Industrial Robot Manipulator Guarding Using Artificial Vision

摘要

Since a long time, the public opinion on robotics is that humans and robots work together, side by side, sharing and interacting in a common space However, until recently reality was quite different. Robots were introduced in the work place in the sixties as very effective, but simple-minded workers. For a long time, there was a lack of concern for safety and for human-robot interaction. Therefore industrial robots have been far too dangerous to share the workspace with humans. It is only since the nineties that academics and researchers from industry started to investigate the possibilities of implementing intelligent security systems in the robot's operating system in order to allow for this human-robot interaction in the future. In this chapter an artificial vision based security system for safeguarding an industrial robot is introduced. As in many electromechanical devices also robots suffer from malfunctioning of machinery e.g. electrical potential drops, falling parts, pressurized fluids, etc. But more important are risks specific to robots and that occur during execution of a robot movement, such as a collision or undesired manipulator acceleration. These events can happen because of human errors, control errors, unauthorized access to the workspace, mechanical failures or improper work cell installation. As mentioned in Main safety methods employed in industrial robots can be divided in two categories, that is, passive protection and active protection. Passive protection or passive safety refers to safety devices that improve the human safety without changing the robot's behaviour. Passive safety is static and simple to design; therefore it is very reliable but easily bypassed. Examples of these devices are visual devices such as warning lights, warning signs, boundary chains and painted boundaries, also physical devices such as fences, barriers and robot cages. On the other hand, active protection or active safety systems refer to safety devices that modify the robot's behaviour, or the environment, in order to avoid dangerous situations. In fact, they sense and react to changes in the cell's environment. The most 23 www.intechopen.com