In warehouses and on production lines worldwide, a new generation of robots is taking automation to the next level.
The Slovak company Asseco CEIT, a CoreRFID partner, has been a pioneer of this Industry 4.0 revolution and its automated guided vehicles (AGVs) have transformed operations for companies such as Jaguar Land Rover, Skoda, Volkswagen and Velux.
Asseco CEIT’s forklifts, tuggers and under-runs can transport materials around the factory floor without the need for human intervention. Its Twiserion software controls their movements and allows managers to monitor operations in real time, while the use of digital twin technology provides valuable data insights to help eliminate bottlenecks and optimise production and logistics.
Controlling vehicle movements
However, the efficiency and safety of the whole operation depends on an accurate system of navigation to guide robots from one location to another while avoiding unexpected obstacles such as another forklift or a human strolling around the aisles.
Early automation systems used magnetic tape to guide automated vehicles along a fixed route. The introduction of RFID – which uses tags positioned at strategic points to identify the vehicle’s exact location – marked a major step forward.
According to Asseco CEIT, newer systems are increasingly based on SLAM (Simultaneous Localization and Mapping) navigation, which uses sensors on board the vehicle to create a map of the environment and pinpoints its position. SLAM systems can incorporate a range of technologies such as LIdar, cameras or ultrawide band (UWB), which is the option typically used by Asseco CEIT.
RFID vs SLAM: what is the difference?
Both RFID and SLAM have different benefits and drawbacks which need to be taken into account when considering their suitability.
RFID is highly accurate and can pinpoint the exact location of a vehicle and offer continuous monitoring. However, it does depend on having RFID tags positioned at key points which can then be read by a sensor on the vehicle as they come into range. In practice tags are usually set into the floor or a gateway at junctions or, in a warehouse, may be arranged in the form of a grid. Therefore, RFID is mainly suitable for indoor environments with a static layout.
SLAM systems are better suited to dynamic or changing environments and can be used indoors and outdoors. They use sensors to identify features such as edges or corners, then create a map and identify their position on it. The data is continuously updated as the vehicle moves along. SLAM systems require far more processing power and are ultimately more complex systems. As they estimate their position, there is always some margin of error which can grow over time and distort the map data so they may need regular calibration.
Insights from Asseco CEIT
Martin Záhradník, Electrical HW Team Leader at Asseco CEIT, says: “We primarily use RFID tags in AGVs that are navigated along magnetic tape. RFID tags enable us to accurately determine the AGV’s position and assign specific commands to be executed at designated locations. This solution is easy to implement and, when used in environments with only autonomous vehicles, it is virtually maintenance-free. With proper implementation, the risk of vehicles damaging the tags by driving over them can be effectively eliminated.”
Martin says that RFID tags are selected based on the specific environment and application, with options including flat tags with a diameter of 30mm or 50mm. However, for some customers, capsule-shaped RFID tags have proven to be the most suitable option.
Martin adds: “The introduction of RFID tags marked a breakthrough during the transition to navigation using magnetic tape or induction wire. Today, customer demand is increasingly shifting toward SLAM navigation. Nevertheless, RFID tags continue to hold an important role in the automation of logistics vehicles. Ultimately the choice will depend on a range of factors such as the application, the client’s requirements and the environment in which they are deployed. “