An automated test equipment for an array magnetometer electric control system

Abstract

The application discloses an automatic test equipment of an array type magnetometer electric control system, which comprises a host computer and an analog probe connected with the host computer; the analog probe comprises: a current simulation module which simulates the photoelectric current output of the magnetometer to a detection object according to the instruction of a master control module; a signal sampling module which samples three-axis magnetic compensation signals and heating signals or signal source signals and transmits the signals to the master control module; an amplitude detection module which converts the heating signals into direct current signals in linear relation with signal peaks and inputs the signals into the signal sampling module; a signal shaping module which converts the heating signals into square wave signals and inputs the signals into the master control module for frequency detection; and a switching multiplexing module which selects and switches the signal channels according to the instruction of the master control module. The application greatly simplifies manual wiring and switching processes, improves the automation degree of the system, and can significantly improve the detection efficiency and consistency of the array type magnetometer electric control system.

Description

Technical Field

[0001] This invention relates to the field of magnetometer testing technology, and in particular to an automated testing device for an array-type magnetometer electronic control system. Background Technology

[0002] The array-type magnetometer control system and the magnetometer probe array together constitute the array-type magnetometer system. Based on the principle of spinless exchange relaxation, the magnetometer probe can achieve high-sensitivity measurement of extremely weak magnetic signals, with an average sensitivity of up to 20 fT / Hz for magnetic field acquisition. 1 / 2 An array structure constructed using multiple probes enables high spatial resolution magnetic source imaging. To ensure the magnetometer probe operates normally, it must run in a controlled magnetic environment. The array magnetometer's control system first performs high-precision temperature control on the probe's internal gas chamber, while simultaneously implementing triaxial magnetic compensation to establish a near-zero magnetic field operating environment. Under the premise of meeting external environmental conditions, the system detects the photocurrent signal output by the magnetometer probe, and, combined with internal signal processing and calculation algorithms, ultimately obtains the target magnetic field strength value. For any electronic equipment intended for mass production and delivery, there is typically a need for automated testing and rapid verification. However, for array magnetometer control systems, there is currently no mature, dedicated automated testing solution in the industry. Existing testing methods still mainly rely on traditional general-purpose testing instruments, such as oscilloscopes and signal generators, manually verifying the function of each channel one by one. This is not only cumbersome in wiring and configuration, but also highly dependent on the professional expertise of operators, resulting in low testing efficiency and difficulty in meeting the testing requirements of large-scale, high-consistency, and rapid delivery.

[0003] The patent document "A Calibration Device and Method for an Array Magnetometer Based on a Magnetic Dipole Model" published in Chinese patent literature, with publication number CN117110965A and publication date of 2023-11-24, includes a spherical magnetic source model and a calibration base. The spherical magnetic source model has an array of coil-wound cylinders distributed on its spherical surface, with each coil-wound cylinder protruding from the spherical surface. A transverse circular shaft extending to the right from the center of the right side surface of the spherical surface connects to a disk base. The calibration base has a square cavity with an upper opening. An array of SERF atomic magnetometer slots, penetrating both the inner and outer sides, is formed on the left side wall of the square cavity. The upper half of the front side wall and the upper half of the rear side wall of the square cavity both have upward-opening coil slot arrays. The right side of the square cavity is a semi-circular groove. A calibration base groove is formed between the right end face of the semi-circular groove and the right end plate of the calibration base. The calibration base groove matches the disk base, and the semi-circular groove of the semi-circular groove matches the transverse circular shaft. The spherical surface is located within the square cavity. This technology is a device and method for calibrating array magnetometers. However, there is still a lack of equipment for automatically testing the electronic control system of array magnetometers. It is necessary to rely on traditional general-purpose testing instruments to manually test each channel one by one, which is complicated and inefficient. Summary of the Invention

[0004] The present invention aims to overcome the problems of existing technologies that mainly rely on traditional general-purpose testing instruments to manually verify the function of each channel of an array magnetometer control system. This is not only cumbersome in terms of wiring and configuration, but also highly dependent on the professional expertise of the operators and has low testing efficiency. The present invention provides an automated testing device for array magnetometer control systems.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] An automated testing device for an array-type magnetometer control system includes a host computer and a simulated probe connected thereto; the simulated probe includes:

[0007] The current simulation module simulates the magnetometer photocurrent output to the detection object according to the instructions of the main control module;

[0008] The signal sampling module samples the triaxial magnetic compensation signal, as well as the heating signal or signal source signal, and transmits them to the main control module.

[0009] The amplitude detection module converts the heating signal into a DC signal that is linearly related to the signal peak value. (Input signal sampling module)

[0010] The signal shaping module converts the heating signal into a square wave signal, which is then input into the main control module for frequency detection.

[0011] The switching multiplexing module selects and switches signal channels according to the instructions of the main control module.

[0012] Preferably, the automated testing equipment uses an array-type magnetometer electronic control system as the testing object, and the host computer is communicatively connected to the analog probe and the testing object to control the analog probe and the testing object respectively.

[0013] The array magnetometer's electronic control system connects to the analog probes via adapter cables, and the corresponding number of analog probes are connected according to the number of channels of the object being detected.

[0014] Preferably, the current simulation module includes a first simulation unit and a second simulation unit with the same circuit structure;

[0015] The first analog unit includes a digital-to-analog converter chip with several independent output channels. Each independent output channel is connected to a constant current source circuit and outputs the analog magnetometer photocurrent from the output terminal of the constant current source circuit.

[0016] Preferably, in the constant current source circuit, the independent output channel is connected to one end of the second resistor, one end of the first capacitor, and the non-inverting input terminal of the second operational amplifier through the first resistor; the other end of the first capacitor is grounded, and the other end of the second resistor is connected to the output terminal and the inverting input terminal of the first operational amplifier; the inverting input terminal of the second operational amplifier is grounded through the third resistor and connected to the output terminal of the second operational amplifier through a parallel resistor and capacitor; the output terminal of the second operational amplifier is connected to the non-inverting input terminal of the first operational amplifier through the fourth resistor, serving as the output terminal of the constant current source circuit.

[0017] Preferably, the signal sampling module includes an analog-to-digital converter chip with at least four sampling channels;

[0018] The first to third sampling channels in the analog-to-digital converter chip acquire triaxial magnetic compensation signals respectively; the fourth sampling channel detects the heating signal amplitude or the signal source signal, and switches between the two detection signals through a relay.

[0019] Preferably, the signal sampling module further includes a switching circuit and an amplification circuit corresponding to the triaxial magnetic compensation signal;

[0020] For any axis of magnetic compensation signal, the gain of the analog probe circuit is automatically adjusted according to the magnitude of the magnetic compensation signal output by the array magnetometer control system. The magnetic compensation signal is then amplified or attenuated before being input into the signal sampling module for sampling.

[0021] Preferably, the amplitude detection module includes a signal conditioning circuit, a rectifier circuit, and a filter circuit connected in sequence;

[0022] The signal conditioning circuit amplifies or attenuates the heating signal by using a combination of a third operational amplifier and different feedback resistors;

[0023] The rectifier circuit rectifies the conditioned signal in one direction through a half-wave rectifier, and then inverts it through a fourth operational amplifier before outputting it to the filter circuit.

[0024] The filter circuit is an RC low-pass filter circuit, which outputs a DC signal that is linearly related to the peak value of the heating signal.

