Act naturally

03 May, 2016

Festo, the leading supplier of automation equipment, has supplied its ultra-modern fluidic muscles and piezo valve technology to Engineered Arts Limited for use in the fourth generation of its ‘robot actor’, RoboThespian.

RoboThespian is a life-sized humanoid robot designed for human interaction in a public setting. It is fully interactive, multilingual, and user-friendly, making it a perfect device for communicating with and entertaining people. It currently greets visitors to NASA’s Kennedy Space Centre in Florida, provides information at the Phaeno Science Centre in Wolfsburg and interacts with visitors to Australia’s National Science and Technology Centre, Questacon.

Standing 1.75m tall and weighing around 33kg, RoboThespian’s chassis is made from aluminium, and its body shell from plastic. It is brought to life by a total of 30 motion axes, which are all controlled by an integrated computer, to make it move its head, arms and hands in an incredibly lifelike way. Finally, it interacts and communicates with the people it meets via a touchscreen and on-board sensors.

Invented and developed in the UK

RoboThespian was invented and developed in the UK, by Engineered Arts Ltd. in Penryn, Cornwall, which is also where he is manufactured. Now in its fourth generation, its current form is the product of more than 10 years’ continuous development. When looking for a technology that would make RoboThespian’s movements seem as human as possible, the company turned to Festo for its expertise in pneumatics: “We use the fluidic muscle from Festo because it makes RoboThespian’s movements appear very natural,” says Will Jackson, Director of Engineered Arts and inventor of the RoboThespian.

Bernd Lorenz, head of membrane technologies at Festo, said: “The DMSP fluidic muscle is ideal for this application as it acts like a human muscle, it contracts and relaxes without friction resistance or breakaway torque, and is even stick-slip free. It is hermetically sealed and clean, as no lubricant is required. All movements, whether slow or quick, are jerk-free and perfectly smooth. With its flexible structure and its compliant behaviour it is the perfect drive for cooperation between man and machine.”

RoboThespian’s arms and hands are each moved by a total of two and eight fluidic muscles respectively (DMSP-10 and DMSP-20). The finger movements are executed by Festo’s new, small DMSP-5. The fluidic muscle is a membrane-based actuator comprising of a flexible hose embedded with rhomboidal shaped multifilament yarns that mimics natural muscular movement. When internal pressure is applied, the hose expands in its peripheral direction, thus creating a tensile force and a contraction motion in the muscle’s longitudinal direction. The usable tensile force is at its maximum at the start of the contraction and then decreases in a virtually linear manner as a function of stroke.