Electromagnetic interference scanner, control method and storage medium

Abstract

The present application discloses an electromagnetic interference scanner, a control method and a storage medium, and the technical field to which it belongs is electromagnetic interference imaging technology. The electromagnetic interference scanner includes: a multi-degree-of-freedom scanning platform, a near-field scanning unit, a main control unit, a motion control unit, a visual positioning unit and a laser ranging unit; the multi-degree-of-freedom scanning platform includes a base, a gantry structure, an X-axis moving mechanism, a Z-axis moving mechanism and a storage table; the visual positioning unit is used to collect images of the object to be measured, and the laser ranging unit is used to collect three-dimensional point cloud data of the object to be measured; the main control unit is used to generate a three-dimensional motion path based on the image of the object to be measured and the three-dimensional point cloud data, and send the three-dimensional motion path to the motion control unit; the motion control unit is used to control the movement of the near-field probe according to the motion instruction, so that the near-field probe scans the object to be measured according to the three-dimensional motion path. The present application can automatically generate the scanning path of the near-field probe and improve the working accuracy of the electromagnetic interference scanner.

Description

Technical Field

[0001] The present application relates to the field of electromagnetic interference imaging technology, and in particular to an electromagnetic interference scanner, a control method and a storage medium. Background Art

[0002] An electromagnetic interference scanner, also known as an electromagnetic interference element comprehensive analysis device, is an instrument used to detect and analyze the electromagnetic radiation of equipment. It uses a high-precision near-field probe to scan the electronic equipment to be tested in order to measure the electromagnetic field strength.

[0003] In the related art, workers are usually required to plan a scanning path for the near-field probe of an electromagnetic interference scanner. However, due to certain differences in the appearance of electronic devices to be tested, workers are often required to plan a corresponding scanning path for each electronic device to be tested. The above process is inefficient and prone to errors.

[0004] Therefore, how to automatically generate the scanning path of the near-field probe and improve the working accuracy of the electromagnetic interference scanner is a technical problem that those skilled in the art currently need to solve. Summary of the invention

[0005] The purpose of this application is to provide an electromagnetic interference scanner, a control method for an electromagnetic interference scanner and a storage medium, which can automatically generate a scanning path of a near-field probe and improve the working accuracy of the electromagnetic interference scanner.

[0006] In order to solve the above technical problems, the present application provides an electromagnetic interference scanner, comprising: a multi-degree-of-freedom scanning platform, a near-field scanning unit, a main control unit, a motion control unit, a visual positioning unit and a laser ranging unit;

[0007] The multi-degree-of-freedom scanning platform includes a base, a gantry structure, an X-axis moving mechanism, a Z-axis moving mechanism and a storage table, the base is provided with a Y-axis guide rail, the gantry structure is installed on the Y-axis guide rail, the crossbeam of the gantry structure is provided with an X-axis guide rail, the X-axis moving mechanism is installed on the X-axis guide rail, the X-axis moving mechanism is provided with a Z-axis track, the Z-axis moving mechanism is installed on the Z-axis track, the Z-axis moving mechanism is provided with a rotating mechanism for rotating around the Z-axis, the near-field scanning unit includes a probe fixture assembly and a near-field probe, the probe fixture assembly is installed on the rotating mechanism, the probe fixture assembly is used to install the near-field probe, the storage table is installed on the base, and the storage table is used to place the object to be measured;

[0008] The visual positioning unit and the laser ranging unit are installed on the Z-axis moving mechanism, the visual positioning unit is used to collect the image of the object to be measured, and the laser ranging unit is used to collect the three-dimensional point cloud data of the object to be measured;

[0009] The main control unit is connected to the motion control unit, the visual positioning unit and the laser ranging unit respectively; the main control unit is used to generate a three-dimensional motion path according to the image of the object to be measured and the three-dimensional point cloud data, and send a motion instruction corresponding to the three-dimensional motion path to the motion control unit;

[0010] The motion control unit is connected to the gantry structure, the X-axis moving mechanism and the Z-axis moving mechanism respectively, and is used to control the movement of the near-field probe according to the motion instruction so that the near-field probe scans the object to be measured according to the three-dimensional motion path.

[0011] Optionally, the near-field scanning unit further includes a spectrum module and a low-noise amplifier;

[0012] The RF output port of the near-field probe is connected to the input port of the low-noise amplifier, the output port of the low-noise amplifier is connected to the RF input port of the spectrum module, and the communication port of the spectrum module is connected to the communication port of the main control unit.

[0013] Optionally, the probe fixture assembly includes: a fixed bracket, a slide rail seat, a slide rail, a positioning block with a V-shaped protrusion, a connecting piece with a V-shaped groove, and a probe fixing fixture;

[0014] The slide rail seat is mounted on the rotating mechanism through the fixing bracket, and the slide rail is mounted in the slide rail seat;

[0015] The slide rail comprises a fixed portion and a movable portion, wherein the fixed portion is fixed to the slide rail seat by means of threads, and the movable portion is used to move along the Z-axis direction in the slide rail seat;

[0016] The positioning block is installed on the moving part, and a magnet is embedded in the positioning block;

[0017] The positioning block has a V-shaped protrusion on one side thereof, and a positioning shaft is provided on the connecting piece, and the connecting piece is provided with a positioning hole, and the connecting piece is a connecting piece made of a magnetic material; when the connecting piece is installed on the positioning block through the positioning hole and the positioning shaft, the V-shaped protrusion of the positioning block and the V-shaped groove of the connecting piece are in contact with each other, and the magnet embedded in the positioning block generates suction force on the connecting piece;

[0018] A probe fixing fixture is installed on the connecting piece, and the probe fixing fixture is used to install the near-field probe.

[0019] Optionally, the fixing bracket is connected to the slide rail seat via threads;

[0020] The upper end of the slide rail seat is provided with a groove, and the fixing bracket cooperates with the groove at the upper end of the slide rail seat through a thread to achieve a fixed connection;

[0021] The probe fixing fixture fixes the near-field probe via a probe fixing cover plate.

[0022] In order to solve the above technical problems, the present application provides a control method of an electromagnetic interference scanner, which is applied to a main control unit of any of the above electromagnetic interference scanners. The control method of the electromagnetic interference scanner includes:

[0023] Acquire the image of the object to be tested collected by the visual positioning unit;

[0024] Performing edge detection on the image of the object to be tested to obtain position information of the object to be tested; wherein the position information is used to describe the position of the projection of the object to be tested in the Z-axis direction;

[0025] Controlling the laser ranging unit to perform laser scanning on the object to be measured to obtain three-dimensional point cloud data;

[0026] Generate a three-dimensional model of the object to be measured according to the three-dimensional point cloud data;

[0027] Perform path planning according to the position information of the object to be measured and the three-dimensional model to obtain a three-dimensional motion path;

[0028] The near-field probe on the electromagnetic interference scanner is controlled to scan the object to be measured according to the three-dimensional motion path.

[0029] Optionally, edge detection is performed on the image of the object to be detected to obtain position information of the object to be detected, including:

[0030] Using Gaussian filtering to smooth the image of the object to be tested, and calculating the gradient information of the image of the object to be tested;

[0031] Performing non-maximum suppression on the image of the object to be tested according to the gradient information to obtain edge points;

[0032] The edge points are screened using a threshold, and the position information of the object to be detected is generated according to the screening result.

[0033] Optionally, performing path planning according to the position information of the object to be measured and the three-dimensional model to obtain a three-dimensional motion path includes:

[0034] Performing two-dimensional path planning according to the position information of the object to be measured to obtain a two-dimensional motion path; wherein the two-dimensional motion path includes a plurality of traversal points, and the traversal points include X-axis coordinates and Y-axis coordinates;

[0035] Setting a point in the three-dimensional model that has the same X-axis coordinate and Y-axis coordinate as the traversal point as a scanning point;

[0036] The three-dimensional motion path is generated according to the three-dimensional coordinate values ​​of all the scanning points and the size of the near-field probe.

