A deformable land-air multimodal robotic system and motion control method

Abstract

The application discloses a deformable land-air multi-modal robot system and a motion control method, which comprises a body, an autopilot, a wing arm device and a wheel wing device. The autopilot is fixedly installed on the body, the wing arm device is symmetrically installed on the side of the body, and the wheel wing device is rotatably installed at the tail end of the wing arm device. The body is used for serving as a structural framework and carrying and connecting other components. The autopilot is used for acquiring motion state information of the land-air multi-modal robot and executing a preset control program, controlling the wing arm device to drive the wheel wing device to reach a specified position, and realizing switching and operation of a motion mode. The land-air multi-modal robot system has the advantages of simple structure, low power consumption, strong environmental adaptability, good stability, strong maneuverability, multi-modal operation capacity and the like, and can meet task requirements in various complex and severe scenes.

Description

Technical Field

[0001] This invention relates to the field of cross-domain multimodal robot technology, and in particular to a deformable land-air multimodal robot system and motion control method. Background Technology

[0002] In recent years, with the continuous development of robotics technology, humans have developed different types of robots for application in different spatial domains. However, traditional robots are mostly fixed in a single medium space, possess only a single motion mode, and cannot achieve complex cross-domain movements. Their capabilities in multi-domain situational awareness, multi-dimensional information fusion, and cross-domain penetration attacks are limited, making them unable to adapt to changing and complex environments and mission requirements. Therefore, researching cross-domain multimodal robots that can adapt to varied terrain environments and possess high mobility is of great significance for disaster relief, resource exploration, and national defense security.

[0003] Existing land-air multimodal robots mainly consist of flight mechanisms and crawling mechanisms. Flight mechanisms typically employ fixed-wing, multi-rotor, and flapping-wing designs, while crawling mechanisms generally use wheeled, tracked, or legged systems. The University of Lisbon in Portugal designed a land-air multimodal robot system with a quadcopter and passive wheels. By adding wheels and links to both sides of the aircraft, it achieved cross-domain movement from air to land. However, this simple and direct connection method increased the robot's weight, and its overall balance was difficult to control during land movement. Patent application number 202310397138.9, entitled "Land-Air Amphibious Robot," designed a land-air amphibious robot with four rotor modules mounted on a four-wheeled chassis. This robot can freely retract and deploy the rotor modules to achieve mode switching, but its overall structure is too bulky, and the joints connecting the rotors are unprotected and easily damaged.

[0004] In summary, although current land-air multimodal robots all possess amphibious mobility, they are generally unable to balance lightweight design with ease of control. Furthermore, they cannot adapt well to complex ground environments and are ill-equipped to handle tasks in complex and unknown scenarios such as rescue and search operations and environmental exploration. Summary of the Invention

[0005] To address the shortcomings of the existing technologies, this invention proposes a deformable land-air multimodal robot system and control method. In addition to having walking and flying capabilities, the robot can autonomously switch its body state and working mode according to different environments, thereby reducing power consumption and making it better suited for complex environments and handling multiple tasks.

[0006] To achieve the above objectives, the present invention provides a deformable land-air multimodal robot system, comprising a body, an autopilot, wing arms, and wheel-wing devices. The autopilot is fixedly mounted on the body, the wing arms are symmetrically mounted on the sides of the body, and the wheel-wing devices are rotatably mounted on the ends of the wing arms.

[0007] The main body is rectangular in shape and consists of two layers of hollowed-out rectangular plates, which serve as a structural skeleton to support and connect other components.

[0008] The autopilot is used to acquire motion state information of land and air multimodal robots and execute preset control programs to control the wing arm device to drive the wheel wing device to the designated position, thereby realizing the switching and operation of motion modes.

[0009] Preferably, the wing arm assembly includes a left front wing arm, a right front wing arm, a left rear wing arm, and a right rear wing arm that are structurally identical and symmetrically mounted on the side of the body in an X-shape, wherein the left front wing arm and the right rear wing arm are located on the same diagonal line, and the right front wing arm and the left rear wing arm are located on the same diagonal line.

[0010] Preferably, each wing arm includes a second servo, a first servo, and a connector. One end of the first servo is fixedly mounted on the main body, and the other end of the first servo is connected to the second servo through the connector. The second servo can rotate relative to the first servo. The wheel wing device is fixedly mounted on the second servo. The wheel wing device can be in a horizontal or vertical position under the drive of the second servo, so as to be parallel or perpendicular to the plane of the upper rectangular plate of the main body.

[0011] Preferably, the wheel device includes a rotor mechanism and a wheel mechanism, which are rotatably connected by a drive shaft.

[0012] Preferably, the rotor mechanism includes a propeller and a motor. The propeller is fixedly mounted on the end of the motor's drive shaft. The wheel mechanism includes a first axle seat, a second axle seat, several spokes, a hub ring, a drive gear, and a pair of driven gears. The first axle seat and the second axle seat are fixedly connected. The motor is embedded in the first axle seat and the second axle seat. The drive gear is fixedly mounted on the motor's drive shaft and close to the first axle seat. Several spokes are arranged between the first axle seat, the second axle seat, and the hub ring. An internal gear is provided on the hub ring. The drive gear meshes with the pair of driven gears, and the pair of driven gears mesh with the internal gears on the hub ring.

[0013] Preferably, all spokes are flat.

[0014] Preferably, the autopilot 20 includes an onboard computer and a data transmission radio, a remote control receiver, a pressure sensor, a power module, an IMU module, a vision sensor, and a GPS module connected to the onboard computer, wherein:

[0015] The power module is used to provide power to the onboard EEG;

[0016] The IMU module is used to sense the position, attitude, and velocity of the land-air multimodal robot system and send the position, attitude, and velocity information to the onboard computer.

