Three-axis fundamental mode orthogonal fluxgate sensor control circuit

Abstract

The invention relates to a three-axis fundamental mode orthogonal fluxgate sensor control circuit. Comprising a time-sharing work control module, and a three-axis fundamental mode orthogonal fluxgate sensor, an excitation module and a detection feedback module which are connected with the time-sharing work control module, the excitation module is used for generating excitation current and outputting the excitation current to the time-sharing work control module; the time-sharing work control module is used for controlling time-sharing work of the three shaft magnetic cores and generating an induced voltage signal based on the excitation current; the detection feedback module is used for conditioning the induced voltage signal and generating a corresponding feedback current signal; and the time-sharing work control module is also used for inputting the feedback current signal to an induction coil corresponding to a target axis magnetic core, and the target axis magnetic core is an axis magnetic core in a working state. By adopting the method, noise suppression and power consumption optimization can be realized.

Description

Technical Field

[0001] This application relates to the field of circuit technologies, and particularly to a control circuit for a three-axis fundamental-mode orthogonal fluxgate sensor. Background Art

[0002] In existing three-axis fundamental-mode orthogonal fluxgate sensors, when the three axes work simultaneously, the magnetic field coupling between the axes will cause a significant increase in noise, reducing the measurement accuracy of the sensor and limiting its application in the field of high-precision magnetic field measurement. In addition, when existing three-axis fundamental-mode orthogonal fluxgate sensors work simultaneously, since all three axes remain in an excited state, the power consumption is relatively high, which is an important limiting factor in power-sensitive application scenarios such as portable devices or remote monitoring systems. Therefore, there are problems of high noise and high power consumption in existing three-axis fundamental-mode orthogonal fluxgate sensors. Summary of the Invention

[0003] Based on this, it is necessary to provide a control circuit for a three-axis fundamental-mode orthogonal fluxgate sensor to address the above technical problems.

[0004] In a first aspect, this application provides a control circuit for a three-axis fundamental-mode orthogonal fluxgate sensor, including:

[0005] A three-axis fundamental-mode orthogonal fluxgate sensor, an excitation module, a time-sharing operation control module, and a detection and feedback module;

[0006] The excitation module is configured to generate an excitation current and output the excitation current to the time-sharing operation control module;

[0007] The time-sharing operation control module is configured to control the time-sharing operation of the three-axis magnetic cores and generate an induced voltage signal based on the excitation current;

[0008] The detection and feedback module is configured to condition the induced voltage signal and generate a corresponding feedback current signal;

[0009] The time-sharing operation control module is further configured to input the feedback current signal into the induction coil corresponding to the target-axis magnetic core, where the target-axis magnetic core is the magnetic core in the working state.

[0010] In some embodiments, the three-axis fundamental-mode orthogonal fluxgate sensor includes: an X-axis magnetic core, a Y-axis magnetic core, a Z-axis magnetic core, an X-axis induction coil, a Y-axis induction coil, and a Z-axis induction coil;

[0011] The first input port of the time-sharing operation control module is connected to the excitation module for receiving the excitation current;

[0012] The first output port, the second output port, and the third output port of the time-sharing working control module are respectively connected to the X-axis magnetic core, the Y-axis magnetic core, and the Z-axis magnetic core;

[0013] The first bidirectional transmission port, the second bidirectional transmission port, and the third bidirectional transmission port of the time-sharing working control module are connected to the X-axis induction coil, the Y-axis induction coil, and the Z-axis induction coil;

[0014] The fourth bidirectional transmission port of the time-sharing working control module is connected to the detection feedback module.

[0015] In some embodiments, the time-sharing working control module is configured to:

[0016] In the first state, control the first output port to be connected to the first input port, and the first bidirectional transmission port to be connected to the fourth bidirectional transmission port;

[0017] Or,

[0018] In the second state, control the second output port to be connected to the first input port, and the second bidirectional transmission port to be connected to the fourth bidirectional transmission port;

[0019] Or,

[0020] In the third state, control the third output port to be connected to the first input port, and the third bidirectional transmission port to be connected to the fourth bidirectional transmission port.

