CN115201510A - Front-end signal processing circuit suitable for marine electromagnetic sensor - Google Patents

Abstract

The invention discloses a front-end signal processing circuit suitable for a marine electromagnetic sensor, which relates to the technical field of electromagnetic principle flow velocity measurement and comprises the following components: the filter circuit, the amplifying circuit and the differential output circuit are connected in sequence; the input end of the filter circuit is connected with an electrode of the electromagnetic sensor; and the output end of the differential output circuit is connected with the electric connector of the electromagnetic sensor through a connecting cable. The invention improves the anti-interference capability of the electromagnetic sensor for the ship and realizes stable and reliable transmission of induced electromotive force.

Description

Translated fromChinese

一种适用于船用电磁传感器的前端信号处理电路A front-end signal processing circuit suitable for marine electromagnetic sensor

技术领域technical field

本发明涉及电磁原理流速测量技术领域，更具体的说是涉及一种适用于船用电磁传感器的前端信号处理电路。The invention relates to the technical field of electromagnetic principle flow velocity measurement, and more particularly to a front-end signal processing circuit suitable for marine electromagnetic sensors.

背景技术Background technique

电磁原理测量流速装置如电磁计程仪，被广泛用于舰船、潜艇测速。Electromagnetic principle measurement devices such as electromagnetic log, are widely used in ships, submarines speed measurement.

电磁传感器是电磁计程仪的一个敏感元件，通过给硅钢片组成的励磁线圈加上交变磁场，用电极拾取海水切割磁力线引起的感应电动势，并将感应电动势转为与航速成正比的电信号。电磁传感器的电极易受海水腐蚀、海生物覆盖，加之其他设备的电磁干扰，易使微弱的感应电动势被噪声淹没。工程实践中，电磁传感器与信号处理电路之间采用长线传输，加剧了这一趋势。The electromagnetic sensor is a sensitive element of the electromagnetic log. By adding an alternating magnetic field to the excitation coil composed of silicon steel sheets, the electrode picks up the induced electromotive force caused by seawater cutting the magnetic field line, and converts the induced electromotive force into an electrical signal proportional to the speed of the ship. . Electromagnetic sensor electrodes are easily corroded by seawater, covered by sea creatures, and the electromagnetic interference of other equipment can easily cause the weak induced electromotive force to be overwhelmed by noise. In engineering practice, long-term transmission between electromagnetic sensors and signal processing circuits has exacerbated this trend.

信号处理电路前置能够提高电磁传感器的抗干扰能力，实现感应电动势稳定、可靠传输。The front of the signal processing circuit can improve the anti-interference ability of the electromagnetic sensor, and realize the stable and reliable transmission of the induced electromotive force.

因此，如何提高船用电磁传感器的抗干扰能力，实现感应电动势稳定、可靠传输是本领域技术人员亟需解决的问题。Therefore, how to improve the anti-interference ability of the marine electromagnetic sensor and realize the stable and reliable transmission of the induced electromotive force is an urgent problem to be solved by those skilled in the art.

发明内容SUMMARY OF THE INVENTION

有鉴于此，本发明提供了一种适用于船用电磁传感器的前端信号处理电路，能够有效从噪声信号中检出信号，实现船用电磁传感器的高测量精度、高稳定性及高可靠性。In view of this, the present invention provides a front-end signal processing circuit suitable for a marine electromagnetic sensor, which can effectively detect signals from noise signals and achieve high measurement accuracy, high stability and high reliability of the marine electromagnetic sensor.

为了实现上述目的，本发明采用如下技术方案：In order to achieve the above object, the present invention adopts the following technical solutions:

一种适用于船用电磁传感器的前端信号处理电路，包括：依次连接的滤波电路、放大电路及差分输出电路；所述滤波电路的输入端与电磁传感器的电极连接；所述差分输出电路的输出端通过连接电缆与电磁传感器的电连接器连接。A front-end signal processing circuit suitable for a marine electromagnetic sensor, comprising: a filter circuit, an amplifier circuit and a differential output circuit connected in sequence; the input end of the filter circuit is connected with the electrode of the electromagnetic sensor; the output end of the differential output circuit It is connected with the electrical connector of the electromagnetic sensor through a connecting cable.

