psb AGVs with laser contour navigation – efficient and flexible
So far, low-profile psb carobot AGVs have been guided by an induction wire »buried« in the floor. However, due to the related extensive and elaborate floor works, a flexible adaptation or expansion of the AGV tracks has been inconvenient. High-profile vehicles, on the other hand, are navigated by laser technology, with reflectors attached in the environment specifically for navigation purposes. This technology allows for a much more flexible adaptation of the travel course, which, after a brief training, can be carried out by the customers’ staff as well.
After the very positive experience with an automatic vehicle system with 19 carobot vehicles, which was installed in the year 1998, a large hospital ordered four new vehicles to be delivered in 2014. The enhanced type CAR-817 can be directly integrated into the existing system with inductive guidance. However, it is also designed for a modern forward-looking variant of laser navigation.
The »laser contour navigation«, introduced in 2013, works with the environment scanning technology of the two safety scanners of a carobot. In an »orientation tour« during the commissioning phase, a »map« of the environment is drawn on the basis of tens of thousands of scans. In real operation later on, the vehicle control will determine on the basis of this map and the current laser scans the actual position of the vehicle (according to methods of pattern recognition). In contrast to »traditional« laser navigation, the environment – i.e. walls, machines, pillars, etc. – is directly used for determining the position, so that additional reflectors do not need to be installed. Changes in the environment after reconstruction works are simply »acquired«.
The laser scans of the personnel safety scanners are taken in about ankle height, so that for the pattern recognition it is important that the operation environment is »tidied up«. In this respect, the supply tunnels, underneath the hospital building, offer close to perfect conditions. At spots, where at ground level often other obstacles may be present, the pattern recognition can take into account the position of additional reflectors too.
The connection of a new ward, planned for the year 2015, can be implemented without laying expensive induction wires. At that time, the 19 existing vehicles type CAR-801, operated in the hospital, will be also equipped with psb laser contour navigation.