[0037] Optionally, performing two-dimensional path planning according to the position information of the object to be measured to obtain a two-dimensional motion path includes:

[0038] Determine a scanning area according to the position information of the object to be measured; wherein the scanning area is a projection of the object to be measured in the Z-axis direction;

[0039] The coordinate extreme value of the scanning area is determined, the scanning area is traversed in a reciprocating forward manner according to the coordinate extreme value, and the two-dimensional motion path is generated according to the traversed points.

[0040] Optionally, after controlling the near-field probe on the electromagnetic interference scanner to scan the object to be detected according to the three-dimensional motion path, the method further includes:

[0041] Acquire electromagnetic radiation data scanned by the near-field probe;

[0042] Performing a preprocessing operation on the electromagnetic radiation data; wherein the preprocessing operation includes outlier removal, data normalization and boundary condition setting;

[0043] Constructing an interpolation function, and using the interpolation function to perform interpolation processing on the electromagnetic radiation data to obtain an interpolation result;

[0044] The interpolation result is visualized.

[0045] Optionally, after acquiring the electromagnetic radiation data scanned by the near-field probe, the method further includes:

[0046] Electromagnetic characteristics of components and / or circuits on the object to be tested are analyzed according to the electromagnetic radiation data.

[0047] The present application also provides a storage medium on which a computer program is stored. When the computer program is executed, the steps of the control method of the electromagnetic interference scanner are implemented.

[0048] The present application provides an electromagnetic interference scanner, including: a multi-degree-of-freedom scanning platform, a near-field scanning unit, a main control unit, a motion control unit, a visual positioning unit and a laser ranging unit. The visual positioning unit can collect images of the object to be measured, and the laser ranging unit can collect three-dimensional point cloud data of the object to be measured; the main control unit can generate a three-dimensional motion path based on the image of the object to be measured and the three-dimensional point cloud data, and then control the near-field probe to scan the object to be measured according to the three-dimensional motion path through the motion control unit and the multi-degree-of-freedom scanning platform. The present application realizes the automatic generation of the near-field probe scanning path by combining the automated processing capabilities of the visual positioning unit, the laser ranging unit and the main control unit, thereby improving the working accuracy of the electromagnetic interference scanner. The present application also provides a control method and a storage medium for an electromagnetic interference scanner, which have the above-mentioned beneficial effects and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0050] Figure 1 A schematic diagram of the structure of an electromagnetic interference scanner provided in an embodiment of the present application;

[0051] Figure 2 A schematic diagram of the structure of an electromagnetic interference scanner provided in an embodiment of the present application;

[0052] Figure 3 A schematic diagram of a disassembled probe fixture assembly provided in an embodiment of the present application;

[0053] Figure 4 A top view of a positioning block provided in an embodiment of the present application when it is separated from a connecting piece;

[0054] Figure 5 A top view of a connecting member provided in an embodiment of the present application when installed on a positioning block;

[0055] Figure 6 A schematic diagram of anti-collision principle when a near-field probe moves downward provided in an embodiment of the present application;

[0056] Figure 7 A schematic diagram of the anti-collision principle when a near-field probe moves backwards provided in an embodiment of the present application;

[0057] Figure 8 A schematic diagram of anti-collision principle when a near-field probe moves forward provided in an embodiment of the present application;

[0058] Fig. 9 A schematic diagram of anti-collision when a near-field probe moves to the right provided in an embodiment of the present application;

[0059] Fig.10 A schematic diagram of anti-collision when a near-field probe moves to the left provided in an embodiment of the present application;

[0060] Fig.11 A flowchart of a comprehensive analysis method of electromagnetic interference elements provided in an embodiment of the present application;

[0061] Fig.12 A flowchart of a visual positioning algorithm for edge detection provided in an embodiment of the present application. DETAILED DESCRIPTION

[0062] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0063] See below Figure 1 , Figure 1 A structural schematic diagram of an electromagnetic interference scanner provided in an embodiment of the present application includes: a multi-degree-of-freedom scanning platform, a main control unit, a motion control unit, a visual positioning unit, a laser ranging unit, a near-field scanning unit and a human-computer interaction unit.

[0064] The multi-degree-of-freedom scanning platform is used to move the scanning probe in multiple directions to achieve a comprehensive scan of the object to be measured. The multi-degree-of-freedom scanning platform may include a base, a gantry structure, an X-axis moving mechanism, a Z-axis moving mechanism and a storage table.

[0065] The near-field scanning unit comprises a probe fixture assembly and a near-field probe.

[0066] The multi-degree-of-freedom scanning platform may have at least 4 degrees of freedom. Specifically, the base is provided with a Y-axis guide rail, the gantry structure is installed on the Y-axis guide rail, the crossbeam of the gantry structure is provided with an X-axis guide rail, the X-axis moving mechanism is installed on the X-axis guide rail, the X-axis moving mechanism is provided with a Z-axis track, the Z-axis moving mechanism is installed on the Z-axis track, the Z-axis moving mechanism is provided with a rotating mechanism for rotating around the Z-axis, the probe fixture assembly is installed on the rotating mechanism, the probe fixture assembly is used to install a near-field probe, the placement table is installed on the base, and the placement table is used to place the object to be tested. The Y-axis guide rail, the X-axis guide rail and the Z-axis guide rail are linear guide rails, and any two of the Y-axis guide rails, the X-axis guide rails and the Z-axis guide rails are perpendicular to each other. The X-axis, Y-axis and Z-axis are coordinate axes in a spatial rectangular coordinate system.

[0067] Specifically, the base is the basic support structure of the entire scanning platform, and a Y-axis guide rail is provided on the base for installing and supporting the gantry structure. The above-mentioned base can be provided with two Y-axis guide rails so that the gantry structure can perform linear motion in the Y-axis direction through the Y-axis guide rails, providing freedom of motion in the Y-axis direction. The above-mentioned gantry structure is a Y-axis moving mechanism, and the gantry structure includes two vertical columns and a crossbeam, and the columns can be installed on the Y-axis guide rail of the base through a slider. An X-axis guide rail is provided on the crossbeam for installing the X-axis moving mechanism. The movement of the gantry structure can be driven by a stepper motor, and precise Y-axis motion can be achieved through ball screw transmission. The X-axis moving mechanism is installed on the crossbeam of the gantry structure, and is used to move along the X-axis direction, providing freedom of motion in the X-axis direction. The X-axis moving mechanism can be installed on the X-axis guide rail through a slider, and a Z-axis track is provided on the X-axis moving mechanism for installing the Z-axis moving mechanism. The movement of the X-axis moving mechanism can be driven by a stepper motor, and precise X-axis motion can be achieved through ball screw transmission. The Z-axis moving mechanism can be installed on the Z-axis track through a slider, and is used to move along the Z-axis direction to provide freedom of movement in the Z-axis direction. The movement of the Z-axis moving mechanism can be driven by a stepper motor, and precise Z-axis movement can be achieved through a ball screw drive. A rotating mechanism is provided on the Z-axis moving mechanism for installing the probe fixture assembly. The rotating mechanism includes a rotating platform, a stepper motor and a gear, and the rotating mechanism can realize the rotation of the rotating platform around the Z-axis by a stepper motor + gear transmission. The probe fixture assembly is used to fix and install the near-field probe to ensure that the probe remains stable during the scanning process. The probe fixture assembly is installed on the rotating mechanism and moves with the rotating mechanism. The storage table is installed on the base, which is used to place the object to be tested to ensure that the object to be tested remains stable during the scanning process. The above-mentioned multi-degree-of-freedom scanning platform can also have other degrees of freedom of movement, which are not specifically limited here.

[0068] The visual positioning unit and the laser ranging unit are installed on the Z-axis moving mechanism so that they can move with the Z-axis moving mechanism and jointly perform multi-angle and all-round detection of the object to be tested. The visual positioning unit is used to collect images of the object to be tested and upload the collected images of the object to be tested to the main control unit; the laser ranging unit is used to collect three-dimensional point cloud data of the object to be tested and upload the three-dimensional point cloud data to the main control unit.

[0069] The main control unit is connected to the motion control unit, the visual positioning unit and the laser ranging unit respectively; the main control unit is used to generate a three-dimensional motion path according to the image of the object to be measured and the three-dimensional point cloud data, and send motion instructions corresponding to the three-dimensional motion path to the motion control unit.

