I've got a lot going on in the next two months, so I probably won't get finished with this project for the contest - but I thought it would be fun to participate and start building this robot.
I am going to take the standard AlphaBot chassis and try to add some customization that I'll figure out on the fly . The AlphaBot is an older (2017) Waveshare product that seems like an ideal platform for customization. It is configured to use an Arduino Uno Plus and a Raspberry Pi 3B, but it should be easily adapted to use other processors. The kit included an Uno Plus with a BlueTooth shield, so I'll get it running with that. Then I'll decide what modifications I want to make.
The AlphaBot is pretty simple. Two drive wheels with motors and a pivot roller. The drive axles are fitted with slotted disks, so that speed can be determined using a photo detector. I was initially surprised that there was so much mounting hardware (screws, nuts, standoffs, etc), but I soon realized that they had included two sets with the kit. Assembly was pretty easy with a little filing and lead trimming...
The top of the main PCB has two forward facing IR obstruction detectors (on the left) and just behind them are the two photo detector assemblies for the wheel disks.
The bottom of the main PCB holds the two motor assemblies and a line tracking sensor assembly at the rear.
The assembled unit with the wheels attached.
Next step is to program the Uno Plus and verify basic functionality.