Multi-degree-of-freedom bionic robotic fish multifunctional hydrodynamic test platform and test method

Abstract

The invention relates to the technical field of underwater vehicle test, in particular to a multi-degree-of-freedom bionic robotic fish multifunctional hydrodynamic test platform and test method, which comprises a static water tank, a support frame, an air floating guide rail carrying platform, a four-degree-of-freedom assembly and a test system, the four-degree-of-freedom assembly is used for driving the bionic robotic fish to drag and glide in the static water tank or autonomously swim under the limitation of the direction of the four-degree-of-freedom assembly; the test system is used for detecting the speed of the bionic robotic fish in a steady cruise stage in an autonomous movement test; detecting the energy utilization rate and the thrust coefficient of the bionic robotic fish; detecting an acceleration change curve of the bionic robotic fish in autonomous swimming and a course angle change curve of the robotic fish in a turning mode, and detecting a motion track of each key position point of a body of the bionic robotic fish; and the lift-drag ratio of the bionic robotic fish in a drag gliding test is obtained. According to the invention, the hydrodynamic test of the bionic robotic fish under the free swimming test and the dragging gliding test is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of underwater vehicle testing, in particular to a multi-degree-of-freedom bionic robotic fish multifunctional hydrodynamic test platform and testing method. BACKGROUND

[0002] Deep sea contains rich material resources and unsolved mysteries. With the advancement of deep sea exploration technology, efficient and accurate deep sea observation technology is increasingly urgent. As the core equipment of deep sea exploration, the propulsion efficiency of underwater vehicles directly affects the endurance and task adaptability. Among them, bionic robotic fish has become a research hotspot due to its high efficiency and concealment of chest fin / tail fin propulsion. In the process of designing bionic robotic fish, model test is an essential step. Key hydrodynamic performance parameters of the robotic fish are obtained through model test, so as to evaluate the performance of the robotic fish and provide reference and basis for design.

[0003] However, the mechanism research of bionic robotic fish hydrodynamic performance lacks high-precision experimental data support. The existing test platform is mainly aimed at fixed bionic robotic fish model, and the model is measured by using flow with fixed speed to flush the model. The motion freedom is limited, and the real swimming condition cannot be simulated. Only the average parameters in the steady flow field can be measured, and the mechanical properties of acceleration, deceleration and turning transient process cannot be captured. The real-time coupling effect of robotic fish flapping motion and flow field is ignored in the fixed model test method, resulting in a certain deviation between the experimental data and the real swimming condition. It is difficult to simulate the mechanical dynamic data and motion posture change process of the robotic fish under real autonomous swimming, resulting in lack of empirical basis for engineering prototype design.

[0004] Therefore, it is necessary to provide a multi-degree-of-freedom bionic robotic fish multifunctional hydrodynamic test platform and testing method to solve the above problems. SUMMARY

[0005] To solve the problem that the existing test platform is mainly aimed at fixed bionic robotic fish model and uses flow with fixed speed to flush the model for measurement, the motion freedom is limited, and the real swimming condition cannot be simulated, the present application provides a multi-degree-of-freedom bionic robotic fish multifunctional hydrodynamic test platform and testing method to solve the existing problems.

[0006] The first aspect of the present application provides a multi-degree-of-freedom bionic robotic fish multifunctional hydrodynamic test platform, which adopts the following technical scheme, comprising: A still water tank made of transparent material; Support frame, which is erected on a static water tank, is provided with an air floating guide rail loading platform, the air floating guide rail loading platform is provided with a four-degree-of-freedom assembly, and the output end of the four-degree-of-freedom assembly is used for mounting a bionic robotic fish, wherein the four-degree-of-freedom assembly is used for driving the bionic robotic fish to perform a towed gliding in the static water tank or is used for the bionic robotic fish to perform autonomous swimming under the limitation of four degrees of freedom of the four-degree-of-freedom assembly; and a test system for detecting the speed of the bionic robotic fish in a steady cruising stage in autonomous movement test, the energy utilization rate of the bionic robotic fish, the thrust coefficient, the acceleration change curve of the bionic robotic fish in autonomous swimming and the heading angle change curve of the bionic robotic fish in a turning mode and the motion trajectory of each key position point of the body of the bionic robotic fish, and for obtaining the lift-drag ratio of the bionic robotic fish in a towed gliding test and the motion trajectory of each key position point of the body of the bionic robotic fish.

[0007] Further technical solutions of the present application, the air floating guide rail loading platform is a quadrilateral structure formed by connecting two short rails and two long rails, and the short rails and the long rails of the air floating guide rail loading platform are fixed on the loading support frame through a plurality of corner codes.

[0008] Further technical solutions of the present application, the four-degree-of-freedom assembly comprises: X-axis air floating guide rails, each provided with an X-axis air floating guide rail on the two long rails, and an X-axis sliding block freely sliding along the axial direction of the X-axis air floating guide rail is slidingly arranged on the X-axis air floating guide rail; An X-axis buffer is arranged on the short rail of the air floating guide rail loading platform and is used for preventing mechanical hard collision when the X-axis sliding block moves; Two Y-axis air floating guide rails, the ends of the two Y-axis air floating guide rails are connected with the corresponding X-axis sliding blocks of the two X-axis air floating guide rails through an X-axis sliding block connecting plate, and a Y-axis sliding block is slidingly arranged on the Y-axis air floating guide rail, and the bottoms of the two Y-axis sliding blocks are connected through a Y-axis sliding block connecting plate; A Z-axis air floating guide rail is arranged on the Y-axis sliding block connecting plate, and a limiting assembly limiting the position of the Z-axis air floating guide rail in the Z-axis direction is arranged on the Y-axis sliding block connecting plate, a Z-axis sliding block is slidingly arranged on the Z-axis air floating guide rail, and the Z-axis sliding block is rotationally connected with the Z-axis air floating guide rail; A connecting rod is connected to the Z-axis sliding block, and the connecting rod is parallel to the Z-axis air floating guide rail, and the end of the connecting rod away from the Z-axis sliding block is used for connecting the bionic robotic fish; And an electric driving assembly is used for driving the X-axis sliding block to move along the X-axis air floating guide rail.

[0009] The further technical scheme of the present application, the limiting assembly comprises: a limiting sleeve, one end of the limiting sleeve is fixed on the Y-axis sliding block connecting plate, the Z-axis air floating guide rail passes through the Y-axis sliding block connecting plate and then passes out from the limiting sleeve, and a hand screw is arranged on the limiting sleeve, the hand screw passes into the limiting sleeve from the outer wall of the limiting sleeve to abut against the Z-axis air floating guide rail in the limiting sleeve.

