Are Robots Really Safe?
By: Malhar Surangalikar
Tags: Robotics, Safety, Automation, Robotics Automation, Accident

Robots are becoming increasingly popular in workplaces around the globe, especially Cobots, the machines designed to work next to humans. But when considering implementing any technology, it’s essential to keep safety at the forefront. What possibilities exist for robots malfunctioning and hurting people or otherwise compromising worker well-being?

But are they really safe?

Industries worldwide are evolving towards the extensive use of automation and industrial robots to deliver process and system efficiencies. With the increasing Automation, it is equally important to follow proper safety protocols. However, given that a system failure can carry severe consequences for both people and equipment, compliance with regional and international robot safety standards is becoming a key concern for suppliers, manufacturers and system integrators.

Now let us see some of the types of accidents that can happen:

The operational characteristics of robots can be significantly different from other machines and equipment. Any change to the object being worked or the environment can affect the programmed movements. Some maintenance and programming personnel may be required to be within the restricted envelope while power is available to actuators. The restricted envelope of the robot can overlap a portion of the restricted envelope of other robots or work zones of other industrial machines and related equipment. Thus, a worker can get hit by one robot while working on another, trapped between them or peripheral equipment, or hit by flying objects released by the gripper.

1. Impact or Collision Accidents: Unpredicted movements, component malfunctions, or unpredicted program changes related to the robot’s arm or peripheral equipment can result in contact accidents.

2.Crushing and Trapping Accidents: A worker’s limb or other body part can be trapped between a robot’s arm and other peripheral equipment, or the individual may be physically driven into and crushed by other peripheral equipment.

3.Mechanical Part Accidents: The breakdown of the robot’s drive components, tooling or end-effector, peripheral equipment, or its power source is a mechanical accident. The release of parts, failure of gripper mechanism, or the failure of end-effector power tools (e.g., grinding wheels, buffing wheels, deburring tools, power screwdrivers, and nut runners) are a few types of mechanical failures.

4.Other Accidents: Other accidents can result from working with robots. Equipment that supplies robot power and control represents potential electrical and pressurized fluid hazards. Ruptured hydraulic lines could create dangerous high-pressure cutting streams or whipping hose hazards. Environmental accidents from arc flash, metal spatter, dust, electromagnetic, or radio-frequency interference can also occur. In addition, equipment and power cables on the floor present tripping hazards.

Role of Human Errors in Accidents:

Robots are smart, but most of the times they need humans to program them for tasks. Those people could make mistakes that lead to unintended consequences. For Example, Robotic surgery involves risk, some of which may be similar to those of conventional open surgery, such as a small risk of infection and other complications. It’s essential to realize that the Da Vinci system never operates independently, but gets guided by surgeons using foot pedals, joysticks and a viewer.

Robots bring many pros and cons to workplaces, especially concerning enhanced labor output and increased consistency. But benefitting from the advantages requires ensuring workers have the knowledge needed to use the machinery safely and confidently. Despite the examples of events mentioned above, data collected by OSHA reveals that there have been only 40 incidents of injuries or deaths related to robots in the workplace.

Studies shows that most of the injuries happen not during normal operation but the times when human interaction is most prevalent. By System design, robots rarely need human interaction during normal functioning and operations but when programming, testing, inspection or repair is required.

Inherent prior programming, interfacing activated peripheral equipment, or connecting live input-output sensors to the microprocessor or a peripheral can cause dangerous, unpredicted movement or action by the robot from human error.

Apart from human errors there can be many other reasons which can lead to accidents like Intrinsic faults within the control system of the robot, errors in software, electromagnetic interference, and radio frequency interference are control errors. In addition, these errors can occur due to faults in the hydraulic, pneumatic, or electrical sub-controls associated with the robot or robot system. Mechanical Failures , power failure and improper installation of robot or robotic system can lead to inherent hazards.

What precautions should we take reduce accidents and increase safety of robots?

1. Before installing any robot or robotic system Risk Assessment must be done. There are different system and personnel safeguarding requirements at each stage. The appropriate level of safeguarding determined by the risk assessment should be applied.

