A torsional vibration measurement system

At the development stage of building an automobile, many power-train configurations are considered, and problems may arise when the different components are assembled. Torsional vibration, which can cause unforeseen problems, is difficult to measure when a shaft is rotating. A torsional measurement system designed so that measurements of translational and torsional motion can be taken at points along a rotating shaft is described. Extensive probe tests revealed accuracy errors of less than 1% in the rotational speed measurement, and shaft speed capabilities of at least 3400 r.p.m. The hardware selected restricts the data transfer to 1 byte per 13 μs. For a three-channel station with 64 stripes per revolution, the maximum theoretical rotation speed at which reliable measurements can be taken is 8000 r.p.m. Results of preliminary tests showed good agreement between a commercially available torsional vibration measurement system and the prototype system