Clamping device

Abstract

The clamping device comprises a fixed base, a transmission mechanism, a driving mechanism and a clamping finger assembly, the fixed base is fixedly installed at the tail end of a mechanical arm, the transmission mechanism comprises a first connecting rod set, a second connecting rod set, a third connecting rod and a fourth connecting rod, and the clamping finger assembly comprises a first clamping finger and a second clamping finger. One ends of the first connecting rod group and the second connecting rod group are connected with the driving mechanism, one ends are hinged with the clamping fingers, a first end of the third connecting rod is hinged with the fixed base, a second end is rotatably connected with the first connecting rod group through a first shaft, a first end of the fourth connecting rod is hinged with the fixed base, and a second end is rotatably connected with the second connecting rod group through a second shaft. Therefore, the first clamping finger and the second clamping finger can clamp the object along the linear motion trail, shear stress parallel to the surface of the object cannot be generated on the surface of the object, the object is prevented from sliding along the inner side surfaces of the clamping fingers, and the clamping stability is improved.

Description

Technical Field

[0001] This specification relates to the field of robot technology, and particularly to a clamping device. Background Art

[0002] The end effector of a robot is a device installed at the end of the robot arm for performing specific tasks, and is currently widely used in multiple fields such as manufacturing, logistics, medical, and service industries. Among them, the clamping device installed at the end of the robot arm can not only complete basic operations such as traditional grasping and handling, but also complete specific tasks in different application scenarios by clamping different parts and tools.

[0003] Currently, the clamping device usually adopts a multi-link control method for the movement of the fingers to achieve clamping and releasing of an object. As Figure 1 shown, the first end of the link is hinged to the base, and the second end of the link is hinged to the finger. When the link rotates around the first end of the link, it will drive the finger to move, thereby achieving clamping (refer to the dotted line shown in Figure 1 ) and releasing (refer to the solid line shown in Figure 1 ).

[0004] However, during the process of clamping an object by the above clamping device, the movement trajectory of the finger is actually a curve, resulting in a shear stress being generated between the finger and the surface of the object. Since this shear stress is a force parallel to the surface of the object, this shear stress will cause the object to have a tendency to slide along the inner surface of the finger, thereby reducing the stability of the clamping device when clamping the object. Utility Model Content

[0005] This specification provides a clamping device to partially solve the above problems existing in the prior art.

[0006] This specification adopts the following technical solutions:

[0007] This specification provides a clamping device, which includes a fixed base 1, a transmission mechanism 2, a driving mechanism 3, and a finger assembly 4; wherein, the fixed base 1 is fixedly installed at the end of the robotic arm, the transmission mechanism 2 includes a first link group 21, a second link group 22, a third link 23, and a fourth link 24; the finger assembly 4 includes a first finger 41 and a second finger 42;

[0008] The first end of the first link group 21 is connected to the driving mechanism 3, and the second end of the first link group 21 is hinged to the first finger 41; the first end of the second link group 22 is connected to the driving mechanism 3, and the second end of the second link group 22 is hinged to the second finger 42;

[0009] The first end of the third link 23 is hinged to the fixed base 1, and the second end of the third link 23 is rotatably connected to the first link group 21 through a first shaft; the first end of the fourth link 24 is hinged to the fixed base 1, and the second end of the fourth link 24 is rotatably connected to the second link group 22 through a second shaft.

[0010] Optionally, when the drive mechanism 3 receives a drive signal, it drives the first link group 21 and the second link group 22 to move, drives the third link 23 to rotate around the first end of the third link 23, and drives the fourth link 24 to rotate around the first end of the fourth link 24, so as to control the first finger 41 and the second finger 42 to move in opposite directions along a linear trajectory, so that the gripping device clamps or releases the target object.

[0011] Optionally, the drive mechanism 3 includes a moving base 31 and a gear set 32; the gear set 32 is installed on the moving base 31; the gear set 32 includes a driving gear 321, a first driven gear 322 and a second driven gear 323; the driving gear 321 meshes with the first driven gear 322, and the first driven gear 322 meshes with the second driven gear 323;

[0012] When the drive mechanism 3 receives a drive signal, it controls the driving gear 321 to rotate in a specified direction, drives the first driven gear 322 to rotate in the opposite direction of the specified direction, so as to drive the second driven gear 323 to rotate in the specified direction;

[0013] Wherein, the rotation angles of the first driven gear 322 and the second driven gear 323 are the same.

[0014] Optionally, a third driven gear 11 and a fourth driven gear 12 are installed on the fixed base 1, and the third driven gear 11 meshes with the fourth driven gear 12; the rotation angles of the third driven gear 11 and the fourth driven gear 12 are the same;

[0015] The first end of the third link 23 is connected to the third driven gear 11, and the first end of the fourth link 24 is connected to the fourth driven gear 12.

