Rigidity-variable flexible self-sensing actuator

Abstract

The invention belongs to the technical field of soft robots, and particularly relates to a variable-rigidity flexible self-sensing actuator which comprises a flexible actuator, a flexible magnetorheological fluid damping cavity, a flexible magneto-rheological fluid damping device, a flexible magneto-rheological fluid control device, a flexible magneto-rheological fluid control device, a flexible magneto-rheological fluid control device and a flexible magneto-rheological fluid control device. And the square electromagnet is arranged in the middle of the flexible actuator and used for applying a magnetic field to change the viscosity of the magnetorheological fluid. In the use process, after the flexible actuator is driven by pressure fluid, the flexible actuator captures a target object after being pressed, bent and deformed; the magnetorheological fluid is adsorbed in a flow channel of the flexible magnetorheological fluid damping cavity under the action of a magnetic field of the square electromagnet, so that the flow resistance of the magnetorheological fluid in the flexible magnetorheological fluid damping cavity is greatly increased, the clamping force of the flexible actuator is enhanced, and the situation that after the flexible actuator captures a target object, the clamping force is insufficient due to a complex environment, and the clamping force is not enough is avoided. And the object slides down.

Description

Technical Field

[0001] The invention belongs to the technical field of soft robots, and in particular relates to a variable-rigidity flexible self-sensing actuator. Background Art

[0002] Traditional rigid actuators are widely used in industries such as industry, medicine, and food processing, but technical difficulties such as large motor drive inertia, inflexible movement, and high control difficulty limit their scope of application, such as grasping fragile objects, underwater operations, and complex space operations.

[0003] Flexible actuators are a hot topic in current research. They can change their posture to adapt to complex spaces, have good adaptability, and have good grasping effects on fragile and fragile items and irregular objects. They are mainly used in lightweight object grasping scenarios in food processing, medicine, and electronic manufacturing.

[0004] Common driving modes of flexible actuators are pressure fluid driving and smart material driving. Faced with more complex and changeable working requirements and operating spaces, flexible actuators need stronger clamping force and more variable grasping capabilities, and a single driving mode is insufficient. Therefore, a variable stiffness flexible self-sensing actuator is urgently needed to solve this problem. Summary of the invention

[0005] The purpose of the present invention is to provide a variable stiffness flexible self-sensing actuator to solve the above problems.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] A variable stiffness flexible self-sensing actuator, comprising a flexible actuator,

[0008] A flexible magnetorheological fluid damping chamber is arranged at the bottom of the flexible actuator, and magnetorheological fluid flows in the flexible magnetorheological fluid damping chamber;

[0009] A square electromagnet is arranged in the middle of the flexible actuator and is used to apply a magnetic field to change the viscosity of the magnetorheological fluid.

[0010] Preferably, the flexible actuator comprises:

[0011] End seat;

[0012] A flexible claw arm, one end of which is fixed to the end seat;

[0013] There are a plurality of rectangular columns, which are arranged at intervals on the top surface of the flexible claw arm, and the rectangular columns are fixedly connected to the flexible claw arm;

[0014] The square electromagnet is fixedly connected to the middle part of the top surface of the flexible claw arm;

[0015] An internal communication flow channel is provided in the flexible claw arm, one end of the internal communication flow channel is closed, and the other end is connected to a flow channel opening, and the flow channel opening is provided on the end seat;

[0016] A rectangular chamber is provided in the rectangular column, and the rectangular chamber is communicated with the internal communication channel;

[0017] The flexible magnetorheological fluid damping chamber is embedded in the inner side of the bottom of the flexible claw arm.

[0018] Preferably, the flexible magnetorheological fluid damping chamber comprises a root flexible magnetorheological fluid storage chamber, a magnetorheological fluid damping channel and an end flexible magnetorheological fluid storage chamber which are interconnected;

[0019] The root flexible magnetorheological fluid storage chamber, the magnetorheological fluid damping channel and the end flexible magnetorheological fluid storage chamber are embedded on the inner side of the bottom of the flexible claw arm.

[0020] Preferably, the magnetorheological fluid damping channel is a continuously bent structure.

