Bionic frog jumping robot and control method thereof

Abstract

The invention discloses a bionic frog jumping robot and a control method thereof, and belongs to the technical field of bionic machinery. Comprising a bottom plate, a leg mechanism, a driving mechanism and a multi-mode control system, the multi-mode control system comprises a nine-axis inertial sensor, a front leg steering engine, a rear leg steering engine, a posture adjusting flywheel, a flywheel driving motor, a damping mechanism and a control module; the driving mechanism comprises a gear-rack assembly and an energy storage spring; the rear leg mechanism is of a multi-stage connecting rod structure, the shape of the multi-stage connecting rod structure of the rear leg mechanism is changed through a gear-rack assembly, and the multi-stage connecting rod structure stretches out and draws back to simulate stretching out and drawing back of the legs of the frog so that stored energy of an energy storage spring can be converted into jumping driving force. A multi-stage connecting rod structure and a gear-rack transmission mechanism are cooperatively designed, the jumping action is driven through a spring energy storage and release mechanism, and the energy utilization efficiency is improved in combination with a lightweight fuselage; a posture adjusting flywheel is integrated at the gravity center position of the robot and works cooperatively with a multi-axis sensor, and multi-mode control is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of bionic machinery, and particularly relates to a bionic frog jumping robot and a control method thereof. Background Art

[0002] As a rapidly developing research field, bionic robots cover the research of bionics principles, the development and application of prototype designs. In recent years, bionic robots have been widely studied and practically applied in environments with complex terrains, especially in the fields of exploration of complex terrains such as mountains, steps, mud, etc. and performing dangerous tasks. Bionic robots have characteristics such as autonomous movement and intelligent decision-making, and have become key devices in many high-tech applications. For example, the quadruped bionic robot BIGDOG developed by Boston Dynamics in the United States can walk stably on complex road surfaces such as snow and ice, and can autonomously maintain stability after being impacted by the outside world. The quadruped bionic robot in Russia is equipped with medium-caliber weapons and can be used for combat tasks in complex environments; countries such as Germany, Italy, and South Korea have also carried out relevant technical research and achieved remarkable progress. In China, nearly ten research institutions are committed to the research and development of quadruped bionic unmanned platforms. However, these high-end bionic robots usually have complex structures and high costs, and are more applied in the military field and are difficult to be widely applied in the civilian field. Therefore, in order to meet civilian needs and better integrate bionic robots into daily life, it is of great practical significance to develop a bionic robot with a simple structure and low cost. Summary of the Invention

[0003] Aiming at the defects of the prior art, the present invention uses a gear-rack transmission mechanism for power transmission, which has the advantages of simple working principle, compact structure, easy control and manufacture, etc. And through the combination with the multi-stage link structure and multi-modal control system of the robot's hind legs to simulate the jumping motion of a frog, the design of the robot effectively realizes the control and optimization of the jumping behavior, so as to realize the detection and adaptation of multi-terrains.

[0004] To achieve the above object, the present invention provides a bionic frog jumping robot, including: a bottom plate, a leg mechanism, a driving mechanism, and a multi-modal control system;

[0005] The multi-modal control system includes a nine-axis inertial sensor, a front leg servo, a hind leg servo, an attitude adjustment flywheel, a flywheel drive motor, a shock absorption mechanism, and a control module;

[0006] The driving mechanism includes a gear-rack assembly and a energy storage spring;

[0007] The leg mechanism includes a front leg mechanism and a rear leg mechanism. The front leg mechanism is connected to a front leg servo through a shock absorption mechanism, and the front leg servo is fixed on the bottom plate through a servo fixing bracket. The rear leg mechanism is a multi-stage linkage structure, connected to a storage spring, and connected to a rear leg servo through a gear-rack assembly. The rear leg servo changes the shape of the multi-stage linkage structure of the rear leg mechanism through the gear-rack assembly, so that it can stretch and contract to simulate the stretching and contracting of a frog's legs to convert the stored energy of the storage spring 16 into a jumping driving force.

[0008] The attitude adjustment flywheel is located at the center of gravity of the robot and is connected to the flywheel driving motor. The flywheel driving motor, the nine-axis inertial sensor, and the control module are all installed on the bottom plate. The control module is respectively connected to the nine-axis inertial sensor, the front leg servo, the rear leg servo, and the flywheel driving motor for control and data transceiver.

