key points:

• Functional safety enables industrial robots to collaborate with humans in a safer, more predictable, and more reliable manner.
• Risk assessment and multi-layered protection measures are critical for mitigating robot-related hazards.
• As robot autonomy continues to grow, safety requirements are becoming increasingly complex.
• Functional safety rests on three pillars: systematic capability, hardware reliability, and fault-tolerant safety architecture.
• In the field of industrial automation, outstanding safety performance is gradually becoming a competitive advantage.

Industrial robots are no longer confined behind protective cages. Collaborative robots, Autonomous Mobile Robots (AMRs), and emerging humanoid robots can now work alongside humans in dynamically changing and unpredictable environments. This shift is unlocking higher levels of productivity, precision, and operational flexibility, while also raising the bar for safety standards.

Robots must operate safely in every operation and under all conditions. High-speed manipulators can exert forces capable of causing injury in milliseconds. As robot applications scale up and autonomy increases, the margin for error continues to narrow. The question is no longer whether an industrial robot can perform a task, but whether it can operate safely, consistently, and predictably under all circumstances — and whether the systems governing its operation are properly designed to ensure these outcomes.

What is functional safety, and how does it work?

Functional safety ensures that a system executes safety-related functions when needed — for example, stopping motors quickly to prevent personal injury, or forcing the robot to reduce speed and output force when a nearby human is detected. In industrial systems, functional safety mitigates harm caused by unintended actions. In essence, it depends on the correct operation of safety systems and effective risk reduction measures, such as automatic protection mechanisms that respond properly when a safety demand arises. As a proactive and intelligent protection mechanism, functional safety is embedded into the design and operation of the system.

Functional safety is defined by three fundamental elements:

• ‌Reliability‌: The ability to perform a task without failure under specified conditions for a defined interval of time.
• ‌Architectural Constraints‌: Failures are inevitable; what matters is the system’s ability to tolerate them.
• ‌System Integrity‌: It is necessary not only to guard against hardware faults but also to prevent design errors.

Leading standards such as IEC 61508, ISO 13849-1, and IEC 62061 define the methods for designing, validating, and maintaining functional safety. For industrial robots, ISO 10218 sets out requirements for basic safety design and risk reduction techniques, including the minimum functional safety performance levels that deployed safety functions must achieve. These frameworks are built on decades of real-world accident data and engineering practices, and are designed to ensure that advances in automation technology do not lead to increased risk.

Functional Safety Lifecycle (IEC 61508)

Risk is Multidimensional and Growing

Functional safety begins with risk — and in the world of industrial robotics, risks are both complex and constantly evolving. Understanding these risks requires a structured approach. Risk assessment provides a framework to systematically evaluate not only the robot’s designed functions, but also the existing hazards, exposed personnel, and the ways in which a fault could lead to harm.

Risk reduction follows a three-step hierarchy: inherently safe design eliminates hazards at the source; safety safeguards mitigate residual risks; and instructions for use ensure that operators and integrators understand the remaining limitations. ISO 12100, the core standard for risk assessment and risk reduction in industrial machinery, clearly defines this methodology.

Each safety function must be assessed against three core parameters:

1. The severity of potential harm
2. The frequency and duration of exposure
3. The ability to avoid or limit harm

This framework defines the required Performance Level — a quantifiable benchmark that every safety function must meet or exceed.

The current challenge lies in scale and complexity. Modern robot applications can include dozens of interdependent safety functions, ranging from protective stops to real-time speed and separation monitoring. Each function must be individually designed and validated, and interactions between them must be strictly controlled to ensure safe behavior across the entire system.

Dealing with Faults

Functional safety standards distinguish between two types of faults and their corresponding handling methods:

• ‌Random Hardware Faults‌: Unpredictable component failures that occur over time with a finite probability. These are mitigated through diagnostic coverage requirements and redundant design.
• ‌Systematic Faults‌: Defects introduced by design or process (such as poor EMC robustness, unclear requirements, insufficient verification and validation, or software bugs). These are addressed through rigorous development processes, independent reviews, and diverse redundancy to avoid common-cause failures.

The scope of the challenge is expanding rapidly. The latest revision of ISO 10218 covers design, operation, and safeguarding requirements for industrial robots, defining 30 separate safety functions — up from only 12 in the 2011 edition. This tripling reflects how risk profiles have expanded as robots grow more capable and become deeply integrated into human environments. For connected factories, functional safety must also address cybersecurity threats.

Three Pillars, One Unified Integrated Framework

Tackling this level of complexity requires far more than a compliance checklist. Functional safety is built on three interdependent pillars: systematic capability, reliability, and architecture. Together, they define how risks are reduced to a tolerable level — and how that risk reduction is implemented, verified, and sustained over time.

Systematic capability refers to the rigor of the development process. Functional safety relies on disciplined engineering workflows to reduce systematic faults caused by design flaws, incomplete specifications, or implementation oversights. Standards-based processes, structured documentation, and rigorous verification and validation all contribute to stronger systematic capability. Well-defined processes reduce the probability of undetected errors in safety-critical functions.

The primary causes of dangerous failures of the control system by the safety lifecycle phase

Reliability targets the hardware dimension. It is the probability that a product will perform its intended function under stated conditions without failure over a defined period. In functional safety, reliability is quantified using metrics such as Mean Time to Dangerous Failure (MTTFD) and Average Frequency of Dangerous Failures per Hour (PFH). These engineering targets are derived from component data and validated through systematic analysis.

Reliability is the probability of a product performing its intended function under stated conditions without failure over a defined period.

Architectural constraints face an objective reality: no component is entirely failure-free. Safety architectures use hardware fault tolerance to prevent a single failure from disabling a safety function. Redundancy, diagnostics, and fault detection work together to preserve protective functionality even when components degrade or fail — maintaining system integrity throughout the entire operational lifetime.

Architectural Constraints (Type B)

Functional Safety as a Differentiator

ADI views functional safety both as a product capability and as an engineering discipline aligned with global standards. ADI’s in-house functional safety specialists support customers in developing systems that meet relevant certification requirements, with a product portfolio spanning safety semiconductors, precision sensing, power and battery management, isolation, and motion control technologies. ADI provides foundational building blocks, supplemented by reliability data, safety documentation, and standards-based design practices. This enables automotive, industrial, and robot manufacturers to implement SIL- and ASIL-compliant systems, and achieve safe operation in an increasingly robot-centric and human-centered industrial environment.

Looking Ahead: Safety as a Strategic Enabler
Functional safety is not a constraint on innovation — it is a prerequisite for the large-scale deployment of industrial robots. As robots move deeper into human-centered environments, only those enterprises and organizations that adopt rigorous safety frameworks will be able to deploy at scale with confidence, and earn the lasting trust of operators, regulators, and the workforce.

Standards for next-generation systems are continuously evolving to cover humanoid robots and mobile platforms with active stability control. This sends a clear signal: functional safety is advancing in lockstep with robotics innovation. Organizations that treat functional safety as a core engineering discipline — rather than an afterthought — will be better positioned to deploy intelligent automation in a responsible, effective, and scalable way.

OMAGINE specializing in ODM PCB design, PCB assembly, open source hardware related modules and sourcing service.