Development of Automated Pipe Grinding Robot System

Abstract

The work to remove the defects generated on the steel pipe surface by grinding is required to be automated because of the large load on the worker. Although automatic machining by large equipment is carried out, there is a problem of low efficiency. The authors proposed a system to automatically remove only surface defects using a 3D camera and a grinder held by a robot arm.

This system is composed of a 3D camera capable of measuring the shape of the steel pipe surface, including defect areas to be maintained, a processor and controller that automatically generate grinding operations, a robot arm as an actuator, and a pressure control device that maintains a constant grinding pressure, which is the grinding device. In this system, the shape of the grinding object is extracted by combining three-dimensional shape measurement and point group processing with two-dimensional image processing, and the machining locus including the tool contact attitude and the motion of the robot are automatically generated based on the shape.

In addition, it became possible to obtain a smooth and high-quality grinding profile by controlling the grinding depth by a pressure control device and controlling the feed rate during machining. By introducing this system into the factory, work efficiency has increased by approximately 2.5 times. And, the production process was made safe, and the engagement of the workplace was improved, because the worker did not handle the dangerous grinder directly.