Structural design, paddling gait planning and testing device of bionic dog amphibious robot

Abstract

The invention discloses a structural design, paddling gait planning and testing device of a bionic dog amphibious robot, belongs to the technical field of amphibious robots, and enables the robot to imitate gaits of mammals in the nature by means of the bionics principle so as to achieve water environment movement with higher speed and higher efficiency. The gait is more scientific and reasonable, movement in the land environment and the water environment can be achieved without an additional propelling device or a deformation device, the mechanical structure is simple, some interlayer type waterproof structures are added, the value of force borne by a measured object during underwater movement can be directly obtained, and the measurement accuracy is improved. The force measuring device can measure the numerical values of forces in two opposite directions, can measure the stress conditions in other directions only by changing the connection direction of the aluminum profile, is good in integration degree, can still accurately measure the borne force when the gait of underwater movement of the robot is changed, and has good adaptability.

Description

Technical Field

[0001] The invention relates to the structural design and paddling gait planning of a bionic canine amphibious robot, and in particular to the structural design, paddling gait planning and testing device of a bionic canine amphibious robot, belonging to the technical field of amphibious robots. Background Art

[0002] After a long evolutionary process, animals in nature have developed excellent adaptability to complex natural environments. For example, in order to survive and hunt, agile mammals such as canines and cats have demonstrated much better terrain adaptability in the wild environment. Behind this is the result of their special body structure and movement gait. These characteristics have attracted widespread attention from robotics researchers. The four-legged robots designed to imitate canines and cats, such as ANYmal, MITCheetah, HyQReal, SPOTmini, Jueying and UnitreeRobot, have become more mature in structural design, and some have even been commercialized. These mammal-inspired quadruped robots By integrating reinforcement learning and other intelligent motion control algorithms, quadruped robots can imitate real mammals in nature and walk and move in complex terrains such as grass, mud, snow and sand, maintaining good balance and maneuverability, and demonstrating their great value in application scenarios such as field search and rescue and inspection services. Although these bionic quadruped robots have excellent performance on land, there is a relative lack of research on their propulsion mechanisms and mechanical models for movement in water. When performing field search and rescue and exploration missions, robots often face challenges from changing climates and diverse geological environments, especially complex aquatic and terrestrial environments, such as small rivers and lakes. The lack of movement ability in water will become an obstacle to their mission execution.

[0003] At the same time, with the development of industrial technology, the requirements for robot motion stability and controllability are becoming increasingly higher, but the force conditions of robots during movement in underwater environments are usually difficult to calculate or directly measure through existing sensing technologies.

[0004] Most of the existing robots that can realize amphibious functions use two sets of propulsion devices to propel themselves in water and land environments respectively.

[0005] For example, patent CN202110998674.5 proposes a multi-terrain amphibious robot with wheels and fins. The robot uses a wheel structure for land propulsion on land and a flexible fin surface for propulsion underwater. That is, there are two sets of propulsion devices to propel the robot in the water and land environment respectively. This increases the complexity of the robot's mechanical structure and motion control, and the propulsion force generated by the flexible fin surface is relatively small. At the same time, the force condition of the robot in the water is not analyzed.

[0006] The patent CN112265420B only uses one set of propulsion devices for both land and water propulsion. The robot uses a composite crank rocker slider mechanism as a propulsion mechanism. It can walk on land and swing in water to provide thrust, so that the robot can quickly switch between land and water environments. It solves the problem that propellers are easily damaged in water. However, the water gait used in this invention is relatively simple and is not based on the principle of bionics. It does not have a very high movement efficiency, but the force conditions of the robot in water are not analyzed.

[0007] Another example is patent CN113459738B, which includes a support frame, an electronic control component, a sealed shell, a floating leg and a flexible driving module for webbed feet. The four floating legs are arranged on the front and rear sealing cover plates of the sealed shell in a centrally symmetrical manner. A flexible driving module for webbed feet is arranged at the calf of each floating leg. The flexible driving module for webbed feet is arranged in the sealed shell of the robot, and the driving force is transmitted to the webbed foot mechanism through a flexible rope to control the floating leg to switch between the foot form and the webbed foot form, so that it can maintain the ability of the legged robot to move on land and obtain the ability to swim or walk underwater. However, the patent still does not analyze the stress conditions generated by the proposed underwater movement scheme, and the structural design mentioned is based on the adjustment of the webbed foot structure, and does not have the structural universality of the current quadrupedal robot.

[0008] Deficiencies in the existing technology:

[0009] Most existing amphibious robots use two sets of propulsion devices or deformation devices to achieve movement in water environments and land environments respectively, which increases the complexity of the mechanical structure and the complexity of the control algorithm. Even if some robots can achieve movement in water and land environments using only one device, their gait in water is not flexible enough and their movement efficiency is not high.

[0010] The existing methods for calculating the underwater force of amphibious robots can be roughly divided into three types: theoretical calculation, finite element simulation and actual measurement. Since the hydrodynamic formula acting on the legs during paddling is related to the speed, it can be seen from the first-order differential kinematics of the robot that the movement speed of each microelement of the leg is related to its position on the leg. Therefore, the leg hydrodynamics of paddling involves integral calculation, and it is too difficult to perform theoretical calculations. Although the method based on Fluent finite element simulation is desirable, the underwater force on the quadruped robot is too complex, resulting in a long calculation time. In addition, the finite element simulation method cannot correctly describe the connection relationship between the joints, resulting in the possible inaccuracy of the transmission of the hydrodynamic force of the whole machine. Therefore, by building an actual measurement device, the force on the single leg and the whole machine of the amphibious quadruped robot during underwater movement can be clearly and effectively obtained. However, the existing technology still lacks a method for direct measurement. In most cases, the force can only be obtained indirectly, such as measuring the robot's posture information through IMU, estimating the current state information of the quadruped robot, and combining the dynamic model to calculate the robot's force condition. This has high requirements on the accuracy of model establishment and the method is relatively complicated.

[0011] Therefore, a bionic canine amphibious robot with structural design, paddling gait planning and testing equipment is needed to improve the above-mentioned deficiencies. Summary of the invention

[0012] The main purpose of the present invention is to provide a structural design, paddling gait planning and testing device for a bionic canine amphibious robot.

