Underactuated hand with cable-actuated fingers

Abstract

The robotic hand system can include a palm region and one or more fingers, each finger including an actuator device; a proximal member having a first end mechanically coupled to the palm region robot and configured to rotate about a first pivot relative to the palm region; a distal member mechanically coupled to a second end of the proximal member and configured to rotate about a second pivot relative to the proximal member; and a cable having a first portion coupled to the actuator and a second portion extending along the proximal and distal members, the second portion having an end spaced from the first and second pivots and having a dimension larger than a diameter of the cable, the end with the larger dimension structured to engage the distal member when the cable is pulled by the actuator.

Description

[Technical Field]

[0001] [Cross-reference to related patent applications] This application claims priority to U.S. Provisional Application No. 63 / 377,919, filed September 30, 2022, and to U.S. Provisional Application No. 63 / 378,034, filed September 30, 2022, both of which are incorporated by reference in their entirety for all purposes.

[0002] The present disclosure relates generally to underactuated hands with cable-driven fingers. In particular, the present disclosure relates to cable-driven robotic hands and fingers with adaptive grasps, and an optimization framework for optimizing various design parameters of cable-driven robotic hands and fingers. [Background technology]

[0003] A robot can be viewed as a chain or collection of joints that allow the robot to achieve desired motion. Each joint allows adjacent structures or elements to move relative to one another. The motion of adjacent elements is driven by one or more actuators associated with the joints. A computer system controls the actuators to achieve the desired motion.

[0004] The design of a joint defines the range of motion of corresponding adjacent elements and can affect the number and / or type of actuators used, as well as the efficiency of the actuators. Summary of the Invention

[0005] For a variety of reasons, hands and fingers are among the most complex and challenging robotic components in terms of design and optimization of design parameters. The first challenge is how to achieve adaptive and stable object grasping. Adaptability refers to the ability of the fingers and individual joints to adapt their position and / or motion based on the location and characteristics of contact with another object. Stability refers to a good grasp of an object without slipping or falling. A second challenge is how forces and torques are transmitted to the different links and members of the fingers. Another challenge is how to optimize or improve the efficiency of force application to an object. These and other challenges make robotic hand and finger design a complex, multidimensional problem, requiring new techniques to approximate the characteristics and capabilities of the human hand.

[0006] This disclosure describes systems and methods for robotic hands and cable-actuated fingers configured to mimic human hands and fingers. In particular, the systems and methods described herein provide novel routing for cable-actuated fingers, enabling more adaptive, stable, and efficient object grasping. The cable routing described herein provides different patterns of force and / or torque transmission to various links and structures in the finger, allowing for a range of motion and / or location that mimics, to some extent, the motion or location of a human finger. The fingers described herein are underactuated with a single actuator driving two joints in the finger.

[0007] The systems and methods described in this disclosure also provide an optimization and simulation framework for achieving increased adaptability, stability, and efficiency, particularly with respect to grasping objects with the hands and fingers described herein. Specifically, the optimization and simulation framework allows for the optimization of various parameters of the finger designs or finger systems described herein.

[0008] According to at least one aspect, a robotic hand system can include a palm region and one or more fingers, each finger comprising: an actuator device; a respective proximal member having a first end mechanically coupled to the palm region robot and configured to rotate about a respective first pivot relative to the palm region; a respective distal member mechanically coupled to a second end of the proximal member and configured to rotate about a respective second pivot relative to the proximal member; and a respective cable having a first portion coupled to the actuator and a second portion extending along the proximal and distal members, the second portion having an end spaced from the first and second pivots and having a dimension larger than a diameter of the cable, the end with the larger dimension structured to engage the distal member when the cable is pulled by the actuator.

[0009] The end having the larger dimension may float within the region of the distal member. In some implementations, the end having the larger dimension includes at least one of a potted end or an end having a potted insert.

[0010] Each finger may include a respective channel structure extending at least partially along the respective proximal member and the respective distal member, the respective channel structure at least partially accommodating the second portion of the respective cable.

[0011] The enlarged end of the second portion of each cable may be structured to engage a ledge structure of the respective channel structure when the respective cable is pulled by the respective actuator.

[0012] Each finger may include a respective first torsion spring disposed about a respective first pivot and a respective second torsion spring disposed about a respective second pivot.

[0013] Each finger may include a respective magnet coupled to a respective first pivot and a respective Hall Effect sensor disposed proximate to the respective magnet. In some implementations, the respective magnet includes a ring magnet disposed around the respective first pivot.

[0014] Each finger may include a respective magnet coupled to a respective second pivot and a respective Hall Effect sensor disposed proximate to the respective magnet.

[0015] The distance between each cable and each first pivot may vary, and / or the distance between each cable and each second pivot may vary.

[0016] According to at least one aspect, a finger device can include an actuator device; a proximal member having a first end mechanically coupled to a base member and configured to rotate about a first pivot relative to the base member; a distal member mechanically coupled to a second end of the proximal member and configured to rotate about a second pivot relative to the proximal member; and a cable having a first portion coupled to the actuator and a second portion extending along the proximal and distal members, the second portion having an end spaced from the first and second pivots and having a dimension larger than a diameter of the cable, the end with the larger dimension structured to engage the distal member when the cable is pulled by the actuator.

[0017] The end with the larger dimension may float within the confines of the distal member.

