Electro-responsive material driven biomimetic obstacle crossing robot

Abstract

The application provides an electric response material driven bionic obstacle crossing robot, which comprises a first driver, a second driver, a multi-section elastic framework, a foot support, a foot bottom buffer layer structure and a polymer fastener; the multi-section elastic framework comprises a front section framework and a rear section framework; the first driver is installed on the front section framework, the rear section framework is provided with a hollow structure; the second driver is installed on the hollow structure; the foot support is installed on the rear section framework, and the foot bottom buffer layer structure is installed on the foot support. The first driver is a shape memory alloy spring, two groups of the shape memory alloy springs are symmetrically distributed on the upper and lower sides of the front section framework, the interval of the fixed positions of the two ends of the spring is greater than the length of the spring in a natural state, and the two ends of each spring are connected to the positive and negative poles of an external power supply through external wires. The application adopts the structure that the front section framework cooperates with the shape memory alloy spring, can realize controllable energy storage and release, and realizes the jumping obstacle crossing movement of the robot.

Description

Technical Field

[0001] This invention relates to the field of soft robotics, and more specifically, to a biomimetic obstacle-crossing robot driven by an electrically responsive material. Background Technology

[0002] In recent years, with the continuous development of materials science and technology, various new drive technologies have emerged and been applied to the field of robotics, such as drive technologies based on electroactive materials, shape memory materials, and magnetic materials. The application of these drive technologies effectively reduces the stiffness and size of robots and lowers their manufacturing costs, enabling robots to be better applied in complex and confined environments, or to achieve biomimetic designs that more closely resemble the shape and movement patterns of living organisms in nature. These technologies have broad application prospects in fields such as medicine, search and rescue, and marine environmental exploration.

[0003] Currently, intelligent drive technology based on electroresponsive materials (such as shape memory alloys and electroactive polymers) is widely used in the field of micro and small mobile robots due to its excellent performance and ease of control.

[0004] However, most current electrically responsive robots do not have jumping or obstacle-crossing capabilities. For example, the running legged robot designed by the Soft Robotics Laboratory of Harbin Institute of Technology uses two dielectric elastomer minimum energy structures connected in series. When the two actuators drive together, the robot can achieve forward airborne movement and a running speed of 6 times its body length per second. However, the robot can only perform a single mode of movement on flat ground and cannot perform turning, obstacle crossing, or other actions, which limits its application scenarios. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a biomimetic obstacle-crossing robot driven by an electrically responsive material.

[0006] According to the present invention, an electroresponsive material-driven biomimetic obstacle-crossing robot includes a first actuator, a second actuator, a multi-segment elastic skeleton, a foot support, a foot cushioning layer structure, and polymer fasteners.

[0007] The multi-segment elastic skeleton includes a front skeleton and a rear skeleton.

[0008] The first driver is mounted on the front frame via polymer fasteners, and the rear frame has a hollow structure; the second driver is mounted on the hollow structure; the foot support is mounted on the rear frame, and the foot support has a foot cushioning layer structure.

[0009] The first actuator is mounted on the front frame via polymer fasteners and is capable of driving the front frame to achieve bidirectional bending deformation.

[0010] Preferably, the first actuator is a shape memory alloy spring, and the shape memory alloy springs are symmetrically distributed in pairs on the upper and lower sides of the front frame. The interval between the fixed positions of the two ends of the spring is greater than the length of the spring in its natural state. The two ends of each spring are connected to the positive and negative terminals of an external power supply through external wires.

[0011] Preferably, the second actuator is an electroactive polymer actuator, which includes multiple electroactive polymer actuator units arranged in a stacked manner.

[0012] Each electroactive polymer actuator unit includes an electroactive polymer and two layers of flexible electrodes, with the electroactive polymer located between the two layers of flexible electrodes, which are respectively connected to the two poles of an external power source.

[0013] Preferably, the foot support is bent at a preset angle, and the foot support contacts the ground through the foot cushioning layer structure.

[0014] Preferably, the polymer fastener is made of a heat-resistant and insulating resin material.

[0015] Preferably, the foot cushioning layer structure is made of silicone rubber or sponge material.

[0016] Preferably, the front skeleton and the rear skeleton have the same or different thicknesses, and the multi-segment elastic skeleton is made of polymer material.

[0017] Preferably, the electroactive polymer is made of silicone or acrylate.

[0018] Preferably, the shape memory alloy spring is made of nickel-titanium alloy material.

