Thursday, July 28, 2011

Testing, testing, testing (and more testing)

To ensure that the boats will perform as expected they must go through the most rigorous of testing. These tests have been designed to take the boat through a full range conditions that it will face in the real world.

Test Phase #1 - with Amphibious attachment

Initially the boats are put through a indoor test on a custom built amphibious attachment to the boat.

This attachment (patent pending) allows out engineers to fully test the steering of the boats without getting their delicate feet wet.

Once we are sure that the boats perform perfectly on land we are ready to take them to the water.

Test Phase #2 - in the pool

The second phase of testing involves taking the boats to the local pool to see how they go. Swimming pools give ideal conditions for the these early testing for a number of reasons. Firstly, without annoying environmental factors like wind and strong currents the steering seems to work perfectly. Secondly, with few spectators there is little embarrassment when everything thing goes wrong. Thirdly, if (or perhaps when) everything does go wrong, the water is clean enough for one of the engineers interns to dive in and rescue the boat.

If the boat passes testing phase #2 we can take it outdoors in testing phase #3.

Test phase #3 - at Panther Hollow lake

Next, we take the boat out to local Panther Hollow lake. This lake, which is about 70 metres wide, gives great opportunity for the GPS and wireless testing of the boat to occur. The lake provides fantastic outdoor conditions and is only a short work from the Robotics Institute. A fishing line is tied to the rear of the boat for when the fan inevitably stops working.

Above: when hundreds of dollars worth of equipment onboard the boats stops working we often have to resort to the most humble of tools - "the stick".

Test phase #4 (optional) - in the flood

Sometimes we get unlucky and sometimes we get lucky. One day last week, when the basement of the CMU Robotics Institute flooded, we got lucky. Rarely do we get the chance to test the boats in real life flood conditions. Our engineers were very excited and quickly deployed a boat on a reconnaissance mission. The results were great and there were high fives and back slapping all round.

As you can see, a key part of Field Robotics is working in the field (the other part being robots). All of these tests have been designed to put the boats through a variety of different conditions in order to bug fix. Hopefully, as the tests get more and more difficult the boats will continue to perform at or above what is expected.

Tuesday, July 26, 2011

The First Post

Welcome to the first post of the CMU Cooperative Robotic Watercraft (crw-cmu) blog.

At the time of writing we have completed two boats:

Boat 1:

Boat 1 was constructed with a balsa wood hull that was coated in fibreglass. It uses a brushless motor to run and is steered by a steering servo on the rear.

Boat 2:

Boat 2 was constructed using insulation foam. Two pieces of insulation foam were glued together to make a hull that was 4" high. This foam was cut using hot wire. The foam was then sanded and painted before being coated in a protective (and glossy) resin. The boat is powered by a larger fan than boat one. Instead of using two out-of-water rudders to control the boat the entire fan is rotated using a servo.

Boats 3, 4 and 5 are in some stages of production. Hopefully we can post more photos soon.