Industrial Robots and Safety in the Workplace
Industrial robots are a very important part of most types of manufacturing today. As robots are becoming more common in the workplace, it is essential to have safety standards to protect workers from injuries and accidents.
These potentially dangerous pieces of equipment have many hazards which need to be safeguarded against. One hazard is pinch points. A pinch point occurs whenever one or more parts are moving and come in contact with another part. Pinch points on industrial robots can trap and harm workers.
In today’s world, there are three laws of robotics that illustrate the importance of keeping workers safe while working around industrial robots. These laws outline that robots should not hurt humans and that they should follow specific orders in order to maintain their functionality. Two things that help keep workers safe are Safety Mechanisms and Safety Precautions.
Safety mechanisms are designed to stop or slow down a piece of equipment.
Emergency stops, also known as an E-stops, are designed to allow a worker to shut down a piece of equipment, such as a robot. Similar to the emergency stop is the Dead Man switch. This is a switch that needs to be held down by a person while they are programming a robot using a teach pendant. While the switch is held down, the robot will move in a slow programming mode. If the switch is released during this programming mode, the robot’s motors will stop. This allows a worker to safely be within a robot’s workspace while programming the robot.
Other safety mechanisms function automatically and are designed to keep workers out of the workspace the equipment is working within. Light curtains will shut down a piece of equipment if an object blocks the light beams. For instance, if a worker left a tool besides a robotic arm and reached in to get it while the arm was running, the light curtain would shut down the arm, keeping the worker from accidentally being crushed. Collision detectors on the equipment also stop accidents. If a worker’s metal lunch box accidentally fell into the workspace of a robotic arm, the arm’s collision detection sensor would detect a foreign object, and stop the arm from moving before anything would be damaged.
Additional safety mechanisms are designed to stop equipment before a worker enters its workspace. Pressure mats can be placed all around a robotic arm. If a worker steps on the mat, sensors in the mat will detect the person and stop the arm from moving. Many pieces of industrial equipment have barriers such as a chain-linked fence around them. If the barrier has a gate, it might contain an interlocked barrier guard. This is an example of a sensor that would automatically turn off the equipment if the gate to the barrier is opened.
Safety precautions are measures that are put in place to protect workers and prevent accidents and injuries.
One type of safety precaution that is required in all manufacturing workplaces is called Personal Protective Equipment (PPE). This equipment comes in many different types and levels of protection. These types of protective equipment are designed to protect things such as a person’s head, eyes, face, hearing, body, hands, and feet. They also can protect people from falling, or from breathing in dangerous material. Their level of protection can be as complete as a HAZMAT (hazardous material) suit, which covers the entire body and has its own air supply, to as simple as a set of foam earplugs. Some common examples of PPE are hard hats, safety glasses, earplugs, dust masks, gloves, and protective-toed shoes.
Safety alerts are another type of safety precaution that is found in all manufacturing workplaces. These alerts are usually visual or auditory warnings that alert workers and visitors. Safety signs are a common type of alert that can provide warnings, precautions, or instructions. Another type of visual alert is beacon lights that could light up in an emergency, or be used to indicate that a piece of machinery is about to start up. Examples of auditory alerts include alarms, sirens, buzzers, or even pre-recorded spoken messages. For instance, someone could open a door and a speaker might announce, “you are entering a restricted area.”
There are also structures that are designed to protect and warn people about areas that should not be entered. These are called barriers and can be as advanced as a “clean room,” where the air is filtered so not even a piece of dust can enter, or as simple as a chain hitched to posts keeping people away from a piece of equipment.
There are times when workers need to be in the same space as a piece of equipment while it operates. This might be to change or adjust a tool, perform maintenance, or to make a repair. When this occurs, the power for the equipment needs to be turned off for the safety of the worker. There are two types of safety precautions that prevent the power from being accidentally turned on while a worker is in the equipment’s operating space. Tagout is when a tag can be placed on the power switch indicating work is being done and do not turn the equipment on. A more secure system uses a keylock to physically lock the power switch off. This is known as lockout and requires a key or a code to turn the equipment back on.
Safety Mechanisms and Safety Precautions will help keep industrial robots from injuring a human being or, through inaction, allow a human being to come to harm.
Industrial Robots Safety Standards
Safety Standards Regulatory Organizations
- Robotic Industry Association (RIA) - The association that sets safety standards for industrial robots.
- American National Standards Institute (ANSI) - An institute that maintains standards for workplace safety in the United States.
- International Organization for Standardization (ISO) - An organization that maintains the international standards for workplace safety.
- Occupational Safety and Health Administration (OSHA) - The federal administration that sets and enforces workplace safety regulations.
Industrial safety standards are set by certain organizations. The Robotics Industry Association (RIA) sets many of the standards for industrial robots. These standards include things like risk assessments (which can identify safety issues of robots), safeguards which can be put in place to reduce the chance of injuries and accidents, and special safety considerations for collaborative robots, also known as Cobots.
In the United States, some workplace safety standards are kept by the American National Standards Institute (ANSI) and they are regulated and enforced by the Occupational Safety and Health Administration (OSHA).
Workplace safety standards are an international concern. To keep safety standards consistent and repeated from country to country, many workplace safety standards are kept by the International Organization of Standardization (ISO).