760 results about "Time difference" patented technology

The invention relates to the technical field of fault monitoring, in particular to a power transmission line fault monitoring and positioning method, system and device and a medium. The method comprises the following steps: firstly, performing digital conversion on an original current signal to obtain time sequence data, and then identifying and classifying fault events through threshold detection and a feature extraction algorithm to obtain classification labels of fault types; then, based on the classification label, establishing a traveling wave propagation model and carrying out time difference calculation, carrying out clustering analysis on a plurality of wave head data in a preset time window, and judging whether the fault is a single-point fault or a multi-point fault through a clustering result; and finally, a positioning result is transmitted to the central server for comprehensive verification and alarm management, and a final fault response is formed. By introducing a time series data analysis and clustering judgment mechanism, the fault type can be accurately identified, single-point and multi-point fault conditions can be effectively distinguished, and meanwhile, the reliability of a positioning result is improved through comprehensive verification of the central server.

The invention relates to the technical field of edge computing, in particular to a safety production monitoring method based on edge collaboration, which comprises the following steps: collecting multi-node clock pulses, calculating adjacent time differences to form a pulse difference parameter set, carrying out statistical distribution, setting a dynamic tolerance boundary, and constructing an effective deviation parameter set; the method comprises the following steps of: generating a weighted smooth deviation result by combining clock stability and link delay weighted normalization, sorting monitoring data according to a timestamp to identify duplication abrupt change exception, constructing a cross-node exception time sequence by associating nodes and time information, and judging a safety state transition result of equipment. A time difference parameter is constructed through multi-node reference pulse arrival time, a dynamic deviation constraint is formed by combining distribution characteristics, clock stability and link measurement weighted smoothing are introduced, cross-node time reference consistency is kept, operation data unified time sequence rearrangement is carried out, a sudden change event reliably reappears in a time window, and an abnormal identifier is associated with a node identity. And forming a cross-node event evolution link.

The invention relates to the technical field of atomic clock control, and discloses a punctuality type atomic clock control method based on a microwave frequency band. The method comprises the following steps: firstly, acquiring microwave frequency band signal data and atomic state data, and constructing a time calculation model in combination with historical operation data to output a theoretical time value; performing multi-dimensional difference analysis on the theoretical time value and the actual measurement time value to generate a time difference coefficient matrix; inputting the matrix into a spatial propagation analysis network, and combining atomic clock component parameters and environmental parameters to generate a time anomaly probability distribution diagram; and finally, configuring microwave control parameters according to the distribution diagram, including starting a high-frequency monitoring mode for a high-probability abnormal region and applying a disturbance test to adjacent frequency bands. According to the method, through multi-dimensional data modeling, difference analysis and dynamic parameter configuration, the accuracy and adaptability of atomic clock control are improved, and the operation stability of the atomic clock in a complex environment can be enhanced.

The invention discloses a real-time monitoring and intelligent early warning method for ultrasonic equipment, and relates to the technical field of ultrasonic equipment monitoring, and the method comprises the steps: obtaining the input condition parameters of the ultrasonic equipment, and obtaining the calling part information of equipment parts related to the ultrasonic equipment based on the obtained input condition parameters; generating a simulation state parameter diagram according to the obtained operation parameter items and the input condition parameters; real-time equipment operation parameters of the ultrasonic equipment are obtained, and a real-time state parameter diagram is generated; performing differential comparison on the obtained real-time state parameter diagram and the simulation state parameter diagram, analyzing whether the operation state of the equipment component is abnormal or not according to a differential comparison result, and generating corresponding early warning information; according to the numerical difference and the time difference of each parameter item of the actual operation parameters, whether the operation of each parameter item of the corresponding equipment component in the corresponding operation stage is abnormal is comprehensively evaluated, so that more refined early warning of the ultrasonic equipment is realized.

The invention discloses a foundation pit support deformation real-time monitoring method based on edge calculation, and aims to solve the problems of multi-node time synchronization and clock drift compensation caused by unavailability or poor quality of satellite navigation and precise time protocols in an underground or shielded environment. According to the method, through event dictionary learning, partition time slot scheduling and safety coding micro excitation time synchronization, matched filtering decoding, multi-scale arrival time estimation, paired time difference robust fusion, frequency priority and phase speed limit correction and network disconnection time holding, the time synchronization efficiency is improved; the technical effects that multi-source data alignment, deformation field reconstruction and graded early warning are completed on the unified virtual reference time scale, and high-precision synchronization and online drift compensation are obtained without depending on the external time service condition are achieved.

