A flapping-gliding switching mechanism, method and system for a flapping-wing flying robot

Abstract

The present invention provides a flapping-gliding switching mechanism, method and system of a flapping-wing flying robot, and relates to the technical field of unmanned aerial vehicles. The mechanism includes: a main beam, a mounting frame, a motor, a gear assembly and a crank-connecting rod assembly, wherein the mounting frame is mounted on the main beam and arranged below the main beam; the gear assembly is mounted on the mounting frame, and the motor drives the gear assembly to rotate; two crank-rocker arm structures are respectively mounted on both sides of the gear assembly and are symmetrically arranged, one end of the crank-connecting rod assembly is connected to the output shaft of the gear assembly, and the other end of the crank-connecting rod assembly is rotatably mounted on a fixed frame, and the fixed frame is mounted on the mounting frame; when the flapping mode is switched to the gliding mode, the motor drives the crank-rocker arm assembly to rotate so that the wing hovers at the target flapping angle, which solves the problems of failure rate and difficulty in changing the wing flapping angle during gliding under the traditional mechanical solution.

Description

Technical Field

[0001] The present invention relates to the technical field of unmanned aerial vehicles, and in particular to a flapping-gliding switching mechanism, method and system of a flapping-wing flying robot. Background Art

[0002] The bionic flapping-wing flying robot is a new type of unmanned aerial vehicle, which is characterized by imitating the flying mode of birds or insects and obtaining lift and thrust by flapping its wings. Compared with traditional fixed-wing and rotary-wing aircraft, flapping-wing flying robots have the advantages of high flight efficiency, good concealment, low noise, and flexible control. Therefore, they have broad application prospects in military and civilian fields. According to observations, in addition to flapping their wings when flying, birds often switch to a gliding posture. This flying mode allows birds to make full use of wind energy and improve energy utilization efficiency. Therefore, in order to improve the bionics and energy utilization efficiency of flapping-wing flying robots, it is necessary to add a gliding function to them.

[0003] At present, the flapping-gliding switching function of flapping-wing flying robots usually requires additional design of mechanical structures for gliding. During the flapping flight of the flapping-wing flying robot, when the operator issues a gliding command, the gliding mechanism moves to limit the rotation of the gears, thereby fixing the wings in a certain position and completing the switching of the gliding posture. This type of gliding mechanism is widely used because of its simple and intuitive idea, but it still has many defects: during the process of the flapping-wing flying robot switching from flapping flight to gliding flight, when the high-speed rotating gears are instantly decelerated to a stationary state under the action of external forces, greater wear will occur, and the flapping-wing flying robot will also vibrate. In addition, the size of the gliding mechanism needs to be designed in advance so that the wings can reach the specified position during gliding. If you want to change the wing locking position, you need to modify the size and reprocess the gliding mechanism parts. This gliding solution based on mechanical limit also makes the wing position during gliding unable to change after takeoff.

[0004] In addition, the driving motor of the flapping-wing flying robot is a DC permanent magnet brushless motor, which is mostly controlled by a brushless electric regulator. The brushless electric regulator adopts a six-step commutation speed control strategy. This strategy has the disadvantages of torque fluctuation, poor low-speed performance and inability to achieve position servo, which will reduce the flight performance of the flapping-wing flying robot. Summary of the invention

[0005] In order to solve the technical problems existing in the prior art, the embodiments of the present invention provide a flapping-gliding switching mechanism, method and system for a flapping-wing flying robot. The technical solution is as follows:

[0006] A flapping-gliding switching mechanism of a flapping-wing flying robot, comprising:

[0007] A main beam and a mounting frame, wherein the mounting frame is mounted on the main beam and arranged below the main beam;

[0008] A motor and a gear assembly, wherein the gear assembly is mounted on the mounting frame, and the motor drives the gear assembly to rotate;

[0009] A crank-connecting rod assembly, wherein two crank rocker arm structures are respectively mounted on both sides of the gear assembly and are symmetrically arranged, one end of the crank-connecting rod assembly is connected to the output shaft of the gear assembly, and the other end of the crank-connecting rod assembly is rotatably mounted on a fixing frame, and the fixing frame is mounted on the mounting frame;

[0010] When the flapping mode is switched to the gliding mode, the motor drives the crank rocker assembly to rotate so that the wing hovers at a target flapping angle.

[0011] Optionally, the crank-connecting rod assembly comprises:

[0012] A crank block, wherein the input end of the crank block is connected to the output shaft of the gear assembly, and the output end of the crank block is connected to the connecting rod;

[0013] A connecting rod, wherein the connecting rod is L-shaped, one end of the horizontal rod of the connecting rod is connected to the output of the crank block, the other end of the horizontal rod of the connecting rod is connected to one end of the longitudinal rod of the connecting rod, and the other end of the longitudinal rod of the connecting rod is connected to the rocker arm;

[0014] The rocker arm is integrally arranged, and includes a first arm section and a second arm section. The connection between the first arm section and the second arm section is arranged at an obtuse angle. One end of the first arm section is rotatably mounted in the mounting frame, and the other end of the first arm section is connected to the second arm section. A boss is arranged at the bottom end of the second arm section, and the longitudinal rod of the connecting rod is mounted on the boss.

