A piezoelectrically driven tiltable multi-rotor unmanned aerial vehicle

Abstract

The application discloses a piezoelectric driving tiltable multi-rotor unmanned aerial vehicle, and solves the technical problems of slow response speed, electromagnetic interference and serious mechanical wear caused by the motor used by the existing tiltable rotor unmanned aerial vehicle. The unmanned aerial vehicle comprises a rotor assembly, a body frame, an electromagnetic motor and a power module, the body frame is connected with the rotor assembly through an arm, a tilting mechanism is arranged in the arm, and a control system is arranged in the body frame; the rotor assembly comprises rotor blades and a rotor shaft, the rotor shaft is connected with the output end of the electromagnetic motor; the tilting mechanism comprises a piezoelectric driving shaft and an ultrasonic motor, the ultrasonic motor is connected with the piezoelectric driving shaft through a bearing; the control system is integrated in the body frame and comprises a sensor module and a controller; and the power module is arranged at the bottom of the body frame. By adopting the piezoelectric driving technology, the tiltable rotor unmanned aerial vehicle has the advantages of high response speed, low noise, no electromagnetic interference and multi-mode flight capability.

Description

Technical Field

[0001] This invention relates to the field of unmanned aerial vehicle (UAV) technology, and more specifically to a piezoelectrically driven tiltable multirotor UAV. Background Technology

[0002] Multirotor drones, with their vertical takeoff and landing, hovering, and agile maneuverability, are widely used in logistics inspection, disaster relief, and military reconnaissance. However, traditional multirotor drones typically use electromagnetic motors to drive the rotors, which presents significant technical bottlenecks: First, electromagnetic motors have a slow response speed (milliseconds), resulting in lag in flight attitude adjustment and making it difficult to meet the demands of high-dynamic flight; second, the motors generate electromagnetic interference during operation, affecting the stability of onboard electronic equipment, especially limiting their application in sensitive electromagnetic environments; third, the mechanical transmission structure is complex, and components such as gears and bearings are prone to wear, leading to high maintenance costs and short lifespans. Furthermore, traditional drones have a limited range of flight modes, making it difficult to simultaneously meet the requirements of vertical takeoff and landing and efficient horizontal flight.

[0003] To address the issue of limited flight modes, existing technologies have proposed tilt-rotor UAVs that use servo motors to drive the rotors to tilt and switch flight modes. However, these solutions still rely on traditional motors, resulting in problems such as insufficient response speed (typically greater than 50 milliseconds), high energy consumption, and accelerated mechanical wear. For example, the tilt mechanism driven by the servo motor requires a complex reduction gear set, which not only increases weight and size but also reduces system reliability due to frictional losses. Furthermore, the electromagnetic noise and mechanical vibration generated during motor operation further limit its application in covert missions or low-noise environments.

[0004] In recent years, piezoelectric actuation technology has been regarded as a potential solution for UAV drive systems due to its advantages such as high response speed (microsecond level), no electromagnetic interference, and compact structure. However, existing piezoelectric actuation technologies suffer from technical challenges such as small drive displacement and limited output torque, making it difficult to directly meet the power requirements of rotor tilting. In addition, piezoelectric materials have low energy conversion efficiency and lack effective vibration energy recovery mechanisms, which limits the improvement of endurance. How to combine piezoelectric actuation technology with tilt-rotor UAVs to achieve efficient power output while solving the problems of energy utilization and structural reliability has become a key challenge that urgently needs to be overcome in the current technological field. Summary of the Invention

[0005] The purpose of this invention is to provide a piezoelectrically driven tiltable multi-rotor drone to solve the technical problems of traditional multi-rotor drones, such as complex structure, high energy consumption, slow response speed, single flight mode, as well as the slow response speed, electromagnetic interference, and severe mechanical wear caused by the motors used in existing tiltable rotor drones.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] This invention provides a piezoelectric-driven tilting multirotor unmanned aerial vehicle (UAV), comprising: a rotor assembly, a fuselage frame, an electromagnetic motor for driving the rotor assembly to rotate, and a power module. The fuselage frame is connected to the rotor assembly via an arm, and the arm contains a tilting mechanism. The fuselage frame also contains a control system. The rotor assembly includes rotor blades and a rotor shaft, which is connected to the output end of the electromagnetic motor. The tilting mechanism includes a piezoelectric drive shaft and an ultrasonic motor, which is connected to the piezoelectric drive shaft via a bearing. The control system is integrated within the fuselage frame and includes a sensor module and a controller. The sensors include a gyroscope and an accelerometer for real-time acquisition of flight attitude data. The controller is used to adjust the rotor speed and tilt angle. The power module is located at the bottom of the fuselage frame and drives the electromagnetic motor and the ultrasonic motor to work together. The ultrasonic motor drives the arm and rotor assembly to tilt together via the piezoelectric drive shaft, with a tilt angle range of -90° to +90°, to achieve seamless switching between vertical takeoff and landing (VTOL) and horizontal flight modes.

