Realization of a “sensing grinding spindle” by integrated sensors – smaller than a 1 € coin

“I am leading a project for the development and prototypical implementation of an “intelligent machine tool”, which optimizes process stability and output during operation. Therefore we need a robust strain-gauge telemetry with additional MEMS sensors and fast rechargeable battery integrated in our grinding machine.”

When we received this request, we thought: “Great, that’s exactly our core competency!” Then we saw the available installation space:
In total smaller than a 1 € coin! – Fortunately, we love challenges and realized an integrated process and condition monitoring system.

We developed a telemetry 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 on-air sampling rate) as well as for the connection of 4 semiconductor strain gauge full bridges (24 bits, up to 1.5 kHz on-air sampling rate). In addition to that, we developed a power management board for connection of a rechargeable Li-Ion battery. Telemetry board, power management board, Li-Ion battery and board with charging contacts are integrated in four tiny recesses of the grinding spindle (each smaller than 30 x 5 x 8.5 mm³). When the machine is at standstill, a voltage source for charging the Li-Ion battery with high charging power (2 minutes battery charging for more than 8 minutes runtime, max. 80 minutes) is connected autonomously via a pin. Live measured data is transmitted wirelessly with a board-integrated antenna via 2.4 GHz radio link to a nemi Connect receiver module.

Benefits for our customer:
– Structure-integrated measurement of process and condition data
– Monitoring sensitive properties by integrated sensors
– Reliable wireless data transmission even through seal and housing
– Power supply concept suitable for series production
– Autonomous, fast battery charging during short machine standstill times without retooling the machine
– High measurement data quality / low noise due to energy supply via rechargeable battery

Many thanks for the successful and uncomplicated cooperation to the IFW Hannover and especially to Henning Buhl. Find this use case online.

Do you need substantial data from your structures, machines or assets? We will also find a solution for your application!