CNSD: A Causal Neuro-Symbolic Diagnosis Framework Enabling AI to Not Only Predict Failures But Also Explain Their Causes

CNSD (Causal-Neuro-Symbolic Diagnosis) is an industrial fault detection framework integrating neural networks, symbolic reasoning, and Judea Pearl's causal model. Its core goal is to solve the problem that traditional ML systems can only predict fault types but cannot explain causes or provide intervention suggestions. Developed independently by a high school student, this framework achieves complete diagnostic capabilities from "what happened" to "why it happened" and then to "what if we intervene", demonstrating the potential of AI democratization.

In the industrial fault detection field, most ML systems can only identify fault types but cannot answer engineers' concerns about "why" and "how to prevent". CNSD fills three major research gaps: 1) No unified framework applies Pearl's do-calculus to neuro-symbolic pipelines for fault diagnosis; 2) JEPA self-supervised learning has not been applied in this field; 3) There is a lack of industrial diagnostic systems covering all three layers of Pearl's causal ladder. Its cross-disciplines include causal machine learning, neuro-symbolic AI, and ML-based fault detection.

CNSD adopts a unique five-layer bidirectional architecture:

1. Neural Perception Layer: 1D CNN (100% weighted F1 on CWRU dataset) + S-JEPA (self-supervised learning with linear probing F1 of 99.52%), balancing high accuracy and generalization;
2. Symbolic Rule Engine: Maps fault labels to human-readable root causes, severity levels (four levels), and maintenance suggestions;
3. Causal Inference Layer: Based on Pearl's structural causal model, calculates the ATE of vibration energy on fault probability (0.3409 for CWRU with a placebo ratio of 29.05x; 0.0546 for CMAPSS with a ratio of 25.92x);
4. Counterfactual Analysis Layer: Answers "what if we intervene" by quantifying risk reduction from 25%/50%/80% vibration reduction;
5. Bidirectional Consensus Mechanism: Bidirectional feedback between the forward path (data → perception → symbol → causal → counterfactual → scoring) and backward path (adjusting CNN thresholds based on causal doubts, etc.).

CNSD is built using open-source tools:

• Python3.10+: Core language;
• PyTorch: Implements the neural perception layer;
• DoWhy: Causal inference and do-calculus;
• causalnex: Causal DAG construction;
• pyDatalog: Symbolic reasoning layer;
• pandas/numpy: Data processing. The selection principle is pragmatism—using the best existing tools to focus on architectural innovation.

CNSD is validated on two benchmark datasets:

• CWRU Bearing Dataset: 1D CNN F1=100%, Random Forest baseline F1=94%;
• NASA CMAPSS Turbofan Dataset: Validates domain generalization ability. Key metrics: JEPA linear probing F1=99.52% (zero labels), RUL prediction RMSE=41.35 cycles, all three layers of Pearl's causal ladder implemented, 2 bidirectional paths.

CNSD can be applied in manufacturing (optimizing maintenance plans), aerospace (engine health monitoring), energy (wind turbine maintenance), transportation (heavy equipment early warning), and other fields. Its core value lies in providing interpretable diagnostic results and actionable intervention suggestions, meeting regulatory compliance requirements for safety-critical applications.

Current limitations: Validated only on standard datasets; needs to address engineering issues like real-time performance, edge computing, and multi-sensor fusion. Future directions: Expand to more industrial fields, optimize computing efficiency, develop visualization interfaces, and establish industrial system integration interfaces.

CNSD represents the evolution of AI diagnostic systems from correlation prediction to causal understanding and counterfactual reasoning. It proves that the organic integration of neural perception, symbolic interpretability, and causal reasoning can create more powerful systems. Developed independently by a high school student, this project suggests the threshold for AI innovation is lowering, and its core idea (AI should predict, understand, and learn from mistakes) will guide the next generation of intelligent diagnostic systems.