A rope-driven dexterous hand force-position fusion measurement device and method based on series torsional spring angle difference

Abstract

A kind of rope-driven dexterous hand force-position fusion measuring device and method based on series torsion spring angle difference. It relates to the technical field of rope-driven dexterous hand force-position sensing, aiming at the problems that the existing rope-driven dexterous hand joint side sensor arrangement is complex, the rear vision measurement occupies large space and it is difficult to synchronously obtain the rope tension and displacement, the following scheme is proposed: the module includes a fixed support, a power unit, a rotary elastic element, a winding winch, a traction rope, a rope guide structure, a winch position sensor and a control unit, the rotary elastic element is connected in series between the output end of the power unit and the winding winch, the control unit obtains the rope tension according to the difference between the power end angle and the winch end angle, and obtains the rope winding and unwinding displacement according to the winch end angle. The present application is suitable for driving measurement, state estimation, contact sensing and compliant control of rope-driven dexterous hand.

Description

Technical Field

[0001] This invention relates to the fields of robot mechanical system design, rope-driven dexterous hands, tendon transmission mechanisms, series elastic measurement mechanisms, force-position fusion perception, and robot hand state estimation. Specifically, it relates to a compact force-position fusion drive measurement module for rope-driven dexterous hands, a multi-degree-of-freedom dexterous hand system based on the module, and a method for perceiving joint states, contact states, grasping states, and external disturbance states using the rope tension and rope displacement information output by the module. Background Technology

[0002] With the development of robotics technology, dexterous hands are increasingly being applied to precision grasping, human-computer interaction, service robots, humanoid manipulation, flexible assembly, and end-effector tasks in complex environments. Compared to traditional two-finger grippers, dexterous hands typically have more degrees of freedom and more complex finger movements, enabling them to perform actions such as grasping, pinching, twisting, plucking, pushing, delivering, and tool manipulation. To achieve these complex operations, dexterous hands not only need to control the position of the finger joints but also need to sense joint forces, rope tension, contact states, and changes in external loads in order to provide compliant control, overload protection, and stability assessment during the grasping process.

[0003] In existing dexterous hand structures, tethered or tendon-driven methods are common technical approaches. These structures typically place the motor, servo motor, or other power units on the hand base or away from the finger joints, then transmit power to the finger joints via traction ropes, pulleys, guide holes, guide grooves, or guide sleeves. Because the drive components can be rear-mounted, tethered dexterous hands can reduce the structural volume at the finger joints, making the fingers lighter and suitable for multi-degree-of-freedom, miniaturized, and anthropomorphic robotic hand structures. However, the control accuracy and interactivity of tethered structures largely depend on measurements of rope extension and retraction displacement, rope tension, and finger joint states. Estimating these based solely on the output angle of the power unit or control commands is susceptible to the effects of rope elastic elongation, transmission backlash, friction, changes in winding radius, and external contact loads, making it difficult to accurately reflect the actual movement and force state of the fingers.

[0004] To obtain the state of finger joints, a common approach is to directly place angle encoders, torque sensors, pressure sensors, or other force sensors at the finger joints. This method can directly obtain information on joint angles, joint torques, or contact forces. However, for multi-degree-of-freedom dexterous hands, the number of finger joints is large, and the internal space of each joint is limited. Placing an independent sensor at each joint significantly increases the joint size, the number of wiring, the number of power supply and signal acquisition channels, and increases assembly complexity and system cost. Especially in miniaturized or high-degree-of-freedom dexterous hands, the large number of joint-side sensors can also affect the structural strength, movement flexibility, and long-term reliability of the fingers, making it difficult to achieve multi-joint, multi-channel integration within a limited space.

[0005] To reduce the number of joint-side sensors, existing technologies include placing the measurement unit within the hand base or drive base. For example, a tension spring can be connected in series in the cable transmission path, and the cable tension can be calculated from the axial deformation of the spring. Alternatively, a visual measurement structure can be formed using a camera, plane mirror, light shield, light source, or marker points to observe the spring extension or cable displacement. This approach avoids directly placing force sensors at each finger joint to some extent and obtains indirect information about cable tension or joint status through rear-mounted measurement. However, because the tension spring needs to generate measurable axial extension along the straight segment of the cable, and the visual measurement structure needs to reserve space for the camera's field of view, reflected light path, light shielding space, and marker recognition area, it occupies a significant amount of internal space in the hand base, making it difficult to further compress the base's height and lateral dimensions. For dexterous hands that require multiple drive and measurement channels to be arranged within the hand base, this space occupancy issue directly limits the number of modules, channel density, and overall miniaturization.

[0006] Meanwhile, visual measurement schemes are also affected by factors such as sampling frequency, image resolution, lens distortion, lighting conditions, occlusion relationships, and image processing latency in practical applications. When the system requires high dynamic response, increasing the camera frame rate often reduces the available image resolution; when the system requires high displacement recognition accuracy, it may increase the image processing burden and reduce real-time performance. For elastic elements with high stiffness, the elastic deformation corresponding to changes in rope tension is small, and insufficient visual resolution will limit the accuracy of tension measurement. For multi-channel rope-driven dexterous hands, the arrangement of multiple elastic elements and ropes can easily lead to occlusion or field-of-view overlap problems, further increasing the difficulty of structural design and signal processing. Therefore, relying solely on visual observation of elastic deformation is difficult to simultaneously achieve compact hand base, high-density multi-channel integration, and high-frequency, high-resolution measurement of rope tension and displacement.

[0007] Furthermore, existing series elastic measurement structures typically focus on placing an elastic element between the actuator and the load, estimating the actuator's output force or torque through elastic deformation. While such structures can achieve a certain degree of force sensing, their direct application to rope-driven dexterities still falls short of fully addressing the unique challenges of rope-driven scenarios. On one hand, rope-driven dexterities require not only output force but also simultaneous rope extension and retraction displacement to further calculate joint angles, joint velocities, or fingertip poses. On the other hand, multi-DOF dexterities often require multiple identical or similar drive measurement channels compactly arranged within the hand base. Ordinary single-axis series elastic measurement structures do not adequately consider the coordination between the winch, rope guide, displacement measurement reference, and multi-channel array arrangement. Therefore, simply applying existing series elastic force measurement concepts to rope-driven dexterities often only yields single force or torque information, failing to adequately achieve simultaneous measurement of rope tension and extension / retraction displacement, and hindering the comprehensive estimation of joint states, contact states, grasping states, and external disturbance states.

[0008] In summary, existing technologies suffer from drawbacks such as large space requirements for joint-side sensor placement in rope-driven dexterous hands, complex wiring and assembly, the need to reserve space for spring linear extension and optical measurement in rear-mounted vision measurement schemes, difficulty in achieving multi-channel high-density integration within a compact hand base, and difficulty in simultaneously obtaining rope tension and rope extension / retraction displacement through the same compact module to support hand status perception. Summary of the Invention

[0009] To address the shortcomings of existing technologies, such as the large space required for sensor placement on the joint side of the rope-driven dexterous hand, complex wiring and assembly, the need to reserve space for spring linear extension and optical measurement in rear-mounted vision measurement schemes, the difficulty in achieving multi-channel high-density integration within a compact hand base, and the difficulty in simultaneously obtaining rope tension and rope extension / retraction displacement through a single compact module to support hand status sensing, the technical solution provided by this invention is as follows: A compact force-position fusion drive measurement module for rope-driven dexterous hands includes a fixed support, a power unit, a rotating elastic element, a winding winch, a traction rope, a rope guide structure, a winch position sensor, and a control unit. The power unit is mounted on the fixed support, the winding winch is rotatably mounted on the fixed support, and the rotating elastic element is disposed between the output end of the power unit and the winding winch. The rotating elastic element has a first connecting part and a second connecting part. The first connecting part is connected to the output end of the power unit, and the second connecting part is connected to the winding winch, so that the power unit, the rotating elastic element and the winding winch constitute a series rotating transmission structure. The traction rope is connected to the winding winch and led out through the rope guide structure to the finger joints of the rope-driven dexterous hand. The winding winch is used to rotate and retract the traction rope as the power unit outputs. The power unit is equipped with a first angle measuring unit for acquiring the angle of the power end, and the winch position sensor is correspondingly set with the winding winch for acquiring the angle of the winch end; The control unit is connected to the first angle measuring unit, the winch position sensor and the power unit respectively. The control unit obtains the torsional deformation of the rotating elastic element based on the relative angle difference between the power end angle and the winch end angle, and obtains the winding and unwinding displacement of the traction rope based on the winch end angle.

