Technical Paper
A New Method for Measurement of Rotating Objects Utilizing Laser Doppler Vibrometry Combined with an Optical Derotator with Focus on Automotive Applications
2011-01-19
2011-26-0043
For more than 20 years Laser Doppler Vibrometry (LDV) is an established tool in vibration engineering for non-contact vibration measurements. The LDV method is not only limited to measurements on single test points. Utilizing a pair of galvanoelectrical mirrors for steering the laser beam in x and y directions across the surface the vibration pattern of full areas can be mapped. Such scanning LDVs (SLDV) have found many applications in the automotive industry as well as in institutional research. However the use of the SLDV technology is limited to stationary objects and rotating objects with smooth uninterrupted structures such as brake discs or tires. Up until now measurements on objects with complex noncontinuous structures such as bladed discs, fans, propellers have not been possible yet. Furthermore, interpretation of travelling non-stationary modes which can be found on rotating tires, saw blades, etc. has been difficult with conventional SLDV technology.
