Rigid-flexible coupling space capturing clamping jaw based on active and passive combined driving

Abstract

The invention relates to the technical field of spacecrafts, and discloses a rigid-flexible coupling space capturing clamping jaw based on active and passive combined driving, which comprises a clamping jaw body, a connecting part, a passive pressure driving part and at least one group of clamping units. The clamping unit comprises an active motor driving part, a rigid clamping jaw part and a flexible clamping jaw part, wherein the flexible clamping jaw part is provided with a cavity of an asymmetric structure. And the passive pressure driving part is connected in series with all the cavities with the asymmetric structures through connecting pipelines to form a closed fluid system. During working, rigid grabbing is achieved through active driving; when the passive part is extruded, the pressure intensity of the system is increased, the flexible cavity is driven to generate self-adaptive bending towards the inner side, and flexible enveloping and energy absorption are achieved. The device has reliable clamping force and low disturbance, and is suitable for on-orbit safe operation of high-value spacecrafts.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of spacecraft, in particular to a rigid-flexible coupling space capture gripper based on active-passive composite driving. BACKGROUND

[0002] Space activities are moving from exploration to routine operation, and the number, complexity and value of on-orbit spacecraft are growing exponentially. The design life of high-value assets often ends prematurely due to the failure of a single component or the depletion of fuel, resulting not only in high economic losses, but also in the accumulation of space debris in Earth orbit, posing a serious sustainability challenge. Therefore, the development of active intervention to achieve life extension, function upgrade and fault rescue on-orbit service technology is the key to protecting the long-term value of space assets and the safety of the space environment. The core prerequisite for performing these tasks is that the service robot must be able to achieve safe, reliable and flexible attachment and movement on the surface of the target spacecraft, and traditional docking mechanisms cannot meet the needs of such large-scale fine operations.

[0003] Existing non-invasive attachment technologies mainly focus on electrostatic adsorption and dry adhesion, but both have insurmountable obstacles in actual space applications. Electrostatic adsorption technology relies on high-voltage electric fields to generate adsorption force, which is easily affected by the target surface contamination, roughness changes and the complex space environment of atomic oxygen, charged particle irradiation, etc., and its stability is questionable. At the same time, its high-voltage working characteristics bring an unavoidable power burden and potential discharge risk, which may cause electromagnetic interference to the sensitive electronic systems of the spacecraft. On the other hand, dry adhesion materials inspired by gecko toes can achieve repeatable adhesion, but their performance is heavily dependent on atomically smooth and clean contact surfaces, which is almost impossible to guarantee on the real spacecraft surface covered with thermal control coatings and possibly small protrusions. Moreover, the "preload" mechanism required to establish effective contact is difficult to control accurately in microgravity, and it can easily cause irreversible damage such as extrusion, scratching and even puncture to fragile components such as solar cell arrays. In addition, the "adhesion-slippage" dynamic behavior during movement will transfer significant momentum and attitude disturbance to the target spacecraft, disrupting its stable operation.

[0004] Therefore, there is an urgent need for a new attachment mechanism that can attach to the surface of a high-value spacecraft without damaging the spacecraft surface and has a micro-disturbance capability. SUMMARY

[0005] The present application provides a rigid-flexible coupling space capture gripper based on active-passive composite driving to solve the above problems.

[0006] In a first aspect, the present application provides a rigid-flexible coupling space capture gripper based on active-passive composite driving, comprising: a gripper body; a connecting portion disposed on the jaw body for connecting the jaw body to the end of the mechanical arm of the on-track service robot; a passive pressure-driven portion disposed on the jaw body; at least one set of clamping units, each set of the clamping units comprising two jaw arms, any of the jaw arms comprising: an active motor-driven portion mounted on the jaw body; a rigid jaw portion in transmission connection with the active motor-driven portion to perform opening and closing movements under the drive of the active motor-driven portion; a flexible jaw portion comprising an asymmetric structure cavity attached to the outside of the rigid jaw portion; wherein the passive pressure-driven portion and the asymmetric structure cavity are in communication with each other through a connecting pipeline to form a closed fluid system; and when the passive pressure-driven portion is extruded by external force, the pressure in the fluid system is increased, driving the asymmetric structure cavity to bend and deform towards the clamping center, and forcing the rigid jaw portion to bend towards the clamping center.

