A team of mechanical engineering researchers at Carnegie Mellon University in Pittsburgh has create a steerable bipedal robot with only one motor, which they claim is the first of its kind.
Small robots are important tools for the investigation and inspection of small spaces. They can carefully place their steps, allowing them to navigate around obstacles, capabilities that larger robots don’t always possess. This can enable them to inspect machinery or search through rubble in disaster scenarios that other robots can’t reach. However, due to their size constraints, building small robots that can steer themselves and carry their own power sources is difficult.
Aaron Johnson, an associate professor of mechanical engineering, and Sarah Bergbreiter, a professor of mechanical engineering, and their team of researchers revolutionised the field with the construction of Mugatu, the first steerable bipedal robot that contains only a single motor. Mugatu is also self-contained and self-starting, open-loop stable in its gait, and has controlled left, right and straight steering. The design uses two rigid bodies and one actuator – a simple walker design that’s still capable of the complex motions displayed by other robots.
‘The first direction of the project was aimed at simplifying the way robots walk as much as possible,’ said James Kyle, a recent mechanical engineering graduate. ‘Once we understand how scaling affects locomotion, it can be extremely useful for taking something that already exists and scaling it up or down to do things like fit through smaller pipes or carry more load.’
Another team member, undergraduate mechanical engineering student Kendall Hart, worked on the robot’s current sensor – the part of the robot that allowed the team to calculate the total cost of transport, that is the amount of energy used over a certain distance. ‘Before I came into the lab, I had a vague understanding of MATLAB (a programming and numeric computing platform), but working on this project allowed me to apply what I learned in class,’ he said. ‘When we were working on implementing the current sensor, there was a lot of debugging there, but now it’s made me more confident in debugging without my mentors.’
Nicknamed the LEGO Project, the team aims to eventually get these walkers down to the size of a LEGO. ‘It’s going to take a while because the mechanics of everything changes as you start down-sizing,’ Hart said. ‘But what makes the project so special and so impactful in the community is because it’s never been seen before.’
According to the team, the drastic simplification of this walking device, combined with its single degree of freedom, is a promising step (pun intended) toward highly efficient small robots.
Further detail on the project can be found here.