Interference signal elimination device and method and inertial navigator

Abstract

The invention provides an interference signal elimination device and method and an inertial navigator. The invention relates to the technical field of navigation. The interference signal elimination device comprises a first inertial sensor and a processor. And the processor actively detects a first target signal of which the frequency is higher than the motion cut-off frequency of the inertial navigator in the first motion signal by executing an interference signal elimination algorithm, and eliminates an interference signal of which the frequency is higher than the motion cut-off frequency of the inertial navigator in the second motion signal by using the first target signal. The motion cut-off frequency of the inertial navigator is the cut-off frequency of the inertial navigator for the motion signal processing frequency spectrum, and the cut-off frequency of the inertial navigator for the motion signal processing frequency spectrum is smaller than or equal to the frequency range corresponding to the transition zone area. And the interference signal elimination device successfully eliminates the interference signal in the transition zone area. Therefore, interference signals can be eliminated to the greatest extent, the measurement precision of the inertial navigator is improved, and the measurement performance of the inertial navigator is improved.

Description

Technical Field

[0001] This application relates to the field of navigation technology, and particularly to an interference signal cancellation device, method, and inertial navigator. Background Art

[0002] An inertial navigator is a device capable of implementing a positioning and navigation function, and is widely used in fields such as aerospace and automobiles. The inertial navigator mainly relies on a micro-electro-mechanical system (MEMS) inertial sensor to achieve a high-precision positioning and navigation function. Among them, the MEMS inertial sensor includes: a gyroscope and an accelerometer. The inertial navigator uses the gyroscope and the accelerometer to measure the angular velocity and acceleration of the object to be measured respectively. Thus, the inertial navigator calculates the movement position and attitude of the object to be measured through the angular velocity and acceleration to achieve the positioning and navigation function.

[0003] In the related art, an inertial navigator includes a MEMS inertial sensor and a low-pass filter. Generally, the inertial navigator measures the motion signal of the object to be measured through the MEMS inertial sensor, and uses the low-pass filter to attenuate the interference signal in the motion signal to reduce the measurement error caused by the interference signal to the inertial navigator.

[0004] However, the inertial navigator in the related art cannot eliminate the interference signal to the greatest extent, resulting in a reduction in the measurement accuracy of the inertial navigator, especially reducing the measurement performance of the inertial navigator during long-term operation. Summary of the Invention

[0005] This application provides an interference signal cancellation device, method, and inertial navigator, which can attenuate and eliminate the interference signal to a greater extent, improve the measurement accuracy of the inertial navigator, especially improve the measurement performance of the inertial navigator during long-term operation.

[0006] In a first aspect, this application provides an interference signal cancellation device. The interference signal cancellation device is connected to an inertial measurement device in an inertial navigator. The interference signal cancellation device includes: a first inertial sensor and a processor; The first inertial sensor is configured to collect a first motion signal of a target device within a first time period and send the first motion signal to the processor; The processor is configured to receive a second motion signal sent by the inertial measurement device; wherein, the second motion signal is a motion signal collected by the inertial measurement device for the target device within the first time period; and the signal sampling rate of the first inertial sensor is higher than the signal sampling rate of the inertial measurement device; the output signal bandwidth of the first inertial sensor is higher than the output signal bandwidth of the inertial measurement device; The processor is further configured to detect a first target signal in the first motion signal, and perform interference signal cancellation processing on the second motion signal by using the first target signal to obtain a second target signal; wherein, the first target signal includes signals in the first motion signal whose frequencies are higher than the motion cut-off frequency of the inertial navigator; the second target signal is the second motion signal with interference signals whose frequencies are higher than the motion cut-off frequency of the inertial navigator removed, and the motion cut-off frequency of the inertial navigator is the cut-off frequency of the motion signal processing spectrum of the inertial navigator for the target device.

[0007] Through the interference signal cancellation device provided by the first aspect, since the signal sampling rate of the first inertial sensor included in the interference signal cancellation device is higher than that of the inertial measurement device, and the output signal bandwidth of the first inertial sensor is higher than that of the inertial measurement device, it means that the first inertial sensor has a wider frequency response range than the inertial measurement device. Based on this, the first motion signal collected by the interference signal cancellation device can obtain more detailed motion information, especially including a wider interference signal bandwidth, making the motion information contained in the first motion signal more detailed than the motion information contained in the second motion signal collected by the inertial measurement device. Thus, the processor actively detects the first target signal in the first motion signal whose frequency is higher than the motion cut-off frequency of the inertial navigator by executing the interference signal cancellation algorithm, and uses the actively detected first target signal to cancel the interference signals in the second motion signal whose frequencies are higher than the motion cut-off frequency of the inertial navigator. Since the motion cut-off frequency of the inertial navigator is the cut-off frequency of the motion signal processing spectrum of the inertial navigator for the target device, the cut-off frequency of the motion signal processing spectrum of the inertial navigator is less than or equal to the frequency range corresponding to the transition band region. Furthermore, the interference signal cancellation device cancels the interference signals located in the transition band region. Thus, the interference signal cancellation device can cancel the interference signals to the greatest extent and improve the measurement accuracy of the inertial navigator, especially the measurement performance of the inertial navigator during long-term operation.

[0008] In a possible design, the processor is specifically configured to convert the first motion signal from the time domain to the frequency domain, and detect, based on the frequency characteristics and amplitude characteristics of the first motion signal in the frequency domain, the first periodic interference signal and the first non-periodic interference signal in the first motion signal whose frequencies are higher than the motion cut-off frequency of the inertial navigator as the first target signal; wherein, the first periodic interference signal is used to cancel the periodic interference signals in the second motion signal whose frequencies are higher than the motion cut-off frequency of the inertial navigator, and the first non-periodic interference signal is used to cancel the non-periodic interference signals in the second motion signal whose frequencies are higher than the motion cut-off frequency of the inertial navigator.

[0009] In a possible design, when the inertial measurement device includes a second inertial sensor and a digital low-pass filter, the second motion signal is the original motion signal measured by the second inertial sensor for the target device within the first time period; The processor is specifically configured to perform a conversion process from the frequency domain to the time domain, a time-domain signal phase inversion process by 180°, and a signal superposition process on the first periodic interference signal in sequence to obtain a third motion signal, where the third motion signal is the second motion signal with the periodic interference signal having a frequency higher than the motion cut-off frequency of the inertial navigator eliminated; wherein, the time-domain signal phase inversion process by 180° is used to invert the phase of the first periodic interference signal in the time domain by 180°; the signal superposition process is used to superpose the amplitudes of the first periodic interference signal with its phase inverted by 180° and the second motion signal in the time domain; The processor is configured to perform noise reduction processing on the third motion signal based on the first aperiodic interference signal to obtain the second target signal; The processor is further configured to perform digital low-pass filtering on the second target signal using a digital low-pass filter, where the cut-off frequency of the digital low-pass filter is the motion cut-off frequency of the inertial navigator.

[0010] In a possible design, when the inertial measurement device includes a second inertial sensor and an electronic low-pass filter, the second motion signal is the signal obtained by performing low-pass filtering on the original motion signal measured by the second inertial sensor for the target device within the first time period through the electronic low-pass filter; The processor is specifically configured to perform attenuation processing on the first periodic interference signal and the first aperiodic interference signal respectively according to the attenuation characteristics of the electronic low-pass filter to obtain an attenuated first periodic interference signal and an attenuated first aperiodic interference signal; The processor is specifically configured to perform a conversion process from the frequency domain to the time domain, a time-domain signal phase inversion process by 180°, and a signal superposition process on the attenuated first periodic interference signal in sequence to obtain a fourth motion signal, where the fourth motion signal is the second motion signal with the periodic interference signal having a frequency higher than the motion cut-off frequency of the inertial navigator eliminated; wherein, the time-domain signal phase inversion process by 180° is used to invert the phase of the attenuated first periodic interference signal in the time domain by 180°; the signal superposition process is used to superpose the amplitudes of the attenuated first periodic interference signal with its phase inverted by 180° and the second motion signal in the time domain; The processor is configured to perform noise reduction processing on the fourth motion signal based on the attenuated first aperiodic interference signal to obtain the second target signal.

[0011] In a possible design, the processor is specifically configured to perform a Fourier transform on the first motion signal to convert the first motion signal from the time domain to the frequency domain; The processor is specifically configured to perform an inverse Fourier transform on the first periodic interference signal or the attenuated first periodic interference signal to convert the first periodic interference signal or the attenuated first periodic interference signal from the frequency domain to the time domain.

