12 KiB
12 KiB
Sanad Fleet — Data Pipeline
How robot state becomes a record on the YS Lootah fleet dashboard, end to end. This is the reference for what flows, in what shape, when, and how failures are handled. For install/ops, see README.md.
1. Big picture
ROBOT (edge) │ YS LOOTAH (cloud)
│
┌───────────────┐ read ┌──────────────┐ │ HTTPS POST ┌──────────────┐
│ robot sources │ ─────────▶ │ sanad_api_* │ ─┼───────────────▶ │ fleet server │
│ DDS / files │ │ (Docker) │ │ Bearer token │ (ingest API) │
└───────────────┘ └──────────────┘ │ └──────┬───────┘
▲ │ │ │
│ passive, read-only │ systemd │ ▼
│ (never commands motion) │ user svc │ ┌──────────────┐
▼ │ │ dashboard │
stays "online" │ │ storage │
via heartbeat │ │ alerts │
│ └──────────────┘
- Direction: outbound only. The robot opens no inbound ports; every call is an
HTTPS
POSTto the fleet server. - Transport: HTTP/1.1 + JSON (telemetry) or
multipart/form-data(map). - Auth:
Authorization: Bearer <device_token>on every request. - Identity: each robot is keyed by
sn(fleet id, e.g.r1_82); the hardwaremacrides along in telemetry.
2. API contract
The full spec (from sanad-tasks-en.html) defines these ingest endpoints. This
repo currently implements the bold ones; the rest are documented for later.
| endpoint | method | agent | status |
|---|---|---|---|
/api/v1/fleet/ingest/telemetry |
POST | R1, Go2 | ✅ implemented |
/api/v1/fleet/ingest/{sn}/map |
POST | G1 | ✅ implemented |
/api/v1/fleet/ingest/{sn}/commands |
GET | — | ⏳ spec'd, not built |
/api/v1/fleet/ingest/commands/{id}/ack |
POST | — | ⏳ |
/api/v1/fleet/ingest/{sn}/alert |
POST | — | ⏳ (critical faults; ordinary ones ride in telemetry faults[]) |
/api/v1/fleet/ingest/{sn}/logs |
POST | — | ⏳ |
/api/v1/fleet/ingest/{sn}/remote |
POST | — | ⏳ (tunnel/SSH registration) |
Auth header (all): Authorization: Bearer <device_token>.
3. Telemetry pipeline (R1, Go2)
Goal: a fresh status record every ~2 s; never go dark.
DDS topics agent (2 s loop) server
────────── ──────────────── ──────
rt/lowstate ─┐ callbacks ┌─ snapshot() ─┐ build_telemetry() ┌ POST
(LowState_) ├─────────────▶ │ battery ├──────────────────────▶│ /ingest/
rt/lf/bmsstate│ (background │ temps/dq │ derive status+faults │ telemetry
(BmsState_) ─┘ threads) │ liveness/age │ read mac └ (JSON)
└──────────────┘
│ no data?
└────────▶ heartbeat (battery:null, offline)
3.1 Sources per robot
| field | R1 (unitree_hg) |
Go2 (unitree_go) |
|---|---|---|
battery (0–100) |
rt/lf/bmsstate → BmsState_.soc |
rt/lowstate → LowState_.bms_state.soc |
charging |
BmsState_.current > +0.05 A |
bms_state.current > +0.05 A |
faults[] |
rt/lowstate motor temps + staleness |
same |
status |
derived (see 3.3); optional loco FSM GET 7001 |
derived |
position |
optional rosbridge /odom |
optional rosbridge /odom or rt/lf/sportmodestate |
mac |
NIC (/sys/class/net/<iface>/address) |
NIC |
DDS is initialized once (ChannelFactoryInitialize(domain, interface)); each
topic has a subscriber whose callback updates a locked in-memory snapshot. The
loop reads the snapshot — it never blocks on the network.
3.2 Payload
POST /api/v1/fleet/ingest/telemetry
Authorization: Bearer <device_token>
Content-Type: application/json
{ "sn": "r1_82",
"mac": "4c:bb:47:51:25:9a",
"battery": 80,
"charging": false,
"status": "idle",
"position": { "x": 12.4, "y": 3.1 }, // or null when no localization source
"faults": [],
"ts": 1731000000 }
3.3 Status derivation
if no rt/lowstate for >3 s AND never saw battery → "offline"
elif charging (bms current > +0.05 A) → "charging"
elif max |joint velocity| > 0.15 rad/s → "moving"
elif R1_READ_FSM and FSM id known → FSM label (811 ready / 4 standing / 1 damping / 0 zero_torque)
else → "idle"
3.4 Faults
Ordinary faults ride inside telemetry faults[] (the spec reserves the separate
/alert endpoint for critical, immediate events like e-stop):
| code | trigger | severity |
|---|---|---|
LOW_BATTERY |
soc ≤ LOW_SOC (default 15) |
warning |
MOTOR_OVERTEMP |
any motor temp ≥ MOTOR_TEMP_MAX (default 85 °C) |
warning |
COMMS_STALE |
no rt/lowstate for > 3 s |
critical |
3.5 Heartbeat & failure handling
- No DDS / no state → still POST with
battery:null,status:"offline"so the dashboard shows the robot as reachable (the spec's "send a heartbeat" rule). - unitree_sdk2py missing → the agent logs a warning and runs in heartbeat mode (no crash).