[0021] Preferably, it also includes a flexible sensing layer, and the flexible sensing layer is arranged on the bottom surface of the flexible claw arm.

[0022] Preferably, the flexible sensing layer comprises:

[0023] A signal detection part, wherein the signal detection part is a continuously bent structure and is laid on the bottom surface of the flexible claw arm, and a flexible sensing material is applied on the signal detection part;

[0024] A flexible sensing detection signal inlet is arranged at one end of the signal detection location;

[0025] The flexible sensing detection signal outlet is arranged at the other end of the signal detection location.

[0026] Preferably, the flexible sensing material is a mixture of a conductive filler and an elastomer or a conductive paste, and is printed on the bottom surface of the flexible claw arm by lamination.

[0027] Preferably, the magnetorheological fluid is a micro-nano composite magnetorheological fluid, which is prepared by a method in which micron magnetic particles and nano magnetic particles are mixed and doped and then dispersed in a silicone oil-based carrier fluid.

[0028] Compared with the prior art, the present invention has the following advantages and technical effects:

[0029] When in use, after the flexible actuator is driven by the pressure fluid, the flexible actuator bends and deforms under pressure to capture the target object; the magnetorheological fluid is adsorbed in the flow channel of the flexible magnetorheological fluid damping cavity under the action of the magnetic field of the square electromagnet, which greatly increases the flow resistance of the magnetorheological fluid in the flexible magnetorheological fluid damping cavity, enhances the clamping force of the flexible actuator, and prevents the flexible actuator from slipping due to insufficient clamping force caused by complex environment after capturing the target object. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative labor:

[0031] Figure 1 It is a structural schematic diagram of the variable stiffness flexible self-sensing actuator of the present invention;

[0032] Figure 2 It is a schematic diagram of the bottom structure of the variable stiffness flexible self-sensing actuator of the present invention;

[0033] Figure 3 It is a schematic diagram of the cross-sectional structure of the variable stiffness flexible self-sensing actuator of the present invention;

[0034] Figure 4 It is a schematic structural diagram of the flexible magnetorheological fluid damping chamber of the present invention;

[0035] Figure 5 is a schematic structural diagram of the flexible sensing layer of the present invention;

[0036] Figure 6 This is a simulation diagram of the deformation effect of the flexible actuator of the present invention under the action of pressure fluid;

[0037] Among them, 1. flexible actuator; 2. square electromagnet; 3. flexible magnetorheological fluid damping chamber; 4. flexible sensing layer; 1.1. end seat; 1.2. rectangular cylinder; 1.3. flexible claw arm; 1.4. flow channel outlet; 1.5. rectangular chamber; 1.6. internal connecting flow channel; 3.1. root flexible magnetorheological fluid storage chamber; 3.2. magnetorheological fluid damping flow channel; 3.3. end flexible magnetorheological fluid storage chamber; 4.1. flexible sensor detection signal inlet; 4.2. signal detection place; 4.3. flexible sensor detection signal outlet. DETAILED DESCRIPTION

[0038] 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.

[0039] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] Reference Figures 1 to 6 The present invention discloses a variable stiffness flexible self-sensing actuator, comprising a flexible actuator 1,

[0041] A flexible magnetorheological fluid damping chamber 3 is arranged at the bottom of the flexible actuator 1, and magnetorheological fluid flows in the flexible magnetorheological fluid damping chamber 3;

[0042] The square electromagnet 2 is arranged in the middle of the flexible actuator 1 and is used to apply a magnetic field to change the viscosity of the magnetorheological fluid.

[0043] When in use, after the flexible actuator 1 is driven by the pressure fluid, the flexible actuator 1 is compressed and deformed to capture the target object; under the action of the magnetic field of the square electromagnet 2, the magnetorheological fluid is adsorbed in the flow channel of the flexible magnetorheological fluid damping chamber 3, which greatly increases the flow resistance of the magnetorheological fluid in the flexible magnetorheological fluid damping chamber 3, enhances the clamping force of the flexible actuator 1, and prevents the flexible actuator 1 from slipping due to insufficient clamping force caused by complex environment after capturing the target object.