[0012] In a second aspect, the present application provides an interference signal cancellation method. The interference signal cancellation method is applied to the interference signal cancellation device in the first aspect and each possible design of the first aspect above. The interference signal cancellation device is connected to the inertial measurement device of the inertial navigation instrument; the method includes: Obtain a first motion signal of the target device collected by a first inertial sensor of the interference signal cancellation device within a first time period; Receive a second motion signal sent by the inertial measurement device; wherein, the second motion signal is a motion signal collected by the inertial measurement device for the target device within the first time period; and the signal sampling rate of the first inertial sensor is higher than the signal sampling rate of the inertial measurement device; the output signal bandwidth of the first inertial sensor is higher than the output signal bandwidth of the inertial measurement device; Detect a first target signal in the first motion signal whose frequency is higher than the motion cut-off frequency of the inertial navigation instrument; Perform interference signal cancellation processing on the second motion signal by using the first target signal to obtain a second target signal; wherein, the second target signal is the second motion signal from which interference signals with frequencies higher than the motion cut-off frequency of the inertial navigation instrument are eliminated, and the motion cut-off frequency of the inertial navigation instrument is a set cut-off frequency in the motion signal spectrum processed by the inertial navigation instrument for the target device.

[0013] In a possible design, the detecting a first target signal in the first motion signal whose frequency is higher than the motion cut-off frequency of the inertial navigation instrument includes: Convert the first motion signal from the time domain to the frequency domain; Based on the frequency characteristics and amplitude characteristics of the first motion signal in the frequency domain, detect a first periodic interference signal and a first aperiodic interference signal in the first motion signal whose frequencies are higher than the motion cut-off frequency of the inertial navigation instrument as the first target signal; Wherein, the first periodic interference signal is used to eliminate the periodic interference signal in the second motion signal with a frequency higher than the motion cut-off frequency of the inertial navigator, and the first aperiodic interference signal is used to eliminate the aperiodic interference signal in the second motion signal with a frequency higher than the motion cut-off frequency of the inertial navigator.

[0014] In a possible design, the inertial measurement device includes a second inertial sensor and a low-pass filter; the process of using the first target signal to eliminate the interference signal from the second motion signal to obtain a target motion signal includes: When the low-pass filter is a digital low-pass filter, perform a conversion process from the frequency domain to the time domain, a 180° phase flip process for the time-domain signal, and a signal superposition process on the first periodic interference signal in sequence to obtain a third motion signal, where the third motion signal is the second motion signal after eliminating the periodic interference signal with a frequency higher than the motion cut-off frequency of the inertial navigator; wherein, the 180° phase flip process for the time-domain signal is used to flip the phase of the first periodic interference signal in the time domain by 180°; the signal superposition process is used to superpose the amplitudes of the first periodic interference signal with its phase flipped by 180° and the second motion signal in the time domain; Perform noise reduction processing on the third motion signal based on the first aperiodic interference signal to obtain the second target signal; The method further includes: using a digital low-pass filter to perform digital low-pass filtering on the second target signal, where the cut-off frequency of the digital low-pass filter is the motion cut-off frequency of the inertial navigator; Or, When the low-pass filter is an electronic low-pass filter, perform attenuation processing on the first periodic interference signal and the first aperiodic interference signal respectively according to the attenuation characteristics of the electronic low-pass filter to obtain an attenuated first periodic interference signal and an attenuated first aperiodic interference signal; Perform a conversion process from the frequency domain to the time domain, a 180° phase flip process, and a signal superposition process on the attenuated first periodic interference signal in sequence to obtain a fourth motion signal, where the fourth motion signal is the second motion signal after eliminating the periodic interference signal with a frequency higher than the motion cut-off frequency of the inertial navigator; wherein, the 180° phase flip process for the time-domain signal is used to flip the phase of the attenuated first periodic interference signal in the time domain by 180°; the signal superposition process is used to superpose the amplitudes of the attenuated first periodic interference signal with its phase flipped by 180° and the second motion signal in the time domain; Performing noise reduction processing on the fourth motion signal based on the attenuated first aperiodic interference signal to obtain the second target signal.

[0015] For what is provided in the second aspect above and each possible design of the second aspect, the beneficial effects can be referred to the beneficial effects brought by the first aspect above and each possible implementation manner of the first aspect, which will not be elaborated here.

[0016] In a third aspect, the present application provides an inertial navigator, including: an inertial measurement device and an interference signal elimination device in the first aspect above and each possible design of the first aspect; wherein, the inertial measurement device is connected to the interference signal elimination device; The inertial measurement device is configured to collect a second motion signal of a target device within a first time period and send the second motion signal to the interference signal elimination device, so that the interference signal elimination device performs interference signal elimination processing on the second motion signal.

[0017] In a possible design, the inertial measurement device includes: a second inertial sensor and a low-pass filter; When the low-pass filter is a digital low-pass filter, the second motion signal sent by the inertial measurement device to the interference signal elimination device is the original motion signal measured by the second inertial sensor for the target device within the first time period; When the low-pass filter is an electronic low-pass filter, the second motion signal sent by the inertial measurement device to the interference signal elimination device is the signal obtained by performing low-pass filtering processing on the original motion signal measured by the second inertial sensor for the target device within the first time period through the electronic low-pass filter.

[0018] In a fourth aspect, the present application provides an interference signal elimination device, which includes: An acquisition module, configured to acquire a first motion signal of a target device collected by a first inertial sensor of the interference signal elimination device within a first time period.

[0019] A receiving module, configured to receive the second motion signal sent by the inertial measurement device; wherein, the second motion signal is a motion signal collected by the inertial measurement device for the target device within the first time period; and the signal sampling rate of the first inertial sensor is higher than the signal sampling rate of the inertial measurement device; the output signal bandwidth of the first inertial sensor is higher than the output signal bandwidth of the inertial measurement device.

[0020] A detection module, configured to detect a first target signal in the first motion signal whose frequency is higher than the motion cut-off frequency of the inertial navigator.

[0021] An elimination module, configured to perform interference signal elimination processing on the second motion signal by using the first target signal to obtain a second target signal; wherein, the second target signal is the second motion signal from which interference signals with frequencies higher than the motion cut-off frequency of the inertial navigator are eliminated, and the motion cut-off frequency of the inertial navigator is the set cut-off frequency in the motion signal spectrum of the inertial navigator for processing the target device.

[0022] In a fifth aspect, the present application provides an electronic device, including one or more processors; a memory; and one or more computer programs, wherein the one or more computer programs are stored on the memory, and when the computer programs are executed by the one or more processors, the electronic device is caused to implement the interference signal elimination method in the second aspect and any possible design of the second aspect.

[0023] In a sixth aspect, the present application provides a chip, including: an interface circuit and a logic circuit, the interface circuit is configured to receive a signal from another chip outside the chip and transmit it to the logic circuit, or send a signal from the logic circuit to another chip outside the chip, and the logic circuit is configured to implement the interference signal elimination method in the second aspect and any possible design of the second aspect when implemented.

[0024] In a seventh aspect, the present application provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the electronic device is caused to implement the interference signal elimination method in the second aspect and the design of the second aspect.

[0025] In an eighth aspect, the present application provides a computer program product, including: execution instructions, the execution instructions are stored in a readable storage medium, and at least one processor of the electronic device can read the execution instructions from the readable storage medium, and the at least one processor executes the execution instructions to cause the electronic device to implement the interference signal elimination method in the second aspect and the design of the second aspect.

[0026] The above description is only an overview of the technical solutions of the embodiments of the present application. In order to be able to understand the technical means of the embodiments of the present application more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of the embodiments of the present application more obvious and understandable, the following specifically illustrates the specific implementation manners of the present application. Description of the Drawings

[0027] To more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0028] Figure 1 It is a schematic structural diagram of an inertial navigator in the related art; Figure 2 It is a schematic installation structure diagram of an inertial navigator and a buffer in the related art; Figure 3 It is a schematic diagram of a spectral curve of a low-pass filter in an inertial navigator in the related art; Figure 4 It is another schematic diagram of a spectral curve of a low-pass filter in an inertial navigator in the related art; Figure 5 It is a schematic structural diagram of an inertial navigator provided by an embodiment of the present application; Figure 6 It is a schematic flowchart of a method for eliminating interference signals provided by an embodiment of the present application; Figure 7 It is a schematic flowchart of the working process of a processor in an interference signal elimination device provided by an embodiment of the present application; Figure 8 It is a schematic diagram of signal superposition processing of a processor in an interference signal elimination device provided by an embodiment of the present application; Figure 9 It is another schematic flowchart of the working process of a processor in an interference signal elimination device provided by an embodiment of the present application; Figure 10 It is a schematic flowchart of the working process of an inertial navigator provided by an embodiment of the present application; Figure 11 It is another schematic flowchart of the working process of an inertial navigator provided by an embodiment of the present application; Figure 12 It is a schematic structural diagram of an interference signal elimination device provided by an embodiment of the present application. Detailed implementation manners

[0029] In this application, "at least one" means one or more, and "a plurality" means two or more. "And / or" describes the relationship between related objects and indicates that three relationships may exist. For example, A and / or B may mean: A exists alone, A and B exist simultaneously, or B exists alone, where A and B may be singular or plural. The character " / " generally indicates that the related objects before and after are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, at least one of a alone, b alone, or c alone may mean: a alone, b alone, c alone, the combination of a and b, the combination of a and c, the combination of b and c, or the combination of a, b, and c, where a, b, and c may be single or multiple. In addition, the terms "first" and "second" are used only for descriptive purposes and should not be construed as indicating or implying relative importance.