优选的，所述滤波电路包括RLC低通滤波电路，所述RLC低通滤波电路包括电感L1、电阻R1、电感L2、电阻R2、电容C1、电容C2及电容C3；所述电感L1的一端连接滤波电路的第一输入端，所述电感L1的另一端连接电阻R1的一端，所述电阻R1的另一端分别与电容C1的第一端和电容C3的第一端连接；所述电感L2的一端连接滤波电路的第二输入端，所述电感L2的另一端连接电阻R2的一端，所述电阻R2的另一端分别与电容C2的第二端和电容C3的第二端连接，所述电容C2的第一端与所述电容C1的第二端连接后共同接地。Preferably, the filter circuit includes an RLC low-pass filter circuit, and the RLC low-pass filter circuit includes an inductor L1, a resistor R1, an inductor L2, a resistor R2, a capacitor C1, a capacitor C2, and a capacitor C3; one end of the inductor L1 is connected to The first input end of the filter circuit, the other end of the inductor L1 is connected to one end of the resistor R1, and the other end of the resistor R1 is connected to the first end of the capacitor C1 and the first end of the capacitor C3 respectively; One end is connected to the second input end of the filter circuit, the other end of the inductor L2 is connected to one end of the resistor R2, the other end of the resistor R2 is connected to the second end of the capacitor C2 and the second end of the capacitor C3 respectively, the capacitor The first end of C2 and the second end of the capacitor C1 are connected to the ground together.

优选的，所述电阻R1及电阻R2均采用铁氧体磁珠。Preferably, both the resistor R1 and the resistor R2 use ferrite beads.

优选的，所述放大电路包括仪表放大电路。Preferably, the amplifier circuit includes an instrumentation amplifier circuit.

优选的，所述差分输出电路包括运算放大电路、电阻R8、电阻R9和电容C8，所述运算放大电路的反向输入端和输出端之间连接所述电阻R9与电容C8，所述电阻R9与电容C8并联，所述仪表放大电路的输出端与所述运算放大电路的反向输入端之间连接所述电阻R8，所述运算放大电路的输出端连接至仪表放大电路的基准电压端。Preferably, the differential output circuit includes an operational amplifier circuit, a resistor R8, a resistor R9 and a capacitor C8, the resistor R9 and the capacitor C8 are connected between the inverting input terminal and the output terminal of the operational amplifier circuit, and the resistor R9 In parallel with the capacitor C8, the resistor R8 is connected between the output end of the instrumentation amplifier circuit and the reverse input end of the operational amplifier circuit, and the output end of the operational amplifier circuit is connected to the reference voltage end of the instrumentation amplifier circuit.

优选的，所述连接电缆包括屏蔽双绞线，所述屏蔽双绞线包括屏蔽层以及由双绞线构成的芯线。Preferably, the connection cable includes a shielded twisted pair, and the shielded twisted pair includes a shielding layer and a core wire composed of the twisted pair.

优选的，所述滤波电路、放大电路及差分输出电路集成在一张印制电路板上，所述印制电路板安装在电磁传感器的腔体内部，所述印制电路板的电路距离电磁传感器内部硅钢片上沿的距离不小于2.5倍硅钢片的宽度。Preferably, the filter circuit, the amplifier circuit and the differential output circuit are integrated on a printed circuit board, the printed circuit board is installed inside the cavity of the electromagnetic sensor, and the circuit of the printed circuit board is far from the electromagnetic sensor The distance between the upper edge of the inner silicon steel sheet is not less than 2.5 times the width of the silicon steel sheet.

经由上述的技术方案可知，与现有技术相比，本发明公开提供了一种适用于船用电磁传感器的前端信号处理电路，具有以下有益效果：As can be seen from the above technical solutions, compared with the prior art, the present invention provides a front-end signal processing circuit suitable for a marine electromagnetic sensor, which has the following beneficial effects:

本发明能够提高船用电磁传感器的抗干扰能力，实现感应电动势稳定、可靠传输。The invention can improve the anti-interference ability of the marine electromagnetic sensor and realize stable and reliable transmission of the induced electromotive force.

附图说明Description of drawings

为了更清楚地说明本发明实施例或现有技术中的技术方案，下面将对实施例或现有技术描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本发明的实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据提供的附图获得其他的附图。In order to illustrate the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that are used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only It is an embodiment of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to the provided drawings without creative efforts.