[0010] Furthermore, in a preferred embodiment, the rotating elastic element is arranged coaxially or nearly coaxially with the winding winch, and the rotating elastic element is sleeved on the output shaft of the power unit, the winch shaft or connecting shaft of the winding winch, the first connecting part is fixedly connected to the output end of the power unit, and the second connecting part is fixedly connected to the winding winch.

[0011] Furthermore, in a preferred embodiment, the winding winch is mounted on the fixed support via a bearing, bushing, or low-friction support structure, and the outer periphery of the winding winch is provided with a winding groove for fixing or winding the traction rope.

[0012] Furthermore, in a preferred embodiment, the winch position sensor includes a magnet coaxially fixed with the winding winch and a magnetic encoding chip mounted on the fixed support or circuit board, the magnetic encoding chip being connected to the control unit.

[0013] Furthermore, in a preferred embodiment, the rope guiding structure includes one or more of a guide pulley, a guide hole, a guide groove, or a guide sleeve, and the rope guiding structure is disposed on the traction rope guide path between the winding winch and the finger joint.

[0014] A force-position fusion measurement device for a rope-driven dexterous hand based on series torsion spring angle difference includes a palm base, multiple traction ropes, multiple finger joints, and multiple compact force-position fusion drive measurement modules as described above for rope-driven dexterous hands. Multiple compact force-position fusion drive measurement modules are disposed within the palm base and arranged along the length direction, width direction, annular direction, or layered direction of the palm base; Each of the compact force-position fusion drive measurement modules corresponds to at least one traction rope. One end of the traction rope is connected to the winding winch of the corresponding compact force-position fusion drive measurement module, and the other end is connected to the finger joint via the rope guide structure of the corresponding compact force-position fusion drive measurement module. Each of the compact force-position fusion drive measurement modules obtains the tension of the corresponding traction rope based on the relative angle difference between the power end angle and the winch end angle, and obtains the winding and unwinding displacement of the corresponding traction rope based on the winch end angle. The rope-driven dexterous hand force-position fusion measurement device based on the series torsion spring angle difference obtains the joint state, contact state, grasping state or external disturbance state of the finger joints according to the tension and release displacement of the multiple traction ropes.

[0015] A method for force-position fusion measurement of a rope-driven dexterous hand based on the angle difference of a series torsion spring, the method being implemented using the aforementioned force-position fusion measurement device for a rope-driven dexterous hand, comprising: The power end angle of the power unit in each compact force-position fusion drive measurement module is collected, and the winch end angle of the corresponding winding winch is also collected. The torsional deformation of the corresponding rotating elastic element is obtained based on the relative angle difference between the power end angle and the winch end angle. Based on the torsional deformation and the pre-calibrated torsional stiffness of the rotating elastic element, the output torque on the corresponding winding winch side is obtained, and the tension of the corresponding traction rope is obtained based on the output torque. The release and take-up displacement of the corresponding traction rope is obtained based on the change in the angle of the winch end and the equivalent radius of the corresponding winding winch. The tension and release displacement of the multiple traction ropes are used to form force-position fusion measurement data, and the joint state, contact state, grasping state or external disturbance state of the rope-driven dexterous hand are obtained based on the force-position fusion measurement data.

[0016] A computer storage medium for storing a computer program, which, when read by the computer, is executed by the computer using the method described thereon.

[0017] A computer, including a processor and a storage medium, executes the method when the processor reads a computer program stored in the storage medium.

[0018] A computer program product, which, as a computer program, implements the method when the computer program is executed.

[0019] Compared with the prior art, the advantages of the technical solution provided by the present invention are as follows: By placing the rotating elastic element between the power unit output and the winch, a series rotational transmission chain is formed between the power unit output, the rotating elastic element, and the winch. This concentrates the elastic deformation caused by the rope load onto the relative angle between the power end and the winch end, rather than using a tension spring on the straight section of the rope to generate axial expansion and contraction. Therefore, the force measurement structure no longer relies on the linear travel of the spring, and there is no need for additional observation space around the linear spring. This facilitates reducing the internal height and lateral dimensions of the hand base, and makes it easier to miniaturize and integrate the drive measurement unit of the rope-driven dexterous hand.

[0020] The winch serves as both the actuator for winding and releasing the traction rope and the reference for measuring rope displacement, eliminating the need for additional linear displacement sensors or visual measurement devices to obtain rope displacement. The winch rotation directly corresponds to the winding or releasing of the traction rope. The control unit only needs to calculate the rope winding and releasing displacement based on the winch end angle and the winch's equivalent radius, thereby reducing the number of independent displacement measurement mechanisms, lowering the complexity of additional structures along the rope path, and improving the consistency between displacement measurement and actual rope winding and releasing actions.

[0021] The power unit is equipped with a first angle measurement unit, and the winch is equipped with a second angle measurement unit, enabling the angles at the power end and the winch end to be obtained separately. The relative angle difference between the two reflects the torsional deformation of the rotating elastic element. This structure converts the elastic deformation required for force measurement into a differential result of two rotation angle signals, avoiding the influence of camera frame rate, image resolution, lighting, occlusion, and image processing delay on the force measurement results in visual measurement. This makes rope tension measurement more suitable for high-frequency sampling and real-time control.

[0022] The control unit determines the torsional deformation of the rotating elastic element based on the relative angular difference between the power end angle and the winch end angle, and calculates the output torque on the winch side and the tension of the traction rope based on the torsional stiffness of the rotating elastic element, thus providing a clear mechanical transmission basis for obtaining the rope tension. Compared with methods that estimate the load solely based on the power unit current or control commands, this scheme directly uses the elastic relative displacement between the power end and the winch end to characterize the actual load change, reducing the interference of rope friction, transmission clearance, and joint contact state changes on tension judgment and improving the reliability of rope tension measurement.

[0023] The control unit simultaneously calculates the traction rope's extension and retraction displacement based on the winch end angle, enabling the same drive measurement module to synchronously output the traction rope tension and displacement. This feature means that this is not simply a series elastic force measurement structure, but rather unifies the force measurement reference and displacement measurement reference into the rope drive execution link. It can simultaneously serve joint torque estimation, joint angle estimation, contact judgment, and gripping status judgment, solving the problem that ordinary single-axis series elastic measurement structures can only focus on output force or output torque and cannot take into account rope displacement sensing.

[0024] The rotating elastic element and the winding winch are arranged coaxially or nearly coaxially and can be mounted on the output shaft of the power unit, the winch shaft, or the connecting shaft, so that the torsional elastic structure, the winch structure, and the angle measurement structure are compactly integrated along the rotation axis. Compared with the arrangement of tension springs along the rope direction, this arrangement can reduce the requirements for linear length and optical cavity of the module within the palm base, making it easier to install multiple drive measurement modules side by side, in layers, or in an array in a limited space.

[0025] The winch is mounted on a fixed support via bearings, bushings, or a low-friction support structure, enabling the winch to generate an elastic relative angle with respect to the output end of the power unit, constrained by a rotating elastic element. This support structure ensures that the winch has a stable rotational measurement reference and prevents yaw, friction jamming, or uncontrolled displacement during winch rotation from affecting the angle difference results, thereby improving the stability of tension calculation and rope displacement calculation.

[0026] The second angle measuring unit can employ a magnetic encoder, with the magnet coaxially fixed to the winch and the magnetic encoding chip fixed to a support or circuit board. This allows for the acquisition of the absolute angle at the winch end within a smaller installation space. This structure eliminates the need for a camera, a mirror reflection path, and an external light source, as well as complex optical recognition components around the rope. It reduces the sensitivity of the measuring structure to ambient light, occlusion, and assembly posture, and is more suitable for installation inside enclosed or compact palm-sized bases.

[0027] The traction rope is wound or fixed to a winch and connected to one or more finger joints via pulleys, guide holes, guide grooves, or guide sleeves, forming a continuous mechanical transmission link for power output, rope winding and unwinding, tension measurement, and joint actuation. This rope guiding structure decouples the module placement from the finger joint positions, allowing the drive and measurement modules to be centrally located within the palm base while still transmitting traction force to different finger joints, thereby reducing the space occupied by joint-side sensors and drive components.

