Edge-Native Temporal--Graph Dual-Expert Inference for Dexterous Grasp Classification

Edge-Native Temporal--Graph Dual-Expert Inference for Dexterous Grasp Classification

Jiajian Zheng, Bin Zhang, Wen Fan, Yanan Liu · N/A · 2026

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Summary

Multi-finger hands contact objects at different times, so a global close command can overload early-contact fingers while others are still moving. Dense tactile arrays address this problem but add hardware, calibration, bandwidth, and computation.

Abstract Summary

Multi-finger hands contact objects at different times, so a global close command can overload early-contact fingers while others are still moving. Dense tactile arrays address this problem but add hardware, calibration, bandwidth, and computation. We present an edge-native pipeline that uses only built-in joint-angle and pre-use-calibrated actuator-load feedback to recognize the grasped object and predict an independent Stop event for each finger. Four samples and their first differences form a 4-by-20 contact-evolution window. At its core is a heterogeneous dual-expert architecture, termed DualExpert, that assigns complementary tasks to a Temporal Convolutional Network (TCN) and a Finger Graph Filter Network (FGFN). The TCN models short-term contact evolution and supplies all five Stop probabilities, while the FGFN encodes finger topology and contributes only to object classification. Fixed 0.7/0.3 class-probability fusion reaches 93.78\% trajectory-level classification accuracy on 225 held-out trials, improving the standalone TCN and FGFN by 4.00 and 2.22 percentage points, respectively. The TCN Stop path attains 95.25\% F1. The dataset contains 1,500 automatically collected trajectories from five object instances. In Flash deployment, mixed accelerator execution retains 93.78\% classification accuracy and 94.84\% Stop F1 with 2.890~ms mean inference time and 9.172~ms mean sample-to-stop latency. Across 50 physical trials, the system achieves 96.00\% recognition and 98.00\% grasp success while the complete embedded board draws approximately 0.80~W.

Key Points

  • Multi-finger hands contact objects at different times, so a global close command can overload early-contact fingers while others are still moving.
  • Dense tactile arrays address this problem but add hardware, calibration, bandwidth, and computation
  • We present an edge-native pipeline that uses only built-in joint-angle and pre-use-calibrated actuator-load feedback to recognize the grasped object and predict an independent Stop event for each finger.
  • Four samples and their first differences form a 4-by-20 contact-evolution window
  • At its core is a heterogeneous dual-expert architecture, termed DualExpert, that assigns complementary tasks to a Temporal Convolutional Network (TCN) and a Finger Graph Filter Network (FGFN).

System and Problem Formulation

The system combines sparse hand feedback with local recognition and per-finger stopping. Fig. 1 shows the complementary experts. TCN96b5 denotes a 96-channel Temporal Convolutional Network with five residual blocks, while FGFN80 denotes an 80-channel Finger Graph Filter Network. The TCN models contact evolution and stopping; the FGFN exposes neighboring-finger agreement and imbalance for classification.

The platform combines the RH56 hand, an embedded inference board, and a half-duplex RS-485 link [ 29 ] .

System and Problem Formulation — Edge-Native Temporal--Graph Dual-Expert Inference for Dexterous Grasp Classification
Fig. 1: Architectures of the complementary experts: (a) TCN96b5 models four-frame contact evolution and predicts object class and five-finger Stop probabilities; (b) FGFN80 injects the fixed finger topology through low/high graph responses for more balanced object classification.

Heterogeneous Dual-Expert Network

Fig. 2 presents the Heterogeneous Temporal–Graph Dual-Expert, abbreviated as DualExpert. Both experts share the contact window. Their class distributions are fused, while all learned Stop scores come from TCN96b5 because it is substantially stronger on that task. Firmware angle and target limits remain independent completion conditions. As shown in Fig.

1 (a), TCN96b5 projects each frame to 96 channels and applies five residual depthwise-separable blocks with $k=3$.

Heterogeneous Dual-Expert Network — Edge-Native Temporal--Graph Dual-Expert Inference for Dexterous Grasp Classification
Fig. 2: Heterogeneous DualExpert. The topology-aware FGFN complements temporal classification, while control-sensitive Stop outputs remain on TCN96b5.

Embedded Deployment and Control

ST Edge AI stores model weights and operators with the firmware in Flash. At runtime, each validated RS-485 sample enters SRAM, updates the four-frame buffer, and forms the normalized $4\times 20$ input. The Cortex-M55-only or Neural-ART mixed-execution path writes class and Stop probabilities back to SRAM for immediate finger-latch updates, without returning raw windows to the computer.

The Cortex-M55-only build uses 178.08 KiB of weights, 8.46 KiB of peak activations, and 405,516 MACs per window.

Embedded Deployment and Control — Edge-Native Temporal--Graph Dual-Expert Inference for Dexterous Grasp Classification
Fig. 3: On-board per-finger grasp flow. Measured feedback forms each new contact frame; model-triggered Stop states are monotonic while other fingers continue incremental closure.

Experiments

Experiments evaluate recognition, per-finger stopping, expert complementarity, and embedded execution using the platform and five object instances shown in Fig. 4 . Deployment uses an STM32N647 on the ATK-DNN647 board and evaluates both Cortex-M55-only execution and Neural-ART mixed execution [ 30 , 31 ] . The measured board-side data path is shown in Fig. 5 .

The acquisition application performs repeatable close-record-open cycles over RS-485 and saves a trial only after complete five-finger feedback and a final synchronized read.

Experiments — Edge-Native Temporal--Graph Dual-Expert Inference for Dexterous Grasp Classification
Fig. 4: Experimental platform and evaluated instances. From left to right: RH56 hand, plastic bottle, paper box, sponge, paper cup, and paper roll.

Sources and Demonstrations

Figures are reproduced from Zheng et al. See the full paper for experimental details and the project page, when the paper links one, for demonstrations and videos.

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