Autonomous Driving

AI Technologies & Tricks

BEV · LiDAR · fusion · occupancy · motion · planning · end-to-end (UniAD / VAD / Tesla FSD)

VLM reasoning · world models (GAIA / Cosmos) · neural simulators

24 sections • foundations through the 2026 frontier

The AI stack behind every robotaxi and FSD

April 2026 • Version 1.0

Algorithm names link to their original papers (arXiv / publisher).

Contents

1. Foundations: The AV Stack

2. Sensor Stack

3. Camera-Only Perception (BEV)

4. LiDAR Perception

5. Sensor Fusion

6. Occupancy Networks

7. Online HD Mapping

8. Tracking and Multi-Object Tracking

9. Motion Prediction

10. Planning and Control

11. End-to-End Driving

12. VLM-Based Reasoning Driving

13. World Models for AV

14. Closed-Loop Simulation

15. Auto-Labeling and Data Engines

16. Neural Reconstruction for AV

17. Foundation Models for AV

18. Safety and Verification

19. On-Vehicle Compute

20. Industry Players and Approaches

21. Datasets

22. Training Infrastructure for AV

23. Recent Frontier (2025–2026)

24. Production Stack 2026

Appendix A: Twenty-Five Things to Know

Appendix B: Decision Tree — “Which AV Component?”

Appendix C: Year-by-Year AV Milestones

1. Foundations: The AV Stack

1.1 Levels of autonomy (SAE)

1.2 The classical AV stack

1. Sensor synchronization + calibration.

2. Per-sensor perception (2D detection, 3D detection from LiDAR).

3. Sensor fusion to BEV / unified rep.

4. Tracking + ID across frames.

5. Lane / road geometry / HD map matching.

6. Motion prediction for tracked objects.

7. Planning + control.

1.3 The 2024–26 trend: end-to-end

Collapse stages 2–6 (sometimes 1–7) into a single neural network. Pioneered by Tesla FSD v12; followed by Wayve, Waymo, NVIDIA, etc.

1.4 Three architectural approaches

1. Modular classical: Waymo (mostly), Cruise, Mobileye.

2. Modular neural (each stage NN, joint training): UniAD-style.

3. End-to-end neural: Tesla FSD v12+, Wayve, Hydra-MDP.

1.5 Hybrid is dominant

Key

The 2026 reality: end-to-end is the new baseline for academic / startup work. Modular hybrid (with neural perception + classical safety overlay) dominates production at most large players. Neither is purely winning yet.

1.6 Industry split

2. Sensor Stack

2.1 Camera

2.2 LiDAR

2.3 Radar

2.4 Ultrasonic / IMU / GNSS

2.5 HD map (controversial)

2.6 Sensor calibration

2.7 Sensor trade-offs (Tesla vs Waymo)

Vision-only (Tesla) Sensor-rich (Waymo)
Hardware cost low ($100s) high ($10k+)
Weather robustness lower higher
Long-range detection limited strong
Scale economics better worse
Compute requirement high (vision is heavy) moderate
Edge-case generalization TBD better in some

3. Camera-Only Perception (BEV)

3.1 The BEV approach

Convert per-camera image features into a top-down “bird’s-eye-view” representation. Standardized output format for downstream prediction / planning.

3.2 LSS (Lift-Splat-Shoot)

First major BEV-from-camera method (Philion & Fidler 2020):

3.3 BEVFormer (Li et al. 2022)

Cross-attention from BEV queries to multi-camera features: DA(q, p) = X m Wm X k Amk Vm(p + ∆pmk), deformable attention with predicted offsets. Temporal self-attention pulls from BEVt−1. Standard since 2022.

3.4 BEVFormer V2

Adds perspective view auxiliaries; longer temporal context. Stronger.

3.5 BEVDet, BEVDepth

Variants of LSS with improved depth estimation. BEVDepth: explicit depth supervision via LiDAR.

3.6 PETR / PETRv2 / StreamPETR

Position-encoded queries; multi-view 3D detection without explicit BEV. StreamPETR: streaming temporal. State-of-the-art camera-only 3D detection.

3.7 Far3D

Long-range detection (up to 150m) via two-stage refinement.

