Multi-joint machine dolphin with independently adjustable body wave frequency and amplitude

Abstract

The application discloses a multi-joint machine dolphin with independently adjustable body wave frequency and amplitude, which comprises a dolphin shell, a frequency modulation driving mechanism located in the dolphin shell, an amplitude modulation slide rail mechanism located in the dolphin shell, a driving motor located in the dolphin shell and used for driving the frequency modulation driving mechanism, and a rudder located in the dolphin shell and used for driving the amplitude modulation slide rail mechanism. The frequency modulation driving mechanism comprises a driving joint and a plurality of driven joints which are connected in series with the output shaft of the driving motor in sequence. The tail of the last driven joint is hinged to the tail end of the amplitude modulation slide rail mechanism. The frequency modulation driving mechanism drives the dolphin shell to swing in a wave shape. The frequency modulation driving mechanism adjusts the swing frequency by adjusting the rotating speed of the driving motor. The amplitude modulation slide rail mechanism adjusts the swing amplitude by adjusting the distance between the driving joint and the driven joints through the rudder. The dolphin body can swing in a wave shape, and the swing frequency, the swing amplitude and the wave shape can be independently adjusted.

Description

Technical Field

[0001] This invention relates to the field of robotics, and more particularly to a multi-jointed robotic dolphin with independently adjustable body wave frequency and amplitude. Background Technology

[0002] Fish exhibit high efficiency and excellent maneuverability in turning, hovering, reversing, and braking. Compared to propeller-driven boats, fish movements are more stealthy and produce less noise. Dolphins, as swimming champions in the ocean, can reach speeds of up to 80 kilometers per hour and can perform highly difficult maneuvers such as leaping and hovering upright on the water's surface.

[0003] The swimming pattern of biological dolphins involves the overall wave-like undulation of their body and tail fin to maximize swimming efficiency. However, most existing biomimetic robotic dolphins can only complete the tail fin undulation, failing to achieve the overall body undulation characteristic of fish, resulting in low swimming efficiency. Furthermore, existing biomimetic robotic dolphins' tail fins are mainly divided into mechanical structure types and servo-controlled types. However, mechanical structure types are complex in design, making it difficult to freely adjust the amplitude and waveform of the undulation; servo-controlled types require complex control strategies.

[0004] Therefore, it is urgent to solve the above problems. Summary of the Invention

[0005] Purpose of the invention: The purpose of this invention is to provide a multi-jointed robotic dolphin with independently adjustable body wave frequency and amplitude, so as to realize the dolphin's body body moving in a wave-like motion, and the swing frequency, swing amplitude and wave shape can be adjusted independently.

[0006] Technical Solution: To achieve the above objectives, this invention discloses a multi-jointed robotic dolphin with independently adjustable body wave frequency and amplitude, comprising a dolphin shell, a frequency modulation drive mechanism located within the dolphin shell, an amplitude modulation slide rail mechanism located within the dolphin shell, a drive motor located within the dolphin shell for driving the frequency modulation drive mechanism, and a servo motor located within the dolphin shell for driving the amplitude modulation slide rail mechanism. The frequency modulation drive mechanism includes a drive joint and several driven joints connected in series with the output shaft of the drive motor. The tail of the last driven joint is hinged to the tail end of the amplitude modulation slide rail mechanism. The frequency modulation drive mechanism drives the dolphin shell to swing in a wave-like manner. The frequency modulation drive mechanism adjusts the swing frequency by adjusting the rotation speed of the drive motor. The amplitude modulation slide rail mechanism adjusts the swing amplitude by adjusting the distance between the drive joint and the driven joint through the servo motor.

[0007] The amplitude adjustment slide rail mechanism includes a guide rail plate arranged longitudinally along the dolphin's shell, a long slide groove opened along the guide rail plate, a guide rail slider located in the long slide groove and capable of moving back and forth along the long slide groove, a servo crank connected to the servo output shaft, a crank connecting rod connected at one end to the servo crank, and several short connecting rods and several long connecting rods connected to the crank connecting rod and forming a rhomboid structure. The driving joint is fixedly connected to the guide rail plate, and the driven joint is fixedly connected to the guide rail slider.

[0008] Preferably, the servo motor is fixed to the guide rail plate, one end of the servo motor crank is provided with a protrusion, and one end of the crank connecting rod is provided with a groove through which the protrusion can pass, and the protrusion can move back and forth along the groove.

