Abstract:
A robotic manipulator arm is disclosed. The arm includes joints that are attachable and detachable in a tool-free manner via a universal mating adapter. The universal mating adapter includes a built-in electrical interface for an operative electrical connection upon mechanical coupling of the adapter portions. The universal mating adapter includes mechanisms and the ability to store and communicate parameter configurations such that the joints can be rearranged for immediate operation of the arm without further reprogramming, recompiling, or other software intervention.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. provisional patent application Ser. No. 61/655,485 filed Jun. 5, 2012, and entitled “Apparatus, Systems, and Methods for Reconfigurable Robotic Manipulator and Coupling,” which is hereby incorporated herein by reference in its entirety. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    At least some portion of the technology disclosed herein was developed while work was performed for NASA on contract number NNJ08JA66C during the period that includes Jan. 29, 2007 to Aug. 29, 2010. 
     
    
     BACKGROUND 
       [0003]    The disclosure relates generally to automation and robotics, and more particularly, the disclosure relates to manipulator arms, end-effectors, and adapter mechanisms for manipulator arms and end-effectors. Still more particularly, the present disclosure relates to apparatus and methods for interchanging and operating manipulator arms and end-effectors. 
         [0004]    The field of automation and robotics augments and extends human activities and exploration both on earth and in space. Stationary robots are common in industrial settings for repetitive tasks such as product assembly and packaging. Mobile robots work in a variety of indoor and outdoor settings, moving through varied terrain and in varied environmental conditions. Mobile robots travel on the ground, through the air, and through water to investigate difficult-to-reach locations, handle chemicals, collect environmental samples and data, patrol property, search for people trapped in rubble, and perform a variety of other tasks. 
         [0005]    The physical work of a robot is performed by end-effectors mounted on manipulator arms. Mating adapters connect the end-effector to the manipulator arm and the manipulator arm to the body of the robot. The end-effector may be a hand tool, a power tool, a dexterous gripper, a scientific probe, a scoop, or any other attachable device that allows the robot to engage its surroundings. A manipulator arm connects an end-effector to the body of the robot and provides reach capability. A manipulator arm includes one or more segments or joints each with the ability to move in prescribed directions. Basic movements for joints include pitch, which is like the rotational motion of a human elbow, roll, which is like the motion of a human wrist when the hand is rotated about the forearm axis, and linear extension/retraction. Forming a manipulator arm from multiple joints gives the manipulator more flexibility, i.e., the ability to move in more directions. The objective is to move the end-effector toward a target and to engage the target. Basic movements for an end-effector include translation (up-down, forward-backward, and left-right) and rotation (clockwise and counterclockwise). Each of the three translational movements may be assigned to one axis of a coordinate system defined by three orthogonal, mutually perpendicular axes. The axes may be called x, y, and z. The orientation and starting point (origin) of the group of axes may be defined with reference to one of several places. For example, the orientation and origin may be established at a fixed spot within the region being explored (earth or moon), on the robot body, or at the connection point of the end-effector. The last two locations would define a moving and rotating coordinate system because the robot moves and turns. 
         [0006]    The total number of independent, basic movements that a particular manipulator arm or an end-effector may make is known as its degrees-of-freedom (DOF). Three DOF are achieved by the translational movement along the three axes. Forward and reverse movement along any one axis is considered one DOF. When the end-effector is rotated clockwise or counter-clockwise around any of the three axes, this capability adds three more DOF, for a total of six DOF. Adding more joints to a manipulator arm adds more DOF. 
         [0007]    When a manipulator arm is formed from joints with pitch and roll capabilities, performing a straight translational movement of the end-effector requires the simultaneous movement of multiple joints. Moving multiple joints simultaneously is governed by software algorithms stored in a computer or in another control system that may be on the main body of the robot or separate from the robot. 
         [0008]    The work required of a particular robot may change, often requiring modifications to the robot. Common modifications or reconfigurations involve replacing the end-effector or the entire manipulator arm. If the new equipment has a different connecting adapter, the adapter on the robot must be either modified or replaced. If the new equipment has the same adapter as the previous manipulator or end-effector, then the exchange will be simpler but may still require significant effort. The end-effector and manipulator arm may be coupled by an adapter using threaded fasters such as bolts and nuts or machine screws, or coupled by clamps, or coupled by a pneumatically-actuated lock mechanism. These coupling methods require one or more tools or a source of compressed air. Furthermore, the exchange of an end-effector and manipulator arm typically requires adjustment to the controlling software to account for the reach, DOF, lift capability, and other parameters of the new equipment. Seemingly simple modifications to a robot can often be time-consuming and labor intensive. 
