A robot safety incident can occur for a variety of reasons. There are three broader classifications. First, a robotic arm or equipment can cause an accident, putting an operator in a risky situation. Second, a mechanical part fails in the robot system. Lastly, there could be an uncontrolled power supply to the robot. All of these pose severe risks to an operator. Let's understand robotic safety incidents and systematically apply them to cobots, minimizing incidents. Our philosophy here reminds me of a Chinese proverb, "Give a man a fish and you feed him for a day, teach a man to fish and you feed him for a lifetime." Based on safety incidents just mentioned, robotic accidents have four broad classifications. Impact or collision, crushing or trapping, mechanical, and others. We'll spend the next few minutes understanding the causes and effects of these accidents. Once we gain this understanding, we'll be well-prepared to apply this knowledge from robots to cobots. Even if you do get a club robot, people make this assumption that it's safe. It's not the case. Even with any robotic application, with any robotic system being clever or non clever, you still have to do a task based risk assessment. You have to figure out every possible way a human's going to interact with the system and figure out where the potential hazards are, you walk through them, you think about how you eliminate them or alleviate them. Now, the club of robots have given me more tools to alleviate these problems. Before, the old days, task-based reassessment, possible hazard, robot swinging around taking somebody else that may in it's position. Obvious solution, fence, safety guarding, switch. These days it's okay, robot swings around hits somebody, evaluate forces of impact. The rules have changed. So, first and foremost, I always go back to is it truly a collaborative application? Then even if it is, it,s not, you can't assume it's safe, you still have to go through the steps to make sure you have a safe system that your people are protective. The first type of accident is an impact accident. Also known as collision accident. Unpredicted changes or movement related to the robot equipment or parts such as the peripheral equipment or competent malfunction can result in contact between a robot and a human. This type is similar to a car crash which delivers impact to the driver or a passenger inside the car. The cause is unpredicted moment or component malfunction, and the result is an impact or collision. The second type of accident is crushing accident. Does this is ring any bell? It's very similar to quasistatic contact we study. In the scrapping incident, a robot part such as an arm or equipment can trap between an operator's body part or the operator can be physically be crushed against another piece of equipment. An example of this accident is a forklift physically forcing an operator to smash against another standing truck. The cause is a trapping moment by the robot and the effect is crushing or trapping. In a mechanical part accident, a robot tooling or any factor such as screwdriver nut fastener etc can break-down resulting in mechanical failure. This breakdown could lead to multiple hazards. Mechanical failures can be severe depending on the speed and pressure of the contact. The cause is the failure of a mechanical part and effects are severe depending on if it resulted in a contact or crushing. Other accidents can result from working in proximity with robots. Electrical wiring of the robots and their control power represent a significant hazard to an operator. A high pressure cutting stream can occur if a hydraulic proline is ruptured. Environments with radio frequencies, dust, and scrape pose threats. Slip surfaces in cold regions and excessive wiring present a tripping hazard. The cause of these accidents are diverse. If you notice, this is precisely where knowledge transfer from OSHA ties in. As we spoke about in a previous lesson, the effect of these accidents can vary anywhere from a bruise or a scratch to a life threatening incident. Collaborative robots are continually evolving field and there's still some discovery to do concerning safety. With so many variables, the preventive action process is by far the most safest, efficient, and cost effective practice. Although having a reactive process such as a corrective action or problem solving is necessary, they take up time, capital, and resources. Our robust preventive action on the other hand focuses on stopping an undesirable event from happening in the first place. We have a good understanding of different types of robot accidents. Now, let's understand why an accident occurs and try to prevent it from happening. We will identify the root cause of a problem and remove it so that the incident is likely never to occur in the first place. We're applying our robot lessons to cobot. Here is an extensive list of identified root causes or sources of hazards in the different type of accidents. Although one or more of these sources can cause an accident, a good starting point is to extinguish these hazards. Let's take a moment to identify and define these root causes. Human interaction with a robot has the potential to cause dangerous or unpredicted moment or reaction by a robot. Control errors are intrinsic or inherent faults or bugs within the control system. These errors could also be in the soft fair of the robot system. Unauthorized access is when personal are unfamiliar with the safeguards in place or their activation status. A mechanical failure like we spoke about, is conducive to an unexpected operation or end-effector failure. Power systems pose serious fire risks costs by disruptive electrical signals. Lastly, the design of a collaborative robot cell is critical. If the design or the layout is inadequate, it can lead to inherent risks in the system. These root causes can exist in silos or can be combined to cause an undesired event to occur. Hence the proactive preventive approach. Identifying root causes is the first step to realizing a safe workplace. I encourage you to brainstorm with your diverse team to identify further sources of hazards and how you can prevent them. Putting it all together, we learned different kinds of robotic accidents. We now have an understanding of their cause and effect. We problem solved and identified the root causes of these accidents. Being proactive preventive advocates, we looked at the sources of these hazards in the context of cobots and discussed how to extinguish them. Now, if you connect this tool to the risk assessment, you will be able to identify your immediate action items based on your risk priorities and present the hazards. We not only fished but also gathered an appreciation for learning to fish. The beauty of this philosophy lies in its flexibility. We're certain when you apply the proactive preventive approach to your organization or cobot, it will reap an efficient, beneficial, and ultimately safer workplace.
