Wrist exoskeleton mechanism for collecting three-degree-of-freedom posture of wrist

Abstract

The invention provides a wrist exoskeleton mechanism which comprises a plurality of shaft collection units, a first shaft collection unit comprises a wrist seat sleeve, a wrist bearing and a first encoder assembly, the wrist seat sleeve rotates around a first axis through the wrist bearing, and the first encoder assembly collects a first rotation angle of the first encoder assembly. The second axis acquisition unit comprises a first curve track and a second encoder assembly, the first curve track is sleeved with the second encoder assembly, and the second encoder assembly acquires a second rotation angle around a second axis. And the third axis acquisition unit comprises a second curve track and a third encoder assembly, the second curve track is fixed with the first curve track, and the third encoder assembly moves along the second curve track and rotates around a third axis so as to acquire a third rotation angle. And at the wrist rotation zero point position, the first axis and the third axis are both perpendicular to the second axis, and the three axes are always intersected at the same point and correspond to a roll (R) axis, a pitch (P) axis and a deflection (Y) axis of rotation of the wrist joint RPY respectively.

Description

Technical Field

[0001] This application relates to wearable device technology, and more particularly to a wrist exoskeleton mechanism for collecting three degrees of freedom postures of the wrist. Background Technology

[0002] With the rapid development of robotics, sensing technology, and materials science, wearable exoskeleton gloves are increasingly becoming a research focus in the field of humanoid robot big data acquisition. These devices, as important wearable human-computer interaction tools, are widely used in scenarios such as remote robot operation, high-precision motion capture and data acquisition, and rehabilitation training.

[0003] As a key part connecting the hand and forearm, the wrist involves complex coordination of multiple degrees of freedom in its movement patterns. Therefore, the core function of the wrist mechanism is to accurately capture the wrist's posture changes and rotation angle data, and effectively coordinate with finger movements to build a complete upper limb motion capture system.

[0004] In related technologies, exoskeleton devices typically employ a "parallel" structure at the wrist, resulting in a significant offset between the rotation axis center of the actual human wrist and the rotation axis center of the exoskeleton structure. This offset not only causes significant differences in movement range but also leads to frequent mechanical interference and singularity issues, resulting in decreased flexibility in motion acquisition and a substantial increase in data errors. Summary of the Invention

[0005] This application provides a wrist exoskeleton mechanism for acquiring three-degree-of-freedom wrist postures.

[0006] According to a first aspect of the embodiments of this application, a wrist exoskeleton mechanism for acquiring three-degree-of-freedom wrist postures is provided, comprising: a first axis acquisition unit, including a wrist seat, a wrist bearing, and a first encoder assembly, wherein the wrist seat is connected to the wrist bearing to achieve rotational movement around a first axis, and the first encoder assembly is used to acquire the rotation angle of the wrist seat around the first axis; a second axis acquisition unit, including a first curved track and a second encoder assembly, wherein the second encoder assembly is fixedly connected to the wrist seat, and the first curved track is sleeved within the second encoder assembly to slide under the constraint of the second encoder assembly to achieve rotational movement around a second axis, and the second encoder assembly is also used to acquire the rotation angle of the first curved track around the second axis; and a third axis acquisition unit, including a second curved track and a third encoder assembly, wherein the second curved track is fixedly connected to the first curved track, and the third encoder assembly is movable on the second curved track to achieve rotational movement around a third axis, and the third encoder assembly is used to acquire its own rotation angle around the third axis; at the zero point of wrist rotation, both the first axis and the third axis are perpendicular to the second axis, and the first axis, the second axis, and the third axis always intersect at the same point.

[0007] In some embodiments, the wrist exoskeleton mechanism includes two second-axis acquisition units, two second encoder assemblies of the two second-axis acquisition units are fixed at intervals on the wrist seat along the extension direction of the second axis; the two ends of the second curved track are respectively connected to two first curved tracks of the two second-axis acquisition units; the wrist exoskeleton mechanism also includes a track connector, the two ends of the track connector are respectively connected to the end of the first curved track away from the second curved track.

[0008] In some embodiments, the wrist seat is fixedly connected to the outer ring of the wrist bearing, the wrist seat has a through hole extending along the extension direction of the first axis, the user's forearm passes through the through hole, and the first axis coincides with the roll (R) axis of the user's wrist.

[0009] In some embodiments, the two first curved tracks, the second curved track, and the track connector together form a first receiving space, in which the user's wrist is received. The second axis coincides with the pitch (P) axis of the user's wrist, and the third axis coincides with the deflection (Y) axis of the user's wrist.

[0010] In some embodiments, the wrist exoskeleton mechanism further includes an end effector assembly connected to the third encoder assembly. The end effector assembly is used to connect to the user's fingers or palm, and when the user's wrist moves, the end effector assembly drives the second encoder assembly and / or the first curved track and / or the wrist seat to rotate.

[0011] In some embodiments, the generatrix of the first curved track is an arc, the line connecting the centers of the two generatrixes of the first curved track coincides with the second axis, and the two first generatrix planes containing the generatrixes of the two first curved tracks are parallel to each other.

