A magnetic drive compatible indirect magnetic positioning system and method

Abstract

The application discloses a magnetic drive compatible indirect magnetic positioning system and a positioning method, and the system comprises a magnetic source device relay sensor array and a positioned device; the relay sensor array is a sensor array provided with a plurality of magnetic sensors; the method comprises the following steps: calibrating the relay sensor array and the magnetic source device; changing the pose of the magnetic source device while keeping the pose of the positioned device unchanged; acquiring first magnetic field signals collected by each magnetic sensor on the relay sensor array; constructing a first cost function by using the first magnetic field signals; minimizing the first cost function to estimate the pose of each magnetic sensor on the relay sensor array; acquiring magnetic field prediction values of the positioned device at each magnetic sensor on the relay sensor array; constructing a second cost function according to the magnetic field prediction values and the difference between actual magnetic field values and theoretical magnetic field values; and minimizing the second cost function to estimate the pose of the positioned device.

Description

Technical Field

[0001] This invention belongs to the field of medical device technology, specifically relating to a magnetic drive-compatible indirect magnetic positioning system and positioning method. Background Technology

[0002] Minimally invasive interventional therapy refers to medical procedures that diagnose and treat diseases using interventional instruments under the guidance of equipment such as ultrasound and CT. Over the past two centuries, with the advent and application of technologies such as endoscopy, minimally invasive interventional surgery, characterized by minimal trauma, rapid recovery, and high precision, has been widely used in clinical practice, gradually replacing traditional open surgery. In minimally invasive interventional surgery, the guidewire is the first step in the entire process. It is precisely because of the guidewire inserted into the body cavity that subsequent catheters and instruments can arrive smoothly and safely. Currently, techniques such as twisting, bent catheter guidance, and sharp opening are commonly used in clinical surgery to guide the guidewire into the selected cavity. This requires doctors to manipulate the guidewire with special skills and feel. Encountering tortuous, narrow, or multi-branched lesions often reduces the success rate of interventional treatment and increases the risk of surgical complications. Magnetic drive, as a new technology, has unique advantages. First, magnetic drive allows doctors to directly manipulate the head of a guidewire robot containing magnetic materials using an external magnetic field, achieving tetherless "end-to-end" drive, which greatly improves the maneuverability of the guidewire. Secondly, enabling the guidewire to have magnetic drive capability does not require significant modifications to the guidewire's structure. Simply embedding magnets or spraying a coating containing magnetic materials at the predetermined bending points allows the guidewire to respond to magnetic fields. This ease of manufacturing can greatly reduce the production cost of magnetically driven guidewire robots, increasing the possibility of large-scale clinical application. Thirdly, the magnetic field itself is not affected by human tissue components and can be easily applied from outside the body. It is clean, safe, and radiation-free, making it a reasonable choice for medical applications.

[0003] To more accurately control the direction of the guidewire using a magnetic field, it is essential to estimate the force and torque exerted by the magnetic field on the magnetic material of the guidewire and to determine the specific magnetic field on the driven magnetic material. Therefore, to accurately determine the magnetic field at the driven magnetic material, it is necessary to know the precise pose of the driven magnetic material at the magnetic field location, necessitating a reliable real-time positioning technology in a non-field-of-view environment. However, traditional ultrasound or CT-based image positioning is not only slow but also requires precise registration of the image with the external magnetic field environment; positioning technology based on flexible shape sensors using fiber Bragg gratings is extremely costly; and traditional electromagnetic positioning technology is susceptible to interference from external magnetic fields and cannot function properly in this working environment. Summary of the Invention

[0004] In view of this, the present invention provides a magnetic drive-compatible indirect magnetic positioning system and positioning method.

[0005] According to a first aspect of the present invention, a magnetic drive-compatible indirect magnetic positioning method is provided, which is implemented based on a magnetic drive-compatible indirect magnetic positioning device, wherein the magnetic drive-compatible indirect magnetic positioning device includes: a magnetic source device, a relay sensor array, and a positioning device; wherein the relay sensor array is a sensor array equipped with a plurality of magnetic sensors.

[0006] The method includes:

[0007] Calibrate each magnetic sensor in the relay sensor array;

[0008] Calibrate the magnetic field model corresponding to the magnetic source device;

[0009] Keeping the orientation of the device being positioned unchanged, the orientation of the magnetic source device is changed to obtain the first magnetic field signal collected by each magnetic sensor on the relay sensor array; using the first magnetic field signal, a first cost function is constructed, and the orientation of each magnetic sensor on the relay sensor array is estimated by minimizing the first cost function.

