We consider transporting a heavy payload that is attached to multiple multirotors. The current state-of-the-art controllers either do not avoid inter-robot collision at all, leading to crashes when tasked with carrying payloads that are small in size compared to the cable lengths, or use computational demanding nonlinear optimization. We propose an efficient optimization-based cable force allocation for a geometric payload transport controller to effectively avoid such collisions, while retaining the stability properties of the geometric controller. Our approach introduces a cascade of carefully designed quadratic programs that can be solved efficiently on highly constrained embedded flight controllers. We show that our approach exceeds the state-of-the-art controllers in terms of scalability by at least an order of magnitude for up to 10 robots. We demonstrate our method on challenging scenarios with up to three small multirotors with various payloads and cable lengths, where our controller runs in realtime directly on a microcontroller on the robots.

翻译：我们考虑吊运附有多架多旋翼飞行器的重型载荷。当前先进控制器要么完全避免机间碰撞（导致在吊运尺寸相对于缆绳长度较小的载荷时发生碰撞），要么依赖计算成本高昂的非线性优化。本文提出一种基于优化的高效索力分配方法，用于几何载荷吊运控制器，在保留几何控制器稳定性的同时有效避免此类碰撞。该方法引入精心设计的二次规划级联结构，可在高度受限的嵌入式飞控上高效求解。研究表明，对于多达10台机器人的编队，本方法在可扩展性方面较现有先进控制器提升至少一个数量级。我们通过包含多达三架小型多旋翼飞行器、多种载荷与缆绳长度的挑战性场景验证该方法，控制器直接在机器人微控制器上实时运行。