34 n ROBOTICS AND AUTOMATED MANUFACTURING July/August 2023 www.drivesncontrols.com In the machinery industry, the importance of functional safety is increasing as a result of advancing digitalisation. Digital technologies have contributed significantly to improved efficiency and higher degrees of automation – as well as improving operability and profitability. However, the increasing connectivity of systems and plants, plus the growing possibilities of remote control, has seen a shift away from the prevention of access and the reliable shutdown of machines, towards the reliable identification of people and continued operation. Due to this trend, possible damage events and the safety-related parts of control systems have both become more complex. One example is the introduction of collaborative operation with robots, where people and machines work more closely together, offering enormous potential for improving efficiency. The complex semiconductors used in functionally safe embedded systems need a high degree of miniaturisation with to reduce size and cost. The embedded safety features also need to be compatible and re-usable. These requirements have a massive impact on the assessment of device functional safety, especially as new fault models caused by new technologies must be considered. In addition, verification approaches must be developed to show the effectiveness of safety measures. Due to massively increasing system complexity, high-quality development and lifecycle processes are therefore needed to ensure low levels of systematic faults. Assessing design and manufacturing processes is another key to avoiding the consequences of systematic faults. Informative and complete documentation is needed to realise safe, straightforward system designs. This means that great care must be taken when generating the user documentation with respect to completeness of the system integration. Consequently, the generic normative requirements should be interpreted and extended, based on the current state-of-the-art and the specific technology being considered. Despite technological advances, it is ultimately organisations and people that are responsible for realising functionally safe products and systems. Verification approaches must be developed to show the effectiveness of safety measures. Implementing the many different requirements of functional safety requires a management framework which regulates processes and organisation of the activities to be performed. Functional safety management is therefore a key element of relevant functional safety standards. This includes the definition of the roles and tasks of the individuals involved, proof of their competence, and the qualification measures necessary to ensure upto-date knowledge. Further elements that must be defined within the safety lifecycle include both the type and scope of the required documentation and quality assurance. This spans the preparation of documented procedures, work instructions and checklists, as well as official signature authorisations. Recording of field experience must also be regulated, as must modification and configuration management. Functional safety management should also have numerous interfaces with the higher-level quality management systems typically found in organisations, which must therefore be given special attention. It is good practice to define the responsibilities of each party clearly and early on in the quotation phase. This is because functional safety is not solely the responsibility of the component or system supplier alone, but also that of the future owner of these systems. Growing digitalisation and automation across all areas of life and industry not only increases the significance of functional safety, but also offers economic opportunities. Safe product design, early prevention of conformity-related problems, fewer product recalls, and shorter time-to-market are some examples. Manufacturers and owners can exploit these opportunities by establishing a systematic process focus. This should include consideration of the entire system lifecycle, at an early stage – ideally during the development phase. To mitigate against systematic faults, the effectiveness of safety measures must also be fully verified. This will confirm the robustness of components, as well as the complete lifecycle, and the development process must also be considered during such an assessment. A holistic approach to functional safety is therefore required, which requires expertise in various application fields across all project phases, from design and development to manufacturing and installation, testing, certification, placing into service, and eventual decommissioning. n The growing complexity and connectivity in industrial machinery brings new requirements for the functional safety of systems and plant technology. Stewart Robinson, principal engineer and functional safety expert at the product testing and certification organisation TÜV SÜD, examines some of the issues. Functional safety in a digital world
RkJQdWJsaXNoZXIy MjQ0NzM=