[0007] The jaw mainly comprises a jaw body, a connecting portion, a passive pressure-driven portion, and two sets of clamping units. The connecting portion is disposed on the upper part of the jaw body for connecting the entire jaw to the end of the mechanical arm of the on-track service robot. The passive pressure-driven portion is disposed in the central region of the jaw body, and its interior is filled with fluid (such as gas or liquid) as the core buffer and driving source of the entire system. The clamping unit comprises two oppositely disposed jaw arms, which are both mounted on the jaw body. Each jaw arm integrates an active motor-driven portion, a rigid jaw portion, and a flexible jaw portion. The active motor-driven portion is fixedly mounted on the jaw body, and its output end is in transmission connection with the rigid jaw portion. By controlling the active motor-driven portion, the rigid jaw portion can be accurately driven to perform active opening or closing movements, thereby achieving preliminary grasping or releasing of the target object. The core of the flexible jaw portion is an asymmetric structure cavity attached and fixed to the outside profile of the rigid jaw portion.

[0008] In the process of the gripper approaching or contacting the target object, the centrally located passive pressure driven part will first contact the surface of the target object and be squeezed. This squeezing causes the total volume of the closed fluid system to decrease, thereby causing the internal pressure of the system to instantaneously increase. Due to the synchronization of pressure transmission, the pressure inside the two asymmetric structure cavities also synchronously increases. Under the driving of the increased pressure, the asymmetric structure cavities will deform towards the center of the clamping (the center of the two gripper arms) due to their structural characteristics. This deformation process has a dual benefit: first, it enables the flexible gripper part to more compliantly and more closely conform to the irregular surface of the target object, achieving adaptive wrapping and reducing local stress; second, it converts part of the kinetic energy in the process of the collision between the gripper and the target object into the internal energy (pressure potential energy) of the fluid system, thereby playing a role in energy absorption and significantly reducing the impact force and attitude disturbance transmitted to the target spacecraft.

[0009] When the target object needs to be released, the active motor driven part drives the rigid gripper part to open. The movement of the rigid part will release the constraint on the flexible gripper part and increase the closed volume of the system, causing the internal pressure to decrease. The stored pressure potential energy is released, driving the fluid to flow back, and the asymmetric structure cavities gradually return to their original state, thereby enabling the gripper to stably separate from the target object and complete the detachment.

[0010] This rigid-flexible coupling space capture gripper based on active-passive composite driving can convert the kinetic energy of the gripper movement into internal energy for driving clamping through the passive pressure driven part, and achieve compliant clamping through the flexible gripper part. On the one hand, it minimizes the damage to the clamping surface through rigid-flexible coupling, and on the other hand, the existence of the flexible structure stores the momentum disturbance brought by the robot in the form of internal energy, reducing energy dissipation while minimizing the impact on the spacecraft in the form of small disturbance, thereby providing technical support for the safe, reliable, and flexible attachment and movement of the service robot on the target spacecraft.

[0011] In an alternative embodiment, the clamping unit is two groups arranged in a front-rear symmetrical layout on the gripper body.

[0012] In an alternative embodiment: The rigid gripper part includes a first rigid joint, a second rigid joint, and a third rigid joint connected in sequence, and a connecting rod connected to the first rigid joint at one end; The active motor driven part includes a steering engine and a driving member connected to the output shaft of the steering engine, the driving member being connected to the other end of the connecting rod to convert the rotary motion of the steering engine into the opening and closing motion of the rigid gripper part.

[0013] Through the above design, the servo motor, drive component, connecting rod, and first rigid joint together form a precise transmission link. When the servo motor is activated, the drive component swings accordingly, converting the rotational motion into a pushing or pulling motion of the connecting rod through its hinge point with the connecting rod. The connecting rod then drives the first rigid joint to rotate around its hinge point with the gripper body, and through the linkage of the second and third rigid joints, the power is ultimately transmitted to the end of the entire rigid gripper section, achieving a stable and definite opening or closing motion.

