PRIME: Perception Feedback with Situational Memory Embeddings in VLA Models
Authors: Erik Deinzer, Naya Baslan, Luca Paparusso, Narunas Vaskevicius, Peter Knott, Luigi Palmieri
Organizations: Department of Electrical Engineering and Information Technology, RWTH Aachen University, Germany · Corporate Research, Robert Bosch GmbH, Renningen, Germany · Chair of Radar System Engineering, RWTH Aachen University, Aachen, Germany
Current Vision-Language-Action (VLA) models for autonomous driving operate primarily through feedforward inference across the perception--reasoning--planning hierarchy. While modern architectures maintain temporal recurrence within the perceptual module, early perception remains blind to downstream reasoning and navigation goals, processing visual inputs agnostically without prioritizing cues informed by prior decisions. To bridge this gap, this paper introduces PRIME, a learned feedback mechanism that conditions the VLA perceptual queries on a novel Situational Memory. By aggregating latent representations of past perception, reasoning, navigation goals, and predicted behaviors across an L-step window via cross-attention, PRIME enables intent-driven perceptual attention at minimal computational cost, adding only a maximum of 29.7M parameters (0.41% of the 7.3B-parameter base model). Evaluated on the Bench2Drive closed-loop benchmark, PRIME achieves a state-of-the-art Driving Score of 82.47 (+4.73 over ORION) and a Success Rate of 60.00% (+5.38 percentage points), the highest reported Driving Score among published VLAs trained on Think2Drive demonstrations.
Figures & tables
Fig. 1 : Comparison of typical feedforward inference versus the proposed integration of situational memory via a feedback path.
Fig. 2 : Feedback injection in the QT-Former. The Situational Memory conditions decoder queries before they attend to current camera features.
Fig. 3 : FiLMXAttn processes compact sources, Attention Pooling compresses high-cardinality sources, and the resulting representations are merged before gated residual fusion with the current queries.
Fig. 4 : Attention Pooling summarizes a structured memory buffer using a fixed set of learned Extraction Queries.
Fig. 5 : Shared feedback integration. Source-specific representations from FiLMXAttn and Attention Pooling are augmented with source embeddings and concatenated. Cross-attention allows the current queries to retrieve relevant feedback context, which is fused through a gated residual connection.
Name
Trained
Epochs
QT-Former
LLM
Planner
Feedback
Adapter
✓
8
Alignment
✓
✓
4
E2E
✓
✓
✓
✓
6
TABLE I : Training modes used for PRIME. Checkmarks denote trainable components; the E2E LLM update uses LoRA.
Model
Training mode
Feedback sources
Performance
Adapt.
Align.
E2E
Q
M
R
P
S
T
NDS
mL2
DS
SR (%)
ORION (Baseline)
71.72
0.6757
77.74
54.62
PRIME-Align
✓
✓
✓
✓
✓
✓
✓
72.60
0.9595
59.74
33.63
PRIME-E2E
✓
✓
✓
✓
✓
✓
✓
70.33
0.6698
70.96
50.00
PRIME-Full
✓
✓
✓
✓
✓
✓
✓
✓
73.62
0.6788
82.47
60.00
Full vs. ORION
+1.90
+0.0031
+4.73
+5.38
TABLE II : Training-recipe ablation for the complete six-source Situational Memory. Training-mode checkmarks denote the applied optimisation phases. Feedback-source checkmarks denote the active Situational Memory sources. Lower mL2 is better.
Model
Training mode
Feedback sources
Performance
Adapt.
Align.
E2E
Q
M
R
P
S
T
NDS
mL2
DS
SR (%)
ORION (Baseline)
71.72
0.6757
77.74
54.62
PRIME- Q †
✓
✓
72.51
0.7545
61.76
32.72
PRIME- R
✓
✓
72.36
0.7259
79.31
56.36
PRIME- S †
✓
✓
72.58
0.6968
62.96
39.09
TABLE III : Single-source adapter ablation on a frozen ORION backbone. Feedback-source checkmarks denote the active Situational Memory source. Lower mL2 is better. † denotes improved detection but degraded closed-loop driving.
Model
Training mode
Feedback sources
Performance
Adapt.
Align.
E2E
Q
M
R
P
S
T
NDS
mL2
DS
SR (%)
ORION (Baseline)
71.72
0.6757
77.74
54.62
PRIME-SA1
✓
✓
✓
✓
71.96
0.6114
64.18
42.27
PRIME-Full
✓
✓
✓
✓
✓
✓
✓
✓
73.62
0.6788
82.47
60.00
TABLE IV : Combined-source ablation under sequential Alignment → E2E training. PRIME-SA1 activates only perception-side Feedback Sources ( Q and M ), similar to perception memory in tracking modules, whereas PRIME-Full uses the complete Situational Memory. Lower mL2 is better.
Method
Expert
Overall
Scenario ability SR (%)
DS
SR
Merge
Overtake
E. Brake
G. Way
T. Sign
UniAD [ 4 ]
T2D
45.81
16.36
14.10
17.78
21.67
10.00
14.21
VAD [ 5 ]
T2D
42.35
15.00
8.11
24.44
18.64
20.00
19.15
ORION [ 2 ]
T2D
77.74
54.62
25.00
71.11
78.33
30.00
69.15
SpaceDrive [ 8 ]
PDM
78.02
55.11
–
–
–
–
–
AutoVLA [ 7 ]
PDM
78.84
57.73
–
–
–
–
–
TABLE V : Comparison with published Bench2Drive VLA models. T2D and PDM denote Think2Drive and PDM-Lite training experts; scenario columns report Success Rate.