[0009] Further, the multi-stage linkage structure of the rear leg mechanism is as follows: The steel pipe fixing bracket is horizontally fixed at the end of the bottom plate, and steel pipes are vertically fixed at both ends thereof, and the steel pipes are parallel to the bottom plate (20). The gear connecting frame is slidably connected to the two steel pipes so that it can move along the direction of the steel pipes. The two ends of the gear connecting frame are respectively rotatably connected to the first link. The first link is rotatably connected to the second link. The second link is simultaneously rotatably connected to the third link and the fourth link. The third link is simultaneously rotatably connected to the steel pipe fixing bracket.

[0010] The fourth link is rotatably connected to the fifth link and is simultaneously connected to the extended end of the spring link connected to the bottom plate through a spring mechanism. The fifth link is an L-shaped link, and the other end of the L-shape is rotatably connected to the sixth link. The inflection point position of the L-shape is rotatably connected to the bottom plate connection end of the spring link of the bottom plate. The seventh link serves as the output link of the multi-stage linkage structure, and the end is rotatably connected to the foot of the robot, and the other end is rotatably connected to the extended end of the spring link of the bottom plate and the spring mechanism, and the middle position is rotatably connected to the sixth link.

[0011] The gear-rack assembly is: the third gear, the second gear, and the first toothless gear are connected in sequence, and at the same time, the first toothless gear meshes with the rack. The first toothless gear has teeth missing on its circumference, forming a periodic transmission interruption window, and is symmetrically distributed with double helical teeth to cancel the axial force.

[0012] The third gear is rigidly connected to the rear leg servo through a keyway, and the first toothless gear is connected to the gear connecting frame, coordinating the rear leg servo, the gear-rack assembly, and the multi-stage linkage structure of the rear leg mechanism.

[0013] The hind leg servo controls the operation of the gear-rack assembly. When the first toothless gear meshes with the rack, energy is stored by rigidly driving and compressing the energy storage spring. At this time, the upper part of the fifth connecting rod moves backward, and the lower part moves forward, putting the robot in a compressed state. When in the toothless section, the gear is allowed to rotate idly. At this time, the energy storage spring releases energy, the upper part of the fifth connecting rod moves forward, and the lower part moves backward, causing the hind leg mechanism to unfold again, converting the rotational motion into a parabolic trajectory of the foot to simulate a biological jumping motion.

[0014] Furthermore, a damping ball is installed at the bottom end of the front leg mechanism;

[0015] The shock absorption device uses a helical compression spring, and a rubber buffer block is set at its elastic limit position. One end is connected to the front leg mechanism, and the other end is connected to the front leg servo through the upper support structure of the robot.

[0016] Furthermore, there are two front leg servos, which respectively control two front leg mechanisms through two shock absorption mechanisms; there is only one hind leg servo, which is connected to the multi-stage connecting rod structures of two hind leg mechanisms and two energy storage springs respectively through the gear-rack assembly.

[0017] The present invention also provides a control method for a bionic frog jumping robot. Based on the above-mentioned bionic frog jumping robot, it includes the following steps:

[0018] (1) Real-time obtain the data of the nine-axis inertial sensor, and obtain the acceleration and angle information of the robot through quaternion calculation;

[0019] (2) According to the angle information, and in combination with the attitude adjustment flywheel, judge the takeoff stability;

[0020] (3) If it is judged that takeoff is possible, the energy of the energy storage spring is released through the cooperation of the first toothless gear and the rack in the gear-rack assembly to complete the takeoff of the robot;

[0021] (4) After the robot takes off, according to the angle information obtained in real time, use the flywheel drive motor to perform closed-loop control on the attitude adjustment flywheel to maintain the aerial attitude balance;

[0022] (5) When it is judged that the robot is approaching the ground, complete the landing of the robot through the shock absorption mechanism and adjusting the closed-loop control parameters of the flywheel drive motor in the adjustment step.

[0023] Furthermore, the acceleration information obtained in the above steps includes the acceleration along the X-axis, the acceleration along the Y-axis, and the acceleration along the Z-axis; the angle information includes the pitch angle of the rotation angle around the X-axis, the roll angle of the rotation angle around the Y-axis, and the yaw angle of the rotation angle around the Z-axis.

[0024] Furthermore, the specific content of the step (2) is:

[0025] (2.1) Calculate the rate of change of the pitch angle, roll angle, and yaw angle obtained in real time respectively to obtain the angular velocity.

