Initial situation

Driven by the ongoing digitalization in mechanical engineering, there is a continually growing demand for data on relevant state and process variables from technical systems, such as in intelligent quality assurance systems or condition monitoring. The quality and reliability of the data and information provided by sensor-based functions play a critical role in safety engineering, particularly in the subfield of functional safety.

When sensor-based functions are used as part of a safety function in the context of functional safety, they are subject to specific requirements compared to conventional applications. In this regard, the robustness and resilience of sensor functions are particularly important, as they significantly influence the reliability and availability of a technical system with an integrated safety function.

A resilient system can be characterized by two features: First, a resilient system must guarantee a predefined minimum functionality, even in the presence of disturbances. Second, a resilient system must be capable of recovering to at least its original functionality level once the disturbance subsides. This recovery can be automatic or supported manually.

To implement sensor-based functions, measurement techniques that meet these criteria need to be developed. In order to develop resilient measurement techniques, it is essential, among other things, to generate knowledge through an analysis of the disturbances that occur and their impact on the measurement method and the elements used within it.

Project objectives

The primary goal of this project is to develop a methodology for the design and evaluation of resilient measurement techniques based on sensing machine elements (SMEs). This will be carried out primarily within the context of functional safety and will include an initial evaluation of the methodology using a practical example.

Procedure

The methodology consists of two interrelated methods – one for designing resilient measurement techniques and one for evaluating the resilience properties achieved – along with the associated models. The development of these will follow the steps outlined in the project:

First, the understanding of technical resilience must be transferred from the initial context to measurement techniques, and the necessary properties must be quantified. The necessary and sufficient requirements for a resilient measurement technique that can implement a safety function must be identified. Using suitable models, resilience properties will be systematically identified and deduced. This will then enable the development of the methodology for designing resilient measurement techniques.

For the subsequent evaluation of resilient measurement techniques, quantitative evaluation criteria will be derived based on the previously developed holistic requirements. Building on this, criteria for an evaluation method will be developed to identify measurement techniques with sufficient resilience properties.

After an initial evaluation of the methodology using a practical example and experimental validation of the resilience properties achieved by the developed resilient measurement technique, general design guidelines will be derived. These guidelines will help support the synthesis of resilient measurement techniques, with a particular focus on solutions based on SMEs as a resource-efficient alternative.