[0013] The purpose of the present invention can be achieved by adopting the following technical solutions:

[0014] A structural design, paddling gait planning and testing device of a bionic canine amphibious robot, comprising a body lower cover for limiting, the body lower cover is installed on the amphibious quadruped robot, and the lower legs cover 1, lower legs cover 2, knee joint motor, thigh cover 2, thigh cover 1 and hip joint motor are installed on both sides of the body lower cover on the thigh cover 2 in a correspondingly alternating manner;

[0015] Hip joint motors are symmetrically installed on both sides of the lower cover of the fuselage, thigh cover one is installed on the output end of the hip joint motor, thigh cover one is covered with thigh cover two on the outside, and knee joint motors are installed on the inside of thigh cover two and the end of thigh cover one;

[0016] The output end of the knee joint motor is provided with a calf cover 2, and the outer side of the calf cover 2 is covered with a calf cover 1;

[0017] The lower cover of the fuselage, the thigh cover 1, the thigh cover 2, the knee joint motor, the calf cover 2 and the calf cover 1 are covered with a waterproof component;

[0018] An operating module assembly is installed in the lower cover of the fuselage;

[0019] A guide limit assembly is installed on the lower cover of the fuselage.

[0020] Preferably, the lower cover of the fuselage is correspondingly covered with the upper front cover and the upper rear cover of the fuselage, the upper rear cover of the fuselage is equipped with a power switch, and the upper front cover of the fuselage is respectively equipped with a code burning port and a charging port.

[0021] Preferably, the waterproof component includes a fuselage lower cover interlayer, a hip joint fixing interlayer, a calf cover interlayer, a fuselage upper cover interlayer, a thigh cover interlayer and a single chip computer;

[0022] The fuselage lower cover interlayer is installed around the inner side of the fuselage lower cover, the fuselage upper cover interlayer is installed around the inner and outer circles of the fuselage front cover and the fuselage rear cover shells, the thigh cover interlayer is installed at the joint between the inner side of thigh cover two and thigh cover one, a hip joint fixing interlayer one is installed at one end of the fuselage lower cover, a single-chip computer is installed on the right side of the hip joint fixing interlayer one, a calf cover interlayer is installed at the joint between the inner side of calf cover two and calf cover one, and the fuselage lower cover interlayer and the fuselage upper cover interlayer are fitted and connected to each other.

[0023] Preferably, the operation module assembly separates the communication module, and the communication module is installed on one side of the single-chip microcomputer in the lower cover of the fuselage.

[0024] Preferably, the guide limit assembly includes a quadruped robot fixing frame, a guide rail, a slide rail support plate, a sensor connector, a force sensor, an upper sensor fixing frame, a lower sensor fixing frame, a profile and a small slider;

[0025] The outer side of the amphibious quadruped robot is clamped and installed with a quadruped robot fixing frame, the upper end of the quadruped robot fixing frame is installed with a slide rail support plate, the two sides of the slide rail support plate are symmetrically installed with an upper sensor fixing frame and a lower sensor fixing frame, a sensor connector and a force sensor are installed between the upper sensor fixing frame and the lower sensor fixing frame, the slide rail support plate is sleeved on the profile, a small slider is flipped on the guide rail, the guide rail is fixed to the slide rail support plate by screws and nuts, the slide rail support plate is clamped on the profile by screws and nuts, guide rails are installed on both sides of the slide rail support plate, the upper sensor fixing frame and the lower sensor fixing frame are adjusted and connected along the guide rails.

[0026] Preferably, thigh cover 1 and thigh cover 2 are assembled and the knee joint motor is fixed using the reserved holes at both ends.

[0027] Preferably, the small slider and the quadruped robot fixing frame move up and down with the amphibious quadruped robot, and the lower cover of the fuselage, the upper front cover of the fuselage and the upper rear cover of the fuselage are sealed and connected by the first waterproof glue coating point and the second waterproof glue coating point.

[0028] Preferably, the amphibious quadruped robot is connected by linear motion along the guide rail under the action of water power.

[0029] Preferably, the calf cover 1, calf cover 2, knee joint motor, thigh cover 2, thigh cover 1 and hip joint motor symmetrical on both sides of the amphibious quadruped robot are structures that move alternately with one side forward and the other side backward.

[0030] A structural design and paddling gait planning test method of a bionic canine amphibious robot, based on the structural design and paddling gait planning test device of a bionic canine amphibious robot described in claims 1-9, further comprising the following steps:

[0031] Step 1: The profiles are connected vertically through die-cast angle aluminum and then fastened with bolts. The two slide rail support plates are fixed by screws to wrap the aluminum profiles. The guide rails are placed on the top of the support plates and stuck in the groove of the small slider with a smooth surface. The two quadruped robot fixing frames are fixed by screws, with the upper support surface placed on the small slider, and the large groove at the lower end is used to clamp the body of the amphibious quadruped robot.

[0032] Step 2: The clamping plate and the slider can follow the robot's forward movement. The rear end of the quadruped robot's fixed frame is first fixed with a sensor fixing piece by screws, and the sensor connector 1 and the connector are then fixed in the axial direction by cylindrical pins; a force sensor is clamped between the sensor connector and the sensor fixing frame, and the groove of the sensor fixing frame is also stuck on the guide rail, and the fixing frames are fastened with screws;

[0033] Step 3: Sensor connection parts 1. Force sensor, upper sensor bracket and lower sensor bracket follow the up and down movement of the amphibious quadruped robot, rather than measuring the forward and backward movement of the drag force. The connection method of the parts is the same in measuring thrust and drag force, only the installation method of the profile and the splint is changed. The shell of the quadruped robot is made of PLA material 3D printing, and the rotation joint of the leg is built by a waterproof motor;

[0034] Step 4: When the legs of the amphibious quadruped robot are subject to thrust or resistance while moving underwater, the quadruped robot drives the clamping plate, fixing frame, connecting parts, etc. supported by the aluminum profile to move linearly along the guide rail under the action of hydrodynamic force because the grooves of the small slider and the lower fixing frame of the sensor are smooth enough. The upper fixing frame of the sensor is completely stuck, and the lower fixing frame of the sensor is movable. The strain sensor measures the force received by the change of strain, so one end is stuck and the other end is movable, that is, one end of the sensor is fixed to the upper fixing frame of the sensor, and the other end is connected to the lower fixing frame of the sensor and is movable;

[0035] The profile, sensor, upper sensor mounting frame, slide rail, and guide rail support plate are all fixed, while the amphibious quadruped robot, quadruped robot mounting frame, sensor lower mounting frame, and connector will move on the slide rail according to the force received;

[0036] Step 5: Since the force sensor is clamped by the sensor connector 1, the upper sensor bracket and the lower sensor bracket, when the robot moves forward, the force sensor can measure the thrust provided by the bracket, which is the total thrust of paddling; when the amphibious quadruped robot moves backward, the force sensor can measure the thrust provided by the sensor connector, which is the total resistance of paddling;

[0037] Step 6: When the amphibious quadruped robot is subjected to force, it drives the quadruped robot fixing frame and the lower fixing frame of the sensor to move on the small slider, thereby changing the strain of the sensor. The thrust is the lift of the amphibious quadruped robot when paddling. When the force is downward, the force sensor detects the thrust of the upper fixing frame and the lower fixing frame of the sensor, which is the negative lift of the robot when paddling. By comparing the two force measuring devices, it can be found that only by modifying the installation method of the aluminum profile and the installation method of the splint, the force conditions in multiple directions can be measured.