[0026] (2.2) If all the obtained angular velocities are less than the angular velocity threshold, and the pitch angle, roll angle, and yaw angle are all within the predetermined angle threshold range, it is preliminarily determined that a takeoff can be made. Record the current angle information and enter step (2.3); otherwise, abandon the takeoff.

[0027] (2.3) Start the attitude adjustment flywheel and close it after the preset time. Obtain the angle information at this time in real time. If the angle change values of the pitch angle and roll angle before and after starting are less than the preset angle difference threshold, the takeoff condition is met. If the change value before and after starting is greater than or equal to the preset angle difference threshold, start the attitude adjustment flywheel again until the takeoff condition is met or the preset takeoff time is reached and still not met, then abandon the takeoff.

[0028] Further, the specific content of step (3) is as follows:

[0029] (3.1) Drive the gear-rack assembly to rotate through the rear leg servo, and then drive the multi-link structure of the rear leg mechanism to compress the energy storage spring backward to store energy.

[0030] (3.2) Adjust the angles of the two front leg mechanisms (2) through two front leg servos (4).

[0031] Adjust the angles of the two front leg servos (4) progressively according to the following formula, so that the pitch angle of the robot approaches the target pitch angle and the roll angle approaches the target roll angle.

[0032] α = α0 + K·(θ targe_pitch -θ curren_pitch )

[0033] α Δ + = K·(θ target_roll -θ current_roll )

[0034] α left = α + α Δ

[0035] α right = α - α Δ

[0036] α0 = α

[0037] Where: The initial α0 is the reference deployment angle, K is the proportionality coefficient, θ target_pitch is the target pitch angle, θ curren_pitch is the pitch angle obtained in real time currently; θ target_roll is the target roll angle, θ current_rollis the current roll angle obtained in real time; α left is the left front leg servo angle, α right is the right front leg servo angle;

[0038] (3.3) The gear-rack assembly runs to the toothless section of the first toothless gear, and the first toothless gear disengages from the rack. The energy storage spring rebounds, causing the multi-link structure of the hind leg mechanism to open, completing the robot's takeoff.

[0039] Further, the step (4) is specifically as follows:

[0040] (4.1) Calculate the angle deviation of the pitch angle according to the pitch angle obtained in real time;

[0041] Δφ = φ current - φ target

[0042] where: θ target is the target pitch angle, θ current is the pitch angle obtained in real time currently;

[0043] (4.2) Calculate the dynamic compensation term u according to the angle deviation:

[0044]

[0045] K p (Δφ) = K p0 + λ·|Δφ|

[0046]

[0047] C loss (ω current ) = K c * ω curren

[0048] where: ω_max, K p0 , , K c , ω_th are set parameters;

[0049] (4.3) The flywheel drive motor controls the speed of the attitude adjustment flywheel through the field-oriented control algorithm according to the dynamic compensation term u to maintain the aerial attitude balance;

[0050]

[0051] where: ω current is the current speed of the attitude adjustment flywheel, ω target is the adjusted speed of the attitude adjustment flywheel, I flywhee is the moment of inertia of the attitude adjustment flywheel, and Δt is the adjustment period of the attitude adjustment flywheel.

[0052] Further, step (5) is specifically as follows:

[0053] When the acceleration information along the Z-axis obtained in real time is greater than the set landing threshold, it is determined that the robot is approaching the ground;

[0054] Adjust the deployment angle of the front leg mechanism to the landing set value through the front leg servo;

[0055] According to the control method in step (4) and adjust the parameters K p0 、 、K c , perform closed-loop control on the attitude adjustment flywheel through the flywheel drive motor to complete the landing of the robot.

[0056] Advantages of the present invention:

[0057] 1. The present invention adopts the collaborative design of gear-rack transmission and multi-stage link mechanism, with a compact mechanical structure and efficient power transmission, significantly reducing the manufacturing cost and maintenance difficulty.

[0058] 2. The present invention realizes the simplified control of bionic jumping actions through the precise cooperation of servos and multi-stage gears, improving the system response speed and reliability.

[0059] 3. The present invention combines the toothless gear trigger mechanism with the spring energy storage release, with high energy conversion efficiency and reduced driving energy consumption. The landing impact force assists the spring pre-compression to realize the recycling of energy and improve the system energy efficiency ratio.

[0060] 4. The present invention integrates a nine-axis sensor and an attitude adjustment flywheel, and reduces the air attitude error through a closed-loop control algorithm (adaptive PID and smoothing differential suppression) to make it land stably.

[0061] 5. The front leg shock absorption mechanism of the present invention can reduce the peak impact force and adapt to continuous jumps on complex terrains such as slopes and gravel.