[0010] The further technical scheme of the present application, the electric driving assembly comprises: Two supports are arranged on one side of the long rail of the air floating guide rail loading platform; A stepping motor is arranged on one of the supports, and the output end of the stepping motor is connected with a driving pulley; A driven pulley is arranged on the other support; And a belt is drivingly connected with the driving pulley and the driven pulley, and the belt is detachably connected with the X-axis sliding block.

[0011] The further technical scheme of the present application, a guide rail connecting piece is arranged on the X-axis sliding block, the top of the guide rail connecting piece is connected with the Y-axis air floating guide rail, and the bottom surface of the guide rail connecting piece and the belt are connected through screws.

[0012] The further technical scheme of the present application, the test system comprises: A high-speed camera is arranged on a monitoring platform arranged on one side of the still water tank, and is used for detecting the speed of the bionic robotic fish in a steady-state cruising stage in the process of autonomous movement of the bionic robotic fish in the four-degree-of-freedom loading platform in three-axis directions; A force / torque sensor is connected between the back of the bionic robotic fish and the end of the connecting rod, and is used for detecting the mechanical data generated by the bionic robotic fish, wherein the mechanical data in the autonomous swimming test includes: thrust, lift and pitch moment, and the mechanical data in the towing gliding test includes: drag and lift; A gyroscope and an acceleration sensor are arranged on the connecting rod away from the bionic robotic fish, the gyroscope is used for detecting the yaw angle of the bionic robotic fish in the turning stage in the autonomous swimming or towing gliding, and the acceleration sensor is used for detecting the acceleration of the bionic robotic fish in the acceleration stage in the autonomous swimming test; A front-view angle camera and a side-view angle camera, the front-view angle camera is arranged on the inner wall surface corresponding to the short side of the still water tank, and the side-view angle camera is arranged on the outer side of the long wall surface of the still water tank, wherein the end of the X-axis sliding block connecting plate is connected with a fixed plate parallel to the wall surface of the still water tank in a vertical downward direction, the fixed plate is used for fixing the side-view angle camera, the side-view angle camera is used for synchronously detecting the side-view angle image in the movement process of the bionic robotic fish, and the front-view angle camera is used for synchronously detecting the front-view angle image in the movement process of the bionic robotic fish; and a computer for marking target points of videos of the living robotic fish taken by the high-speed camera in the autonomous swimming test, and measuring the speed of the living robotic fish in the steady cruising stage; according to the thrust of the living robotic fish and the speed, the energy utilization rate of the living robotic fish is obtained; the thrust of the living robotic fish is dimensionless to obtain the thrust coefficient; according to the heading angle of the living robotic fish and the acceleration of the living robotic fish, the acceleration change curve of the living robotic fish and the heading angle change curve of the living robotic fish in the turning mode are obtained; the videos taken by the front-view camera and the side-view camera in the autonomous swimming test are processed to obtain the motion trajectories of each key position point of the body of the living robotic fish; according to the lift and the drag of the living robotic fish in the towed gliding test, the lift-drag ratio of the living robotic fish is obtained; the videos taken by the front-view camera and the side-view camera in the towed gliding test are processed to obtain the motion trajectories of each key position point of the body of the living robotic fish in the towed gliding test.

[0013] In a further aspect of the present application, the length and width of the static water tank are greater than 5 times the length of the body of the living robotic fish.

[0014] In a second aspect of the present application, a water dynamic test method for free swimming test of a multi-degree-of-freedom living robotic fish is provided, which comprises: using the multi-functional water dynamic test platform for multi-degree-of-freedom living robotic fish provided in the first aspect of the present application to perform testing, and the testing steps comprise: The living robotic fish is installed at a set attack angle, and the initial position of the living robotic fish is calibrated, and the buoyancy is adjusted so that the living robotic fish is suspended in the water in the static water tank; The guide rail connecting piece is removed, so that the living robotic fish freely swims forward without the interference of the friction force of the belt; and all power supplies except the step motor are turned on; The recording software corresponding to each sensor is opened, the communication between each sensor and the computer is established, and the installation direction of each sensor is adjusted; The camera parameters of each camera are adjusted so that the captured picture is complete and clear; The living robotic fish is started, and the living robotic fish freely swims forward in the water, and test data in the swimming process are collected, which include: the mechanical data of the living robotic fish measured by the force / torque sensor, the heading angle of the living robotic fish measured by the gyroscope, the acceleration of the living robotic fish measured by the acceleration sensor, the videos taken by the high-speed camera, and the videos of the living robotic fish collected by the front-view camera and the side-view camera; After waiting for the liquid surface in the static water tank to be stable, the motion parameters of the living robotic fish are changed to perform the test again; According to the video shot by the high-speed camera, the target point is marked and the speed of the bionic robotic fish in the steady cruising stage of the autonomous swimming test is calculated, the useful work of the bionic robotic fish is obtained according to the thrust in the mechanical data of the bionic robotic fish and the calculated speed of the bionic robotic fish, the total work of the bionic robotic fish is obtained according to all parameters of the driving rudder of the bionic robotic fish, the energy utilization rate of the bionic robotic fish is obtained according to the total work and the useful work, the thrust coefficient is obtained by dimensionless processing of the thrust in the mechanical data of the bionic robotic fish, the acceleration change curve of the bionic robotic fish in the autonomous swimming and the heading angle change curve of the bionic robotic fish in the turning mode are obtained according to the heading angle of the bionic robotic fish and the acceleration of the bionic robotic fish, and the motion trajectories of the key position points of the body of the bionic robotic fish in the autonomous swimming test are obtained according to the videos shot by the front-view camera and the side-view camera.