[0028] The pre-tensioning structure is used to set the initial pre-torsion angle of the rotating elastic element and the initial tension of the traction rope, enabling the module to achieve a stable initial working state after assembly or calibration. By pre-establishing the initial tension through structures such as adjustable end caps, ratchet adjusters, adjusting screws, positioning grooves, or rotating adjusting rings, the influence of rope slack, zero-point drift, and assembly errors on tension measurement can be reduced, allowing the difference between the power end angle and the winch end angle to more accurately correspond to actual load changes.

[0029] Mechanical limiting structures or overload protection structures are used to limit the maximum torsion angle of the rotating elastic element, preventing the torsion spring from continuing to deform excessively when the traction rope is overloaded, the joint jams, or there is an external impact. This structure enables the rotating elastic element to not only act as a force-measuring element, but also to provide a certain degree of mechanical compliance and protection, preventing sudden load changes from being directly transmitted to the power unit, winch, traction rope, and finger joints, thereby improving the safety and reliability of the rope-driven dexterous hand during grasping and contact processes.

[0030] When a transmission mechanism exists between the output end of the power unit and the input end of the rotating elastic element, the control unit converts the angle at the power end into an equivalent angle on the input side of the torsion spring or the winch side, and then performs a differential calculation with the angle at the winch end. This process enables the module to adapt to coaxial direct connection, reduction transmission, or other intermediate transmission structures, avoiding distortion in the calculation of torsional deformation due to differences in transmission ratio, transmission direction, and zero-point relationship, thereby improving the applicability of the module to different power units and different transmission layouts.

[0031] The winch can employ single-layer winding grooves, multi-layer winding grooves, spiral grooves, or variable radius profiles. The tension and release displacement of the traction rope are calculated using an equivalent radius or an equivalent radius function that varies with the winch angle. This feature allows the module to be suitable not only for constant radius winches but also for multi-turn windings, non-circular winches, or structures with varying winding radii. It avoids deviations in tension and displacement calculations caused by changes in the actual winding radius, improving measurement accuracy in different rope arrangement scenarios.

[0032] The control unit calculates the joint torque based on the tension of the traction rope and the equivalent force arm at the finger joint, or calculates the joint torque of multi-joint fingers based on the Jacobian relationship of the rope path, enabling the rope-side measurement results to be further converted into joint-side state information. This feature solves the problem of correlation between post-measurement results and finger joint control, allowing the drive measurement module set in the palm base to replace some joint-side force sensors, reducing the number of sensors and wiring complexity at the joints.

[0033] Multiple compact force-position fusion drive measurement modules are integrated in an array within the hand base. Each module corresponds to at least one traction rope, enabling the multi-degree-of-freedom rope-driven dexterous hand to form multiple drive and measurement channels through multiple identical modules. Since each module does not rely on a unified camera field of view, plane mirror reflection path, light shield, or light source, only necessary installation gaps, heat dissipation space, and rope guide paths need to be maintained between adjacent modules. Therefore, it is more conducive to achieving high-density arrangement within the limited space of the hand base.

[0034] The control unit synchronously acquires the power end angle and winch end angle of multiple modules, and calculates the tension and release displacement of each traction rope separately, enabling the dexterous hand to generate multiple tension vectors and multiple rope displacement vectors. This multi-channel data structure can reflect the force and motion state of multiple finger joints or multiple degrees of freedom. Compared with a single-channel force measurement structure, it is more suitable for supporting multi-finger collaborative grasping, contact judgment, grasping stability analysis, and external disturbance recognition.

[0035] The tension-displacement-time series is formed by combining the tension of the traction rope and the displacement of the traction rope during take-off and release. This allows the control unit to not only obtain the tension or displacement value at a certain moment, but also to observe the corresponding relationship between the two over time. By comparing the measured tension with the free-motion reference tension, it is possible to determine contact, changes in external load, or obstruction of joint movement when the tension residual, the rate of change of the residual, or the window statistic exceeds a threshold. This enables the rope-driven dexterous hand to obtain contact sensing capabilities without significantly increasing the number of joint-side sensors.

[0036] After contact, the relative stiffness of the object or contact environment is estimated based on the local slope of the tension-displacement curve, allowing the module's output information to be further used to determine the hardness or softness of the grasped object and the trend of contact changes. This feature enables the measurement results in this case to go beyond the feedback quantities in drive control, and also to serve grasping state estimation and compliance control, improving the adaptability of dexterous hands when facing different objects in unstructured environments.

[0037] By calibrating the torsional stiffness of the rotating elastic element, the initial relative angle offset, the equivalent radius of the winch or its equivalent radius function, and the mapping relationship between rope displacement and joint angle, a clear correspondence is established between the power end angle, winch end angle, rope tension, rope displacement, and joint state. This calibration system can compensate for errors caused by differences in assembly zero point, initial preload, rope winding radius, and joint transmission geometry, resulting in better reproducibility and measurement consistency for the same structural design across different modules, fingers, and dexterity hand systems.

[0038] It is suitable for multi-degree-of-freedom drive of rope-driven dexterous hands, synchronous measurement of rope tension and displacement, joint state estimation, contact sensing and compliant grasping control. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the overall structure of the present invention applied to a rope-driven dexterous hand.

[0040] Figure 2 This is a schematic diagram of the structure of a single force-position fusion drive measurement module.

[0041] Figure 3 This is a cross-sectional schematic diagram of a coaxial series structure of a power unit, a rotating elastic element, and a winding winch.

[0042] Figure 4 This is a schematic diagram of the installation structure of the winch position sensor.

[0043] Figure 5 This is a schematic diagram of the array arrangement of multiple force-position fusion drive measurement modules within the palm base.

[0044] Figure 6 This is a schematic diagram comparing the base space of the present invention with that of a linear spring scheme based on visual observation.

[0045] Among them, 1 is the dexterous hand body, 2 is the palm base, 3 is the Livina fusion drive measurement module, 4 is the traction rope, 5 is the winch position sensor, 6 is the winding winch, 7 is the rotating elastic element, 8 is the power unit, 9 is the second connection part of the torsion spring, 10 is the first connection part of the torsion spring, 11 is the drive measurement module one, 12 is the drive measurement module two, 13 is the drive measurement module three, 15 is the drive measurement module five, 16 is the drive measurement module six, and 17 is the drive measurement module seven. Detailed Implementation

[0046] To make the advantages and benefits of the technical solution provided by the present invention clearer, the technical solution provided by the present invention will now be described in further detail with reference to the accompanying drawings, specifically: Implementation Method 1: This implementation method provides a compact force-position fusion drive measurement module for rope-driven dexterous hands, including a fixed support, a power unit, a rotating elastic element, a winding winch, a traction rope, a rope guide structure, a winch position sensor, and a control unit. The power unit is mounted on the fixed support, the winding winch is rotatably mounted on the fixed support, and the rotating elastic element is disposed between the output end of the power unit and the winding winch. The rotating elastic element has a first connecting part and a second connecting part. The first connecting part is connected to the output end of the power unit, and the second connecting part is connected to the winding winch, so that the power unit, the rotating elastic element and the winding winch constitute a series rotating transmission structure. The traction rope is connected to the winding winch and led out through the rope guide structure to the finger joints of the rope-driven dexterous hand. The winding winch is used to rotate and retract the traction rope as the power unit outputs. The power unit is equipped with a first angle measuring unit for acquiring the angle of the power end, and the winch position sensor is correspondingly set with the winding winch for acquiring the angle of the winch end; The control unit is connected to the first angle measuring unit, the winch position sensor and the power unit respectively. The control unit obtains the torsional deformation of the rotating elastic element based on the relative angle difference between the power end angle and the winch end angle, and obtains the winding and unwinding displacement of the traction rope based on the winch end angle.

[0047] The rotating elastic element is arranged coaxially or nearly coaxially with the winding winch. The rotating elastic element is sleeved on the output shaft of the power unit, the winch shaft or connecting shaft of the winding winch. The first connecting part is fixedly connected to the output end of the power unit, and the second connecting part is fixedly connected to the winding winch.

[0048] The winding winch is mounted on the fixed support via a bearing, bushing, or low-friction support structure, and the outer periphery of the winding winch is provided with a winding groove for fixing or winding the traction rope.

