Motion control method and device, storage medium and program product

Abstract

The invention discloses a motion control method and device, a storage medium and a program product, and relates to the technical field of unmanned aerial vehicles, the motion control method is applied to an unmanned aerial vehicle, wings of the unmanned aerial vehicle comprise an inner wing section and an outer wing section, the outer wing section is provided with at least two flapping wings, and the method comprises the steps that a water-air medium conversion instruction is received; according to the water-air medium conversion instruction, whether the forms of the flapping wings are switched or not is determined, and the forms of the flapping wings comprise the fixed wing form and the flapping wing form; and after the forms of the flapping wings are determined and switched, according to the current medium of the unmanned aerial vehicle, control parameters of the flapping wings after form switching are adjusted, and the unmanned aerial vehicle is driven to move in the current medium through the flapping wings after parameter adjustment. The unmanned aerial vehicle motion control of flapping wing form switching and parameter adjustment is achieved, the problem that an existing water-air amphibious unmanned aerial vehicle is insufficient in motion stability in a medium is solved, and the motion stability of the unmanned aerial vehicle in the water-air medium is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of unmanned aerial vehicles, and particularly relates to a motion control method and device, a storage medium and a program product. BACKGROUND

[0002] With the continuous development of unmanned aerial vehicle technology, as a new type of aircraft, the amphibious unmanned aerial vehicle usually adopts a fixed-wing structure or a morphing wing structure. When switching the flight mode in air and water, it is usually through complex mechanical structure deformation or replacement of the power system to adapt to the motion requirements of different media to realize the amphibious function.

[0003] However, due to the great difference in physical properties such as density and resistance between air and water, the existing unmanned aerial vehicle is difficult to maintain sufficient stability and control accuracy in the medium conversion process, which leads to the problem that the unmanned aerial vehicle is prone to attitude loss of control and unstable motion when switching the medium between air and water, thereby affecting the task execution.

[0004] The above content is only used to assist in understanding the technical solutions of the present application and does not represent the acknowledgement of the above content as prior art. SUMMARY

[0005] The main purpose of the present application is to provide a motion control method, device, storage medium and program product, which aims to solve the technical problem of insufficient stability of the existing amphibious unmanned aerial vehicle in the medium.

[0006] To achieve the above-mentioned purpose, the present application provides a motion control method, which is applied to an unmanned aerial vehicle, the wing of the unmanned aerial vehicle comprises an inner wing segment and an outer wing segment, the outer wing segment is configured with at least two flapping wings, and the motion control method comprises the following steps: receiving a water-air medium conversion instruction; determining whether to switch the mode of the flapping wing according to the water-air medium conversion instruction, the mode of the flapping wing comprising a fixed-wing mode and a flapping-wing mode; After determining and switching the mode of the flapping wing, adjusting the control parameters of the flapping wing after switching the mode according to the current medium where the unmanned aerial vehicle is located, and driving the unmanned aerial vehicle to move in the current medium through the flapping wing after parameter adjustment.

[0007] In an embodiment, the water-air medium conversion instruction comprises a water entry conversion instruction and a water exit reflight instruction, and the step of determining whether to switch the mode of the flapping wing according to the water-air medium conversion instruction comprises: when the water-air medium conversion instruction is the water entry conversion instruction, switching the mode of the flapping wing to the flapping-wing mode; when the water-air medium conversion instruction is the water exit reflight instruction, switching the mode of the flapping wing to the fixed-wing mode.

[0008] In an embodiment, the UAV is further configured with a pressure sensor and / or an optical sensor, and before the step of adjusting the control parameters of the flapping wings after the determination and switching of the morphing of the flapping wings according to the current medium in which the UAV is located, the method further comprises: detecting medium density data by the pressure sensor and / or the optical sensor; judging a medium type of the current medium in which the UAV is located according to the medium density data, so as to adjust the motion parameters of the flapping wings after the morphing according to the density characteristics corresponding to the medium type, the medium type including air medium or water medium.

[0009] In an embodiment, the step of adjusting the control parameters of the flapping wings after the determination and switching of the morphing of the flapping wings according to the current medium in which the UAV is located comprises: if the current medium is air medium, adjusting the control parameters of the flapping wings after the morphing to be static locking; if the current medium is water medium, calculating flapping parameters based on a preset flapping motion equation, and adjusting the control parameters of the flapping wings after the morphing to be the flapping parameters.

[0010] In an embodiment, the flapping wings comprise fin strips and fin strip servos, the fin strips are controlled to flap by the fin strip servos, and the step of calculating the flapping parameters based on the preset flapping motion equation comprises: constructing a rotation angle control equation of the fin strip corresponding to the fin strip servo based on the flapping motion equation; solving and calculating the rotation angle control equation of the fin strip corresponding to the fin strip servo to obtain the flapping parameters.

[0011] In an embodiment, the outer wing segment and the inner wing segment are connected by a swing servo, and the step of driving the UAV to move in the current medium by the flapping wings after the parameter adjustment comprises: when the flapping parameters are two-degree-of-freedom symmetrical flapping parameters, the fin strips are controlled to perform vertical flapping by the fin strip servos to drive the UAV to perform snorkeling movement in the water medium; when the flapping parameters are three-degree-of-freedom diagonal flapping parameters, the fin strips are controlled to perform a composite motion of vertical flapping and front and rear swing by the fin strip servos and the swing servo to drive the UAV to perform propulsion movement in the water medium.

[0012] In addition, to achieve the above object, the application further provides a motion control device, which is applied to a UAV, the wings of the UAV comprise an inner wing segment and an outer wing segment, the outer wing segment is configured with at least two flapping wings, and the motion control device comprises: an instruction receiving module configured to receive a water-air medium conversion instruction; a mode switching module configured to determine whether to switch a mode of the flapping wing according to the water-air medium conversion instruction, the mode of the flapping wing including a fixed-wing mode and a flapping-wing mode; a motion executing module configured to adjust a control parameter of the flapping wing after the mode of the flapping wing is determined and switched, and drive the unmanned aerial vehicle to move in the current medium according to the adjusted control parameter of the flapping wing.

[0013] In addition, to achieve the above object, the present application further provides a motion control device, which comprises a memory, a processor and a computer program stored in the memory and executable on the processor, and the computer program is configured to implement the steps of the motion control method as described above.

[0014] In addition, to achieve the above object, the present application further provides a storage medium, which is a computer readable storage medium, and the storage medium stores a computer program, and the computer program is executed by a processor to implement the steps of the motion control method as described above.

[0015] In addition, to achieve the above object, the present application further provides a computer program product, which comprises a computer program, and the computer program is executed by a processor to implement the steps of the motion control method as described above.

[0016] The present application provides a motion control method, first, by receiving a water-air medium conversion instruction, the unmanned aerial vehicle can be timely informed of the need for medium conversion; then, the flapping wing mode is switched according to the instruction, and it is determined whether to switch the mode of the flapping wing, so that the unmanned aerial vehicle has the hardware basis to adapt to different medium motion modes, and provides the possibility for air stable flight and underwater flexible diving; and then the flapping wing control parameter is adjusted according to different media and the unmanned aerial vehicle is driven to move, so that the unmanned aerial vehicle can run in a suitable way in air and water, effectively solving the problem of insufficient stability of the existing water-air amphibious unmanned aerial vehicle when converting media, and improving the reliability, adaptability and motion efficiency of the unmanned aerial vehicle in the cross-medium task. BRIEF DESCRIPTION OF DRAWINGS

[0017] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and serve to explain the principles of the present application together with the specification.

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, the drawings can also provide further understanding of the prior art for those of ordinary skill in the art without any inventive effort.

[0019] Figure 1 The flowchart provided for the first embodiment of the motion control method of the present application; Figure 2 The flowchart provided for the second embodiment of the motion control method of the present application; Figure 3 The flowchart provided for the third embodiment of the motion control method of the present application; Figure 4 The module structure diagram of the motion control device of the embodiment of the present application; Figure 5 The device structure diagram of the hardware running environment involved in the motion control method in the embodiment of the present application.

[0020] The object implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0021] It should be understood that the specific embodiments described herein are only used to explain the technical solutions of the present application, and are not used to limit the present application.

[0022] In order to better understand the technical solutions of the present application, the following will be described in detail in combination with the accompanying drawings and specific embodiments.

[0023] The main solution of the embodiment of the present application is: receiving water-air medium conversion instruction; determining whether to switch the mode of the flapping wing according to the water-air medium conversion instruction, the mode of the flapping wing including fixed wing mode and flapping wing mode; after determining and switching the mode of the flapping wing, adjusting the control parameter of the flapping wing after switching the mode according to the current medium where the unmanned aerial vehicle is located, and driving the unmanned aerial vehicle to move in the current medium through the flapping wing after parameter adjustment.

