Abstract:Recent advances in diffusion models hold significant potential in robotics, enabling the generation of diverse and smooth trajectories directly from raw representations of the environment. Despite this promise, applying diffusion models to motion planning remains challenging due to their difficulty in enforcing critical constraints, such as collision avoidance and kinematic feasibility. These limitations become even more pronounced in Multi-Robot Motion Planning (MRMP), where multiple robots must coordinate in shared spaces. To address this challenge, this work proposes Simultaneous MRMP Diffusion (SMD), a novel approach integrating constrained optimization into the diffusion sampling process to produce collision-free, kinematically feasible trajectories. Additionally, the paper introduces a comprehensive MRMP benchmark to evaluate trajectory planning algorithms across scenarios with varying robot densities, obstacle complexities, and motion constraints. Experimental results show SMD consistently outperforms classical and learning-based motion planners, achieving higher success rates and efficiency in complex multi-robot environments.
Abstract:Speculative decoding has emerged as a widely adopted method to accelerate large language model inference without sacrificing the quality of the model outputs. While this technique has facilitated notable speed improvements by enabling parallel sequence verification, its efficiency remains inherently limited by the reliance on incremental token generation in existing draft models. To overcome this limitation, this paper proposes an adaptation of speculative decoding which uses discrete diffusion models to generate draft sequences. This allows parallelization of both the drafting and verification steps, providing significant speed-ups to the inference process. Our proposed approach, \textit{Speculative Diffusion Decoding (SpecDiff)}, is validated on standard language generation benchmarks and empirically demonstrated to provide a \textbf{up to 8.7x speed-up over standard generation processes and up to 2.5x speed-up over existing speculative decoding approaches.}
Abstract:Generative diffusion models excel at robustly synthesizing coherent content from raw noise through a sequential process. However, their direct application in scenarios requiring outputs to adhere to specific, stringent criteria faces several severe challenges. This paper aims at overcome these challenges and introduces Projected Generative Diffusion Models (PGDM), an approach that recast traditional diffusion models sampling into a constrained-optimization problem. This enables the application of an iterative projections method to ensure that generated data faithfully adheres to specified constraints or physical principles. This paper provides theoretical support for the ability of PGDM to synthesize outputs from a feasible subdistribution under a restricted class of constraints while also providing large empirical evidence in the case of complex non-convex constraints and ordinary differential equations. These capabilities are demonstrated by physics-informed motion in video generation, trajectory optimization in path planning, and morphometric properties adherence in material science.