ROBOT LOCALISATION & MAPPING:NAVIGATION

Ken Birbeck

Introduction

Talk about Navigation Path finding

What is path finding How robots are able to find a path

My background Initial to do list Final deliverable

Navigation

Navigation is the process in which the robot looks at data about its surroundings, determines where the desired targets are located and then using this data, determines a safe path to a target from its current location.

Thus navigation has 2 main phases Planning Motion.

Planning the path to follow

Path finding The process through which a path to travel

is determined Relatively easy for humans but not so

easy for robots Examples of path finding algorithms

A-star D-star

A-star path finding

Divides a map into sections/nodes Plans a least-cost path based on a

distance plus cost heuristic function. Sum of 2 functions

Path cost function Admissible heuristic estimate of the distance to

the desired location.

D-star path finding

D-star pseudo code: Makes assumptions about unknown parts of

the environment Finds the shortest path from the robots

location to a given location based on those assumptions

Detects obstacles and updates the map Calculates a new shortest path

Background

My background – worked on the lynx robot as part of robotic systems last year

Developed simple navigation programs: Wall follower program Imprinting program

Project start to do list

Adaptation of programs from last year to a proximity alert program using IR sensors

Produce a simple exploring algorithm Produce a path finding algorithm

Determining a path to a know location of a target

Determine the location of a target and then a path to it

Final Deliverable

Final deliverables: lynx robot to autonomously map and

navigate an indoor area. If time permits expanded to navigating a

outside area and 3D mapping.

Questions?

Thank you for your time. Any questions?