[0016] Optionally, the first link group 21 includes a first link 211 and a second link 212, and the second link group 22 includes a fifth link 221 and a sixth link 222; wherein, the first link 211 is parallel to the second link 212, and the fifth link 221 is parallel to the sixth link 222;

[0017] The first end of the first link 211 is hinged to the moving base 31, and the second end of the first link 211 is hinged to the first finger 41; the first end of the second link 212 is fixedly connected to the second passive gear 323, and the second end of the second link 212 is hinged to the first finger 41;

[0018] The first end of the fifth link 221 is hinged to the moving base 31, and the second end of the fifth link 221 is hinged to the second finger 42; the first end of the sixth link 222 is fixedly connected to the first passive gear 322, and the second end of the fifth link 221 is hinged to the second finger 42.

[0019] Optionally, the first shaft is disposed at the midpoint between the two ends of the first link 211, and the second shaft is disposed at the midpoint between the two ends of the fifth link 221;

[0020] The second end of the third link 23 is rotatably connected to the first link 211 through the first shaft, and the second end of the fourth link 24 is rotatably connected to the fifth link 221 through the second shaft.

[0021] Optionally, the lengths of the first link 211, the second link 212, the fifth link 221, and the sixth link 222 are the same and are a first specified length; the lengths of the third link 23 and the fourth link 24 are the same and are a second specified length, wherein the relationship between the first specified length and the second specified length is a preset relationship.

[0022] Optionally, the maximum distance between the surface of the first finger 41 for contacting the target object and the surface of the second finger 42 for contacting the target object is in a proportional relationship with the first specified length.

[0023] Optionally, a first pressure sensor 43 is disposed on the surface of the first finger 41 for contacting the target object, and a second pressure sensor 44 is disposed on the surface of the second finger 42 for contacting the target object;

[0024] When controlling the gripper to grip the target object, the clamping force of the gripper for gripping the target object is determined according to the first pressure value obtained by the first pressure sensor 43 and the second pressure value obtained by the second pressure sensor 44.

[0025] Optionally, the gripper further includes an absolute encoder for obtaining the real-time distance between the surface of the first finger 41 for contacting the target object and the surface of the second finger 42 for contacting the target object.

[0026] The above at least one technical solution adopted in this specification can achieve the following beneficial effects:

[0027] In the clamping device provided in this specification, the clamping device includes a fixed base, a transmission mechanism, a driving mechanism, and a finger assembly. The fixed base is fixedly installed at the end of the robotic arm. The transmission mechanism includes a first link group, a second link group, a third link, and a fourth link. The finger assembly includes a first finger and a second finger. One end of both the first link group and the second link group is connected to the driving mechanism, and the other end is hinged to the fingers. The first end of the third link is hinged to the fixed base, and the second end is rotatably connected to the first link group through a first shaft. The first end of the fourth link is hinged to the fixed base, and the second end is rotatably connected to the second link group through a second shaft. Thus, the first finger and the second finger can clamp an object along a linear movement trajectory, and no shear stress parallel to the object's surface will be generated on the object's surface, preventing the object from sliding along the inner surface of the fingers and improving the clamping stability. Description of the Drawings

[0028] The drawings described herein are used to provide a further understanding of this specification and form a part of this specification. The schematic embodiments of this specification and their descriptions are used to explain this specification and do not constitute an improper limitation to this specification. In the drawings:

[0029] Figure 1 is a schematic diagram of an existing clamping device in this specification;

[0030] Figure 2 is a schematic diagram of an existing clamping device in this specification;

[0031] Figure 3 is a schematic diagram of a clamping device in this specification;

[0032] Figure 4 is a comparison schematic diagram of a clamping device in this specification in the open state and the closed state respectively;

[0033] Figure 5 is a three-dimensional schematic diagram of a clamping device in this specification. Detailed Embodiments

[0034] To make the objectives, technical solutions, and advantages of this specification clearer, the technical solutions of this specification will be clearly and completely described below in conjunction with specific embodiments of this specification and the corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this specification, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this specification without creative efforts shall fall within the scope of protection of this specification.

[0035] In addition, it should be noted that all actions of obtaining signals, information, or data in this specification are carried out on the premise of complying with the corresponding data protection regulations and policies of the location and with the authorization given by the owner of the corresponding device.

[0036] It should be noted that, without conflict, the features in the following embodiments and implementation manners can be combined with each other.