[0062] 6. The lightweight body design of the present invention supports the expansion of peripherals such as cameras and environmental sensors, and is suitable for high-mobility scenarios such as disaster rescue and search, and dynamic environment monitoring. Description of the Drawings

[0063] Figure 1 It is a schematic structural diagram of the bionic frog jumping robot according to an embodiment of the present invention.

[0064] Figure 2 It is a side view of the bionic frog jumping robot according to an embodiment of the present invention.

[0065] Figure 3 It is a top view of the bionic frog jumping robot according to an embodiment of the present invention.

[0066] Figure 4 This is a schematic diagram of the gear-rack assembly structure of the bionic frog jumping robot according to an embodiment of the present invention.

[0067] Figure 5 This is a schematic diagram of the front leg structure of the bionic frog jumping robot according to an embodiment of the present invention.

[0068] Figure 6 This is a partial schematic diagram of the hind leg structure of the bionic frog jumping robot according to an embodiment of the present invention. Detailed implementation manners

[0069] The present invention will be further explained and described below with reference to the accompanying drawings and embodiments.

[0070] As Figures 1-3 shown, the present invention provides a bionic frog jumping robot, including: a bottom plate 20, a leg mechanism, a driving mechanism, and a multi-modal control system. The multi-modal control system includes a nine-axis inertial sensor, a front leg servo 4, a hind leg servo 12, an attitude adjustment flywheel 6, a flywheel driving motor 7, a shock absorption mechanism 3, and a control module. The driving mechanism includes a gear-rack assembly and a energy storage spring 16. The leg mechanism includes a front leg mechanism 2 and a hind leg mechanism.

[0071] As Figure 5 shown, the front leg mechanism 2 is controlled by two independent front leg servos 4. The front leg mechanism 2 is connected to the front leg servo 4 through the shock absorption mechanism 3, and the front leg servo 4 is fixed on the bottom plate 20 through a servo fixing bracket 5. The shock absorption device 3 uses a helical compression spring, and a rubber buffer block is arranged at its elastic limit position. One end is connected to the front leg mechanism 2, and the other end is connected to the front leg servo 4 through the upper support structure of the robot. The outputs of the front leg servos 4 are respectively transmitted to the two front leg mechanisms 2 of the bionic frog to complete forward, backward, and turning actions. At the same time, a damping ball 1 is installed at the bottom end of the front leg mechanism. By cooperating with the shock absorption device 3, it helps the bionic frog jumping robot land smoothly and complete various actions smoothly.

[0072] The hind-leg structure is a multi-stage linkage structure, which is connected to the energy storage spring 16 and connected to the hind-leg servo 12 through a gear-rack assembly. The hind-leg servo 12 changes the shape of the multi-stage linkage structure of the hind-leg mechanism through the gear-rack assembly, making it stretch and contract to simulate the stretching and contracting of a frog's leg for converting the stored energy of the energy storage spring 16 into jumping driving force. The multi-stage linkage structure of the hind-leg mechanism is as follows: the steel pipe fixing bracket 14 is horizontally fixed at the end of the bottom plate 20, and steel pipes 24 are vertically fixed at both ends thereof, and the steel pipes 24 are parallel to the bottom plate 20; the gear connecting bracket 23 is slidably connected to the two steels 24, and the gear connecting bracket 23 can move along the direction of the steel pipes 24; both ends of the gear connecting bracket 23 are rotatably connected to the first link 22 respectively; the first link 22 is rotatably connected to the second link 11; the second link 11 is rotatably connected to the third link 13 and the fourth link 15 at the same time; the third link 13 is rotatably connected to the steel pipe fixing bracket 14 at the same time. The fourth link 15 is rotatably connected to the fifth link 19, and is simultaneously connected to the extending end of the spring link connecting the bottom plate 20 through the spring mechanism 16; the fifth link 19 is an L-shaped link, and the other end of the L-shape is rotatably connected to the sixth link 18, and the inflection point position of the L-shape is rotatably connected to the bottom plate connecting end of the spring link of the bottom plate 20; the seventh link (17) is used as the output link of the multi-stage linkage structure, the end is rotatably connected to the robot foot, the other end is rotatably connected to the extending end of the spring link of the bottom plate 20 and the spring mechanism (16), and the middle position is rotatably connected to the sixth link 18; as Figure 6 shown, the fifth link 19, the sixth link 18, and the seventh link 17 form a four-bar linkage structure.

