Vehicle-mounted terminal positioning trajectory fitting method based on b-spline curve

Abstract

The invention discloses a vehicle-mounted terminal locating track fitting method based on a B spline curve. A locating track of a vehicle-mounted terminal is fitted by means of the B spline curve, and therefore the better fitting degree of the actual running track of a vehicle is achieved, a fitted curve has a good smoothness effect, and definite control and filtering characteristics are achieved for errors of local position sampling points. According to the vehicle-mounted terminal locating track fitting method, the three-order B spline curve algorithm is adopted because in a running process of the vehicle, collecting quantity of locating data is large, calculating quantity higher than the three-order B spline curve algorithm is very large, and the smoothness effect on a node is relatively poor when the calculating quantity is lower than the three-order B spline curve algorithm. The three-order B spline curve algorithm has two-order derivative continuous characteristics at the node of a section, is relatively matched with actual running track of the vehicle, and has small calculating quantity, and the vehicle-mounted terminal locating track fitting method is suitable for being applied to engineering.

Description

technical field [0001] The invention belongs to the field of satellite navigation, and in particular relates to a B-spline curve-based positioning track fitting method for a vehicle-mounted terminal. Background technique [0002] At present, many devices (such as vehicle-mounted terminals, mobile phone terminals and other positioning terminals) mostly have the function of positioning based on GNSS (Global Navigation Satellite System, global satellite navigation system). [0003] The positioning vehicle terminal fits the vehicle trajectory, generally by obtaining the location information of the vehicle at a certain frequency, and then calculates the approximate continuous driving trajectory through the collected location information. This process can be regarded as supplementing a continuous function on the basis of discrete data, and estimating the approximate value of the function at other points through the value of the function at a limited number of points, that is, the ...

AI Technical Summary

Problems solved by technology

At present, polynomial interpolation or fitting is widely used in engineering. This method can reduce the error between the interpolation or fitting curve and the actual trajectory curve to a certain extent, but it has higher requirements for interpolation or fitting functions. Often, the curve that fits the node (collection point) polygon (the polygon connected by a straight line to the adjacent nodes) has poor smoothness, and the curve with high smoothness has a poor fit with the node polygon.

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