We present, to our knowledge, the first sign language-driven Vision-Language-Action (VLA) framework for intuitive and inclusive human-robot interaction. Unlike conventional approaches that rely on gloss annotations as intermediate supervision, the proposed system adopts a gloss-free paradigm and directly maps visual sign gestures to semantic instructions. This design reduces annotation cost and avoids the information loss introduced by gloss representations, enabling more natural and scalable multimodal interaction. In this work, we focus on a real-time alphabet-level finger-spelling interface that provides a robust and low-latency communication channel for robotic control. Compared with large-scale continuous sign language recognition, alphabet-level interaction offers improved reliability, interpretability, and deployment feasibility in safety-critical embodied environments. The proposed pipeline transforms continuous gesture streams into coherent language commands through geometric normalization, temporal smoothing, and lexical refinement, ensuring stable and consistent interaction. Furthermore, the framework is designed to support future integration of transformer-based gloss-free sign language models, enabling scalable word-level and sentence-level semantic understanding. Experimental results demonstrate the effectiveness of the proposed system in grounding sign-derived instructions into precise robotic actions under diverse interaction scenarios. These results highlight the potential of the framework to advance accessible, scalable, and multimodal embodied intelligence.
Figures & tables
Fig. 1 : Qualitative demonstration of the Sign-VLA policy across three distinct tasks. The sequences show the robot successfully executing instructions for (a) color-specific objects, (b) localized target areas, and (c) basic geometric shapes.
Method
100 Classes
500 Classes
CNN + LSTM
82.08%
71.71%
ResNet + LSTM
93.54%
83.17%
3D CNN
58.86%
45.07%
3D ResNet34
94.78%
81.61%
ResNet (2+1)D
98.68%
94.85%
Skeleton + LSTM
84.30%
70.62%
TABLE I : Performance comparison on isolated sign language recognition. We report Top-1 accuracy on the CSL dataset under different model families.
Method
WER ↓
Loss
Encoder-Decoder (word level)
1.01%
0.0346
Encoder-Decoder (char level)
1.19%
0.0494
TABLE II : Continuous sign language recognition results on CSL.
Instruction
Success Rate (%)
Time (s)
Stability
Text
86.5
6.2
High
Sign
79.3
7.1
Medium
Sign + Temporal Smoothing
84.7
6.6
High
TABLE III : Preliminary evaluation of sign-conditioned VLA control.
Fig. 2 : Illustration of a potential future extension of our framework using a transformer-based gloss-free sign language model. The encoder extracts spatial and temporal features from continuous sign videos, while the decoder generates natural language instructions that can be directly grounded by the VLA policy [ 15 ] .