[0009] Furthermore, there are three short connecting rods. One end of the short connecting rod located at the head of the fish is hinged to the middle of the crank connecting rod. The other end of the short connecting rod located at the head of the fish is hinged to one end of a pair of cross-hinged long connecting rods. The other end of the crank connecting rod is hinged to the other end of the pair of cross-hinged long connecting rods. Several pairs of cross-hinged long connecting rods are hinged sequentially. One end of the two short connecting rods located at the tail of the fish is hinged to each other. The other ends of the two short connecting rods located at the tail of the fish are respectively hinged to one end of a pair of cross-hinged long connecting rods. The intersection of each pair of long connecting rods is the first hinge point, and the hinge point of the pair of short connecting rods located at the tail of the fish is the second hinge point. Guide rail sliders are connected to both the first and second hinge points.

[0010] Furthermore, the drive joint includes a drive base, drive grooves vertically opened on both sides of the drive base, a drive slider that passes through the drive groove and can slide up and down along the drive groove, a drive connecting rod for connecting the drive slider and the dolphin shell, and a straight crank that passes through the slot of the drive slider and is connected to the output shaft of the drive motor. When the drive motor is started, it drives the straight crank to rotate, thereby driving the drive slider to slide up and down.

[0011] Preferably, the straight crank includes a straight rod and first cranks of the same length located at both ends of the straight rod. The first crank at the beginning of the straight rod is connected to the output shaft of the drive motor, and the first crank at the end of the straight rod is connected to the driven joint via a connecting rod.

[0012] Furthermore, the driven joint includes a driven base, driven grooves vertically opened on both sides of the driven base, a driven slider that passes through the driven groove and can slide up and down along the driven groove, a driven connecting rod for connecting the driven slider and the dolphin shell, and a slanted crank that passes through the slot of the driven slider and is connected to the drive joint. The drive joint moves, causing the slanted crank to rotate, thereby causing the driven slider to slide up and down.

[0013] Furthermore, the slant crank includes a slant bar, a second crank located at the head end of the slant bar, and a third crank located at the tail end of the slant bar. The length of the second crank is greater than the length of the third crank. The second crank points towards the fish head, and the third crank points towards the fish tail.

[0014] Preferably, the cranks of the driving joint and several driven joints all have a phase difference along the circumferential direction, and the phase differences should be arranged in an arithmetic sequence.

[0015] Furthermore, the number of dolphin shells corresponds one-to-one with the number of drive joints and driven joints. One dolphin shell is provided with a connecting rod with a protrusion, and adjacent dolphin shells are provided with sliding grooves that allow the protrusion to pass through and slide back and forth along it.

[0016] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: The present invention uses a frequency modulation drive mechanism to drive the dolphin's shell to swing in a wave-like manner. The frequency modulation drive mechanism adjusts the swing frequency by adjusting the speed of the drive motor, and only requires a single motor drive, making the structure reliable and the control strategy simple. Secondly, the present invention uses an amplitude modulation slide rail mechanism to adjust the distance between the drive joint and the driven joint through a servo motor, thereby adjusting the swing amplitude and realizing the control of the swing amplitude and swing waveform of the robotic dolphin's body. This makes the movement of the robotic dolphin more in line with the movement law of biological dolphins, improves the swimming efficiency of the robotic dolphin, and only requires a single servo motor control, simplifying the structure and control strategy. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the present invention;

[0018] Figure 2 This is a schematic diagram of the internal skeleton structure in this invention;

[0019] Figure 3 This is a schematic diagram of the drive joint structure in this invention;

[0020] Figure 4 This is a schematic diagram of the driven joint in this invention;

[0021] Figure 5 This is a schematic diagram of the amplitude adjustment slide rail mechanism in this invention;

[0022] Figure 6 This is a bottom schematic diagram of the amplitude adjustment slide rail mechanism in this invention;

[0023] Figure 7 This is a schematic diagram showing the connection between adjacent dolphin shells in this invention;

[0024] Figure 8 This is a schematic diagram of the phase difference between the straight crank and the inclined crank in this invention;

[0025] Figures 9(a) to 9(h) This is a schematic diagram illustrating the motion pattern within one cycle of the slow propulsion mode in this invention.

[0026] Figures 10(a) to 10(h) This is a schematic diagram illustrating the motion pattern within one cycle of the rapid propulsion mode in this invention;

[0027] Figure 11 This is a schematic diagram of the retracted state of the multi-jointed robotic dolphin when its shell is removed in this invention;

[0028] Figure 12 This is a schematic diagram of the extended state of the multi-jointed robotic dolphin when its shell is removed in this invention.