[0037] As mentioned above, Figure 1 In an existing clamping device controlled by a multi-link, the two symmetrically installed links are respectively hinged at the first end to a fixed base, and the second end is hinged to the clamping fingers. Thus, when controlling the movement of the clamping fingers, in fact, it is to control the two links to rotate around their respective first ends, driving the two clamping fingers to move, so as to achieve clamping (refer to Figure 1 the dotted line shown) and release (refer to Figure 1 the solid line shown). In fact, Figure 1 the movement trajectories of the two clamping fingers shown are curves, which results in shear stress being generated between the clamping fingers and the object surface. Since this shear stress is a force parallel to the object surface, this shear stress will cause the object to have a tendency to slide along the inner surface of the clamping fingers, thereby reducing the stability of the clamping device for clamping the object.

[0038] In addition, Figure 2 Shown is an existing clamping device that realizes linear motion. In this clamping device, the two clamping fingers are respectively fixed on two sliders, and these two sliders are installed on a linear guide rail. By moving the sliders on the linear guide rail, clamping and release of the two clamping fingers in the horizontal direction are realized. Although this clamping device will not generate shear stress on the object surface when clamping an object, the maximum opening distance of the clamping fingers is restricted by the length of the linear guide rail. If the clamping fingers need to clamp a larger object, it is necessary to open the clamping fingers to a larger opening, then the length of the linear guide rail will inevitably increase accordingly. Since the clamping device can be installed at the end of a robotic arm for work, if the length of the linear guide rail is too long, it will occupy a large working space, resulting in the robotic arm being able to carry this clamping device for work only in scenarios with a large working space, greatly limiting the applicable working scenarios of this clamping device. In addition, when the clamping fingers are clamped, the length of the linear guide rail remains unchanged, which will also affect the passing performance and flexibility of the robotic arm on which this clamping device is installed.

[0039] Based on this, this specification provides a clamping device. The first clamping finger and the second clamping finger can clamp an object along a linear movement trajectory, without generating shear stress parallel to the object surface on the object surface, avoiding the object from sliding along the inner surface of the clamping fingers, and improving the clamping stability. At the same time, when clamping an object, the overall size of the clamping device will shrink correspondingly with the movement of the clamping fingers, so that this clamping device can be used in a limited working space, making this clamping device applicable to more working scenarios.

[0040] The technical solutions provided in each embodiment of this specification will be described in detail below with reference to the accompanying drawings.

[0041] A gripping device provided in this specification, as Figure 3 shown, the gripping device includes a fixed base 1, a transmission mechanism 2, a driving mechanism 3, and a finger assembly 4.

[0042] The fixed base 1 (refer to Figure 3 and Figure 5 shown) is fixedly installed at the end of a robotic arm (not shown in the figure) for installing the gripping device at the end of the robotic arm. By controlling the gripping device installed at the end of the robotic arm to grip or release an object, basic operations such as sorting and handling can be completed, or specific tools can be gripped to complete tasks in specific fields. For example, in the medical field, the gripping device is controlled to grip test tubes and reagents to complete the reagent addition task. Another example is in the manufacturing field, where the gripping device is controlled to grab a grinding tool to perform grinding and polishing procedures on metal parts or products. This specification does not limit the type of target object gripped by the gripping device.

[0043] The finger assembly 4 includes a first finger 41 and a second finger 42 (refer to Figure 3 shown). In this specification, the first finger 41 and the second finger 42 can be two structures for gripping an object with the same shape and size and symmetrically deployed. The surfaces of the first finger 41 for contacting the target object and the second finger 42 for contacting the target object can be smooth surfaces, or surfaces that have been specially treated, such as texturing or coating the contact surface to increase surface roughness and improve friction; or soft materials such as sponge or foam are configured on the contact surface to better fit the irregular surface of the target object, thereby achieving more stable gripping. In addition, pressure sensors can also be configured on the contact surface to monitor the gripping force in real time, avoiding damage to the target object caused by excessive clamping and avoiding slippage of the target object due to too small a gripping force.