[0025] Preferably, the signal shaping module includes a comparator; the heating signal is coupled through a second capacitor and clamped to a safe level by a limiting diode; the clamped signal is input to the inverting input of the comparator through a fifth resistor; a reference level is input to the non-inverting input of the comparator; and a square wave signal is output to the main control module after current limiting by a sixth resistor.

[0026] Preferably, in the switching multiplexing module, the instruction issued from the main control module is output through the displacement register and then controlled by the Darlington transistor to switch the relay array on and off, thereby selecting and switching the signal channel.

[0027] The relay array includes a first relay array that switches between analog current output and noise testing, and a second relay array that selectively tests one of several channels of the object under test.

[0028] The first relay array includes several first subarrays with identical structures, each first subarray corresponding to a channel of a detection object.

[0029] Preferably, in the first sub-array, the simulated magnetometer photocurrent is input to the moving contact of the fifth relay, the normally closed contact of the fifth relay is grounded through the seventh resistor, the normally open contact of the fifth relay is connected to the normally open contact of the first relay, the moving contact of the first relay outputs the simulated magnetometer photocurrent to the object being detected, the normally closed contact of the first relay is connected to the normally open contacts of the second to fourth relays respectively, and the moving contacts of the second to fourth relays are respectively connected to the triaxial magnetic compensation signal of the object being detected and output by the corresponding normally closed contact.

[0030] This invention offers the following advantages: By integrating multiple functional modules and programmable control logic, a high-precision, high-efficiency, and highly compatible integrated automatic testing device is constructed, which can significantly improve the detection efficiency and consistency of the array magnetometer control system during production testing, R&D verification, and fault diagnosis. It can selectively connect one or two analog probes to cover all channels based on the number of channels of the object being tested, enhancing the flexibility of the control system. A heating signal shaping module is designed to accurately detect the heating signal frequency, ensuring the consistency of the magnetometer array's heating frequency and improving the accuracy of magnetic field detection. A switching and multiplexing module is designed to dynamically switch and acquire different types of signals, greatly simplifying manual wiring and switching processes and improving the system's automation level. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the automated testing equipment for the array-type magnetometer electrical control system in this invention.

[0032] Figure 2 This is the circuit diagram of the main control module in this invention.

[0033] Figure 3 This is a circuit diagram of the communication connection unit in the main control module of this invention.

[0034] Figure 4 This is a circuit diagram of the first simulation unit in the current simulation module of this invention.

[0035] Figure 5 This is a circuit diagram of the second simulation unit in the current simulation module of this invention.

[0036] Figure 6This is a circuit diagram of the signal acquisition module in this invention.

[0037] Figure 7 This is a circuit diagram of the signal switching and amplification process in the signal acquisition module of this invention.

[0038] Figure 8 This is a circuit diagram of the amplitude detection module and the signal shaping module in this invention.

[0039] Figure 9 This is a circuit diagram of the switching multiplexing module in this invention.

[0040] Figure 10 This is a circuit diagram of the first relay array and the second relay array in the switching multiplexing module of this invention.

[0041] Figure 11 This is a circuit diagram of the remaining relay arrays in the switching multiplexing module of this invention.

[0042] Figure 12 This is a schematic diagram of the adapter cable between the analog probe and the array magnetometer control system in this invention.

[0043] Figure 13 This is a flowchart of the overall testing process of the automated testing equipment in this invention. Detailed Implementation

[0044] The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

[0045] like Figure 1 As shown, an automated testing device for an array magnetometer control system includes an array magnetometer control system as the object of testing and a simulated probe connected thereto; the simulated probe includes:

[0046] The current simulation module simulates the magnetometer photocurrent output to the detection object according to the instructions of the main control module;

[0047] The signal sampling module samples the triaxial magnetic compensation signal, as well as the heating signal or signal source signal, and transmits them to the main control module.

[0048] The amplitude detection module converts the heating signal into a DC signal that is linearly related to the signal peak value. (Input signal sampling module)

[0049] The signal shaping module converts the heating signal into a square wave signal, which is then input into the main control module for frequency detection.

[0050] The switching multiplexing module selects and switches signal channels according to the instructions of the main control module.

[0051] It should be noted that this invention integrates multiple functional modules to construct a high-precision, high-efficiency, and highly compatible integrated automatic testing device. This significantly improves the testing efficiency and consistency of the array magnetometer control system during production testing, R&D verification, and fault diagnosis. It allows for selective access of one or two analog probes to cover all channels, enhancing the flexibility of the control system's testing capabilities, based on the number of channels of the object being tested. A heating signal shaping module is included to accurately detect the heating signal frequency, ensuring the consistency of the magnetometer array's heating frequency and improving magnetic field detection accuracy. A switching and multiplexing module dynamically switches between different signal types, greatly simplifying manual wiring and switching processes and increasing the system's automation level. By replacing manual testing of the array magnetometer control system with automated testing equipment, tedious wiring and operations are eliminated, thereby improving testing efficiency and avoiding human error, thus enhancing reliability.

[0052] It's worth noting that the array magnetometer system mainly consists of an array magnetometer control system and a magnetometer probe array. During normal use, the array magnetometer control system detects the current signal output by the magnetometer probes and calculates the magnetic field strength using an internal algorithm. However, before formal delivery, it's necessary to verify the current detection accuracy of the array magnetometer control system. Therefore, this control system is connected to automated testing equipment. This equipment outputs a known, high-precision current to the control system. By comparing the current detection value and the actual output value, it's possible to determine if the detection accuracy meets the requirements and perform testing on the control system. (For example, a simulated probe might output multiple fixed current values ​​within the array magnetometer control system's current detection range for testing. If the error exceeds ±5%, it's considered unqualified; when the output current value is 0, the standard is -2uA to 2uA, and values ​​exceeding this range are considered unqualified.) In addition, the magnetometer probe needs to be in a specific temperature environment to work properly, generally 150℃. To meet this condition, a heating coil is installed inside the probe. The array magnetometer control system outputs a fixed 400KHz sin waveform to the coil. In order to accurately control the temperature, a PT1000 is also used as a temperature feedback unit.

[0053] Specifically, the analog probe mainly consists of a main control module, a current simulation module, a signal sampling module, an amplitude detection module, a signal shaping module, and a switching and multiplexing module. The current simulation module is a 16-bit four-channel digital-to-analog converter (DAC) used to generate analog PD current signals, which are then output to the array-type magnetometer control system via a dual operational amplifier constant current source composed of OPA2192 for current detection and verification. The signal sampling module is a 16-bit analog-to-digital converter used to detect the three-axis magnetic compensation signal, heating signal, and signal source signal output by the array-type magnetometer control system. During magnetic compensation signal measurement, XYZ axis signals can be measured simultaneously as needed; during signal source signal measurement, only one signal is detected at a time.

[0054] For the data acquisition and processing of the three-axis magnetic compensation signal, the actual detection result is obtained by comparing the ADC detection value acquired by the signal sampling module with the circuit gain; and the signal frequency of any one axis is calculated separately. The actual voltage value of that axis is the actual voltage value minus the voltage bias of that axis. The zero-crossing point of the actual voltage value is detected and the zero-crossing time is recorded (the previous voltage value of that axis was greater than 0 and the current voltage value of that axis is less than 0, which can be judged as a zero-crossing point). The time between two adjacent zero points is one period, and the reciprocal of the period is the frequency. The three-axis voltage signal and the frequency of that axis are uploaded to the host computer for display. The host computer converts the three-axis voltage signal into a current value and compares it with a preset current range. If it exceeds the preset current range, it is judged as unqualified.

