Project status: Active, started 22/06/2009

About

ATB1 is my foray into robotic autonomy and control. ATB1 will hopefully be the first of many testing platforms for evaluating my ideas and designs for autonomy.

I am working on this project currently, and I will update progress where and when I can, there may be some elements that need to be kept under wraps so that I have a chance for future developments… but there are no such elements at the moment! I hope to reach a conclusion on the current implementation of ATB1 in the coming months.

Progress is good, I have completed the vehicle and manufactured and tested my circuit board. I hope to initially be able to drive the vehicle around manually collecting the data streams from various sensors for later analysis. From the data analysis of the sensor outputs I will try to find some useful information that will in the end lead to the sensors being used to drive the vehicle. The sensors that are currently on ATB1 are:

An accelerometer for logging motion

• A digital compass for heading
• An ultrasonic range finder to detect objects
• A GPS unit for position data
• Xbee 2.4GHz radio system

The radio links the vehicle with my laptop where all the calculations will be performed. The calculations will involve floating point arithmetic which is not possible with the current on-board processor. It is my ultimate aim to have a fully on-board system with no external PC link. I am aware of maths co-processor chips which are capable of the 32bit floating point calculations necessary to achieve this, and I’m looking into them. This initial set up will be easier for prototyping if the calculations are done off-board, I would not need to complicate the circuit board further or spend more money on it to achieve a fully on-board system. After all it is the first step in an ongoing project, there is no need to try and finish it all in one go.

Progress

• 22/06/2009 - Stage 1: Researching, testing and prototyping of electronics components began. Including GPS and accelerometer testing, details on how to use both are in the tutorials section.
• 8/07/2009 - Stage 2 manufacturing vehicle side: Circuit board designs completed.
• 10/07/2009 - Printed circuit board (PCB) manufactured.
• 13/07/2009 - Test vehicle designed and completed.
• 14/07/2009 - Circuit board soldered.
• 15/07/2009 - Circuit boar electrically tested.
• 17/07/2009 - Mounting components to PCB and PCB to vehicle.
• 18/07/2009 - Completed servo/ultrasound unit. mounting of digital compass. The compass was sensitive to magnetic objects around it and as a result is raised about 5cm off the PCB away from the motors that drive the wheels.
• 19/07/2009 - Stage 2 complete.

Stage 3 will be software development, i.e. programming both on the PC and vehicle side. I expect this to be the most difficult part of the project.

Images

The test vehicle, taken 17/07/2009

The ultrasound ranger on top of a servo, taken 18/07/09. The ranger will sweep across the path of the vehicle scanning for obstacles.

Design and Construction

Results

The ATB1 project has been active over two months now. Some of the tasks were harder than expected and some things just didn’t go smoothly, but so far I have had many successes with the platform. I now have some results ready to be uploaded onto this page. There is more to come up but I still need to write up and document those results so that they can be uploaded. I also have more work to do as I did not manage to explore everything on ATB1 to the extent I wanted, I have not yet worked with the ultrasound unit and the digital compass and there is more to be added to the accelerometer work. So watch this space as I post more results and continue with the ATB1 development.

               

Creating a serial connection          Using the accelerometer