[0012] In some embodiments, the generatrix of the second curved track is an arc, and the second generatrix plane containing the generatrix of the second curved track is perpendicular to the first generatrix plane, and the third axis is perpendicular to the second generatrix plane.

[0013] In some embodiments, the first encoder assembly, the second encoder assembly, and the third encoder assembly are one of a photoelectric encoder, a magnetoelectric encoder, or an inductive encoder.

[0014] In some embodiments, the second encoder assembly includes a first support unit and a first magnetic grating read head; the first curved track has a V-shaped cross-section, and the cross-section of the first curved track includes a first conical surface and a second conical surface arranged at an angle; the first support unit includes a first roller, a second roller, and a third roller, the first roller and the second roller respectively abutting against the first conical surface and the second conical surface, and the third roller abutting against the radially outer surface of the first curved track; the first curved track also includes a first magnetic grating extending along the generatrix of the first curved track, and the first magnetic grating read head is used to determine the arc position of the first curved track relative to the second encoder assembly based on its relative positional relationship with the first magnetic grating, so as to determine the rotation angle of the second shaft.

[0015] In some embodiments, the third encoder assembly includes a second support unit and a second magnetic grating read head; the cross-section of the second curved track is V-shaped, and the cross-section of the second curved track includes a third conical surface and a fourth conical surface arranged at an angle; the second support unit includes a fourth roller, a fifth roller, and a sixth roller, the fourth roller and the fifth roller respectively abutting against the third conical surface and the fourth conical surface, and the sixth roller abutting against the radially outer surface of the second curved track; the second curved track also includes a second magnetic grating extending along the generatrix of the second curved track, and the second magnetic grating read head is used to determine the arc position of the third encoder assembly relative to the second curved track based on its relative positional relationship with the second magnetic grating, so as to determine the rotation angle of the third shaft.

[0016] The technical solution provided by the embodiments of this application can include the following beneficial effects: by setting up mutually cooperating first, second, and third axis acquisition units, three-dimensional precise acquisition of wrist three-degree-of-freedom postures can be achieved, covering the rotation angles of the wrist around three orthogonal axes, meeting the needs of multi-degree-of-freedom posture acquisition. The first axis acquisition unit achieves stable rotation around the first axis through the cooperation of the wrist seat and the wrist bearing, and can accurately acquire the wrist roll direction rotation angle in conjunction with the first encoder assembly; the second and third axis acquisition units acquire the rotation angles around the second and third axes respectively through the sliding cooperation of the curved track and the encoder assembly, ensuring comprehensive acquisition dimensions. The three axes are perpendicular to each other and intersect at the same point, which is highly adapted to the human wrist movement trajectory, can truly restore the natural wrist movement posture, and reduce acquisition errors.

[0017] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0019] Figure 1 This is a schematic structure of the wrist exoskeleton mechanism provided in the embodiments of this application. Figure 1 ;

[0020] Figure 2 This is a schematic structure of the wrist exoskeleton mechanism provided in the embodiments of this application. Figure 2 ;

[0021] Figure 3 yes Figure 1 Side view of the wrist exoskeleton mechanism in the image;

[0022] Figure 4 yes Figure 1 AA section view;

[0023] Figure 5 yes Figure 1 BB cross-sectional view. Detailed Implementation

[0024] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0025] In the following description, references are made to “some embodiments,” which describe a subset of all possible embodiments. However, it is understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0026] If the application documents contain similar descriptions such as "first / second", the following explanation shall be added: In the following description, the terms "first / second / third" are used only to distinguish similar objects and do not represent a specific order of objects. It is understood that "first / second / third" may be interchanged in a specific order or sequence where permitted, so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.

[0027] Unless otherwise defined, all technical and scientific terms used in the embodiments of this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the embodiments of this application is for the purpose of describing the embodiments of this application only and is not intended to limit this application.

[0028] In fields such as human-computer interaction, rehabilitation training, motion capture, robot teleoperation, and proprioceptive data acquisition, accurate wrist posture acquisition is a core prerequisite for achieving precise control and status monitoring. As a key joint in human upper limb movement, the wrist exhibits complex motion patterns, primarily involving three degrees of freedom: roll, pitch, and yaw. These three degrees of freedom are coupled, placing extremely high demands on the flexibility, accuracy, and wearability of the posture acquisition mechanism. Especially in the field of proprioceptive data acquisition for large-scale humanoid robot models, due to the compact structure and multiple degrees of freedom at the wrist, traditional proprioceptive dexterity hand manipulation data acquisition typically avoids wrist posture acquisition. Instead, a spatial locator is placed on the back of the hand to collect the motion trajectory and posture as base coordinates. The wrist posture is then inversely solved by a 6-axis or 7-axis robotic arm algorithm (which suffers from problems such as inability to solve the problem or discontinuous trajectory). Using a back-of-hand locator also presents significant error problems: during dexterous hand manipulation, the palm's posture angle changes greatly, and the angular velocity is also high. Back-of-hand locators are susceptible to increased errors or even tracking loss due to excessively fast movement and visual obstruction. After acquiring wrist posture using the three-DOF exoskeleton structure of this invention, the spatial locator can be placed on the forearm. Compared to the palm, the forearm's posture angle changes and angular velocities are significantly reduced during dexterous hand manipulation. Therefore, obtaining the base coordinates through the spatial locator on the forearm significantly improves the accuracy and consistency of the overall data trajectory and posture. Furthermore, because the wrist's three-DOF posture data has been accurately acquired, subsequent data processing only requires inverse kinematics using a 4-axis or 5-axis robotic arm to obtain the complete posture and path of the dexterous hand in the absolute coordinate system of the acquisition space. Therefore, this invention plays a crucial role in improving trajectory accuracy, reducing inverse kinematics processing complexity, and increasing data availability in large-scale model data acquisition related to humanoid robot dexterous hands.