- POST fails (transport or non-2xx) → logged, loop continues; next tick retries
in
POLL_INTERVALseconds. No back-pressure, no queue (latest state wins). - Every tick is wrapped — one bad read can't kill the loop.
4. Map pipeline (G1)
Goal: keep the server's copy of the nav map current, sending only on change.
files on disk agent (30 s scan) server
───────────── ───────────────── ──────
maps/<robot>/*.db ─┐ discover ┌ fingerprint (size+mtime) ─┐ changed? ┌ POST
maps_meta.json ├────────▶ │ if changed: sha256 ├──yes──────▶│ /ingest/
web/data/<robot>/ │ │ load places → points[] │ │ {sn}/map
places/<map>.json ┘ └ build meta + db bytes ─────┘ └ (multipart)
│ unchanged
└────────▶ skip (state/uploaded.json)
4.1 Sources
- Map file: RTAB-Map SQLite
.db—maps/<robot>/<name>.db(web_nav3). - Metadata:
maps/<robot>/maps_meta.json→{ "<db>": {description, created_at} }. - Places → points:
web/data/<robot>/places/<map>.json({ "<name>": {x, y, z, qx, qy, qz, qw} }), converted to{name, type:"waypoint", x, y, yaw}(yaw computed from the quaternion).
4.2 Change detection
- Cheap pre-check:
size + mtimevsSTATE_DIR/uploaded.json. - If different, compute
sha256of the.db(content-true). - Upload; on success, record the new fingerprint. A restart re-reads state → no redundant re-upload.
MAP_SELECT chooses scope: all (default), active (via web_nav3
GET /api/status), or newest.
4.3 Payload (two wire formats)
multipart/form-data (default) — file part db + form field meta:
POST /api/v1/fleet/ingest/g1_7892/map
Authorization: Bearer <device_token>
Content-Type: multipart/form-data
db = <floor-1.db bytes> (application/octet-stream)
meta = { "sn":"g1_7892", "name":"floor-1", "file":"floor-1.db",
"format":"rtabmap_db", "size_bytes":6994944, "sha256":"…",
"mtime":1731000000, "description":"ground floor",
"points":[ {"name":"dock","type":"waypoint","x":1.2,"y":3.4,"yaw":0.0} ] }
base64json (set MAP_UPLOAD_MODE=base64json) — same fields as JSON with the
.db as db_base64.
Server note: this uploads the raw RTAB-Map
.db(not a rendered PNG), so the server must accept aformat:"rtabmap_db"artifact. The spec's image-based map body (image_base64/resolution/origin) would instead require rendering the live/mapOccupancyGrid over rosbridge — a different path, not used here.
5. Timing
| stream | cadence | trigger |
|---|---|---|
| telemetry (R1/Go2) | every POLL_INTERVAL (2 s) |
timer |
| map (G1) | scan every POLL_INTERVAL (30 s) |
uploads only on content change |
| DDS reads | continuous (subscriber callbacks) | firmware publish rate |
| heartbeat | same as telemetry cadence | when state is unreadable |
6. Where it runs
robot host
└─ systemd --user
└─ sanad-api-<type>.service (Restart=always, enabled at boot via linger)
└─ docker start -a sanad-api-<type>
└─ container (--network host)
└─ python -u sanad_api_<type>.py ← the loop above
--network host: DDS multicast visibility (R1/Go2) and localhost access to web_nav3:8765 (G1); also the robot's real NIC MAC.- Single owner: the container is
docker created without a docker restart policy; systemd owns start/stop/restart.
7. End-to-end sequences
Telemetry tick
loop DDS(sub) agent fleet server
│ (2 s) │ │ │
│────────────▶│ snapshot │ │
│ │───────────▶│ build payload │
│ │ │──── POST JSON ────▶│ (Bearer)
│ │ │◀──── 200 OK ───────│
│ │ │ log "telemetry ok" │
Map change
scan(30s) disk agent fleet server
│────────────▶│ discover │ │
│ │───────────▶│ fingerprint │
│ │ │ changed → sha256 │
│ │ │ load points │
│ │ │── POST multipart ─▶│ (db + meta)
│ │ │◀──── 200 OK ───────│
│ │ │ save state │
8. Verified behavior (real hardware)
Confirmed against the live fleet during bring-up:
- R1 streamed real telemetry every 2 s; battery read live and drained
97 → 80%across the session;mac/sncorrect; heartbeat kicked in when the server was down. - G1 uploaded a map (
multipart,format:rtabmap_db, points with correct yaw) to the server. - The fleet server received a G1 map and R1 telemetry in the same window — the multi-robot pipeline works concurrently.
- Go2: pipeline code + image verified (builds,
unitree_goimports, simulate payloads correct); not yet run on a real Go2.