Creating virtual mechanisms in real robots using modular compliant actuators
Actuator systems in robotics have, for a long time, followed the industrial paradigm where rigidity and precise control over position and velocity are maintained. This method of control is in stark contrast to biological systems where opposing muscles can work to vary the stiffness or compliance of a joint and generate motion that is determined as much by external forces as by the intentions of the agent. New approaches to actuator design have concentrated on generating controlled compliance in order to mimic biology and give autonomous systems better adaptive capabilities.
Combining new compliant actuator concepts with novel embedded control methods has the potential to create a new class of actuator for robotic systems, one where virtual mechanisms consisting of springs, dampers, biological muscles and other mechanical elements can be defined in software, and emulated in hardware. These Modular Electronic Mechanical Emulators, or MEME actuators, are proposed as a general purpose ‘construction kit’ for autonomous robotics, replacing the ubiquitous robot servo with a module that can emulate the behaviour of a wide variety of other mechanical systems. The benefits and limitations of this approach, the general design goals and the results of preliminary experiments will be discussed.
Bill Bigge completed a PhD in Computer Science and Artificial Intelligence at the University of Sussex. He has since set up a robotics company in the UK, Creative Robotics Ltd, to develop advanced actuator technology.