[0015] The third aspect of the present application provides a water dynamic test method for a multi-degree-of-freedom bionic robotic fish in a towing gliding test, comprising: testing by using the multi-functional water dynamic test platform for the multi-degree-of-freedom bionic robotic fish provided by the first aspect of the present application, and the testing steps comprising: The bionic robotic fish is installed at a set attack angle, and the initial position of the bionic robotic fish is calibrated, and the buoyancy is adjusted so that the bionic robotic fish is suspended in the water of the still water tank; The guide rail connecting piece is installed, all power supplies are connected, the recording software corresponding to each sensor is opened, the communication between each sensor and the computer is established, and the installation direction of each sensor is adjusted; The camera parameters of each camera are adjusted so that the shot picture is complete and clear; The gliding posture of the bionic robotic fish is set, and after reaching the preset speed at a uniform speed or a given acceleration, uniform acceleration / uniform deceleration sliding is performed, and the operation parameters of the stepping motor are set; The stepping motor is started, and the test data of the bionic robotic fish when sliding stably in the water of the still water tank under the driving of the stepping motor are recorded, and the test data comprises: the mechanical data of the bionic robotic fish measured by the force / torque sensor, the heading angle of the bionic robotic fish measured by the gyroscope, the acceleration of the bionic robotic fish measured by the acceleration sensor, the video shot by the high-speed camera, and the video of the bionic robotic fish collected by the front-view camera and the side-view camera; After waiting for the liquid surface in the still water tank to be stable, the attack angle of the bionic robotic fish is adjusted or the gliding posture of the bionic robotic fish is changed to retest; According to the lift and drag in the mechanical data of the bionic robotic fish measured in each towing gliding test, the lift-drag ratio of the bionic robotic fish corresponding to the speed and attack angle in each towing gliding test is obtained, and the motion trajectories of the key position points of the body of the bionic robotic fish in the towing gliding test are obtained by processing the videos shot by the front-view camera and the side-view camera.

[0016] The beneficial effects of the present application are: 1. The multifunctional water dynamic test platform for multi-degree-of-freedom bionic robotic fish is proposed, the bionic robotic fish can be freely replaced according to actual conditions, and the universality of the test platform is improved. The four-degree-of-freedom assembly on the air float guide rail carrying platform realizes four-degree-of-freedom unconstrained autonomous swimming simulation of the bionic robotic fish in X / Y / Z three-direction translation and yaw angle rotation, overcomes the limitation that the traditional bionic robotic fish model fixed test table cannot simulate dynamic swimming, through cooperation of multiple high-precision sensors, the energy utilization rate, thrust coefficient, speed and acceleration of the bionic robotic fish in the acceleration stage and the steady cruising stage under the action of the thrust generated by the pectoral fin / tail fin of the bionic robotic fish can be synchronously measured, so as to measure the advantages and disadvantages of the performance parameters of the bionic robotic fish; the three-dimensional motion trajectory of the bionic robotic fish can also be recorded and reconstructed in real time through a high-speed camera and a trajectory tracking algorithm.

[0017] 2. The multifunctional water dynamic test platform and test method for multi-degree-of-freedom bionic robotic fish are proposed, for the bionic robotic fish whose main propulsion mode is pectoral fin flapping, the platform can be switched to an external force driving gliding mode. In the gliding mode, by fixing the gliding posture, driving the speed of the bionic robotic fish through the stepping motor and changing the attack angle, two of the three are changed to adjust the test, so as to measure the lift-drag ratio of the bionic robotic fish under different speeds, different attack angles and different gliding postures, and the gliding motion trajectory of the bionic robotic fish, and provide guidance for the shape design of the bionic robotic fish engineering prototype. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0019] Figure 1 It is a general structure schematic diagram of a multifunctional water dynamic test platform for multi-degree-of-freedom bionic robotic fish of the present application; Figure 2 It is a structure schematic diagram of an air float guide rail carrying platform and a four-degree-of-freedom assembly in the embodiment of the present application; Figure 3 It is a partial schematic diagram of the structure of the air float guide rail carrying platform and the four-degree-of-freedom assembly in the embodiment of the present application; Figure 4 It is a test system layout diagram of a test section in the embodiment of the present application; Figure 5 It is a test flow chart of autonomous swimming test in the embodiment of the present application; Figure 6The test flowchart of the drag gliding test in the embodiment of the present application.

[0020] In the figure: 1, a still water tank; 2, a monitoring platform; 3, a high-speed camera; 4, a support frame; 5, a Fomar wheel; 6, a front-view camera; 7, a side-view camera; 8, an air-floating guide rail carrying platform; 9, a stepping motor; 10, a belt; 11, a guide rail connecting piece; 12, a driving pulley; 13, an angle code; 14, an X-axis buffer; 15, a support; 16, an X-axis air-floating guide rail; 17, an X-axis sliding block; 18, a Y-axis sliding block; 19, a Z-axis sliding block; 20, a connecting rod; 21, a Y-axis buffer; 22, an X-axis sliding block connecting plate; 23, a Y-axis sliding block connecting plate; 24, a hand-tightened screw; 25, a Z-axis connecting piece; 26, a Y-axis air-floating guide rail; 27, a Z-axis air-floating guide rail; 28, a gyroscope; 29, an acceleration sensor; 30, a force / torque sensor; 31, a bionic robotic fish. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0022] An embodiment of the present application is shown in FIGS. 1-3. Figure 1 and Figure 2 The embodiment of the present application is shown in FIGS. 1-3.

[0023] It should be noted that, as shown in FIGS. 1-3, Figure 1As shown, the wall plate of the still water tank 1 is bonded by transparent acrylic plate, the still water tank 1 occupies an area of about 6 square meters, the support frame 4 is assembled by alloy steel, the support frame 4 is three "door" shaped frames, two of which are vertically arranged, and the other frame is connected to the top of the two vertical frames, and a form wheel 5 is installed at the bottom of the vertical frame, which facilitates the free movement of the air floating guide rail carrying platform 8 and the installation and fixation of the biomimetic robotic fish 31; the hoisting of the biomimetic robotic fish 31 is realized through the connecting rod 20 on the air floating guide rail carrying platform 8.

[0024] Exemplarily, in a specific embodiment, the air floating guide rail carrying platform 8 is a quadrilateral structure formed by connecting two short rails and two long rails, and the short rails and the long rails of the air floating guide rail carrying platform 8 are fixed on the carrying support frame 4 through a plurality of corner codes 13.