[0029] Dolphin shell 1, connecting rod 101, sliding groove 102, servo motor 2, drive motor 3, drive joint 4, drive base 401, straight crank 402, drive slider 403, drive connecting rod 404, drive sliding groove 405, driven joint 5, driven base 501, inclined crank 502, driven slider 503, driven connecting rod 504, driven sliding groove 505, guide rail plate 6, long sliding groove 601, guide rail slider 7, servo crank 8, protrusion 801, crank connecting rod 9, sliding groove 901, short connecting rod 10, long connecting rod 11. Detailed Implementation

[0030] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0031] like Figure 1 and Figure 2 As shown, this invention discloses a multi-jointed robotic dolphin with independently adjustable body wave frequency and amplitude. It includes a dolphin shell 1, a frequency modulation drive mechanism, an amplitude modulation slide rail mechanism, a servo motor 2, and a drive motor 3. The frequency modulation drive mechanism, amplitude modulation slide rail mechanism, servo motor 2, and drive motor 3 are all located within the dolphin shell 1. The frequency modulation drive mechanism includes a drive joint 4 and several driven joints 5. The number of driven joints 5 is at least two; in this embodiment, the number of driven joints 5 is three. The dolphin shell 1 is fixedly connected to the drive joints 4 and driven joints 5 via connecting rods. The gaps between the dolphin shells 1 should be covered with a flexible waterproof material to prevent water from flowing into the machine body. Figure 7 As shown, the dolphin shells 1 are interconnected via a slider slot structure. The number of dolphin shells 1 corresponds one-to-one with the number of drive joints and driven joints. Each dolphin shell has a connecting rod 101 with a protrusion, and adjacent dolphin shells 1 have sliding grooves 102 for the protrusion to pass through and slide back and forth along. The output end of the drive motor 3 is connected in series with the drive joint 4 and the driven joint 5. The tail of the last driven joint 5 is hinged to the tail end of the amplitude-adjusting slide rail mechanism. The frequency-adjusting drive mechanism can realize the undulating sway of the robotic dolphin's body, and the swaying frequency of the robotic dolphin can be independently adjusted by adjusting the speed of the drive motor 3. The amplitude-adjusting slide rail mechanism adjusts the distance between the drive joint 4 and the driven joint 5 through the servo motor 2, thereby adjusting the swaying amplitude. Figures 9(a) to 9(h) This is a schematic diagram illustrating the motion pattern within one cycle of the slow propulsion mode in this invention. Figures 10(a) to 10(h) This is a schematic diagram illustrating the motion pattern within one cycle of the rapid propulsion mode in this invention.

[0032] like Figure 5 and Figure 6 As shown, the amplitude adjustment slide rail mechanism includes a guide rail plate 6, a guide rail slider 7, a servo crank 8, a crank connecting rod 9, several short connecting rods 10, and several long connecting rods 11. The guide rail plate 6 is arranged longitudinally along the dolphin's shell, and a long slide groove 601 is formed on the guide rail plate. The guide rail slider 7 is located in the long slide groove 601 and can move back and forth along the long slide groove 601. The drive joint 4 is fixedly connected to the guide rail plate 6, and the driven joint 5 is fixedly connected to the guide rail slider 7. The servo crank 8 is connected to the servo output shaft, and one end of the crank connecting rod 9 is connected to the servo crank. The servo 2 is fixed at the head round hole on the guide rail plate 6. A protrusion 801 is provided at one end of the servo crank 8, and a slide groove 901 is formed at one end of the crank connecting rod 9 for the protrusion 801 to pass through. The protrusion 801 can move back and forth along the slide groove 901. Several short connecting rods 10 and several long connecting rods 11 form a rhomboid structure. There are three short connecting rods 10. One end of the short connecting rod 10 located at the head of the fish is hinged to the middle of the crank connecting rod 9. The other end of the short connecting rod 10 located at the head of the fish is hinged to one end of a pair of cross-hinged long connecting rods 11. The other end of the crank connecting rod 9 is hinged to the other end of the pair of cross-hinged long connecting rods 11. Several pairs of cross-hinged long connecting rods 11 are hinged sequentially. One end of the two short connecting rods 10 located at the tail of the fish is hinged to each other. The other ends of the two short connecting rods 10 located at the tail of the fish are respectively hinged to one end of a pair of cross-hinged long connecting rods 11. The intersection of each pair of long connecting rods 11 is the first hinge point, and the hinge point of the pair of short connecting rods 10 located at the tail of the fish is the second hinge point. Guide rail sliders 7 are connected to both the first hinge point and the second hinge point.