[0014] This transmission scheme, based on multi-joint articulation and linkage drive, has the advantages of controllable motion trajectory, clear force transmission path, and high structural rigidity. It ensures that the rigid gripper can provide strong and precise clamping force during the active drive phase, laying a solid mechanical foundation for subsequent passive compliant adaptation.

[0015] In one alternative embodiment, the asymmetric cavity is limited and fixed by a slot and a fixing frame disposed on the outside of the rigid gripper portion.

[0016] In one optional implementation, the asymmetric cavity includes: Multiple asymmetric cavities are used to guide bending, and the connection between two adjacent asymmetric cavities is a folded surface; Multiple flexible contact pouches are disposed on the contact surface of the asymmetric structure cavity facing the clamping center.

[0017] Multiple asymmetric cavities are connected in series via their folded surfaces, allowing the entire asymmetric structure to undergo continuous, smooth inward bending deformation under pressure, much like the bending of a multi-jointed finger, thus perfectly adapting to and enveloping target objects of different shapes. Furthermore, multiple flexible contact capsules are disposed on the inner contact surfaces of the asymmetric structure facing the clamping center. These flexible contact capsules are also connected to the fluid system, maintaining the same internal pressure as the system. During clamping, they directly contact the surface of the target object. As the final contact medium, their soft material effectively avoids scratching the surface of high-value spacecraft; secondly, their own deformation under pressure can further absorb minor localized impacts and increase the actual contact area, improving the stability and reliability of the adhesion.

[0018] In one optional embodiment, the first rigid joint, the second rigid joint, and the third rigid joint are each provided with at least one flexible contact pouch facing the clamping center, and the first rigid joint, the second rigid joint, and the third rigid joint are each provided with at least one wrinkled surface away from the clamping center.

[0019] When the rigid joints come into direct or indirect contact with the surface of the target object during clamping operations, these flexible contact pockets can absorb local contact impacts, increase friction, and prevent hard, rigid materials from scratching or indenting the surface of precision spacecraft through their own elastic deformation. On the other hand, at least one corrugated surface is provided on the side of the first, second, and third rigid joints away from the clamping center (i.e., the back side), which can drive the movement of the second and third rigid joints through the expansion of the corrugated surfaces.

[0020] In one alternative embodiment, when the pressure inside the fluid system increases, the folded surface of the asymmetric cavity undergoes a more significant volume expansion compared to the other side, thereby driving the second and third rigid joints to rotate toward the clamping center side.

[0021] In one alternative embodiment, the passive pressure drive portion is located between the two clamping units and includes a central fluid bladder made of flexible material and a flexible covering layer covering the outside of the central fluid bladder.

[0022] In one alternative implementation, the passive pressure drive section is connected in series with the connecting pipes of all the flexible gripper sections through a main pipe port, so that the internal pressure of the fluid system remains dynamically consistent.

[0023] In one alternative embodiment, the connection portion includes a connection snap for quick plug-in connection with the end effector of the robot arm and a mounting flange for securing to the gripper body. Attached Figure Description

[0024] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the overall structure of a rigid-flexible coupling space capture gripper based on active-passive composite drive according to an embodiment of the present invention. Figure 2 This is a front view of a rigid-flexible coupling spatial capture gripper based on active-passive composite drive according to an embodiment of the present invention. Figure 3 This is a side view of a rigid-flexible coupling spatial capture gripper based on active-passive composite drive according to an embodiment of the present invention. Figure 4This is a schematic diagram of the gripping unit in a rigid-flexible coupling spatial capture gripper based on active-passive composite drive according to an embodiment of the present invention. Figure 5 This is a schematic diagram of the internal structure of a clamping unit in a rigid-flexible coupling spatial capture gripper based on active-passive composite drive, according to an embodiment of the present invention.