3.8 SparseBEV

Sparse query-based BEV (one query per object). Cheaper compute, comparable quality to dense BEV.

3.9 Camera-only frontier (2026)

4. LiDAR Perception

4.1 VoxelNet / SECOND

4.2 PointPillars (Lang et al. 2019)

Pillar (vertical column) encoding:

4.3 CenterPoint (Yin et al. 2021)

Anchor-free; predict center heatmap of objects + per-center offsets / boxes. Two-stage refinement on second pass. Strong on Waymo / nuScenes.

4.4 PV-RCNN++

Point + voxel hybrid; strong on long-tail.

4.5 TransFusion

Transformer-based; fuses LiDAR + camera. Standard fusion baseline.

4.6 DSVT (Dynamic Sparse Voxel Transformer)

Sliding-window voxel attention; balances dense / sparse.

4.7 SAFDNet

2024 SOTA fully sparse detector. Comparable accuracy at much faster runtime.

4.8 LiDAR-only choice

5. Sensor Fusion

5.1 The fusion problem

Combine camera (rich semantics, no depth) + LiDAR (dense depth, sparse semantics) + radar (velocity / weather) into one BEV representation.

5.2 BEVFusion (MIT and PKU variants)

5.3 TransFusion (Bai et al.)

LiDAR-first; camera as cross-attention conditioning. Each LiDAR query attends to relevant camera regions.

5.4 CMT (Cross-Modal Transformer)

Token-level fusion; LiDAR + camera tokens jointly attended.

5.5 FUTR3D

3D detection via cross-modal transformer; supports camera + LiDAR + radar.

5.6 SparseBEV-fusion

Sparse query-based BEV fusion; cheap.

5.7 Camera-LiDAR alignment

Critical: precise extrinsic calibration; time synchronization. Calibration drift hurts fusion quality dramatically.

5.8 Late vs early fusion

5.9 Radar fusion

Active research:

6. Occupancy Networks

6.1 The occupancy formulation

3D voxel grid V ∈{0, 1}X×Y ×Z + multi-class semantics c ∈{1, . . . , C}. Predict per-voxel occupancy + class. Catches general obstacles regardless of category.

6.2 Why occupancy?

6.3 TPVFormer

Tri-plane (XY, YZ, XZ) representation instead of full voxel grid. Compact and effective.

6.4 OccFormer / SurroundOcc / FB-OCC

Variants on dense voxel prediction:

6.5 SparseOcc / OPUS

Sparse occupancy: only predict non-empty voxels. ∼100× memory savings. Production-friendly.

6.6 Occupancy loss

Locc = CEvoxel + λg Lov´asz + λa Affinity, where Lov´asz handles class imbalance, affinity preserves local structure.

6.7 COTR, CVT-Occ

2024+ improvements; better long-tail handling.

6.8 Tesla’s occupancy network

Occupancy network is a core component of Tesla FSD perception (revealed at AI Day 2022). General obstacle detection without box-style classification.

6.9 Occupancy + flow

Some methods predict occupancy flow (per-voxel velocity). Useful for motion prediction: OccWorld, FlowOcc3D.

7. Online HD Mapping

7.1 The mapless trend

Replace pre-built HD maps with online perception. Tesla’s bet; increasingly adopted.

7.2 HDMapNet (early 2022)

Predict semantic BEV map (lanes, road boundaries, pedestrian crossings).

7.3 MapTR (Liao 2022)

7.4 MapTRv2

Improved: hierarchical predictions, PV (perspective-view) auxiliary.

7.5 StreamMapNet

Streaming temporal aggregation; better consistency over time.

7.6 MapEX

Map prior conditioning; combine pre-built + online.

7.7 PivotNet

Pivot-point prediction for cleaner topology.

7.8 VectorMapNet

Earlier vectorized map prediction.

7.9 Online map components

7.10 Why online mapping?

7.11 HD map vs online: hybrid

Many production stacks use both:

8. Tracking and Multi-Object Tracking

8.1 Tracking-by-detection

8.2 Transformer trackers

TransTrack, MOTR, MeMOTR: end-to-end track-by-attention. Track queries propagate across frames.

