sl-perception
c1b82608d5
Adds stereo ORB-based visual odometry to saltybot_visual_odom package. New modules: - orb_stereo_matcher.py: ORB feature detection (cv2.ORB_create) with BFMatcher NORM_HAMMING + Lowe ratio test for temporal matching (infra1 prev→curr). Stereo scale method matches infra1↔infra2 under epipolar row constraint (|Δrow|≤2px), computes depth = baseline_m * fx / disparity. - stereo_orb_node.py: StereoOrbNode subscribes to infra1+infra2+depth (ApproximateTimeSynchronizer 3-topic), detects/matches ORB temporally, estimates SE(3) via Essential matrix (5-point RANSAC) using StereoVO, recovers metric scale from D435i aligned depth (primary) or stereo baseline disparity (fallback). Publishes nav_msgs/Odometry on /saltybot/visual_odom and broadcasts TF2 odom→camera_link. Baseline auto-updated from infra2 camera_info Tx (overrides parameter). - config/stereo_orb_params.yaml, launch/stereo_orb.launch.py - setup.py: adds stereo_orb entrypoint, installs launch+config dirs 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.