[0055] Specifically, for circuit gain settings, when the voltage amplitude is below 4mVrms, enable 3-stage amplification (amplification factor can be 441 times); when the voltage amplitude is between [4mVrms and 100mVrms], enable 2-stage amplification (amplification factor can be 21 times); and when the voltage amplitude is above 100mVrms, enable 1-stage amplification (amplification factor can be 1 times). The setting is based on the principle that the smaller the signal, the greater the gain, so that small signals can be amplified as much as possible to improve signal detection accuracy; the processed signal cannot exceed the sampling range of the signal sampling module.

[0056] The signal processing method for the signal source differs from that of the triaxial magnetic compensation signal. When detecting the frequency, the voltage signal is fixed at a preset voltage bias (e.g., 100mV) to ensure the signal source signal crosses zero. Specifically, the actual detection result is acquired by the signal sampling module; the signal source frequency is calculated by subtracting the preset voltage bias from the signal source voltage value; the zero-crossing point of the signal voltage is detected and recorded (a zero-crossing is determined when the previous signal voltage value is greater than 0 and the current signal voltage value is less than 0); the time between two adjacent zero points constitutes one period; the reciprocal of the period is the frequency; the signal source voltage signal and frequency are then uploaded to the host computer for display. The host computer compares the signal source voltage signal with a preset voltage range; if it exceeds the preset voltage range, it is considered unqualified.

[0057] The amplitude detection circuit converts a fixed-frequency 400kHz heating signal (the frequency of which is shaped by the signal shaping module and then calculated by the main control module) into a DC signal. Its output is linearly related to the peak value of the original heating signal, allowing the amplitude of the heating signal to be calculated from the ADC sampling results of the signal sampling module. The data processing of the heating signal includes: acquiring the frequency of the heating signal and converting it into a DC signal linearly related to its peak value; calibrating the testing equipment; and calculating the peak value of the heating signal.

[0058] Test equipment calibration: For heating signals, due to the clipping of the heating signal waveform output by the array magnetometer's electronic control system, a linear error occurs between the amplitude detection value and the actual amplitude value. Therefore, it is necessary to calibrate the amplitude detection value of the heating signal. The calibration steps are as follows: Use an oscilloscope to obtain the actual amplitude value of the heating signal waveform; use an analog probe to detect the heating signal and obtain the amplitude detection value; use the least squares method to fit the [amplitude detection value, actual amplitude value] dataset to obtain the k and b coefficients; obtain the calibration relationship between the actual amplitude value and the amplitude detection value, then the actual amplitude value = k * amplitude detection value + b, and the calibration is complete.

[0059] Peak value calculation of heating signal: First, the voltage value of the heating signal is sampled from the signal sampling module. The voltage value is divided by the circuit gain and then multiplied by 2 to obtain the amplitude detection value. The amplitude detection value is calibrated using a calibration formula to obtain the actual amplitude value. The actual amplitude value and the frequency of the heating signal are uploaded to the host computer for display. The host computer compares the actual amplitude value with the preset amplitude range. If it exceeds the preset amplitude range, it is judged as unqualified.

[0060] To achieve accurate detection of the heating signal frequency, this invention uses a signal shaping module to convert the original heating signal into a square wave signal with a consistent frequency, and then inputs this signal to the timer unit of the main control module. The main control module uses a high-precision frequency counting method to count the number of square wave pulses within a set time window, thereby calculating the frequency of the heating signal. Specifically, TIM1 is set to external trigger mode, and the count value is incremented by 1 for each rising edge of the received heating signal; TIM2 is set to record the TIM1 count value at fixed intervals (e.g., 50ms); the frequency is the difference between the TIM1 count value and the previous TIM1 count value divided by the fixed interval.

[0061] The switching and multiplexing module consists of a GN595T shift register and a relay array, used for flexible switching between different signal channels and simulating a PT1000 resistor output to support the calibration and verification of the temperature measurement function. Specifically, the temperature measurement module of the array magnetometer system has linearity errors and needs to be calibrated before delivery. The calibration method is as follows: a known resistance value is output to the magnetometer using an analog probe to obtain a dataset of [theoretical temperature, measured temperature]. The dataset is then fitted using the least squares method to obtain the corresponding coefficients k and b, thus obtaining the final measured temperature as k * initial measured temperature + b, achieving temperature calibration.

[0062] Furthermore, the automated testing equipment also includes a host computer, which communicates with both the analog probes and the object being tested, controlling both. The array magnetometer's electrical control system connects to the analog probes via adapter cables, connecting a corresponding number of analog probes based on the number of channels on the object being tested. The entire equipment is powered by a power supply module, with the corresponding power source connected based on the power requirements of each module within the equipment. Since the specific power supply circuitry uses existing conventional technology, it will not be described in detail.

[0063] It should be noted that the device of this invention consists of a host computer and an analog probe, and uses an array-type magnetometer control system (which can be divided into a 4-channel single-light acquisition board and a miniaturized main control system based on the number of channels) as the detection object. High-speed communication between the host computer and the analog probe is achieved through a USB 2.0 interface, and data exchange between the host computer and the array-type magnetometer control system is achieved through a network cable. The analog probe is powered by a DC 12V / 1A power adapter, which has good portability and power adaptability.

[0064] It is worth noting that the host computer integrates analog probe control, acquisition board control, and miniaturized main control (i.e., control of the array magnetometer's electronic control system). It can manage up to two analog probes simultaneously, enabling up to eight channels of analog output for photocurrent, analog output for resistance, triaxial magnetic compensation signal detection, heating signal detection, signal source signal detection, and input / output noise testing. When testing a 4-channel single-light acquisition board, only one analog probe needs to be connected to complete the entire testing process; however, for the functional verification of the miniaturized main control, two analog probes need to be connected simultaneously to cover all channels.

[0065] As a specific example, such as Figure 2The circuit diagram of the main control module in this invention is shown. The MCU of the main control module is an STM32F407VET6. The STM32F407xx series is based on the high-performance Arm Cortex-M4, a 32-bit RISC core, with an operating frequency of up to 168 MHz. The Cortex-M4 core has a single-precision floating-point unit (FPU) and supports all ARM single-precision data processing instructions and data types. It also implements a complete set of DSP instructions and a memory protection unit (MPU), improving the security of the application. The main control module is connected to the current simulation module, signal sampling module, signal shaping module, and switching multiplexing module.

[0066] Specifically, the main control module and the current simulation module are connected and exchange information through seven ports: 8734_CS, 8734_SCK, 8734_SDI, 8734_SDO, 8734_LDAC, 8734_CS2, and 8734_LDAC2. The main control module is connected to the first simulation unit in the current simulation module through five ports: 8734_CS, 8734_SCK, 8734_SDI, 8734_SDO, and 8734_LDAC. The second simulation unit in the current simulation module is connected through five ports: 8734_CS2, 8734_SCK, 8734_SDI, 8734_SDO, and 8734_LDAC2.

[0067] The main control module and the signal sampling module are connected via seven ports: 2357_PD, 2357_BUSY, 2357_CNV, 2357_CS, 2357_SCK, 2357_SDI, and 2357_SDO0, for information exchange. Simultaneously, the main control module connects to the relay control circuit of the amplitude detection module via the HBP and HDX terminals to control the on / off state of the corresponding relays. The main control module also connects to the relay control circuit of the switching circuit in the signal sampling module via the XBP, YBP, ZBP, and HOC terminals to control the on / off state of the corresponding relays. The main control module connects to the signal shaping module via the HEATF terminal to receive information from the signal shaping module.

