The human factor in virtual commissioning
We define virtual commissioning as a quality gate for the system and commissioning. It is the first time that the PLC and robot programs actually work together. EPLAN, PPlan, function plans and other documents are checked during modelling, and the system itself is put through its paces during virtual commissioning… Only one crucial part is not put through its paces: the human factor.
We have recognized this and decided to include people in the virtual commissioning process. The time behavior is particularly important to us in order to be able to analyze and assess the influence on the ongoing process and the workload of the people themselves.
To do this, we brought the experts in human simulation on board. The ema software suite from imk Industrial Intelligence GmbH is just right for the job. In close cooperation we developed the integration of the ema human simulation into our 3D simulation RF::YAMS. The result is RF::emaHM.
Project planning
Unlike projects without emaHM, where logic is created for the creation of products, interruption of scanners/light barriers and confirmation by the operator, this process is now planned in emaHM. Different sequences are created, which are then triggered by a start command. The virtual operator starts to pick up one or two parts, inserts them, closes the manual clamp and confirms the safety gate.
It is now possible to analyze whether the worker manages to load one or more stations in the specified time, so that there are no waiting times in the system. It is also easy to see how busy a worker is during his activity. Is there enough of a buffer to be able to carry out unforeseen work, or would the worker have to rush from one station to another for eight hours, which is not sustainable in the long term? What happens if the operator cannot keep up with one or more cycles or has to repair a fault? All these questions can only be answered with certainty if the operator is also adequately simulated.
Case study
As part of a project involving several manual stations, we tested the newly developed function directly in practice for the first time. As the integration of the human simulation into the existing virtual commissioning workflow was not yet complete, not all the necessary information was available. To be able to fully and correctly evaluate the results of the simulation, we needed detailed information on the paths and positioning of the products outside the cell, in addition to the data available as standard. Working closely with our customer, we were able to easily obtain this additional information.
In the specific application, the system under investigation had two separate insertion stations, located on two sides of the cell. Three products had to be inserted at one station and four products at the other. The evaluation of the test run showed that although the operator was able to supply both stations in time, it also showed that the originally estimated time had been calculated too tightly. This tight schedule therefore posed a risk to the reliability and safety of the entire production process. Adjustments were made to the process design to ensure safe and trouble-free production in the long term.
emaHM
The integrated human simulation is a further step towards holistic simulation. The digital twin powered by RF::SUITE has been extended by another important piece of the puzzle.
