An Online Optimization-Based Trajectory Planning Approach for Cooperative Landing Tasks

This paper presents a real-time trajectory planning scheme for a heterogeneous multi-robot system (consisting of a quadrotor and a ground mobile robot) for a cooperative landing task, where the landing position, landing time, and coordination between the robots are determined autonomously under the consideration of feasibility and user specifications. The proposed framework leverages the potential of the complementarity constraint as a decision-maker and an indicator for diverse cooperative tasks and extends it to the collaborative landing scenario. In a potential application of the proposed methodology, a ground mobile robot may serve as a mobile charging station and coordinates in real-time with a quadrotor to be charged, facilitating a safe and efficient rendezvous and landing. We verified the generated trajectories in simulation and real-world applications, demonstrating the real-time capabilities of the proposed landing planning framework.

💡 Research Summary

The paper introduces a real‑time trajectory planning framework for a heterogeneous multi‑robot system composed of a quadrotor and an omnidirectional ground robot, aimed at achieving a coordinated landing. Unlike prior works that treat the UAV’s landing as a unilateral problem—assuming the ground vehicle’s trajectory is known—the authors formulate a single‑step optimal control problem that simultaneously accounts for the full nonlinear dynamics of both robots, user‑specified constraints, and the decision of when and where to land.

The core of the decision‑making mechanism is a complementarity constraint of the form a·b = 0, a ≥ 0, b ≥ 0. Here, the binary‑like landing index εₖ ∈