[0018] The end having the larger dimension may include at least one of a potted end and an end having a potted insert.

[0019] The finger device may include a channel structure extending at least partially along the proximal and distal members, the channel structure at least partially accommodating the second portion of the cable.

[0020] The enlarged ends of the second portions of the cables may be structured to engage with ledge structures of the channel structures when the respective cables are pulled by the respective actuators.

[0021] The finger device may further include a first torsion spring disposed about the first pivot and a second torsion spring disposed about the second pivot.

[0022] The finger device may further include a magnet coupled to the first pivot and a Hall Effect sensor disposed proximate to the magnet. In some implementations, the magnet includes a ring magnet disposed around the first pivot.

[0023] In some implementations, the finger device system may further include a magnet coupled to the second pivot and a Hall Effect sensor positioned proximate to the magnet.

[0024] The distance between the cable and the first pivot may vary and / or the distance between the cable and the second pivot may vary. [Brief explanation of the drawings]

[0025] Non-limiting embodiments of the present disclosure are illustrated by way of example with reference to the accompanying drawings, which are schematic and are not intended to be drawn to scale, and in which, unless indicated as representing background art, the figures represent aspects of the present disclosure.

[0026] [Figure 1] FIG. 1 shows a diagram of an exemplary humanoid robot in which the systems and methods described herein can be integrated, according to one embodiment.

[0027] [Figure 2]FIG. 1 illustrates a front view of a robotic hand, according to one embodiment.

[0028] [Figure 3A] 3 illustrates a partial see-through view of the hand of FIG. 2 according to one embodiment. [Figure 3B] 3 illustrates a partial see-through view of the hand of FIG. 2 according to one embodiment. [Figure 3C] 3 illustrates a partial see-through view of the hand of FIG. 2 according to one embodiment.

[0029] [Figure 4A] 1 illustrates a diagram of a cable drive finger (or finger device), according to one embodiment. [Figure 4B] 1 illustrates a diagram of a cable drive finger (or finger device), according to one embodiment. [Figure 4C] 1 illustrates a diagram of a cable drive finger (or finger device), according to one embodiment. [Figure 4D] 1 illustrates a diagram of a cable drive finger (or finger device), according to one embodiment. [Figure 4E] 1 illustrates a diagram of a cable drive finger (or finger device), according to one embodiment. [Figure 4F] 1 illustrates a diagram of a cable drive finger (or finger device), according to one embodiment.

[0030] [Figure 5A] 10 illustrates an internal view of another finger (or finger system), according to one embodiment. [Figure 5B] 10 illustrates an internal view of another finger (or finger system), according to one embodiment.

[0031] [Figure 6A] 1 illustrates kinematic simulation results for a system including two fingers, according to one embodiment. [Figure 6B] 1 illustrates kinematic simulation results for a system including two fingers, according to one embodiment. [Figure 6C] 1 illustrates kinematic simulation results for a system including two fingers, according to one embodiment. [Figure 6D]1 illustrates kinematic simulation results for a system including two fingers, according to one embodiment. [Figure 6E] 1 illustrates kinematic simulation results for a system including two fingers, according to one embodiment. [Figure 6F] 1 illustrates kinematic simulation results for a system including two fingers, according to one embodiment. [Figure 6G] 1 illustrates kinematic simulation results for a system including two fingers, according to one embodiment.

[0032] [Figure 7A] 1 illustrates a diagram of a gearbox according to one embodiment. [Figure 7B] 1 illustrates a diagram of a gearbox according to one embodiment. [Figure 7C] 1 illustrates a diagram of a gearbox according to one embodiment.

[0033] [Figure 8A] 1 illustrates the use of Hall Effect sensors to monitor the location of a finger or corresponding member, according to one embodiment. [Figure 8B] 1 illustrates the use of Hall Effect sensors to monitor the location of a finger or corresponding member, according to one embodiment.

[0034] [Figure 9] 1 illustrates a framework for optimizing cable drive finger parameters, according to one embodiment.

[0035] [Figure 10A] 1 illustrates an optimization model, according to one embodiment. [Figure 10B] 1 illustrates a simulation of an optimized hand model, according to one embodiment.

[0036] [Figure 11A] 10 shows simulation results illustrating the effective lever arm, according to one embodiment. [Figure 11B] 10 shows simulation results illustrating achievable force ranges, according to one embodiment. [Figure 11C] 10 illustrates simulation results showing contact vector fields and energy losses, according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0037] Reference will now be made to the exemplary embodiments illustrated in the drawings, and specific language will be used to describe them. It will nevertheless be understood that no limitation of the scope of the claims or the present disclosure is intended. Alterations and further modifications of the features of the invention shown herein, and further applications of the principles of the subject matter shown herein, which will occur to those skilled in the relevant art and in possession of this disclosure, should be considered within the scope of the subject matter disclosed herein. Other embodiments may be utilized and / or other changes may be made without departing from the spirit or scope of the present disclosure. The exemplary embodiments described in the detailed description do not limit the presented subject matter.

[0038] This disclosure describes systems and methods for robotic hands and cable-driven fingers. The robotic hands and cable-driven fingers described herein enable adaptive and stable finger motion. Adaptability refers to the fact that the motion of the finger links adapts to the contact points and contact force points. The robotic hands and cable-driven fingers described herein also enable more stable and efficient object grasping. The robotic hands and cable-driven fingers described herein mimic, at least to some extent, human hands and fingers.

