CN102114907B - Flexible dual-drive biomimetic fish with variable drive position - Google Patents

Abstract

A flexible dual-drive bionic fish with variable driving positions relates to a bionic robot fish to solve the shortcomings of poor stability and poor maneuverability of the existing bionic fish. Both the movable caudal fin driver and the fixed caudal fin driver of the present invention are composed of an elastic substrate, a fishtail, a silica gel layer, a shape memory alloy wire fixing base and two shape memory alloy wires coated with an insulating layer, and the movable caudal fin driver and the fixed caudal fin driver are connected with each other. The longitudinal centerline of the bionic fish body is parallel and symmetrically arranged with respect to the longitudinal centerline of the bionic fish body, and two shape memory alloy wire fixing seats are respectively arranged in the corresponding driver installation grooves to fix the shape memory alloy wire fixing seats on the caudal fin driver The spacer is fixed to the bionic fish body, the shape memory alloy wire fixing seat on the movable caudal fin driver is fixed to one end of the rotating beam through the connecting piece, and the other end of the rotating beam is fixed to the steering gear shaft on the bionic fish body. The invention is used for underwater detection and investigation.

Description

Flexible dual-drive bionic fish with variable drive positions

technical field

The invention relates to a double-drive bionic fish.

Background technique

At present, in the application of underwater detection and reconnaissance, there is an urgent need for a tiny underwater robot that can be stable, flexible, and highly maneuverable in water or other liquids. It can be driven wirelessly in a liquid environment and has high mobility and flexibility. The bionic robot fish is one of the tiny devices with this function. The patent application number is 200610151170.5, the publication number is CN 1986330A, and the invention patent application with the publication date of June 27, 2007 discloses a double-tail bionic tail propeller; The wheel and crank linkage mechanism drives the rigid tail handle to swing, which mainly solves the problem of the bow of the ship; however, because the patent application is rigidly driven by the motor, there are problems of low driving efficiency, high noise and poor maneuverability. The patent application number is 200610010348.4, the publication number is CN 1887646.A, and the invention patent application with the publication date of July 31, 2006 discloses a bionic robot fish driven by shape memory alloy wires with body fluctuations; The memory alloy wire is attached to the elastic sheet, and the shape memory alloy wire is energized and heated to deform the elastic body, so that the shape memory alloy wire drives the elastic body to fluctuate and propels the bionic robot fish. Although the patent application has the characteristics of small size, simple structure, good bionic effect, and no noise; however, the bionic fish driven by the shape memory alloy wire cannot swing at a high frequency, and the shape memory alloy wire is prone to overheating, resulting in relatively low fatigue damage. Seriously, the elastic skin on the surface is easily damaged, and at the same time, the patent has a relatively large turning radius and poor maneuverability.

Contents of the invention

The purpose of the present invention is to provide a flexible dual-drive bionic fish with variable driving positions in order to solve the problems of poor stability and poor maneuverability of the existing bionic robotic fish.

The invention includes a bionic fish body, a rotating beam, a movable caudal fin driver, a fixed caudal fin driver, connecting pieces and gaskets, and the movable caudal fin driver and the fixed caudal fin driver are composed of an elastic substrate, a fish tail, a silica gel layer, a shape memory alloy wire fixing seat and It consists of two shape memory alloy wires coated with an insulating layer. There is a gap on the outer end surface of the shape memory alloy wire fixing seat. One end of the elastic substrate is inserted into the gap on the shape memory alloy wire fixing seat. The other end of the elastic substrate It is connected with the fish tail, and the silicone layer is wrapped on the outer surface of the elastic substrate. Alloy wire grooves are symmetrically arranged on the silicone layer on both sides of the elastic substrate, and each alloy wire groove is equipped with a shape coated with an insulating layer. Memory alloy wire, the tail of the bionic fish body is provided with two driver installation slots, the two driver installation slots are symmetrically arranged relative to the longitudinal centerline of the bionic fish body, and the movable caudal fin driver and the fixed caudal fin driver are parallel to the longitudinal centerline of the bionic fish body And it is arranged symmetrically with respect to the longitudinal center line of the bionic fish body, and the shape memory alloy wire fixing seat on the movable tail fin driver and the fixed tail fin driver are respectively arranged in the corresponding driver installation groove, and the shape memory alloy wire fixing seat on the fixed tail fin driver The spacer is fixed to the bionic fish body, the shape memory alloy wire fixing seat on the movable caudal fin driver is fixed to one end of the rotating beam through the connecting piece, and the other end of the rotating beam is fixed to the steering gear shaft on the bionic fish body.

The present invention has the following beneficial effects: 1. Since the present invention designs a movable caudal fin driver and a fixed caudal fin driver on the bionic fish body, the stability of the existing single-drive bionic robotic fish is improved. The movable tail fin driver is driven by the rotating crossbeam to realize reverse propulsion, angle-changing propulsion and emergency stop, so that the turning radius of the present invention is relatively small, thereby improving maneuverability. 2. The present invention can utilize the change of the resistance of the shape memory alloy itself with the temperature to realize feedback control without the need of additional sensor devices, which simplifies the control system and improves the control precision. 3. The structure of the bionic fish of the present invention is simple, and its control can be realized only by adjusting the frequency and magnitude of the driving current. It can be controlled with a well-established pulse width modulation (PWM) technique.

