Query, Align, and Distill: Navigation-Aware Cross-Modal Interaction for Efficient Vision-and-Language Navigation
Authors: Zhihao Chen, Yiyuan Ge, Ziyang Wang, Pu Cao, Lu Yang
Organizations: School of Intelligent Engineering and Automation, Beijing University of Posts and Telecommunications, Beijing, China · School of Electronic and Information Engineering, South China University of Technology, Guangzhou, China · School of Computer Science and Digital Technologies, Aston University, Birmingham, U.K.
Recent large-scale Vision-and-Language Navigation (VLN) models deliver strong accuracy but remain costly to deploy due to their large parameter counts and computational requirements. We tackle efficient VLN in two steps. First, we build a high-performing teacher that makes navigation evidence selection explicit and compressible. The teacher introduces a small set of learnable query slots to extract global and local action-sufficient navigable evidence from panoramic observations via a Navigable Query Generator, then progressively grounds these evidence tokens to the instruction with an Instruction-Query Aligner for policy prediction. Second, using this explicit query bottleneck as a distillation interface, we train a compact student by transferring both where to attend and what to do. We distill the teacher's global and local navigable queries with a navigation-aware token-adaptive objective, then further match action distributions during fine-tuning. Experiments on standard VLN benchmarks demonstrate that our student nearly matches the teacher's navigation performance while reducing the number of parameters by 93.65% compared to the teacher.
Figures & tables
Fig. 1: Accuracy–efficiency trade-off on R2R (test unseen). We plot success rate (SR) against model computation (GFLOPs). Our compact student achieves near-teacher performance with substantially lower computation. Bubble size represents GFLOPs, with the 5G–300G reference bubbles indicating the scale.
Fig. 2: Overview of Query, Align, and Distill. Following the global-planning and local-acting paradigm in Vision-and-Language Navigation, history-based global candidates support long-range planning, while current-view local candidates support fine-grained action selection. The Navigable Query Generator extracts action-sufficient global and local queries, which the Instruction–Query Aligner grounds with the instruction for policy prediction. The shallower student is trained by Navigation-aware Token-adaptive Distillation and policy distribution distillation during fine-tuning. Blue and orange dashed lines denote global and local query distillation, respectively. Flame and snowflake icons mark trainable and frozen modules, respectively.
Validation Seen
Validation Unseen
Test Unseen
Method
SR ↑
SPL ↑
OSR ↑
NE ↓
SR ↑
SPL ↑
OSR ↑
NE ↓
SR ↑
SPL ↑
OSR ↑
NE ↓
Param (M)↓
GFLOPs↓
HOP+ ‡ [ 46 ]
78
73
-
2.33
67
61
-
3.49
66
60
-
3.71
164.62
50.77
KERM ‡ [ 47 ]
80
74
-
2.19
72
61
-
3.22
70
59
-
3.61
222.04
169.46
GeoVLN ‡ [ 26 ]
79
76
-
2.22
68
63
-
3.35
65
61
-
3.95
182.64
296.65
DSRG ‡ [ 48 ]
81
76
88
2.23
73
62
81
3.00
72
61
78
3.33
188.87
102.85
BEVBert ‡ [ 49 ]
81
74
88
2.17
75
64
84
2.81
73
62
81
3.13
181.08
294.32
TABLE I: Comparison with state-of-the-art methods on R2R. Pink, yellow, and orange indicate the best, second-best, and third-best results, respectively, and “–” denotes unavailable results. ‡ marks Params/GFLOPs measured from released code under our protocol, whereas † marks values reported in the original papers under the same protocol.
Validation Seen
Validation Unseen
Test Unseen
Method
SR↑
SPL↑
RGS↑
RGSPL↑
SR↑
SPL↑
RGS↑
RGSPL↑
SR↑
SPL↑
RGS↑
RGSPL↑
BEVBert [ 49 ]
73.72
65.32
57.70
51.73
51.78
36.37
34.71
24.44
52.81
36.41
32.06
22.09
GOAT [ 36 ]
78.64
71.40
63.74
57.85
53.37
36.70
38.43
26.09
57.72
40.53
38.32
26.70
EAM [ 53 ]
72.59
64.96
57.83
51.80
48.00
35.65
32.72
24.22
-
-
-
-
WPCL [ 56 ]
79.71
71.39
-
-
54.03
37.41
-
-
-
-
-
-
CONSOLE [ 57 ]
74.14
65.15
60.08
52.69
50.07
34.40
34.05
23.33
55.13
37.13
33.18
22.25
TABLE II: Comparison with state-of-the-art methods on REVERIE. Pink, yellow, and orange indicate the best, second-best, and third-best results, respectively, and “–” denotes unavailable results.