[0038] Beneficial technical effects of the present invention:

[0039] The present invention provides a structural design, paddling gait planning and testing device of a bionic canine amphibious robot.

[0040] 1) In view of the shortcomings of the current amphibious robot propulsion structure being complex or requiring a deformable structure to achieve propulsion in an amphibious environment, the invention does not require an additional propulsion device, and uses the same propulsion device both on land and underwater to achieve movement, that is, the four-legged robot on land uses the foot end to support the ground and the legs to swing alternately to move forward, and the four-legged robot in water relies on the paddling movement of the legs to propel itself, without the need for an additional propulsion device or a deformable device;

[0041] 2) To realize the underwater movement of quadruped robots, based on the principle of bionics, two paddling gaits of quadruped robots are proposed, namely Lateral-Sequence Padding Gait (LSPG) and Trot-Like Padding Gait (TLPG), in order to enable the robot to achieve underwater movement by imitating the movements of mammals in nature. The two gaits in the water environment have their own advantages and disadvantages and are suitable for different environments. The gait that meets the movement requirements can be selected according to the specific situation in the current environment. For example, when the water surface is calm, the gait LSPG with faster speed but poorer stability can be selected. When the water surface waves are large and the robot needs to pass through the river more stably, LSPG can be selected.

[0042] 3) The present invention uses the principle of bionics to allow the robot to imitate the gait of mammals in nature to achieve faster and more efficient water environment movement. This gait is more scientific and reasonable, and can achieve movement in land and water environments without additional propulsion devices or deformation devices. The mechanical structure is simple, and compared with the current quadruped robot, some sandwich waterproof structures are added;

[0043] 4) Compared with the prior art, the present invention can directly obtain the numerical value of the force exerted on the object under test when it moves underwater, without the need for the additional calculation and fitting steps required by the stiffness calculation method proposed in the prior patent. At the same time, the numerical values ​​of forces in two opposite directions can be measured at a time, and the force conditions in other directions can be measured by only changing the connection direction of the aluminum profile. The degree of integration is good, and when the gait of the robot moving underwater is changed, the force measuring device can still accurately measure the force exerted, and has good adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 A schematic diagram of a quadruped robot leg assembly according to a preferred embodiment of a structural design, paddling gait planning and testing device for a bionic canine amphibious robot of the present invention;

[0045] Figure 2 A schematic diagram of a quadruped robot interface according to a preferred embodiment of a structural design, paddling gait planning and testing device of a bionic canine amphibious robot of the present invention;

[0046] Figure 3 A schematic diagram of a quadruped robot body assembly according to a preferred embodiment of a structural design, paddling gait planning and testing device of a bionic canine amphibious robot of the present invention;

[0047] Figure 4 A schematic diagram of a waterproof structure of a quadruped robot according to a preferred embodiment of a structural design, paddling gait planning and testing device of a bionic canine amphibious robot of the present invention;

[0048] Figure 5 A side view of a device for measuring drag and thrust according to a preferred embodiment of a structural design, paddling gait planning and testing device of a bionic canine amphibious robot of the present invention;

[0049] Figure 6 A front view of a device for measuring drag and thrust according to a preferred embodiment of a structural design, paddling gait planning and testing device of a bionic canine amphibious robot of the present invention;

[0050] Figure 7It is an assembly detail diagram of a drag force and thrust measuring device according to a preferred embodiment of a structural design, paddling gait planning and testing device of a bionic canine amphibious robot of the present invention;

[0051] Figure 8 It is an assembly detail diagram of a drag force and thrust measuring device according to a preferred embodiment of a structural design, paddling gait planning and testing device of a bionic canine amphibious robot of the present invention;

[0052] Fig. 9 It is an assembly detail diagram of a lift and resistance measuring device according to a preferred embodiment of a structural design, paddling gait planning and testing device of a bionic canine amphibious robot of the present invention;

[0053] Fig.10 A side view of a lift and drag measuring device according to a preferred embodiment of a structural design, paddling gait planning and testing device of a bionic canine amphibious robot of the present invention;

[0054] Fig.11 A preferred embodiment of the structural design, paddling gait planning and testing device of a bionic canine amphibious robot according to the present invention includes: (a) a phase diagram of the limbs of a real canine mammal swimming and paddling; (b) a schematic diagram of the robot's leg paddling in the Power Phase; and (c) a schematic diagram of the robot's leg paddling in the Recovery Phase.

[0055] Fig.12 A schematic diagram of the stages of a quadruped robot paddling gait according to a preferred embodiment of a structural design, paddling gait planning and testing device for a bionic canine amphibious robot of the present invention;

[0056] Fig.13 The Lateral-SequencePaddingGait proposed in (a) of a preferred embodiment of the structural design, paddling gait planning and testing device of a bionic canine amphibious robot of the present invention is derived from the paddling action of canine mammals; the Trot-LikePaddingGait gait limb phase diagram proposed in (b) is derived from the paddling action of mink mammals;

[0057] Fig.14 A schematic diagram of a canine mammal's paddling limb motion according to a preferred embodiment of a structural design, paddling gait planning and testing device of a bionic canine amphibious robot of the present invention;

[0058] Fig.15In accordance with a preferred embodiment of the structural design, paddling gait planning and testing device of a bionic canine amphibious robot of the present invention, Fourier function is used to fit 12 key positions, (a) the fitting situation where PowerPhase accounts for 50%, and (b) the schematic diagram of the fitting situation where PowerPhase accounts for 25%.

