Variable stiffness fingers and biomimetic devices

Abstract

The present invention relates to the technical field of mechanical fingers, and provides a variable stiffness finger and a bionic device. The variable stiffness finger comprises a finger body, a sensor, a first driving line and a second driving line. The finger body is provided with a front side and a back side that are separated from each other; the sensor is at least partially embedded in the finger body; the first driving line runs through the finger body, and the first driving line is arranged near the front side, one end of the first driving line is fixedly connected to one end of the finger body, and the first driving line is pulled, the finger body is deformed to squeeze the sensor; the second driving line runs through the finger body, and the second driving line is arranged near the back side, one end of the second driving line is fixedly connected to one end of the finger body, the second driving line is provided with an elastic member, and the second driving line is pulled, the elastic member is elastically deformed. The variable stiffness finger is adjusted to improve its adaptability.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical fingers, and in particular to a variable stiffness finger and a bionic device. Background Art

[0002] With the rapid development of the robotics industry, the application areas of robots are constantly expanding, and new requirements are being put forward for their performance in all aspects. From the perspective of bionics, when a human finger is subjected to external force, it can quickly adjust its own rigidity according to its deformation to adapt to different working environments. As for the mechanical fingers on the robot, low-rigidity mechanical fingers have better compliance and are safer for the environment, but they need sufficient rigidity when bearing loads. The current mechanical fingers cannot adjust their own rigidity in time and have poor adaptability. Summary of the invention

[0003] The present invention provides a variable stiffness finger, which is used to solve the defect of inconvenient stiffness adjustment of mechanical fingers in the prior art, realizes stiffness adjustment of the variable stiffness finger, and improves its adaptability.

[0004] The present invention provides a variable stiffness finger, comprising:

[0005] A finger body, wherein the finger body has a front side and a back side that are separated from each other;

[0006] a sensor, wherein the sensor is at least partially embedded in the finger body;

[0007] a first driving line, the first driving line movably passes through the finger body, and the first driving line is arranged adjacent to the front side, one end of the first driving line is fixedly connected to one end of the finger body, and the finger body is deformed by pulling the first driving line to squeeze the sensor;

[0008] The second driving line is movable through the finger body, and the second driving line is arranged adjacent to the back side, one end of the second driving line is fixedly connected to one end of the finger body, and the second driving line is provided with an elastic member, and when the second driving line is pulled, the elastic member undergoes elastic deformation.

[0009] According to a variable stiffness finger provided by the present invention, the variable stiffness finger further includes a connecting member, the connecting member is provided at the movable ends of the first driving wire and the second driving wire, and the connecting member connects the first driving wire and the second driving wire respectively.

[0010] According to a variable stiffness finger provided by the present invention, the finger body comprises:

[0011] A main body portion, wherein the main body portion is provided with the front side and the back side, and the first driving wire and the second driving wire movably pass through the main body portion;

[0012] An end portion is arranged at one end of the main body portion, and the first driving line and the second driving line are both fixedly connected to the end portion, and the sensor is clamped between the main body portion and the end portion.

[0013] According to a variable stiffness finger provided by the present invention, the main body is provided with a connecting channel and two through holes running through both ends, the two through holes are respectively located on both sides of the connecting channel, the first driving line is passed through one of the through holes, the second driving line is passed through the other through hole, the sensor is provided with two through holes corresponding to the first driving line and the second driving line, and the first driving line and the second driving line are respectively passed through the two through holes.

[0014] According to a variable stiffness finger provided by the present invention, the end portion is provided with two mounting holes, and the first driving wire and the second driving wire are respectively passed through the two mounting holes to be connected to the end portion.

[0015] According to a variable stiffness finger provided by the present invention, the elastic member is a spring, and the spring is located at one end of the second driving line adjacent to the active end.

