Organizations: Dept. of Systems Innovation, Graduate School of Engineering Science, The University of Osaka, Japan. · International Research Center for Neurointelligence, The University of Tokyo, Japan.
Vision-Language-Action models (VLAs) allow users to specify manipulation tasks in natural language, but distinguishing a target or placement goal among objects of the same category or similar appearance requires detailed expressions that VLAs may not use reliably. We propose DeicticVLA, which canonicalizes Language Instruction (LI), Vision-Language Instruction (VLI), and Visual Instruction (VI) into a text prompt and deictic masks through text-prompt completion and deictic gesture grounding, enabling a single pretrained VLA to handle all three instruction modes. With a shared backbone, demonstrations, and matched training steps, we compare two RGB visual prompting methods, two separate-channel mask prompting methods, and three training strategies in simulation. Under two-stage training, the four prompting methods achieve high in-distribution success but differ in their ability to use deictic masks in unseen layouts. Across methods, training-strategy ablations show that two-stage training improves such use, while retaining second-stage LI data mitigates forgetting without reducing VLI and VI performance. In three real-world tasks, one policy supports all modes. VLI and VI outperform LI under unseen expressions, appearance changes, and novel objects. For unseen categories, both achieve 100% success, compared with 16.7% for jointly trained LI. These results demonstrate the unified three-mode interface and guide DeicticVLA design.
Figures & tables
Fig. 1: Overview of the DeicticVLA system and the prompting methods evaluated in this work. (a) The user specifies a task through LI, VLI, or VI, which provide language only, language with a deictic gesture, or a deictic gesture only, respectively. Instruction canonicalization converts these user inputs into a canonical representation consisting of a text prompt and deictic masks through text-prompt completion and deictic gesture grounding. DeicticVLA uses this representation together with RGB observations and the robot state to generate an action chunk. (b) VP-BBox and VP-Fade construct RGB visual prompts by drawing a bounding box or fading regions outside the deictic mask on the RGB observation, respectively. MP-Early and MP-Late encode the mask separately and fuse the resulting mask prompt embeddings before and after the visual encoder, respectively.
Fig. 2: Roles of deictic masks in task specification. Mask-T specifies the object to be manipulated, Mask-G specifies the placement goal, and Mask-R specifies a reference object used in a spatial referring expression. For example, in “put the green tea on the tray,” the green-tea bottle is Mask-T and the tray is Mask-G. In “put the tea next to this on the tray,” the deictically indicated green-tea bottle serves as Mask-R.
Fig. 3: Example inputs for the three instruction modes in (a) LIBERO-Object, (b) LIBERO-Spatial, and (c) LIBERO-Goal. LI uses the original LIBERO text prompt. VLI uses Mask-T, Mask-R, or Mask-G depending on the suite. VI uses the fixed text prompt “follow visual instruction” with Mask-T+G, which consists of separate Mask-T and Mask-G deictic masks shown together in the same panel.
Optimizer
AdamW ( β1=0.9 , β2=0.95 , ϵ=10−8 )
Weight decay
10−10
Gradient clipping
∥g∥2≤1.0
LR schedule
Cosine decay (warmup: 1k steps)
Learning rate
2.5×10−5→2.5×10−6
Total training steps
60,000
Batch size
32
TABLE I: Training Hyperparameters
In-distribution SR
In-distribution ΔSR
Object-ZS ΔSR
Spatial-ZS ΔSR
Training
Prompting
LI
VLI
VI
Mean
VLI
VI
VLI
VI
VLI
VI
2S
MP-Early
93.0
96.3
96.9
95.4
+23.1
+31.7
+9.1
+10.0
+3.1
+4.4
MP-Late
91.5
95.5
95.3
94.1
+22.3
+33.4
+29.2
+25.2
+0.9
+1.7
VP-Fade
93.1
96.2
95.6
95.0
+25.6
+35.2
+26.2
+24.8
+1.3
+5.8
VP-BBox
94.0
96.8
96.1
95.6
+25.6
+34.0
+29.2
+27.8
+16.0
+11.1
1S
MP-Early
90.5
92.3
91.4
91.4
+19.1
+24.1
+3.5
+3.4
+0.2
+0.9
TABLE II: Simulation results. Mean SR is averaged over LI, VLI, and VI. Higher Δ SR indicates greater contribution from deictic masks.