[0059] In the figure: 1. quadruped robot fixing frame; 2. guide rail; 3. slide rail support plate; 4. amphibious quadruped robot; 5. sensor connector 1; 6. force sensor; 7. sensor upper fixing frame; 8. sensor lower fixing frame; 9. profile; 10. small slider; 11. calf cover 1; 12. calf cover 2; 13. knee joint motor; 14. thigh cover 2; 15. thigh cover 1; 16. hip joint motor; 17. fuselage lower cover; 18. waterproof glue application point 1; 19. power switch; 20. code burning port; 201. charging port; 21. fuselage front cover; 22. fuselage upper and rear covers; 23. waterproof glue application point 2, 24. fuselage lower cover interlayer; 25. communication module; 26. hip joint fixing interlayer; 27. calf cover interlayer; 28. fuselage upper cover interlayer; 29. ​​thigh cover interlayer; 30. single chip microcomputer. DETAILED DESCRIPTION

[0060] In order to make the technical solution of the present invention more clear and specific to those skilled in the art, the present invention is further described in detail below in conjunction with embodiments and drawings, but the implementation manner of the present invention is not limited thereto.

[0061] like Figure 1 - Fig.10 As shown, the structural design, paddling gait planning and testing device of a bionic canine amphibious robot provided in this embodiment includes a body lower cover 17 for limiting, the body lower cover 17 is installed on the amphibious quadruped robot 4, and the lower leg cover 1 11, the lower leg cover 2 12, the knee joint motor 13, the thigh cover 2 14, the thigh cover 1 15 and the hip joint motor 16 are installed on both sides of the body lower cover 17 on the thigh cover 2 14 in an alternating manner;

[0062] Hip joint motors 16 are symmetrically mounted on both sides of the lower cover 17 of the fuselage, thigh cover 15 is mounted on the output end of the hip joint motor 16, thigh cover 15 is covered on the outer side of thigh cover 15 by thigh cover 2 14, and knee joint motors 13 are mounted on the inner side of thigh cover 2 14 and the end of thigh cover 1 15;

[0063] The output end of the knee joint motor 13 is installed with a calf cover 2 12, and the outer side of the calf cover 2 12 is covered with a calf cover 1 11;

[0064] The body lower cover 17, thigh cover one 15, thigh cover two 14, knee joint motor 13, calf cover two 12 and calf cover one 11 are covered with waterproof components;

[0065] An operating module assembly is installed in the lower cover 17 of the fuselage;

[0066] A guide and limit assembly is installed on the lower cover 17 of the fuselage.

[0067] The amphibious quadruped robot 4 is driven by the hip joint motor 16 and the knee joint motor 13, and the two sides of the lower body cover 17 on the thigh cover 2 14 are correspondingly installed with the calf cover 1 11, the calf cover 2 12, the thigh cover 2 14 and the thigh cover 1 15 to move alternately.

[0068] The lower body cover 17 is correspondingly covered with an upper front cover 21 and an upper rear cover 22 . The upper rear cover 22 is provided with a power switch 19 . The upper front cover 21 is provided with a code burning port 20 and a charging port 201 .

[0069] The waterproof component includes a fuselage lower cover interlayer 24, a hip joint fixing interlayer 26, a calf cover interlayer 27, a fuselage upper cover interlayer 28, a thigh cover interlayer 29 and a single chip computer 30;

[0070] A fuselage lower cover interlayer 24 is installed around the inner side of the fuselage lower cover 17, an fuselage upper cover interlayer 28 is installed around the inner and outer circles of the fuselage front cover 21 and the fuselage rear cover 22, a thigh cover interlayer 29 is installed at the joint between the inner side of the thigh cover 2 14 and the thigh cover 1 15, a hip joint fixing interlayer 1 26 is installed at one end of the fuselage lower cover 17, a single-chip computer 30 is installed on the right side of the hip joint fixing interlayer 1 26, a calf cover interlayer 27 is installed at the connection between the inner side of the calf cover 2 12 and the calf cover 1 11, and the fuselage lower cover interlayer 24 and the fuselage upper cover interlayer 28 are connected to each other.

[0071] The operation module assembly separates the communication module 25 , and the communication module 25 is installed on one side of the single chip microcomputer 30 in the lower cover 17 of the fuselage.

[0072] The guide limit assembly includes a quadruped robot fixing frame 1, a guide rail 2, a slide rail support plate 3, a sensor connector 5, a force sensor 6, an upper sensor fixing frame 7, a lower sensor fixing frame 8, a profile 9 and a small slider 10;

[0073] The outer side of the amphibious quadruped robot 4 is clamped and installed with a quadruped robot fixing frame 1, and a slide rail support plate 3 is installed on the upper end of the quadruped robot fixing frame 1. The upper sensor fixing frame 7 and the lower sensor fixing frame 8 are symmetrically installed on both sides of the slide rail support plate 3. A sensor connector 5 and a force sensor 6 are installed between the upper sensor fixing frame 7 and the lower sensor fixing frame 8. The slide rail support plate 3 is sleeved on the profile 9, and the small slider 10 is flipped on the guide rail 2. The guide rail 2 is fixed on the slide rail support plate 3 by screws and nuts. The slide rail support plate 3 is clamped on the profile 9 by screws and nuts. The guide rails 2 are installed on both sides of the slide rail support plate 3, and the upper sensor fixing frame 7 and the lower sensor fixing frame 8 are adjusted and connected along the guide rail 2;

[0074] The clamping plate and the slider can follow the robot's forward movement. The rear end of the quadruped robot fixing frame 1 is first fixed with a sensor fixing piece by screws, and the sensor connecting piece 1 and the connecting piece are then fixed in the axial direction by cylindrical pins. A force sensor 6 is clamped between the sensor connecting piece 2 and the sensor fixing frame. The groove of the sensor fixing frame is also stuck on the guide rail 2, and the fixing frames are fastened with screws.

[0075] The sensor connector 1 5, the force sensor 6, the upper sensor bracket 7 and the lower sensor bracket 8 follow the up and down movement of the amphibious quadruped robot 4, rather than measuring the forward and backward movement of the drag force. The connection method of the parts is the same in measuring thrust and drag force, but the installation method of the profile and the splint is changed. The shell of the quadruped robot is made of PLA material 3D printing, and the rotation joint of the leg is built by a waterproof motor;

[0076] The profile 9 is vertically connected by die-casting angle aluminum and then fastened by bolts. The two slide rail support plates are fixed by screws to wrap the aluminum profile. The guide rail 2 is placed on the top of the support plate and stuck in the groove of the small slider 10 with a smooth surface. The two quadruped robot fixing frames 1 are fixed by screws, and the upper support surface is placed on the small slider 10. The large groove at the lower end is used to clamp the body of the amphibious quadruped robot 4.

