Sensor Assembly for Safe Condition Detection in Automated Systems
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing sensor arrangements for automated systems lack a cost-effective and compact solution that can seamlessly transition between standard and failsafe applications, requiring separate designs and additional approvals for failsafe applications due to higher safety standards.
Innovation Solution
A sensor arrangement with an evaluation unit that generates both redundant and non-redundant signal pairs, utilizing individual identification codes from actuators to differentiate between input signals, allowing the same unit to function in both standard and failsafe modes, thus reducing complexity and cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate sensor arrangements are used for standard and failsafe applications, then safety standards are met, but device complexity and cost increase
Solution Approach 1:
The sensor arrangement is designed to perform both standard detection functions and failsafe safety functions using the same physical device. The evaluation unit can operate in two modes: standard mode for normal detection and failsafe mode for safety-critical detection, eliminating the need for separate sensor arrangements and reducing overall system complexity
Solution Approach 2:
The sensor arrangement dynamically switches between standard and failsafe operating modes based on the detection task. The evaluation unit can change its evaluation criteria and output signal characteristics depending on whether it is performing standard detection or failsafe detection, allowing one device to adapt to different functional requirements
2Reliability
If separate sensor arrangements are used for standard and failsafe applications, then safety standards are met, but cost increases
Solution Approach 1:
By designing a universal sensor arrangement that can perform both standard and failsafe functions, the patent eliminates the need to manufacture and stock separate sensor types. The same evaluation unit hardware and software can be used for both application types, reducing manufacturing costs and simplifying supply chain management
Solution Approach 2:
The patent changes operational parameters of the evaluation unit rather than physical hardware to differentiate between standard and failsafe modes. By modifying evaluation criteria, signal processing algorithms, and output signal characteristics through software configuration, the same physical device can meet different functional requirements without requiring different hardware components
3Reliability
If redundant signal pairs are generated for failsafe applications, then safety is ensured, but the number of outputs increases
Solution Approach 1:
The patent segments the output signals into different types: redundant signal pairs for failsafe applications and individual non-redundant signals for standard applications. The evaluation unit can selectively generate different signal types based on the detection mode, allowing efficient use of output channels and reducing the total number of required outputs
Data Source
Figure 1
Figure 2
AI summary
The arrangement (18) has an input circuit (60) receiving two input signals (66a, 66c), which depend on a safe installation state to be detected and an operational state, respectively. Two outputs output first and second output signals (76, 78) to a control unit. Evaluation units (64a, 64b) evaluate the input signals in a fail-safe manner to generate the first, second, third and fourth output signals (80, 82) at the outputs. The output signals form a redundant signal pair and a non-redundant signal pair, which is differ from the redundant signal pair.