[0049] The winch position sensor includes a magnet fixed coaxially with the winding winch and a magnetic encoding chip mounted on the fixed support or circuit board. The magnetic encoding chip is connected to the control unit.

[0050] The rope guiding structure includes one or more of a guide pulley, a guide hole, a guide groove, or a guide sleeve, and the rope guiding structure is disposed on the traction rope guide path between the winding winch and the finger joint.

[0051] A force-position fusion measurement device for a rope-driven dexterous hand based on series torsion spring angle difference includes a palm base, multiple traction ropes, multiple finger joints, and multiple compact force-position fusion drive measurement modules as described above for rope-driven dexterous hands. Multiple compact force-position fusion drive measurement modules are disposed within the palm base and arranged along the length direction, width direction, annular direction, or layered direction of the palm base; Each of the compact force-position fusion drive measurement modules corresponds to at least one traction rope. One end of the traction rope is connected to the winding winch of the corresponding compact force-position fusion drive measurement module, and the other end is connected to the finger joint via the rope guide structure of the corresponding compact force-position fusion drive measurement module. Each of the compact force-position fusion drive measurement modules obtains the tension of the corresponding traction rope based on the relative angle difference between the power end angle and the winch end angle, and obtains the winding and unwinding displacement of the corresponding traction rope based on the winch end angle. The rope-driven dexterous hand force-position fusion measurement device based on the series torsion spring angle difference obtains the joint state, contact state, grasping state or external disturbance state of the finger joints according to the tension and release displacement of the multiple traction ropes.

[0052] A method for force-position fusion measurement of a rope-driven dexterous hand based on the angle difference of a series torsion spring, the method being implemented using the aforementioned force-position fusion measurement device for a rope-driven dexterous hand, comprising: The power end angle of the power unit in each compact force-position fusion drive measurement module is collected, and the winch end angle of the corresponding winding winch is also collected. The torsional deformation of the corresponding rotating elastic element is obtained based on the relative angle difference between the power end angle and the winch end angle. Based on the torsional deformation and the pre-calibrated torsional stiffness of the rotating elastic element, the output torque on the corresponding winding winch side is obtained, and the tension of the corresponding traction rope is obtained based on the output torque. The release and take-up displacement of the corresponding traction rope is obtained based on the change in the angle of the winch end and the equivalent radius of the corresponding winding winch. The tension and release displacement of the multiple traction ropes are used to form force-position fusion measurement data, and the joint state, contact state, grasping state or external disturbance state of the rope-driven dexterous hand are obtained based on the force-position fusion measurement data.

[0053] A computer storage medium for storing a computer program, which, when read by the computer, is executed by the computer using the method described thereon.

[0054] A computer, including a processor and a storage medium, executes the method when the processor reads a computer program stored in the storage medium.

[0055] A computer program product, which, as a computer program, implements the method when the computer program is executed.

[0056] Implementation Method Two: This implementation method is a further detailed description of the technical solution provided in Implementation Method One, specifically: This embodiment provides a force-position fusion measurement device for a rope-driven dexterous hand based on the angle difference of a series torsion spring. This device is applied to the rope-driven dexterous hand body 1, which includes a palm base 2, multiple finger joints, and multiple force-position fusion drive measurement modules 3 disposed within the palm base 2. The multiple force-position fusion drive measurement modules 3 are centrally installed within the internal space of the palm base 2. Each force-position fusion drive measurement module 3 corresponds to at least one traction rope 4. After being led out from the corresponding force-position fusion drive measurement module 3, the traction rope 4 enters the corresponding finger along the rope channel inside the palm base 2 and forms a traction connection with one or more finger joints. Thus, power output, rope retraction and extension, tension detection, and joint actuation are all completed within the palm base 2, eliminating the need for numerous independent angle and force sensors at the finger joints.

[0057] like Figure 1As shown, the palm base 2 serves as the supporting foundation for the dexterous hand body 1, with multiple finger joints connected to its upper part. Its interior forms mounting cavities for installing multiple force-position fusion drive measurement modules 3. The force-position fusion drive measurement modules 3 are arranged within the palm base 2 along the height, width, or layering directions, with guide spaces between each module for the traction rope 4 to pass through. Since each force-position fusion drive measurement module 3 employs a compact rotating structure consisting of a power unit 8, a rotating elastic element 7, a winding winch 6, and a winch position sensor 5, there is no need to reserve linear extension space for the tension spring within the palm base 2, nor is it necessary to set up a camera field of view, a plane mirror reflection path, a light shield, or a light source mounting area. This allows the palm base 2 to integrate multiple drive measurement channels within a relatively small volume.

[0058] like Figure 2 and Figure 3 As shown, the single force-position fusion drive measurement module 3 includes a power unit 8, a rotating elastic element 7, a winding winch 6, a traction rope 4, a winch position sensor 5, a fixed support, a rope guide structure, and a control unit. The power unit 8 is fixedly installed on one side of the fixed support. The power unit 8 can be a servo motor, a motor, a geared motor, or a rotary driver with a reduction mechanism. The output end of the power unit 8 is connected to the first connecting part of the rotating elastic element 7, and the second connecting part of the rotating elastic element 7 is connected to the winding winch 6, so that the power unit 8, the rotating elastic element 7, and the winding winch 6 are connected in series along the rotation direction, forming a series rotary transmission chain from the power unit 8 to the rotating elastic element 7 and then to the winding winch 6.

[0059] The rotating elastic element 7 is preferably a torsion spring, which is sleeved on the outside of the output end of the power unit 8, the connecting shaft, or the winch shaft. The first connecting part 10 of the torsion spring is fixedly connected to the output component of the power unit 8, and the second connecting part 9 of the torsion spring is fixedly connected to the winding winch 6. When the power unit 8 outputs rotational motion, the output component of the power unit 8 drives the first connecting part 10 of the torsion spring to rotate, and the second connecting part 9 of the torsion spring then drives the winding winch 6 to rotate. When the traction rope 4 is subjected to finger joint load, external contact load, or joint resistance, the winding winch 6, relative to the output end of the power unit 8, exhibits elastic lag or elastic lead constrained by the torsion spring, forming a measurable relative angle difference between the first connecting part 10 of the torsion spring and the second connecting part 9 of the torsion spring. This relative angle difference serves as the basis for calculating the rope tension, shifting the force measurement position from the straight section of the rope to the rotating connection between the power unit 8 and the winding winch 6.

[0060] The winding winch 6 is mounted on a fixed support via bearings, bushings, or a low-friction support structure, enabling it to rotate stably relative to the fixed support around its own axis. The outer circumference of the winding winch 6 has a winding groove. One end of the traction rope 4 is fixed to or wound within the winding groove, and the other end of the traction rope 4 is connected to the corresponding finger joint via a rope guide structure. The rope guide structure can be a guide pulley, guide hole, guide groove, or guide sleeve, and its installation position corresponds to the exit direction of the traction rope 4. It is used to limit the path of the traction rope 4 and prevent interference between the traction rope 4 and adjacent modules, the inner wall of the hand base 2, or other structures during winding and unwinding. In this embodiment, the winding winch 6 not only serves as the actuator for winding and unwinding the traction rope 4 but also as a measurement reference for the displacement of the traction rope 4. The change in the rotation angle of the winding winch 6 directly corresponds to the change in the winding and unwinding length of the traction rope 4.

[0061] like Figure 4 As shown, the winch position sensor 5 is located at or adjacent to the axial end of the winding winch 6 to obtain the winch end angle of the winding winch 6. The winch position sensor 5 preferably employs a magnetic encoder structure, with the magnet coaxially fixed to the winding winch 6. The magnetic encoding chip is mounted on a fixed support or circuit board, maintaining a predetermined detection distance from the magnet. When the winding winch 6 rotates, the magnet rotates synchronously with the winding winch 6, and the magnetic encoding chip detects the change in the magnetic field angle and outputs the winch end angle signal. This installation method allows the winch position sensor 5 and the winding winch 6 to form a compact coaxial detection structure, eliminating the need for external light sources, cameras, or visual recognition space, making it suitable for installation in the limited space inside the palm base 2.