[0010] Based on the poses of each magnetic sensor on the relay sensor array, calculate the theoretical magnetic field value of the magnetic source device relative to the location of the k-th magnetic sensor in the i-th pose; obtain the predicted magnetic field value of the device to be located at each magnetic sensor on the relay sensor array; construct a second cost function based on the predicted magnetic field value and the difference between the actual magnetic field value and the theoretical magnetic field value, and minimize the second cost function to estimate the pose of the device to be located.

[0011] According to a second aspect of the present invention, a magnetic drive-compatible indirect magnetic positioning system is provided, the system comprising:

[0012] Magnetic source device, a magnetic generating device;

[0013] A relay sensor array is a sensor array equipped with several magnetic sensors, used to collect magnetic field signals generated by the magnetic source device and the positioning device.

[0014] The positioning device, containing a magnetic element;

[0015] Among them, the magnetic source device, the relay sensor array and the positioning device are not mechanically connected; the relative distance between the relay sensor array and the magnetic source device must be within the effective working space allowed by the magnetic field of the magnetic source device, and the relative distance between the positioning device and the relay sensor array must be within the effective working space allowed by the positioning device.

[0016] An information processing device is used to convert superimposed magnetic field signals into digital signals and to filter them;

[0017] The host computer is used to receive the filtered digital signal and implement the above-mentioned magnetic drive-compatible indirect magnetic positioning method.

[0018] According to a third aspect of the present invention, an electronic device is provided, including a memory and a processor, the memory being coupled to the processor; wherein the memory is used to store program data, and the processor is used to execute the program data to implement the above-described magnetic drive-compatible indirect magnetic positioning method.

[0019] According to a fourth aspect of the present invention, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the above-described magnetic drive-compatible indirect magnetic positioning method.

[0020] The beneficial effects of the present invention are as follows: The present invention determines the relative pose of the relay sensor array by applying a magnetic source device to the magnetic field on the relay sensor array, and then determines the pose of the positioned device by applying a magnetic field to the relay sensor array through the superposition and transformation of the poses. The method of the present invention provides a reliable real-time positioning technology in a non-field-of-view environment, which can obtain the accurate pose of the driven magnetic material at the magnetic field. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 A schematic diagram illustrating the application of a magnetic drive-compatible indirect magnetic positioning system provided in an embodiment of the present invention;

[0023] Figure 2 A schematic diagram of a magnetic source device provided in an embodiment of the present invention;

[0024] Figure 3 This is a schematic diagram of the sensor array device and the positioning device provided in an embodiment of the present invention;

[0025] Figure 4 A schematic diagram of positioning coordinates provided in an embodiment of the present invention;

[0026] Figure 5 This is a schematic diagram of the magnetic field distribution of the magnetic source device provided in an embodiment of the present invention;

[0027] Figure 6 This is a schematic diagram of an electronic device provided in an embodiment of the present invention. In the diagram, 1. Magnetic source device; 2. Relay sensor array device; 3. Endoscope equipped with relay sensor; 4. Guide wire equipped with positioning module; 5. Host computer; 6. Magnetic source body; 7. Permanent magnet clamp connected to motor; 8. Robotic arm; 9. Information processing device; 10. Connection cable to host computer; 11. Flexible flat cable; 12. Flat cable adapter board; 13. FPC flexible board equipped with relay sensor; 14. Magnetic sensor chip; 15. Positioned device; 16. Global coordinate system; 17. Local coordinate system of magnetic source; 18. Local coordinate system of sensor; 19. Local coordinate system of positioning device. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] It should be noted that, unless otherwise specified, the features in the following embodiments and implementation methods can be combined with each other.

[0030] Figure 1 This illustration shows an application diagram of the magnetic drive-compatible indirect magnetic positioning system provided in an embodiment of the present invention. This example provides a typical application of the magnetic drive-compatible indirect magnetic positioning system in endoscopic retrograde cholangiopancreatography (ERCP) procedure, which includes: a magnetic source device 1, a relay sensor array 2, a positioning device 15, an information processing device 9, and a host computer 5.

