Memory alloy and magnet hybrid driven flexible gripper and use method

Abstract

The invention relates to the technical field of flexible grippers, and discloses a memory alloy and magnet hybrid driven flexible gripper and a use method. Comprising an end cover for fixing a manipulator, four hybrid-driven manipulator components matched with the end cover, a shape memory alloy strip, a side link, an open flexible finger, a closed flexible finger, a bottom plate of the flexible fingers, a top plate for fixing a magnetic ball, a clamping groove for fixing the magnetic ball and a heat insulation plate. According to the memory alloy and magnet hybrid-driven flexible gripper and the using method, the magnetic field intensity is controlled through the current, the higher the magnetic field intensity is, the higher the response speed of stretching of the flexible fingers is, otherwise, the response speed is slow, meanwhile, the enveloping range of the flexible fingers can be adjusted according to the size of an object, the flexible fingers are tightly attached to the object, and the flexibility of the gripper is improved. The whole mechanism is simple, low in energy consumption and wide in application range.

Description

Technical Field

[0001] The present invention relates to the technical field of flexible grippers, in particular to a flexible gripper driven by a memory alloy and a magnet and a use method thereof. Background Art

[0002] As the end effector of the robot, the flexible gripper plays a vital role in the robot system, directly affecting the robot's operational flexibility and intelligence level. They are the key interface for the robot to interact with the external environment, and determine the accuracy, efficiency and adaptability of the robot when performing various tasks. Due to the complex structure, large size, lack of flexibility and various driving methods of traditional rigid mechanical grippers, a large number of researchers at home and abroad are looking for smart materials to make up for the shortcomings of traditional rigid manipulators, such as shape memory alloys, piezoelectric effect, electrostriction, magnetostriction and electrorheological effect. Piezoelectric effect, electrostriction and magnetostriction have a fast response speed, but the driving strain and stress are small, and their use is greatly restricted. Relatively speaking, shape memory alloys have large driving strain, smooth movement, and a high output force-to-weight ratio, which has a broader application prospect in flexible manipulators.

[0003] Shape memory alloy is a new material in a completely new sense in terms of principle, structure, and operation control method. It uses the shape memory effect (SME) supplemented by a certain biasing device (spring or elastomer), and through specific control means, it forms a two-way reversible actuating element to realize the conversion of electromechanical energy. Shape memory alloy drive control is flexible, the action is smooth, and there is no vibration or noise. It has superior performance and structural miniaturization and integration prospects that traditional flexible manipulator drivers cannot match. The main disadvantage of shape memory alloy drive is the hysteresis, which brings inconvenience to control. The general shape memory alloy hybrid drive forms are as follows: shape memory alloy and rope composite drive, shape memory alloy and spring composite drive, shape memory alloy and elastomer hybrid drive, shape memory alloy and water temperature combination, shape memory alloy and fan combination, etc. These drive methods cause the overall mechanism to be complex, the cost becomes larger, the flexibility is poor, and the response time is slow.

[0004] Therefore, the present invention designs a flexible gripper based on shape memory alloy and magnet hybrid drive to solve the problems of complex structure, high cost, poor flexibility and slow response time of existing flexible mechanical grippers. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] In view of the shortcomings of the prior art, the present invention provides a flexible gripper driven by a hybrid of memory alloy and magnet and a method of use, which has the advantages of simple overall structure, low energy consumption and a wide range of applications, and solves the problems of complex structure, high cost, poor flexibility and slow response time of existing flexible robotic grippers.

[0007] (II) Technical solution

[0008] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a flexible gripper driven by a hybrid of memory alloy and magnet, comprising an end cover for fixing the manipulator, four hybrid-driven manipulator components matched with the end cover, a shape memory alloy strip, a connecting rod, an open flexible finger, a closed flexible finger, a bottom plate of the flexible finger, a top plate for fixing the magnetic ball, a slot for fixing the magnetic ball, and a heat insulation plate; the four hybrid-driven manipulator components are distributed at the bottom of the end cover of the manipulator at intervals of 90°, and the hybrid-driven manipulator components are divided into flexible fingers and a fixed plate; a track is provided on the fixed plate, and a controllable electromagnet is provided in the fixed plate; the flexible fingers and the fixed plate are connected by a connecting rod; the flexible gripper is opened in an unconstrained state; the shape memory alloy strip can be closed inward to shrink the flexible gripper after being slightly energized.

