Created by Juncheng Chen, Siyuan Jing and Lydia Zhou at the Bartlett School of Architecture (Interactive Architecture Lab), this project explores possibilities in mobile structures by investigating various strategies for locomotion.
Inspired by Theo Jansen’s mechanism designed for walking movements, the project began with investigation into a structure of a machine named Golem, a lightweight, low-cost and sustainable mobile structure, using air as the main energy input. The team developed an air muscle actuator to generate movements of the robot, experimented with different designs from tensegrity structure to biomorphic mechanism.
↑ The first prototype came from their soft robotics workshop. It combined rigid structures (two tetrahedrons) with soft actuators (the air muscles). This simple robot could walk on different ground surfaces and the walking direction could be controlled by gestures.
↑ In the second step of the project, the team eliminated the base tetrahedron of the last prototype, simplified the basic structure to make modular robots. The actuator system was also updated. Multiple modules could be assembled in creative ways resulting in different behaviours.
↑ The third design, a free standing structure was developed incorporating three legs and extra joints. Using these the robot could stand on the ground freely and get a much smoother movement, simulating natural walking. The robot could also perform more complex behaviours due to two-part control system but failed to walk as expected because the force generated by air muscle is being consumed by the joints.
The final design (video below) of Golem includes a much reduced control mechanism and although it has four legs with three PAMs (pneumatic artificial muscles) controlling each of them, the actuation sequence is very simple: each leg can stretch out with 3 PAMs pressurised at the same time, which means 1 solenoid valve can control three PAMs to accomplish this task. When one of the bottom legs stretches out, the structure is able to roll over in direction opposite of the leg. In the event the structure rolls over, a top leg will stretch out in the same direction to ensure the structure regains balance – a half-cycle of rolling movement can be accomplished by controlling a single solenoid valve.
In all four prototypes genetic algorithms were used as a method to optimise structure. By testing numerous possibilities, the algorithm can find the best result according to the fitness. Software included Grasshopper, MaxMSP, and Arduino components to control the valves.
Learn more about the project in this thesis report by Lydia Zhou which includes a vast number of references as well as some in-depth information about project’s scope and future development.