A flexible drive with segmentally adjustable stiffness

Abstract

The application discloses a flexible driver capable of segmentally adjusting rigidity, which comprises a clamping disc, a flexible driver body, elastomer actuators and electromagnetic coils; a flow channel opening is arranged on the clamping disc; the flexible driver body is fixed on one side of the clamping disc, a straight-through cavity is arranged in the flexible driver body, and the straight-through cavity is communicated with a pressure fluid conveying system through the flow channel opening; a plurality of elastomer actuators are arranged on the same side of the flexible driver body, a wrinkle cavity is arranged in each elastomer actuator, and the wrinkle cavity is communicated with the straight-through cavity; a plurality of electromagnetic coils are wound on the flexible driver body, and each electromagnetic coil is arranged in a gap between two adjacent elastomer actuators; a plurality of magnetorheological liquid cavities are arranged in the flexible driver body along the length direction, and the magnetorheological liquid cavities are filled with magnetorheological liquid, and the viscosity of the magnetorheological liquid is controlled by a magnetic field generated by the electromagnetic coils. The application has the function of segmentally adjusting rigidity, and has the advantages of simple structure and convenient operation.

Description

Technical Field

[0001] This invention relates to the field of soft robot technology, and more particularly to a flexible actuator with segmented adjustable stiffness. Background Technology

[0002] With the development of modern industry, traditional rigid robotic arms are widely used in industrial production, medical care, scientific research, and daily life. However, they suffer from problems such as poor environmental adaptability, insufficient flexibility, high power consumption, poor safety, high manufacturing costs, and high maintenance costs.

[0003] Flexible robots are currently a hot research area. Due to their material properties, flexible robots can perform complex movements and adapt to different working environments and applications. Furthermore, their enveloping nature simplifies control systems, and they are safer in interactions with living organisms.

[0004] One of the main methods for existing flexible actuators involves using three or more flexible actuators in combination to form a flexible robotic hand for pinching or grasping targets. However, this method suffers from limitations due to the low stiffness of the flexible components, resulting in weak grasping force and unstable gripping posture. Therefore, there is an urgent need to provide a flexible actuator with segmented adjustable stiffness to address the problems of the existing technology. Summary of the Invention

[0005] The purpose of this invention is to provide a flexible actuator with segmented adjustable stiffness to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides a flexible actuator with segmented adjustable stiffness, comprising: A clamping plate, wherein a flow channel is provided on the clamping plate; A flexible actuator body is fixedly installed on one side of the clamping disk. The flexible actuator body has a straight cavity inside, and the straight cavity is connected to a pressure fluid delivery system through the flow channel. An elastomeric actuator, wherein a plurality of the elastomeric actuators are disposed on the same side of the flexible actuator body, and the plurality of elastomeric actuators are equally spaced along the length direction of the flexible actuator body; the elastomeric actuators are provided with a pleated cavity inside, and the pleated cavity is connected to the through cavity; An electromagnetic coil, several of which are wound around the flexible actuator body, and the electromagnetic coil is disposed in the gap between two adjacent elastic actuators; the interior of the flexible actuator body is provided with several magnetorheological fluid chambers along the length direction, the magnetorheological fluid chambers are disposed on the side of the through cavity away from the pleated cavity, the magnetorheological fluid chambers are filled with magnetorheological fluid, and the viscosity of the magnetorheological fluid is controlled by the magnetic field generated by the electromagnetic coil.

[0007] Preferably, the material of the elastomeric actuator is a thermoplastic elastomer.

[0008] Preferably, the magnetorheological fluid cavity includes several independent chambers, which are arranged along the length direction of the flexible actuator body and are equally spaced along the width direction of the flexible actuator body; the distance between the several independent chambers and the clamping disk increases sequentially.

[0009] Preferably, the magnetorheological fluid cavity includes two independent chambers, which are respectively disposed at both ends of the flexible actuator body, and the two independent chambers overlap at their closest ends.

[0010] Preferably, the number of elastomeric actuators between two adjacent electromagnetic coils that are disposed corresponding to the overlapping section of the independent chamber is one; the number of elastomeric actuators between adjacent electromagnetic coils that are not disposed corresponding to the overlapping section of the independent chamber is two.

