Industrial robots are very often part of so-called robotic systems, which, alongside the robot itself, may also include: additional work elements, devices and sensors enabling or facilitating work, and an interface that influences the robot’s operation and monitors the correct execution of tasks. Therefore, in addition to a number of guidelines regarding the safe design and construction of the robot itself (Safety in the industrial robot environment – part 2, Logistyka 3/2003), one must also remember about the other elements of the robotic system.
A very important aspect when designing a robotic system is the safe arrangement of its individual elements. Therefore, all possible collisions between the moving parts of the robot and other fixed or moving objects located in its protected space must be prevented. This applies to both the structural elements of the room in which the device operates, such as support columns, ceiling or floor beams, walls, fences, etc., as well as all cables supplying electricity and other media. This rule does not apply to devices cooperating with the robotic system within its protected space and necessary for the implementation of the production process being performed. Such devices can be not only setting tables, numerical machine tools, conveyors, etc., but also control cabinets. Such cabinets are usually placed outside the protected space, but in specific situations (e.g., related to lack of space), their location inside is permitted. In such cases, the positioning and mounting of the cabinets and the proper functioning of the protective device should ensure maximum safety during their operation. A similar procedure is adopted when part of the activities related to operating the robot must be performed manually. Such activities can be, for example, loading and unloading operations. In such a case, one must first limit the operator’s access, along with the loading device, to the restricted and maximum space of the working robot as much as possible, and secondly, equip the space where manual operations take place with appropriate safety devices, e.g., mechanical limiters, already mentioned in the second part of the article.
All working elements of the robotic system should be designed and manufactured in such a way that they do not cause a hazard in the event of a power failure. Therefore, the interruption of the energy supply must not cause the load to be released, and the static and dynamic forces caused by the load and the working elements must be within the range of the robot’s lifting capacity and strength properties. As in the case of the robot itself, the robotic system should also be equipped with an emergency stop device, i.e., a device enabling the immediate cessation of work and the cutting off of power sources in the event of a dangerous situation. Restarting the robotic system should require the emergency stop system to be re-engaged.
The article comes from the magazine “Logistyka” 4/2003.