[0077] When the legs of the amphibious quadruped robot 4 are subject to thrust or resistance while moving underwater, the quadruped robot, under the action of hydrodynamic force, drives the splints, fixing frames, connectors, etc. supported by the aluminum profile to move in a straight line along the guide rail 2 because the grooves of the small slider 10 and the upper sensor fixing frame 7 and the lower sensor fixing frame 8 are smooth enough.

[0078] Thigh cover 1 15 and thigh cover 2 14 are assembled and the knee joint motor 13 is fixed by using the reserved holes at both ends.

[0079] The small slider 10 and the quadruped robot fixing frame 1 move up and down following the amphibious quadruped robot 4 , and the fuselage lower cover 17 , the fuselage front cover 21 , and the fuselage upper rear cover 22 are sealed and connected by a waterproof glue coating location 18 and a waterproof glue coating location 23 .

[0080] The amphibious quadruped robot 4 is connected by linear motion along the guide rail 2 under the action of water power.

[0081] The amphibious quadruped robot 4 has a symmetrical lower leg cover 11, lower leg cover 2 12, knee joint motor 13, thigh cover 2 14, thigh cover 1 15 and hip joint motor 16, which are structures that move alternately one side forward and one side backward.

[0082] like Figure 1 - Fig.10 As shown, the working process of the structural design, paddling gait planning and testing device of a bionic canine amphibious robot provided in this embodiment is as follows:

[0083] Step 1: The profile 9 is vertically connected by die-casting angle aluminum, and then fastened by bolts. The two slide rail support plates are fixed by screws and then wrapped with the aluminum profile. The guide rail 2 is placed on the top of the support plate and stuck in the groove of the small slider 10 with a smooth surface; the two quadruped robot fixing frames 1 are fixed by screws, and the upper support surface is placed on the small slider 10, and the large groove at the lower end is used to clamp the fuselage of the amphibious quadruped robot 4;

[0084] Step 2: The clamping plate and the slider can follow the robot's forward movement. The rear end of the quadruped robot fixing frame 1 is first fixed with a sensor fixing piece by screws, and the sensor connecting piece 1 5 and the connecting piece are then fixed in the axial direction by cylindrical pins; a force sensor 6 is clamped between the sensor connecting piece 2 and the sensor fixing frame, and the groove of the sensor fixing frame is also stuck on the guide rail 2, and the fixing frames are fastened with screws;

[0085] Step 3: The sensor connector 1 5, force sensor 6, upper sensor bracket 7 and lower sensor bracket 8 follow the up and down movement of the amphibious quadruped robot 4, rather than measuring the forward and backward movement of the drag force. The connection method of the parts is the same in measuring thrust and drag force, only the installation method of the profile and the splint is changed. The shell of the quadruped robot is made of PLA material 3D printing, and the rotation joint of the leg is built by a waterproof motor;

[0086] Step 4: When the legs of the amphibious quadruped robot 4 are subject to thrust or resistance while moving underwater, the small slider 10 and the grooves of the sensor lower fixing frame 8 are smooth enough, so the quadruped robot drives the clamping plate, fixing frame, connecting parts and the like supported by the aluminum profile to move linearly along the guide rail 2 under the action of hydrodynamic force. The upper fixing frame 7 of the sensor is completely stuck, and the lower fixing frame 8 of the sensor is movable. The strain sensor measures the force received by the change of strain, so one end is stuck and the other end is movable, that is, one end of the sensor is fixed to the upper fixing frame 7 of the sensor, and the other end is connected to the lower fixing frame 8 of the sensor and is movable;

[0087] The profile 9, the sensor 6, the upper sensor bracket 7, the slide rail 2, and the guide rail support plate 3 are all fixed, and the amphibious quadruped robot 4, the quadruped robot bracket 1, the lower sensor bracket 8, and the connector 5 will move on the slide rail according to the force received;

[0088] Step 5: Since the force sensor 6 is clamped by the sensor connector 5, the upper sensor fixing frame 7 and the lower sensor fixing frame 8, when the robot moves forward, the force sensor 6 can measure the thrust provided by the fixing frame, and the thrust is the total thrust of paddling; when the amphibious quadruped robot 4 moves backward, the force sensor 6 can measure the thrust provided by the sensor connector, and the thrust is the total resistance of paddling;

[0089] Step six: When the amphibious quadruped robot 4 is subjected to force, it drives the quadruped robot fixing frame 1 and the lower fixing frame 8 of the sensor to move on the small slider 10, thereby changing the strain of the sensor. The thrust is the lift experienced by the amphibious quadruped robot 4 when paddling. When the force is downward, the force sensor 6 detects the thrust of the upper fixing frame 7 and the lower fixing frame 8 of the sensor, which is the negative lift experienced by the robot when paddling. By comparing the two force measuring devices, it can be found that only by modifying the installation method of the aluminum profile and the installation method of the splint, the force conditions in multiple directions can be measured.

[0090] Embodiment 1

[0091] Use a sandwich structure for waterproofing, see the specific picture Figure 4 There is a layer between the upper and lower covers of the fuselage to enhance the sealing and prevent water penetration;

[0092] An extra space is reserved above the body for code burning and battery charging. When code burning and battery charging are not needed, it is sealed with silicone and covered with waterproof tape. When code burning and charging are needed, the tape and silicone are peeled off. It is easier to charge than disassembling the body to take out the battery. The specific picture can be seen Figure 2 ;

[0093] In order to lower the center of gravity of the quadruped robot and increase the center of buoyancy, the amphibious quadruped robot uses direct knee joint drive, and installs the drive motor at the knee joint to lower the center of gravity of the quadruped robot. To increase buoyancy, the volume of the fuselage can be increased, but in order to reduce the resistance brought by the fuselage, the volume is increased by the height or length of the fuselage, not the width. The length, width, and height ratio of the robot's body is about 15:5:3;

[0094] In order to maximize the propulsion of the quadruped robot underwater, we need to expand the width of the robot's legs, that is, widen the width of the quadruped robot's legs. However, too wide a leg width will add extra weight and affect its mobility on land. Therefore, we increase the width of the robot's legs to the same width as the motor, and use a hollow cavity structure to widen the robot's leg structure without adding too much weight, thereby achieving a larger contact area between the legs and the water and increasing the propulsion ability. The specific picture can be seen Figure 1 ;

[0095] Necessary components for the robot underwater force measuring device:

[0096] The device bracket is constructed of profile 9, quadruped robot fixing frame 1, sensor connector 1 5, sensor connector 25, sensor fixing frame 7, guide rail 2, small slider 10, slide rail support plate 3, force sensor 6, amphibious quadruped robot 4 and several screws. The device numbers for measuring drag force, thrust, lift and resistance are the same as shown in the following figure description. Figure 5-10 Several die-cast aluminum angles, 2 quadruped robot fixing frames, 2 sensor connectors, a sensor fixing frame, a guide rail, a small slider, 2 slide rail support plates, a one-dimensional force sensor, a quadruped robot, and several screws;

[0097] Connection of force measuring device parts: Profile 9 is vertically connected by die-casting angle aluminum and then fastened by bolts. Two slide rail support plates are fixed by screws to wrap the aluminum profile. The guide rail 2 is placed on the top of the support plate and stuck in the groove of the small slider 10 with a smooth surface.

