Position detection method, device and system and storage medium

Abstract

The invention relates to the technical field of tracking and positioning, and provides a position detection method, device and system and a storage medium. The method is used for detecting the position of a to-be-detected object, and the to-be-detected object is provided with a receiver. The method comprises the following steps: controlling at least two magnets in an emitter matched with the receiver to rotate to generate a low-frequency magnetic field; receiving a magnetic field change induction electric signal obtained by a coil in a receiver in the low-frequency magnetic field; and determining the position of the to-be-detected object based on the magnetic field change induction electric signal. According to the scheme, position detection is achieved through the magnetic field change induction electric signal generated by the low-frequency magnetic field in the coil, interference of a metal conductor on the position detection device can be reduced, the size of the coil can be flexibly customized, the application scene of the position detection method is expanded, and the detection precision is improved.

Description

Technical Field

[0001] The present application relates to the field of tracking and positioning technology, and more specifically, to a position detection method, device, system and storage medium. Background Art

[0002] Electromagnetic tracking systems use electromagnetic signals to track a target's location or navigate. They typically consist of a transmitter and a receiver. The transmitter transmits electromagnetic signals, while the receiver receives and processes them, analyzing signal strength, direction, and phase to detect the target's location, direction, or motion. Electromagnetic tracking systems are widely used in healthcare, navigation, geological exploration, indoor positioning, and other fields.

[0003] However, in the prior art, the AC magnetic field is easily interfered by metal conductors, which stimulates eddy currents on the metal surface, thereby affecting the measured magnetic field and distorting the positioning results. Transmitters using static magnetic fields are generally used for passive positioning and are easily interfered with by environmental magnetic fields (such as the Earth's magnetic field). Moreover, conventional transmitters are usually patched on PCBs (Printed Circuit Boards) in the form of electronic components, and their shape restricts their integration with some precision instruments. For example, magnetic sensors are mostly manufactured on a large scale using semiconductor technology, and are difficult to customize flexibly, especially when it is necessary to detect slender surgical instruments such as micro-surgical probes, catheters for vascular intervention, or endoscopes.

[0004] How to flexibly customize the size of the position detection system for precision instruments such as surgical instruments to detect the position of the precision instruments and reduce the interference of metal conductors during the position detection process has become an urgent problem that needs to be solved. Summary of the Invention

[0005] The embodiments of the present application provide a position detection method, device, system and storage medium, which can combine the advantages of magnetic positioning and coils as receivers, reduce interference from metal conductors, and flexibly customize the size of the coils to expand the application scenarios of the position detection method while improving detection accuracy.

[0006] In a first aspect, an embodiment of the present application provides a position detection method for detecting the position of an object to be detected, wherein the object to be detected is equipped with a receiver, and the method includes:

[0007] Controlling at least two magnets in a transmitter matched with a receiver to rotate to generate a low-frequency magnetic field;

[0008] Receiving an electrical signal induced by a magnetic field change obtained by a coil in a receiver in a low-frequency magnetic field;

[0009] The position of the object to be measured is determined based on the electrical signal induced by the magnetic field change.

[0010] In an embodiment of the present application, a low-frequency magnetic field is generated by controlling the rotation of at least two magnets in a generator that matches the receiver, and a magnetic field change induced electrical signal obtained by the receiver coil in the low-frequency magnetic field is received. The magnetic field change induced electrical signal generated in the coil by the low-frequency magnetic field is used to realize position detection, which can reduce the interference caused by the metal conductor. The size of the coil can be flexibly customized, which expands the application scenarios of the position detection method and improves the detection accuracy.

[0011] In one possible implementation, the transmitter further includes an encoder, and the encoder is connected to the magnet via a coupling. The method further includes:

[0012] The rotary encoding information is determined by reading the magnet rotation angle fed back by the encoder;

[0013] Determining the position of an object to be measured based on an electrical signal induced by a magnetic field change includes:

[0014] The position of the object to be measured is determined based on the rotation encoding information and the electrical signal induced by the magnetic field change.

[0015] In one possible implementation, receiving an electrical signal induced by a magnetic field change obtained by a coil in a receiver in a low-frequency magnetic field includes:

[0016] Receiving the relationship between the coil induced voltage value and time in the target period obtained by measurement to determine the magnetic field change induced electrical signal obtained by the coil in the receiver in the low-frequency magnetic field; or

[0017] The coil induced voltage values ​​in the coil at different frequencies obtained by measurement are received to determine the magnetic field change induced electrical signal obtained by the coil in the receiver in the low-frequency magnetic field.