[0017] The GPS module is used to obtain the real-time position coordinates of the land-air multimodal robot system and send the real-time position coordinate information to the onboard computer;

[0018] Visual sensors are used to perceive the environment in front of the land-air multimodal robotic system and send the acquired image information to the onboard computer;

[0019] Pressure sensors are used to collect load information from the land-air multimodal robot system and send the collected load information to the onboard computer.

[0020] The remote control receiver is used to receive control commands from the remote control transmitter and send the control commands to the onboard computer;

[0021] The onboard computer receives position, attitude, and velocity information, real-time position coordinate information, image information, load information, and control commands from the land-air multimodal robot system and runs a preset control program to enable the land-air multimodal robot to operate in different modes.

[0022] The data transmission radio is used to transmit the operational status information of the land-air multimodal robot system in different modes to the ground control station.

[0023] Preferably, the IMU module includes a three-axis gyroscope, a three-axis accelerometer, and a three-axis geomagnetic sensor, which are used to detect the three-axis angular velocity, three-axis acceleration, and geomagnetic intensity components on the x, y, and z axes of the land-air multimodal robot, respectively.

[0024] Another aspect of the present invention provides a motion control method for a deformable land-air multimodal robot system, the method comprising the following steps:

[0025] S100. Design the control program, set the starting point and ending point according to the task requirements and complete the path planning. Place the land and air multimodal robot system at the starting point, divide the planned path into an air flight path and a ground movement path according to the road conditions, and store the designed control program and the divided air flight path and ground movement path in the autopilot.

[0026] S200 sends the corresponding operation mode command according to the path of the land and air multimodal robot system. The autopilot receives the operation mode command and controls the wing arm device to drive the wheel wing device to run along the divided air flight path or ground operation path according to the control program.

[0027] S300: Preset control coefficient threshold. The autopilot acquires the real-time status information of the land-air multimodal robot system during operation, calculates the control coefficient based on the real-time status information, and determines whether the current actual environment meets the conditions for continuing to execute the current operation mode command based on the control coefficient and the control coefficient threshold. If it meets the conditions, proceed to step S600; otherwise, proceed to step S400.

[0028] The S400 and autopilot control the wing arm device to drive the wheel wing device to the designated position, enabling the land-air multimodal robot system to complete the motion mode switching;

[0029] The S500 and autopilot acquire real-time status information of the land-air multimodal robot system during operation after switching modes, calculate and adjust control coefficients based on the real-time status information, and make the real-time path close to the predefined air flight path or ground operation path.

[0030] The S600 autopilot acquires the real-time position of the land-air multimodal robot system, compares the real-time position with the destination position, and if the real-time position is near the destination position, it determines that the land-air multimodal robot system has reached the destination and ends motion control.

[0031] Preferably, the motion modes include flight modes and ground modes, and S400 specifically includes:

[0032] If the current motion mode is flight mode, the autopilot controls the second servo to rotate vertically downwards until the wheel assembly is brought to a vertical position, making the wheel assembly perpendicular to the plane of the upper rectangular plate of the main body, thus completing the switch from flight mode to ground mode; or

[0033] If the current motion mode is ground mode, the autopilot controls the first servo to drive the second servo through the connector to adjust the orientation of the wheel wing device to face forward without deflection. Then the second servo rotates vertically upward to drive the wheel wing device to a horizontal position, making the wheel wing device parallel to the plane of the upper rectangular plate of the body, thus completing the switch from ground mode to flight mode.

[0034] By adopting the above technical solution, the present invention has the following technical effects:

[0035] (1) The design of the deformation device is ingenious and the power consumption of the robot is reduced. The design of the wheel and wing device enables the land and air multimodal robot system to switch between two motion modes at will. Compared with the problem of excessive increase in robot weight caused by the complicated structural design of existing land and air multimodal robots, the present invention has a good balance between the two, greatly reducing the burden on the robot and reducing power consumption.

[0036] (2) It has strong environmental adaptability and can cope with tasks in a variety of different scenarios. On flat ground, the land-air multimodal robot system is in ground mode; when encountering obstacles or rugged muddy roads, it can switch to flight mode, which has cross-domain multimodal operation capability and can well meet the task requirements in various environments. Attached Figure Description

[0037] Figure 1 This is a structural schematic diagram of a deformable land-air multimodal robot system in flight mode according to an embodiment of the present invention;

[0038] Figure 2 This is a schematic diagram of the structure of a deformable land-air multimodal robot system in ground motion mode according to an embodiment of the present invention;

[0039] Figure 3 This is a schematic diagram of the wing arm structure in one embodiment of the present invention;

[0040] Figure 4 This is a schematic diagram of the wheel wing device in one embodiment of the present invention;

[0041] Figure 5 This is a schematic block diagram of the structure of an autopilot in one embodiment of the present invention;

[0042] Figure 6 This is a flowchart of a motion control method for a deformable land-air multimodal robot system according to an embodiment of the present invention.

[0043] Explanation of reference numerals in the attached figures:

[0044] 10. Main body; 20. Autopilot; 30. Wing arm assembly; 40. Wheel assembly; 31. Left front wing arm; 32. Right front wing arm; 33. Left rear wing arm; 34. Right rear wing arm; 300. Second servo; 301. First servo; 302. Connector; 41. Rotor mechanism; 42. Wheel mechanism; 400. Propeller; 401. Motor; 402. First axle seat; 403. Second axle seat; 404. Spoke; 405. Wheel hub; 406. Drive gear; 407. Driven gear. Detailed Implementation

[0045] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0046] In the description of this invention, the relevant orientation or positional relationship is based on Figure 1 The directions or positional relationships shown, where "up" and "down" refer to... Figure 1 The up and down directions, with Figure 1For example, vertically upwards is "up," vertically downwards is "down," vertically left is "right," vertically right is "left," vertically outwards is "front," vertically inwards is "back," left and right are horizontal directions, and up and down are vertical directions. It should be understood that these directional terms are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention.

