Study on Geometric Path Tracking Algorithm for Tracked Vehicle Model

摘要

This paper proposes a geometric path tracking algorithm for miningrnrobot. In Korea, the pilot mining robot has been developed forrncollecting manganese nodules from deep seabed. The pilot miningrnrobot demands a localization algorithm to determine an accuraternposition and an automatic path tracking algorithm. The fundamentalrnperformances of two algorithms are verified by using a ground trackedrnvehicle to reduce the time and cost for in-situ test. Ultrasonic positionrnsystem (UPS) is selected to measure the position. UPS is very similarrnwith the measuring principle of LBL. The localization is realized byrndata-fusion of UPS (data period of 0.6sec) and motor encoder (datarnperiod of 0.1sec). It focuses on how to decide weighting values of twornposition data having different periods in order to produce betterrnposition information. For tracking the specified path, two algorithms,rnthe follow-the-carrot and the pure pursuit, are comparativelyrninvestigated. The follow-the-carrot algorithm finds a line passingrnbetween the center point of vehicle and the target point, and controlsrnthe vehicle to follow the line with constant speed. The pure pursuitrnalgorithm is that vehicle is controlled through radius of a circlerncontacting with forward vector of the vehicle and passing between therncenter point of vehicle and the target point. The appropriate algorithmrnfor driving on soft-soil can be selected and proven by numericalrnsimulation and experiment.