[0025] Exemplarily, as shown in FIG. 1, the biomimetic robotic fish 31 is connected to the air floating guide rail carrying platform 8 through a connecting rod 20, and the air floating guide rail carrying platform 8 is connected to the support frame 4 through a connecting rod 20. Figure 2 and Figure 3As shown, in one embodiment, the long rail direction of the air floating guide rail carrying platform 8 is the X-axis direction, the short rail direction of the air floating guide rail carrying platform 8 is the Y-axis direction, the direction perpendicular to the bottom surface of the still water tank 1 is the Z-axis direction, and the four-degree-of-freedom assembly includes two X-axis air floating guide rails 16, two X-axis buffers 4, two Y-axis air floating guide rails 26, two Y-axis buffers 21, one Z-axis air floating guide rail 27, one connecting rod 20, and an electric drive assembly. One X-axis air floating guide rail 16 is arranged on each of the two long rails, and an X-axis sliding block 17 that can freely slide along the axial direction of the X-axis air floating guide rail 16 is arranged on the X-axis air floating guide rail 16. An X-axis buffer 4 is also arranged on the short rail of the air floating guide rail carrying platform 8 to prevent mechanical hard collision when the X-axis sliding block 17 moves; the ends of the two Y-axis air floating guide rails 26 are connected to the corresponding X-axis sliding blocks 17 of the two X-axis air floating guide rails 16 through X-axis sliding block connecting plates 22, i.e., the left and right X-axis sliding blocks 17 are matched into a whole through the Y-axis air floating guide rails 26 to ensure that the left and right two X-axis sliding blocks 17 can slide synchronously and smoothly, and a Y-axis sliding block 18 is arranged on the Y-axis air floating guide rail 26. The bottoms of the two Y-axis sliding blocks 18 are connected through a Y-axis sliding block connecting plate 23 to ensure the synchronous sliding of the two Y-axis sliding blocks 18, and a Y-axis buffer 21 is arranged on the X-axis sliding block connecting plate 22, and the two Y-axis buffers 21 are opposite. The Y-axis buffer 21 is used to prevent mechanical hard collision between the Y-axis sliding block 18 and the fixed part at the end of the Y-axis air floating guide rail 26; the Z-axis air floating guide rail 27 is arranged through the Y-axis sliding block connecting plate 23, and a limiting component that limits the position of the Z-axis air floating guide rail 27 in the Z-axis direction is arranged on the Y-axis sliding block connecting plate 23. A Z-axis sliding block 19 is arranged on the Z-axis air floating guide rail 27 in a sliding manner, and the Z-axis sliding block 19 is rotationally connected to the Z-axis air floating guide rail 27; the connecting rod 20 is arranged on the Z-axis sliding block 19, and the connecting rod 20 is parallel to the Z-axis air floating guide rail 27. The end of the connecting rod 20 away from the Z-axis sliding block 19 is used to connect the bionic robotic fish 31; and the electric drive assembly is used to drive the X-axis sliding block 17 to move along the X-axis air floating guide rail 16.

[0026] Wherein, in the embodiment, the limiting assembly comprises a limiting sleeve, one end of the limiting sleeve is fixed to the top of the Z-axis air floating guide rail 27, the Z-axis air floating guide rail 27 passes through the Y-axis sliding block connecting plate 23 and goes out from the limiting sleeve, and the limiting sleeve is provided with a hand screw 24, the hand screw 24 goes into the limiting sleeve from the outer wall of the limiting sleeve to be fastened on the Z-axis air floating guide rail 27 in the limiting sleeve. It should be noted that in the embodiment, the X-axis air floating guide rail 16 is 3m long, the X-axis buffer 14 prevents the hard collision of the mechanical mechanism between the X-axis sliding block 17 and the end of the X-axis air floating guide rail 16; the Y-axis air floating guide rail 26 is 0.8m long; the Y-axis sliding block connecting plate 23 is provided with a through hole matched with the Z-axis air floating guide rail 27, the Z-axis air floating guide rail 27 can move up and down in the through hole of the Y-axis sliding block connecting plate 23 to change the minimum depth of the bionic robot fish in the still water tank 1, and after the depth is determined, the Z-axis air floating guide rail 27 is fixed by the hand screw 24 to ensure the minimum depth of the bionic robot fish 31 during the whole test process, the Z-axis air floating guide rail 27 is 0.8m long; the Z-axis sliding block 19 is slidingly arranged on the Z-axis air floating guide rail 27, one side of the Z-axis sliding block 19 is fixed with a Z-axis connecting piece 25, and the Z-axis connecting piece 25 is fixed with a connecting rod 20; the connecting rod 20 is provided with a mounting groove at the upper end for mounting a gyroscope 28 and an acceleration sensor 29, and the bionic robot fish is hung at the lower end of the connecting rod 20.

[0027] For example, in a specific embodiment, the electric drive assembly comprises a step motor 9, a driving pulley 12, a driven pulley, a belt 10, and two supports 15, the two supports 15 are respectively arranged on one side of the two ends of the long rail of the air floating guide rail mounting platform 8; the step motor 9 is arranged on one of the supports 15, and the output end of the step motor 9 is connected with the driving pulley 12; the driven pulley is mounted on the other support 15; the belt 10 is drivingly connected to the driving pulley 12 and the driven pulley, and the belt 10 is detachably connected with the X-axis sliding block 17, the driving pulley 12 and the driven pulley are both provided with a clamping groove, the clamping groove is tightly matched with the belt 10 to tighten the belt 10, and it is ensured that the driving pulley 12 is driven by the step motor 9 to smoothly drive the X-axis sliding block 17 connected to the belt 10 to move forward / backward through the belt 10. Wherein, in a specific embodiment, the X-axis sliding block 17 is provided with a guide rail connecting piece 11, the top of the guide rail connecting piece 11 is connected with the Y-axis air floating guide rail 26, and the bottom surface of the guide rail connecting piece 11 and the belt 10 are connected by screws, so that the X-axis sliding block 17 can be dragged and glided forward / backward along the direction of the X-axis air floating guide rail 16 under the drive of the step motor 9; the moving speed of the X-axis sliding block 17 under the drive of the step motor 9 is continuously adjustable at 0.01m / s to 0.5m / s, the control accuracy is 0.002m / s, and uniform acceleration / a uniform deceleration motion at a certain acceleration a can be realized.