图1为本发明提供的前端信号处理电路原理框架示意图；1 is a schematic diagram of the principle framework of a front-end signal processing circuit provided by the present invention;

图2为本发明提供的滤波电路示意图；2 is a schematic diagram of a filter circuit provided by the present invention;

图3为本发明提供的放大电路及差分输出电路示意图；3 is a schematic diagram of an amplifying circuit and a differential output circuit provided by the present invention;

图4为本发明提供的船用电磁传感器整体结构示意图。FIG. 4 is a schematic diagram of the overall structure of the marine electromagnetic sensor provided by the present invention.

具体实施方式Detailed ways

下面将结合本发明实施例中的附图，对本发明实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅仅是本发明一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本发明保护的范围。The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

如图1所示，本发明实施例公开了一种适用于船用电磁传感器的前端信号处理电路，包括：As shown in FIG. 1 , an embodiment of the present invention discloses a front-end signal processing circuit suitable for a marine electromagnetic sensor, including:

依次连接的滤波电路、放大电路及差分输出电路；所述滤波电路的输入端与电磁传感器的电极连接；所述差分输出电路的输出端通过连接电缆与电磁传感器的电连接器连接。The filter circuit, the amplifier circuit and the differential output circuit are connected in sequence; the input end of the filter circuit is connected with the electrode of the electromagnetic sensor; the output end of the differential output circuit is connected with the electrical connector of the electromagnetic sensor through the connecting cable.

船用电磁传感器从自身的电极得到的测量信号很弱，一般为微伏级别，要进行精确测量就需要对测量信号进行滤波并放大处理。The measurement signal obtained by the marine electromagnetic sensor from its own electrodes is very weak, generally at the microvolt level. To perform accurate measurement, the measurement signal needs to be filtered and amplified.

如图2所示，滤波电路可采用RLC低通滤波电路，RLC低通滤波电路包括电感L1、电阻R1、电感L2、电阻R2、电容C1、电容C2及电容C3；所述电感L1的一端连接滤波电路的第一输入端，所述电感L1的另一端连接电阻R1的一端，所述电阻R1的另一端分别与电容C1的第一端和电容C3的第一端连接；所述电感L2的一端连接滤波电路的第二输入端，所述电感L2的另一端连接电阻R2的一端，所述电阻R2的另一端分别与电容C2的第二端和电容C3的第二端连接，所述电容C2的第一端与所述电容C1的第二端连接后共同接地。As shown in FIG. 2 , the filter circuit can use an RLC low-pass filter circuit. The RLC low-pass filter circuit includes an inductor L1, a resistor R1, an inductor L2, a resistor R2, a capacitor C1, a capacitor C2, and a capacitor C3; one end of the inductor L1 is connected to The first input end of the filter circuit, the other end of the inductor L1 is connected to one end of the resistor R1, and the other end of the resistor R1 is connected to the first end of the capacitor C1 and the first end of the capacitor C3 respectively; One end is connected to the second input end of the filter circuit, the other end of the inductor L2 is connected to one end of the resistor R2, the other end of the resistor R2 is connected to the second end of the capacitor C2 and the second end of the capacitor C3 respectively, the capacitor The first end of C2 and the second end of the capacitor C1 are connected to the ground together.

作为一种优选的技术方案，在另外一个实施例中电阻R1及电阻R2均采用铁氧体磁珠。铁氧体磁珠作为一种抗干扰组件，可以在高频信号通过时呈现较大的阻抗，而在低频信号输入时呈现极低的阻抗，能够显著对输入的高频噪声造成衰减，又对低频信号无相移，利于后序电路信号处理。As a preferred technical solution, in another embodiment, both the resistor R1 and the resistor R2 use ferrite beads. As an anti-interference component, ferrite beads can present a large impedance when a high-frequency signal passes through, and a very low impedance when a low-frequency signal is input, which can significantly attenuate the input high-frequency noise. The low-frequency signal has no phase shift, which is beneficial to the signal processing of the subsequent circuit.