[0044] Further optimizing the scheme, the flexible actuator 1 includes:

[0045] End seat 1.1;

[0046] A flexible claw arm 1.3, one end of which is fixed on the end seat 1.1;

[0047] A plurality of rectangular cylinders 1.2 are provided, and the plurality of rectangular cylinders 1.2 are arranged at intervals on the top surface of the flexible claw arm 1.3, and the rectangular cylinders 1.2 are fixedly connected to the flexible claw arm 1.3;

[0048] The square electromagnet 2 is fixedly connected to the middle of the top surface of the flexible claw arm 1.3;

[0049] An internal communication channel 1.6 is provided in the flexible claw arm 1.3. One end of the internal communication channel 1.6 is closed, and the other end is connected to a channel opening 1.4. The channel opening 1.4 is provided on the end seat 1.1.

[0050] A rectangular chamber 1.5 is provided in the rectangular column 1.2, and the rectangular chamber 1.5 is connected to the internal communication channel 1.6;

[0051] The flexible magnetorheological fluid damping chamber 3 is embedded inside the bottom of the flexible claw arm 1.3.

[0052] The rectangular column 1.2 of the flexible actuator 1 is connected to the flexible claw arm 1.3. A rectangular chamber 1.5 is provided inside the rectangular column 1.2. The rectangular chambers 1.5 are connected through an internal connecting channel 1.6. A channel opening 1.4 is provided on the end seat 1.1. The channel opening 1.4 is connected to the internal connecting channel 1.6 to form a chamber structure inside the flexible actuator 1. The channel opening 1.4, the rectangular chamber 1.5 and the internal connecting channel 1.6 are connected to each other.

[0053] According to a further optimized solution, the flexible magnetorheological fluid damping chamber 3 includes a root flexible magnetorheological fluid storage chamber 3.1, a magnetorheological fluid damping channel 3.2 and an end flexible magnetorheological fluid storage chamber 3.3 which are interconnected;

[0054] The root flexible magnetorheological fluid storage chamber 3.1, the magnetorheological fluid damping channel 3.2 and the end flexible magnetorheological fluid storage chamber 3.3 are embedded in the bottom inner side of the flexible claw arm 1.3.

[0055] According to a further optimization scheme, the magnetorheological fluid damping channel 3.2 is a continuously bent structure.

[0056] The square electromagnet 2 is arranged between two adjacent rectangular columns 1.2 in the middle of the flexible actuator 1, and is bonded to the flexible claw arm 1.3, and adsorbs the magnetorheological fluid by turning the power on and off.

[0057] The flexible magnetorheological fluid damping chamber 3 is filled with magnetorheological fluid and is arranged inside the flexible claw arm 1.3.

[0058] The flexible magnetorheological fluid damping chamber 3 is composed of a root flexible magnetorheological fluid storage chamber 3.1 and an end flexible magnetorheological fluid storage chamber 3.3 connected by a magnetorheological fluid damping channel 3.2. The flexible magnetorheological fluid damping chamber 3 is filled with magnetorheological fluid, which is prepared by mixing and doping micron magnetic particles with nano magnetic particles and then dispersing them in a silicone oil-based carrier liquid.

[0059] The principle and process of the flexible magnetorheological fluid damping chamber 3 increasing the clamping force of the flexible actuator: when the flexible actuator 1 is deformed under pressure to grasp the target object, the flexible magnetorheological fluid damping chamber 3 deforms along with the deformation of the flexible actuator 1, and the volume of the root flexible magnetorheological fluid storage chamber 3.1 and the end flexible magnetorheological fluid storage chamber 3.3 changes. The magnetorheological fluid inside them flows through the magnetorheological fluid damping channel 3.2, so that the internal pressure of the flexible magnetorheological fluid damping chamber 3 reaches equilibrium. Then, the square electromagnet 2 is energized to generate a magnetic field, and the magnetorheological fluid inside the flexible magnetorheological fluid damping chamber 3 The viscosity of the liquid increases due to the influence of the magnetic field, so that the magnetorheological fluid will encounter great flow resistance when flowing in the magnetorheological fluid damping channel 3.2, ensuring that the volume of the root flexible magnetorheological fluid storage chamber 3.1 and the end flexible magnetorheological fluid storage chamber 3.3 will not change again with the external environmental disturbance, that is, the deformation after grasping the object will no longer change, which is ultimately manifested as an increase in the stiffness of the flexible actuator 1, achieving the purpose of "self-locking". When grasping objects of different weights, by passing currents of different sizes into the square electromagnet 2, the effect of variable stiffness within a certain range can be achieved.

