Production processes are constantly being optimized. Both time and cost pressure require the constant revision and reorganization of organizational structures in internal logistics, and this is no different in the glass industry. With companies increasing their digital networks, the use of automated guided vehicles will also make it easier to implement these processes.
The magic words are shop floor logistics. People are, and will always be, part of the logistics chain. With the help of automated work steps, employees are able to focus on their tasks more closely and therefore work in a more targeted manner. Mobile and driverless machines are deployed to complete distracting ancillary activities or transport routes, and not just at the cold end of glass production.
The first step is an analysis, a data-based process which requires as much data to be collected as possible. The company Hegla-Hanic GmbH & Co. KG has defined the necessary steps for its production solutions. The challenge in production is coordinating the machining and cycle times of the equipment. What happens at individual steps, how good are the interfaces and how smooth are the transitions? How well is the supply of work materials coordinated? Machine parks are generally designed to be very heterogeneous, certain processes have “grown”, habits have crept in, information is scattered and, of course, there are always unplanned downtimes.
CONTRARY TO EXPECTATIONS
Taking a closer look at processes often shows that they are far more complex than initially thought, despite the fact that they should be simple and efficient. The goal is to determine the ideal state, an analysis process which is more successful the more data the company has collected. Scenarios can be simulated to determine the steps where production needs adapting.
To do so, affected teams must describe the requirements and the ideal process and then compare both with the actual state. Simulating scenarios with the respective production software enables different solutions to be tested, which in turn allows the optimal process to be honed in on. Driverless transport systems are flexible in this context, particularly when it comes adapting to future requirements, meaning production lines will no longer require redesigning.
GEOPOSITIONING IN PRODUCTION FACILITIES
The use of automated guided vehicles is conceivable in any industry sector, regardless of the product. Transporting glass is a particular challenge.
Grenzebach GmbH & Co. KG has devised solutions for these specific applications, in particular for transporting glass racks and L-frames. However, this is just a single part of the digital system. The company has developed its own application server as a modular platform on which all digital production processes can be mapped. All devices and machines on the shop floor are connected to the server via adapters, allowing adjustments to be integrated quickly and the results to be analyzed.
The quantity and speed of production require the material flow to be reliable, a step during which automated guided vehicles are often deployed to cover a wide range of tasks. Grenzebach has installed a laser system in the entire driving area which is used to navigate the machines. The environment is mapped using a navigation scanner which detects how light reflects off reflectors installed on the walls at certain distances. As soon as two or more reflectors are detected, the vehicle is able to accurately determine its current position. Using a triangulation algorithm in the control software, the necessary steering commands are sent to the vehicle. The company also uses a second navigation system, known as a dead reckoning navigation system. This system is equipped with an odometer and an angle encoder and is installed on the vehicle’s drive wheels, resulting in even more accurate navigation, while a map of the environment is marked with the precise positions of the wall reflectors. An alternative method is to use contour navigation, which does not require an unrestricted view of reflectors, but is performed by the transport system itself using safety scanners.
STILL ROOM FOR IMPROVEMENT
According to Dipl.-Ing. Thomas Albrecht, an expert on automated guided vehicles at the Fraunhofer Institute for Material Flow and Logistics (IML), the topic has been trending across industries for three to four years. Compared to other automation solutions, these systems are the most flexible when it comes to linking production processes. Compared to manually operated forklifts, AGVs are gentler on the transported product and also do not cause accidents. However, as long as people remain in the driving area, the vehicles must be able to perform emergency stops, a process generally associated with abrupt braking.
The share of automated guided vehicles in the floor conveyors product group is currently still in the low single-digit percentage range, exact figures are not (yet) available.
VDMA – Forum Glastechnik