[0062] The power unit 8 itself is equipped with a first angle measurement unit. This first angle measurement unit can be an internal encoder of the power unit 8, or a magnetic encoder, photoelectric encoder, potentiometer-type angle sensor, or Hall effect angle sensor located at the output end of the power unit 8. The first angle measurement unit outputs the power end angle signal, and the winch position sensor 5 outputs the winch end angle signal; both are electrically connected to the control unit. After receiving the power end angle signal and the winch end angle signal, the control unit performs differential processing on the power end angle and the winch end angle to obtain the actual torsional deformation of the rotating elastic element 7. Combined with the pre-calibrated torsional stiffness, it obtains the output torque on one side of the winding winch 6, and then obtains the tension of the traction rope 4 based on the equivalent radius of the winding winch 6. Simultaneously, the control unit obtains the winding and unwinding displacement of the traction rope 4 based on the change in the winch end angle and the equivalent radius of the winding winch 6. Therefore, the same force-position fusion drive measurement module 3 can simultaneously obtain the tension and displacement information of the traction rope 4.

[0063] When a reduction mechanism, gear mechanism, or coupling mechanism is provided between the power unit 8 and the rotating elastic element 7, the control unit first converts the power end angle obtained by the first angle measurement unit into an equivalent angle on the input side of the rotating elastic element 7, and then compares this equivalent angle with the winch end angle. This signal processing relationship can adapt to different transmission ratios, transmission directions, and zero-point relationships between the power unit 8 and the winding winch 6, avoiding deviations in torsional angle calculation caused by intermediate transmission structures. If the output end of the power unit 8 is directly coaxially connected to the rotating elastic element 7, the control unit can directly use the power end angle as the input side angle of the rotating elastic element 7, and form an angle difference with the winch end angle.

[0064] In this embodiment, the rotating elastic element 7 can also be used in conjunction with a pre-tensioning structure. The pre-tensioning structure can be located at one or both ends of the rotating elastic element 7 and cooperate with at least one of the torsion spring first connecting part 10, torsion spring second connecting part 9, power unit 8 output component, or winding winch 6. The pre-tensioning structure can be an adjustable end cap, a rotating adjusting ring, a positioning groove, an adjusting screw, or a ratchet adjusting component, used to adjust the initial pre-torsion angle of the rotating elastic element 7 during the assembly stage, so that the traction rope 4 has a predetermined tension in the initial state. This pre-tensioning structure can reduce the impact of slack in the traction rope 4, inconsistent initial zero points, and assembly errors on the tension detection results.

[0065] In this embodiment, a mechanical limiting structure can also be provided between the output component of the power unit 8 and the winding winch 6, or between the winding winch 6 and the fixed support component. The mechanical limiting structure limits the maximum elastic relative rotation angle of the winding winch 6 relative to the output end of the power unit 8. When a finger joint becomes stuck, the traction rope 4 is overloaded, or an external impact causes the torsion angle of the rotating elastic element 7 to exceed the allowable range, the mechanical limiting structure abuts against the corresponding limiting surface, thereby preventing the rotating elastic element 7 from continuing to deform excessively. This structure can protect the power unit 8, the rotating elastic element 7, the winding winch 6, the traction rope 4, and the finger joint, preventing sudden load changes from being entirely applied to the transmission link.

[0066] like Figure 5As shown, multiple force-position fusion drive measurement modules 3 can be arranged in an array within the palm base 2. Drive measurement modules 11, 21, 31, 51, 61, and 717 are installed at different positions on the palm base 2. Each module can be arranged side-by-side along the width of the palm base 2, or layered vertically along the height, or arranged in a ring or staggered manner depending on the number of fingers, joints, and the exit direction of the traction rope 4. Each force-position fusion drive measurement module 3 has an independent power unit 8, a rotating elastic element 7, a winding winch 6, and a winch position sensor 5. Therefore, the channels do not need to share a camera field of view or optical measurement path, and the traction rope 4 only needs to be led out through its corresponding rope guide structure.

[0067] Multiple force-position fusion drive measurement modules 3 are electrically connected to the same control unit or multiple distributed control units. The control unit collects the power end angle signal and winch end angle signal from each force-position fusion drive measurement module 3, and calculates the tension and retraction displacement of each traction rope 4. The tension information of each traction rope 4 can form multi-channel tension data, and the displacement information of each traction rope 4 can form multi-channel displacement data. The control unit then uses the multi-channel tension data and multi-channel displacement data, combined with the equivalent force arm at the finger joint, the rope routing relationship, or the joint transmission geometry, to obtain the joint angle, joint torque, joint movement trend, contact state, or grasping state of the corresponding finger joint. The control unit can also feed the above data back to the power unit 8 to achieve position control, tension closed-loop control, compliance control, overload protection, or contact judgment.

[0068] When the winch 6 adopts a single-layer constant radius winding structure, the control unit uses the fixed equivalent radius of the winch 6 as the conversion basis, obtains the winding and unwinding displacement of the traction rope 4 based on the change in the winch end angle, and obtains the tension of the traction rope 4 based on the output torque transmitted to the winch 6 by the torsion spring and the equivalent radius. When the winch 6 adopts a multi-layer winding groove, a helical winding groove, or a variable radius profile, the control unit can determine the equivalent radius that changes with the winch end angle based on the geometric parameters or calibration data of the winch 6, and use this variable radius to convert the tension and winding and unwinding displacement of the traction rope 4. This structure can adapt to the use of the traction rope 4 with multiple turns or non-constant winding radius, reducing measurement deviations caused by changes in the winding radius.

[0069] like Figure 6As shown, in this embodiment, the rotating elastic element 7 is positioned between the output end of the power unit 8 and the winding winch 6. Tension-related information is obtained through the difference between the angle at the power end and the angle at the winch end, making the measurable elastic deformation manifest as a relative angular change in the rotation direction. Compared to a scheme that connects a tension spring in series on the straight section of the rope and visually observes the spring's extension and contraction, this embodiment eliminates the axial extension and contraction stroke of the linear spring, as well as the optical cavities required for the camera, plane mirror, light shield, and light source. Therefore, the force-position fusion drive measurement module 3 can be compactly arranged around the output axis of the power unit 8, the central axis of the rotating elastic element 7, and the central axis of the winding winch 6, compressing the height and lateral dimensions of the hand base 2.

[0070] In actual assembly, the power unit 8 is first fixed to the fixed support. The connecting shaft or power output component is connected to the output end of the power unit 8. The rotating elastic element 7 is sleeved on the connecting shaft or winch shaft, and the first connecting part 10 of the torsion spring is fixed to the output component of the power unit 8, while the second connecting part 9 of the torsion spring is fixed to the winding winch 6. The winding winch 6 is mounted on the fixed support via bearings, enabling it to rotate stably on the fixed support. One end of the traction rope 4 is fixed in the winding groove of the winding winch 6, and the other end passes through the corresponding rope guide structure and is connected to the finger joint. The magnet is fixed to the end of the winding winch 6 and rotates synchronously with the winding winch 6. The magnetic encoding chip is mounted on the circuit board or the fixed support and connected to the control unit. The first angle measuring unit of the power unit 8, the winch position sensor 5, and the control unit are electrically connected via signal lines or circuit boards. The control unit is then connected to the power unit 8 via drive control lines, thus forming an integrated structure of drive, detection, calculation, and feedback control.

[0071] In this embodiment, the control unit can be located inside the palm base 2, or in the wrist base connected to the palm base 2, or in an external control board. When the control unit is located inside the palm base 2, the first angle measuring unit of each force-position fusion drive measurement module 3 and the winch position sensor 5 can be connected to the control unit via short-distance cabling, circuit board wiring, or connectors, which helps reduce the number of external wiring harnesses. When the control unit is located in the wrist base or external control board, the angle signals of each force-position fusion drive measurement module 3 are transmitted to the control unit via a centralized wiring harness, and the control unit then outputs control signals to each power unit 8. Regardless of the arrangement, the control unit uses the power end angle and the winch end angle as basic inputs, and the tension and retraction displacement of the traction rope 4 as basic outputs, and is further used for joint state estimation and grasping control of the dexterous hand body 1.

[0072] Implementation Method 3: This implementation method is described in detail with reference to the accompanying drawings. Specific embodiments are provided to further illustrate the technical solutions offered above. Specifically: This implementation aims to solve at least the following technical problems.

