Now that Personal Computers (PCs) have become omnipresent, Personal Robots (PRs) could soon be making their way into our working and business lives, where they might serve us as ″electronic butlers″, fetching newspapers, pouring coffee, or clearing the table. Since the 1990s, the Fraunhofer Institute for Industrial Engineering and Automation (Fraunhofer-Institut für Produktionstechnik und Automatisierung, IPA) has been working to develop these types of innovative service robots for use in the home environment, in hotels, care and nursing homes, or hospitals, to name a few. The fourth generation of Care-O-bots, introduced at the beginning of 2015, are not only more motile and ″charming″ than their predecessors, but they also shine with cost-mitigating design features.
Major Sensorics Challenges
In order for the robot to flawlessly execute its movements and gestures, the controller must be able to query a joint’s current position at any time. This requires sensors that provide the respective positions as absolute signals, making the robot immediately operative after a reboot, without the need for reference runs.
Therefore, an absolute rotation angle multiturn sensor was needed for the position sensing of the joints. It was to feature a minimal footprint, to make the sensor suitable for tight spaces.
The chosen model was our non-contacting Multiturn sensor of the RSM series. The sensor runs very smoothly while providing the desired features. At the same time, it is the most inexpensive product on the market. With its small diameter of only 28mm, it easily fit into the joint.
