Manufacturers of AGVs and AGVs can obtain the complete sensor technology from SICK as an integration-friendly complete solution without interface risks. The complete solutions are integrated systems that cover all aspects of localization and collision avoidance, personal safety and the handling and identification of typical hospital load carriers. Increasingly, these systems focus on the use of sensor data and system information - which represent the physical transport processes in digital form - when integrating AGVs into hospitals' information and merchandise management systems. Increasing digitalization with the possibility of making the complex networking of logistical processes transparent and providing a wide range of data, as well as the ongoing shortage of skilled workers in the care sector, will further increase the importance of AGVs in this area.

Collision avoidance with sensors
In the past, the use of driverless vehicles in hospitals was often limited to restricted, non-public areas, but their use is now also being extended to publicly accessible areas. In particular, small parts are increasingly being transported. This means that these AGVs are increasingly moving around with people in the same environment. This results in special requirements for the safe operation of AGVs and the use of safety-certified sensor and control components. They can be configured to form a safety system individually for each vehicle type and each clinical environment. Safety laser scanners from the S300, S300 Mini or microScan3 product families with individually programmable protective fields detect people and obstacles in the corridors and travel paths and slow the vehicle down to a safe stop.

At the same time, safe encoders such as the DFS60S Pro and safe non-contact limit switches monitor the driving speed as well as the current and maximum permissible steering angle of the vehicles. They are coordinated by the Flexi Soft safety controller, which merges the signals from the safe encoders, 2D LiDAR sensors, limit switches and emergency stop buttons, thus enabling situation-dependent person detection. In addition, collision protection can be further improved with 3D LiDAR sensors such as the MRS1000 multi-layer scanner, which actively measures on several levels simultaneously, as well as 3D snapshot detection sensors from the Visionary T product family. Thanks to their high resolution, they are also able to detect narrow objects such as walking sticks, rollators, wheelchairs, infusion stands or equipment trolleys.

Localizing and navigating
Current figures indicate the extent of the intralogistical challenges in hospitals. The leader in terms of patients (almost 137,000 cases) and doctors employed (1,650) is Berlin's Charité hospital, which is also the lone leader with just over 3,000 beds. If you take all hospitals together, they have an average of 245. In relation to the total number of almost two million patients in 2017, this means that each hospital in Germany treats several 1,000 patients a year. This results in a large number of material flows in hospitals, with vehicles increasingly moving around public areas in the future. They will share corridors and elevators with doctors, nurses and care staff, as well as patients and visitors. Reliable localization and route-optimized navigation are required in order to make optimum use of transport capacities and routes and to ensure that individual areas are supplied and disposed of on time, which is essential in many cases.

The SICK safety laser scanners with 2D LiDAR technology are used not only for their actual purpose as a person recognition system, but also for measuring spatial contours and artificial landmarks. The contour data is compared in the navigation computer with the reference data stored in a map and the current vehicle position is calculated from this. The continuous position information is sent from the AGV's on-board computer to the central control system via W-LAN and simultaneously used for navigation. As an alternative to increasing local accuracy and robustness, optical or magnetic tracking systems from SICK's OLS or MLS product families can be used for localization. The GLS grid localization sensor is suitable for verifying the absolute position in the material flow.

Means of transport as the basis for Hospital 4.0
Standard and special containers, trolleys and pallet cages are the main means of transport used in AGV systems in hospitals. They are often only approved for certain types of transport or for use in specific areas. They are either currently in use, being cleaned or waiting for their next job. In order for the container management system to be able to manage and schedule the means of transport and enable seamless and timely shipment tracking in the central control system, the containers need to be clearly identified. Barcode technology is ideal for this purpose. Containers marked with such an optical code can be quickly and reliably identified both by readers on the AGV and by hand-held scanners. RFID systems are suitable for marking containers that have to be cleaned and disinfected regularly.

By identifying all containers, they are visible in the AGV control system at all times - their physical activities are networked with the data in the control level, so that the digitized processes of hospital logistics always map the actual transport and goods flows in an up-to-date and congruent manner. This makes it possible to provide transport aids efficiently, to avoid using defective or unclean means of transport or to plan trips exclusively for approved areas - for example in hygiene-sensitive departments.

From transport to service solution
Cost pressure, increased efficiency and digitalization are also key drivers of automation in hospitals. For technical and economic reasons alone, AGVs will therefore play an increasingly important role in ensuring high logistics availability in hospitals. Mobile robots that provide bedside meals and other services will enable hospital staff to concentrate on their core competencies.