[0024] In the prior art, the propulsion system of water-air amphibious unmanned aerial vehicles (UAVs) usually adopts propeller propulsion and biomimetic flapping wing propulsion. Propeller propulsion system generates thrust by rotating propeller, which has the advantages of simple structure and high efficiency, and can work in air and water. However, due to the large difference in density between air and water, the optimal working parameters of propeller in the two media are significantly different. In the air, propeller needs high speed to generate enough lift; while in the water, too high speed may cause cavitation phenomenon, reducing the propulsion efficiency, and even damaging the propeller blades. Biomimetic flapping wing propulsion system simulates the movement of living beings, generating thrust through the up-down flapping and twisting motion of flapping wings. This way has high efficiency and maneuverability underwater, but in the air, due to the small resistance, the propulsion efficiency of flapping wings may be low. In addition, the multi-degree-of-freedom motion of flapping wings requires a complex control system to coordinate, increasing the technical difficulty.

[0025] Firstly, it is difficult to achieve both cross-medium efficiency and stability. When propeller switches between air and water, due to the difference in physical properties of the two media, it is difficult to maintain stable thrust output at the moment of conversion, resulting in the possibility of speed drop or attitude instability of the UAV. Although biomimetic flapping wing has high efficiency underwater, its propulsion efficiency is low in the air, and it needs to quickly adjust the motion mode when switching between media, which puts high requirements on the response speed and accuracy of the control system.

[0026] Secondly, the complex motion mechanism of biomimetic flapping wing is difficult to control accurately. The multi-degree-of-freedom motion of flapping wings (such as up-down flapping, twisting, etc.) needs to be accurately coordinated to adapt to the fluid mechanics characteristics of different media. The existing technology is difficult to adjust the frequency, amplitude and phase of flapping wings in real time, resulting in the UAV's inability to quickly adapt to environmental changes when crossing media, affecting stability and propulsion efficiency. Furthermore, the impact problem during the transition between media is prominent. When the UAV enters or exits the water, it will be subjected to a large change in medium resistance. For example, at the moment of entering the water, the body of the UAV enters the high-resistance water environment from the low-resistance air environment. If there is no effective buffer and stability mechanism, the UAV may stall or even be damaged due to the impact force. The existing technology lacks effective transition strategies, making it difficult to smoothly complete this process.

[0027] Finally, the balance problem of the power system is serious. The UAV needs to provide stable power output in different media, but the torque of propeller is significantly different in air and water. Without effective balancing measures, the body may rotate, damaging the flight stability. The power system of biomimetic flapping wing also needs to be balanced in the two media, otherwise it will affect the propulsion efficiency and the overall performance of the UAV. The existing technology often cannot smoothly switch and balance the power system between the two media, further exacerbating the difficulty of cross-medium motion.

[0028] In the present application, the unmanned aerial vehicle can adjust the flapping wing shape according to the instruction when entering or leaving the water, reduce the impact force and resistance change, and ensure the smooth transition of cross-medium conversion. In the water medium, the bionic flapping wing can simulate the biological motion mode, overcome the water resistance by adjusting the flapping wing frequency, amplitude and other parameters to generate stable thrust; in the air medium, it can be switched to the fixed wing shape, and the propeller provides propulsion to realize efficient flight. The present application combines bionic flapping wing and propeller propulsion, which not only utilizes the bionic flapping wing to generate stable thrust underwater, but also uses the propeller to provide efficient propulsion in the air. By optimizing the power output, the unmanned aerial vehicle can maintain the best performance in different media, effectively solving the problem that the power system is difficult to balance in the prior art, and improving the overall performance and reliability of the unmanned aerial vehicle.

[0029] It should be noted that the execution subject of the present embodiment can be a computing service device with data processing, network communication and program running functions, such as a tablet computer, a personal computer, a mobile phone, etc., or an electronic device, a motion control device, etc. capable of realizing the above functions. The present embodiment and the following embodiments will be described below taking the motion control device as an example.

[0030] Based on this, the present embodiment provides a motion control method, which will be described below with reference to Figure 1 , Figure 1 The flowchart of the first embodiment of the motion control method of the present application is shown in the figure.

[0031] In the present embodiment, the motion control method is applied to an unmanned aerial vehicle, the wings of the unmanned aerial vehicle include an inner wing segment and an outer wing segment, and the outer wing segment is configured with at least two flapping wings, including steps S10-S30: Step S10, receiving a water-air medium conversion instruction; It should be noted that the wings of the unmanned aerial vehicle are the key components for generating lift, and the wings as a whole are divided into inner wing segments and outer wing segments, and the segmented design enables the unmanned aerial vehicle to flexibly adjust the wing shape in different media. The planar shape, airfoil shape, aspect ratio and other parameters of the wing affect the lift coefficient, resistance characteristics, flight speed range and maneuverability of the unmanned aerial vehicle. In the fixed-wing unmanned aerial vehicle, the wing is usually designed in a streamlined shape to reduce air resistance and generate enough lift to enable the unmanned aerial vehicle to fly stably in the air. In the amphibious unmanned aerial vehicle, the design of the wing needs to take into account the characteristics of both air and water media to realize stable movement across media.

[0032] The inner wing section is a fixed part of the wing connected to the fuselage of the UAV, adopting a traditional fixed-wing form. During flight in the air, the main function of the inner wing section is to generate lift, and its airfoil and size are optimized to enable the UAV to fly stably in the air and provide sufficient lift to overcome gravity. The inner wing section usually adopts the aerodynamic layout of a traditional fixed wing, and its airfoil and size are optimized according to the aerodynamic requirements of the UAV to ensure good lift characteristics and flight stability during flight in the air. In addition, some power system components such as motors and propellers may be installed inside the inner wing section to provide power for flight in the air.

[0033] The outer wing section is a variable part of the wing connected to the inner wing section, and is provided with at least two pairs of flapping wings arranged symmetrically, which can switch the shape of the flapping wings according to the water-air medium conversion instruction. During flight in the air, the flapping wings of the outer wing section remain in the fixed-wing form and form a complete fixed-wing structure with the inner wing section to ensure the aerodynamic performance and flight stability of the UAV. When underwater, the flapping wings of the outer wing section are switched to the flapping form and start to perform biomimetic flapping motion to provide underwater propulsion for the UAV.

[0034] In addition, it should be noted that the water-air medium conversion instruction is a control instruction for triggering the UAV to convert between air medium and water medium, so that the UAV can flexibly switch between water and air media according to task requirements, which can be issued by an operator according to a task scenario or a preset task program and transmitted to the control system of the UAV through a communication link.

[0035] It can be understood that in order to clearly define the task requirements of the UAV currently requiring medium conversion, when the UAV needs to convert from flight mode in the air to underwater mode or from underwater mode to flight mode in the air, the corresponding water-air medium conversion instruction is received, otherwise the UAV will maintain the original flight state. The control logic inside the UAV is triggered by external instructions or preset task programs to ensure that the UAV can convert media at the appropriate time, thereby adapting to different task scenarios and medium environments, improving the flexibility and task adaptability of the UAV.

[0036] Specifically, receiving the water-air medium conversion instruction can be achieved in various ways. For example, in a reconnaissance task, the operator can send a water-entry conversion instruction to the UAV through a ground control station to make the UAV enter an underwater covert reconnaissance mode after completing air reconnaissance; in a marine environment monitoring task, according to a preset task program, the UAV automatically receives a water-entry conversion instruction when it reaches a specified sea area, and starts underwater monitoring work. It can meet the instruction transmission requirements in different task scenarios, such as remote manual control and preset program automatic triggering, so as to realize the on-demand conversion of the UAV between different media.

[0037] Step S20, according to the water-air medium conversion instruction, determine whether to switch the form of the flapping wing, the form of the flapping wing includes fixed wing form and flapping wing form; It should be noted that the form of the flapping wing includes the fixed wing form and the flapping wing form, the fixed wing form refers to the outer wing segment remains horizontal and stationary, like the wing form of the traditional fixed wing unmanned aerial vehicle, mainly used for flying in the air, the form switching can be realized by using the linkage mechanism driven by the motor, the motor drives the linkage to make the flapping wing of the outer wing segment to expand or retract, and the form switching is completed. The flapping wing form refers to the flapping wing of the outer wing segment is in active state, which can perform up and down flapping and twisting motion, so as to realize the underwater propulsion function.