[0031] The magnetic source device 1 is a magnetic generating device.

[0032] The relay sensor array 2 is a sensor array equipped with several Hall magnetic sensors 14, used to collect magnetic field signals generated by the magnetic source device 1 and the positioning device 15.

[0033] The positioning device 15 is a magnetic element. The magnetism of the positioning device 15 must be inherent, quantifiable, and unaffected by changes in the external magnetic field.

[0034] The information processing device 9 is used to convert the superimposed magnetic field signal into a digital signal and perform filtering;

[0035] The host computer 5 receives the filtered digital signal and calculates the precise pose of the relay sensor array 2 according to the first magnetic field model; based on the second magnetic field model, it calculates the relative pose of the relay sensor array 2 and the positioning device 15 according to the precise pose of the relay sensor array 2, and then determines the absolute pose of the positioning device 15.

[0036] It should be noted that the magnetic source device 1, the relay sensor array 2, and the positioning device 15 are not mechanically connected. However, the relative distance between the relay sensor array 2 and the magnetic source device 1 must be within the effective working space allowed by the magnetic properties of the magnetic source device 1, and the relative distance between the positioning device 15 and the relay sensor array must be within the effective working space allowed by the positioning device 15.

[0037] like Figure 2 As shown, the magnetic source body 6 can be a saturated magnetized neodymium iron boron cylindrical permanent magnet or a solenoid with a current generating device; in this example, a cylindrical permanent magnet is used. The magnetic source device 1 includes the magnetic source body 6, which is fixed to the end of the robotic arm 8 by a permanent magnet clamp 7. A motor is also installed on the permanent magnet clamp 7. The motor adjusts the position and orientation of the magnetic source body 6 to change its magnetic field at the magnetic sensor 14. The spatial orientation of the magnetic source body 6 is provided to the host computer 5 through the forward kinematics of the robotic arm 8 or optical means such as a camera. The magnetic field distribution generated by the magnetic source device can be described by a mathematical analytical expression. Furthermore, the robotic arm 8 can be replaced with a non-ferrous support.

[0038] Furthermore, such as Figure 3 As shown, the relay sensor array 2 includes several magnetic sensors 14 with different ranges and accuracies. The magnetic sensors 14 are arranged in a rectangular array on the FPC flexible circuit board 13. The magnetic sensors 14 are triaxial Hall sensors. The magnetic field information collected by the relay sensor array 2 is transmitted to the information processing device 9 via wired or Bluetooth connection. In this embodiment, the relay sensor device 2 is installed inside the endoscope 3 and is inserted orally near the duodenal papilla of the patient. Due to the bendable nature of the flexible circuit board (FPC), the FPC flexible circuit board 13 can be wrapped around the end opening of the endoscope 3. It is connected to the information processing device 9, which is placed outside the human body, through the internal channel of the endoscope 3 via a flexible flat cable 11. If the length of the flexible flat cable 11 is insufficient, it can be extended by a cable adapter plate 12. The information processing device 9 obtains the magnetic field information received by the magnetic sensors 14 mounted on the relay sensor array 2 through the flexible flat cable 11, and sends the magnetic field information to the host computer 5 via the connection line 10 after filtering.

[0039] Furthermore, the positioning device 15 can be spherical or cylindrical, and can be installed in the object to be positioned. In this example, the positioning device 15 is a miniature cylindrical permanent magnet, whose actively emitted magnetic field can be detected by multiple magnetic sensors 14 on the relay sensor array device 2. The positioning device 15 is installed at the free end of the guide wire 4.

[0040] This invention also provides a magnetic drive-compatible indirect magnetic positioning method. Next, this invention will be combined with... Figure 4 and Figure 5 The positioning method provided by this invention is described in detail, along with the underlying physical principles.