[0030] The orientation or positional relationship indicated by terms such as "center", "longitudinal", "lateral", "upper", "lower", "left", "right", "front", "rear", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to this application.

[0031] The terms "connected" and "coupled" should be understood in a broad sense. For example, the "connection" or "coupling" of a circuit structure can refer not only to a physical connection but also to an electrical connection or a signal connection. For example, it can be a direct connection, that is, a physical connection, or it can be indirectly connected through at least one intermediate element, as long as the circuit is connected. It can also be the communication inside two elements; the signal connection can refer not only to the signal connection through a circuit but also to the signal connection through a media medium, such as radio waves. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0032] An inertial navigator mainly relies on MEMS inertial sensors to achieve high-precision positioning and navigation functions. For the convenience of description, the MEMS inertial sensors will be abbreviated as inertial sensors hereinafter. Inertial sensors mainly include: gyroscopes and accelerometers. Since gyroscopes can measure the angular velocity of the object to be measured in the navigation coordinate system, and accelerometers can measure the acceleration of the object to be measured in the navigation coordinate system. Therefore, an inertial navigator can calculate the motion position and attitude of the object to be measured based on the angular velocity and acceleration using inertial navigation algorithms to achieve the positioning and navigation functions.

[0033] Among them, inertial navigators usually use single-axis inertial sensors or multi-axis inertial sensors.

[0034] An inertial navigator is usually installed on a measured object that needs to measure its attitude, such as an aircraft, an aerospace vehicle, an autonomous driving device, etc. When the inertial navigator performs a navigation task, mechanical vibrations such as the periodic vibration, aperiodic vibration, or external shock of the measured object itself will be conducted to the inertial navigator in the form of mechanical waves, causing measurement errors in the inertial navigator. Moreover, the measurement errors will accumulate as the number and intensity of the mechanical vibrations increase, resulting in greater measurement errors in the inertial navigator. Thus, mechanical vibrations such as the periodic vibration, aperiodic vibration, or external shock of the inertial navigator itself are considered interference signals. Therefore, how to eliminate the interference signals to reduce the measurement errors of the inertial navigator has become an urgent problem to be solved for the inertial navigator.

[0035] Generally, when the measured object is in a moving state, the frequency of the effective motion signal of the measured object is relatively low, about 0 - 500 Hz. Therefore, signals with frequencies higher than the motion signal frequency are considered interference signals. Among them, the interference signals can include signals with frequencies higher than and lower than the motion signal frequency, can also include periodic signals and aperiodic signals, and can further include external motion interference signals and internal electronic interference signals.

[0036] Refer to Figure 1 , Figure 1 which is a schematic structural diagram of an inertial navigator in the related art. As Figure 1 shown, the inertial navigator may include: an inertial sensor and a low-pass filter. The inertial sensor obtains the motion signal filtered by the buffer according to the mechanical wave motion direction 102, enabling the low-pass filter to attenuate the interference signals in the motion signal to eliminate the interference signals. Thus, the measurement accuracy of the inertial navigator is improved.

[0037] Among them, the low-pass filter can be an electronic low-pass filter, a digital low-pass filter, or a multi-order digital low-pass filter. An electronic low-pass filter is a circuit that relies on electronic components to achieve the low-pass filtering effect, and is generally integrated inside the inertial sensor. When the inertial sensor outputs the motion signal, the electronic low-pass filter has already performed low-pass filtering on the motion signal. A digital low-pass filter is a digital signal processing algorithm, which usually performs low-pass filtering on the original motion signal output by the inertial sensor or the motion signal processed by other algorithms to achieve the effect of anti-interference and accuracy improvement.

[0038] Since the buffer contains elastic structures or materials inside, it has an absorption effect on mechanical vibrations. Therefore, the buffer can be regarded as a mechanical low-pass filter. The buffer has a greater attenuation effect on mechanical vibrations above its absorption frequency, while the attenuation effect on mechanical vibrations below its absorption frequency is smaller. Usually, the buffer is installed at the connection between the inertial navigator and the target device. When the target device is working, the mechanical waves on the target device are conducted to the buffer in the direction of motion 101. In this way, the buffer can significantly attenuate the mechanical waves above its absorption frequency, and the attenuated mechanical waves are conducted to the inertial navigator in the direction of motion 102. Thus, the buffer can achieve the effect of mechanical anti-interference.

[0039] Among them, for the selection of the buffer, it is necessary to ensure that the absorption frequency of the buffer is higher than the maximum operating frequency measured by the inertial navigator.

[0040] Exemplarily, referring to Figure 2 , Figure 2 shows Figure 1 the schematic diagram of the installation structure of the inertial navigator and the buffer in Figure 2 As shown, the installation structure of the inertial navigator and the buffer mainly includes: a buffer 110, a bracket 112, and an inertial navigator main board 111. Among them, the buffer 110 is installed in the connection hole between the inertial navigator main board 111 and the bracket 112. The bracket 112 is locked and fixed on the target device and is rigidly connected to the target device. Components such as inertial sensors are installed on the inertial navigator main board 111. Such a connection structure makes the inertial navigator main board 111 and components such as inertial sensors indirectly connected to the bracket 112 through the buffer 110, which belongs to a flexible connection. Therefore, it can ensure the absorption and filtering effect on the high-frequency interference mechanical waves conducted from the target device.

[0041] During the operation of the inertial navigator, the motion signals of the target device measured by the inertial sensors can be processed through the electronic circuits and software algorithms inside the inertial navigator. Since the inertial navigator has a certain selectivity in the frequency of the motion signals, usually a low-pass filter is used to attenuate the motion signals above the cut-off frequency of the low-pass filter.

[0042] Among them, the low-pass filter has a very small attenuation amplitude for the motion signals below the cut-off frequency, and the attenuation amplitude for the motion signals above the cut-off frequency will increase as the frequency of the motion signals increases, achieving the effect of low-pass filtering. For example, using a first-order low-pass filter, the attenuation amplitude for the motion signals 10 times the cut-off frequency is 20 dB, and using a second-order low-pass filter, the attenuation amplitude for the motion signals 10 times the cut-off frequency can be 40 dB.

[0043] In actual use, for target devices such as airplanes and cars, the frequency range of motion signals that an inertial navigator can measure is mostly from 0 to 500 Hz. To match the motion characteristics of the target device, the cut-off frequency of the low-pass filter needs to be consistent with the motion cut-off frequency of the target device. Therefore, the low-pass filter attenuates motion signals with frequencies higher than the cut-off frequency. An ideal low-pass filter does not attenuate motion signals with frequencies lower than the cut-off frequency, while it can attenuate motion signals with frequencies higher than the cut-off frequency to 0. However, the low-pass filter cannot achieve the effect of attenuating motion signals with frequencies higher than the cut-off frequency to 0.

[0044] Referring to Figure 3 and Figure 4 , Figure 3 shows Figure 1 a schematic diagram of the frequency spectrum curve of a low-pass filter in Figure 4 shows Figure 1 another schematic diagram of the frequency spectrum curve of a low-pass filter in. For the low-pass filter used in practice, as Figure 3 and Figure 4 shown, the low-pass filter has a smaller attenuation amplitude for motion signals with frequencies lower than the cut-off frequency point f0, and a larger attenuation amplitude for motion signals with frequencies exceeding the cut-off frequency point f0. Moreover, the higher the frequency of the motion signal, the greater the attenuation amplitude of the low-pass filter for the motion signal. When the frequency of the motion signal is at the transition band frequency point f1, the amplitude of the motion signal will be attenuated by the low-pass filter to close to 0. At this time, it can be considered that the motion signal is completely attenuated.

[0045] Among them, the cut-off frequency point f0 is the frequency value corresponding to the amplitude value A1 after the normalized amplitude A is attenuated by 3 dB. The region from 0 to the cut-off frequency point f0 is the passband region of the low-pass filter. The transition band frequency point f1 is the frequency value corresponding to the amplitude value A2 when the normalized amplitude A is attenuated to close to 0. The region from the cut-off frequency point f0 to the transition band frequency point f1 is the transition band region of the low-pass filter. The region above the transition band frequency point f1 is the stopband region of the low-pass filter.

