Overview

Background

Acorn is an organic farming automation research platform, designed to aid in research and development of new automated organic farming systems. Acorn is a mobile platform designed to support the future addition of farming tools suitable for use in a solar powered system.

This development platform solves the problems of mobile autonomous operation and power management, and serves as a tool for early adopters and developers to research new farming automation tool development on a standardized open source platform.

Long term, these tools will be integrated in to the main system design, creating a complete open source farming automation system.

Our entire system source design files are available on our github: https://github.com/Twisted-Fields

System Design

Acorn is a rectangular aluminum robot with a power system, main computer, and four robotic corner assemblies which each contain a drive motor and steering motor in an aluminum weldment with additional supporting electronics inside.

The main computer is a Raspberry Pi Compute Module 4, and our main software stack is in python.

The power system is comprised of a solar panel system operating at 45 volts nominal, an array of supercapacitors to temporarily store power, and simple power electronics to protect the supercapacitors. There are no batteries - Acorn operates directly off of solar power.

Corner Assembly

Most of the robotic complexity of Acorn is confined to the four identical modular corner assemblies that handle drive and steering. These assemblies bolt to the frame and attach to the chassis wiring to complete the robot.

For more details see Corner Assembly

Electronics

Acorn uses a custom motherboard to hold the main computer and interface to the chassis wiring, a motor control board in each corner assembly, and quite a few additional support PCBs.

For more details see Electrical

Software

Acorn’s system software is primarily written in python. Embedded systems code is written in C++.

For more details see Software

Mechanical

Acorn uses a MIG welded aluminum frame built from aluminum tubes and CNC plasma cut aluminum plate.

For more details see Mechanical See also Frame Design