[0041] First, it should be clarified that in this embodiment, the technical problem solved by the present invention is to determine the position and orientation of the guidewire 4 head without using imaging. This is because during endoscopic retrograde cholangiopancreatography (ERCP), the working area of ​​the guidewire 4 will not be within the field of view of the endoscope 3, and the space at the head of the guidewire 4 is limited, making it impossible to install a separate sensor and its associated electrical connection device. Similarly, due to the limited size of its head, the size of the miniature permanent magnet constituting the positioning device 15 that can be mounted is also limited. The magnetism of the positioning device 15 is directly linked to the size of the miniature permanent magnet, and the magnetism of the positioning device 15 cannot be detected by a sensor placed outside the human body. Therefore, the present invention designs a relay sensor array that can be mounted on the end of the endoscope 3. 2. The aim is to minimize the distance between the relay sensor array device 2 and the positioning device 15. However, since the relay sensor array device 2 and the endoscope 3 are inserted into the human body together, their pose becomes an uncertain value. However, through the magnetic field exerted on the relay sensor array 2 by the magnetic source device 1, the relative pose of the relay sensor array 2 to the magnetic source device 1 can be determined. Then, through the magnetic field applied to the relay sensor array 2 by the positioning device 15, the relative pose of the positioning device 15 to the relay sensor array 2 can be determined. Finally, through the superposition and transformation of the poses, the relative pose of the positioning device 15 and the magnetic source device 1 can be determined. Since the absolute pose of the magnetic source device 1 is known, the absolute pose of the positioning device 15 can be derived accordingly.

[0042] Figure 4 A schematic diagram of the different coordinate systems in the entire positioning process is given. The global coordinate system 16 is represented by {o}, which is a static absolute coordinate system. Other local coordinate systems determine their own pose based on this coordinate system. The origin of the magnetic source local coordinate system 17 is located at the center of the magnetic source body 6, the positive z-axis points to the N pole along the magnet axis, and the x and y axes are not specifically defined local coordinate systems. The origin of the sensor coordinate system 18 is located at the center of each magnetic sensor on the relay sensor array 2. It is a three-axis local coordinate system along the sensor reading direction. All magnetic sensors have their own sensor local coordinate systems, which are distinguished by subscripts 1, 2, ..., K. The origin of the local coordinate system 19 of the positioned device is located at the center of the positioned device 15. The attitude displacement vector u and attitude angle vector θ of each local coordinate system are represented. The displacement vector refers to the vector pointing from the origin of the global coordinate system 16 to the origin of each local coordinate system under the global coordinate system 16. The attitude angle vector refers to the rotation angle of each local coordinate system under the global coordinate system 16, which is represented by the axis angle method.

[0043] Figure 5 A schematic diagram of the magnetic field distribution of the magnetic source body 6 under the local coordinate system 17 of the magnetic source is given; for any point p in this coordinate system, let its position vector in the local coordinate system 17 of the magnetic source be r, and the magnetic moment of the permanent magnet be m, then its magnetic field is:

[0044]

[0045] Where, μ0=4π×10 -7 T·m·A -1 μ0 is the free permeability, m is the total magnetic moment of the magnet, and r is the position vector. x Let r be the component of the magnetic source's local coordinate system along the x-axis. y Let r be the component of the magnetic source's local coordinate system along the y-axis. z Let be the y-axis component of the local coordinate system of the r-magnetic source, and K(m) be a scalar function with the total magnetic moment as the independent variable. It is a vector function with position vector r as its independent variable, specifically:

[0046]

[0047] Next, in this embodiment of the invention, the specific steps of the magnetic drive-compatible indirect magnetic positioning system will be described in detail in conjunction with relevant principles and procedures:

[0048] Step S1: Calibrate each magnetic sensor in the relay sensor array 2 to solve the problems of sensor size inaccuracy, triaxial mismatch and inherent hysteresis interference.

[0049] In this embodiment of the invention, the triaxial magnetic sensor is arbitrarily rotated in a geomagnetic environment free from other interference, and the magnetic field value in its stable state is recorded. An ellipse fitting algorithm is then used to fit the sensor onto a three-dimensional ellipse. The center and three-axis lengths of the ellipse are calculated, and the sensor is then transformed into a standard sphere to complete the calibration. Let's assume the sensor's measurement value is h. m Its truth value is h, and the specific steps are as follows:

[0050] S1.1. By actively rotating the magnetic sensor, record the sensor measurement values ​​under different postures, which are h respectively. m1 ,…,h mN If we fit this equation onto an ellipse, then the general equation of the ellipse is:

[0051]

[0052] in, The fitting coefficients for the ellipse equation are denoted as .

[0053] S1.2 Calculate the measured value h using the coefficients of the ellipse equation.m Formula for mapping to the truth value h The coefficients are as follows:

[0054]

[0055] Where F is the magnitude of the geomagnetic vector, which in this example is obtained by querying the geomagnetic value of the location.