8.3 3D MOT

8.4 Streaming temporal aggregation

Cumulative state across past frames. StreamPETR / StreamMapNet pattern.

8.5 Long-tail tracking

Rare object classes (animals, debris) hard. Open-vocabulary tracking emerging (OVTrack).

8.6 Track-then-detect vs detect-then-track

Detect-then-track: classical; per-frame detect + associate. Robust. Track-then-detect: track queries propagate; emergent tracking. End-to-end.

9. Motion Prediction

9.1 The problem

Given current ego-state + tracked objects, predict their next-T trajectory distribution.

9.2 Vector representations

VectorNet: encode all map + agent context as polyline vectors with attention. TNT (Trajectory NN with Targets): target-driven trajectory. MultiPath++: multi-modal trajectory + endpoints.

9.3 Wayformer (Waymo)

Transformer over diverse inputs (map, agents, traffic lights). Multi-axis attention. Strong baseline.

9.4 MTR (Motion TransfoRmer)

Anchor-trajectory queries refined per-step. SOTA on Waymo Open Motion 2023.

9.5 MTR++

Multi-agent joint prediction. Models interactions explicitly.

9.6 QCNet (Query-Centric Network)

Query-centric encoding for invariance to ego frame. Strong generalization.

9.7 SmartRefine

Iterative trajectory refinement.

9.8 Output structure

Predict K trajectory modes with probabilities πk + per-step Gaussians: p(τ|h) = X k πk(h) Y t N(τt; µk,t, Σk,t).

9.9 Loss

Min-of-K: only the best mode trains for displacement; mode classification on closest mode (winner-takes-all). Avoids mode-averaging. L = min k ∥ˆτk −τ ∗∥2 + λc CE(ˆπ, k∗).

9.10 Multi-agent joint prediction

Predict joint trajectory of all agents. Models interactions (e.g., one car yielding to another). MTR++, JFP, M2I.

9.11 Closed-loop integration

Motion prediction →planning input. Reactive planning depends on accurate prediction.

10. Planning and Control

10.1 Classical planning

10.2 ML-based planning

10.3 Hierarchical planner-controller

10.4 Control

10.5 Reactive vs deliberative

10.6 Safety overlay

11. End-to-End Driving

11.1 The premise

Single neural network from sensor input to control output. Joint training on all stages.

11.2 Why end-to-end?

11.3 UniAD (CVPR 2023 best paper)

Unified architecture with shared BEV features driving:

11.4 VAD / VADv2*** (Vectorized Autonomous Driving)

Replace dense BEV with vectorized representations throughout. Faster + lighter.

11.5 GenAD

Generative architecture: predict the trajectory distribution explicitly.

11.6 GraphAD

Scene graph for compositional reasoning.

11.7 SparseDrive***

Sparse queries throughout. Production-friendly.

11.8 DriveTransformer ***

Heavy Transformer architecture for end-to-end.

11.9 Hydra-MDP

Multi-Diversity Planning with multiple anchor trajectories. Hedged prediction.

11.10 PARA-Drive***

Parallel architecture for end-to-end.

11.11 Tesla FSD v12+ (2024)

11.12 End-to-end loss

Le2e = X τ λτLτ + λpLplan, Lplan = ∥ˆτ −τ ∗∥2 + λcCollisionPenalty(ˆτ). Sum of auxiliary task losses + planning loss + safety penalty.

11.13 Scaling story

11.14 Limitations

12. VLM-Based Reasoning Driving

12.1 The premise

Use a VLM to reason about complex driving scenarios. Combine perception + language reasoning.

12.2 Wayve LINGO-1 / LINGO-2

12.3 DriveGPT4 / DriveLM / DriveVLM

VLMs fine-tuned on driving Q&A. Produce reasoning + plans:

12.4 LMDrive (closed-loop)

LM in closed-loop driving. Conditional generation of trajectories.

12.5 Senna (Wayve)

VLM as high-level planner + low-level control net.

12.6 Reason2Drive

Causal-reasoning benchmark + dataset.

12.7 DriveMM, DriveDPO

Various VLM-based driving frameworks.

