Whittall has created a list of the steps that should be taken to avoid robot-related accidents in applications when humans and robots need to share the same workspace.
Scope out all the potential hazards: Safety risks will vary depending on the particular robot and application. Always start with a well-documented risk assessment. Most robot-related accidents occur during non-routine operating conditions, for example when operators enter the cell for programming, maintenance, testing, setup, or adjustment tasks.
Revisit the regulations: The Health and Safety Executive (HSE) offers industrial robot safety guidance in the HSG43, Industrial Robot Safety publication. International standards are set out in EN ISO 10218 - Part 1 Robots and robotic devices - Safety requirements for industrial robots, while EN ISO 10218 - Part 2 goes into more detail about robot systems and integration.
Use simulation software to plan out and test robotic concepts: As well as flagging up potential new-build issues, simulation software should be able to model all of the variable robotic movements, obstacles and potential collision scenarios, in a 3D virtual world.
Introduce safeguards: Seek expert guidance early in the design phase when building a safety related control system (SRCS). There are many different concepts to consider, including whether the SRCS should be a dedicated system or integrated within the robot controller or robot safety software.
Provide employees with the right information: Reduce the risk of incidents by ensuring that employees receive regular operator training and
are issued with appropriate personal protective equipment (PPE).
Consider the cost benefit and effectiveness of software-enabled technology: Commonplace in the automotive sector, having less hardware means that safety can be integrated more cost-effectively. Cost reductions of up to 50% are possible for a small single robot applications with multiple safety devices. FANUC’s latest DCS (Dual Check Safety) software is able to monitor position and speed of the robot. The removal of limit and zone switches also makes work cell configurations tighter and simpler.
Create adaptive zones: It is now possible to programme, enable and disable the zone that the robot can or cannot enter, depending on the task in hand. This feature, available through DCS Position Check, is particularly useful for compact cell configurations.
Define maximum robot speed: This can be done during normal operation or adjusted to a defined event, enabling an operator to work safely within the proximity of the robot. FANUC’s DCS Speed Check monitors the speed of the robot, ensuring the whole robot, including the end-effector, remains motionless when required.
Compliance with machine safety standards: Check whether the system meets the PL (performance level) safety standards specified in BS EN ISO 13849-1. As a benchmark, FANUC’s DCS Position and Speed Check functions are certified to PL d and Safe IO Connect to PL e.
Stay on top of safety requirements:
In today’s fast-paced manufacturing environments, robotic work cells and plant layouts evolve quickly. This results in a need to constantly revisit and modify safety considerations. With software being more flexible and simpler to upgrade and integrate, this is when a software-based robot comes into its own.