[0021] In some embodiments, the time-sharing working control module includes: a first connection control sub-module, a second connection control sub-module, and a microcontroller;

[0022] The first input port, the first output port, the second output port, and the third output port of the time-sharing working control module are ports on the first connection control sub-module;

[0023] The first bidirectional transmission port, the second bidirectional transmission port, the third bidirectional transmission port, and the fourth bidirectional transmission port of the time-sharing working control module are ports on the second connection control sub-module;

[0024] The microcontroller is configured to connect or disconnect the ports on the first connection control sub-module and connect or disconnect the ports on the second connection control sub-module, so as to implement one of the first state, the second state, and the third state.

[0025] In some embodiments, the microcontroller is configured to:

[0026] In the first state, control the connection between the first output port and the first input port on the first connection control sub-module, and control the connection between the first bidirectional transmission port and the fourth bidirectional transmission port on the second connection control sub-module;

[0027] Or,

[0028] In the second state, control the connection between the second output port and the first input port on the first connection control sub-module, and control the connection between the second bidirectional transmission port and the fourth bidirectional transmission port on the second connection control sub-module;

[0029] Or,

[0030] In the third state, control the connection between the third output port and the first input port on the first connection control sub-module, and control the connection between the third bidirectional transmission port and the fourth bidirectional transmission port on the second connection control sub-module.

[0031] In some embodiments, the first connection control sub-module and the second connection control sub-module are multiplexers.

[0032] In some embodiments, the first state, the second state, and the third state appear alternately in sequence.

[0033] In some embodiments, the detection feedback module includes:

[0034] A detection sub-module and a feedback sub-module;

[0035] The input end of the detection sub-module is connected to the fourth bidirectional transmission port, the output end of the detection sub-module is connected to the feedback sub-module, and the output end of the feedback sub-module is connected to the fourth bidirectional transmission port.

[0036] In some embodiments, the detection sub-module is used to demodulate and filter the induced voltage signal to extract the amplitude of the induced voltage signal and form a detected voltage signal;

[0037] The feedback sub-module is used to generate a corresponding feedback current signal according to the detected voltage signal.

[0038] In some embodiments, the three-axis fundamental-mode orthogonal fluxgate sensor includes: an X-axis fundamental-mode orthogonal fluxgate, a Y-axis fundamental-mode orthogonal fluxgate, and a Z-axis fundamental-mode orthogonal fluxgate. The X-axis fundamental-mode orthogonal fluxgate includes the X-axis magnetic core and the X-axis induction coil. The Y-axis fundamental-mode orthogonal fluxgate includes the Y-axis magnetic core and the Y-axis induction coil. The Z-axis fundamental-mode orthogonal fluxgate includes the Z-axis magnetic core and the Z-axis induction coil;

[0039] The measuring directions of the X-axis fundamental mode orthogonal fluxgate, Y-axis fundamental mode orthogonal fluxgate, and Z-axis fundamental mode orthogonal fluxgate are aligned with the X, Y, and Z axes in an orthogonal Cartesian coordinate system.

[0040] The above-mentioned three-axis fundamental mode orthogonal fluxgate sensor control circuit includes: a three-axis fundamental mode orthogonal fluxgate sensor, an excitation module, a time-sharing operation control module, and a detection and feedback module; the excitation module is used to generate an excitation current and output the excitation current to the time-sharing operation control module; the time-sharing operation control module is used to control the time-sharing operation of the three-axis magnetic cores and generate an induced voltage signal based on the excitation current; the detection and feedback module is used to condition the induced voltage signal and generate a corresponding feedback current signal; the time-sharing operation control module is also used to input the feedback current signal into the induction coil corresponding to the target-axis magnetic core, and the target-axis magnetic core is the magnetic core of the axis in the working state. In this solution, by introducing a time-sharing operation control module and adopting a time-sharing driving mechanism, the three-axis magnetic cores work alternately in the time dimension, fundamentally solving the noise problem caused by three-axis magnetic field coupling in the prior art. Since only a single-axis magnetic core is in the excited state at the same time, and the other two axes are in the non-working silent state, the inter-axis magnetic field crosstalk is significantly reduced, thereby suppressing the generation of coupling noise, improving the signal-to-noise ratio and measurement accuracy of the sensor, and providing a feasible solution for high-precision magnetic field measurement scenarios. At the same time, the time-sharing operation mode reduces the parallel excitation requirements of the sensor system, distributes the power consumption of traditional three-axis continuous excitation to different time windows, and reduces the system average power consumption to the single-axis working level. In addition, the dynamic signal conditioning and closed-loop control mechanism of the detection and feedback module ensure the continuity of signal detection and the pertinence of feedback compensation during the time-sharing switching process, further optimizing the system energy efficiency while maintaining the measurement accuracy. This design realizes noise suppression and power consumption optimization through spatio-temporal decoupling and dynamic resource allocation, expanding the applicable boundaries of three-axis fluxgate sensors in precision measurement and low-power consumption scenarios. Description of the Drawings

