CAD Sketch Constraint Sequencing for Reliable Dimensioning

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Solution Overview

Problem

Conventional constraint solvers in parametric CAD software often result in over-constrained or under-constrained conditions, leading to solver failures and unpredictable constraint sets, while machine learning models struggle with training data limitations and generate incorrect constraints due to hidden correlations and coverage gaps.

Innovation Solution

A computer-implemented method involving a constraint generation model trained using a scoring module to evaluate candidate sequences, combined with preference-based optimization and reinforcement learning, to generate accurate and convergent constraint sequences.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If traditional constraint solvers insert every identifiable constraint or dimension, then constraint completeness is improved, but solver reliability deteriorates due to over-constrained conditions or solver failures

Engineering Contradiction:
Improveconstraint completenessVSAvoidsolver reliability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent changes the approach from inserting all identifiable constraints to selectively generating constraints based on learned design patterns. The machine learning model predicts which constraints are most likely to be needed based on geometric relationships and design context, transforming the constraint generation process from exhaustive to intelligent selection.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces traditional mechanical constraint solving approaches with machine learning-based constraint generation. Instead of using heuristic rules and partial ordering techniques, the system uses trained neural networks to predict and generate appropriate constraints, substituting the mechanical constraint satisfaction process with an AI-driven approach.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Device complexity

If conventional constraint solvers rely on guesswork to decide which constraints are needed, then device complexity is reduced, but manufacturing precision deteriorates due to unpredictable or incomplete constraint sets

Engineering Contradiction:
Improveconstraint solver complexityVSAvoidconstraint accuracy
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent replaces guesswork-based constraint selection with machine learning models that have learned from extensive training data. The neural networks analyze geometric relationships and design patterns to accurately predict which constraints are needed, eliminating the need for complex heuristic rules while improving constraint accuracy.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent transforms the constraint generation approach from simple guesswork to data-driven prediction. The machine learning model uses learned parameters from training data to accurately determine which constraints should be applied, achieving both simplicity in the system architecture and high accuracy in constraint generation.

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If machine learning models use constrained or sparsely labeled training examples, then training data requirements are reduced, but manufacturing precision deteriorates due to incorrect or misaligned constraints

Engineering Contradiction:
Improvetraining data quantityVSAvoidconstraint accuracy
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The patent incorporates feedback mechanisms where the system evaluates generated constraints against the original design intent and geometric relationships. This feedback loop allows the model to learn from its mistakes and refine its constraint generation, ensuring high accuracy even when training data is limited or imperfectly labeled.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent performs preliminary actions by pre-processing and curating training data to ensure quality before training the model. The system prepares labeled examples that capture accurate geometric relationships and design patterns, so that when the model generates constraints, they are already aligned with correct geometric relationships, reducing the need for extensive training data.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS20260080126A1Generative constraining and dimensioning of computer-aided design sketches
Publication Date: 2026.03.19 AUTODESK INC
  • US20260080126A1 patent drawing
  • US20260080126A1 patent drawing
  • US20260080126A1 patent drawing

AI summary

Generative constraining and dimensioning of CAD sketches includes generating one or more candidate constraint sequences using a constraint generation model, generating one or more quality scores for each of the candidate constraint sequences, and performing alignment training on the constraint generation model based on the one or more quality scores and the one or more candidate constraint sequences.