## 1 Introduction
Furthermore, [PERSON] designed a dual-function landing gear system based on a Delta parallel robot, capable of performing grasping tasks while serving as the drone's landing gear, enhancing system usability but causing excessive energy consumption due to the increased number of actuators [22]. [PERSON] et al. proposed a foldable hybrid aerial-underwater vehicle design aimed at performing tasks in complex environments [23]. Meanwhile, [PERSON] et al. studied a foldable quadrotor drone, which can be quickly folded and deployed for easy transport [24]. Existing aerial grasping mechanisms, while capable of providing precise manipulation and handling, often face challenges related to mechanical complexity, increased weight, and high energy consumption. Many of these systems require additional actuators or complex mechanical components, which limit their practicality and overall performance. Therefore, simplifying the grasping mechanism while improving overall performance, without compromising the drone's takeoff, landing, and grasping capabilities, is crucial. The limitations of existing designs motivate the search for a new solution that integrates self-locking and clutch mechanisms into a single actuator, aiming to balance the drone's multifunctionality while minimizing energy consumption. This raises a fundamental scientific challenge--how to achieve complex multifunctional operations, such as landing and grasping, using a single actuator while maintaining high precision, reliability, and lightweight characteristics. Specifically, how to design the quick-release mechanism to efficiently switch between locked and released states without introducing excessive friction, delays, or failure risks is a significant challenge. We must address this issue to ensure the system's reliability and performance. Additionally, another key scientific challenge is how to optimize the design of the spring-driven mechanism to balance grasping force, speed, and structural stability, ensuring reliable and consistent operation under varying conditions. To address these challenges, this paper designed a lightweight dual-function landing gear that incorporates a quick-release mechanism, enabling ultra-fast object grasping. This mechanism consists of a self-locking mechanism and a clutch mechanism, both driven by a DC-geared motor. In this design, the DC-geared motor transmits power to the winch through a combination of mechanical systems, including the clutch mechanism and the self-locking mechanism, which play crucial roles in achieving multifunctional operations. When the drone lands or releases a grasped object, the operator uses the remote control to switch the clutch mechanism to the connected state. The DC-geared motor then transmits power to the winch, causing the landing gear to open under the tension of the cable wound on the winch. By monitoring feedback from the encoder at the motor's tail, the DC-geared motor automatically stops when the landing gear reaches the preset angle. Once the motor stops, the self-locking mechanism ensures that the cable on the winch remains taut, keeping the landing gear in the open position. When the drone performs grasping tasks, the micro-camera at the bottom of the fuselage transmits images to the ground station. The operator remotely controls the DC-geared motor to switch the clutch mechanism to the separated state and the self-locking mechanism to the released state. At this point, the dual-function landing gear, under the tension of the spring, actively grasps objects at an ultra-fast speed (0.167 s). This process demonstrates how optimizing the design can balance grasping force, speed, and structural stability to ensure efficient and stable grasping. Since the dual-function landing gear also serves as the gripper, it eliminates the additional weight of robotic arms, significantly reducing the complexity of the mechanism while enhancing the drone's endurance and payload capacity.