Linear actuator and bionic manipulator

Abstract

The utility model relates to the technical field of robots, in particular to a linear actuator and a bionic manipulator. The linear actuator comprises a driving module, the driving module comprises a lead screw and a motor, and the motor is connected with the lead screw and used for driving the lead screw to rotate; the passive module can move along the lead screw, the passive module comprises a nut, the nut is arranged on the lead screw in a sleeving mode, the nut comprises a screw hole part and a first installation part, the screw hole part is arranged on the lead screw in a sleeving mode, the first installation part protrudes in the direction perpendicular to the axis of the screw hole from the screw hole part, and a push rod hinge part is arranged on the first installation part; one end of the push rod is hinged to the push rod hinge part, and the other end of the push rod is hinged to a target component; and the passive module moves along the lead screw to enable the target component to rotate.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of robotics, and in particular, to a linear actuator and a bionic manipulator. BACKGROUND

[0002] The significant increase in labor costs and the development trend of small and micro operation objects have put forward the demand for precise and fine operation hardware to achieve precise and fine operation and product miniaturization. Under the driving of the foregoing demand, the related technical field develops a multi-degree-of-freedom robot simulating the upper limb movement of a human primate under the guidance of bionics, and the technology frontier evolves to and promotes the development of a dexterous hand bionic manipulator simulating the movement of a human primate hand.

[0003] Under this background, the precise operation and miniaturization of the mechanical bionic hand fingers are problems to be solved in the prior art. CONTENT OF THE INVENTION

[0004] In view of the above analysis, the embodiments of the present disclosure aim to provide a linear actuator and a bionic manipulator.

[0005] Some embodiments of the present disclosure provide a linear actuator, comprising:

[0006] a driving module, the driving module comprising:

[0007] a lead screw;

[0008] a motor, the motor being connected with the lead screw and configured to drive the lead screw to rotate;

[0009] a passive module, the passive module being movable along the lead screw, the passive module comprising:

[0010] a nut, the nut being sleeved on the lead screw, the nut comprising a threaded hole portion and a first mounting portion, the threaded hole portion being sleeved on the lead screw, the first mounting portion protruding from the threaded hole portion in a direction perpendicular to an axis of the threaded hole, and a push rod hinging portion being arranged on the first mounting portion;

[0011] a push rod, one end of the push rod being hinged to the push rod hinging portion of the nut, and the other end of the push rod being configured to hinge a target component;

[0012] wherein the movement of the passive module along the lead screw causes the target component to rotate.

[0013] In some embodiments, the linear actuator further comprises a position sensing assembly, the position sensing assembly comprising:

[0014] a brush, the brush being connected with the nut of the passive module;

[0015] a conductor, the conductor being connected with the motor;

[0016] The position sensing component is configured such that the brush maintains sliding contact with the conductor as the nut moves along the lead screw.

[0017] In some embodiments, the position sensing component further includes: a mounting plate, one end of which is connected to the motor and is arranged parallel to the axis of the lead screw; and a conductor is disposed on the side of the mounting plate near the brush.

[0018] In some embodiments, the position sensing component further includes:

[0019] The connector is mounted on the nut, and the brush is mounted on the connector.

[0020] A wire clamp is located on the end of a mounting plate away from the conductor. The wire clamp is used to hold the wires that are electrically connected to the conductor.

[0021] Some embodiments of this disclosure also provide a bionic robotic hand, including:

[0022] Hand frame;

[0023] The fingers, with their bases hinged to the frame of the hand;

[0024] As in any of the above embodiments, the linear actuator is fixed to the palm frame, the target component is a finger, and the other end of the push rod is hinged to the root of the finger.

[0025] The passive module moves along the lead screw, causing the fingers to rotate relative to the palm frame.

[0026] In some embodiments, the palm frame has a palmar side and a dorsal side; the base of the fingers includes:

[0027] The first hinge portion is disposed near the palm side and is used to hinge with the palm frame.

[0028] The second hinge is located near the back of the hand and is used to hinge with the push rod.

