Difference in the hardware between FortyTwo and Charm important for the corridor following

The first difference comes from the way to give orders to the motors of each robot. The fact that Charm uses the serial port to receive orders does not allow us to control it from different programs. This restriction can be bypassed by using threads in the program that controls the robot.

The different drive systems have also a great impact on the way of programming each robot. As we can see on figures 3.7(a) and 3.7(b), FortyTwo is able to turn its turret independently of the position and speed of its other axes. Furthermore, in our experiments, the camera was placed on the top of the turret. So we were able to fix the direction of the camera.

Figure 3.7: Drive systems. FortyTwo has three independent axes, one controlling the orientation of the three wheels, one controlling the speed of the three wheels and the last one controlling the orientation of the turret. Charm has two independent axes, one controlling the speed of the left wheel and the other one controlling the speed of the right wheel.

With Charm, it is not possible to fix the direction of the camera anymore. Indeed, only the speed of the two wheels can be controlled. So all the parts of the robot are turning when we have to turn the robot, including the camera.

Another points with differs is the way we moved with FortyTwo. It is not possible to specify a constant speed without a lot of computation. The fact that FortyTwo had different axes for the steering angle and for the speed of the wheels makes it easier to drive. For Charm, it is better to adopt another way of control.