The invention discloses a cosmic ray muon-based time synchronization system and synchronization method, and relates to the field of digital information transmission. The system comprises a time detector and a track detector which are arranged corresponding to a standard clock, and a case matching module, a time difference calculation module, a time adjusting module, a time detector and a track detector which are arranged corresponding to a clock to be calibrated, the case matching module is used for matching the cosmic ray muons according to the track information of the cosmic ray muons detected by the two track detectors and determining whether the cosmic ray muons penetrating through the two time synchronization devices belong to the same muon case or not, and if the cosmic ray muons penetrating through the two time synchronization devices belong to the same muon case, the time difference calculation module is used for obtaining theoretical flight time according to the track information detected by the track detectors; actual flight time is obtained according to a time detector; the time deviation is calculated according to the actual flight time and the theoretical flight time, the time adjusting module calibrates the clock to be calibrated according to the time deviation, and the precision and reliability of time synchronization in complex environments such as underwater and underground environments are improved.

The invention relates to a long-gap discharge leader development speed measurement method based on radiated electromagnetic wave detection. The method comprises a set of high-frequency antennas and a high-speed oscilloscope and a long-gap discharge leader development speed calculating method. The method adopts a certain antenna arrangement form; long-gap discharge radiated electromagnetic wave pulse time is detected simultaneously through the plurality of antennas; leader head position is positioned according to time difference of a signal arriving at different antennas; and furthermore, the long-gap discharge leader development speed can be calculated. The method can effectively improve the measurement precision of the discharge leader development speed, and resolution reaches the level of 0.1 ns.

Methods for tracking a signal origin by a spectrum analysis and management device are disclosed. Signal characteristics of other known emitters are used for obtaining a position of an emitter of a signal of interest. In one embodiment, frequency difference of arrival technique is implemented. In another embodiment, time difference of arrival technique is implemented.

Disclosed are a system on chip, method and device supporting time synchronization, and a storage medium, which relate to the technical field of time synchronization, the system on chip synchronizes the time of an STBM in the system on chip with the time of an off-chip master clock through a first processor core according to a first preset period; based on the first time of the STBM after time synchronization, calibrating a hardware clock of the first network card to obtain a first time reference; calibrating the time of the STBM based on the first time to obtain a second time reference; synchronizing, by the second processor core, the time of the second network card with the time of the first time reference based on a first time difference between the first network card and the second network card; and synchronizing the system time with the time of the second time reference based on a second time difference between the second time reference and the system time of the operating system. According to the system, double time references can be obtained, sub-microsecond-level synchronization precision is realized, and the strict requirement of a high-precision time synchronization scene on time synchronization precision is met.

The invention discloses a virtual digital human multimedia teaching interaction method and system and a storage medium, and the method comprises the steps: calculating an audio mouth shape time difference, a mouth shape subtitle time difference, an audio subtitle time difference and a video mouth shape time difference based on a same-window data group on the basis of a unified time aperture and a window, comparing the time differences with a time difference threshold value, and outputting a dislocation alarm result, unified constraint on four types of key alignment relationships is realized; when an alarm is triggered, selecting a degradation strategy according to a dislocation alarm result and generating an execution record, and summarizing the dislocation alarm result and the execution record to form an evidence chain data packet; when the cumulative number of times in the preset window number exceeds a diffusion blocking threshold value, recording output is switched into a video stream which retains audio and subtitles and does not overlap mouth shapes; and generating a correction release stream based on the evidence chain data packet, and replacing the recorded broadcast corresponding time slice and retaining the Hash verification value when the time sequence consistency index meets the release threshold, thereby realizing drivable treatment action, suppressible diffusion and replaceable correction.

The invention relates to the technical field of numerical control compensation, in particular to a first bending position deviation correction method and system for a servo pipe bender, in the first bending position deviation correction method and system for the servo pipe bender, fuzzy logic judgment is carried out on deviation direction consistency, a collaborative deviation behavior between feeding and clamping is converted into a trend quantity, parameter items influencing first bending error changes are accurately extracted, and the deviation correction accuracy is improved. Linkage combination of three types of control section instructions is realized, a time difference change trend is learned and extracted through a long-short-term memory network, a control time period with overlapped structure characteristics is identified, stable interval priority ordering and cross-section buffering of an error high-incidence area are realized in instruction section structure rearrangement, and the accuracy of instruction section structure rearrangement is improved. Multiple structural variables such as error trend, trigger delay and control index compression ratio are introduced into a control regulation system in participation item selection, so that the response timeliness of a key decision in a deviation correction path and the instruction chain stability under error interference are remarkably improved, and the transmission amplification risk of errors in a forming path is effectively controlled.