[0009] Preferably, the fingers of the flexible gripper are made of finger parts formed by solidifying silicone and shape memory alloy strips embedded in the finger bodies.

[0010] Preferably, a magnet is embedded in the back of the flexible finger, and the magnet and the electromagnet in the fixed plate that cooperates with the magnet are of opposite polarity.

[0011] Preferably, an adjustable electromagnet is arranged in the fixing plate, a magnetic ball is built into the flexible finger, and the magnetism of the electromagnet is opposite to that of the magnetic ball in the flexible finger.

[0012] Preferably, a guide rail is provided on the fixing plate, and the connecting rod passes through the guide rail.

[0013] Preferably, the upper end of the fixing plate is embedded in the upper end of the flexible finger.

[0014] Preferably, the upper ends of the stacked flexible fingers and the fixed plate are provided with a slot for fixing the end cover of the manipulator, and the slot for fixing the end cover of the manipulator is in interference fit with the end cover of the manipulator.

[0015] Preferably, the method for using the flexible gripper comprises the following steps:

[0016] S1. Use shape memory alloy strips and electromagnets as driving devices, where the shape memory alloy strips are responsible for closing the flexible fingers, and the electromagnets are responsible for opening the flexible fingers. Built-in sensors in the soft flexible fingers measure the bending degree of the soft flexible fingers, so as to achieve the effect of detecting the bending state of the soft hand in real time;

[0017] S2. The hybrid-driven manipulator component is divided into a flexible finger and a fixed plate, which are connected by a connecting rod. The connecting rod runs through the track of the fixed plate and is responsible for the movement trajectory of the flexible finger. The flexible gripper is contracted by slightly energizing the shape memory alloy strip and closing it inward. The flexible gripper is opened by controlling the size of the magnetism of the electromagnet.

[0018] S3, the flexible gripper is in an open state in a natural state, and there are three shape memory alloy strips in the flexible fingers, which are trained to be in a bent state when heated and in an open state when cooled;

[0019] S4. When the flexible gripper needs to grasp something, the flexible fingers are bent by energizing the shape memory alloy strip and inputting different high duty cycle voltages to achieve the final grasping purpose;

[0020] S5. When the flexible gripper needs to put something, the size of the magnetic field can be achieved by adjusting the size of the current controller. The adjustable electromagnet can solve the problem of slow cooling of the shape memory alloy strip and also improve the response time of the flexible finger.

[0021] Compared with the prior art, the present invention provides a flexible gripper driven by a memory alloy and a magnet and a method of using the same, which has the following beneficial effects:

[0022] 1. The flexible gripper driven by a hybrid of memory alloy and magnet and the method of use use the magnitude of the current to control the magnitude of the magnetic field strength. The greater the magnetic field strength, the faster the response speed of the flexible fingers to extend, and vice versa. At the same time, the envelope range of the flexible fingers can be adjusted according to the size of the object so that it fits tightly to the object. The overall structure is simple, the energy consumption is low, and the application range is wide.

[0023] 2. The flexible gripper driven by a hybrid of shape memory alloy and magnet and its use method: the gripper is in an open state in its natural state, and there are three shape memory alloy strips in the flexible fingers, which are trained to be bent when heated and open when cooled. When the flexible gripper needs to grab something, the flexible fingers are bent by energizing the shape memory alloy strips and inputting different high duty cycle voltages to achieve the ultimate grasping purpose. When the flexible gripper needs to put something, the size of the magnetic field can be achieved by adjusting the size of the current controller. The adjustable electromagnet can solve the problem of slow cooling of the shape memory alloy and also improve the response time of the flexible fingers. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a front view of the three-dimensional structure of an open flexible claw hand driven by a hybrid of shape memory alloy and magnet according to the present invention.

[0025] Figure 2 It is a side view of the three-dimensional structure of an open flexible claw hand driven by a hybrid of shape memory alloy and magnet according to the present invention.

[0026] Figure 3 It is a front view of a three-dimensional structure of a closed flexible claw hand based on the mixed drive of shape memory alloy and magnet according to the present invention.