[0044] Specifically, a first pressure sensor 43 is disposed on the surface of the first finger 41 for contacting the target object, and a second pressure sensor 44 is disposed on the surface of the second finger 42 for contacting the target object. The first pressure sensor 43 can obtain the pressure value on the surface of the first finger 41 for contacting the target object, and the second pressure sensor 44 can obtain the pressure value on the surface of the second finger 42 for contacting the target object. Among them, the first pressure value can represent the force received by the surface of the first finger 41 for contacting the target object, thereby representing the clamping force received by the surface of the target object in contact with the first finger 41. Correspondingly, the second pressure value can represent the force received by the surface of the second finger 42 for contacting the target object, thereby representing the clamping force received by the surface of the target object in contact with the second finger 42. When controlling the gripping device to grip the target object, according to the first pressure value obtained by the first pressure sensor 43 and the second pressure value obtained by the second sensor, it is possible to determine the clamping force borne by the target object when the gripping device grips the target object. Thus, according to the clamping force of the gripping device for gripping the target object, the opening and closing degrees of the first finger 41 and the second finger 42 are adjusted. When the clamping force is too small, the driving mechanism 3 is adjusted to increase the closing degree of the first finger 41 and the second finger 42, and increase the clamping force between the first finger 41 and the second finger 42 to ensure that there is sufficient pressure to firmly grip the target object. Or when the clamping force is too large, the driving mechanism 3 is adjusted to reduce the closing degree of the first finger 41 and the second finger 42, and reduce the clamping force between the first finger 41 and the second finger 42 to prevent damage to the object caused by excessive clamping. In this specification, the first pressure sensor 43 disposed on the first finger 41 and the second pressure sensor 44 disposed on the second finger 42 can be any existing type of pressure sensor for real-time monitoring of pressure values, such as pressure sensors in the form of resistance strain gauges, piezoresistive, capacitive, piezoelectric, etc. This specification does not make any limitations on this.

[0045] The transmission mechanism 2 includes a first link group 21, a second link group 22, a third link 23, and a fourth link 24 (refer to Figure 3 as shown). Among them, the first end of the first link group 21 is connected to the driving mechanism 3, and the second end of the first link group 21 is hinged to the first finger 41. The first end of the second link group 22 is connected to the driving mechanism 3, and the second end of the second link group 22 is hinged to the second finger 42. The number of links included in the first link group 21 is usually the same as the number of links included in the second link group 22. For example, Figure 3 as shown, both the first link group 21 and the second link group 22 include two links. This specification does not make any limitations on the number of links included in the first link group 21 and the number of links included in the second link group 22 in practical applications.

[0046] The first end of the third link 23 in the transmission mechanism 2 is hinged to the fixed base 1, and the second end of the third link 23 is rotatably connected to the first link group 21 through a first shaft (refer to Figure 3 as shown). The first end of the fourth link 24 is hinged to the fixed base 1, and the second end of the fourth link 24 is rotatably connected to the second link group 22 through a second shaft. The first ends of the third link 23 and the fourth link 24 may be hinged at the same position on the fixed base 1 or may be respectively hinged at different positions on the fixed base 1, which is not limited in this specification. Among them, the first shaft is arranged on one of the links in the first link group 21. For example, Figure 3 as shown, the first shaft is arranged on the first link 211 in the first link group 21, and the second shaft is arranged on one of the links in the second link group 22. For example, Figure 3 as shown, the second shaft is arranged on the fifth link 221 of the second link group 22.

[0047] The driving mechanism 3 is used to provide a power source for the transmission mechanism 2. The driving mechanism 3 may include a moving base 31 (refer to Figure 3 as shown), a motor 33 (refer to Figure 5 as shown), and a controller 34 (refer to Figure 3 as shown). The first link group 21 and the second link group 22 of the transmission mechanism 2 can actually be connected to the driving mechanism 3 by connecting to the moving base 31. The driving mechanism 3 can drive the transmission mechanism 2 to move in response to the received driving signal, so as to drive the finger assembly 4 to move, so that the gripping device clamps or releases the target object. In this process, the controller 34 in the driving mechanism 3 can receive the driving signal through a wired communication medium or a wireless communication medium. The controller 34 controls the operation of the motor 33 according to the driving signal, so as to drive the first link group 21 in the transmission mechanism 2 to rotate around the first end of the first link group 21, and at the same time drive the second link group 22 to rotate around the second end of the second link group 22, thereby driving the third link 23 to rotate around the first end of the third link 23, and driving the fourth link 24 to rotate around the first end of the fourth link 24, so as to control the first finger 41 and the second finger 42 to move in opposite directions along a straight-line trajectory, so that the gripping device clamps or releases the target object.

[0048] In the clamping device provided in this specification, the clamping device includes a fixed base 1, a transmission mechanism 2, a driving mechanism 3, and a finger assembly 4. The fixed base 1 is fixedly installed at the end of the robotic arm. The transmission mechanism 2 includes a first link group 21, a second link group 22, a third link 23, and a fourth link 24. The finger assembly 4 includes a first finger 41 and a second finger 42. One end of both the first link group 21 and the second link group 22 is connected to the driving mechanism 3, and the other end is hinged to the fingers. The first end of the third link 23 is hinged to the fixed base 1, and the second end is rotatably connected to the first link group 21 through a first shaft. The first end of the fourth link 24 is hinged to the fixed base 1, and the second end is rotatably connected to the second link group 22 through a second shaft.