[0060] The stiffness of the flexible actuator 1 is manifested as the flow resistance of the magnetorheological fluid in the magnetorheological fluid damping channel 3.2. The flow resistance is determined by the magnetic field strength generated by the square electromagnet 2 and the cross-sectional area of ​​the magnetorheological fluid damping channel 3.2. The viscosity of the magnetorheological fluid increases with the increase of the magnetic field strength, and the flow resistance increases with the increase of the viscosity of the magnetorheological fluid. The flow resistance of the magnetorheological fluid flowing through the magnetorheological fluid damping channel 3.2 increases with the decrease of the cross-sectional area of ​​the magnetorheological fluid damping channel 3.2. When the stiffness requirement is high, the ideal effect can be achieved by designing the square electromagnet 2 and adjusting the cross-sectional area of ​​the magnetorheological fluid damping channel 3.2.

[0061] Furthermore, the magnetorheological fluid damping channel 3.2 is in a winding form, which greatly increases the flow distance of the magnetorheological fluid while reducing the cross section. By applying an electromagnetic field to the winding magnetorheological fluid damping channel 3.2, the flow resistance of the magnetorheological fluid in the magnetorheological fluid damping channel 3.2 can be greatly enhanced.

[0062] By designing the magnetorheological fluid damping channel 3.2 to be in a meandering form, only a square electromagnet 2 is required to be arranged therein to meet the design requirements, thereby greatly saving costs and improving efficiency while retaining the structure and function of the flexible actuator 1.

[0063] The variable stiffness flexible self-sensing actuator has high flexibility and a wide adjustment range, and solves the problem of the single control scheme of the current variable stiffness flexible self-sensing actuator.

[0064] According to a further optimization scheme, the magnetorheological fluid is a micro-nano composite magnetorheological fluid, which is prepared by a method in which micron magnetic particles and nano magnetic particles are mixed and doped and then dispersed in a silicone oil-based carrier liquid.

[0065] A further optimized solution further includes a flexible sensing layer 4, which is arranged on the bottom surface of the flexible claw arm 1.3.

[0066] Further optimizing the solution, the flexible sensing layer 4 includes:

[0067] The signal detection part 4.2 is a continuously bent structure, which is laid on the bottom surface of the flexible claw arm 1.3. The signal detection part 4.2 is coated with a flexible sensing material;

[0068] The flexible sensing detection signal inlet 4.1 is arranged at one end of the signal detection location 4.2;

[0069] The flexible sensing detection signal outlet 4.3 is arranged at the other end of the signal detection location 4.2.

[0070] According to a further optimization scheme, the flexible sensing material is a mixture of a conductive filler and an elastomer or a conductive paste, which is printed on the bottom surface of the flexible claw arm 1.3 by lamination.

[0071] The flexible sensing layer 4 is composed of a flexible sensing detection signal inlet 4.1, a signal detection part 4.2, a flexible sensing detection signal outlet 4.3 and a flexible sensing material coated thereon. The flexible sensing material includes a mixture of conductive filler and elastomer or conductive paste, and is formed on the bottom of the flexible actuator 1 by lamination printing.

[0072] The principle and process of the flexible sensing layer 4 monitoring the deformation signal of the flexible actuator 1: During the compression deformation process of the flexible actuator 1, the flexible sensing layer 4 located at the bottom surface of the flexible actuator 1 deforms along with the deformation of the flexible actuator 1, and the signal detection part 4.2 coated with the flexible sensing material deforms accordingly. The flexible sensing material coated at the signal detection part 4.2 can be equivalent to a long resistance wire. As the flexible sensing layer 4 deforms, the equivalent length and equivalent cross-sectional area of ​​the long resistance wire change, which is manifested as a change in the resistance value of the signal detection part 4.2. The motion state of the flexible actuator 1 can be obtained by processing and applying it.