[0070] The motion control unit is connected to the gantry structure, the X-axis moving mechanism and the Z-axis moving mechanism respectively, and is used to control the movement of the near-field probe according to the motion instruction so that the near-field probe scans the object to be measured according to the three-dimensional motion path.

[0071] Specifically, the main control unit can receive the image of the object to be measured uploaded by the visual positioning unit, and can also receive the three-dimensional point cloud data uploaded by the laser ranging unit. In combination with the two-dimensional image and the three-dimensional point cloud data, the main control unit runs the path planning algorithm to generate the three-dimensional motion path of the near-field probe. The three-dimensional motion path generated above can be converted into specific motion instructions, including information such as position, speed, and rotation angle, and the main control unit sends these motion instructions to the motion control unit through the communication interface. After the motion control unit parses the motion instructions, it controls the motors of the gantry structure, the X-axis moving mechanism, the Z-axis moving mechanism, and the rotating mechanism to drive the near-field probe to move along a predetermined path. In this embodiment, a grating ruler can also be installed on the X, Y, and Z axes to provide real-time feedback on the current position of the near-field probe to ensure the accuracy and stability of the movement.

[0072] This embodiment realizes the automatic generation of the near-field probe scanning path by combining the automated processing capabilities of the visual positioning unit, the laser ranging unit and the main control unit, thereby improving the working accuracy of the electromagnetic interference scanner.

[0073] See also Figure 2 , Figure 2 This is a structural schematic diagram of an electromagnetic interference scanner provided in an embodiment of the present application, in which 1-1 represents a frame, 1-2 represents a scanning platform (i.e., a storage table), 1-3 represents a stepper motor, 1-5 represents a guide rail, 1-6 represents a grating ruler, 1-7 represents a fixture for the object to be measured, 2-2 represents a near-field probe, 2-4 represents a probe fixture assembly (also called a near-field probe fixture), 5-1 represents a camera, 6-1 represents a laser sensor, 7-1 represents a touch screen, and 7-2 represents a control button.

[0074] The electromagnetic interference scanner includes a four-degree-of-freedom scanning platform, a near-field scanning unit, a main control unit, a motion control unit, a visual positioning unit, a laser ranging unit and a human-computer interaction unit.

[0075] The four-degree-of-freedom scanning platform includes a frame, a scanning platform, a stepper motor, a ball screw, a guide rail, a grating ruler and a fixture for the object to be measured. Specifically, the scanning platform, the stepper motor, the ball screw, the guide rail, and the grating ruler are installed on the frame, and the fixture for the object to be measured is installed on the scanning platform. The four-degree-of-freedom scanning platform can realize horizontal movement in the three directions of X, Y and Z and rotational movement around the Z axis. Among them, the movement of the three axes of X, Y and Z is realized by the stepper motor + screw transmission, and the rotation around the Z axis is realized by the stepper motor + gear transmission. Grating rulers are installed on the three axes of X, Y and Z of the four-degree-of-freedom scanning platform to realize the closed-loop control of the system, thereby improving the positioning accuracy;

[0076] The frame of the four-degree-of-freedom scanning platform includes a base and a gantry structure made of aluminum alloy. The longitudinal direction of the frame is the Y axis, the horizontal direction is the X axis, and the vertical direction is the Z axis.

[0077] Among them, guide rails are installed on the left and right sides of the frame, the gantry structure is fixed together with the guide rail slider, the Y-axis stepper motor and the lead screw are inverted inside the base, the lead screw nut is connected to the gantry, and the Y-axis stepper motor is used to drive the gantry structure to move along the Y-axis; the gantry structure is horizontal (horizontal of the frame) as the X-axis, and there are guide rails and lead screws on the crossbeam of the gantry structure. The Z-axis part is installed on the guide rail of the Y-axis and connected to the lead screw nut of the X-axis. The X-axis stepper motor is used to drive the Z-axis part to move along the X direction; the Z-axis rotation mechanism is connected to the Z-axis lead screw nut, driven by the Z-axis stepper motor, and moves along the Z-axis. Specifically, the stepper motors of the X, Y, and Z axes and the corresponding ball screws are respectively driven by synchronous belts to change the transmission direction of the motion, making the structure more compact. The Z-axis rotation mechanism includes a hollow rotating platform, in which a stepper motor and a gear transmission mechanism are installed. A probe fixture assembly is installed on the Z-axis rotation mechanism, and a near-field probe is installed on the probe fixture assembly. The Z-axis rotation stepper motor drives the near-field probe to rotate a certain angle (polarization operation) through a gear structure. The near-field probe is located in the hollow area in the middle of the rotation mechanism. By adjusting the positioning hole on the probe fixture, the probe is placed at the center of the circle to ensure that the near-field probe will not be eccentric during polarization operation.

[0078] The near-field scanning unit includes a spectrum module, a near-field probe, a low-noise amplifier and a probe fixture assembly. The near-field probe is installed on the probe fixture assembly, and the probe fixture assembly is fixed on the rotating mechanism at the end of the Z-axis. The RF output port of the near-field probe is connected to the input port of the low-noise amplifier, the output port of the low-noise amplifier is connected to the RF input port of the spectrum module, and the communication port of the spectrum module is connected to the communication port of the main control unit.

[0079] The low noise amplifier includes a low frequency low noise amplifier with an operating frequency of 0.009~3000MHz and a high frequency high noise amplifier with an operating frequency of 1~18GHz.

[0080] In practical applications, there are at least three ways to connect the near-field probe and the spectrum module:

[0081] Connection method 1: The output port of the near-field probe is connected to the RF in port of the high-frequency low-noise amplifier, and the RF out port of the high-frequency low-noise amplifier is connected to the RF in port of the spectrum module;

[0082] Connection method 2: The output port of the near-field probe is connected to the RF in port of the low-frequency low-noise amplifier, and the RF out port of the low-frequency low-noise amplifier is connected to the RF in port of the spectrum module;

[0083] Connection method three: Connect the output port of the near-field probe to the RF in port of the spectrum module.

[0084] The main control unit is connected to the near-field scanning unit, the motion control unit, the visual positioning unit, the laser ranging unit and the human-computer interaction unit respectively, so as to realize the control and data interaction of the whole system.

[0085] The communication port of the motion control unit is connected to the main control unit and the grating ruler to receive the control instructions of the main control unit and the position information fed back by the grating ruler. The control port of the motion control unit is connected to the corresponding stepper motor to control the rotation of the stepper motor. The data acquisition port of the motion control unit is connected to the data acquisition module in the laser ranging module to receive the data of the laser sensor.

[0086] The visual positioning unit is connected to the communication port of the main control unit. The camera transmits the captured image of the object to be tested to the industrial control unit for subsequent processing. When collecting images, the camera position can be adjusted through the control button to ensure that the object to be tested can be fully imaged in the camera. The laser ranging unit includes a laser sensor and a data acquisition module. The laser sensor is connected to the acquisition port of the data acquisition module, and the data acquisition module is connected to the data acquisition port of the motion control unit. The laser ranging performs a three-dimensional scan on the electronic components to be tested to obtain the three-dimensional point cloud data of the object to be tested.

[0087] The data acquisition module collects data from the laser sensor and transmits it to the motion control unit for conversion between analog and digital quantities. It also integrates the X-axis and Y-axis data of the current measurement point returned by the grating ruler to obtain complete three-dimensional coordinate information (x, y, z).

[0088] The human-machine interaction unit includes: a touch screen, control buttons and a data interaction interface. The touch screen is connected to the main control unit, the control buttons are connected to the motion control unit, and the data interaction interface is connected to the main control unit and the near-field scanning unit. The touch screen in the human-machine interaction unit can be a 10.1-inch capacitive touch screen. The control buttons include the forward and reverse movement buttons of the X, Y, and Z axes, the forward and reverse buttons of the probe rotation mechanism, and the emergency stop button. The data interaction interface includes a double-layer USB (Universal Serial Bus), an Ethernet port, an HDMI (High Definition Multimedia Interface), and an SMA (SubMiniature Version A, a microwave high-frequency connector) radio frequency port.