[0033] like Figure 3 As shown, the drive joint 4 includes a drive base 401, a straight crank 402, a drive slider 403, a drive connecting rod 404, and a drive groove 405. The drive base 401 is fixedly connected to the guide rail plate 6. The drive groove 405 is vertically opened on both sides of the drive base 401. The drive slider 403 passes through the drive groove 405 and can slide up and down along the drive groove 405. The drive connecting rod 404 is disposed on both sides and the upper surface of the drive slider 403. The other end of the drive connecting rod 404 is fixedly connected to the inner side of the dolphin shell 1. The straight crank 402 passes through the groove of the drive slider 403 and is connected to the output shaft of the drive motor 3. The straight crank 402 includes a straight rod and first cranks of the same length located at both ends of the straight rod. The first crank at the first end of the straight rod is connected to the output shaft of the drive motor. The first crank at the tail end of the straight rod is connected to the second crank of the inclined crank of the first driven joint 5 through a connecting rod. The drive motor 3 starts, which drives the straight crank 402 to rotate, thereby causing the drive slider 403 to slide up and down.

[0034] like Figure 4As shown, the driven joint 5 includes a driven base 501, a slanted crank 502, a driven slider 503, a driven connecting rod 504, and a driven groove 505. The driven base 501 is fixedly connected to the guide rail slider 7. The driven groove 505 is vertically formed on both sides of the driven base 501. The driven slider 503 passes through the driven groove 505 and can slide up and down along the driven groove 505. The driven connecting rod 504 is located at the left and right ends of the driven slider 503. Rod 504 is used to connect driven slider 503 and dolphin shell 1. Inclined crank 502 passes through the slot of driven slider 503. Inclined crank 502 of the first driven joint is connected to the first crank at the tail end of the straight crank 402 of the drive joint. Inclined crank 502 includes an inclined rod, a second crank at the head end of the inclined rod, and a third crank at the tail end of the inclined rod. The length of the second crank is greater than the length of the third crank. The second crank points towards the fish head, and the third crank points towards the fish tail. The second crank on the inclined crank 502 of the first driven joint is connected to the first crank located at the tail end of the straight crank 402 via a connecting rod. The third crank on the inclined crank 502 of the first driven joint is connected to the second crank on the inclined crank 502 of the second driven joint via a connecting rod. The third crank on the inclined crank 502 of the second driven joint is connected to the second crank on the inclined crank 502 of the third driven joint via a connecting rod. The third crank on the inclined crank 502 of the third driven joint is connected to the tail end of the guide plate 6. The cranks of the driving joint 4, the first driven joint A, the second driven joint B, and the third driven joint C all have a phase difference along the circumferential direction, and the phase difference should be arranged in an arithmetic sequence. The phase difference can be 30°. Figure 8 , Figure 11 and Figure 12 As shown. The drive joint 4 moves, causing the inclined crank 502 to rotate, which in turn causes the driven slider 503 to slide up and down. The length of the first crank in the straight crank 402, the length of the second and third cranks on the inclined crank 502, and the lengths of the straight and inclined rods can all be changed according to specific needs to change the swing amplitude and amplitude adjustment range of the robotic dolphin.

[0035] This invention is based on the series connection of multiple crank-connecting rod mechanisms and the control of the slide rail mechanism to realize the overall wave-like oscillation of the dolphin's body. The oscillation frequency, oscillation amplitude and wave shape can be adjusted independently. The control is simple and improves the underwater propulsion efficiency and environmental adaptability of the robotic dolphin.

Claims

1. A multi-jointed robotic dolphin with independently adjustable body wave frequency and amplitude, characterized in that: The device includes a dolphin shell (1), a frequency modulation drive mechanism located inside the dolphin shell, an amplitude modulation slide rail mechanism located inside the dolphin shell, a drive motor (3) located inside the dolphin shell and used to drive the frequency modulation drive mechanism, and a servo motor (2) located inside the dolphin shell and used to drive the amplitude modulation slide rail mechanism. The frequency modulation drive mechanism includes a drive joint (4) connected in series with the output shaft of the drive motor and several driven joints (5). The tail of the last driven joint (5) is hinged to the tail end of the amplitude modulation slide rail mechanism. The frequency modulation drive mechanism drives the dolphin shell (1) to swing in a wave-like manner. The frequency modulation drive mechanism adjusts the swing frequency by adjusting the speed of the drive motor (3). The amplitude modulation slide rail mechanism adjusts the swing amplitude by adjusting the distance between the drive joint (4) and the driven joint (5) through the servo motor (2). The amplitude modulation slide rail mechanism includes a drive joint (4) connected in series with the output shaft of the drive motor and several driven joints (5). The housing has a longitudinally arranged guide rail plate (6), a long slide groove (601) opened along the guide rail plate, a guide rail slider (7) located in the long slide groove and able to move back and forth along the long slide groove, a servo crank (8) connected to the servo output shaft, a crank connecting rod (9) with one end connected to the servo crank, and several short connecting rods (10) and several long connecting rods (11) connected to the crank connecting rod and forming a rhomboid structure. The drive joint (4) is fixedly connected to the guide rail plate (6), and the driven joint (5) is fixedly connected to the guide rail slider (7). The servo (2) is fixed on the guide rail plate (6). One end of the servo crank (8) is provided with a protrusion (801), and one end of the crank connecting rod (9) is provided with a slide groove (901) through which the protrusion (801) can pass. The protrusion (801) can move back and forth along the slide groove (901).