[0028] Exemplarily, in one specific embodiment, the test system comprises: a high-speed camera 3, a force / torque sensor 30, a gyroscope 28, an acceleration sensor 29, a front-view angle camera 6, a side-view angle camera 7, and a computer, the high-speed camera 3 is arranged on a monitoring platform 2 arranged on one side of the static water tank 1 to ensure the horizontal and vertical degrees of the high-speed camera 3, and is used to detect the video of the bionic robotic fish 31 in the autonomous swimming test; the force / torque sensor 30 is connected between the back of the bionic robotic fish 31 and the end of the connecting rod 20, and is used to detect the mechanical data generated by the bionic robotic fish 31 in the test, the mechanical data in the autonomous swimming test includes: thrust, lift, and pitch moment, the stability of the bionic robotic fish in the swimming process is analyzed according to the pitch moment; the mechanical data in the towed gliding test includes: thrust and lift; the gyroscope 28 and the acceleration sensor 29 are both arranged on the connecting rod 20 away from the bionic robotic fish 31, the gyroscope 28 is used to detect the yaw angle of the bionic robotic fish 31 in the turning stage in the autonomous swimming or towed gliding; the acceleration sensor 29 is used to detect the acceleration of the bionic robotic fish 31 in the acceleration stage of the autonomous swimming; the front-view angle camera 6 is arranged on the inner wall surface corresponding to the short side of the static water tank 1, and the side-view angle camera 7 is arranged on the outer side of the long wall surface of the static water tank 1, wherein the free end of the X-axis sliding block connecting plate 22 is connected with a fixed plate parallel to the wall surface of the static water tank 1 vertically downward, the fixed plate is used to fix the side-view angle camera 7, the side-view angle camera 7 is used to synchronously detect the side-view angle video in the moving process of the bionic robotic fish 31, and the front-view angle camera 6 is used to synchronously detect the front-view angle video in the moving process of the bionic robotic fish 31; the computer is used to mark the target points of the video of the bionic robotic fish 31 in the autonomous swimming test shot by the high-speed camera 3, calculate the speed of the bionic robotic fish 31 in the steady cruising stage, obtain the energy utilization rate of the bionic robotic fish 31 according to the mechanical data of the bionic robotic fish 31 and the speed of the bionic robotic fish calculated by the high-speed camera 3, obtain the acceleration change curve of the bionic robotic fish 31 in the autonomous swimming and the heading angle change curve of the bionic robotic fish 31 in the turning mode according to the heading angle of the bionic robotic fish 31 and the acceleration of the bionic robotic fish 31, process the side-view angle video and the front-view angle video to obtain the motion trajectories of each key position point of the body of the bionic robotic fish 31, and take the ratio of the lift and the drag of the bionic robotic fish 31 in the towed gliding test as the lift-drag ratio of the bionic robotic fish 31. The video shot by the front-view angle camera 6 and the side-view angle camera 7 in the towed gliding test can also be processed to obtain the motion trajectories of each key position point of the body of the bionic robotic fish 31 in the towed gliding test.

[0029] Exemplarily, in one specific embodiment, to avoid the influence of the wall surface of the static water tank 1 on the bionic robotic fish 31 in the swimming, the length and width dimensions of the static water tank 1 are both greater than 5 times the body length of the bionic robotic fish 31.

[0030] An embodiment of the water power test method for free swimming test of a multi-degree-of-freedom bionic robotic fish of the present application is shown in Figure 4 and Figure 5 The embodiment includes: testing by using the multi-degree-of-freedom bionic robotic fish multifunctional water power test platform, and the testing steps include: Step 1, install the bionic robotic fish, calibrate the initial position of the bionic robotic fish, and adjust the buoyancy of the bionic robotic fish; Specifically, install the bionic robotic fish 31 at a set attack angle, calibrate the initial position of the bionic robotic fish 31, and adjust the buoyancy to make the bionic robotic fish 31 suspended in the water in the still water tank 1.

[0031] For example, in this embodiment, the force / torque sensor 30 is connected with the connecting rod 20, the gyroscope 28 and the acceleration sensor 29 are installed in the clamping groove on the upper end of the connecting rod 20, the bionic robotic fish 31 is connected with the force / torque sensor 30, the connecting rod 20 is inserted into the mounting through hole of the Z-axis air floating guide rail 27 of the Y-axis sliding block connecting plate 23 on the air floating guide rail loading platform 8, and after the test minimum depth is determined, the hand screw 24 is used to fasten the Z-axis air floating guide rail 27; ensure that the bionic robotic fish 31 can be suspended in the water, determine the attack angle of the bionic robotic fish 31, and calibrate the initial position.

[0032] Step 2, disconnect the guide rail connecting piece and the belt, and connect all power sources except the stepping motor; Specifically, the guide rail connecting piece 11 and the belt 10 are disconnected, so that the bionic robotic fish 31 can freely swim forward without the interference of the friction force of the belt; the power supply of the controller of the bionic robotic fish 31, the power supply of the force / torque sensor 30, the power supply of the gyroscope 28, the power supply of the acceleration sensor 29, the power supply of the high-speed camera 3, the power supply of the front-view camera 6, and the power supply of the side-view camera 7 are connected.

[0033] Step 3, open the recording software corresponding to each sensor, establish the communication between each sensor and the computer, and adjust the installation direction of each sensor; Specifically, the recording software corresponding to the force / torque sensor 30, the gyroscope 28, and the acceleration sensor 29 is opened, the communication between the force / torque sensor 30, the gyroscope 28, and the acceleration sensor 29 and the computer is established, the installation direction of the force / torque sensor 30 is adjusted to be consistent with the direction of the force, the yaw angle zero position of the gyroscope 28 is adjusted to be consistent with the direction of the head of the robotic fish, and it is ensured that the test data can be accurately recorded and transmitted in the later test.

[0034] Step 4, adjust the camera parameters of each camera to make the shooting picture complete and clear; For example, in a specific embodiment, the step includes observing the computer screen to ensure that the high-speed camera 3, the front-view camera 6, and the side-view camera 7 can completely capture the area of interest, and then adjusting the parameters. When adjusting the resolution, attention should be paid to the coordination of the camera parameters and the lens parameters. The real-time situation of the camera shooting in the computer should be observed carefully to ensure that the complete and clear image of the motion trajectory of the robotic fish 31 can be captured in the test.

[0035] Step 5, start the robotic fish for free swimming test and record the test data; Specifically, the robotic fish 31 is started, and the robotic fish 31 freely swims forward in the water and collects the test data during the swimming process of the robotic fish 31. The test data includes the mechanical data of the robotic fish 31 measured by the force / torque sensor 30, the heading angle of the robotic fish 31 measured by the gyroscope 28, the acceleration of the robotic fish 31 measured by the acceleration sensor 29, the video captured by the high-speed camera 3, and the video of the robotic fish captured by the front-view camera 6 and the side-view camera 7. After the liquid surface in the still water tank 1 is stable, the motion parameters of the robotic fish 31 are changed to retest. After all the tests are completed, all power supplies are turned off. It should be noted that the motion parameters of the robotic fish 31 include the flapping frequency, amplitude, and phase difference of the pectoral fins / tail fins of the robotic fish 31.

