Laser navigation, also known as contour navigation or natural navigation, is recommended for particularly precise and flexible navigation of the AGV. This is based on laser scanners or lidar (light detection and ranging). The AGV first drives through its surroundings in "learning mode", detects fixed points using a rotating laser beam and creates a map from this. The AGV uses this map to orient itself autonomously in space. Obstacles can be reliably detected and, if necessary, avoided. Compared to camera-based systems, laser navigation works even in dark environments and in poor lighting conditions. Please note: Dust or dirt can impair the precision of the system. Regular maintenance and cleaning are therefore necessary. In addition, the range of the laser beams is limited. Laser navigation is therefore more suitable for work areas with clearly defined contours than for wide, contourless environments. The main advantage of laser navigation is precise and flexible navigation. The sensors that can be used for this are safety laser scanners, such as the RSL 400 safety laser scanner from Leuze. It combines safety technology and measured value output in one device.

For dynamic environments

Laser triangulation uses reflectors in the room to determine the AGV position with a laser scanner. The scanner requires visual contact with at least three reflectors, which are installed at a height of several meters. This enables very precise positioning and navigation of the AGV. This technology is useful in dynamic, frequently changing environments. On the cost side, it must be taken into account that the sensor must be attached to the AGV at reflector height. In addition, the reflectors must be installed in the room. These must be visible at all times in order to reliably determine the position of the AGV. Please note: Additional sensors are required for route protection. Lidar sensors are used here.

Always follow the path

Another type of AGV navigation is optical or inductive guidance. With inductive guidance, the AGV follows a magnetic tape or induction cable laid in the ground; with optical guidance, it follows a track laid on the ground. Sensors installed on the AGV detect the path, enabling the vehicle to be precisely aligned. The advantage is that the acquisition and installation costs for the sensors are manageable. This technology is particularly suitable for environments with clear and predictable paths. It is independent of the vehicle type: the sensor is simply attached to the AGV at a short distance from the ground. The disadvantages include the effort required on site if magnetic tape or induction cables are laid. In this case, vehicles are also fixed to the previously defined lane. This limits flexibility for new layouts or routes. In addition, navigation can be less precise compared to lidar or camera technologies when there are many bends or narrow passages. The sensor technology that can be used for this: optical guidance sensors, such as the OGS 600 from Leuze. The sensor uses edge detection to recognize the lane and sends corresponding signals to the control system.

AGV navigation by structure

Grid navigation is based on a coordinate system. It consists of 2D codes on the ground or transponders embedded in the ground. These are attached in a grid pattern and serve as reference points that the AGV uses to determine its position. The AGV moves along predefined grid paths. This technology is easy to implement. The coordinate system enables precise positioning and high navigation accuracy. Grid navigation is particularly useful in environments with predictable and structured routes, such as warehouses or production facilities with clear lanes. The disadvantage is the lack of flexibility for new routes or frequently changing environments. The installation of transponders also requires physical intervention in the floor. This is where 2D code readers come in, such as the DCR 200i from Leuze. Installed on the AGV, the sensor reads the codes as it drives over them. The advantages are the extremely compact design and the large working range of 40 to 360 mm.