[0047] See Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of the structure of a deformable land-air multimodal robot system in flight mode according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the structure of a deformable land-air multimodal robot system in ground motion mode according to an embodiment of the present invention.

[0048] A deformable land-air multimodal robot system includes: a body 10, an autopilot 20, wing arm devices 30, and wheel-wing devices 40. The autopilot 20 is fixedly mounted on the body 10, the wing arm devices 30 are symmetrically mounted on the sides of the body 10, and the wheel-wing devices 40 are rotatably mounted on the ends of the wing arm devices 30, wherein:

[0049] The main body 10 is generally rectangular, consisting of two layers of hollowed-out rectangular plates, which serve as a structural skeleton to support and connect other components;

[0050] The autopilot 20 is used to control the wing arm device 30 to drive the wheel wing device 40 to a designated position, thereby realizing the switching and operation of motion modes.

[0051] Furthermore, the wing arm assembly 30 includes a left front wing arm 31, a right front wing arm 32, a left rear wing arm 33, and a right rear wing arm 34, which are structurally identical and symmetrically mounted on the side of the main body 10 in an X-shape. The left front wing arm 31 and the right rear wing arm 34 are located on the same diagonal line, and the right front wing arm 32 and the left rear wing arm 33 are located on the same diagonal line.

[0052] The four wing arms are all fixedly installed with wheel and wing devices 40 to form a quadcopter structure. The quadcopter structure makes the robot highly stable and maneuverable when flying. When moving on the ground, the four-wheel design also makes the robot safer and more stable, and provides greater traction and grip, as well as improving load capacity.

[0053] See Figure 3 , Figure 3 This is a schematic diagram of the wing arm structure in one embodiment of the present invention.

[0054] In one embodiment, each of the left front wing arm 31, right front wing arm 32, left rear wing arm 33 and right rear wing arm 34 includes a second servo motor 300, a first servo motor 301 and a connector 302. One end of the first servo motor 301 is fixedly mounted on the body 10, and the other end of the first servo motor 301 is connected to the second servo motor 300 through the connector 302. The second servo motor 300 can rotate relative to the first servo motor 301. The wheel wing device 40 is fixedly mounted on the second servo motor 300. The wheel wing device 40 can be in a horizontal or vertical position under the drive of the second servo motor 300, so as to be parallel or perpendicular to the plane of the upper rectangular plate of the body (10).

[0055] Specifically, one end of the first servo motor 301 is fixedly mounted on the body 10 with screws, thus fixing the first servo motor 301 relative to the body 10. The other end of the first servo motor 301 is provided with a rotating shaft, and the connecting piece 302 is designed with a first set of mounting holes that are perpendicular to each other in three-dimensional space (the axis of the first set of mounting holes corresponds to...). Figure 3 Y1 in the middle) and the second set of mounting holes (the axis where the second set of mounting holes is located corresponds to the axis of the second set of mounting holes) Figure 3 In the Y2 configuration, the connecting member 302 is rotatably connected to the first servo 301 via a rotating shaft through the first set of mounting holes. The second servo 300 has a rotating shaft at one end near the connecting member 302, and the connecting member 302 is rotatably connected to the rotating shaft of the second servo 300 via the second set of mounting holes. This design allows the second servo 300 to move up and down or forward and backward relative to the first servo 301. The other end of the second servo 300 is fixedly connected to the wheel wing device 40. The wheel wing device 40 can move up and down under the drive of the second servo 300, thus allowing it to be in a horizontal or vertical position, achieving a switching of motion modes: when the second servo 300 rotates vertically upward relative to the connecting member 302, it can drive the wheel wing device 40 to a horizontal position, thus parallel to the plane of the upper rectangular plate of the main body 10; when the second servo 300 rotates vertically downward relative to the connecting member 302, it can drive the wheel wing device 40 to a vertical position, thus perpendicular to the plane of the upper rectangular plate of the main body 10.

[0056] It should be noted that the first servo motor 301 is fixed relative to the main body 10, and it and the main body can be understood as a whole. However, the second servo motor 300 can rotate back and forth under the drive of the connecting piece 302. This means that although the first servo motor 301 and the main body 10 are fixed and always located in the diagonal direction, the connecting piece 302 and the second servo motor 300 driven by the first servo motor 301 will not necessarily always be on the diagonal. Only when they are rotated to a certain angle can the connecting piece 302 and the second servo motor 300 be on the same straight line as the first servo motor 301, that is, on the diagonal.

[0057] See Figure 4 , Figure 4This is a schematic diagram of the wheel wing device in one embodiment of the present invention.

[0058] In one embodiment, the wheel device 40 includes a rotor mechanism 41 and a wheel mechanism 42, which are rotatably connected by a drive shaft.

[0059] Furthermore, the rotor mechanism 41 includes a propeller 400 and a motor 401. The propeller 400 is fixedly mounted on the end of the drive shaft of the motor 401. The wheel mechanism 42 includes a first axle seat 402 and a second axle seat 403, several spokes 404, a hub ring 405, a drive gear 406, and a pair of driven gears 407. The first axle seat 402 and the second axle seat 403 are fixedly connected. The motor 401 is embedded in the first axle seat 402 and the second axle seat 403. The drive gear 406 is fixedly mounted on the drive shaft of the motor 401 and close to the first axle seat 402. Several spokes 404 are arranged between the first axle seat 402 and the second axle seat 403 and the hub ring 405. An internal gear is provided on the hub ring 405. The drive gear 406 meshes with the pair of driven gears 407, and the pair of driven gears 407 mesh with the internal gear on the hub ring 405.