Fig. 4: Real-world experiment setup and task environments. (a) Hardware setup with a UR5e, Robotiq 2F-85 with Fin-ray fingers, overhead camera, and wrist camera. (b) PickBlock : pick up a specified block from six colored blocks on the table. (c) PutBlock : put a block into a specified bowl among visually identical white bowls arranged in a row. (d) OrganizeToy : pick up a specified stuffed toy and place it into a specified basket; left shows the standard setting, right shows the VC-Surface condition with a tablecloth not seen during training. (e) Stuffed toys used in OrganizeToy across two super-categories: animal and vegetable. TL1 denotes seen objects used for both training and evaluation, while NO-Instance and NO-Category denote novel objects used only for evaluation.
TL
PickBlock
PutBlock
OrganizeToy
TL1
pick up …
put the block into …
put the …
the {yellow, black, blue, red} block,
the {1st, 2nd} bowl from the right ( N=2–5 ),
{animal, vegetable} into the
the {1st, 2nd, 3rd, 4th} block from the left,
the 3rd bowl from the right ( N=3–5 ).
{front, back left, back right} basket,
the {yellow, blue} block on the right,
<category> into the
the {black, red} block on the left.
{front, back left, back right} basket.
TL2
pick up …
put the block into …
TABLE III: Task templates for each task and condition.
Condition
Animal
Vegetable
TL1
dachshund (dog),
carrot-bunch (carrot),
chihuahua (dog),
lettuce, green onion,
hedgehog, bird, elephant, pig.
tomato.
NO-Instance
bulldog (dog), wanwan (dog),
carrot-single (carrot),
pink bear (animal),
cucumber (vegetable),
monkey (animal),
mushroom (vegetable),
TABLE IV: Stuffed toys used in OrganizeToy. For entries containing parentheses, the toy name appears first, followed by the category label used in LI in parentheses.
PickBlock
PutBlock
OrganizeToy
Instruction mode
TL1
TL2
TL3
TL1
TL2
TL3
TL1
VC-Surface
NO-Instance
NO-Category
( n=24 )
( n=16 )
( n=16 )
( n=15 )
( n=15 )
( n=20 )
( n=40 )
( n=40 )
( n=24 )
( n=12 )
LI (baseline)
70.8 (17)
12.5 ( 0 2)
18.8 ( 0 3)
80.0 (12)
0 6.7 ( 0 1)
30.0 ( 0 6)
67.5 (27)
65.0 (26)
66.7 (16)
33.3 ( 0 4)
LI
29.2 ( 0 7)
12.5 ( 0 2)
18.8 ( 0 3)
40.0 ( 0 6)
26.7 ( 0 4)
20.0 ( 0 4)
62.5 (25)
60.0 (24)
62.5 (15)
16.7 ( 0 2)
VLI
50.0 (12)
62.5 (10)
68.8 (11)
73.3 (11)
86.7 (13)
80.0 (16)
77.5 (31)
87.5 (35)
95.8 (23)
0. 100 (12)
VI
45.8 (11)
62.5 (10)
93.8 (15)
53.3 ( 0 8)
86.7 (13)
75.0 (15)
75.0 (30)
90.0 (36)
95.8 (23)
0. 100 (12)
TABLE V: Success rates in real-world experiments. Values outside and inside parentheses denote success rates (%) and numbers of successful trials, respectively; n denotes the total number of trials in each column.
Fig. 5: Evaluation GUI for aligning the initial scene configuration. Before each trial, the evaluator adjusts the objects so that their positions in the live overhead-camera image (Live) match those in the overlaid reference image (Reference).
Nanjing University, Nanjing, China · Institute of Automation, Chinese Academy of Sciences, Beijing, China · University of Chinese Academy of Sciences, Beijing, China