[0089] The scanning plane of the above-mentioned four-degree-of-freedom scanning platform is provided with an array of fixing holes, and the object to be tested fixture is fixed on the scanning plane by screw fastening. The front end of the object to be tested fixture is provided with a V-shaped groove, and the front end is made of flexible material. In actual use, multiple object to be tested fixtures can be used to fix the object to be tested. For example, for an object to be tested of a regular shape, two object to be tested fixtures can be used to fix it; for an object to be tested of an irregular shape, multiple object to be tested fixtures can be used to fix it.

[0090] The above-mentioned near-field probe includes an electric field probe and a magnetic field probe. In this embodiment, an electric field probe or a magnetic field probe can be selected as the near-field probe according to actual test requirements, and the corresponding near-field probe can be installed on the rotating mechanism using a probe fixture assembly.

[0091] Electric field probes are mainly used to measure the strength and distribution of electric fields. Electric field probes are usually composed of a thin metal probe with a sensitive area at the end of the probe. When the electric field acts on the probe, the probe will sense the charge or voltage change of the electric field and convert it into a voltage or current output related to the electric field signal.

[0092] Magnetic field probes are mainly used to measure magnetic field strength and its distribution. Magnetic field probes are usually made of a thin coil or magnetic material, and detect magnetic field changes in the surrounding environment through the induction principle. When the magnetic field acts on the probe, the magnetic field probe will sense the changing magnetic field and convert it into a voltage or current output related to the magnetic field signal.

[0093] As for Figure 1Further introduction to the corresponding embodiment, the above-mentioned probe clamp assembly can be a probe clamp assembly with an anti-collision function; specifically, the above-mentioned probe clamp assembly includes: a fixed bracket, a slide rail seat, a slide rail, a positioning block with a V-shaped protrusion (also called a V-shaped positioning block), a connecting piece with a V-shaped groove (also called a V-shaped groove), and a probe fixing clamp.

[0094] See also Figure 3 , Figure 3 A disassembled schematic diagram of a probe clamp assembly provided in an embodiment of the present application, in which A1 represents a fixed bracket, A2 represents a slide rail seat, A3 represents a slide rail, A4 represents a magnet, A5 represents a positioning block with a V-shaped protrusion, A6 represents a connecting piece with a V-shaped groove, A7 represents a probe fixing cover plate, A8 represents a probe fixing clamp, and A9 represents a near-field probe.

[0095] The slide rail seat is installed on the rotating mechanism through the fixed bracket, and the slide rail is installed in the slide rail seat; the slide rail (such as a micro slide rail) includes a fixed part and a moving part, the fixed part is fixed to the slide rail seat by a thread, and the moving part is used to move in the slide rail seat along the Z-axis direction; the positioning block is installed on the moving part, and a magnet is embedded in the positioning block; the positioning block has a V-shaped protrusion on one side, and a positioning shaft is provided, and the connecting piece is provided with a positioning hole, and the connecting piece is a connecting piece made of magnetic material; when the connecting piece is installed on the positioning block through the positioning hole and the positioning shaft, the V-shaped protrusion of the positioning block and the V-shaped groove of the connecting piece are in contact with each other, and the magnet embedded in the positioning block generates suction to the connecting piece; the probe fixing fixture is installed on the connecting piece, and the probe fixing fixture is used to install the near-field probe. Magnet adsorption can ensure that the probe falls when it contacts the object to be measured, and no hard contact occurs.

[0096] The above-mentioned fixing bracket is connected to the slide rail seat through threads; the upper end of the slide rail seat is provided with a groove, and the fixing bracket cooperates with the groove at the upper end of the slide rail seat through threads to achieve fixed connection; the probe fixing fixture fixes the near-field probe through a probe fixing cover plate.

[0097] The V-shaped protrusion of the positioning block has two inclined surfaces, and the V-shaped groove of the connector also has two inclined surfaces. The inclined surfaces of the positioning block and the connector have the same inclination angle. When the connector is installed on the positioning block through the positioning hole and the positioning shaft, the four inclined surfaces are tightly attached to each other. Figure 4 and Figure 5 , Figure 4 A top view of a positioning block and a connecting member when they are separated provided by an embodiment of the present application. Figure 5 A top view of a connector provided in an embodiment of the present application when installed on a positioning block. Figure 4 and Figure 5In the figure, A5 represents a positioning block with a V-shaped protrusion, and A6 represents a connecting piece with a V-shaped groove.

[0098] The probe fixture assembly is a specific tooling for the near-field probe, which can prevent the near-field probe from making hard contact with the object to be tested or the rack during operation, thereby preventing the near-field probe from being damaged. The probe fixture assembly can meet the use requirements of two types of near-field probes and can achieve mechanical anti-collision functions in the three dimensions of X, Y, and Z.

[0099] Specifically, the fixed bracket is connected to the rotating mechanism through threads and is positioned by a pin hole. Two pin holes may be provided on the fixed bracket to correspond to two types of near-field probes respectively.

[0100] The slide rail is divided into a fixed end (i.e. the end where the fixed part is located) and a movable end (i.e. the end where the movable part is located). The fixed end is fixed to the slide rail seat by threads. A groove and a threaded hole are provided at the upper end of the slide rail seat. The fixed bracket cooperates with the groove and is connected by threads. The slide rail seat can limit the upper and lower positions of the slide rail.

[0101] The back side (i.e. the side facing the slide rail) of the V-shaped protrusion positioning block (also called V-shaped positioning block) is provided with a stepped hole, in which magnets of equal diameters are embedded. There are two mounting holes on the front side of the positioning block, which are fixed to the moving end of the slide rail through threaded connections, and there is a positioning shaft on the front side of the positioning block.

[0102] The connector with a V-shaped groove (also called a V-shaped groove) has a positioning hole. The notch direction of the V-shaped groove and the positioning block are positioned through the positioning axis on the front side of the positioning block (i.e., the side facing the positioning block). The magnet embedded in the stepped hole on the back side of the positioning block adsorbs the connector to fix the connector. The bottom of the connector is connected to the probe fixing part. The probe fixing fixture is processed according to the size of the probe to limit the probe. The cover plate is installed above the probe fixing fixture and fixed by threaded connection to fix the probe.

[0103] The principle of the probe fixture assembly to achieve near-field probe collision prevention is as follows:

[0104] During the up and down movement of the near-field probe, the slide rail can slide up and down. Under the action of gravity, the near-field probe is at the lowest point of the slide rail. When the near-field probe moves downward and contacts the object to be tested, the near-field probe is lifted upward along the direction of the slide rail. Figure 6 , Figure 6 A schematic diagram of the anti-collision principle of a near-field probe moving downward is provided in an embodiment of the present application. The diagram shows the positional relationship between the near-field probe and the object to be measured, 601 represents the overall movement direction, 602 represents the movement direction of the probe along the guide rail, and 603 represents the reaction force applied by the object to be measured to the end of the probe.

[0105] When the near-field probe moves back and forth, it contacts the object to be tested. When the reaction force exerted by the object to the near-field probe is greater than the adsorption force of the magnet, the near-field probe will fall off directly. Figure 7 , Figure 7 This is a schematic diagram of the anti-collision principle of a near-field probe moving backwards provided in an embodiment of the present application. The diagram shows the positional relationship between the near-field probe and the object to be tested. 701 indicates the overall movement direction, 702 indicates the probe falling direction, and 703 indicates the reaction force applied by the object to be tested to the end of the probe. Figure 8 , Figure 8 A schematic diagram of the anti-collision principle of a near-field probe moving forward provided in an embodiment of the present application shows the positional relationship between the near-field probe and the object to be measured, 801 represents the overall movement direction, 802 represents the probe falling direction, and 803 represents the reaction force applied by the object to be measured to the end of the probe.