The invention provides a TDOA (Time Difference Of Arrival) positioning method and a TDOA positioning system. The TDOA positioning method comprises the following steps: respectively receiving signals transmitted by the same target equipment in a measurement range through TDOA sites; according to the signal received by each TDOA station, acquiring a peak-to-average ratio between the signals received by every two TDOA stations in each combined station; screening a first type of combined sites and a second type of combined sites in all the combined sites; screening out the first type of combination sites meeting the time difference closed-loop constraint from all the first type of combination sites, and putting the screened first type of combination sites into a target combination site set; obtaining a target time difference after time difference correction of each second type combination station; screening out a second type of combination sites meeting time difference closed-loop constraints, and incorporating the second type of combination sites into a target combination site set; and obtaining a positioning result of the target equipment based on the time differences corresponding to all the first type of combined stations in the target combined station set and the target time differences in all the second type of combined stations. Therefore, the positioning precision of the unmanned aerial vehicle in a complex electromagnetic environment is improved.

The invention provides a TSN time synchronization method based on dynamic jitter compensation and double-clock domain collaboration, which comprises the following steps: in a single clock domain, carrying out real-time analysis on a time difference of a synchronization message and dynamically compensating clock jitter so as to establish a high-precision local synchronization reference; based on a local synchronization reference, performing time information interaction and weighted fusion with at least one other clock domain to generate system-level global reference time, and calibrating a local clock to realize time collaboration across the clock domains; predicting a future change trend of the network delay, and pre-adjusting a dynamic compensation and / or time information interaction strategy according to a prediction result; dynamic compensation, time coordination and pre-adjustment are mutually coupled and have a synergistic effect, so that the time synchronization precision of the system is maintained in a predetermined target range, clock jitter in a single clock domain is effectively inhibited, the synchronization precision is controlled within 20ns, and the strict requirements of the fields of industrial control, automatic driving and the like on high-precision synchronization within 20ns are met.

The invention discloses a conductive slurry production control method and system based on multi-parameter cooperative control, and relates to the field of conductive slurry production, and the method comprises the steps: obtaining rheological characteristic data; according to the rheological characteristic data, a zero crossing point time difference between the excitation signal and the response signal is extracted, and a rheological phase angle is calculated; whether the rheological phase angle is located in a preset optimal dissipation interval or not is judged; if yes, the intrinsic relaxation time of the slurry microstructure is determined, and compensation frequency is generated according to the intrinsic relaxation time; the compensation frequency is used as a perturbation signal to be superposed to a driving voltage waveform of a driving motor, so that the stirring blades generate high-frequency vibration; and acquiring the deviation direction of the rheological phase angle, and dynamically adjusting the speed ratio of the revolution speed of the revolution shaft to the rotation speed of the rotation shaft under the condition of keeping the total power unchanged, so as to lock the rheological phase angle in the optimal dissipation interval. According to the invention, the yield and reliability of the electronic product can be effectively guaranteed.

According to the switch cabinet vibration signal positioning method and device, the storage medium and the computer equipment provided by the invention, in the operation process of the switch cabinet, the vibration signals generated by the switch cabinet are collected in multiple directions, amplitude detection is carried out after multi-channel time sequence data are formed, and signal segments with potential defects are extracted from the multi-channel time sequence data; further generating a vibration event data packet corresponding to each vibration signal so as to carry out targeted analysis; as the convolution iteration filtering algorithm has better anti-noise capability and higher time resolution, the method can be adopted to extract the signal first arrival time of each vibration event data packet more accurately; and directly performing time difference analysis on the first arrival time of each signal by using the mathematical relationship between the time difference and the vibration source point position established in the finite difference time domain simulation model to obtain the defect vibration source point position of the switch cabinet, so that large-scale disassembly or complex measurement of the switch cabinet is not needed, and the time difference analysis efficiency is improved. Therefore, the position of the defect vibration source point can be accurately determined.

