Current projects


Development of a sensory spindle of machine tools based on the measurement of rolling bearing impedance

Initial situation

Production companies are increasingly facing high price and time pressure. In the effort to improve machine availability, the reduction of service times (such as component replacement or repair) is an evident approach. However, SMEs in particular are reluctant to expand their manufacturing facilities into cyber-physical production systems (CPPS) and open up to data-based business areas. This is due to a variety of reasons such as a possible dependency on the cloud provider, cost forecasts that are difficult to plan, or concerns about data security.

This project will therefore address the question of how SMEs can build business models on their own digital and sensory technology developments, enabling participation along a data value chain. The data value chain extends from data acquisition by the physical sensor to the utilization of the acquired information within the framework of a business model.

To answer this question, a prototype of an end-to-end data value chain is being developed. To accomplish this, the project team combines a wide range of competencies from various project partners. It is composed of the SMEs optiMEAS (hardware and software) and Christ (motor spindles), the institutes PTW (business models and machine tools) and pmd (sensor integration and impedance measurement) of the TU Darmstadt as well as the associated partner DATRON (machine tools).

Figure 1: Concept of the end-to-end data value chain with the project partners
Figure 1: Concept of the end-to-end data value chain with the project partners

Project goals

The overall objective of this project is to develop a prototype of an end-to-end data value chain from sensor data acquisition to financial utilization. The prototype consists of a physical sensor spindle, an analysis algorithm and a suitable business model.

The sensor spindle to be developed is the motor spindle of a machine tool. This is to be extended by a sensor-integrated bearing, which collects operating data directly at the bearing. For the intended sensor concept, the impedance oft he bearing is measured. The analysis algorithm is used to analyze and process the collected sensor data so that usable information can be extracted. A suitable business model needs to be developed for this information, which enables the usage in such a way that the stakeholders derive a financial benefit. An example of this would be pay-per-stress payment models.


The development of the prototype is based on an identification of the requirements of all stakeholders and project participants. For the development of the sensor spindle, the tool spindle itself is revised on the one hand and the sensor concept is designed on the other. These are to be coordinated with each other. After manufacturing, the next step is to develop measuring electronics for the sensor spindle, which will later process and prepare the acquired data. The combination of sensor spindle and measurement electronics is subjected to simulated application scenarios in test stations. The acquired sensor data will be analyzed and transferred into analysis algorithms, which will later be validated on a real machine tool. Parallel to the development of the sensor spindle, a suitable business model will be designed. Aspects from the technical development are taken into account to ensure a holistic view.


This project is funded by the Hessian State Chancellery – Minister for Digital Strategy and Development.