[0019] Preferably, the multi-segment elastic skeleton is made of polyimide and polyethylene terephthalate; the polymer fastener is made of polytetrafluoroethylene and polyamide.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The present invention adopts a structure that combines a front frame with a shape memory alloy spring, which can realize controllable energy storage and release, and enable the robot to jump and overcome obstacles.

[0022] 2. By designing the second actuator as an electroactive polymer actuator, the present invention enables the robot to run by energizing the electroactive polymer actuator.

[0023] 3. The present invention can increase the contact area between the rear of the robot and the ground through the foot bracket, and can increase the elasticity, friction coefficient and friction force of the interaction between the foot and the ground through the foot cushioning layer structure, so that the robot can achieve better forward movement effect. Attached Figure Description

[0024] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0025] Figure 1 This is a schematic diagram of the structure of the present invention;

[0026] Figure 2 This is a schematic diagram of the structure of the invention as a top view after it has been unfolded;

[0027] Figure 3 This is a schematic diagram of the robot obstacle-crossing action provided by the present invention. The diagram shows the three stages of the robot's obstacle-crossing process: preparation, take-off, and landing.

[0028] The diagram shows:

[0029] Detailed Implementation

[0030] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0031] This invention provides a biomimetic obstacle-crossing robot driven by an electrically responsive material, such as... Figure 1-2 As shown, it includes a first actuator 1, a second actuator 6, a multi-segment elastic skeleton 2, a foot support 5, a foot cushioning layer structure 4, and a polymer fastener 3.

[0032] The multi-segment elastic skeleton serves as the main structure of the robot and is processed by laser cutting. The multi-segment elastic skeleton 2 includes a front skeleton 21 and a rear skeleton 22, which are assembled and connected by polymer fasteners 3. The rear skeleton is a curved structure with a hollow structure in the curved part. The second driver 6 is installed on the hollow structure and is fixed to the rear section of the robot, driving the rear structure to change the bending angle.

[0033] The first actuator 1 is mounted on the front frame 21 via polymer fasteners 3, enabling the front frame 21 to achieve bidirectional bending and torsional deformation, and to store and release energy during the bidirectional bending deformation process; the foot support 5 is mounted on the rear frame 22, and a foot cushioning layer structure 4 is installed on the foot support 5. In a preferred embodiment, the polymer fastener 3 is a screw and nut structure.

[0034] The first actuator 1 is a shape memory alloy spring. Two shape memory alloy springs are symmetrically distributed on the upper and lower sides of the front frame 21. The two ends of each spring are fixed to different polymer fasteners 3. The distance between the fixed positions of the two ends of the spring is greater than the length of the spring in its natural state, so that the spring generates tension in the fixed state. After stretching, the two ends of the spring are fixed to the through holes reserved in the elastic frame by the fasteners 3. Each spring's two ends are connected to the positive and negative terminals of an external DC power supply via external wires. Specifically, the two ends of the spring are connected to an external DC current source, and the spring temperature is controlled by the magnitude of the current passing through the spring. In a preferred embodiment, there are multiple sets of shape memory alloy springs. Each pair of symmetrical shape memory alloy springs and the intermediate elastic frame (i.e., the front frame 21) constitute a driving unit. Each driving unit can independently control the bending deformation in the vertical direction. Multiple driving units are equidistantly separated laterally and fixed at both ends. The torsional deformation of the entire structure is achieved by different bending angles of the driving units. Figure 1-2 The drive unit consists of three sets: shape memory alloy springs on the upper and lower sides and an elastic skeleton in the middle. The drive unit can achieve controllable energy storage and release during bending, and realize the robot's jumping and obstacle-crossing movement through the energy release process.

[0035] The shape memory alloy spring is made of nickel-titanium alloy, a material capable of undergoing a phase transformation between martensite and austenite under temperature changes, thereby generating varying degrees of contraction force. Specifically, when the power is turned on, current flows through a single spring, generating heat. The increased temperature causes a martensite-to-austenite phase transformation, leading to spring contraction. The central elastic skeleton (i.e., the front skeleton 21) bends away from the heated spring under the spring tension. When the elastic skeleton bends to the middle position, the direction of the spring tension on both the upper and lower sides changes abruptly, and the energy stored in the heated and contracted spring is rapidly released in a short time, accelerating the bending deformation of the elastic skeleton. More specifically, as... Figure 3As shown, the invention is first prepared by manual labor or by energizing the upper spring. At this time, the tension direction of the upper spring is consistent with the length direction of the spring, and the tension direction of the lower spring is along the tangential direction of the front frame 21. Then, the lower spring is energized, and the lower spring contracts and shortens in length. The elastic frame between the upper and lower springs bends upward under the action of the spring tension. When the elastic frame bends to the middle position, the tension direction of the upper and lower springs will change abruptly (that is, the tension direction of the lower spring becomes along the length direction of the spring, and the tension direction of the upper spring becomes along the tangential direction of the front frame 21). The energy stored in the heated and contracted spring is released rapidly in a short time, which causes the elastic frame to bend upward and deform faster, thereby making the robot jump forward to cross the obstacle.

