The resulting product redefines the standard for cobots by being the first integrated motion device in an extremely compact design to offer certified functional safety in accordance with IEC61508, SIL3, EN ISO 13849, PL-e and IEC61800-5-2.
Safety Drive: Technical challenge and solution approach
The close cooperation between the two companies enabled the perfect integration of the brake system, two integrated encoders and safety electronics with ten certified advanced safety functions in the smallest possible installation space.
The challenge during development was to accommodate the redundant safety electronics (1oo2) in the smallest possible installation space and to implement all the required safety drive functions in accordance with IEC61800-5-2 for SIL3.
The development of the product was based on an existing customer servo drive. The electronics were expanded in the project in accordance with the standards for functional safety, with the Safe Motion Options Board (SMO) playing a decisive role as safety monitoring electronics. MESCO designed and developed the SMO, while the customer implemented the hardware based on the MESCO safety concept approved by TÜV SÜD.
Time savings: MESCO Safety Design Packages and simultaneous hardware and software development
MESCO’s core software development was based on artifacts from the proven MESCO Safety Design Packages. The design packages are a kind of eco-system and provide the functions frequently used in drive technology in tested software modules. The software libraries for the Advanced Safety Functions (ASF) were also used here. This significantly reduced the effort required for implementation and documentation creation.
This basic implementation formed the basis for an initial software prototype. This meant that the first hardware prototypes could be put into operation at an early stage, which resulted in a significant time advantage. The development process was also accelerated by a parallel approach with simultaneous hardware and software development, in which MESCO developed the security software and supported the optimization of the hardware design with agile reviews.
Functional safety for cobots: success factors and outlook
The agile and cooperative project process made it possible to develop the highly complex and safety-relevant product within the cost and time frame, with a calculable development risk and achieved TÜV certification from TÜV SÜD. On the customer side, the required and relevant safety processes were quickly introduced in the company thanks to the joint development with MESCO and the practical application of the standards.
The short development time provides the decisive market advantage.
The key factors for success:
- Very close and trusting cooperation with a strong focus on the respective core competencies of the companies involved throughout the entire development period.
- Early implementation of the MESCO Safety Software prototypes on the Design Package Evaluation Board hardware to minimize risk and optimize project duration.
- Use of the MESCO Safety Design Package SW libraries, documentation templates and test procedures. This greatly reduces the development time by using the existing development artifacts.
- Use of common tool chains and security development processes for optimum coordination and collaboration in the development phases.
- Efficient and short concept and certification phase at TÜV SÜD through the creation of traceability-compliant, tool-supported documentation sets.