Description of drawings

Fig. 1 is a perspective view of the overall structure of the present invention (mark 10 is a sealing ring among the figures); Fig. 2 is a front structural view of a movable tail fin driver 3 or a fixed tail fin driver 4; Fig. 3 is a shape memory alloy wire holder 3-4 Structural perspective view; Fig. 4 is a position state diagram of the movable caudal fin driver 3 and the fixed caudal fin driver 4 when the double-drive bionic fish of the present invention swims forward; Fig. 5 is the movable caudal fin driver 3 when the double-drive bionic fish of the present invention turns Figure 6 is a positional diagram of the movable caudal fin driver 3 and the fixed caudal fin driver 4 when the dual-drive bionic fish of the present invention stops suddenly.

Detailed ways

Specific embodiment 1: This embodiment is described in conjunction with Fig. 1 to Fig. 3. This embodiment includes a bionic fish body 1, a rotating beam 2, a movable caudal fin driver 3, a fixed caudal fin driver 4, a connecting piece 5 and a gasket 6, and a movable caudal fin driver. 3 and the fixed caudal fin driver 4 are composed of elastic substrate 3-1, fishtail 3-2, silica gel layer 3-3, shape memory alloy wire holder 3-4 and two shape memory alloy wires 3-4 coated with insulating layer 5 components, the shape memory alloy wire holder 3-4 is provided with a gap 3-4-1 on the outer end surface, and one end of the elastic substrate 3-1 is inserted into the gap 3-4- on the shape memory alloy wire holder 3-4 In 1, the other end of the elastic substrate 3-1 is connected to the fishtail 3-2, the silicone layer 3-3 is wrapped on the outer surface of the elastic substrate 3-1, and the silicone on the two outer surfaces of the elastic substrate 3-1 Alloy wire grooves 3-3-1 are arranged symmetrically on the layer 3-3, and a shape memory alloy wire 3-5 coated with an insulating layer is installed in each alloy wire groove 3-3-1, and the tail of the bionic fish body 1 There are two drive installation slots 1-1, the two drive installation slots 1-1 are arranged symmetrically with respect to the longitudinal centerline of the bionic fish body 1, the movable caudal fin driver 3 and the fixed caudal fin driver 4 and the longitudinal centerline of the bionic fish body 1 Parallel and symmetrically arranged with respect to the longitudinal center line of the bionic fish body 1, and the shape memory alloy wire fixing seats 3-4 on the movable tail fin driver 3 and the fixed tail fin driver 4 are respectively arranged in the corresponding driver installation grooves 1-1, fixed The shape memory alloy wire fixing seat 3-4 on the caudal fin driver 4 is fixedly connected to the bionic fish body 1 through the gasket 6, and the shape memory alloy wire fixing seat 3-4 on the movable caudal fin driver 3 is connected to the rotating beam 2 through the connecting piece 5. One end is fixedly connected, and the other end of the rotating beam 2 is fixedly connected with the steering gear shaft 1-2 on the bionic fish body 1 . The effect of the alloy wire groove 3-3-1 on the silica gel layer 3-3: because the shape memory alloy wire 3-5 coated with an insulating layer is protected by the alloy wire groove 3-3-1, it can reduce water flow away heat, and then can realize the rapid heating of the shape memory alloy wire 3-5 coated with an insulating layer, which ensures that the present invention can still work normally at high speed; when the shape memory alloy wire reaches the phase transition temperature and begins to strain, the coated The shape memory alloy wire 3-5 with an insulating layer will break away from the alloy wire slot 3-3-1 and enter the water flow. Water as a general coolant can well remove the shape memory alloy wire coated with an insulating layer that needs to be cooled when the power is off. The wires 3-5 cool down, thereby realizing rapid cooling and heating of the movable caudal fin driver 3 and the fixed caudal fin driver 4, while preventing the alloy wire from overheating and fatigue.

Shape memory alloy wire (SMA wire) is a smart material that exhibits a thermoelastic martensitic change that can sense temperature and displacement. Generally, if a metal is plastically deformed by an external force, it will leave a permanent deformation when the stress is removed. When the SMA wire is in the low-temperature martensitic phase, it will also undergo a large deformation after unloading. When it is heated above a certain critical temperature (reverse phase transition point), it can completely restore its original shape through the reverse phase transition. The present invention utilizes this thermoelastic martensitic change to alternately turn on and off power to the shape memory alloy wire, so that the memory alloy wire realizes phase transition contraction and recovery, thereby generating swing or fluctuation, and realizing fish-like swimming.

Embodiment 2: This embodiment is described with reference to FIG. 1 . The rotating beam 2 in this embodiment is an arched beam. This design can reduce the resistance of the rotating beam 2, thereby reducing the resistance of the bionic fish body 1. Other components and connections are the same as those in the first embodiment.