[0068] The main control module and the switching multiplexing module are connected through five ports: 595_SER, 595_G, 595_RCK, 595_SCK and 595_SCLR. The main control module outputs corresponding information to the shift register in the switching multiplexing module to control the relay array on and off, and then selects and switches the signal channel.

[0069] like Figure 3As shown, the main control module also includes a communication connection unit, which is divided into an Ethernet unit and a USB unit. The Ethernet unit uses the YT8512C as its Ethernet PHY chip and implements all physical layer functions required for sending and receiving data via an RJ45 interface. This Ethernet unit connects to the MCU in the main control module via a standard RMII interface. The USB unit uses a TYPE, 16P, QTGM027 USB interface and connects to the MCU in the main control module via the USB_P and USB_N terminals.

[0070] As a specific embodiment, the current simulation module includes a first simulation unit and a second simulation unit with identical circuit structures; such as Figure 4 The circuit diagram of the first analog unit is shown below. Figure 5 The circuit diagram of the second analog unit is shown below.

[0071] The first analog unit includes a digital-to-analog converter chip with several independent output channels VO. Each independent output channel VO is connected to a constant current source circuit and outputs an analog magnetometer photocurrent from the output terminal of the constant current source circuit.

[0072] It should be noted that this invention uses a DAC (Digital-to-Analog Converter) chip combined with a constant current source circuit to simulate the photocurrent output of a magnetometer. Two DAC8734 chips are used to simulate the photocurrent signal outputs of PD1 and PD2 respectively. Each DAC8734 chip has four independent output channels VO0-VO3. The DAC8734 communicates with the MCU via SPI. The constant current source circuit is implemented using a dual operational amplifier configuration based on OPA2192. This structure has good output accuracy and noise performance, with noise levels as low as below 100nA. This circuit converts voltage into current, which is output through the PDXXOUT terminal. Since both PD1 and PD2 photocurrent signals have four channels, two DAC8734 chips are used. The first DAC chip is used in the first analog unit to output the PD1 current signal, and the second DAC chip is used in the second analog unit to output the PD2 current signal.

[0073] Furthermore, in the constant current source circuit, the independent output channel is connected to one end of the second resistor, one end of the first capacitor, and the non-inverting input terminal of the second operational amplifier through the first resistor; the other end of the first capacitor is grounded, and the other end of the second resistor is connected to the output terminal and the inverting input terminal of the first operational amplifier, respectively; the inverting input terminal of the second operational amplifier is grounded through the third resistor and connected to the output terminal of the second operational amplifier through a parallel resistor and capacitor; the output terminal of the second operational amplifier is connected to the non-inverting input terminal of the first operational amplifier through the fourth resistor, serving as the output terminal of the constant current source circuit.

[0074] Specifically, the circuit of the first analog unit includes a digital-to-analog converter chip U26. The U26 connects to the MCU of the main control module through five ports: 8734_CS, 8734_SCK, 8734_SDI, 8734_SDO, and 8734_LDAC. Based on current analog commands from the main control module, the U26 outputs signals from four independent output channels (8734_VO0 to 8734_VO3) to their respective constant current source circuits. The signal output from 8734_VO0 outputs an analog current PD11OUT after passing through the constant current source circuit; the signal output from 8734_VO1 outputs an analog current PD12OUT; the signal output from 8734_VO2 outputs an analog current PD13OUT; and the signal output from 8734_VO3 outputs an analog current PD14OUT.

[0075] Since the four constant current source circuits in the first analog unit have the same circuit structure, the constant current source circuit connected to the output of the 8734_VO0 channel will be used as an example for explanation.

[0076] The 8734_VO0 channel is connected via resistor R137 to one end of resistor R138, one end of capacitor C193, and the non-inverting input of op-amp U28B. The other end of capacitor C193 is grounded. The other end of resistor R138 is connected to the output and inverting input of op-amp U28A. Op-amp U28A is connected to a bias voltage of AN15V. The inverting input of op-amp U28B is grounded via resistor R131 and connected to the output of op-amp U28B via resistor R132 and capacitor C191 in parallel. The output of op-amp U28B is connected to the non-inverting input of op-amp U28A via resistor R134 as the output of the constant current source circuit PD11OUT, and this terminal is grounded via resistor R140.

[0077] The circuitry for the second analog unit includes a digital-to-analog converter chip U61. U61 connects to the MCU of the main control module via five ports: 8734_CS2, 8734_SCK, 8734_SDI, 8734_SDO, and 8734_LDAC2. Based on current analog commands from the main control module, U61 outputs signals from four independent output channels (8734_VO0A to 8734_VO3A) to their respective constant current source circuits. The signal output from 8734_VO0A, after passing through the constant current source circuit, outputs an analog current PD21OUT; the signal output from 8734_VO1A, after passing through the constant current source circuit, outputs an analog current PD22OUT; the signal output from 8734_VO2A, after passing through the constant current source circuit, outputs an analog current PD23OUT; and the signal output from 8734_VO3A, after passing through the constant current source circuit, outputs an analog current PD24OUT.

[0078] For the four constant current source circuits in the second analog unit, since their circuit structures are the same, the constant current source circuit connected to the 8734_VO0A channel output will be used as an example for explanation.

[0079] The 8734_VO0A channel is connected via resistor R184 to one end of resistor R185, one end of capacitor C268, and the non-inverting input of op-amp U58B. The other end of capacitor C268 is grounded. The other end of resistor R185 is connected to the output and inverting input of op-amp U58A. Op-amp U58A is connected to a bias voltage of AN15V. The inverting input of op-amp U58B is grounded via resistor R175, and connected to the output of op-amp U58B via parallel resistor R176 and capacitor C266. The output of op-amp U58B is connected to the non-inverting input of op-amp U58A via resistor R181, serving as the output terminal PD21OUT of the constant current source circuit. This terminal is also grounded via resistor R229.

[0080] It should be noted that the current simulation module has four outputs for both analog current PD1 and PD2, forming eight current output channels: PD11OUT, PD12OUT, PD13OUT, PD14OUT, PD21OUT, PD22OUT, PD23OUT, and PD24OUT, through two DAC8734 chips and eight OPA2192 chips. These eight analog current outputs are connected to the first relay array of the switching multiplexing module, and the switching of analog current output and noise testing is based on the on / off control of the relay array.

[0081] As a specific embodiment, the signal sampling module includes an analog-to-digital converter chip containing at least four sampling channels;

[0082] The first to third sampling channels in the analog-to-digital converter chip acquire triaxial magnetic compensation signals respectively; the fourth sampling channel detects the heating signal amplitude or the signal source signal, and switches between the two detection signals through a relay.

[0083] It should be noted that, as Figure 6 As shown, the LTC2357 in the signal sampling module is a 4-channel ADC chip with 16-bit resolution. Channels 1-3 are used for triaxial magnetic compensation signal acquisition, and channel 4 is used for heating signal amplitude detection or signal source signal detection. The two signals are switched via a relay. The LTC2357 communicates with the MCU of the main control module via SPI. To prevent the ADC from burning out due to excessive input signals, diodes D16-D23 are added to the circuit for protection.

[0084] Specifically, the circuit for the signal sampling module includes an analog-to-digital converter chip U30. The analog-to-digital converter chip U30 is connected to the MCU of the main control module through seven ports: 2357_PD, 2357_BUSY, 2357_CNV, 2357_CS, 2357_SCK, 2357_SDI and 2357_SDO0. It inputs the acquired triaxial magnetic compensation signal, heating signal or signal source signal into the main control module.

