|The Still VNA truck MX-X and the FM interact at high precision in computer controlled automatic operation|
About one year ago the Hamburg company, Still GmbH, presented the newly developed order picker series MX-X. Parallel to the field testing at a large customer operating five trucks, full automating of the trucks was developed. From now on, the automated version or the interface for later automating is available as a module.
As with other trucks in the past, Still developed the MX-X trucks as a modular kit which has been consistently implemented in all hardware and software components for all functions. The control panel, the load take-up, the travel drive, the hydraulics and the steering system are equipped with individual control modules which are connected by a modern CAN bus system. This technology also allows the adaptation of the automatic components which are additionally supported by the standard height measuring system.
Alternative automating by wire or by laser
On the floor level the automated MX-X is wire guided. In the vertical direction, the intended position is approached by the height measuring system and the fine-positioning is achieved by a light emitter and reflectors. The permitted travel speeds are detected by the truck controls, the location is detected by transponders and the different routes are distinguished by multi-frequency technology. Corresponding detector coils transmit the signals to the electronics of the autopilot. Measuring of the travel distance is achieved by a runner wheel mounted on the drive shaft of the corresponding wheel of the truck. This technology serves navigation purposes, not positioning. As a modern alternative, laser navigation is available as well. This solution was developed by SSI Schäfer, a system partner of Still and LogObject AG.
Different warehouses require different solutions. In this way it is possible to install the automating solution in existing rail guiding systems or in warehouses fitted with wire guiding systems. The highest technical requirements are doubtlessly posed by shifting racks, but this application was realised as well.
The performance of the automated truck is slightly lower compared to manually operated trucks in single or double cycles. If, however, breaks and distribution times are considered, the automated truck achieves a higher performance per shift.
Retrofitting of existing warehouses for automated operation
The automated trucks have considerable advantages compared to the curve travelling rack feeders which transit on rails. The installations act as barriers and a possible emergency operation of the warehouse with conventional trucks is not possible. Also, the transition is very time consuming. These disadvantages are avoided by automated MX-X systems. They can also operate in existing warehouses, the combined use with manually operated trucks is possible without problems, corresponding planning provided. Also, the parallel operation of an automated truck in a manually served area is possible to cover peaks.
Altogether the new MX-X series by Still allows extremely flexible use.
This is also shown in the interaction between an automated order picker with an autonomous FM reach truck in an implied warehouse which Still is presenting at the CeMAT 2005. The automatic operation shows the high precision with which both trucks interact computer controlled to demonstrate the vision of an unattended warehouse.