[0098] After two quadruped robot clamps 1 are fixed by screws, the upper support surface is placed on the small slider 10, and the large groove at the lower end is used to clamp the quadruped robot body. The clamp and the slider can move forward with the robot. The rear end of the quadruped robot fixing frame 1 is first fixed by screws to a sensor fixing part 1, and the sensor connecting part 1 and the connecting part 2 are then screwed to ensure the fixing in the axial direction;

[0099] A force sensor is clamped between the sensor connector 2 and the sensor fixing frame, the groove of the sensor fixing frame is also stuck on the guide rail 2, and the fixing frames are fastened with screws;

[0100] The devices for measuring drag and lift are based on the same principles. The only difference is that the slider and sensor plate follow the robot up and down, rather than measuring the forward and backward movement of the drag force. The connection method of the parts is the same in measuring thrust and drag, only the installation method of the profiles and the splints is changed. The shell of the quadruped robot is made of 3D printed PLA material, and the rotating joints of the legs are built with waterproof motors to ensure stable experimental power.

[0101] Embodiment 2

[0102] like Figure 7 When the quadruped robot or its legs are subject to thrust or resistance while moving underwater, the grooves of the slider and the sensor holder are smooth enough, so the quadruped robot drives the clamping plate, the holder, the connecting parts and the like supported by the aluminum profile to move linearly along the guide rail under the action of the hydrodynamic force. Since the force sensor is clamped by the connecting parts and the holder, when the robot moves forward, the force sensor can measure the thrust provided by the holder, which is the total thrust of the stroke. When the robot moves backward, the force sensor can measure the thrust provided by the sensor connecting parts, which is the total resistance of the stroke.

[0103] like Fig. 9 When the robot is acted on by water upward, the force sensor measures the thrust provided by the fixed frame, which is the lift force of the robot when paddling. When the force is downward, the force sensor detects the thrust of the fixed frame, which is the negative lift force of the robot when paddling. By comparing the two force measuring devices, it can be found that only by modifying the installation method of the aluminum profile and the installation method of the splint, the force conditions in multiple directions can be measured.

[0104] The underwater gait of the bionic quadruped amphibious robot is proposed and its principle is introduced:

[0105] In order to help quadruped robots advance in water environments, the traditional land motion scheme may not work. We propose two swimming gaits suitable for bionic quadruped amphibious robots to advance underwater, which can help quadruped robots cope with water environments. When quadruped robots need to cross rivers during field operations, they can cross the rivers by gait conversion. The proposed swimming gaits are Lateral-Sequence Padding Gait (LSPG), which is translated into lateral sequence paddling gait in Chinese, and Trot-Like Padding Gait (TLPG), which is translated into diagonal paddling gait in Chinese. Fig.13 , (a) is the present invention based on Fig.11 ,(a) Phase diagram of the limbs of the optimized quadruped robot when swimming.,In a complete stroke cycle, there are two main phases, namely PowerPhase and RecoveryPhase. Fig.11 , (b) shows that the robot's legs are paddling backwards. At this time, the legs are stretched as much as possible to obtain a larger contact area with the water, thereby generating a greater forward propulsion force. The recovery phase is as follows Fig.11 In (c), the robot's legs are shrunk as much as possible to keep parallel to the body, reducing the force acting on the water, thereby reducing the resistance on the legs. Through the periodic and repeated movement of the legs, the propulsion force of the legs is greater than the resistance, thus achieving the forward movement of mammals;

[0106] The power phase of the four-limb paddling of real canine mammals accounts for about 24.3% to 33.7%. This data comes from a bionics paper. Figure 1 In (a), LH stands for LeftHind, i.e., the left hind leg, LFLeftFront is the left front leg, RFRightFront is the right front leg, and RHRightHind is the right hind leg. Therefore, the figure expresses the proportion of the four-legged power stage of real canine mammals in the entire cycle. Fig.11 , (a) Phase diagram of the limbs of a real canine mammal swimming and paddling, (b) Schematic diagram of the robot leg paddling in the PowerPhase stage, (c) Schematic diagram of the robot leg paddling in the RecoveryPhase stage;

[0107] like Fig.12 As shown, state 1 indicates that the robot's right front leg is at the end of the power stage and is about to enter the recovery stage. State 2 indicates that the robot's right front leg is at the end of the recovery stage and is about to enter the power stage. The following is a detailed introduction to Lateral-SequencePaddingGait. The phase diagram is shown in Fig.13 , (a) shows that compared with Fig.11 ,(a) Phase diagram of a real canine mammal. The power phases of the four limbs are different. We made some simplifications and evenly distributed the power phases of the robot's four legs with the same proportion, which is 25%. LSPG imitates the swimming action of canine mammals in nature. The four legs take turns to do the paddling action to achieve the paddling sequence of the four legs as LH-RF-RH-LF. Due to the fast instantaneous paddling speed of the robot's legs and the large reaction force, the robot can get a larger acceleration and speed limit;

[0108] Next, we will introduce Trot-LikePaddingGait, which is a diagonal paddling gait. TLPG imitates the swimming action of minks in nature and realizes the robot's forward movement by paddling diagonally. The gait phase diagram is shown in the figure below: Fig.13 , as shown in (b), compared with the alternating stroke, this gait is changed to using the diagonal legs to perform the stroke respectively, and two legs are in the power stage at the same time, for example, at 0% to 50% of the cycle, LH and RF are in the power stage, at 50% and 100% of the cycle, LF and RH are in the power stage. Compared with the above-mentioned canine-like swimming gait, the power stage of this gait accounts for a larger proportion, and the relative stroke speed is slower, that is, in the same cycle, the speed of the backward stroke becomes slower, so the propulsion force obtained is smaller;

[0109] Fig.13, (a) The proposed Lateral-SequencePaddingGait, comes from the paddling action of canine mammals (b) The proposed Trot-LikePaddingGait gait limb phase diagram, comes from the paddling action of mink mammals, Summary: When the water surface is relatively calm, LSPG is used. This gait imitates canine mammals in nature. The robot propels itself in the water environment by paddling with four legs in turn. This scheme has a higher speed but poor stability. In the case of wanting to obtain a larger acceleration and speed, another gait, TLPG, is characterized by slow speed but strong stability. It is suitable for scenarios where you want to obtain higher stability but do not require high speed.

