Buoyancy-adjustable amphibious humanoid robot underwater posture adjusting method

Abstract

A buoyancy-adjustable amphibious humanoid robot underwater posture adjusting method comprises the following steps that an amphibious humanoid robot enters water in a cross-medium mode, and the water entering state of the amphibious humanoid robot is judged by conducting data detection through a first depth meter; after the amphibious humanoid robot is completely submerged in water, the underwater posture of the amphibious humanoid robot is adjusted through a buoyancy adjusting device and a posture adjusting propeller; when the amphibious humanoid robot goes out of water, the thrust of the propeller is adjusted to adjust the pitch attitude until the third depth gauge does not display corresponding data, it is indicated that the head of the amphibious humanoid robot goes out of water at the moment, then the buoyancy adjusting cabin is controlled to slide upwards to the topmost end, and the legs of the amphibious humanoid robot are controlled to rotate; and controlling the amphibious humanoid robot to walk out of the water surface until the first depth gauge does not display data, and indicating that the amphibious humanoid robot is completely discharged out of the water as a whole.

Description

Technical Field:

[0001] The present invention relates to a method for adjusting the underwater posture of an amphibious humanoid robot with adjustable buoyancy. Background Art:

[0002] In recent years, amphibious humanoid robots have become a research hotspot in the field of robotics due to their adaptability and flexibility in complex environments. They can freely switch between walking on land and swimming in water, and have broad application prospects in fields such as disaster rescue, environmental monitoring, and military reconnaissance.

[0003] Due to the difference in density between water and air, an amphibious humanoid robot will be subjected to strong impact forces and torques during the process of entering the water body from land, resulting in the loss of stability of the robot's posture and even capsizing. At the same time, the buoyancy, resistance, and fluid uncertainty underwater will further increase the difficulty of robot posture control. Therefore, the existing conventional technologies are difficult to meet the posture adjustment requirements of a bipedal amphibious humanoid robot when walking from land to water. Summary of the Invention:

[0004] An embodiment of the present invention provides a method for adjusting the underwater posture of an amphibious humanoid robot with adjustable buoyancy. The method is reasonably designed. Aiming at the instability problem caused by fluid impact and sudden change of buoyancy during the land-water transition of the amphibious humanoid robot, a regulation form combining buoyancy regulation and cooperative control of thrusters is adopted to reduce the impact forces and torques received by the amphibious humanoid robot when entering the water, ensure the stability of the posture of the amphibious humanoid robot, avoid the occurrence of capsizing phenomena, reduce the difficulty of adjusting the posture control of the amphibious humanoid robot, improve the stability and adaptability of the robot in tasks such as rescue and reconnaissance, and solve the problems existing in the prior art.

[0005] The technical solution adopted by the present invention to solve the above technical problems is:

[0006] A method for adjusting the underwater posture of an amphibious humanoid robot with adjustable buoyancy, the posture adjustment method includes the following steps:

[0007] S1, the amphibious humanoid robot enters the water across media, and a first depth gauge is used to detect data to judge the water entry state of the amphibious humanoid robot;

[0008] S2, after the amphibious humanoid robot is completely submerged in water, a buoyancy adjustment device and a posture adjustment thruster are used to adjust the posture of the amphibious humanoid robot underwater;

[0009] S3. When the amphibious humanoid robot emerges from the water, adjust the thrust of the thrusters to achieve pitch attitude adjustment until the third depth gauge no longer displays corresponding data, indicating that the head of the amphibious humanoid robot has emerged from the water. Then, control the buoyancy adjustment chamber to slide upward to the topmost position, control the legs of the amphibious humanoid robot to rotate so that the amphibious humanoid robot forms a standing posture, and control the amphibious humanoid robot to walk out of the water until the first depth gauge no longer displays data, indicating that the amphibious humanoid robot has completely emerged from the water.

[0010] For the amphibious humanoid robot to enter the water across different media and use the first depth gauge to detect data to determine the entry state of the amphibious humanoid robot, the following steps are included:

[0011] S1.1. Slide the buoyancy adjustment device to the uppermost position, set the distance between the second depth gauge and the fourth depth gauge as L1, and the electric push rod pushes the piston to the lowermost position.

[0012] S1.2. When the first depth gauge detects data, it indicates that the amphibious humanoid robot starts to enter the water. When the fourth depth gauge detects data, the piston gradually moves upward, sucking seawater into the buoyancy adjustment chamber; when the third depth gauge detects data, it means that the amphibious humanoid robot has completely submerged in the water.

[0013] S1.3. Move the piston downward to drain all the seawater, control the first servo and the second servo to push the waterproof sealing slider for sealing, control the third servo to open the gas cylinder, the piston gradually moves upward, and the buoyancy adjustment chamber gradually moves downward to adjust the center of buoyancy of the amphibious humanoid robot. Set the distance between the fourth depth gauge and the second depth gauge at this time as L2.

