Condition monitoring of a grinding machine – Realization of a "sensing grinding spindle" by integrated sensors

Use Case Titelbild: Condition Monitoring einer Schleifmaschine


Wireless integration of radio sensors in a grinding spindle of a machine tool to measure vibrations and forces occurring during the grinding process.


Institute of Production Engineering and Machine Tools, Leibniz University Hannover

Project period

2021 / 2022


  • Extremely small installation space (30 x 5 x 5-8,5) mm
  • Battery charging without retooling the machine
  • Resistance of electronics to high temperatures (85°C)
  • Wireless data transmission from the inside of the machine / through the seal
  • Electromagnetic interference from the additional eroding process and the spindle drive


  • Integration of a wireless measuring system in four tiny recesses of a grinding spindle
  • Development of a board for data acquisition (DAQ) and data transmission with integrated MEMS 6-DoF-IMU for the measurement of accelerations, rotation rates and temperature (16 bits, up to 6,5 kHz sampling rate) as well as for the connection of 4 semiconductor strain gauge full bridges (24 bits, up to 1,5 kHz sampling rate)
  • Development of a power management board for connection of the rechargeable battery
  • At downtime of the machine: autonomous connection of a voltage source via a stylus for charging the Li-Ion battery with high charging power (2 minutes battery charging for 8 minutes runtime, max. 80 minutes)
  • Wireless data transmission via board-integrated antenna per 2.4 GHz radio link to a nemi Connect receiver module


  • Structure-integrated measurement of condition data of an autonomous machine tool
  • Mapping of sensitive properties by integrated sensors in the machine tool
  • Reliable wireless data transmission even through seal and housing of the machine tool
  • Energy supply concept suitable for series production
  • Autonomous, fast battery charging during short machine downtimes
  • High measurement data quality / low noise due to energy supply via rechargeable battery

Deployed nemione® products

  • nemi Connect
Charging Contact
Telemetry Board
Power Management Board
Graphic: mode of operation grinding spindle
Logo IFW - Institut für Fertigungstechnik und Werkzeugmaschinen

„Within a very short time, i4M technologies designed, developed and manufactured a fully functional, wireless telemetry system for the condition monitoring of a tool grinding machine. The telemetry system is very small, battery-powered and fully integrated into the grinding spindle. The system reliably

transmits from a machine tool. This solution enables structural integration of sensor technology on rotating machine components, so that process forces can be detected close to the point of action and additional cost-intensive measurement technology components can be dispensed with. I also articularly

liked the uncomplicated and goal-oriented cooperation with the team.“

M.Sc. Henning Buhl

Head of Department Machine Components

Institute of Production Engineering and Machine Tools,

Leibniz University Hannover

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We are looking forward to getting into conversation with you and to starting a partnership to find the optimal solution for your challenges.

Stephanie Paulus, Martin Noll & Lois Jacobs

i4M technologies GmbH

Foersterstr. 5
52072 Aachen

+49 241 56 00 22 00