[0056] Step S2: Calibrate the parameters of the magnetic field model corresponding to the magnetic source device.

[0057] In this embodiment of the invention, the magnetic field model parameter to be calibrated is the total magnetic moment m1 of the cylindrical permanent magnet. By measuring the magnetic field value on the axis of the cylindrical permanent magnet, the corresponding vector r can be determined. i =[0,0,r zi The magnetic field value at [location] is The theoretical magnetic field value here is make constitute B i If B is formed, then the total magnetic moment m1 can be calculated as follows:

[0058]

[0059] Step S3: Keep the pose of the positioned device 15 unchanged, change the pose of the magnetic source device 1, and acquire the first magnetic field signal collected by each magnetic sensor on the relay sensor array 2; use the first magnetic field signal to construct a first cost function, and minimize the first cost function to estimate the pose (u) of each magnetic sensor on the relay sensor array 2. sk ,θ sk The specific steps are as follows:

[0060] S3.1. While ensuring that the position of the positioned device 15 remains unchanged, actively change the position of the magnetic source device 1 and record its position as (u Mi ,θ Mi The magnetic field read by each sensor on the corresponding relay sensor array is... Then magnetic fields can be used Construct the first cost function:

[0061]

[0062] in,

[0063]

[0064]

[0065] In the formula, sk RMi This is the rotation matrix that transforms the coordinates from the local coordinate system of the magnetic source to the local coordinate system of the sensor; Mi R o The rotation matrix θ transforms the coordinates from the global coordinate system to the sensor's local coordinate system. Mi The known attitude angle of the cylindrical permanent magnet in the global coordinate system; u Mi The position vector of the known cylindrical permanent magnet; A magnetic field model for a cylindrical permanent magnet; u sk Let θ be the pose of the sensor in the global coordinate system, which is a quantity to be estimated; sk The sensor's attitude angle in the global coordinate system is also a quantity to be estimated.

[0066] S3.2 Minimize the cost function using an optimization algorithm. k E1,k=1,2,…,K, to obtain the poses (u) of all sensors. sk ,θ sk Let k = 1, 2, ..., K, where K is the total number of magnetic sensors. In this example, the Levenberg-Marquardt optimization algorithm is used.

[0067] Step S4: Based on the pose (u) of each magnetic sensor on the relay sensor array 2 sk ,θ sk The theoretical magnetic field value of the magnetic source device 1 relative to the location of the k-th magnetic sensor is calculated in the i-th pose. The predicted magnetic field value of the positioning device 15 at each magnetic sensor on the relay sensor array 2 is obtained. Based on the predicted magnetic field value and the difference between the actual magnetic field value and the theoretical magnetic field value, a second cost function is constructed. The pose (u) of the positioning device 15 is estimated by minimizing the second cost function. m ,θ m The magnetic moment m2 of the positioned device is determined by the following sub-steps:

[0068] S4.1 Using the results of step S3, calculate the theoretical magnetic field value of the cylindrical permanent magnet at the location of the aforementioned k-th sensor, based on the i-th pose of the cylindrical permanent magnet. The expression is as follows:

[0069]

[0070] S4.2, Set the sensor to measure the magnetic field value. Subtract the theoretical magnetic field value calculated in step S4.1 sk B Mi The expression is as follows:

[0071]

[0072] S4.3 Construct the second cost function, the expression of which is as follows:

[0073]

[0074] in, sk B mi The predicted magnetic field value of the device being positioned at the sensor; K is the rotation matrix that transforms the coordinates from the local coordinate system of the positioning device to the local coordinate system of the sensor; K(m2) is the scalar function part in the magnetic field model; In the magnetic field model, m2 represents the magnetic moment of the positioned device, which is a quantity to be estimated; u m The pose of the device being positioned in the global coordinate system is a quantity to be estimated; θ m The attitude angle of the positioned device in the global coordinate system is also a quantity to be estimated.

[0075] Step S4.4: Minimize the cost function E2 using an optimization algorithm to obtain the pose (u) of the device being positioned. m ,θ m ) and magnetic moment m2. In this example, the optimization algorithm used is the Levenberg-Marquardt method.

[0076] like Figure 6 As shown, this application provides an electronic device including a memory 101 for storing one or more programs and a processor 102. When the one or more programs are executed by the processor 102, they implement the method as described in any of the first aspects above.