[0085] The X-axis magnetic compensation signal is sampled in the first sampling channel of the analog-to-digital converter chip U30. The positive terminal of the first sampling channel is connected to one end of capacitor C240 ​​and one end of resistor R219, respectively; the negative terminal of the first sampling channel is connected to the other end of capacitor C240 ​​and grounded; the other end of resistor R219 is connected to the input terminal X of the X-axis magnetic compensation signal; one end of resistor R219 is connected to the AP5V power supply through diode D16 and to the AN5V power supply through diode D17.

[0086] The circuit structure of the second to fourth sampling channels of the analog-to-digital converter chip U30 is the same as that of the first sampling channel. The second sampling channel is connected to the input terminal Y of the Y-axis magnetic compensation signal, the third sampling channel is connected to the input terminal Z of the Z-axis magnetic compensation signal, and the fourth sampling channel is connected to the input terminal H / C of the heating signal or the signal source signal.

[0087] Furthermore, the signal sampling module also includes a switching circuit and an amplification circuit corresponding to the triaxial magnetic compensation signal; and a switching circuit corresponding to the heating signal or the signal source signal;

[0088] For any axis of magnetic compensation signal, the gain of the analog probe circuit is automatically adjusted according to the magnitude of the magnetic compensation signal output by the array magnetometer control system. The magnetic compensation signal is then amplified or attenuated before being input into the signal sampling module for sampling.

[0089] Specifically, such as Figure 7 The diagram shows a switching circuit, a corresponding relay array, and an amplification circuit for the three-axis magnetic compensation signal.

[0090] In this invention, the switching circuit is configured to achieve the specific switching function through the on / off control of relays in the circuit. In this embodiment, there are six relays, K31 to K36. In order to reduce the number of relays used in the switching circuit, double-pole double-throw relays of model HFD4 / 5SR are used to connect to the switching circuit. The control circuits of relays K34 and K36 in the amplitude detection module are connected through the HBP and HDX terminals to control the on / off of the corresponding relays. The control circuits of relays K31, K32, K33 and K35 in the switching circuit of the signal sampling module are connected through the XBP, YBP, ZBP and HOC terminals.

[0091] For specific relay control circuits, the six relay control circuits in this embodiment have the same structure, therefore... Figure 7 The following explanation uses the relay control circuit connected to the XBP terminal as an example. The XBP terminal input of the main control module MCU is connected to the gate of MOSFET Q13. The MOSFET can be a 2N7002LT3G. The gate of MOSFET Q13 is connected to the source of MOSFET Q13 through resistor R159 and grounded. The drain of MOSFET Q13 is connected to one end of the coil of relay K31 and the anode of diode D24. The other end of the coil of relay K31 is connected to the cathode of diode D24 and connected to the P5V_1 power supply. The two ends of the coil of relay K31 are also connected to a series branch of resistor R145 and LED D26.

[0092] For the remaining relay control circuits, the YBP terminal controls the on / off state of relay K32, the ZBP terminal controls the on / off state of relay K33, the HBP terminal controls the on / off state of relay K34, the HOC terminal controls the on / off state of relay K35, and the HDX terminal controls the on / off state of relay K36.

[0093] The switching circuit includes a switching circuit for the heating signal and the signal source signal, as well as a switching circuit for the triaxial magnetic compensation signal. The switching circuit for the heating signal and the signal source signal is controlled by a relay K35. The first moving contact of relay K35 is connected to the H / C terminal of the fourth sampling channel, its first normally closed contact is connected to the heating signal amplitude HA terminal, and its first normally open contact is connected to the signal source signal CA terminal.

[0094] For the switching circuit of the three-axis magnetic compensation signal, the X-axis magnetic compensation signal is switched and controlled by relay K31. The X-axis magnetic compensation signal X_IN acquired from the detection object is connected to the first moving contact of K31. The first normally closed contact of K31 is connected to the second normally closed contact of K31. The first normally open contact of K31 is connected to the input terminal XB of the X-axis amplifier circuit. The output terminal XP of the X-axis amplifier circuit is connected to the second normally open contact of K31. The second moving contact of K31 is connected to the X terminal of the first sampling channel.

[0095] The Y-axis magnetic compensation signal is switched and controlled by relay K32. The Y_IN terminal of the Y-axis magnetic compensation signal acquired from the detection object is connected to the first moving contact of K32. The first normally closed contact of K32 is connected to the second normally closed contact of K32. The first normally open contact of K32 is connected to the input terminal YB of the Y-axis amplifier circuit. The output terminal YP of the Y-axis amplifier circuit is connected to the second normally open contact of K32. The second moving contact of K32 is connected to the Y terminal of the second sampling channel.

[0096] The Z-axis magnetic compensation signal is switched and controlled by relay K33 and part of relay K35. The Z-axis magnetic compensation signal Z_IN acquired from the detected object is connected to the first moving contact of K33. The first normally closed contact of K33 is connected to the second normally closed contact of K33. The first normally open contact of K33 is connected to the input terminal ZB of the Z-axis amplifier circuit. The first output terminal ZP of the Z-axis amplifier circuit is connected to the second normally open contact of K33. The second moving contact of K33 is connected to the Z terminal of the third sampling channel. As a further optional improvement, an additional amplification and switching circuit can be connected between the second moving contact of K33 and the Z terminal, allowing the Z-axis magnetic compensation signal to be selectively amplified in two stages. That is, the second moving contact of K33 is connected to the second normally closed contact of K35. The second normally open contact of K35 is connected to the second output terminal ZZ of the Z-axis amplifier circuit. The second moving contact of K35 is connected to the Z terminal of the third sampling channel.

[0097] For the amplification circuit of the three-axis magnetic compensation signal, the amplification circuit of the X-axis magnetic compensation signal is as follows: the input terminal XB is grounded through resistor R231 and connected to the non-inverting input terminal of op-amp U53A (OPA2191) through resistor R230. The inverting input terminal of op-amp U53A is grounded through resistor R233 and connected to the output terminal of op-amp U53A through resistor R234. The output terminal is connected to the output terminal XP through resistor R232.

[0098] The amplification circuit for the Y-axis magnetic compensation signal is as follows: the input terminal YB is grounded through resistor R241 and connected to the non-inverting input terminal of op-amp U53B (OPA2191) through resistor R239. The inverting input terminal of op-amp U53B is grounded through resistor R237 and connected to the output terminal of op-amp U53B through resistor R235. This output terminal is connected to the output terminal YP through resistor R238.

[0099] The amplification circuit for the Z-axis magnetic compensation signal is as follows: the input terminal ZB is grounded through resistor R251 and connected to the non-inverting input terminal of op-amp U54A (OPA2191) through resistor R248. The inverting input terminal of op-amp U54A is grounded through resistor R250 and connected to the output terminal of op-amp U54A through resistor R253. This output terminal is connected to the first output terminal ZP through resistor R249. The first output terminal ZP is connected to the non-inverting input terminal of op-amp U54B through resistor R271. The inverting input terminal of op-amp U54B is grounded through resistor R273 and connected to the output terminal of op-amp U54B through resistor R274. This output terminal is connected to the second output terminal ZZ through resistor R272.

[0100] As a specific example, such as Figure 8 As shown, the amplitude detection module includes a signal conditioning circuit, a rectifier circuit, and a filter circuit connected in sequence.

