Smart vehicles with an almost human capacity for navigation are an increasingly common feature in warehouses and logistics halls. One major element of Industry 4.0 involves a start-to-finish optimization of processes, systems and workflows. A study is first made of the complete production environment and flow of goods and then used for comprehensive optimization, streamlining and simplification. The goal is efficient, disruption-free production: from order entry to raw materials management (i.e. getting goods to the right location in an appropriate timing, quantities and price) and delivery of the goods. Production chain optimization has been a major point of emphasis since at least the rise of the Toyota Principle and Six Sigma. Optimization of warehouse logistics has been somewhat less strongly affected by these changes to date. Against the background of Industry 4.0, automation is now expected to bring change in this area as well, as logistics and warehousing are of increasing importance in a global business environment. Yet warehouse logistics are a complex topic requiring perfect harmonization of many sub-processes. Among the crucial factors: where precisely will the goods be stored? Where does it need to go, and when precisely? Which storage slots are still available for incoming goods? Transportation of goods had been performed with the aid of warehouse vehicles such as reach trucks that are either manually operated or which move driverlessly along pre-defined routes.

Traditional Forklifts

Half of a forklift operator's working day is spent moving and positioning the truck. He needs to stop, climb down, retrieve and palletize the goods, remount the vehicle and then drive to the next stop. The forklift operator is perpetually looking upwards when working with high rack systems, which puts heavy strain on the neck and shoulders and can lead to permanent damage. The existing generation of driverless vehicles are limited to following predefined routes and cannot react flexibly to change. If a barrier is encountered, the vehicle is forced to make an emergency stop. These incidents break up the smooth flow of goods, as the disrupting object must be removed before the driverless vehicle can then resume its journey. Problems also arise when the goods to be transported are not in precisely the expected location. The driverless vehicles are typically unable to cope with the unexpected, and human intervention is required. In addition, these vehicles require extensive orientation aids, such as magnetic sensors or marked pathways along the floor, to understand where in the storage or product halls they are currently located. As a result, the current systems are seen as highly time-intensive and expensive to implement, and are essentially only an option for large companies.

Automation Brings Major Improvements to Warehouse Logistics

The "Autonomik für Industrie 4.0" technology program, sponsored by the German Federal Ministry for Economic Affairs and Energy (BMWi), has developed driverless vehicles that survey their own environment so as to orient themselves in unfamiliar warehouse and factory halls. Humans can interact intuitively with the vehicles, and they are capable of understanding voice and gesture commands. Industry 4.0 promises new approaches for providing machines with the innate human ability to orient themselves without expensive aids. The intelligent, driverless reach trucks developed as part of the research project learn to orient themselves based on their environment. They take advantage of an initial human-guided tour of the facility to note all aspects of their environment. Speech or gesture commands can be used for easy command of the vehicles. When a warehouse worker issues a command such as "Store this pallet on shelf 3," the vehicle can interpret both the spoken word and the associated gesture. It can reliably identify which of many different potential pallets is desired. The reach truck then performs the requested storage, fetching or repositioning task completely autonomously. The experimental technology is intended to permit transportable goods to be reliably identified, picked, transported and ultimately deposited at their destination through smart autonomous floor vehicles. Because the units are easy to operate, one single warehouse worker can control multiple vehicles at once.

How Exactly Do They Work?

3D information is required for safe navigation through warehouse halls. Three Basler Time-of-Flight (ToF) Cameras are used to provide this information to the forklift trucks from the Autonomik program.

These cameras are using the "pulsed time-of-flight principle" to capture 3D information. An integrated light source issues a pulse of light that strikes an object and rebounds back toward the camera. A special ToF sensor captures each of the returning pulses of light. Thanks to the intelligent alignment of the sensor's electronic shutter, an equation based on the speed of light is used to calculate the distance to objects in the field of view. Each individual camera uses this principle to capture its environment and creates a reliable orientation. Two cameras are mounted on the roof to allow for free movement in all directions and detect barriers. The intelligent forklift truck takes note of landmarks within its environment, establishing its own internal map. The forklift truck immediately notices changes to the environment, such as when a shelving unit is repositioned or a barrier is placed in its path, and reacts to them appropriately, for example by edging around a barrier the same way a human would. Emergency stops that block the flow of goods are avoided. The forklift can move freely and flexibly throughout the warehouse space. The third camera is a Basler ToF Camera that has been modified in size and ability to handle scattered light, and mounted on the right tine of the reach arm. It is required for precision pick-up of pallets. The 3D data delivered by that camera ensures that the reach truck tines navigate precisely into the pallet on the first try, without needing human guidance.

Unlike previous systems, there is no need for costly and time-intensive initial and ongoing configuration phases, including establishment of a fixed warehouse map and mounting of artificial landmarks or magnetic sensors. For customers, this means significant savings. Driverless transport systems are poised to make a breakthrough with small and mid-sized companies in the future as well.

Summary

Warehouse logistics are improving in the age of Industry 4.0 thanks to smart vehicles. The intelligent forklifttruck currently under development as part of a research project is not yet commercially available; a related technology study was presented at Hannover Messe 2016.  Nevertheless, it represents a significant milestone for optimization in the world of autonomous floor vehicles.