[0060] Specifically, Figure 4 The wheel assembly 40 includes a rotor mechanism 41 and a wheel mechanism 42. The rotor mechanism 41 includes a propeller 400 and a motor 401. The propeller 400 is screwed into the end of the drive shaft of the motor 401 through a threaded hole. The wheel mechanism 42 includes a first axle seat 402, a second axle seat 403, a hub ring 405, six spokes 404, a drive gear 406, and four driven gears 407. The first axle seat 402 and the second axle seat 403 are fixedly connected by screws. The motor 401 is embedded in the first axle seat 402 and the second axle seat 403. The drive gear 406 is fixedly installed on the drive shaft of the motor 401 and close to the first axle seat 402. In this way, the propeller 400 and the drive gear 406 can rotate synchronously with the motor 401. The hub ring 405 is provided with an internal gear. The drive gear 406 meshes with the internal gear of the hub ring 405 through the four driven gears 407, thereby driving the hub ring 405 to rotate.

[0061] Furthermore, the spokes 404 are specifically flat. Compared to traditional round spokes, the flat spoke design can reduce wheel weight, while also reducing air resistance, improving heat dissipation, and enhancing stability during driving.

[0062] Figure 5 This is a schematic block diagram of the structure of an autopilot in one embodiment of the present invention.

[0063] In one embodiment, the autopilot 20 includes an onboard computer and a data transmission radio, a remote control receiver, a pressure sensor, a power module, an IMU module, a vision sensor, and a GPS module connected to the onboard computer, wherein:

[0064] The power module is used to provide power to the onboard EEG;

[0065] The IMU module is used to sense the position, attitude, and velocity of the land-air multimodal robot system and send the position, attitude, and velocity information to the onboard computer.

[0066] The GPS module is used to obtain the real-time position coordinates of the land-air multimodal robot system and send the real-time position coordinate information to the onboard computer;

[0067] Visual sensors are used to perceive the environment in front of the land-air multimodal robotic system and send the acquired image information to the onboard computer;

[0068] Pressure sensors are used to collect load information from the land-air multimodal robot system and send the collected load information to the onboard computer.

[0069] The remote control receiver is used to receive control commands from the remote control transmitter and send the control commands to the onboard computer;

[0070] The onboard computer receives position, attitude, and velocity information, real-time position coordinate information, image information, load information, and control commands from the land-air multimodal robot system and runs a preset control program to enable the land-air multimodal robot system to operate in different modes.

[0071] The data transmission radio is used to transmit the operational status information of the land-air multimodal robot system in different modes to the ground control station.

[0072] It should be noted that the ground control station is a communication tool and is not part of the aforementioned land-air multimodal robot system.

[0073] Furthermore, the IMU module includes a three-axis gyroscope, a three-axis accelerometer, and a three-axis geomagnetic sensor, which are used to detect the three-axis angular velocity, three-axis acceleration, and geomagnetic intensity components on the x, y, and z axes of the land-air multimodal robot, respectively.

[0074] See Figure 6 , Figure 6 This is a flowchart of a motion control method for a deformable land-air multimodal robot system according to an embodiment of the present invention.

[0075] A motion control method for a deformable land-air multimodal robot system, the method comprising the following steps:

[0076] S100: Design the control program, set the starting point and ending point according to the task requirements and complete the path planning, place the land and air multimodal robot system at the starting point, divide the planned path into an air flight path and a ground movement path according to the road conditions, and store the designed control program and the divided air flight path and ground movement path in the autopilot.

[0077] Specifically, the control program includes a geometry controller in air flight mode and a motion controller in ground motion mode. It sets the start and end points based on mission requirements and characteristics, uses the time required to complete the mission as a constraint, and minimizes overall energy consumption as the optimization objective for path planning. The planned path is then divided into air flight path and ground motion path based on road conditions. Existing geometry and motion controllers can be used, and they, along with the divided air flight path and ground motion path, are stored in the autopilot.

[0078] Furthermore, the geometric controller specifically comprises:

[0079]

[0080]

[0081] In the formula, and These represent the total thrust and total torque generated by the land-air multimodal robot, respectively. Let R represent the position of the land-air multimodal robot system in the inertial coordinate system, and let R∈SO(3) represent the attitude of the land-air multimodal robot system. It also represents the rotation matrix from the body coordinate system to the inertial coordinate system. Let represent the angular velocity of the land-air multimodal robot system in the body coordinate system, where g is the constant gravitational acceleration, and e3 = [0, 0, 1]. T m represents the standard mass of a land-air multimodal robot system. Let k be the inertial matrix of the land-air multimodal robot system. The symbol "^" indicates that the vector is mapped to the corresponding antisymmetric matrix. x k v k R k Ω All are positive constants, e x e v Let e ​​represent the tracking errors of the land-air multimodal robot system for the desired position and desired velocity, respectively, obtained by subtracting the desired position from the actual position and the desired velocity from the actual velocity. R e Ω Let x represent the tracking errors of the land-air multimodal robot system for the desired attitude and desired angular velocity, respectively, obtained by subtracting the actual attitude from the desired attitude and the actual angular velocity from the desired angular velocity. d For the desired position, x represents d The second derivative, Represents Ω d The first differential.