[0039] FIG. 1 is a diagram of an exemplary humanoid robot 100 that can integrate the systems and methods described herein, according to one illustrative embodiment. The humanoid robot 100 may include an upper body 102, two arms 104, and two legs 106. The upper body 102 may include a controller 108 for controlling the robot 100. The controller 108 may include a processing circuit 110 and a communication interface 112. The processing circuit 110 may be communicatively coupled to the communication interface 112. The processing circuit 110 may include a processor 114 and a memory 116. The robot 100 may include multiple actuators 118 associated with multiple joints. Each arm 104 may include a corresponding hand 120. The robot 100 may include one or more sensors for sensing parameters of the robot 100 or its surroundings. The robot 100 may include one or more cameras.

[0040] The processor 114 may be realized as a single-chip or multi-chip processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The processor 114 may be a microprocessor. The processor 114 may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. In some implementations, the controller 108 may include one or more processors 114.

[0041] Memory 116 (e.g., memory units and / or storage devices) may include one or more devices (e.g., RAM, ROM, flash memory, hard disk storage) that store data and / or computer code for completing or facilitating the various processes described in this disclosure. Memory 116 may be communicatively coupled to processor 114 and provide processor 114 with computer code or instructions for executing at least some of the processes described herein. Additionally, memory 116 may be or include tangible, non-transitory, volatile or non-volatile memory. For example, memory 116 may include database components, object code components, script components, or any other type of information structure for supporting the various activities and information structures described herein.

[0042] The communication interface 112 may include any combination of wired and / or wireless interfaces (e.g., jacks, antennas, transmitters, receivers, transceivers, wired terminals) for communicating data with various systems or devices of the robot 100. For example, the communication interface 112 may enable communication between the processing circuit 110 (or processor 114) and actuators 118, sensors, or cameras integrated into the robot 100. In some implementations, the communication interface 112 may enable communication with remote systems or devices.

[0043] The processing circuit 110 or processor 114 can be configured to control the joints of the robot 100. The processing circuit 110 or processor 114 can control the joints or the movement associated with the joints by controlling corresponding actuators 118. In particular, each joint can include or be associated with one or more actuators 118 configured to drive the movement of a robot part or element connected via the joint. As described in further detail below, the processing circuit 110 or processor 114 can send commands to the actuators 118 to cause or trigger precise movement of one or more elements or parts of the robot 100. The processing circuit 110 or processor 114 can control multiple joints simultaneously to achieve coordinated movement of the robot 100.

[0044] The processing circuit 110 or processor 114 can receive data from sensors and / or cameras integrated into the robot 100 and make decisions based on the received data, such as regarding which elements of the robot 100 to move and how. For example, the data received from the sensors and / or cameras can indicate an obstacle in the path of the robot 100. The processing circuit 110 or processor 114 can decide to modify the path and, based on the modified path, determine the movement of one or more limbs or parts of the robot 100. In some implementations, the processing circuit 110 or processor 114 can receive data from a remote device or system indicating a task to be performed by the robot 100 and determine a series of movements of the limbs or parts of the robot 100 to perform the task.

[0045] 1 shows the controller 108 being integrated into the chest or upper body of the robot 100, in general, the controller 108 can be located on or integrated into other areas or portions of the robot 100. For example, the robot 100 can include a head, and the controller 108 can be integrated into or in the head. In some implementations, the controller 108 can be located on the back, the lumbar region, and / or one of the limbs of the robot 100.

[0046] 2 shows a front view of a robotic hand 200, according to one embodiment. The hand 200 can include a palm region 202 and multiple digits, such as fingers 204a-204e, which are also referred to herein individually or collectively as fingers 204. The hand 200 is similar in structure to a human hand, having a thumb 204a and four fingers 204b-204e. Each of the fingers 204a-204e can include a respective proximal member, e.g., proximal members 206a-206e, and a respective distal member, e.g., distal members 2081-208e.

[0047] Proximal members 206a-206e are also referred to herein as proximal members 206 or proximal links 206. Distal members 208a-208e are also referred to herein as distal members 206 or distal links 204. As described in further detail below, each proximal member 206 can be configured or structured to rotate relative to palm region 202, e.g., about a corresponding first pivot connecting the proximal member 206 to the palm region. Additionally, each distal member 208 can be configured or structured to rotate relative to the corresponding proximal member 206, e.g., about a corresponding second pivot connecting the distal member 208 to the corresponding proximal member 206.

[0048] In some implementations, each of the fingers 204a-204e (or a subset thereof) can include a respective base member, for example, base members 210a-210e. The base members 210a-210e are also referred to herein as base members 210 or base links 210. Each base member 210 can be mechanically fixed to the palm region 202 and can be mechanically coupled to a corresponding proximal member 206 of the same finger 204. For example, each proximal member 204 can be mechanically coupled to a corresponding base member 210 via a corresponding first pivot. Each proximal member 206 can be configured or structured to rotate relative to the corresponding base member 210, for example, about the corresponding first pivot.