Specific embodiment three: this embodiment is described in conjunction with Fig. 1, the spacing between the movable tail fin driver 3 and the fixed tail fin driver 4 of the present embodiment is greater than 2.5 times of the maximum amplitude of the movable tail fin driver 3 or the fixed tail fin driver 4. This design can avoid mutual interference of eddy currents generated when the two fishtails 3-2 swing. Other components and connections are the same as those in the first embodiment.

Working principle of the present invention: first the ends of two shape memory alloy wires 3-5 coated with an insulating layer on the fixed tail fin driver 4 are all passed through the shape memory alloy wire holder 3-4 on the fixed tail fin driver 4, The gasket 6, the end face of the driver installation groove 1-1 are respectively connected with the drive circuit 8 in the bionic fish body 1; the ends of the two shape memory alloy wires 3-5 coated with an insulating layer on the movable caudal fin driver 3 are respectively It is connected with the driving circuit 8 through wires, and the wires are fixed on the rotating beam 2 .

(1), the movable caudal fin driver 3 and the fixed caudal fin driver 4 swing in the same direction: the PWM wave phases for driving the movable caudal fin driver 3 and the fixed caudal fin driver 4 are the same, that is, the same direction driving of the caudal fin is realized.

(2), the movable caudal fin driver 3 and the fixed caudal fin driver 4 swing oppositely: the PWM wave phases of driving the movable caudal fin driver 3 and the fixed caudal fin driver 4 are opposite, that is, the opposite driving of the caudal fin is realized.

(3), Turning: When turning is required, as shown in Figure 5, start the steering gear 7 in the bionic fish body 1, the steering gear 7 drives the movable tail fin driver 3 to rotate around the steering gear shaft by turning the beam 2, and simultaneously turns the movable tail fin The shape memory alloy wires on the driver 3 and the fixed tail fin driver 4 are energized on one side to drive, that is, the movable tail fin driver 3 and the fixed tail fin driver 4 only swing to the side opposite to the turning direction, thereby realizing fast turning, and the fixed tail fin driver 4 can also be turned. The caudal fin driver 4 is not energized and driven, but the active caudal fin driver 3 is driven to realize fast turning.

(4), emergency stop: the fixed caudal fin driver 4 is not energized, so the fixed caudal fin driver 4 does not move. When the movable caudal fin driver 3 turns to the front of the bionic fish body 1, the high-frequency swing generates a thrust force, which impels the bionic fish to stop.

Claims (2)

1. flexible pair of a variable drive position drives Biomimetic Fishs, described Biomimetic Fish comprises Biomimetic Fish body (1), movable tail fin actuator (3) and fixing tail fin actuator (4), movable tail fin actuator (3) and fixedly tail fin actuator (4) by flexible substrates (3-1), fish tail (3-2), layer of silica gel (3-3), shape-memory alloy wire permanent seat (3-4) and two shape-memory alloy wires (3-5) that scribble insulating barrier form, shape-memory alloy wire permanent seat (3-4) outside end face is provided with crack (3-4-1), in the crack (3-4-1) on the one end inserted-shape memory alloy wire permanent seat (3-4) of flexible substrates (3-1), the other end of flexible substrates (3-1) is connected with fish tail (3-2), layer of silica gel (3-3) is wrapped on the outside face of flexible substrates (3-1), be enclosed with on two lateral surfaces of flexible substrates (3-1) of layer of silica gel (3-3) and be arranged with the shape-memory alloy wire (3-5) that scribbles insulating barrier, it is characterized in that: be arranged with B alloy wire groove (3-3-1) on the layer of silica gel (3-3) on flexible substrates (3-1) two lateral surfaces, a shape-memory alloy wire (3-5) that scribbles insulating barrier is housed in each B alloy wire groove (3-3-1), described Biomimetic Fish also comprises rotating beam (2), connecting strap (5) and pad (6), the afterbody of Biomimetic Fish body (1) is provided with two actuator mounting grooves (1-1), two actuator mounting grooves (1-1) are symmetrical arranged with respect to the longitudinal centerline of Biomimetic Fish body (1), movable tail fin actuator (3) and fixedly tail fin actuator (4) and Biomimetic Fish body (1) longitudinal center's line parallel and be symmetrical arranged with respect to the longitudinal centerline of Biomimetic Fish body (1), and movable tail fin actuator (3) and fixedly the shape-memory alloy wire permanent seat (3-4) on the tail fin actuator (4) be separately positioned in the corresponding actuator mounting groove (1-1), fixedly the shape-memory alloy wire permanent seat (3-4) on the tail fin actuator (4) is affixed by pad (6) and Biomimetic Fish body (1), shape-memory alloy wire permanent seat (3-4) on the movable tail fin actuator (3) is affixed with an end of rotating beam (2) by connecting strap (5), and the steering wheel axle (1-2) on the other end of rotating beam (2) and the Biomimetic Fish body (1) is affixed.

2. flexible two Biomimetic Fishs that drive of described variable drive position according to claim 1, it is characterized in that: described rotating beam (2) is arch beam.

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