[0008] Furthermore, the tilting mechanism integrates a PVDF thin-film sensor for real-time monitoring of the tilt angle and vibration status.

[0009] Furthermore, the power module is connected to an energy recovery circuit, which includes a rectifier and an energy storage capacitor. The energy recovery circuit converts vibration energy into electrical energy through the positive piezoelectric effect of the piezoelectric material and stores it in the power module.

[0010] Furthermore, the control module adopts an adaptive PID control algorithm, dynamically adjusts control parameters based on feedback data from the sensor module, and integrates fault detection and fault-tolerant control functions to monitor the working status of the piezoelectric drive unit and the tilting mechanism in real time.

[0011] Furthermore, the fuselage frame is made of a lightweight material, namely carbon fiber.

[0012] Furthermore, a landing gear is installed at the bottom of the fuselage frame.

[0013] Based on the above technical solution, the embodiments of the present invention can produce at least the following technical effects:

[0014] The piezoelectric-driven tilting multirotor UAV provided by this invention achieves high response speed, low noise, no electromagnetic interference, and multimodal flight capabilities by employing piezoelectric drive technology. The piezoelectric drive mechanism significantly improves the accuracy and efficiency of flight control, while the energy recovery circuit extends endurance. Lightweight design and adaptive PID control algorithm further optimize the UAV's performance and stability, making it suitable for sensitive environments and diverse mission requirements. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the overall structure of the UAV of the present invention;

[0017] Figure 2 This is a schematic diagram of the piezoelectric-driven tilting mechanism;

[0018] Figure 3 This is a schematic diagram of the rotor tilting operation.

[0019] In the diagram: 1-rotor assembly, 2-arm, 3-landing support, 4-fuselage frame, 5-tilt mechanism, 6-electromagnetic motor, 7-piezoelectric drive shaft, 8-bearing, 9-ultrasonic motor, 10-rotor blade, 11-rotor shaft. Detailed Implementation

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. In addition, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0021] This invention provides a piezoelectrically driven tiltable multirotor unmanned aerial vehicle (UAV) designed to achieve seamless switching between rotor tilting and multimodal flight through piezoelectric actuation technology. For example... Figures 1-2 As shown, it includes: rotor assembly 1, fuselage frame 4, electromagnetic motor 6 for driving the rotor assembly 1 to rotate, and power supply module.

[0022] The fuselage frame 4 is made of lightweight carbon fiber material and has a symmetrical multi-rotor layout. Landing supports 3 are installed at the bottom for landing cushioning. The control system is integrated inside the frame, and the rotor assembly 1 is connected to the outside via four arms 2.

[0023] Each rotor assembly 1 includes rotor blades 10 and a rotor shaft 11, with the rotor shaft 11 directly connected to the output of an electromagnetic motor 6. The electromagnetic motor 6 controls the rotor speed via a high-frequency drive signal, providing vertical lift or horizontal thrust.

[0024] Arm 2 is a hollow tubular structure, with a tilting mechanism 5 installed inside. The tilting mechanism 5 includes an ultrasonic motor 9 and a piezoelectric drive shaft 7. The ultrasonic motor 9 is connected to the piezoelectric drive shaft 7 via a bearing 8. The piezoelectric drive shaft 7 drives arm 2 and rotor assembly 1 to tilt together. Figure 3 As shown, the tilt angle range is -90° to +90°. The tilt mechanism 5 integrates a PVDF thin-film sensor for real-time monitoring of the tilt angle and vibration status.

[0025] The control system is integrated inside the fuselage frame and includes a sensor module and a controller. The sensors include gyroscopes and accelerometers for real-time acquisition of flight attitude data. The controller adopts an adaptive PID control algorithm to dynamically adjust the rotor speed and tilt angle, and integrates fault detection and fault tolerance functions to monitor the working status of the piezoelectric drive unit in real time.