Provided is a TD converter including: a plurality of oscillators which at least include a first oscillator and a second oscillator receiving control signals input thereto, respectively, and operating in operating modes with oscillation frequencies different from each other, respectively, wherein each control signal indicates a time difference between a reference clock and a target clock; and a computation circuit which calculates a digital output value depending on the time difference, by using a plurality of pieces of phase information retained according to the reference clock in the plurality of oscillators, respectively.

The invention provides an energy storage equipment phase synchronization control method and an energy storage system, relates to the technical field of energy storage equipment, and aims to solve the problem of phase tracking lag of slave machines caused by communication link delay when multiple machines are connected in parallel. The energy storage device phase synchronization control method comprises the steps that a first synchronization frame is received from a first energy storage device, and the first synchronization frame comprises a first voltage phase; a second synchronization frame is received from the first energy storage device, the second synchronization frame comprises a first time difference, and the first time difference is the difference value between the sending completion time and the sending start time of the first synchronization frame; calculating a second time difference based on a first reception time of the first synchronization frame and a second reception time of the second synchronization frame; and performing phase synchronization based on the first voltage phase, the first time difference and the second time difference. According to the phase synchronization control method, the communication processing total delay of the whole link is actively calculated, then the real-time phase of the host at the current moment is dynamically predicted, and finally accurate synchronization without lag errors is achieved.

The invention discloses an overhead line fault rapid positioning method and system, and belongs to the field of power system overhead line fault detection. According to the method, traveling wave acquisition assemblies are arranged at the head end and the tail end of an overhead line, and dual-mode redundant clock synchronization is used for guaranteeing time consistency of the two ends; obtaining a multi-feature fault signal, and carrying out preprocessing and weighted fusion to calculate the final time difference of the two ends of the fault traveling wave; correcting the wave velocity by combining the inherent electrical parameters of the line with the real-time environment and state parameters to obtain a dynamic propagation velocity; modeling is carried out according to the time difference, the dynamic wave velocity and the total length of the line, the distance from the head end to the fault point is solved, and a result is verified through signal attenuation characteristics. The method improves the positioning precision and reliability, avoids wrong positioning, shortens the troubleshooting period, and guarantees the stable power supply of a power system.

The invention provides a sound source localization method using time delay and dead reckoning. The method comprises the following steps: acquiring an original sound signal and carrying out noise reduction preprocessing; virtual sound rotation processing is carried out on the two sound source directions, interpolation simulation rotation is carried out on effective sound signals after noise reduction, and angle differences before and after rotation are compared to eliminate false angles; and finally calculating the position of the sound source through a geometric positioning algorithm by combining the unique sound source direction, the movement distance and the movement direction of the equipment and the time difference between the sound source and the two microphones. According to the method, acoustic orientation and a smart phone inertial navigation technology are deeply fused, a displacement vector is obtained by utilizing dead reckoning, and multi-position TDOA measurement information is combined, so that sound source three-dimensional space positioning only depending on single mobile equipment is realized, and the inherent defect that a traditional pure acoustic positioning method cannot measure distance is overcome.

A repeater relays communications between UEs and a first BS. The repeater measures a time difference between signals received from the first BS and from a second BS. The repeater performs cell measurements of these signals. The repeater sends, to the first BS, information indicative of the measured time difference and of the cell measurements. The first BS communicates with the UEs through the repeater. The first BS receives, from the repeater, information indicative of a time difference between signals received from the first BS and signals received from a second BS as measured by the repeater, and of cell measurements by the repeater of these signals. The first BS makes a handover decision for the UEs based at least on the received information indicative of the cell measurements.

The application relates to the technical field of time synchronization, and discloses a mixed time service method based on Beidou satellite navigation and TSN, which comprises the following steps: acquiring network topology structure information and historical time service error data of each synchronization node in a target distributed system, and constructing a dynamic time delay state set for jitter identification; based on the dynamic time delay state set, a current global time reference is extracted through a time calibration algorithm, a time difference reference vector sequence is generated, and initial synchronization adjustment is carried out on a TSN master node; according to the response stability of a slave node, a clock convergence function curve between nodes is constructed, whether the synchronization network is in a low jitter interval is judged based on time offset rate and time drift trend change; in combination with the node time state after directional offset suppression, a multi-channel redundant time adjustment mechanism in a time window is applied, a weight adjustment coefficient is extracted, and a non-uniform calibration factor is introduced; and according to a regression correction result, a time service stability index is evaluated in real time. The application has the advantages of improving time service stability.