[0015] Optionally, the gear assembly comprises:

[0016] A driving gear, the driving gear being mounted on an output shaft of the motor;

[0017] A driven gear, the driven gear is mounted on a mounting shaft, the mounting shaft is mounted on the mounting frame, and the driven gear is meshed with the driving gear;

[0018] A driving gear, wherein the driving gear is fixedly mounted on a side surface of the driven gear, and the driving gear and the driven gear are coaxially arranged;

[0019] An output gear, the output gear is mounted on the output shaft of the gear assembly, the output shaft is mounted on the mounting frame, both ends of the output shaft are respectively connected to corresponding crank blocks, and the output gear is meshed with the driving gear;

[0020] When the active gear and the driving gear drive the output gear to rotate, the output gear drives the output shaft to rotate, the output shaft drives the crank block to rotate, and the crank block drives the rocker arm to rotate upward or downward through the connecting rod.

[0021] Optionally, the mechanism further comprises: a ring encoder and a ring magnet;

[0022] The annular encoder is mounted on the mounting frame, and the annular encoder is coaxially arranged with the output shaft;

[0023] The annular magnet is mounted on the output shaft, the annular magnet rotates with the output shaft, and the annular magnet is arranged in a cavity at the center of the annular encoder;

[0024] The motor is a brushless DC motor.

[0025] Optionally, the mounting frame comprises:

[0026] Two parallel structure frames, the tops of the two structure frames are respectively mounted on two opposite outer side walls of the mounting beam;

[0027] Connecting members, a plurality of connecting members are arranged between the two structural frames, and the connecting members enable the two structural members to be arranged in parallel;

[0028] Wherein, the gear assembly is installed between two structural frames, and the output shaft of the motor passes through one of the structural frames and is connected to the driving gear.

[0029] Optionally, the fixing frame is integrally provided;

[0030] The mounting end of the fixing frame is two parallel mounting plates, the mounting half of the fixing frame is mounted on the main beam, and the two fixing plates are respectively fitted with the outer surfaces of two side walls opposite to the main beam;

[0031] The receiving end of the fixing frame is arranged above the two fixing plates and is integrally formed with the two fixing plates. The receiving end of the fixing frame includes two parallel mounting plates. The two mounting plates are respectively arranged parallel to the two end surfaces of the main beam. The distance between the two mounting plates is equal to the width of the fixing plates. Through holes are respectively arranged at both ends of the two mounting plates. The first sections of the two rocker levers are respectively installed between the two mounting plates through rotating shafts.

[0032] Wherein, an inner cavity is arranged on the second arm section of the rocker arm, and the inner cavity is arranged along the central axis of the arm body of the second arm section. The inner cavity of the rocker arm supports the installation of the wing frame.

[0033] A flapping-gliding switching method for a flapping-wing flying robot is applied to the flapping-gliding switching mechanism of the flapping-wing flying robot, and includes the following method:

[0034] The annular encoder detects the rotation angle of the output shaft, and obtains the wing flapping angle according to the rotation angle of the output shaft;

[0035] Differentiating the wing flapping angle to obtain the actual wing flapping frequency;

[0036] A motor PID control strategy is obtained according to the expected flapping frequency of the wing and the actual flapping frequency of the wing to give an input of the current loop;

[0037] Decoupling the input of the current loop given by the PID control strategy to obtain the input current of the motor;

[0038] The motor drives the wing to glide according to the input current.

[0039] Optionally, the annular encoder detects the rotation angle of the output shaft, and the formula for obtaining the wing flapping angle according to the rotation angle of the output shaft is formula (1):

[0040] ; (1)

[0041] in, is the rotation angle of the output shaft, θ is the flapping angle of the wing, b is the crank length, L is the connecting rod length, c is the rocker arm length, a is the length of the output shaft of the gear set, and h is the distance from the gear output shaft to the rocker arm rotating shaft.

[0042] Optionally, the formula for obtaining the input of the current loop by the motor PID control strategy according to the expected flapping frequency of the wing and the actual flapping frequency of the wing is formula (2):

[0043] ; (2)

[0044] Among them, e(k) is the error between the expected beat frequency and the actual beat frequency, k is the number of PID, K p is the proportionality coefficient, K i is the integration coefficient, is the integral term, K d is the differential coefficient, [e(k)-e(k-1)] is the differential term, T is the control period, and u(k) is the input of the current loop given by the motor PID control strategy.

[0045] A flapping-gliding switching system for a flapping-wing flying robot comprises the flapping-gliding switching mechanism of the flapping-wing flying robot, and further comprises: a host computer, a communication module and a vector control module;

[0046] The vector control module is connected to the host computer through the communication module, and the vector control module receives the information of the rotation angle of the output shaft collected by the magnetic encoder;

[0047] The vector control module collects information about the rotation angle of the output shaft according to the instruction of the host computer and the magnetic encoder;

[0048] The rotation angle of the output shaft is obtained by the motor PID control strategy to give the input of the current loop;

[0049] The vector control module decouples the input of the current loop given by the motor PID control strategy to obtain the input current of the motor;

[0050] The vector control module drives the motor to work according to the input current of the motor so that the flapping-gliding switching mechanism of the flapping-wing flying robot completes the instruction issued by the host computer.

