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GeCo-SRT: Geometry-aware Continual Adaptation for Robotic Cross-Task Sim-to-Real Transfer

Conference: CVPR 2026 arXiv: 2602.20871 Code: N/A Area: Robotics

TL;DR

This paper proposes GeCo-SRT, a geometry-aware continual adaptation method that extracts cross-domain and cross-task invariant knowledge from local geometric features, enabling knowledge accumulation across successive sim-to-real transfers to efficiently adapt to new tasks.

Background & Motivation

  1. The sim-to-real gap is a core bottleneck in robot learning: Policies trained in simulation suffer significant performance degradation when deployed in the real world due to discrepancies in visual rendering and physical dynamics (Direct Deploy achieves only 3.1% average success rate).
  2. Existing methods treat each sim-to-real transfer as an isolated process: System Identification relies on hand-crafted modeling, and Domain Randomization requires expert-level parameter tuning; both support only single-task transfer, requiring the process to restart from scratch for every new task at high cost.
  3. Lack of cross-task knowledge accumulation: Different manipulation tasks share many geometric primitives (e.g., edges, planes), yet existing methods do not exploit these transferable geometric priors to accelerate adaptation to subsequent tasks.
  4. Catastrophic forgetting in continual learning: When learning multiple tasks sequentially, training on new tasks overwrites knowledge from previous ones; standard PER methods prioritize sampling based on task loss, neglecting expert-level knowledge preservation.

Method

3.1 Human-Correction-Based Sim-to-Real Transfer Framework

For each task \(i\), a base diffusion policy \(\pi^{b_i}\) (comprising a point cloud encoder \(E_p^{b_i}\) and a diffusion policy head \(\pi_h^{b_i}\)) is first trained in simulation via imitation learning using an L2 diffusion loss:

\[\mathcal{L}_{\text{diff}} = \mathbb{E}_{(a_t, o_t) \sim \mathcal{D}_{sim}^{e_i}, \epsilon \sim \mathcal{N}(0,I)} \left[ \| \epsilon - \epsilon_\theta(a_t^k, k, o_t) \|^2 \right]\]

The base policy is deployed in the real world, and human correction trajectories \(\mathcal{D}_{real}^{h_i}\) are collected via a human-in-the-loop shared autonomy framework. The base policy parameters are frozen, and a shared perceptual residual module \(E_p^s\) (i.e., Geo-MoE) is introduced and continuously updated using a mixed replay buffer \(D_{buf}^{m_i}\) of simulation and real-world data.

3.2 Geometry-aware Mixture of Experts Module (Geo-MoE)

The core insight is that local geometric features possess dual invariance:

  • Domain invariance: Local geometry (e.g., planarity, linearity) is structurally consistent between simulation and the real world, unaffected by texture or material differences.
  • Task invariance: Geometric primitives (e.g., edges, corners) are shared across different manipulation tasks (e.g., "pick cube" and "stack cube" both involve the planar surfaces of a cube).

Implementation details:

  1. Local point groups \(g_i\) are sampled from the input point cloud \(P\) via k-NN.
  2. Geometric features (planarity, linearity, saliency) of each group are estimated via local PCA.
  3. A lightweight gating network \(G\) produces routing weights \(w_i = \text{Softmax}(G(g_i))\).
  4. \(M\) parallel expert networks are fused with weighted aggregation:
\[g_i' = \sum_{j=1}^{M} w_{i,j} \cdot \text{Expert}_j(g_i)\]
  1. All group features are aggregated to yield a correction residual vector \(g_{res}'\), which is concatenated with the frozen encoder output: \(\hat{f} = \text{Concat}(E_p^{b_i}(o), g_{res}')\).

Training loss:

\[L_{total} = \text{MSE}(\hat{a}, a) + \alpha L_{balance}\]

where \(L_{balance}\) is a load-balancing loss to prevent gating collapse.

3.3 Geometry Expert-Guided Prioritized Experience Replay (Geo-PER)

Standard PER prioritizes sampling based on task loss, neglecting knowledge degradation in underutilized experts. Geo-PER redefines the priority metric from task loss to expert utilization:

For each historical sample \(i \in \mathcal{R}\), its expert activation vector \(W_i = \{w_{i,1}, \dots, w_{i,M}\}\) is recorded, and the average expert utilization \(U^{\text{new}}\) on the current new task is computed to dynamically update sampling priorities:

\[P_i \propto \sum_{j=1}^{M} w_{i,j} \cdot \frac{1}{u_j^{\text{new}} + \epsilon}\]

The intuition is: if expert \(j\) has low utilization on the current task (small \(u_j^{\text{new}}\)), historical samples that strongly activate that expert receive higher sampling probability, ensuring that underutilized expert parameters continue to receive gradient updates to counter forgetting.

