Everything is Vibration

ARTIS offers sensors in the measurement range between 10 Hz and 5 kHz for acceleration measurement on one to three axes.

Measurement of vibrations and accelerations plays an important role in process monitoring on machine tools. Vibration measurements are used in different ways for the safeguarding and stabilization of processes: as signals from the machine control or from external sensors. Vibration measurement is made as close to the process as possible. Sensors are integrated directly into the spindle or placed on the workpiece holder.

Measuring acceleration

Acceleration can be measured with a sensor integrated into the spindle or with external sensors placed in the machine. A transducer then converts the values for the process monitoring system into information about the vibration speed. ARTIS offers sensors in the measurement range between 10 Hz and 5 kHz for acceleration measurement on one to three axes.

Acoustic emission, a special form of vibration, is measured with external sensors and transmitted over a separate fieldbus. The sensors for acoustic emission cover the measurement range of 10 to 250 kHz.

Collision monitoring

Acceleration sensors can be used for collision monitoring. When tool and workpiece collide, which the sensor detects from the sudden change in material vibration, the machine shuts off immediately. Here, the measurement means a gain of approx. 200 milliseconds until the machine’s overload protection would take hold. It is exactly during this time after a collision that serious damage results, because the machine at first “reacts” to resistance with increased power.

Optimization in the ongoing process

Vibration measurement is also used for process optimization, such as in gear cutting with profile milling cutters. Tool wear here depends on the vibration speed of the tool. Experiments show that an increase in cutting speed of only 10 percent results in a significant decrease in the vibration speed. So here, optimization can be achieved by simple means. Additionally, with Adaptive Control, the vibration behavior at the milling head can be optimized in the ongoing process.