[0027] Figure 4 It is a side view of the three-dimensional structure of a closed flexible claw hand based on the hybrid drive of shape memory alloy and magnet according to the present invention.

[0028] Figure 5 It is a schematic diagram of the three-dimensional structure of the flexible claw hand finger closure based on the mixed drive of shape memory alloy and magnet according to the present invention.

[0029] Figure 6 It is a schematic diagram of the three-dimensional structure of a flexible claw hand with fingers opened based on the mixed drive of shape memory alloy and magnet according to the present invention.

[0030] Figure 7 It is a schematic diagram of the three-dimensional structure of the explosion of the flexible claw hand fingers based on the mixed drive of shape memory alloy and magnet in the present invention.

[0031] Figure 8 It is an overall cross-sectional view of a flexible claw hand based on the mixed drive of shape memory alloy and magnet according to the present invention.

[0032] Fig. 9 It is a schematic diagram of overall control of a flexible claw hand based on mixed drive of shape memory alloy and magnet according to the present invention.

[0033] Among them: 1. End cover of the manipulator; 2. Fixed plate; 3. Open flexible fingers; 4. Connecting rod; 5. Closed flexible fingers; 6. Slot for fixing the end cover of the manipulator; 7. Bottom plate of the flexible fingers; 8. Magnetic ball; 9. Top plate for fixing the magnetic ball; 10. Slot for fixing the magnetic ball; 11. Heat insulation board; 12. Shape memory alloy strip; 13. Top plate of the flexible fingers; 14. Electromagnet; 15. Coil; 16. Guide rail. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] The present invention is a flexible gripper based on shape memory alloy and magnet hybrid drive, and its structure is as follows: Figure 1 As shown, it includes an end cover 1 for fixing the manipulator, four hybrid-driven manipulator components, the hybrid-driven manipulator components are divided into flexible fingers 3 and a fixed plate 2, a guide rail 16 is arranged on the fixed plate, and a connecting rod 4 connecting the flexible fingers and the fixed plate.

[0036] The structure of the flexible finger is shown in the figure Figure 7 As shown, the bottom plate 7 of the flexible finger, the magnetic ball 8, the top plate 9 for fixing the magnetic ball, the heat insulation plate 11, the shape memory alloy strip 12 and the top plate of the flexible finger are stacked in sequence from left to right. An adjustable electromagnet 14 is arranged in the fixed plate 2, and the magnetism of the electromagnet 14 is opposite to the magnetism of the magnetic ball 8 in the flexible finger. The flexible finger and the fixed plate are connected by a connecting frame, and the upper end of the fixed plate is embedded in the upper end of the flexible finger.

[0037] A card slot 6 is provided at the upper end of the superimposed flexible finger and the fixed plate, and the card slot 6 is an interference fit with the end cover 1 of the manipulator. The driving plate in the flexible finger is composed of three shape memory alloy strips 12 for bending. The three shape alloy memory strips 12 are arranged in sequence in the top plate of the flexible finger and form a driving plate.

[0038] Working principle: The flexible gripper based on the hybrid drive of shape memory alloy and magnet of the present invention has four fingers, including a fixed manipulator end cover and four hybrid drive manipulator components, using shape memory alloy and electromagnet as driving devices, wherein the shape memory alloy is responsible for the closing of the flexible fingers, and the electromagnet is responsible for the opening of the flexible fingers. Sensors are built into the soft flexible fingers to measure the bending degree of the soft flexible fingers, so as to achieve the effect of detecting the bending state of the soft hand in real time. The hybrid drive manipulator components are divided into flexible fingers and fixed plates, which are connected by a connecting frame. The connecting frame runs through the track of the fixed plate and is responsible for the movement trajectory of the flexible fingers. The whole working principle of the flexible gripper is to shrink the flexible gripper by slightly energizing the shape memory alloy strips and closing them inwards, and open the flexible gripper by controlling the magnetism of the electromagnet; the magnitude of the current is used to control the magnitude of the magnetic field strength. The greater the magnetic field strength, the faster the response speed of the flexible fingers to open, and vice versa. At the same time, the envelope range of the flexible fingers can be adjusted according to the size of the object so that they can fit tightly on the object. The overall structure is simple, the energy consumption is low, and the application range is wide.