[0106] When the near-field probe moves left and right and contacts the object to be tested, the object will give the near-field probe a reaction force; when the reaction force is greater than the magnet adsorption force, the connector with the V-shaped groove will fall off along the direction of the oblique edges on both sides of the V-shaped groove. Fig. 9 , Fig. 9 This is a schematic diagram of the anti-collision principle when a near-field probe moves to the right provided by an embodiment of the present application. The diagram shows the positional relationship between the near-field probe and the object to be tested. 901 indicates the overall movement direction, 902 indicates the direction in which the probe falls off, and 903 indicates the reaction force applied by the object to be tested to the end of the probe. Fig.10 , Fig.10 A schematic diagram of the anti-collision principle of a near-field probe moving to the left provided in an embodiment of the present application shows the positional relationship between the near-field probe and the object to be measured, 1001 represents the overall movement direction, 1002 represents the probe falling direction, and 1003 represents the reaction force applied by the object to be measured to the end of the probe.

[0107] Based on the above electromagnetic interference scanner, an embodiment of the present application provides a control method for an electromagnetic interference scanner, comprising the following steps:

[0108] Step 101: Acquire an image of the object to be measured collected by a visual positioning unit;

[0109] This step can be applied to the main control unit of the electromagnetic interference scanner, and the main control unit can obtain the image of the object to be tested on the placement table captured by the visual positioning unit, that is, the image of the object to be tested.

[0110] Step 102: performing edge detection on the image of the object to be tested to obtain position information of the object to be tested;

[0111] In order to obtain the position information of the object to be tested, this embodiment can perform edge detection on the image of the object to be tested collected by the visual positioning unit to obtain the position information. The above position information is used to describe the position of the object to be tested projected in the Z-axis direction, which is perpendicular to the plane where the platform is located.

[0112] Furthermore, the process of edge detection on the image of the object to be tested includes: smoothing the image of the object to be tested using Gaussian filtering, and calculating the gradient information of the smoothed image of the object to be tested; performing non-maximum suppression on the image of the object to be tested based on the gradient information to obtain edge points; screening the edge points using a threshold, and generating the position information of the object to be tested based on the screening results.

[0113] Step 103: controlling the laser ranging unit to perform laser scanning on the object to be measured to obtain three-dimensional point cloud data;

[0114] Before this step, the position and / or scanning angle of the laser distance measuring unit can be adjusted, thereby controlling the laser distance measuring unit to perform laser scanning on the object to be measured to obtain three-dimensional point cloud data. The three-dimensional point cloud data is used to describe the surface shape and structure of the object to be measured.

[0115] Step 104: generating a three-dimensional model of the object to be measured according to the three-dimensional point cloud data;

[0116] Among them, through this step, discrete three-dimensional point cloud data can be converted into a continuous three-dimensional model, so as to accurately represent the shape and structure of the object to be measured.

[0117] Step 105: performing path planning according to the position information of the object to be measured and the three-dimensional model to obtain a three-dimensional motion path;

[0118] Among them, the position information of the object to be measured is used to describe the position of the object to be measured in space, and the three-dimensional model of the object to be measured is used to describe the shape of the object to be measured. By combining the position information and the three-dimensional model to plan the path of the near-field probe, a path that can fully cover the surface of the object to be measured and avoid collision can be obtained, that is, a three-dimensional motion path.

[0119] As a feasible implementation method, this embodiment can first perform two-dimensional path planning, and then combine the two-dimensional path planning results with the three-dimensional model to generate a three-dimensional motion path. The specific process is as follows: perform two-dimensional path planning according to the position information of the object to be measured to obtain a two-dimensional motion path; set the point in the three-dimensional model (i.e., the three-dimensional model corresponding to the outer surface of the object to be measured) that has the same X-axis coordinate and Y-axis coordinate as the traversal point as the scanning point; generate the three-dimensional motion path according to the three-dimensional coordinate values ​​of all the scanning points and the size of the near-field probe. Among them, the two-dimensional motion path includes multiple traversal points, and the traversal points include X-axis coordinates and Y-axis coordinates. If there are multiple points with the same X-axis coordinates and Y-axis coordinates in the three-dimensional model, the point with the largest Z-axis coordinate is set as the scanning point.

[0120] Taking the above process as an example, the points in the two-dimensional motion path include (X1, Y1), (X3, Y3), (X5, Y5), and the points in the three-dimensional model include (X1, Y1, Z1), (X2, Y2, Z2), (X3, Y3, Z3), (X4, Y4, Z4), (X5, Y5, Z5), (X6, Y6, Z6), then the points in the three-dimensional motion path include (X1, Y1, Z1), (X3, Y3, Z3), (X5, Y5, Z5).

[0121] Furthermore, the present embodiment can perform two-dimensional path planning in the following manner: determine the scanning area according to the position information of the object to be measured; wherein the scanning area is the projection area of ​​the object to be measured in the Z-axis direction; determine the coordinate extreme values ​​of the scanning area, traverse the scanning area back and forth according to the coordinate extreme values, and generate the two-dimensional motion path according to the traversed points.

[0122] Step 106: Control the near-field probe on the electromagnetic interference scanner to scan the object to be tested according to the three-dimensional motion path.

[0123] Wherein, on the basis of obtaining the three-dimensional motion path, the near-field probe on the electromagnetic interference scanner can be controlled to move according to the three-dimensional motion path, and the object to be measured can be scanned during the movement.

[0124] This embodiment realizes the automatic generation of the near-field probe scanning path by combining the automated processing capabilities of the visual positioning unit, the laser ranging unit and the main control unit, thereby improving the working accuracy of the electromagnetic interference scanner.

[0125] As a feasible implementation, after controlling the near-field probe to scan the object to be tested according to the three-dimensional motion path, the following electromagnetic imaging operations can also be performed: obtaining electromagnetic radiation data obtained by scanning the near-field probe; performing preprocessing operations on the electromagnetic radiation data; constructing an interpolation function, using the interpolation function to interpolate the electromagnetic radiation data to obtain an interpolation result; and visualizing the interpolation result. The preprocessing operations include outlier removal, data normalization, and boundary condition setting.

[0126] As a feasible implementation, after acquiring the electromagnetic radiation data obtained by scanning the near-field probe, the following element analysis operation may be performed: performing electromagnetic characteristic analysis on the components and / or circuits on the object to be tested according to the electromagnetic radiation data.

[0127] This embodiment also provides a comprehensive analysis method for electromagnetic interference factors, including a visual positioning algorithm based on edge detection, a three-dimensional reconstruction algorithm, a near-field scanning path planning algorithm based on three-dimensional features, and an element analysis algorithm and an electromagnetic imaging algorithm. The above algorithms are embedded in the main control unit, and the overall process is as follows: edge detection is performed on the image to determine the detection area of ​​the object to be measured and locate it; a laser sensor is used to perform laser scanning on the detection area determined in the first step to obtain point cloud information of the object to be measured and construct a three-dimensional feature model of the object to be measured; based on a reciprocating forward traversal scanning method, three-dimensional path planning of near-field scanning of the near-field probe is performed in combination with the boundary of the object to be measured and the three-dimensional features of the object to be measured; element analysis and electromagnetic imaging processing are performed on the data collected by the near-field probe.

[0128] See also Fig.11 , Fig.11 A flowchart of a comprehensive analysis method for electromagnetic interference elements provided by an embodiment of the present application, the process of which is as follows: acquiring an image, determining whether the image is complete, and reacquiring the image if the image is incomplete. If the image is complete, edge detection, expansion corrosion, and boundary extraction are performed in sequence. Determine whether the boundary is complete, and if the boundary is incomplete, enter the expansion corrosion operation, and if the boundary is complete, perform a three-dimensional feature modeling operation of the object to be tested and a three-dimensional near-field scanning path planning operation to perform element analysis and electromagnetic imaging.

[0129] In this embodiment, the detection area of ​​the object to be detected can be identified and located by performing edge detection on the image of the object to be detected collected by the visual positioning unit. Fig.12 , Fig.12This is a flow chart of a visual positioning algorithm for edge detection provided in an embodiment of the present application. The process of the visual positioning algorithm is as follows: after inputting a picture, the edge detection algorithm Canny is run, the edge detection result is expanded and eroded, the maximum edge contour is extracted and the coordinates are converted, and the coordinates are output. This embodiment applies edge detection to the field of electromagnetic emission detection. The object to be tested can be placed arbitrarily in the working area, making the positioning of the object to be tested easier.

