In real-world indoor fire environments, visual degradation severely impairs instruction grounding, waypoint prediction, and long-horizon exploration in vision-language navigation (VLN). Although image restoration offers a natural means to mitigate such visual degradation, existing methods primarily optimize reconstruction fidelity, which does not necessarily translate into better navigation decisions and may even corrupt task-critical cues when applied indiscriminately. In this paper, we present FireNav, a decision-oriented reconstruction evidence routing framework that aligns visual restoration with navigation utility in VLN. To advance this task, we first contribute FireVLN-Bench, a paired indoor fire navigation benchmark with clean references preserving task semantics, safety supervision, and matched settings for continuous navigation and robot execution with simulated dynamics. Our FireNav retains native visual tokens and treats latent reconstruction features as auxiliary evidence, where a lightweight router leverages visual features, task context, and prior execution states to determine whether such evidence should be admitted and how strongly it should contribute to the visual tokens. To learn when reconstruction is beneficial, we further introduce decision utility calibration, which compares action prediction losses with and without candidate evidence under the same state, thereby supervising evidence selection according to its contribution to waypoint, heading, and arrival prediction. Experiments demonstrate that FireNav consistently outperforms state-of-the-art baselines in both navigation success and path efficiency across evaluation settings.
Figures & tables
Figure 1: Overview of FireVLN-Bench. The figure shows construction pipeline indoor fire scene dataset statistics and qualitative samples.
Figure 2: Overview of FireNav. A frozen native branch provides visual tokens, while a frozen reconstruction branch exposes mid-level features for fast execution and multiscale features for slow planning. FireNav aligns reconstruction features with native tokens, routes them according to the current decision state, and injects bounded residual evidence while preserving the native visual identity. The slow system uses multiscale evidence for memory-based subgoal planning, whereas the fast system uses mid-level evidence for local waypoint prediction.
Method
Venue
Physical Environment
Continuous Environment
NE ↓
OS ↑
SR ↑
SPL ↑
NE ↓
OS ↑
SR ↑
SPL ↑
Native VLN (clean)
-
4.58
68.2
54.1
42.3
3.32
79.7
67.5
56.6
Native VLN (degraded)
-
7.34
43.0
26.8
17.3
5.94
56.3
41.8
29.9
Reconstructed RGB Frontends
AdaIR ( Cui et al., 2025 )
ICLR’25
7.10
45.1
29.4
19.7
5.82
57.2
42.7
30.5
DCPT ( Hu et al., 2025 )
ICLR’25
6.68
48.8
34.1
25.1
5.33
62.0
47.5
36.6
Table 1: Quantitative comparison on FireVLN-Bench unseen test split. Among methods with degraded observations, best and second-best results are highlighted in bold and underline, respectively.
Figure 3: Qualitative comparison of waypoint predictions and trajectories. Each row shows a model configuration. The first three columns show local waypoint predictions at keyframes, and the last shows trajectories on occupancy maps. Red crosses mark task interruptions ( STOP ).
Variant
Physical Environment
Continuous Environment
SR ↑
SPL ↑
Clean SR ↑
SR ↑
SPL ↑
Clean SR ↑
Full FireNav
41.6
32.0
52.8
56.1
45.5
67.1
Always-on evidence
36.1
26.0
50.4
50.5
38.6
65.6
w/o decision context
38.9
29.0
53.2
53.7
42.1
67.1
w/o quality statistics
39.8
30.0
53.6
54.4
43.1
66.8
w/o utility calibration
37.8
28.0
52.9
52.2
40.6
66.7
Table 2: Ablation study of FireNav. Clean SR measures retention of the native behavior under clean observations. All variants use the same navigation backbone and evaluation protocol.
Method
Additional Cost
End-to-End Latency
System
Encoder/Restoration (ms) ↓
Fusion (ms) ↓
P50 (ms) ↓
P95 (ms) ↓
Hz ↑
Peak GB ↓
Native VLN
0.0
0.0
280.1
359.2
3.53
18.06
AdaIR
209.9
2.0
491.9
597.4
2.02
20.26
DCPT
96.5
2.0
378.8
464.8
2.62
19.16
MoCE-IR-S
126.1
2.0
408.5
498.1
2.43
19.36
DFPIR
113.9
2.0
396.9
485.0
2.51
19.66
Table 3: Runtime comparison under the same execution setting. P50/P95 denote update latency.
Appendix figures & tables9 assets
Supplementary material from the paper’s appendix.
Appendix
Split
Scenes
Layouts
Routes/Layout/Task
Episodes/Task
Four-Task Episodes
Train
40
160
100
16,000
64,000
Validation Seen
40
160
25
4,000
16,000
Validation Unseen
8
32
25
800
3,200
Test Unseen
12
48
25
1,200
4,800
Appendix
Table 4: Data allocation in FireVLN-Bench. Validation seen uses held-out episodes from the training scenes and therefore does not introduce additional scene identities.