[0038] It can be understood that in order to make the wing structure of the unmanned aerial vehicle adapt to the physical characteristics of different media, based on the variable wing structure design of the unmanned aerial vehicle, the mechanical device and the control system are coordinated to realize the rapid conversion of the flapping wing form. When the unmanned aerial vehicle receives the water-air medium conversion instruction, it needs to confirm whether to switch the flapping wing to the flapping wing form or the fixed wing form, so that the unmanned aerial vehicle can flexibly switch the form between the air flight and underwater navigation modes, fully play the advantages of the unmanned aerial vehicle in different media, and improve the task execution ability and adaptability of the unmanned aerial vehicle.

[0039] Step S30, after determining and switching the form of the flapping wing, according to the current medium where the unmanned aerial vehicle is located, adjusting the control parameters of the flapping wing after switching the form, and driving the unmanned aerial vehicle to move in the current medium through the flapping wing with adjusted parameters.

[0040] It should be noted that the current medium refers to the physical environment where the unmanned aerial vehicle is located when performing the task, that is, the air medium or the water medium, which determines the fluid mechanics characteristics (such as density, resistance, etc.) of the unmanned aerial vehicle and the required motion mode and power characteristics. The control parameters of the flapping wing include the flapping frequency, flapping amplitude, twisting angle, phase difference and other parameters of the flapping wing, which directly affect the motion state and generated propulsion or lift of the flapping wing. Parameter adjustment refers to optimizing the setting of the control parameters of the flapping wing according to the characteristics of the current medium, so that the flapping wing can efficiently drive the unmanned aerial vehicle to move in the current medium, and ensure that the unmanned aerial vehicle can stably and efficiently operate in different media to achieve its task target. For example, in the air, due to the lower density and smaller resistance, the control parameters of the flapping wing need to be adjusted to generate sufficient lift while maintaining lower energy consumption; in water, the density is larger and the resistance is larger, the control parameters of the flapping wing need to be able to provide sufficient propulsion to overcome the resistance of water.

[0041] It can be understood that, in order to enable the unmanned aerial vehicle to adapt to the physical characteristics of different media, maintain stability and motion efficiency, according to the current medium environment in which the unmanned aerial vehicle is located, the motion parameters of the flapping wing are adjusted in real time, so that the flapping wing can generate appropriate fluid power in different media, thereby driving the unmanned aerial vehicle to move, ensuring that the unmanned aerial vehicle can stably and efficiently operate in both water and air media, and improving the cross-media adaptability and task execution capability of the unmanned aerial vehicle.

[0042] In a possible implementation, when the water-air medium conversion instruction is a water-entry conversion instruction, the step of determining whether to switch the form of the flapping wing according to the water-air medium conversion instruction comprises: Step S201: determining whether the form of the flapping wing is a fixed-wing form. Step S202: if the form of the flapping wing is a fixed-wing form, switching the form of the flapping wing to a flapping-wing form.

[0043] It should be noted that the water-entry conversion instruction is a key control signal for triggering the unmanned aerial vehicle to convert from an air flight mode to an underwater diving mode. The flapping-wing form refers to the flapping wing of the outer wing segment being in an active state and being capable of upward and downward flapping and twisting movements, so as to realize underwater propulsion.

[0044] It can be understood that, when the unmanned aerial vehicle receives the water-entry conversion instruction, it means that the unmanned aerial vehicle needs to convert from an air flight mode to an underwater diving mode, and therefore the flapping wing needs to be quickly converted from a fixed-wing form to a flapping-wing form, so that the unmanned aerial vehicle can use the biomimetic motion of the flapping wing for underwater propulsion after entering the water. At this time, the wing structure of the unmanned aerial vehicle adapts to the physical characteristics of the water medium, generates sufficient propulsion force through the biomimetic motion of the flapping wing, overcomes the resistance of water, and realizes stable underwater motion. Rapidly changing the form of the flapping wing after receiving the instruction ensures that the unmanned aerial vehicle can quickly adapt to the underwater environment after entering the water, start underwater tasks, and improve the stability and efficiency of the unmanned aerial vehicle in underwater motion.

[0045] Specifically, after the unmanned aerial vehicle receives the water-entry conversion instruction, the flapping wing of the outer wing segment can be unfolded through a linkage mechanism driven by a motor, so as to convert from a fixed-wing form to a flapping-wing form. For example, when the unmanned aerial vehicle approaches the water surface, the motor is started after receiving the instruction, drives the flapping wing to unfold outward through a linkage, and adjusts the angle and position of the flapping wing, so that the flapping wing can start flapping immediately after entering the water. In addition, a hydraulic drive device can also be used to trigger the conversion of the flapping-wing form at the moment of entering the water by using water flow pressure, so as to realize rapid response.

[0046] In another possible implementation, when the water-air medium conversion instruction is a water-exit and fly-again instruction, the step of determining whether to switch the form of the flapping wing according to the water-air medium conversion instruction comprises: Step S203, judging whether the form of the flapping wing is the flapping wing form or not. Step S204, if the form of the flapping wing is the flapping wing form, determining to switch the form of the flapping wing to the fixed wing form.

[0047] It should be noted that the water-out reflight instruction is a key control signal triggering the conversion of the unmanned aerial vehicle from the underwater diving mode to the air flight mode. The fixed wing form refers to the outer wing segment remaining horizontal and stationary, like the wing form of the traditional fixed wing unmanned aerial vehicle, mainly used for air flight.

[0048] It can be understood that when the unmanned aerial vehicle needs to return to the air after completing the underwater task, the water-out reflight instruction is received, and according to the water-out reflight instruction, the flapping wing needs to be quickly converted from the flapping wing form to the fixed wing form. At this time, the wing structure of the unmanned aerial vehicle adapts to the physical properties of the air medium, and the lift generated by the fixed wing can enable the unmanned aerial vehicle to fly in the air like a fixed wing aircraft after the water-out, ensuring that the unmanned aerial vehicle can quickly adapt to the air environment after the water-out, restore the flight state, and improve the stability and efficiency of the unmanned aerial vehicle in the air flight.

[0049] Specifically, after the unmanned aerial vehicle receives the water-out reflight instruction, the motor-driven linkage mechanism can be used to make the flapping wing of the outer wing segment retract, and convert from the flapping wing form to the fixed wing form. For example, when the unmanned aerial vehicle is about to water-out, the motor starts after receiving the instruction, drives the flapping wing to retract inward through the linkage, and makes it remain horizontal and stationary to form a fixed wing structure. At the same time, the angle and position of the flapping wing can be adjusted during the retraction to reduce air resistance and optimize the generation of lift, in combination with aerodynamic design. In addition, a spring reset device can be used to trigger the conversion of the flapping wing form at the moment of water-out by using the kinetic energy of the unmanned aerial vehicle, to achieve a quick response.

[0050] Illustratively, taking the underwater reconnaissance task of the amphibious unmanned aerial vehicle as an example. When the unmanned aerial vehicle completes the underwater reconnaissance task, it needs to return to the air. At this time, the ground control station sends a water-out reflight instruction to the unmanned aerial vehicle. After receiving the instruction, the unmanned aerial vehicle first switches the form of the flapping wing from the flapping wing form to the fixed wing form according to the water-out reflight instruction. At this time, the flapping wing of the outer wing segment retracts and remains horizontal and stationary to form a fixed wing structure. Subsequently, the unmanned aerial vehicle uses the lift generated by the propeller of the inner wing segment in combination with the lift generated by the fixed wing to gradually climb to the air and restore the air flight state. During the task, the unmanned aerial vehicle realizes a smooth conversion from underwater diving to air flight, and maintains stable flight in the air, effectively solving the problem of insufficient stability of the existing amphibious unmanned aerial vehicle during medium conversion, making the action of the unmanned aerial vehicle during medium conversion more accurate and efficient, and improving the success rate and reliability of task execution.

[0051] In this embodiment, through the specific type of water-air medium conversion instruction and the corresponding flapping wing mode switching, the unmanned aerial vehicle can fully exert the advantages of the two modes, realize seamless switching of underwater propulsion and aerial flight, and make the unmanned aerial vehicle more accurately and efficiently adjust the wing mode during the medium conversion process to adapt to the physical characteristics of different media.

[0052] In a feasible implementation, the unmanned aerial vehicle is further configured with a pressure sensor and / or an optical sensor, and before the step of adjusting the control parameters of the flapping wing after the switching of the mode according to the current medium in which the unmanned aerial vehicle is located, the method further comprises: Step S301: detecting medium density data through the pressure sensor and / or the optical sensor; It should be noted that the pressure sensor is a device capable of detecting the pressure of the environment in which the unmanned aerial vehicle is located, and can be installed on the body or wing surface of the unmanned aerial vehicle. In the amphibious unmanned aerial vehicle, the depth or height of the unmanned aerial vehicle can be determined by detecting the change of water pressure or air pressure, and then the medium type is indirectly reflected. The optical sensor detects the characteristics of the ambient light using optical principles, such as light intensity, color, etc. In the amphibious unmanned aerial vehicle, the light intensity change or spectral characteristics in water can be detected and compared with the light environment in the air to assist in determining the medium type in which the unmanned aerial vehicle is located. The medium density data refers to the data that can reflect the density characteristics of the medium detected by the pressure sensor and / or the optical sensor, such as pressure value, light intensity value, etc.

