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The proposed architecture for augmenting human-AI cooperation uses an adaptive multimodal interaction pipeline combining vision and speech modalities in a dynamic, hierarchical reasoning framework. This study used publicly available data from previously published experiments. No new human subjects were involved, and no additional ethical approval was required.
Proposed adaptive multimodal interaction architecture
Fundamentally, the system begins with perception modules, such as visual stream captures user pose and motion using RGB-D sensors, and an audio stream analyzes speech inputs using a light-weight ASR (Automatic Speech Recognition) engine. Such raw inputs are fed into the Transformer-based action prediction module, which encodes temporal dependencies in pose and command sequences to reason about low-level human actions. Subsequently, to enable high-level collaboration planning, a Dynamic Time Warping (DTW) mechanism aligns the detected actions with nodes of a pre-defined task graph to predict user goals and next actions. A new attention-based fusion module decides, at every timestep, which modality (audio or vision) is giving the most contextually important information and adjusts the input weights dynamically. To individualize interaction, the system includes online model adaptation, adapting action predictors in real-time to changing user behavior. A light-weight explainability module also creates user-friendly summaries of predicted intentions and AI decisions to improve transparency and trust. The whole system is tested in a simulated but real-world cooperative assembly environment, allowing comparison across unimodal and adaptive-multimodal environments. Such an approach facilitates more adaptable, more intuitive, and more reliable collaboration with AI agents in all areas.
Figure 1 shows the architecture of the described Adaptive Multimodal Interaction Framework aimed at improving Human-AI collaboration. It starts with the Input Acquisition phase, which is based on two main sensing devices: an RGB-D camera for observing depth-enhanced visual information (e.g., human posture and movement) and a directional microphone for collecting speech commands. Raw signals are subsequently run through the Pre-Processing module, which processes the audio-visual data for subsequent analysis by cleaning, normalizing, and formatting the input streams. Then, the pipeline proceeds to the Feature Extraction phase, where the data is split into two streams: The Visual Stream, which isolates pose and motion features through pose estimation algorithms, and the Audio Stream, which transcribes speech into interpretable command embeddings. A multimodal Transformer encoder, which uses multi-head self-attention and temporal positional encoding to express long-range interdependence across interaction sequences, then processes the fused representation. The user's current goal state is estimated by a long-horizon intention and task progress predictor, and low-level actions are mapped to nodes in a hierarchical task graph for reliable task tracking by a DTW-based alignment module. Fusion weights and prediction parameters are continuously updated via an online model adaptation loop in response to interaction feedback, and an explainability module provides clear explanations to promote openness and confidence. The whole pipeline allows the system to adaptively and efficiently work together with users on dynamic tasks and environments.

Figure 1: An overview of the suggested multimodal interaction framework based on transformers. An attention-guided technique is employed to encode and dynamically integrate visual and aural data. A Transformer module, which integrates hierarchical task modeling and online adaptation, processes the fused representation for long-horizon intention prediction and task progress estimation.. Please click here to view a larger version of this figure.
The suggested system incorporates a lightweight explainability module that works in tandem with the multimodal fusion and hierarchical planning components to improve transparency and user confidence. The module derives interpretable cues from the DTW-based task graph alignment (e.g., current task progress and anticipated next action) and the attention-based fusion layer (e.g., modality importance weights). These cues are converted into comprehensible explanations for humans, such as whether spoken commands or visual gestures primarily affected a system choice and how the anticipated action fits into the broader work plan. Users receive explanations in the form of succinct written or visual feedback, which helps them comprehend, predict, and, if needed, rectify system behavior. Improved user happiness, interaction smoothness, and trust-related metrics indicated in the evaluation are indirect indicators of user perception of explainability. The findings imply that in long-term human-AI interaction, transparent reasoning for AI decisions enhances user confidence, facilitates collaboration, and increases acceptance of adaptive system behavior.