[0018] In one possible implementation, receiving a measured relationship between a change in a coil induced voltage value in a coil over time within a target period to determine a magnetic field change induced electrical signal obtained by a coil in a receiver in a low-frequency magnetic field includes:

[0019] Performing signal amplification processing on the relationship between the received coil induced voltage value and time, to obtain a first induced electrical signal;

[0020] filtering the first induced electrical signal to obtain a second induced electrical signal;

[0021] The second induced electrical signal is converted into digital form, and the relationship between time and the induced voltage value of the target coil is determined as the magnetic field change induced electrical signal, and the induced voltage value of the target coil is a digital signal value.

[0022] In one possible implementation, receiving coil induced voltage values ​​in a coil at different frequencies obtained by measurement to determine a magnetic field change induced electrical signal obtained by a coil in a receiver in a low-frequency magnetic field includes:

[0023] receiving a reference electrical signal at a fixed frequency;

[0024] Phase demodulation is performed based on the reference electrical signal and the coil induced voltage values ​​received in the coil at different frequencies;

[0025] Filtering the phase-demodulated signal to obtain a third induced electrical signal;

[0026] A DC signal in the third induced electrical signal is extracted and restored to obtain a magnetic field change induced electrical signal.

[0027] In a possible implementation, the method further includes:

[0028] Calibrate the transmitter parameters to determine the positions of at least two magnets in the transmitter and the rotation axis vectors of the magnets;

[0029] The coil in the receiver is calibrated to determine the ratio of the effective area of ​​the coil to the demagnetization factor.

[0030] In one possible implementation, determining the position of the object to be measured based on an electrical signal induced by a magnetic field change includes:

[0031] The position of the receiver is calculated based on the positions of at least two magnets, the rotation axis vector of the magnet, the ratio of the effective area of ​​the coil to the demagnetization factor, the rotation encoding information, and the induced electrical signal of the magnetic field change to determine the position of the object to be measured.

[0032] In a second aspect, an embodiment of the present application provides a position detection device for detecting the position of an object to be detected, wherein the object to be detected is equipped with a receiver; the device includes:

[0033] A magnetic field generating module, used to control the rotation of at least two magnets in a transmitter matched with the receiver to generate a low-frequency magnetic field;

[0034] A signal receiving module is used to receive an electrical signal induced by a magnetic field change obtained by a coil in a receiver in a low-frequency magnetic field;

[0035] The position determination module is used to determine the position of the object to be measured based on the electrical signal induced by the magnetic field change.

[0036] In a third aspect, an embodiment of the present application provides a position detection system, including an object to be measured and a position detection device, wherein the object to be measured is equipped with a receiver. The position detection device includes a receiver and a transmitter.

[0037] a transmitter for generating a low-frequency magnetic field;

[0038] A receiver is used to obtain an electrical signal induced by a magnetic field change through a coil;

[0039] An electromagnetic positioning device is used to control the low-frequency magnetic field generated by the rotation of at least two magnets in a transmitter that matches a receiver; receive the magnetic field change induced electrical signal voltage obtained by the coil in the receiver in the low-frequency magnetic field; and determine the position of the object to be measured based on the magnetic field change induced voltage electrical signal.

[0040] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements the method of the first aspect described above.

[0041] In a fifth aspect, an embodiment of the present application provides a computer program product, which, when executed on a position detection device, enables the position detection device to execute the method of the first aspect described above.

[0042] It can be understood that the second aspect, third aspect, fourth aspect and fifth aspect provided above are all used to execute the corresponding methods provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding methods provided above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 A schematic diagram of the structure of a position detection system provided in an embodiment of the present application;

[0044] Figure 2 A schematic diagram of the structure of a transmitter and a receiver provided in an embodiment of the present application;

[0045] Figure 3 A flow chart of a position detection method provided in an embodiment of the present application;

[0046] Figure 4 Schematic diagram of the transmitter structure;

[0047] Figure 5 It is a structural diagram of the receiver;

[0048] Figure 6 A schematic diagram of a process for receiving an electrical signal induced by a magnetic field change according to an embodiment of the present application;

[0049] Figure 7 A schematic diagram of another process for receiving an electrical signal induced by a magnetic field change according to an embodiment of the present application;

[0050] Figure 8 A schematic structural diagram of a position detection device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0051] In the following description, specific details such as specific system structures and techniques are provided for purposes of illustration rather than limitation to facilitate a thorough understanding of the embodiments of the present application. However, it will be apparent to those skilled in the art that the present application may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid obscuring the description of the present application with unnecessary detail.

[0052] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or collections thereof.

[0053] It will also be understood that the term "and / or" used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0054] As used in this specification and the appended claims, the term "if" can be interpreted as "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "upon determination" or "in response to determining" or "upon detection of [described condition or event]" or "in response to detecting [described condition or event]," depending on the context.