         [0009]    Accordingly, there remains a need in the art for improved devices and methods for reconfiguring robotic manipulators arms and end-effectors. 
       SUMMARY 
       [0010]    A robotic manipulator arm is disclosed. The arm includes joints that are attachable and detachable in a tool-free manner via a universal mating adapter. The universal mating adapter includes a built-in electrical interface for an operative electrical connection upon mechanical coupling of the adapter portions. The universal mating adapter includes mechanisms and the ability to store and communicate parameter configurations such that the joints can be rearranged for immediate operation of the arm without further reprogramming, recompiling, or other software intervention. 
         [0011]    In some embodiments, a reconfigurable robotic manipulator arm includes a first joint including a first end assembly having a mechanical coupling interface and an electrical interface, and a second end assembly having a mechanical coupling interface and an electrical interface, a second joint including a third end assembly having a mechanical coupling interface and an electrical interface, and a fourth end assembly having a mechanical coupling interface and an electrical interface, wherein the first and fourth end assemblies are connectable at the first and fourth mechanical coupling interfaces to form a first adapter between the first and second joints including an operative electrical connection between the first and fourth electrical interfaces, and wherein the first and second joints are detachable at the first adapter and re-connectable at the second and third mechanical coupling interfaces to form a second adapter between the first and second joints including an operative electrical connection between the second and third electrical interfaces. In some embodiments, at least one of the adapters includes a control board. In some embodiments, the control board is configured to store electrical data, such as operational parameters of at least one of the joints. In some embodiments, the control board is configured to pass power or electrical signals between coupled joints. In some embodiments, the control board is configured to pass power or electrical signals between a joint coupled to a robot or end-effector. 
         [0012]    In some embodiments, a joint for a robotic manipulator arm includes a base section, a rotatable section, a motor configured to rotate the rotatable section or the base section with respect to the other section, a brake, and a magnetic brake release switch configured to be activated by a removable external magnet and when activated to release the joint to move freely, wherein a ferrous metal member may augment the performance of the magnetic brake release switch. In some embodiments, the joint includes a position sensor assembly configured to detect the absolute angular position of the rotatable section with respect to the base section wherein the position sensor assembly is mounted on one of the joint sections and passes or moves near a position-indicating design mounted on the other section of the joint. 
         [0013]    In some embodiments, an adapter for connecting different portions of a robotic system includes a first assembly including a mechanical coupling interface and an electrical interface, and a second assembly including a mechanical coupling interface and an electrical interface, wherein the first assembly is connectable to a first portion of the robotic system, wherein the second assembly is connectable to a second portion of the robotic system, wherein the mechanical interfaces are connectable in a tool-free manner whereby the electrical interfaces are brought into contact to form an operative electrical connection in the adapter. In some embodiments, the first assembly and the second assembly comprise a plurality of mating pairs of slidably engageable electrical connectors to transfer data and power signals between the first and second assemblies and one or more attached joints. In some embodiments, the transfer of data or power will not occur unless at least one specified pair of mating electrical connectors is engaged, and wherein the other mating pairs of electrical connectors are always engaged whenever the at least one specified pair is partially engaged or engaged. In some embodiments, the first assembly forms a hermetically sealed barrier, or the second assembly forms a hermetically sealed barrier. In some embodiments, the adapter further includes a mechanism for automatically detaching an object from or attaching the object to a robotic joint or manipulator arm, the mechanism including a socket portion including the first assembly, a plug portion including the second assembly, at least one motor-driven surface, wherein the object to be detached or attached may be an end-effector or another joint, wherein the motor-driven surface is configured to induce the rotational engagement of the first and second assemblies, and wherein the mechanism is configured for automatic or manual operation. 
