Force-Aware Residual DAgger via Trajectory Editing for Precision Insertion with Impedance Control
Organizations: All authors are with Xi’an Jiaotong-Liverpool University, Suzhou, China.
Abstract
Imitation learning (IL) has shown strong potential for contact-rich precision insertion tasks. However, its practical deployment is often hindered by covariate shift and the need for continuous expert monitoring to recover from failures during execution. In this paper, we propose Trajectory Editing Residual Dataset Aggregation (TER-DAgger), a scalable and force-aware human-in-the-loop imitation learning framework that mitigates covariate shift by learning residual policies through optimization-based trajectory editing. This approach smoothly fuses policy rollouts with human corrective trajectories, providing consistent and stable supervision. Second, we introduce a force-aware failure anticipation mechanism that triggers human intervention only when discrepancies arise between predicted and measured end-effector forces, significantly reducing the requirement for continuous expert monitoring. Third, all learned policies are executed within a Cartesian impedance control framework, ensuring compliant and safe behavior during contact-rich interactions. Extensive experiments in both simulation and real-world precision insertion tasks show that TER-DAgger improves the average success rate by over 37% compared to behavior cloning, human-guided correction, retraining, and fine-tuning baselines, demonstrating its effectiveness in mitigating covariate shift and enabling scalable deployment in contact-rich manipulation.
Figures & tables
| Method | Simulation | Real | Average | |||
|---|---|---|---|---|---|---|
| USB | Two-pin Plug | USB | Two-pin Plug | Three-pin Plug | ||
| ACT [ 1 ] | 26% | 22% | 2% | 64% | 24% | 27.6% |
| FILIC [ 11 ] | 20% | 30% | 10% | 44% | 24% | 25.6% |
| HG-DAgger [ 13 ] | 50% | 44% | 16% | 36% | 12% | 31.6% |
| Retrain | 48% | 56% | 0% | 36% | 22% | 32.4% |
| Finetune | 68% | 54% | 10% | 28% | 40% | 40.0% |
| Task | Metric | KL Loss | Reconstruction Loss | Position Prediction Error | Force Prediction Error (Ours) |
| Two-pin Plug | Precision Recall | 90 100 | 98 100 | 76 100 | 100 100 |
| USB | Precision Recall | 74 100 | 78 100 | 78 100 | 100 100 |
| Two-pin Plug (Real) | Precision Recall | 50 100 | 40 100 | 36 100 | 100 100 |
| USB (Real) | Precision Recall | 100 100 | 96 100 | 100 100 | 100 100 |
| Three-pin Plug (Real) | Precision Recall | 64 100 | 64 100 | 76 100 | 94 100 |
| Average | Precision Recall | 75.6 100.0 | 75.2 100.0 | 73.2 100.0 | 98.8 100.0 |
| Task | KL | Recon. | Pos. | Force (Ours) |
|---|---|---|---|---|
| Loss | Loss | Err. | Err. | |
| USB | 0.00056 | 0.00162 | 0.012 | 11.0 |
| Two-pin Plug | 0.0011 | 0.00086 | 0.012 | 13.0 |
| USB (Real) | 0.014 | 0.00078 | 0.018 | 16.0 |
| Two-pin Plug (Real) | 0.00109 | 0.005 | 0.024 | 15.0 |
| Three-pin Plug (Real) | 0.0015 | 0.0006 | 0.025 | 14.0 |
| Method | Simulation | Real | Average | |||
|---|---|---|---|---|---|---|
| USB | Two-pin Plug | USB | Two-pin Plug | Three-pin Plug | ||
| ACT [ 1 ] | 26% | 22% | 2% | 64% | 24% | 27.6% |
| Base Policy (Ours) | 34% | 28% | 4% | 68% | 28% | 32.4% |
| Residual Training Samples | Success Rate |
| Base Policy (Ours) | 28% |
| Transition | 32% |
| Demonstration | 34% |
| Post-editing | 66% |
| Transition + Demonstration | 42% |
| Transition + Post-editing | 56% |
| Number of Points | Success Rate |
|---|---|
| 10 | 94% |
| 20 | 96% |
| 30 | 88% |
| 40 | 80% |
Interactive Imitation Learning
Interactive imitation learning trains agents by querying experts or accepting corrections during execution to recover from learner-induced errors.
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