[0073] As Figure 4 shown, the gear-rack assembly is: the third gear 10, the second gear 9, and the first toothless gear 8 are connected in sequence, and at the same time the first toothless gear 8 meshes with the rack 21. The first toothless gear 8 has teeth missing on its circumference, forming a periodic transmission interruption window, and is symmetrically distributed with double helical teeth to offset the axial force.

[0074] The third gear 10 is rigidly connected to the hind-leg servo 12 through a keyway, so that the gear-rack assembly can rotate under the drive of the hind-leg servo 12; the first toothless gear 8 is connected to the gear connecting bracket 23, so that the gear connecting bracket 23 can move with the rotation of the first toothless gear 8; therefore, the hind-leg servo 12, the gear-rack assembly and the multi-stage linkage structure of the hind-leg mechanism can work together. There is only one hind-leg servo, which is connected to the multi-stage linkage structures of the two groups of hind-leg structures and the two groups of energy storage springs 16 respectively through the gear-rack assembly.

[0075] The working principle of the hind-leg mechanism is as follows: The hind-leg servo 12 controls the operation of the gear-rack assembly. Through rigid transmission in the meshing section of the first toothless gear 8 and the rack 21, the gear connecting frame 23 moves backward along the steel pipe 24, thereby driving the fourth connecting rod 15 to compress the spring device 16 backward. At the same time, the upper part of the fifth connecting rod 19 moves backward and the lower part moves forward, driving the seventh connecting rod 17 to rotate clockwise, making the robot in a compressed state; in the toothless section, the gear is allowed to idle. At this time, the energy storage spring 16 releases energy, the gear connecting frame 23 moves forward along the steel pipe 24, the upper part of the fifth connecting rod 19 moves forward and the lower part moves backward, driving the seventh connecting rod 17 to rotate counterclockwise, so that the hind-leg mechanism is re-expanded, converting the rotational motion into a parabolic trajectory of the foot, simulating the biological jumping action.

[0076] The attitude adjustment flywheel is located at the center of gravity of the robot and is connected to the flywheel drive motor for controlling the stability of the robot. The flywheel drive motor 7, the nine-axis inertial sensor and the control module are all installed on the bottom plate 20; the control module is respectively connected to the nine-axis inertial sensor, the front-leg servo 4, the hind-leg servo 12 and the flywheel drive motor 6 for control and data transceiver.

[0077] The embodiment of the present invention also provides a control method for a bionic frog jumping robot. Based on the above bionic frog jumping robot, it includes the following steps:

[0078] S101. Obtain the nine-axis inertial sensor data in real time, and obtain the acceleration and angle information of the robot through quaternion calculation.

[0079] Based on the gyroscope and accelerometer data of the nine-axis inertial sensor, calculate the acceleration and angle based on the quaternion method.

[0080] The information includes the acceleration along the X axis, the acceleration along the Y axis, and the acceleration along the Z axis.

[0081] The angle information includes the pitch angle of the rotation angle around the X axis, the roll angle of the rotation angle around the Y axis, and the yaw angle of the rotation angle around the Z axis.

[0082] S102. According to the angle information, and combined with the attitude adjustment flywheel 6, judge the takeoff stability.

[0083] (1) According to the pitch angle, roll angle and yaw angle obtained in real time, calculate their change rates respectively to obtain the angular velocity.

[0084] (2) If all the obtained angular velocities are less than the angular velocity threshold, and the pitch angle, roll angle and yaw angle are all within the predetermined angle threshold range, it is initially determined that takeoff is possible, record the current angle information, and enter step (3); otherwise, abandon takeoff.

[0085] Under rational conditions, to meet the takeoff determination, all angular velocities should be equal to 0, that is, in a stationary state. In practice, it can be set to be less than a certain value.

[0086] (3) After starting the attitude adjustment flywheel 6 for a preset time (such as 0.5 - 1 second) and then turning it off, obtain the angle information in real time. If the angle change values of the pitch angle and roll angle before and after startup are less than the preset angle difference threshold, the takeoff condition is met. If the change values before and after startup are greater than or equal to the preset angle difference threshold, start the attitude adjustment flywheel 6 again until the takeoff condition is met or the preset takeoff time is reached but still not met, then abandon the takeoff.

[0087] S103. If it is determined that takeoff is possible, through the cooperation of the first tooth - missing gear 8 and the rack 21 in the gear - rack assembly, store and release the energy of the energy - storage spring 16 to complete the robot's takeoff.

