Embedded Motion Control 2017 Group 1

Group Members

Name:	Student id:
Karel van de Plassche	0653197
Joey Hendriks	0773023
Ioannis-Dionysios Bratis	0978560
Jad Haj Mustafa	0979428
Jip Reinders	0853301
Juliana Langen	0988532
Yanick Douven	Tutor

 

Initial Design

Link to the PDF version of the initial design: PDF

Overview

In this article a summary of the embedded software design is presented.This software is used to solve the following problems:

1. Corridor challenge: The robot should drive through a corridor and take the first exit.
2. Maze challenge: The robot should drive through a maze and find the exit.

Requirements/Specifications

Type	Requirement	Specification
General	- Be able to 'solve' any given configuration of walls. - Do not bump into walls: Detect walls, define minimum distance. - Move autonomously: Detect openings, junctions, crossings, dead ends, open spaces etc. and make optimal decision. - Software easy to set up: As defined on general wiki page. - Only one executable is allowed. The software will be updated on the robot before the challenge starts. - Do not stand still too long: Detect time that robot is standing still, initiate movement after set time. - Stop movement after task is achieved.	- The maximal translational velocity of PICO is 0.5 m/s. - The maximal rotation velocity of PICO is 1.2 rad/s. - Pico should not stay still for more than 30 seconds. - Complete task within 2 attempts. - The LRF has a width of about 4 rad (from -2 to 2 rad), with a resolution of about 1000 points.
Corridor	- Finish the corridor challenge fast: Detect opening either on left/right, take turn, stop after finish line.	- Back wheel across finish line within 5 minutes. Terminate afterwards.
Maze	- Finish the maze challenge fast: Navigate maze, find exit, stop after finish line. - Be able to reconstruct maze. - Determine difference between dead end and door. - Deal with open spaces. - Deal with loops. - Be able to open doors.	- Back wheel across finish line within 7 minutes. Terminate afterwards. - Decide where to go when at a T-junction or crossing. - Ring a bell and wait at a dead end to check for a door.

Functions

	Function	Description
Low-level	initialize	Initialize actuators
	readSensors	Read the odometer and laser data
	turnLeft	Turn 90° left
	turnRight	Turn 90° right
	turnAround	Turn 180°
	stopMovement	Stop omniwheels
	driveForward	Accelerate or decelerate
	driveBackward	Drive backward
	driveLeft	Move left
	driveRight	Move right
	ringBell	Ring the bell of the door.
Mid-level	detectWall	Detect a wall (~30cm)
	detectCorner	Detect a corner (crossing of two walls)
	detectDeadEnd	Detect a dead end
	detectFinish	Detect the finish line
	detectOpenSpace	Detect an open space
	detectOpenWorld	Detect if in the open world (like the maxe exit)
	detectTJunction	Detect a T-junction (where three corridors meet)
	detectCrossing	Detect a crossing (where the four corridors meet)
	shutDown	Terminate robot, if required
	checkDoor	Send a signal and wait x seconds
	chooseCorridor	Choose which corridor to take
High-level	stayBetweenWalls	Stay in the center of two walls
	createMap	Build map of surroundings
	trackPath	track the path through the map
	detectLoop	Detect a loop in the maze
	detectStack	Detect if stuck
	optimalDecision	Decide next move based on given algorithm

Components

The PICO robot consists of multiple components which are listed below:

1. Sensors:
   1. Laser Range Finder (LRF): Through the LRF on the PICO one can detect the distance to an object.This is accomplished by sending a laser pulse in a narrow beam towards the object and measuring the time taken by the pulse to be reflected on the target and returned to the sender.
   2. Wheel encoders (odometry): Through the encoder one can obtain the speed of the wheels which can be used to control PICO based on the provided data.
2. Actuators:
   1. Holonomic base (omni-wheels)
   2. Pan-tilt unit for head
3. Computer
   1. Ubuntu14.04
   2. Intel I7

Interfaces