[0029] Wrist posture acquisition typically utilizes mechanical joint-driven acquisition mechanisms. These mechanisms constrain wrist movement through mechanical structures and use encoders to acquire joint rotation angles, resulting in high accuracy. However, existing structures often suffer from drawbacks such as coupled degrees of freedom, high mechanical friction, and poor fit. Furthermore, most mechanisms cannot achieve independent and accurate acquisition of the three degrees of freedom of the wrist posture, or they are complex and bulky, affecting normal wrist movement and making them unsuitable for long-term wear and practical applications. In addition, existing exoskeleton devices often employ a parallel structure at the wrist, leading to a significant offset between the rotation axis of the actual human wrist and the rotation axis of the exoskeleton structure. This offset not only causes significant differences in movement range but also results in frequent mechanical interference and singularity issues, greatly increasing the error in motion acquisition data and making it impossible to accurately reconstruct the actual wrist posture.

[0030] To address the aforementioned issues, this application provides a wrist exoskeleton mechanism that enables independent and precise acquisition of three degrees of freedom of wrist posture: roll, pitch, and yaw. It also features a compact structure and a comfortable fit, making it suitable for various applications such as human-computer interaction and rehabilitation training.

[0031] The technical solution of this application will now be described in detail with reference to the accompanying drawings. Figure 1 This is a schematic structural diagram of the wrist exoskeleton mechanism 100 provided in the embodiments of this application. Figure 1 The wrist exoskeleton mechanism 100 includes a first axis acquisition unit 110, a second axis acquisition unit 120, and a third axis acquisition unit 130.

[0032] The first axis acquisition unit 110 includes a wrist seat 111, a wrist bearing 112, and a first encoder assembly 113.

[0033] The wrist support 111 is cylindrical and has a through hole 1111 inside, through which the user's forearm can be inserted.

[0034] The wrist seat 111 is the basic load-bearing component of the entire wrist exoskeleton mechanism 100, providing an installation reference. The wrist seat 111 is connected to the wrist bearing 112, which can be a rolling bearing or a sliding bearing, to support the wrist seat 111 in rotational movement around a first axis (R-axis). More specifically, the wrist seat 111 can be fixedly connected to the outer ring of the wrist bearing 112, and the inner ring of the wrist bearing 112 can be fixed to the forearm support or wear base, so that the wrist seat 111 can rotate freely around the first axis.

[0035] The first encoder assembly 113 is a sensing component for roll attitude acquisition, and its main function is to determine the rotation angle of the wrist seat 111. For example, the first encoder assembly 113 can be an incremental encoder, which can convert mechanical rotational motion into detectable electrical signals. Incremental encoders have advantages such as fast response speed, high acquisition accuracy, simple structure, and moderate cost, and can convert the mechanical rotational motion of the wrist seat 111 into detectable and transmittable electrical signals, providing accurate raw data for subsequent attitude calculation.

[0036] In this embodiment of the application, the first encoder assembly 113 can be fixed on the wrist seat 111 and rotate synchronously with the wrist seat 111. During the rotation of the wrist seat 111, the first encoder assembly 113 indirectly obtains the rotation angle of the wrist seat 111 by detecting the rotation angle of the inner ring of the wrist bearing 112 relative to the outer ring, thereby accurately obtaining the roll posture data of the wrist.

[0037] In practical applications, the user places their arm through the through-hole 1111 of the wrist seat 111 and adjusts the forearm position to ensure a tight fit between the wrist seat 111 and the forearm. During a rolling motion of the wrist, the wrist seat 111 rotates around the first axis. At this time, the first encoder assembly 113 acquires the rotation angle of the first axis of the wrist seat 111 in real time and transmits the acquired angle electrical signal to the external control unit. The external control unit can quickly and accurately acquire the user's wrist rolling posture through simple attitude calculation.

[0038] The second-axis acquisition unit 120 is the core component for wrist pitch attitude acquisition. Its main function is to acquire the rotation angle of the wrist around the second axis (P-axis), and at the same time provide a stable mounting base for the third-axis acquisition unit 130, realizing the coordinated linkage of multiple acquisition units. The second-axis acquisition unit 120 includes a first curved track 121 and a second encoder assembly 122.

[0039] The first curved track 121 can cooperate with the second encoder assembly 122 to realize rotational movement around the second axis. At the same time, the first curved track 121 also provides an installation base for the second curved track 131 in the subsequent third axis acquisition unit 130.