[0130] This embodiment uses the Canny edge detection algorithm to determine the detection area of ​​the object to be tested. Through the camera coordinate conversion and calibration process, the object to be tested is described in the rack coordinate system, which realizes adaptive positioning of randomly placed objects to be tested and determines boundary constraints for near-field scanning.

[0131] The process of implementing the edge detection algorithm includes: smoothing the image using Gaussian filtering, pixel gradient calculation, non-maximum suppression, determining the threshold and edge connection.

[0132] Among them, the formula of Gaussian filtering is as follows:

[0133] ;

[0134] represents the value of the Gaussian function, represents the variance of the Gaussian distribution, represents the base of natural logarithm, x represents the horizontal coordinate, and y represents the vertical coordinate.

[0135] The pixel gradient is calculated as follows:

[0136] Horizontal convolution template for: ;

[0137] Vertical convolution template for: ;

[0138] Gradient Amplitude for: ;

[0139] Gradient direction for: .

[0140] The visual positioning algorithm based on edge detection is as follows: take pictures of the object to be tested: the position of the camera needs to be manually adjusted during shooting to ensure the image quality; edge detection based on the Canny algorithm: adjust the threshold to obtain accurate edge information, and perform preprocessing to make the edge smoother and more complete; positioning of the object to be tested: extract the outer edge contour of the object to be tested, perform coordinate transformation, and convert the position information of the object to be tested into the coordinate system of the four-degree-of-freedom scanning platform.

[0141] Coordinate transformation is to transform the image data captured by the camera from the pixel coordinate system to the world coordinate system to determine the exact position of the object being measured on the scanning platform. The matrix used in the transformation process is as follows:

[0142] ;

[0143] X W , Y W and Z W Represents the coordinates in the scanning platform coordinate system (world coordinate system); represents the focal length of the camera; dx and dy represent the pixel size; Zc represents the distance from the point in the world coordinate system to the center of the optical axis. represents the rotation matrix, represents the translation vector, Indicates that the image center is The coordinate offset in the direction, Indicates that the image center is The coordinate offset in the direction, and Represents the horizontal and vertical coordinates in the image coordinate system.

[0144] In this embodiment, a 3D reconstruction algorithm can be used to reconstruct the point cloud information obtained by scanning the object to be measured by a laser sensor to obtain the 3D features of the object to be measured; the 3D reconstruction algorithm can implement key steps such as point cloud acquisition, preprocessing, feature extraction, alignment, surface reconstruction and visualization by calling the PCL library.

[0145] In the near-field scanning path planning algorithm based on three-dimensional features provided in this embodiment, the three-dimensional near-field scanning path can be obtained by reciprocatingly traversing and fusing the height features of the object to be tested based on the boundary of the object to be tested obtained by the visual positioning algorithm of edge detection and the three-dimensional features obtained by the three-dimensional reconstruction algorithm. This embodiment applies laser three-dimensional modeling and path planning to the field of electromagnetic emission detection: laser three-dimensional modeling is to obtain the three-dimensional features of the object to be tested, and to ensure that the near-field probe does not collide with the object to be tested when the near-field probe is at a small distance from the detection object.

[0146] The near-field scanning path planning algorithm based on three-dimensional features can realize the anti-collision function of the near-field probe from the control level. Combined with the probe fixture assembly, it realizes the near-field probe anti-collision function at the hardware and software levels.

[0147] The near-field scanning path planning algorithm based on three-dimensional features performs path planning using the boundary of the object to be measured obtained by the visual positioning algorithm and the three-dimensional features of the object to be measured obtained by the three-dimensional reconstruction algorithm. The implementation method is as follows: a two-dimensional path planning is performed according to the boundary conditions of the object to be measured, and a three-dimensional path planning is performed. According to the result of the two-dimensional path planning, the maximum height of the two-dimensional path point in the three-dimensional features of the object to be measured is searched point by point within the probe range to obtain a three-dimensional path result (i.e., a three-dimensional motion path).

[0148] The above reciprocating forward traversal is a reciprocating forward traversal with a variable step length. Two step length values ​​are introduced to control the distances of the front and back and left and right of the scanning point respectively, so that the scanning step length has more options and can meet different test requirements. The algorithm flow of the reciprocating forward traversal with a variable step length provided in the embodiment of the present application is as follows:

[0149] Step 201: Determine X min Is it unique? If yes, go to step 202; if no, go to step 203;

[0150] Step 202: Let x1=X min +S2,y1=Y(X min +S2) min , proceed to step 204;

[0151] Step 203: Let x1=X min , y1=Y(X min ) min , proceed to step 204;

[0152] Step 204: Let y j+1 =y j + S1, go to step 205;

[0153] Step 205: Determine y j+1 Is it included in U? If yes, go to step S204; if no, go to step 206;

[0154] Step 206: y j+1 =Y,x i+1 =x i + S2, go to step 207;

[0155] Step 207: Determine whether x i+1 ≥X max ; If yes, proceed to step 208; if no, set y1=Y(x i ) and proceed to step 204;

[0156] Step 208: Determine x i+1 Is it equal to X max+S2; if yes, then end the process; if no, then set x i+1 =X max , y1=Y(x i ) and proceed to step 204.

[0157] X min Indicates the minimum value of the X axis, X max Indicates the maximum value of the X-axis, x1, x i 、x i+1 Indicates the coordinates of the X axis, y1, y j ,y j+1 Indicates the coordinate of the Y axis. S1 and S2 indicate the moving step. min +S2) min Indicates that the horizontal axis is X min +S2 is the minimum value of the Y axis coordinate. U represents the boundary coordinate information of the object to be measured. Y represents the boundary value, Y (x i ) indicates that the horizontal axis is x i The boundary value when .

[0158] In the reciprocating forward traversal scanning algorithm, U (X, Y) represents the boundary coordinate information of the object to be measured, (x i ,y i ) represents the traversal point, the starting point is (X min , Y(X min )); The traversal directions of two adjacent columns are different. If the traversal direction of the i-th column is along the direction of decreasing Y, then the i+1-th column is traversed along the direction of increasing Y. When traversing the first column, it is necessary to determine when x=X min When Y has a unique value, if not, then traverse it, if yes, then x1=X min +S1; the overall traversal is controlled by two steps, S1 is the distance between the two points before and after the i-th column, and S2 is the distance between the two adjacent columns. These two steps are independent of each other and do not affect each other; when traversing near the boundary, if the last point of the i-th column is outside the area U, then y i =Y, that is, the point is on the boundary. Based on the reciprocating scanning method, the integrity of the scanned area can be guaranteed, and the front and back and left and right distances S1 and S2 of the scanning point in the scanning can be flexibly adjusted to meet more test requirements.

[0159] The specific steps are as follows:

[0160] Step 301: Load the coordinate information of the scanning area U (X, Y), and traverse the entire area along the increasing direction of X;

[0161] Step 302: Determine X min When , whether Y has a unique value, initialize the traversal direction of the i-th column;

[0162] Step 303: Traverse, y j+1 =y j +S1;

[0163] Step 304: Determine y j+1 Is it contained in U? If yes, return to step 3, otherwise continue to execute;

[0164] Step 305: Assign boundary value Y to y j+1 ;

[0165] Step 306: Start the next column traversal, x i+1 =x i +S2;

[0166] Step 307: Determine x i+1 Is it greater than or equal to X? max , if yes, execute step 309, otherwise execute step 308;

[0167] Step 308: Convert Y(x i ) is assigned to y1;

[0168] Step 309: Determine x i+1 Is it equal to X max + S2, if yes, then exit the loop and the program ends, otherwise, execute step 310;

[0169] Step 310: Set x i+1 Assign X max .

[0170] The three-dimensional path planning in this embodiment refers to combining the result of the two-dimensional path planning with the three-dimensional characteristics of the object to be measured, taking into account the actual size of the probe, to obtain a three-dimensional path.

[0171] For the three-dimensional feature data of the object to be measured Indicates that the data of the two-dimensional path is expressed as It means that when fusing point cloud data with the scanning path, the size of the near-field probe should be considered to avoid collisions on the formed path points. The Z value is searched in the three-dimensional feature data of the object to be measured according to the coordinates of the two-dimensional path. When searching, a search radius r, that is, the width of the near-field probe, needs to be considered.