[0046] Figure 3 In, 103 is the frequency spectrum curve of an ideal first-order low-pass filter; 104 is the frequency spectrum curve of a first-order low-pass filter used in practice; 105 is the passband region of the first-order low-pass filter; 106 is the transition band region of the first-order low-pass filter; 107 is the stopband region of the first-order low-pass filter; f0 is the cut-off frequency point of the first-order low-pass filter; f1 is the transition band frequency point of the first-order low-pass filter; the horizontal axis is the frequency axis of the first-order low-pass filter, and the vertical axis |H(jf)| is the amplitude axis of the first-order low-pass filter; A is the normalized amplitude value corresponding to the frequency of 0 of the first-order low-pass filter; A1 is the normalized amplitude value corresponding to the cut-off frequency f0; A2 is the normalized amplitude value corresponding to the transition band frequency f1.

[0047] Among them, Figure 4 the spectrum curve of a multi-stage low-pass filter is shown. Figure 4 In it, 115 is the spectrum curve of an ideal multi-stage low-pass filter; 116 is the spectrum curve of an actually used multi-stage low-pass filter; 117 is the passband region of the multi-stage low-pass filter; 118 is the transition band region of the multi-stage low-pass filter; 119 is the stopband region of the multi-stage low-pass filter; f0 is the cut-off frequency point of the multi-stage low-pass filter; f1 is the transition band frequency point of the multi-stage low-pass filter; the horizontal axis is the frequency axis of the multi-stage low-pass filter, and the vertical axis |H(jf)| is the amplitude axis of the multi-stage low-pass filter; A is the normalized amplitude value corresponding to when the frequency of the multi-stage low-pass filter is 0; A1 is the normalized amplitude value corresponding to the cut-off frequency f0; A2 is the normalized amplitude value corresponding to the transition band frequency f1.

[0048] In the related art, a buffer can attenuate a motion signal with a frequency higher than the absorption frequency of the buffer, and a low-pass filter can attenuate a motion signal with a frequency higher than the cut-off frequency of the low-pass filter. That is to say, the buffer and the low-pass filter can attenuate interference signals.

[0049] However, this method of attenuating interference signals through a buffer and a low-pass filter has the problem that it cannot attenuate or eliminate the interference signals on the target device to the greatest extent. In particular, for interference signals in the transition band region, only attenuation can be achieved, and elimination is impossible. As a result, the measurement accuracy of the inertial navigator is reduced, especially the measurement performance of the inertial navigator during long-term operation.

[0050] Among them, when the frequency of the interference signal falls in the transition band region, the buffer and the low-pass filter only attenuate the amplitude of the interference signal, rather than completely eliminating it. Moreover, the closer the frequency of the interference signal is to the absorption frequency of the buffer and the cut-off frequency of the low-pass filter, the smaller the attenuation amplitude of the buffer and the low-pass filter for the interference signal.

[0051] Although a multi-stage low-pass filter can be used for the low-pass filter of an inertial navigator, although the transition band region of the multi-stage low-pass filter is relatively more compressed compared to a low-order filter, there are still two disadvantages. First, the transition band region cannot be eliminated. Second, in the region below and close to the cut-off frequency of the multi-stage low-pass filter, signal amplification will occur. And these two disadvantages will both cause measurement errors during the operation of the inertial navigator. In this way, when the inertial navigator performs inertial navigation calculations using the motion signal processed by the low-pass filter, the interference signal will be processed by the inertial navigator together for calculation, and the motion attitude and position of the target device will be calculated. Moreover, as the target device operates for a long time, the measurement errors generated by the interference signal will gradually accumulate, resulting in greater errors and deteriorating the measurement accuracy of the inertial navigator.

[0052] Based on the above description, when the amplitude and energy of the target device are large, since the attenuation coefficient of the inertial navigator for the interference signal remains unchanged, the amplitude of the interference signal that can be measured by the inertial sensor in the inertial navigator is large, resulting in a large deterioration of the measurement accuracy of the inertial navigator. Therefore, relying solely on the low-pass filter to attenuate the interference signal or eliminate the interference signal, the inertial navigator cannot eliminate the interference signal to the greatest extent, reducing the measurement accuracy of the inertial navigator, especially reducing the measurement performance of the inertial navigator during long-term operation.

[0053] Therefore, the present application provides an interference signal cancellation device, method and inertial navigator.

[0054] Refer to Figure 5 , Figure 5 which is a schematic structural diagram of an inertial navigator provided by an embodiment of the present application. As Figure 5 shown, the inertial navigator may include: an inertial measurement device and an interference signal cancellation device. Among them, the inertial measurement device is connected to the interference signal cancellation device.

[0055] The inertial measurement device can collect the second motion signal of the target device within the first time. And the inertial measurement device can send the second motion signal to the interference signal cancellation device, so that the interference signal cancellation device can obtain the second motion signal. Furthermore, the interference signal cancellation device can perform interference signal cancellation processing on the second motion signal to eliminate the interference signal located in the transition band region of the inertial measurement device, greatly reducing the influence of the interference signal on the measurement accuracy of the inertial navigator. Thus, the measurement accuracy of the inertial navigator can be improved, especially the measurement performance of the inertial navigator during long-term operation.

[0056] Among them, the interference signal cancellation device collects the first motion signal of the target device within the first time period and detects the first target signal in the first motion signal whose frequency is higher than the motion cut-off frequency of the inertial navigator. In this way, the interference signal cancellation device can use the first target signal to cancel the interference signal in the second motion signal whose frequency is higher than the motion cut-off frequency of the inertial navigator. Thus, the interference signal cancellation device can obtain the second target signal.

[0057] Figure 5Reference numeral 201 in [the figure] illustrates the connection between the target device and the inertial navigator, and also represents the channel through which interference signals in the second motion signal of the target device are conducted to the inertial navigator. 201 may be a rigid connection or may be connected through a buffer. When connected through a buffer, the inertial navigator's calculation of the target device's attitude needs to consider the low-pass filtering effect of the buffer on the interference signals in the second motion signal. For ease of explanation, the embodiments of this application will all be described by taking the direct connection between the target device and the inertial navigator as an example.

[0058] Among them, when connected through a buffer, since the buffer performs low-pass filtering on the interference signals in the second motion signal. Therefore, the first motion signal obtained by the interference signal elimination device also needs to be low-pass filtered by the buffer. Thus, the interference signal elimination device uses the first motion signal that has been low-pass filtered by the buffer to perform interference signal elimination processing on the second motion signal that has been low-pass filtered, so as to eliminate the interference signals located in the transition band region of the inertial measurement device.

[0059] In some examples, as Figure 5 shown, the inertial measurement device may include: a second inertial sensor and a low-pass filter.

[0060] When the low-pass filter is a digital low-pass filter, the second motion signal sent by the inertial measurement device to the interference signal elimination device is the original motion signal measured by the second inertial sensor for the target device within the first time period. That is to say, the second motion signal is the signal on which the low-pass filter has not performed low-pass filtering on the original motion signal.

[0061] When the low-pass filter is an electronic low-pass filter, the second motion signal sent by the inertial measurement device to the interference signal elimination device is the signal obtained by performing low-pass filtering on the original motion signal measured by the second inertial sensor for the target device within the first time period through the electronic low-pass filter. That is to say, the second motion signal is the signal on which the electronic low-pass filter has performed low-pass filtering on the original motion signal.

[0062] A digital low-pass filter is one that realizes the low-pass filtering effect based on digital signal processing algorithms. Generally, digital low-pass filters are designed using algorithms such as the window function method, frequency sampling method, bilinear transformation method, or impulse invariance method. A digital low-pass filter can be understood as a software-based low-pass filter.

[0063] An electronic low-pass filter is a circuit that relies on electronic components to achieve the low-pass filtering effect. Generally, an electronic low-pass filter is designed by selecting appropriate components, designing the circuit topology, and determining the filter parameters. An electronic low-pass filter can be understood as a hardware-based low-pass filter.

[0064] Among them, the transition band region specifically refers to the transition band region of the low-pass filter.

[0065] The working principle of the interference signal cancellation device will be described in detail below, and the content is as follows: As Figure 5 shown, the interference signal cancellation device may include: a first inertial sensor and a processor.

[0066] The first inertial sensor can collect the first motion signal of the target device within the first time period. Moreover, the first inertial sensor can send the first motion signal to the processor so that the processor can obtain the first motion signal.

[0067] In this way, the processor can receive the second motion signal sent by the inertial measurement device.

[0068] Among them, the second motion signal is the motion signal collected by the inertial measurement device for the target device within the first time period.