[0014] The vertical distance L1 between the second depth gauge and the fourth depth gauge is:

[0015] L1 = h 41 -h 21

[0016] L max = L1 + H

[0017] Where h 21 is the data detected by the second depth gauge when the amphibious humanoid robot first enters the water, and h 41 is the data detected by the fourth depth gauge when the amphibious humanoid robot first enters the water; L max is the maximum vertical distance reached by the second depth gauge and the fourth depth gauge, and H is the maximum distance that the buoyancy adjustment chamber moves;

[0018] The forces acting on the amphibious humanoid robot in the water are:

[0019]

[0020] At this time, the resultant moment acting on the center of gravity of the amphibious humanoid robot is:

[0021] τ total = ∑(r i × F i )

[0022] where F b is the buoyancy force, ρ is the density of water, V is the volume of the amphibious humanoid robot immersed in water, g is the acceleration due to gravity, F d is the resistance force acting on the robot in water, C d is the drag coefficient, which is related to the shape and surface characteristics of the amphibious humanoid robot, A is the projection of the amphibious humanoid robot in the direction of motion, v is the velocity vector of the amphibious humanoid robot relative to the water, ||v|| is the magnitude of the velocity, F a is the added mass force generated when the amphibious humanoid robot accelerates in water, M a is the added mass matrix, ɑ is the acceleration of the amphibious humanoid robot, F h is the hydrodynamic force, C h is the hydrodynamic force coefficient, n is the direction vector of the force, and m is the mass of the amphibious humanoid robot.

[0023] After the amphibious humanoid robot is completely submerged in water, adjusting the attitude of the amphibious humanoid robot underwater using the buoyancy adjustment device and the attitude adjustment thruster includes the following steps:

[0024] S2.1, fix the moment of the upper body torso of the amphibious humanoid robot, and control the lower body to rotate the thighs backward to change the moment of the resultant force on the five-degree-of-freedom legs;

[0025] S2.2, the position reached by the rotation of the legs is N, lower the buoyancy adjustment compartment to change the position of the center of buoyancy. At this time, the distance L2 between the second depth gauge and the fourth depth gauge is:

[0026]

[0027] where h 12 is the data detected by the first depth gauge during attitude adjustment in water, h 22 is the data detected by the second depth gauge during attitude adjustment in water, h 32 is the data detected by the third depth gauge during attitude adjustment in water, h 42 is the data detected by the fourth depth gauge during attitude adjustment in water, and β is the angle between the amphibious humanoid robot and the horizontal plane;

[0028] S2.3. Determine the overall posture of the amphibious humanoid robot via the first depth gauge, the second depth gauge, and the third depth gauge, and control the rotation of the four thrusters. The first thruster and the second thruster generate forces perpendicular to the fuselage of the amphibious humanoid robot, and the third thruster and the fourth thruster generate forces parallel to the fuselage of the amphibious humanoid robot, enabling the amphibious humanoid robot to enter the diving state. The thrust and torque generated by the thrusters are as follows:

[0029]

[0030] where k is the thrust coefficient of the thruster, μ is the control input of the thruster, and r i is the thruster;

[0031] S2.4. Control the rotation of the four thrusters via the servos to change the direction of the forces generated by the thrusters.

[0032]

[0033] where θ1 is the angle between the forces generated by the first thruster and the second thruster and the fuselage of the amphibious humanoid robot, and θ3 is the angle between the forces generated by the third thruster and the fourth thruster and the fuselage of the amphibious humanoid robot.

[0034] The amphibious humanoid robot includes a trunk, a five-degree-of-freedom leg, a two-degree-of-freedom arm, a buoyancy adjustment device, a motion and attitude adjustment thruster, and an attitude perception device that are cooperatively arranged;

[0035] The trunk includes a chest cavity and a waist. The buoyancy adjustment device is slidably installed on the back of the chest cavity. The two-degree-of-freedom arms are symmetrically installed on both sides of the chest cavity. There is a one-dimensional joint adjustment at the shoulder joint and the elbow joint of the two-degree-of-freedom arms, which can realize the up-and-down rotation of the upper arm and the forearm. The waist is connected below the chest cavity, and the five-degree-of-freedom leg is installed below the waist.

[0036] The buoyancy adjustment device includes a buoyancy adjustment chamber, an electric slider, a gas cylinder, an electric push rod, a motor, a threaded lead screw, a waterproof sealing slider, a first servo, a second servo, and a third servo that are cooperatively arranged;

[0037] The electric slider is fixed on the back of the chest cavity, and the buoyancy adjustment chamber is fixed on the electric slider. A gas cylinder, a first servo, and a second servo are installed below the buoyancy adjustment chamber. The third servo is installed below the interior of the buoyancy adjustment device. An electric push rod is installed above the buoyancy adjustment device, and the electric push rod is integrally installed inside the buoyancy adjustment device.

[0038] A motor is installed above the electric slider, and the motor controls the electric slider via the threaded lead screw; the first servo and the second servo adjust the left-right movement of the waterproof sealing slider by rotation, enabling water to penetrate into the buoyancy adjustment device to achieve sealing.

[0039] The motion and attitude adjustment thrusters include a first thruster, a second thruster, a third thruster, and a fourth thruster that are cooperatively arranged. The first thruster and the second thruster are symmetrically installed on the outer side above the large arm, and the third thruster and the fourth thruster are symmetrically installed below the waist. The above four thrusters are all fixedly installed on the servo motors, and the thrust direction is changed by the rotation of the servo motors.

[0040] The attitude sensing device includes a first depth gauge, a second depth gauge, a third depth gauge, a fourth depth gauge, and an IMU.