[0029] In some embodiments, when the direction of the base of the finger is parallel to the plane on the palm side of the hand frame, the finger is at a 0-degree position, and the angle through which the finger rotates towards the palm side is a positive angle, and vice versa is a negative angle.

[0030] The linear actuator is configured to allow the finger to rotate between -15 degrees and 90 degrees.

[0031] In some embodiments, when the root of the finger is defined to be parallel to the plane containing the palm side of the hand frame, the finger is at a 0-degree position. When the finger is at a 0-degree position, the passive module is in a position before the two extreme positions of movement along the lead screw.

[0032] In some embodiments, the back side of the palm frame is provided with a fixing groove for fixing the motor of the linear actuator.

[0033] In some embodiments, the nut is provided with a sliding connection part, and the back side of the palm frame is provided with:

[0034] a limiting groove for limiting the motor;

[0035] a guide slide rail arranged along the length direction of the limiting groove, and forming a sliding pair with the sliding connection part. BRIEF DESCRIPTION OF DRAWINGS

[0036] The accompanying drawings are included to provide a further understanding of the embodiments and are incorporated in and constitute a part of this specification, illustrate embodiments and together with the description serve to explain the principles of the present disclosure. The same reference numerals in the drawings and the description below represent the same or similar elements.

[0037] Figure 1 Linear actuator structure schematic provided for embodiments of the present disclosure Figure 1 ;

[0038] Figure 2 Linear actuator structure schematic provided for embodiments of the present disclosure Figure 2 ;

[0039] Figure 3 Nut-related structure schematic Figure 1 ;

[0040] Figure 4 Nut-related structure schematic Figure 2 ;

[0041] Figure 5 Push rod structure schematic

[0042] Figure 6 Bionic robot hand partial structure schematic provided for embodiments of the present disclosure Figure 1 ;

[0043] Figure 7 Bionic robot hand partial structure schematic provided for embodiments of the present disclosure Figure 2 ;

[0044] Figure 8 Finger structure schematic

[0045] Figure 9 Bionic robot hand partial structure schematic provided for embodiments of the present disclosure Figure 3 ;

[0046] Figure 10 Bionic robot hand overall schematic provided for embodiments of the present disclosure.

[0047] REFERENCE NUMERALS:

[0048] 30, linear actuator; 31, drive module; 311, screw rod; 312, motor; 312a, fixed part; 32, passive module; 321, nut; 321a, screw hole part; 321b, first mounting part; 321c, second mounting part; 321d, sliding connection part; 322, push rod; 323, push rod hinged part; 33, position sensing assembly; 331, brush; 332, conductor; 333, mounting plate; 334, lug; 335, wire pressing plate; 40, bionic manipulator; 41, palm frame; 41a, palm side; 41b, back side of palm; 411, mounting platform; 42, finger; 421, first hinged part; 422, second hinged part; 412, fixed groove; 413, limiting groove; 414, guide slide rail; 43, thumb. DETAILED DESCRIPTION

[0049] The preferred embodiments of the present disclosure will be described in detail below with reference to the drawings, in which the drawings constitute a part of the present disclosure and are used to explain the principles of the present disclosure, and are not used to limit the scope of the present disclosure.

[0050] In the description of the embodiments of the present disclosure, it should be noted that unless otherwise explicitly specified and limited, the term "connected" should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrally connected, which can be mechanically connected, or it can be electrically connected, which can be directly connected, or it can be indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above-mentioned term in the present disclosure can be understood according to the specific circumstances.

[0051] The terms "top", "bottom", "above", "under" and "on" used throughout the description are relative positions of the components of the device, for example, the relative positions of the top and bottom substrates inside the device. It can be understood that the device is multifunctional, regardless of their orientation in space.

[0052] The general working surface of the present disclosure can be a plane or a curved surface, which can be inclined or horizontal. For the convenience of description, the embodiments of the present disclosure are placed on a horizontal plane and used on the horizontal plane, and "high and low" and "up and down" are defined accordingly.