[0110] Embodiment 3

[0111] Based on the above bionic principles, we proposed two gaits to help the robot move forward in the water environment. For the robot's paddling action, we refer to the real paddling action of canine mammals, such as Fig.14 As shown in the figure, by imitating the real canine mammals’ paddling motion, we developed a paddling motion suitable for robots. We determined the range of motion and motion cycle of the thighs and calves, and decomposed a paddling motion into 12 key position points, namely Fig.11 , (b) (c) show the 12 key positions of the stroke motion we proposed;

[0112] Fig.14 , a schematic diagram of the paddling limbs of canine mammals, which comes from the paper "The "dog paddle": Stereotypic swimming gait pattern in different dog breeds";

[0113] After obtaining these 12 key positions, we actually get the angle relationship between the thigh and the calf. We get the joint angles of the 12 key positions by solving the inverse kinematics of the leg. We use Fourier function to fit the joint angles of the 12 key positions, such as Figure 5 As shown in the figure, θ1 is the angle of the thigh along the negative direction of the x-axis, and θ2 is the angle between the calf and the thigh. Fig.11 (b)(c), the Fourier function expression used is, where the various parameters can be seen in Table S1.Fourier parameter table. With the expression of the angle of the upper and lower legs over time, we only need to let the motor angle move according to this function expression to realize the robot's paddling gait;

[0114]

[0115] Table S1.Fourier parameter table

[0116]

[0117] Fig.15 - Use Fourier function to fit 12 key positions. (a) The fitting situation when PowerPhase accounts for 50%. The solid line is the fitting curve of the thigh angle changing with time, and the dotted line is the fitting curve of the calf joint angle changing with time. The solid triangle is the angle of the key position of the thigh, and the hollow triangle is the angle of the key position of the calf. (b) The fitting situation when PowerPhase accounts for 25%.

[0118] The beneficial effects of this embodiment are:

[0119] 1- The quadruped robot can move in amphibious environments without the need for additional propulsion devices or deformation devices;

[0120] 2- The underwater gait is scientific and reasonable according to the bionics principle and existing bionics articles. After experimental testing, the underwater movement speed can reach 0.6BL / s, that is, 0.6 body length / second, which has laid an important foundation for the amphibious quadruped robot.

[0121] 3- The basic structural changes to the current quadruped robot are very small, just adding waterproof function and slightly increasing the width of the quadruped robot's legs, so that it can achieve movement in amphibious environments;

[0122] 4- The underwater force measurement method proposed in the present invention solves the problem that the power exerted on an amphibious robot while moving in water is difficult to be directly obtained. Through the method of equivalent replacement, the thrust of the fixing frame or the connecting piece on the force sensor is equivalent to the thrust and resistance exerted on the quadruped robot while moving in water. The method is clear and efficient, the connection between the components is reliable, it can adapt to different underwater environments, and the force exerted on the robot can be measured without disassembling the device;

[0123] 5- By slightly changing the connection method between the aluminum profiles, the hydrodynamic conditions of the robot in the direction orthogonal to the current force measurement direction can be obtained, and the measured force is not just in one vector direction. The device can obtain the force conditions in two opposite vector directions. Compared with the existing technology, this force measurement method is more efficient and accurate, and can change the force measurement direction according to actual needs to achieve autonomous measurement without manual operation. It has a wide range of applications and can be used for force measurement of a single leg or the entire machine of an amphibious robot.

[0124] The above description is only a further embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and concepts of the present invention within the scope disclosed by the present invention, which belong to the protection scope of the present invention.

Claims

1. A bionic canine amphibious robot structure design and paddling gait planning test device, characterized by: The invention comprises a body lower cover (17) for limiting position, the body lower cover (17) being mounted on the amphibious quadruped robot (4), and the two sides of the body lower cover (17) on the thigh cover 2 (14) being correspondingly and alternately mounted with a calf cover 1 (11), a calf cover 2 (12), a knee joint motor (13), a thigh cover 2 (14), a thigh cover 1 (15) and a hip joint motor (16); Hip joint motors (16) are symmetrically mounted on both sides of the lower cover (17) of the body, thigh cover one (15) is mounted on the output end of the hip joint motor (16), thigh cover one (15) is covered on the outer side of thigh cover one (15), and knee joint motors (13) are mounted on the inner side of thigh cover two (14) and the end of thigh cover one (15); The output end of the knee joint motor (13) is installed with a calf cover 2 (12), and the outer side of the calf cover 2 (12) is covered with a calf cover 1 (11); A waterproof component is covered between the lower cover (17) of the body, the thigh cover 1 (15), the thigh cover 2 (14), the knee joint motor (13), the calf cover 2 (12) and the calf cover 1 (11); An operating module assembly is installed in the lower cover (17) of the fuselage; A guide limit assembly is installed on the lower cover (17) of the fuselage.

2. The structural design and paddling gait planning and testing device of a bionic canine amphibious robot according to claim 1, characterized in that: The fuselage lower cover (17) is correspondingly covered with a fuselage upper front cover (21) and a fuselage upper rear cover (22), a power switch (19) is installed on the fuselage upper rear cover (22), and a code burning port (20) and a charging port (201) are respectively installed on the fuselage upper front cover (21).

3. The structural design and paddling gait planning and testing device of a bionic canine amphibious robot according to claim 2, characterized in that: The waterproof component comprises a fuselage lower cover interlayer (24), a hip joint fixing interlayer (26), a calf cover interlayer (27), a fuselage upper cover interlayer (28), a thigh cover interlayer (29) and a single chip computer (30); A fuselage lower cover interlayer (24) is installed around the inner side of the fuselage lower cover (17); a fuselage upper cover interlayer (28) is installed around the inner and outer circles of the fuselage front cover (21) and the fuselage upper rear cover (22); a thigh cover interlayer (29) is installed at the joint between the inner side of the thigh cover 2 (14) and the thigh cover 1 (15); a hip joint fixing interlayer 1 (26) is installed at one end of the fuselage lower cover (17); a single chip computer (30) is installed on the right side of the hip joint fixing interlayer 1 (26); a calf cover interlayer (27) is installed at the joint between the inner side of the calf cover 2 (12) and the calf cover 1 (11); and the fuselage lower cover interlayer (24) and the fuselage upper cover interlayer (28) are connected to each other.