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following will briefly introduce the drawings required for use in the description of the embodiments or related technologies. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0042] Figure 1 It is a schematic structural diagram of a fundamental mode orthogonal fluxgate;

[0043] Figure 2 It is a schematic structural diagram of a three-axis fundamental mode orthogonal fluxgate sensor;

[0044] Figure 3Schematic diagram of the structure of a control circuit for a three-axis fundamental-mode orthogonal fluxgate sensor in an embodiment Figure 1 ;

[0045] Figure 4 Schematic diagram of the structure of a control circuit for a three-axis fundamental-mode orthogonal fluxgate sensor in an embodiment Figure 2 ;

[0046] Figure 5 Schematic diagram of connections in three states in an embodiment. Detailed implementation manners

[0047] In order to make the objectives, technical solutions and advantages of the present application clearer and more understandable, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0048] A fluxgate sensor is a high-precision magnetic field measurement device that can detect the intensity and direction of a magnetic field. Its working principle is similar to using a "magnet probe" to sense the environment: when a special magnetic material (magnetic core) is repeatedly magnetized to saturation by an alternating current, a slight change in the external magnetic field will significantly change the magnetization characteristics of the magnetic core, and the magnetic field value can be deduced by measuring this change. This kind of sensor has the advantages of high sensitivity (it can detect one-thousandth of the geomagnetic field), low noise, and the ability to measure the magnetic field direction, and is widely used in fields such as geological exploration, aerospace navigation, and medical equipment.

[0049] According to the different designs of the magnetic field direction, fluxgate sensors are divided into two categories: parallel type and orthogonal type. In a parallel type sensor, two sets of coils are wound around the magnetic core - an excitation coil is supplied with an alternating current to generate a periodic magnetic field in the same direction as the measured magnetic field, and the induction coil detects the change in the state of the magnetic core; in the orthogonal type, the excitation magnetic field is perpendicular to the measured magnetic field. Among them, the fundamental-mode orthogonal fluxgate significantly reduces the Barkhausen noise generated by the magnetic domain mutation by superimposing a direct current on the alternating current, and at the same time simplifies the structure and is more conducive to miniaturization.

[0050] As Figure 1 shown, it is a schematic diagram of the structure of a fundamental-mode orthogonal fluxgate. The fundamental-mode orthogonal fluxgate is a kind of orthogonal fluxgate. Figure 1 In Figure 1The magnetic field vector in the measurement direction indicated by the arrow. The main feature of the fundamental-mode orthogonal fluxgate is that a DC current is superimposed on the original alternating excitation current. This design enables an induced voltage signal with the same frequency as the alternating excitation current signal to be induced on the induction coil, and the amplitude of this signal can represent the magnitude of the magnetic field to be measured in the measurement direction of the fluxgate. The excitation method of the fundamental-mode orthogonal fluxgate reduces the large Barkhausen noise caused by magnetic domain reversal, and has the advantages of low noise, simple structure, and small volume.

