Project history

As I mentioned in the project overview, this project consists already for a while. Right now, I am currently working on Proto Lite - the third-generation prototype. The first version was a test prototype for autonomous driving and sensor testing. The second prototype, on the other hand, was used to investigate the cleaning properties.

The third version consists of the main functions from the prototypes. Simply put, the robot should clean and drive. (There are of course other requirements, such as those from the project overview.)

Electronics

The electronics are based on an FPGA, which executes all processes to control and monitor the behavior of the robot. It communicates with the motor drivers, controls the sensors, evaluates their data and converts them into useful information. This information can then be used to draw conclusions about the behavior of the robot under certain situations such as obstacle detection.

Because you don't program an FPGA (like an Arduino), the robot has no software program. Instead, a bitstream file containing the circuit and all other specifications (clock, IOs) is loaded into the FPGA's configuration memory. The FPGA is then configured to create the desired circuit.

I have written a code in the hardware description language VHDL which describes the circuit of the on-board computer. This code can be synthesized and loaded into the configuration memory of the FPGA, so that the FPGA emulates the circuit. The code is still under development, as some functions are still being added.

Mechanics

I constructed the body of the robot in Fusion 360 and 3d printed all parts. Moreover, I am using almost PLA for the prints. An exception is the profile of the wheels, which is based on TPU. Because there are still a few bugs to be fixed, the design files aren’t available right now. For 3d printing I am using a Prusa i3 MK3S.

This is just an abstract and basic overview about the project. In further articles I will go into detail and try to document my tests and experiences so that they do not only benefit me alone. 

If you have suggestions, improvements or whatever, feel free to leave a comment or contact me.