This work has been done in collaboration with Camatec Industriteknik AB, who wanted to investigate how to manufacture hydraulic valve blocks, safety blocks, according to ISO 13849 and the PL scale. As this standard is being increasingly implemented in everything from industrial machines to mobile hydraulics, it is desired to conduct an early investigation on the possibilities of producing valve blocks in compliance with this standard. The work lasted for a period of 10 weeks and was carried out at LiU (Linköpings Universitet) and Camatec's office in Karlstad. It started by determening whether a design could comply with the PL scale from the standard and if so, how. A requirement specification was compiled based on the requirements that concerned the block itself. An existing concept proposal was iterated and formed the basis for a calculation model. With a preliminary stress-value, several materials were found based on recommendations and databases that met the set requirements. The materials were weighted in a weighting matrix and two final materials was determined. A final concept was made including a fatigue analysis with the selected materials. When material selection, construction and calculation were completed, a drawing was created that was used for manufacturing quotes. The result was a construction with two different material proposals. One version is designed for an MTTFD value of 150 years and the other for an infinite MTTFD. Depending on other components of a system, these safety blocks are compatible up to PLe, the highest level in the scale. When implementing this safety block, other parts of the system must meet the set requirements, it is recommended that the development of ISO 13849 is carefully followed in the future. / Detta arbete har gjorts i samarbete med Camatec Industriteknik AB som önskade att undersöka hur man kan tillverka hydrauliska ventilblock, så kallade säkerhetsblock, enligt ISO 13849 och PL-skalan. Då denna standard implementeras allt mer i allt från industrimaskiner till mobilhydraulik vill man tidigt undersöka möjligheterna att saluföra ventilblock enligt denna standard. Arbetet pågick under en period på 10 veckor och utfördes på LiU (Linköpings Universitet) samt Camatecs kontor i Karlstad. Man började med att ta reda på huruvida en konstruktion kunde uppfylla PL-skalan som definierades i ISO 13849 och hur detta då skulle realiseras. En kravspecifikation sammanställdes utifrån de krav som berörde själva blocket. Ett befintligt konceptförslag itererades och låg till grund för en beräkningsmodell. Med ett preliminärt spänningsfall hittades ett antal material utifrån rekommendationer och databaser som uppfyllde de satta kraven. Materialen viktades i en viktningsmatris och två slutgiltiga material kunde bestämmas. Ett slutgiltigt koncept gjordes där man utförde en utmattningsanalys med de valda materialen. När materialval, konstruktion och beräkning var klart skapades ett ritningsunderlag som kom att användas för tillverkningsofferter. Resultatet blev en konstruktion med två olika materialförslag. Den ena versionen är konstruerad för ett MTTFD-värde på 150 år och den andra är konstruerad för ett MTTFD-värde på oändligheten. Beroende på ett systems övriga komponenter och struktur är dessa säkerhetsblock kompatibla upp till PLe, den högsta nivån i skalan. Vid en implementering av detta säkerhetsblock måste övriga delar av systemet uppfylla ställda krav, det rekommenderas att man noga följer utvecklingen kring ISO 13849 även i framtiden.

Många arbetsrelaterade olyckor sker av att säkerhet kring att LOTO-principen är undermålig och att maskiners rörliga delar är lätt att komma åt. Vid konstruktion av en maskin är det viktigt att ta hänsyn till maskinens farliga upphov. För att konstruera bort detta är det viktigt redan på ett konstruktionsstadie att identifiera och bygga bort dessa områden med till exempel ett maskinskydd kring maskiner. Tillträdesplatser måste vara noga övervakad för att det ska vara en säker användning av maskin enligt maskindirektivet 2006/42/EG. I denna rapport har säkerhet såväl som kostnader setts över för en befintlig förreglingsbrytare på tillträdesplatser för en balningslinje och undersökt om kostnader kan minskas med föreslagen PROFInet baserat förreglingsbrytare. Den harmoniserade standarden EN ISO 13849-1:2016 tar upp ett sätt för att utvärdera säkerheten kring en maskins styrsystem allt utvärderas efter begreppet PL, Performance Level. För att räkna ut PL vid säkerhetsjämförelse användes SiSteMa och för att räkna ut kostnaden av dem olika alternativen emellan har en intervju kring kostnader gjorts och presenterats som en kvot. Säkerhetsjämförelse visar att PLd är bibehållen. Kostnadsjämförelsen visar att den föreslagna lösningen är dyrare än den befintliga men att en undermålig prisuppskattning kan ligga bakom detta. En aspekt av den nya förreglingsbrytaren som inte sågs över i rapporten men värt att nämna i slutsatsen kring säkerhets- och kostnadsjämförelse är att det föreslagna förreglingsbrytaren med PROFInet är en flexibel lösning med enkel felsökning. Framtida arbeten kring säkerhet vid balningslinje hade varit att titta på resterande tillträdesplatser som övervakas av ljusbomar och se om kostnader går att få ner där. / Many work-related accidents occur because safety around the LOTO principle is substandard and that the moving parts of machines are easy to access. When designing a machine, it is important to consider the machine's dangerous origin. To design this, it is important to identify and build these areas already at a design stage with, for example, a fence around machines. Access places must be carefully monitored for safe machine use according to the Machinery Directive 2006/42 / EC. In this report, safety as well as costs have been considered to an existing guard lock on access places for a baling line and examined whether costs can be reduced with the proposed PROFInet based guard lock. The harmonized standard EN ISO 13849-1: 2016 addresses one way of evaluating the safety of a machine's control system, all being evaluated according to the concept of PL, Performance Level. To calculate PL when comparing safety, SiSteMa was used and to calculate the cost of their different alternatives, an interview on costs has been made and presented as a quota. Safety comparison shows that PLd is retained. The cost comparison shows that the proposed solution is more expensive than the existing solution, but that a substandard price estimate may be behind this. One aspect of the new guard lock that was not seen in the report but worth mentioning in the conclusion about safety and cost comparison is that the proposed guard lock with PROFInet is a flexible solution with simple troubleshooting. Future work on safety at baling line would have been to look at remaining access places that are monitored by light curtains and see if costs can be reduced there.

