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Potentials of human-technology interaction

19 Apr 2021

Task-oriented Human Machine Interfaces (HMI) design in the process - The HMI as mediator between man and machine

Carola K. Herbst, Project Manager Specialist Centre Food of the DLG (German Agricultural Society), conducted the interview with Paul Weber, Head of the Assistance Systems Team at the Fraunhofer Institute.

Paul Weber, Director of the Assistance Systems Team of the Fraunhofer Institute Source: Fraunhofer Institute

Paul Weber, Director of the Assistance Systems Team of the Fraunhofer Institute Source: Fraunhofer Institute

The assistance systems team at the Fraunhofer Institute for Process Engineering and Packaging (IVV), researches and develops cognitive assistance systems for the operating staff of processing and packing machines for food production. These systems combine human knowledge with artificial intelligence and make a significant contribution to the increased process efficiency of the production. Task and target group-oriented design plays a key role in developing such systems. In the same way, psychological principles and methods applied and tested for the purpose have to be transferred over to the general design and structure of the information content of classic operating panels of machines. Paul Weber, Director of the Assistance Systems Team of the Fraunhofer Institute, reveals below some exciting insights into the task-oriented design of so-called HMIs (Human Machine Interfaces) and outlines their advantages.

Which role do humans play in highly-automated production processes?

Processing machines and plants used for production display an ever increasing degree of automation, which means the machine operators are becoming more and more passive observers instead of active participants. The humans only have to actively participate in problem situations and in the scope of the machine processing and packing of foodstuffs this occurs very frequently. The empirical values of the research team of the Fraunhofer IVV in Dresden are based on operating data analyses carried out and show an average unplanned downtime of almost 30% of the machine operating times, which are due to faults occurring. The operating staff require in-depth knowledge about machine processes and their correlations to resolve such faults efficiently. Correlations with the frequently volatile characteristics of the packaged goods and packing materials being processed as well as the environmental conditions also have to be taken into consideration. If the operators don't have much practical knowledge or if it is only limited down to individual persons, it makes diagnosing the faults more difficult. As a result, faults are not resolved efficiently or sustainably. In addition to losing valuable time for the production of finished goods that satisfy the required quality demands, resources such as rejected packing materials and packaged goods are wasted.

How can one support the operating staff in dealing with this task?

Basically, all operating staff should dispose of all of the necessary information and knowledge so that they know what to do should critical situations occur or so that they can already foresee such situations in advance and intervene accordingly. There are different possibilities of ensuring the provision of such knowledge. The implementation and establishment of assistance systems and suitable qualification measures are possible options, which we investigate and develop in research projects in the processing technology part of the institute. These do however involve a higher effort compared to a third, possible idea for supporting the operators, which we describe as "low hanging fruit" due to the lower implementation of effort required. In concrete terms, this involves the task-oriented design of operating panels on machines, so-called HMIs. The design and structure of these is at present normally not aligned with the needs of the operating staff and their work tasks. Hence, they normally only offer an insufficient offer of information for supporting an efficient fault diagnosis for instance. If one selectively places the focus on the tasks and demands of the operating staff when designing such an operating panel, one can succeed in increasing the satisfaction of the co-workers and the overall efficiency of the plant with relatively low effort.

HMI design rethought. Source: Fraunhofer Institute

HMI design rethought. Source: Fraunhofer Institute

How can one actually envisage a task-oriented HMI design and which principles and methods have to be applied to design such an operating interface?

Efficient machine operation as a result of the satisfying completion of work tasks can be promoted by linking up relevant process data, knowledge and appropriate visualisation possibilities in a user and task-oriented HMI concept. Necessary information for the assessment of the status of the machine and the fault diagnosis and elimination can thus be provided along the production chain in the scope of a logical, consistent HMI concept with the appropriate degree of detail. It is recommendable here to especially take the psychological principles of the human/machine interaction into account. Representation Aiding and the principles of Ecological Interface Design can be mentioned as examples here. Representation Aiding provides support in taking decisions in critical situations by finding and integrating relevant information through the graphic processing of the information which is aligned on human perception. Ecological Interface Design aims to depict the relations within a system in order to display the available options for action and their corresponding consequences to the operator. To-date these and further psychological concepts have rarely been taken into account when creating current HMIs, because this knowledge is not known and is hardly mentioned in the general guidelines of HMI design. At the Fraunhofer IVV we have thus expanded our know-how in the areas digitalisation and machine construction and are letting the cognitions of our engineer/psychologist team flow into our developments.

How can I now put this into practice? How do I gain the necessary knowledge?

Existing cognitions on task-oriented HMI design originally stem from fields such as aerospace or medicine. No simply applicable orientation tools have arisen so far for the machine manufacturers of the food processing and packaging industry such as the sweets and snacks industry, which support the developers of task-oriented HMI design. We have thus set ourselves the task of supporting them with our competence from the area of engineering psychology. Among others, we analyse the existing HMIs of interested customers and underline the resulting, specific optimisation potential by developing newly adapted design concepts. Here, of course, we always place the focus on the people in the production department and their demands. Furthermore, we convey our expertise in the scope of workshops for developers. In addition to the psychological basics that are explained in an exemplary way, the participants work together on case studies in individual workshop groups so that what has been learnt can be directly put into practice. This support aims to help the participants be able to design task-oriented HMI concepts themselves in future.