[0073] First, if multiple angle and force sensors are placed at the finger joints of existing rope-driven dexterous hands, it will result in large joint space occupation, complex wiring, high cost, difficult assembly and reduced reliability.

[0074] Secondly, the rear-view vision measurement scheme, which consists of a tension spring, camera, plane mirror, light shield and light source, requires a large space to be reserved for the axial extension and contraction of the spring and the optical field of view. This makes it difficult to compress the volume of the palm base or drive base, which is not conducive to the miniaturization and high-density integration of multi-degree-of-freedom dexterous hands.

[0075] Third, visual measurement methods involve a trade-off between frame rate and resolution, and are affected by lighting, occlusion, lens distortion, and image processing delays, making it difficult to simultaneously obtain high-frequency and high-resolution rope tension and rope displacement measurement results.

[0076] Fourth, if a conventional single-axis series elastic force measurement structure is directly used in a rope-driven dexterous hand, it often only focuses on the output force or output torque, without fully solving the problems of rope-driven displacement measurement benchmark, multi-channel array arrangement, and tension-displacement joint state perception.

[0077] To address the aforementioned issues, this embodiment proposes a compact force-position fusion drive measurement module for rope-driven dexterous hands. The module includes a fixed support, a power unit, a rotating elastic element, a winding winch, a winch position sensor, a traction rope, a rope guiding structure, and a control unit.

[0078] The output end of the power unit is connected to the first connecting part of the rotating elastic element, and the second connecting part of the rotating elastic element is connected to the winding winch, forming a series rotary transmission chain between the power unit output end, the rotating elastic element, and the winding winch. The traction rope is wound or fixed to the winding winch and connected to one or more finger joints of the dexterous hand via pulleys, guide holes, guide grooves, or guide sleeves. The power unit is equipped with a first angle measuring unit to obtain the angle at the power end; the winding winch is equipped with a second angle measuring unit to obtain the angle at the winch end.

[0079] The control unit determines the torsional deformation of the rotating elastic element based on the relative angular difference between the power end angle and the winch end angle, and calculates the output torque on the winch side and the tension of the traction rope based on the torsional stiffness of the rotating elastic element. Simultaneously, the control unit calculates the traction rope retraction displacement based on the winch end angle, and obtains the joint angle, joint angular velocity, joint torque, or fingertip posture by combining the rope transmission geometry at the finger joints.

[0080] The basic transmission chain of this embodiment can be summarized as follows: Power unit—rotating elastic element—winch—rope—finger joint.

[0081] Unlike the approach of placing the tension spring on the straight section of the rope, this embodiment transfers the measurable elastic deformation from the straight section of the rope to the rotary connection between the output end of the power unit and the winding winch, so that the elastic element, the winch, the sensor and the power unit form a coaxial or near-coaxial compact module, thereby eliminating the linear extension space of the tension spring and the optical path space for visual measurement.

[0082] In a preferred embodiment, the rotational elastic element is a torsion spring. The torsion spring is sleeved on the servo motor output shaft, the winch shaft, or a connecting shaft coaxial with both. The first torsion arm, first end cap, or first connecting portion of the torsion spring is fixedly connected to the power unit output component, and the second torsion arm, second end cap, or second connecting portion of the torsion spring is fixedly connected to the winding winch. The winch is supported on a fixed support component by bearings, allowing the winch to generate an elastic relative angle with respect to the power unit output end, permitted by the torsion spring.

[0083] In another embodiment, the rotating elastic element may be a leaf spring-type torsional elastic element, a flexible torsion beam, an elastic coupling, a torsional flexible disc, or other rotating elastic elements with known torsional stiffness. As long as the element can create a measurable elastic relative angular displacement between the power end and the winch end, it can be used in this embodiment.

[0084] In a preferred embodiment, the winch position sensor is a magnetic encoder. A magnet is coaxially fixed to the winch, and the magnetic encoder chip is fixed to a support or circuit board. The winch end angle is obtained by measuring the angle of the magnet. In other embodiments, the winch position sensor may also be a photoelectric encoder, a potentiometer-type angle sensor, a Hall effect angle sensor, a rotary transformer, or other sensors capable of measuring the angular displacement of the winch.

[0085] In a preferred embodiment, multiple drive measurement modules are integrated in an array within the base of the dexterous hand. Each module corresponds to at least one traction rope. The control unit simultaneously acquires the power end angle and winch end angle of multiple modules, calculates the tension and release displacement of each rope, and further estimates the state, contact state, and grasping state of multiple finger joints.

[0086] For ease of explanation, the following symbols are defined. Angle variables are expressed in radians by default; if the sensor output is in degrees, it should be converted to radians first. The signs in the following formulas are determined by the winch rotation direction, rope winding direction, and joint coordinate system conventions; when only the tension or torque magnitude is required, the absolute value of the corresponding quantity can be taken.

[0087] : Angle of the power unit output end.

[0088] The equivalent angle after converting the power end angle to the torsion spring input side or winch side.

[0089] : Winch end angle.

[0090] : The amount of torsional deformation of a rotating elastic element relative to its initial bias state.

[0091] Initial pre-torsion angle, assembly zero-point offset, or initial relative angle offset.

[0092] Torsional stiffness of a rotating elastic element.

[0093] : Equivalent torsional damping coefficient, optional.

[0094] The output torque transmitted to the winch side by the rotating elastic element.

[0095] : Equivalent radius of the winch.

[0096] : The equivalent radius function that varies with the winch angle.

[0097] : Tension of the traction rope.

[0098] : The displacement of the traction rope during its deployment and retraction.

[0099] Equivalent force arm or equivalent transmission radius at the finger joint.

[0100] : finger joint angle.

[0101] : Torque of finger joints.

[0102] Step 1: Connect a rotating elastic element in series between the output end of the power unit and the winding winch, and pre-calibrate the torsional stiffness of the rotating elastic element. And record or calibrate the initial relative angle offset. This bias may include the assembly zero point, sensor zero point error, and initial preload angle.

[0103] Step 2: During the operation of the dexterous hand, the angle of the power end is obtained by the encoder inside the power unit or by the first angle sensor set at the output end of the power unit. The winch end angle is obtained by the winch position sensor. .

[0104] If there is a transmission mechanism between the output end of the power unit and the input end of the rotating elastic element, then the angle at the power end is converted into an equivalent angle on the input side of the torsion spring or the winch side. This conversion can be expressed as:

[0105] in, This is the angle conversion function determined by the transmission ratio, transmission direction, and zero-point relationship. In the case of a direct coaxial connection, we have:

[0106] If the transmission ratio is defined as the ratio of the power end angle to the equivalent angle:

[0107] Then we have:

[0108] Step 3: Calculate the torsional deformation of the rotating elastic element based on the relative angle difference between the equivalent angle at the power end and the angle at the winch end.

[0109] in, This is the actual torsion angle relative to the initial bias state. If the zero point is automatically defined at the initial moment, it can also be written as:

[0110] If the initial state has an additional preload angle Then it can be incorporated into It can also be written as:

[0111] Step 4: Calculate the output torque on the winch side based on the torsional stiffness of the rotating elastic element. Under ideal static conditions, we have:

[0112] When considering the effects of dynamic response, damping, or high-speed motion, an equivalent torsional damping term can be introduced:

[0113] in, This is the equivalent torsional damping coefficient. This refers to the torsional angular velocity of the rotating elastic element.

[0114] Step 5: Calculate the tension of the traction rope based on the equivalent radius of the winch. If the equivalent radius of the winch is constant... Then we have:

[0115] If we only care about the magnitude of the tension, then we have:

[0116] When the rope is wound in multiple layers on the winch, or when the winch has structures such as helical grooves or variable radius profiles that cause the effective winding radius to change with the winch angle, an equivalent radius function can be used. ,at this time:

[0117] If we only care about the magnitude of the tension, then we have:

[0118] Step Six: Based on the equivalent force arm at the finger joints Alternatively, a rope routing geometry model can be used to convert the tension of the traction rope into joint torque. For the case of a single joint, fixed equivalent arm, we have:

[0119] If we consider the direction of the torque, it can be written as:

[0120] in, This indicates the direction of the torque exerted by the rope on the joint.