[0053] Some embodiments of the present disclosure provide a linear actuator, which comprises a drive module and a passive module.

[0054] The drive module includes a lead screw and a motor, with the motor driving the lead screw to rotate. Optionally, the lead screw can be connected to the output shaft of the motor, or the lead screw can serve as the output shaft of the motor. The motor includes a motor housing (or casing), which protects the internal components of the motor (such as the stator, rotor bearings, etc.), provides mechanical support, and isolates the internal components of the motor to a certain extent from external influences.

[0055] The passive module can move along the lead screw. The passive module includes a nut and a push rod. The nut is fitted onto the lead screw, and one end of the push rod is hinged to the nut while the other end is connected to the target component. When the motor drives the lead screw to rotate, the nut and the lead screw rotate relative to each other, thereby driving the push rod to move along the lead screw.

[0056] The linear actuator provided in this disclosure can be used to realize relative movement between two components, and can also be used to realize relative rotation between two components.

[0057] Figure 1 and Figure 2 Linear actuator 30 provided by some embodiments of this disclosure is shown, such as Figure 1 As shown, the linear actuator 30 includes a drive module 31 and a passive module 32.

[0058] The drive module 31 includes a lead screw 311 and a motor 312, with the motor 312 used to drive the lead screw 311 to rotate.

[0059] The passive module 32 is movable along the lead screw 311. The passive module 32 includes a nut 321 and a push rod 322. The nut 321 is sleeved on the lead screw 311, and the push rod 322 is hinged to the nut 321. Optionally, as... Figure 3 As shown, the nut 321 is provided with a push rod hinge portion 323. One end of the push rod 322 is hinged to the nut 321 at the push rod hinge portion 323, and the other end of the push rod 322 is hinged to the target component. Optionally, the nut 321 includes a threaded hole portion 321a and a first mounting portion 321b. The threaded hole portion 321a is sleeved on the lead screw 311, and the push rod hinge portion 323 is connected to the first mounting portion 321b. Optionally, the push rod 322 is located on the side away from the motor 312 relative to the nut 321.

[0060] In alternative implementations, such as Figure 3 As shown, the hinge axis of the push rod hinge portion 323 is out of plane with the screw hole axis of the nut 321. This allows the push rod hinge portion 323 to be positioned closer to the motor 312, so that the push rod 332 does not significantly increase the axial dimension of the linear actuator 30, thus saving space. Optionally, the hinge axis of the push rod hinge portion 323 and the screw hole axis of the nut 321 can be out of plane and perpendicular.

[0061] In some embodiments, the motor 312 can be fixedly arranged on the rack, the target member is hingedly connected to the rack, and when the motor 312 drives the screw rod 311 to rotate, the nut 321 drives the push rod hinged part 323 and one end of the push rod 322 to move along the screw rod 311 together, thereby driving the target member to rotate through the other end of the push rod 322.

[0062] In the embodiments of the present disclosure, one end of the push rod 322 is hingedly connected to the push rod hinged part 323 of the nut 321, and the other end of the push rod 322 is hingedly connected to the target member, and the hinged axis of the push rod hinged part 323 is out of surface relationship with the screw hole axis of the nut 321. During the rotation of the target member, the push rod 322 can swing to a certain extent, which is beneficial to make the rotation angle range of the target member larger; and the hinged axis of the push rod hinged part 323 is out of surface relationship with the screw hole axis of the nut 321, so that the push rod 322 does not significantly increase the axial size of the linear actuator 30, and the target member can have a larger rotation range in a limited space.

[0063] Optionally, as shown in Figure 3 and Figure 4 , the first mounting part 321b protrudes from the screw hole part 321a in a direction perpendicular to the screw hole axis, the push rod hinged part 323 is connected to the first mounting part 321b, and the push rod hinged part 323 protrudes from the end surface of the screw hole part 321a away from the motor 312. Optionally, the push rod hinged part 323 includes two hinged ears, and the two hinged ears are symmetrically arranged on both sides of the first mounting part 321b; or the push rod hinged part 323 can include a pin shaft or a shaft sleeve, and the other of the pin shaft or the shaft sleeve is connected in cooperation.

