FlowDPG: Deterministic Policy Gradient on Flow Matching Policies for Real-World Manipulation
This work addresses the computational burden and numerical instability of flow-matching–based reinforcement learning in real-world robotic manipulation, which stems from its reliance on backpropagation through time (BPTT). To overcome this limitation, the authors propose FlowDPG, a BPTT-free DDPG-style algorithm that distills critic gradients into a velocity field, thereby integrating demonstration-driven motion with critic-guided corrections during policy optimization. Theoretical analysis demonstrates that FlowDPG’s update direction aligns with the classical deterministic policy gradient. Evaluated on a multi-stage dual-arm AirPods assembly task, FlowDPG achieves a 92% end-to-end success rate, substantially outperforming existing approaches based on value conditioning, auxiliary module adaptation, and adjoint gradients.