[0051] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention include at least:

[0052] The present invention combines motor vector control with a flapping-wing flying robot for the first time. The vector control technology used in the motor servo module has the characteristics of small torque fluctuation, high energy utilization rate and excellent low-speed performance, and can provide a stable and controllable flapping frequency for the flapping-wing flying robot. The vector control technology realizes the decoupling of the current excitation component and torque component of the permanent magnet brushless DC motor. The operator can obtain the output torque of the motor through the current information sent by the motor servo module and evaluate the current working status of the flapping-wing flying robot.

[0053] The present invention proposes for the first time a flapping-gliding flight mode switching scheme for a flapping-wing flying robot based on motor vector control. When the operator sends a gliding command to the flapping-wing flying robot through a remote controller, the motor servo module can quickly drive the wings to the specified position and generate a certain torque to fix the wings, allowing the flapping-wing flying robot to quickly enter the gliding state, thereby solving the problems of complex design, high failure rate and mechanical wear of the gliding scheme based on a mechanical limit device.

[0054] The present invention realizes for the first time the function of a flapping-wing flying robot to change the position of its wings in real time during gliding. When the flapping-wing flying robot is gliding, the operator can change the flapping angle of the flapping-wing flying robot's wings in real time through remote control signals, thereby realizing gliding flight of the flapping-wing flying robot's wings at different angles, thus solving the problem of a traditional gliding scheme in which the wings are locked at a single flapping angle and cannot be flexibly adjusted. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0056] Figure 1 It is a first-perspective axonometric diagram of a flapping-gliding switching mechanism of a flapping-wing flying robot provided by an embodiment of the present invention;

[0057] Figure 2 is a side view of a flapping-gliding switching mechanism of a flapping-wing flying robot provided by an embodiment of the present invention;

[0058] Figure 3 It is a second-view axonometric diagram of a flapping-gliding switching mechanism of a flapping-wing flying robot provided by an embodiment of the present invention;

[0059] Figure 4 It is a third-perspective axonometric diagram of a flapping-gliding switching mechanism of a flapping-wing flying robot provided by an embodiment of the present invention;

[0060] Figure 5 is a labeled schematic diagram of a flapping-gliding switching mechanism of a flapping-wing flying robot provided by an embodiment of the present invention from a first perspective;

[0061] Figure 6 is a labeled schematic diagram of a side view of a flapping-gliding switching mechanism of a flapping-wing flying robot provided by an embodiment of the present invention;

[0062] Figure 7 It is a structural schematic diagram of a rocker arm of a flapping-gliding switching mechanism of a flapping-wing flying robot provided by an embodiment of the present invention;

[0063] Figure 8 It is a structural schematic diagram of a gear assembly of a flapping-gliding switching mechanism of a flapping-wing flying robot provided by an embodiment of the present invention;

[0064] Fig. 9 is a schematic diagram of a mounting frame of a flapping-gliding switching mechanism of a flapping-wing flying robot provided by an embodiment of the present invention;

[0065] Fig.10 It is a framework diagram of a flapping-gliding switching solution of a flapping-wing flying robot provided by an embodiment of the present invention;

[0066] Fig.11 It is a structural block diagram of a motor servo module in a flapping and gliding switching system of a flapping-wing flying robot provided by an embodiment of the present invention;

[0067] Fig.12The present invention provides a flowchart of a motor servo module in a flapping-gliding switching system of a flapping-wing flying robot performing closed-loop feedback control on the flapping frequency and flapping angle of the flapping-wing flying robot.

[0068] Figure Number:

[0069] 1. Main beam; 2. Mounting frame; 21. Structural frame; 22. Connecting piece; 3. Motor; 4. Gear assembly; 41. Active gear; 42. Driven gear; 43. Driving gear; 44. Output gear; 45. Output shaft; 5. Crank-connecting rod assembly; 51. Crank block; 52. Connecting rod; 521. Horizontal rod; 522. Longitudinal rod; 53. Rocker rod; 531. First arm section; 532. Second arm section; 533. Boss; 6. Ring encoder; 7. Ring magnet; 8. Fixing frame; 81. Fixing plate; 82. Mounting plate. DETAILED DESCRIPTION

[0070] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0071] Unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one", "one" or "the" do not indicate a quantitative limitation, but indicate the existence of at least one. Words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

[0072] It should be noted that the terms "up", "down", "left", "right", "front", "back", etc. used in the present invention are only used to indicate relative position relationships. When the absolute position of the object being described changes, the relative position relationship may also change accordingly.