[0049] Each of the fingers 204 can be actuated independently of the other fingers 204. The hand (or hand device) 200 shown in FIG. 2 is an anthropomorphic hand configured to mimic a human hand. In particular, the hand 200 includes a thumb 204 and four fingers 204b-204e. However, it should be noted that the systems described herein can also be employed with other types of robotic hands having any number of fingers 204. For example, the systems and methods described herein can be integrated into or employed in a single-fingered robotic hand or a multi-fingered robotic hand. More generally, the systems and methods described herein can be used with or integrated into other parts of a robot other than, for example, fingers and / or hands.

[0050] 3A-3C show various partially transparent views of the hand 200 of FIG. 2, according to one embodiment. Fig. 3A shows a front view of the hand 200 with a partially transparent palm region 202. Fig. 3B shows the hand 200 without the thumb 204a and with a transparent palm region. Fig. 3C shows the hand 200 with the thumb 204a but without the fingers 204b-204e and with a transparent palm region.

[0051] The hand 200 may include six actuators 302a-302f. Each of the fingers 204b-204e may include or be associated with a corresponding actuator 302b-302e. For example, actuator 302b may actuate movement of the proximal and distal members 206b-208b of finger 204b, actuator 302c may actuate movement of the proximal and distal members 206c-208c of finger 204c, actuator 302d may actuate movement of the proximal and distal members 206d-208d of finger 204d, and actuator 302e may actuate movement of the proximal and distal members 206e-208e of finger 204e. Each of the actuators 302b-302e may be disposed in or integrated with the palm region 202 and may be aligned or substantially aligned with a corresponding finger 204. More generally, the actuators 302b-302e may be arranged or positioned in the palm region 202 along the length of the hand 200 and / or fingers 204.

[0052] Each of actuators 302b-302e can be considered to be part of a corresponding finger (or finger device) 204. For example, finger (or finger device) 204b can include corresponding actuator 302b, finger (or finger device) 204c can include corresponding actuator 302c, finger (or finger device) 204d can include corresponding actuator 302d, and finger (or finger device) 204e can include corresponding actuator 302e. Each of actuators 302b-302e can include a corresponding gearbox, for example, among gearboxes 304b-304e. For example, actuator 302b can include gearbox 304b, actuator 302c can include gearbox 304c, actuator 302c can include gearbox 304d, and actuator 302e can include gearbox 304e.

[0053] 3C , thumb 204a can include or be associated with two actuators 302a and 302f. Actuator 302a can be a thumb-driven actuator similar to actuators 302b-302e. In other words, actuator 302a can be configured or structured to cause movement of proximal member 206a and distal member 308a in a manner similar to that which actuators 302b-302e do for corresponding proximal members 206b-206e and distal members 208b-208e, respectively. Actuator 302f can be an abduction / adduction (Ab / Ad) actuator configured or structured to cause abduction and adduction movement of the thumb. In some implementations, actuators 302a and 302f can be located or integrated in the palm region and can be horizontal or substantially perpendicular to the longitudinal direction of hand 200 or fingers 204b-204e. Actuator 302a can include gearbox 304a, and actuator 302f can include gearbox 304f.

[0054] Each of actuators 302a-302f may be referred to herein individually or collectively as actuator 302. Additionally, gearboxes 304a-304f may be referred to herein individually or collectively as gearbox 304. Actuators 302 and gearboxes 304 are described in further detail below.

[0055] 4A-4F, various views of a cable actuated finger (or finger device) 400 are shown, according to one embodiment. FIGS. 4A and 4C show a front view of the finger 400 in a straight position, and FIG. 4B shows a back view of the finger 400 in a straight position. FIG. 4D shows a side view of the finger 400 in a straight position, and FIG. 4E shows a side view of the finger 400 in a bent position. FIG. 4F shows an exploded view of the finger 400, according to one embodiment.

[0056] 4A-4C , a finger 400 may include a proximal member 402 mechanically coupled to the palm region 202 and having a first end 404 configured to rotate about a first pivot 406 relative to the palm region 202. The first pivot 406 may be referred to herein as a pivot structure and may include a pin, a dowel, or some other coupling structure that allows for rotation of the proximal member 402. The finger 400 may include a distal member 408 mechanically coupled to a second end 412 of the proximal member 402 and having a first end 410 configured to rotate about a second pivot 414 relative to the proximal member 402. The second pivot 414 may be referred to herein as a pivot structure and may include a pin, a dowel, or some other coupling structure that allows for rotation of the distal member 408 relative to the proximal member 402.

[0057] The finger 400 may include a cable 416 coupled (or mechanically coupled) to the actuator 302. A first end or first portion of the cable 416 may be coupled to the actuator 302 and a second portion 418. In some implementations, the first portion of the cable 416 may be wrapped around a pulley of the actuator 302 or a corresponding gearbox 304. The cable 416 may include a second portion 418 that extends or floats along the proximal member 402 and the distal member 408. For example, when the cable 416 is actuated (e.g., pulled) by the actuator 302, the second portion 418 may move freely along the finger 400. In some implementations, the cable 416 or the second portion 418 may not be pinned or fixed in any position relative to the proximal member 402, and may not be pinned or fixed in any position relative to the distal member 408.