[0041] The first depth gauge is installed on the upper surface of the right foot of the foot, the second depth gauge is installed on the front end cover of the hip seal cabin in the middle of the waist, and is at the same horizontal plane as the center of gravity. The third depth gauge is installed on the top surface of the head, the fourth depth gauge is installed below the outside of the buoyancy adjustment cabin, and the IMU is installed inside the hip seal cabin.

[0042] The present invention adopts the above structure and method. The water entry state of the amphibious humanoid robot is judged by detecting data through the first depth gauge; the attitude of the amphibious humanoid robot underwater is adjusted by the buoyancy adjustment device and the attitude adjustment thrusters; when the amphibious humanoid robot exits the water, the thrust of the thrusters is adjusted to achieve the adjustment of the pitching attitude until the third depth gauge does not display the corresponding data, indicating that the head of the amphibious humanoid robot has exited the water at this time; the first servo motor and the second servo motor rotate to adjust the left and right movement of the waterproof sealing slider, so that water penetrates into the buoyancy adjustment device to achieve sealing, which has the advantages of safety, stability, simplicity and practicality. Description of the Drawings:

[0043] Figure 1 It is the first structural schematic diagram of the buoyancy adjustment device of the present invention.

[0044] Figure 2 It is the second structural schematic diagram of the buoyancy adjustment device of the present invention.

[0045] Figure 3 It is the schematic diagram of the water entry attitude of the amphibious humanoid robot of the present invention.

[0046] Figure 4 It is the schematic diagram of the attitude adjustment of the amphibious humanoid robot of the present invention.

[0047] Figure 5 It is the force analysis diagram of the attitude adjustment of the amphibious humanoid robot of the present invention.

[0048] Figure 6 It is the flow chart of the attitude adjustment in water of the present invention.

[0049] In the figure, 1 is the torso, 101 is the chest cavity, 102 is the waist, 103 is the front end cover of the hip seal cabin; 2 is the five-degree-of-freedom leg, 201 is the thigh, 202 is the calf, 203 is the foot; 3 is the two-degree-of-freedom arm, 301 is the upper arm, 302 is the forearm; 4 is the buoyancy adjustment device, 401 is the buoyancy adjustment cabin, 402 is the electric slider, 403 is the gas cylinder, 404 is the electric push rod, 405 is the motor, 406 is the threaded lead screw, 407 is the waterproof seal slider, 408 is the first servo motor, 409 is the second servo motor, 410 is the third servo motor; 5 is the motion and attitude adjustment thruster, 501 is the first thruster, 502 is the second thruster, 503 is the third thruster, 504 is the fourth thruster; 6 is the attitude perception device, 601 is the first depth gauge, 602 is the second depth gauge, 603 is the third depth gauge, 604 is the fourth depth gauge, 605 is the IMU. Detailed implementation method:

[0050] To clearly illustrate the technical features of this solution, the present invention will be elaborated in detail below through specific implementation methods and in conjunction with its attached drawings.

[0051] As Figure 1-6 shown in [the figure], a method for adjusting the underwater attitude of an amphibious humanoid robot with adjustable buoyancy, the attitude adjustment method includes the following steps:

[0052] S1. The amphibious humanoid robot enters the water across media, and the first depth gauge is used to detect data to judge the entry state of the amphibious humanoid robot.

[0053] S2. After the amphibious humanoid robot is completely submerged in water, the buoyancy adjustment device and the attitude adjustment thruster are used to adjust the attitude of the amphibious humanoid robot underwater.

[0054] S3. When the amphibious humanoid robot emerges from the water, adjust the thrust of the thruster to achieve the adjustment of the pitching attitude until the third depth gauge does not display the corresponding data, indicating that the head of the amphibious humanoid robot has emerged from the water at this time. Then control the buoyancy adjustment cabin to slide upward to the topmost position, control the legs of the amphibious humanoid robot to rotate, so that the amphibious humanoid robot forms a standing posture, and control the amphibious humanoid robot to walk out of the water until the first depth gauge does not display data, indicating that the amphibious humanoid robot has completely emerged from the water.

[0055] The amphibious humanoid robot enters the water across media, and the first depth gauge is used to detect data to judge the entry state of the amphibious humanoid robot, including the following steps:

[0056] S1.1. The buoyancy adjustment device slides to the uppermost position, set the distance between the second depth gauge and the fourth depth gauge as L1, and the electric push rod pushes the piston to the lowermost position.

[0057] S1.2. When the first depth gauge detects data, it indicates that the amphibious humanoid robot starts to enter the water. When the fourth depth gauge detects data, the piston gradually moves upward, sucking seawater into the buoyancy adjustment chamber. When the third depth gauge detects data, it means that the amphibious humanoid robot has been completely submerged in the water.

[0058] S1.3. The piston moves downward to discharge all the seawater, controls the first servo and the second servo to push the waterproof seal slider for sealing, controls the third servo to open the gas cylinder, the piston gradually moves upward, and the buoyancy adjustment chamber gradually moves downward to adjust the center of buoyancy of the amphibious humanoid robot. Set the distance between the fourth depth gauge and the second depth gauge at this time as L2.