[0069] Since both the first motion signal and the second motion signal are collected for the target device within the first time period. Therefore, the time stamp of the first motion signal is the same as that of the second motion signal. That is to say, the first motion signal and the second motion signal are collected in the same time period, ensuring that the processor can use the first motion signal to accurately cancel the interference signal in the second motion signal with a frequency higher than the motion cut-off frequency of the inertial navigator.

[0070] Among them, the signal sampling rate of the first inertial sensor is higher than that of the inertial measurement device; the output signal bandwidth of the first inertial sensor is higher than that of the inertial measurement device.

[0071] Among them, the signal sampling rate and measurement accuracy of the inertial sensor are a pair of contradictions. The lower the signal sampling rate, the higher the measurement accuracy; the higher the signal sampling rate, the lower the measurement accuracy.

[0072] Based on the above description, it can be known that the second motion signal is specifically obtained by sampling with the second inertial sensor. Therefore, the signal sampling rate of the first inertial sensor is higher than that of the second inertial sensor, and the output signal bandwidth of the first inertial sensor is higher than that of the second inertial sensor. Among them, the output signal bandwidth of the first inertial sensor being higher than that of the second inertial sensor means that the first inertial sensor has a wider frequency response range than the inertial measurement device. Thus, the measurement accuracy of the first inertial sensor is lower than that of the second inertial sensor. The first inertial sensor can measure the first motion signal of the target device within a larger frequency range, making the motion information contained in the first motion signal more detailed than the motion information contained in the second motion signal collected by the inertial measurement device, especially the interference signal information is more detailed. As a result, the processor can use the first motion signal to perform interference signal cancellation processing on the second motion signal.

[0073] In some possible embodiments, the first inertial sensor is a high-speed inertial sensor, and the second inertial sensor is a high-precision inertial sensor.

[0074] Among them, due to the high measurement accuracy of the second inertial sensor, the signal sampling rate is usually low, about 1KHz - 5KHz, and the frequency of the motion signal that can be measured more accurately is about 100Hz - 500Hz. The signal sampling rate of the first inertial sensor is relatively high, about 50KHz - 500KHz.

[0075] It should be noted that before the first inertial sensor and the second inertial sensor sample the motion signal, the first inertial sensor and the second inertial sensor need to be calibrated in the same calibration system so that the first inertial sensor and the second inertial sensor have the same response coefficient. Thus, error signals caused by different response coefficients will not be introduced into the motion signals collected by the first inertial sensor and the second inertial sensor, improving the cancellation accuracy of the interference signal cancellation device.

[0076] In this way, the processor can detect the first target signal in the first motion signal, and use the first target signal to perform interference signal cancellation processing on the second motion signal to obtain the second target signal.

[0077] Among them, the first target signal includes the signal in the first motion signal whose frequency is higher than the motion cut-off frequency of the inertial navigator; the second target signal is the second motion signal with the interference signal whose frequency is higher than the motion cut-off frequency of the inertial navigator eliminated.

[0078] Among them, the motion cut-off frequency of the inertial navigator is the cut-off frequency of the motion signal processing spectrum of the inertial navigator for the target device. Specifically, the motion cut-off frequency of the inertial navigator refers to the cut-off frequency of the low-pass filter. The transition band region refers to the region that is higher than the cut-off frequency of the low-pass filter and lower than the transition band frequency point of the low-pass filter. In this way, the processor can eliminate the interference signals that are higher than the cut-off frequency of the low-pass filter and within the transition band region.

[0079] Since the first target signal includes the signals in the first motion signal whose frequencies are higher than the motion cut-off frequency of the inertial navigator. Therefore, the processor can use the first target signal to eliminate the interference signals in the second motion signal whose frequencies are higher than the motion cut-off frequency, so that the interference signals in the transition band region of the low-pass filter in the inertial navigator are eliminated. Thus, the interference signal elimination device can eliminate the interference signals to the greatest extent, improve the measurement accuracy of the inertial navigator, especially improve the measurement performance of the inertial navigator during long-term operation.

[0080] For the interference signal elimination device provided in this application, since the signal sampling rate of the first inertial sensor included in the interference signal elimination device is higher than the signal sampling rate of the inertial measurement device, and the output signal bandwidth of the first inertial sensor is higher than the output signal bandwidth of the inertial measurement device, it means that the first inertial sensor has a wider frequency response range than the inertial measurement device. Based on this, the first motion signal collected by the interference signal elimination device can obtain more detailed motion information, especially including a wider interference signal bandwidth, so that the motion information included in the first motion signal is more detailed than the motion information included in the second motion signal collected by the inertial measurement device. In this way, the processor can use the first motion signal to perform interference signal elimination processing on the second motion signal. In this way, the processor actively detects the first target signal in the first motion signal whose frequency is higher than the motion cut-off frequency of the inertial navigator by executing the interference signal elimination algorithm, and uses the actively detected first target signal to eliminate the interference signals in the second motion signal whose frequencies are higher than the motion cut-off frequency of the inertial navigator. Since the motion cut-off frequency of the inertial navigator is the cut-off frequency of the motion signal processing spectrum of the inertial navigator for the target device, and the cut-off frequency of the motion signal processing spectrum of the inertial navigator is less than or equal to the frequency range corresponding to the transition band region. Furthermore, the interference signal elimination device eliminates the interference signals in the transition band region. Thus, the interference signal elimination device can eliminate the interference signals to the greatest extent, improve the measurement accuracy of the inertial navigator, especially improve the measurement performance of the inertial navigator during long-term operation.

[0081] The following combines Figure 6 to illustrate the process of the interference signal elimination algorithm executed by the processor. Refer to Figure 6 , Figure 6The flowchart of an interference signal cancellation method provided by an embodiment of this application. The method of this embodiment is applied to the processor included in the interference signal cancellation device. As Figure 6 shown, the method includes: S101. Obtain the first motion signal of the target device collected by the first inertial sensor of the interference signal cancellation device within the first time period.

[0082] The first inertial sensor of the interference signal cancellation device collects the first motion signal of the target device within the first time period, and sends the collected first motion signal to the processor of the interference signal cancellation device. The processor receives the first motion signal.

[0083] S102. Receive the second motion signal sent by the inertial measurement device.

[0084] Wherein, the processor receives the second motion signal sent by the inertial measurement device, so that the processor can perform interference signal cancellation processing on the second motion signal by using the first motion signal.

[0085] S103. Detect the first target signal in the first motion signal whose frequency is higher than the motion cut-off frequency of the inertial navigator.

[0086] Wherein, the processor detects the first periodic interference signal and the first non-periodic interference signal according to the frequency characteristics and amplitude characteristics of the first motion signal in the frequency domain, so that the processor can obtain the first target signal.

[0087] S104. Perform interference signal cancellation processing on the second motion signal by using the first target signal to obtain the second target signal.

[0088] Wherein, the processor uses the first periodic interference signal in the first target signal to cancel the periodic interference signal in the second motion signal that is higher than the motion cut-off frequency of the inertial navigator, and uses the first non-periodic interference signal in the first target signal to perform noise reduction processing on the periodic interference signal in the second motion signal that is higher than the motion cut-off frequency of the inertial navigator. Based on this, the processor can cancel the interference signal in the second motion signal whose frequency is higher than the motion cut-off frequency of the inertial navigator to obtain the second target signal.

[0089] Based on the above interference signal cancellation method, since the signal sampling rate of the first inertial sensor included in the interference signal cancellation device is higher than that of the inertial measurement device, and the output signal bandwidth of the first inertial sensor is higher than that of the inertial measurement device, it means that the first inertial sensor has a wider frequency response range than the inertial measurement device. Based on this, the first motion signal collected by the interference signal cancellation device can obtain more detailed motion information, especially including a wider interference signal bandwidth, making the motion information contained in the first motion signal more detailed than that contained in the second motion signal collected by the inertial measurement device. Thus, the processor can use the first motion signal to perform interference signal cancellation processing on the second motion signal. In this way, the processor actively detects the first target signal in the first motion signal whose frequency is higher than the motion cut-off frequency of the inertial navigator by executing the interference signal cancellation algorithm, and uses the actively detected first target signal to cancel the interference signal in the second motion signal whose frequency is higher than the motion cut-off frequency of the inertial navigator. Since the motion cut-off frequency of the inertial navigator is the cut-off frequency of the motion signal processing spectrum of the inertial navigator for the target device, the cut-off frequency of the motion signal processing spectrum of the inertial navigator for the target device is less than or equal to the frequency range corresponding to the transition band region. Furthermore, the interference signal cancellation device cancels the interference signal located in the transition band region. Thus, the interference signal cancellation device can cancel the interference signal to the greatest extent, improve the measurement accuracy of the inertial navigator, especially improve the measurement performance of the inertial navigator during long-term operation.