[0058] The cable 416 or second portion 418 can be routed along the proximal and distal members 408 such that it is spaced away from the first pivot 406 and the second pivot 414. In other words, the cable 416 or second portion 418 does not have to wrap around the first pivot 406 and does not have to wrap around the second pivot 414. For example, the cable 416 or second portion 418 can be routed toward (or near) the front of the finger 400 relative to the first pivot 406 and does not have to wrap around the second pivot 414. This is particularly the case when the routing or path of the cable 416 or second portion 418 does not have to pass around the first pivot 406 and does not have to pass around the second pivot 414, especially when the proximal member 402 rotates about the first pivot 406 and / or the distal member 408 rotates about the second pivot 414.

[0059] 4D and 4E , the end 420 of the cable 416 or second portion 418 can be associated with or have a dimension (e.g., thickness or diameter) that is larger than the diameter of the cable 416. The end 420 associated with or having the larger dimension can be located within or at the distal member 408 and can be structured to engage with the distal member when the cable 416 is pulled by the actuator 302. For example, the end 420 can include a potted end, an end with a potted insert, or an end coupled to a knob or other structure that has a dimension larger than the diameter of the cable 416. When the cable 416 is pulled by the actuator 302, the end 420 can engage with the distal member 408 or a structure thereof to cause movement of at least one of the proximal member 402 or the distal member 408. For example, when the cable 416 is pulled by the actuator 302, the end 420 can engage with the distal member 408 or structure thereof to rotate the proximal member 402 about the first pivot 406 and / or rotate the distal member 408 about the second pivot 414.

[0060] In some implementations, the finger 400 may include a channel structure 424 extending at least partially along the proximal member 402 and the distal member 408. The channel structure may at least partially receive or accommodate the second portion 418 of the cable 416. In some implementations, the channel structure 424 may include one or more grooves, valleys, or tubes. The channel structure 424 may provide a conduit for the cable 416 or the second portion 418 to move back and forth along the finger 400 when actuated by the actuator 302. In some implementations, as shown in FIGS. 4D and 4E , the channel structure 424 may include a first channel portion 426 located in or on the proximal member 402 and a second channel portion 428 located in or on the distal member 408. In other words, the channel structure 424 may be discontinuous around the joint between the proximal member 402 and the distal member 408.

[0061] In some implementations, the second channel portion 428 located in or on the distal member 408 can include a ledge structure 430. The end 420 (of the cable 416 or second portion 418) associated with or having a larger dimension can be structured to engage with the ledge structure 430 of the second channel portion 428 located on the distal member 408 when the cable 416 is pulled by the actuator 302. In some implementations, the end 420 (of the cable 416 or second portion 418) associated with or having a larger dimension can be structured to engage with the end of the second channel portion 428 (or channel structure 424) located on the distal member 408 when the cable 416 is pulled by the actuator 302.

[0062] In some implementations, the end 420 of the cable (or second portion 418) can float within the second channel portion 428 (or channel structure 424). In other words, the end 420 of the cable (or second portion 418) may not be connected or fixed to the distal member 408. In some implementations, the end 420 of the cable 416 (or second portion 418) can float within a pocket or space located within the distal member 408. For example, the pocket or space can be located at the end of the distal member 408 beyond the second channel portion 428 (or channel structure 424).

[0063] In some implementations, and as shown in FIGS. 4D and 4E , the proximal member 402 and the distal member 408 can be structured to form a convexly curved surface 432, for example, between the first channel portion 426 and the second channel portion 428, to allow or force the cable 416 to bend according to a predetermined radius when the finger 400 bends or the distal member 408 rotates about the pivot 414. Cables typically have a small bending radius, which can cause breakage when bent. By forcing the cable 416 to bend according to a relatively large radius, e.g., a radius larger than the typical bending radius of the cable 416, breakage of the cable 416 can be avoided, which means improved cable stability. A portion of the convexly curved surface 432 can be within the proximal member 402, and another portion can be within the distal member 408.

[0064] 4A-4C , finger 400 can include a first torsion spring 434 disposed around or at first pivot 406 and a second torsion spring 436 disposed around or at second pivot 414. First torsion spring 434 can be structured or configured to create some stiffness at the joint between proximal member 402 and palm region 202, and second torsion spring 436 can be structured or configured to create some stiffness at the joint between proximal member 402 and distal member 408. The stiffness at the joints or pivots 406 and 414 contributes to the stability of finger system 400.

[0065] In some implementations, the finger (or finger system) 400 can include a base member 438. The base member 438 can be fixed to the palm region 202. The proximal member 402 can be coupled to the palm region 202 via the base member 438. For example, the proximal member 402 can be coupled to the base member 438 via a pivot 406 and can be structured to rotate about the pivot 406 relative to the base member 438.

[0066] FIG. 4F shows an exploded view of finger (or finger system) 400, according to one embodiment. Each of pivots 406 and 414 can include a dowel. Torsion spring 436 (referred to as a distal torsion spring in FIG. 4F) can be disposed on the dowel, which can be secured to distal member (or distal link) 408 and / or proximal member (or proximal link) 402 via bearings. Torsion spring 434 (referred to as a proximal torsion spring in FIG. 4F) can be larger (e.g., have a larger diameter) and have greater stiffness than torsion spring 436. A spring standoff can be disposed on the dowel to hold torsion spring 434, which can be secured to distal member (or distal link) 408 and / or proximal member (or proximal link) 402 via bearings.

