Robot safety basics: standards, risk assessment and collaborative operation

Robots are powerful machines. Making them safe is a legal requirement in most countries and a matter of good engineering. This guide is an introduction, not legal advice: for a real installation, follow the applicable standards and involve a qualified integrator.

The application, not just the robot

Safety is assessed for the whole application: the robot, its tool, the parts it handles, the workspace and the people around it. A collaborative robot holding a knife is not safe just because the robot is collaborative.

Standards

• ISO 10218 covers the safety of industrial robots (part 1 for the robot, part 2 for the system and integration).
• ISO/TS 15066 gives guidance for collaborative operation, including limits for contact between robot and person.
• Mobile robots in industry follow their own standards, and in the EU machines must meet the machinery legislation to carry the CE marking.

Risk assessment

Before a robot goes into production, the integrator identifies hazards (crushing, impact, cutting, falling loads, electrical and more), estimates the risk and reduces it with design changes, safeguards and procedures, documenting everything.

Common safety functions

• Emergency stop buttons.
• Protective stops triggered by fences, light curtains or scanners.
• Speed and separation monitoring: the robot slows down or stops as people approach.
• Power and force limiting: the robot limits the force it can apply and stops on contact, the basis of most cobot applications.
• Safety-rated monitored stop and limited zones or joint ranges.

Mobile robots in public spaces

Service robots in restaurants, hotels and shops rely on sensors to slow down and stop around people, and on low speeds and light weight. Check the manufacturer's safety documentation and local rules.

Compare cobots and industrial arms, and find integrators who can carry out a risk assessment.