[0073] like Figures 1 to 10As shown, in order to solve the problems existing in the prior art, the present invention provides a flapping-gliding switching mechanism of a flapping-wing flying robot in a first aspect, comprising: a main beam 1, a mounting frame 2, a motor 3, a gear assembly 4 and a crank-connecting rod assembly 5.

[0074] The mounting frame 2 is installed on the main beam 1 and is arranged below the main beam 1; the gear assembly 4 is installed on the mounting frame 2, and the motor 3 drives the gear assembly 4 to rotate; the two crank rocker arm structures are respectively installed on both sides of the gear assembly 4 and are symmetrically arranged, one end of the crank connecting rod assembly 5 is connected to the output shaft 45 of the gear assembly 4, and the other end of the crank connecting rod assembly 5 is rotatably installed on the fixing frame 8, and the fixing frame 8 is installed on the mounting frame 2; when the flapping mode is switched to the gliding mode, the motor 3 drives the crank rocker arm assembly to rotate so that the wing hovers at the target flapping angle.

[0075] In a specific implementation manner, the crank-connecting rod assembly 5 includes a crank block 51 , a connecting rod 52 and a rocker arm 53 .

[0076] The input end of the crank block 51 is connected to the output shaft 45 of the gear assembly 4, and the output end of the crank block 51 is connected to the connecting rod 52. The crank rocker structure itself is a prior art. The driving principle of the crank-connecting rod assembly 5 of the present invention is consistent with the prior art. In addition, the purpose of the present invention is mainly to switch a drone flying in a flapping mode to a drone flying in a gliding mode. When switching between the two modes, since the rocker arm is a structure used to drive the wing to flap, the rocker arm needs to stop at a flapping angle that can achieve gliding. Therefore, it is necessary to control the motor 3 to drive the gear assembly 4 to rotate so that the rocker arm stops at the flapping angle of gliding. In the gliding mode, the wing does not flap. The connecting rod 52 is set in an L shape, one end of the horizontal rod 521 of the connecting rod 52 is connected to the output of the crank block 51, the other end of the horizontal rod 521 of the connecting rod 52 is connected to one end of the longitudinal rod 522 of the connecting rod 52, and the other end of the longitudinal rod 522 of the connecting rod 52 is connected to the rocker arm 53; the rocker arm 53 is set as an integral part, and the rocker arm 53 includes a first arm section 531 and a second arm section, and the connection between the first arm section 531 and the second arm section is set at an obtuse angle, one end of the first arm section 531 is rotatably installed in the mounting frame 2, the other end of the first arm section 531 is connected to the second arm section, and a boss 533 is set at the bottom end of the second arm section, and the longitudinal rod 522 of the connecting rod 52 is installed on the boss 533, and an inner cavity is set on the second arm section of the rocker arm 53, and the inner cavity is set along the central axis of the arm body of the second arm section, and the inner cavity of the rocker arm 53 supports the installation of the wing frame.

[0077] In a specific embodiment, the gear assembly 4 includes: a driving gear 41, a driven gear 42, a driving gear 43, an output gear 44 and an output shaft 45;

[0078] The driving gear 41 is mounted on the output shaft 45 of the motor 3; the driven gear 42 is mounted on the mounting shaft, the mounting shaft is mounted on the mounting frame 2, and the driven gear 42 is meshed with the driving gear 41; the driving gear 43 is fixedly mounted on the side of the driven gear 42, and the driving gear 43 is coaxially arranged with the driven gear 42; the output gear 44 is mounted on the output shaft 45 of the gear assembly 4, the output shaft 45 is mounted on the mounting frame 2, the two ends of the output shaft 45 are respectively connected to the corresponding crank blocks 51, and the output gear 44 is meshed with the driving gear 43; when the driving gear 41 and the driving gear 43 drive the output gear 44 to rotate, the output gear 44 drives the output shaft 45 to rotate, the output shaft 45 drives the crank block 51 to rotate, and the crank block 51 drives the rocker arm 53 to rotate upward or downward through the connecting rod 52.

[0079] In this embodiment, the transmission ratios of the active gear 41, the driven gear 42, the driving gear 43 and the output gear 44 are set according to the experience of those skilled in the art and are referenced according to the size of the drone.

[0080] In a specific embodiment, the mechanism further includes: a ring encoder 6 and a ring magnet 7;

[0081] The annular encoder 6 is installed on the mounting frame 2, and the annular encoder 6 is coaxially arranged with the output shaft 45; the annular magnet 7 is installed on the output shaft 45, and the annular magnet 7 rotates with the output shaft 45, and the annular magnet 7 is arranged in a cavity at the center of the annular encoder 6; the motor 3 is a DC brushless motor 3, the annular magnet 7 is fixedly connected to the output shaft 45 by an interference fit, the annular encoder is fixedly connected to the carbon plate of the flapping-wing flying robot body, and the center of the circle and the annular magnet 7 are located in the same plane.

