During this class we had to choose which component we need. We decided first to choose the vehicle speed and second the maximum weight of the Evacuator 3000. So we decided a max speed of 0,5kph and a maximum load of 40kg.
Based on those numbers, we designed the wheels and the DC motors with its reducing (50:1). We picked up two scooter wheel to make the traction and a caddy-like free wheel to insure the stability.
The power is insured with a 12V motor cycle battery. The size is quite a problem because it involve a heavy weight but it is the only solution we saw to have enough power.
We now know the power, current, speed and torque we need for the process. Once the sizing done, we checked home to know what is available and what is not to know what must be order on the internet. We checked the prices and we have looked to order them.
A problem appeared about the using of the battery: how can we know the power remaining in the battery? We solved the problem by using a dividing bridge. The Arduino will be able to analyze the voltage remaining and inform an operator in charge of the robot management.