Input data
Input acquisition in the envisioned framework for Human-AI collaboration is carried out through a structured multimodal sensing mechanism that combines both vision and hearing modalities to effectively realize human actions and intentions. Visual input is acquired with an RGB-D camera, which captures real-time pose information of humans, spatial location, and context of the surroundings. Visual data is processed through pretrained models such as BlazePose to get upper-body keypoints of interest for interaction tasks. At the same time, auditory information is gained from a directional microphone and interpreted through a pretrained DeepSpeech model to identify speech commands that disambiguate or provide supplementary uncertain visual cues. In cooperative settings, the dual-input system offers dynamic adaptation and context-aware perception. The training and evaluation dataset comprises more than 5,000 multimodal human motion trajectories1 for a range of interaction activities, such as assembly and handover behaviors, gathered from four users in controlled and semi-structured settings. To enhance generalization, the system enables online model adaptation in deployment, which allows the model to update its predictions in real time as a function of changing user behavior and environmental dynamics.
Dataset description
The training and evaluation dataset for the suggested framework was obtained from real-world human-robot collaboration experiments under a toy car assembly task using the KINOVA GEN3 robot1. The experimental environment aimed to mimic long-term collaborative activities encompassing multimodal interaction, which included both visual and auditory modalities. In particular, the training dataset is comprised of 3,003 sequences of trajectories from two users, and the test dataset holds 2,088 sequences, including data from two new users for assessing model generalization. Every trajectory records a 5-step sequence of upper-body pose keypoints retrieved with BlazePose, along with corresponding speech commands transcribed by DeepSpeech33. The collected data depicts natural human variation in gesture and command expression on activities including object delivery, tool use, and cooperative actions. The multimodal dataset is the foundation for supervised learning of the DLinear action and trajectory forecasting models, and is the central benchmark in the user studies performed under vision-only, audio-only, and multimodal conditions. Incorporating different types of users and realistic noise conditions guarantees robustness and adaptability testing for permanent HRC systems. Table 2 shows the detailed dataset description.
| Attributes | Details |
| Dataset Name | Toy Car Assembly Dataset (collected in-house) |
| Collection Environment | Real-world HRC experiment with KINOVA GEN3 arm |
| Number of Users (Training) | 2 users |
| Number of Users (Testing) | 4 users (2 from training set, 2 unseen) |
| Total Trajectories (Training) | 3,003 trajectories |
| Total Trajectories (Testing) | 2,088 trajectories |
| Modalities Captured | Visual (RGB-D for pose), Audio (Speech commands) |
| Data Format | Pose keypoints (from BlazePose), speech-to-text commands |
| Temporal Resolution | Each trajectory includes 5-time steps |
| Tasks Covered | 3 main tasks: Pick-and-place, object rotation, collaborative assembly |
| Usage | Supervised training of action/trajectory prediction models; user study |
Table 2: Dataset Description. Information on the simulation environment, including programming framework, hardware settings, and evaluation environment.
Dataset pre-processing
To enable adaptive multimodal interaction in human-AI collaboration, the raw dataset, such as visual (RGB and depth images), auditory (speech commands), and temporal behavior data (pose keypoints), is subjected to structured preprocessing. Visual data are first extracted by a pose estimation model fpose, commonly derived from BlazePose or OpenPose. For frame t, the human pose vector is defined as:
(1)
Where k is the number of keypoints and every keypoint contains 2D coordinates. The sequences are normalized by torso length and smoothed over time with a Savitzky-Golay filter:
(2)
where w is the size of the filtering window. Second, raw audio streams At are sliced into segments using a Voice Activity Detector (VAD). Credible segments are fed into a speech recognition model fspeech, (e.g., DeepSpeech) to pull out command tokens:
(3)
where V is the vocabulary of recognized commands. For integration, command tokens for all are time-aligned to visual pose timestamps using an interpolation-based alignment function τ:
(4)
Third, to form the temporal intention training sequences
, we define trajectory sequences , along with associated speech commands
. These are windowed into fixed-length segments utilizing sliding windows of size l:
(5)
(6)
Lastly, the inputs are normalized to zero mean and unit variance per keypoint dimension for convergence in trajectory-based prediction models:
(7)
where μj, σj are the mean and standard deviation of keypoint j completed the training set.
Feature extraction
In the outlined adaptive multimodal interaction paradigm, strong and real-time cooperation is enabled by combining visual, audio, and contextual task features. The pipeline of feature extraction starts with concurrent data acquisition from two main modalities: visual signals
and audio signals
, indexed at time step t. These observations are passed through corresponding perception modules to obtain high-level semantic features pertaining to human behavior, intention, and speech command.