[0051] To achieve three-dimensional space magnetic field measurement, usually three fundamental-mode orthogonal fluxgates are combined into a triaxial probe in the vertical directions of the X, Y, and Z axes, that is, a triaxial fundamental-mode orthogonal fluxgate sensor. As Figure 2 shown, it is a schematic structural diagram of a triaxial fundamental-mode orthogonal fluxgate sensor, which includes an X-axis fundamental-mode orthogonal fluxgate, a Y-axis fundamental-mode orthogonal fluxgate, and a Z-axis fundamental-mode orthogonal fluxgate. During operation, the excitation circuit provides a specific current for each sensor to saturate its magnetic core periodically, and the induction coil generates a voltage signal. The detection circuit extracts the magnetic field strength information. If the magnetic field is too strong, the feedback circuit will generate a reverse current to cancel the external magnetic field, and the value of the reverse current can be used to calculate the value of the strong magnetic field, thereby expanding the measurement range.

[0052] However, the existing triaxial systems have two major defects: one is noise interference. When the three axes work simultaneously, the magnetic field generated by one axis will interfere with the measurement of other axes; the other is high power consumption. The continuous operation of the three axes requires a large amount of electrical energy, which limits its application in portable devices or long-term monitoring.

[0053] To solve the above problems, the embodiment of the present application provides a control circuit for a triaxial fundamental-mode orthogonal fluxgate sensor. By introducing a time-sharing working control module and adopting a time-sharing driving mechanism, the triaxial magnetic cores work alternately in the time dimension, fundamentally solving the noise problem caused by triaxial magnetic field coupling in the prior art. Since only a single-axis magnetic core is in the excited state at the same time, and the other two axes are in the non-working silent state, the inter-axis magnetic field crosstalk is significantly reduced, thereby suppressing the generation of coupling noise, improving the signal-to-noise ratio and measurement accuracy of the sensor, and providing a feasible solution for high-precision magnetic field measurement scenarios. At the same time, the time-sharing working mode reduces the parallel excitation requirements of the sensor system, distributes the power consumption of traditional triaxial continuous excitation to different time windows, and reduces the system average power consumption to the single-axis working level. In addition, the dynamic signal conditioning and closed-loop control mechanism of the detection feedback module ensure the continuity of signal detection and the pertinence of feedback compensation during the time-sharing switching process, further optimizing the system energy efficiency while maintaining the measurement accuracy. This design realizes noise suppression and power consumption optimization through spatio-temporal decoupling and dynamic resource allocation, and expands the applicable boundaries of triaxial fluxgate sensors in precision measurement and low-power consumption scenarios.

[0054] Exemplarily, as Figure 3As shown, it is a schematic structure of a control circuit for a three-axis fundamental-mode orthogonal fluxgate sensor Figure 1 . Figure 3 In this, the control circuit for the three-axis fundamental-mode orthogonal fluxgate sensor includes:

[0055] A time-sharing operation control module 31, and a three-axis fundamental-mode orthogonal fluxgate sensor 32, an excitation module 33, and a detection and feedback module 34 connected to the time-sharing operation control module 31;

[0056] The excitation module 33 is used to generate an excitation current and output the excitation current to the time-sharing operation control module 31;

[0057] The time-sharing operation control module 31 is used to control the three magnetic cores of the three-axis fundamental-mode orthogonal fluxgate sensor 32 to operate in a time-sharing manner and generate an induced voltage signal based on the excitation current;

[0058] The detection and feedback module 34 is used to condition the induced voltage signal and generate a corresponding feedback current signal;

[0059] The time-sharing operation control module 31 is further used to input the feedback current signal into the induction coil corresponding to the target axis magnetic core, and the target axis magnetic core is the axis magnetic core in the working state.

[0060] Exemplarily, the above excitation current is composed of an alternating current with a frequency of 100 kHz and an amplitude of 30 mA and a direct current bias current of 40 mA, and is switched to the magnetic core of the corresponding axis by the time-sharing operation control module 31 according to the current working state.

[0061] In some embodiments, the three-axis fundamental-mode orthogonal fluxgate sensor includes: an X-axis fundamental-mode orthogonal fluxgate, a Y-axis fundamental-mode orthogonal fluxgate, and a Z-axis fundamental-mode orthogonal fluxgate. The X-axis fundamental-mode orthogonal fluxgate includes an X-axis magnetic core and an X-axis induction coil. The Y-axis fundamental-mode orthogonal fluxgate includes a Y-axis magnetic core and a Y-axis induction coil. The Z-axis fundamental-mode orthogonal fluxgate includes a Z-axis magnetic core and a Z-axis induction coil;

[0062] The measurement directions of the X-axis fundamental-mode orthogonal fluxgate, the Y-axis fundamental-mode orthogonal fluxgate, and the Z-axis fundamental-mode orthogonal fluxgate are aligned with the X, Y, and Z axes in an orthogonal Cartesian coordinate system.