[0121] For multi-joint coupling, underactuated finger, or variable lever arm structures, the joint torque can be represented by the Jacobian relationship of the rope path:

[0122] in, This is the joint torque vector. For multi-rope tension vectors, This is the Jacobian matrix of the rope length relative to the joint angle. For a calibrated dexterous hand, the calibration mapping function can also be used:

[0123] Step 1: Record the winch angle at the initial moment. And determine the equivalent radius of the winch. or equivalent radius function .

[0124] Step 2: During the operation of the dexterous hand, the winch position sensor measures the winch angle in real time. When the equivalent radius of the winch is constant, the displacement of the traction rope during winding and unwinding is:

[0125] in, This indicates the length of the traction rope relative to the initial moment, and its sign is determined by the direction of the winch rotation and the direction of the rope winding.

[0126] When the equivalent radius of the winch changes with the angle, the displacement of the traction rope during winding and unwinding is:

[0127] If we only care about the magnitude of the expansion and contraction displacement, it can be written as:

[0128] Step 3: Calculate the joint angle based on the transmission relationship between the displacement of the traction rope and the rotation angle of the finger joint. For a single joint with a fixed equivalent radius... The following situations are possible:

[0129] in, This represents the joint angle at the initial moment. If only the relative angular displacement is described, it can also be written as:

[0130] For multi-joint or underactuated fingers, the relationship between rope displacement and joint angle is usually not a simple one-to-one linear one; a rope path model can be used.

[0131] The joint angles are obtained through model solving or calibration lookup tables.

[0132] Or it can be expressed as:

[0133] Step 4: The rope velocity can be obtained from the first derivative of the winch angle. When the equivalent radius of the winch is constant, we have:

[0134] When the equivalent radius of the winch changes with the angle, we have:

[0135] For a single-joint fixed-radius structure, the joint angular velocity is:

[0136] Meanwhile, the dynamic deformation speed of the rotating elastic element can be obtained from the relative change between the equivalent angle at the power end and the angle at the winch end.

[0137] This quantity can be used for damping compensation, dynamic tension estimation, and compliance control.

[0138] This embodiment uses an angle sensor to measure the relative rotation angle between the two ends of the rotating elastic element. If the equivalent angle measurement resolution at the power end is... The winch end angle measurement resolution is Since the errors of the two are independent of each other, the torsional angular resolution can be approximated as:

[0139] When the winch radius is constant, the rope tension resolution can be approximated as:

[0140] The rope displacement resolution can be approximated as:

[0141] The above relationship illustrates that, under the same structural dimensions, improving the resolution of the angle sensor and appropriately selecting the torsion spring stiffness and winch radius can improve the minimum resolution capability of rope tension and rope displacement.

[0142] The control unit in this embodiment can measure the tension of the traction rope output by each drive measurement module. and the displacement of the traction rope The combination is a tension-displacement-time series:

[0143] Under conditions of no contact or known free motion, a reference curve can be pre-calibrated for the tension of the traction rope relative to the rope displacement and the velocity of motion.

[0144] During operation, the control unit can calculate the residual between the measured tension and the free-moving reference tension:

[0145] when , When its window statistics exceed a set threshold, it can be determined that a finger is in contact with an object, there is a change in external load, or joint movement is obstructed. Contact determination can be expressed as:

[0146] in, This indicates that a contact or external load event has been detected. This is the tension residual threshold.

[0147] After contact, the control unit can estimate the relative stiffness of the object or the contact environment based on the local slope of the tension-displacement curve:

[0148] In practical discrete sampling, window fitting or difference approximation can be used:

[0149] When the change in control input or winch displacement is small while the tension residual increases rapidly, it can be determined that there is an external disturbance, slippage of the grasped object, jamming of the target object, or obstruction of the fingers. Therefore, this embodiment not only provides rope tension and rope displacement, but also further supports multimodal proprioception of the dexterous hand.

[0150] In a specific implementation: Example 1: Single coaxial force-position fusion drive measurement module In this embodiment, a servo motor with an internal encoder is selected as the power unit. The servo motor is fixed on the module bracket, and the servo motor output shaft is fixedly connected to the connecting shaft. A torsion spring is sleeved on the connecting shaft. The first connecting part of the torsion spring is fixedly connected to the servo motor output component, and the second connecting part of the torsion spring is fixedly connected to the winding winch. The winding winch is supported on the module bracket by bearings, so that the winch can generate an elastic relative angle with respect to the servo motor output component, constrained by the torsion spring.

[0151] The winch has a winding groove on its outer circumference. One end of the traction rope is fixed or wound in the winding groove, and the other end is connected to a finger joint via a guide pulley, guide hole, or guide groove. A magnet is coaxially fixed on the winch, and a magnetic encoding chip is fixed on the module bracket or circuit board. The magnetic encoding chip is used to measure the absolute angle of the winch. The encoder inside the servo motor is used to measure the angle of the power end. .

[0152] When the servo motor drives the winch to wind up or down the rope, if a finger joint or external object applies a load to the rope, the winch end will elastically lag or lead relative to the servo motor end, causing the torsion spring to deform to the twist. The control unit calculates the torsion angle of the torsion spring based on the difference between the angle at the servo motor end and the angle at the winch end, and then calculates the rope tension. Simultaneously, the winch angle itself is used to calculate the rope windup / windup displacement. Therefore, the same module can simultaneously provide power output, tension measurement, and displacement measurement.

[0153] Example 2: Module with pre-tensioning and mechanical limiting This embodiment adds a pre-tensioning structure and a mechanical limiting structure based on Embodiment 1. The pre-tensioning structure can be an adjustable end cap, a ratchet adjustment component, an adjusting screw, a positioning groove, or a graduated rotary adjustment ring, used to set the initial pre-torsion angle of the torsion spring during the assembly or calibration stage, and thereby set the initial tension of the rope.

[0154] A mechanical limiting structure is installed between the servo motor output component and the winch, or between the winch and the fixed support component, to limit the maximum torsion angle of the torsion spring. When external impact, misoperation, or rope jamming causes the torsion spring's torsion angle to exceed the set range, the mechanical limiting structure prevents the torsion spring from continuing to deform, thereby protecting the servo motor, winch, rope, and finger joints. The overload protection threshold can be expressed as:

[0155] The corresponding maximum measurable or maximum permissible rope tension is approximately:

[0156] Example 3: Multi-channel rope-driven dexterous hand system In this embodiment, multiple force-position fusion drive measurement modules are integrated within the dexterous hand base. Each module corresponds to a traction cable, or to a finger joint, a joint group, an underactuated finger unit, or a degree of freedom. The multiple modules can be compactly arranged along the length, width, radial, annular, or in a layered manner.

[0157] Since each module employs a coaxial or near-coaxial rotating structure consisting of a power unit, a rotating elastic element, a winch, and a winch position sensor, there is no need to reserve a large, unified cavity for the camera field of view, mirror reflection path, light shield, or linear travel of the tension spring. Only necessary installation gaps, heat dissipation space, and rope guide paths need to be reserved between the modules, which facilitates the integration of multiple drive and measurement channels within the limited space of the palm-sized base.

[0158] The control unit synchronously collects the power end angle and winch end angle of each module to form multiple tension vectors and multiple rope displacement vectors:

[0159]

[0160] in, The number of driving measurement modules or rope channels is determined by the control unit. The control unit can estimate the finger joint state based on the displacement of multiple ropes, and estimate the gripping force, contact state, gripping stability, or external disturbance state based on the tension of multiple ropes.

[0161] Example 4: Variable radius or multi-layer winding winch In this embodiment, the winch can adopt a single-layer winding groove, a multi-layer winding groove, a spiral groove, or a variable radius profile. When the winch has a single-layer constant radius winding structure, a constant radius can be used. Calculate rope tension and release / retraction displacement. When the winch has a multi-layer winding or variable radius structure, the control unit obtains the equivalent radius function based on the winch's geometric parameters or calibration function. .

[0162] In the case of variable radius, rope tension and rope displacement are calculated using the following formulas:

[0163]

[0164] This implementation method can adapt to multiple rope turns, varying winch radius, or non-circular winch designs, and improves model adaptability.

[0165] Example 5: Calibration Method In this embodiment, the module can be calibrated according to the following steps.

[0166] First, fix the winch end or apply a known torque, record the relative angle difference between the power end angle and the winch end angle, establish the calibration relationship between torque and torsion angle, and thus obtain the torsional stiffness. Within the linear elastic range, the following can be used:

[0167] Second, under conditions of no external load or with a set initial tension, record the equivalent angle at the power end and the angle at the winch end to determine the zero-point offset or initial preload angle. .