4. The structural design, paddling gait planning and testing device of a bionic canine amphibious robot according to claim 3 is characterized by: The operation module assembly separates the communication module (25), and the communication module (25) is installed on one side of the single chip computer (30) in the lower cover (17) of the machine body.

5. The structural design and paddling gait planning and testing device of a bionic canine amphibious robot according to claim 4, characterized in that: The guide and limit assembly comprises a quadruped robot fixing frame (1), a guide rail (2), a slide rail support plate (3), a sensor connecting piece (5), a force sensor (6), an upper sensor fixing frame (7), a lower sensor fixing frame (8), a profile (9) and a small sliding block (10); The outer side of the amphibious quadruped robot (4) is clamped and installed with a quadruped robot fixing frame (1), the upper end of the quadruped robot fixing frame (1) is installed with a slide rail support plate (3), the two sides of the slide rail support plate (3) are symmetrically installed with a sensor upper fixing frame (7) and a sensor lower fixing frame (8), a sensor connecting piece (5) and a force sensor (6) are installed between the sensor upper fixing frame (7) and the sensor lower fixing frame (8), the slide rail support plate (3) is sleeved on the profile (9), a small slider (10) is flipped on the guide rail (2), the guide rail (2) is fixed on the slide rail support plate (3) by screws and nuts, the slide rail support plate (3) is clamped on the profile (9) by screws and nuts, the guide rails (2) are installed on the two sides of the slide rail support plate (3), and the sensor upper fixing frame (7) and the sensor lower fixing frame (8) are adjusted and connected along the guide rail (2).

6. The structural design and paddling gait planning and testing device of a bionic canine amphibious robot according to claim 5, characterized in that: Thigh cover 1 (15) and thigh cover 2 (14) are assembled and the knee joint motor (13) is fixed using the reserved holes at both ends.

7. The structural design and paddling gait planning and testing device of a bionic canine amphibious robot according to claim 6, characterized in that: The small slider (10) and the quadruped robot fixing frame (1) move up and down following the amphibious quadruped robot (4), and the lower cover (17) of the fuselage, the upper front cover (21) of the fuselage, and the upper rear cover (22) of the fuselage are sealed and connected by a first waterproof glue coating point (18) and a second waterproof glue coating point (23).

8. The structural design and paddling gait planning and testing device of a bionic canine amphibious robot according to claim 7, characterized in that: The amphibious quadruped robot (4) is connected by linear motion along the guide rail (2) under the action of water power.

9. The structural design and paddling gait planning and testing device of a bionic canine amphibious robot according to claim 8, characterized in that: The symmetrical lower leg cover 1 (11), lower leg cover 2 (12), knee joint motor (13), thigh cover 2 (14), thigh cover 1 (15) and hip joint motor (16) of the amphibious quadruped robot (4) are a structure that moves alternately one side forward and the other side backward.

10. A method for testing the structural design and paddling gait planning of a bionic canine amphibious robot, based on the device for testing the structural design and paddling gait planning of a bionic canine amphibious robot according to claims 1 to 9, characterized in that: The following steps are also included: Step 1: The profile (9) is vertically connected by die-casting angle aluminum and then fastened by bolts. The two slide rail support plates are fixed by screws and then wrapped with the aluminum profile. The guide rail (2) is placed on the top of the support plate and stuck in the groove of the small slider (10) with a smooth surface; the two quadruped robot fixing frames (1) are fixed by screws, and the upper support surface is placed on the small slider (10), and the large groove at the lower end is used to clamp the body of the amphibious quadruped robot (4); Step 2: The clamping plate and the slider can follow the robot's forward movement. The rear end of the quadruped robot fixing frame (1) is first fixed with a sensor fixing piece by screws. The sensor connecting piece (5) and the connecting piece are then fixed in the axial direction by cylindrical pins. A force sensor (6) is clamped between the sensor connecting piece and the sensor fixing frame. The groove of the sensor fixing frame is also stuck on the guide rail (2). The fixing frames are fastened with screws. Step 3: The sensor connector 1 (5), the force sensor (6), the upper sensor bracket (7) and the lower sensor bracket (8) follow the up and down movement of the amphibious quadruped robot (4), rather than measuring the forward and backward movement of the drag force. The connection method of the parts is the same in measuring thrust and drag force, only the installation method of the profile and the splint is changed. The shell of the quadruped robot is made of PLA material 3D printing, and the rotation joint of the leg is built by a waterproof motor; Step 4: When the legs of the amphibious quadruped robot (4) are subject to thrust or resistance while moving underwater, the small slider (10) and the grooves of the sensor lower fixing frame (8) are sufficiently smooth, so the quadruped robot drives the clamping plate, fixing frame, connecting parts, etc. supported by the aluminum profile to move linearly along the guide rail (2) under the action of hydrodynamic force. The upper fixing frame (7) of the sensor is completely stuck, and the lower fixing frame (8) of the sensor is movable. The strain sensor measures the force received by the change of strain, so one end is stuck and the other end is movable, that is, one end of the sensor, the part fixed to the upper fixing frame (7) of the sensor is stuck, and the other end connected to the lower fixing frame (8) of the sensor is movable; The profile (9), the sensor (6), the upper sensor fixing frame (7), the slide rail (2), and the guide rail support plate (3) are all fixed, and the amphibious quadruped robot (4), the quadruped robot fixing frame (1), the lower sensor fixing frame (8), and the connecting member (5) move on the slide rail according to the force received; Step 5: Since the force sensor (6) is clamped by the sensor connecting member 1 (5), the upper sensor fixing frame (7) and the lower sensor fixing frame (8), when the robot moves forward, the force sensor (6) can measure the thrust provided by the fixing frame, and the thrust is the total thrust of paddling; when the amphibious quadruped robot (4) moves backward, the force sensor (6) can measure the thrust provided by the sensor connecting member, and the thrust is the total resistance of paddling; Step 6: When the amphibious quadruped robot (4) is subjected to force, it drives the quadruped robot fixing frame (1) and the sensor lower fixing frame (8) to move on the small slider (10) to change the strain of the sensor.

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