[0036] Step 6, obtain the energy utilization rate, thrust coefficient, acceleration change curve, heading angle change curve, and motion trajectory of the robotic fish during the test process; For example, in a specific embodiment, the step of obtaining the energy utilization rate of the robotic fish 31 is as follows: target point marking is performed according to the video captured by the high-speed camera 3, and the speed of the robotic fish in the steady cruising stage is calculated. The useful work of the robotic fish 31 is obtained according to the thrust in the mechanical data of the robotic fish 31 in the autonomous swimming test and the speed of the robotic fish 31 calculated by the high-speed camera 3. The total work of the robotic fish is obtained according to all the parameters of the driving steering gear of the robotic fish 31. The energy utilization rate of the robotic fish 31 is obtained according to the total work and the useful work. In this embodiment, the useful work of the robotic fish 31 is the product of the thrust of the robotic fish 31 and the speed of the robotic fish calculated by the high-speed camera. The percentage of the useful work to the total work is taken as the energy utilization rate of the robotic fish 31.

[0037] For example, in a specific embodiment, the step of obtaining the speed of the robotic fish is as follows: target point marking is performed according to the video captured by the high-speed camera 3, and the speed of the robotic fish in the steady cruising stage is calculated.

[0038] For example, in a specific embodiment, the thrust in the mechanical data of the robotic fish 31 in the autonomous swimming test is dimensionless to obtain the thrust coefficient.

[0039] Exemplarily, in one specific embodiment, the step of acquiring the motion trajectory of the bionic robotic fish in the autonomous swimming test process is: according to the videos captured by the front-view camera and the side-view camera, video post-processing editing is performed by using the Tracker software, the key position points of the body of the bionic robotic fish 31 are labeled, and then the motion trajectory of the key position points of the body of the bionic robotic fish 31 is obtained.

[0040] Exemplarily, in one specific embodiment, the step of acquiring the acceleration change curve of the bionic robotic fish in the autonomous swimming and the heading angle change curve of the bionic robotic fish in the turning mode is: according to the acceleration of the bionic robotic fish 31, the acceleration change curve of the bionic robotic fish 31 in the autonomous swimming is acquired, and according to the heading angle of the bionic robotic fish 31, the heading angle change curve of the bionic robotic fish 31 in the turning mode is acquired.

[0041] An embodiment of the water dynamic test method of the multi-degree-of-freedom bionic robotic fish towing gliding test of the application is shown in Figure 4 and Figure 6 which comprises: testing by using the multi-degree-of-freedom bionic robotic fish multifunctional water dynamic test platform, and the testing steps comprise: Step 1, installing the bionic robotic fish, calibrating the initial position of the bionic robotic fish, and adjusting the buoyancy of the bionic robotic fish; Specifically, the bionic robotic fish 31 is installed at a set attack angle, the initial position of the bionic robotic fish 31 is calibrated, and the buoyancy is adjusted so that the bionic robotic fish 31 is suspended in the water of the still water tank 1.

[0042] Exemplarily, in this embodiment, the force / torque sensor 30 is connected with the connecting rod 20, the gyroscope 28 and the acceleration sensor 29 are installed in the clamping groove on the upper end of the connecting rod 20, the bionic robotic fish 31 is connected with the force / torque sensor 30, the connecting rod 20 is inserted into the mounting through hole of the Z-axis air floating guide rail 27 of the Y-axis sliding block connecting plate 23 on the air floating guide rail loading platform 8, the test minimum depth is determined, and the hand screw 24 is used to fasten the Z-axis air floating guide rail 27; it is ensured that the bionic robotic fish 31 can be suspended in the water, the attack angle of the bionic robotic fish 31 is determined, and the initial position is calibrated.

[0043] Step 2, connecting the guide rail connecting piece and the belt, and connecting all the power supplies of the test platform; Specifically, the guide rail connecting piece 11 and the belt 10 are connected, the power supply of the controller of the bionic robotic fish 31 is connected, the power supply of the force / torque sensor 30, the gyroscope 28 and the acceleration sensor 29 is connected, and the power supply of the high-speed camera 3, the front-view camera 6 and the side-view camera 7 is connected.

[0044] Step 3, open the corresponding record software of each sensor, establish the communication between each sensor and the computer, and adjust the installation direction of each sensor; Specifically, open the corresponding record software of the force / torque sensor 30, the gyroscope 28, and the acceleration sensor 29, establish the communication between the force / torque sensor 30, the gyroscope 28, and the acceleration sensor 29 and the computer, adjust the installation direction of the force / torque sensor 30 to be consistent with the direction of the force, and adjust the yaw angle zero position of the gyroscope 28 to be consistent with the direction of the head of the robotic fish, so as to ensure that the test data can be accurately recorded and transmitted in the later test.

[0045] Step 4, adjust the camera parameters of each camera to make the shooting picture complete and clear; For example, in a specific embodiment, this step includes: observing the computer screen to ensure that the high-speed camera 3, the front-view camera 6, and the side-view camera 7 can completely shoot the concerned area, then setting the parameters, and adjusting the clarity. When adjusting the clarity, attention should be paid to the cooperation of the camera parameters and the lens parameters, and the real-time situation of the camera shooting position displayed on the computer should be observed carefully to ensure that the image of the movement trajectory of the robotic fish can be shot completely and clearly in the test.

[0046] Step 5, set the gliding posture of the bionic robotic fish and the running parameters of the stepping motor, perform the drag gliding test, and record the test data; Specifically, the gliding posture of the bionic robotic fish 31 is set, the uniform speed or given acceleration is reached to a preset speed, and then the uniform acceleration / uniform deceleration sliding is performed, and the running parameters of the stepping motor are set. The mechanical data of the bionic robotic fish 31 measured by the force / torque sensor 30, the heading angle of the bionic robotic fish 31 measured by the gyroscope 28, the acceleration of the bionic robotic fish 31 measured by the acceleration sensor 29, the video shot by the high-speed camera 3, and the video of the bionic robotic fish shot by the front-view camera 6 and the side-view camera 7; wait for the liquid surface in the static water tank 1 to be stable, then change the movement parameters of the bionic robotic fish 31 to perform the test again, and after all the tests are completed, turn off all the power supplies; wait for the liquid surface in the static water tank to be stable, then adjust the attack angle of the bionic robotic fish 31 or change the movement parameters of the bionic robotic fish 31 to perform the test again.