[0026] Explanation of reference numerals in the attached figures: 101. Clamp body; 211. First rigid joint; 212. Second rigid joint; 213. Third rigid joint; 221. Connecting rod; 231. Slot; 232. Fixing frame; 311. Connecting pipes; 312. Asymmetric structure cavity; 313. Flexible contact bladder; 401. Active motor drive unit; 411. Servo motor; 412. Drive unit; 511. Central fluid capsule; 512. Flexible covering layer; 513. Main port; 601. Connection part. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Space activities have transitioned from exploration to routine operation, with the number, complexity, and value of spacecraft in orbit growing exponentially. High-value assets often have their design lifespans prematurely ended due to single component failures or fuel depletion, resulting not only in substantial economic losses but also in the continuous accumulation of space debris in Earth orbit, posing a serious sustainability challenge. Therefore, developing on-orbit servicing technologies that enable proactive intervention to extend lifespan, upgrade functionality, and facilitate fault recovery is crucial for ensuring the long-term value of space assets and the safety of the space environment. A core prerequisite for performing these tasks is that service robots must be able to safely, reliably, and flexibly attach and move on the surface of the target spacecraft, a requirement that traditional docking mechanisms cannot meet for such large-scale, delicate operations.

[0029] Existing non-invasive adhesion technologies mainly revolve around two categories: electrostatic adsorption and dry adhesion. However, both face insurmountable obstacles in practical space applications. Electrostatic adsorption technology relies on a high-voltage electric field to generate adsorption force. Its performance is extremely susceptible to rapid degradation due to surface contamination, changes in roughness, and the complex space environment, including atomic oxygen and charged particle radiation present in orbit, raising concerns about its stability. Furthermore, its high-voltage operation introduces a significant power burden and potential discharge risk, which may cause electromagnetic interference to the spacecraft's sensitive electronic systems. On the other hand, while dry adhesion materials inspired by gecko toes achieve reusable adhesion, their effectiveness heavily relies on atomically smooth and clean contact surfaces, which is almost impossible to guarantee on the actual spacecraft exterior surfaces covered with thermal control coatings and potentially containing minute protrusions. Furthermore, the "preload" mechanism required for establishing effective contact is difficult to control precisely under microgravity, and it is extremely easy to cause irreversible damage to fragile components such as solar cell arrays by squeezing, scratching or even puncturing. In addition, its "adhesion-slip" dynamic behavior during travel will transmit significant momentum and attitude disturbances to the target spacecraft, interfering with its stable operation.

[0030] The following is combined with Figures 1 to 5 The following describes embodiments of the present invention.

[0031] According to an embodiment of the present invention, a rigid-flexible coupling space capture gripper based on active-passive composite drive is provided, comprising a gripper body 101, a connecting portion 601, a passive pressure drive portion, and at least one set of gripping units; the connecting portion 601 is disposed on the gripper body 101 for connecting the gripper body 101 to the end effector of the robotic arm of an on-orbit service robot; the passive pressure drive portion is disposed on the gripper body 101; each set of gripping units includes two gripper arms, each gripper arm including an active motor drive portion 401, a rigid gripper portion, and a flexible gripper portion, the active motor drive portion 401 being mounted on the gripper body 101; the rigid-flexible coupling space capture gripper based on active-passive composite drive is provided, comprising a gripper body 101, a connecting portion 601, a passive pressure drive portion, and at least one set of gripping units; the connecting portion 601 is disposed on the gripper body 101 for connecting the gripper body 101, a connecting portion 601 for connecting the gripper body 101, a passive pressure drive portion 601 for connecting the gripper body 101, and a passive pressure drive portion 601 for connecting the gripper body 101; the passive pressure drive portion 601 is disposed on ... The flexible gripper portion is connected to the active motor drive portion 401 for transmission, so as to perform opening and closing movements under the drive of the active motor drive portion 401; the flexible gripper portion includes an asymmetric structure cavity 312, which is attached to the outside of the rigid gripper portion; wherein, the passive pressure drive portion and the asymmetric structure cavity 312 are interconnected through the connecting pipe 311 to form a closed fluid system; and when the passive pressure drive portion is squeezed by external force, the pressure in the fluid system increases, driving the asymmetric structure cavity 312 to generate bending deformation towards the clamping center, and forcing the rigid gripper portion to bend towards the clamping center.