[0055] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0056] References to "one embodiment" or "some embodiments" in this specification mean that a particular feature, structure, or characteristic described in conjunction with that embodiment is included in one or more embodiments of the present application. Thus, phrases such as "in one embodiment," "in some embodiments," "in other embodiments," and "in other embodiments" appearing in various places in this specification do not necessarily refer to the same embodiment, but rather mean "one or more but not all embodiments," unless otherwise specifically emphasized. The terms "including," "comprising," "having," and variations thereof all mean "including but not limited to," unless otherwise specifically emphasized.

[0057] See Figure 1 , Figure 1 The figure is a schematic diagram of the structure of the position detection system, wherein the position detection system includes an object to be detected and a position detection device, and the object to be detected is equipped with a receiver, and the position detection device includes a transmitter and a receiver.

[0058] The transmitter of the position detection device includes at least two magnets that can generate a low-frequency magnetic field through rotation. The magnets can be permanent magnets. When the permanent magnets rotate, the magnetic field around them changes accordingly. The frequency of this change is usually low, thereby generating a low-frequency magnetic field. The coil in the receiver is located in this low-frequency magnetic field and can obtain an induced electrical signal from the magnetic field change. After the position detection device receives the induced electrical signal from the magnetic field change obtained by the coil, it can determine the position of the receiver based on the induced electrical signal from the magnetic field conversion. Since the receiver is installed on the object to be measured, the position of the object to be measured can be determined.

[0059] In an embodiment of the present application, the transmitter is used to generate a low-frequency magnetic field, the receiver is used to obtain an induced electrical signal of a magnetic field change through a coil, the position detection device is used to control the rotation of at least two magnets in the generator to generate a low-frequency magnetic field, and receive the magnetic field change induced electrical signal obtained by the coil of the receiver in the low-frequency magnetic field, and finally determine the position of the object to be measured based on the induced voltage electrical signal of the magnetic field change.

[0060] For example, Figure 2 As shown in FIG. 1 , a schematic diagram of the structure of a transmitter and a receiver provided in an embodiment of the present application is shown. The transmitter may include four permanent magnets distributed at the four corners of a square in a rotationally symmetrical manner, and each of the four permanent magnets rotates around its own axis of symmetry. The receiver may be a long-axis coil with an iron core, and the position vectors of the center of the receiving coil from the centers of the four permanent magnets are respectively The coil is wound around an iron core. To allow the receiver to be integrated into the surgical instrument, it is generally made into a slender shape with a diameter of 0.2 to 0.8 mm and a length of 2 to 8 mm. The iron core is generally made of a magnetic material with high magnetic permeability such as ferrite, permalloy, or amorphous alloy. Adding this iron core to the coil can greatly increase the induced voltage, which is related to the demagnetization factor N of the iron core. d and magnetic permeability μ r It matters.

[0061] After theoretical derivation, it can be concluded that the magnetic induction intensity at the center of the coil after adding the iron core is The magnetic induction intensity at the center of the coil is the same as that of an air-core coil. By the following relationship:

[0062]

[0063] Because μ r >>1, then:

[0064]

[0065] Therefore, after adding the iron core, the magnetic induction intensity passing through the coil is Therefore, adding an iron core to the coil can greatly enhance the induced voltage, facilitating subsequent position detection.

[0066] It should be understood that in the prior art, AC magnetic fields are easily interfered with by metal conductors, stimulating eddy currents on the metal surface, thereby affecting the measured magnetic field and distorting the positioning results. Transmitters using static magnetic fields are generally used for passive positioning and are easily interfered with by environmental magnetic fields (such as the Earth's magnetic field). Moreover, conventionally used transmitters are usually patched on PCBs in the form of electronic components, and their shape restricts their integration with some precision instruments. For example, magnetic sensors are mostly manufactured on a large scale using semiconductor technology, and are difficult to customize flexibly, especially when it is necessary to detect slender surgical instruments such as micro-surgical probes, catheters for vascular intervention, or endoscopes.

[0067] In order to solve the above problems, the present application provides a position detection method, which generates a low-frequency magnetic field by controlling the rotation of at least two magnets in a generator matched with a receiver, and receives the magnetic field change induced electrical signal obtained by the receiver coil in the low-frequency magnetic field. The position detection is realized by utilizing the magnetic field change induced electrical signal generated in the coil by the low-frequency magnetic field, which can reduce the interference caused by the metal conductor. The size of the coil can be flexibly customized, which expands the application scenarios of the position detection method and improves the detection accuracy.