[0082] In a specific embodiment, the mounting frame 2 includes: two parallel structural frames 21 and a plurality of connecting members 22, and the connecting members 22 can be a structure that supports fixed connection such as bolts. The tops of the two structural frames 21 are respectively mounted on two outer side walls of the mounting beam that are opposite to each other; a plurality of connecting members 22 are arranged between the two structural frames 21, and the connecting members 22 make the two structural members arranged in parallel; the gear assembly 4 is installed between the two structural frames 21, and the output shaft 45 of the motor 3 passes through one structural frame 21 and is connected to the driving gear 41.

[0083] The specific structure of the structural frame 21 is a structural frame set up according to needs. The structural frame is mainly a plurality of rod-like structures set up in one body, not a panel structure. For example, for a structural frame 21, it is coupled together by two diamond structures. The vertices of the connecting ends of the two diamond structures are removed and coupled together, and reinforcing ribs are set between the relative vertices or relative concave points. The other parts are hollowed out to reduce the weight of the structural frame 21 and not bring more resistance factors to the flight of the drone.

[0084] In a specific implementation manner, the fixing frame 8 is integrally arranged; the mounting end of the fixing frame 8 is two parallel mounting plates 82, the mounting half of the fixing frame 8 is installed on the main beam 1, and the two fixing plates 81 are respectively arranged to fit the outer surfaces of the two side walls opposite to the main beam 1; the accommodating end of the fixing frame 8 is arranged above the two fixing plates 81 and is integrally formed with the two fixing plates 81, the accommodating end of the fixing frame 8 includes two parallel mounting plates 82, the two mounting plates 82 are respectively arranged parallel to the two end surfaces of the main beam 1, the distance between the two mounting plates 82 is equal to the width of the fixing plate 81, through holes are respectively arranged at both ends of the two mounting plates 82, and the first sections 531 of the two rocker levers 53 are respectively installed between the two mounting plates 82 through rotating shafts.

[0085] A flapping-gliding switching method for a flapping-wing flying robot is applied to the flapping-gliding switching mechanism of the flapping-wing flying robot, and includes the following method:

[0086] The ring encoder detects the rotation angle of the output shaft, and the wing flapping angle is obtained according to the rotation angle of the output shaft;

[0087] Differentiate the wing flapping angle to get the actual wing flapping frequency;

[0088] According to the expected flapping frequency and the actual flapping frequency of the wing, the motor PID control strategy is obtained to give the input of the current loop;

[0089] Decouple the input of the current loop given by the PID control strategy to obtain the input current of the motor;

[0090] The motor drives the wings to glide according to the input current.

[0091] The ring encoder detects the rotation angle of the output shaft, and the formula for obtaining the wing flapping angle according to the rotation angle of the output shaft is formula (1):

[0092] ; (1)

[0093] in, is the rotation angle of the output shaft, θ is the flapping angle of the wing, b is the crank length, L is the connecting rod length, c is the rocker arm length, a is the length of the output shaft of the gear set, and h is the distance from the gear output shaft to the rocker arm rotating shaft.

[0094] Among them, the formula for the input of the current loop obtained by the motor PID control strategy based on the expected flapping frequency of the wing and the actual flapping frequency of the wing is formula (2):

[0095] ; (2)

[0096] Among them, e(k) is the error between the expected beat frequency and the actual beat frequency, k is the number of PID, K p is the proportionality coefficient, Ki is the integration coefficient, is the integral term, K d is the differential coefficient, [e(k)-e(k-1)] is the differential term, T is the control period, and u(k) is the input of the current loop given by the motor PID control strategy.

[0097] In another invention, the present invention provides a flapping-gliding switching system for a flapping-wing flying robot, comprising the flapping-gliding switching mechanism of the flapping-wing flying robot mentioned above, and also comprising: a host computer, a communication module and a vector control module; the vector control module is connected to the host computer via the communication module, and the vector control module receives information about the rotation angle of the output shaft collected by the magnetic encoder; the vector control module collects information about the rotation angle of the output shaft according to the instructions of the host computer and the magnetic encoder; the rotation angle of the output shaft obtains the input of the current loop given by the motor PID control strategy; the vector control module decouples the input of the current loop given by the motor PID control strategy to obtain the input current of the motor; the vector control module drives the motor to work according to the input current of the motor so that the flapping-gliding switching mechanism of the flapping-wing flying robot completes the instructions issued by the host computer.

[0098] like Figure 10-12 As shown, in this system, the wing drive module is equivalent to the crank-connecting rod assembly in the flapping and gliding switching mechanism of the flapping-wing flying robot, the wing flapping angle detection module is equivalent to the ring encoder and the ring magnet, the motor servo module includes a communication module, a motor and a vector control module, the vector control module and the motor servo module are installed on a circuit board, and the vector control module is used to execute the vector control algorithm, including a main control chip, an inverter module, a buck module and a current sampling module.

[0099] Motor servo module, wing drive module and wing flapping angle detection module. The motor servo module is used to servo control the motor, the wing drive module is used to convert the rotational motion of the motor into the up and down flapping of the wing, providing lift and thrust for the flapping-wing flying robot, and the wing position detection module is used to collect the wing flapping angle information and flapping frequency information and send them to the motor servo module, which realizes the closed-loop control of the flapping frequency and wing flapping angle of the flapping-wing flying robot.