[0049] Since the first ends of the third link 23 and the fourth link 24 are respectively hinged to the fixed base 1, and the third link 23 and the fourth link 24 are respectively rotatably connected to the first link group 21 and the second link group 22 in the transmission mechanism 2, the first finger 41 and the second finger 42 can clamp an object along a linear movement trajectory, and no shear stress parallel to the object surface will be generated on the object surface, avoiding the object from sliding along the inner surface of the fingers, and improving the clamping stability.

[0050] At the same time, when the clamping assembly 4 in the clamping device changes from the open state to the closed state (refer to the upper figure to the lower figure shown Figure 4 ), the dimension of the clamping device in the Y-axis direction will change from K to K', where K is greater than K'. It can be seen that the overall dimension of the clamping device will correspondingly shrink with the movement of the first finger 41 and the second finger 42. Therefore, the clamping device can be used in a limited working space, enabling the clamping device to be applicable to more working scenarios and improving the versatility and flexibility of the clamping device.

[0051] In one or more embodiments of this specification, the driving mechanism 3 further includes a gear set 32 installed on a moving base 31, as shown in Figure 3As shown. The gear set 32 includes a driving gear 321, a first driven gear 322 and a second driven gear 323. The driving gear 321 meshes with the first driven gear 322, and the first driven gear 322 meshes with the second driven gear 323. The motor 33 in the driving mechanism 3 is connected to the driving gear 321. In this way, the rotation of the rotor of the motor 33 can control the driving gear 321 to rotate in a specified direction, thereby driving the first driven gear 322 to rotate in the opposite direction of the specified direction, so as to drive the second driven gear 323 to rotate in the specified direction. Thus, since the driving gear 321 and the first driven gear 322 are directly meshed, and the first driven gear 322 and the second driven gear 323 are directly meshed, the rotation direction of the driving gear 321 is opposite to that of the first driven gear 322 and the same as that of the second driven gear 323. In practical applications, the specified direction can be the clockwise direction or the counterclockwise direction. The specific direction of the specified direction can be determined according to whether the clamping device changes from open to closed or from closed to open. This specification does not limit this. And, since the module and the number of teeth of the first driven gear 322 can be the same as those of the second driven gear 323, the rotation angle of the first driven gear 322 is the same as that of the second driven gear 323. The module and the number of teeth of the driving gear 321 can be the same as or different from those of the first driven gear 322. The relationship between the rotation angle of the driving gear 321 and the rotation angle of the first driven gear 322 can be determined according to the relationship between the module and the number of teeth of the driving gear 321 and the first driven gear 322 in practical applications.

[0052] In one or more embodiments of this specification, the first ends of the third link 23 and the fourth link 24 can be hinged at the same position on the fixed base 1. That is, a hinge hole is provided at a preset position on the fixed base 1. The first end of the third link 23 is hinged at the preset position of the fixed base 1 through this hinge hole. Similarly, the first end of the fourth link 24 is also hinged at the preset position of the fixed base 1 through this hinge hole. In this way, while the third link 23 rotates around the first end of the third link 23, the fourth link 24 will also rotate around the first end of the fourth link 24.

[0053] In one or more embodiments of this specification, the first ends of the third link 23 and the fourth link 24 can be hinged at different positions on the fixed base 1. In this case, a third driven gear 11 and a fourth driven gear 12 are installed on the fixed base 1, as Figure 3As shown, the third driven gear 11 meshes with the fourth driven gear 12. Subsequently, the first end of the third link 23 is connected to the third driven gear 11, such as by a rigid connection, and the first end of the fourth link 24 is connected to the fourth driven gear 12, such as by a rigid connection. Thus, when the third driven gear 11 rotates, the fourth driven gear 12 can rotate in the opposite direction to the rotation direction of the third driven gear 11. Consequently, when the first link group 21 and the second link group 22 move, it drives the third link 23 to rotate around the first end of the third link 23, and drives the fourth link 24 to rotate around the first end of the fourth link 24. At the same time, it drives the third driven gear 11 and the fourth driven gear 12 to rotate in opposite directions to each other, thereby ensuring that the rotation angles of the third link 23 and the fourth link 24 are the same.

[0054] In one or more embodiments of this specification, the first link group 21 includes a first link 211 and a second link 212, and the second link group 22 includes a fifth link 221 and a sixth link 222. Among them, the first link 211 is parallel to the second link 212, and the fifth link 221 is parallel to the sixth link 222. The first end of the first link group 21 is connected to the driving mechanism 3. In fact, it can be that the first end of the first link 211 in the first link group 21 is hinged to the moving base 31 in the driving mechanism 3, and the first end of the second link 212 is fixedly connected to the second driven gear 323. The second end of the first link group 21 is hinged to the first finger 41. In fact, it can be that the second end of the first link 211 is hinged to the first finger 41, and the second end of the second link 212 is hinged to the first finger 41. Since the first link group 21 and the second link group 22 are symmetrically arranged, the first end of the second link group 22 is connected to the driving mechanism 3. In fact, it can be that the first end of the fifth link 221 in the second link group 22 is hinged to the moving base 31, and the first end of the sixth link 222 is fixedly connected to the first driven gear 322. The second end of the second link group 22 is hinged to the second finger 42. In fact, it can be that the second end of the fifth link 221 is hinged to the second finger 42, and the second end of the sixth link 222 is hinged to the second finger 42.