[0053] It can be understood that, in order to obtain the physical characteristic information of the environment in which the unmanned aerial vehicle is located, so as to accurately determine the medium type, based on the differences in pressure and optical characteristics of different media, the sensors convert these physical quantities into electrical signals, which are then recognized and processed by the control system of the unmanned aerial vehicle. In the application scenario of the amphibious unmanned aerial vehicle, the pressure sensor can effectively distinguish whether the unmanned aerial vehicle is flying in the air (with lower air pressure and changes with height) or diving underwater (with higher water pressure and increasing with depth); the optical sensor can use the significant difference in light environment between water and air (such as weaker light intensity and different spectral characteristics in water) to assist in determining the medium type, providing reliable data support for accurately determining the medium type and adjusting the flapping wing movement parameters, and improving the self-adaptability and stability of the unmanned aerial vehicle during the medium conversion process.

[0054] Step S302: determining the medium type of the medium in which the unmanned aerial vehicle is currently located according to the medium density data, and adjusting the movement parameters of the flapping wing after the switching of the mode according to the density characteristics corresponding to the medium type, wherein the medium type includes air medium or water medium.

[0055] It should be noted that the medium type includes air medium and water medium, which are two main physical environments in which the UAV executes tasks, and their density differences are large (the density of water is about 800 times that of air), resulting in completely different motion characteristics and power requirements of the UAV. The flapping wing motion parameters include flapping frequency, flapping amplitude, twist angle, phase difference, etc., which directly affect the propulsion or lift generated by the flapping wing in different media.

[0056] It can be understood that, due to the different reaction forces of different media on the flapping wing motion, in the air, due to the lower density, the flapping wing needs a higher flapping frequency and a smaller flapping amplitude to generate sufficient lift; in water, the density is higher, and the flapping wing needs a lower flapping frequency and a larger flapping amplitude to overcome the resistance of water to generate propulsion. According to the judged medium type, the motion parameters of the flapping wing after shape switching are adjusted, so that the flapping wing can efficiently drive the UAV to move in the current medium with a specific shape, so that the UAV can automatically adapt to the physical characteristics of the current medium, optimize the motion state of the flapping wing, and thus improve the motion efficiency and stability. According to the medium type, the motion parameters of the flapping wing are adjusted, so that it can generate appropriate fluid power in different media, realizes automatic perception and self-adaptive adjustment of the UAV to the current medium, improves the intelligent level and task execution ability of the UAV, and solves the stability problem of the existing amphibious UAV caused by the inability to adapt to the change of medium characteristics in time during medium conversion.

[0057] In the embodiment, the medium density data is detected by the pressure sensor and / or optical sensor, and the medium type is judged according to the detection data, and the flapping wing motion parameters are adjusted, so that the UAV can automatically perceive the medium type, and automatically adjust the motion state of the flapping wing according to the medium characteristics, thereby improving the intelligent level and self-adaptive ability of the UAV. Through real-time monitoring and feedback control of the sensor, the UAV can more accurately and timely adjust the flapping wing parameters during medium conversion, and ensure the stability and motion efficiency in different media.

[0058] In a feasible embodiment, after the shape of the flapping wing is determined and switched, the step of adjusting the control parameters of the flapping wing after shape switching according to the current medium in which the UAV is located includes: In step S303, if the current medium is an air medium, the control parameters of the flapping wing after shape switching are adjusted to be static locking. It should be noted that the current medium refers to the physical environment in which the UAV is located when performing a task, i.e., an air medium or a water medium. The air medium is an aerial environment with low density and small resistance, away from the ground, which is suitable for fixed-wing flight mode. The control parameters of the flapping wing include flapping frequency, flapping amplitude, twist angle, phase difference, etc., which determine the motion state of the flapping wing. Static locking refers to setting the control parameters of the flapping wing to keep the flapping wing in a static state, which can be achieved by locking the driving mechanism (such as a rudder, a motor, etc.) of the flapping wing.

[0059] It can be understood that when the UAV is in the air medium, its flight mode mainly relies on the lift generated by the fixed wing, and by locking the flapping wing in a static state, it forms an integrated fixed-wing structure with the inner wing segment, so that the UAV can obtain better aerodynamic performance when flying in the air. At this time, in the air medium, the fixed-wing structure can generate lift with high efficiency, while the motion of the flapping wing may interfere with the airflow, reducing the lift efficiency and increasing the resistance. Adjusting the control parameters of the flapping wing to static locking can avoid unnecessary motion of the flapping wing in the air, reduce energy consumption, maintain the overall rigidity of the wing, improve the stability and control accuracy of flight, and avoid the low efficiency and stability problems caused by the motion of the flapping wing of the amphibious UAV in the air.

[0060] Specifically, the static locking of the flapping wing can be achieved in various ways. For example, an electromagnetic brake is used, and when it is detected that the UAV is in the air medium, the electromagnetic brake generates a braking torque by being powered on, locking the driving motor shaft of the flapping wing, so that the flapping wing remains static; or a mechanical locking device such as a spring-type locking pin is used, and in the air flight mode, the locking pin is inserted into the joint part of the flapping wing to prevent its motion.

[0061] Step S304, if the current medium is a water medium, calculate based on a preset flapping wing motion equation to obtain flapping parameters, and adjust the control parameters of the flapping wing after switching to the flapping parameters.

[0062] It should be noted that the water medium refers to an underwater environment with high density and large resistance, which is suitable for flapping wing propulsion mode. The flapping wing motion equation is a mathematical model established based on the principles of fluid mechanics and the structural characteristics of the UAV, which is used to describe the motion trajectory and dynamic characteristics of the flapping wing in the water medium, and can include the relationship between the flapping frequency, flapping amplitude, twist angle, phase difference, etc. parameters of the flapping wing and the generated propulsion force. The flapping parameters refer to the motion parameter combination calculated by the flapping wing motion equation that can make the flapping wing efficiently propel in the water medium, such as the optimal flapping frequency, amplitude, etc.

[0063] It can be understood that when the unmanned aerial vehicle is in the water medium, its movement mainly depends on the propulsion force of the flapping wing. According to the physical characteristics of the water medium, the flapping wing motion equation is solved by combining the current task demand and environmental conditions, and the flapping parameters suitable for the current underwater environment movement of the unmanned aerial vehicle are obtained, so that the flapping wing can efficiently generate propulsion force to resist the resistance of the unmanned aerial vehicle moving in water, drive the unmanned aerial vehicle to move stably, make the motion state of the flapping wing match the fluid mechanics characteristics of the water medium, maximize the propulsion efficiency, and at the same time maintain the stability and control accuracy of the movement, optimize the propulsion performance of the unmanned aerial vehicle in the water medium, improve the energy utilization efficiency and the movement stability, and avoid the low efficiency and stability problem caused by the mismatch of flapping wing parameters when the amphibious unmanned aerial vehicle propels in water.

[0064] Specifically, the control system of the unmanned aerial vehicle pre-stores the flapping wing motion equation. After detecting that the unmanned aerial vehicle is in the water medium, the control system sets the target propulsion force according to the current task demand (such as movement speed, direction, etc.) and environmental conditions, and then optimizes and solves the flapping wing motion equation to obtain the flapping parameter combination that makes the propulsion force reach the target value and the energy consumption is minimum. After obtaining the flapping parameters, the control system converts these parameters into specific control signals and sends them to the driving mechanism (such as rudder, motor, etc.) of the flapping wing to drive the flapping wing to move according to the calculated parameters. For example, the control system sends pulse width modulation (PWM) signals to the rudder of the flapping wing according to the calculated flapping frequency and amplitude, controls the turning angle and rotating speed of the rudder, and thus realizes the precise motion control of the flapping wing. In addition, real-time feedback control can also be combined to detect the actual motion state of the flapping wing and the motion response of the unmanned aerial vehicle through sensors, dynamically adjust the flapping parameters, and further improve the control accuracy and propulsion efficiency.

