I Built an AI Pilot That Plans Like a Robot and Dodges Like a Human
Summary
A developer created an AI pilot for an SR-71 aircraft in Unity 2022.3, demonstrating a hybrid architecture that combines classical AI with deep reinforcement learning. The system uses an A* algorithm for routine path planning through a procedural maze and a Deep Q-Network (DQN) for real-time missile evasion. This hybrid agent was trained over 5 million steps using PPO via the ML-Agents trainer, with 24 parallel environments to enhance sample efficiency. The project highlights that classical methods excel at deterministic problems like route planning, while RL is superior for non-stationary, partially observable problems like threat evasion. The architecture allows for a real-time switch between the A* planner and the DQN policy, triggered by a sphere-cast around the missile launcher.
Key takeaway
For AI Engineers developing autonomous systems, consider adopting hybrid architectures that integrate classical algorithms with deep reinforcement learning. This approach can significantly improve sample efficiency and overall system robustness by assigning each problem type (e.g., routine planning vs. dynamic evasion) to the most suitable AI paradigm. Your systems will benefit from the predictability of classical methods and the adaptive capabilities of learned policies.
Key insights
Hybrid AI architectures combining classical and deep learning methods are more effective for complex autonomous systems.
Principles
- Use classical AI for deterministic problems.
- Employ RL for non-stationary, partially observable challenges.
- Stabilize inner-loop dynamics with classical control.
Method
The system switches between an A* path planner for routine navigation and a DQN policy for threat evasion, triggered by real-time environmental cues like missile detection. Training uses 24 parallel Unity environments for sample efficiency.
In practice
- Implement A* for known obstacle avoidance.
- Train DQN for dynamic threat evasion.
- Use parallel environments for faster RL training.
Topics
- Hybrid AI Architecture
- Deep Reinforcement Learning
- A* Pathfinding
- Unity ML-Agents
- Autonomous Systems
Code references
Best for: AI Engineer, Machine Learning Engineer, Robotics Engineer
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Editorial summary, takeaway, and curation by AIssential. Original article published by Towards AI - Medium.