[0055] The first link 211 and the second link 212 included in the first link group 21 are parallel to each other, and the fifth link 221 and the sixth link 222 included in the second link group 22 are also parallel to each other. Moreover, the length of the first link 211 is generally the same as the length of the second link 212, and the length of the fifth link 221 is generally the same as the length of the sixth link 222. Therefore, the first link 211 and the second link 212 included in the first link group 21 actually form Figure 4 a parallelogram as shown by the dashed line in the above figure. Similarly, the fifth link 221 and the sixth link 222 included in the second link group 22 also form Figure 4The parallelogram shown by the dashed line in the above figure.

[0056] In an optional embodiment of this specification, based on the structure that the above-mentioned first link group 21 includes a first link 211 and a second link 212, and the second link group 22 includes a fifth link 221 and a sixth link 222, the first shaft can be arranged between the two ends of the first link 211, and the second shaft can be arranged between the two ends of the fifth link 221. In this way, the second end of the third link 23 can be rotatably connected to the first link 211 through the first shaft, and the second end of the fourth link 24 can be rotatably connected to the fifth link 221 through the second shaft. Among them, the position of the first shaft between the two ends of the first link 211 can be the same as the position of the second shaft between the two ends of the fifth link 221, that is, the distance from the first end of the first link 211 to the first shaft is the same as the distance from the first end of the fifth link 221 to the second shaft. In practice, the specific setting position of the first shaft between the two ends of the first link 211 and the specific setting position of the second shaft between the two ends of the fifth link 221 can be flexibly determined according to the actual application scenario, and this specification does not limit this.

[0057] Optionally, the first shaft is arranged at the midpoint position between the two ends of the first link 211, and the second shaft is arranged at the midpoint position between the two ends of the fifth link 221.

[0058] In one or more embodiments of this specification, the lengths of the first link 211, the second link 212 in the first link group 21, the length of the fifth link 221, and the length of the sixth link 222 in the second link group 22 can be the same. The lengths of the third link 23 and the fourth link 24 can be the same. When the length of the first link 211 is the first specified length and the length of the third link 23 is the second specified length, the relationship between the first specified length and the second specified length can be a preset relationship, and this preset relationship can be represented by a function. Assuming that the first specified length is a and the second specified length is b, the preset relationship between the first specified length and the second specified length can be represented by a = F(b), where a and b are positive numbers. For example, if the first specified length is twice the second specified length, the preset relationship between the first specified length and the second specified length is a double multiple relationship, that is, a = 2b.

[0059] Optionally, when the first axis is set at the midpoint position between the two ends of the first link 211, the second axis is set at the midpoint position between the two ends of the fifth link 221, and at the same time the first specified length is twice the second specified length, then in fact, the length from the first end of the first link 211 to the first axis and the length from the second end of the fifth link 221 to the second axis are both equal to the second specified length. Then, the first link 211 (from the first end of the first link 211 to the first axis), the fifth link 221 (from the first end of the fifth link 221 to the second axis), the third link 23, and the fourth link 24 actually form a parallelogram, referring to Figure 4 the dotted line shown in the above figure. For example, the first specified length is a, and the second specified length is b, where a = 2b. When the first axis is set at the midpoint position between the two ends of the first link 211 and the second axis is set at the midpoint position between the two ends of the fifth link 221, the length from the first end of the first link 211 to the first axis is b, and the length from the second end of the fifth link 221 to the second axis is also b. Also, the first link 211 is parallel to the fourth link 24, and the fifth link 221 is parallel to the third link 23.

[0060] In one or more embodiments of the present specification, the maximum distance between the surface of the first finger 41 for contacting the target object and the surface of the second finger 42 for contacting the target object is in a proportional relationship with the first specified length. That is, the larger the first specified length, the larger the maximum distance between the surface of the first finger 41 for contacting the target object and the surface of the second finger 42 for contacting the target object in the gripping device, and the larger the maximum size of the target object that the gripping device can grip. Conversely, the smaller the first specified length, the smaller the maximum distance between the surface of the first finger 41 for contacting the target object and the surface of the second finger 42 for contacting the target object, and the smaller the maximum size of the target object that the gripping device can grip. Thus, in an actual application scenario where the size of the target object to be gripped is relatively large, the size of the fully expanded gripping device can be increased by increasing the first specified length.

