Continuous Geometric Data Generation for Road Course Representation
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Solution Overview
Problem
Existing navigation and ADAS systems face challenges in processing discontinuous point data for extended geographic objects like roads, as they are not suitable for continuous representation and display functions.
Innovation Solution
A method that determines primary and secondary base elements from subsets of points, connects them with transition curves maintaining gradient and curvature continuity, and adjusts these elements to generate continuous geometric data for geographic objects, such as roads, stored in a database.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If discontinuous point data are used to represent geographic objects, then data storage and processing are simplified, but the suitability for continuous representation and display functions deteriorates
Solution Approach 1:
The method segments the continuous geometric representation into discrete base elements (line segments, circular arcs, clothoids) that can be individually processed and stored. Each base element represents a portion of the geographic object's course, allowing discontinuous point data to be transformed into a structured sequence of geometric segments that maintain mathematical continuity properties.
Solution Approach 2:
The invention changes the parameter representation from simple discontinuous coordinates to a structured format including base element type, control points, and continuity parameters (gradient and curvature values). This parameter transformation enables the data to support continuous representation functions while remaining computationally manageable.
2Manufacturing precision
If continuous geometric elements are generated from point data, then representation accuracy is improved, but computational complexity and processing time increase
Solution Approach 1:
By dividing the continuous geometric representation into discrete base elements with specific mathematical definitions, the method enables efficient computational processing. Each element type (line, arc, clothoid) has well-established algorithms for generation and intersection calculation, maintaining accuracy while improving processing efficiency compared to purely continuous representations.
Solution Approach 2:
The method performs preliminary classification and organization of point data into subsets that will form individual base elements before generating the continuous representation. This preliminary structuring of data reduces the computational complexity of subsequent processing steps by pre-organizing input data according to geometric characteristics.
3Reliability
If transition curves are inserted to ensure gradient and curvature continuity, then mathematical robustness is improved, but the complexity of geometric data generation increases
Solution Approach 1:
The method applies different continuity requirements to different locations in the geometric representation. Transition curves (clothoids) are inserted specifically at locations where gradient or curvature discontinuities would otherwise occur, while maintaining simplicity in regions where continuity is already satisfied. This localized application of complexity ensures mathematical robustness only where necessary.
Solution Approach 2:
Transition curves act as intermediary elements between adjacent base elements with different geometric properties. These intermediary clothoid segments smoothly connect elements with different gradients or curvatures, mediating the transition while maintaining overall continuity. The intermediary structure simplifies the overall generation process by providing a standardized solution for handling discontinuities.
4Reliability
If primary base elements are reduced in length upon inserting secondary base elements, then continuity is improved, but the number of processing operations increases
Solution Approach 1:
Adjacent primary base elements are merged or combined when secondary base elements are inserted between them. The reduction in length of primary elements is coordinated with the insertion of secondary elements to maintain overall continuity without requiring separate processing of each individual element adjustment, thereby reducing the total number of processing operations.
Data Source
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AI summary
A technique for generating from a point set geometric data that continuously describe a course of a geographic object is presented. The technique may be used in the context of generating data for a navigation device or driver assistend system. A method implementation of this technique comprises determining, from sub-sets of two or more road points, a sequence of primary base elements. For adjacent primary base elements, an interconnecting secondary base element is determined that continuously connects to and at a connection point has the same gradient as each of the interconnected primary base elements. Further, for adjacent primary and secondary base elements, an interconnecting transition curve is determined that continuously connects to and at a connection point has the same gradient and the same curvature as each of the interconnected primary and secondary base elements. Geometric data that continuously describe a course of the geographic object is determined from the primary base elements, the one or more secondary base elements and the one or more transition curves.