[0068] It should be understood that the order of execution of the steps in this embodiment does not necessarily imply a specific order of execution. The order of execution of each process should be determined by its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of this application. In order to illustrate the technical solution of this application, the following is an illustration using specific embodiments.

[0069] See Figure 3 , shows a flow chart of a position detection method provided in an embodiment of the present application, the method comprising the following steps:

[0070] Step 301: Control the rotation of at least two magnets in a transmitter that matches a receiver to generate a low-frequency magnetic field.

[0071] The transmitter may refer to a device for transmitting electromagnetic signals. In an embodiment of the present application, the transmitter is a device comprising at least two magnets, which generates a low-frequency magnetic field by controlling the rotation of the magnets.

[0072] A magnet is an object that can generate a magnetic field. In the embodiments of this application, the magnet is defined as a permanent magnet, which can be made of materials such as ferrite, neodymium iron boron, aluminum nickel cobalt, or samarium cobalt. The atoms or molecules in the magnet spontaneously arrange themselves into a magnetic structure, allowing it to maintain a magnetic field of a certain strength and direction even in the absence of an external magnetic field. Unlike temporary magnets, permanent magnets do not require external magnetic field excitation to maintain their magnetism.

[0073] For example, when the permanent magnet rotates, the magnetic field around it will change accordingly, and the frequency of this change is usually low, so that a low-frequency magnetic field can be generated. The low-frequency magnetic field refers to a magnetic field with a lower frequency and a slower change rate, such as 5-40Hz. It should be understood that in the low-frequency range, the shielding of the electromagnetic field by the metal conductor mainly relies on the electromagnetic induction phenomenon, that is, when the magnetic field passes through the metal conductor, it will cause the movement of free electrons in the conductor, thereby generating current. These currents will generate additional magnetic fields in the conductor, and their direction is opposite to the original magnetic field, thereby weakening the propagation of the external magnetic field in the metal conductor. However, for low-frequency magnetic fields, the movement speed of free electrons in the metal conductor is relatively slow, so the induced current generated is also relatively small. This results in a weaker shielding effect of the metal conductor on the low-frequency magnetic field, allowing the magnetic field to pass through the metal conductor relatively easily and continue to propagate. Therefore, performing position detection in a low-frequency magnetic field can reduce interference from the metal conductor.

[0074] In the embodiment of the present application, it is first necessary to control at least two magnets in the transmitter. A motor or other mechanical device can be used to control the rotation of the magnets at a certain speed and direction, thereby generating a low-frequency magnetic field.

[0075] For example, see Figure 4 The transmitter structure diagram shown in the figure consists of four rotating units, each including a magnet, motor, encoder, and corresponding structural frame. The four units are arranged 90 degrees around the center and distributed at four symmetrical angles. The motor, magnet, and encoder are connected together via a coupling. When the motor rotates, it drives the magnet and encoder to rotate together, generating a low-frequency magnetic field. The encoder provides real-time feedback on the magnet's rotation angle.

[0076] Step 302: Receive an electrical signal induced by a magnetic field change in a coil in a receiver in a low-frequency magnetic field.

[0077] The receiver in the embodiment of the present application includes a coil and a signal detection circuit. For details, please refer to Figure 5 The structural diagram of the receiver shown in FIG. 1 shows a structure of a receiver, in which a magnetic bar coil can be used as the coil, that is, an iron core is added at the center of the coil to increase the magnetic field change to induce an electrical signal, thereby facilitating detection.

[0078] For example, the diameter of the magnetic bar coil can be 0.6 mm, the length can be 6 mm, and the core is made of manganese-zinc ferrite. The wire diameter of the coil can be 0.05 mm, and a single layer is wound around the core with 110 turns.

[0079] Among them, the magnetic field change induced electrical signal refers to the electrical signal generated by the magnetic field change. When the magnetic field changes on the coil in the receiver, according to Faraday's law of electromagnetic induction, an electric current will be induced in the coil, thereby generating an electrical signal.

[0080] In an embodiment of the present application, first, the coil in the receiver is placed in a low-frequency magnetic field. When the magnetic field strength or direction in the magnetic field changes (for example, due to the rotation of the magnet in the transmitter causing the magnetic field to change), the coil in the receiver will sense these changes. According to Faraday's law of electromagnetic induction, these magnetic field changes will generate an induced current in the coil, and the induced current in the coil changes with the magnetic field, forming a magnetic field change induced electrical signal. Then, the receiver can amplify, filter and process these induced electrical signals through internal circuits or processors. Ultimately, the processed electrical signals are used to determine the position of the object to be measured.