[0061] In one or more embodiments of the present specification, the midpoint of the line connecting the centers of the third passive gear 11 and the fourth passive gear 12 can be defined as the origin O, the line connecting the centers of the third passive gear 11 and the fourth passive gear 12 can be defined as the Y-axis, and the direction from the origin O to the center of the third passive gear 11 can be defined as the positive direction of the Y-axis; the perpendicular line to the line connecting the centers of the third passive gear 11 and the fourth passive gear 12 can be defined as the X-axis, and the direction from the origin O to the midpoint of the line connecting the centers of the first passive gear 322 and the second passive gear 323 can be defined as the negative direction of the X-axis to establish a coordinate system, as shown in detail in Figure 4 shown. Since the fixed base 1 is fixed to the end of the robotic arm, thus, during the process of the gripping assembly 4 in the gripping device changing from the open state to the closed state (referring to from Figure 4The above figure changes to Figure 4 as shown in the following figure), the moving base 31 in the driving mechanism 3 will actually move along the negative direction of the X-axis. Refer to Figure 4 the edge of the moving base 31 in the above figure and Figure 4 the distance difference L between the edges of the moving base 31 in the following figure. That is, during the process of the clamping component 4 changing from the open state to the closed state, the moving base 31 moves a distance L along the negative direction of the X-axis. At the same time, the distance between the fixed base 1 and the moving base 31 will increase. Correspondingly, during the process of the clamping component 4 in the clamping device changing from the closed state to the open state, the moving base 31 in the driving mechanism 3 will actually move along the positive direction of the X-axis, that is, the distance between the fixed base 1 and the moving base 31 will decrease. In practical applications, when the clamping component 4 switches between the open state and the closed state, the distance that the moving base 31 moves along the X-axis can be determined according to the actual application situation and the actual dimensions of each component in the clamping device, and this specification does not limit it.

[0062] In addition, it should be noted that in one or more embodiments of this specification, refer to Figure 4 the above figure and the following figure shown. The moving directions of the first finger 41 and the second finger 42 in the clamping component 4 can be: when the clamping component 4 changes from the open state to the closed state, the first finger 41 moves linearly along the negative direction of the Y-axis, and the second finger 42 moves linearly along the positive direction of the Y-axis; when the clamping component 4 changes from the closed state to the open state, the first finger 41 moves linearly along the positive direction of the Y-axis, and the second finger 42 moves linearly along the negative direction of the Y-axis. And, the moving distances of the first finger 41 and the second finger 42 are the same.

[0063] In one or more embodiments of this specification, the clamping device further includes an absolute encoder (not shown in the figure). The absolute encoder can be used to obtain the real-time distance between the surface of the first finger 41 for contacting the target object and the surface of the second finger 42 for contacting the target object. Through the real-time distance obtained by the absolute encoder, during the process of clamping or releasing the target object, the opening and closing degrees of the first finger 41 and the second finger 42 can be precisely adjusted to ensure that the target object is accurately clamped or placed. Through the position feedback of the absolute encoder, the clamping failure or object damage caused by position error can be avoided.

[0064] In one or more embodiments of this specification, the clamping device further includes a vision sensor 5 (refer to Figure 5As shown (in the figure), such as cameras, infrared cameras, stereo vision systems, etc. The vision sensor 5 is used to collect image data near the clamping device, so as to obtain the position and posture of the clamping device, assist the clamping device to accurately position and grasp the target object, and perform specific tasks that require high-precision operations. In addition, the vision sensor 5 can also identify features such as the shape, color, and texture of the target object, so as to distinguish different types of objects, so that the clamping device can be applied in an automated production scenario that needs to process multiple types of items, such as sorting different types of commodities in a logistics center. Of course, in addition, the vision sensor 5 configured on the clamping device can also be used for other types of practical applications, which are not limited in this specification. In short, by configuring the vision sensor 5 on the clamping device, the flexibility, precision, and reliability of the automation of the clamping device can be significantly improved, so that the clamping device configured at the end of the robotic arm can be applied in more complex and diverse industrial scenarios.

[0065] Each embodiment in this specification is described in a progressive manner. The same or similar parts between each embodiment can be referred to each other, and the differences between each embodiment and other embodiments are emphasized. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the description of the method embodiment.

[0066] The above is only the embodiment of this specification and is not used to limit this specification. For those skilled in the art, this specification can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this specification shall be included within the scope of the claims of this specification.