[0059] The vertical distance L1 between the second depth gauge and the fourth depth gauge is:

[0060] L1 = h 41 -h 21

[0061] L max = L1 + H

[0062] Where h 21 is the data detected by the second depth gauge when the amphibious humanoid robot just enters the water, h 41 is the data detected by the fourth depth gauge when the amphibious humanoid robot just enters the water; L max is the maximum vertical distance reached by the second depth gauge and the fourth depth gauge, and H is the maximum distance that the buoyancy adjustment chamber moves;

[0063] The force exerted on the amphibious humanoid robot in the water is:

[0064]

[0065] At this time, the resultant moment acting on the center of gravity of the amphibious humanoid robot is:

[0066] τ totol = Σ(r i ×F i )

[0067] Where F b is the buoyancy, ρ is the density of water, V is the volume of the amphibious humanoid robot immersed in water, g is the acceleration due to gravity, F d is the resistance exerted on the robot in the water, C d is the drag coefficient, related to the shape and surface characteristics of the amphibious humanoid robot, A is the projection of the amphibious humanoid robot in the direction of motion, v is the velocity vector of the amphibious humanoid robot relative to the water, ||v|| is the magnitude of the velocity, F a is the added mass force generated when the amphibious humanoid robot accelerates in the water, M ais the added mass matrix, ɑ is connected to the acceleration of the amphibious humanoid robot, and F h is the hydrodynamic force, and C h is the hydrodynamic coefficient, n is the direction vector of the force, and m is the mass of the amphibious humanoid robot.

[0068] When the amphibious humanoid robot is completely submerged in water, adjusting the attitude of the amphibious humanoid robot underwater by using the buoyancy adjustment device and the attitude adjustment thrusters includes the following steps:

[0069] S2.1, fix the upper body torso torque of the amphibious humanoid robot, and control the lower body to rotate the thighs backward to change the torque of the resultant force received by the five-degree-of-freedom legs;

[0070] S2.2, the position reached by the rotation of the legs is N, and move the buoyancy adjustment compartment downward to change the position of the center of buoyancy. At this time, the distance L2 between the second depth gauge and the fourth depth gauge is:

[0071]

[0072] where h 12 is the data detected by the first depth gauge when adjusting the attitude in water, h 22 is the data detected by the second depth gauge when adjusting the attitude in water, h 32 is the data detected by the third depth gauge when adjusting the attitude in water, h 42 is the data detected by the fourth depth gauge when adjusting the attitude in water, and β is the angle between the amphibious humanoid robot and the horizontal plane;

[0073] S2.3, determine the overall attitude of the amphibious humanoid robot via the first depth gauge, the second depth gauge and the third depth gauge, control the four thrusters to rotate, the first thruster and the second thruster generate forces perpendicular to the fuselage of the amphibious humanoid robot, and the third thruster and the fourth thruster generate forces parallel to the fuselage of the amphibious humanoid robot, so that the amphibious humanoid robot enters the diving state. The thrust and torque generated by the thrusters are:

[0074]

[0075] where k is the thrust coefficient of the thruster, μ is the control input of the thruster, and r i is the thruster;

[0076] S2.4, control the four thrusters to rotate via the servos to change the direction of the forces generated by the thrusters

[0077]

[0078] Among them, θ1 is the angle between the forces generated by the first thruster and the second thruster and the fuselage of the amphibious humanoid robot, and θ3 is the angle between the forces generated by the third thruster and the fourth thruster and the fuselage of the amphibious humanoid robot.

[0079] The amphibious humanoid robot includes a trunk 1, five-degree-of-freedom legs 2, two-degree-of-freedom arms 3, a buoyancy adjustment device 4, a motion and attitude adjustment thruster 5, and an attitude sensing device 6 that are cooperatively arranged;

[0080] The trunk 1 includes a chest cavity 101 and a waist 102. The buoyancy adjustment device 5 is slidably installed on the back of the chest cavity 101. The two-degree-of-freedom arms 3 are symmetrically installed on both sides of the chest cavity 101. There is a one-dimensional joint adjustment at the shoulder joint and elbow joint of the two-degree-of-freedom arms 3, which can realize the up-and-down rotation of the upper arm 301 and the lower arm 302. The waist 102 is connected below the chest cavity 101, and the five-degree-of-freedom legs 2 are installed below the waist 102.

[0081] The buoyancy adjustment device 4 includes a buoyancy adjustment chamber 401, an electric slider 402, a gas cylinder 403, an electric push rod 404, a motor 405, a threaded lead screw 406, a waterproof sealing slider 407, a first servo 408, a second servo 409, and a third servo 410 that are cooperatively arranged;

[0082] The electric slider 402 is fixed on the back of the chest cavity 101. The buoyancy adjustment chamber 401 is fixed on the electric slider 402. A gas cylinder 403, a first servo 408, and a second servo 409 are installed below the buoyancy adjustment chamber 401. The third servo 410 is installed below the interior of the buoyancy adjustment device 4. An electric push rod 404 is installed above the buoyancy adjustment device 4, and the electric push rod 404 is integrally installed inside the buoyancy adjustment device 4.

[0083] A motor 405 is installed above the electric slider 402, and the motor 405 controls the electric slider 402 through the threaded lead screw 406; the first servo 408 and the second servo 409 adjust the left-right movement of the waterproof sealing slider 407 by rotation, so that water penetrates into the buoyancy adjustment device 4 to achieve sealing.