[0081] In one possible implementation, receiving an electrical signal induced by a magnetic field change obtained by a coil in a receiver in a low-frequency magnetic field includes:

[0082] Receiving the relationship between the coil induced voltage value and time in the target period obtained by measurement to determine the magnetic field change induced electrical signal obtained by the coil in the receiver in the low-frequency magnetic field; or

[0083] The coil induced voltage values ​​in the coil at different frequencies obtained by measurement are received to determine the magnetic field change induced electrical signal obtained by the coil in the receiver in the low-frequency magnetic field.

[0084] In an embodiment of the present application, the received magnetic field change induced electrical signal can be the relationship between the change of the coil induced voltage value in the coil within the target period and time, or can be the coil induced voltage value in the coil at different frequencies; according to the difference of the received magnetic field change induced voltage signal, different data processing methods are used to detect the position of the object to be measured.

[0085] In one possible implementation, see Figure 6 , shows a schematic diagram of a process for receiving an electrical signal induced by a magnetic field change provided by an embodiment of the present application; the method comprises the following steps:

[0086] Step 601: Amplify the received coil induced voltage value according to its temporal relationship to obtain a first induced electrical signal.

[0087] Step 602: Filter the first induced electrical signal to obtain a second induced electrical signal.

[0088] Step 603 : Perform analog-to-digital conversion on the second induced electrical signal, determine the relationship between time and the target coil induced voltage value as the magnetic field change induced electrical signal, and the target coil induced voltage value is a digital signal value.

[0089] In the embodiment of the present application, at different distances and orientations from the center of the transmitter, the measured relationship between the change in the coil induced voltage over time within one cycle is relatively weak. In addition, due to the inclusion of noise from the circuit itself, the signal detection circuit in the receiver must include amplification, filtering, and analog-to-digital conversion functions to extract the useful signal and send it to the processing unit in the form of a digital signal.

[0090] Specifically, the signal detection circuit in the receiver transmits the temporal variation of the coil's induced voltage to a signal amplifier for processing. The signal amplifier increases the signal's amplitude to ensure sufficient strength and clarity for subsequent processing. This is because the received induced voltage can be very weak and requires amplification to reach an appropriate level. A signal amplifier typically increases the signal's amplitude by a specific amplification factor.

[0091] After signal amplification, the first induced electrical signal may contain some unwanted high-frequency noise or interference. Therefore, the signal needs to be filtered to remove these unnecessary components, thereby obtaining a purer and smoother signal. The filter can selectively pass or suppress different parts of the signal according to a specific frequency range. In the embodiment of the present application, a low-pass filter can be used to filter out high-frequency components and retain low-frequency components.

[0092] After filtering, the second induced electrical signal is converted into a digital signal. This is typically accomplished using an analog-to-digital converter (ADC). The ADC converts a continuous analog signal into a discrete digital signal for easy digital processing and storage. In this embodiment of the present application, the ADC determines the relationship between the change in time and the target coil induced voltage value as a magnetic field change induced electrical signal, and converts the target coil induced voltage value into a corresponding digital signal value.

[0093] In one possible implementation, see Figure 7 , shows another flow chart of receiving an electrical signal induced by a magnetic field change according to an embodiment of the present application; the method comprises the following steps:

[0094] Step 701: Receive a reference electrical signal at a fixed frequency.

[0095] Step 702: Perform phase demodulation based on the reference electrical signal and the received coil induced voltage values ​​in the coil at different frequencies.

[0096] Step 703: Filter the phase-demodulated signal to obtain a third induced electrical signal.

[0097] Step 704: extract the DC signal from the third induced electrical signal and restore it to obtain a magnetic field change induced electrical signal.

[0098] It should be understood that the method provided in the above embodiment for receiving the induced electrical signal of the magnetic field change is to use the phase method to extract the induced voltage value of a complete cycle, but another method can also be used at the same time, that is, the phase-locked amplification method provided in the embodiment of the present application, which is used to remove the voltage amplitude of the induced voltage at different frequencies.

[0099] In the embodiments of this application, the magnet can rotate at different frequencies, and the corresponding induced voltage is the superposition of time-varying signals of different frequencies. A Fourier transform is performed on the induced voltage value, converting the induced electrical signal of the magnetic field change from the time domain to the frequency domain for calculation. Therefore, as long as the position of each resonant peak can be accurately determined, the principle of phase-locked amplification can be used to extract the amplitude of the coil induced voltage value at different frequencies, thereby realizing the posture solution.