[0064] In the embodiments of the present disclosure, the push rod hinged part 323 is connected to the first mounting part 321b, and the first mounting part 321b protrudes from one side of the screw hole part 321a in a direction perpendicular to the screw hole axis, so that the push rod hinged part 323 can be arranged close to the motor 312, and thus the push rod 332 does not significantly increase the axial size of the linear actuator 30, which is beneficial to save space. The push rod 332 is hingedly connected to the push rod hinged part 323, allowing the push rod 332 to swing relative to the nut 321, which is beneficial to make the rotation angle range of the target member larger.

[0065] In some embodiments, as shown in Figure 1 and Figure 2 , the linear actuator 30 further includes a position sensing assembly 33. The position sensing assembly 33 includes an electric brush 331 and a conductor 332, the electric brush 331 is connected to the nut 321 of the passive module 32, and the conductor 332 is connected to the motor 312. During the movement of the nut 321 along the screw rod 311, the electric brush 331 and the conductor 332 keep sliding contact.

[0066] Optionally, as shown in Figure 3 andFigure 4 As shown, the nut 321 further comprises a second mounting portion 321c, and the brush 331 is mounted and fixed to the second mounting portion 321c of the nut 321. Alternatively, the second mounting portion 321c protrudes from the other side of the threaded hole portion 321a in a direction perpendicular to the threaded hole axis; the second mounting portion 321c can be located on the adjacent side of the threaded hole portion 321a as the first mounting portion 321b, or on the opposite side of the threaded hole portion 321a.

[0067] In the embodiments of the present disclosure, the brush 331 and the conductor 332 form a sliding variable resistance structure. During the movement of the nut 321 along the lead screw 311, the brush 331 slides along the surface of the conductor 332, and the movement distance of the passive module 32 is monitored by reading the resistance value change of the conductor 332 connected to the circuit. When the linear actuator 30 is used to realize the rotation between target components, the resistance value change of the brush 331 can be used to monitor the rotation angle of the target components.

[0068] In some embodiments, as Figure 2 As shown, the position sensing assembly 33 further comprises a mounting plate 333, one end of the mounting plate 333 is connected with the motor 312 and is arranged in parallel with the axis direction of the lead screw 311. The conductor 332 is arranged on the mounting plate 333 close to one side of the brush 331.

[0069] In the embodiments of the present disclosure, the mounting plate 333 of the conductor 332 is arranged on the motor 312, and the mounting plate 333 is arranged in parallel with the axis direction of the lead screw 311, so that the sliding contact between the brush 331 and the conductor 332 can be ensured during the movement of the passive module 32. The mounting plate 333 is directly connected to the housing of the motor 312, without the need to arrange additional fixing structures, and only a slight increase in size in the radial direction of the linear actuator 30 exists.

[0070] In some embodiments, the position sensing assembly 33 further comprises a terminal 334. As Figure 3 As shown, the terminal 334 is arranged on the nut 321, and the brush 331 is arranged on the terminal 334. Alternatively, the terminal 334 can be arranged on the end side of the second mounting portion 321c. Alternatively, an insulating mounting block is arranged between the terminal 334 and the second mounting portion 321c.

[0071] In some embodiments, the position sensing assembly further comprises a wire pressing plate 335, as Figure 2 As shown, the wire pressing plate 335 is arranged on the end of the mounting plate 333, and the wire pressing plate 335 is arranged on the end of the mounting plate 333 close to the motor 312. The wire pressing plate 335 is used to accommodate the wire electrically connected with the conductor 332.

[0072] Alternatively, as Figure 5As shown, the push rod 322 comprises two rod-shaped structures symmetrically arranged and connected by a connecting structure. The distance between the two rod-shaped structures and the end of the push rod articulation part articulating with the two rod-shaped structures can be the same or different from the distance between the two rod-shaped structures and the end of the push rod articulation part articulating with the target member. For example, the distance between the two rod-shaped structures and the end of the push rod articulation part articulating with the target member is greater.