[0026] The power module is located at the bottom of the fuselage frame 4 and provides high-voltage power to the electromagnetic motor 6, ultrasonic motor 9, and piezoelectric drive unit. The power module is connected to the energy recovery circuit, which consists of a rectifier and an energy storage capacitor. Through the positive piezoelectric effect of the piezoelectric material, the vibration energy generated during flight is converted into electrical energy and stored in the power module, with an energy recovery efficiency of 15%-20%.

[0027] The working principle of this invention is as follows:

[0028] 1. Vertical Take-off and Landing Mode

[0029] All rotor components remain horizontal, and the electromagnetic motor drives the rotor to rotate at high speed, generating vertical lift to achieve hovering or vertical takeoff and landing. At this time, the tilt mechanism is in its initial position (tilt angle 0°), and the PVDF thin-film sensor monitors the rotor vibration status in real time.

[0030] 2. Horizontal flight mode

[0031] When switching to level flight is required, the controller module sends a drive signal to the ultrasonic motor. The piezoelectric drive shaft drives the rotor to tilt around the arm axis to the target angle (0°–90°), causing the rotor thrust direction to deflect and propelling the UAV into level flight. During this process, the adaptive PID algorithm dynamically adjusts the tilt angle and rotor speed based on gyroscope and accelerometer data to ensure flight stability.

[0032] 3. Transition mode and seamless switching

[0033] During flight mode switching, the controller gradually adjusts the rotor tilt angle based on data feedback from the sensor module, while coordinating the rotational speeds of each rotor to achieve a smooth transition between lift and thrust. The tilt mechanism has a response time of less than 10 milliseconds, ensuring high dynamic performance during mode switching.

[0034] 4. Energy recovery and range optimization

[0035] During flight, the vibration energy of the fuselage is converted into electrical energy through piezoelectric materials. After being rectified by a rectifier, it is stored in an energy storage capacitor and finally fed back to the power module, extending the flight time by 10%-15%.

[0036] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A piezoelectrically driven tiltable multi-rotor unmanned aerial vehicle, characterized in that, include: The rotor assembly (1), fuselage frame (4), electromagnetic motor (6) for driving the rotor assembly (1) to rotate, and power module are provided. The fuselage frame (4) is connected to the rotor assembly (1) through arm (2). The arm (2) is provided with a tilting mechanism (5). The fuselage frame (4) is provided with a control system. The rotor assembly (1) includes rotor blades (10) and rotor shaft (11), and the rotor shaft (11) is connected to the output end of the electromagnetic motor (6); The tilting mechanism (5) includes a piezoelectric drive shaft (7) and an ultrasonic motor (9), and the ultrasonic motor (9) and the piezoelectric drive shaft (7) are connected by a bearing (8); The control system is integrated within the fuselage frame (4) and includes a sensor module and a controller. The sensor module includes a gyroscope and an accelerometer for real-time acquisition of flight attitude data. The controller is used to adjust the rotor speed and tilt angle. The power module is located at the bottom of the body frame (4) and drives the electromagnetic motor (6) and the ultrasonic motor (9) to work together; The ultrasonic motor (9) drives the arm (2) and rotor assembly (1) to tilt together via the piezoelectric drive shaft (7), with a tilt angle range of -90° to +90°, so as to achieve seamless switching between vertical take-off and landing mode and horizontal flight mode; The tilting mechanism (5) integrates a PVDF thin film sensor for real-time monitoring of the tilt angle and vibration status; The power module is connected to an energy recovery circuit, which includes a rectifier and an energy storage capacitor. The energy recovery circuit converts vibration energy into electrical energy through the positive piezoelectric effect of the piezoelectric material and stores it in the power module. The control system adopts an adaptive PID control algorithm, dynamically adjusts control parameters based on feedback data from the sensor module, and integrates fault detection and fault-tolerant control functions to monitor the working status of the piezoelectric drive unit and the tilting mechanism in real time.

2. The piezoelectrically driven tiltable multi-rotor UAV according to claim 1, characterized in that, The fuselage frame (4) is made of lightweight material, namely carbon fiber.

3. The piezoelectrically driven tiltable multi-rotor UAV according to claim 1, characterized in that, The fuselage frame (4) is equipped with landing gear (3) at the bottom.

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