[0040] The second encoder assembly 122 is fixed on the wrist seat 111. On the one hand, it is used to constrain the movement trajectory of the first curved track 121, so that the first curved track 121 can rotate around the second axis when sliding relative to the second encoder assembly 122. On the other hand, the second encoder assembly 122 is used to collect the rotation angle of the first curved track 121 around the second axis.

[0041] In practical applications, when a user's wrist makes a pitching motion, the first curved track 121 will rotate around the second axis. At this time, the second encoder assembly 122 is used to determine the rotation angle of the second axis of the first curved track 121, thereby realizing the acquisition of the user's wrist pitch posture.

[0042] The third-axis acquisition unit 130 is a key unit for achieving full-coverage acquisition of the wrist's three degrees of freedom postures. Its main function is to accurately acquire the wrist's rotation angle around the third axis (Y-axis). Working in conjunction with the first-axis acquisition unit 110 and the second-axis acquisition unit 120, it completes the acquisition of the wrist's roll, pitch, and yaw postures. The third-axis acquisition unit 130 includes a second curved track 131 and a third encoder assembly 132.

[0043] The second curved track 131 and the first curved track 121 are fixedly connected and serve as the motion track of the third encoder assembly 132, providing sliding support for the third encoder assembly 132.

[0044] The third encoder assembly 132 can move on the second curved track 131 to achieve rotational motion around the third axis and acquire its own third axis rotation angle. For example, the second curved track 131 can be an arc track. The third encoder assembly 132 is provided with a slider and a sensor that cooperate with the guide rail. When the third encoder assembly 132 moves along the guide rail, the sensor detects its position change to determine the third axis rotation angle.

[0045] In specific application scenarios, when a user's wrist makes a deflection movement (i.e., the wrist swings left and right, such as swinging inward or outward towards the body), the force of the wrist movement is transmitted to the third encoder component 132, causing the third encoder component 132 to rotate synchronously around the third axis, with the motion trajectories of the two being completely consistent. At this time, the third encoder component 132 is used to collect its own third axis rotation angle in real time, and the angle electrical signal is transmitted to the external control unit. Through attitude calculation, the user's wrist deflection attitude can be accurately collected. This collected data, combined with roll and pitch attitude data, can achieve full coverage of the wrist's three degrees of freedom attitude.

[0046] In this embodiment, at the zero point of wrist rotation, both the first and third axes are configured to be perpendicular to the second axis. Furthermore, the first, second, and third axes always intersect at the same point. This geometric configuration simulates the natural physiological structure and movement patterns of the human wrist, ensuring that the rotation centers of the three degrees of freedom coincide spatially with the actual rotation center of the user's wrist, achieving complete decoupling of the three degrees of freedom. When the user performs complex movements such as roll, pitch, and yaw, multiple encoder components can capture the actual wrist movement posture, avoiding the problems of stroke differences, mechanical interference, and singularities caused by inconsistent rotation axis centers in traditional solutions.

[0047] In the embodiments of this application, it is understood that the first curved track 121 and the second curved track 131 can be formed from metallic materials, such as stainless steel or aluminum alloy, through precision machining such as CNC milling or wire cutting, and the surface is polished or hardened to ensure the geometric accuracy and surface smoothness of the arc generatrix. Alternatively, as an implementation method, the curved tracks can also be made of polymeric materials, such as engineering plastics or composite materials, manufactured by injection molding or 3D printing technology, and surface treated after molding to achieve the desired arc shape and surface properties.

[0048] In some embodiments, continue reading Figure 1To further improve the structural stability, smoothness of movement and acquisition accuracy of the mechanism, the wrist exoskeleton mechanism 100 includes two second axis acquisition units 120. The two second encoder assemblies 122 in the two second axis acquisition units 120 are spaced apart on the wrist seat 111 along the extension direction of the second axis.

[0049] The two ends of the second curved track 131 are respectively connected to the two first curved tracks 121 in the two second-axis acquisition units 120. The wrist exoskeleton mechanism also includes a track connector 140, the two ends of which are respectively connected to the ends of the two first curved tracks 121 away from the second curved track 131. In this way, the two first curved tracks 121, the second curved track 131, and the track connector 140 form a track assembly with an integral frame structure. This track assembly is connected to the wrist seat 111 by two encoder assemblies. It can also be understood that the two encoder assemblies are arranged at intervals along the second axis, which can constrain and support the track assembly from both sides, avoiding the problems of motion offset and jamming caused by unilateral support, and improving structural stability.

[0050] It should also be noted that the connection between the first curved track 121 and the second curved track 131 can be a detachable or semi-permanent connection, such as a pin connection, bolt connection, or snap-fit ​​connection, to facilitate manufacturing, assembly, maintenance, or replacement. Alternatively, the connection can be achieved through bonding, welding, or integral casting to form a tighter and seamless connection, reducing gaps and potential movement errors at the connection point. Similarly, the connection between the track connector 140 and the two first curved tracks 121 can be achieved through screw fastening, riveting, or welding to ensure the strength of the connection.

[0051] Based on the above technical means, by setting two second-axis acquisition units 120 and setting the curved track as an overall frame structure, balanced support is provided for the entire mechanism, the rigidity of the mechanism is improved, deformation or shaking caused by single-point force during movement is avoided, thereby reducing the probability of singularity.