In the automotive industry, the Safety Function-FMEA according to ISO 26262 and its application to functional safety relevant systems is a well-established process in the form of Automotive Safety Integrity Levels (ASILs). These represent the failure mitigation that must be applied to ensure an acceptable residual risk of malfunctioning behaviour. The DIN EN ISO 13849 (ISO 13849) already describes a process to reduce risks for machines which starts with a Hazard And Risk Analysis (HARA) as described in DIN EN ISO 12100 and concludes with the Safety Requirements Specification (SRS). The SRS is a functional and technical safety concept defining requirements and guidelines to make sure the design conforms to defined safety goals. ISO 13849 lists important faults and failures for various technologies. The defined Safety Functions (SFs) can be classified in corresponding categories that lead to the particular hardware/system structure. This applies to mechatronic systems consisting of at least one sensor, one control unit and one actuator to monitor the system and effect a response in case of failure. Compared to the methods described in ISO 13849, the Safety Function-FMEA allows systematic identification of additional failures resulting from combinations of effects, rather than only listing the main failure causes. Based on the complexity of the machines it is highly recommended to perform a Safety Function-FMEA as a complementary method to assess and improve the overall safety of machinery.

The need for safety components in safety-related control systems arises in developing basic principles for preventing mechanical accidents and protecting safety for people and machines, especially in the development of automated drive systems for mobile construction machinery. An important parameter when using safety-relevant components respectively safety devices of automation technology-according to E DIN EN ISO 13849-1:2020-08 - in mobile machinery is the Diagnostic Coverage. The Diagnostic Coverage measures the effectiveness of the diagnosis as the ratio of the failure rate of noticed dangerous failures and failure rate of total dangerous failures. Because single- and dual-channel safety circuits from the Safety Related Parts of Control Systems (SRP/CS) might fail or get defective, a known level of Diagnostic Coverage helps to design such systems. As a supplementary method, the paper discusses the possibility of deriving a failure rate from empiric investigations via the context of fault classification known for electrical components from DIN EN 61508.-6:2011-02. Test procedures are not available in the development phase of new machines and new components in the field of mobile machines. Nevertheless, the Diagnostic Coverage is required for the calculation and design process. Similar to this test approach, the fault behaviour of technical products, defined in the FMEA (Failure Mode and Effects Analysis), can be applied to estimate the fault conditions in parallel to the design development as a first step. The target of estimating the diagnostic coverage already in the development phase of safety-relevant hydraulic components and systems can thus be achieved more effectively, and is illustrated in the article employing an example. The Diagnostic Coverage must be determined to classify the entire SRP/CS and each individual component according to ISO 13849 in category 2 and categories 3 & 4. In practice, this means that the calculation must be executed for the respective sensors, the controller and the actuator individually, and the entire functional channel as a whole in the single- or dual-channel safety circuit system. This enables an initial estimate and calculation of the Diagnostic Coverage according to ISO 13849 in the development phase without executing time-consuming prototype tests or test results from the field. This results in time savings and an increase in effectiveness of the internal work processes. Furthermore, the early avoidance of potential systematic risks of product and process failures, allows to reduce the costs of the development phase significantly.