At the international Field Robot Event 2014, the team from the University of Osnabrück won 3rd place in the overall ranking with its robot, ‘The Great Cornholio’. mayr power transmission supported the students and contributed backlash-free, elastic ROBA-ES shaft couplings. These compensate for shaft misalignment, are simple to install and are maintenance-free – prerequisites for application in the small, yet robust field robots.
They weed, fertilise, monitor the health status of plants and communicate with each other – that the little, intelligent field robot can work completely autonomously has been clearly shown by this annual international Field Robot Event. In 2014, 23 teams from 10 European countries competed against each other in Bernburg, near Halle in Saxony-Anhalt. The team from the University of Osnabrück took 3rd place in the overall ranking with its robot ‘The Great Cornholio’. Furthermore, the team around captain Heiko Wilms was able to assert itself in the ‘Cooperative Task’: ‘The Great Cornholio’ not only autonomously navigates in almost impassable terrain, but in the process can also communicate with other field robots and coordinate its work. Backlash-free, vibration-damping ROBA-ES shaft couplings from mayr power transmission are deployed in the drive line of the robot. The couplings compensate for radial, axial and angular shaft misalignment, and provide convincing results through a simple plug-in assembly and maintenance-free operation.
‘The Great Cornholio’ measures around half a metre in length, width and height, and is based on a modular, component-based robot modular system. It is equipped with cameras, laser scanners and measuring units, which are used for detection or position determination of the weeds and obstacles. ‘The Great Cornholio’ is made from aluminium in order to save weight and to enable higher driving speeds. The robot is driven by two DC motors excited by permanent magnets, with planetary gears, and the torque totals 15Nm. A ROBA-ES claw coupling transmits the torque and speed from the motor shaft to one wheel each on each side. The other wheel is connected via a chain drive to the first wheel. The separate drive units allow each side of the robot to be controlled independently of the other. The advantage of this concept is the small turning radius and the associated improved manoeuvrability, which is especially important for the robot in the narrow, winding rows of the test corn fields.
The elastic ROBA-ES couplings for the connection of two shafts transmit the torque backlash-free and compensate for shaft misalignments. The damping compensation element protects the drive system from critical vibrations. Nevertheless, the couplings are so torsionally rigid that, even in case of highly dynamic servo drives, no compromises are made on accuracy. With the ROBA-ES coupling, claws reciprocally engage into the input and output side hub in a star-shaped intermediate ring made from elastomer. Under slight pre-tension, this transmission elastomer made from polyurethane fills the space between the claw profiles and absorbs vibrations. The damping properties and the rigidity of the coupling can be varied via different shore hardnesses of the plastic. These clamping hubs, made of aluminium, guarantee a minimal mass inertia and ensure quick and reliable installation.
To learn more about the backlash-free, elastic ROBA-ES shaft couplings, please visit www.mayr.com.