Uploaded August 2020 | Updated September 2026, 2 days ago
Video for the RA-L (accepted) with ICRA2021 option.
Preprint: arxiv.org/abs/2008.08835
Code: github.com/ZJU-FAST-Lab/ego-planner
The gradient-based planner is widely used for quadrotor local planning, in which Euclidean Signed Distance Fields (ESDFs) is crucial for evaluating gradient magnitude and direction. Nevertheless, computing such a field contains significant redundancy since the trajectory optimization procedure only covers a very limited subspace of the ESDF updating range. In this paper, an ESDF-free gradient-based planning framework is proposed, which reduces computation time by an order of magnitude. The main improvement is that the collision term in penalty function is formulated by comparing the colliding trajectory with a collision-free guiding path. The resulting obstacle information will be stored only if the trajectory hits obstacles, so that the trajectory will rebound between nearby obstacles several times during optimizing. Then, we lengthen the time allocation if dynamical infeasibility is detected. An anisotropic curve fitting algorithm is introduced to adjust the higher-order derivatives of the trajectory while maintaining the original shape. Benchmark comparisons and real-world experiments verify its robustness and high-performance. The source code is released as ros-packages.
Video for the RA-L (accepted) with ICRA2021 option.
Preprint: arxiv.org/abs/2008.08835
Code: github.com/ZJU-FAST-Lab/ego-planner
The gradient-based planner is widely used for quadrotor local planning, in which Euclidean Signed Distance Fields (ESDFs) is crucial for evaluating gradient magnitude and direction. Nevertheless, computing such a field contains significant redundancy since the trajectory optimization procedure only covers a very limited subspace of the ESDF updating range. In this paper, an ESDF-free gradient-based planning framework is proposed, which reduces computation time by an order of magnitude. The main improvement is that the collision term in penalty function is formulated by comparing the colliding trajectory with a collision-free guiding path. The resulting obstacle information will be stored only if the trajectory hits obstacles, so that the trajectory will rebound between nearby obstacles several times during optimizing. Then, we lengthen the time allocation if dynamical infeasibility is detected. An anisotropic curve fitting algorithm is introduced to adjust the higher-order derivatives of the trajectory while maintaining the original shape. Benchmark comparisons and real-world experiments verify its robustness and high-performance. The source code is released as ros-packages.



![Canfly: A Can-sized Autonomous Mini Coaxial Helicopter
Video for the IROS 2023 submission.
The video presents the paper Canfly: A Can-sized Autonomous Mini Coaxial Helicopter.
The development of autonomous rotary-wing UAVs has shown an evident tendency in miniaturization. However, the side effects brought by miniaturization, such as decreased load capability, shorter flight duration, and reduced autonomous ability, seriously hinder the process. In this paper, we firstly investigate into the configuration of different rotary-wing aircraft and optimize the configuration selection. Afterward, with several elaborate mechanisms contributing for the miniaturization, we present the hardware design and control strategy of a mini coaxial helicopter, which is 62% smaller than the smallest autonomous quadrotor so far [1] in the collision area. Abundant experiments reveal that it achieves impressive traversability and is capable of carrying autonomous tasks in unknown dense scenarios, while maintaining satisfactory performance regarding loadability and flight duration. Canfly: A Can-sized Autonomous Mini Coaxial Helicopter](https://i.ytimg.com/vi/Wx2LKPgmtd4/mqdefault.jpg)