[0067] The cable 416 is referred to as a tendon in FIG. 4F. An end 420 of the cable 416 located within the distal member 408 can be attached or connected to a manual tensioner such that the cable 416 engages the distal member 408 when actuated by the actuator 302. The manual tensioner can float within an automatic tensioner (having a spring). The automatic tensioner can be located in a pocket or space in the distal member 408 at the end of the channel structure 424.

[0068] In some implementations, as shown in FIGS. 4D-4F, the channel portion 428 that houses the floating end 420 of the cable 416 can be angled relative to or relative to the back surface of the finger 400.

[0069] 5A and 5B, an internal view of another finger (or finger system) 500 is shown, according to one embodiment. Similar to finger 400, finger 500 can include a proximal member 502 and a distal member 504. Finger 500 can also include a base member 506. Distal member 502 can be structured or configured to rotate about pivot 506 relative to base member 506 or relative to palm region 202. Distal member 504 can be configured to rotate about pivot 510 relative to the proximal member. Finger 500 can include a cable 512 connected at a first end to actuator 302 and a second end disposed at distal region 504. Cable 512, or a portion thereof, can extend along proximal region 502 and distal region 505 and can be spaced apart from pivots 508 and 510.

[0070] Finger 500 may include one or more tubes, such as tubes 514 and 516, that form a channel that partially houses or receives cable 512. A second end of cable 512 may be free-floating (not connected, fastened, or secured) within a region (or pocket region) 518 of distal member 504. The second end of cable 512 may have a potted insert 520 structured to engage the end of pocket region 518 when cable 512 is pulled by actuator 302.

[0071] Fingers (or finger systems) 400 and 500, or mechanisms thereof, can be used on or integrated into hand 200 of FIG. 2. Any of fingers 204a-204e of FIG. 2 can be implemented as finger 400 or finger 500. Note that features described in different figures or embodiments can be combined in a single embodiment. For example, pocket region 518 of finger 500 can be implemented in finger 400. Also, potted insert 520 may be integrated into finger 400 of FIG. 4.

[0072] The routing of the cables 416, 512 described in connection with Figures 4A-4F and 5A-5B has several technical advantages over conventional cable-driven systems. Specifically, conventional cable-driven fingers wrap the cable 416 around the pivots 406 and 414. The cable 416 can include a metal cable, which has a fixed bend radius. In conventional systems, the cable 416 has a very small bend radius, so it is wrapped around the joint pivot to maintain a fixed radius when bent and avoid cable breakage. However, wrapping the cable 416 around the pivots 406 and 414 limits the range of motion of the finger (or the range of motion of the proximal and distal members 402, 408).

[0073] The cable routing described in FIGS. 4A-4F and 5A-5B allows for much greater force application, especially as the angle between the proximal member 402 and the distal member 408 decreases. The amount of force applied is actually a function of how far the cable 416 is from the joint. As the cable 416 moves further away from the joint, more force can be applied as the hand 200 closes, allowing for fine tuning of the torque graph in space. The cable routing described herein (rather than wrapping around a pivot) also helps generate more uniform joint torque and allows for fine tuning of torque instead of fine tuning a gearbox, as is typically done in conventional systems. Fine tuning a gearbox introduces various issues, such as the use of non-concentric and / or asymmetric gears, which makes the design more complex. Using the finger structure (e.g., cable position relative to the joint, finger member length, and / or other parameters) to fine tune torque instead of fine tuning a gearbox reduces the number and complexity of parts.

[0074] Another advantage of the described cabling is the fact that the two joints of the finger 400 are driven by the same actuator 302, making it more adaptive. The finger 400 is adaptive in the sense that different links or members move as the location of contact (or contact force by an object) changes. In other words, which of the proximal and distal members 402 and 408 moves can change depending on the point of contact.

[0075] Additionally, maintaining the end of cable 420 floating within distal member 408 prevents breakage or damage to cable 416. Specifically, if finger 400 contacts or presses against another object, the fact that cable 416 is floating provides a degree of flexibility, preventing breakage or denting of cable 416. Additionally, the use of torsion springs 434 and 436 provides a degree of stability to finger system 400, especially when finger 400 is grasping an object or experiencing some external force. Torsion springs 434 and 436 also provide anti-backlash protection.

[0076] 6A-6G, motion simulation results are shown for a system 600 including two fingers, according to one embodiment. Figure 6A shows system 600 including thumb 602 and index finger 604. Figures 6B-6G show sample frames from a video sequence depicting the motion of fingers 602 and 604 toward each other.

[0077] When the cables of both fingers 602 and 604 are pulled by the actuator 302 or gearbox 304, the fingers 602 and 604 move toward each other. The circles in Figures 6B-6G indicate divots (or curved surfaces) on the fingers 400 that prevent the cables from bending and allow for torque adjustment. As the fingers 602 and 604 bend, the distance between the corresponding cables (shown as black lines) and the corresponding joints increases, meaning that the radius or distance between each joint and the cable changes. The movement of the proximal and distal members of each finger indicates that the cables are acting in a manner similar to the tendons in a human finger. Additionally, the fact that the radius (or distance from the joint) of the cables is changing helps shift some of the complexity from the gearbox 304 to the fingers themselves.