[0016] According to a variable stiffness finger provided by the present invention, the sensor comprises:

[0017] A sensing portion, the sensing portion is sandwiched between the main body portion and the end portion, and the sensing portion extends in a direction of a line connecting the front side and the back side;

[0018] A connecting part, one end of which is connected to the sensing part, the connecting part is arranged in the communicating channel, and one end of the connecting part away from the sensing part is used to connect to an external device to transmit data.

[0019] According to a variable stiffness finger provided by the present invention, the variable stiffness finger also includes two bosses, the two bosses are clamped between the main body and the end, the first driving line and the second driving line pass through the two bosses respectively, and the bosses abut against the sensing part.

[0020] According to a variable stiffness finger provided by the present invention, the variable stiffness finger also includes a gasket, which is clamped between the main body and the end portion, and the gasket is located on the side of the sensing portion facing the end portion or facing away from the end portion, and the two bosses are connected to the gasket, and the two bosses are located on the side of the gasket facing the sensing portion.

[0021] The present invention also provides a bionic device, comprising a mechanical body and the variable stiffness finger as described above, wherein the variable stiffness finger is arranged on the mechanical body.

[0022] The variable stiffness finger provided by the present invention has a finger body with a front side and a back side that are separated from each other. The first driving line and the second driving line are respectively arranged on the front side and the back side, and the first driving line and the second driving line are movable through the finger body, thereby pulling the finger body to deform. At the same time, an elastic member is connected to the second driving line. When the first driving line and the second driving line are pulled at the same time, the finger body will bend toward the front side. At this time, the first driving line can provide a load for the finger body, while the second driving line provides antagonism, and the variable stiffness control of the finger body is realized through the elastic deformation of the elastic member. In addition, the sensor embedded in the finger body can calculate the stiffness of the finger body by measuring the force condition, thereby realizing the stiffness perception of the finger body. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 is an exploded view of the variable stiffness finger provided by the present invention;

[0025] Figure 2 It is a partial structural schematic diagram of the variable stiffness finger provided by the present invention.

[0026] Reference numerals:

[0027] 100. Variable stiffness finger; 1. Finger body; 11. Main body; 111. Front side; 112. Back side; 113. Connecting channel; 114. Through hole; 12. End; 121. Mounting hole; 2. Sensor; 21. Sensing part; 211. Through hole; 22. Connecting part; 3. First driving line; 4. Second driving line; 41. Elastic member; 5. Connecting member; 6. Gasket; 61. Boss. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are 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.

[0029] Please refer to Figure 1 and Figure 2 The present invention provides a variable stiffness finger 100, comprising a finger body 1, a sensor 2, a first driving line 3 and a second driving line 4, wherein the finger body 1 is provided with a front side 111 and a back side 112 which are separated from each other; the sensor 2 is at least partially embedded in the finger body 1; the first driving line 3 movably passes through the finger body 1, and the first driving line 3 is arranged adjacent to the front side 111, one end of the first driving line 3 is fixedly connected to one end of the finger body 1, and when the first driving line 3 is pulled, the finger body 1 is deformed to squeeze the sensor 2; the second driving line 4 movably passes through the finger body 1, and the second driving line 4 is arranged adjacent to the back side 112, one end of the second driving line 4 is fixedly connected to one end of the finger body 1, and the second driving line 4 is provided with an elastic member 41, and when the second driving line 4 is pulled, the elastic member 41 is elastically deformed.

[0030] In this embodiment, the finger body 1 can be a continuous body and can be elastically deformed to achieve corresponding functions, such as grasping, bending, etc. It can be understood that the sensor 2 is embedded in the finger body 1. When the finger body 1 is deformed, the sensor 2 can collect data according to the extrusion force it receives and transmit it to an external device. Specifically, the first drive line 3 and the second drive line 4 are movable through the finger body 1 at one end of the finger body 1, and are fixedly connected to the finger body 1 at the other end of the finger body 1. In this way, when the first drive line 3 and the second drive line 4 are pulled, the finger body 1 is bent and deformed under the pull of the first drive line 3 and the second drive line 4. It should be noted that the first drive line 3 and the second drive line 4 are respectively arranged adjacent to the front side 111 and the back side 112 to pull the finger body 1 to bend and deform. It should be noted that the front side 111 and the back side 112 can simulate the front and back of a human finger.