[0088] (1) Drive the gear - rack assembly to rotate through the hind - leg servo 12, and then drive the multi - link structure of the hind - leg mechanism to compress the energy - storage spring 16 backward to store energy for it.

[0089] (2) Adjust the angles of the two front - leg mechanisms 2 through the two front - leg servos 4.

[0090] Gradually adjust the angles of the two front - leg servos 4 according to the following formula, so that the pitch angle of the robot approaches the target pitch angle and the roll angle approaches the target roll angle.

[0091] α = α0 + K·(θ targe_pitch - θ curren_pitch )

[0092] α Δ += K·(θ target_roll - θ current_roll )

[0093] α left = α + α Δ

[0094] α right = α - α Δ

[0095] α0 = α

[0096] Where: The initial α0 is the reference deployment angle, K is the proportionality coefficient, θ target_pitch is the target pitch angle, θ curren_pitch is the currently obtained real - time pitch angle; θ target_roll is the target roll angle, θ current_roll is the currently obtained real - time roll angle; α left is the left front - leg servo angle, α right is the right front - leg servo angle.

[0097] (3) When the gear-rack assembly rotates to the toothless section of the first toothless gear 8, the first toothless gear 8 disengages from the rack 21, and the energy storage spring 16 rebounds, causing the multi-link structure of the hind leg structure to open, completing the robot's takeoff.

[0098] S104. After the robot takes off, according to the angle information obtained in real time, the attitude adjustment flywheel 6 is closed-loop controlled by the flywheel drive motor 7 to maintain the attitude balance in the air.

[0099] (1) Calculate the angle deviation of the pitch angle based on the pitch angle obtained in real time.

[0100] Δφ = φ current - φ target

[0101] Where: θ target is the target pitch angle, and θ current is the pitch angle obtained in real time currently.

[0102] (2) Calculate the dynamic compensation term u based on the angle deviation.

[0103]

[0104] K p (Δφ) = K p0 + λ·|Δφ|

[0105]

[0106] Where: C loss (ω current ) is the compensation term for frictional loss; ω_max, K p0 , , ω_th, λ are set parameters.

[0107] (3) The flywheel drive motor 7 controls the rotational speed of the attitude adjustment flywheel 6 according to the dynamic compensation term u through the field-oriented control algorithm to maintain the attitude balance in the air.

[0108]

[0109] Where: ω current is the rotational speed of the current attitude adjustment flywheel, ω target is the rotational speed of the adjusted attitude adjustment flywheel, I flywhee is the moment of inertia of the attitude adjustment flywheel, and Δt is the adjustment period of the attitude adjustment flywheel.

[0110] S105. When it is judged that the robot is approaching the ground, the robot lands by means of the shock absorption mechanism 3 and adjusting the closed-loop control parameters of the flywheel drive motor 7 in step S104 for the attitude adjustment flywheel 6.

[0111] When the acceleration information along the Z-axis obtained in real time is greater than the set landing threshold, it is determined that the robot is approaching the ground.

[0112] Adjust the deployment angle of the front leg mechanism 2 by the front leg servo 4 to the landing set value. According to the control method in step S104, adjust the parameter K p0 , , K c , and perform closed-loop control on the attitude adjustment flywheel 6 through the flywheel drive motor 7 to complete the landing of the robot.

[0113] The above specific description further details the purpose, technical solution, and beneficial effects of the invention. It should be understood that the above is only a specific embodiment of the present invention and is not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A bionic frog jumping robot, characterized in that: It includes a bottom plate (20), a leg mechanism, a driving mechanism, and a multi-modal control system; The multi-modal control system includes a nine-axis inertial sensor, a front leg servo (4), a rear leg servo (12), an attitude adjustment flywheel (6), a flywheel driving motor (7), a shock absorption mechanism (3), and a control module; The driving mechanism includes a gear-rack assembly and a energy storage spring (16); The leg mechanism includes a front leg mechanism (2) and a rear leg mechanism. The front leg mechanism (2) is connected to the front leg servo (4) through the shock absorption mechanism (3), and the front leg servo (4) is fixed on the bottom plate (20) through a servo fixing bracket (5); The rear leg mechanism is a multi-stage link structure, connected to the energy storage spring (16), and connected to the rear leg servo (12) through a gear-rack assembly. The rear leg servo (12) changes the shape of the multi-stage link structure of the rear leg mechanism through the gear-rack assembly, so that it can stretch and contract to simulate the stretching of the frog's legs to convert the stored energy of the energy storage spring (16) into jumping driving force; The attitude adjustment flywheel (6) is located at the center of gravity of the robot and is connected to the flywheel driving motor (7); The flywheel driving motor (7), the nine-axis inertial sensor, and the control module are all installed on the bottom plate (20); The control module is respectively connected to the nine-axis inertial sensor, the front leg servo (4), the rear leg servo (12), and the flywheel driving motor (6) for control and data transceiver.

