In addition, it is obvious that the word "comprising" does not exclude other units or steps, and the singular does not exclude the plural. Multiple units, modules or devices stated in the system, device or terminal claims can also be implemented by the same unit, module or device through software or hardware. The words first, second, etc. are used to indicate names, and do not indicate any particular order.

[0039] Finally, it should be noted that the above implementation modes are only used to illustrate the technical solutions of the embodiments of the present invention and are not intended to limit them. Although the embodiments of the present invention have been described in detail with reference to the above preferred implementation modes, those skilled in the art should understand that the technical solutions of the embodiments of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A control system applied to a Doppler speed measurement system, characterized in that: include: A receiving board, a transmitting board, a control board and a signal processing board are connected in sequence.

2. A control system for a Doppler speed measurement system as claimed in claim 1, characterized in that: The receiving board includes an isolation transformer, a front-end amplifier circuit, a high-frequency bandpass filter circuit, a mixing circuit, a low-pass filter circuit, a phase shift circuit, a signal operation circuit, and a gain control circuit; wherein: The isolation transformer determines the output current according to the conductance value of the transducer, and determines the inductance of the transformer according to the susceptance value of the transducer; the primary winding of the isolation transformer is connected to the transducer in a single path, one path of the secondary winding is connected to the receiving circuit, and the other path is connected to the transmitting circuit; The front-end amplifier circuit converts the received signal into a signal amplitude range that satisfies the requirements of the receiving circuit for processing the signal; The high-frequency bandpass filter circuit is used to filter out high-frequency noise and DC signals in the signal to obtain a signal whose center frequency is the transmitter frequency; The mixing circuit is used to reduce the sampling rate of the signal; The low-pass filter circuit is a processing circuit after mixing, which is used to filter out the high-frequency signal after mixing to obtain an effective low-frequency signal; The phase shift circuit generates three signals from the received low-frequency signal, namely the original signal, the positive 45° signal and the negative 45° signal, and then enters the signal operation circuit; The signal operation circuit is used to operate on four signal channels, wherein the four signals are front, rear, left and right signals respectively; The gain signal of the gain control circuit is provided by the control board and the signal processing board circuit, and is converted by the DA chip to obtain a gain analog signal, so that the amplitudes of the four-channel waveforms remain consistent.

3. A control system for a Doppler speed measurement system as claimed in claim 2, characterized in that: The specific parameters of the isolation transformer design are related to the measured parameters of the transducer.

4. A control system for a Doppler speed measurement system as claimed in claim 2 or 3, characterized in that: The gain resistor of the front-end amplifier circuit is a high-precision resistor.

5. A control system for a Doppler speed measurement system as claimed in claim 2 or 3, characterized in that: The sampling rate of the signal is reduced by the following method: the square wave signal output by the signal processing board circuit is passed through a square wave bandpass filter circuit to obtain a sine wave signal, and the signal is mixed with the output signal of the previous high-frequency bandpass filter circuit through a mixer and then sent to the low-pass filter circuit.

6. A control system for a Doppler speed measurement system as claimed in claim 5, characterized in that: The operation is specifically as follows: subtracting the positive 45° signal and the negative 45° signal of the forward channel, adding the signal of the backward channel to obtain the signal, and then performing gain control; The positive 45° signal and the negative 45° signal of the backward channel are subtracted, and then added to the signal of the forward channel to obtain the signal for gain control.

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