12.8 The two-network split (Helix-style)

12.9 Benefits

12.10 Challenges

13. World Models for AV

13.1 Why world models?

Closed-loop simulation: re-render real driving log under perturbed trajectories. Train policies in counterfactual scenarios. Plan over imagined futures.

13.2 GAIA-1 / GAIA-2 (Wayve)

13.3 DriveDreamer / DriveDreamer-2

Open AV world models. Text + action-controlled scenario generation.

13.4 Vista

Driving / scene-level video synthesis with controllability.

13.5 MagicDrive / MagicDrive3D

3D-aware video synthesis for AV.

13.6 Cosmos (NVIDIA)

General world-model platform; positioned as substrate for AV + robotics. Open weights for some variants.

13.7 WoVoGen

World-volumetric generation. Voxel-grid-style world model.

13.8 DriveWorld / OccWorld

Occupancy-grid-based world models. Predict future occupancy.

13.9 Closed-loop AV simulation pipeline

1. Capture real driving log.

2. Reconstruct scene (NeuRAD / EmerNeRF / StreetGaussians).

3. Replay with counterfactual actions.

4. Render via world model (or neural simulator).

5. Evaluate policy.

13.10 Long-tail edge case generation

World models can:

14. Closed-Loop Simulation

14.1 Why closed-loop?

Open-loop evaluation (replay logs) doesn’t capture how policy interacts with environment. Closed-loop is essential for true policy testing.

14.2 Classical simulators

14.3 Benchmarks

14.4 Neural simulators (the new wave)

14.5 Hybrid: physics + neural

14.6 Cosmos Predict (NVIDIA)

Diffusion + autoregressive variants. Action-conditioned video. Closed-loop ready.

14.7 Sim-to-real transfer

14.8 Production simulator stacks

15. Auto-Labeling and Data Engines

15.1 The data problem

AV needs orders of magnitude more data than typical CV:

15.2 Tesla’s data engine

1. Fleet captures driving.

2. Rare-event triggers (intervention, near-miss, model uncertainty).

3. Rare events uploaded.

4. Auto-labeled by larger offline ensemble.

5. Used to train production model.

6. Iterate weekly / monthly.

15.3 Long-tail mining

15.4 Auto-labeling

Larger / slower offline model labels frames; production model trained on labels.

15.5 Active learning

Rank candidate frames by:

15.6 Programmatic supervision

15.7 Synthetic data

15.8 Industry labeling vendors

Scale AI, Surge, Mercor, internal at Waymo / Cruise. Combination of human + auto.

16. Neural Reconstruction for AV

16.1 Why neural reconstruction?

Reconstruct real driving logs as differentiable scenes. Re-render under perturbations. Free closed-loop testing.

16.2 Block-NeRF (Tancik et al.)

Decompose city-scale scene into spatial blocks; train per-block NeRF; composite. SF / Mission Bay results.

16.3 Mega-NeRF

Multi-NeRF for large scenes; spatial partitioning + visibility prediction.

16.4 StreetGaussians

3DGS for streets. Dynamic vehicle handling via separate Gaussians per object.

16.5 EmerNeRF

Decompose static / dynamic; emerge object motion from supervision.

16.6 S-NeRF

Scalable per-scene NeRF for AV.

16.7 DrivingGaussian

3DGS for driving with multi-camera fusion.

16.8 OmniRe

Open-source comprehensive AV scene reconstruction.

16.9 NeuRAD

NeRF-based AV reconstruction with sensor fusion.

16.10 Production application

16.11 Combined with world models

Cosmos / GAIA + neural reconstruction = full closed-loop simulator.

17. Foundation Models for AV

17.1 Vision foundation models

17.2 VLM grounding for AV

17.3 Cosmos World Foundation Models (NVIDIA)

17.4 Pretrained encoders for AV

Use frozen DINOv3 / SigLIP as feature extractor; train AV-specific head. Saves data + compute.

