Representing Surfaces in Reverse Engineering Using Analogue Signals

Reverse engineering is the process of reconstructing a computer model for physical objects based on 3D data points captured from the surface of the object. This work presents a low end and extremely cost effective technique for representing free-form surfaces of physical objects in a CAD model. An analogue signal was used to acquire the free-form surface data unlike conventional methods like laser scanners or Coordinate Measurement Machines (CMM). The examined surface was scanned using a Linear Variable Differential Transducer, (LVDT) as position sensor for measuring the data from the surface of the object. The analogue signal of the LVDT was acquired through a data acquisition system in a continuous fashion to PC. Solid-Works CAD/CAM software was used to obtain the free-form surface from the acquired 3D data using spline technique.