[0063] In the above embodiments, by introducing a time-sharing working control module and adopting a time-sharing driving mechanism, the three-axis magnetic core works alternately in the time dimension, fundamentally solving the noise problem caused by three-axis magnetic field coupling in the prior art. Since only a single-axis magnetic core is in the excited state at the same time, and the other two axes are in the non-working silent state, the inter-axis magnetic field crosstalk is significantly reduced, thereby suppressing the generation of coupling noise, improving the signal-to-noise ratio and measurement accuracy of the sensor, and providing a feasible solution for high-precision magnetic field measurement scenarios. At the same time, the time-sharing working mode reduces the parallel excitation requirement of the sensor system, distributes the power consumption of traditional three-axis continuous excitation to different time windows, and reduces the system average power consumption to the single-axis working level. In addition, the dynamic signal conditioning and closed-loop control mechanism of the detection feedback module ensure the continuity of signal detection and the pertinence of feedback compensation during the time-sharing switching process, further optimizing the system energy efficiency while maintaining the measurement accuracy. Through spatio-temporal decoupling and dynamic resource allocation, this design realizes noise suppression and power consumption optimization, and expands the applicable boundary of three-axis fluxgate sensors in precision measurement and low-power scenarios.

[0064] Exemplarily, in combination with Figure 3 , such as Figure 4 shown, is a schematic structural diagram of a control circuit of a three-axis fundamental-mode orthogonal fluxgate sensor. Figure 2 .

[0065] Among them, Figure 4 in, the three-axis fundamental-mode orthogonal fluxgate sensor includes: an X-axis magnetic core, a Y-axis magnetic core, a Z-axis magnetic core, an X-axis induction coil, a Y-axis induction coil, and a Z-axis induction coil; the first input port COM1 of the time-sharing working control module 31 is connected to the excitation module 33 for receiving the excitation current output by the excitation module 33; the first output port EX of the time-sharing working control module 31 is connected to the X-axis magnetic core, the second output port EY is connected to the Y-axis magnetic core, and the third output port EZ is connected to the Z-axis magnetic core; the first bidirectional transmission port SX of the above time-sharing working control module 31 is connected to the X-axis induction coil, the second bidirectional transmission port SY is connected to the Y-axis induction coil, and the third bidirectional transmission port SZ is connected to the Z-axis induction coil; the fourth bidirectional transmission port COM2 of the time-sharing working control module 31 is connected to the time-sharing working control module 31.

[0066] In some embodiments, the time-sharing working control module 31 is configured to, in the first state, control the first output port EX to be connected to the first input port COM1, and the first bidirectional transmission port SX to be connected to the fourth bidirectional transmission port COM2.

[0067] In some embodiments, the time-sharing operation control module 31 is configured to control the second output port EY to be connected to the first input port COM1 and the second bidirectional transmission port SY to be connected to the fourth bidirectional transmission port COM2 in the second state.

[0068] In some embodiments, the time-sharing operation control module 31 is configured to control the third output port EZ to be connected to the first input port COM1 and the third bidirectional transmission port SZ to be connected to the fourth bidirectional transmission port COM2 in the third state.

[0069] In some embodiments, the time-sharing operation control module 31 described above includes: a first connection control sub-module, a second connection control sub-module, and a microcontroller; wherein, the first connection control sub-module and the second connection control sub-module are multiplexers. Exemplarily, as Figure 4 shown in, the first connection control sub-module can be Figure 4 the multiplexer 1 in, and the second connection control sub-module can be Figure 4 the multiplexer 2 in. The first connection control sub-module (multiplexer 1) and the second connection control sub-module (multiplexer 2) are electronic switch array chips for switching the circuit connection path through microcontroller instructions.