17.5 Multi-modal foundation models for AV

18. Safety and Verification

18.1 Safety frameworks

18.2 RSS (Responsibility-Sensitive Safety, Mobileye)

Formal mathematical model of safe driving:

18.3 Statistical safety case (Waymo’s approach)

18.4 Adversarial testing

18.5 Driver state, attentiveness

18.6 Disengagement metrics

18.7 Long-tail coverage

18.8 Formal verification

19. On-Vehicle Compute

19.1 Latency budgets

19.2 NVIDIA AV hardware

19.3 Tesla AV chip

19.4 Mobileye EyeQ

19.5 Other ASIC players

Qualcomm Snapdragon Ride, Black Sesame, Horizon Robotics, NVIDIA Drive Concierge.

19.6 Optimization for vehicles

19.7 Energy / cooling

On-vehicle compute power draw: ∼100–500 W. Range impact + heat dissipation matters. Drives chip selection.

20. Industry Players and Approaches

20.1 Tesla

20.2 Waymo (Alphabet)

20.3 Wayve

20.4 Mobileye

20.5 Cruise (paused)

Multi-sensor stack; SF robotaxi paused after 2023 incident; rebuilding under GM.

20.6 Zoox (Amazon)

Multi-sensor; purpose-built robotaxi pod; SF deployment.

20.7 Aurora

Trucking + ride-hailing focus. Sensor-rich.

20.8 Pony.ai, WeRide

Chinese players; robotaxi in Beijing, Guangzhou, Shenzhen.

20.9 Xpeng, Li Auto, Nio, BYD

Chinese OEMs with proprietary AV stacks. Aggressive end-to-end deployment.

20.10 Huawei AD/ADS

Provides AV stack to Chinese OEMs.

20.11 Mercedes Drive Pilot, Honda Sensing Elite

L3 systems certified in some regions.

20.12 Comma.ai

Open-source-ish; OpenPilot driver assistance for retrofit.

20.13 NVIDIA Drive

Platform for OEMs (chips + software). Used by Mercedes, Volvo, others.

21. Datasets

21.1 Public AV datasets

Dataset Size Notes
KITTI (2012) 22 sequences legacy; small
KITTI-360 (2020) 320 km 360-camera + LiDAR
nuScenes (2019) 1000 scenes 6 cam + LiDAR + radar
Waymo Open (2019) 2000+ scenes 5 LiDAR + 5 camera
Argoverse 1/2 (2019/2022) varies motion forecasting
Lyft Level 5 (2020) 24k frames motion + maps
ApolloScape varies Chinese roads
Cityscapes (2016) 5000 imgs semantic seg
BDD100K (2018) 100k videos diverse
Mapillary Vistas 25k street-level
ZOD (Zenseact 2023) varies Sweden
DriveLM, DriveVLM-data language QA for VLM

21.2 Synthetic datasets

21.3 Motion forecasting

21.4 Closed-loop benchmarks

21.5 HD map data

22. Training Infrastructure for AV

22.1 Tesla Dojo

Tesla’s custom training cluster. D1 chip. 10× scaling roadmap. Trains FSD on 100k+ H100-equivalent.

22.2 Cloud training

22.3 Distillation pipelines

22.4 Continuous training

22.5 A/B testing

22.6 Closed-loop training

23. Recent Frontier (2025–2026)

23.1 End-to-end is mainstream

Tesla FSD v12+ proved end-to-end works. Wayve / Xpeng / Li Auto follow. Modular stacks under pressure.

23.2 VLM reasoning integration

DriveVLM / Senna / LINGO-2 demonstrate VLM-based explanation + planning. Latency vs reasoning trade-off improving.

23.3 World models for sim

GAIA-2, Cosmos, NeuRAD: closed-loop neural simulation. Replaces some real-world testing.

23.4 Online HD mapping mainstream

MapTRv2 / StreamMapNet: production-grade. Reduces dependency on pre-built maps.

23.5 Foundation-model perception

DINOv3 / SigLIP / SAM 2 as backbones. Less custom architecture; more data + scale.

23.6 NVIDIA Cosmos as platform

Cosmos Predict / Transfer / Reason for AV simulation + perception. Open weights.