[0101] The signal conditioning circuit amplifies or attenuates the heating signal by using a combination of a third operational amplifier and different feedback resistors;

[0102] The rectifier circuit rectifies the conditioned signal in one direction through a half-wave rectifier, and then inverts it through a fourth operational amplifier before outputting it to the filter circuit.

[0103] The filter circuit is an RC low-pass filter circuit, which outputs a DC signal that is linearly related to the peak value of the heating signal.

[0104] It should be noted that the heating signal itself is a sinusoidal signal with a frequency of 400kHz and an amplitude varying between 0 and 12V. Since the signal sampling module's sampling frequency is only 20kHz, far lower than the heating signal frequency, it cannot directly sample the original high-frequency signal. Therefore, an amplitude detection module circuit was designed to rectify and filter the heating signal, converting it into a DC voltage signal linearly related to its peak amplitude for sampling by the signal sampling module. The operational amplifiers in this circuit are all LT1122CS8 op-amps.

[0105] Specifically, the entire circuit mainly consists of three parts: a signal conditioning circuit, a rectifier circuit, and a filter circuit. The heating signal is first pre-conditioned by an inverting operational amplifier with U19 as its core. Different combinations of feedback resistors are switched by relays K34 and K36 to amplify or attenuate signals of different amplitudes, ensuring that the DC voltage signal output by the amplitude detection module is not too large or too small, thus exceeding the detection range of the signal sampling module.

[0106] The HEAT signal terminal is connected to the moving contact of relay K36. The normally closed contact of relay K36 is connected to the first moving contact of relay K34. The normally open contact of relay K36 is connected to the second moving contact of relay K34. The two normally open contacts and two normally closed contacts of relay K34 are connected to the inverting input terminal of operational amplifier U19 through four different resistors. The non-inverting input terminal of operational amplifier U19 is grounded through resistor R77. The inverting input terminal of operational amplifier U19 is connected to the output terminal.

[0107] The conditioned signal is fed into a precision rectifier circuit centered around operational amplifiers U5 and U29. This section utilizes a combination of operational amplifiers and a high-speed small-signal diode (1N4148) to eliminate the 0.7V forward voltage drop of ordinary diode rectification, enabling high-precision rectification even for low-amplitude signals. Operational amplifier U5 forms a precision half-wave rectifier, unidirectionally rectifying the input high-frequency sine wave, which is then inverted by operational amplifier U29, ensuring that the output signal accurately reflects the peak value changes of the input signal.

[0108] The conditioned signal is connected to the inverting input of operational amplifier U5 through resistor R240 and to the non-inverting input of operational amplifier U29 through resistor R22. The non-inverting input of operational amplifier U5 is grounded through resistor R24. The inverting input of operational amplifier U5 is connected to the anode of diode D37 and one end of resistor R258. The cathode of diode D37 is connected to the output of operational amplifier U5 and the anode of diode D36. The anode of diode D36 is connected to the non-inverting input of operational amplifier U29. The other end of resistor R258 is connected to the inverting input and output of operational amplifier U29.

[0109] The rectified signal is smoothed by an RC low-pass filter network composed of R242, R246, and C277, which filters out high-frequency components and retains only the DC component that reflects the peak change trend, thus effectively extracting the envelope of the original high-frequency signal. Finally, the output voltage is led out from the HA terminal and sent to the signal sampling module for sampling, completing the indirect measurement of the heating signal peak value.

[0110] As a specific embodiment, the signal shaping module includes a comparator; the heating signal is coupled through a second capacitor, clamped to a safe level by a limiting diode, and the clamped signal is input to the inverting input terminal of the comparator through a fifth resistor; the non-inverting input terminal of the comparator receives a reference level; the output terminal of the comparator is current-limited through a sixth resistor and then outputs a square wave signal to the main control module.

[0111] It should be noted that when multiple magnetometer probes are heated simultaneously, the heating frequency must be kept consistent. The error must be less than or equal to 0.025% at 400kHz. If the heating signal frequency is inconsistent across different magnetometer probes, low-frequency noise will be generated, affecting the accuracy of magnetic field detection. Therefore, it is necessary to detect the frequency of the heating signal.

[0112] Specifically, such as Figure 8 As shown, in order to accurately detect the 400kHz heating signal frequency, this embodiment uses signal shaping to process the original sine wave to adapt it to the digital input characteristics of the main control module MCU. Since the MCU cannot directly process analog sine waves, it must first be converted into a square wave with clearly defined high and low levels. This processing is completed by a high-frequency comparator circuit, with the core device being the TLV9024IDR operational amplifier U30.

[0113] The 400kHz sine wave signal is input from the left HEAT input and coupled into the shaping circuit through capacitor C320. The capacitor acts as DC blocker, preventing subsequent circuits from being affected by DC bias. The signal is then clamped to a safe level by limiting diodes D38 and D39 to prevent instantaneous overvoltage from damaging the comparator or affecting the comparison result. The clamped signal then enters the inverting input of comparator U30 through R275, where it is compared with the reference level at the non-inverting input.

[0114] The non-inverting input of comparator U30 is provided with a reference level by an RC network (R264, R265, R266, and C321), which is set to 1.65V here to achieve symmetrical comparison of the input signal. When the instantaneous voltage of the input sine wave is higher than the reference value, the comparator outputs a high level; otherwise, it outputs a low level, thus converting the continuous sine wave signal into a corresponding 400kHz square wave signal. This output signal is current-limited by R257 and then output to the main control module through the HEATF terminal.

[0115] To enhance the stability and anti-interference capability of the shaped signal, resistor R263 is used to form a feedback path between the output and non-inverting input of comparator U30, giving the comparator a certain hysteresis characteristic, thereby avoiding output jitter caused by noise near the zero point of the input signal and improving the stability of the square wave signal.

[0116] The final shaped 400kHz square wave signal is output from the HEATF terminal and sent to the digital input port of the main control module MCU. The MCU accurately calculates the frequency of the heating signal by counting the number of high-level pulses, realizing the frequency detection function. After testing, the frequency detection accuracy can reach 0.005%.

[0117] As a specific example, such as Figure 9 In the switching multiplexing module shown, the instruction issued from the main control module is output through the displacement register and then controlled by the Darlington transistor to switch the signal channel.

[0118] The relay array includes a first relay array that switches between analog current output and noise testing, and a second relay array that selectively tests one of several channels of the object under test.

[0119] The first relay array includes several first subarrays with identical structures, each first subarray corresponding to a channel of a detection object.

[0120] It should be noted that, in order to achieve the switching and channel selection functions of the simulated PT1000 resistor, this invention uses a method of using a shift register RS595SXTSS16, a Darlington transistor ULN2003A, and a relay array. The MCU of the main control module is connected to the shift register in the switching multiplexing module through ports 595_SER, 595_G, 595_RCK, 595_SCK, and 595_SCLR, and inputs the corresponding on / off control commands to it. Each shift register is connected to a Darlington transistor, and the on / off control commands issued by the main control module are output through each output pin of the Darlington transistor to control the on / off state of the corresponding relay.

[0121] Furthermore, in the first subarray, the simulated magnetometer photocurrent is input to the moving contact of the fifth relay. The normally closed contact of the fifth relay is grounded through the seventh resistor. The normally open contact of the fifth relay is connected to the normally open contact of the first relay. The moving contact of the first relay outputs the simulated magnetometer photocurrent to the object being detected. The normally closed contact of the first relay is connected to the normally open contacts of the second to fourth relays respectively. The moving contacts of the second to fourth relays are respectively connected to the triaxial magnetic compensation signal of the object being detected and output by the corresponding normally closed contact.