[0078] 7A-7C show diagrams of the gearbox 304, according to one embodiment. The gearbox 304 can include a gear 702 (e.g., a worm gear) and a worm wheel 704. The gear 702 can be fixed to a shaft of the actuator 302. Rotation of the shaft by a motor rotates the gear, which rotates the worm wheel 704. The worm wheel 704 can include a pulley 706, and the cable 416 can be connected to the pulley 706. For example, a portion of the cable 416 can be wound around the pulley 706. As the gear 702 rotates, the cable is pulled or wound from the pulley 706.

[0079] 8A and 8B illustrate the use of a Hall Effect sensor 802 to monitor the location of a finger or corresponding member, according to one embodiment. A finger, such as finger 400, can include a magnet 804, such as a ring magnet. The magnet 304 can be coupled to a pivot 406 between the proximal member 402 and the palm region 202 (or the base member 438). The finger 400 can include a Hall Effect sensor 302 disposed proximate to the respective magnet 804. For example, the Hall Effect sensor 803 can be disposed or located on the base member 438 or the palm region 202. The Hall Effect sensor 802 can sense or measure a magnetic field generated by the magnet 804. As the proximal member 402 rotates, the magnet 804 also rotates. The Hall Effect sensor 804 does not move with the proximal member 402 and can detect changes in the magnetic field as the proximal member 402 rotates. The Hall Effect sensor 802 can be communicatively coupled to the processor 114. The processor 114 can determine the location or angle of rotation of the proximal member 402 based on the measured magnetic field.

[0080] In some implementations, each finger of the hand 200 can include a respective Hall Effect sensor 802 and a respective magnet 804. In some implementations, the finger 400 (or each finger of the hand 200) can include a magnet disposed at or around the pivot 414 and a Hall Effect sensor 802 disposed on a proximal member proximate to the magnet 804. The Hall Effect sensor 802 can be used by the processor 114 to detect the location or rotational angle of the distal member relative to the proximal member 402. In some implementations, the finger 400 (or each finger of the hand 200) can include a first Hall Effect sensor and a first magnet for monitoring the location of the proximal member 402 and a second Hall Effect sensor and a second magnet for monitoring the location of the distal member 408 relative to the proximal member 402. In some implementations, the magnet 804 can include a ring magnet disposed around the pivot 406 or the pivot 414.

[0081] FIG. 9 illustrates a framework 900 for optimizing parameters of a cable-driven finger, according to one embodiment. The framework includes two fingers and an object grasped (or to be grasped) by the two fingers. Each finger can have a corresponding proximal link and a corresponding distal link. Each finger can be actuated by a corresponding cable. Each finger exerts a corresponding force on the object.

[0082] The mechanism of adaptive fingers is inherently unstable. The goal of optimization is to solve for optimal finger parameters, including finger length (e.g., the length of the finger's proximal and distal members), joint stiffness (e.g., the stiffness introduced by the corresponding torsional springs), joint location, and cable routing (e.g., distance from the joints). Optimization can include minimizing post-contact work (e.g., object displacement relative to the finger) and maximizing resistible external forces. Minimizing post-contact work means minimizing object movement (e.g., slippage) relative to the finger once grasped. This is expected to lead to a more secure and stable grasp. Maximizing resistible external forces means maximizing resistance to any external forces after grasping the object. This can prevent or reduce the possibility of the object falling, for example, if it hits an obstacle.

[0083] force F xL ,F yL represents the force of the left finger on the x-axis and y-axis. xR ,F yR represent the forces of the right finger in the x-axis and y-axis. Both forces depend on the position or routing of the cable. The optimization can be performed subject to a set of constraints such as equilibrium, torque equilibrium, hand model constraints, closure constraints, and / or kinematic constraints, among other constraints.

[0084] In some implementations, grasping a wide variety of objects can be modeled or simulated at different locations, and a computer system including a memory and a processor can solve for optimal parameters (e.g., optimal parts and part locations). Failure modes can include object ejection, loss of grasp, and / or loss of stability. Solving the optimization problem can include determining cable locations and distances from joints, spring stiffness, and / or finger and link lengths.

[0085] 10A and 10B show an optimization model and a simulation of the optimized hand model. In particular, FIG. 10A shows the variables considered for the proximal and distal members in the optimization. FIG. 10B shows a simulation of an exemplary hand model with estimated cable locations and representative shapes determined by solving the optimization problem on a computer system as depicted in FIG. 10A.

[0086] 11A-11C show simulation results illustrating the effective lever arm, achievable force range, contact vector field, and energy dissipation for an example cable driven finger described herein.

[0087] Although the embodiments described herein are described in the context of a knee joint assembly for a humanoid robot, the embodiments may be used or applied to other types of joints and / or other types of robots.

[0088] The various illustrative logic blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or a combination of both. To clearly illustrate this interchangeability between hardware and software, the various illustrative components, blocks, modules, circuits, and steps have been described generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in various ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure or the claims.

[0089] Computer software-implemented embodiments may be implemented in software, firmware, middleware, microcode, hardware description languages, or any combination thereof. A code segment or machine-executable instruction may represent a procedure, a function, a subprogram, a program, a link, a sublink, a module, a software package, a class, or any combination of instructions, data structures, or program statements. A code segment may be coupled to another code segment or a hardware circuit by passing and / or receiving information, data, arguments, parameters, or memory contents. Information, arguments, parameters, data, etc. may be passed, forwarded, or transmitted via any suitable means including memory sharing, message passing, token passing, network transmission, etc.