[0065] Exemplarily, taking the water-air amphibious unmanned aerial vehicle as an example, when the unmanned aerial vehicle flies over the designated sea area, the pressure sensor detects a lower pressure value, and it is judged that the current medium is air medium. At this time, the control parameters of the flapping wing are adjusted to be static locking. The flapping wing is locked by the electromagnetic brake, and remains horizontal and static as a part of the fixed wing. The unmanned aerial vehicle relies on the propeller of the inner wing segment to generate lift force, and flies in the air in the traditional fixed-wing flight mode to perform the aerial monitoring task. When the unmanned aerial vehicle needs to enter the water to perform underwater monitoring, the water entry conversion instruction is received, and the water entry action is started. During the water entry process, the pressure sensor detects that the pressure gradually increases, and when it is judged that the current medium is water medium, the flapping wing motion equation is calculated based on the preset flapping wing motion equation. According to the current task requirement (such as underwater cruising speed) and the characteristics of the water medium, the genetic algorithm is used to optimize and solve the flapping wing motion equation, and the optimal flapping parameters such as flapping frequency of 1.5 Hz, flapping amplitude of 40 degrees and torsion angle of 30 degrees are obtained. Subsequently, the control system converts these parameters into specific control signals and sends them to the steering wheel of the flapping wing to drive the flapping wing to start three-degree-of-freedom diagonal flapping according to the calculated parameters, generate propulsion, and drive the unmanned aerial vehicle to stably dive in the water to perform the underwater monitoring task. The unmanned aerial vehicle realizes efficient flight in the air medium and efficient propulsion in the water medium, effectively solving the problem of insufficient motion efficiency and stability of the unmanned aerial vehicle in different media in the prior art. At the same time, through the specific adjustment mode of the flapping wing control parameters in different media, especially the calculation method based on the flapping wing motion equation introduced for the water medium, the motion of the flapping wing is more accurate and efficient, and the cross-medium adaptability and task execution capability of the unmanned aerial vehicle are further improved.

[0066] In this embodiment, for the air medium, the flapping wing is statically locked, the aerodynamic performance of the unmanned aerial vehicle when flying in the air is optimized, and the flight efficiency and stability are improved; for the water medium, the calculation method based on the flapping wing motion equation is introduced, which can accurately adjust the motion parameters of the flapping wing, so that it can efficiently propel in the water medium, improve the energy utilization efficiency and motion stability, and make the unmanned aerial vehicle can fully exert the respective advantages in different media, and realize efficient cross-medium motion.

[0067] The embodiment provides a motion control method, first, by receiving a water-air medium conversion instruction, it can be known in time that a UAV needs to be converted; then, according to the instruction, the flapping wing mode is switched, whether the flapping wing mode is switched is determined, the UAV is provided with a hardware basis for adapting to different medium motion modes, and air stable flight and underwater flexible diving are provided; and according to different media, the flapping wing control parameter is adjusted and the UAV is driven to move, so that the UAV can operate in a suitable way in air and water, the problem of insufficient stability of an existing water-air amphibious UAV when converting media is effectively solved, and the reliability, adaptability and motion efficiency of the UAV in the cross-medium task are improved.

[0068] Based on the first embodiment of the application, in the second embodiment of the application, the same or similar contents as the above first embodiment can be referred to the above introduction, and the subsequent will not be repeated. On this basis, please refer to Figure 2 , Figure 2 The flowchart of the second embodiment of the motion control method of the application is shown.

[0069] In the embodiment, the flapping wing includes a fin strip and a fin strip steering engine, the fin strip is controlled to flap by the fin strip steering engine, the step of calculating the flapping parameter based on the preset flapping wing motion equation includes: Step S3041, based on the flapping wing motion equation, an angle control equation of the fin strip corresponding to the fin strip steering engine is constructed; It should be noted that the fin strip is a key component of the flapping wing, which is usually made of light and high-strength materials, such as carbon fiber square tube, and is covered with flexible materials (such as silica gel skin) for simulating the fin strip movement of organisms to generate propulsion. The fin strip steering engine is an actuator for driving the fin strip to move, and the up-and-down flapping and torsional movement of the fin strip are realized by controlling the angle of the fin strip steering engine. The angle control equation is derived from the flapping wing motion equation, which is a mathematical expression for describing the relationship between the angle of the fin strip steering engine and the flapping wing motion parameters, and is the basis for realizing the precise control of the flapping wing. Kinematics modeling and coordinate transformation can be used to associate the parameters in the flapping wing motion equation with the angle of the fin strip steering engine, establish a mapping relationship, so that the control system can realize the expected flapping wing movement by adjusting the angle of the steering engine.

[0070] It can be understood that due to the multiple degrees of freedom and complex dynamics of the flapping motion of the unmanned aerial vehicle in the underwater environment, it is difficult to directly control the flapping motion. The complex flapping kinematic model is decomposed into a mathematical expression of the directly controllable actuator, so that the control system can accurately control the motion state of the flapping wing according to the task requirements, and the motion parameters of the flapping wing are converted into specific angle instructions of the fin rudder through the conversion of the flapping motion equation into the fin rudder angle control equation, so as to realize the accurate control of the flapping motion. The accurate motion control of the flapping wing provides a theoretical basis and mathematical tool, improves the control accuracy and motion efficiency, and solves the stability problem caused by insufficient control accuracy of the existing amphibious unmanned aerial vehicle in underwater propulsion.

[0071] In step S3042, the fin rudder angle control equation corresponding to the fin rudder is solved to obtain the flapping parameters.

[0072] It can be understood that in the actual application of the amphibious unmanned aerial vehicle, different task scenarios (such as fast propulsion, flexible turning, stable hovering, etc.) and environmental conditions (such as water flow speed, water temperature, depth, etc.) have different requirements for the motion parameters of the flapping wing. The flapping parameters that meet the current task requirements and environmental conditions are obtained by solving the angle control equation, so as to convert the constructed mathematical model into specific control instructions, so that the control system can accurately adjust the motion state of the flapping wing according to the task requirements and environmental conditions, and realize the accurate control of the flapping motion in water, improve the propulsion efficiency and motion stability.

[0073] In a possible implementation, the outer wing segment and the inner wing segment are connected through a swing rudder, and the step of driving the unmanned aerial vehicle to move in the current medium through the flapping wing with the adjusted parameters includes: In step S305, when the flapping parameters are two-degree-of-freedom symmetric flapping parameters, the fin rudder controls the fin to perform vertical flapping to drive the unmanned aerial vehicle to perform floating motion in the water medium. It should be noted that the fin rudder is an actuator for driving the fin to perform vertical flapping, and the up-down motion of the fin is realized by controlling the angle of the fin rudder. The vertical flapping refers to the pitch rotation motion of the flapping wing around the horizontal axis and the up-down motion in the vertical direction, which is the main feature of the two-degree-of-freedom symmetric flapping. The floating motion refers to the up-down motion of the unmanned aerial vehicle in the water medium, which is usually controlled by adjusting the flapping frequency and amplitude of the flapping wing to control the floating speed and depth.

[0074] It can be understood that when the unmanned aerial vehicle needs to perform the snorkeling motion in the water medium, based on the lift and thrust generation mechanism in fluid mechanics, vertical flapping of the flapping wing is controlled by using the two-degree-of-freedom symmetric flapping parameters, vertical propulsion force is generated by using the up-down motion of the flapping wing, and therefore the unmanned aerial vehicle is implemented to float or dive. In the two-degree-of-freedom symmetric flapping, the motion trajectory of the flapping wing is relatively simple and mainly concentrates in the vertical direction, which enables the flapping wing to effectively generate the vertical propulsion force and simultaneously reduce the horizontal displacement, is suitable for the snorkeling motion, and enables the unmanned aerial vehicle to flexibly adjust the depth in the water and adapt to different underwater task requirements, such as performing the environment monitoring, target searching and the like at different depths, and improves the underwater mobility and task adaptability of the unmanned aerial vehicle.

[0075] Specifically, the two-degree-of-freedom symmetric flapping parameter control vertical flapping can be implemented in multiple ways. For example, when the unmanned aerial vehicle needs to float, the control system sets a higher flapping frequency and a larger flapping amplitude according to the task requirement, controls the fin strip steering engine by using the PWM signal, and enables the fin strip to flap up and down at a larger amplitude and frequency, generates the upward propulsion force, and drives the unmanned aerial vehicle to float. Conversely, when diving is needed, the flapping frequency and amplitude are appropriately reduced, the propulsion force direction is downward, and the unmanned aerial vehicle is driven to dive. Meanwhile, the flapping wing propulsion force and the buoyancy can be coordinated and controlled by combining the buoyancy adjustment system (such as the ballast water tank) of the unmanned aerial vehicle, and more accurate snorkeling motion is implemented. For example, in the fine detection task, the flapping parameters of the flapping wing and the water amount of the ballast water tank are adjusted, the unmanned aerial vehicle is kept hovering at a specific depth, and detailed detection is performed. In addition, the depth information fed back by the sensor can be used, the flapping parameters are adjusted in real time by using the closed-loop control algorithm, external disturbances such as water flow changes are coped with, and the stability and precision of the snorkeling motion are improved.