[0122] Specifically, such as Figure 10 The diagram shows a partial schematic of the first relay array in the switching multiplexing module and a schematic of the relay control circuit. In the circuit of the switching multiplexing module of this embodiment, the output pin of the Darlington transistor is connected as follows: Figure 10 The relay array shown represents the switching control relay array for analog current output and noise testing (first relay array), the relay array for selecting the detection target channel (second relay array), and as shown in the diagram. Figure 11 The diagram shows a third relay array for selecting analog resistors and a fourth relay array for selecting the signal source channel. Simultaneously, the connection terminals in all relay arrays corresponding to the detected object are connected via... Figure 12 The adapter cable shown is connected to the switching multiplexing module of this embodiment.

[0123] The first relay array includes control circuits for 12 relays, K1 to K12, which are controlled by the outputs of Darlington transistors PD1AL, XA, YA, ZA, PD1A, PD2A, PD1BL, XB, YB, ZB, PD1B, and PD2B. The second relay array includes control circuits for 6 relays, K16 to K21, which are controlled by the outputs of Darlington transistors XYA, XYB, XYC, ZHA, ZHB, and ZHC.

[0124] The third relay array includes control circuits for nine relays, K13 to K15 and K22 to K27, which are controlled by the outputs of Darlington transistors PTA, PTB, PTC, 1.1K_CON, 1.2K_CON, 1.37K_CON, 1.47K_CON, 1.5K_CON, and 1.54K_CON. The fourth relay array includes control circuits for two relays, K28 and K29, which are controlled by the outputs of Darlington transistors K28 and K29.

[0125] The first relay array includes several identical first subarrays, each corresponding to one channel of the detection object. Since each first subarray has the same structure, only one of them will be used as an example for explanation.

[0126] In the current simulation module, the output terminal PD11OUT of the first simulation unit is connected to the first moving contact of relay K5. The first normally closed contact of K5 is grounded through resistor R12. The first normally open contact of K5 is connected to the first normally open contact of relay K1. The first moving contact of relay K1 outputs simulated current to the object being detected through the PD11 terminal. The first normally closed contact of relay K1 is connected to the first normally open contacts of relays K2, K3, and K4 respectively. Relay K2 connects the X-axis magnetic compensation signal of the first channel of the object being detected through its first moving contact and first normally closed contact. Relay K3 connects the Y-axis magnetic compensation signal of the first channel of the object being detected through its first moving contact and first normally closed contact. Relay K4 connects the Z-axis magnetic compensation signal of the first channel of the object being detected through its first moving contact and first normally closed contact. The output terminal PD21OUT of the second simulation unit is connected to the first moving contact of relay K6. The first normally closed contact of K6 is grounded through resistor R20. The first normally open contact of K6 outputs simulated current to the object being detected through the PD21 terminal. The first contact pairs (moving contact, normally open contact, and normally closed contact) of relays K1 to K6 are used to connect the current simulation module and the signal sampling module to the second channel of the object being detected.

[0127] When the first normally open contact of relay K5 is connected to the first moving contact, and the first normally open contact of relay K1 is connected to the first moving contact, PD11OUT and PD11 are connected, and the analog probe outputs analog current to the object being tested; when the first normally closed contact of relay K1 is connected to the first moving contact, and relays K2 to K4 are all connected to the first moving contact and the first normally open contact, a loopback test is performed to check the noise.

[0128] The second contacts of relays K1 to K6 are used to connect the current simulation module and the signal sampling module to the second channel of the object being detected; the first contacts of relays K7 to K12 are used to connect the current simulation module and the signal sampling module to the third channel of the object being detected; and the second contacts of relays K7 to K12 are used to connect the current simulation module and the signal sampling module to the fourth channel of the object being detected.

[0129] For the second relay array, taking the selection of one of the X-axis magnetic compensation signals of the four channels of the detection object as an example, the X_IN terminal connected to the signal sampling module is connected to the first moving contact of relay K18, the first normally open contact of relay K18 is connected to the first moving contact of relay K17, and the first normally closed contact of relay K18 is connected to the first moving contact of relay K16. The X-axis magnetic compensation signals of the four channels of the detection object are connected through the first contacts of relays K16 and K17.

[0130] The second contacts of relays K16 to K18 transmit the Y-axis magnetic compensation signals of the four channels connecting the signal sampling module and the detection object; the first contacts of relays K19 to K21 transmit the Z-axis magnetic compensation signals of the four channels connecting the signal sampling module and the detection object; the second contacts of relays K19 to K21 transmit the heating signals of the four channels connecting the signal sampling module and the detection object; and the two sets of contacts of relays K13 to K15 transmit the heating signals of the four channels connecting the signal sampling module and the detection object. Figure 11 The PTP and PTN terminals of the analog resistor selection correspond to the signals of the four channels of the object being detected.

[0131] As a specific example, such as Figure 13 As shown, the specific operating steps of the automated testing equipment include: after the equipment starts, it waits for instructions from the host computer; if the host computer sends a signal source signal measurement instruction, a triaxial magnetic compensation signal measurement instruction, or a heating signal measurement instruction, the signal sampling module will continuously collect voltage data at a frequency of 20KHz and upload it to the host computer. The heating signal frequency is detected through TIM1 / 2. If the heating signal is too small or too large, the host computer can send an instruction to amplify or attenuate the signal through the amplitude detection module; if the host computer sends a signal generator instruction, the current simulation module will output a current waveform according to the configuration; if the host computer sends a noise test instruction, the relay array will enable the corresponding channel according to the configuration. The host computer automatically controls the automated testing equipment to sequentially complete PD AC / DC testing, temperature detection, triaxial magnetic compensation testing, heating signal detection, noise detection, and signal source function testing. During the test, the host computer will compare the test data with a pre-set reasonable data range. If the data exceeds the reasonable range, it is considered unqualified. After the test is completed, the test results will be displayed on the host computer. A green indicator shows a passed test item, and a red indicator shows a failed test item. The user can export the test report to complete the test.

[0132] Optionally, in cost-sensitive applications, the high-resolution 16-bit ADC (such as the LTC2357) in the above embodiments can be replaced with a lower-resolution 12-bit ADC (such as the ADS7818 or the STM32 built-in ADC module). This can effectively reduce system hardware costs and power consumption, and is suitable for testing environments where noise detection accuracy requirements are not high. Although some measurement accuracy and dynamic range will be sacrificed, it can still achieve the detection and verification of basic functions such as heating signals and magnetic compensation signals of the acquisition board.

[0133] For applications requiring greater flexibility or portability, wireless communication technologies such as Bluetooth, ZigBee, and Wi-Fi can be used to replace USB 2.0 or wired Ethernet communication. This is suitable for distributed testing, remote control, and data acquisition in mobile scenarios. Although wireless transmission suffers from bandwidth limitations and unstable latency, making it unsuitable for high-frequency, high-throughput data scenarios, with proper configuration of communication protocols and data compression methods, it can still meet most functional control and data feedback requirements.

[0134] Besides using a timer counting method, the frequency of the heating signal can also be detected using software edge detection or an external dedicated frequency counting chip (such as TDC-GPX). This can further improve the resolution of frequency measurement or reduce MCU resource consumption, making it suitable for scenarios with extreme accuracy requirements or ultra-high-speed signal frequency detection.