[0168] Third, drive the winch to rotate by a known angle, measure the actual length of the rope that is wound up and down, and calibrate the equivalent radius of the winch. or equivalent radius function .

[0169] Fourth, through experiments with known joint angles or known rope displacements, the mapping relationship between rope displacement and joint angles is calibrated. or .

[0170] Fifth, a compensation model can be established based on factors such as temperature, friction, rope elastic elongation, or transmission clearance:

[0171] in, This represents the ambient temperature or module temperature. The compensation model can be obtained through analytical modeling, table lookup, or data calibration.

[0172] The beneficial effects of this embodiment are as follows: First, this embodiment moves the measurable elastic element from the straight section of the rope to between the output end of the power unit and the winding winch, so that the elastic deformation appears in the form of rotational angular displacement, and forms a coaxial or near-coaxial module with the power unit, winch, and angle sensor. This structure eliminates the axial extension space of the tension spring, the camera field of view, the plane mirror reflection path, the light-shielding structure, and the light source installation space, which is beneficial to significantly reduce the height and lateral dimensions of the base of the rope-driven dexterous hand.

[0173] Secondly, this implementation method obtains the torsional angle of the rotating elastic element by measuring the difference between the angle at the power end and the angle at the winch end, and then calculates the rope tension from the torsional stiffness; simultaneously, it directly calculates the rope release and retraction displacement through the winch end angle. This scheme clearly distinguishes the signal sources for "force measurement" and "displacement measurement," enabling the simultaneous output of traction rope tension and traction rope displacement from the same compact module.

[0174] Third, this implementation uses an angle sensor for measurement, which avoids the strong trade-off between frame rate and image resolution in visual measurement, and also reduces the impact of lighting, occlusion, lens distortion and image processing delay on the measurement results, thereby helping to improve the measurement frequency and resolution of rope tension, rope displacement and joint torque.

[0175] Fourth, the rotating elastic element in this embodiment is not only used for force measurement, but also provides mechanical compliance for the rope drive system. When the finger is subjected to external impact, gripping overload, joint jamming, or misoperation, the rotating elastic element can absorb some of the energy; in conjunction with the mechanical limiting structure and the overload judgment of the control unit, the risk of damage to the power unit, rope, winch, and finger joints can be reduced.

[0176] Fifth, the single drive measurement module in this embodiment can be replicated into multiple channels and integrated in an array within the dexterous hand base. Each channel does not depend on a unified camera field of view and a unified optical path, and the channels are easier to arrange in a modular fashion, making it suitable for tethered dexterous hand systems with eighteen or more degrees of freedom.

[0177] Sixth, this implementation can output a tension-displacement-time sequence, and based on this sequence, it can perform contact detection, external disturbance judgment, relative stiffness estimation of objects, grasping state estimation, and compliant control, thereby enabling the rope-driven dexterous hand to obtain richer proprioceptive capabilities.

[0178] The above description of several specific embodiments further details the technical solution provided by the present invention in order to highlight the advantages and benefits of the technical solution provided by the present invention. However, the above-described specific embodiments are not intended to limit the present invention. Any reasonable modifications and improvements to the present invention, combinations of embodiments, and equivalent substitutions based on the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A compact force-position hybrid drive and measurement module for a rope-driven dexterous hand, characterized by, It includes fixed support components, power unit, rotating elastic element, winding winch, traction rope, rope guide structure, winch position sensor and control unit; The power unit is mounted on the fixed support, the winding winch is rotatably mounted on the fixed support, and the rotating elastic element is disposed between the output end of the power unit and the winding winch. The rotating elastic element has a first connecting part and a second connecting part. The first connecting part is connected to the output end of the power unit, and the second connecting part is connected to the winding winch, so that the power unit, the rotating elastic element and the winding winch constitute a series rotating transmission structure. The traction rope is connected to the winding winch and led out through the rope guide structure to the finger joints of the rope-driven dexterous hand. The winding winch is used to rotate and retract the traction rope as the power unit outputs. The power unit is equipped with a first angle measuring unit for acquiring the angle of the power end, and the winch position sensor is correspondingly set with the winding winch for acquiring the angle of the winch end; The control unit is connected to the first angle measuring unit, the winch position sensor and the power unit respectively. The control unit obtains the torsional deformation of the rotating elastic element based on the relative angle difference between the power end angle and the winch end angle, and obtains the winding and unwinding displacement of the traction rope based on the winch end angle.

2. The compact force-position hybrid drive and measurement module for a rope-driven dexterous hand according to claim 1, wherein, The rotating elastic element is arranged coaxially or nearly coaxially with the winding winch. The rotating elastic element is sleeved on the output shaft of the power unit, the winch shaft or connecting shaft of the winding winch. The first connecting part is fixedly connected to the output end of the power unit, and the second connecting part is fixedly connected to the winding winch.

3. The compact force-position hybrid drive and measurement module for a rope-driven dexterous hand according to claim 1, wherein, The winding winch is mounted on the fixed support via a bearing, bushing, or low-friction support structure, and the outer periphery of the winding winch is provided with a winding groove for fixing or winding the traction rope.

4. A compact force-position fusion drive measurement module for rope-driven dexterous hands according to claim 1, characterized in that, The winch position sensor includes a magnet fixed coaxially with the winding winch and a magnetic encoding chip mounted on the fixed support or circuit board. The magnetic encoding chip is connected to the control unit.

5. A compact force-position fusion drive measurement module for rope-driven dexterous hands according to claim 1, characterized in that, The rope guiding structure includes one or more of a guide pulley, a guide hole, a guide groove, or a guide sleeve, and the rope guiding structure is disposed on the traction rope guide path between the winding winch and the finger joint.

6. A rope-driven dexterous hand force-position fusion measurement device based on series torsion spring angle difference, characterized in that, It includes a hand base, multiple traction ropes, multiple finger joints, and multiple compact force-position fusion drive measurement modules for rope-driven dexterous hands as described in claim 1. Multiple compact force-position fusion drive measurement modules are disposed within the palm base and arranged along the length direction, width direction, annular direction, or layered direction of the palm base; Each of the compact force-position fusion drive measurement modules corresponds to at least one traction rope. One end of the traction rope is connected to the winding winch of the corresponding compact force-position fusion drive measurement module, and the other end is connected to the finger joint via the rope guide structure of the corresponding compact force-position fusion drive measurement module. Each of the compact force-position fusion drive measurement modules obtains the tension of the corresponding traction rope based on the relative angle difference between the power end angle and the winch end angle, and obtains the winding and unwinding displacement of the corresponding traction rope based on the winch end angle. The rope-driven dexterous hand force-position fusion measurement device based on the series torsion spring angle difference obtains the joint state, contact state, grasping state or external disturbance state of the finger joints according to the tension and release displacement of the multiple traction ropes.

7. A method for force-position fusion measurement of a rope-driven dexterous hand based on the angle difference of a series torsion spring, characterized in that, The method is implemented based on the rope-driven dexterous hand force-position fusion measurement device as described in claim 6, and includes: The power end angle of the power unit in each compact force-position fusion drive measurement module is collected, and the winch end angle of the corresponding winding winch is also collected. The torsional deformation of the corresponding rotating elastic element is obtained based on the relative angle difference between the power end angle and the winch end angle. Based on the torsional deformation and the pre-calibrated torsional stiffness of the rotating elastic element, the output torque on the corresponding winding winch side is obtained, and the tension of the corresponding traction rope is obtained based on the output torque. The release and take-up displacement of the corresponding traction rope is obtained based on the change in the angle of the winch end and the equivalent radius of the corresponding winding winch. The tension and release displacement of the multiple traction ropes are used to form force-position fusion measurement data, and the joint state, contact state, grasping state or external disturbance state of the rope-driven dexterous hand are obtained based on the force-position fusion measurement data.

8. A computer storage medium for storing computer programs, characterized in that, When the computer program is read by the computer, the computer executes the method of claim 7.

9. A computer, comprising a processor and a storage medium, characterized in that, When the processor reads the computer program stored in the storage medium, the computer executes the method of claim 7.

10. A computer program product, as a computer program, is characterized by: When the computer program is executed, it implements the method of claim 7.

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