[0076] Step S306, when the flapping parameters are the three-degree-of-freedom diagonal flapping parameters, the fin strip is controlled to perform the compound motion of the vertical flapping and the front-back swing by using the fin strip steering engine and the swing steering engine, and the unmanned aerial vehicle is driven to perform the propulsion motion in the water medium.

[0077] It should be noted that the three-degree-of-freedom diagonal flapping parameters can include the flapping frequency, the flapping amplitude, the torsion angle, the phase difference and the stroke angle of the front-back swing, and the like, and are used to describe the compound motion of the flapping wing in the vertical flapping and the front-back swing. The swing steering engine is an execution mechanism for driving the outer wing segment to perform the front-back swing motion relative to the inner wing segment, and the swing motion of the flapping wing is realized by controlling the rotation angle. The compound motion of the vertical flapping and the front-back swing refers to the complex motion mode that the flapping wing simultaneously performs the up-down flapping and the front-back swing, which is the main feature of the three-degree-of-freedom diagonal flapping. The propulsion motion refers to the horizontal propulsion motion of the unmanned aerial vehicle in the water medium, and is usually used for underwater cruising, rapid maneuvering and the like.

[0078] It can be understood that when the unmanned aerial vehicle needs to move forward in the water medium, the compound motion of the flapping wing is controlled by three degrees of freedom diagonal flapping parameters, and the high efficient horizontal propulsion force is generated by the multi-degree of freedom motion of the flapping wing, and a certain direction control ability is also considered. In the three degrees of freedom diagonal flapping, the front and rear swing motion of the flapping wing increases the generation dimension of the propulsion force, and by adjusting the swing angle of the swing rudder and the phase difference between the fins through the three degrees of freedom diagonal flapping parameters, the propulsion efficiency can be optimized and the direction control can be realized. Based on the propulsion force generation mechanism in fluid mechanics, the multi-degree of freedom flapping wing motion can generate more complex flow field structure in water, thereby generating greater propulsion force and better maneuverability, so that the unmanned aerial vehicle can realize fast and flexible propulsion motion in water, adapt to various complex underwater task requirements such as fast cruising, emergency obstacle avoidance, target pursuit, etc., and significantly improve the underwater maneuverability and task execution ability of the unmanned aerial vehicle.

[0079] Specifically, the three degrees of freedom diagonal flapping parameter control compound motion can be realized by various control strategies. For example, when the unmanned aerial vehicle needs to move forward quickly, the control system sets a larger flapping frequency, amplitude and swing angle according to the task requirement, and controls the fin rudder and swing rudder through PWM signals respectively, so that the fin performs forward swing while flapping up and down, thereby generating forward propulsion force. At the same time, by adjusting the phase difference of the forward swing of the two symmetrical flapping wings, the propulsion efficiency can be optimized and the direction control can be realized. For example, when turning left, the swing phase of the left flapping wing is adjusted appropriately to generate a larger left thrust component, thereby realizing the left turning of the unmanned aerial vehicle. In addition, real-time feedback control can also be combined, and the speed, attitude and position information of the unmanned aerial vehicle are detected by sensors to dynamically adjust the flapping parameters and swing angle, so as to cope with complex water flow environment and task requirements. For example, in the strong water flow area, the flapping frequency and amplitude are increased to improve the propulsion force to overcome the water flow resistance and maintain the stable propulsion of the unmanned aerial vehicle.

[0080] Exemplarily, taking the water-air amphibious unmanned aerial vehicle performing underwater pipeline inspection task as an example. When the unmanned aerial vehicle needs to perform fine inspection near the underwater pipeline, first, according to the task requirement, enter the two-degree-of-freedom symmetric flapping mode. The control system sets the flapping frequency to 1 Hz, the flapping amplitude to 0.05 m according to the pre-set floating task parameters, controls the fin strip rudder to drive the fin strip to perform vertical flapping, so that the unmanned aerial vehicle performs floating motion in the water medium, and gradually approaches the pipeline target depth. After approaching the target depth, by adjusting the flapping parameters, the unmanned aerial vehicle can be kept hovering at a specific depth to perform close-in detection of the pipeline. Subsequently, when horizontal propulsion inspection along the pipeline is needed, the control system switches to the three-degree-of-freedom diagonal flapping mode, sets the flapping frequency to 1.5 Hz, the flapping amplitude to 0.1 m, and the swing angle to 45°, and controls the fin strip rudder and swing rudder at the same time, so that the fin strip performs the composite motion of vertical flapping and forward and backward swing, generates horizontal propulsion force, and drives the unmanned aerial vehicle to move forward along the pipeline at a high speed. During the propulsion process, by adjusting the swing phase difference, the unmanned aerial vehicle can flexibly avoid obstacles such as pipeline supports, and realize efficient and stable underwater inspection task. The unmanned aerial vehicle can flexibly switch between the flapping modes in the water medium according to the task requirement, realize seamless connection between the floating motion and the propulsion motion, and effectively solve the problem of insufficient mobility of the unmanned aerial vehicle in the underwater complex task due to the single flapping motion mode in the prior art.

[0081] In the embodiment, by the two-degree-of-freedom symmetric flapping and the three-degree-of-freedom diagonal flapping modes, the floating motion and the propulsion motion of the unmanned aerial vehicle in the water medium are realized respectively, so that the unmanned aerial vehicle can flexibly adjust the motion state in the water according to the task requirement, improve the underwater mobility and task adaptability, and meet the diversified demand of underwater complex task.

[0082] In the embodiment, by constructing the turning angle control equation of the fin strip rudder and solving the flapping parameters, the precise control of the flapping motion is realized, so that the unmanned aerial vehicle can accurately adjust the motion state of the flapping wing in the water medium according to the task requirement and environmental conditions, improve the propulsion efficiency and motion stability, fully exert the performance advantage of the flapping wing even in the complex underwater task, and realize efficient and stable propulsion and flexible motion control.

[0083] Based on the first embodiment and / or the second embodiment of the present application, in the third embodiment of the present application, the same or similar contents as the above first embodiment and second embodiment can be referred to the above introduction, and will not be described hereinafter.

[0084] Exemplarily, in order to help understand the implementation process of the motion control method obtained by combining the above first embodiment and second embodiment, specifically: A kind of amphibious unmanned aerial vehicle using traditional layout is proposed, which flies in fixed-wing mode in the air and swims in flapping-wing mode underwater. The wing of the unmanned aerial vehicle is divided into two parts, the inner wing segment is in fixed-wing form, and the outer wing segment is in flapping-wing form. The flapping-wing is composed of three fin strips made of carbon fiber square tube and outer silicone skin driven by servo as actuator, and the up-and-down flapping of each fin strip is controlled by the rotation of the servo arm of each fin strip servo. The flapping and torsional motion of the outer wing segment are coupled, and the torsional motion is realized by the phase difference motion between the fin strips, so as to realize the biomimetic flapping motion of the unmanned aerial vehicle underwater. At the same time, a swing servo actuator is also arranged at the connection between the inner and outer wing segments to realize the forward and backward swing of the outer wing end underwater. In the air flight mode, the outer wing segment remains horizontal and stationary, and the flight power is provided by a pair of symmetrical motors and propellers arranged in the inner wing segment, and the rotation directions of the propellers are opposite, which ensures that the counter-torque generated by the two blades during operation is offset, ensuring the stability of the unmanned aerial vehicle during the water-air cross-medium process.

[0085] As shown in Figure 3 , Figure 3 The flight attitude flowchart of the unmanned aerial vehicle provided by the third embodiment of the motion control method of the present application is shown. It mainly includes four flight working conditions: 1. When the aerial vehicle is in air flight mode, the lift required for flight is mainly provided by the inner wing segment, the pitch control depends on the horizontal tail of the aerial vehicle, and the roll is realized by the fin strip driving the aileron composed of silicone skin at the rear of the outer wing end.

[0086] 2. During the conversion from air to water, the aerial vehicle first lowers the height in the air, and gently falls on the water surface when it is close to the water surface. The open wing tip and the water inlet hole make the body sink underwater.

[0087] 3. When swimming underwater, the power of the unmanned aerial vehicle is mainly provided by the flapping of the outer wing end, and the horizontal and vertical tails are responsible for adjusting the attitude of the unmanned aerial vehicle underwater and floating.

