Skin a wonderfully tactile and complex part of the human condition that often goes unnoticed. Scientists this week have demonstrated the most complex artificial skin for robots yet produced. Containing infra-red, heat and accelerometer sensors this is an intelligent hard shell for our robotic creations. Still lagging a long way behind human skin this new robotic facsimile is a huge advancement on previous technology that will eventually be able to include other sensors to enhance our robots sense of touch.
The skin itself is made from a collection of small hexagonal circuit boards – 5 square centimeters each– that are connected to form the skin. Each circuit board contains four infra-red sensors to detect objects within a few centimeters of the skin, six temperature sensors for heat / cold and an accelerometer. The circuit boards have their own processor and communications hardware used to form a network of skin cells.
The network functionality built into each hexagon cell allows signal information to travel different routes to its brain, allowing broken communications links to be worked around. So far Philip Mittendorfer and his team have assembled a skin consisting of 15 hexagon sensors plates covering the front, back and an arm of the test robot, Robbie. Once assembled the hexagons form a honeycomb like skin that is worn by the robot and feeds information back to a central processor or brain.
“We will close the skin and generate a prototype which is completely enclosed with these sensors and can interact anew with its environment,” claims Mittendorfer’s supervisor, Prof. Gordon Cheng. Prof. Cheng expounds that this will be “a machine that notices when you tap it on the back… even in the dark.”
While most research into robotic sensors is concerned with giving the robot a sense of where it is in any environment – environmental awareness – the team at TUM – Technische Universität München – were aiming to instill a sense of self-awareness. In practice this means the robot can move a limb and confirm the motion using its sensors, confirm that it has moved the limb. This will allow the robot to avoid what is technically termed ‘The Robot Idiot’, where a robot repeatedly bumps into the same object over and over. As soon as the sensors on the limb are different from the instructions sent to the limb a problem is detected.
One of the issues already being experienced is data overload. To cover the entire body of a full sized robot would require network to rival our nervous system, something even an entire corporate network would struggle to do. Once all of the sensory information is delivered to the robots brain it must be processed into meaningful information like move your hand it’s getting burned. If you consider all of the sensory information, not just the skin, the complexity raises even more. The processing power required for all of this information is still well above what we can fit into a portable package like a robot. The simulations of robotic systems such as this are run on mainframes that occupy whole floors of buildings, and that’s just the simulation. Although this is a serious issue it’s actually the easiest to fix, just wait. Computer processing technology is evolving fast enough that it’s only a matter of time till the required processing power is available.
One of the interesting by-products of all of this work in Robotics is what we learn about ourselves. By trying to instill our own abilities into these tin men we are trying to replicate what nature has perfected over billions of years. We quickly realize the actual complexity rolled into our bodies. Take skin for example, one of the bodies more complex organs, it carries out many functions from sensory information to cooling us down, immune system functions and impact resistance the skin is some incredible stuff, self repairing and flexible to boot. The pain threshold is one of the more important collective functions of the skin and brain. This is a self-preservation instinct that has been extremely important in human evolution. In essence it detects when an external object exerts enough force on the skin to cause damage. This can be from solid impact or simply energy being absorbed, heat for example. Once our sensors detect a damaging situation the brain should try to correct it, by moving your hand away from the flame for example. All of the artificial skins developed so far are a long way off being to emulate this instinct.
Will we one day be able to shake hands with a robot and have it mean the same things as shaking hands with a human being ? The future is approaching faster than we think. The face of robotics is changing, no longer simply industrial work horses robots are about to develop a gentle touch.
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