[0100] The output shaft of the gear assembly serves as the rotating shaft of the crank block in the spatial crank-connecting rod structure, converting the rotational motion into the up and down reciprocating swing of the rocker arm, driving the wing inserted in the rocker arm to flap up and down, generating lift and thrust.

[0101] A monitor is also provided on the motor to monitor the rotation angle of the output end of the motor. The monitor may be a magnetic encoder. The magnetic encoder of the motor is installed at the end of the brushless DC motor. The magnetic field generated by the magnet that rotates synchronously with the rotor obtains the angle information of the motor and sends it to the vector control module.

[0102] The wing position detection module includes a ring magnetic encoder and a ring magnet. The ring magnet is installed on the output shaft of the three-stage gear set and rotates synchronously with the output shaft; the ring magnetic encoder is installed above the ring magnet and is fixed to the carbon plate of the flapping-wing flying robot body through a 3D printed bracket. The rotation angle information of the output shaft of the gear set is obtained by detecting the magnetic field change of the ring magnet. The wing flapping angle can be calculated by differential operation to obtain the wing flapping frequency. The wing position detection module sends the flapping angle and flapping frequency to the motor servo module to realize the closed-loop control of the flapping frequency and flapping angle of the wing of the flapping-wing flying robot.

[0103] In this embodiment, the host computer sends the instruction, and the host computer may be a remote controller, a computer, a mobile phone or other related equipment. The host computer is connected to the motor servo module via a communication module.

[0104] The vector control module includes a main control chip, an inverter module, a buck module and a current sampling module. Among them, the main control chip is used to run the vector control algorithm, and the inverter module includes a motor front drive chip and a three-phase half-bridge inverter circuit. Among them, the three-phase half-bridge inverter circuit uses MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor field effect transistor) as a switching device to convert the PWM (Pulse-Width Modulation) signal issued by the main control chip into a sinusoidal signal of the three-phase winding of the DC brushless motor. The buck module is used to reduce the bus input voltage to 5V and 3.3V, respectively, to power the inverter module and the main control chip. Among them, the bus input voltage is reduced to 5V through the DCDC (DC-to-DCconverter DC-DC converter) chip, and the 5V network is reduced to 3.3V through the LDO (Low Dropout Regulator low voltage difference linear regulator) chip. Current sampling chip. The current sampling module includes a sampling resistor and an operational amplifier, which is used to collect the phase current of the brushless DC motor and send it to the main control chip.

[0105] The working process of the motor servo module to perform closed-loop feedback control on the flapping frequency and flapping angle of the flapping-wing flying robot is as follows:

[0106] By receiving the channel information of the host computer, it is determined whether the current flight mode is a flapping flight mode or a gliding flight mode, which corresponds to the flapping frequency closed-loop control and the flapping angle closed-loop control of the motor servo module respectively;

[0107] The motor servo module adopts a cascade PID control strategy. In the flapping flight mode, its outer loop is the flapping frequency loop; in the gliding flight mode, its outer loop is the flapping angle loop; the inner loop of the motor servo module is the current loop, that is, the torque loop, which outputs the corresponding torque according to the requirements of the flapping frequency loop and the flapping angle loop. Among them, the flapping frequency of the flapping-wing flying robot is obtained from the magnetic encoder installed on the output shaft of the three-stage gear set. The encoder is used to detect the rotation angle of the output shaft of the gear set. The wing flapping angle can be calculated by the above formula (1), and the actual flapping frequency of the wing can be obtained after differential calculation of the wing flapping angle.

[0108] In the flapping mode, the motor servo module makes a difference between the given desired flapping frequency and the actual flapping frequency, and uses the PID control strategy to give the input of the current loop, wherein the input of the current loop given by the PID control strategy is obtained by the above formula (2).

[0109] In order to achieve torque control of brushless DC motor, it is necessary to decouple the current. Under the action of Clark transformation and Park transformation, the three-phase current i in the stationary coordinate system is a 、i b 、i c First, it is transformed into i in the stationary coordinate system α 、i β , i0, and then transformed into i in the rotating coordinate system d 、i q , the specific transformation process is as follows:

[0110] ; (3)

[0111] ; (4)

[0112] ; (5)

[0113] ; (6)

[0114] Among them, T 3s / 2s is the Clark transformation, T 2s / 2r is the Park transform, θ e It is the electrical angle information of the motor rotor, which is obtained by the magnetic encoder installed at the tail of the motor.

[0115] In the rotating coordinate system, the relationship between the dq axis voltage and current is as follows (7)

[0116] ; (7)

[0117] Among them, u d is the d-axis voltage, u q is the q-axis voltage, i qis the q-axis current, i d is the d-axis current, L d is the d-axis inductance, L q is the q-axis inductance, ψ f is the permanent magnet flux, p n is the number of motor pole pairs, ω e is the electrical angular velocity, T e is the output torque.