[0047] It should be noted that the gliding posture is the bending angle and the upward angle of the pectoral fin of the bionic robotic fish 31. When the test is performed again, two of the gliding posture, the speed of the bionic robotic fish 31 driven by the stepping motor, and the attack angle are fixed, and only one of them needs to be changed to adjust the test.

[0048] Step 6, perform test data processing to obtain the lift-drag ratio of the bionic robotic fish and the movement trajectory of each key position point of the body; Exemplarily, in one specific embodiment, the step of obtaining the lift-drag ratio of the biomimetic robotic fish is: according to the lift and drag of the biomimetic robotic fish 31 measured in each towed gliding test, obtaining the lift-drag ratio of the biomimetic robotic fish 31 in the corresponding speed and attack angle during the towed gliding in each towed gliding test, that is, in this embodiment, the ratio of the lift and drag of the biomimetic robotic fish 31 is taken as the lift-drag ratio.

[0049] Exemplarily, in one specific embodiment, the step of obtaining the motion trajectory of the biomimetic robotic fish 31 in the towed gliding test is: according to the videos taken by the front-view camera 6 and the side-view camera 7, the videos are post-processed and edited by Tracker software, the key position points of the body of the biomimetic robotic fish 31 are labeled, and then the motion trajectories of the key position points of the body of the biomimetic robotic fish 31 are obtained.

[0050] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A multi-functional hydrodynamic test platform of multi-degree-of-freedom bionic robotic fish, characterized by: include: Still water tank, which is made of transparent material; A support frame is mounted on the still water tank and is provided with an air-floating guide rail mounting platform. The air-floating guide rail mounting platform is provided with a four-degree-of-freedom component. The output end of the four-degree-of-freedom component is used to mount a bionic robotic fish. The four-degree-of-freedom component is used to drive the bionic robotic fish to tow and glide in the still water tank, or to enable the bionic robotic fish to swim autonomously within the four degrees of freedom directions of the four-degree-of-freedom component. And a test system for detecting the speed of the bionic robotic fish in the steady-state cruising stage in the autonomous movement test, the energy utilization rate and thrust coefficient of the bionic robotic fish, the acceleration change curve of the bionic robotic fish in autonomous swimming, the heading angle change curve of the robotic fish in the turning mode, and the motion trajectory of each key position point of the bionic robotic fish's fuselage; and for obtaining the lift-to-drag ratio of the bionic robotic fish in the towed gliding test and the motion trajectory of each key position point of the bionic robotic fish's fuselage.

2. The multi-functional hydrodynamic test platform of a multi-degree-of-freedom bionic robotic fish according to claim 1 is characterized in that: The air-floating guide rail carrying platform is a quadrilateral structure formed by connecting two short rails and two long rails. The short rails and long rails of the air-floating guide rail carrying platform are fixed to the carrying support frame through multiple angle brackets.

3. The multi-functional hydrodynamic test platform of a multi-degree-of-freedom bionic robotic fish according to claim 2 is characterized in that: The four-degree-of-freedom components include: An X-axis air-floating guide rail is provided on each of the two long rails, and an X-axis slider is slidably provided on the X-axis slider and can slide freely along the axial direction of the X-axis air-floating guide rail; The X-axis buffer is installed on the short rail of the air-floating guide rail platform to prevent mechanical hard collision when the X-axis slider moves; The Y-axis air-floating guide rails include two Y-axis air-floating guide rails, the ends of which are connected to the corresponding X-axis sliders of the two X-axis air-floating guide rails through X-axis slider connecting plates. A Y-axis slider is slidably provided on the Y-axis air-floating guide rails, and the bottoms of the two Y-axis sliders are connected through a Y-axis slider connecting plate. The Z-axis air-floating guide rail is provided on the Y-axis slider connecting plate, and the Y-axis slider connecting plate is provided with a limit assembly for limiting the position of the Z-axis air-floating guide rail in the Z-axis direction. The Z-axis slider is slidably provided on the Z-axis air-floating guide rail, and the Z-axis slider is rotatably connected to the Z-axis air-floating guide rail; A connecting rod, which is connected to the Z-axis slider and parallel to the Z-axis air-floating guide rail, and whose end facing away from the Z-axis slider is used to connect to the bionic robotic fish; and an electric drive assembly for driving the X-axis slider to move along the X-axis air-floating guide rail.

4. The multi-functional hydrodynamic test platform of a multi-degree-of-freedom bionic robotic fish according to claim 3 is characterized in that: The limiting assembly includes: a limiting sleeve, one end of which is fixed to the Y-axis slider connecting plate, the Z-axis air-floating guide rail passes through the Y-axis slider connecting plate and out of the limiting sleeve, and a hand screw is provided on the limiting sleeve, which passes through the outer wall of the limiting sleeve into the limiting sleeve to tighten the Z-axis air-floating guide rail in the limiting sleeve.

5. The multi-functional hydrodynamic test platform of a multi-degree-of-freedom bionic robotic fish according to claim 3 is characterized in that: The electric drive components include: Two brackets are respectively arranged on one side of the two ends of the long rail of the air-floating guide rail carrying platform; A stepper motor is mounted on one of the brackets, and an output end of the stepper motor is connected to a driving pulley; A driven pulley is mounted on another bracket; and a belt, which is connected to the driving pulley and the driven pulley for transmission, and the belt and the X-axis slider are detachably connected.

6. The multi-degree-of-freedom bionic robotic fish multifunctional hydrodynamic test platform according to claim 5, characterized in that: A guide rail connector is provided on the X-axis slider, the top of the guide rail connector is connected to the Y-axis air-floating guide rail, and the bottom surface of the guide rail connector and the belt are connected by screws.