[0090] The following separately describes how the processor detects the first target signal and uses the first target signal to perform interference signal cancellation processing on the second motion signal to obtain the second target signal in the case where the inertial measurement device includes a second inertial sensor and a digital low-pass filter, and in the case where the inertial measurement device includes a second inertial sensor and an electronic low-pass filter.

[0091] In the case where the inertial measurement device includes a second inertial sensor and a digital low-pass filter, referring to Figure 7 , Figure 7 shows Figure 5 a schematic diagram of the working process of the processor in an interference signal cancellation device in Figure 7 . As shown in

[0092] In some examples, the processor performs a Fourier transform on the first motion signal so that the first motion signal can be converted from the time domain to the frequency domain. Thus, the processor can study the spectral structure and transformation law of the first motion signal, and improve the processing efficiency of the processor for detecting the first target signal.

[0093] Among them, the Fourier transform refers to a signal analysis method that studies the spectral structure and transformation law of the first motion signal by converting the first motion signal from the time domain to the frequency domain. The time domain is a coordinate system that describes the relationship between a signal and time. The frequency domain is a coordinate system that describes the relationship between a signal and frequency.

[0094] Moreover, the processor can detect a first periodic interference signal and a first non-periodic interference signal in the first motion signal whose frequencies are higher than the motion cut-off frequency of the inertial navigator based on the frequency characteristics and amplitude characteristics of the first motion signal in the frequency domain, enabling the processor to use the first periodic interference signal to eliminate the periodic interference signal in the second motion signal whose frequency is higher than the motion cut-off frequency of the inertial navigator.

[0095] Among them, the frequency characteristic refers to the frequency change law of the first motion signal, and the amplitude characteristic refers to the amplitude change law of the first motion signal. The processor can determine a signal in the first motion signal whose frequency is higher than the motion cut-off frequency of the inertial navigator and shows a periodic change law and whose amplitude value exceeds a certain amplitude value as the first periodic interference signal. The processor can determine a signal in the first motion signal whose frequency is higher than the motion cut-off frequency of the inertial navigator and shows a non-periodic change law and whose amplitude value exceeds a certain amplitude value as the first non-periodic interference signal.

[0096] Among them, the first periodic interference signal is used to eliminate the periodic interference signal in the second motion signal whose frequency is higher than the motion cut-off frequency of the inertial navigator, and the first non-periodic interference signal is used to eliminate the non-periodic interference signal in the second motion signal whose frequency is higher than the motion cut-off frequency of the inertial navigator.

[0097] In this way, the processor can successively perform conversion processing from the frequency domain to the time domain, 180° phase flipping processing of the time-domain signal, and signal superposition processing on the first periodic interference signal, so that the periodic interference signal in the second motion signal whose frequency is higher than the motion cut-off frequency of the inertial navigator is eliminated, enabling the processor to obtain a third motion signal.

[0098] Among them, the processor can use the first periodic interference signal to eliminate the periodic interference signal in the second motion signal whose frequency is higher than the motion cut-off frequency of the inertial navigator to obtain a third motion signal.

[0099] Among them, the second motion signal is the original motion signal measured by the second inertial sensor for the target device within the first time period. The third motion signal is the second motion signal from which the periodic interference signal whose frequency is higher than the motion cut-off frequency of the inertial navigator has been eliminated.

[0100] In some examples, the processor performs an inverse Fourier transform on the first periodic interference signal, enabling the first periodic interference signal to be converted from the frequency domain to the time domain.

[0101] Among them, the inverse Fourier transform algorithm refers to a signal conversion method that converts the first periodic interference signal from the frequency domain to the time domain to restore the first periodic interference signal in the time domain state.

[0102] Among them, the 180° phase flipping processing of the time-domain signal means that the processor flips the phase of the first periodic interference signal in the time domain by 180°. That is to say, the phase difference between the first periodic interference signal with its phase flipped by 180° in the time domain and the first periodic interference signal in the time domain is 180°.

[0103] Among them, the signal superposition processing is used to superpose the amplitudes of the first periodic interference signal with its phase flipped by 180° and the second motion signal in the time domain, so as to eliminate the periodic interference signals in the second motion signal with frequencies higher than the motion cut-off frequency of the inertial navigator. Refer to Figure 8 , Figure 8 shows Figure 5 the schematic diagram of the signal superposition processing of the processor in the interference signal elimination device in Figure 8 As shown, the first periodic interference signal 210 in the time domain and the first periodic interference signal 211 with its phase flipped by 180° are waveform-superposed in the time domain, so as to eliminate the periodic interference signals in the second motion signal. Thus, the processor can obtain the third motion signal 212.

[0104] Figure 8 In

[0105] Furthermore, the processor can perform noise reduction processing on the third motion signal based on the first aperiodic interference signal to reduce the influence of the aperiodic signal in the third motion signal on the measurement accuracy of the inertial navigator, so that the processor can obtain the second target signal. Based on this, the processor filters out the aperiodic interference signals in the second motion signal.

[0106] Through this embodiment, the interference signal elimination device eliminates the interference signals to the greatest extent.

[0107] Among them, the noise reduction processing refers to clipping processing or enhanced attenuation processing.

[0108] Thus, the processor can perform digital low-pass filtering processing on the second target signal using a digital low-pass filter, further attenuate the motion signals above the cut-off frequency of the inertial navigator, reduce the interference signals of the second target signal after the digital low-pass filtering processing, and further improve the measurement accuracy of the inertial navigator.

[0109] Among them, the cut-off frequency of the digital low-pass filter is the motion cut-off frequency of the target device measured by the inertial navigator.

[0110] In the case where the inertial measurement device includes a second inertial sensor and an electronic low-pass filter, refer to Figure 9 , Figure 9 shows Figure 5 a schematic diagram of the working process of the processor in another interference signal cancellation device in Figure 9 . As shown in

[0111] , the processor can convert the first motion signal from the time domain to the frequency domain. In this way, the processor can study the spectral structure and transformation law of the first motion signal, and improve the processing efficiency of the processor to detect the first target signal.

[0112] Moreover, the processor can detect a first periodic interference signal and a first non-periodic interference signal in the first motion signal whose frequencies are higher than the motion cut-off frequency of the inertial navigator based on the frequency characteristics and amplitude characteristics of the first motion signal in the frequency domain.

[0113] Among them, the frequency characteristic refers to the frequency transformation law of the first motion signal, and the amplitude characteristic refers to the amplitude transformation law of the first motion signal. The processor can determine a signal in the first motion signal whose frequency is higher than the motion cut-off frequency of the inertial navigator and shows a periodic change law and whose amplitude value exceeds a certain amplitude value as the first periodic interference signal. The processor can determine a signal in the first motion signal whose frequency is higher than the motion cut-off frequency of the inertial navigator and shows a non-periodic change law and whose amplitude value exceeds a certain amplitude value as the first non-periodic interference signal.

[0114] In this way, the processor can perform attenuation processing on the first periodic interference signal according to the attenuation characteristic of the electronic low-pass filter to obtain an attenuated first periodic interference signal, and perform attenuation processing on the first non-periodic interference signal to obtain an attenuated first non-periodic interference signal.

[0115] Among them, since the second motion signal is the signal obtained by performing low-pass filtering on the original motion signal measured by the second inertial sensor for the target device within the first time period through the electronic low-pass filter. Therefore, the processor needs to perform attenuation processing on the first periodic interference signal and the first non-periodic interference signal according to the attenuation characteristic of the electronic low-pass filter. Based on this, the processor can use the first motion signal to perform cancellation processing on the periodic interference signal in the second motion signal whose frequency is higher than the motion cut-off frequency of the inertial navigator.

[0116] In this way, the processor can successively perform a conversion process from the frequency domain to the time domain, a 180° phase flip processing on the time-domain signal, and a signal superposition processing on the attenuated first periodic interference signal, so as to eliminate the periodic interference signal with a frequency higher than the motion cut-off frequency of the inertial navigator, enabling the processor to obtain a fourth motion signal.

[0117] Among them, the processor can use the attenuated first periodic interference signal to eliminate the periodic interference signal with a frequency higher than the motion cut-off frequency of the inertial navigator in the second motion signal, obtaining a fourth motion signal.

[0118] Among them, the fourth motion signal is the second motion signal from which the periodic interference signal with a frequency higher than the motion cut-off frequency of the inertial navigator has been eliminated. The second motion signal is the signal obtained by performing low-pass filtering on the original motion signal measured by the second inertial sensor for the target device within the first time period through an electronic low-pass filter.

[0119] In some examples, the processor performs an inverse Fourier transform on the attenuated first periodic interference signal, enabling the attenuated first periodic interference signal to be converted from the frequency domain to the time domain.