The invention relates to the technical field of electric power, and discloses a rapid load response control method for deep peak regulation of a thermal power generating unit, which comprises the steps of collecting multi-dimensional parameters for load index prediction, predicting a climbing rate based on historical operation data of the unit, comparing the deviation between an actual load and a predicted load, and correcting a load index prediction result. Fusing the corrected load index with a climbing rate prediction result, establishing a key operation parameter change model, carrying out parameter adjustment in advance, combining the corrected load index and the climbing rate, verifying the safety domain boundary of the unit, and guaranteeing the operation safety of the unit. According to the method, the problem of adjustment lag or excessive adjustment caused by inaccurate load pre-judgment in traditional response is solved, panoramic perception of load fluctuation is achieved, pre-judgment adjustment is achieved at the same time, the unit parameter change rhythm and the load demand are synchronized, the time difference between load change and unit adjustment is remarkably shortened, and the load response speed is improved. And the response capability to the rapid fluctuation load is improved.

The invention provides a green construction building digital management system and method, and relates to the technical field of digital management. The system performs format unification and numerical value standardization processing on the original records to generate a preliminary record set associated with the process information; uniquely affiliating the record to a corresponding process according to the process time interval and the resource list to form a process record sequence; establishing cross-process one-way time association, and forming a deterministic mapping relation between previous and next process records; a three-section increment generation method is adopted to calculate a process resource usage amount, a weight group is generated by extracting a source attribute, a time continuous attribute and a preorder process inheritance attribute, weighted operation is carried out by combining a recorded numerical value, a time difference and a numerical value difference to obtain increment contribution, and finally accumulation is carried out to obtain a total process usage amount. And irreversible forward transmission of the resource usage amount along the process sequence is supported. According to the system, accurate calculation and dynamic management of resource loads in the construction process are realized.

The invention relates to the technical field of audio and video synchronization, in particular to a video call real-time audio and video synchronous monitoring system which comprises a frame time extraction module, a main time sequence locking module, a delay structure analysis module, a synchronous node generation module and a synchronous control instruction module. According to the invention, through real-time extraction and analysis of timestamp difference calculation of audio and video frames and establishment of a transmission delay interval comparison sequence, the time difference in audio and video transmission can be effectively identified, the monitoring accuracy of an audio and video asynchronization phenomenon is enhanced, and through real-time adjustment of timestamp offset, the synchronization accuracy of the audio and video in a playing process is ensured; in a dynamic network environment, the offset rate is monitored and adjusted in real time, the continuity and fluency of interactive experience are ensured, the synchronization state of the audio and video frames can be controlled more accurately by analyzing the offset difference value centralized distribution section and marking the synchronization fluctuation section, and the situation that the large-scale user experience is reduced due to synchronization error accumulation is avoided.

The invention discloses a rolling bearing fault detection method based on synchronous time difference of double optical encoders, and the method comprises the steps: respectively collecting pulse signals of an external encoder and a motor encoder, obtaining the zero-crossing time of the two groups of pulse signals through a zero-crossing time method, and carrying out the angle downsampling of the zero-crossing time of the motor encoder; performing delay compensation on the zero-crossing time of the external encoder and the zero-crossing time of the motor encoder after down-sampling by adopting a cross-correlation algorithm, and reconstructing the zero-crossing time of the external encoder and the zero-crossing time of the motor encoder after down-sampling as an angle-time signal; performing differential processing on the two groups of reconstructed angle-time signals to obtain a residual signal, performing offset compensation on the residual signal, and inversely constructing an instantaneous angular velocity signal; according to the method, the problem that the rolling bearing fault feature signal is covered due to the speed trend component and the ionization error can be solved, and rolling bearing fault detection under the variable rotating speed working condition is achieved.