Extracting visual features
The raw visual data
from RGB-D cameras is fed through a human pose estimator (e.g., BlazePose), providing a spatial keypoint vector
, where k represents the detected number of keypoints and each contains 3D coordinates:
(8)
These keypoints are time-embedded into a pose trajectory
, from which motion dynamics are extracted via trend-seasonal decomposition:
(9)
where ∈_t represents the residual noise.
Extracting audio features
Audio input
is processed through a pre-trained speech recognition model (e.g., DeepSpeech) and produces a tokenized command representation
, where n is the token length:
(10)
Multimodal fusion
To construct a unified interaction context, we combine the features by a confidence-weighted attention based on confidence and mutual information:
(11)
where ϕV and ϕA are the projection functions for visual and auditory features into a shared latent space, and αt∈[0,1] is a dynamic modality weighting term calculated on the basis of entropy:
(12)
Here,
and
are mutual information between the goal state g and observed modalities.
Planning using Contextual Embedding
The last multimodal feature vector Ft is enriched with task context and progress Pt and becomes the state input to the adaptive planning module:
(13)
This extracted feature xt is used as input to the downstream intention prediction and motion planning models, supporting adaptive and robust human-AI collaboration in dynamic and uncertain settings.
Action and plan prediction via Task Graph Alignment
Following the multimodal feature extraction process, where speech intent (audio), pose trajectory (visual), and contextual (e.g., task logs or emotion) data are integrated in the subsequent processing includes adaptive human action prediction and plan inference using hierarchical task graph alignment.
Let the integrated multimodal feature vector at time step t be represented as:
(14)
The system initially forecasts the low-level human action via a function fact, which is often represented as a recurrent encoder-decoder or transformer:
(15)
where F(t-k:t) denotes the feature fusion sequence in the last k time steps, and
is the forecasted action from the action set A. The module is online fine-tuned by adaptive loss:
(16)
Here, CE is the action classification cross-entropy loss, then the second term nudges good future trajectory prediction.
For high-level plan prediction, we frame the task as a progression along a Hierarchical Task Graph G = (N, E), wherein every node ni ∈N signifies a sub-task or intermediate goal. The objective is to match the observed action sequence against a reference task path R*∈G by reducing the distance:
(17)
Where Pt denotes the current progress trace and d(⋅) denotes the Dynamic Time Warping (DTW) distance or soft alignment metric.
The ultimate plan-level intent
is then derived by projecting the predicted action a ̂_t onto the most probable next step in the aligned path
:
(18)
This hierarchical decoding guarantees that even with unclear or noisy sensory input, the system picks the most contextually relevant high-level intent consistent with the current task sequence. This predictive planning not only enhances collaboration efficiency but also enhances anticipation and adaptability within multi-turn Human-AI interaction.
Multimodal fusion (attention-based) mechanism
In adaptive human-AI collaboration, multimodal integration of several sensory modalities (e.g., visual: human pose, trajectory; auditory: speech commands) is necessary for proper interpretation of user intention. A rule-based or static fusion approach cannot cope with real-world dynamic human interactions. For this, a fusion mechanism based on attention is presented here to dynamically weight each modality according to its contextual importance at every time step.
Let us denote the extracted feature vectors from the visual and audio modalities as
and
, respectively. These vectors encode semantic information obtained through earlier processing pipelines, e.g., visual features may result from pose estimation and action prediction, while audio features may be derived from speech embeddings using models like DeepSpeech or wav2vec.
The objective of attention-based fusion is to calculate modality-specific attention weights that capture the relative significance of every modality. This is done using a soft attention mechanism.
Attention-weight computation
In a first step, both vectors are transformed into a shared attention space through a learnable transformation. That is, for every modality i∈{V,A}, the intermediate attention score is calculated as:
(19)
where
and
are attention network learnable parameters, and tanh is a non-linear activation function. This conversion allows the model to extract high-level correlations and contextual saliency of each modality.
These unnormalized attention scores eV and αA are then normalized with a softmax function such that they add up to 1
(20)
Here, αV and αA are the attention weights over the visual and audio modalities, respectively. The weights are adaptive and then they are updated over time depending on the existing task context, signal quality, and user activity.