[0120] Among them, the 180° phase flip processing of the time-domain signal means that the processor flips the phase of the attenuated first periodic interference signal in the time domain by 180°. That is to say, the phase difference between the attenuated first periodic interference signal in the time domain and the attenuated first periodic interference signal with its phase flipped by 180° in the time domain is 180°.

[0121] Among them, the signal superposition processing is used to perform amplitude superposition of the attenuated first periodic interference signal with its phase flipped by 180° and the second motion signal in the time domain, so as to eliminate the periodic interference signal with a frequency higher than the motion cut-off frequency of the inertial navigator in the second motion signal.

[0122] Furthermore, the processor can perform noise reduction processing on the fourth motion signal based on the attenuated first aperiodic interference signal, obtaining a second target signal. Based on this, the processor filters out the aperiodic interference signal in the fourth motion signal.

[0123] Through this embodiment, the interference signal elimination device eliminates interference signals to the greatest extent.

[0124] In addition, the interference signal elimination device can replace the anti-interference function of the buffer to avoid the use of the buffer, which can further reduce the cost of the inertial navigator.

[0125] The following combines Figure 10 and Figure 11The working principles of an inertial navigator with a digital low-pass filter and an inertial navigator with an electronic low-pass filter are introduced separately as follows: Refer to Figure 10 , Figure 10 which shows Figure 5 a schematic diagram of the working process of an inertial navigator in Figure 10 As shown, the working principle of an inertial navigator with a digital low-pass filter is as follows: After the inertial navigator is powered on, the first inertial sensor and the second inertial sensor are started. In this way, the first inertial sensor collects the first motion signal of the target device within the first time period and sends the first motion signal to the processor. The second inertial sensor collects the second motion signal of the target device within the first time period and sends the second motion signal to the processor. Thus, the processor spontaneously and actively uses the interference signal in the first motion signal to perform interference signal cancellation processing on the second motion signal by executing the interference signal cancellation method. Furthermore, the processor can eliminate the interference signal in the second data signal to the greatest extent and obtain the second target signal. Therefore, the inertial navigator can directly calculate the attitude data of the target device by using the inertial navigation algorithm with the second target signal to obtain the attitude data of the target device, improving the measurement accuracy of the inertial navigator, especially the measurement performance of the inertial navigator during long-term operation.

[0126] Refer to Figure 11 , Figure 11 which shows Figure 5 a schematic diagram of the working process of an inertial navigator in Figure 11 As shown, the working principle of an inertial navigator with an electronic low-pass filter is as follows: After the inertial navigator is powered on, the inertial navigator activates the first inertial sensor and the second inertial sensor. In this way, the first inertial sensor collects the first motion signal of the target device within the first time period and sends the first motion signal to the processor. The second inertial sensor measures the target device within the first time period to obtain the original motion signal, and sends the original motion signal to the electronic low-pass filter, so that the electronic low-pass filter performs low-pass filtering on the original motion signal to obtain the second motion signal. In this way, the electronic low-pass filter can send the second motion signal to the processor, so that the processor can obtain the second motion signal. Furthermore, the processor spontaneously and actively uses the interference signal in the first motion signal to perform interference signal cancellation processing on the second motion signal by executing the interference signal cancellation method, so as to cancel the interference signal in the second data signal to the greatest extent and obtain the second target signal. Thus, the inertial navigator can directly calculate the attitude data of the target device by using the inertial navigation algorithm with the second target signal, so as to obtain the attitude data of the target device, improve the measurement accuracy of the inertial navigator, especially improve the measurement performance of the inertial navigator during long-term operation.

[0127] Embodiments of the present application can divide the interference signal cancellation device into functional modules according to the above method examples. For example, each functional module can be corresponding to each function, or two or more functions can be integrated into one processing unit. The above integrated unit can be implemented in the form of hardware or in the form of a software functional module.

[0128] The division of modules in the embodiments of the present application is illustrative, only a logical function division, and there can be other division methods in actual implementation.

[0129] Refer to Figure 12 , Figure 12 FIG. An acquisition module 801, configured to acquire a first motion signal of a target device collected by a first inertial sensor of the interference signal cancellation device within a first time period.

[0130] A receiving module 802, configured to receive a second motion signal sent by the inertial measurement device; wherein, the second motion signal is a motion signal collected by the inertial measurement device for the target device within the first time period; and the signal sampling rate of the first inertial sensor is higher than the signal sampling rate of the inertial measurement device; the output signal bandwidth of the first inertial sensor is higher than the output signal bandwidth of the inertial measurement device.

[0131] A detection module 803, configured to detect a first target signal in the first motion signal whose frequency is higher than the motion cut-off frequency of the inertial navigator.

[0132] An elimination module 804, configured to perform interference signal elimination processing on the second motion signal by using the first target signal to obtain a second target signal; wherein, the second target signal is the second motion signal from which interference signals with frequencies higher than the motion cut-off frequency of the inertial navigator are eliminated, and the motion cut-off frequency of the inertial navigator is the set cut-off frequency in the motion signal spectrum of the inertial navigator for processing the target device.

[0133] Exemplarily, the present application provides an electronic device, including a processor; when the processor executes computer code or instructions in a memory, the electronic device is caused to execute the interference signal elimination method in the foregoing embodiments.

[0134] Exemplarily, the present application provides an electronic device, one or more processors; a memory; and one or more computer programs, wherein one or more computer programs are stored on the memory, and when the computer programs are executed by one or more processors, the electronic device is caused to execute the interference signal elimination method in the foregoing embodiments.

[0135] It can be understood that, in order to implement the above functions, the electronic device includes corresponding hardware and / or software modules for executing each function. Combining the algorithm steps of each example described in the embodiments disclosed in this article, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a certain function is executed in the way of hardware or computer software driving hardware depends on the specific application and design constraint conditions in the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application in combination with the embodiments, but such implementation should not be considered to exceed the scope of the present application.

[0136] The electronic device provided by the embodiments of the present application is used to execute the above interference signal elimination method, and thus can achieve the same effect as the above implementation method.

[0137] Exemplarily, the present application provides a chip, including: an interface circuit and a logic circuit, the interface circuit is configured to receive signals from other chips outside the chip and transmit them to the logic circuit, or send signals from the logic circuit to other chips outside the chip, and the logic circuit is configured to implement the interference signal elimination method in the foregoing embodiments.

[0138] Exemplarily, the present application provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the electronic device is caused to execute the interference signal elimination method in the foregoing embodiments when executed.

[0139] Exemplarily, the present application provides a computer program product, including: execution instructions stored in a readable storage medium. At least one processor of the electronic device can read the execution instructions from the readable storage medium, and the at least one processor executes the execution instructions to enable the electronic device to implement the interference signal cancellation method in the foregoing embodiments.

[0140] Among them, the electronic device, chip, computer-readable storage medium, and computer program product provided in the embodiments of the present application 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 elaborated here.

[0141] In the above embodiments, all or part of the functions can be implemented by software, hardware, or a combination of software and hardware. When implemented by software, it can be implemented in the form of a computer program product in whole or in part. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the processes or functions according to the present application are generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium. The computer-readable storage medium can be any available medium that the computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (for example, a floppy disk, a hard disk, a magnetic tape), an optical medium (for example, a DVD), or a semiconductor medium (for example, a solid state disk (SSD)), etc.

[0142] Those of ordinary skill in the art can understand all or part of the processes in implementing the methods in the above embodiments. These processes can be controlled by relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the above method embodiments. The foregoing storage medium includes various media that can store program codes, such as read-only memory (ROM), random access memory (RAM), magnetic disks, or optical discs.

[0143] As described above, the above embodiments are only used 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 foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit of the technical solutions of the embodiments of the present application and the scope protected by the claims.

Claims

1. An interference signal elimination device, characterized in that: The interference signal elimination device is connected to an inertial measurement device in an inertial navigation system, and the interference signal elimination device includes: a first inertial sensor and a processor; The first inertial sensor is used to collect a first motion signal of the target device within a first time period and send the first motion signal to the processor; The processor is configured to receive a second motion signal sent by the inertial measurement device; wherein the second motion signal is a motion signal collected by the inertial measurement device for the target device within the first time period; and a signal sampling rate of the first inertial sensor is higher than a signal sampling rate of the inertial measurement device; and an output signal bandwidth of the first inertial sensor is higher than an output signal bandwidth of the inertial measurement device; The processor is also used to detect a first target signal in the first motion signal, and to use the first target signal to perform interference signal elimination processing on the second motion signal to obtain a second target signal; wherein the first target signal includes a signal in the first motion signal whose frequency is higher than the motion cutoff frequency of the inertial navigator; the second target signal is a second motion signal from which interference signals with frequencies higher than the motion cutoff frequency of the inertial navigator are eliminated, and the motion cutoff frequency of the inertial navigator is the cutoff frequency of the motion signal processing spectrum of the target device by the inertial navigator.