[0135] The above embodiments are further elaborations and descriptions of the present invention to facilitate understanding, and are not intended to limit the present invention in any way. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An automated testing device for an array-type magnetometer control system, characterized in that, The analog probe comprises: The current simulation module simulates the magnetometer photocurrent output to the detection object according to the instruction of the host computer module; The signal sampling module comprises an analog-to-digital conversion chip comprising at least four sampling channels, samples the three-axis magnetic compensation signal, the signal source signal and the heating signal converted by the amplitude detection module from the detection object, and transmits them to the host computer module; The first to third sampling channels in the analog-to-digital conversion chip respectively collect the three-axis magnetic compensation signal; the fourth sampling channel detects the heating signal amplitude or the signal source signal, and switches the two detection signals through a relay; The host computer module compares the data processing result of the sampling data with the preset data range to determine whether the detection object is qualified; The amplitude detection module converts the heating signal from the detection object into a direct current voltage signal in linear relationship with the peak value of the heating signal and inputs it into the signal sampling module; The signal shaping module converts the heating signal into a square wave signal and inputs it into the host computer module for frequency detection; The switching and multiplexing module selects and switches the signal channel according to the instruction of the host computer module, and at least includes analog current output and noise test switching, and selective detection of a plurality of channels of the detection object.

2. The automated test equipment for an array magnetometer electronic control system of claim 1, wherein, The arrayed magnetometer electric control system is taken as the detection object, and the host computer is in communication connection with the analog probe and the detection object for analog probe control and detection object control; The arrayed magnetometer electric control system is connected with the analog probe through a conversion line, and a corresponding number of analog probes are connected according to the number of channels of the detection object.

3. The automated test equipment for an electric control system of an array magnetometer according to claim 1 or 2, characterized in that, The current simulation module comprises a first simulation unit and a second simulation unit with the same circuit structure; The first simulation unit comprises a digital-to-analog conversion chip with a plurality of independent output channels, each independent output channel is connected with a constant current source circuit, and the constant current source circuit outputs the simulated magnetometer photocurrent from the output end of the constant current source circuit; In the constant current source circuit, the independent output channel is connected with one end of the second resistor, one end of the first capacitor and the positive input end of the second operational amplifier through the first resistor; the other end of the first capacitor is grounded, and the other end of the second resistor is connected with the output end and the inverting input end of the first operational amplifier; the inverting input end of the second operational amplifier is grounded through the third resistor, and is connected with the output end of the second operational amplifier through the parallel resistor-capacitor; The output end of the second operational amplifier is connected with the positive input end of the first operational amplifier through the fourth resistor, serving as the output end of the constant current source circuit.

4. The automated test equipment for an electric control system of an array magnetometer according to claim 1 or 2, characterized in that, The signal sampling module further comprises a switching circuit and an amplification circuit corresponding to the three-axis magnetic compensation signal; for the magnetic compensation signal of any axis, the circuit gain of the analog probe is automatically adjusted according to the size of the magnetic compensation signal output by the arrayed magnetometer electric control system, and the magnetic compensation signal is amplified or attenuated before being input into the signal sampling module for sampling.

5. The automated test equipment for an array magnetometer electronic control system of claim 4, wherein, The data processing of the three-axis magnetic compensation signal comprises: The detection value collected by the signal sampling module is compared with the circuit gain to obtain the three-axis voltage signal; The signal frequency of any axis is calculated, the actual voltage value of the axis is the voltage value of the axis minus the voltage bias of the axis, the zero crossing point of the actual voltage value is detected and the zero crossing time is recorded, the interval between two adjacent zero crossing times is a period, and the reciprocal of the period is the frequency; The three-axis voltage signals and the frequency are uploaded to the upper computer, the three-axis voltage signals are converted into current values, and the current values are compared with the preset current range, and if the current values exceed the preset current range, the product is determined to be unqualified; The data processing of the signal source signal includes: collecting the signal source voltage signal by the signal sampling module; calculating the signal source signal frequency in the same way as the three-axis magnetic compensation signal; uploading the signal source voltage signal and the frequency to the upper computer, and comparing the signal source voltage signal with the preset voltage range, and if the signal source voltage signal exceeds the preset voltage range, the product is determined to be unqualified.

6. The automated test equipment for an electronic control system of an array magnetometer according to claim 1 or 2 or 5, characterized in that, The amplitude detection module includes a signal conditioning circuit, a rectifier circuit and a filter circuit connected in sequence; The signal conditioning circuit amplifies or attenuates the heating signal through the combination of the third operational amplifier and different feedback resistors; The rectifier circuit performs one-way rectification on the conditioned signal through a half-wave rectifier, and then performs inverse processing through the fourth operational amplifier to output to the filter circuit; The filter circuit is an RC low-pass filter circuit, which outputs a direct current signal in linear relationship with the peak value of the heating signal.

7. The automated test equipment for an array magnetometer electronic control system of claim 6, wherein, The data processing of the heating signal includes: The frequency of the heating signal is obtained, and the heating signal of the frequency is converted into a direct current voltage signal in linear relationship with the peak value of the heating signal; The device is calibrated, a calibration relationship between the amplitude detection values of a plurality of heating signals detected by the analog probe and the corresponding actual amplitude values is fitted, and the calibration relationship is obtained; The signal sampling module collects the voltage value of the heating signal, and the voltage value is divided by the circuit gain and then multiplied by 2 to obtain the amplitude detection value; the actual amplitude value is obtained by using the calibration relationship; the actual amplitude value and the frequency of the heating signal are uploaded to the upper computer, and the upper computer compares the actual amplitude value with the preset amplitude range, and if the actual amplitude value exceeds the preset amplitude range, the product is determined to be unqualified.

8. The automated test equipment for an electric control system of an array magnetometer according to claim 1 or 2 or 5 or 7, characterized in that, The signal shaping module includes a comparator; after the heating signal is coupled through the second capacitor, it is clamped to a safe level through a limiting diode, and the clamped signal is input to the inverting input terminal of the comparator through the fifth resistor; the non-inverting input terminal of the comparator inputs a reference level; The output terminal of the comparator outputs a square wave signal to the main control module after current limiting through the sixth resistor.

9. The automated test equipment for an electric control system of an array magnetometer according to claim 1 or 2 or 5 or 7, characterized in that, In the switching multiplexing module, the instructions from the main control module are output through the shift register, and then drive and control the on-off of the relay array through the Darlington tube to select and switch the signal channel; The relay array includes a first relay array for switching between analog current output and noise testing, a second relay array for selecting one of a plurality of channels of a detection object, a third relay array for selecting an analog resistor, and a fourth relay array for selecting a signal source signal channel; The first relay array includes a plurality of first sub-arrays with the same structure, and each first sub-array corresponds to a channel of a detection object.

10. The automated test equipment for an array magnetometer electronic control system of claim 9, wherein, In the first sub-array, the analog magnetometer photocurrent is input into the moving contact of the fifth relay, the normally closed contact of the fifth relay is connected to the ground through the seventh resistor, the normally open contact of the fifth relay is connected to the normally open contact of the first relay, the moving contact of the first relay outputs the analog magnetometer photocurrent to the detection object, the normally closed contact of the first relay is connected to the normally open contacts of the second to fourth relays respectively, and the moving contacts of the second to fourth relays are connected to the three-axis magnetic compensation signals of the detection object respectively and output by the corresponding normally closed contacts.

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