[0052] In some embodiments, the wrist seat 111 is fixedly connected to the outer ring of the wrist bearing 112, and the inner ring of the wrist bearing 112 is fixed to the forearm support or wearing base. This ensures that the wrist seat 111 can rotate flexibly relative to the external support or wearing base, while ensuring the reliability of the connection and preventing loosening during rotation.

[0053] The wrist support 111 has a through hole 1111 extending along a first axis. This through hole 1111 allows the user's forearm to pass through and is fixed relative to the user's forearm. The through hole 1111 can be designed as circular, elliptical, or other geometric shapes suitable for the cross-sectional shape of the forearm to accommodate different user anatomy. For example, the inner wall of the through hole 1111 can be designed as a smooth surface to reduce friction with the forearm and improve wearing comfort. Furthermore, the size of the through hole 1111 can be designed to be adjustable, for example, by incorporating removable padding or a telescopic structure, to accommodate forearms of different sizes, thereby ensuring a close fit between the mechanism and the forearm.

[0054] The aforementioned first axis coincides with the roll axis of the user's wrist. This coincidence ensures that the mechanical rotation axis of the wrist exoskeleton mechanism 100 is consistent with the physiological motion axis of the user's wrist, thereby enabling direct and accurate measurement of the user's wrist roll angle. During mechanism design, the position of the first axis can be determined based on the average physiological dimensions and kinematic characteristics of the human wrist. During wear, the user can be guided to adjust the position of their forearm within the through-hole 1111 through visual markers, tactile feedback, or software calibration until the first axis achieves optimal coincidence with the user's wrist roll axis.

[0055] As a specific implementation, the wrist seat 111 can be made of lightweight, high-strength engineering plastics or aluminum alloys to balance comfort and structural strength. The wrist seat 111 is fixedly connected to the outer ring of the wrist bearing 112 using an interference fit, where the inner diameter of the wrist seat 111 is slightly smaller than the outer diameter of the outer ring of the wrist bearing 112. This is achieved through heating or press-fitting to form a secure connection. The through-hole 1111 extending along the first axis of the wrist seat 111 can be lined with a skin-friendly material such as medical-grade silicone or memory foam to improve user comfort and reduce skin friction. The cross-sectional shape of the through-hole 1111 can be designed as an ellipse to better conform to the natural shape of the forearm. To accommodate different forearm sizes, the inner diameter of the through-hole 1111 can be designed to be adjustable, for example, by providing removable pads of different thicknesses on the inner wall of the through-hole 1111, or by using a segmented design and adjusting bolts to change the effective diameter of the through-hole 1111. When the user wears the device, the forearm can be inserted through one end of the through hole 1111 until the wrist is located in the center area of ​​the wrist seat 111. To ensure that the first axis coincides with the roll axis of the user's wrist, calibration marks can be set on the outside of the wrist seat 111, and the virtual model on the software interface can guide the user to adjust the posture of the forearm so that the axis of the mechanism is visually aligned with the physiological axis of the user's wrist.

[0056] Through the above technical solution, the fixed connection between the wrist seat 111 and the outer ring of the wrist bearing 112 provides stable mechanical support for the wrist exoskeleton mechanism 100, effectively preventing loosening or displacement that may occur during movement, thereby ensuring the operational stability of the first axis acquisition unit 110. The through hole 1111 extending along the first axis on the wrist seat 111, combined with the user's forearm insertion, achieves a close fit between the wrist exoskeleton mechanism 100 and the user's body, ensuring that the mechanism can rotate synchronously with the user's wrist movement and avoiding relative displacement interference. The first axis coincides with the user's wrist roll axis. This solution fundamentally solves the problem of mismatch between the mechanical axis and the physiological axis in traditional wrist exoskeleton mechanisms 100, significantly eliminating data acquisition deviations and greatly improving the acquisition accuracy of the first axis rotation angle.

[0057] In some embodiments, continue reading Figure 1 The two first curved tracks 121, the second curved track 131, and the track connector 140 together form a first accommodating space, within which the user's wrist is accommodated. In this way, the wrist exoskeleton mechanism 100 can perfectly conform to the contour of the wrist, avoiding interference with the mechanism during wrist movement, while ensuring that the mechanism can synchronously follow wrist movements, thus improving the real-time performance and accuracy of data acquisition.

[0058] As one implementation method, the exoskeleton structure within the first receiving space does not need to conform to the wrist. This reduces collisions and interference during wrist movements and allows the overall wrist exoskeleton structure to adapt to individual wrist size differences. The movement of the wrist exoskeleton structure is driven by the end effector 150 connected to 132.

[0059] The aforementioned second axis coincides with the pitch axis of the user's wrist, and the third axis coincides with the deflection axis of the user's wrist, thereby ensuring that the second axis rotation angle acquired by the second axis acquisition unit 120 can accurately correspond to the actual pitch posture of the wrist, and the third axis rotation angle acquired by the third axis acquisition unit 130 can accurately correspond to the actual deflection posture of the wrist.

