Safely and efficiently integrating AMRs into industry 4.0 operations for maximum benefit
Another important standard is EN ISO 13849, which defines the safety performance levels (PLs) for various types of equipment. There are five levels, from PLa to PLe, with increasingly stringent requirements. AGV and AMR makers must reach PLd safety that ensures continuous safe operation in the event of a single fault, i.e., by using redundant systems. ANSI/A3 R15.08-2 requires a risk assessment for integrating and deploying AMRs. The risk assessments defined by ISO 12100 and ANSI B11.0-2010 are very similar, though not identical.
Next is risk estimation, which looks at the likely severity of harm from each hazard and the probability of its occurrence. A very severe hazard with a low likelihood of occurrence may receive a similar ranking as a hazard with a less severe outcome that’s more likely to occur. All identified risks are evaluated and ranked to prioritize risk reduction efforts. Risk assessment can be an iterative process, identifying the most severe risks and reducing their probability of occurrence and/or the severity of their outcome until an acceptable level of residual risk has been achieved (Figure 2).
AMR classes
R15.08 recognizes three types of AMRs: Type A: AMR platform only. In contrast with AGVs, type A AMRs can function as independent systems without requiring environmental changes. They can include optional features like a battery management system, the ability to independently locate a charger and recharge its battery, the ability to integrate with centralized fleet management software, etc. Type A AMRs are most often used to move materials around a factory or warehouse. Type B: A type A AMR with the addition of a passive or active attachment that is not a manipulator (Figure 3). Typical attachments include conveyors, roller tables, fixed or removable totes, lifting devices, vision systems, weighing stations, etc. Type B AMRs can be used for more complex logistics tasks. Vision systems can be used for product inspections and identification, weighing (or estimating the number of) parts, and so on.
ISO 12100 targets original equipment manufacturers,
whereas ANSI B11.0 focuses more on machinery and end-user safety. The basics of risk assessment are similar for both standards. Risk assessment A risk assessment is a highly structured analysis to arrive at an acceptable level of risk. It recognizes that no system or environment is perfect; inherent risks can be managed but not eliminated. It begins by determining the limits of the machine’s operation and identifies hazards that can arise if the machine operates near or outside of those limits.
Figure 2: Key components of a risk assessment include risk analysis, evaluation, and reduction. (Image source: SICK)
22
Powered by FlippingBook