# SLAM Setup Plan — Jetson Orin Nano Super

**Bead:** bd-wax (plan), bd-a2j (sensor drivers done PR #17)
**Phase:** 2 | **Owner:** sl-perception
**Updated:** 2026-03-01 — revised for Jetson Orin Nano Super (replaces Nano 4GB)

> All Nano-era constraints (10W cap, 2Hz detection, 400 features, no 3D) are obsolete.

---

## Hardware

| Component | Specs |
|-----------|-------|
| AI Brain | **Jetson Orin Nano Super 8GB** — 6-core A78AE, 1024-core Ampere, **67 TOPS**, JetPack 6 |
| Depth Cam | Intel RealSense D435i — 848×480 @ 90fps, BMI055 IMU |
| LIDAR | RPLIDAR A1M8 — 360° 2D, 12m range, ~5.5 Hz |
| Wide Cams | 4× IMX219 160° CSI — front/right/rear/left 90° intervals *(arriving)* |
| FC | STM32F722 — UART bridge `/dev/ttyACM0` @ 921600 |

---

## 1. OS & ROS2

JetPack 6 = Ubuntu 22.04 → ROS2 Humble via **native apt** (no Docker workarounds needed).

```bash
sudo apt install ros-humble-desktop ros-humble-rtabmap-ros \
  ros-humble-rplidar-ros ros-humble-realsense2-camera \
  ros-humble-slam-toolbox ros-humble-nav2-bringup
```

Docker still supported for CI. Updated `Dockerfile` uses `nvcr.io/nvidia/l4t-jetpack:r36.2.0`.

---

## 2. SLAM Stack

### Primary: RTAB-Map (RGB-D + 2D LIDAR fusion)

| Parameter | Nano 4GB (old) | **Orin Nano Super** |
|-----------|---------------|---------------------|
| Detection rate | 2 Hz | **10 Hz** |
| Visual features | 400 | **1000** |
| D435i profile | 640×480×15fps | **848×480×30fps** |
| 3D point cloud | disabled | **enabled** |
| Map type | 2D only | **2D + 3D** |
| Processing time limit | 700ms | **none** |
| Short-term memory | 30 keyframes | **unlimited** |

Fusion: RPLIDAR `/scan` (fast 2D loop closure) + D435i depth (3D reconstruction + visual odometry).

### Secondary: slam_toolbox (LIDAR-only localization / pre-built map mode)

---

## 3. Architecture

```
Jetson Orin Nano Super (Ubuntu 22.04 / JetPack 6 / CUDA 12.x)

  realsense2_camera          rplidar_ros
  848×480×30fps              /scan ~5.5Hz 360°
  /camera/color              │
  /camera/depth              │
  /camera/imu ~400Hz         │
        │                    │
        └──────────┬─────────┘
                   ▼
            rtabmap_ros
            10Hz | 3D cloud | 1000 features
            → /rtabmap/map         (OccupancyGrid)
            → /rtabmap/cloud_map   (PointCloud2)
            → /rtabmap/odom        (Odometry)
                   │
                   ▼
             Nav2 stack            (Phase 2b)
             20Hz costmap
             /cmd_vel → STM32

  4× IMX219 CSI               (Phase 2c — pending hardware)
  front/right/rear/left 160°
  → panoramic stitch, person tracking
```

---

## 4. Phases

| Phase | Status | Description |
|-------|--------|-------------|
| 2a | ✅ Done (PR #17) | Sensor drivers — `saltybot_bringup` package |
| 2a+ | ✅ Done (PR #36) | Orin update: Dockerfile JetPack 6, RTAB-Map launch + config |
| 2b | ✅ Done (PR #49) | Nav2 integration — path planning + obstacle avoidance |
| 2c | ✅ Done (PR #52) | 4× IMX219 surround vision + Nav2 camera obstacle layer |
| 2d | ✅ Done (this PR) | Outdoor navigation — OSM routing + GPS waypoints + geofence |

---

## 5. RTAB-Map Config (Orin)

Full config: `jetson/config/rtabmap_params.yaml`

```yaml
Rtabmap/DetectionRate: "10"     # was 2 on Nano
Kp/MaxFeatures:        "1000"   # was 400
RGBD/LinearUpdate:     "0.05"   # 5cm  (was 10cm)
RGBD/AngularUpdate:    "0.05"   # ~3°  (was 5°)
Grid/3D:               "true"   # 3D cloud enabled  (was false)
Rtabmap/TimeThr:       "0"      # no limit  (was 700ms)
Mem/STMSize:           "0"      # unlimited  (was 30)
```

---

## 6. 4× IMX219 Layout (Phase 2c)

```
      FRONT (CSI0) 160°
LEFT  (CSI3) ×  RIGHT (CSI1)
      REAR  (CSI2) 160°
```

90° between cameras, 160° FOV → ~70° overlap at each boundary, full 360° coverage.

ROS topics (planned): `/camera/{front,right,rear,left}/image_raw` @ 30Hz,
`/camera/panoramic/image_raw` @ 15Hz (stitched equirectangular).

---

## 7. Power Budget (Orin Nano Super)

| Scenario | Total |
|----------|-------|
| SLAM active (RTAB-Map + D435i + RPLIDAR) | ~16W |
| + 4× IMX219 | ~17W |
| + Nav2 + TensorRT person detection | ~22W |

Orin Nano Super TDP: **25W max**. Recommended PSU: 5V 5A (25W) from robot buck converter.
No power gating needed. Run `sudo nvpmodel -m 0 && sudo jetson_clocks` for full performance.

---

## 8. Milestones

- [ ] Flash JetPack 6 on Orin (arriving March 1)
- [ ] `sudo apt install ros-humble-desktop ros-humble-rtabmap-ros ...`
- [ ] Verify D435i: `lsusb | grep "8086:0b3a"`
- [ ] Verify RPLIDAR: `ls /dev/rplidar`
- [ ] `colcon build --packages-select saltybot_bringup`
- [ ] `ros2 launch saltybot_bringup sensors.launch.py` — verify topics
- [ ] `ros2 launch saltybot_bringup slam_rtabmap.launch.py` — verify `/rtabmap/map`
- [ ] `ros2 topic hz /rtabmap/cloud_map` — verify 3D cloud
- [ ] Record rosbag, monitor `tegrastats` for thermal headroom
- [ ] Update static TF with real mount measurements
- [ ] Open bead: Phase 2b Nav2
- [ ] Open bead: Phase 2c IMX219 (after hardware arrives)

---

## 9. References

- [Jetson Orin Nano Super](https://www.nvidia.com/en-us/autonomous-machines/embedded-systems/jetson-orin/)
- [JetPack 6 / L4T R36](https://developer.nvidia.com/embedded/jetpack)
- [dusty-nv/jetson-containers JetPack 6](https://github.com/dusty-nv/jetson-containers)
- [rtabmap_ros ROS2](https://github.com/introlab/rtabmap_ros)
- [realsense-ros](https://github.com/IntelRealSense/realsense-ros)
- [IMX219 / nvarguscamerasrc on Jetson](https://developer.ridgerun.com/wiki/index.php/NVIDIA_Jetson_ISP_Control)