[0032] Please see Figures 1 to 3The gripper mainly comprises a gripper body 101, a connecting portion 601, a passive pressure drive portion, and two sets of gripping units. The connecting portion 601 is located on the upper part of the gripper body 101 and connects the entire gripper to the end effector of the on-orbit service robot's robotic arm. The passive pressure drive portion is located in the central region of the gripper body 101 and is filled with fluid (such as gas or liquid), serving as the core buffer and drive source for the entire system. Each gripping unit includes two opposing gripper arms, both mounted on the gripper body 101. Each gripper arm integrates an active motor drive portion 401, a rigid gripper portion, and a flexible gripper portion. The active motor drive portion 401 is fixedly mounted on the gripper body 101, and its output end is connected to the rigid gripper portion for transmission. By controlling the active motor drive portion 401, the rigid gripper portion can be precisely driven to perform opening or closing active movements, thereby achieving initial grasping or release of the target object. The core of the flexible gripper part is an asymmetric structure cavity 312, which is attached to and fixed on the outer contour of the rigid gripper part.

[0033] The key is that the passive pressure drive part and the asymmetric structure cavity 312 on the two claw arms are connected to each other through the connecting pipe 311, forming a closed fluid system, so that the pressure inside the system remains consistent.

[0034] The working process of this gripper embodies its core concept of "active and passive combined drive".

[0035] When it is necessary to grasp the target object, the active motor drive unit 401 first works, driving the two rigid gripper parts to close and move, so that the gripper roughly hugs the target object.

[0036] As the grippers approach or contact the target object, the passive pressure-driven part at the center first contacts and is compressed against the target object's surface. This compression reduces the overall volume of the closed fluid system, causing a sudden increase in internal pressure. Due to the synchronicity of pressure transmission, the pressure inside the two asymmetric structural cavities 312 also increases synchronously. Driven by the increased pressure, the asymmetric structural cavities 312, due to their structural characteristics, undergo bending deformation towards the gripping center (the center of the two gripper arms). This deformation process has two benefits: first, it allows the flexible gripper part to conform more compliantly and tightly to the irregular surface of the target object, achieving adaptive wrapping and reducing local stress; second, it converts some of the kinetic energy during the collision between the grippers and the target object into the internal energy of the fluid system (pressure energy), acting as a buffer and significantly reducing the impact force and attitude disturbance transmitted to the target spacecraft.

[0037] When the target object needs to be released, the active motor drive unit 401 drives the rigid gripper part to open. The movement of the rigid part releases the constraint on the flexible gripper part and increases the sealed volume of the system, resulting in a decrease in internal pressure. The stored pressure energy is released, driving the fluid to flow back, and the asymmetric structure cavity 312 gradually returns to its original shape, thereby allowing the gripper to smoothly separate from the target object, completing the desorption.

[0038] In one embodiment, there are two sets of clamping units, arranged in a symmetrical layout on the gripper body 101.

[0039] In this embodiment, there are two sets of clamping units. These two sets of clamping units are arranged symmetrically on the gripper body 101, and can be defined as the front gripper and the rear gripper, respectively. Figure 1 In the diagram, the left side is defined as the front side, and the right side is defined as the back side.

[0040] The two sets of grippers share the same gripper body 101, connecting portion 601, and passive pressure drive portion located at the center of the body. Each gripping unit independently includes two gripper arms, each gripper arm containing its own active motor drive portion 401, rigid gripper portion, and flexible gripper portion (including asymmetric structure cavity 312). All asymmetric structure cavities 312 of the two gripping units are connected to the central passive pressure drive portion through their respective connecting pipes 311, together forming a unified closed fluid system.

[0041] During the capture process, when the central passive pressure-driven part is squeezed, the increased system pressure simultaneously drives all the asymmetric structural cavities 312 in both the front and rear grippers to undergo inward bending deformation. This enhances the overall gripping stability and envelopment.

[0042] In one embodiment, the rigid gripper portion includes a first rigid joint 211, a second rigid joint 212, and a third rigid joint 213 that are hinged in sequence, and a connecting rod 221 with one end hinged to the first rigid joint 211; the active motor drive portion 401 includes a servo motor 411 and a drive member 412 connected to the output shaft of the servo motor 411, the drive member 412 being hinged to the other end of the connecting rod 221 to convert the rotational motion of the servo motor 411 into the opening and closing motion of the rigid gripper portion.