[0036] The second actuator 6 is an electroactive polymer actuator. This actuator employs a sandwich structure of multiple polymer films and flexible electrodes. The flexible electrodes on both sides of each electroactive polymer film are connected to the two poles of a high-voltage DC power supply. Under the action of the high-voltage power supply switching signal, the rear bending section of the robot outputs oscillating motion at the same frequency as the switching signal. When the switching signal frequency approaches the resonant frequency of the robot's motion, the robot achieves rapid forward running. This invention uses an electric field to induce compressive deformation in the intermediate electroactive polymer film perpendicular to the electrode plane. The electroactive polymer actuator undergoes bidirectional equal stretching parallel to the film direction, resulting in pre-existing tension within it when fixed to the elastic skeleton. The structure exhibits a natural bending state under the balance of the electroactive polymer tension and the elastic skeleton's elastic force. The bending angle can change under the influence of the electric field within the electroactive polymer actuator. The electroactive polymer is selected from flexible film materials with good dielectric properties, such as silicone and acrylate. The material is biaxially stretched parallel to the film plane and fixed to the rear section of the elastic skeleton. In other words, the second actuator 6 is pre-stretched and fixed to the rear elastic skeleton of the robot. The tension inside the polymer and the elastic force of the skeleton balance each other, causing the structure to form a natural bending state. By controlling the change in tension inside the electroactive polymer actuator with voltage, the bending angle of the structure can be controlled. Alternatively, the electroactive polymer actuator can be understood as comprising multiple electroactive polymer actuator units, which are stacked in layers. Each electroactive polymer actuator unit includes an electroactive polymer and two layers of flexible electrodes, with the electroactive polymer located between the two layers of flexible electrodes. The flexible electrodes are respectively connected to the two poles of an external high-voltage DC power supply.

[0037] The foot support 5 is pre-bent at a preset angle and contacts the ground through the foot cushioning layer structure 4. The foot support 5 increases the contact area between the robot's rear end and the ground, while the foot cushioning layer structure 4 increases the elasticity, coefficient of friction, and frictional force of the interaction between the foot and the ground, allowing the robot to achieve better forward movement and increase its running speed. The contact position and frictional distribution of the foot cushioning layer structure with the ground can be controlled by the torsional deformation of the robot's front structure, thereby adjusting the robot's forward direction and allowing the robot's movement to adapt to different ground materials. In a preferred embodiment, the foot cushioning layer structure 4 is made of silicone rubber or sponge material, and the preset angle is 90°.

[0038] The polymer fastener 3 is made of heat-resistant and insulating resin materials such as polytetrafluoroethylene (PTFE) and polyamide (PA), and is used to fix different elastic skeletons and shape memory alloy springs. The heat resistance of the material can ensure that it maintains the required mechanical properties when the shape memory alloy spring heats up. The insulation ensures that there is no current path between different shape memory alloy springs fixed on the same fastener (i.e., between the upper and lower shape memory alloy springs in the same group), so as to realize independent control of each shape memory alloy spring driver.

[0039] The multi-segment elastic skeleton 2 is made of polymer materials, such as polyimide (PI) and polyethylene terephthalate (PET). The front skeleton 21 and the rear skeleton 22 may have the same or different thicknesses. By selecting different materials and thicknesses, the elastic skeleton can obtain different bending stiffnesses to meet the mechanical performance requirements of different actuators in the front and rear sections of the robot, while also being able to withstand the high temperature and high voltage generated by the electro-responsive actuators during operation.

[0040] In this invention, the first actuator 1 and the front section of the multi-segment elastic skeleton constitute a naturally bending drive structure. This structure can achieve bending and torsional deformation through the electrical heating and contraction of shape memory alloy springs at different positions, and achieve controllable storage and release of energy within the springs during bending deformation. The electroactive polymer actuator can be fixed to the rear section of the multi-segment elastic skeleton by the adhesive properties of the material itself, or by a separate adhesive or fastener. Before fixing, the electroactive polymer actuator is pre-stretched, allowing the rear of the robot to bend naturally under the balance of polymer tension and elastic skeleton force. Under voltage, the electroactive polymer actuator controls the rear structure to change the bending angle. Combined with the foot support and foot cushioning layer structure fixed to the bottom of the robot's rear section, this enables the robot to run forward quickly. The shape memory alloy spring control structure in the front section undergoes torsional deformation during running, changing the robot's bottom contact position and corresponding friction distribution, enabling the robot to turn left and right. The bending energy storage and release process of the shape memory alloy spring drive structure allows the robot to complete jumps at different angles forward and upward.