[0082] The motion controller is specifically:

[0083]

[0084]

[0085] In equations (3) and (4), r represents the turning radius, and l d This represents a user-defined distance along a planned ground movement path; the endpoint of this distance is called the aiming point. d This is called the aiming distance, where α represents the angle between the aiming point and the land-air multimodal robot system, and δ... f The value indicates the front wheel offset angle, and L indicates the wheelbase.

[0086] S200 sends corresponding operational mode commands according to the road segment where the land-air multimodal robot system is located. The autopilot receives the operational mode commands and controls the wing arm device to drive the wheel wing device to run along the pre-defined air flight path or ground operation path according to the control program.

[0087] Specifically, the operational modal commands include air flight commands and ground movement commands. When executing air flight commands, the land-air multimodal robot system executes the flight mode, controlling the land-air multimodal robot system to fly in the air through the designed geometric controller; when executing ground movement commands, the land-air multimodal robot system executes the ground mode, controlling the land-air multimodal robot system to move on the ground through the designed motion controller.

[0088] S300: Preset control coefficient threshold. The autopilot acquires the real-time status information of the land-air multimodal robot system during operation, calculates the control coefficient based on the real-time status information, and determines whether the current actual environment meets the conditions for continuing to execute the current operation mode command based on the control coefficient and the control coefficient threshold. If it meets the conditions, proceed to step S600; otherwise, proceed to step S400.

[0089] Specifically, the control coefficients include lift coefficient, roll coefficient, pitch coefficient, and yaw coefficient, where: the lift coefficient is used to adjust the lift provided by the motor to the land-air multimodal robot system; the roll coefficient is used to adjust the roll torque provided by the motor to the land-air multimodal robot system; the pitch coefficient is used to adjust the pitch torque provided by the motor to the land-air multimodal robot system; and the yaw coefficient is used to adjust the yaw torque provided by the motor to the land-air multimodal robot system.

[0090] In ground mode, the control coefficient threshold can generally be set to (0, 0.5]. The autopilot acquires the real-time status information of the land-air multimodal robot system during operation and calculates the control coefficients of the control program based on the real-time status information. If the calculated lift coefficient, roll coefficient, pitch coefficient, and yaw coefficient are all within the threshold range (0, 0.5), it is determined that the current actual environment meets the conditions for continuing to execute the current operation mode command. If any of the calculated control coefficients is greater than the upper limit of the threshold, it is determined that the current actual environment cannot continue to execute the current operation mode command, and it is necessary to switch the motion mode of the deformable land-air multimodal robot system.

[0091] In flight mode, the control coefficient threshold can generally be set to (0.5, 1]. The autopilot acquires the real-time status information of the land-air multimodal robot system during operation and calculates the control coefficients of the control program based on the real-time status information. If the calculated lift coefficient, roll coefficient, pitch coefficient, and yaw coefficient are all within the threshold range (0.5, 1), it is determined that the current actual environment meets the conditions for continuing to execute the current operation mode command. If any of the calculated control coefficients is greater than the upper limit of the threshold, it is determined that the current actual environment cannot continue to execute the current operation mode command, and it is necessary to switch the motion mode of the deformable land-air multimodal robot system.

[0092] Furthermore, the calculation method and judgment process of the control coefficient are as follows:

[0093] 1) Calculate the lift coefficient: The load weight of the land-air multimodal robot system can be collected by pressure sensors. Based on the load weight and the mass of the land-air multimodal robot, the lift force that the motors on the wheel device should provide for the land-air multimodal robot system is calculated. The lift force is normalized with the overall weight of the land-air multimodal robot system (including the load weight) as the upper limit to obtain the lift coefficient.

[0094] When the land-air multimodal robot system is in flight mode, the calculated lift coefficient is greater than 1, indicating that the motors cannot continuously provide the lift required for the overall weight of the land-air multimodal robot system to take off, and it needs to switch from flight mode to ground mode; or

[0095] When the land-air multimodal robot system is in ground mode, the calculated lift coefficient is greater than 0.5, indicating that the land-air multimodal robot system is experiencing hovering during operation, its driving state is unstable, and there is a possibility of rollover. Therefore, it is not suitable to continue driving on the ground and needs to switch from ground mode to flight mode.

[0096] 2) Calculate the roll coefficient: The actual roll angle and actual roll velocity of the land-air multimodal robot system are collected by the IMU module. The current roll angle balance torque is obtained by "proportional-integral-derivative" calculation based on the actual roll angle, target roll angle, and actual roll velocity. The current roll angle balance torque is normalized with the maximum roll angle balance torque that the motor can provide as the upper limit to obtain the roll coefficient.

[0097] When the land-air multimodal robot is in flight mode, if the calculated roll coefficient is greater than 1, it indicates that the maximum roll torque provided by the motors is insufficient for the robot to continue stable flight. The robot will then experience shaking and needs to switch from flight mode to ground mode; or

[0098] When the land-air multimodal robot system is in ground mode, the calculated roll coefficient is greater than 0.5, indicating that the roll angle of the land-air multimodal robot system fluctuates greatly and there is a risk of rollover. Therefore, it is not suitable to continue to travel on the ground and needs to switch from ground mode to flight mode.

[0099] 3) Calculate the pitch coefficient: The actual pitch angle and actual pitch velocity of the land-air multimodal robot system are collected by the IMU module. The current pitch angle balance torque is obtained by performing "proportional-integral-derivative" calculation based on the actual pitch angle, target pitch angle, and actual pitch velocity. The current pitch angle balance torque is normalized with the maximum pitch angle balance torque that the motor can provide as the upper limit to obtain the pitch coefficient.