[0043] In this embodiment, for any claw arm, the rigid gripper portion includes a first rigid joint 211, a second rigid joint 212, and a third rigid joint 213 that are hinged sequentially. These three rigid joints together form a multi-link mechanism, laying the foundation for the gripper to achieve stable grasping motion. Furthermore, this portion also includes a connecting rod 221, one end of which is hinged to the first rigid joint 211. The active motor drive portion 401 specifically includes a servo motor 411 and a drive component 412 fixedly connected to the output shaft of the servo motor 411. The free end of the drive component 412 is hinged to the other end of the connecting rod 221.

[0044] Through the above design, the servo motor 411, drive component 412, connecting rod 221, and first rigid joint 211 together form a precise transmission link. When the servo motor 411 is activated, the drive component 412 swings accordingly, converting the rotational motion into a pushing and pulling motion of the connecting rod 221 through its hinge point with the connecting rod 221. The connecting rod 221 then drives the first rigid joint 211 to rotate around its hinge point with the gripper body 101, and through the linkage of the second rigid joint 212 and the third rigid joint 213, the power is finally transmitted to the end of the entire rigid gripper section, achieving a stable and definite opening or closing motion.

[0045] This transmission scheme, based on multi-joint articulation and linkage drive, has the advantages of controllable motion trajectory, clear force transmission path, and high structural rigidity. It ensures that the rigid gripper can provide strong and precise clamping force during the active drive phase, laying a solid mechanical foundation for subsequent passive compliant adaptation.

[0046] In one embodiment, the asymmetric cavity 312 is limited and fixed by a slot 231 and a fixing frame 232 provided on the outside of the rigid gripper portion.

[0047] In this embodiment, the asymmetric cavity 312 of the flexible gripper portion is limited and fixed in coordination with the fixing frame 232 through the slot 231 provided on the outside of the rigid gripper portion.

[0048] Specifically, the slot 231 is formed on the rigid gripper portion and extends along its length. The root or base portion of the asymmetric cavity 312 is provided with a flange or insert structure that matches the slot 231. During installation, the insert structure is first aligned and inserted into the slot 231. This operation achieves initial axial positioning of the asymmetric cavity 312 on the rigid gripper portion, effectively preventing its movement along the length of the rigid frame and ensuring the reference accuracy of the installation.

[0049] To further provide robust constraint, at least one fixing frame 232 is provided on the rigid gripper portion. This fixing frame 232 can be a separate clamp, pressure plate, or a frame structure integrally formed with the rigid joint. After the asymmetric cavity 312 is engaged with the slot 231, the fixing frame 232 is fitted or fastened to the outside of the cavity and pressed against the contour surface of the rigid gripper portion. The fixing frame 232 provides the main radial and circumferential constraint forces, preventing the cavity from loosening from the slot 231 under stress or vibration, ensuring the reliability of the connection.

[0050] In one embodiment, the asymmetric structure cavity 312 includes a plurality of asymmetric small cavities for guiding bending and a plurality of flexible contact pouches 313, wherein the connection between two adjacent asymmetric small cavities is a pleated surface; the flexible contact pouches 313 are disposed on the contact surface of the asymmetric structure cavity 312 facing the clamping center side.

[0051] In this embodiment, the internal structure of the asymmetric cavity 312 is specifically designed as follows: it includes multiple asymmetric small cavities for guiding bending and multiple flexible contact bladders 313.

[0052] Specifically, multiple (preferably eight) asymmetric cavities are arranged in series along the length of the asymmetric structural cavity 312. The connection between two adjacent asymmetric cavities forms a deformable folded surface. The structural stiffness of this folded surface is significantly lower than that of other parts of the cavity wall, acting like a pre-designed hinge. When the pressure within the closed fluid system increases, fluid flows into and fills these cavities, and the folded surface, due to its highly stretchable nature, experiences the most significant volume expansion.

[0053] Multiple such asymmetric cavities are connected in series through their folded surfaces, enabling the entire asymmetric structure cavity 312 to produce continuous and smooth inward bending deformation under pressure, like the bending of a multi-jointed finger, thus perfectly adapting to and enveloping target objects of different shapes.

[0054] In addition, multiple flexible contact capsules 313 are disposed on the inner contact surface of the asymmetric structural cavity 312 facing the clamping center. These flexible contact capsules 313 are also connected to the fluid system, and their internal pressure is consistent with that of the system. During clamping, they directly contact the surface of the target object. As the final contact medium, their soft material can effectively avoid scratching the surface of high-value spacecraft; secondly, their own deformation under pressure can further absorb minor local impacts and increase the actual contact area, thereby improving the stability and reliability of the attachment.

