ROOT CAUSE:
donkey_sim.py calc_reward() uses forward_vel = dot(heading, velocity).
A spinning car ALWAYS has forward_vel > 0 (always moving 'forward' relative
to its own heading), so it earned positive reward indefinitely while circling.
v3 WAS INSUFFICIENT:
v3 applied efficiency only to the speed BONUS: original × (1 + speed×eff×scale)
But 'original' from sim was still exploitable: CTE≈0 while spinning → original=1.0/step
Efficiency killed the speed bonus but not the base reward.
47k-step run: spinning = 1.0/step × 47k = 47k reward (never crashes in circle)
v4 FIX — base × efficiency × speed:
reward = (1 - abs(cte)/max_cte) × efficiency × (1 + speed_scale × speed)
Completely ignores sim's bogus forward_vel reward.
Spinning (eff≈0): reward ≈ 0 regardless of CTE or speed.
ALL three terms must be high to earn reward — cannot be gamed.
Key new test: test_circling_at_zero_cte_gives_near_zero_reward
Worst-case exploit (CTE=0 spinning) → avg reward < 0.15 (was 1.0 in v3)
forward_beats_circling_by_3x confirmed.
Also: update Phase 2 autoresearch timesteps test, research log updated.
Agent: pi/claude-sonnet
Tests: 40/40 passing
Tests-Added: +1 (core v4 circling guarantee)
TypeScript: N/A
Problems fixed:
- Timesteps 5k-30k caused all trials to timeout (PPO+CNN+CPU needs ~0.1s/step)
- New range: 1000-5000 steps fits well within 480s timeout
- PPO random init policy outputs throttle~0 -> car sits still -> fix with ThrottleClampWrapper (min 0.2)
- Sim stuck detection: if speed<0.02 for 100 consecutive steps, stop training and report error
- Sim frozen detection: if observation unchanged for 30 steps, stop training (connection lost)
- eval_episodes reduced to 3 to speed up evaluation phase
Agent: pi/claude-sonnet
Tests: 37/37 passing
Tests-Added: 0 (behaviour change only)
TypeScript: N/A
- Rebuilt donkeycar_sb3_runner.py: real PPO/DQN model.learn() + evaluate_policy() + model.save()
- Added SpeedRewardWrapper: reward = speed * (1 - |cte|/max_cte)
- Added ChampionTracker: tracks best model across all trials, writes manifest.json
- Rebuilt autoresearch_controller.py: Phase 1 results separated from random-policy data
- Added timesteps to GP search space
- Added --push-every N for automatic git push
- Added 37 passing tests: discretize_action, reward_wrapper, autoresearch_controller, runner_integration
- Scaffolded project with agent harness (large mode): PROJECT-SPEC, DECISIONS, IMPLEMENTATION_PLAN, EXECUTION_MASTER
- Fixed: model.save() never called before model is defined (was root cause of all prior NameError crashes)
- Fixed: random policy replaced with real trained policy evaluation
Agent: pi/claude-sonnet
Tests: 37/37 passing
Tests-Added: +37
TypeScript: N/A
Paul Huliganga