[0060] As one possible implementation, during the mechanism design, the central axis of the second-axis acquisition unit 120 is geometrically aligned with the pitch motion center of the user's wrist in its natural state, and this alignment is fine-tuned by adjusting the installation position or size of the mechanism. Alternatively, during wear, visual or tactile guidance can be used to ensure that the user's wrist pitch axis and the mechanism's second axis are spatially aligned as much as possible, for example, by setting alignment marks or adjustable support points on the mechanism. Similarly, for the third-axis acquisition unit 130, a reasonable structural design can be used to ensure that the motion axis of the third-axis acquisition unit 130 is geometrically coincident with the deflection motion center of the user's wrist, allowing for a certain range of adjustment to accommodate individual differences.

[0061] In some embodiments, see Figure 2 The wrist exoskeleton 100 also includes an end effector 150, which is a device for physical contact and connection with the user's limb end (such as fingers or palm). Its main function is to transmit the user's limb movement to the sensing components of the wrist exoskeleton 100 and provide wearing comfort and stability.

[0062] For example, the aforementioned end component 150 may be Figure 2 The finger sleeve assembly with a skeleton structure shown can be fitted onto the user's finger; or, the end component 150 can be a flexible or semi-flexible ring structure, such as a finger ring or palm rest made of elastic material, which is secured to the user's finger or palm by Velcro, snaps or elastic bands.

[0063] The end effector 150 is connected to the third encoder assembly 132. When the user's wrist makes a yaw motion, the end effector 150 moves, which in turn drives the third encoder assembly 132 to move, thereby collecting yaw attitude data through the third encoder assembly 132. When the user's wrist makes a pitch motion, the end effector 150, the third encoder assembly 132 connected to the end effector 150, the second curved track 131 fixed to the third encoder assembly 132, and the first curved track 121 connected to the second curved track 131 simultaneously perform pitch motion, and pitch attitude data can be collected by the second encoder assembly 122. When the user's wrist makes a roll motion, the end effector 150, the third encoder assembly 132, the second curved track 131, the first curved track 121, the second encoder assembly 122, and the wrist seat 111 simultaneously perform roll motion, and roll attitude data can be collected by the first encoder assembly 113.

[0064] In some embodiments, see Figures 1-3 The generatrix of the first curved track 121 is an arc, meaning that the first curved track 121 is arc-shaped as a whole, and its arc trajectory is consistent with the trajectory of the wrist pitching motion.

[0065] The line connecting the centers P3 and P4 of the generatrices of the two first curved tracks 121 coincides with the second axis. In other words, the line connecting the two centers P3 and P4 is the second axis. This ensures that the rotation centers of the two first curved tracks are consistent and their motion is synchronized, avoiding deviation or interference between the two tracks.

[0066] In addition, the two first generatrix planes on which the generatrixes of the two first curved tracks 121 lie are parallel to each other, which ensures the symmetry and motion stability of the two first curved tracks 121 and prevents interference caused by track twisting.

[0067] In some embodiments, see Figure 1 and Figure 2 The generatrix of the second curved track 131 is also an arc, that is, the second curved track 131 is arc-shaped as a whole. Its arc trajectory is consistent with the trajectory of the wrist deflection movement, and its radius is consistent with the radius of the wrist deflection movement, ensuring that the third encoder component 132 can slide smoothly along the second curved track 131 when the user's wrist makes a deflection movement.

[0068] The plane containing the generatrix of the second curved track 131 is perpendicular to the aforementioned first generatrix plane. In other words, the plane containing the second generatrix track is perpendicular to the plane containing the generatrix of the first curved track 121. This perpendicularity ensures that the motions of the second and third axes are geometrically orthogonally decoupled. This allows the pitch motion (acquired by the second axis) and yaw motion (acquired by the third axis) of the wrist to be performed independently without interference, thereby improving the accuracy of attitude acquisition and matching the physiological motion axes (pitch and yaw axes) of the human wrist. It can also directly correspond to the operations of the three-degree-of-freedom wrist part of an isomorphic robot arm.

[0069] See Figures 1-3 The center of the generatrix of the second curved track 131 is P2, and the line connecting this center to point P0 is the third axis. The rotation center of the wrist seat 111 is P1, and the line connecting this point to P0 is the first axis. Point P0 is the intersection of the first axis, the second axis, and the third axis.

[0070] Figure 4 yes Figure 1 AA sectional view, see Figure 4 In some embodiments of this application, the second encoder assembly 122 includes a first support unit 1221 and a first magnetic grating read head (not shown). The cross-section of the first curved track 121 is V-shaped, and the cross-section includes a first conical surface 1211 and a second conical surface 1212 arranged at an angle. The first support unit 1221 includes a first roller 12211, a second roller 12212 and a third roller 12213. For example, the number of the first roller 12211 and the second roller 12212 can be two, and the four rollers form a structure similar to a cart. The first roller 12211 and the second roller 12212 abut against the first conical surface 1211 and the second conical surface 1212 respectively, and the third roller 12213 abuts against the radial outer surface of the first curved track 121; the first curved track 121 also includes a first magnetic grating extending along the generatrix of the first curved track 121, used to determine the arc position of the first curved track 121 relative to the second encoder assembly 122 according to the relative positional relationship with the first magnetic grating, so as to determine the rotation angle of the second shaft.

