World-class snake robotics from Scandinavia
Posted by: Åse Dragland
“We bump into challenges all the time, and we experiment with various techniques.”
Erik Kyrkjebø lowers his hands and looks down. On the floor in front of us lie Aiko, Anna Konda, PiKo and Kulko.
“Our hope is that that we will be able to train them to receive information, process it, utilise it and learn once and for all. So far, we haven’t got that far,” says Kyrkjebø.
Anna Konda lies in a heap of red and white. Just beside her shines Aiko’s polished cranium: the seven-kilo rascal can’t even be bothered lift his head today. PiKo is partly hidden in a corner. They all look innocent enough as they lie perfectly still. And they are definitely not listening to what we say.
World-class snake robotics
Japan has its guru, and the US has a first-class milieu. But apart from these two countries, NTNU and SINTEF in Norway are far advanced in world terms as far as snake robotics is concerned.
“More than 20 people are working in robotics, which is an area of special effort in SINTEF ICT,” says Kyrkjebø’s colleague Ingrid Schølberg.
“Norwegian industry lies disgracefully far behind other countries. Sweden is putting twice as much effort into automatic control as we do. Countries such as India and China have started the robotisation process. We need to recruit to robot science and ensure that help is made available to industry that is exposed to competition”, says Schølberg.
Kyrkjebø adds: “The snake robots provide us with specialist expertise in motor systems and in how mechanical and electrical units can be integrated. We aim to develop core competence and create a platform with control systems that can be used in several different practical applications”.
It started with Anna Konda. The news about SINTEF’s snake robot that could save lives spread like wildfire in the media in the spring of 2005. Chinese, American and Brazilian newspapers and net-sites wrote about the Norwegian robot that could climb stairs, get past beams and sneak round corners, always in order to perform lifesaving missions in the event of fires or explosions.
Anna Konda has 20 hydraulic motors that actuate the joints in its 75 kg body. As many valves control the flow of hydraulic fluid to the motors. Each of the robot’s modules contains two hydraulic cylinders and two valves. The steel outer cladding also contains linking modules that can move in two axes.
“We developed Anna Konda in order to demonstrate the SnakeFighter concept. As far as we know, she is the biggest and strongest snake robot in the world, as well as the first hydraulic snake robot ever built”, says Erik Kyrkjebø proudly.
The scientists’ idea was to equip a fire hose with a hydraulic system. The strength of the powerful water flow would enable the hose to move on its own. Its advantage over a robot with wheels or legs would be its robustness and ability to penetrate difficult environments.
After five years the team have still not reached their goal, but they have great faith in the underlying concept of Anna Konda.
The Trondheim robots are similar to large-scale control systems, and they take their power from cables or batteries. The large system controls the overall movements of the robot, while a number of small systems control its individual joints. Every joint contains a small electric motor and a printed circuit board that reads information from the external world. The joints are interconnected, and each module can communicate with the others.
In the course of the four years since 2005, that single snake robot has turned into three or four. The family has grown because the robot scientists needed more knowledge that could be transferred back to the original model. Aiko came in order to find out what sort of electronics Anna Konda needed, and to make it easier to carry out experiments. It is easier to supply power for seven kilos than 75. For a good while, Aiko acted as a platform for testing the mathematical equations from the large unit until the smaller system worked properly, but eventually the limits of learning were reached. Now Kulko has arrived and will function as a platform for implementation.
“Kulko is not quite as stupid as the others,” as Erik Kyrkjebø puts it, meaning that this robot is fitted with power sensors that measure all its contacts with its environment.
PiKo is the robot that has taught the scientists most about vertical movement. It climbs up tubes, and when it is in vertical position it can propel its way up a pipe-wall. The cybernetics experts have been working on its propulsion system, while optics researchers have given the little robot “vision”.
PiKo differs from the other members of the snake family in that it moves on wheels, although, like its siblings, it is jointed.
“These snake robots have made us good at controlling jointed mechanisms,” comments Kyrkjebø, “but we also need experts who can help us with vision, which is why we are collaborating with experts from the Department of Optical Measurement and Data-analysis, and getting help from them.”
PiKo is designed to be able to cleanse ventilation systems and check leakafes in pipework with diameters as small as 20 cm, both vertically and at junctions”. So far, the scientists have managed to develop a propulsion system, and a 3D camera combined with a map and position recognition enable it to compare the map with vision to see whether it is on the right track.
There is long distance between a robot and an intelligent robot. To grip an object, for example, is a simple task for a human being. Programming such a task and transferring it to a robot is more difficult.
“A robot needs six degrees of freedom of movement,” outlines Kyrkjebø: Moving up or down; left or right; forwards or backwards; Tilting forwards or backwards; Turning left or right; Tilting side to side
“When we grap a door handle, for example, we need to be able to twist and rotate our hand.”
“How do you manage to do that?”
“Well, we need to supply the robot with visual information via its camera and sensors.”
The robot needs to compare the visual impressions that it captures in the present with its images and memories in its “experience base”; a little database in its head that houses memory, decision-making circuitry and interpretation of sensor-data. This might be an action that the robot has been trained to perform, a map, or images of lines and geometric figures that the scientists have input to the database.
In the database, images are connected up to create an action. When the robot checks whether it has seen a particular image before, and the answer is positive, the appropriate action immediately takes place.
“This is similar to what takes place when we humans see a door,” says Kyrkjebø. “From our own experience, we know that we should turn the handle. Even though doors look different and the handle may be high or low, we realise that the same type of action must be performed. We may have to test out a swing-door the first time we see one, but after a short learning process, that goes well too. That is how learning ought to take place in robots too.”
“Of course, we are the robots’ teachers, and by and large, they do what WE tell them. But it is just the same as with children: you learn a lot just by being together!” concludes Kyrkjebø.
Illustrations by Geir Mogen:
Featured image: Ingrid Schølberg and Erik Kyrkjebø of SINTEF ICT believe that robotsnakes have brought their group special expertise in motor systems and in how mechanical and electrical systems can be integrated.
Image 2: At four years of age, Aiko has tested out mathematical equations.
Image 3: Anna Konda (5 years old) is the mother of the family
Image 4: Two-year-old Piko climbs up vertical pipes.
Åse Dragland is the editor of GEMINI magazine, and has been a science journalist for 20 years. She was educated at the University in Tromsø and Trondheim, where she studied Nordic literature, pedagogics and social science.