30 results about "Trajectory compression" patented technology

The invention discloses a bus GPS correction method based on abnormal point elimination and a trajectory compression algorithm. The method comprises the following steps: step 1, acquiring historical GPS data of a specified bus route; step 2, performing filtration treatment on the acquired historical GPS data of the specified bus route by applying a local abnormal factor algorithm; step 3, simulating GPS trajectory data of the specified bus route; and step 4, based on the GPS coordinate point information of the specified bus route, performing trajectory correction on the real-time GPS data acquired from message-oriented middleware by utilizing the GPS trajectory data of the specified bus route, and taking the coordinate value of the midpoint of two coordinate points closest to the real-timeGPS point on the GPS trajectory of the specified bus route as a correction point of a bus GPS location drift point. The method provided by the invention can improve the accuracy of the GPS route point of a specific vehicle shift on a map location.

The invention discloses a trajectory preprocessing method for a taxi data set. The method comprises the steps of firstly obtaining trajectory data, wherein each sampling trajectory point comprises longitude, latitude and timestamp information; secondly analyzing the trajectory data, performing abstract storage in entity objects, numbering trajectories, and adding trajectory point IDs; thirdly searching for missing values of the trajectories, and supplementing the missing values by utilizing a linear interpolation method or a mean value method; fourthly clustering the trajectory points, detecting abnormal points, and accurately analyzing and processing the abnormal points; fifthly detecting a data redundancy region, extracting redundant data and performing trajectory compression; sixthly searching for the trajectory points at the corners in the trajectories, generating a corner point set, combining and adjusting the corner point set, and performing trajectory cutting according to the corner point set; and finally updating and outputting the trajectory information. According to the method, the missing values can be processed; the abnormal points can be detected and processed; and complex and overlapped trajectories can be cut.

The invention belongs to the field of ship data management, particularly relates to a ship trajectory data screening method and device, and aims at solving the problems that in an existing method, thejudgment precision of trajectory points is not high, and important trajectory points can be lost. According to the method, ship trajectory data stored in a period of time is used as to-be-screened data, a ship moving trajectory is used as a first to-be-tested curve, and a retention point of the first to-be-tested curve is determined through a Douglas algorithm; the ship moving track between two adjacent reserved points is taken as a second to-be-measured curve, and the reserved points are determined for each second to-be-measured curve through a method based on an angle limit value; and the information data of the track points corresponding to the reserved points obtained twice are taken as a data screening result. According to the method, the track compression precision is improved, andtrack points with large spatial feature information amount are greatly reserved; when the data in the track segment is screened, a multi-thread parallel computing method is adopted, so that the algorithm execution time is shortened, and the real-time data processing requirement is met.

The invention relates to the field of ship trajectory compression, in particular to a ship trajectory compression method based on course and navigational speed change rate, which comprises the following steps: step 1, AIS data processing: performing quality control on AIS data, and constructing a single-ship AIS time series data record; step 2, coordinate system conversion: converting longitude and latitude coordinates into coordinates under a Mercator coordinate system; 3, constructing a track compression model; ship trajectory feature points are extracted by taking the navigational speed change rate and the course change rate as indexes to compress ship trajectory data; by applying the method, effective compression of the ship trajectory data is realized, the constraint indexes of the compression method consider ship position information and own motion characteristics, the consistency of ship trajectory characteristics before and after compression is ensured, and a foundation is laidfor improving the mining efficiency based on the ship trajectory data.

The invention provides a geographic position trajectory optimization method and device, which can remove abnormal points in a trajectory. In addition, repeating points in the trajectory can be removed with a trajectory compression mode to achieve the purposes of reducing the network transmission pressure and saving the disk storage space. The method comprises the following steps: acquiring original geographical position trajectory data; removing the abnormal points in the original geographical position trajectory data to obtain a geographical position abnormal point removed trajectory; compressing the geographic position abnormal point removed trajectory to obtain a geographical position optimization trajectory.

The invention discloses a compression method and a decompression method of a handwritten terminal track, belonging to the field of image compression. The method for compressing the trajectory of the handwriting terminal includes: calculating the coordinate difference between the actual coordinates of each trajectory point and the predicted coordinates of the point; performing entropy encoding on the coordinate difference to obtain a code word to complete the compression of each trajectory. The decompression method of the trajectory of the handwriting terminal includes: performing entropy decoding on the saved codewords to obtain the coordinate difference between the actual coordinates of each trajectory point and the predicted coordinates of the point; obtaining the predicted coordinates of each trajectory point according to the predicted tap coefficient; The coordinate difference between the predicted coordinates and the actual coordinates of the point and the predicted coordinates of the point is used to obtain the actual coordinates of each track point. In the present invention, the correlation of the coordinates of the track points is utilized when compressing and encoding the track, which overcomes the disadvantage of large storage space caused by uniformly adopting fixed-length encoding to encode the track in the prior art.

The invention discloses a spatio-temporal trajectory compression method based on a trajectory dictionary, comprising two parts of establishing a trajectory dictionary set and performing trajectory compression based on the trajectory dictionary set. In this manner, for spatial trajectory data and temporal trajectory data, three methods of trajectory establishment and two algorithms of trajectory compression are proposed, which guarantee the compression rate, guarantee the high quality of trajectory compression, and have the advantages of high reliability and high accuracy. At the same time, themethod has a wide market prospect in database, data analysis, data mining, trajectory data query and analysis, and the application and popularization of trajectory data mining.