[0084] The motion and attitude adjustment thruster 5 includes a first thruster 501, a second thruster 502, a third thruster 503, and a fourth thruster 504 that are cooperatively arranged. The first thruster 501 and the second thruster 502 are symmetrically installed on the outer side above the upper arm 301. The third thruster 503 and the fourth thruster 504 are symmetrically installed below the waist 102; the above four thrusters are all correspondingly fixed on the servos, and the thrust direction is changed by the rotation of the servos.

[0085] The attitude perception device 6 includes a first depth meter 601, a second depth meter 602, a third depth meter 603, a fourth depth meter 604, and an IMU 605;

[0086] The first depth meter 601 is installed on the upper surface of the right foot at the foot 203, the second depth meter 602 is installed on the front end cover 103 of the hip seal cabin in the middle of the waist 102, at the same horizontal plane as the center of gravity; the third depth meter 603 is installed on the top surface of the head, the fourth depth meter 604 is installed below the outside of the buoyancy adjustment cabin 401, and the IMU 605 is installed inside the hip seal cabin.

[0087] The working principle of an underwater attitude adjustment method for an amphibious humanoid robot with adjustable buoyancy in an embodiment of the present invention is as follows: Aiming at the instability problem caused by fluid impact and sudden buoyancy change during the water-land transition of the amphibious humanoid robot, an adjustment form combining buoyancy adjustment and thruster cooperative control is adopted to reduce the impact force and moment received by the amphibious humanoid robot when entering the water, ensure the stability of the attitude of the amphibious humanoid robot, avoid the occurrence of capsizing phenomena, reduce the difficulty of attitude control adjustment of the amphibious humanoid robot, and improve the stability and adaptability of the robot in tasks such as rescue and reconnaissance.

[0088] Generally, existing conventional technical means are difficult to meet the attitude adjustment requirements of an amphibious humanoid robot when moving from land to water. Therefore, there is an urgent need for a new technical solution that can achieve fast, stable, and adaptive attitude adjustment to ensure the smooth water-land transition of the robot.

[0089] In the overall solution, the attitude adjustment method includes the following steps: The amphibious humanoid robot enters the water across media, and the first depth meter is used for data detection to judge the water entry state of the amphibious humanoid robot; when the amphibious humanoid robot is completely submerged in water, a buoyancy adjustment device and an attitude adjustment thruster are used to adjust the attitude of the amphibious humanoid robot underwater; when the amphibious humanoid robot exits the water, the thrust of the thruster is adjusted to achieve the adjustment of the pitch attitude until the third depth meter does not display the corresponding data, indicating that the head of the amphibious humanoid robot has exited the water at this time. Then, the buoyancy adjustment cabin is controlled to slide upward to the topmost position, and the legs of the amphibious humanoid robot are controlled to rotate so that the amphibious humanoid robot forms a standing posture, and the amphibious humanoid robot is controlled to walk out of the water until the first depth meter does not display data, indicating that the amphibious humanoid robot has completed the overall water exit.

[0090] For the amphibious humanoid robot of the present application, it includes a trunk, a five-degree-of-freedom leg, a two-degree-of-freedom arm, a buoyancy adjustment device, a motion and attitude adjustment thruster, and an attitude sensing device which are cooperatively arranged; the trunk includes a chest cavity and a waist, the buoyancy adjustment device is slidably installed on the back of the chest cavity, the two-degree-of-freedom arms are symmetrically installed on both sides of the chest cavity, and each of the shoulder joint and elbow joint of the two-degree-of-freedom arm has a one-dimensional joint adjustment, capable of realizing the up-and-down rotation of the upper arm and the lower arm. The waist is connected below the chest cavity, and the five-degree-of-freedom leg is installed below the waist.

[0091] The buoyancy adjustment device can adjust the center of buoyancy and the drainage volume of the robot, and the motion and attitude adjustment thruster can be steered by a servo motor to cooperate with the leg movement to balance the hydrodynamic force received; the attitude sensing device can monitor the attitude of the robot during the adjustment process.

[0092] Specifically, the buoyancy adjustment device includes a buoyancy adjustment chamber, an electric slider, a gas cylinder, an electric push rod, a motor, a threaded lead screw, a waterproof sealing slider, a first servo motor, a second servo motor, and a third servo motor which are cooperatively arranged; the electric slider is fixed on the back of the chest cavity, the buoyancy adjustment chamber is fixed on the electric slider, a gas cylinder, a first servo motor, and a second servo motor are installed below the buoyancy adjustment chamber, the third servo motor is installed below the interior of the buoyancy adjustment device, and an electric push rod is installed above the buoyancy adjustment device. The electric push rod is integrally installed inside the buoyancy adjustment device, capable of accurately adjusting the buoyancy received by the amphibious humanoid robot, and further completing the attitude adjustment of the amphibious humanoid robot in water.

[0093] Furthermore, a motor is installed above the electric slider, and the motor controls the electric slider through the threaded lead screw; the first servo motor and the second servo motor adjust the left-right movement of the waterproof sealing slider by rotation, so that water penetrates into the buoyancy adjustment device to achieve sealing.