[0100] It should be understood that phase-locked amplification is a commonly used signal processing technique that can amplify and extract signals of a specific frequency f, effectively improving the signal-to-noise ratio. Using this technique requires a reference signal with a fixed frequency f. A reference coil can be added to the transmitter. Because this coil is very close to the magnet, the induced voltage is relatively strong, making it very easy to extract. Using this signal as the reference signal, the input signal from the receiving coil is multiplied by two multipliers with 90° phase differences. The signal is then low-pass filtered to remove noise, and the DC signal is directly acquired. The root sum of squares is then taken to recover the true induced voltage signal—the electrical signal induced by the magnetic field changes.

[0101] In the embodiment of the present application, if the phase-locked amplification method is used, the receiving coil needs to use two or three axes. Otherwise, relying solely on four observations is not enough to calculate the 6-DOF posture. In this embodiment, there is no limit on the number of magnets. Two or three magnets can rotate around their own rotation axis, or a single magnet can simultaneously revolve around an axis and rotate around its own symmetry axis. In short, as long as the configuration can achieve permanent magnetic rotation positioning, this application does not limit the number of magnets when using this method.

[0102] Step 303: Determine the position of the object to be measured based on the electrical signal induced by the magnetic field change.

[0103] In an embodiment of the present application, according to the above steps, a magnetic field change induced electrical signal has been obtained through the coil in the receiver. This signal reflects the change of the magnetic field in the environment. This change is usually caused by the movement of the object to be measured. Therefore, the position of the object to be measured can be determined based on the magnetic field change induced electrical signal. Specifically, the position of the object to be measured can be determined based on the change of the magnetic field change induced electrical signal and the positioning algorithm.

[0104] In one possible implementation, the position of the object to be measured is not only related to the electrical signal induced by the magnetic field change, but also to the rotation angle of the magnet in the transmitter. Therefore, the position detection method may further include:

[0105] The rotary encoding information is determined by reading the magnet rotation angle fed back by the encoder;

[0106] Determining the position of an object to be measured based on an electrical signal induced by a magnetic field change includes:

[0107] The position of the object to be measured is determined based on the rotation encoding information and the electrical signal induced by the magnetic field change.

[0108] In an embodiment of the present application, the original signal read from the encoder and the magnetic field induced electrical signal are converted to obtain the rotation angle of the magnet and the time induced voltage value of the coil, and time alignment is completed, that is, the coil induced voltage corresponding to the magnet rotation angle at the same moment is determined, and then the position of the object to be measured is determined based on the magnet rotation angle at the same moment and the corresponding coil induced voltage.

[0109] In one possible implementation, before determining the position of the object to be detected based on the rotation encoding information and the electrical signal induced by the magnetic field change, the position detection method further includes:

[0110] Calibrate the transmitter parameters to determine the positions of at least two magnets in the transmitter and the rotation axis vectors of the magnets;

[0111] The coil in the receiver is calibrated to determine the ratio of the effective area of ​​the coil to the demagnetization factor.

[0112] In an embodiment of the present application, the transmitter parameter calibration can be completed by a three-axis translation stage and a magnetic sensor, which is used to calibrate the positions of at least two magnets equivalent to a magnetic dipole model and their rotation axis vectors.

[0113] In the embodiment of the present application, the ratio of the effective area of ​​the receiving coil to the demagnetization factor can also be calibrated using a three-axis translation stage. Specifically, the receiving coil is precisely displaced relative to the transmitter. The change in displacement will cause a change in the induced voltage. By measuring the induced voltage corresponding to multiple moving points, the following formula can be used to fit the parameters, namely, the ratio of the effective area of ​​the receiving coil to the demagnetization factor NS / N d, thereby calibrating the coil.

[0114]

[0115] Where E is the coil induced voltage value in the low-frequency magnetic field, is the axial vector of the coil, is the rotation axis vector of the i-th magnet, I is a 3*3 diagonal matrix, μ0 is the magnetic permeability, where the transmitter is calibrated to obtain the equivalent magnetic dipole moment of multiple magnets equivalent to the magnetic dipole model and its rotation axis vector is the equivalent magnetic dipole moment of each magnet, f i is the rotation frequency of the i-th magnet.

[0116] Based on the above analytical formula, by measuring the size of E over a period of time, or the size of E at different frequencies, the position vector of the receiver can be calculated. and the axial vector Then the position of the receiver is determined to determine the position of the object to be measured.

[0117] Specifically, determining the position of the object to be measured based on the electric signal induced by the magnetic field change includes:

[0118] The position of the receiver is calculated based on the positions of at least two magnets, the rotation axis vector of the magnet, the ratio of the effective area of ​​the coil to the demagnetization factor, the rotation encoding information, and the induced electrical signal of the magnetic field change to determine the position of the object to be measured.