Encoder
Physical Environment
Continuous Environment
Always-on
Quality Gate
FireNav
Always-on
Quality Gate
FireNav
AdaIR
23.6
26.0
27.8
35.6
38.0
40.3
DCPT
27.0
28.6
32.5
39.2
41.2
46.0
MoCE-IR-S
26.4
29.4
32.3
39.1
42.1
45.7
DFPIR
25.4
28.6
30.8
37.9
41.2
44.2
R2R-Compos
26.0
29.2
32.0
38.6
41.9
45.5
Appendix
Table 5: Factorial comparison of reconstruction encoders and evidence routing strategies. Values are SPL (%). Each encoder uses the same evidence budget and optimization recipe.
Intervention
Physical Environment
Continuous Environment
SR ↑
SPL ↑
Clean SR ↑
SR ↑
SPL ↑
Clean SR ↑
Matched evidence
41.6
32.0
52.8
56.1
45.5
67.1
Exact bypass
26.8
17.3
54.1
41.8
29.9
67.5
Zero spatial features
28.0
18.0
54.0
41.2
29.5
68.1
Shuffled content
29.3
19.0
53.6
42.4
30.4
66.9
Incorrect view content
27.3
17.4
53.4
40.5
29.2
67.3
Appendix
Table 6: Evidence intervention analysis with the same trained FireNav checkpoint. Evidence content or router context is modified without retraining the navigator.
Method
Degraded Observations
Clean Observations
ADE ↓
FDE ↓
Heading ↓
Arrival F1 ↑
ADE ↓
Heading ↓
Arrival F1 ↑
Native VLN
0.666
1.101
21.0
0.474
0.504
17.0
0.670
MoCE-IR-S
0.595
0.991
18.8
0.546
0.516
17.5
0.657
R2R-Compos
0.615
1.021
19.5
0.523
0.522
17.8
0.644
HOGformer
0.615
1.036
19.8
0.509
0.511
17.3
0.663
BiLaLoRA
0.600
1.001
18.6
0.552
0.514
17.4
0.663
Appendix
Table 7: Action prediction under degraded and clean observations. ADE/FDE are measured in meters, heading error in degrees, and arrival F1 as a fraction.
Method
Image Quality
Action ADE
Cost
PSNR ↑
SSIM ↑
Degraded ↓
Clean ↓
RGB ms ↓
Raw degraded
16.8
0.680
0.666
0.504
0.0
AdaIR
15.9
0.648
0.645
0.533
69.9
DCPT
17.8
0.717
0.603
0.518
31.8
MoCE-IR-S
18.2
0.728
0.595
0.516
42.0
DFPIR
17.6
0.711
0.608
0.520
38.1
Appendix
Table 8: Relationship between image reconstruction quality, action prediction, and RGB reconstruction cost.
Method
Physical Environment
Continuous Environment
Collision ↓
Fall ↓
Stuck ↓
False STOP ↓
Collision ↓
False STOP ↓
Native VLN (clean)
10.3
1.9
6.3
3.2
3.5
3.3
Native VLN (degraded)
33.2
3.2
16.2
13.5
19.8
14.5
AdaIR
31.0
3.2
15.7
12.7
18.1
13.2
DCPT
23.6
2.2
13.7
10.0
13.2
10.2
MoCE-IR-S
22.5
2.1
12.8
9.0
11.8
10.1
Appendix
Table 9: Safety and terminal behavior on FireVLN-Bench. All values are percentages of test episodes.
Method / Split
Physical Environment
Continuous Environment
SR ↑
SPL ↑
SR ↑
SPL ↑
Native VLN / Seen Val.
36.4
26.2
45.8
35.0
Native VLN / Unseen Val.
33.5
22.6
40.0
29.5
Native VLN / Unseen Test
26.8
17.3
41.8
29.9
BiLaLoRA / Seen Val.
44.7
34.0
53.8
43.0
BiLaLoRA / Unseen Val.
40.6
29.6
48.0
37.4
Appendix
Table 10: Generalization across seen validation, unseen validation, and unseen test environments.
Method / Task
Physical Environment
Continuous Environment
SR ↑
SPL ↑
SR ↑
SPL ↑
Native VLN / Instruction
26.8
17.3
41.8
29.9
Native VLN / Object
20.0
12.0
28.1
18.4
Native VLN / Point
48.3
35.8
63.0
50.7
BiLaLoRA / Instruction
35.6
25.2
48.8
40.1
BiLaLoRA / Object
25.3
16.1
34.3
23.5
Appendix
Table 11: Generalization across instruction, object, and point goal tasks.
Configuration
Cache
Runtime
PE
CE
Calls
Hit (%)
P50
P95
SR
SPL
SR
SPL
No history, 3 current views
3
0.0
206.1
256.5
37.9
28.0
52.5
41.5
4 history + 3 current views
3
57.1
242.1
302.2
40.8
30.7
54.8
43.9
10 history + 3 current views
3
76.9
277.9
348.9
41.2
31.5
56.0
45.2
20 history + 3 current views
3
87.0
310.1
389.4
41.6
32.0
56.1
45.5
20 history, front-view evidence only
1
95.2
292.1
369.5
39.2
29.2
54.1
42.8
Appendix
Table 12: Effect of visual history and feature caching.