RoboThespian robot uses Festo fluidic muscles

Engineered Arts Ltd, a company that specialises in hi-tech multi-media, has created a unique interactive robot - named RoboThespian - that is wowing audiences around the world. Initially developed to provide entertaining semi-autonomous theatrical performances, the life-sized robot's capabilities have recently been expanded to facilitate far higher levels of audience interaction. The robot's siblings are now much in demand at science and technology centres as highly animated public orators, tireless front-of-house presenters and generally all-round benevolent funsters!

Engineered Arts specialises in the design and build of highly imaginative interactive exhibitions, audio visual and mixed media installations, involving a combination of art and engineering. Based in Cornwall, the company has established an enviable reputation for creating exhibits that are humorous, captivating, intelligent and informative.

The first generation of RoboThespian robots were developed in January 2005, when Engineered Arts was commissioned to create a troupe of robotic actors to perform at the Eden Project's Mechanical Theatre. The initial design work focused on the necessary mechanical engineering and control systems, resulting in a hugely popular installation piece that featured tireless performers who needed no lunch. However, it soon became obvious that audiences craved more than a one-way relationship - they wanted to interact with the robots. So Engineered Arts embarked on an extensive development programme to create a set of fully-integrated hardware modules for controlling the robots' various valves and motors, and added internet connectivity to the control software to facilitate access to web-based public information sources such as Wikipedia.

Audience participation

The first interactive RoboThespian was exhibited at a conference hosted by the Association of Science-Technology Centers, in Los Angeles, in November 2007. The robot's repertoire included a series of song-and-dance routines, and, for the first time, it was able to respond to its audience vocally and through reactive physical movement. This was much appreciated but, of course, eventually even this was not enough! People wanted to be able to shake RoboThespian by the hand, and to make the robot perform their own routines.

As a consequence, Engineered Arts has now added articulated hands, an additional axis in each arm, and feedback sensors on all movement axes. In total there are 31 powered axes - six per arm, four per head and two per leg, plus four in the head, two in the body and one for rotating the entire figure through 180 degrees - each of which features full proportional control. The robot contains six DC motors, but all its major movements are controlled by Festo DMSP series fluidic muscles. These very high power-to-weight pneumatic actuators essentially comprise a flexible tube with reinforcing fibres in the form of a lattice structure; unlike conventional pneumatic cylinders they contract as they are filled with compressed air, and elongate again when the air is removed. Fluidic muscles are used for highly dynamic, short stroke applications such as this, and their peristaltic type movement is exceptionally smooth and lifelike (see a close-up photo of the arm).

Festo currently produces three variants of fluidic muscles, with diameters of 10, 20 and 40mm. The company is also considering developing a 5mm version but, as yet, testing and development is still underway. However, as Will Jackson, Director of Engineered Arts, points out: "For obvious reasons, we are very interested in small diameter fluidic muscles - they would make great RoboThespian fingers! For this type of non-industrial application, involving relatively low duty cycles, we could probably live with the performance figures that Festo is already achieving, so we are keen to participate in the product evaluation process. In fact, this degree of co-operation typifies our experience with Festo - we have enjoyed superb service from the company, all the way along the line. Their technical support is second to none, their local representative is almost part of our team, and their products are always delivered on time and to budget."

Drag-and-drop robot programming

The first interactive RoboThespian was installed at the Goonhilly Future World exhibition in Cornwall back in March 2008. It features a new remote control console fitted with a 19-inch touch-sensitive screen, linked to the robot via an industry-standard LAN; the control software employs an advanced graphical user interface with drag-and-drop editing facilities, enabling visitors to create their own movement sequences using a virtual on-screen robot, and to then watch them being performed live by RoboThespian. Needless to say, the installation is proving to be a real crowd puller and is especially popular with children!

Engineered Arts is already seeing considerable interest in RoboThespian from commercial organisations and businesses, and its order book is fast filling up. The company recently installed a robot at the newly modernised Industrion Science Park in Kerkrade in The Netherlands - where, of course, it is obliged to speak fluent Dutch and German - as well as a Spanish-speaking model at the Parque de las Ciencias open-air museum in Granada, Spain. Engineered Arts is now in the process of commissioning a robot for the Copernicus Science Centre in Warsaw, Poland.

RoboThespian has its own very informative website, featuring a number of highly entertaining video clips. Take a look at the entertainment technology of the future by visiting www.robothespian.com.

Or follow the link for more information about Festo's fluidic muscle pneumatic actuators.