FireCheetah is running
Good news — FireCheetah’s remote control mode is working! Here is a video of the bot in action:
The robot is actually quite fast. I had to slow it down to 30% of full speed to control it reliably by hand. The weight is unevenly distributed right now as well, which adds to the challenge. I have heard that victory in robot combat is often determined by the skill of the driver, and I believe it. Driving well takes practice. Fortunately, this part of the event is not timed; the kids can take their time getting the robot to where it needs to be.
As planned, for remote control I am using ROS on a PC talking to the Arduino on the robot. The ROS portion was surprisingly easy. Where I did have difficulty were the limits of the microcontroller. One painful discovery is that should your program crash, you won’t know it has happened, and very weird things can happen. (However, you may see the reset button flash on the micro as it reboots.) A keep-alive signal of some kind is a good idea. I chased some long rabbit holes before realizing that a program crash was the issue. The crashing, in turn, was through attempting to do some pin manipulation in class constructors, before the microcontroller was ready. This cost me a few days, very expensive at this point.
I am changing the architecture for the autonomous mode. I won’t be using ROS. The bandwidth limitations became obvious even in remote-control mode, my sensor suite is limited, and the robot needs to move fast. More significantly, I did some research on previous winners of the Trinity firefighting competition. Wall following is a proven technique, and can be done in an elegant way.
There is a lot of work to be done in the next few weeks. I need to mount the sensors, and build the circuits for the fan and candle detection.