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MultiRoombaRover/server/src/services/roverLearningService/workers/infer.py
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2026-09-28 14:18:35 -04:00

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8.2 KiB
Python

#!/usr/bin/env python3
"""Live policy worker. JSON state on stdin, proposals on stdout; no rover writes."""
import argparse
import collections
import hashlib
import json
import math
from pathlib import Path
import sys
import threading
import time
import av
import numpy as np
import torch
from policy import Policy, VERSION, SLOTS, VALUES, HEIGHT, WIDTH, encode_command, sensor_vector
def main():
parser = argparse.ArgumentParser(description=__doc__)
parser.add_argument('--model', required=True)
parser.add_argument('--url', required=True)
parser.add_argument('--threads', type=int, default=4)
parser.add_argument('--threshold', type=float, default=0.7)
args = parser.parse_args()
torch.set_num_threads(args.threads)
torch.set_num_interop_threads(1)
directory = Path(args.model)
metadata = json.loads((directory / 'model.json').read_text())
if metadata['specification']['version'] != VERSION:
raise ValueError('Model specification is incompatible')
if hashlib.sha256((directory / 'weights.pt').read_bytes()).hexdigest() != metadata['sha256']:
raise ValueError('Model weights checksum mismatch')
schema = metadata['specification']['commands']
model = Policy().eval()
model.load_state_dict(torch.load(directory / 'weights.pt', map_location='cpu', weights_only=True))
observations = collections.deque(maxlen=2048)
mutex = threading.Lock()
closed = threading.Event()
def read_input():
try:
for line in sys.stdin:
event = json.loads(line)
with mutex:
observations.append(event)
finally:
closed.set()
threading.Thread(target=read_input, daemon=True).start()
values = np.zeros((SLOTS, VALUES), dtype=np.float32)
last_commands = np.full(SLOTS, -np.inf)
sensors, sensor_time = {}, 0
history = collections.deque(maxlen=32)
latched = set()
sampled = 0
with av.open(args.url, options={'rtsp_transport': 'tcp', 'timeout': '3000000',
'use_wallclock_as_timestamps': '1'}) as video:
stream = video.streams.video[0]
stream.codec_context.thread_count = 1
for frame in video.decode(stream):
if closed.is_set():
return
if frame.pts is None:
continue
stamp = float(frame.pts * frame.time_base) * 1000
now = time.time() * 1000
if not math.isfinite(stamp) or abs(now - stamp) > 2000:
raise ValueError('Video time is stale or not aligned to server time')
if stamp - sampled < 99:
continue
sampled = stamp
with mutex:
while observations and observations[0]['ts'] < stamp:
event = observations.popleft()
if event['kind'] == 'settings':
args.threshold = max(.05, min(.99, float(event['threshold'])))
elif event['kind'] == 'sensor':
sensors, sensor_time = event['data'], event['ts']
elif event['kind'] == 'command':
try:
encoded = encode_command(event['data'], schema)
if encoded:
slot, vector = encoded
values[slot], last_commands[slot] = vector, event['ts']
except ValueError:
pass # Unseen manual controls do not stop autonomy.
if stamp - sensor_time > 1000:
history.clear()
continue
state = np.concatenate((sensor_vector(sensors), values.flatten(),
np.minimum((stamp - last_commands) / 10000, 1).astype(np.float32),
np.isfinite(last_commands).astype(np.float32)))
pixels = frame.to_ndarray(width=WIDTH, height=HEIGHT, format='rgb24').transpose(2, 0, 1).copy()
history.append((stamp, pixels, state))
selected = []
for offset in (900, 600, 300, 0):
candidates = [entry for entry in history if entry[0] <= stamp - offset + .01]
if not candidates or stamp - offset - candidates[-1][0] > 200:
break
selected.append(candidates[-1])
if len(selected) != 4:
continue
before = time.perf_counter()
with torch.inference_mode():
logits, numeric, wheel_output = model(torch.from_numpy(np.stack([row[1] for row in selected])).unsqueeze(0).float() / 255,
torch.from_numpy(np.stack([row[2] for row in selected])).unsqueeze(0))
probabilities = logits[0].sigmoid().tolist()
predictions = numeric[0].tolist()
wheel_speeds = [round(value * 500) for value in wheel_output[0].tolist()]
if not all(math.isfinite(value) for value in probabilities):
raise ValueError('Nonfinite model output')
families = {}
active = set()
proposals = []
for slot, descriptor in enumerate(schema):
if descriptor['template']['type'] == 'drive':
continue
command = json.loads(json.dumps(descriptor['template']))
family = command['type']
if family == 'peripheral':
family += ':' + str(command['peripheral']['id']) + ':' + str(command['peripheral']['control'])
for index, field in enumerate(descriptor['fields']):
number = predictions[slot][index]
if not math.isfinite(number):
raise ValueError('Nonfinite control value')
number = math.tan(max(-.98, min(.98, number)) * math.pi / 2) * field['scale']
target = command
for key in field['path'][:-1]:
target = target[key]
target[field['path'][-1]] = round(number) if field['integer'] else number
proposals.append({'slot': slot, 'score': probabilities[slot], 'command': command,
'reason': 'Below threshold'})
if probabilities[slot] < args.threshold:
continue
active.add(slot)
discrete = command['type'] in ('headlight', 'laser', 'horn', 'song', 'raw')
if family not in families or probabilities[slot] > families[family][0]:
families[family] = (probabilities[slot], command, slot, discrete)
latched.intersection_update(active)
# Choose the winning action before latching, so a held toggle cannot
# expose a competing lower-confidence toggle on the following tick.
commands = [command for _, command, slot, discrete in families.values()
if not discrete or slot not in latched]
winners = {row[2]: row for row in families.values()}
for proposal in proposals:
slot = proposal['slot']
if slot in active:
proposal['reason'] = ('Competing action' if slot not in winners else
'Held discrete action' if winners[slot][3] and slot in latched else 'Proposed')
for _, _, slot, discrete in families.values():
if discrete:
latched.add(slot)
commands.insert(0, {'type': 'drive', 'driveDirect': dict(zip(('left', 'right'), wheel_speeds))})
print(json.dumps({'kind': 'prediction', 'frameAt': stamp, 'sensorAt': sensor_time,
'latencyMs': (time.perf_counter() - before) * 1000,
'wheelSpeeds': wheel_speeds, 'sensorPresent': sensor_vector(sensors)[32:].tolist(),
'commands': commands, 'proposals': proposals, 'threshold': args.threshold}, allow_nan=False), flush=True)
if __name__ == '__main__':
try:
main()
except Exception as error:
print(json.dumps({'kind': 'error', 'message': str(error)}), flush=True)
raise SystemExit(1)