A new multi-probe arrangement for surface profile measurement of cylinders

This paper presents a new scanning multi-probe arrangement for precision measurement of surface profiles of cylinders. Analysis of the influence of error motions associated with the scanning on the probe output showed that the minimum number of the displacement probes is five for separating the surface profile of the cylinder from error motions of scanning. The surface of the cylinder was sampled by the five probes in a scanning system where the rotation of the cylinder spindle and the movement of the probe carriage were synchronized. The five probes were arranged in such a way that the sampling points of the all the probes were located on the same spiral line over the surface of the cylinder. This probe-arrangement and sampling strategy makes the scanning over the entire cylinder surface effective. It also makes it possible to make use of the inverse filtering method for data processing of the probe outputs, which has been well-developed in straightness measurement of using multiprobes. A prototype instrument based on the proposed multi-probe method was constructed for measurement experiments. Comparison between the results of the prototype instrument and a commercially available roundness measuring machine has indicated the feasibility of the proposed method for roundness measurement.