[0118] Adopt i d =0 control strategy, assuming that L d With L q Approximately equal, then

[0119] ; (8)

[0120] Among them, the output torque of the motor is T e and q-axis current i q There is a linear relationship, for i q The output torque can be controlled by controlling the output torque.

[0121] The PI controller is used to control the dq axis current. The input of the q axis PI controller is the desired torque, that is, the output of the speed loop or position loop, and the output is u q ; The input of the d-axis PI controller is 0 and the output is u d .u d and u q After the inverse Park transformation, it is transformed into u in the stationary coordinate system α with u β , the process of inverse park transformation is as follows:

[0122] ; (9)

[0123] ; (10)

[0124] u α with u β Under the action of SVPWM, an electromagnetic field is synthesized that is always 90° ahead of the rotor magnetic field, and the permanent magnet rotor is pulled to rotate under the action of the magnetic field force.

[0125] During operation, the motor servo module sends the current i to the ground station in real time through the communication module. q , motor temperature and motor speed, so that ground operators can judge the current working condition of the flapping-wing flying robot.

[0126] The present invention combines motor vector control with a flapping-wing flying robot for the first time. The vector control technology used in the motor servo module has the characteristics of small torque fluctuation, high energy utilization rate and excellent low-speed performance, and can provide a stable and controllable flapping frequency for the flapping-wing flying robot. The vector control technology realizes the decoupling of the current excitation component and torque component of the permanent magnet brushless DC motor. The operator can obtain the output torque of the motor through the current information sent by the motor servo module and evaluate the current working status of the flapping-wing flying robot.

[0127] The present invention proposes for the first time a flapping-gliding flight mode switching scheme for a flapping-wing flying robot based on motor vector control. When the operator sends a gliding command to the flapping-wing flying robot through a remote controller, the motor servo module can quickly drive the wings to the specified position and generate a certain torque to fix the wings, allowing the flapping-wing flying robot to quickly enter the gliding state, thereby solving the problems of complex design, high failure rate and mechanical wear of the gliding scheme based on a mechanical limit device.

[0128] The present invention realizes for the first time the function of a flapping-wing flying robot to change the position of its wings in real time during gliding. When the flapping-wing flying robot is gliding, the operator can change the flapping angle of the flapping-wing flying robot's wings in real time through remote control signals, thereby realizing gliding flight of the flapping-wing flying robot's wings at different angles, thus solving the problem of a traditional gliding scheme in which the wings are locked at a single flapping angle and cannot be flexibly adjusted.

[0129] The following points need to be explained:

[0130] (1) The drawings of the embodiments of the present invention only relate to the structures related to the embodiments of the present invention. Other structures may refer to the general design.

[0131] (2) For the sake of clarity, in the drawings used to describe the embodiments of the present invention, the thickness of layers or regions is exaggerated or reduced, that is, these drawings are not drawn according to the actual scale. It is understood that when an element such as a layer, film, region or substrate is referred to as being "on" or "under" another element, the element may be "directly" "on" or "under" the other element or there may be intermediate elements.

[0132] (3) In the absence of conflict, the embodiments of the present invention and the features therein may be combined with each other to obtain new embodiments.

[0133] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A flapping-gliding switching method for a flapping-wing flying robot, characterized in that: A switching mechanism is included, wherein the switching mechanism includes: A main beam and a mounting frame, wherein the mounting frame is mounted on the main beam and arranged below the main beam; A motor and a gear assembly, wherein the gear assembly is mounted on the mounting frame, and the motor drives the gear assembly to rotate; A crank-connecting rod assembly, wherein two crank rocker arm structures are respectively mounted on both sides of the gear assembly and are symmetrically arranged, one end of the crank-connecting rod assembly is connected to the output shaft of the gear assembly, and the other end of the crank-connecting rod assembly is rotatably mounted on a fixing frame, and the fixing frame is mounted on the mounting frame; When the flapping mode is switched to the gliding mode, the motor drives the crank rocker assembly to rotate so that the wing hovers at a target flapping angle; The switching methods include: The annular encoder detects the rotation angle of the output shaft, and obtains the wing flapping angle according to the rotation angle of the output shaft; Differentiating the wing flapping angle to obtain the actual wing flapping frequency; A motor PID control strategy is obtained according to the expected flapping frequency of the wing and the actual flapping frequency of the wing to give an input of the current loop; Decoupling the input of the current loop given by the PID control strategy to obtain the input current of the motor; the motor drives the wing to glide according to the input current; The annular encoder detects the rotation angle of the output shaft, and the formula for obtaining the wing flapping angle according to the rotation angle of the output shaft is formula (1): (bsinφ) 2 +(a-ccosθ) 2 +(bcosφ-h-csinθ) 2 =L 2 ; (1) Among them, φ is the rotation angle of the output shaft, θ is the flapping angle of the wing, b is the crank length, L is the connecting rod length, c is the rocker arm length, a is the length of the output shaft of the gear set, and h is the distance from the gear output shaft to the rocker arm rotating shaft; The formula for obtaining the input of the current loop by the motor PID control strategy according to the expected flapping frequency of the wing and the actual flapping frequency of the wing is formula (2): Among them, e(k) is the error between the expected beat frequency and the actual beat frequency, k is the number of PID, K p is the proportionality coefficient, K i is the integration coefficient, Σ j＝0 e(j) is the integral term, K d is the differential coefficient, [e(k)-e(k-1)] is the differential term, T is the control period, and u(k) is the input of the current loop given by the motor PID control strategy.

