Spinal Rhythms

By designing a robot's body as a primitive abstraction, a connected system of bare limbs linked by articulated joints, the spotlight lies on the action that brings those inorganic shapes to life - the motion. It is movement that superimposes life and characteristics onto the abstract inorganic skeleton.

The movement becomes the expression of the creature's individualism, the language that communicates its identity.

Actuated by shape memory alloy springs the robot performs slow and elastic movements that differ from robotics' typical electrical motor characteristics. Their noiseless activation and stepless transformation grants the robots a much more graceful and life-like appearance.

The perceived movement of the robots is the interdependent product of software, hardware and environment. The computation unit sends activation patterns to the muscles elements, they apply forces onto the mechanics of the robotic skeleton which are transformed into kinetic energy that moves the whole body against environmental forces. The close coupling between the control signals and the mechanical dynamics of the body often makes a clear definition of the origins of the resulting behavior impossible. The body puts the constraints on what the control signals are able to do. By performing evolutionary computation on the actuation patterns, the control system learns to adapt itself to the morphology it has to deal with. The evaluation process uses image analysis to grade the performance of motion patterns according to a fixed set of fitness functions and attempts to find activation patterns that produce more movement while consuming less energy. The robot gets the chance to experience its own body through a simple trial and error process and learns to achieve better and better results with time.

Trained in an autonomous loop without human supervision the robot is granted a certain awareness of its own body.

Robotic control systems are usually evolved in simulation and are less efficient than expected due to a lack in complexity in the simulated testing environment. An embodied evolution solves the reality gap problem by performing all the tests on the hardware robot itself. The fault-prone hardware-body of the robot and changing environmental conditions create an unstable fitness landscape that demands continuous adaptation of the activation patterns. Instead of training for a fixed set of conditions, the inclusion of possible alteration during the evolution invokes autonomous adaptation and damage repair in close interaction with the changing environment.

As the project employs the techniques of artificial evolution in an embodied setup, it tries to bridge between artificial life art in the digital domain and in robotics. The crucial differences between digital and analog worlds - constituted in the messiness and unpredictability of real life - are emphasized instead of being inhibited. The evolution of movements and motion patterns has been the subject of projects like Strandbeests or Evolving Virtual Creatures, yet the actual evolutionary process has always been conducted in physical-world simulation programs. Embodied evolutions are yet rarely carried out in artificial life art and are more common in the evolutionary robotics discipline. Even though actual reproduction and mutation techniques are only applied to the control software of the moving robots, the robotic body and all its constraints and instabilities become the main carrier of the evolutionary focus.