[0031] It is understandable that when the second driving line 4 is pulled, the elastic member 41 is extended accordingly to increase the resistance to the first driving line 3 pulling the finger body 1, thereby realizing the variable stiffness control of the finger body 1. The elastic member 41 can be a tension spring or a spring, as long as it can produce elastic deformation when pulled, and is not limited here. Here, the elastic member 41 is taken as a spring as an example. The spring is located at one end of the second driving line 4 adjacent to the active end, that is, the spring is located outside the finger body 1 to leave enough installation space for the spring, and a part of the second driving line 4 passes through the finger body 1 and is fixed at the other end of the finger body 1.

[0032] The variable stiffness finger 100 provided by the present invention has a finger body 1 provided with a front side 111 and a back side 112 which are separated from each other. The first driving line 3 and the second driving line 4 are respectively provided at the front side 111 and the back side 112, and the first driving line 3 and the second driving line 4 are movable through the finger body 1, thereby pulling the finger body 1 to deform. At the same time, an elastic member 41 is connected to the second driving line 4. When the first driving line 3 and the second driving line 4 are pulled at the same time, the finger body 1 will bend toward the front side 111. At this time, the first driving line 3 can provide a load for the finger body 1, and the second driving line 4 provides antagonism. The variable stiffness control of the finger body 1 is realized by the elastic deformation of the elastic member 41. In addition, the sensor 2 embedded in the finger body 1 can calculate the stiffness of the finger body 1 by measuring the force condition, thereby realizing the stiffness perception of the finger body 1.

[0033] like Figure 1 As shown, according to a variable stiffness finger 100 provided by the present invention, the variable stiffness finger 100 also includes a connecting member 5, which is arranged at the active ends of the first driving line 3 and the second driving line 4, and the connecting member 5 connects the first driving line 3 and the second driving line 4 respectively.

[0034] It should be noted that one end of the first drive line 3 and the second drive line 4 connected to the finger body 1 is a fixed end, and the other end is a movable end. The movable end is used to connect to an external drive component, so that the external drive component pulls the first drive line 3 and the second drive line 4 to deform the end 12 and the main body 11. The external drive component can be a motor, a telescopic cylinder, etc. The connecting member 5 connects the first drive line 3 and the second drive line 4 so as to pull the first drive line 3 and the second drive line 4 together. In this way, the first drive line 3 can provide a load for the finger body 1, while the second drive line 4 provides antagonism, and the variable stiffness control of the finger body 1 is achieved through the elastic deformation of the elastic member 41. Optionally, the connecting member 5 is annular to match the finger body 1, and a wiring hole is provided in the middle of the connecting member 5 so that the sensor 2 can be connected to the external device data through the wiring hole.

[0035] like Figure 2 As shown, according to a variable stiffness finger 100 provided by the present invention, the finger body 1 includes a main body 11 and an end 12, the main body 11 is provided with a front side 111 and a back side 112, the first driving line 3 and the second driving line 4 movably pass through the main body 11; the end 12 is provided at one end of the main body 11, and the first driving line 3 and the second driving line 4 are both fixedly connected to the end 12, and the sensor 2 is clamped between the main body 11 and the end 12.