2. The interference signal elimination device according to claim 1, characterized in that: The processor is specifically configured to convert the first motion signal from the time domain to the frequency domain, and based on the frequency characteristics and amplitude characteristics of the first motion signal in the frequency domain, detect a first periodic interference signal and a first non-periodic interference signal in the first motion signal having a frequency higher than a motion cutoff frequency of the inertial navigation device as the first target signal; Among them, the first periodic interference signal is used to eliminate the periodic interference signal in the second motion signal whose frequency is higher than the motion cutoff frequency of the inertial navigator, and the first non-periodic interference signal is used to eliminate the non-periodic interference signal in the second motion signal whose frequency is higher than the motion cutoff frequency of the inertial navigator.

3. The interference signal elimination device according to claim 2, characterized in that: In the case where the inertial measurement device includes: a second inertial sensor and a digital low-pass filter, the second motion signal is an original motion signal obtained by the second inertial sensor measuring the target device within the first time period; The processor is specifically used to perform frequency domain to time domain conversion processing, time domain signal phase flip 180° processing and signal superposition processing on the first periodic interference signal in sequence to obtain a third motion signal, wherein the third motion signal is a second motion signal from which the periodic interference signal having a frequency higher than the motion cutoff frequency of the inertial navigation device is eliminated; wherein the time domain signal phase flip 180° processing is used to flip the phase of the first periodic interference signal in the time domain by 180°; and the signal superposition processing is used to superimpose the amplitudes of the first periodic interference signal and the second motion signal after the phase is flipped by 180° in the time domain; The processor is configured to perform noise reduction processing on the third motion signal based on the first non-periodic interference signal to obtain the second target signal; The processor is further configured to perform digital low-pass filtering processing on the second target signal using a digital low-pass filter, wherein the cutoff frequency of the digital low-pass filter is the motion cutoff frequency of the inertial navigation system.

4. The interference signal elimination device according to claim 2, characterized in that: In the case where the inertial measurement device includes: a second inertial sensor and an electronic low-pass filter, the second motion signal is a signal obtained by low-pass filtering the original motion signal obtained by the second inertial sensor for the target device during the first time period through the electronic low-pass filter; The processor is specifically used to perform attenuation processing on the first periodic interference signal and the first non-periodic interference signal respectively according to the attenuation characteristics of the electronic low-pass filter to obtain the attenuated first periodic interference signal and the attenuated first non-periodic interference signal; The processor is specifically used to perform frequency domain to time domain conversion processing, time domain signal phase flip 180° processing and signal superposition processing on the attenuated first periodic interference signal in sequence to obtain a fourth motion signal, wherein the fourth motion signal is a second motion signal from which the periodic interference signal having a frequency higher than the motion cutoff frequency of the inertial navigation device is eliminated; wherein the time domain signal phase flip 180° processing is used to flip the phase of the attenuated first periodic interference signal in the time domain by 180°; and the signal superposition processing is used to superimpose the amplitude of the attenuated first periodic interference signal after the phase is flipped by 180° and the second motion signal in the time domain; The processor is used to perform noise reduction processing on the fourth motion signal based on the attenuated first non-periodic interference signal to obtain the second target signal.

5. The interference signal elimination device according to claim 3 or 4, characterized in that: The processor is specifically configured to perform Fourier transform on the first motion signal to convert the first motion signal from the time domain to the frequency domain; The processor is specifically configured to perform an inverse Fourier transform on the first periodic interference signal or the attenuated first periodic interference signal to convert the first periodic interference signal or the attenuated first periodic interference signal from the frequency domain to the time domain.

6. A method for eliminating interference signals, characterized in that: The interference signal elimination device according to any one of claims 1 to 5 is connected to an inertial measurement device of an inertial navigation system; the method comprises: Acquire a first motion signal of a target device collected by a first inertial sensor of the interference signal elimination device within a first time period; Receiving a second motion signal sent by the inertial measurement device; wherein the second motion signal is a motion signal collected by the inertial measurement device for the target device within the first time period; and the signal sampling rate of the first inertial sensor is higher than the signal sampling rate of the inertial measurement device; and the output signal bandwidth of the first inertial sensor is higher than the output signal bandwidth of the inertial measurement device; Detecting a first target signal having a frequency higher than a motion cutoff frequency of the inertial navigation device in the first motion signal; The first target signal is used to perform interference signal elimination processing on the second motion signal to obtain a second target signal; wherein the second target signal is a second motion signal from which interference signals having a frequency higher than an action cutoff frequency of the inertial navigation system are eliminated, and the motion cutoff frequency of the inertial navigation system is a cutoff frequency set in a motion signal spectrum of the target device processed by the inertial navigation system.

7. The method according to claim 6, characterized in that The detecting of the first target signal having a frequency higher than the motion cutoff frequency of the inertial navigation device in the first motion signal comprises: converting the first motion signal from the time domain to the frequency domain; Based on the frequency characteristics and amplitude characteristics of the first motion signal in the frequency domain, a first periodic interference signal and a first non-periodic interference signal having a frequency higher than a motion cutoff frequency of the inertial navigation device in the first motion signal are detected as the first target signal; Among them, the first periodic interference signal is used to eliminate the periodic interference signal in the second motion signal whose frequency is higher than the motion cutoff frequency of the inertial navigator, and the first non-periodic interference signal is used to eliminate the non-periodic interference signal in the second motion signal whose frequency is higher than the motion cutoff frequency of the inertial navigator.

8. The method according to claim 7, characterized in that The inertial measurement device includes a second inertial sensor and a low-pass filter; the method of using the first target signal to perform interference signal elimination processing on the second motion signal to obtain a target motion signal includes: In the case where the low-pass filter is a digital low-pass filter, the first periodic interference signal is sequentially subjected to frequency domain to time domain conversion processing, time domain signal phase flip 180° processing and signal superposition processing to obtain a third motion signal, wherein the third motion signal is a signal obtained by eliminating the periodic interference signal having a frequency higher than the motion cutoff frequency of the inertial navigation device from the second motion signal; wherein the time domain signal phase flip 180° processing is used to flip the phase of the first periodic interference signal in the time domain by 180°; and the signal superposition processing is used to superimpose the amplitudes of the first periodic interference signal and the second motion signal after the phase is flipped by 180° in the time domain; Performing noise reduction processing on the third motion signal based on the first non-periodic interference signal to obtain the second target signal; The method further comprises: performing digital low-pass filtering processing on the second target signal using a digital low-pass filter, wherein the cutoff frequency of the digital low-pass filter is the motion cutoff frequency of the inertial navigation system; or, In the case where the low-pass filter is an electronic low-pass filter, the first periodic interference signal and the first non-periodic interference signal are respectively attenuated according to the attenuation characteristics of the electronic low-pass filter to obtain an attenuated first periodic interference signal and an attenuated first non-periodic interference signal; The attenuated first periodic interference signal is sequentially subjected to frequency domain to time domain conversion processing, 180° phase flip processing and signal superposition processing to obtain a fourth motion signal, wherein the fourth motion signal is a signal obtained by eliminating the periodic interference signal having a frequency higher than the motion cutoff frequency of the inertial navigation device from the second motion signal; wherein the 180° phase flip processing of the time domain signal is used to flip the phase of the attenuated first periodic interference signal in the time domain by 180°; and the signal superposition processing is used to superimpose the amplitude of the attenuated first periodic interference signal after the phase is flipped by 180° and the second motion signal in the time domain; The fourth motion signal is subjected to noise reduction processing based on the attenuated first non-periodic interference signal to obtain the second target signal.

9. An inertial navigation system, characterized in that: include: An inertial measurement device and an interference signal elimination device according to any one of claims 1 to 5; wherein the inertial measurement device is connected to the interference signal elimination device; The inertial measurement device is used to collect a second motion signal of the target device within a first time, and send the second motion signal to the interference signal elimination device, so that the interference signal elimination device performs interference signal elimination processing on the second motion signal.

10. The inertial navigation device according to claim 9, characterized in that: The inertial measurement device comprises: a second inertial sensor and a low-pass filter; When the low-pass filter is a digital low-pass filter, the second motion signal sent by the inertial measurement device to the interference signal elimination device is an original motion signal obtained by the second inertial sensor measuring the target device within the first time period; When the low-pass filter is an electronic low-pass filter, the second motion signal sent by the inertial measurement device to the interference signal elimination device is an original motion signal measured by the second inertial sensor for the target device during the first time period, after being low-pass filtered by the electronic low-pass filter.

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