2. Design and position of Control panel is also important for Safe robotic System. The control panel must be located outside of work envelope but must be within sight of robot. Emergency stops should be located in all zones where needed and should be a large part of emergency personnel training.

3. Unauthorized access to the workspace can be hazardous to the personnel. Several methods can be used to protect the work envelope like:

(a) The simplest are known as awareness devices, these devices are intended to define to work envelope and make personnel aware of the hazards. They do not prevent access and consist of fences and roped off areas.

(b) Safeguarding methods are used to prevent unauthorized access to the work envelope. Simplest method is known as fixed barrier method such as a fence or a wall. A physical barrier is put around the workspace and is configured in such a way that prevents access through over or around without a special key or access code.

© Another method of protecting robot workspace employs the use of presence sensing devices. These devices detect the presence of a person in hazardous area and slows down or stops the robots. Pressure mats are installed just outside the robot’s workspace. When a person steps on the mat, a signal is sent to robot to stop or slow the work.

(d) Safety light curtains is another type of presence sensing device. When a person enters the work envelop, the light beam is interrupted which sends a signal to robots. For certain work scenarios, sudden stops could cause the work to become uncontained, objects may continue to move even when the robot stops. In such cases emergency braking of robots is used instead of completely stopping. In emergency braking robots slow down the speed and does not stop suddenly.

4. Operator Safeguards. The system operator should be protected from all hazards during operations performed by the robot. When the robot is operating automatically, all safeguarding devices should be activated, and at no time should any part of the operator’s body be within the robot’s safeguarded area.

5. Maintenance and Repair Personnel. Safeguarding maintenance and repair personnel is very difficult because their job functions are so varied. Troubleshooting faults or problems with the robot, controller, tooling, or other associated equipment is just part of their job. Program touchup is another of their jobs as is scheduled maintenance, and adjustments of tooling, gages, recalibration, and many other types of functions.

These recommended inspection and maintenance programs are essential for minimizing the hazards from component malfunction, breakage, and unpredicted movements or actions by the robot or other system equipment. To ensure proper maintenance, it is recommended that periodic maintenance and inspections be documented along with the identity of personnel performing these tasks.

6. Safety Training. Personnel who program, operate, maintain, or repair robots or robot systems should receive adequate safety training, and they should be able to demonstrate their competence to perform their jobs safely.

What is a Robot Safety Standard?

As industrial robots continue to become more advanced, more capable and more popular on the international stage, the need for comprehensive robot safety standards increases exponentially. Robots can create havoc if they don’t follow safety protocols .

A robot safety standard is a collection of guidelines for robot specifications and safe operations in which all involved in the manufacture, sales and use of robots must follow. Often, standards are created by a diverse group of industry interests to ensure the standards benefit everyone. Every country has different robot safety standards. International standards organizations work to unify and assimilate these separate sets of robot standards into a more cohesive whole.

Some of the popular standards organizations are:

· International Organization for Standardization(ISO): Headquartered in Geneva ,The International Organization for Standardization is an international standard-setting body composed of representatives from various national standards organizations.

International Electrotechnical Commission(ICE): The International Electrotechnical Commission is an international standards organization that prepares and publishes international standards for all electrical, electronic and related technologies — collectively known as “electrotechnology”.

· American National Standards Institute(ANSI): The American National Standards Institute is a private non-profit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States.

· Robotic Industries Association(RIA): The Robotic Industries Association is a United States trade group organized to serve the robotics industry.

· Bureau of Indian Standards (BIS): It is the National Standard Body of India established under the BIS Act 2016 for the harmonious development of the activities of standardization, marking and quality certification of goods and for matters connected therewith, This Organization was formerly known as Indian Standards Institution(ISI)

On concluding, although robots have potential hazards which can prove to be very dangerous, these can be prevented by taking proper safety measures, educating technicians with latest advancements and following standards. If all the necessary care is taken, robots can be highly efficient and safe way to accomplish work and humans and robots can work collaboratively for development for mankind.

By Suraj Shewale, Malhar Surangalikar, Devarshi Talewar, Pooja Tekade and Sarvesh Wadi