[0036] In this embodiment, the main body 11 is a continuum and can be elastically deformed to achieve corresponding functions, such as grasping, bending, etc. Optionally, the main body 11 is cylindrical and the end 12 is hemispherical. In this way, the end face of the end 12 is connected to one end of the main body 11 to clamp the sensor 2 between the end 12 and the main body 11. Optionally, the connection between the end 12 and the main body 11 can be snap connection, bonding, plug-in or connected through a connector 5, which is not limited here. The end 12 can be made of a hard material. When the end 12 is subjected to an external force, it can better transmit the force to the sensor 2, thereby better squeezing the sensor 2 and having higher sensing accuracy. Of course, the end 12 can also be made of an elastomeric material to achieve a better bionic effect. It can be understood that the sensing portion 21 of the sensor 2 is clamped between the end 12 and the main body 11 to collect sensing information, and the connecting portion 22 of the sensor 2 can pass through the main body 11 to connect with an external device to transmit information to the external device. In this way, the external device can learn the force applied to the variable stiffness finger 100 by analyzing the sensing information, and thus timely adjust the contact force between the variable stiffness finger 100 and the contact object.

[0037] In this embodiment, the first driving wire 3 and the second driving wire 4 are both movable and penetrate the main body 11, and one end of the first driving wire 3 and the second driving wire 4 is fixedly connected to the end 12, so that the first driving wire 3 and the second driving wire 4 can pull the end 12 and drive the main body 11 to deform. It can be understood that the first driving wire 3 and the second driving wire 4 are eccentrically arranged with the main body 11, that is, one end of the first driving wire 3 and the second driving wire 4 are connected to the part adjacent to the edge of the end 12, so that when the first driving wire 3 and the second driving wire 4 are pulled at the same time, the finger body 1 will bend to the front side 111, and at this time, the first driving wire 3 can provide a load for the finger body 1, and the second driving wire 4 provides antagonism. The first driving wire 3 and the second driving wire 4 can be wires such as steel wires or copper wires, which are not limited here, as long as they can pull the end 12 and the main body 11 to deform. It is understandable that the ends of the first driving wire 3 and the second driving wire 4 away from the end 12 can be connected to an external driving member, so that the external driving member pulls the first driving wire 3 and the second driving wire 4 to deform the end 12 and the main body 11, and the external driving member can be a motor, a telescopic cylinder, etc. It is understandable that the elastic member 41 is connected to the second driving wire 4. When the first driving wire 3 and the second driving wire 4 are pulled, the first driving wire 3 has a greater force to pull the finger body 1 to deform, and when the second driving wire 4 is pulled, part of the force will be distributed to the elastic member 41 to cause elastic deformation, thereby realizing variable stiffness control of the finger body 1.

[0038] According to a variable stiffness finger 100 provided by the present invention, a main body 11 is provided with a connecting channel 113 and two through holes 114 running through both ends, the two through holes 114 are respectively located on both sides of the connecting channel 113, a first driving line 3 is passed through one through hole 114, and a second driving line 4 is passed through another through hole 114, and a sensor 2 is provided with two through holes 211 corresponding to the first driving line 3 and the second driving line 4, and the first driving line 3 and the second driving line 4 are respectively passed through the two through holes 211.

[0039] In this embodiment, the connecting channel 113 is coaxially arranged with the main body 11, so that the sensor 2 can be connected to an external device through the connecting channel 113 to transmit data. It can be understood that the extension direction of each through hole 114 is parallel to the extension direction of the connecting channel 113. The first driving line 3 is passed through a through hole 114, and the second driving line 4 is passed through another through hole 114, and one end of the first driving line 3 and the second driving line 4 is fixedly connected to the end 12, so that the end 12 and the main body 11 are bent and deformed by pulling the end 12. At the same time, the sensor 2 is provided with a through hole 211 corresponding to the first driving line 3 and the second driving line 4, so that the first driving line 3 and the second driving line 4 pass through the through hole 211 and are connected to the end 12. It can be understood that when the first driving wire 3 and the second driving wire 4 pull the end 12, the end 12 and the part of the main body 11 adjacent to the first driving wire 3 and the second driving wire 4 are subjected to more concentrated force, that is, the sensor 2 is mounted on the first driving wire 3 and the second driving wire 4 to facilitate the collection of force information of the end 12 and the main body 11.

