There are many factors involved in the design and implementation of industrial automation safety. In order to assess the situation and select the best design course, trained experts should conduct a safety audit before planning any safety-related system, as safety standards and laws change over time.
A successful industrial automation safety program requires a multi-faceted strategy that combines the best products, design principles and operator training. Risk assessment is the first step in creating a safe workplace; after identifying possible problems, the focus shifts to reducing risk through different levels of mitigation. The most effective ways to protect workers are guided by a hierarchy of engineering and administrative restrictions.
Although their primary responsibility does not lie in the specific design of the safety system, each member of the project and operations team benefits from an applied knowledge of the relevant safety concepts. It is critical to understand the most commonly discussed safety design issues in order to provide personnel with the overview information they need.
The design of an automation system will certainly affect the safety of any equipment using industrial automation. On the other hand, safety design concepts for worker protection include the physical characteristics and intended use of any associated equipment.
The term "hierarchy of control" does not refer to real-time control; rather, it describes the actions that users should take to minimize the risks associated with each piece of equipment or installation. There are often many possible actions that can be taken in combination with each other.
1 - Elimination
Eliminating or removing potential hazards is the best and most effective method of risk mitigation. Unfortunately, most equipment and processes cannot be designed to completely eliminate all potential hazards, so most of the time this is not an option. But designers should always consider elimination.
2 - Replacement
Even if a risk cannot be completely eliminated, it can be replaced with a less hazardous or less frequently visited risk. This is not always feasible. For example, for equipment that uses chemicals, there may be a chemical that is safer in terms of flammability or toxicity. Even if the safer chemical is more expensive, investing in it is usually worthwhile because it improves working conditions and reduces accidents.
3 - Engineering Controls
While it is always important to investigate the first two steps, the reality is that with modern automated equipment, the next step in applying engineering controls is usually where the greatest risk mitigation is realized. Engineering controls can be simple or complex and can take many forms.
Physical: Security fencing sits at the top of the list of security components for automation systems. To facilitate operator access to critical areas within the cell, security fencing must be developed with operator safety and functionality in mind. Safety fencing prevents operators from inadvertently reaching in.
Sensors: There are a number of sensors that can identify hazardous situations or that can be activated by the user to signal and reduce the hazard. These include light curtains, limit switches, emergency stop (e-stop) buttons, emergency stop pull cords, and more. If someone tries to enter the cell, the sensors may tell the cell to stop. Similar to safety mats, area scanners can be set to slow or stop the machine if an operator is nearby.
INTERLOCKING: Some safety sensors are interlocked, allowing users to lock them out so they can't access the linked device until it is secure.
Removing Energy: Safety relays or safety controllers can be used to connect sensors and interlocks to cut off power to motors, actuators, and any other equipment that could jeopardize the safety of the user. Pneumatic and even hydraulic energy are two of the more commonly overlooked sources of energy, along with power supplies and electrical equipment power. Sensors can be built as stand-alone devices or components of more powerful hard-wired relays or digital safety controller circuits. They can also be connected to remove energy. Safety controllers are sophisticated digital devices that can interface with higher level systems and have extensive software configuration capabilities.
Stopping motion: When an emergency stop occurs, some physical systems require extra care to prevent movement long after the energy is gone. Quick bleed valves may be required in pneumatic circuits to relieve pressure from cylinders that may move. Equipment such as vertical presses or shears may require mechanical stops to stop gravity-induced movement after an emergency stop. Motor-driven mechanical devices may need brakes to stop rotational motion after an emergency stop.
Software: The software that enables us to change the scope of the robot's work has been created by industrial robot manufacturers such as Universal Robots. In many cases, we can change the enclosure to shrink our robot cell and safely remove the fence. In addition, it allows operators to easily interact with the robot using additional safety equipment such as light curtains, area scanners and safety mats when needed.
4 - Administrative controls
Having implemented the previous procedures, it is critical to address the human factor. This includes any personnel involved in the design, engineering, maintenance of the equipment, contractors, visitors, or anyone who may be working near or with the equipment.
5 - Personal Protective Equipment (PPE)
PPE includes safety glasses, earplugs, respirators, safety toe boots, gloves, and similar items that are common in industrial environments. In some cases, more advanced fall protection devices and necessary training are required. While critical to worker safety, these measures are at the bottom of the hierarchy of controls and should not be viewed as mitigating recognized hazards, as they are a last resort.The use of PPE also requires continuous worker effort.
Benefits of Industrial Automation Security
Manufacturing companies can benefit from improved automation safety in a number of ways.
Improved morale
Employees now have more time for tasks that require higher-level thinking because automation does the heavy lifting. Rescuing employees from hazardous environments shows that companies view them as valuable assets whose welfare is a top priority.
Reducing Costs
According to data, nearly $10 billion is spent on injuries and illnesses every year. Furthermore, according to claims, organizations can save 20 to 40 percent of these expenses simply by enhancing safety protocols.
Greater Efficiency
Automation typically produces uniform quality, moves faster and reduces waste. Maintenance costs are far less than continuing to pay for current programs, even though you may have to pay a large fee up front.
More Competitive Advantage
Automation gives organizations a competitive advantage by increasing production while maintaining safety and efficiency.
Developing safe industrial machinery, systems and automation is an ongoing process. Instead, it has a continuous life cycle. In addition, it is in the best interest of the entire team to design and operate safely. Risk assessment, mitigation and validation are all tasks that should be handled by the team. Another suggestion is to add some checks and balances, such as using different people to handle security engineering and validation. The team thus gains additional awareness and can now look at things from different perspectives.