---
pattern_id: pattern_deepmind_fusion_tcv
applicable_symptoms: [deepmind_fusion_tcv]
domain: Control_Locomotion
---

# Plasma shape and position control in tokamak fusion reactors is unstable under varying operating conditions.

**Domain**: `Control_Locomotion`

## Fix

Use reinforcement learning to learn a control policy that directly maps sensor observations to actuator commands for plasma shape and position control.

## Anti-pattern

Traditional PID controllers fail to adapt to the complex, nonlinear dynamics of plasma in a tokamak.

## Cross-domain analogies

- **Perception_Vision** → Incremental object-centric mapping suggests adaptive clustering of plasma states for real-time control.
  - related fix: Incremental object-centric mapping: associate VLM-derived semantic features (captions, embeddings) with LiDAR points via calibrated camera-LiDAR projection, then cluster points into object hypotheses updated frame-by-frame.
- **Planning_Decision** → Augment training dataset with diverse plasma state trajectories spanning full operating envelope.
  - related fix: BridgeNavDataset: a dataset with 55K street-view images, 100+ hours video, and 55K trajectory-instruction pairs for outdoor-to-indoor navigation.
- **Learning_Training** → Train multiple specialized plasma controllers and dynamically weight them based on real-time performance.
  - related fix: Train three specialized RL experts (reaching, squeezing, avoiding) and combine them via dynamic weighting based on individual capability performance.

## Patch

```diff
--- deepmind_fusion_tcv.before.py
+++ deepmind_fusion_tcv.after.py
@@ -1,2 +1,4 @@
-# --- BEFORE (vulnerable to the symptom below) ---

+# --- AFTER (ROSCLAW heuristic graft) ---

 # Symptom: Plasma shape and position control in tokamak fusion reactors is unstable under varying operating conditions.

+# Fix    : Use reinforcement learning to learn a control policy that directly maps sensor observations to actuator commands for plasma shape and position control.

+# Avoid  : Traditional PID controllers fail to adapt to the complex, nonlinear dynamics of plasma in a tokamak.

```
