Hexumi

Hexumi is a low-cost 3D-printed 18 DoF walking hexapod robot built using Raspberry Pi and ROS2.

Acknowledgements

The code for Pimoroni Servo2040 servo driver is based on the C/C++ Pimoroni Pico library and micro-ROS.

Documentation

I am currently working on the documentation, assembly instructions, and installation guide, which will be available shortly.

Installation (WIP)

The main branch contains CAD and STL files. It's meant to be cloned to the development machine.

The hexumi-base branch contains minimal code meant to be run directly on the robot.

Development

For in-depth insights into the development process and detailed build instructions, please refer to my 2023 paper, "Design and Simulation of a Six-Legged Walking Robot", accessible on my ResearchGate profile. Even if you don't intend to replicate Hexumi, the paper provides a valuable roadmap for designing your robot.

Dependencies

Software in this repo requires ROS2 Humble to run.

To use the Pro Controller, you will have to install joycond on your Raspberry Pi.

Building servo driver's firmware requires the Pico SDK and micro-ros-setup. Remember to export PICO_SDK_PATH to point to the folder with the SDK.

Licensing

Code is shared under the MIT license. For details, see src/LICENSE or uros/LICENSE.

CAD files, STL files, and the wiring diagram are shared under the Creative Commons Attribution 4.0 License. For details, see CAD/LICENSE, STL/LICENSE, or img/LICENSE.

Why Hexumi?

I designed Hexumi as the subject of my Mechanical Engineering BSc thesis at the Lodz University of Technology, driven by two significant events: the COVID-19 pandemic and the rise of consumer AI. Over the past years, millions of people lost the ability to interact with the outside world due to lockdowns. Simultaneously, the threat of machine learning systems replacing online work loomed. Existing robotic tools for physical labor were either too expensive or lacked sophistication, making them inaccessible to the average person. Thus, I aimed to contribute to the development of affordable robotic solutions for research, education, and entertainment, with the potential to democratize access to mobile and dextrous robots.

Key Features

• Cost-efficiency and Accessibility: Hexumi is designed for easy replication using consumer-grade 3D printing techniques and off-the-shelf electronic components. Depending on your circumstances and 3D printer availability, the build cost can be as low as 300 EUR.

• Material-efficiency and Sustainability: The mechanical elements require minimal 3D printing supports, reducing material waste and improving sustainability. Its modular structure ensures that you only need to print minor components when replacements are necessary.

• Modifiability and Repairability: Hexumi's components can be easily replaced, whether due to failure or modification. In many cases, only a small amount of material needs to be used for replacements. For example, if you want to change the ground-contact sensors, you only need to modify the tips of the tibias, not the entire links.

• Software and Sensor Expandability: Hexumi is designed to operate with the Robot Operating System, preferably ROS2, as its RP2040-based servo driver is well-suited for Micro-ROS. The robot's housing design, a 5V USB power port, and 1.5kg static payload capacity allow mounting additional sensors, such as LIDARs, cameras, IMUs, and more.

• Ease of Use: Hexumi was designed to be both modifiable and easy to use. Peripheral components, such as the charging port, provide a simple out-of-the-box experience for a novice user.