7. The multi-functional hydrodynamic test platform of a multi-degree-of-freedom bionic robotic fish according to claim 3 is characterized in that: The test system includes: A high-speed camera is installed on a monitoring platform provided on one side of the still water tank and is used to detect the speed of the bionic robotic fish during the steady-state cruising phase during the autonomous movement of the three-axis direction of the four-degree-of-freedom carrying platform; A force / torque sensor connected between the back of the bionic robotic fish and the end of the connecting rod is used to detect the mechanical data generated by the bionic robotic fish. The mechanical data in the autonomous swimming test includes thrust, lift, and pitching moment, and the mechanical data in the towed gliding test includes drag, lift, and pitching moment. The gyroscope and accelerometer are both installed on the connecting rod at the end away from the bionic robotic fish. The gyroscope is used to detect the yaw angle of the bionic robotic fish during the turning phase of autonomous swimming or towing gliding; the accelerometer is used to detect the acceleration of the bionic robotic fish during the acceleration phase of the autonomous swimming test. A front-view camera and a side-view camera, wherein the front-view camera is arranged on the inner wall surface corresponding to the short side of the still water tank, and the side-view camera is arranged on the outer side of the long wall surface of the still water tank, wherein the end of the X-axis slider connecting plate is vertically connected downwardly to a fixed plate parallel to the wall surface of the still water tank, and the fixed plate is used to fix the side-view camera. The side-view camera is used to synchronously detect the side-view image of the bionic robotic fish during movement, and the front-view camera is used to synchronously detect the front-view image of the bionic robotic fish during movement; and a computer, for marking target points in a video of a bionic robotic fish captured by a high-speed camera during an autonomous swimming test, and measuring the speed of the bionic robotic fish during a steady-state cruising phase; obtaining the energy utilization rate of the bionic robotic fish based on the thrust and speed of the bionic robotic fish, and non-dimensionalizing the thrust of the bionic robotic fish to obtain a thrust coefficient; obtaining an acceleration change curve of the bionic robotic fish and a heading angle change curve of the bionic robotic fish in a turning mode based on the heading angle and acceleration of the bionic robotic fish; processing the video captured by the front-view camera and the side-view camera during the autonomous swimming test to obtain the motion trajectory of each key position of the bionic robotic fish during the autonomous swimming test; obtaining the lift-to-drag ratio of the bionic robotic fish based on the lift and drag of the bionic robotic fish during a towed gliding test; and processing the video captured by the front-view camera and the side-view camera during the towed gliding test to obtain the motion trajectory of each key position of the bionic robotic fish during the towed gliding test.

8. The multi-degree-of-freedom bionic robotic fish multifunctional hydrodynamic test platform according to claim 1, characterized in that: The length and width of the still water tank are both 5 times greater than the body length of the bionic robotic fish.

9. A hydrodynamic test method for a multi-degree-of-freedom bionic robotic fish free swimming test, characterized in that: include: The multi-degree-of-freedom bionic robotic fish multifunctional hydrodynamic test platform according to any one of claims 1 to 8 is used for testing, and the testing steps include: Installing the bionic robotic fish according to the set angle of attack, calibrating the initial position of the bionic robotic fish, and adjusting the buoyancy so that the bionic robotic fish is suspended in the water of the still water tank; Remove the connection between the guide rail connector and the belt, so that the bionic robotic fish can swim forward freely without being disturbed by the friction of the belt; turn on all power sources except the stepper motor; Open the recording software corresponding to each sensor, establish communication between each sensor and the computer, and adjust the installation direction of each sensor; Adjust the camera parameters of each camera to make the captured image complete and clear; The bionic robotic fish is started, and it swims freely forward in the water. Test data is collected during the swimming process. The test data includes: mechanical data of the bionic robotic fish measured by the force / torque sensor, the heading angle of the bionic robotic fish measured by the gyroscope, the acceleration of the bionic robotic fish measured by the acceleration sensor, video captured by the high-speed camera, and video of the bionic robotic fish captured by the front-view camera and the side-view camera; Wait until the liquid level in the still water tank is stable, then change the motion parameters of the bionic robotic fish and repeat the experiment; According to the video captured by the high-speed camera, target points are marked and the speed of the bionic robotic fish in the steady-state cruising stage of the autonomous swimming test is measured. The useful work of the bionic robotic fish is obtained based on the thrust in the mechanical data of the bionic robotic fish and the measured speed of the bionic robotic fish. The total work of the bionic robotic fish is obtained based on all parameters of the bionic robotic fish's driving servo, and the energy utilization rate of the bionic robotic fish is obtained based on the total work and useful work. The thrust in the mechanical data of the bionic robotic fish is dimensionless to obtain the thrust coefficient. According to the heading angle and acceleration of the bionic robotic fish, the acceleration change curve of the bionic robotic fish in autonomous swimming and the heading angle change curve of the robotic fish in turning mode are obtained. According to the videos captured by the front-view camera and the side-view camera, the motion trajectory of each key position point of the bionic robotic fish in the autonomous swimming test is obtained.

10. A hydrodynamic test method for a multi-degree-of-freedom bionic robotic fish towing and gliding test, characterized in that: include: The multi-degree-of-freedom bionic robotic fish multifunctional hydrodynamic test platform according to any one of claims 1 to 8 is used for testing, and the testing steps include: Installing the bionic robotic fish at a set angle of attack, calibrating the initial position of the bionic robotic fish, and adjusting the buoyancy so that the bionic robotic fish is suspended in the water of the still water tank; Connect the guide rail connector and the belt, turn on all power supplies, open the recording software corresponding to each sensor, establish communication between each sensor and the computer, and adjust the installation direction of each sensor; Adjust the camera parameters of each camera to make the captured image complete and clear; Set the gliding posture of the bionic robotic fish, perform uniform acceleration / deceleration sliding after reaching the preset speed at a constant speed or a given acceleration, and set the operating parameters of the stepper motor; Start the stepper motor and record test data as the bionic robotic fish slides steadily in the water of the still water tank driven by the stepper motor. The test data includes: mechanical data of the bionic robotic fish measured by the force / torque sensor, the heading angle of the bionic robotic fish measured by the gyroscope, the acceleration of the bionic robotic fish measured by the acceleration sensor, video captured by the high-speed camera, and video of the bionic robotic fish captured by the front-view camera and the side-view camera. Wait until the liquid level in the still water tank is stable, then adjust the attack angle of the bionic robotic fish or change the gliding posture of the bionic robotic fish and repeat the test; Based on the lift and drag in the mechanical data of the bionic robotic fish measured in each towed gliding test, the lift-to-drag ratio of the bionic robotic fish at the corresponding speed and angle of attack during each towed gliding test was obtained; the videos captured by the front-view camera and the side-view camera during the towed gliding test were processed to obtain the motion trajectory of each key position point of the bionic robotic fish's body in the towed gliding test.

Images