The human-machine interface represents the analog or digital interaction interface between a person, i.e. a user, and a machine. It is a part of human-machine communication (also human-machine interaction). In its simplest form, this interface can be a simple on-off switch; in a more sophisticated form, it can be the software interface of an enterprise-wide IT system. With growing digitization in all areas of life, especially in industry, the interface to technology and its ease of use is becoming increasingly important.

The processes in industrial software systems have become very complex. Industry 4.0, the digital networking of the entire supply chain and the use of cyber-physical systems in production are leading to the technologization of once manual fields of work. For employees in the operational business, this also means that they have to find their way around in digital working environments. Logically, it would be far too burdensome for the operator to have to learn the program code and programming language of the underlying system in order to easily control a machine. That is why there are visual and audio-based dialog systems that form an interface between humans and machines.

Graphical User Interfaces (GUI)

In industry, a widespread form of user interaction with an IT system is communication via graphically visualized software interfaces, so-called Graphical User Interfaces (GUI). Since humans cannot interact directly in the language of the IT system, all information is translated (encoded or decoded) for the respective other side into their understandable language. Extensive computing operations and database queries take place in the background, invisible to the user. The results of these computational processes are finally visible as visual information for the user in the dialog. The employee can respond or interact with the system. These user dialogs can be made available to the user via different end devices such as PCs, stationary terminals, smartphones, tablets, mobile industrial terminals or data glasses. To ensure a smooth process, it is important that all operations and data required for a system process are recorded in full. This is partly automated, partly the user has to provide data manually.

Human-machine interfaces in intralogistics

In intralogistics, there are interfaces between humans and machines at various points. Essential communication points are the logistics control center and order picking.

Interface: warehouse control center

In simple terms, the control center is the operations center of a distribution center – this is where all the information about throughput, personnel deployment, key figures, system statuses and any problems that occur comes together. Monitoring takes place via PC, tablet or smartphone, and the information is presented graphically to the responsible employee, giving him a quick overview. If there is a need, he can interact with the warehouse management system and fine-tune the process. A large amount of data is processed by the machine in the background, and human actions at the control center are minimal at best.

Interface: Order picking

The picking business process is probably the area in the warehouse that has the most pronounced human-machine communication in both directions. This is because, on the one hand, the picker receives information about the pick orders from the warehouse management system, and on the other hand, he continuously reports back to the system the status of his tour, missing quantities and the confirmation of completed picks. In addition, picking is usually the area in the warehouse with the highest volume of personnel. So it is not surprising that efficiency and accuracy are constantly put to the test here and new technologies and processes are continuously being used.

Visually via displays (pick-by-MDT)

The most common picking method in distribution centers is user-guided picking via a mobile device. This is usually an industry-standard mobile data entry (MDT) device that has both a display (data output) and a scanner and various keys (data input). The picker is guided via instructions on the display and confirms order completion via scan or manual entry on the device. The MDE is directly connected to the IT system via WLAN. In addition to MDTs, smartphones and tablets are increasingly being used in the industry.

Visually via light signals (pick-by-light)

In pick-by-light picking, the employee receives picking instructions via signal lamps and numerical displays attached to the corresponding shelf. It acknowledges the removal manually via a button or automatically via sensors.

Visuell über Head-Mounted Displays (Pick-by-Vision)

Pick-by-vision is a picking method that is still in the early stages of development. The information on the pick order is projected directly into the picker’s field of vision via data glasses. Depending on the features of these augmented reality solutions, navigation support can also be provided. The employee interacts with the system either via buttons on the glasses or an additional device, via speech, or via gestures captured by a camera integrated into the glasses.

Auditory via voice instructions (pick-by-voice)

In pick-by-voice picking, the picker is controlled by voice instructions. He wears either headphones or a special vest with integrated loudspeakers, via which he is told the position and removal quantity of the pick parts. He or she confirms the removal either via a voice command as well or via buttons of an associated hardware.

For more information on handling data in intralogistics, see the article Smart Data.

Teaser image: geralt

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