[0100] When the land-air multimodal robot is in flight mode, if the calculated pitch coefficient is greater than 1, it indicates that the maximum pitch torque provided by the motors is insufficient for the robot to continue stable flight. The robot is about to flip and needs to switch from flight mode to ground mode; or

[0101] When the land-air multimodal robot system is in ground mode, the calculated pitch coefficient is greater than 0.5, indicating that the pitch angle of the land-air multimodal robot system fluctuates greatly, and the forward and backward tilting amplitudes are too large, which can easily lead to rollover. Therefore, it is not suitable to continue driving on the ground and needs to switch from ground mode to flight mode.

[0102] 4) Calculate the yaw coefficient: The actual yaw angle and actual yaw rate are collected by the IMU module. The "proportional-integral-derivative" calculation is performed based on the actual yaw angle, target yaw angle, and actual yaw rate to obtain the current yaw angle balance torque. The current yaw angle balance torque is normalized with the maximum yaw angle balance torque that the motor can provide as the upper limit to obtain the yaw coefficient.

[0103] When the land-air multimodal robot system is in flight mode, if the calculated yaw coefficient is greater than 1, it indicates that the maximum yaw torque provided by the motors is insufficient to keep the system flying smoothly. The system is about to deviate from its target and needs to switch from flight mode to ground mode; or

[0104] When the land-air multimodal robot system is in ground mode, the calculated yaw coefficient is greater than 0.5, indicating that the yaw angle of the land-air multimodal robot system fluctuates greatly at this time, that is, the orientation to the destination is constantly changing. If it continues to travel on the ground, it may deviate from the destination. Therefore, it is not suitable to continue traveling on the ground and it is necessary to switch from ground mode to flight mode.

[0105] 5) The visual sensor collects image information to judge the road conditions ahead of the land-air multimodal robot. When the land-air multimodal robot system is in flight mode, there are tall buildings ahead that are not suitable for flight, or when the land-air multimodal robot system is in ground mode, there are obstacles ahead that prevent passage.

[0106] The system uses image information acquired by visual sensors to assess the road conditions ahead of the land-air multimodal robot system.

[0107] When the land-air multimodal robot system is in flight mode, if the road conditions or buildings ahead are not suitable for flying through or entering, it will switch from flight mode to ground mode.

[0108] When the land-air multimodal robot system is in ground mode, if there is an obstacle in front that cannot be directly crossed or bypassed, it will switch from ground mode to flight mode.

[0109] The S400 and autopilot control the wing arm device to drive the wheel wing device to the designated position, enabling the land-air multimodal robot system to complete the motion mode switching.

[0110] Furthermore, the motion modes include flight modes and ground modes, and S400 specifically includes:

[0111] If the current motion mode is flight mode, the autopilot 20 controls the second servo 300 to rotate vertically downwards until the wheel wing device 40 is driven to a vertical position, making the plane of the wheel wing device 40 perpendicular to the plane of the upper rectangular plate of the main body 10, thus completing the switch from flight mode to ground mode; or

[0112] If the current motion mode is ground mode, the autopilot 20 controls the first servo 301 to drive the second servo 300 through the connector 302 to adjust the orientation of the wheel wing device 40 to face forward without deflection. Then the second servo 300 rotates vertically upward to drive the wheel wing device 40 to a horizontal position, so that the wheel wing device 40 and the plane of the upper rectangular plate of the body 10 are parallel, thus completing the switch from ground mode to flight mode.

[0113] Specifically, when the land-air multimodal robot system is in the air flight mode ( Figure 1 To switch from airborne flight mode to ground motion mode, the following steps are involved:

[0114] (a) The land-air multimodal robot system flies to the designated location and begins fixed-point hovering flight;

[0115] (b) The land-air multimodal robot system descends slowly. The second servo motors 300 on the left and right front wings rotate downward from the vertical direction to the horizontal position. The wheel-wing devices 40 installed on the left and right front wings rotate from the horizontal position to the vertical position during the descent and then contact the ground to become ground moving wheels. The wheel-wing devices 40 installed on the left and right rear wings still maintain the horizontal position and generate lift to control the balance of the land-air multimodal robot system.

[0116] (c) When the wheel wing device 40 on the left and right front wing arms is successfully converted into a ground moving wheel, the second servo motor 300 on the left and right rear wing arms begins to rotate from the vertical position to the horizontal position. After the wheel wing device 40 installed on the left and right rear wing arms rotates from the horizontal position to the vertical position, it contacts the ground and becomes a ground moving wheel.

[0117] After the aforementioned mode switching, the land-air multimodal robot system switches from flight mode to ground mode. In ground mode, all four wheel wing devices are in contact with the ground and perpendicular to it. Then, motor 401 drives the drive gear 406 to rotate, which in turn drives the driven gear 407, thereby rotating the wheel hub 405, providing power to the land-air multimodal robot system. The first servo motor 301 on each wing arm is used to control direction.

[0118] When the land-air multimodal robot system is in the ground motion mode ( Figure 2To switch from ground motion mode to aerial flight mode, the specific steps are the reverse of those for switching from aerial flight mode to ground motion mode, and will not be repeated here. However, it should be noted that in this case, the autopilot 20 first controls the first servo motor 301 on the four wing arms (left front wing arm 31, right front wing arm 32, left rear wing arm 33, and right rear wing arm 34) to drive the second servo motor 300 through the connector 302 to adjust the orientation of the wheel-wing device 40 to face forward without any deflection. This ensures that when the wheel-wing device 40 is subsequently driven to a horizontal position by the second servo motor 300, there will be no friction or collision between the wheel-wing devices 40. Then, the second servo motor 300 rotates vertically upward relative to the connector 302, driving the wheel-wing device 40 to a horizontal position. In flight mode, the wheel-wing device 40 provides lift for the land-air multimodal robot system.