Validation Unseen
Test Unseen
Method
SR↑
SPL↑
OSR↑
RGSPL↑
SR↑
SPL↑
OSR↑
RGSPL↑
DUET [ 18 ]
36.28
22.58
50.91
3.75
33.44
21.42
43.00
4.17
GridMM [ 19 ]
37.46
24.81
53.39
3.91
36.27
21.25
48.02
4.15
GOAT [ 36 ]
40.35
28.05
54.69
5.85
40.50
25.18
50.63
6.10
WPCL [ 56 ]
42.92
26.57
52.21
-
-
-
-
-
NavQ [ 58 ]
39.09
26.65
58.79
5.51
38.59
24.50
48.92
4.48
TABLE III: Comparison with state-of-the-art methods on SOON. Pink, yellow, and orange indicate the best, second-best, and third-best results, respectively, and “–” denotes unavailable results.
Validation Seen
Validation Unseen
Method
SR ↑
SPL ↑
nDTW ↑
sDTW ↑
SR ↑
SPL ↑
nDTW ↑
sDTW ↑
HOP+ [ 46 ]
53.6
47.9
59.0
43.0
45.7
38.4
52.0
36.0
ADAPT [ 60 ]
50.3
44.6
56.3
40.6
46.9
40.2
54.1
37.7
CLEAR-C [ 61 ]
-
-
-
-
46.0
40.1
57.2
38.7
MAR M-MP [ 62 ]
-
-
-
-
50.2
-
60.3
43.9
PETL [ 63 ]
60.5
56.8
65.7
51.7
57.9
54.2
64.9
49.7
TABLE IV: Comparison with state-of-the-art methods on RxR-English. Pink, yellow, and orange indicate the best, second-best, and third-best results, respectively, and “–” denotes unavailable results.
Test Unseen (R2R)
Validation Unseen (RxR-English)
Method
SR↑
SPL↑
OSR↑
NE↓
SR↑
SPL↑
nDTW↑
sDTW↑
Ours-Teacher
80.43 ± 0.04
71.98 ± 0.02
86.14 ± 0.04
2.40 ± 0.03
77.1 ± 0.01
69.8 ± 0.2
73.4 ± 0.3
63.0 ± 0.2
Ours-Student
79.10 ± 0.05
69.53 ± 0.03
83.21 ± 0.05
2.57 ± 0.01
73.1 ± 0.02
67.2 ± 0.1
69.8 ± 0.2
61.2 ± 0.1
TABLE V: Teacher–student performance on R2R test-unseen and RxR-English validation-unseen. Values are reported as mean ± standard deviation over five runs with seeds {0,1,2,3,4} .
Test Unseen (REVERIE)
Test Unseen (SOON)
Method
SR↑
SPL↑
RGS↑
RGSPL↑
SR↑
SPL↑
OSR↑
RGSPL↑
Ours-Teacher
60.18 ± 0.04
44.20 ± 0.02
41.90 ± 0.02
29.62 ± 0.02
43.43 ± 0.01
28.04 ± 0.01
53.45 ± 0.04
7.32 ± 0.02
Ours-Student
59.01 ± 0.03
43.12 ± 0.01
40.32 ± 0.01
28.24 ± 0.03
41.04 ± 0.01
27.13 ± 0.02
51.36 ± 0.02
6.98 ± 0.03
TABLE VI: Teacher–student performance on the goal-oriented REVERIE and SOON test-unseen splits. Values are reported as mean ± standard deviation over five runs with seeds {0,1,2,3,4} .
R2R (Test Unseen)
SOON (Test Unseen)
Interaction design
SR ↑
SPL ↑
OSR ↑
NE ↓
SR ↑
SPL ↑
OSR ↑
RGSPL ↑
DUET-style dense interaction
77.91
68.12
84.31
2.68
40.02
25.47
50.03
6.73
Shared generic queries
79.21
69.21
84.99
2.54
40.54
25.68
50.74
6.95
QAD (Full)
80.43
71.98
86.16
2.41
43.42
28.03
53.44
7.31
TABLE VII: Controlled comparison of teacher-side cross-modal interaction designs on R2R and SOON test-unseen. All non-interaction components and training settings are held fixed.
Fig. 3: Jetson runtime and query-number ablations on R2R. (a) Step throughput (steps/s) measured on Jetson Nano for representative VLN agents, including HOP+, BEVBert, GOAT, and our QAD teacher/student. (b) R2R test-unseen SR and SPL versus the number of navigable queries per branch Kb , where KL=KG=Kb
Fig. 4: Sensitivity to the distillation hyper-parameter α . We sweep the α that balances query-level distillation LNTD and policy KL distillation Lπ during fine-tuning : LD=αLNTD+(1−α)Lπ . Results are reported on R2R ( test-unseen : SR/SPL) and REVERIE ( test-unseen : SR/SPL). A moderate α yields the best trade-off, while overly small/large α over-emphasizes policy- or query-level supervision, respectively.