为了降低两电极在海水中内阻随不同海域会变化的影响，放大电路输入端需要高输入阻抗和低偏置输入电流。同时为了解决供电电源干扰耦合到输入回路所带来的工频干扰以及励磁磁场的交变变化所产生的其它干扰(共模干扰)，采用差分电路来减少共模干扰的影响。In order to reduce the influence of the change of the internal resistance of the two electrodes in seawater with different sea areas, the input end of the amplifier circuit requires high input impedance and low bias input current. At the same time, in order to solve the power frequency interference caused by the power supply interference coupled to the input loop and other interference (common mode interference) caused by the alternating change of the excitation magnetic field, a differential circuit is used to reduce the influence of the common mode interference.

实施例中，放大电路采用仪表放大电路，如图3所示，放大电路采用集成仪表运算放大电路SGM620芯片。In the embodiment, the amplifier circuit adopts an instrumentation amplifier circuit, as shown in FIG. 3 , the amplifier circuit adopts an integrated instrumentation operational amplifier circuit SGM620 chip.

在另外的实施例中，也可采用3个独立运算放大电路构成的仪表放大电路。In another embodiment, an instrumentation amplifier circuit composed of three independent operational amplifier circuits may also be used.

如图3所示，差分输出电路主要包括运算放大电路N2A、电阻R8、电阻R9和电容C8，运算放大电路N2A的反向输入端和输出端之间连接电阻R9与电容C8，电阻R9与电容C8，仪表放大电路SGM620芯片的输出端与运算放大电路N2A的反向输入端之间连接电阻R8，运算放大电路N2A的输出端连接至仪表放大电路SGM620芯片的基准电压端。As shown in Figure 3, the differential output circuit mainly includes an operational amplifier circuit N2A, a resistor R8, a resistor R9 and a capacitor C8. A resistor R9 and a capacitor C8 are connected between the reverse input terminal and the output terminal of the operational amplifier circuit N2A, and the resistor R9 and the capacitor are connected C8, resistor R8 is connected between the output terminal of the instrument amplifier circuit SGM620 chip and the reverse input terminal of the operational amplifier circuit N2A, and the output terminal of the operational amplifier circuit N2A is connected to the reference voltage terminal of the instrument amplifier circuit SGM620 chip.

差分输出电路中，利用了仪表放大电路SGM620芯片对其基准电压(N1的5脚)相关的输出电压的精确控制。差分输出由仪表放大器的输出端和运算放大电路输出端构成，差分输出的精度由仪表放大电路决定，不受运算放大电路和电阻影响。由于该电路易受稳定性影响，电容C8能够限制运算放大电路N2A的带宽使其稳定，通过电阻R10、电阻R11差分输出放大后信号，由连接电缆接至电连接器。In the differential output circuit, the instrument amplifier circuit SGM620 chip is used to precisely control the output voltage related to its reference voltage (pin 5 of N1). The differential output is composed of the output terminal of the instrumentation amplifier and the output terminal of the operational amplifier circuit. The accuracy of the differential output is determined by the instrumentation amplifier circuit and is not affected by the operational amplifier circuit and resistance. Since this circuit is easily affected by stability, capacitor C8 can limit the bandwidth of operational amplifier circuit N2A to make it stable. The amplified signal is differentially output through resistor R10 and resistor R11, and is connected to the electrical connector by the connecting cable.

实施例中，连接电磁传感器的电连接器与差分电路输出端的连接电缆采用屏蔽双绞线，所述屏蔽双绞线包括屏蔽层以及由双绞线构成的芯线。采用屏蔽双绞线能够有效将串扰减至最小。屏蔽线与电磁传感器外壳相连，将外来的干扰信号导入船体，减少外电磁场对电路的影响。In the embodiment, the connecting cable connecting the electrical connector of the electromagnetic sensor and the output end of the differential circuit adopts a shielded twisted pair wire, and the shielded twisted pair wire includes a shield layer and a core wire composed of twisted pair wires. The use of shielded twisted pairs can effectively minimize crosstalk. The shielded wire is connected to the shell of the electromagnetic sensor, and the external interference signal is introduced into the hull to reduce the influence of the external electromagnetic field on the circuit.