[0077] The system also includes a communication interface 103. The memory 101, processor 102, and communication interface 103 are electrically connected directly or indirectly to each other to enable data transmission or interaction. For example, these components can be electrically connected to each other via one or more communication buses or signal lines. The memory 101 can be used to store software programs and modules, and the processor 102 executes various functional applications and data processing by executing the software programs and modules stored in the memory 101. The communication interface 103 can be used for signaling or data communication with other node devices.

[0078] The memory 101 may be, but is not limited to, random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), etc.

[0079] Processor 102 can be an integrated circuit chip with signal processing capabilities. This processor 102 can be a general-purpose processor 102, including a central processing unit (CPU) 102 and a network processor 102.

[0080] (Network Processor, NP), etc.; it can also be a Digital Signal Processor (DSP), Application Specific Integrated Circuit (ASIC), Field-Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0081] In the embodiments provided in this application, it should be understood that the disclosed methods and systems can also be implemented in other ways. The method and system embodiments described above are merely illustrative. For example, the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of methods and systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0082] In addition, the functional modules in the various embodiments of this application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0083] On the other hand, embodiments of this application provide a computer-readable storage medium storing a computer program thereon. When executed by processor 102, the computer program implements the methods described in any of the first aspects above. If the functions are implemented as software functional modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory 101 (ROM), random access memory 101 (RAM), magnetic disks, or optical disks.

[0084] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and embodiments are to be considered exemplary only.

[0085] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope.

Claims

1. A magnetic drive-compatible indirect magnetic positioning method, characterized in that, The magnetic drive compatible indirect magnetic positioning device is implemented based on a magnetic drive compatible indirect magnetic positioning device, which includes: a magnetic source device (1), a relay sensor array (2) and a positioning device (15); the relay sensor array (2) is a sensor array equipped with a number of magnetic sensors. The method includes: Calibrate each magnetic sensor in the relay sensor array (2); The magnetic field model corresponding to the calibrated magnetic source device (1) is determined; Keeping the pose of the positioning device (15) unchanged, the pose of the magnetic source device (1) is changed to obtain the first magnetic field signal collected by each magnetic sensor on the relay sensor array (2); using the first magnetic field signal, a first cost function is constructed, and the pose of each magnetic sensor on the relay sensor array (2) is estimated by minimizing the first cost function. Based on the poses of each magnetic sensor on the relay sensor array (2), calculate the theoretical magnetic field value of the magnetic source device (1) relative to the location of the kth magnetic sensor in the i-th pose; obtain the magnetic field prediction value of the positioning device (15) at each magnetic sensor on the relay sensor array (2); construct a second cost function based on the magnetic field prediction value and the difference between the actual magnetic field value and the theoretical magnetic field value, and minimize the second cost function to estimate the pose of the positioning device (15); Each magnetic sensor in the calibration relay sensor array (2) includes: By arbitrarily rotating the magnetic sensor in a geomagnetic environment free from other interference, the transmitted values ​​of the magnetic sensor under different orientations were recorded. N is the total number of different postures; An ellipse fitting algorithm is used to fit the measured values ​​of the magnetic sensor under different orientations onto a three-dimensional ellipse, as shown in the following expression: ； In the formula, The fitting coefficients for the ellipse equation are . Transforming the solid ellipse into a standard sphere, i.e., the measured value Mapping to real values The calibration of the magnetic sensor is completed, and the expression is as follows: ； ； In the formula, The magnitude of the geomagnetic vector; The magnetic field model corresponding to the calibration magnetic source device (1) includes: By measuring the magnetic field value along the axis of the cylindrical permanent magnet, the corresponding vector... The magnetic field value at that location is ; The theoretical magnetic field value here is , N represents the total number of different postures. make constitute , If B is formed, then the total magnetic moment will be... for: 。 2. The magnetic drive-compatible indirect magnetic positioning method according to claim 1, characterized in that, The estimated poses of each magnetic sensor on the relay sensor array (2) include: Keeping the pose of the positioning device (15) unchanged, the pose of the magnetic source device (1) is changed, and the pose of the magnetic source device (1) is recorded as follows. The first magnetic field signal collected by each magnetic sensor on the relay sensor array (2) is obtained and denoted as . ; Using the first magnetic field signal, a first cost function is constructed, expressed as follows: ； in, ； ； In the formula, Indicates the magnetic source device in the first The magnetic field signal corresponding to each location. Indicates the magnetic source device in the first The magnetic field signal corresponding to each location. This is the rotation matrix that transforms the coordinates from the local coordinate system of the magnetic source to the local coordinate system of the sensor. This is the rotation matrix that transforms the coordinates from the global coordinate system to the sensor's local coordinate system; The position vector of the magnetic source device; A magnetic field model for a magnetic source device; The pose of the magnetic sensor in the global coordinate system; ； ； In the formula, The attitude angle of the magnetic source device in the global coordinate system; The attitude angle of the magnetic sensor in the global coordinate system; Minimize cost function The poses of all magnetic sensors are obtained. K represents the total number of magnetic sensors.

