Autonomous Route Planning
How autonomous navigation works
Navigation via laser scanners and intelligent vehicle control systems enables a high degree of flexibility and does not require any special design. Traditional track-guided vehicles required induction loops or reflection marks on the walls for laser triangulation. The old navigation systems are inflexible when reacting to obstacles or changing environmental conditions.
Autonomous transport robots locate themselves directly relying on the features of the environment. A 2D laser integrated in the robot continuously scans the environment (walls, machines, etc.) In addition, the proANT systems have an odometry system whose results are combined with the localization by the laser scanner. The odometry system determines the path information using the incremental encoders of the output wheels and angular changes of the vehicle, which are monitored by a gyroscopic sensor.
During the first installation of the transport system, a 2D map of the environment is scanned and saved. This map can then be edited on a PC. The target points are drawn in, loading and parking stations are defined. Furthermore, the following special areas can be defined,
- into which vehicles are never allow to drive, e.g. in front of escape doors.
- which may only be used as a one-way street, e.g. because the road would be too narrow for two oncoming vehicles.
- in which only one vehicle is allowed at a time (One-AGV Area), e.g. in places with a lot of passenger traffic or automatic fire doors.
This environment map with all definitions is then sent to all vehicles.
If a vehicle receives its transport order from A to B, it automatically calculates the optimal route there. It also communicates with the other vehicles in order to avoid them in time. If there is an unexpected obstacle in the calculated route, e.g. a pallet parked in the path which the vehicle cannot avoid, it calculates an alternative route. If there is no possible route to the destination, the vehicle just sends a message to the control software that a transport order cannot be executed. Depending on the definition in the software, the material can then be automatically returned to the warehouse after a time-out or an operator intervention can be requested.