[0011] Compared with the prior art, the present invention has the following advantages and technical effects: The flexible actuator with segmented adjustable stiffness provided by this invention features segmented stiffness adjustment. It is pressurized directly through a pressure fluid delivery system connected to the flow channel, allowing for a large angle of change. Depending on the gripping scenario, the pressure input is controlled to adjust the initial posture change, and then the current input is adjusted to adjust the stiffness, stabilizing the gripping posture and increasing the gripping force. The structure is simple and easy to operate. This flexible actuator integrates magnetorheological fluid and electromagnetic coils, ensuring its usability when not needed and providing segmented stiffness adjustment when required, offering a new approach to the use of flexible actuators. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1This is a schematic diagram of the flexible actuator with segmented adjustable stiffness according to the present invention; Figure 2 This is a top view of the flexible actuator with segmented adjustable stiffness according to the present invention; Figure 3 for Figure 2 A cross-sectional view along the AA direction; Figure 4 This is a front view of the flexible actuator with segmented adjustable stiffness according to the present invention. Figure 5 for Figure 4 A cross-sectional view along the BB direction; In the diagram: 1. Clamping disc; 2. Flexible actuator body; 3. Elastomer actuator; 4. Electromagnetic coil; 5. Flow channel; 6. Straight cavity; 7. Pleated cavity; 8. Independent chamber. Detailed Implementation

[0014] It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined with each other. The described embodiments are merely some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention. The invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0015] This invention provides a flexible actuator with segmented adjustable stiffness, comprising: Clamping plate 1, with flow channel opening 5 on clamping plate 1; The flexible actuator body 2 is fixedly installed on one side of the clamping plate 1. The flexible actuator body 2 has a straight cavity 6 inside, and the straight cavity 6 is connected to the pressure fluid delivery system through the flow channel 5. The elastomeric actuator 3 is provided on the same side of the flexible actuator body 2, and the elastomeric actuator 3 is provided at equal intervals along the length direction of the flexible actuator body 2; the elastomeric actuator 3 is provided with a pleated cavity 7 inside, and the pleated cavity 7 is connected to the through cavity 6. Electromagnetic coils 4, several electromagnetic coils 4 are wound on the flexible actuator body 2, and the electromagnetic coils 4 are disposed in the gap between two adjacent elastic actuators 3; the interior of the flexible actuator body 2 is provided with several magnetorheological fluid chambers along the length direction, the magnetorheological fluid chambers are disposed on the side of the straight cavity 6 away from the pleated cavity 7, the magnetorheological fluid chambers are filled with magnetorheological fluid, and the viscosity of the magnetorheological fluid is controlled by the magnetic field generated by the electromagnetic coils 4.

[0016] This invention primarily utilizes bending deformation, relying on the difference in deformation between the two sides of the flexible actuator body 2 to achieve the deformation effect; the greater the difference, the greater the deformation. Compared to the material deformation value on one side of the elastomer actuator 3, the material deformation value on the other side is negligible. Therefore, this invention achieves variable stiffness adjustment, allowing for different deformation effects depending on the pressure input by the pressure fluid delivery system. The viscosity of the magnetorheological fluid increases with the increase of the magnetic field strength, which is generated by the electromagnetic coil 4. Therefore, the magnetic field strength is affected by both the number of coil turns and the applied current. When high stiffness is required but the current is limited, the number of coil turns and the coil material can be adjusted to ultimately achieve the desired effect.

[0017] Furthermore, the material of the elastomer actuator 3 is a thermoplastic elastomer, which is processed and shaped using thermoplastic plastic processing equipment and processes.

[0018] Furthermore, the magnetorheological fluid cavity includes several independent chambers 8, which are arranged along the length of the flexible actuator body 2 and are equally spaced along the width of the flexible actuator body 2; the distance between the several independent chambers 8 and the clamping disk 1 increases sequentially.

[0019] When only stiffness is required at certain locations, this invention employs a segmented isolation method using magnetorheological fluids to achieve better segmented stiffness control.