[0070] Exemplarily, the first input port EX, the second output port EY, and the third output port EZ of the time-sharing operation control module 31 are ports on the multiplexer 1; the first bidirectional transmission port SX, the second bidirectional transmission port SY, the third bidirectional transmission port SZ, and the fourth bidirectional transmission port COM2 of the time-sharing operation control module 31 are ports on the multiplexer 2.

[0071] Among them, the first input port COM1 of the multiplexer 1 receives the superimposed excitation current output by the excitation module 33, and the first input port EX, the second output port EY, and the third output port EZ are respectively connected to the X-axis magnetic core, the Y-axis magnetic core, and the Z-axis magnetic core; the first bidirectional transmission port SX, the second bidirectional transmission port SY, and the third bidirectional transmission port SZ of the multiplexer 2 are respectively connected to the X-axis induction coil, the Y-axis induction coil, and the Z-axis induction coil, and the fourth bidirectional transmission port COM2 is connected to the detection feedback module 34. Among them, the above-mentioned superimposed excitation current can be 30 mA alternating current superimposed on 40 mA direct current.

[0072] Among them, the microcontroller is configured to control the connection or disconnection of the ports on the multiplexer 1 and the connection or disconnection of the ports on the multiplexer 2 to implement one of the first state, the second state, and the third state.

[0073] In some embodiments, the microcontroller is configured to control the connection between the first output port EX on the multiplexer 1 and the first input port COM1 in the first state, and control the connection between the first bidirectional transmission port SX on the multiplexer 2 and the fourth bidirectional transmission port COM2.

[0074] In some embodiments, the microcontroller is configured to control the connection between the second output port EY on the multiplexer 1 and the first input port COM1 in the second state, and control the connection between the second bidirectional transmission port SY on the multiplexer 2 and the fourth bidirectional transmission port COM2.

[0075] In some embodiments, the microcontroller is configured to control the connection between the third output port EZ on the multiplexer 1 and the first input port COM1 in the third state, and control the connection between the third bidirectional transmission port SZ on the multiplexer 2 and the fourth bidirectional transmission port COM2.

[0076] In some embodiments, the above-mentioned first state, second state, and third state appear alternately in sequence. Exemplarily, in combination with Figure 4 the circuit shown, the connection schematic diagrams of the above three states can be as shown in Figure 5 . Figure 5 is a connection schematic diagram in three states, where the above-mentioned first state corresponds to Figure 5 state one in Figure 5 , the above-mentioned second state corresponds to Figure 5 state two in

[0077] Exemplarily, the microcontroller in the time-sharing working control module 31 can cyclically switch the working state at a frequency of 4 kHz.

[0078] In some embodiments, the above-mentioned Figure 4 demodulation feedback module 34 includes: a demodulation sub-module and a feedback sub-module; the input end of the demodulation sub-module is connected to the fourth bidirectional transmission port COM2, the output end of the demodulation sub-module is connected to the feedback sub-module, and the output end of the feedback sub-module is connected to the fourth bidirectional transmission port COM2.

[0079] Among them, the demodulation sub-module is configured to demodulate and filter the induced voltage signal to extract the amplitude of the induced voltage signal and form a detected voltage signal; the feedback sub-module is configured to generate a corresponding feedback current signal according to the detected voltage signal.

[0080] Exemplarily, the above detector sub-module can demodulate and filter the 100 kHz induced voltage signal input from the fourth bidirectional transmission port COM2, extract its amplitude information, and generate a detected voltage signal; feedback sub-module: generate a reverse feedback current according to the detected voltage signal, and transmit it back to the induction coil of the current working axis through the fourth bidirectional transmission port COM2 to form a reverse magnetic field that cancels the magnetic field to be measured.

[0081] In some embodiments, in addition to the above Figure 4 shown scheme, the multiplexer configuration can also be adjusted. In the implementation of the time-sharing working control module, the number and connection method of the multiplexers can be flexibly adjusted according to actual needs.

[0082] Example 1: Multiplexer merging: Integrate the two independent multiplexers (multiplexer 1 and multiplexer 2) in the above scheme into a single chip to reduce the hardware complexity by sharing control signals.

[0083] Example 2: Multiplexer splitting: For scenarios with high channel number requirements, a single multiplexer can be split into multiple levels of sub-multiplexers, such as using a tree-like cascade structure, to expand the channel capacity or adapt to the fundamental mode orthogonal fluxgate sensors with different numbers of axes.

