Concept of an integrated machine sensor system
Nowadays, very high demands are placed on machines in the raw materials and energy industries with regard to plant reliability and plant availability. Unplanned downtimes or sudden plant failures usually cause very high costs for the operators, which must be avoided. Increasing loads to which these increasingly powerful and complex machines are exposed are the cause of this.
Monitoring by "Condition Monitoring" systems has proven to be a proven means of early detection of changes in the condition of plants and the associated increase in the probability of plant failure. With the aid of a wide variety of sensors and the associated evaluation technology, highly stressed machine components are monitored in order to detect changes in condition at an early stage and to be able to initiate appropriate maintenance measures in good time. Although the measuring systems required for condition monitoring cover a broad spectrum of applications within these branches of industry, they reach their limits in special areas. This primarily concerns the size, the type of data transmission, the sensitivity of the measuring equipment to harsh environmental requirements or the price of the commercially available and established systems.
Development of a novel sensor system
The i-MaSS research project, funded by the NRW-EU Objective 2 programme and the European Regional Development Fund (ERDF), addressed precisely this problem. An interdisciplinary consortium from the fields of raw material technology, mechanical engineering and electrical engineering has developed a cost-effective, miniaturised, adaptive and self-sufficient measuring system. The combination of the electronic core components for signal acquisition, processing and storage into a single, very compact SoC (System-on-Chip) was a focal point in order to be able to record measurement data even in hard-to-reach places of a machine. At the same time, this reduced energy consumption, which is optimized by means of intelligent energy management. The i-MaSS system enables long-term measurements or permanent or complete online monitoring, even at critical measuring points that could not be measured previously due to the structural dimensions. A bidirectional radio interface was used for data transmission, so that on the one hand the sensor system could be adapted to the measurements and on the other hand the measurement data, also from rotating machine components, could be transmitted to a host computer.
Testing on practice-oriented applications
Within the scope of the research project, the developed i-MaSS sensor system was tested, validated and verified on real machines and production processes. Four different applications from the raw materials and energy industries were selected to cover as broad a range of applications as possible.
The roller shearer loader and chain scraper conveyor represented the underground machines of the raw materials industry and placed high demands on the sensor system in terms of robustness, reliability and miniaturisation. The primary requirements for the applications in the energy sector, gearboxes and hoisting gear of a wind turbine, were modularity, self-sufficiency and energy efficiency.
Verification of simulation models
The opportunity to collect data at critical and previously inaccessible locations opened up new possibilities for verifying finite element or multi-body simulation models. In the areas of interesting hotspots, the simulation results could be directly compared with real measured data in order to determine the quality of the virtual models and assumed boundary conditions more adequately. Previously, this was often only feasible by approximating the data from nearby measuring points. The knowledge gained about more reliable simulation models can in future be more strongly integrated into the design of machines or used for condition monitoring. This reduces the number of complex practical test series to be carried out, which can reduce high development and maintenance costs.