The invention relates to the technical field of ultrasonic flowmeter calibration, and discloses an ultrasonic flowmeter calibration system and method based on a time difference method. According to the method, original signal data output by the ultrasonic flowmeter at a starting time point and an ending time point are collected, and meanwhile the time interval between the two time points is calculated. Then, the original signal data at the starting time point and the ending time point are preprocessed, and a more accurate starting preprocessing signal and a more accurate ending preprocessing signal are obtained; signal features are extracted from the preprocessed signals, a starting signal feature set and a terminating signal feature set are formed, and feature difference measures between the starting signal feature set and the terminating signal feature set are calculated; the characteristic difference measure is divided by the time interval to obtain the signal change rate. The signal change rate is compared with a preset threshold value, and calibration parameters of the ultrasonic flowmeter are adjusted according to the comparison result. According to the method, the working state of the ultrasonic flowmeter can be deeply analyzed from the signal feature level, and compared with a traditional calibration method, the calibration precision is effectively improved.

The invention relates to a ship traffic control system, in particular to an MMSI duplicate number detection method and system based on AIS message broadcast frequency, and the method comprises the steps: continuously receiving AIS dynamic messages on a time sequence, and carrying out the analysis of the AIS dynamic messages to obtain MMSI and message IDs; each MMSI stores a certain number of dynamic messages; judging the validity of the dynamic message; calculating the time difference of the adjacent dynamic messages for the effective messages and filtering out abnormal values; calculating an average value according to the reserved time difference and an arithmetic average value of the average value deviation, if the absolute value of the obtained result is not greater than 26.67 ms, judging that the MMSI is normal, otherwise, judging that the MMSI is abnormal and performing further duplicate number verification; the system comprises a memory and a processor, and the processor is used for calling and running the instruction from the memory and executing the duplicate number detection method.

The invention relates to the technical field of ultrasonic bonding, in particular to an ultrasonic adjusting method of a bonding system, which comprises the following steps of: acquiring voltage and displacement waveforms, analyzing a power trend, shielding a main window if a rising proportion is high and displacement exceeds a limit, extracting a maximum displacement point frequency to divide a standby window, and generating standby configuration by combining an impedance library. And monitoring peak time difference fluctuation and offset, calling configuration and matching a displacement time sequence generation instruction, monitoring displacement stability to be matched with pressure, setting a standby window as a main window if the condition is met, and generating a reconstruction mark. According to the method, the driving voltage and the transducer displacement waveform are continuously monitored, the power trend and the displacement fluctuation are analyzed in real time, the peak time difference fluctuation is synchronously monitored, the abnormal working conditions are screened to trigger the driving strategy switching, and the main frequency band is reconstructed according to the steady-state displacement characteristics. Pseudo soldering and material damage are avoided, the vibration energy utilization rate is improved, and the bonding pressure control precision and the connection strength are guaranteed.

The invention discloses a power transmission line double-end traveling wave distance measurement method independent of synchronous time synchronization and a related device, and belongs to the technical field of power transmission line traveling wave distance measurement. Carrying out modulus decomposition on the traveling wave electrical quantity to obtain a line mode component and a zero mode component which are independent from each other; calculating line mode wave impedance and zero mode wave impedance based on the frequency change parameters of the power transmission line; calculating to obtain a line-mode inverse traveling wave and a zero-mode inverse traveling wave; discrete wavelet transform is carried out, and the arrival time of a wave head is obtained through detection; for a grounding fault, calculating a fault distance based on a difference value between a line mode wave head arrival time and a zero mode wave head arrival time; for an ungrounded fault, a fault distance is calculated based on a difference value between arrival moments of a traveling wave at the same end and a reflected wave at a fault point. According to the method, the absolute time is replaced by the time difference, the influence of the wave velocity is eliminated through ratio calculation, strict synchronous time synchronization at the two ends is not needed any more for the ground fault and the non-ground fault, and the effectiveness of distance measurement is improved.

The invention provides a course information determination method and device, and the method comprises the steps: obtaining geomagnetic data collected by a geomagnetic sensor at a current moment, and obtaining gyroscope data collected by an inertial measurement unit in a vertical direction at the current moment; under the condition that positioning data acquired by a global positioning system is not acquired, or the positioning data is acquired and the positioning data is smaller than or equal to a first threshold value, determining course angle variation of the current moment relative to the target moment based on gyroscope data in the vertical direction of the current moment and a time difference between the current moment and the target moment; the target moment refers to a moment when the positioning data is greater than a first threshold value for the last time before the current moment; obtaining a geomagnetic course angle at the current moment based on the geomagnetic data at the current moment; and obtaining the final course angle at the current moment based on the final course angle at the target moment in the preset storage space, the course angle variable quantity and the geomagnetic course angle at the current moment.