Appendix figures & tables1 asset
Supplementary material from the paper’s appendix.
Appendix
Parameter
Adapter
Alignment
E2E
Batch size
32
32
32
Learning rate
1×10−5
1×10−5
1×10−5
Epochs
8
4
6
Feedback Timesteps ( L )
12
12
12
Feedback Embed Dims
256
256
256
Feedback gate init ( α )
0.1
0.1
0.1
Appendix
TABLE VI : Training hyperparameters for PRIME. Adapter, Alignment, and E2E correspond to the training modes in Table I .
Vision-Language-Action (VLA) models have recently emerged in autonomous driving, with the promise of leveraging rich world knowledge to improve the cognitive capabilities of driving systems. However, adapting such models for driving tasks currently faces a critical dilemma between spatial perception and semantic reasoning. Consequently, existing VLA systems are forced into suboptimal compromises: directly adopting 2D Vision-Language Models yields limited spatial perception, whereas enhancing them with 3D spatial representations often impairs the native reasoning capacity of VLMs. We argue that this dilemma largely stems from the coupled optimization of spatial perception and semantic reasoning within shared model parameters. To overcome this, we propose UniDriveVLA, a Unified Driving Vision-Language-Action model based on Mixture-of-Transformers that addresses the perception-reasoning conflict via expert decoupling. Specifically, it comprises three experts for driving understanding, scene perception, and action planning, which are coordinated through masked joint attention. In addition, we combine a sparse perception paradigm with a three-stage progressive training strategy to improve spatial perception while maintaining semantic reasoning capability. Extensive experiments show that UniDriveVLA achieves state-of-the-art performance in open-loop evaluation on nuScenes and closed-loop evaluation on Bench2Drive. Moreover, it demonstrates strong performance across a broad range of perception, prediction, and understanding tasks, including 3D detection, online mapping, motion forecasting, and driving-oriented VQA, highlighting its broad applicability as a unified model for autonomous driving. Code and model have been released at https://github.com/xiaomi-research/unidrivevla
Yongkang Li, Lijun Zhou, Sixu Yan +11
Huazhong University of Science and Technology · Xiaomi EV · SKL-IOTSC, University of Macau
Vision-Language-Action (VLA) models have emerged as a promising paradigm for end-to-end autonomous driving. However, existing VLAs' training relies heavily on text-centric visual question answering and chain-of-thought reasoning data, which emphasizes linguistic reasoning rather than action-grounded planning. As a result, the learned representations capture semantic knowledge but lack spatial dependencies crucial for reliable trajectory prediction. We propose DriveTeach-VLA, a framework that explicitly teaches VLAs what to see and where to look. Driving-aware Vision Distillation (DVD) injects driving-specific perceptual priors into the vision encoder, while 2D Trajectory-Guided Prompts (2D-TGP) provide spatial conditioning aligned with feasible driving trajectories. Together, they form a vision-guided learning pipeline: what to see (DVD pretraining) - where to look (TGP-guided SFT) - how to act (TGP-guided GRPO). DriveTeach-VLA achieves the state-of-the-art performance on NAVSIM and nuScenes. Our code is available at: https://github.com/ShivaTeam/DriveTeach-VLA.
Yuguang Yang, Canyu Chen, Zhewen Tan +10
School of Electronic Information Engineering, Beihang University · Institute for AI Industry Research (AIR), Tsinghua University · National College for Excellent Engineers, Beihang University +5
Vision-Language-Action (VLA) models have recently emerged as a promising paradigm for end-to-end autonomous driving by enabling unified reasoning across perception, language, and planning. However, existing approaches lack mechanisms to exploit past failures or adapt to distribution shifts, causing the model to persistently underperform on similar scenarios where it has previously failed. In this paper, we propose DriveVLA-M0, a retrieval-augmented VLA with failure-aware latent memory. We construct a latent memory pool that stores failure cases along with their structure scene representations and expert trajectory labels, and design a dedicated Retrieve Model that decouples static road structure and dynamic agent interactions to enable structurally grounded retrieval. At inference time, retrieved cases are injected into the model via a lightweight decoupled LoRA-based test-time training (TTT) mechanism, allowing targeted and scenario-specific correction without modifying the backbone. Extensive experiments on NAVSIMv1 and NAVSIMv2 benchmark demonstrate that our approach consistently outperforms prior methods, achieving 94.1 PDMS on Navtest and 47.0 EPDMS on Navhard with only 26.44 ms TTT backward latency overhead. Furthermore, we show that DriveVLA-M0 scales effectively with additional memory, enabling training-free performance gains through memory expansion. The code is available at https://github.com/ZebinX/DriveVLA-M0.
Zebin Xing, Yupeng Zheng, Qiang Chen +10
Institute of Automation, Chinese Academy of Sciences, Beijing, China · Chongqing Chang’an Technology Co., Ltd., Chongqing, China