[0119] The S500 and autopilot acquire real-time status information of the land-air multimodal robot system during operation after switching modes. Based on the real-time status information, they calculate and adjust control coefficients to make the real-time path approximate the predefined air flight path or ground operation path.

[0120] When adjusting the control coefficient, the adjustment variable of the control coefficient changes in a direct proportion.

[0121] The S600 autopilot acquires the real-time position of the land-air multimodal robot system, compares the real-time position with the destination position, and if the real-time position is near the destination position, it determines that the land-air multimodal robot system has reached the destination and ends motion control.

[0122] The aforementioned deformable land-air multimodal robot system and motion control method include a main body, an autopilot, wing arms, and wheel-wing devices. The autopilot is fixedly mounted on the main body, the wing arms are symmetrically mounted on the sides of the main body, and the wheel-wing devices are rotatably mounted at the ends of the wing arms. The main body serves as the structural skeleton, carrying and connecting other components. The autopilot acquires the motion state information of the land-air multimodal robot and executes a preset control program, controlling the wing arms to drive the wheel-wing devices to a designated position, thus achieving motion mode switching and operation. This system features a simple structure, low power consumption, strong environmental adaptability, good stability, and high mobility, possessing multimodal operation capabilities and meeting the task requirements in various complex and harsh scenarios.

[0123] The above provides a detailed description of a deformable land-air multimodal robot system and its motion control method provided by the present invention. Specific examples have been used to illustrate the principles and implementation methods of the invention, and the descriptions of the embodiments are merely for the purpose of helping to understand the core ideas of the invention. It should be noted that those skilled in the art can make various improvements and modifications to the invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A deformable land-air multimodal robot system, characterized in that, include: The system comprises a main body (10), an autopilot (20), a wing arm assembly (30), and a wheel assembly (40). The autopilot (20) is fixedly mounted on the main body (10). The wing arm assembly (30) is symmetrically mounted on the sides of the main body (10). The wheel assembly (40) is rotatably mounted on the end of the wing arm assembly (30). The main body (10) is generally rectangular, consisting of two layers of hollowed-out rectangular plates, which serve as a structural skeleton to support and connect other components; The autopilot (20) is used to acquire motion state information of the land and air multimodal robot and execute a preset control program to control the wing arm device (30) to drive the wheel wing device (40) to the designated position, thereby realizing the switching and operation of motion modes; The motion control method for deformable land-air multimodal robotic systems includes the following steps: S100. Design the control program, set the starting point and ending point according to the task requirements and complete the path planning. Place the land and air multimodal robot system at the starting point, divide the planned path into an air flight path and a ground movement path according to the road conditions, and store the designed control program and the divided air flight path and ground movement path in the autopilot. S200 sends the corresponding operation mode command according to the path of the land and air multimodal robot system. The autopilot receives the operation mode command and controls the wing arm device to drive the wheel wing device to run along the divided air flight path or ground operation path according to the control program. S300: Preset control coefficient thresholds. The autopilot acquires real-time status information of the land-air multimodal robot system during operation and calculates control coefficients based on the real-time status information. The control coefficients include lift coefficient, roll coefficient, pitch coefficient, and yaw coefficient. The lift coefficient is used to adjust the lift provided by the motor to the land-air multimodal robot system; the roll coefficient is used to adjust the roll torque provided by the motor to the land-air multimodal robot system; the pitch coefficient is used to adjust the pitch torque provided by the motor to the land-air multimodal robot system; and the yaw coefficient is used to adjust the yaw torque provided by the motor to the land-air multimodal robot system. Based on the control coefficients and control coefficient thresholds, it is determined whether the current actual environment meets the conditions for continuing to execute the current operation mode command. If the calculated lift coefficient, roll coefficient, pitch coefficient, and yaw coefficient are all within the threshold range, then step S600 is executed; otherwise, step S400 is executed. The S400 and autopilot control the wing arm device to drive the wheel wing device to the designated position, enabling the land-air multimodal robot system to complete the motion mode switching; The S500 and autopilot acquire real-time status information of the land-air multimodal robot system during operation after switching modes, calculate and adjust control coefficients based on the real-time status information, and make the real-time path close to the predefined air flight path or ground operation path. The S600 autopilot acquires the real-time position of the land-air multimodal robot system, compares the real-time position with the destination position, and if the real-time position is near the destination position, it determines that the land-air multimodal robot system has reached the destination and ends motion control.

2. The deformable land-air multimodal robot system according to claim 1, characterized in that, The wing arm assembly (30) includes a left front wing arm (31), a right front wing arm (32), a left rear wing arm (33), and a right rear wing arm (34) that are identical in structure and symmetrically mounted on the side of the main body (10) in an X-shape. The left front wing arm (31) and the right rear wing arm (34) are located on the same diagonal line, and the right front wing arm (32) and the left rear wing arm (33) are located on the same diagonal line.

3. The deformable land-air multimodal robot system according to claim 2, characterized in that, Each wing arm includes a second servo (300), a first servo (301), and a connector (302). One end of the first servo (301) is fixedly mounted on the main body (10), and the other end of the first servo (301) is connected to the second servo (300) through the connector (302). The second servo (300) can rotate relative to the first servo (301). The wheel wing device (40) is fixedly mounted on the second servo (300). The wheel wing device (40) can be in a horizontal or vertical position under the drive of the second servo (300), so as to be parallel or perpendicular to the plane of the upper rectangular plate of the main body (10).