[0094] For the motion and attitude adjustment thruster, it includes a first thruster, a second thruster, a third thruster, and a fourth thruster which are cooperatively arranged. The first thruster and the second thruster are symmetrically installed on the outer side above the upper arm, and the third thruster and the fourth thruster are symmetrically installed below the waist; the above four thrusters are all correspondingly fixed on servo motors, and the thrust direction is changed by the rotation of the servo motors.

[0095] For the attitude perception device, it includes a first depth gauge, a second depth gauge, a third depth gauge, a fourth depth gauge and an IMU; the first depth gauge is installed on the upper surface of the right foot of the foot, the second depth gauge is installed on the front end cover of the hip seal cabin in the middle of the waist, at the same horizontal plane as the center of gravity; the third depth gauge is installed on the top surface of the head, the fourth depth gauge is installed below the outside of the buoyancy adjustment cabin, and the IMU is installed inside the hip seal cabin; it can detect and summarize various types of data in three motion states of the robot entering the water across media, moving in water, and exiting the water across media.

[0096] For the process steps of this application, preferably, when the amphibious humanoid robot enters the water across media and the first depth gauge is used for data detection to judge the entry state of the amphibious humanoid robot, it includes the following steps: the buoyancy adjustment device slides to the uppermost position, the distance between the second depth gauge and the fourth depth gauge is set as L1, and the electric push rod pushes the piston to the lowermost position; when the first depth gauge detects data, it indicates that the amphibious humanoid robot starts to enter the water. When the fourth depth gauge detects data, the piston gradually moves upward, sucking seawater into the buoyancy adjustment cabin; when the third depth gauge detects data, it means that the amphibious humanoid robot has been completely submerged in water; the piston moves downward, discharging all the seawater, controlling the first servo and the second servo to push the waterproof seal slider for sealing, controlling the third servo to open the gas cylinder, the piston gradually moves upward, and the buoyancy adjustment cabin gradually moves downward to adjust the center of buoyancy of the amphibious humanoid robot, and the distance between the fourth depth gauge and the second depth gauge is set as L2 at this time.

[0097] Further, the vertical distance L1 between the second depth gauge and the fourth depth gauge is:

[0098] L1 = h 41 -h 21

[0099] L max = L1 + H

[0100] Where, h 21 is the data detected by the second depth gauge when the amphibious humanoid robot just enters the water, h 41 is the data detected by the fourth depth gauge when the amphibious humanoid robot just enters the water; L max is the maximum vertical distance reached by the second depth gauge and the fourth depth gauge, and H is the maximum distance that the buoyancy adjustment cabin moves;

[0101] The force received by the amphibious humanoid robot in water is:

[0102]

[0103] At this time, the resultant moment received at the center of gravity of the amphibious humanoid robot is:

[0104] τ totol= ∑(r i ×F i )

[0105] where F b is the buoyancy force, ρ is the density of water, V is the volume of the amphibious humanoid robot immersed in water, g is the acceleration due to gravity, F d is the resistance force on the robot in water, C d is the drag coefficient, related to the shape and surface characteristics of the amphibious humanoid robot, A is the projection of the amphibious humanoid robot in the direction of motion, v is the velocity vector of the amphibious humanoid robot relative to the water, ||v|| is the magnitude of the velocity, F a is the added mass force generated when the amphibious humanoid robot accelerates in water, M a is the added mass matrix, ɑ is the acceleration of the amphibious humanoid robot, F h is the hydrodynamic force, C h is the hydrodynamic coefficient, n is the direction vector of the force, and m is the mass of the amphibious humanoid robot.

[0106] Through force analysis, the corresponding torque and direction are determined, and combined with the detection function of the depth gauge, the data determination for cross-media water entry is completed.

[0107] Preferably, when the amphibious humanoid robot is completely immersed in water, adjusting the attitude of the amphibious humanoid robot underwater using the buoyancy adjustment device and the attitude adjustment thruster includes the following steps: fixing the torque of the upper body trunk of the amphibious humanoid robot, controlling the lower body to rotate the thighs backward to change the torque of the resultant force on the five-degree-of-freedom legs; the position reached by the rotation of the legs is N, and the buoyancy adjustment chamber is moved downward to change the position of the center of buoyancy. At this time, the distance L2 between the second depth gauge and the fourth depth gauge is:

[0108]

[0109] where h 12 is the data detected by the first depth gauge during attitude adjustment in water, h 22 is the data detected by the second depth gauge during attitude adjustment in water, h 32 is the data detected by the third depth gauge during attitude adjustment in water, h 42 is the data detected by the fourth depth gauge during attitude adjustment in water, and β is the angle between the amphibious humanoid robot and the horizontal plane.

[0110] Then, the overall posture of the amphibious humanoid robot is determined based on the data detected by the first depth gauge, the second depth gauge, and the third depth gauge. The four thrusters are controlled to rotate. The first thruster and the second thruster generate forces perpendicular to the fuselage of the amphibious humanoid robot, and the third thruster and the fourth thruster generate forces parallel to the fuselage of the amphibious humanoid robot, enabling the amphibious humanoid robot to enter the diving state. The thrust and torque generated by the thrusters are as follows:

[0111]

[0112] where k is the thrust coefficient of the thruster, μ is the control input of the thruster, and r i is the thruster;

[0113] Finally, the four thrusters are controlled to rotate via the servo motors, changing the direction of the forces generated by the thrusters.

