Robotic manipulation based on visual observations and natural language instructions is a long-standing challenge in robotics. Yet prevailing approaches model action distribution by adopting explicit or implicit representations, which often struggle to achieve a trade-off between accuracy and efficiency. In response, we propose PDFactor, a novel framework that models action distribution with a hybrid triplane representation. In particular, PDFactor decomposes 3D point cloud into three orthogonal feature planes and leverages a tri-perspective view transformer to produce dense cubic features as a latent diffusion field aligned with observation space representing 6-DoF action probability distribution at an arbitrary location. We employ a small denoising network conceptually as both a parameterized loss function measuring the quality of the learned latent features and an action gradient decoder to sample actions from the latent diffusion field during inference. This design enables our PDFactor to benefit from spatial awareness of explicit representation and arbitrary resolution of implicit representation, rendering it with manipulation accuracy, inference efficiency, and model scalability. Experiments demonstrate that PDFactor outperforms state-of-the-art approaches across a diverse range of manipulation tasks in RLBench simulation. Moreover, PDFactor can effectively learn multi-task policies from a limited number of human demonstrations, achieving promising accuracy in a variety of real-world manipulation tasks.

Robotic manipulation in high-precision tasks is essential for numerous industrial and real-world applications where accuracy and speed are required. Yet current diffusion-based policy learning methods generally suffer from low computational efficiency due to the iterative denoising process during inference. Moreover, these methods do not fully explore the potential of generative models for enhancing information exploration in 3D environments. In response, we propose FlowRAM, a novel framework that leverages generative models to achieve region-aware perception, enabling efficient multimodal information processing. Specifically, we devise a Dynamic Radius Schedule, which allows adaptive perception, facilitating transitions from global scene comprehension to fine-grained geometric details. Furthermore, we integrate state space models to integrate multimodal information, while preserving linear computational complexity. In addition, we employ conditional flow matching to learn action poses by regressing deterministic vector fields, simplifying the learning process while maintaining performance. We verify the effectiveness of the FlowRAM in the RLBench, an established manipulation benchmark, and achieve state-of-the-art performance. The results demonstrate that FlowRAM achieves a remarkable improvement, particularly in high-precision tasks, where it outperforms previous methods by 12.0% in average success rate. Additionally, FlowRAM is able to generate physically plausible actions for a variety of real-world tasks in less than 4 time steps, significantly increasing inference speed.