TriPed Robot

Goal

The TriPed is a new robot at Heidelberg University. It was build according to our specifications at the IMT Stuttgart. The Final Aim of this robot is to study cooperation between machines and humans or machines and machines. But before this is possible, the robot needs to be actuated. For this purpose, a control, hardware and software architecture was developed and is currently being implemented.

Problem/Complication

The University of Stuttgart delivered the system without any embedded hardware. This meant I had to choose suitable embedded controllers, wire up all sensors and actuators, and write the communication interfaces.

The embedded control was further made difficult by the complicated mechanical design of the robot, which is further explored here. This made many traditional control approaches impossible.

Contribution

As project lead and principal engineer, I am involved in every aspect of the TriPeds development. This development includes everything from PCB design, embedded control to high-level gait generation.

Initially, I headed a team of 3 research assistants as well as our lab engineer. To coordinate the group, I developed a system architecture encompassing feedback controllers, software, and embedded hardware.

More information about the software architecture can be found here

I then formulated and supervised work packages helping out with them where needed.

Additionally, I combined the embedded interfaces into PID position controllers for each joint. This meant dealing with mutual exclusion and other parallel computing-related problems. The documentation of the resulting package can be found here

I also developed simplified geometric models to mitigate the effect of the complicated mechanical design of the leg controllers.

Since much of the initial sensor/actuator integration is now finished, I continue developing and implementing the higher functionality mostly by myself, supported by only a few students whose theses I supervise.

Result

The project is still ongoing. For more information, visit the TriPed project page by clicking on the image below.

What I learned

This project has certainly opened my eyes to the intricacies of controller design when dealing with a physical system. I learned to deal with real constraints such as BUS communication limitations, gear backlash, or even communication breakdown-based bugs.

However, the most significant learning experience was how to break down a project into work packages and how to manage a team. Minimizing cross-team dependencies and estimating development times is something that can not be taught in a lecture. Likewise, managing people, dealing with interpersonal conflicts and different personality types is a matter of practice.