23.7 Robotaxi expansion

23.8 Open research

24. Production Stack 2026

Stage Default approach Notes
3D detection (camera) StreamPETR / SparseBEV state-of-the-art
3D detection (LiDAR) PointPillars (prod) or DSVT / SAFDNet SOTA vs cheap
Sensor fusion (BEV) BEVFusion / TransFusion / CMT camera + LiDAR
Occupancy FB-OCC / SparseOcc / OPUS general obstacles
Online HD mapping MapTRv2 / StreamMapNet vectorized
Tracking ByteTrack / OC-SORT / TransTrack + 3D variants
Motion prediction Wayformer / MTR++ / QCNet multi-modal
End-to-end driving UniAD / VAD / Hydra-MDP / Tesla FSD joint train
VLM-based reasoning Wayve LINGO-2 / DriveVLM / Senna explainable
World model (closed sim) GAIA-2 / Cosmos Predict action-conditioned
Neural reconstruction StreetGaussians / EmerNeRF / OmniRe 3DGS
Sim platform Waymax / NAVSIM / Bench2Drive / CARLA open
Open-source backbone DINOv3 / SigLIP frozen features
On-vehicle compute NVIDIA Thor / Tesla AI5 / Mobileye EyeQ Ultra 1000+ TOPS
Long-tail mining active learning + auto-label + data engine Tesla-style continuous

Appendix A: Twenty-Five Things to Know

1. Levels of autonomy: L0 (none) to L5 (full).

2. Sensor stack: camera + LiDAR + radar + IMU + GNSS.

3. BEV (Bird’s-Eye-View): unified top-down representation.

4. LSS / BEVFormer / PETR for camera-only 3D detection.

5. PointPillars / CenterPoint / SAFDNet for LiDAR.

6. BEVFusion / TransFusion for sensor fusion.

7. Occupancy networks (FB-OCC / SparseOcc) for general obstacles.

8. MapTR / MapTRv2 for online HD mapping.

9. Tracking-by-detection (ByteTrack) + Transformer trackers (TransTrack).

10. Motion prediction: Wayformer / MTR++ / QCNet.

11. Min-of-K loss for multi-modal trajectory prediction.

12. UniAD (CVPR 2023) pioneered end-to-end joint training.

13. VAD / Hydra-MDP / SparseDrive: end-to-end variants.

14. Tesla FSD v12+ is end-to-end neural, mostly imitation-learned.

15. Wayve LINGO-2 / DriveVLM / Senna: VLM-based driving.

16. GAIA-1/2 / Cosmos / DriveDreamer: AV world models.

17. StreetGaussians / EmerNeRF / OmniRe: neural AV simulators.

18. RSS (Mobileye): formal safety framework.

19. Tesla data engine pattern: rare-event mining + auto-label.

20. NVIDIA Thor 2000 TOPS / Tesla HW4 / Mobileye EyeQ for on-vehicle.

21. Waymo: sensor-rich modular; Tesla: vision-only end-to-end.

22. Tesla mapless vs Waymo HD-map: opposing bets.

23. Closed-loop sim (GAIA + Cosmos + Waymax): replaces some real testing.

24. Foundation model backbones (DINOv3 / SigLIP) increasingly in AV.

25. Long-tail edge cases dominate L4 deployment effort.

Appendix B: Decision Tree — “Which AV Component?”

1. Camera-only 3D detection? →StreamPETR or SparseBEV.

2. LiDAR-only 3D detection? →PointPillars (production) or DSVT/SAFDNet (SOTA).

3. Sensor fusion? →BEVFusion / TransFusion / CMT.

4. Free-space + general obstacles? →Occupancy network (FB-OCC / SparseOcc).

5. Online HD mapping? →MapTRv2 / StreamMapNet.

6. Multi-object tracking? →ByteTrack / OC-SORT / TransTrack.

7. Motion prediction? →Wayformer / MTR++ / QCNet.

8. End-to-end driving (research)? →UniAD / VAD / Hydra-MDP.

9. VLM-based reasoning? →Wayve LINGO-2 / DriveVLM / Senna.

10. World model for closed-loop? →GAIA-2 / Cosmos Predict.

11. Neural reconstruction (sim re-render)? →StreetGaussians / EmerNeRF / OmniRe.

12. Closed-loop benchmark? →Bench2Drive / NAVSIM / Waymax.

13. On-vehicle compute platform? →NVIDIA Thor or Tesla AI5 or Mobileye EyeQ Ultra.

Appendix C: Year-by-Year AV Milestones