[0055] In one embodiment, the first rigid joint 211, the second rigid joint 212, and the third rigid joint 213 are each provided with at least one flexible contact pouch 313 facing the clamping center side, and the first rigid joint 211, the second rigid joint 212, and the third rigid joint 213 are each provided with at least one wrinkled surface away from the clamping center side.

[0056] In this embodiment, for any rigid gripper portion of the claw arm, the first rigid joint 211, the second rigid joint 212, and the third rigid joint 213 all adopt a rigid-flexible integrated surface design: At least one flexible contact pouch 313 is provided on the side (i.e., the inner contact surface) of the first rigid joint 211, the second rigid joint 212, and the third rigid joint 213 facing the clamping center. When the rigid joint parts directly or indirectly contact the surface of the target object during clamping operations, these flexible contact pouches 313 can absorb local contact impacts, increase friction, and prevent hard rigid materials from causing scratches or indentations on the surface of precision spacecraft through their own elastic deformation. On the other hand, at least one corrugated surface is provided on the side (i.e., the back side) of the first rigid joint 211, the second rigid joint 212, and the third rigid joint 213 away from the clamping center, which can drive the movement of the second rigid joint 212 and the third rigid joint 213 through the expansion of the corrugated surface.

[0057] In one embodiment, when the pressure inside the fluid system increases, the folded surface of the asymmetric cavity produces a more significant volume expansion compared to the other side, thereby driving the second rigid joint 212 and the third rigid joint 213 to rotate toward the clamping center side.

[0058] Since the asymmetric cavity 312 is firmly attached to the outer contour of the rigid gripper portion via the slot 231 and the fixing frame 232, its deformation is spatially constrained by the rigid skeleton. In particular, the position of the asymmetric small cavity corresponds to the back region of the second rigid joint 212 and the third rigid joint 213. When the folded surface expands, it generates an inward thrust on the back side of the second rigid joint 212 and the third rigid joint 213 to which it is attached.

[0059] Since the first rigid joint 211, the second rigid joint 212, and the third rigid joint 213 of the rigid gripper are hinged, and the first rigid joint 211 is hinged to the gripper body 101, and the second rigid joint 212 and the third rigid joint 213 are also hinged, the entire rigid part forms a kinematic chain. When the back side of the second and third joints is subjected to a continuous and increasing thrust generated by the expansion of the flexible cavity, this thrust is converted into a torque that forces the second rigid joint 212 to rotate about its hinge point with the first rigid joint 211, and the third rigid joint 213 about its hinge point with the second rigid joint 212, toward the gripping center.

[0060] In one embodiment, the passive pressure drive portion is located between the two clamping units and includes a central fluid bladder 511 made of flexible material and a flexible covering layer 512 covering the outside of the central fluid bladder 511.

[0061] The passive pressure-driven component specifically includes a central fluid bladder 511 made of a flexible material. This bladder is filled with a working fluid (gas or liquid), forming the core pressure source and volume compensation unit of the closed fluid system. The central fluid bladder 511 possesses sufficient flexibility and elasticity to undergo significant deformation under positive compression, absorbing impact kinetic energy.

[0062] Furthermore, a flexible covering layer 512 is applied to the outside of the central fluid capsule 511. This covering layer is also made of a flexible material and protects the central fluid capsule 511 from being scratched or punctured by sharp objects in the space environment or protrusions on the spacecraft surface.

[0063] In one embodiment, the passive pressure drive section is connected in series with the connecting pipes 311 of all flexible gripper sections through the main port 513, so that the internal pressure of the fluid system remains dynamically consistent.

[0064] In one embodiment, the connection portion 601 includes a connection snap for quick-connection to the end effector of a robot arm and a mounting flange for securing to the gripper body 101.

[0065] The mounting flange serves as the base of the connecting part 601 and is rigidly fixed to the gripper body 101 by bolts, welding or other means, providing a stable mounting base for the entire gripper.

