Installing a collaborative robot safely requires a detailed risk assessment. Consideration should be given to the risks that may occur during the cobots cycle, its movements and the human interaction
Collaborative Robot Safety
How we can help you
Working with our clients, we have CE marked collaborative robots in a range of different industries. Some projects have been as simple as force and pressure testing the cobot and issuing the reports to show compliance has been achieved. We can tailor our service to you based on your needs and knowledge.
Often we undertake all the safety requirements for the application from the risk assessments, through to conceptual safety design, force and pressure testing, safety calculations, compliance to the Essential Health and Safety Requirements, building of the technical file and production of the Declaration of Conformity certificate ready for signing. This way our clients know that when their collaborative robot is in use, it is safe and that they have met all their safety obligations.
Have a cobot project in mind and not sure which way to turn? Want to discuss your options?
What safety is involved around a collaborative robot?
Although there is lots of safety information available regarding collaborative robots, it is often overlooked due to the way cobots have been marketed.
Often sold as 'safe out of the box', this is true until the tooling or gripper is attached to the end. This then changes the whole safety of the cobot and the safety of the application then needs to be risk assessed.
Installing a cobot safely requires a detailed risk assessment. Consideration should be given to the risks that may occur during the cobots cycle, its movements and the human interaction.
As cobots are lightweight and portable they have a variety of uses within the same work environment. For each separate task and location, a risk assessment should be completed.
What is a cobot risk assessment?
When it comes to cobot risk assessments, the risk assessment process should follow the guidance found in the international safety standards;
EN ISO 12100 Safety of machinery - General principles for design - Risk assessment and risk reduction,
EN ISO 10218-2 Robot and robotic devices. Safety requirements for industrial robots. Robot systems and integration.
ISO/TS 15066 Robots and robotic devices. Collaborative robots.
The findings of the risk assessment will determine the corrective measures that can be applied. The risk assessment should be reviewed several times during the design and build of the cobot application.
There is a legal requirement for anyone who integrates a cobot (whether it be a system integrator or an end user) to conduct a risk assessment as part of the design, the build or the integration of a cobot into a machine. This includes both new and existing machinery.
The risk assessment is one of the key documents used to assist with the overall CE marking process of the Machinery Directive 2006/42/EC to ensure the cobot application is safe.
There is also a requirement for the end user to meet the requirements of PUWER to ensure that the cobot application is safe and compliant.
Why are risk assessments important?
Cobots are designed to work alongside humans, so we need to be aware of its movements, the end tooling and what the process involves.
As an employer you are required by law to protect your employees from harm.
CMS can conduct the risk assessment on your cobot application to:
Identify what could cause injury
Decide how likely it is that someone could be harmed
Offer solutions to control or reduce the identified risk
When should a risk assessment be carried out?
The earlier the better! There have been cobots implemented to work collaboratively but ended up in guarded cells in the same manor as a traditional industrial robot due to the lack of understanding of collaborative applications. These issues should have been highlighted in the design risk assessment stage.
Risk assessments are also required when:
Purchasing new equipment or machinery with a cobot as part of the process
Modifying existing machinery to allow for a cobot to be integrated.
The cobot is relocated to a new location.
The cobot is given a new task or operation.
How do you make a cobot safe?
Using a collaborative robot or a cobot, can come with some safety concerns. The type of tooling, the gripper or the work-piece that is handled can cause injury to those working alongside them.
The amount of force and pressure that can be exerted in a collision could result in injury. Different parts of the body can receive different forces and pressures and it is the scope of the risk assessment to define these points.
Testing the force & pressure of a cobot
During the commissioning stage, it is important to validate the forces and pressures that can be exerted by the cobot movements. Annex A of ISO/TS 15066 lists the permissible force and pressure values that can be exerted onto the body.
Where the values are above the permissible limits, measures must be put in place to reduce the values to the acceptable level. This is to ensure that in the unlikely event of a collision with the cobot, the operator is unharmed.
As the cobot application is completed, the risk assessment should be closed out, ensuring that all hazards have been adequately reduced.
As the cobot is subject to mechanical wear, testing should be repeated on a periodic basis to ensure that nothing has changed or deteriorated.
CE Marking of the cobot application
A cobot is supplied with a Declaration of Incorporation (DOI) from the manufacturer, as it is considered a partly completed piece of machinery.
This means the system integrator or end user is legally responsible for the overall CE marking process including building the technical file and issuing a Declaration of Conformity (DOC) for the cobot application.