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Within a company or plant, there are several issues involved in selecting industrial robots which aren’t always compatible with choosing the best robot to perform the task. You must consider maintenance issues to move forward and ensure efficiency. Here’s your guide to the obstacles your business may face.
Different robotics manufacturers all produce their own control systems (some create more than one) and many produce their own drive systems. This means maintenance personnel require different specialist training to be able to deal with each different manufacturers’ robots.
Difficulties can arise when electric connections (power supply, safety circuits and signalling), programming language and operating software vary. The electrical connections are not generally too much of a problem as company standards will set out how these are to be done. However, differences in the robot programming languages and operating software can cause problems when maintenance staff are not all familiar with them.
To navigate some of the possible problems, a PLC is sometimes included in the cell to handle most of the signalling requirements rather than doing this within the robot controller. Provided the PLCs are standard throughout the factory, any member of your maintenance staff should then be able to deal with problems in the machine communications. Most companies also restrict the choice of robot vendor to give some standardisation in robot controllers.
Over the past 10 years, there have been several academic projects looking at producing a standard robot programming language. These have never been widely adopted as people buying robots have not specified them and manufacturers of robots have continued with developing their own languages to achieve a technological lead over their competition.
At some stage in the future when the development of robot programming languages slows down we believe that a standard will emerge. This may well be the Programming Language for Robots (PLR) which is currently under development by the International Organization for Standardization (ISO).
Another maintenance issue is the requirement to reprogram robots after maintenance of the arm or replacement by another identical arm. This is caused by the difficulty of setting up the datums or zero points on the robot axes which leads to every robot arm having a unique arm signature.
Tools and methods of setting the robot zero points have been developed, but as yet these are complex, expensive systems which cannot always be used with the robot installed on the shop floor. Some makes of robot are better than others in this respect and in general the more recent the robot design the less likely you are to suffer from these problems.
Increasingly, robot systems have plenty of potential applications in a wide variety of environments. However, safety must always be a primary consideration when planning their use. The core function of any robot safety system is to ensure that there is no chance of inadvertent contact between a robot and an operator or its environment.
It’s also important to remember that the type and degree of protection are not only dependent on the manipulator but also on the process and the end effector. Other ancillary systems such as fixtures or conveyors must also be taken into consideration.
The type and degree of protection required may differ depending on the intended application. It can include a combination of:
The legal aspects of safety are important and are governed by a few international standards that are usually embodied into national laws. The underlying International Standard for Robot Safety is ISO (International Organization for Standardization) 10218-1:2018, but there are also a few associated standards that should be considered such as those for collaborative robots.
As with all safety requirements, you must seek professional advice where there is any doubt or danger. This expertise is available from safety specialists or the Health and Safety Executive (HSE).