[0066] The connecting clip is located above the mounting flange and is specifically designed to enable quick plug-and-play connection with the end effector of the on-orbit service robot's robotic arm. This clip structure includes, but is not limited to, quick-connect mechanisms such as bayonet type, conical locking type, elastic tongue type, or electromagnetic adsorption type.

[0067] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A rigid-flexible coupled spatial capture gripper based on active-passive composite drive, characterized in that, include: Clamp body (101); A connecting part (601) is disposed on the gripper body (101) for connecting the gripper body (101) to the end of the robotic arm of the on-orbit service robot; A passive pressure drive component is disposed on the gripper body (101); At least one set of clamping units, each set of clamping units including two claw arms, each of the claw arms including: An active motor drive unit (401) is installed on the gripper body (101). The rigid gripper portion is connected to the active motor drive portion (401) for transmission, so as to perform opening and closing movements under the drive of the active motor drive portion (401); The flexible gripper portion includes an asymmetric structure cavity (312) attached to the rigid gripper portion; The passive pressure drive part and the asymmetric structure cavity (312) are interconnected by a connecting pipe (311) to form a closed fluid system; and when the passive pressure drive part is squeezed by an external force, the pressure in the fluid system increases, driving the asymmetric structure cavity (312) to generate bending deformation toward the clamping center, and forcing the rigid claw part to bend toward the clamping center.

2. The rigid-flexible coupling spatial capture gripper based on active-passive composite drive according to claim 1, characterized in that, The clamping units are in two sets, arranged in a symmetrical manner on the gripper body (101).

3. The rigid-flexible coupling spatial capture gripper based on active-passive composite drive according to claim 2, characterized in that: The rigid gripper portion includes a first rigid joint (211), a second rigid joint (212) and a third rigid joint (213) that are hinged in sequence, and a connecting rod (221) with one end hinged to the first rigid joint (211). The active motor drive unit (401) includes a servo motor (411) and a drive member (412) connected to the output shaft of the servo motor (411). The drive member (412) is hinged to the other end of the connecting rod (221) to convert the rotational motion of the servo motor (411) into the opening and closing motion of the rigid gripper part.

4. The rigid-flexible coupling spatial capture gripper based on active-passive composite drive according to claim 3, characterized in that, The asymmetric structure cavity (312) is limited and fixed by the slot (231) and the fixing frame (232) provided on the outside of the rigid gripper portion.

5. The rigid-flexible coupling spatial capture gripper based on active-passive composite drive according to claim 4, characterized in that, The asymmetric structure cavity (312) includes: Multiple asymmetric cavities are used to guide bending, and the connection between two adjacent asymmetric cavities is a folded surface; Multiple flexible contact pouches (313) are disposed on the contact surface of the asymmetric structure cavity (312) facing the clamping center.

6. The rigid-flexible coupling spatial capture gripper based on active-passive composite drive according to claim 5, characterized in that, The first rigid joint (211), the second rigid joint (212), and the third rigid joint (213) are each provided with at least one flexible contact pouch (313) facing the clamping center side, and the first rigid joint (211), the second rigid joint (212), and the third rigid joint (213) are each provided with at least one pleated surface away from the clamping center side.

7. The rigid-flexible coupling spatial capture gripper based on active-passive composite drive according to claim 6, characterized in that, When the pressure inside the fluid system increases, the folded surface of the asymmetric cavity expands more significantly than the other side, thereby driving the second rigid joint (212) and the third rigid joint (213) to rotate toward the clamping center side.

8. The rigid-flexible coupling spatial capture gripper based on active-passive composite drive according to claim 2, characterized in that, The passive pressure drive section is located between the two clamping units and includes a central fluid capsule (511) made of flexible material and a flexible covering layer (512) covering the outside of the central fluid capsule (511).

9. The rigid-flexible coupling spatial capture gripper based on active-passive composite drive according to claim 8, characterized in that, The passive pressure drive section is connected in series with the connecting pipes (311) of all the flexible gripper sections through the main pipe (513) to keep the internal pressure of the fluid system dynamically consistent.

10. The rigid-flexible coupling spatial capture gripper based on active-passive composite drive according to any one of claims 1-9, characterized in that, The connecting portion (601) includes a connecting snap for quick plug-in connection with the end of the robot arm and a mounting flange for fixing to the gripper body (101).

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