In the rapid development of the low-altitude economy, multirotor UAVs are widely used in aerial photography, logistics transportation, and emergency rescue. However, traditional fixed landing gear often faces contradictions between “portability” and “flight performance”—bulky structures increase storage space, while simple retractable designs lack stability. Servo motors, with their advantages of high-precision angle positioning, fast response speed (millisecond-level actuation), and stable torque output, have become the core driving force to break through these bottlenecks. They not only optimize the retraction and deployment efficiency of landing gear but also integrate with sensor systems to achieve adaptive control in complex scenarios. The following details the innovative application ideas of servo motors in multirotor UAV landing gear from four core directions.
1. Precision Retraction & Deployment Mechanisms: Balancing Portability and Structural Stability
The core demand for landing gear retraction is to switch between “storage state” and “working state” quickly and reliably. Servo motors enable precise control of mechanical movements, solving the problems of jamming and poor positioning in traditional manual or electromagnetic retraction systems.
- Dual-Mode Retractable Systems: For consumer-grade UAVs (e.g., 450mm wheelbase models weighing ≤2000g ), integrating servo motors into carbon fiber landing gear joints allows for one-key retraction/deployment. When the UAV takes off and reaches an altitude of 2 meters (detected by the barometer), the flight controller sends a signal to the servo motor, which drives the rotating shaft to fold the landing gear upward at a speed of 15°/s until it is parallel to the fuselage—reducing wind resistance by 30% compared to fixed landing gear. During landing, the servo motor extends the landing gear to a 90° vertical state and locks it with a torque of 5kg·cm to bear the impact of touchdown. For industrial UAVs with larger loads, a dual-servo drive design is adopted: one servo controls the folding angle, and the other drives the locking pin to extend, ensuring structural rigidity comparable to fixed landing gear .
- Adaptive Attitude Alignment: When landing on uneven terrain (e.g., grasslands or slopes), traditional landing gear may tilt and cause rollovers. By installing a servo motor with a built-in encoder at each landing gear leg, the system can adjust the extension length in real time based on gyroscope data. For example, if the left front leg is on a 15° slope, the servo motor extends that leg by an additional 2cm to keep the fuselage horizontal, while the other legs maintain standard length—this precision (adjustable in 1mm increments) significantly improves landing stability.
2. Scene-Linked Retraction Logic: Synergizing with Flight Missions
Servo motors act as “executors” of mission-linked control, integrating landing gear movements with UAV flight states and task requirements to optimize operational efficiency.
- Payload-Centric Deployment Control: For logistics UAVs carrying 0.5kg+ loads , the servo motor adjusts the landing gear height according to payload weight. When loaded with 1kg of goods, the motor extends the landing gear by 5cm to increase ground clearance and avoid friction between the payload and the ground; when unloaded, it retracts to the standard height to reduce energy consumption. For aerial photography UAVs, the servo motor coordinates with the camera gimbal: 2 seconds before starting shooting, it retracts the landing gear to avoid blocking the lens, and extends it immediately after shooting—ensuring unobstructed footage without manual intervention.
- Environmental Adaptive Adjustment: In harsh environments, the servo motor adjusts the landing gear state based on sensor data. When the rain sensor detects precipitation, the motor drives the landing gear to retract 10° upward to prevent water from entering the joint bearings; when landing on soft ground (e.g., mud), it extends the gear by 3cm and increases the contact area with the ground, reducing the risk of sinking. For coastal missions, servo motors with IP67 waterproof ratings are used to resist salt spray corrosion, ensuring reliable operation in high-humidity environments.
3. Shock Absorption & Buffering Enhancement: Improving Landing Safety
Landing impact is a key factor affecting UAV lifespan. Servo motors collaborate with shock absorption components to achieve adaptive buffering, complementing the performance of traditional oil-gas dampers .
- Dynamic Damping Adjustment: Integrating servo motors into the landing gear shock absorber (composed of springs and hydraulic cylinders) allows for real-time adjustment of damping force. During normal landing, the motor keeps the damper in a “soft” state (damping coefficient 0.3) to absorb impact; if the UAV experiences an emergency landing (descending speed >3m/s), the motor increases the damping coefficient to 0.8 within 0.2 seconds to prevent excessive compression of the shock absorber. This dual-mode damping design reduces landing impact force by 40% compared to fixed-damping systems.
- Emergency Collision Mitigation: When the ultrasonic sensor detects an obstacle 1 meter below the landing gear during descent, the servo motor triggers an emergency retraction—folding the landing gear inward to avoid direct collision, while the UAV adjusts its attitude for a secondary landing. For eVTOLs like the “Yutu A100” , which operate at low altitudes (less than 10m), this function prevents landing gear damage from ground debris, enhancing operational safety.
4. Lightweight & Reliability Optimization: Addressing Industrial Pain Points
For UAVs, “lightweight” and “reliability” are equally important. Servo motors enable structural simplification and fault tolerance, addressing the contradictions in traditional landing gear design.
- Lightweight Integrated Design: Adopting micro-servo motors (weight ≤15g) and combining them with aluminum alloy landing gear frames reduces the overall weight of the landing gear system by 25% compared to electromagnetic drive systems. For foldable UAVs like the Typhoon H , the servo motor is integrated into the retractable joint of the carbon fiber landing gear, eliminating the need for independent drive boxes—making the folded volume 40% smaller and easier to transport.
- Dual-Redundancy Safety Mechanisms: Referencing the multi-redundancy design concept of eVTOLs , a dual-servo backup system is adopted for critical UAVs (e.g., emergency rescue models). If the main servo motor fails (detected by encoder signal loss), the backup motor takes over within 0.1 seconds to complete landing gear extension/retraction. Additionally, the servo motor provides real-time torque feedback: if the landing gear is stuck (torque exceeding 8kg·cm), the motor reverses 5° immediately and tries again, avoiding component damage caused by forced actuation—this fault-tolerance capability reduces mission failure rates by 60%.
Established in 2005, Kpower has been dedicated to a professional compact motion unit manufacturer, headquartered in Dongguan, Guangdong Province, China. Leveraging innovations in modular drive technology, Kpower integrates high-performance motors, precision reducers, and multi-protocol control systems to provide efficient and customized smart drive system solutions. Kpower has delivered professional drive system solutions to over 500 enterprise clients globally with products covering various fields such as Smart Home Systems, Automatic Electronics, Robotics, Precision Agriculture, Drones, and Industrial Automation.