[0119] In the above embodiment, a low-frequency magnetic field is generated by controlling the rotation of at least two magnets in a generator that matches the receiver, and a magnetic field change induced electrical signal obtained by the receiver coil in the low-frequency magnetic field is received. The magnetic field change induced electrical signal generated in the coil by the low-frequency magnetic field is used to realize position detection, which can reduce the interference caused by the metal conductor. Moreover, the size of the coil can be flexibly customized, which expands the application scenarios of the position detection method and improves the detection accuracy.

[0120] Corresponding to the position detection method in the above embodiment, Figure 8 A structural schematic diagram of a position detection device provided in an embodiment of the present application is shown. For ease of explanation, only the parts related to the embodiment of the present application are shown.

[0121] See also Figure 8 , the position detection device 800 includes:

[0122] A magnetic field generating module 801 is used to control the rotation of at least two magnets in a transmitter that matches the receiver to generate a low-frequency magnetic field;

[0123] The signal receiving module 802 is used to receive the magnetic field change induced electrical signal obtained by the coil in the receiver in the low-frequency magnetic field;

[0124] The position determination module 803 is configured to determine the position of the object to be measured based on the electrical signal induced by the magnetic field change.

[0125] In the embodiment of the present application, the transmitter further includes an encoder, which is connected to the magnet via a coupling. The position detection device 800 further includes:

[0126] The coding information reading module is used to determine the rotation coding information by reading the magnet rotation angle fed back by the encoder.

[0127] The location determination module 803 may specifically include the following units:

[0128] The first position determining unit is used to determine the position of the object to be measured based on the rotation coding information and the electric signal induced by the magnetic field change.

[0129] In the embodiment of the present application, the signal receiving module 802 may specifically include the following units:

[0130] A first receiving unit is configured to receive a relationship between a coil induced voltage value in the coil and a time change obtained by measuring within a target period, so as to determine a magnetic field change induced electrical signal obtained by the coil in the receiver in the low-frequency magnetic field; or

[0131] The second receiving unit is used to receive the coil induced voltage values ​​in the coil at different frequencies obtained by measurement, so as to determine the magnetic field change induced electrical signal obtained by the coil in the receiver in the low-frequency magnetic field.

[0132] In the embodiment of the present application, the first receiving unit may be specifically configured to:

[0133] Performing signal amplification processing on the relationship between the received coil induced voltage value and time, to obtain a first induced electrical signal;

[0134] filtering the first induced electrical signal to obtain a second induced electrical signal;

[0135] The second induced electrical signal is converted into digital form, and the relationship between time and the induced voltage value of the target coil is determined as the magnetic field change induced electrical signal, and the induced voltage value of the target coil is a digital signal value.

[0136] In the embodiment of the present application, the second receiving unit may be specifically configured to:

[0137] receiving a reference electrical signal at a fixed frequency;

[0138] Phase demodulation is performed based on the reference electrical signal and the coil induced voltage values ​​received in the coil at different frequencies;

[0139] Filtering the phase-demodulated signal to obtain a third induced electrical signal;

[0140] A DC signal in the third induced electrical signal is extracted and restored to obtain a magnetic field change induced electrical signal.

[0141] In the embodiment of the present application, the position detection device 800 may further include:

[0142] A first calibration module is used to calibrate the parameters of the transmitter and determine the positions of at least two magnets in the transmitter and the rotation axis vector of the magnet;

[0143] The second calibration module is used to perform parameter calibration on the coil in the receiver to determine the ratio of the effective area of ​​the coil to the demagnetization factor.

[0144] In the embodiment of the present application, the location determination module 803 may further include the following units:

[0145] The second position determination unit is used to calculate the position of the receiver based on the positions of at least two magnets, the rotation axis vector of the magnet, the ratio of the effective area of ​​the coil to the demagnetization factor, the rotation encoding information, and the electrical signal induced by the magnetic field change to determine the position of the object to be measured.

[0146] It should be noted that the information interaction, execution process, etc. between the above-mentioned devices / units are based on the same concept as the method embodiment of this application. Their specific functions and technical effects can be found in the method embodiment section and will not be repeated here.

[0147] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0148] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0149] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0150] In the embodiments provided in the present application, it should be understood that the disclosed devices / measuring equipment and methods can be implemented in other ways. For example, the device / measuring equipment embodiments described above are merely schematic. For example, the division of the modules or units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components that can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of the devices or units, which can be electrical, mechanical or other forms.

[0151] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0152] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0153] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the process in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and when the computer program is executed by the processor, it can implement the steps of the above-mentioned various method embodiments. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0154] The present application implements all or part of the processes in the above-mentioned embodiment method, and can also be completed through a computer program product. When the computer program product is run on a measuring device, the measuring device can implement the steps in the above-mentioned method embodiments when executed.