[0039] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A flexible gripper driven by a memory alloy and a magnet, characterized in that: The invention comprises an end cover (1) for fixing a manipulator, four hybrid-driven manipulator components matched with the end cover, a shape memory alloy strip (12), a connecting rod (4), an open flexible finger (3), a closed flexible finger (5), a bottom plate (7) of the flexible finger, a top plate (9) for fixing a magnetic ball, a slot (10) for fixing a magnetic ball, and a heat insulation plate (11); the four hybrid-driven manipulator components are distributed at a spacing of 90° at the bottom of the end cover of the manipulator, and the hybrid-driven manipulator components are divided into flexible fingers and a fixed plate; a track is arranged on the fixed plate, and a controllable electromagnet (14) is arranged in the fixed plate; the flexible fingers and the fixed plate are connected by a connecting rod (4); the flexible gripper is opened in an unconstrained state; the shape memory alloy strip (12) can be closed inwards to shrink the flexible gripper after being slightly energized.

2. The flexible gripper driven by a memory alloy and a magnet according to claim 1, characterized in that: The fingers of the flexible gripper are finger parts formed by solidifying silicone and shape memory alloy strips (12) embedded in the finger bodies.

3. The flexible gripper driven by a memory alloy and a magnet according to claim 1, characterized in that: A magnet is embedded in the back of the flexible finger, and the magnet and the electromagnet (14) in the fixed plate matched with the magnet are of opposite polarity.

4. The flexible gripper driven by a memory alloy and a magnet according to claim 1, characterized in that: An adjustable electromagnet (14) is arranged inside the fixing plate (2), a magnetic ball (8) is built into the flexible finger, and the magnetism of the electromagnet (12) is opposite to that of the magnetic ball (8) inside the flexible finger.

5. The flexible gripper driven by a memory alloy and a magnet according to claim 1, characterized in that: A guide rail (16) is arranged on the fixing plate (2), and the connecting rod (4) passes through the guide rail (16).

6. The flexible gripper driven by a memory alloy and a magnet according to claim 1, characterized in that: The upper end of the fixing plate (2) is embedded in the upper end of the flexible finger.

7. The flexible gripper driven by a memory alloy and a magnet according to claim 1, characterized in that: A slot (6) for fixing the end cover of the manipulator is provided at the upper end of the superimposed flexible finger and the fixed plate (2), and the slot (6) for fixing the end cover of the manipulator is in interference fit with the end cover of the manipulator.

8. A method for using a flexible gripper driven by a memory alloy and a magnet according to claims 1 to 7, characterized in that: The steps for using the flexible gripper are as follows: S1. Using a shape memory alloy strip (12) and an electromagnet (14) as a driving device, wherein the shape memory alloy strip (12) is responsible for closing the flexible finger, and the electromagnet (14) is responsible for opening the flexible finger. A sensor is built into the soft flexible finger to measure the bending degree of the soft flexible finger, so as to achieve the effect of being able to detect the bending state of the soft hand in real time; S2. The hybrid-driven manipulator component is divided into a flexible finger and a fixed plate (2), which are connected by a connecting rod (4). The connecting rod (4) runs through the track of the fixed plate (2) and is responsible for the movement trajectory of the flexible finger. The flexible gripper is contracted by slightly energizing the shape memory alloy strip (12) and closing it inwards. The flexible gripper is opened by controlling the magnetic size of the electromagnet (14); S3, the flexible gripper is in an open state in a natural state, and there are three shape memory alloy strips (12) in the flexible fingers, and the shape memory alloy strips (12) are trained to be in a bent state when heated and in an open state when cooled; S4, when the flexible gripper needs to grasp something, the flexible fingers are bent by energizing the shape memory alloy strip (12) and inputting different high duty cycle voltages, so as to achieve the ultimate grasping purpose; S5. When the flexible gripper needs to place something, the size of the magnetic field can be achieved by adjusting the size of the current controller. The adjustable electromagnet (14) can solve the problem of slow cooling of the shape memory alloy strip (12) and also improve the response time of the flexible finger.

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