Key Experimental Results

Experimental Setup

Four sequential robotic manipulation tasks are used for evaluation: Pick Cube → Stack Cube → Pick Banana → Plug Insert. The real hardware consists of an Xarm5 robotic arm, a Rotiq2F140 gripper, and dual RealSense depth cameras. Sixty human correction trajectories are collected per task.

Single-Task Sim-to-Real Transfer

Method Pick Cube Stack Cube Pick Banana Plug Insert Avg. SR
Direct Deploy 5.7% 0% 6.7% 0% 3.1%
Action Residual 16.7% 3.3% 13.3% 0.0% 9.2%
Transic 66.7% 30.0% 23.3% 33.3% 38.3%
Geo-MoE 80.0% 43.3% 40.0% 36.7% 50.0%

Geo-MoE outperforms the strongest baseline Transic by 11.7% on average, validating the advantage of geometry-aware features in bridging the observation domain gap.

Cross-Task Continual Learning

Method Pick Cube SR↑ N-NBT↓ Stack Cube SR↑ N-NBT↓ Pick Banana SR↑ N-NBT↓ Plug Insert SR↑ Avg. SR↑ Avg. N-NBT↓
Naive Fine-tuning 16.7% 100% 3.3% 100% 13.3% 100% 3.3% 9.2% 75.0%
Transic + PER 76.7% 81.2% 30.0% 72.3% 20.0% 66.5% 33.3% 40.0% 55.0%
Geo-MoE + PER 83.3% 34.6% 50.0% 76.8% 46.7% 7.1% 43.3% 55.7% 29.6%
Geo-MoE + EWC 80.0% 70.8% 36.7% 77.3% 20.0% 50.0% 16.7% 38.3% 49.5%
GeCo-SRT 86.7% 28.3% 53.3% 72.0% 60.0% 5.5% 53.3% 63.3% 26.5%

GeCo-SRT achieves an average success rate of 63.3%, surpassing baselines by 52%; its average forgetting rate N-NBT is only 26.5%, substantially outperforming all other methods.

Data Efficiency

With only 20 correction trajectories, the continual learning method achieves 76.6% success rate on Pick Cube, nearly matching the performance of training from scratch with 60 trajectories. Overall, only 1/6 of the data is required to match the full-data performance of baselines.

Highlights & Insights

  • Paradigm innovation: This is the first work to elevate sim-to-real transfer from an "isolated single-instance" to a "continual cross-task" paradigm, enabling knowledge accumulation.
  • Dual geometric invariance: The paper cleverly leverages the domain invariance and task invariance of local geometric features as a carrier for transferable knowledge.
  • Expert-level forgetting protection: Geo-PER redefines priority from the perspective of expert utilization, precisely protecting the specialized knowledge of underutilized experts.
  • Rigorous real-world validation: A complete continual transfer experiment across 4 tasks is conducted on a real robot (Xarm5), rather than purely in simulation.
  • Significant data efficiency: Only 1/6 of the data is needed to reach the full-data performance of baselines, which is highly meaningful for data-scarce real-world scenarios.

Limitations & Future Work

  • Focus limited to the observation domain gap: The method primarily bridges the visual observation sim-to-real gap via geometric features, with limited capacity to handle complex dynamics discrepancies (e.g., friction, contact forces).
  • Limited number of tasks: Experiments involve only 4 sequential tasks; scalability to longer task sequences remains unvalidated.
  • Dependence on human correction: Each task still requires a human operator to collect 60 correction trajectories, leaving the degree of full autonomy insufficient.
  • Reliance on task geometric similarity: Cross-task transfer effectiveness is highly dependent on geometric similarity; negative transfer may occur between tasks with large geometric differences.

Rating

  • ⭐⭐⭐⭐ Novelty: The first to propose a continual cross-task sim-to-real paradigm; the insight of using geometric invariance as a carrier of transferable knowledge is novel.
  • ⭐⭐⭐⭐ Value: Significantly reduces the data cost of adapting to new tasks, offering direct value for real-robot deployment.
  • ⭐⭐⭐ Experimental Thoroughness: Real-robot experiments are complete but limited in scale (4 tasks); more diverse scenarios are absent.
  • ⭐⭐⭐ Writing Quality: Structure is clear and motivation is well-articulated, though some mathematical notation is inconsistent.