[0040] According to a variable stiffness finger 100 provided by the present invention, the end portion 12 is provided with two mounting holes 121 , and the first driving wire 3 and the second driving wire 4 are respectively passed through the two mounting holes 121 to be connected with the end portion 12 .

[0041] In this embodiment, each mounting hole 121 is arranged corresponding to a through hole 114, so that the driving wire can be arranged in the mounting hole 121 after being arranged in the through hole 114. In order to facilitate the connection and fixation of the first driving wire 3 and the second driving wire 4 with the end 12, the mounting hole 121 is arranged to pass through the end 12, that is, the first driving wire 3 and the second driving wire 4 pass through the end 12 from the side of the end 12 facing the main body 11, so that the first driving wire 3 and the second driving wire 4 can be fixed on the side of the end 12 facing away from the main body 11. If the first driving wire 3 and the second driving wire 4 are fixed on the side of the end 12 facing the main body 11, when the end 12 and the main body 11 are close to clamp the sensor 2, it is not convenient to fix the first driving wire 3 and the second driving wire 4. After the first driving wire 3 and the second driving wire 4 are arranged to pass through the mounting hole 121, the side of the end 12 facing away from the main body 11 is not blocked, so it is convenient to connect the first driving wire 3 and the second driving wire 4 to the end 12. Optionally, the first driving wire 3 and the second driving wire 4 may be fixed to the end 12 by a connector 5 such as a screw or a nut, as long as the first driving wire 3 and the second driving wire 4 can be pulled to bend the variable stiffness finger 100 .

[0042] According to a variable stiffness finger 100 provided by the present invention, the sensor 2 includes a sensing part 21 and a connecting part 22, the sensing part 21 is clamped between the main body part 11 and the end part 12, and the sensing part 21 extends in the connection direction of the front side 111 and the back side 112; one end of the connecting part 22 is connected to the sensing part 21, the connecting part 22 is penetrated in the connecting channel 113, and the end of the connecting part 22 away from the sensing part 21 is used to connect with an external device to transmit data.

[0043] In this embodiment, the sensing portion 21 extends in the direction of the line connecting the front side 111 and the back side 112 to realize the collection of force information on the front side 111 and the back side 112 of the finger body 1. The sensing portion 21 and the connecting portion 22 can adopt an integrally formed structure to improve the connection stability. The connecting portion 22 can be bent to pass through the connecting channel 113 and connect to an external device. It can be understood that one end of the connecting portion 22 is connected to the sensing portion 21, and the connecting portion 22 is bent 90° at a position adjacent to the sensing portion 21 to pass through the connecting channel 113 to connect to an external device.

[0044] According to a variable stiffness finger 100 provided by the present invention, the variable stiffness finger 100 also includes two bosses 61, the two bosses 61 are clamped between the main body and the end 12, the first driving line 3 and the second driving line 4 pass through the two bosses 61 respectively, and the bosses 61 are in contact with the sensing part 21.

[0045] It is understandable that each boss 61 is set corresponding to the measured point of the sensor 2. When the end 12 and the main body are deformed by force, the boss 61 can concentrate the force of the cross section of the end 12 and the main body 11 to the position of the measured point, so that the force signal can be amplified, thereby improving the sensing accuracy. It is understandable that the boss 61 is in the shape of a ring, and the driving line passes through the boss 61, that is, the measured point of the sensor 2 is located near the driving line to improve the sensing accuracy.

[0046] According to a variable stiffness finger 100 provided by the present invention, the variable stiffness finger 100 also includes a gasket 6, which is clamped between the main body 11 and the end 12, and the gasket 6 is located on the side of the sensing part 21 facing the end 12 or facing away from the end 12, and two bosses 61 are connected to the gasket 6, and the two bosses 61 are located on the side of the gasket 6 facing the sensing part 21.