[0172] The range of the X-axis coordinate of the current search point Pr can be expressed as: i -r≤x≤x i +r;

[0173] The Y-axis coordinate range of the current search point Pr can be expressed as: i -r≤y≤y i +r;

[0174] Search for Z in the three-dimensional feature data of the object under test within the above range max , Z max Assign to (x i ,y i ) to get a three-dimensional path point, and repeat this cycle until all points in the two-dimensional path set are traversed.

[0175] After scanning the object to be tested, the following element analysis operations can be performed based on the scanning results: Analyze the electromagnetic characteristics of different components and circuits on the electronic device to be tested, extract square wave and sine wave interference types, identify potential interference sources or signal strength anomalies, and optimize circuit layout and design.

[0176] After scanning the object under test, the following electromagnetic imaging operations can be performed based on the scanning results: Use the spectrum analyzer module to monitor and record the time domain signals and frequency domain signals on the device under test in real time, helping engineers to gain a deeper understanding of the electromagnetic performance and make corresponding optimizations.

[0177] The main process of electromagnetic imaging includes the following operations:

[0178] Step 401: Data preprocessing.

[0179] (1) The process of outlier monitoring and processing in this embodiment is as follows:

[0180] In electromagnetic radiation data, outliers may be caused by equipment errors, environmental noise, or data recording problems, but some extreme values ​​may reflect important physical phenomena (such as strong interference signals or high radiation intensity from certain specific sources). Outlier monitoring using Z-score (i.e., standard score) is used to process outliers in electromagnetic radiation data. In this process, you can choose to retain extreme values ​​with physical significance and remove unreasonable outliers.

[0181] Z-score is a standardized outlier detection method used to determine the degree of deviation of a data point from the overall data. The calculation formula of Z-score is as follows:

[0182] ;

[0183] Represents the electromagnetic radiation value of the data point, represents the mean of the data set, represents the standard deviation of the data set, Indicates the Z-score value of the data point.

[0184] The specific steps are as follows:

[0185] ① Calculate the Z-score value for each data point and identify outliers. Set an appropriate threshold (like =3), to distinguish normal values ​​from abnormal values.

[0186] ② According to the test results, classify the outliers:

[0187] Abnormal values ​​without physical meaning: such as isolated values ​​or noise values ​​that are obviously beyond the expected range. Extreme values ​​with physical meaning: such as peaks caused by high-energy radiation sources or strong interference sources in specific cases. Although these data are abnormal, they may have important physical meanings and need to be retained.

[0188] ③According to the classification results, different processing strategies are adopted:

[0189] Eliminate outliers that have no physical meaning: directly delete or use interpolation (such as linear interpolation, spline interpolation) to replace these points.

[0190] Keep extreme values ​​with physical significance: Do not process them and keep them directly. If they may be mistaken for outliers, they can be marked and recorded separately for subsequent analysis.

[0191] (2) The process of data normalization in this embodiment is as follows:

[0192] In order to eliminate the influence of dimension on the interpolation result, the electromagnetic radiation value is normalized. Normalization can not only improve the stability of numerical calculation, but also reduce the sensitivity of the algorithm to specific scales. , the normalization process is:

[0193] ;

[0194] , are the minimum and maximum values ​​of electromagnetic radiation data respectively.

[0195] is the normalized electromagnetic radiation value, ranging from [0, 1].

[0196] (3) The process of setting the boundary conditions in this embodiment is as follows: using natural boundary conditions, it is assumed that the second-order derivative of the spline curve at the boundary is 0.

[0197] Step 402: Construct an interpolation function:

[0198] For a given n data points x i , using the interpolation function defined as a cubic polynomial S on each interval i (x):

[0199] ;

[0200] For each interval , we need to determine the four coefficients a of the polynomial i 、b i 、c i ,d i . These coefficients are solved by the following conditions:

[0201] Interpolation condition: interpolation function Si(x) at node x i and x i+1 Satisfaction and .

[0202] First-order derivative continuity: ensure the continuity of the interpolation function at the intersection of adjacent intervals, that is, .

[0203] Second-order derivative continuity: Ensure that the second-order derivative is also continuous at the intersection of adjacent intervals, that is, . Therefore, for n data points, there are n-1 interpolation intervals, and 4(n-1) unknowns need to be solved. With these conditions, a linear system of equations can be formed to solve these coefficients.

[0204] Therefore, for n data points, there are n-1 interpolation intervals, and 4(n-1) unknowns need to be solved. Through these conditions, a linear equation system can be formed to solve these coefficients.

[0205] This embodiment can construct a cubic B-spline basis function in the following manner:

[0206] Cubic B-spline uses a set of piecewise defined basis functions to represent the interpolation curve. Each data point corresponds to a B-spline basis function: .

[0207] In the above formula represents the cubic B-spline basis function, , represents the quadratic B-spline basis function, x represents the independent variable, x i-1 、x i 、x i+1 、x i+2 Represents a node in the node vector.

[0208] Through the recursive relationship, the cubic B-spline basis function in each interval can be generated, and then the entire interpolation function can be constructed.

[0209] Step 403: Solve the equation.

[0210] Through the interpolation conditions and continuity conditions, a linear system of equations can be established to solve the coefficients of each interval. The tridiagonal matrix algorithm (TDMA) is used for efficient solution because the coefficient matrix is ​​in the form of a tridiagonal matrix.

[0211] The linear equations are as follows: Ax=b;

[0212] A represents the coefficient matrix, x represents the unknown vector, and b represents the constant term vector of the equation system. The coefficient matrix A is a tridiagonal matrix, that is, only the elements of the main diagonal and the two diagonals above and below it are non-zero, and the rest of the elements are zero.

[0213] A tridiagonal matrix has the following form:

[0214] ;

[0215] In the above formula, a1, a2, a3, a n , b2, b3, b n , c1, c2, c n-1 Represents the elements in a tridiagonal matrix.

[0216] The basic steps of the catch-up method are as follows:

[0217] (1) Forward elimination coefficient:

[0218] By eliminating the lower three diagonal elements b i , transform the matrix A into an upper triangular matrix. Introduce two new variables:

[0219] Modified main diagonal coefficients ;

[0220] Modified right hand side ;

[0221] The calculation formula is as follows: , ;

[0222] For i=2,3,…,n, recursive calculation:

[0223] ;

[0224] ;

[0225] ;

[0226] In calculating m i , and Then, we can add 1 to the value of i and judge whether i is greater than n. If it is greater than n, we will enter the back-substitution operation. If it is not greater than n, we will enter the calculation of m. i , and The above m i Indicates an intermediate parameter.

[0227] (2) Back-substitution solution:

[0228] After completing forward elimination, the unknown quantity x can be directly solved by back substitution i . Starting from the last equation:

[0229] ;

[0230] Recursive calculation for i=n-1,n-2,…,2:

[0231] ;

[0232] If i < 2, then output x i .

[0233] Step 404: interpolation implementation;

[0234] Once the coefficients for all intervals are obtained, the cubic B-spline interpolation function can be used for interpolation. For a given input x value, find the interval [x i ,x i+1 ], and then substitute the corresponding cubic polynomial S i (x) Calculate the interpolation result.

[0235] Step 405: Restore data scale.

[0236] After the interpolation is complete, remap the interpolated results back to the original data range.

[0237] Step 406: Visualization operation.

[0238] The interpolation results are compared with the original data in a three-dimensional visual manner, and three-dimensional contour maps, heat maps, etc. are used to ensure that the interpolation surface is smooth and reasonable.

[0239] An electromagnetic interference scanner control system provided in an embodiment of the present application includes:

[0240] An image acquisition module is used to acquire the image of the object to be measured collected by the visual positioning unit;

[0241] A position detection module, used to perform edge detection on the image of the object to be tested to obtain position information of the object to be tested; wherein the position information is used to describe the position of the projection of the object to be tested in the Z-axis direction;

[0242] A laser scanning module is used to control the laser ranging unit to perform laser scanning on the object to be measured to obtain three-dimensional point cloud data;

[0243] A modeling module, used for generating a three-dimensional model of the object to be measured according to the three-dimensional point cloud data;

[0244] A path planning module, used to perform path planning based on the position information of the object to be measured and the three-dimensional model to obtain a three-dimensional motion path;

[0245] A control module is used to control the near-field probe on the electromagnetic interference scanner to scan the object to be measured according to the three-dimensional motion path.

