In context
In early 2025, multi-UAV systems were increasingly deployed for industrial inspection, search and rescue, and logistics, yet fixed-wing platforms posed unique control challenges due to underactuation, nonholonomic constraints, minimum speed limits, and input saturation. Existing methods struggled to simultaneously handle these constraints, external disturbances, and inter-UAV collision avoidance in real time, motivating new approaches for safe formation control.
What was reported
Researchers from Southeast University proposed a distributed robust control law for multiple fixed-wing UAVs to achieve formation tracking while ensuring obstacle avoidance and safety. The design first develops a nominal sliding-mode-based controller that satisfies input and velocity constraints under bounded disturbances, enabling precise tracking. Then, improved high-order control barrier functions (HOCBFs) are formulated to enforce collision avoidance between UAVs and with obstacles, explicitly considering input constraints and deriving linear input constraints via invariant set theory.
The final controller is obtained by solving a local quadratic programming problem for each UAV, combining the nominal law with robust avoidance constraints. Simulations compared the method against alternatives: it handled disturbances more effectively than controllers without disturbance compensation, reduced oscillations and better respected speed limits than potential-function methods, and significantly cut computation time compared to distributed model predictive control (MPC) approaches.
Why it mattered
This work advanced the practical deployment of fixed-wing UAV swarms by offering a computationally efficient, robust solution that systematically enforces safety and actuator limits—key for real-time industrial missions such as wide-area monitoring and autonomous logistics. It highlighted the growing role of control barrier functions in addressing complex multi-agent constraints beyond traditional methods.
"The above results validate the innovation and effectiveness of the designed control law."
Source: 《机器人》期刊 (robot.sia.cn) · Published 2025-01-15 · “基于高阶控制障碍函数的多固定翼无人机鲁棒避障安全编队跟踪控制”