2. The bionic frog jumping robot according to claim 1, wherein: The multi-stage link structure of the rear leg mechanism is: a steel pipe fixing bracket (14) is horizontally fixed at the end of the bottom plate (20), and steel pipes (24) are vertically fixed at both ends respectively. The steel pipes (24) are parallel to the bottom plate (20); A gear connecting bracket (23) is slidably connected to the two steel pipes (24) so that it can move along the direction of the steel pipes (24); Both ends of the gear connecting bracket (23) are respectively rotatably connected to the first link (22); The first link (22) is rotatably connected to the second link (11); The second link (11) is simultaneously rotatably connected to the third link (13) and the fourth link (15); The third link (13) is simultaneously rotatably connected to the steel pipe fixing bracket (14); The fourth link (15) is rotatably connected to the fifth link (19), and is simultaneously connected to the extended end of the spring link connecting the bottom plate (20) through a spring mechanism (16); The fifth link (19) is an L-shaped link, and the other end of the L-shape is rotatably connected to the sixth link (18), and the inflection point position of the L-shape is rotatably connected to the bottom plate connection end of the spring link of the bottom plate (20); The seventh link (17) is used as the output link of the multi-stage link structure, the end is rotatably connected to the robot foot, the other end is rotatably connected to the extended end of the spring link of the bottom plate (20) and the spring mechanism (16), and the middle position is rotatably connected to the sixth link (18); The gear-rack assembly is: a third gear (10), a second gear (9), and a first toothless gear (8) are connected in sequence, and at the same time, the first toothless gear (8) meshes with the rack (21); The first toothless gear (8) has teeth missing on its circumference, forming a periodic transmission interruption window, and is symmetrically distributed with double helical teeth to offset the axial force; The third gear (10) is rigidly connected to the hind leg servo (12) through a keyway. The first toothless gear (8) is connected to the gear connecting frame (23) to coordinate the hind leg servo (12), the gear-rack assembly and the multi-link structure of the hind leg mechanism; The hind leg servo (12) controls the operation of the gear-rack assembly. When the first toothless gear (8) meshes with the rack (21), energy is stored by rigidly driving and compressing the energy storage spring (16). At this time, the upper half of the fifth link (19) moves backward and the lower half moves forward, putting the robot in a compressed state. In the toothless section, the gear is allowed to idle. At this time, the energy storage spring (16) releases energy, the upper half of the fifth link (19) moves forward and the lower half moves backward, causing the hind leg mechanism to unfold again, converting the rotational motion into a parabolic trajectory of the foot to simulate a biological jumping action.

3. The bionic frog jumping robot according to claim 1, wherein: A damping ball (1) is installed at the bottom end of the front leg mechanism; The shock absorber (3) uses a helical compression spring, and a rubber buffer block is provided at its elastic limit position. One end is connected to the front leg mechanism (2), and the other end is connected to the front leg servo (4) through the upper support structure of the robot.

4. The bionic frog jumping robot according to claim 1, wherein: There are two front leg servos (4), which respectively control two front leg mechanisms (2) through two shock absorption mechanisms (3); there is only one hind leg servo, which is connected to the multi-link structures of two groups of hind leg mechanisms and two groups of energy storage springs (16) respectively through the gear-rack assembly.

5. A control method for a bionic frog jumping robot, based on the bionic frog jumping robot according to any one of claims 1-4, characterized in that, It includes the following steps: (1) Real-time obtain the data of the nine-axis inertial sensor, and obtain the acceleration and angle information of the robot through quaternion calculation; (2) According to the angle information, and in combination with the attitude adjustment flywheel (6), judge the takeoff stability; (3) If it is judged that it can take off, the energy storage spring (16) is charged and released through the cooperation of the first toothless gear (8) and the rack (21) in the gear-rack assembly to complete the takeoff of the robot; (4) After the robot takes off, according to the angle information obtained in real time, use the flywheel drive motor (7) to perform closed-loop control on the attitude adjustment flywheel (6) to maintain the aerial attitude balance; (5) When it is judged that the robot is approaching the ground, complete the landing of the robot through the shock absorption mechanism (3) and adjusting the closed-loop control parameters of the flywheel drive motor (7) in step (4) for the attitude adjustment flywheel (6).