[0073] Figure 6 A bionic hand 40 provided by some embodiments of the present disclosure is shown as follows: Figure 6 As shown, the bionic hand 40 comprises a palm frame 41, a finger 42, and the linear actuator 30 of any of the above embodiments. The root of the finger 42 is articulated with the palm frame 41. The linear actuator 30 is fixed on the palm frame 41, the target member is the finger 42, the other end of the push rod 322 is articulated with the root of the finger 42; wherein the movement of the passive module 32 along the screw rod 311 causes the finger 42 to rotate relative to the palm frame 41.

[0074] In the embodiments of the present disclosure, the linear actuator 30 is fixed on the palm frame 41, one end of the push rod 322 of the linear actuator 30 is articulated with the push rod articulation part 323 of the nut 321, the other end of the push rod 322 is articulated with the root of the finger 42, and the articulation axis of the push rod articulation part 323 is in a non-coplanar relationship with the screw hole axis of the nut 321. During the rotation of the finger 42 relative to the finger frame 41, the push rod 322 can swing to a certain extent, so that the finger 42 can have a larger rotation range; and the articulation axis of the push rod articulation part 323 is in a non-coplanar relationship with the screw hole axis of the nut 321, so that the push rod 322 does not significantly increase the axial size of the linear actuator 30, and the finger 42 can have a larger rotation range while saving space on the palm frame 41, which is conducive to making the palm frame 41 more compact.

[0075] Optionally, as shown in Figure 6 and Figure 7 The palm frame 41 is a plate structure, similar to a human palm. The palm frame 41 comprises a palm side 41a and a back side 41b. Optionally, the end of the palm frame 41 close to the finger 42 protrudes towards the palm side 41a to form a mounting platform 411, and the platform surface of the mounting platform 411 and the plate surface of the palm side 41a of the palm frame 41 have an included angle, for example, 90 degrees.

[0076] In some embodiments, as shown in Figure 7 and Figure 8As shown, the root of the finger 42 includes a first hinge portion 421 and a second hinge portion 422. The first hinge portion 421 is disposed close to the palm side 41a, and is configured to be hinged with the palm frame 41. The second hinge portion 422 is disposed close to the back side 41b, and is configured to be hinged with the push rod 322. Optionally, the linear actuator 30 is fixed to the back side 41b of the palm frame 41 to facilitate the hinging of the push rod 322 with the second hinge portion 422. Optionally, the first hinge portion 421 is hinged with the mounting platform 411.

[0077] In some embodiments of the present disclosure, the first hinge portion 421 of the finger 42 is disposed close to the palm side, and the finger 42 is hinged with the palm frame 41 via the first hinge portion 421. The second hinge portion 422 of the finger 42 is disposed close to the back side, such that the root of the finger 42 is also hinged with the push rod 322 of the linear actuator 30. During the movement of the passive module 32 of the linear actuator 30 along the screw rod 311, the push rod 322 pushes the finger 42 to rotate around the hinge axis of the first hinge portion 421. The finger 42 can be configured to have a large rotation range.

[0078] In some embodiments of the present disclosure, the screw rod 311 of the linear actuator 30 is arranged parallel to the plate surface of the back side 41b, and is disposed close to the mounting platform 411 relative to the motor 312. Optionally, as shown in Figure 3 and Figure 7 As shown, the push rod hinge portion 323 of the nut 321 is located between the screw hole portion 321a and the palm frame 41, such that the push rod 322 is located in the gap between the screw rod 311 and the palm frame 41. Optionally, the mounting plate 333 of the position sensing assembly 33 is perpendicular to the back side 41b of the palm frame 41.

