Reymond Clavel has been into robotics ever since he was a child. Now, with retirement a year away, it’s time to look back on a career that spans 32 years at the EPFL, where he is Professor and Director of the Laboratory of Robotics Systems(LSRO2). Clavel’s pioneering work marked the field of robotics with the invention of the Delta Robot, which has become the standard in industrial packaging.
In the field of robotics, the name Reymond Clavel is known all over the world thanks to his 1985 invention, the Delta Robot. Here at the EPFL, he directs the Laboratory of Robotics Systems (LSRO2). The Delta Robot was one of the world’s first high-speed parallel robots thanks to its particularly lightweight structure. These characteristics made the Delta Robot a perfect tool for the industrial packaging industry (see video). Over the years the Delta series has been constantly updated and improved, and today it dominates the packaging sector, with over 10,000 units in use worldwide. The latest model, the Delta Direct Drive, was developed in collaboration with Bosch and launched last year at the Interpack 2011 Trade Show in Dusseldorf, Germany. It boasts accelerations of over 15g. A prototype from LSRO2 has even reached 90g! The robot has also been adapted for ultra-high precision applications (on the scale of nanometers) and is used in remote robotic surgery, watch-making and precision machining. We recently talked with Professor Clavel about his life-long love story with robotics and where he got the inspiration for the Delta.
“Back then robotics was tough work!”
Professor Clavel first became interested in machines when he was growing up in the Vaud countryside. “Back then, we had acres and acres of crops, and the fields needed weeding. It all had to be done by hand. This was monotonous work, and I was always wondering about ways to automate it.” The future inventor’s interest in all things mechanical quite naturally took him to the EPFL, where he earned a degree in mechanical engineering in 1973. He then worked in the manufacturing sector for nine years, at Hermes Precisa International, a typewriter manufacturer, before returning to the EPFL as a Professor to teach robotics and microengineering. “Back then robotics was tough work,” says Professor Clavel, who had no idea he was about to revolutionize the field when he joined the EPFL faculty in 1981. “We worked with 8-inch diskettes that held only about 400k of data. Plus, the robots themselves cost a fortune.” Ultimately, though, none of this would prevent him from inventing the Delta.
It all started with a chocolate factory
It all started with a chocolate factory. One of the Robotics lab’s teaching assistants came back from a visit to a chocolate-maker with an idea: why not develop a robot that could place chocolate pralines in their packages automatically? The team was immediately interested. “The goal was to build a high-speed robot,” says Professor Clavel. “Our first idea was to use hydraulic motors because they’re more powerful, but we quickly realized we should take a different approach, since pralines only weigh about ten grams each. A robot with ultra-lightweight arms would be better.” The young Clavel was fascinated by the project, and he and his team constantly tested different designs. “I would come home from work and start tinkering with my wife’s knitting needles, looking for a structure that would work,” he recalls. The solution ultimately came to him: the robot would be composed of three articulated arms that would guide the travelling gripping device through three degrees of freedom in translation. As for the heavier motor components, they were to be placed not on the mobile part of the robot, but on its base. It was these design features that made the Delta so light and so fast. The idea was revolutionary – or so it seemed. In fact, when Professor Clavel filed for a patent he was informed that a 1938 project was similar to his. The "Pollard” robot, like the Delta, featured three kinematic chains that functioned in parallel, although the Pollard model did not allow for spatial translation. After perfecting the Delta’s design and providing more detailed information, Professor Clavel was finally granted a patent in 1985. There was another parallel robot in use at the time, the Steward Hexapod Platform Robot, but it was mainly used in flight simulators. Obtaining the patent was crucial to the success of the Delta, which won a market in manufacturing. "The Delta has been my life’s project ever since," says Professor Clavel.
Need inspiration? “Think outside the box.”
Professor Clavel has always tended to “think outside the box,” working instinctively and developing his designs and concepts from scratch. “You need to consider every possible approach to solving the problem at hand,” he says. “Sure, you have to have excellent knowledge of physics and mechanics,” he adds, “but somewhere along the line you’ve got to innovate.” This philosophy has had a formative influence on his students. "Reymond Clavel taught us to trust our own ideas,” says his former doctoral student and the author of Conception des guidages flexibles Simon Henein. “He advised us to wait a while before reading the literature on a given problem – that way our own creativity and intuition wouldn’t be constricted.” Henein adds that Professor Clavel “has a hands-on, scale-models-based approach that brings out the concreteness of the things we work on.” Professor Clavel would, for instance, take pictures of unusual parallel mechanical parts on logging machines while he was out for a walk in the woods. He would then bring the pictures to the EPFL to show his students. As Professor Clavel himself puts it: "I like to solve concrete, specific problems, and to collaborate with industry. Afterwards, if my solution gets me publications…well, that’s even better."
A productive lab
As his retirement approaches, Professor Clavel’s lab is still humming with numerous projects. One example is the FP7 Femptoprint European Research Project, whose goal is to develop a mobile-prism-based guiding system for femtosecond laser beams used in ultra-high-precision machine tooling (at a nanometric scale, i.e., one-millionth of a millimeter). "One possible application of this technique would make it possible to engrave an identifying code into a watch so that it would be impossible to counterfeit,” says Professor Clavel. In addition, the Lab’s assistants are still working on the Delta Robot, designing different versions as a function of the robot’s various applications. The Delta concept has engendered new ways of thinking about what you can do with robots featuring three to six degrees of freedom in translation. The result: numerous solutions for manufacturing and industry. The future of the Delta robot is therefore assured, and its creator won’t be completely absent after retirement. Professor Clavel is still directing three PhD thesis projects and says he’ll be “available if they need my help on anything —especially start-ups.” Chances are we’ll be seeing him around…