New packages:
saltybot_social_msgs — FusedTarget.msg custom message
saltybot_social_tracking — 4-state Kalman fusion node
saltybot_social_tracking/tracking_fusion_node.py
Subscribes to /uwb/target (PoseStamped, ~10 Hz) and /person/target
(PoseStamped, ~30 Hz) and publishes /social/tracking/fused_target
(FusedTarget) at 20 Hz.
Source arbitration:
• "fused" — both UWB and camera are fresh; confidence-weighted blend
• "uwb" — UWB fresh, camera stale
• "camera" — camera fresh, UWB stale
• "predicted" — all sources stale; KF coasts for up to predict_timeout (3 s)
Kalman filter (kalman_tracker.py):
State [x, y, vx, vy] with discrete Wiener acceleration noise model
(process_noise=3.0 m/s²) sized for EUC speeds (20-30 km/h, ≈5.5-8.3 m/s).
Separate UWB (0.20 m) and camera (0.12 m) measurement noise.
Velocity estimate converges after ~3 s of 10 Hz UWB measurements.
Confidence model (source_arbiter.py):
Per-source confidence = quality × max(0, 1 - age/timeout).
Composite confidence accounts for KF positional uncertainty and
is capped at 0.4 during dead-reckoning ("predicted") mode.
Tests: 58/58 pass (no ROS2 runtime required).
Note: saltybot_social_msgs here adds FusedTarget.msg; PR #98
(Issue #84) adds PersonalityState.msg + QueryMood.srv to the same
package. The maintainer should squash-merge #98 first and rebase
this branch on top of it before merging to avoid the package.xml
conflict.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Jetson Nano — AI/SLAM Platform Setup
Self-balancing robot: Jetson Nano dev environment for ROS2 Humble + SLAM stack.
Stack
| Component | Version / Part |
|---|---|
| Platform | Jetson Nano 4GB |
| JetPack | 4.6 (L4T R32.6.1, CUDA 10.2) |
| ROS2 | Humble Hawksbill |
| DDS | CycloneDDS |
| SLAM | slam_toolbox |
| Nav | Nav2 |
| Depth camera | Intel RealSense D435i |
| LiDAR | RPLIDAR A1M8 |
| MCU bridge | STM32F722 (USB CDC @ 921600) |
Quick Start
# 1. Host setup (once, on fresh JetPack 4.6)
sudo bash scripts/setup-jetson.sh
# 2. Build Docker image
bash scripts/build-and-run.sh build
# 3. Start full stack
bash scripts/build-and-run.sh up
# 4. Open ROS2 shell
bash scripts/build-and-run.sh shell
Docs
docs/pinout.md— GPIO/I2C/UART pinout for all peripheralsdocs/power-budget.md— 10W power envelope analysis
Files
jetson/
├── Dockerfile # L4T base + ROS2 Humble + SLAM packages
├── docker-compose.yml # Multi-service stack (ROS2, RPLIDAR, D435i, STM32)
├── README.md # This file
├── docs/
│ ├── pinout.md # GPIO/I2C/UART pinout reference
│ └── power-budget.md # Power budget analysis (10W envelope)
└── scripts/
├── entrypoint.sh # Docker container entrypoint
├── setup-jetson.sh # Host setup (udev, Docker, nvpmodel)
└── build-and-run.sh # Build/run helper
Power Budget (Summary)
| Scenario | Total |
|---|---|
| Idle | 2.9W |
| Nominal (SLAM active) | ~10.2W |
| Peak | 15.4W |
Target: 10W (MAXN nvpmodel). Use RPLIDAR standby + 640p D435i for compliance.
See docs/power-budget.md for full analysis.