3. The magnetic drive-compatible indirect magnetic positioning method according to claim 1, characterized in that, The pose of the positioning device (15) includes: Based on the poses of each magnetic sensor on the relay sensor array (2), the theoretical magnetic field value of the magnetic source device (1) relative to the location of the k-th magnetic sensor in the i-th pose is calculated, and expressed as follows: ； In the formula, This is the rotation matrix that transforms the coordinates from the local coordinate system of the magnetic source to the local coordinate system of the sensor. This is the rotation matrix that transforms the coordinates from the global coordinate system to the sensor's local coordinate system; A magnetic field model for a magnetic source device; The position vector of the magnetic source device; The pose of the magnetic sensor in the global coordinate system; Calculate the magnetic field signal corresponding to the i-th position of the magnetic source device. The theoretical magnetic field value at the location of the magnetic sensor The difference is expressed as follows: ； Construct the second cost function, as shown in the following expression: ； In the formula, The predicted magnetic field value of the device being positioned at the sensor is expressed as follows: ； ； In the formula, This is a rotation matrix that transforms the coordinates from the local coordinate system of the positioning device to the local coordinate system of the sensor. This refers to the scalar function part in the magnetic field model; This refers to the vector function part in the magnetic field model. The magnetic moment of the device being positioned; The pose of the device being positioned in the global coordinate system; The attitude angle of the magnetic sensor in the global coordinate system; The attitude angle of the positioned device in the global coordinate system; The pose of the positioning device (15) is estimated by minimizing the second cost function. and magnetic moment .

4. A magnetic drive-compatible indirect magnetic positioning system, characterized in that, To implement the magnetic drive-compatible indirect magnetic positioning method according to any one of claims 1-3, the system comprises: Magnetic source device (1), a magnetic generating device; The relay sensor array (2) is a sensor array equipped with several magnetic sensors (14) for collecting magnetic field signals generated by the magnetic source device (1) and the positioning device (15). Positioning device (15), containing a magnetic element; Among them, the magnetic source device (1), the relay sensor array (2) and the positioning device (15) are not mechanically connected; the relative distance between the relay sensor array (2) and the magnetic source device (1) must be within the effective working space allowed by the magnetic field of the magnetic source device (1), and the relative distance between the positioning device (15) and the relay sensor array (2) must be within the effective working space allowed by the positioning device (15); Information processing device (9) is used to convert the superimposed magnetic field signal into a digital signal and perform filtering; The host computer (5) is used to receive the filtered digital signal.

5. The magnetic drive-compatible indirect magnetic positioning system according to claim 4, characterized in that, The magnetic source device (1) includes a magnetic source body (6), which is fixed to the end of the robotic arm (8) by a permanent magnet clamp (7); a motor is also installed on the permanent magnet clamp (7), and the position of the magnetic source body (6) is adjusted by the motor to change its magnetic field at the magnetic sensor (14); the magnetic sensor (14) is arranged on the FPC flexible board (13) in a rectangular array.

6. The magnetic drive-compatible indirect magnetic positioning system according to claim 5, characterized in that, The magnetic source body (6) is selected from a saturated magnetized neodymium iron boron cylindrical permanent magnet or a solenoid with a current generating device.

7. An electronic device comprising a memory and a processor, characterized in that, The memory is coupled to the processor; wherein the memory is used to store program data, and the processor is used to execute the program data to implement the magnetic drive compatible indirect magnetic positioning method according to any one of claims 1-3.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the magnetic drive-compatible indirect magnetic positioning method as described in any one of claims 1-3.

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