[0084] The above adjustment realizes the balance of hardware resources and system costs by changing the multiplexer topology while maintaining the core logic of time-sharing switching, and is applicable to magnetic field measurement systems of different scales.

[0085] In some embodiments, in addition to the above Figure 4 shown scheme, the function of the time-sharing working control module can be realized through module fusion and device-level control.

[0086] Example 1: Add operational amplifiers with enable terminals in the excitation module and the detection feedback module, and control the on / off of the amplifiers through enable signals instead of relying on multiplexer switching. When a certain axis is working, the enable terminal of its corresponding operational amplifier is activated to form a complete signal path; the amplifiers of non-working axes are in the off state, physically isolating the excitation current and the feedback current.

[0087] Example 2: Deploy an enable control switch at the interface between the magnetic core and the induction coil of a three-axis fundamental mode orthogonal fluxgate sensor, and directly send an enable pulse from the microcontroller to select the target axis, and the remaining axes are silent due to power-off. Among them, the enable control switch can be a MOSFET or a relay. Such a scheme can achieve the equivalent time-sharing working effect of the multiplexer scheme through functional module reconstruction and device-level switch control, while reducing the dependence on dedicated multiplexer chips and improving the flexibility of system design.

[0088] In the solution shown in the above embodiments, low-noise and low-power measurement of the three-axis magnetic field is achieved through the refined design of the time-sharing working control module. Its beneficial effects are mainly reflected in the following aspects:

[0089] (1) Noise suppression: The microcontroller switches the multiplexer at a high frequency of 4 kHz (state switching period 250 μs) to ensure that only the magnetic core and induction coil of a single axis are connected to the circuit at the same time, and the other two axes are completely powered off and isolated. This time-sharing driving mechanism eliminates the cross-coupling interference between the three-axis excitation magnetic field and the feedback magnetic field from the physical level, significantly reducing the measurement noise caused by magnetic field crosstalk and improving the signal-to-noise ratio.

[0090] (2) Power consumption optimization: The traditional three-axis system needs to maintain the three-axis excitation current simultaneously (total current about 210 mA), while in this solution, through time-sharing multiplexing of the excitation path, the average current of the system is reduced to the single-axis level (70 mA), and the dynamic power consumption is reduced by more than 66%. It is especially suitable for battery-powered portable devices.

[0091] (3) Guarantee of timing consistency: The high-frequency switching (4 kHz) makes the measurement intervals of the three axes extremely short (measurement period of each axis is about 83 μs), which can be approximately regarded as synchronous measurement, avoiding the measurement deviation between axes caused by the time-varying environmental magnetic field, and ensuring the spatio-temporal consistency of the three-dimensional magnetic field data.

[0092] (4) Hardware simplification and reliability improvement: Using a standardized multiplexer chip to replace the complex three-axis parallel drive circuit not only reduces the number of components and the wiring complexity, but also enhances the anti-interference ability and maintainability of the system through the programmed switching logic of the microcontroller.

[0093] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0094] The above-described embodiments merely represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the patent scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A three-axis fundamental mode orthogonal fluxgate sensor control circuit, characterized in that: include: A time-sharing work control module, and a three-axis fundamental mode orthogonal fluxgate sensor, an excitation module, and a detection feedback module connected to the time-sharing work control module; The excitation module is used to generate an excitation current and output the excitation current to the time-sharing work control module; The time-sharing operation control module is used to control the three-axis magnetic cores in the three-axis fundamental mode orthogonal fluxgate sensor to work in time-sharing mode, and to generate an induced voltage signal based on the excitation current; The detection feedback module is used to condition the induced voltage signal and generate a corresponding feedback current signal; The time-sharing operation control module is further used to input the feedback current signal to the induction coil corresponding to the target shaft magnetic core, and the target shaft magnetic core is the shaft magnetic core in the working state.

