Accuracy Analysis of Point Laser Triangulation Probes Using Simulation

Abstract

Point Laser Triangulation (PLT) probes are relatively new noncontact probes being integrated with Coordinate Measuring Machines (CMMs). Two prominent advantages of PLT probes are fast measuring speeds (typically 100 to 1000 times faster than touch probes) and no contact force is required to take measurements making soft or fragile objects measurable. These advantages have motivated the integration of PLT probes onto CMM. However, because the PLT probe is an electro-optics device, many factors related to optics affect its operation, such as sensor-to-surface orientation and surface reflectivity. To study and better understand these error sources, PLT probe models are needed to simulate observed measurement errors. This article presents a new PLT probe model, which simulates observed measurement errors and shows the effects of placement and orientation of internal components. This PLT probe model is a combination of internal component models developed using geometrical optics. The model successfully simulates measurement errors from specular reflection observed experimentally with real PLT probes. The model also allows the parameters of internal components to be studied.