[0246] Since the embodiments of the apparatus part correspond to the embodiments of the method part, please refer to the description of the embodiments of the method part for the embodiments of the apparatus part, which will not be repeated here.

[0247] The present application also provides a storage medium on which a computer program is stored, and when the computer program is executed, the steps provided in the above embodiment can be implemented. The storage medium may include: a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and other media that can store program codes.

[0248] The present application also provides an electronic device, which may include a memory and a processor, wherein a computer program is stored in the memory, and when the processor calls the computer program in the memory, the steps provided in the above embodiment may be implemented. Of course, the electronic device may also include various network interfaces, power supplies and other components.

[0249] The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the various embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of this application, several improvements and modifications can be made to this application, and these improvements and modifications also fall within the scope of protection of this application.

[0250] It should also be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

Claims

1. An electromagnetic interference scanner, characterized in that: include: Multi-degree-of-freedom scanning platform, near-field scanning unit, main control unit, motion control unit, visual positioning unit and laser ranging unit; The multi-degree-of-freedom scanning platform includes a base, a gantry structure, an X-axis moving mechanism, a Z-axis moving mechanism and a storage table, the base is provided with a Y-axis guide rail, the gantry structure is installed on the Y-axis guide rail, the crossbeam of the gantry structure is provided with an X-axis guide rail, the X-axis moving mechanism is installed on the X-axis guide rail, the X-axis moving mechanism is provided with a Z-axis track, the Z-axis moving mechanism is installed on the Z-axis track, the Z-axis moving mechanism is provided with a rotating mechanism for rotating around the Z-axis, the near-field scanning unit includes a probe fixture assembly and a near-field probe, the probe fixture assembly is installed on the rotating mechanism, the probe fixture assembly is used to install the near-field probe, the storage table is installed on the base, and the storage table is used to place the object to be measured; The visual positioning unit and the laser ranging unit are installed on the Z-axis moving mechanism, the visual positioning unit is used to collect the image of the object to be measured, and the laser ranging unit is used to collect the three-dimensional point cloud data of the object to be measured; The main control unit is connected to the motion control unit, the visual positioning unit and the laser ranging unit respectively; the main control unit is used to generate a three-dimensional motion path according to the image of the object to be measured and the three-dimensional point cloud data, and send a motion instruction corresponding to the three-dimensional motion path to the motion control unit; The motion control unit is connected to the gantry structure, the X-axis moving mechanism and the Z-axis moving mechanism respectively, and the motion control unit is used to control the movement of the near-field probe according to the motion instruction, so that the near-field probe scans the object to be measured according to the three-dimensional motion path; The probe fixture assembly comprises: a fixed bracket, a slide rail seat, a slide rail, a positioning block with a V-shaped protrusion, a connecting piece with a V-shaped groove, and a probe fixing fixture; The slide rail seat is mounted on the rotating mechanism through the fixing bracket, and the slide rail is mounted in the slide rail seat; The slide rail comprises a fixed portion and a movable portion, wherein the fixed portion is fixed to the slide rail seat by means of threads, and the movable portion is used to move along the Z-axis direction in the slide rail seat; The positioning block is installed on the moving part, and a magnet is embedded in the positioning block; The positioning block has a V-shaped protrusion on one side thereof, and a positioning shaft is provided on the connecting piece, and the connecting piece is provided with a positioning hole, and the connecting piece is a connecting piece made of a magnetic material; when the connecting piece is installed on the positioning block through the positioning hole and the positioning shaft, the V-shaped protrusion of the positioning block and the V-shaped groove of the connecting piece are in contact with each other, and the magnet embedded in the positioning block generates suction force on the connecting piece; A probe fixing fixture is installed on the connecting piece, and the probe fixing fixture is used to install the near-field probe.

2. The electromagnetic interference scanner according to claim 1, characterized in that: The near-field scanning unit also includes a spectrum module and a low-noise amplifier; The RF output port of the near-field probe is connected to the input port of the low-noise amplifier, the output port of the low-noise amplifier is connected to the RF input port of the spectrum module, and the communication port of the spectrum module is connected to the communication port of the main control unit.

3. The electromagnetic interference scanner according to claim 1, characterized in that: The fixing bracket is connected to the slide rail seat via threads; The upper end of the slide rail seat is provided with a groove, and the fixing bracket cooperates with the groove at the upper end of the slide rail seat through a thread to achieve a fixed connection; The probe fixing fixture fixes the near-field probe via a probe fixing cover plate.

4. A control method for an electromagnetic interference scanner, characterized in that: The main control unit of the electromagnetic interference scanner according to any one of claims 1 to 3, wherein the control method of the electromagnetic interference scanner comprises: Acquire the image of the object to be tested collected by the visual positioning unit; Performing edge detection on the image of the object to be tested to obtain position information of the object to be tested; wherein the position information is used to describe the position of the projection of the object to be tested in the Z-axis direction; Controlling the laser ranging unit to perform laser scanning on the object to be measured to obtain three-dimensional point cloud data; Generate a three-dimensional model of the object to be measured according to the three-dimensional point cloud data; Perform path planning according to the position information of the object to be measured and the three-dimensional model to obtain a three-dimensional motion path; The near-field probe on the electromagnetic interference scanner is controlled to scan the object to be measured according to the three-dimensional motion path.

5. The control method of the electromagnetic interference scanner according to claim 4, characterized in that: Performing edge detection on the image of the object to be detected to obtain position information of the object to be detected includes: Using Gaussian filtering to smooth the image of the object to be tested, and calculating the gradient information of the image of the object to be tested; Performing non-maximum suppression on the image of the object to be tested according to the gradient information to obtain edge points; The edge points are screened using a threshold, and the position information of the object to be detected is generated according to the screening result.

6. The control method of the electromagnetic interference scanner according to claim 4, characterized in that: Performing path planning according to the position information of the object to be measured and the three-dimensional model to obtain a three-dimensional motion path includes: Perform two-dimensional path planning according to the position information of the object to be measured to obtain a two-dimensional motion path; wherein the two-dimensional motion path includes a plurality of traversal points, and the traversal points include X-axis coordinates and Y-axis coordinates; Setting a point in the three-dimensional model that has the same X-axis coordinate and Y-axis coordinate as the traversal point as a scanning point; The three-dimensional motion path is generated according to the three-dimensional coordinate values ​​of all the scanning points and the size of the near-field probe.

7. The control method of the electromagnetic interference scanner according to claim 6, characterized in that: Performing two-dimensional path planning according to the position information of the object to be measured to obtain a two-dimensional motion path includes: Determine a scanning area according to the position information of the object to be measured; wherein the scanning area is a projection of the object to be measured in the Z-axis direction; The coordinate extreme value of the scanning area is determined, the scanning area is traversed in a reciprocating forward manner according to the coordinate extreme value, and the two-dimensional motion path is generated according to the traversed points.

8. The control method of the electromagnetic interference scanner according to claim 4, characterized in that: After controlling the near-field probe on the electromagnetic interference scanner to scan the object to be detected according to the three-dimensional motion path, the method further includes: Acquire electromagnetic radiation data scanned by the near-field probe; Performing a preprocessing operation on the electromagnetic radiation data; wherein the preprocessing operation includes outlier removal, data normalization and boundary condition setting; Constructing an interpolation function, and using the interpolation function to perform interpolation processing on the electromagnetic radiation data to obtain an interpolation result; The interpolation result is visualized.

9. The control method of the electromagnetic interference scanner according to claim 8, characterized in that: After acquiring the electromagnetic radiation data scanned by the near-field probe, the method further includes: Electromagnetic characteristics of components and / or circuits on the object to be tested are analyzed according to the electromagnetic radiation data.

10. A storage medium, characterized in that: The storage medium stores computer executable instructions, and when the computer executable instructions are loaded and executed by the processor, the steps of the control method of the electromagnetic interference scanner as claimed in any one of claims 4 to 9 are implemented.

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