2. The circuit according to claim 1, characterized in that The three-axis fundamental mode orthogonal fluxgate sensor comprises: an X-axis magnetic core, a Y-axis magnetic core, a Z-axis magnetic core, an X-axis induction coil, a Y-axis induction coil, and a Z-axis induction coil; The first input port of the time-sharing control module is connected to the excitation module for receiving the excitation current; The first output port, the second output port, and the third output port of the time-sharing work control module are connected to the X-axis magnetic core, the Y-axis magnetic core, and the Z-axis magnetic core respectively; The first bidirectional transmission port, the second bidirectional transmission port and the third bidirectional transmission port of the time-sharing work control module are connected to the X-axis induction coil, the Y-axis induction coil and the Z-axis induction coil; The fourth bidirectional transmission port of the time-sharing operation control module is connected to the detection feedback module.

3. The circuit according to claim 2, characterized in that The time-sharing work control module is used to: In a first state, the first output port is controlled to be connected to the first input port, and the first bidirectional transmission port is controlled to be connected to the fourth bidirectional transmission port; or, In the second state, the second output port is controlled to be connected to the first input port, and the second bidirectional transmission port is controlled to be connected to the fourth bidirectional transmission port; or, In the third state, the third output port is controlled to be connected to the first input port, and the third bidirectional transmission port is controlled to be connected to the fourth bidirectional transmission port.

4. The circuit according to claim 3, characterized in that The time-sharing work control module includes: a first connection control submodule, a second connection control submodule and a microcontroller; The first input port, the first output port, the second output port, and the third output port of the time-sharing work control module are ports on the first connection control submodule; The first bidirectional transmission port, the second bidirectional transmission port, the third bidirectional transmission port and the fourth bidirectional transmission port of the time-sharing work control module are ports on the second connection control submodule; The microcontroller is used to achieve one of the first state, the second state and the third state by controlling the connection or disconnection of the port on the first connection control submodule and controlling the connection or disconnection of the port on the second connection control submodule.

5. The circuit according to claim 4, characterized in that The microcontroller is used to: In a first state, controlling the first output port on the first connection control submodule to be connected to the first input port, and controlling the first bidirectional transmission port on the second connection control submodule to be connected to the fourth bidirectional transmission port; or, In the second state, the second output port on the first connection control submodule is controlled to be connected to the first input port, and the second bidirectional transmission port on the second connection control submodule is controlled to be connected to the fourth bidirectional transmission port; or, In the third state, the third output port on the first connection control submodule is controlled to be connected to the first input port, and the third bidirectional transmission port on the second connection control submodule is controlled to be connected to the fourth bidirectional transmission port.

6. The circuit according to claim 5, characterized in that The first connection control submodule and the second connection control submodule are multiplexers.

7. The circuit according to any one of claims 3 to 5, characterized in that: The first state, the second state and the third state appear alternately in sequence.

8. The circuit according to any one of claims 3 to 5, characterized in that: The detection feedback module comprises: Detection submodule and feedback submodule; The input end of the detection submodule is connected to the fourth bidirectional transmission port, the output end of the detection submodule is connected to the feedback submodule, and the output end of the feedback submodule is connected to the fourth bidirectional transmission port.

9. The circuit according to claim 8, characterized in that The detection submodule is used to demodulate and filter the induced voltage signal to extract the amplitude of the induced voltage signal to form a detection voltage signal; The feedback submodule is used to generate a corresponding feedback current signal according to the detection voltage signal.

10. The circuit according to claim 9, characterized in that The three-axis fundamental mode orthogonal fluxgate sensor comprises: an X-axis fundamental mode orthogonal fluxgate, a Y-axis fundamental mode orthogonal fluxgate and a Z-axis fundamental mode orthogonal fluxgate, wherein the X-axis fundamental mode orthogonal fluxgate comprises the X-axis magnetic core and the X-axis induction coil, the Y-axis fundamental mode orthogonal fluxgate comprises the Y-axis magnetic core and the Y-axis induction coil, and the Z-axis fundamental mode orthogonal fluxgate comprises the Z-axis magnetic core and the Z-axis induction coil; The measuring directions of the X-axis base mode orthogonal flux gate, the Y-axis base mode orthogonal flux gate and the Z-axis base mode orthogonal flux gate are aligned with the X, Y and Z axes in the orthogonal Cartesian coordinate system.

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