Claims

1. A clamping device, characterized in that, The clamping device includes a fixed base (1), a transmission mechanism (2), a driving mechanism (3) and a finger assembly (4); wherein, the fixed base (1) is fixedly installed at the end of the robotic arm, the transmission mechanism (2) includes a first link group (21), a second link group (22), a third link (23) and a fourth link (24); the finger assembly (4) includes a first finger (41) and a second finger (42). The first end of the first link group (21) is connected to the driving mechanism (3), and the second end of the first link group (21) is hinged to the first finger (41); the first end of the second link group (22) is connected to the driving mechanism (3), and the second end of the second link group (22) is hinged to the second finger (42). The first end of the third link (23) is hinged to the fixed base (1), and the second end of the third link (23) is rotatably connected to the first link group (21) through a first shaft; the first end of the fourth link (24) is hinged to the fixed base (1), and the second end of the fourth link (24) is rotatably connected to the second link group (22) through a second shaft.

2. The clamping device according to claim 1, wherein When the driving mechanism (3) receives a driving signal, it drives the first link group (21) and the second link group (22) to move, drives the third link (23) to rotate around the first end of the third link (23), and drives the fourth link (24) to rotate around the first end of the fourth link (24), so as to control the first finger (41) and the second finger (42) to move in opposite directions along a linear trajectory, so that the clamping device clamps or releases the target object.

3. The clamping device according to claim 1, wherein The driving mechanism (3) includes a moving base (31) and a gear set (32); the gear set (32) is installed on the moving base (31); the gear set (32) includes a driving gear (321), a first driven gear (322) and a second driven gear (323); the driving gear (321) meshes with the first driven gear (322), and the first driven gear (322) meshes with the second driven gear (323). When the driving mechanism (3) receives a driving signal, it controls the driving gear (321) to rotate in a specified direction, drives the first driven gear (322) to rotate in the opposite direction of the specified direction, so as to drive the second driven gear (323) to rotate in the specified direction. Wherein, the rotation angle of the first driven gear (322) is the same as the rotation angle of the second driven gear (323).

4. The clamping device according to claim 1, characterized in that, A third driven gear (11) and a fourth driven gear (12) are installed on the fixed base (1), and the third driven gear (11) meshes with the fourth driven gear (12); the rotation angle of the third driven gear (11) is the same as the rotation angle of the fourth driven gear (12). The first end of the third link (23) is connected to the third driven gear (11), and the first end of the fourth link (24) is connected to the fourth driven gear (12).

5. The clamping device according to claim 3, characterized in that, The first link group (21) includes a first link (211) and a second link (212), and the second link group (22) includes a fifth link (221) and a sixth link (222); wherein, the first link (211) is parallel to the second link (212), and the fifth link (221) is parallel to the sixth link (222). The first end of the first link (211) is hinged to the moving base (31), and the second end of the first link (211) is hinged to the first finger (41); the first end of the second link (212) is fixedly connected to the second passive gear (323), and the second end of the second link (212) is hinged to the first finger (41). The first end of the fifth link (221) is hinged to the moving base (31), and the second end of the fifth link (221) is hinged to the second finger (42); the first end of the sixth link (222) is fixedly connected to the first passive gear (322), and the second end of the fifth link (221) is hinged to the second finger (42).

6. The clamping device according to claim 5, wherein, The first shaft is arranged at the midpoint position between the two ends of the first link (211), and the second shaft is arranged at the midpoint position between the two ends of the fifth link (221). The second end of the third link (23) is rotatably connected to the first link (211) through the first shaft, and the second end of the fourth link (24) is rotatably connected to the fifth link (221) through the second shaft.

7. The clamping device according to claim 5, characterized in that, The lengths of the first link (211), the second link (212), the fifth link (221), and the sixth link (222) are the same and are a first specified length; the lengths of the third link (23) and the fourth link (24) are the same and are a second specified length, wherein the relationship between the first specified length and the second specified length is a preset relationship.

8. The clamping device according to claim 7, wherein The maximum distance between the surface of the first finger (41) for contacting the target object and the surface of the second finger (42) for contacting the target object is in a proportional relationship with the first specified length.

9. The clamping device according to claim 1, characterized in that, A first pressure sensor (43) is arranged on the surface of the first finger (41) for contacting the target object, and a second pressure sensor (44) is arranged on the surface of the second finger (42) for contacting the target object. When controlling the gripper to grip the target object, the clamping force of the gripper for gripping the target object is determined according to the first pressure value obtained by the first pressure sensor (43) and the second pressure value obtained by the second pressure sensor (44).

10. The clamping device according to claim 1, characterized in that, The gripper further includes an absolute encoder, and the absolute encoder is used to obtain the real-time distance between the surface of the first finger (41) for contacting the target object and the surface of the second finger (42) for contacting the target object.

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