Testing testing

So we did some testing today. My slow and powerful has it's bonuses and drawbacks.

Lessons from testing. My robot is a bit flimsy and needs to be toughened up a little.
When reversing from the white line I should reverse with all three motors. Just in case.
The ultrasonic sensor needs to be dialed right back because I am picking up the audience and the surroundings.

Otherwise the power works awesome. The best was when a motor and wheel got ripped off and my robot kept running and then won!

Yay for Blocks

I got around my problem. And the answer was blocks.

I create a myblock that has the multiple code in it and then insert that into the program.So here is my main program using blocks. I have had to adjust the sensitivity of the Ultrasonic sensor as it was picking up things that wern't there. The turning and moving forward with all wheels driving was working really well.

Next I need to do edge detection and then the touch sensor and I am done.

First Programming Problem

I have struck my first major programming problem.
Because my middle motor is reversed from my other two motors to go full steam full power ahead this is what I want to have happen.

But I cannot drag this parrallel task into a for loop or a while loop! And inside these structures I cannot make this parallel motor task.

Frustration!

Build Complete

Once I had the chassis design all figured out, I took it all apart again and built that configuration but stronger. I then added the sensors and the scoop at the front.

Everything changed when the cables went in. I also added a touch sensor at the back. I'm really happy with the way it looks. It is kinda a Geiger Sumo Robot.

Chassis testing

Here is my test bed. Pushing the button makes it move forward, then another push for a full power turn and then a final pust for a full power turn.

I wanted to have geared wheels. I wanted to use all the tires and I wanted to use all the motors for driving. So I wanted to test the best configuration.

I built the geared wheels and loved them. But they are slow. Power or speed! Agility based or Strength based. I figured there are no small fast Sumo wrestlers so I decided to keep the low gearing.

This meant I needed to test out the best wheelbase for turning and power.

I built a configurable test bed that allowed me to make long and wide or short and skinny or any combination and I tested various groupings. The best one was wide and short so now I am ready to start construciting my chassis.
Long and skinny. This didn't turn very well at all.
Medium configuration was a bit better. Wide and medium length.

Wide as possible with a short wheel base. This turned the best and will be the configuration I will be using.

Testing various configurations was a great idead and I am pleased I didn't start building the first thing that I designed.

Body shape and wheels

Aim: To build a stable robot with a low center of gravity.
I attached the motors to the side of the robot brains. This gives a very low center of gravity and a wide wheel base. Looks awesome. I thought about widening it further and putting two wheels on each motor but then I'd have no wheels for the third driving motor.For the third motor I thought that if it was geared down it could be the extra grunt I need to push out the opponent. I played around with dual geared wheels and found this arrangement worked really well.

The hard part was putting the three motors together so that the read wheel could swivel because I felt that the friction of dragging the rear wheels would slow down the turning. Here is a picture of them put together but the robot is really long which must not help with the turning circle. I will leave it like this for now and do some programming but I am not happy with the length of this design and will have to revisit it soon.

Last Years Robot

So I found my box of lego and my old robot was still constructed. It has a few features that I want to repeat this year so I took a few photos.
Here is the robot I used last year. It has the flap at the front and three motor driving. The rear motor is activated when the touch sensor picks up the fact that the front has been pushed in.

The flap or scoop at the front is there for the opponent to drive onto. Thus taking away their traction.Here are the three motors. The rear one swivels to allow the robot to turn.
Last year my robot building and design worked really well. I didn't win the competition because my program was not fast enough. However I'm sure I can still improve on this design.