2. The multi-jointed robotic dolphin with independently adjustable body wave frequency and amplitude according to claim 1, characterized in that: There are three short connecting rods (10). One end of the short connecting rod (10) located at the head of the fish is hinged to the middle of the crank connecting rod (9). The other end of the short connecting rod (10) located at the head of the fish is hinged to one end of a pair of cross-hinged long connecting rods (11). The other end of the crank connecting rod (9) is hinged to the other end of the pair of cross-hinged long connecting rods (11). Several pairs of cross-hinged long connecting rods (11) are hinged in sequence. One end of the two short connecting rods (10) located at the tail of the fish is hinged to each other. The other ends of the two short connecting rods (10) located at the tail of the fish are respectively hinged to one end of a pair of cross-hinged long connecting rods (11). The cross-hinged joint of each pair of long connecting rods (11) is the first hinge joint. The hinged joint of the pair of short connecting rods (10) located at the tail of the fish is the second hinge joint. The first hinge joint and the second hinge joint are both connected to the guide rail slider (7).

3. The multi-jointed robotic dolphin with independently adjustable body wave frequency and amplitude according to claim 1, characterized in that: The drive joint (4) includes a drive base (401), a drive groove (405) vertically opened on both sides of the drive base, a drive slider (403) passing through the drive groove and sliding up and down along the drive groove, a drive connecting rod (404) for connecting the drive slider (403) and the dolphin shell (1), and a straight crank (402) passing through the slot of the drive slider (403) and connected to the output shaft of the drive motor. When the drive motor (3) is started, it drives the straight crank (402) to rotate, thereby driving the drive slider (403) to slide up and down.

4. The multi-jointed robotic dolphin with independently adjustable body wave frequency and amplitude according to claim 3, characterized in that: The straight rod crank (402) includes a straight rod and a first crank located at both ends of the straight rod and of the same length. The first crank located at the beginning of the straight rod is connected to the output shaft of the drive motor, and the first crank located at the end of the straight rod is connected to the driven joint (5) through a connecting rod.

5. The multi-jointed robotic dolphin with independently adjustable body wave frequency and amplitude according to claim 4, characterized in that: The driven joint (5) includes a driven base (501), a driven slide groove (505) vertically opened on both sides of the driven base, a driven slider (503) passing through the driven slide groove and sliding up and down along the driven slide groove, a driven connecting rod (504) for connecting the driven slider and the dolphin shell, and a slant crank (502) passing through the slot of the driven slider and connected to the drive joint. The drive joint (4) moves to drive the slant crank (502) to rotate, so as to drive the driven slider (503) to slide up and down.

6. The multi-jointed robotic dolphin with independently adjustable body wave frequency and amplitude according to claim 5, characterized in that: The slant crank (502) includes a slant, a second crank located at the head end of the slant and a third crank located at the tail end of the slant. The length of the second crank is greater than the length of the third crank. The second crank points towards the fish head and the third crank points towards the fish tail.

7. The multi-jointed robotic dolphin with independently adjustable body wave frequency and amplitude according to claim 6, characterized in that: The cranks of the driving joint (4) and several driven joints (5) all have a phase difference along the circumferential direction, and the phase differences are arranged in an arithmetic sequence.

8. The multi-jointed robotic dolphin with independently adjustable body wave frequency and amplitude according to claim 1, characterized in that: The number of dolphin shells (1) corresponds one-to-one with the number of drive joints and driven joints. A connecting rod (101) with a protrusion is provided on one dolphin shell, and a sliding groove (102) is provided on the adjacent dolphin shells (1) for the protrusion to pass through and slide back and forth along it.

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