6. The control method of the bionic frog jumping robot according to claim 5, characterized in that The acceleration information obtained in step (1) includes the acceleration along the X-axis, the acceleration along the Y-axis, and the acceleration along the Z-axis; the angle information includes the pitch angle of the rotation angle around the X-axis, the roll angle of the rotation angle around the Y-axis, and the yaw angle of the rotation angle around the Z-axis.

7. The control method of the bionic frog jumping robot according to claim 6, characterized in that, The specific content of step (2) is: (2.1) According to the pitch angle, roll angle and yaw angle obtained in real time, calculate their change rates respectively to obtain the angular velocity; (2.2) If all the obtained angular velocities are less than the angular velocity threshold, and the pitch angle, roll angle and yaw angle are all within the predetermined angle threshold range, it is initially determined that it can take off, record the current angle information, and enter step (2.3); otherwise, abandon the takeoff; (2.3) After starting the attitude adjustment flywheel (6) and closing it after reaching the preset time, obtain the angle information at this time in real time. If the change values of the pitch angle and roll angle before and after starting are less than the preset angle difference threshold, the takeoff condition is met. If the change value before and after starting is greater than or equal to the preset angle difference threshold, start the attitude adjustment flywheel (6) again until the takeoff condition is met or the preset takeoff time is reached and still not met, then abandon the takeoff.

8. The control method of the bionic frog jumping robot according to claim 6, characterized in that, The specific steps of step (3) are as follows: (3.1) Drive the gear-rack assembly to rotate through the hind leg servo (12), and then drive the multi-link structure of the hind leg mechanism to compress the energy storage spring (16) backward to store energy. (3.2) Adjust the angles of the two front leg mechanisms (2) through the two front leg servos (4); gradually adjust the angles of the two front leg servos (4) according to the following formula, so that the pitch angle of the robot approaches the target pitch angle and the roll angle approaches the target roll angle. α = α0 + K·(θ targe_pitch - θ curren_pitch ) α Δ += K·(θ target_roll - θ current_roll ) α left ＝α+α Δ α right ＝α-α Δ α0＝α Where: the initial α0 is the reference expansion angle, K is the proportionality coefficient, θ target_pitch is the target pitch angle, θ curren_pitch is the pitch angle obtained in real time currently; θ target_roll is the target roll angle, θ currnet_roll is the roll angle obtained in real time currently; α left is the left front leg servo angle, α right is the right front leg servo angle; (3.3) The gear-rack assembly runs to the toothless section of the first toothless type gear (8), the first toothless type gear (8) disengages from the rack (21), and the energy storage spring (16) rebounds, causing the multi-link structure of the hind leg mechanism to open, completing the takeoff of the robot.

9. The control method of the bionic frog jumping robot according to claim 6, characterized in that (4.1) Calculate the angle deviation of the pitch angle according to the pitch angle obtained in real time. (4.2) Calculate the dynamic compensation term u according to the angle deviation. Δφ = φ current -φ target Where: θ target is the target pitch angle, and θ current is the pitch angle obtained in real time currently; (4.3) The flywheel drive motor (7) controls the rotational speed of the attitude adjustment flywheel (6) according to the dynamic compensation term u through the field-oriented control algorithm to maintain the aerial attitude balance. K p (Δφ) = K p0 + λ·|Δφ| C loss (ω current )=K c *ω curren where: ω_max, K p0 , K c , ω_th are set parameters; (5.1) When the acceleration information along the Z-axis obtained in real time is greater than the set landing threshold, it is determined that the robot is approaching the ground. Where: ω current is the rotational speed of the attitude adjustment flywheel at present, ω target is the rotational speed of the attitude adjustment flywheel after adjustment, I flywhee is the moment of inertia of the attitude adjustment flywheel, and Δt is the adjustment period of the attitude adjustment flywheel.

10. The control method of the bionic frog jumping robot according to claim 9, characterized in that, (5.2) Adjust the deployment angle of the front leg mechanism (2) to the landing set value through the front leg servo (4). ​ ​ According to the control method in step (4) and adjust the parameter K p0 、 K c , perform closed-loop control on the attitude adjustment flywheel (6) through the flywheel drive motor (7) to complete the landing of the robot.

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