[0155] The above embodiments are intended only to illustrate the technical solutions of the present application and are not intended to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they may still modify the technical solutions described in the above embodiments or replace some of the technical features therein with equivalents; and such modifications or replacements do not deviate from the spirit and scope of the technical solutions of the embodiments of the present application and should be included within the scope of protection of the present application.

Claims

1. A position detection method, characterized in that: The method is used to detect the position of an object to be detected, where the object to be detected is equipped with a receiver; the method comprises: controlling at least two magnets in a transmitter matched with the receiver to rotate and generate a low-frequency magnetic field; Receiving an induced electric signal of a magnetic field change obtained by a coil in a receiver in the low-frequency magnetic field; The position of the object to be measured is determined based on the electrical signal induced by the magnetic field change.

2. The method according to claim 1, wherein The transmitter further includes an encoder, and the encoder is connected to the magnet via a coupling. The method further includes: Determine the rotation encoding information by reading the magnet rotation angle fed back by the encoder; Determining the position of the object to be measured based on the electrical signal induced by the magnetic field change includes: The position of the object to be measured is determined based on the rotation encoding information and the magnetic field change induced electrical signal.

3. The method according to claim 1, wherein The receiving of the magnetic field change induced electrical signal obtained by the coil in the receiver in the low-frequency magnetic field comprises: Receiving a relationship between a coil induced voltage value in the coil and a time change within a target period obtained by measurement, to determine a magnetic field change induced electrical signal obtained by a coil in a receiver in the low-frequency magnetic field; or The coil induced voltage values ​​in the coil at different frequencies obtained by measurement are received to determine the magnetic field change induced electrical signal obtained by the coil in the receiver in the low-frequency magnetic field.

4. The method according to claim 3, wherein The receiving of a change relationship between a coil induced voltage value in the coil and time within a target period obtained by measuring to determine a magnetic field change induced electrical signal obtained by a coil in a receiver in the low-frequency magnetic field includes: Performing signal amplification processing on the received relationship between the coil induced voltage value and time, to obtain a first induced electrical signal; performing filtering processing on the first induced electrical signal to obtain a second induced electrical signal; The second induced electrical signal is converted into digital form, and the relationship between time and the target coil induced voltage value is determined as the magnetic field change induced electrical signal, and the target coil induced voltage value is a digital signal value.

5. The method according to claim 3, wherein The receiving of coil induced voltage values ​​in the coil at different frequencies obtained by measurement to determine a magnetic field change induced electrical signal obtained by the coil in the receiver in the low-frequency magnetic field includes: receiving a reference electrical signal at a fixed frequency; performing phase demodulation according to the reference electrical signal and the received coil induced voltage values ​​in the coil at the different frequencies; performing filtering processing on the phase-demodulated signal to obtain a third induced electrical signal; A direct current signal in the third induced electrical signal is extracted and restored to obtain the magnetic field change induced electrical signal.

6. The method according to claim 2, wherein The method further comprises: Performing parameter calibration on the transmitter to determine the positions of at least two magnets in the transmitter and the rotation axis vectors of the magnets; Parameter calibration is performed on the coil in the receiver to determine the ratio of the effective area of ​​the coil to the demagnetization factor.

7. The method according to claim 6, wherein The determining the position of the object to be measured based on the electric signal induced by the magnetic field change includes: The position of the receiver is calculated based on the positions of the at least two magnets, the rotation axis vector of the magnet, the ratio of the effective area of ​​the coil to the demagnetization factor, the rotation encoding information, and the magnetic field change induced electrical signal to determine the position of the object to be measured.

8. A position detection device, characterized in that: The device is used to detect the position of an object to be detected, and the object to be detected is equipped with a receiver; the device includes: A magnetic field generating module, configured to control the rotation of at least two magnets in a transmitter matched with the receiver to generate a low-frequency magnetic field; A signal receiving module, configured to receive an electrical signal induced by a magnetic field change obtained by a coil in a receiver in the low-frequency magnetic field; A position determination module is used to determine the position of the object to be measured based on the electrical signal induced by the magnetic field change.

9. A position detection system, characterized in that: The position detection system includes an object to be measured and a position detection device, wherein the object to be measured is equipped with a receiver and the position detection device includes a receiver and a transmitter; The transmitter is used to generate a low-frequency magnetic field; The receiver is used to obtain an electrical signal induced by a magnetic field change through a coil; The position detection device is used to control the low-frequency magnetic field generated by the rotation of at least two magnets in the transmitter matched with the receiver; and receive the magnetic field change induced electrical signal obtained by the coil in the receiver in the low-frequency magnetic field; The position of the object to be measured is determined based on the voltage electrical signal induced by the magnetic field change.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

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