如图4所示，滤波电路、放大电路及差分输出电路集成在一张印制电路板2上，印制电路板2安装在电磁传感器的腔体内部，印制电路板2的电路距离电磁传感器内部硅钢片3上沿的距离不小于2.5倍硅钢片的宽度，图中，4表示电磁传感器的电极，1表示连接电缆，5表示电连接器。As shown in Figure 4, the filter circuit, amplifier circuit and differential output circuit are integrated on aprinted circuit board 2, theprinted circuit board 2 is installed inside the cavity of the electromagnetic sensor, and the circuit of theprinted circuit board 2 is far from the electromagnetic sensor. The distance between the upper edge of the innersilicon steel sheet 3 is not less than 2.5 times the width of the silicon steel sheet. In the figure, 4 represents the electrode of the electromagnetic sensor, 1 represents the connecting cable, and 5 represents the electrical connector.

本说明书中各个实施例采用递进的方式描述，每个实施例重点说明的都是与其他实施例的不同之处，各个实施例之间相同相似部分互相参见即可。对于实施例公开的装置而言，由于其与实施例公开的方法相对应，所以描述的比较简单，相关之处参见方法部分说明即可。The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the various embodiments can be referred to each other. As for the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant part can be referred to the description of the method.

对所公开的实施例的上述说明，使本领域专业技术人员能够实现或使用本发明。对这些实施例的多种修改对本领域的专业技术人员来说将是显而易见的，本文中所定义的一般原理可以在不脱离本发明的精神或范围的情况下，在其它实施例中实现。因此，本发明将不会被限制于本文所示的这些实施例，而是要符合与本文所公开的原理和新颖特点相一致的最宽的范围。The above description of the disclosed embodiments enables any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended 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 (7)

1. A front-end signal processing circuit adapted for a marine electromagnetic sensor, the front-end signal processing circuit comprising:

the filter circuit, the amplifying circuit and the differential output circuit are connected in sequence; the input end of the filter circuit is connected with an electrode of the electromagnetic sensor; and the output end of the differential output circuit is connected with the electric connector of the electromagnetic sensor through a connecting cable.

2. The front-end signal processing circuit suitable for the marine electromagnetic sensor according to claim 1, wherein the filter circuit comprises an RLC low-pass filter circuit, and the RLC low-pass filter circuit comprises an inductor L1, a resistor R1, an inductor L2, a resistor R2, a capacitor C1, a capacitor C2 and a capacitor C3; one end of the inductor L1 is connected with a first input end of the filter circuit, the other end of the inductor L1 is connected with one end of the resistor R1, and the other end of the resistor R1 is respectively connected with a first end of the capacitor C1 and a first end of the capacitor C3; one end of the inductor L2 is connected with the second input end of the filter circuit, the other end of the inductor L2 is connected with one end of the resistor R2, the other end of the resistor R2 is connected with the second end of the capacitor C2 and the second end of the capacitor C3 respectively, and the first end of the capacitor C2 is connected with the second end of the capacitor C1 and then is grounded together.

3. The front-end signal processing circuit suitable for the marine electromagnetic sensor according to claim 2, characterized in that the resistors R1 and R2 are ferrite beads.

4. The front-end signal processing circuit suitable for a marine electromagnetic sensor of claim 1, wherein the amplifying circuit comprises an instrument amplifying circuit.

5. The front-end signal processing circuit suitable for the marine electromagnetic sensor according to claim 4, wherein the differential output circuit comprises an operational amplifier circuit, a resistor R8, a resistor R9 and a capacitor C8, the resistor R9 and the capacitor C8 are connected between an inverting input end and an output end of the operational amplifier circuit, the resistor R9 is connected in parallel with the capacitor C8, the resistor R8 is connected between an output end of the instrument amplifier circuit and an inverting input end of the operational amplifier circuit, and an output end of the operational amplifier circuit is connected to a reference voltage end of the instrument amplifier circuit.

6. The front-end signal processing circuit for a marine electromagnetic sensor of claim 1, wherein the connecting cable comprises a shielded twisted pair comprising a core comprised of a twisted pair and a shielding layer.

7. The front-end signal processing circuit applicable to the marine electromagnetic sensor according to any one of claims 1 to 6, wherein the filter circuit, the amplifier circuit and the differential output circuit are integrated on a printed circuit board, the printed circuit board is installed inside a cavity of the electromagnetic sensor, and the distance from the printed circuit board to the edge of the silicon steel sheet inside the electromagnetic sensor is not less than 2.5 times the width of the silicon steel sheet.

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