[0071] More specifically, the first support unit 1221 is used to provide mechanical support for the first curved track 121, ensuring that the first curved track 121 remains stable during operation. The first support assembly may consist of a set of precision rollers or bearings, which restrict the degree of freedom of movement by contacting the track surface, so that the curved track 121 can only slide smoothly along the arc direction of the generatrix of the curved track 121.

[0072] A magnetic grating read head is a non-contact sensing element that can be implemented based on the magnetoresistive effect, Hall effect, or magnetic induction principle. It outputs an electrical signal by sensing changes in the magnetic field of the magnetic grating.

[0073] like Figure 4 As shown, the first curved track 121 has a V-shaped cross-section, which includes a first conical surface 1211 and a second conical surface 1212 set at a specific angle, such as 120° as shown in the figure. This angle design provides precise guidance and constraint for the roller. The radially outer surface of the first curved track 121 provides a contact surface for radial support and guidance.

[0074] In the first support unit 1221, the first roller 12211 and the second roller 12212 abut against the first conical surface 1211 and the second conical surface 1212, respectively, providing constraint on the first curved track 121 along the extension direction of the second axis. The third roller 12213 abuts radially against the first arc surface, providing radial support for the first curved track 121. This multi-point roller abutment structure ensures that the first curved track 121 is strictly limited to the arc direction along the generatrix of the curved track 121 during movement.

[0075] The first magnetic grating can be a magnetic coding stripe extending along the generatrix of the first curved track 121, and can be composed of periodically arranged magnetic poles, moving synchronously with the first curved track 121. By sensing the change in the magnetic field of the first magnetic grating, the first magnetic grating reader can determine the arc displacement of the first curved track 121 relative to the second encoder assembly 122 in a non-contact manner, and thus accurately calculate the rotation angle of the second shaft.

[0076] As a specific implementation, the roller structures in the first support unit 1221 are made of high-strength engineering plastics (such as polyoxymethylene or polyetheretherketone) to form the frame, and miniature stainless steel bearings are used directly for the wheels to ensure low friction and high wear resistance.

[0077] According to the above technical means, the first support unit 1221 with multi-point roller contact design provides reliable motion restriction and stable mechanical support for the sliding of the first curved track 121; the non-contact measurement system composed of the first magnetic grating and the first magnetic grating reading head can obtain the arc position of the first curved track 121 in real time with high resolution and repeatability, avoiding the mechanical wear and error accumulation that may be introduced by traditional contact measurement.

[0078] Figure 5 yes Figure 1 BB sectional view, see Figure 5 In some embodiments of this application, the third encoder assembly 132 includes a second support unit 1321 and a second magnetic grating read head (not shown). The cross-section of the second curved track 131 is V-shaped, and the cross-section of the second curved track 131 includes a third conical surface 1311 and a fourth conical surface 1312 arranged at an angle.

[0079] The second support unit 1321 includes a fourth roller 13211, a fifth roller 13212, and a sixth roller 13213. For example, there may be two fourth rollers 13211 and two fifth rollers 13212, forming a trolley-like structure. The fourth roller 13211 and the fifth roller 13212 abut against the third conical surface 1311 and the fourth conical surface 1312, respectively, while the sixth roller 13213 abuts against the radially outer surface of the second curved track 131. The second curved track 131 also includes a second magnetic grating extending along its generatrix. The second magnetic grating reader is used to determine the arcuate position of the third encoder assembly 132 relative to the second curved track 131 based on its relative position to the second magnetic grating, thereby determining the rotation angle of the third shaft.

[0080] The second support unit 1321 provides mechanical support for the third encoder assembly 132, enabling it to move along the extension direction of the second curved track 131. The second support unit 1321 may consist of a set of precision rollers or bearings, which restrict the degree of freedom of movement by contacting the track surface, so that the curved track 131 can only slide smoothly along the arc direction of the generatrix of the curved track 131.

[0081] like Figure 5 As shown, the second curved track 131 has a V-shaped cross-section, which includes a third conical surface 1311 and a fourth conical surface 1312 set at a specific angle, such as 120°. This angle design provides precise guidance and constraint for the roller. The radially outer surface of the second curved track 131 provides a contact surface for radial support and guidance.

[0082] The fourth roller 13211 and the fifth roller 13212 in the second support unit 1321 abut against the third conical surface 1311 and the fourth conical surface 1312, respectively, providing constraint on the second curved track 131 along the extension direction of the second axis. The sixth roller 13213 abuts against the radially outer surface of the second curved track 131 to provide radial support. This multi-point roller abutment structure allows the third encoder assembly 132 to be strictly limited in the arc direction along the generatrix of the curved track 131 during movement.

[0083] The second magnetic grating can be a magnetic coding stripe extending along the generatrix of the second curved track 131, and can be composed of periodically arranged magnetic poles. When the second magnetic grating read head moves with the second support unit 1321, it can determine the arc displacement of the second magnetic grating relative to the second curved track 131 in a non-contact manner by sensing the change in the magnetic field of the second magnetic grating, and then accurately calculate the rotation angle of the third axis.

[0084] It should be understood that the phrase "one embodiment" or "an embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of this application. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It should be understood that in the various embodiments of this application, the sequence numbers of the above steps / processes do not imply a sequential order of execution; the execution order of each step / process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application. The sequence numbers of the above embodiments of this application are merely descriptive and do not represent the superiority or inferiority of the embodiments.