[0114]

[0115] where θ1 is the angle between the forces generated by the first thruster and the second thruster and the fuselage of the amphibious humanoid robot, and θ3 is the angle between the forces generated by the third thruster and the fourth thruster and the fuselage of the amphibious humanoid robot, thereby completing the underwater posture adjustment.

[0116] Specifically, the overall control and adjustment method can be divided into three stages: when entering the water, the buoyancy chamber is filled with water and the center of buoyancy moves downward to buffer the impact; in the water, the posture is adjusted by thrust distribution of the thrusters and leg movement; when emerging from the water, the thrusters and the buoyancy chamber are reset to complete standing.

[0117] In summary, for the problem of instability caused by fluid impact and sudden change of buoyancy when the amphibious humanoid robot switches between water and land, the underwater posture adjustment method of the adjustable-buoyancy amphibious humanoid robot in the embodiment of the present invention adopts a regulation form combining buoyancy adjustment and coordinated control of thrusters, reduces the impact force and torque received by the amphibious humanoid robot when entering the water, ensures the stability of the posture of the amphibious humanoid robot, avoids the occurrence of capsizing phenomena, reduces the difficulty of posture control and adjustment of the amphibious humanoid robot, and improves the stability and adaptability of the robot in tasks such as rescue and reconnaissance.

[0118] The above specific implementation manners shall not be used as a limitation to the protection scope of the present invention. For those skilled in the art of this technology, any alternative improvement or transformation made to the embodiments of the present invention falls within the protection scope of the present invention.

[0119] Where the present invention is not described in detail, it is all well-known technology to those skilled in the art of this technology.

Claims

1. An underwater attitude adjustment method for an amphibious humanoid robot with adjustable buoyancy, characterized in that, The described attitude adjustment method includes the following steps: S1. The amphibious humanoid robot enters the water across media, and data detection is carried out via the first depth gauge to judge the water entry state of the amphibious humanoid robot; S2. When the amphibious humanoid robot is completely submerged in water, a buoyancy adjustment device and an attitude adjustment thruster are used to adjust the attitude of the amphibious humanoid robot underwater; S3. When the amphibious humanoid robot emerges from the water, adjust the thrust of the thruster to achieve the adjustment of the pitching attitude until the third depth gauge does not display the corresponding data, indicating that the head of the amphibious humanoid robot has emerged from the water at this time. Then control the buoyancy adjustment cabin to slide upward to the topmost position, control the legs of the amphibious humanoid robot to rotate, so that the amphibious humanoid robot forms a standing posture, and control the amphibious humanoid robot to walk out of the water until the first depth gauge does not display data, indicating that the amphibious humanoid robot has completed the whole process of emerging from the water.

2. The method for adjusting the underwater posture of an amphibious humanoid robot with adjustable buoyancy according to claim 1, characterized in that, The amphibious humanoid robot enters the water across media, and data detection is carried out via the first depth gauge to judge the water entry state of the amphibious humanoid robot, including the following steps: S1.

1. The buoyancy adjustment device slides to the uppermost position, the distance between the second depth gauge and the fourth depth gauge is set as L1, and the electric push rod pushes the piston to the lowermost position; S1.

2. When the first depth gauge detects data, it indicates that the amphibious humanoid robot starts to enter the water. When the fourth depth gauge detects data, the piston gradually moves upward, sucking seawater into the buoyancy adjustment cabin; when the third depth gauge detects data, it means that the amphibious humanoid robot has been completely submerged in water at this time; S1.

3. The piston moves downward to discharge all the seawater, control the first servo and the second servo to push the waterproof sealing slider for sealing, control the third servo to open the gas cylinder, the piston gradually moves upward, and the buoyancy adjustment cabin gradually moves downward to adjust the center of buoyancy of the amphibious humanoid robot. Set the distance between the fourth depth gauge and the second depth gauge at this time as L2.

3. A method for adjusting the underwater posture of an amphibious humanoid robot with adjustable buoyancy according to claim 2, characterized in that, The vertical distance L1 between the second depth gauge and the fourth depth gauge is: L1 = h 41 -h 21 L max = L1 + H Among them, h 21 is the data detected by the second depth gauge when the amphibious humanoid robot first enters the water, and h 41 is the data detected by the fourth depth gauge when the amphibious humanoid robot first enters the water; L max is the maximum vertical distance reached by the second depth gauge and the fourth depth gauge, and H is the maximum distance that the buoyancy adjustment chamber moves; The force received by the described amphibious humanoid robot in water is: The resultant moment received at the center of gravity of the amphibious humanoid robot at this time is: τ total = ∑(r i × F i ) Among them, F b is the buoyancy force, ρ is the density of water, V is the volume of the amphibious humanoid robot immersed in water, g is the acceleration due to gravity, and F d is the resistance force on the robot in water, C d is the drag coefficient, which is related to the shape and surface characteristics of the amphibious humanoid robot, A is the projection of the amphibious humanoid robot in the direction of motion, v is the velocity vector of the amphibious humanoid robot relative to water, ||v|| is the magnitude of the velocity, and F a is the added mass force generated when the amphibious humanoid robot accelerates in water, M a is the added mass matrix, ɑ is the acceleration of the amphibious humanoid robot, and F h is the hydrodynamic force, C h is the hydrodynamic coefficient, n is the direction vector of the force, and m is the mass of the amphibious humanoid robot.