[0088] 4. During the water-air cross-medium conversion process, the aerial vehicle floats to the water surface, adjusts the aerial vehicle to a large angle of attack state through the adjustment of the elevator, and finally climbs out of the water surface through the propeller pull force and returns to the fixed-wing cruise mode in the air.

[0089] Among them, according to the angular displacement formula, the basic projection formula, the reference frame transformation formula, the fluid resistance formula and Newton's second law, the motion trajectory equation of the two-degree-of-freedom symmetric flapping and three-degree-of-freedom diagonal flapping of the outer wing end of the unmanned aerial vehicle is derived: (1) The motion trajectory equation of two-degree-of-freedom symmetric flapping relative to the water surface reference frame.

[0090] The two-degree-of-freedom symmetric flapping is a relatively large degree of simplification of the flexible flapping motion in nature, and the two degrees of freedom refer to the pitching rotation freedom of the flapping wing around the horizontal axis and the vertical motion freedom of the flapping wing relative to the horizontal plane in the forward direction.

[0091] The motion angle equation of the control rudder of the fin strip 2 is:

[0092] The motion angle equation of the control rudder of the fin strip 1 and 3 is:

[0093]

[0094] The motion trajectory equation of the two-degree-of-freedom symmetric flapping relative to the water surface reference system is as follows:

[0095]

[0096]

[0097] In the formula, is the vertical direction motion equation, is the horizontal direction motion equation, is the flapping amplitude (m), is the flapping frequency (Hz), is the flow velocity (m / s), is the attack angle amplitude (°).

[0098] (2) The motion trajectory equation of the three-degree-of-freedom diagonal flapping relative to the water surface reference system is given.

[0099] Compared with the symmetric flapping, the three-degree-of-freedom diagonal flapping motion increases the swing motion freedom of the flapping wing segment in front and back, and the direction is parallel to the forward direction. The freedom of swing motion is actually constrained by the swing angle , and the swing angle reflects the angle between the trajectory generated by the flapping wing in the body coordinate system and the actual forward direction of the flapping wing. During the three-degree-of-freedom diagonal flapping motion, the swing motion swing angle have two typical values, i.e. 45° and 135°. Among them, the 45° flapping motion stroke angle makes the body obtain a better lift coefficient, and the 135° flapping motion stroke angle corresponds to better thrust characteristics. The example mainly focuses on the underwater propulsion motion of the amphibious unmanned aerial vehicle, the underwater body posture is mainly controlled by the horizontal tail and the vertical tail, and the flapping section is used to obtain the thrust of underwater propulsion, so the flapping motion stroke angle should be near 135°.

[0100] The motion trajectory equation of the three-degree-of-freedom diagonal flapping relative to the water surface reference system is as follows:

[0101]

[0102]

[0103] In the formula, is the vertical direction motion equation, is the horizontal direction motion equation, is the flapping amplitude (m), is the flapping frequency (Hz), is the incoming flow velocity (m / s), is the attack angle amplitude (°), is the stroke angle (°).

[0104] The two flapping motion modes and the respective motion trajectory equations need to be converted into the rotation angle control equations of the fin control rudder and the flapping rudder in order to realize the predetermined flapping motion mode on the actual flapping unmanned aerial vehicle prototype, and the control equations obtained by decomposition are used to drive and control the actuators, and finally the symmetric flapping and diagonal flapping are realized.

[0105] In the embodiment, the unmanned aerial vehicle can adjust the flapping shape according to the instruction when entering or leaving the water, reduce the impact force and resistance change, and ensure smooth cross-medium conversion. In the water medium, the biomimetic flapping wing can simulate the biological motion mode, overcome the water resistance by adjusting the flapping frequency, amplitude and other parameters to generate stable thrust; in the air medium, it can be switched to a fixed wing shape to provide propulsion by a propeller, realizing efficient flight. The scheme of the application combines biomimetic flapping and propeller propulsion, which not only utilizes the stable thrust generated by the biomimetic flapping wing underwater, but also utilizes the high-efficiency propulsion provided by the propeller in the air. By optimizing the power output, the unmanned aerial vehicle can maintain the best performance in different media, effectively solving the problem that the power system is difficult to balance in the prior art, and improving the overall performance and reliability of the unmanned aerial vehicle.

[0106] It should be noted that the above examples are only used for understanding the present application and do not constitute a limitation on the motion control method of the present application, and more forms of simple transformation based on this technical concept are within the protection scope of the present application.

[0107] The present application also provides a motion control device, please refer to Figure 4 , the motion control device is applied to a UAV, the wing of the UAV includes an inner wing segment and an outer wing segment, the outer wing segment is configured with at least two flapping wings, including: The instruction receiving module 10 is configured to receive a water-air medium conversion instruction. The mode switching module 20 is configured to determine whether to switch the mode of the flapping wings according to the water-air medium conversion instruction, the mode of the flapping wings including a fixed-wing mode and a flapping-wing mode. The motion execution module 30 is configured to, after determining and switching the mode of the flapping wings, adjust the control parameters of the flapping wings after switching the mode according to the current medium in which the UAV is located, and drive the UAV to move in the current medium through the flapping wings after parameter adjustment.

[0108] Optionally, when the water-air medium conversion instruction is a water-entry conversion instruction, the mode switching module 20 is further configured to: determine whether the mode of the flapping wings is a fixed-wing mode. If the mode of the flapping wings is a fixed-wing mode, switch the mode of the flapping wings to a flapping-wing mode.

[0109] Optionally, when the water-air medium conversion instruction is a water-exit reflight instruction, the mode switching module 20 is further configured to: determine whether the mode of the flapping wings is a flapping-wing mode. If the mode of the flapping wings is a flapping-wing mode, determine to switch the mode of the flapping wings to a fixed-wing mode.

[0110] Optionally, the UAV is further configured with a pressure sensor and / or an optical sensor, and the motion execution module 30 is further configured to: detect medium density data through the pressure sensor and / or the optical sensor; determine the medium type of the current medium in which the UAV is located according to the medium density data, so as to adjust the motion parameters of the flapping wings after switching the mode according to the density characteristics corresponding to the medium type, the medium type including an air medium or a water medium.

[0111] Optionally, the motion execution module 30 is further configured to: if the current medium is an air medium, adjust the control parameters of the flapping wings after switching the mode to be static locking; If the current medium is water, the flapping parameters are calculated based on a preset flapping equation, and the control parameters of the flapping wings after switching are adjusted to the flapping parameters.

[0112] Optionally, the flapping wings include fin strips and fin strip servos, the fin strips are controlled to flap by the fin strip servos, and the motion execution module 30 is further configured to: Based on the flapping equation, an angle control equation of the fin strip corresponding to the fin strip servo is constructed; The angle control equation of the fin strip corresponding to the fin strip servo is solved to obtain the flapping parameters.

[0113] Optionally, the outer wing segment and the inner wing segment are connected by a swing servo, and the motion execution module 30 is further configured to: When the flapping parameters are two-degree-of-freedom symmetric flapping parameters, the fin strips are controlled to perform vertical flapping by the fin strip servos to drive the unmanned aerial vehicle to perform a floating motion in the water medium; When the flapping parameters are three-degree-of-freedom diagonal flapping parameters, the fin strips are controlled to perform a composite motion of vertical flapping and front and rear swing by the fin strip servos and the swing servo to drive the unmanned aerial vehicle to perform a propulsion motion in the water medium.

[0114] The motion control device provided in the application adopts the motion control method in the above embodiments, and can solve the technical problem of insufficient stability of the existing water-air amphibious unmanned aerial vehicle in the medium. Compared with the prior art, the motion control device provided in the application has the same beneficial effects as the motion control method provided in the above embodiments, and other technical features in the motion control device are the same as the features disclosed in the above embodiments, which will not be repeated here.

[0115] The application provides a motion control device, which comprises at least one processor and a memory connected with the at least one processor, wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the motion control method in the first embodiment.

[0116] The following refers to Figure 5The diagram illustrates a structural schematic of a motion control device suitable for implementing the embodiments of this application. The motion control device in the embodiments of this application may include, but is not limited to, mobile terminals such as mobile phones, laptops, digital broadcast receivers, PDAs (Personal Digital Assistants), PADs (Portable Application Description), PMPs (Portable Media Players), in-vehicle terminals (e.g., in-vehicle navigation terminals), and fixed terminals such as digital TVs and desktop computers. Figure 5 The motion control device shown is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of this application.