[0079] Optionally, as shown in Figure 8 When the finger 42 is vertically placed in the straightened state, the second hinge portion 422 protrudes downward from the root of the finger 42, that is, when the length direction of the finger 42 is parallel to the plate surface of the back side 41b of the palm frame 41, the second hinge portion 422 is closer to the motor 312 in the axial direction of the screw rod 311 than the first hinge portion 421. In this way, it is beneficial for the push rod to not interfere with the root of the finger 42 when the finger 42 rotates through a large angle range.

[0080] In the embodiments of the present disclosure, the first hinge portion 421 and the second hinge portion 422 are disposed on the root of the finger 42. Due to the limited size of the root of the finger 42 in the radial direction, the distance between the first hinge portion 421 and the second hinge portion 422 is limited. The second hinge portion 422 is disposed closer to the motor 312 in the axial direction of the screw rod 311 than the first hinge portion 421, which is beneficial for reducing the length dimension of the push rod 322. It can be understood that the length dimension of the push rod 322 is, for example, the length dimension of the rod-shaped structure.

[0081] In some embodiments, when the root of finger 42 is parallel to the plane containing the palm side of the hand frame 41, finger 42 is at a 0-degree position, and the angle through which finger 42 rotates towards the palm side 41a is a positive angle, and vice versa; for example, Figure 7 and Figure 9 As shown, the linear actuator 30 is configured such that the rotation angle of the finger 42 is within the range of -15 degrees to 90 degrees. It should be understood that the orientation of the root of the finger 42 can be understood as the length direction of the finger 42 in its extended state.

[0082] This design allows the bionic hand disclosed herein to more accurately mimic the human hand. It not only allows the fingers 42 to rotate significantly toward the palm side 41a to perform routine operations such as grasping, but also allows the fingers 42 to curl slightly toward the back of the hand side 41b, for example, to mimic the local avoidance actions of the human hand in some scenarios.

[0083] In some embodiments, when the root of finger 42 is parallel to the plane containing the palm side of the palm frame 41, finger 42 is at a 0-degree position, and the passive module 32 moves along the lead screw 311 with a first limit position and a second limit position; when finger 42 is at a 0-degree position, the passive module 32 is in a position between the first limit position and the second limit position. When the passive module 32 moves to the first limit position, finger 42 rotates to the maximum extent towards the palm side 41a; when the passive module 32 moves to the second limit position, finger 42 slightly tilts upwards towards the back of the hand 41b.

[0084] In some embodiments, such as Figure 6 As shown, the palm side 41b of the palm frame 41 is provided with a fixing groove 412, which is used to fix the motor 312 of the linear actuator 30. Optionally, as shown... Figure 2 As shown, the motor 312 is also provided with a fixing part 312a, which is sleeved on the motor 312 and is used to fix the motor 312 in the fixing groove 412. Optionally, the mounting plate 333 of the position sensing component 33 is connected to the fixing part 312a.

[0085] In some embodiments, such as Figure 4 As shown, the nut 321 of the linear actuator 30 is provided with a sliding connection portion 321d. Optionally, the sliding connection portion 321d is provided at the end of the first mounting portion 321b, located between the first mounting portion 321b and the palm frame 41.

[0086] like Figure 9As shown, the back of the palm frame 41 is provided with a limiting groove 413 for limiting the motor 312 and a guide rail 414 arranged along the length direction of the limiting groove 413, and the guide rail 414 and the sliding connection part 321d form a sliding pair.

[0087] Optionally, the limiting groove 413 is arranged corresponding to the finger 42 and extends from the end close to the finger 42 to the direction away from the finger 42, and the axis direction of the motor 312 is arranged parallel to the limiting groove 413.

[0088] Optionally, the guide rail 414 includes a limiting plate, one end of the limiting plate is fixedly connected with the palm frame 41, and the other end partially covers the limiting groove 413 to form the guide rail 414, and the sliding connection part 321d is located in the guide rail 414. Optionally, the cross-sectional shape of the guide rail 414 matches the cross-sectional shape of the sliding connection part 321d.