[0090] The actual software code or specialized control hardware used to implement these systems and methods is not a limitation of the claimed features or this disclosure. Thus, although the operation and behavior of the systems and methods have been described without reference to specific software code, it will be understood that software and control hardware can be designed to implement the systems and methods based on the description herein.

[0091] If implemented in software, the functions may be stored as one or more instructions or code on a non-transitory, computer-readable, or processor-readable storage medium. The steps of a method or algorithm disclosed herein may be embodied in a processor-executable software module, which may reside on a computer-readable or processor-readable storage medium. Non-transitory computer-readable or processor-readable media include both computer storage media and tangible storage media that facilitate transfer of a computer program from one place to another. Non-transitory processor-readable storage media may be any available medium that can be accessed by a computer. By way of example, and not limitation, such non-transitory processor-readable media may comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage, or any other tangible storage medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer or processor. As used herein, disk and disc include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), Blu-ray disc, and floppy disk, where a "disk" typically reproduces data magnetically, while a "disk" reproduces data optically with a laser. Combinations of the above should also be included within the scope of computer-readable media. Furthermore, the operations of a method or algorithm may reside as one or any combination or set of code and / or instructions on a non-transitory, processor-readable medium and / or computer-readable medium, which may be incorporated into a computer program product.

[0092] The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the embodiments described herein and variations thereof. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the principles defined herein may be applied to other embodiments without departing from the spirit or scope of the subject matter disclosed herein. Thus, the present disclosure is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the following claims and the principles and novel features disclosed herein.

[0093] While various aspects and embodiments have been disclosed, other aspects and embodiments are contemplated. The various disclosed aspects and embodiments are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

Claims

1. 1. A robotic hand system, comprising: The palm area and one or more fingers; Equipped with Each finger is an actuator device; a respective proximal member having a first end mechanically coupled to the palm area robot and configured to rotate about a respective first pivot relative to the palm area; a respective distal member mechanically coupled to a second end of the proximal member and configured to rotate relative to the proximal member about a respective second pivot; each cable having a first portion coupled to the actuator and a second portion extending along the proximal and distal members, the second portion having an end spaced from the first and second pivots and having a dimension larger than a diameter of the cable, the end with the larger dimension structured to engage the distal member when the cable is pulled by the actuator.

2. The robotic hand system of claim 1 , wherein the end portion having a large dimension is floating within the area of ​​the distal member.

3. The end portion having the larger dimension is Potted ends, or Ends with potted inserts The robotic hand system of claim 1 , comprising at least one of:

4. 2. The robotic hand system of claim 1, wherein each finger comprises a respective channel structure extending at least partially along the respective proximal member and the respective distal member, the respective channel structure at least partially accommodating a second portion of the respective cable.

5. 5. The robotic hand system of claim 4, wherein an enlarged end of the second portion of each cable is structured to engage a ledge structure of the respective channel structure when the respective cable is pulled by a respective actuator.

6. Each finger is a respective first torsion spring disposed about the respective first pivot; a respective second torsion spring disposed about the respective second pivot.

7. Each finger is a respective magnet coupled to said respective first pivot; a respective Hall effect sensor disposed proximate to the respective magnet.

8. The robotic hand system of claim 7 , wherein the respective magnets comprise ring magnets disposed around the respective first pivots.

9. Each finger is a respective magnet coupled to said respective second pivot; a respective Hall effect sensor located proximate to the respective magnet.

10. 2. The robotic hand system of claim 1, wherein the distance between each cable and each first pivot varies and / or the distance between each cable and each second pivot varies.

11. A finger device, an actuator device; a proximal member having a first end mechanically coupled to the base member and configured to rotate relative to the base member about a first pivot; a distal member mechanically coupled to a second end of the proximal member and configured to rotate relative to the proximal member about a second pivot; a cable having a first portion coupled to the actuator and a second portion extending along the proximal and distal members, the second portion having an end spaced from the first and second pivots and having a dimension larger than a diameter of the cable, the end having the larger dimension being structured to engage the distal member when the cable is pulled by the actuator; A finger device comprising:

12. The finger device of claim 11 , wherein the end portion having the larger dimension is floating within the area of ​​the distal member.

13. The end portion having the larger dimension is Potted ends, or Ends with potted inserts The finger device according to claim 11 , comprising at least one of:

14. The finger device of claim 11 , further comprising a channel structure extending at least partially along the proximal and distal members, the channel structure at least partially accommodating a second portion of the cable.

15. 15. The finger device system of claim 14, wherein the enlarged ends of the second portions of the cables are structured to engage with ledge structures of the channel structures when the respective cables are pulled by respective actuators.

16. a first torsion spring disposed about the first pivot; a second torsion spring disposed about the second pivot; The finger device of claim q1 further comprising:

17. a magnet coupled to the first pivot; a Hall effect sensor disposed proximate to the magnet; The finger device of claim 11 further comprising:

18. The finger device of claim 17 , wherein the magnet comprises a ring magnet disposed about the first pivot.

19. a magnet coupled to the second pivot; a Hall effect sensor disposed proximate to the magnet; The finger device system of claim 11 further comprising:

20. The finger device of claim 1 , wherein the distance between the cable and the first pivot varies and / or the distance between the cable and the second pivot varies.

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