[0047] In order to facilitate the installation of the two bosses 61, the two bosses 61 are connected to the gasket 6. The two bosses 61 are integrally formed with the gasket 6, which facilitates the fixing of the installation position of the two bosses 61 to correspond to the measured point setting of the sensor 2. It can be understood that the two bosses 61 are connected to the gasket 6. In this way, by installing the gasket 6 between the end 12 and the main body 11, the two bosses 61 corresponding to the measured point of the sensor 2 can be installed simultaneously, avoiding the two bosses 61 from being installed separately, saving installation steps, and improving installation convenience. It can be understood that the boss 61 is located on the side of the gasket 6 facing the sensor 2, so that the boss 61 can contact the measured point of the sensor 2, thereby concentrating the force on the measured point.

[0048] The present invention further provides a bionic device, comprising a mechanical body and the variable stiffness finger 100 as described above, wherein the variable stiffness finger 100 is arranged on the mechanical body.

[0049] It can be understood that the bionic device can be a robot, a prosthetic device, a rehabilitation device, etc., and the mechanical body can be a mechanical arm, a rehabilitation glove, etc., without limitation here, as long as the device has mechanical fingers.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A variable stiffness finger, characterized in that: The variable stiffness finger comprises: A finger body, wherein the finger body has a front side and a back side that are separated from each other; a sensor, wherein the sensor is at least partially embedded in the finger body; a first driving line, the first driving line movably passes through the finger body, and the first driving line is arranged adjacent to the front side, one end of the first driving line is fixedly connected to one end of the finger body, and the finger body is deformed by pulling the first driving line to squeeze the sensor; A second driving line, the second driving line movably passes through the finger body, and the second driving line is arranged adjacent to the back side, one end of the second driving line is fixedly connected to one end of the finger body, and the second driving line is provided with an elastic member, and the elastic member is elastically deformed when the second driving line is pulled; The finger body comprises: A main body portion, wherein the main body portion is provided with the front side and the back side, and the first driving wire and the second driving wire movably pass through the main body portion; An end portion, the end portion is arranged at one end of the main body portion, and the first driving wire and the second driving wire are both fixedly connected to the end portion, and the sensor is clamped between the main body portion and the end portion; The main body is provided with a connecting passage and two through holes running through both ends, the two through holes are respectively located on both sides of the connecting passage, the first driving line is passed through one of the through holes, the second driving line is passed through the other through hole, the sensor is provided with two through holes corresponding to the first driving line and the second driving line, the first driving line and the second driving line are respectively passed through the two through holes; The sensor comprises: a sensing portion, the sensing portion is sandwiched between the main body portion and the end portion, and the sensing portion extends in the connecting direction of the front side and the back side; a connecting portion, one end of the connecting portion is connected to the sensing portion, the connecting portion is penetrated through the connecting channel, and one end of the connecting portion away from the sensing portion is used to connect to an external device to transmit data; The variable stiffness finger also includes two bosses and a gasket, the two bosses are clamped between the main body and the end, the first driving line and the second driving line pass through the two bosses respectively, and the bosses abut against the sensing part, the gasket is clamped between the main body and the end, and the gasket is located on the side of the sensing part facing the end or facing away from the end, the two bosses are connected to the gasket, and the two bosses are located on the side of the gasket facing the sensing part.

2. The variable stiffness finger according to claim 1, characterized in that: The variable stiffness finger further includes a connecting member, which is disposed at the movable ends of the first driving wire and the second driving wire, and the connecting member connects the first driving wire and the second driving wire respectively.

3. The variable stiffness finger according to claim 1, characterized in that: The end portion is provided with two mounting holes, and the first driving wire and the second driving wire are respectively passed through the two mounting holes to be connected with the end portion.

4. The variable stiffness finger according to claim 1, characterized in that: The elastic member is a spring, and the spring is located at one end of the second driving line adjacent to the movable end.

5. A bionic device, characterized in that: The invention comprises a mechanical body and a variable stiffness finger according to any one of claims 1 to 4, wherein the variable stiffness finger is arranged on the mechanical body.

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