[0089] The sliding pair of the guide rail 414 and the sliding connection part 321d can guide the nut 321 of the linear actuator 30, so that the nut 321 can move along the axis direction of the screw rod 311 accurately. Since the sliding connection part 321d and the guide rail 414 utilize the structural gap between the motor 312 and the palm frame 41, no additional space burden is generated, and the overall size of the palm can be miniaturized.

[0090] Optionally, as Figure 10 As shown, in some embodiments of the present disclosure, the bionic robot hand 40 includes three fingers 42 and a thumb 43, and the thumb 43 is arranged at the end of the palm frame 41 away from the mounting platform 411. Through the cooperation of the fingers 42 and the thumb 43, various actions can be simulated by the human hand.

[0091] The above description is only a preferred embodiment of the present disclosure, but the protection scope of the present disclosure is not limited thereto, and any changes or replacements within the technical scope disclosed by the present disclosure can be easily thought by those skilled in the art, which should be covered within the protection scope of the present disclosure.

Claims

1. A linear actuator, characterized by The linear actuator comprises: a driving module, which comprises: a screw rod; a motor connected with the screw rod for driving the screw rod to rotate; a passive module capable of moving along the screw rod, which comprises: a nut sleeved on the screw rod, the nut comprising a threaded hole portion and a first mounting portion, the threaded hole portion being sleeved on the screw rod, the first mounting portion protruding from the threaded hole portion in a direction perpendicular to the axis of the threaded hole, and a push rod hinging portion being arranged on the first mounting portion; a push rod, one end of which is hinged to the push rod hinging portion, and the other end of which is used for hinging a target component; wherein the movement of the passive module along the screw rod causes the target component to rotate.

2. The linear actuator of claim 1, wherein, The linear actuator further comprises a position sensing assembly, which comprises: a brush connected with the nut of the passive module; a conductor connected with the motor; the position sensing assembly is configured to keep the brush in sliding contact with the conductor during the movement of the nut along the screw rod.

3. The linear actuator of claim 2, wherein, The position sensing assembly further comprises a mounting plate, one end of which is connected with the motor and is arranged in parallel with the axis of the screw rod, and the conductor is arranged on one side of the mounting plate close to the brush.

4. The linear actuator of claim 3, wherein, The position sensing assembly further comprises: a terminal lug arranged on the nut, and the brush is arranged on the terminal lug; a terminal lug arranged on the nut, and the brush is arranged on the terminal lug; 5. A bionic hand, characterized in that, a terminal lug arranged on the nut, and the brush is arranged on the terminal lug; The linear actuator comprises: a palm frame; a finger, the root of which is hinged to the palm frame; the linear actuator as claimed in any one of claims 1-4 is fixed to the palm frame, the target component is the finger, and the other end of the push rod is hinged to the root of the finger; 6. The bionic hand of claim 5, wherein, wherein the movement of the passive module along the screw rod causes the finger to rotate relative to the palm frame. The palm frame has a palm side and a back side; the root of the finger comprises: a first hinging portion arranged close to the palm side, which is used for hinging with the palm frame; 7. The bionic hand of claim 6 wherein, a second hinging portion arranged close to the back side, which is used for hinging with the push rod. When the direction of the root of the finger is parallel to the plane in which the palm side of the palm frame lies, the finger is in a 0-degree position, and the angle of rotation of the finger in the direction of the palm side is a positive angle, and vice versa; 8. The bionic hand of claim 6, wherein, the linear actuator is configured to make the rotation angle of the finger range from -15 degrees to 90 degrees.

9. The bionic hand of claim 6, wherein, When the direction of the root of the finger is parallel to the plane in which the palm side of the palm frame lies, the finger is in a 0-degree position, and when the finger is in the 0-degree position, the passive module is in a position before the two limit positions of movement along the screw rod. The back side of the palm frame is provided with a fixing groove for fixing the motor of the linear actuator.

10. The bionic hand of claim 6, wherein, The nut is provided with a sliding connection part, and the back side of the palm frame is provided with: A limiting groove is used for limiting the motor; A guide sliding rail is arranged along the length direction of the limiting groove, and the guide sliding rail and the sliding connection part form a sliding pair.

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