[0085] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0086] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0087] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0088] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0089] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0090] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0091] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A wrist exoskeleton mechanism for acquiring three-degree-of-freedom wrist postures, characterized in that, include: The first axis acquisition unit includes a wrist sleeve, a wrist bearing, and a first encoder assembly. The wrist sleeve is connected to the wrist bearing to realize rotational movement around a first axis. The first encoder assembly is used to acquire the rotation angle of the wrist sleeve around the first axis. The second axis acquisition unit includes a first curved track and a second encoder assembly. The second encoder assembly is fixedly connected to the wrist seat. The first curved track is sleeved inside the second encoder assembly and slides under the constraint of the second encoder assembly to achieve rotational movement around the second axis. The second encoder assembly is also used to acquire the rotation angle of the first curved track around the second axis. The third axis acquisition unit includes a second curved track and a third encoder assembly. The second curved track is fixedly connected to the first curved track. The third encoder assembly can move on the second curved track to achieve rotational motion around the third axis. The third encoder assembly is used to acquire its own rotation angle around the third axis. At the zero point of wrist rotation, both the first axis and the third axis are perpendicular to the second axis. The first axis, the second axis, and the third axis always intersect at the same point. The first axis, the second axis, and the third axis correspond to the roll (R) axis, pitch (P) axis, and yaw (Y) axis in the RPY rotation of the wrist joint, respectively.

2. The wrist exoskeleton mechanism according to claim 1, characterized in that, The wrist exoskeleton mechanism includes two second axis acquisition units, and two second encoder assemblies in the two second axis acquisition units are fixed at intervals on the wrist seat along the extension direction of the second axis. The two ends of the second curved track are respectively connected to the two first curved tracks in the two second axis acquisition units; The wrist exoskeleton mechanism also includes a track connector, the two ends of which are respectively connected to the end of the first curved track away from the second curved track.

3. The wrist exoskeleton mechanism according to claim 2, characterized in that, The wrist seat is fixedly connected to the outer ring of the wrist bearing. The wrist seat has a through hole extending along the extension direction of the first axis. The user's forearm passes through the through hole. The first axis coincides with the roll (R) axis of the user's wrist.

4. The wrist exoskeleton mechanism according to claim 2, characterized in that, The two first curved tracks, the second curved track, and the track connector together form a first receiving space, in which the user's wrist is received. The second axis coincides with the pitch (P) axis of the user's wrist, and the third axis coincides with the deflection (Y) axis of the user's wrist.

5. The wrist exoskeleton mechanism according to claim 2, characterized in that, It also includes an end effector assembly connected to the third encoder assembly. The end effector assembly is used to connect to the user's finger or palm. When the user's wrist moves, the end effector assembly drives the second encoder assembly and / or the first curved track and / or the wrist seat to rotate.

6. The wrist exoskeleton mechanism according to any one of claims 2-5, characterized in that, The generatrix of the first curved track is an arc, the line connecting the centers of the two generatrixes of the first curved track coincides with the second axis, and the two first generatrix planes containing the generatrixes of the two first curved tracks are parallel to each other.

7. The wrist exoskeleton mechanism according to claim 6, characterized in that, The generatrix of the second curved track is an arc, and the second generatrix plane containing the generatrix of the second curved track is perpendicular to the first generatrix plane, and the third axis is perpendicular to the second generatrix plane.

8. The wrist exoskeleton mechanism according to any one of claims 1-5, characterized in that, The first encoder assembly, the second encoder assembly, and the third encoder assembly are one of photoelectric encoders, magnetoelectric encoders, or inductive encoders.

9. The wrist exoskeleton mechanism according to claim 7, characterized in that, The second encoder assembly includes a first support unit and a first magnetic grating read head; The cross-section of the first curved track is V-shaped, and the cross-section of the first curved track includes a first conical projection and a second conical projection set at an angle. The first support unit includes a first roller, a second roller, and a third roller. The first roller and the second roller abut against the first conical surface and the second conical surface, respectively, and the third roller abuts against the outer radial surface of the first curved track. The first curved track further includes a first magnetic grating extending along the generatrix of the first curved track. The first magnetic grating read head is used to determine the arc position of the first curved track relative to the second encoder assembly based on its relative positional relationship with the first magnetic grating, so as to determine the rotation angle of the second shaft.

10. The wrist exoskeleton mechanism according to claim 7, characterized in that, The third encoder assembly includes a second support unit and a second magnetic grating read head; The cross-section of the second curved track is V-shaped, and the cross-section of the second curved track includes a third conical projection and a fourth conical projection set at an angle; The second support unit includes a fourth roller, a fifth roller, and a sixth roller. The fourth roller and the fifth roller abut against the third conical surface and the fourth conical surface, respectively, and the sixth roller abuts against the outer radial surface of the second curved track. The second curved track also includes a second magnetic grating extending along the generatrix of the second curved track. The second magnetic grating read head is used to determine the arc position of the third encoder assembly relative to the second curved track based on its relative positional relationship with the second magnetic grating, so as to determine the rotation angle of the third shaft.

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