[0041] The shape memory alloy spring actuators at the front of the robot are current-controlled, with each spring having an independent current control switch. When all the springs on the upper or lower side are energized and contracted together, the front structure of the robot undergoes vertical bending deformation, storing and releasing energy. When the energy is released, it is converted into the robot's forward and upward jumping kinetic energy, enabling obstacle crossing. The robot's jumping direction can be adjusted by the bending angle of the rear electroactive polymer drive structure. When the bending angle of the rear structure is smaller, the robot jumps with more forward velocity, while when the bending angle is larger, the robot jumps with more longitudinal velocity. If only the left or right springs on the upper or lower side of the shape memory alloy springs at the front of the robot are energized, the front structure undergoes torsional deformation, causing the bottom of the robot's rear section to shift to the left or right of the contact surface with the ground. This generates a biased frictional force when the robot runs forward, resulting in turning.

[0042] This invention enables forward running, turning, and jumping over obstacles on the ground through the cooperation of two actuator structures, allowing the robot to move in complex environments. It is also simple in structure and easy to manufacture.

[0043] The front drive structure of this invention can achieve controllable energy storage and release, enabling the robot to jump and overcome obstacles; the cooperation between the front and rear drive structures of the robot enables the robot to run forward on the ground and can adjust the robot's direction of movement.

[0044] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0045] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A biomimetic obstacle-crossing robot driven by an electrically responsive material, characterized in that, It includes a first actuator (1), a second actuator (6), a multi-segment elastic skeleton (2), a foot support (5), a foot cushioning layer structure (4), and a polymer fastener (3). The multi-segment elastic skeleton (2) includes a front skeleton (21) and a rear skeleton (22). The first driver (1) is mounted on the front frame (21) by polymer fasteners (3), and the rear frame (22) has a hollow structure; the second driver (6) is mounted on the hollow structure; the foot support (5) is mounted on the rear frame (22), and the foot support (5) has a foot cushioning layer structure (4). The first driver (1) is mounted on the front frame (21) by a polymer fastener (3) and is able to drive the front frame (21) to achieve bidirectional bending deformation. The first actuator (1) is a shape memory alloy spring. The shape memory alloy springs are symmetrically distributed in pairs on the upper and lower sides of the front frame (21). The interval between the fixed positions of the two ends of the spring is greater than the length of the spring in its natural state. The two ends of each spring are connected to the positive and negative poles of an external power supply through external wires. The second actuator (6) is an electroactive polymer actuator, which includes multiple electroactive polymer actuator units, which are stacked in a layered manner. Each electroactive polymer actuator unit includes an electroactive polymer and two layers of flexible electrodes, with the electroactive polymer located between the two layers of flexible electrodes, which are respectively connected to the two poles of an external power source.

2. The biomimetic obstacle-crossing robot driven by electroresponsive materials according to claim 1, characterized in that, The foot support (5) is bent at a preset angle, and the foot support (5) contacts the ground through the foot cushioning layer structure (4).

3. The biomimetic obstacle-crossing robot driven by electroresponsive materials according to claim 1, characterized in that, The polymer fastener (3) is made of heat-resistant and insulating resin material.

4. The biomimetic obstacle-crossing robot driven by electroresponsive materials according to claim 1, characterized in that, The foot cushioning layer structure (4) is made of silicone rubber or sponge material.

5. The biomimetic obstacle-crossing robot driven by an electroresponsive material according to claim 3, characterized in that, The front skeleton (21) and the rear skeleton (22) may have the same or different thicknesses, and the multi-segment elastic skeleton (2) is made of polymer material.

6. The biomimetic obstacle-crossing robot driven by electroresponsive materials according to claim 1, characterized in that, The electroactive polymer is made of silicone or acrylate.

7. The biomimetic obstacle-crossing robot driven by electroresponsive materials according to claim 1, characterized in that, Shape memory alloy springs are made of nickel-titanium alloy.

8. The biomimetic obstacle-crossing robot driven by electroresponsive materials according to claim 5, characterized in that, The multi-segment elastic skeleton (2) is made of polyimide and polyethylene terephthalate; the polymer fastener (3) is made of polytetrafluoroethylene and polyamide.

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