[0073] Furthermore, the variable stiffness flexible self-sensing actuator of the present invention is made in an integrated manner, the manufacturing material is thermoplastic elastomer, and is processed and formed using standard thermoplastic plastic processing equipment and processes. The use of flexible materials such as thermoplastic elastomers can enable the variable stiffness flexible self-sensing actuator to respond to different environmental requirements and achieve a stronger grasping effect. The thermoplastic plastic processing method ensures the flexibility, environmental friendliness and density of the overall structure, so that the variable stiffness flexible self-sensing actuator can adapt well to the surrounding environment, withstand higher pressure, and quickly complete larger deformations, thereby achieving flexible grasping.

[0074] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0075] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A variable stiffness flexible self-sensing actuator, comprising a flexible actuator (1), characterized in that: A flexible magnetorheological fluid damping chamber (3) is arranged at the bottom of the flexible actuator (1), and magnetorheological fluid flows in the flexible magnetorheological fluid damping chamber (3); A square electromagnet (2) is arranged in the middle of the flexible actuator (1) and is used to apply a magnetic field to change the viscosity of the magnetorheological fluid.

2. The variable stiffness flexible self-sensing actuator according to claim 1, characterized in that: The flexible actuator (1) comprises: End seat (1.1); A flexible claw arm (1.3), one end of which is fixed on the end seat (1.1); A plurality of rectangular columns (1.2) are provided, wherein the plurality of rectangular columns (1.2) are arranged at intervals on the top surface of the flexible claw arm (1.3), and the rectangular columns (1.2) are fixedly connected to the flexible claw arm (1.3); The square electromagnet (2) is fixedly connected to the middle of the top surface of the flexible claw arm (1.3); An internal communication flow channel (1.6) is provided in the flexible claw arm (1.3); one end of the internal communication flow channel (1.6) is closed, and the other end is connected to a flow channel opening (1.4); the flow channel opening (1.4) is provided on the end seat (1.1); A rectangular chamber (1.5) is provided in the rectangular column (1.2), and the rectangular chamber (1.5) is connected to the internal communication channel (1.6); The flexible magnetorheological fluid damping chamber (3) is embedded inside the bottom of the flexible claw arm (1.3).

3. The variable stiffness flexible self-sensing actuator according to claim 2, characterized in that: The flexible magnetorheological fluid damping chamber (3) comprises a root flexible magnetorheological fluid storage chamber (3.1), a magnetorheological fluid damping channel (3.2) and an end flexible magnetorheological fluid storage chamber (3.3) which are interconnected; The root flexible magnetorheological fluid storage chamber (3.1), the magnetorheological fluid damping channel (3.2) and the end flexible magnetorheological fluid storage chamber (3.3) are embedded inside the bottom of the flexible claw arm (1.3).

4. The variable stiffness flexible self-sensing actuator according to claim 3, characterized in that: The magnetorheological fluid damping flow channel (3.2) is a continuously bent structure.

5. The variable stiffness flexible self-sensing actuator according to claim 2, characterized in that: It also comprises a flexible sensing layer (4), wherein the flexible sensing layer (4) is arranged on the bottom surface of the flexible claw arm (1.3).

6. The variable stiffness flexible self-sensing actuator according to claim 5, characterized in that: The flexible sensing layer (4) comprises: A signal detection part (4.2), the signal detection part (4.2) is a continuously bent structure, which is laid on the bottom surface of the flexible claw arm (1.3), and a flexible sensing material is applied on the signal detection part (4.2); A flexible sensing detection signal inlet (4.1) is arranged at one end of the signal detection location (4.2); The flexible sensing detection signal outlet (4.3) is arranged at the other end of the signal detection location (4.2).

7. The variable stiffness flexible self-sensing actuator according to claim 6, characterized in that: The flexible sensing material is a mixture of a conductive filler and an elastomer or a conductive paste, and is printed on the bottom surface of the flexible claw arm (1.3) by lamination.

8. The variable stiffness flexible self-sensing actuator according to claim 1, characterized in that: The magnetorheological fluid is a micro-nano composite magnetorheological fluid, which is prepared by a method in which micron magnetic particles and nano magnetic particles are mixed and doped and then dispersed in a silicone oil-based carrier fluid.

Images