[0020] Specifically, in this embodiment, the magnetorheological fluid cavity includes two independent chambers 8, which are respectively disposed at both ends of the flexible actuator body 2, and the two independent chambers 8 overlap at their closest ends; the number of elastomeric actuators 3 between two adjacent electromagnetic coils 4 corresponding to the overlapping section of the independent chamber 8 is one; the number of elastomeric actuators 3 between adjacent electromagnetic coils 4 not corresponding to the overlapping section of the independent chamber 8 is two.

[0021] The flexible actuator with segmented adjustable stiffness provided by this invention operates on the following principle: A pressure fluid delivery system introduces pressure fluid into the straight cavity 6 and the connected pleated cavity 7 through the flow channel 5, causing the pleated cavity 7 to expand. This causes the elastic actuators 3 to compress against each other, resulting in bending deformation of the flexible actuator body 2. As the fluid pressure changes, the bending angle of the flexible actuator body 2 changes accordingly. Once the bending target is reached, the magnetic flux is changed by controlling the current magnitude of each electromagnetic coil 4 according to the required stiffness or posture, thereby altering the viscosity of the magnetorheological fluid and changing the stiffness of the flexible actuator.

[0022] The stiffness of the flexible actuator of the present invention can be adjusted in segments, specifically including the following situations: one is to change the viscosity of the magnetorheological fluid in the independent chamber 8 on the side of the magnetorheological fluid chamber closer to the clamping disk 1; another is to change the viscosity of the magnetorheological fluid in the independent chamber 8 on the side of the magnetorheological fluid chamber farther from the clamping disk 1; another is that when the number of independent chambers 8 of the magnetorheological fluid chamber is greater than two, the viscosity of the magnetorheological fluid in the independent chamber 8 at the same distance from the clamping disk 1 can be changed as needed; and yet another is to change the viscosity of the magnetorheological fluid in all independent chambers 8.

[0023] The flexible actuator provided by this invention has high flexibility and a wide adjustment range, solving the problems of low grasping force, unstable grasping posture, insufficient stiffness of the flexible robot drive part, and non-adjustable stiffness of existing flexible actuators.

[0024] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A flexible actuator with segmented adjustable stiffness, characterized in that, include: Clamping plate (1), the clamping plate (1) is provided with a flow channel (5); The flexible actuator body (2) is fixedly installed on one side of the clamping disk (1). The flexible actuator body (2) has a through cavity (6) inside, and the through cavity (6) is connected to a pressure fluid delivery system through the flow channel (5). An elastomeric actuator (3) is provided on the same side of the flexible actuator body (2), and the elastomeric actuators (3) are equally spaced along the length direction of the flexible actuator body (2); the elastomeric actuator (3) has a pleated cavity (7) inside, and the pleated cavity (7) is connected to the through cavity (6); Electromagnetic coils (4), several of the electromagnetic coils (4) are wound on the flexible actuator body (2), and the electromagnetic coils (4) are disposed in the gap between two adjacent elastic actuators (3); the interior of the flexible actuator body (2) is provided with several magnetorheological fluid chambers along the length direction, the magnetorheological fluid chambers are disposed on the side of the through cavity (6) away from the pleated cavity (7), the magnetorheological fluid chambers are filled with magnetorheological fluid, and the viscosity of the magnetorheological fluid is controlled by the magnetic field generated by the electromagnetic coils (4); The magnetorheological fluid chamber includes two independent chambers (8), which are arranged along the length of the flexible actuator body (2) and are equally spaced along the width of the flexible actuator body (2); the distance between the two independent chambers (8) and the clamping disk (1) increases sequentially. The two independent chambers (8) are respectively disposed at both ends of the flexible actuator body (2), and the two independent chambers (8) overlap at their closest ends; The number of the elastomeric actuators (3) between two adjacent electromagnetic coils (4) that are disposed corresponding to the overlapping section of the independent chamber (8) is one; the number of the elastomeric actuators (3) between adjacent electromagnetic coils (4) that are not disposed corresponding to the overlapping section of the independent chamber (8) is two.

2. The flexible actuator with segmented adjustable stiffness according to claim 1, characterized in that, The material of the elastomeric actuator (3) is thermoplastic elastomer.

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