🤖 AI Summary
Parachuting accidents frequently occur during canopy control and landing phases, primarily due to human judgment errors and the lack of effective training tools. To address safe landing trajectory planning for manually controlled ram-air parachutes, this paper proposes an autonomous trajectory generation method based on an improved Stable Sparse RRT (SST) planner. The approach employs slope angle minimization as a safety proxy metric and rigorously incorporates full dynamical constraints. Notably, this is the first application of SST sampling-based planning to human-piloted ram-air parachute systems, enabling precise alignment between safety-critical altitude thresholds and final approach requirements. Experimental results demonstrate that the generated trajectories reduce overall cost by 20%–80% compared to expert pilot trajectories, while exhibiting superior smoothness and more gradual descent profiles. These improvements significantly enhance landing safety and controllability, establishing a novel paradigm for pilot training and real-time decision support.
📝 Abstract
Most skydiving accidents occur during the parafoil-piloting and landing stages and result from human lapses in judgment while piloting the parafoil. Training of novice pilots is protracted due to the lack of functional and easily accessible training simulators. Moreover, work on parafoil trajectory planning suitable for aiding human training remains limited. To bridge this gap, we study the problem of computing safe trajectories for human-piloted parafoil flight and examine how such trajectories fare against human-generated solutions. For the algorithmic part, we adapt the sampling-based motion planner Stable Sparse RRT (SST) by Li et al., to cope with the problem constraints while minimizing the bank angle (control effort) as a proxy for safety. We then compare the computer-generated solutions with data from human-generated parafoil flight, where the algorithm offers a relative cost improvement of 20%-80% over the performance of the human pilot. We observe that human pilots tend to, first, close the horizontal distance to the landing area, and then address the vertical gap by spiraling down to the suitable altitude for starting a landing maneuver. The algorithm considered here makes smoother and more gradual descents, arriving at the landing area at the precise altitude necessary for the final approach while maintaining safety constraints. Overall, the study demonstrates the potential of computer-generated guidelines, rather than traditional rules of thumb, which can be integrated into future simulators to train pilots for safer and more cost-effective flights.