2. The flapping-gliding switching method of a flapping-wing flying robot according to claim 1, characterized in that: The crank connecting rod assembly comprises: A crank block, wherein the input end of the crank block is connected to the output shaft of the gear assembly, and the output end of the crank block is connected to the connecting rod; A connecting rod, wherein the connecting rod is L-shaped, one end of the horizontal rod of the connecting rod is connected to the output of the crank block, the other end of the horizontal rod of the connecting rod is connected to one end of the longitudinal rod of the connecting rod, and the other end of the longitudinal rod of the connecting rod is connected to the rocker arm; The rocker arm is integrally arranged, and includes a first arm section and a second arm section. The connection between the first arm section and the second arm section is arranged at an obtuse angle. One end of the first arm section is rotatably mounted in the mounting frame, and the other end of the first arm section is connected to the second arm section. A boss is arranged at the bottom end of the second arm section, and the longitudinal rod of the connecting rod is mounted on the boss.

3. The flapping-gliding switching method of the flapping-wing flying robot according to claim 2, characterized in that: The gear assembly comprises: A driving gear, the driving gear being mounted on an output shaft of the motor; A driven gear, the driven gear is mounted on a mounting shaft, the mounting shaft is mounted on the mounting frame, and the driven gear is meshed with the driving gear; A driving gear, wherein the driving gear is fixedly mounted on a side surface of the driven gear, and the driving gear and the driven gear are coaxially arranged; An output gear, the output gear is mounted on the output shaft of the gear assembly, the output shaft is mounted on the mounting frame, both ends of the output shaft are respectively connected to corresponding crank blocks, and the output gear is meshed with the driving gear; When the active gear and the driving gear drive the output gear to rotate, the output gear drives the output shaft to rotate, the output shaft drives the crank block to rotate, and the crank block drives the rocker arm to rotate upward or downward through the connecting rod.

4. The flapping-gliding switching method of the flapping-wing flying robot according to claim 3, characterized in that: The mechanism also includes: a ring encoder and a ring magnet; The annular encoder is mounted on the mounting frame, and the annular encoder is coaxially arranged with the output shaft; The annular magnet is mounted on the output shaft, the annular magnet rotates with the output shaft, and the annular magnet is arranged in a cavity at the center of the annular encoder; The motor is a brushless DC motor.

5. The flapping-gliding switching method of a flapping-wing flying robot according to claim 4, characterized in that: The mounting frame comprises: Two parallel structure frames, the tops of the two structure frames are respectively mounted on two opposite outer side walls of the mounting beam; Connecting members, a plurality of connecting members are arranged between the two structural frames, and the connecting members enable the two structural members to be arranged in parallel; Wherein, the gear assembly is installed between two structural frames, and the output shaft of the motor passes through one of the structural frames and is connected to the driving gear.

6. The flapping-gliding switching method of a flapping-wing flying robot according to claim 1, characterized in that: The fixing frame is integrally arranged; The mounting end of the fixing frame is two parallel mounting plates, the mounting half of the fixing frame is mounted on the main beam, and the two fixing plates are respectively arranged in contact with the outer surfaces of the two side walls of the main beam; The receiving end of the fixing frame is arranged above the two fixing plates and is integrally formed with the two fixing plates. The receiving end of the fixing frame includes two parallel mounting plates. The two mounting plates are respectively arranged parallel to the two end surfaces of the main beam. The distance between the two mounting plates is equal to the width of the fixing plates. Through holes are respectively arranged at both ends of the two mounting plates. The first sections of the two rocker levers are respectively installed between the two mounting plates through rotating shafts. Wherein, an inner cavity is arranged on the second arm section of the rocker arm, and the inner cavity is arranged along the central axis of the arm body of the second arm section. The inner cavity of the rocker arm supports the installation of the wing frame.

7. A flapping-gliding switching system for a flapping-wing flying robot, characterized in that: The flapping-gliding switching method of the flapping-wing flying robot according to any one of claims 1 to 6 further comprises: a host computer, a communication module and a vector control module; The vector control module is connected to the host computer through the communication module, and the vector control module receives information about the rotation angle of the output shaft collected by the magnetic encoder; The vector control module collects information about the rotation angle of the output shaft according to the instruction of the host computer and the magnetic encoder; The rotation angle of the output shaft is obtained by the motor PID control strategy to give the input of the current loop; The vector control module decouples the input of the current loop given by the motor PID control strategy to obtain the input current of the motor; The vector control module drives the motor to work according to the input current of the motor so that the flapping-gliding switching mechanism of the flapping-wing flying robot completes the instruction issued by the host computer.

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