Tolerance Chain Analysis for CAD Assembly Accuracy
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Solution Overview
Problem
Current CAD systems require laborious manual calculations or expertise in Monte Carlo simulation to determine minimum and maximum tolerances in assemblies, and existing tolerance analysis techniques do not efficiently implement industry standards like ASME Y14.5 and ISO 1101, nor do they provide rapid computation of root sum squared values.
Innovation Solution
A computer-implemented method using a push-pull technique to analyze tolerance chains and cross-part associations within assemblies, allowing for rapid computation of minimum and maximum conditions and root sum squared values, without requiring simulation expertise, and adhering to industry standards.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If manual calculation methods are used to determine minimum and maximum tolerances, then engineers can obtain tolerance analysis results, but the process becomes laborious and time-consuming
Solution Approach 1:
The patent replaces manual mechanical calculation methods with an automated computer-based system that uses mathematical algorithms to compute minimum and maximum tolerance conditions. The system automatically processes tolerance chains and performs iterative calculations without requiring manual intervention, thereby eliminating the laborious nature of manual computation while maintaining accuracy.
Solution Approach 2:
The tolerance analysis system performs self-service by automatically identifying tolerance chains, selecting relevant tolerances, and computing minimum and maximum conditions without requiring continuous engineer intervention. The system autonomously iterates through calculations and generates results, freeing engineers from the time-consuming manual process while preserving measurement precision.
2Productivity
If Monte Carlo simulation is used for automatic tolerance analysis, then computation speed improves, but expertise in simulation and statistics is required
Solution Approach 1:
The patent employs simplified mathematical models and algorithms that serve as lightweight alternatives to complex Monte Carlo simulations. These computational models provide sufficient accuracy for tolerance analysis without requiring the heavy statistical framework of Monte Carlo methods, thereby reducing computation requirements and making the system accessible to users without specialized simulation expertise.
Solution Approach 2:
The system changes the computational approach from statistical Monte Carlo simulation to deterministic mathematical algorithms that directly calculate minimum and maximum tolerance conditions. This parameter change in the computational methodology maintains productivity by avoiding random iterations while eliminating the need for statistical expertise, making the system easier to operate.
3Productivity
If kinematics linkages technique is used for tolerance analysis, then computation is efficient, but complete breadth of ASME Y14.5M and ISO 1101 standards is not solved
Solution Approach 1:
The patent creates a universal tolerance analysis system that can handle multiple tolerance standards (ASME Y14.5 and ISO 1101) and various tolerance types within a single computational framework. The system is designed to be multi-functional, accommodating different tolerance chain configurations and standard requirements while maintaining computational efficiency through optimized algorithms.
Solution Approach 2:
The system segments the tolerance analysis process into distinct computational modules that can independently handle different aspects of tolerance chains. This segmentation allows the system to efficiently process complex tolerance scenarios while ensuring complete coverage of standard requirements by breaking down the problem into manageable computational segments that collectively address all standard provisions.
4Loss of information
If complex tolerance chains with multiple parts are analyzed, then comprehensive assembly tolerance information is obtained, but calculation complexity increases significantly
Solution Approach 1:
The patent extracts and isolates only the relevant tolerances that form active tolerance chains affecting the assembly dimension of interest. Rather than processing all tolerances in the assembly, the system identifies and extracts the specific subset of tolerances that contribute to minimum and maximum conditions, thereby reducing calculation complexity while preserving complete tolerance information for the relevant chain.
Solution Approach 2:
The system performs preliminary analysis to identify and organize tolerance chains before conducting the main calculation. By pre-processing the tolerance data to establish chain relationships and select relevant tolerances in advance, the system reduces the complexity of the subsequent computation while ensuring that comprehensive tolerance information is captured and processed efficiently.
Data Source
AI summary
Determining a minimum condition and a maximum condition of an assembly of parts includes determining a subset of the assembly of parts, constructing a tolerance chain comprised of tolerance features associated with the parts and that have tolerances that can assume maximum and minimum values, setting at least one tolerance to a minimum value or a maximum value, and calculating the minimum condition and the maximum condition of the assembly based on the setting of the tolerance.