[0117] like Figure 5 As shown, the motion control device may include a processing unit 1001 (e.g., a central processing unit, a graphics processing unit, etc.), which can perform various appropriate actions and processes according to a program stored in a read-only memory 1002 or a program loaded from a storage device 1003 into a random access memory 1004. The random access memory 1004 also stores various programs and data required for the operation of the motion control device. The processing unit 1001, the read-only memory 1002, and the random access memory 1004 are interconnected via a bus 1005. An input / output interface 1006 is also connected to the bus. Typically, the following systems can be connected to the input / output interface 1006: input devices 1007 including, for example, a touchscreen, touchpad, keyboard, mouse, image sensor, microphone, accelerometer, gyroscope, etc.; output devices 1008 including, for example, a liquid crystal display (LCD), speaker, vibrator, etc.; storage devices 1003 including, for example, magnetic tape, hard disk, etc.; and communication devices 1009. The communication device 1009 allows the motion control device to communicate wirelessly or wiredly with other devices to exchange data. Although the figures show motion control devices with various systems, it should be understood that it is not required to implement or have all of the systems shown. More or fewer systems may be implemented alternatively.

[0118] In particular, according to embodiments of the present disclosure, the processes described above with reference to the flowcharts can be implemented as a computer software program. For example, embodiments of the present disclosure include a computer program product comprising a computer program carried on a computer readable medium, the computer program comprising program code for performing the methods illustrated by the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device, or installed from a storage device 1003, or installed from a read-only memory 1002. When the computer program is executed by the processing device 1001, the above-mentioned functions defined in the methods of the embodiments of the present disclosure are performed.

[0119] The motion control device provided by the present application adopts the motion control method in the above-mentioned embodiments, and can solve the technical problem of insufficient stability of the existing water-air amphibious unmanned aerial vehicle in medium motion. Compared with the prior art, the motion control device provided by the present application has the same beneficial effects as the motion control method provided by the above-mentioned embodiments, and other technical features in the motion control device are the same as the features disclosed in the previous embodiment method, which will not be repeated here.

[0120] It should be understood that parts of the present application can be realized by hardware, software, firmware or a combination thereof. In the description of the above-mentioned embodiments, specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0121] The above is merely specific implementation of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

[0122] The present application provides a computer readable storage medium having stored thereon computer readable program instructions (i.e. computer program) for performing the motion control method in the above-mentioned embodiments.

[0123] The computer readable storage medium provided in the application may, for example, be a U disk, but is not limited to an electric, magnetic, optical, electromagnetic, infrared or semiconductor system, system or device, or any combination of the above. More specific examples of the computer readable storage medium may include, but are not limited to, an electric connection with one or more conductive wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the embodiment, the computer readable storage medium may be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, system or device. The program code contained on the computer readable storage medium can be transmitted by any suitable medium, including but not limited to an electric wire, an optical cable, an RF (Radio Frequency), etc., or any suitable combination of the above.

[0124] The above computer readable storage medium may be contained in the motion control device, or may exist separately without being assembled into the motion control device.

[0125] The above computer readable storage medium carries one or more programs, which, when executed by the motion control device, cause the motion control device to: receive a water-air medium conversion instruction; determine whether to switch the mode of the flapping wing according to the water-air medium conversion instruction, the mode of the flapping wing including a fixed wing mode and a flapping wing mode; after determining and switching the mode of the flapping wing, adjust the control parameter of the flapping wing after switching the mode according to the current medium in which the unmanned aerial vehicle is located, and drive the unmanned aerial vehicle to move in the current medium by the flapping wing after parameter adjustment.

[0126] Computer program code for carrying out operations of the present application can be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code can execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection can be made to an external computer (for example, through the Internet using an Internet Service Provider).

[0127] The computer program instructions can also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks.

[0128] The modules involved in the embodiments of the present application can be implemented in software or hardware. In some cases, the names of the modules do not constitute a limitation on the modules themselves.

[0129] The readable storage medium provided by the present application is a computer readable storage medium, which stores computer readable program instructions (i.e., computer programs) for executing the motion control method described above, and can solve the technical problem of insufficient stability of the existing water-air amphibious unmanned vehicle in the medium. Compared with the prior art, the computer readable storage medium provided by the present application has the same beneficial effects as the motion control method provided by the above embodiments, and will not be repeated here.

[0130] The application further provides a computer program product comprising a computer program which, when executed by a processor, implements the steps of the motion control method as described above.

[0131] The computer program product provided by the application can solve the technical problem of insufficient stability of the existing water-air amphibious unmanned aerial vehicle in medium motion. Compared with the prior art, the beneficial effects of the computer program product provided by the application are the same as those of the motion control method provided by the above-mentioned embodiments, which will not be repeated here.

[0132] The above-mentioned is only part of the embodiments of the application, and does not limit the patent scope of the application. Any equivalent structural transformation, direct / indirect application in other related technical fields based on the technical concept of the application, and the contents of the specification and drawings are included in the patent protection scope of the application.

Claims

1. A motion control method characterized by, The motion control method is applied to a UAV, the wings of the UAV include an inner wing segment and an outer wing segment, the outer wing segment is configured with at least two flapping wings, and the motion control method includes: receiving a water-air medium conversion instruction; determining whether to switch the mode of the flapping wings according to the water-air medium conversion instruction, the mode of the flapping wings including a fixed-wing mode and a flapping-wing mode; after determining and switching the mode of the flapping wings, adjusting the control parameters of the flapping wings after switching the mode according to the current medium in which the UAV is located, and driving the UAV to move in the current medium through the flapping wings with the adjusted control parameters.

2. The motion control method of claim 1, wherein, When the water-air medium conversion instruction is a water-entry conversion instruction, the step of determining whether to switch the mode of the flapping wings according to the water-air medium conversion instruction includes: determining whether the mode of the flapping wings is a fixed-wing mode; if the mode of the flapping wings is a fixed-wing mode, switching the mode of the flapping wings to a flapping-wing mode.

3. The motion control method of claim 1, wherein, When the water-air medium conversion instruction is a water-exit reflight instruction, the step of determining whether to switch the mode of the flapping wings according to the water-air medium conversion instruction includes: determining whether the mode of the flapping wings is a flapping-wing mode; if the mode of the flapping wings is a flapping-wing mode, determining to switch the mode of the flapping wings to a fixed-wing mode.

4. The motion control method of claim 1, wherein, The UAV is also configured with a pressure sensor and / or an optical sensor, and before the step of adjusting the control parameters of the flapping wings after switching the mode according to the current medium in which the UAV is located after determining and switching the mode of the flapping wings, the method further includes: detecting medium density data through the pressure sensor and / or the optical sensor; determining the medium type of the current medium in which the UAV is located according to the medium density data, so as to adjust the motion parameters of the flapping wings after switching the mode according to the density characteristics corresponding to the medium type, the medium type including air medium or water medium.

5. The motion control method of claim 1, wherein, The step of adjusting the control parameters of the flapping wings after switching the mode according to the current medium in which the UAV is located after determining and switching the mode of the flapping wings includes: if the current medium is air medium, adjusting the control parameters of the flapping wings after switching the mode to static locking; if the current medium is water medium, calculating flapping parameters based on a preset flapping-wing motion equation, and adjusting the control parameters of the flapping wings after switching the mode to the flapping parameters.

6. The motion control method of claim 5, wherein, The flapping wings include flippers and flipper servos, the flippers are controlled to flap by the flipper servos, and the step of calculating flapping parameters based on the preset flapping-wing motion equation includes: constructing a flipper angle control equation of the flipper corresponding to the flipper servo based on the flapping-wing motion equation; solving and calculating the flipper angle control equation of the flipper corresponding to the flipper servo to obtain the flapping parameters.

7. The motion control method of claim 6, wherein, The outer wing segment and the inner wing segment are connected through a swing servo, and the step of driving the UAV to move in the current medium through the flapping wings with the adjusted control parameters includes: When the flapping parameter is a two-degree-of-freedom symmetric flapping parameter, the fin strip executes vertical flapping to drive the UAV to perform a snorkeling motion in the water medium through the fin strip servo; When the flapping parameter is a three-degree-of-freedom diagonal flapping parameter, the fin strip executes a compound motion of vertical flapping and front-back waving to drive the UAV to perform a propulsion motion in the water medium through the fin strip servo and the swing servo.

8. A motion control apparatus characterized by comprising: The device comprises a memory, a processor, and a computer program stored on the memory and executable on the processor, and the computer program is configured to implement the steps of the motion control method according to any one of claims 1 to 7.

9. A storage medium, characterized by The storage medium is a computer readable storage medium, and the storage medium stores a computer program, and the computer program is executed by a processor to implement the steps of the motion control method according to any one of claims 1 to 7.

10. A computer program product, characterised in that, The computer program product comprises a computer program, and the computer program is executed by a processor to implement the steps of the motion control method according to any one of claims 1 to 7.

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