(21)
The resulting fused representation
is obtained as a weighted combination of the input modality vectors:
This combined vector encodes the common semantics of the visual and auditory information in a manner that actively highlights the most informative stream. It is then fed into downstream modules like the task graph matching, intention prediction, or robot motion planning engine.
Algorithm 1 : Fusion Based on Multimodal Attention
Input: Visual feature vector is hV∈Rd, Vector of audio features is hA∈Rd
Learnable parameters: W∈Rk*d,w∈Rk and b∈Rk
Output: fused representation hfused∈Rd.
Step 1: Determine intermediate representations by computing using Equation 19
Step 2: Use Softmax to normalize attention scores using Equation 20
Step 3: Calculate the fused vector using Equation 21
Step 4: Return hfused
The Attention-Based Multimodal Fusion algorithm provides a means for smart fusion of features of various input modalities, such as visual and audio streams, together in a context-aware fashion. Fusion is essential in systems wherein each modality presents complementary but varying information, such as in human-AI collaborative environments where vision captures gestures or body position and audio captures speech commands or voice signals.
The Algorithm 1 begins by determining intermediate representations for each modality. To calculate both of these models, eV for the visual flow and eA for the audio stream, a shared neural network layer first performs a non-linear transformation on the corresponding feature vectors. Then, the attention weights αV and αA are calculated by performing a softmax function over the intermediate scores. This helps the weights to be positive and add up to 1, essentially making the contributions from each modality to be normalized. The more informative a modality is, as modelled, the greater its attention weight.
Ultimately, the algorithm calculates the fused depiction hfused through a weighted combination of the graphic and audio feature vectors, normalized with their respective attention weights. This fused vector combines both modalities in a data-driven, context-sensitive fashion and serves for downstream tasks such as intention recognition, decision-making, or robot motion planning. In total, this algorithm enables the system to dynamically focus on the most pertinent modality or modality combination at a specific moment, instead of using fixed or rule-based fusion approaches. This renders the framework stronger, more flexible, and responsive in dynamic human-AI interaction situations.
Figure 2 illustrates the workflow of Attention-Based Multimodal Fusion mechanism that operates in the context-sensitive integration of visual and auditory inputs. Visual Feature Extraction, the first step in the workflow, involves extracting spatial or pose-related features from input images or video (such as RGB-D cameras). These are subsequently input into a Visual Attention module that learns to highlight the most informative content of the visual information. In parallel, Audio Attention modules process speech embeddings or audio tokens from spoken commands, attributing contextual significance to different auditory signals. The resulting attention-weighted features are integrated through an attention-based fusion layer and passed to a position-wise feedforward network with residual connections and layer normalization, forming a standard Transformer encoder block. The output is a unified multimodal embedding that supports robust long-horizon intention prediction and adaptive decision-making under varying interaction conditions. This design enables the system to selectively concentrate on the more robust modality at any point, improving robustness and interpretability in real-time human-AI interaction.

Figure 2: The attention-guided multimodal fusion module's detailed construction. In order to generate a context-aware fused representation at each time step, modality-specific encoders collect features from visual and aural streams. These features are then dynamically weighted using a data-driven attention mechanism. Please click here to view a larger version of this figure.
Online model adaptation
To ensure high-quality human-AI collaboration under different user behaviors and contexts, our framework incorporates an online model adaptation mechanism that progressively optimizes user-specific models during interaction. The module tracks real-time behavioral signals (e.g., pose, gesture trajectories, speech tone) and updates the underlying predictive models with incremental learning algorithms. In particular, trajectory prediction and intent recognition models are fine-tuned with recent input via gradient-based fine-tuning or low-rank adaptation (LoRA) so that the system is able to adapt to changing user behavior or task-specific requirements without having to be fully retrained.
The feedback layer acts harmoniously together with adaptation through both implicit feedback (e.g., corrections, hesitations, delays) and explicit commands (e.g., speech or GUI). It has two purposes: Adaptively calibrating the salience of multimodal cues, and Transmitting trust/confidence measures to the decision and control modules.
The feedback cycle enables smoother task performance and user-oriented responses. To nurture trust and transparency, the framework integrates an explainability module that translates low-level model decisions into human-understandable justifications. It uses rationale maps from multimodal fusion transformer, supplemented with logic tracing through the task graph. It can optionally present this rationale via a GUI or auditory aide to enable users to comprehend and perhaps even correct system behavior.