کنترل حرکت و جمع آوری اطلاعات برای اسکن لیزر با ربات های صنعتی

Reverse engineering is concerned with the problem of creating computer aided design (CAD) models of real objects by interpreting point data measured from their surfaces. For complex objects, it is important that the measuring device is free to move along arbitrary paths and make its measurements from suitable directions. This paper shows how a standard industrial robot with a laser profile scanner can be used to achieve that freedom. The system is planned to be part of a future automatic system for the Reverse Engineering of unknown objects.

In the development of new products, computer aided design (CAD) systems are often used to model the geometry of the objects to be manufactured. The reverse engineering (RE) of geometry is the reverse process where the objects already exist and the CAD models are created by interpreting geometric data measured directly from the surfaces of the objects. One application of RE is to create a three-dimensional (3D) CAD model of some object A and use that model to manufacture new objects that are partly or completely copies of A. An introduction to RE that is often referred to is a paper by Varady et al. [1]. In this paper the RE process is divided into the following four steps: (1) Data capture. (2) Preprocessing. (3) Segmentation and surface fitting. (4) CAD model creation.

This paper presents flexible and controllable laser profile scanning equipment where an industrial robot is used as the translation device. It also describes how the captured data is prepared and stored in a way suitable for further processing. Future work will be focused on developing an automatic algorithm for path planning. The use of an industrial robot and the standard S4C robot controller as part of the measuring system has been shown to be possible by means of the method proposed using time stamps. The robot controller is designed to interpolate between positions at constant speed, and this property has been shown to be important for good scan results. The handling of geometry and topology is a core issue for the software in use, as well as for real-time communication with the robot and the laser system. The Varkon system has been shown to be an effective platform in this respect. A detailed analysis of the sources of errors and verification of the accuracy achieved remains to be done. A better system for tracking the position of the robot arm could enhance accuracy. The experimental setup is best suited for objects in the size range up to approximately 1×0.5×0.5 m. Finally, we would like to point out that the solution proposed is relatively low cost, scalable and flexible. It is also suitable for applications other than RE. Inspection is one example.