4. The deformable land-air multimodal robot system according to claim 3, characterized in that, The wheel assembly (40) includes a rotor mechanism (41) and a wheel mechanism (42), which are rotatably connected by a drive shaft.

5. The deformable land-air multimodal robot system according to claim 4, characterized in that, The rotor mechanism (41) includes a propeller (400) and a motor (401). The propeller (400) is fixedly mounted on the end of the drive shaft of the motor (401). The wheel mechanism (42) includes a first axle seat (402), a second axle seat (403), several spokes (404), a hub ring (405), a drive gear (406), and a pair of driven gears (407). The first axle seat (402) and the second axle seat (403) are fixedly connected. The motor (401) is embedded in the first axle seat (402). 02) and the second shaft seat (403), the drive gear (406) is fixedly installed on the drive shaft of the motor (401) and close to the first shaft seat (402), several spokes (404) are arranged between the first shaft seat (402) and the second shaft seat (403) and the hub ring (405), the hub ring (405) is provided with an internal gear, the drive gear (406) meshes with a pair of driven gears (407), and the pair of driven gears (407) meshes with the internal gear on the hub ring (405).

6. The deformable land-air multimodal robot system according to claim 5, characterized in that, Several spokes (404) are flat.

7. The deformable land-air multimodal robot system according to claim 6, characterized in that, The autopilot (20) includes an onboard computer and a data transmission radio connected to the onboard computer, a remote control receiver, a pressure sensor, a power module, an IMU module, a vision sensor, and a GPS module, wherein: The power module is used to provide power to the onboard EEG; The IMU module is used to sense the position, attitude, and velocity of the land-air multimodal robot system and send the position, attitude, and velocity information to the onboard computer. The GPS module is used to obtain the real-time position coordinates of the land-air multimodal robot system and send the real-time position coordinate information to the onboard computer; Visual sensors are used to perceive the environment in front of the land-air multimodal robotic system and send the acquired image information to the onboard computer; Pressure sensors are used to collect load information from the land-air multimodal robot system and send the collected load information to the onboard computer. The remote control receiver is used to receive control commands from the remote control transmitter and send the control commands to the onboard computer; The onboard computer receives position, attitude, and velocity information, real-time position coordinate information, image information, load information, and control commands from the land-air multimodal robot system and runs a preset control program to enable the land-air multimodal robot system to operate in different modes. The data transmission radio is used to transmit the operational status information of the land-air multimodal robot system in different modes to the ground control station.

8. The deformable land-air multimodal robot system according to claim 7, characterized in that, The IMU module includes a three-axis gyroscope, a three-axis accelerometer, and a three-axis magnetometer, which are used to detect the three-axis angular velocity, three-axis acceleration, and the components of the geomagnetic intensity on the x, y, and z axes of the land-air multimodal robot, respectively.

9. A motion control method for a deformable land-air multimodal robot system, characterized in that, The motion control method includes the following steps: S100. Design the control program, set the starting point and ending point according to the task requirements and complete the path planning. Place the land and air multimodal robot system at the starting point, divide the planned path into an air flight path and a ground movement path according to the road conditions, and store the designed control program and the divided air flight path and ground movement path in the autopilot. S200 sends the corresponding operation mode command according to the path of the land and air multimodal robot system. The autopilot receives the operation mode command and controls the wing arm device to drive the wheel wing device to run along the divided air flight path or ground operation path according to the control program. S300: Preset control coefficient thresholds. The autopilot acquires real-time status information of the land-air multimodal robot system during operation and calculates control coefficients based on the real-time status information. The control coefficients include lift coefficient, roll coefficient, pitch coefficient, and yaw coefficient. The lift coefficient is used to adjust the lift provided by the motor to the land-air multimodal robot system; the roll coefficient is used to adjust the roll torque provided by the motor to the land-air multimodal robot system; the pitch coefficient is used to adjust the pitch torque provided by the motor to the land-air multimodal robot system; and the yaw coefficient is used to adjust the yaw torque provided by the motor to the land-air multimodal robot system. Based on the control coefficients and control coefficient thresholds, it is determined whether the current actual environment meets the conditions for continuing to execute the current operation mode command. If the calculated lift coefficient, roll coefficient, pitch coefficient, and yaw coefficient are all within the threshold range, then step S600 is executed; otherwise, step S400 is executed. The S400 and autopilot control the wing arm device to drive the wheel wing device to the designated position, enabling the land-air multimodal robot system to complete the motion mode switching; The S500 and autopilot acquire real-time status information of the land-air multimodal robot system during operation after switching modes, calculate and adjust control coefficients based on the real-time status information, and make the real-time path close to the predefined air flight path or ground operation path. The S600 autopilot acquires the real-time position of the land-air multimodal robot system, compares the real-time position with the destination position, and if the real-time position is near the destination position, it determines that the land-air multimodal robot system has reached the destination and ends motion control.

10. The motion control method for the deformable land-air multimodal robot system according to claim 9, characterized in that, Motion modes include flight modes and ground modes. Specifically, the S400 includes: If the current motion mode is flight mode, the autopilot (20) controls the second servo (300) to rotate vertically downwards until the wheel wing device (40) is driven to a vertical position, making the plane where the wheel wing device (40) and the upper rectangular plate of the main body (10) are perpendicular, thus completing the switch from flight mode to ground mode; or If the current motion mode is ground mode, the autopilot (20) controls the first servo (301) to drive the second servo (300) through the connector (302) to adjust the orientation of the wheel device (40) to face forward without deflection. Then the second servo (300) rotates vertically upward to drive the wheel device (40) to a horizontal position, so that the plane where the wheel device (40) and the upper rectangular plate of the body (10) are parallel is completed, thus completing the switch from ground mode to flight mode.

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