Embedded Motion Control 2012 Group 3

Contact Info

Name	Number	E-mail address
X. Luo (Royce)	0787321	x.luo@student.tue.nl
A.I. Pustianu (Alexandru)	0788040	a.i,pustianu@student.tue.nl
T.L. Balyovski (Tsvetan)	0785780	t.balyovski@student.tue.nl
R.V Bobiti (Ruxandra)	0785835	r.v.bobiti@student.tue.nl
G.C Rascanu (George)	0788035	g.c.rascanu@student.tue.nl

GOAL

Win the competition!

HOW ?

Good planning and team work

Week 1 + Week 2

1. Installing and testing software tools

• Linux Ubuntu
• ROS
• Eclipse
• Jazz simulator

Remark:

Due to incompatibilities with Lenovo W520 (wireless doesn’t work), Ubuntu (10.04) did not work and other versions were tried and tested to work properly. All the software was installed for all members of the group.

2. Discussion about the robot operation

Targeting units:

1. Maze mapping
2. Moving Forward
3. Steering
4. Decision making

Moving forward and steering

Make choice between what sensors for straight line and what sensors for turning left/right.

Figure 1

Case 1 – Safer, but slower

Case 2- Faster, but more challenging

Time difference between these 2 cases is small or not? According to the simulations we will decide between Case 1 and Case 2.

Backward movement!

Because the target is to get out of the maze as fast as possible this kind of movement will be considered as a safety precaution at the end of the project whether is time or not.

Speed

As mentioned earlier the main requirement is as fast possible, hence take the maximum speed (~ 1 m/s).

Sensors

Web cam -> Identify arrows on the walls by color and shape.

Laser -> Map of the world (range ~< 6 m).

Encoders -> Mounted on each wheel -> used for odometry (estimates change in position over time). How many pulses per revolution?

3. Making planning of the work process

Figure 2

All the team members start reading C++ and ROS tutorials given on the wiki page of the course.

4. Had the first meeting with the tutor.

Week 3

After our meeting, the lecture regarding Tasks of Chapter 5 was split among our team members:

• Introduction + Task definition – Bobiti Ruxandra
• Task states and scheduling – Luo Royce
• Typical task operation - Pustianu Alexandru
• Typical task structure – Rascanu George
• Tasks in ROS - Balyovski Tsvetan

The link for the presentation is given here: http://cstwiki.wtb.tue.nl/images/Tasks.pdf

1. Problem with RViz was fixed and solution was posted in FAQ.
2. Investigation of the navigation stacks and possibility to create map of the environment. The link for relevant messages is given here.
3. Thinking and discussing about smart navigation.

The come up ideas were:

We should save in a buffer the route were the robot went and not go twice through same place. For turning left or right, for case 2 presented in Week 1 and 2, we want to use so cubic or quitting splines. An example of the idea is given in the paper "Task-Space Trajectories via Cubic Spline Optimization" - J. Zico Kolter and Andrew Y. Ng

Week 4

This week was focused mainly on the software structure. The structure we come up was developed after discussing multiple options in such a way to make it simple so that every one can write his own part of the code and no one confuse what is there.In other words: make simple as possible.

Software structure

The structure of the control software is depicted in Figure 1:

Figure 1 Structure of the control software

The robot will use the data from the odometry, laser and camera to navigate through the maze. The raw laser data processed and few relevant points will be extracted from it. The noise will be filtered by averaging the data(after applying trigonometric transformation) from few points around the desired one. The relevant points are shown on the next figure:

Figure 2 Robot raw laser data on left junction