4. The method for adjusting the underwater posture of an amphibious humanoid robot with adjustable buoyancy according to claim 1, characterized in that, When the amphibious humanoid robot is completely submerged in water, using the buoyancy adjustment device and the attitude adjustment thruster to adjust the attitude of the amphibious humanoid robot underwater includes the following steps: S2.

1. Fix the moment of the upper body torso of the amphibious humanoid robot, and control the lower body to rotate the thighs backward to change the moment of the resultant force received by the five-degree-of-freedom legs; S2.

2. The position reached by rotating the legs is N, and the buoyancy adjustment cabin moves downward to change the position of the center of buoyancy. The distance L2 between the second depth gauge and the fourth depth gauge at this time is: h 32 <h 22 Among them, h 12 is the data detected when the first depth gauge adjusts its attitude in water, h 22 is the data detected when the second depth gauge adjusts its attitude in water, h 32 is the data detected when the third depth gauge adjusts its attitude in water, h 42 is the data detected when the fourth depth gauge adjusts its attitude in water, and β is the angle between the amphibious humanoid robot and the horizontal plane; S2.

3. Judge the overall attitude of the amphibious humanoid robot via the first depth gauge, the second depth gauge and the third depth gauge, control the four thrusters to rotate, the first thruster and the second thruster generate forces perpendicular to the fuselage of the amphibious humanoid robot, and the third thruster and the fourth thruster generate forces parallel to the fuselage of the amphibious humanoid robot, so that the amphibious humanoid robot enters the diving state. The thrust and moment generated by the thrusters are: h 33 > h 23 where k is the thrust coefficient of the thruster, μ is the control input of the thruster, and r i is the thruster; S2.

4. Control the four thrusters to rotate via the servo to change the direction of the force generated by the thrusters Among them, θ1 is the angle between the forces generated by the first thruster and the second thruster and the fuselage of the amphibious humanoid robot, and θ3 is the angle between the forces generated by the third thruster and the fourth thruster and the fuselage of the amphibious humanoid robot.

5. A method for adjusting the underwater posture of an amphibious humanoid robot with adjustable buoyancy according to claim 1, characterized in that: The amphibious humanoid robot includes a trunk, five-degree-of-freedom legs, two-degree-of-freedom arms, a buoyancy adjustment device, a motion and attitude adjustment thruster, and an attitude sensing device that are cooperatively arranged; The trunk includes a chest cavity and a waist. The buoyancy adjustment device is slidably installed on the back of the chest cavity. The two-degree-of-freedom arms are symmetrically installed on both sides of the chest cavity. Each of the shoulder joint and elbow joint of the two-degree-of-freedom arms has one-dimensional joint adjustment, capable of realizing the up-and-down rotation of the upper arm and the forearm. The waist is connected below the chest cavity, and the five-degree-of-freedom legs are installed below the waist.

6. A method for adjusting the underwater posture of an amphibious humanoid robot with adjustable buoyancy according to claim 5, characterized in that: The buoyancy adjustment device includes a buoyancy adjustment chamber, an electric slider, a gas cylinder, an electric push rod, a motor, a threaded lead screw, a waterproof seal slider, a first servo, a second servo, and a third servo that are cooperatively arranged; The electric slider is fixed on the back of the chest cavity, and the buoyancy adjustment chamber is fixed on the electric slider. A gas cylinder, a first servo, and a second servo are installed below the buoyancy adjustment chamber. The third servo is installed below the interior of the buoyancy adjustment device. An electric push rod is installed above the buoyancy adjustment device, and the electric push rod is integrally installed inside the buoyancy adjustment device.

7. A method for adjusting the underwater posture of an amphibious humanoid robot with adjustable buoyancy according to claim 5, characterized in that: A motor is installed above the electric slider, and the motor controls the electric slider through a threaded lead screw; the first servo and the second servo adjust the left-right movement of the waterproof seal slider through rotation, so that water penetrates into the buoyancy adjustment device to achieve sealing.

8. A method for adjusting the underwater posture of an amphibious humanoid robot with adjustable buoyancy according to claim 5, characterized in that: The motion and attitude adjustment thruster includes a first thruster, a second thruster, a third thruster, and a fourth thruster that are cooperatively arranged. The first thruster and the second thruster are symmetrically installed on the outer side above the upper arm, and the third thruster and the fourth thruster are symmetrically installed below the waist; the above four thrusters are respectively fixed on servos, and the thrust direction is changed through the rotation of the servos.

9. A method for adjusting the underwater posture of an amphibious humanoid robot with adjustable buoyancy according to claim 5, characterized in that: The attitude sensing device includes a first depth gauge, a second depth gauge, a third depth gauge, a fourth depth gauge, and an IMU; The first depth gauge is installed on the upper surface of the right foot of the foot. The second depth gauge is installed on the front end cover of the hip seal chamber in the middle of the waist, at the same horizontal plane as the center of gravity; the third depth gauge is installed on the top surface of the head, the fourth depth gauge is installed below the outside of the buoyancy adjustment chamber, and the IMU is installed inside the hip seal chamber.

Images