A trajectory data compression method based on LSTM prediction and smooth analysis thoughts and a moving object trajectory data compression method based on LSTM prediction apply a deep learning model to the traditional trajectory compression field, use a neural network to predict and obtain a distance error and a direction error, and use a smooth analysis thought to determine a compression threshold. The method does not need manual setting of an error threshold value, considers the distance and the direction at the same time, fully retains important information of an original track, obtains the error and determines the error threshold value according to the characteristics of the compressed track compared with a traditional track compression algorithm, can be better suitable for track data with different characteristics; the problems that a traditional track compression algorithm is poor in compression effect, errors are manually found, and an error threshold setting experiment is tedious are solved.

The invention discloses an indoor Wifi positioning data preprocessing and trajectory reconstruction method, comprising the following steps: A, defining an indoor space POI; B, extracting correspondingpositioning data according to mac, and forming a mac behavior trajectory, Strj = { p1..., pi, pj,...pn }; C, analyzing the signal loss and an AP point, and judging the invalid trajectory; D, intersecting trajectory points in the Strj trajectory with the indoor POI, ranking all points in the POI, and constructing a temporary trajectory sequence Strjtmp = { p1,..., pi,...pn }; E, merging the trajectory points in the same POI, namely only keeping the earliest and latest trajectory points in a continuous time period in the POI, reconstructing a trajectory Strjnew = { p1,..., pi,...pn }; F, mapping the trajectory data to a two-dimensional plane based on which the drift points and the jump points in the trajectory are deleted; and G, implementing step E again, and merging the trajectory pointsin the same POI, thus realizing trajectory compression, and completing the extraction of a new trajectory. According to the invention, indoor space characteristics and indoor trajectory characteristics are met, the result is reliable, and the processing efficiency is high.

The invention relates to a cosine vertical distance discrimination method, device and equipment for vector trajectory compression. The method comprises the following steps: firstly, acquiring an original vector trajectory data set, constructing a loop body, then sequentially taking three points to form a triple during circulation; and when the triple is processed, dividing each triple into two layers, wherein on the point level, the distance between the front and back adjacent edges of the middle element of the triad is taken as a condition, and the triad is identified to form a dense point set or a sparse point set, and on the online level, a local track formed by connecting triads in sequence is recognized as a curve line condition and a curve line condition through taking a cosine value as a judgment condition; and finally, judging whether the middle vertex elements in each condition are compressed or not further through different vertical distance threshold values d_max and d_min. In the whole processing process, various conditions are considered, a plurality of judgment values are used and work cooperatively, and finally each intermediate point element which does not meet the condition is compressed. Compared with an existing processing method, the invention has a better compression effect and a higher processing speed.

The invention discloses a ship trajectory compression method and system based on ship behavior characteristics, and the method comprises the steps: carrying out the preprocessing of missing value data in a ship trajectory, and constructing a feature matrix; performing density-based clustering on the feature matrix I by using a DBSCAN algorithm to obtain track fragments of different ship behaviors; using a k-Means method to divide the trajectory segment into an anchoring stage, a sailing stage and a fishing stage; and carrying out adaptive compression on the ship trajectory according to different behaviors. According to the method, effective compression of the ship trajectory data is realized, the specific behavior characteristics of the ship trajectory are considered in the compression method, the consistency of the characteristics of the ship trajectory data before and after compression is ensured, the compression of the ship trajectory data is also realized, and the fluency of trajectory query related functions of a ship management system is ensured.

The invention relates to a trajectory compression error evaluation method based on time synchronization speed, and belongs to the technical field of spatio-temporal data processing. The method comprises the following steps: firstly, reading data of a whole track, and respectively calculating speeds in longitude and latitude directions according to space-time positions of the track; compressing the track through various compression algorithms; and based on a speed linear change hypothesis, calculating an error between the time synchronization speed of each track point and the actual speed, and then calculating an average value to obtain a time synchronization speed error of the compressed track. According to the method, modeling is carried out on the speed error of the compressed track based on the speed linear change hypothesis, an SVE model is designed to evaluate the speed error of the compressed track compared with an original track, and the blank of lack of a speed error evaluation method in the current industry is filled. In addition, the evaluation method provided by the invention also has the advantages of small error influence, uniform change along with the compression ratio, strong performance and wider application.

The invention relates to a method and device for detecting the dizziness degree of a user in a virtual environment and a storage medium, and belongs to the technical field of computers. The method comprises the steps that moving track information of the user in a three-dimensional space coordinate system of the virtual environment is acquired; the moving track information is processed based on a track compression algorithm to obtain compression ratio data and track compression ratio variable quantity data of the moving track information; the compression ratio data and the track compression ratio variable quantity data are input into a pre-trained dizziness degree estimation model to obtain a dizziness degree prediction result. The track compression data in the virtual environment is used as the input data of the vertigo degree estimation model, a user does not need to wear redundant sensors and does not need to be separated from the virtual environment, and the immersion experience of the user in the virtual environment is not affected. Moreover, the system completely depends on basic virtual reality equipment, does not need to additionally configure a sensor, simplifies the system structure, and has higher popularization and application potential.

The invention provides a space-time trajectory compression and segmentation state expression method and device. The method comprises the steps: extracting offline trajectories in batches; carrying outprimary filtering processing; constructing track point representation; carrying out secondary filtration and compression; and performing trajectory state expression based on the speed. The inventionprovides a space-time trajectory compression and segmentation state expression method and device, which not only can fully reserve the motion characteristics of the trajectory, but also can compress the redundant part of the trajectory, reduce the memory space, improve the efficiency of display expression, and solve the problem that part of trajectory characteristics are lost in the existing technical scheme.