Collaborative robots are developed to free human hands from tedious and potentially dangerous jobs. With the removal of safety fencing and other safety monitoring devices, collaborative robots (cobots) are revolutionizing and re-shaping the manufacturing world.
Cobots are undoubtedly gaining popularity and it is therefore important to evaluate safety requirements. Safety is a top priority for industries across the globe to ensure human-robot collaboration is done correctly.
ISO/TS 15006, released in January 2016 focuses uniquely on cobot applications and presents various speed, force and pressure guidelines permitted during direct human-cobot collaboration.
However ISO/TS 15006 is a technical specification that does not directly affect the use or the purpose of the cobot and its application.
To date, cobot manufacturers are using third parties to accredit their robots. Therefore under certain given conditions cobots can be certified as being a safe tool to use. Obtaining the cobot certification does not automatically mean that the cobot application is automatically safe.
For this reason it is highly desirable to build a risk assessment document for any new cobot and cobot application.
Risk assessment for collaborative robots is an iterative process with a lot of room for interpretation, therefore it is important to reduce the risk of potential harm in a human-cobot collaboration.
YES! A cobot risk assessment ought to be thought out as a sequence of events that will happen in the collaborative robot cell/ setup. Each sequence shall have its own risk calculation. The calculated risks will be ranked and logged in a risk assessment report. Based on the risk index and the technique used, appropriate risk prevention measures shall be taken to avoid any injuries.
It is important to note that cobots are easily re-programmable. Hence there is a great possibility for processes to evolve in time. Therefore new iteration of the risk assessment sequence will have to evaluated and recorded.
- Front page and document identification
The front page should contain the title of the application. The document identification should contain the project title, project number, revision, author, reviewer and pertinent dates. A good practice is to list all the document modifications in the revision section. That will enable your colleagues to keep track of any changes made to the cobot application.
The main focus why the cobot is being implemented into a specific operation represents the scope of the project. The scope is usually short (3-5 lines) and concise.
- Project information
In the project information section a complete description regarding the who, what, why and how should be provided. This section should contain all the machine types, serial numbers, certifications and so on.
- Applicable standards
Depending on the type of application, various standards will be used in order to obtain a complete certification of the application. Remember that even the risk assessment standard used must be listed.
- Risk reduction methodology
Risk reduction is procedural with lots of different techniques used to achieve a lower risk in the desired application. In this section a short summary explaining what procedure will be used. Such a summary will make things clear for the reader and demonstrate your methodology used.
- Cobot specification
In the cobot specification section, all the technical data about the cobot should be recorded. The robot data will help confirm a potential hazard or where to look for risk reduction.
- Cobot application specification
Like the Cobot specification section, all required information about the cobot application cell, the potential hazards and how to solve them should be recorded. Using visual representations will aid the reader in better understanding the application.
- Risk Estimation and Evaluation
A numerical value to each risk must be determined in order to evaluate and rank each risk associated with a cobot application. There are multiple techniques out there. Therefore establish the factors, parameters and formula to be used.
Once all the risks are listed, apply the formula and evaluate the hazard rating individually.
- Risk Results and ranking
The result and ranking section is by far the most important section of the report. All findings should be listed for the cobot application. Afterwards a priority listing or ranking must be created from the most dangerous to the least dangerous hazard. The purpose of the risk rank is to determine what risks must be eliminated first.
- Report conclusion
Finally, the conclusion will summarize all the findings and the steps taken to mitigate the risks to allow humans to safely work alongside cobots and avoid injuries.