Test Unseen
Option
Model
SR↑
SPL↑
OSR↑
NE↓
1
Teacher (full)
80.43
71.98
86.16
2.41
2
Teacher w/o NQG
78.69
68.67
84.91
2.61
3
Teacher w/o IQA
77.13
67.92
83.11
2.74
4
Student (full)
79.12
69.54
83.21
2.57
5
Student w/o NTD
70.23
61.44
72.14
3.71
TABLE VIII: Component and distillation ablations on R2R test-unseen.
Test Unseen
Option
Model
SR↑
SPL↑
OSR↑
RGSPL↑
1
Teacher (full)
43.42
28.03
53.44
7.31
2
Teacher w/o NQG
40.11
25.51
50.16
6.96
3
Teacher w/o IQA
39.54
24.87
49.45
6.54
4
Student (full)
41.03
27.11
51.34
6.97
5
Student w/o NTD
37.54
25.04
48.26
5.54
TABLE IX: Component and distillation ablations on SOON test-unseen.
Fig. 5: Qualitative trajectory comparison on R2R. The top-down graphs show navigation trajectories, the right panels show final viewpoints, and the corresponding instruction is provided below each episode. Yellow, green, and pink trajectories denote our student, the ground truth, and GOAT [ 36 ] , respectively. Green boxes with check marks indicate correct grounding by our student, whereas red boxes indicate incorrect grounding by GOAT. Our student follows the instructions more faithfully, avoids detours, and reaches the correct destinations.
Test Unseen
Option
N(text)
N(pano)
N(NQG)
N(IQA)
SR↑
SPL↑
Param (M)↓
GFLOPs↓
1 (Teacher)
6
2
4
3
80.43
71.98
150.78
45.56
2
6
2
2
1
80.01
71.21
129.62
38.87
3
3
1
4
3
79.81
70.12
52.81
15.57
4
3
1
2
1
79.32
69.94
31.65
8.06
5 (Student)
1
1
1
1
79.12
69.54
9.56
1.92
TABLE X: Architecture-scaling ablation on R2R test-unseen. We vary the depths of the text encoder, panoramic encoder, Navigable Query Generator, and Instruction–Query Aligner. Performance and efficiency are evaluated using SR, SPL, parameter count, and GFLOPs.
Test Unseen
Option
Model
SR↑
SPL↑
OSR↑
NE↓
1
Global Only
75.41
65.13
80.81
3.05
2
Local Only
74.22
64.34
80.23
3.11
3
Both (Full)
79.12
69.54
83.21
2.57
TABLE XI: Distillation-target ablation on R2R test-unseen, comparing global-only, local-only, and joint global/local navigable-query distillation.
Test Unseen
Option
Model
SR↑
SPL↑
OSR↑
RGSPL↑
1
Global Only
37.94
23.37
47.64
4.94
2
Local Only
38.61
24.51
49.01
5.11
3
Both (Full)
41.03
27.11
51.34
6.97
TABLE XII: Distillation-target ablation on SOON test-unseen, comparing global-only, local-only, and joint global/local navigable-query distillation.
Fig. 6: Step-wise visualization of the navigation process. Each row shows the panoramic observation at one navigation step, and the input instruction is provided at the bottom with key cues highlighted in red. In the left example, the green check and red cross denote correct and incorrect turning decisions, respectively. In the right example, the green and red boxes indicate correctly and incorrectly grounded visual evidence, respectively. Our student follows the highlighted cues more accurately and reaches the destination with a shorter trajectory than GOAT [ 36 ] .
Fig. 7: Teacher–student failure cases. The teacher succeeds while the compact student fails. The left case shows a destination-room grounding error: the student fails to associate “pool room / pool table” with the correct visual evidence. The right case shows a premature STOP error: the student stops once exercise equipment becomes visible, while the teacher moves to the correct viewpoint specified by “next to the exercise equipment.”
Fig. 8: PCA visualization of teacher–student query alignment. Global and local navigable-query slots ( K=32,D=768 ) are projected into a shared 2D PCA space across three training stages. Blue circles and orange crosses denote teacher and student slots, respectively, and each line connects a same-index pair. Shorter links indicate stronger slot-wise alignment.
Fig. 9: Cosine similarity matrices for teacher–student query slots. Each matrix S∈RK×K ( K=32 ) measures Sij=cos(qiT,qjS) . All panels share the same color scale. Stronger diagonal responses indicate better same-index alignment, whereas off-diagonal responses suggest slot permutation or mixing. Distillation progressively sharpens the diagonal structure for both global and local queries.