         [0014]    Thus, embodiments described herein comprise a combination of features and characteristics intended to address various shortcomings associated with certain prior devices, systems, and methods. The various features and characteristics described above, as well as others, will be readily apparent to those of ordinary skill in the art upon reading the following detailed description, and by referring to the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    For a detailed description of the disclosed embodiments of the invention, reference will now be made to the accompanying drawings in which: 
           [0016]      FIG. 1  is side view of an embodiment of a robotic manipulator arm comprising a series of connected joints in accordance with the principles disclosed herein; 
           [0017]      FIG. 2  is a perspective view of a mobile robot base coupled with the manipulator arm of  FIG. 1  and an end-effector tool, in accordance with the principles disclosed herein; 
           [0018]      FIG. 3  is a perspective view of another end-effector tool that may couple to the manipulator arm of  FIG. 1 , in accordance with the principles disclosed herein; 
           [0019]      FIG. 4  is a perspective view of an embodiment of a universal mating adapter (UMA), which may also be referred to as a universal mechanical-electrical coupling (UMEC), in accordance with the principles disclosed herein; 
           [0020]      FIG. 5  is a sectional view of the UMA shown in  FIG. 4 , in accordance with the principles disclosed herein; 
           [0021]      FIG. 6  is an exploded view of the UMA shown in  FIG. 4  with the components of the plug assembly and the socket assembly identified, in accordance with the principles disclosed herein; 
           [0022]      FIG. 7  is a perspective view of the plug connector body of the UMA shown in  FIG. 6 , in accordance with the principles disclosed herein; 
           [0023]      FIG. 8  is a perspective sectional view of the UMA plug connector body shown in  FIG. 7 , in accordance with the principles disclosed herein; 
           [0024]      FIG. 9  is a first perspective view of the control board and power board of the UMA plug assembly shown in  FIG. 6 , in accordance with the principles disclosed herein; 
           [0025]      FIG. 10  is a second perspective view of the control board and power board of  FIG. 9 , in accordance with the principles disclosed herein; 
           [0026]      FIG. 11  is a first perspective view of a mounting plate of the UMA shown in  FIG. 6 , in accordance with the principles disclosed herein; 
           [0027]      FIG. 12  is a second perspective view of the UMA mounting plate of  FIG. 11 , in accordance with the principles disclosed herein; 
           [0028]      FIG. 13  is a first perspective view of a plug interface board for the UMA shown in  FIG. 6 , in accordance with the principles disclosed herein; 
           [0029]      FIG. 14  is a second perspective view of the UMA plug interface board in  FIG. 13 , in accordance with the principles disclosed herein; 
           [0030]      FIG. 15  is a perspective view of the socket connector body of the UMA shown in  FIG. 6 , in accordance with the principles disclosed herein; 
           [0031]      FIG. 16  is a second perspective sectional view of the socket connector body shown in  FIG. 15 , in accordance with the principles disclosed herein; 
           [0032]      FIG. 17  is a first perspective view of a socket power board of the UMA shown in  FIG. 6 , in accordance with the principles disclosed herein; 
           [0033]      FIG. 18  is a second perspective view of the UMA socket power board of  FIG. 17 , in accordance with the principles disclosed herein; 
           [0034]      FIG. 19  is a first perspective view of a socket interface board for the UMA shown in  FIG. 6 , in accordance with the principles disclosed herein; 
           [0035]      FIG. 20  is a second perspective view of the UMA socket interface board in  FIG. 19 , in accordance with the principles disclosed herein; 
           [0036]      FIG. 21  illustrates a sectional view of a roll joint that may be incorporated into the robotic manipulator arm of  FIG. 1 , in accordance with the principles disclosed herein; 
           [0037]      FIG. 22  is a perspective view of a proximal end cap for the roll joint of  FIG. 21  to attach the UMA plug connector body of  FIG. 7 , in accordance with the principles disclosed herein; 
           [0038]      FIG. 23  is perspective sectional view of the proximal end cap of  FIG. 22 , in accordance with the principles disclosed herein; 
           [0039]      FIG. 24  is a perspective view of a distal end cap for the roll joint of  FIG. 21  to attach the UMA socket connector body of  FIG. 15 , in accordance with the principles disclosed herein; 
           [0040]      FIG. 25  is perspective sectional view of the distal end cap of  FIG. 24 , in accordance with the principles disclosed herein; 
           [0041]      FIG. 26  is a perspective view of a pitch joint that may be incorporated into the robotic manipulator arm of  FIG. 1 , in accordance with the principles disclosed herein; 
           [0042]      FIG. 27  illustrates a sectional view of the pitch joint in  FIG. 26 , in accordance with the principles disclosed herein; 
           [0043]      FIG. 28  is a perspective view of automated detach/attach module (ADAM) that incorporates the UMA of  FIG. 4 , in accordance with the principles disclosed herein; 
           [0044]      FIG. 29  is a side view of the combined UMA and automated detach/attach module of  FIG. 28 , in accordance with the principles disclosed herein; 
           [0045]      FIG. 30  is a side view of an ADAM coupled to a portion of the robotic manipulator arm of  FIG. 1  and coupled to an end-effector tool in accordance with the disclosure of  FIG. 3 , for which the outline of a tool holder is shown; 
           [0046]      FIG. 31  is a perspective view of a position sensor assembly for a joint, such as the roll joint of  FIG. 21 , in accordance with the principles disclosed herein; and 
           [0047]      FIG. 32  is a position-indicating label to be read by digital and analog sensors of the position sensor assembly of  FIG. 31 , in accordance with the principles disclosed herein. 
       
    
    
     DETAILED DESCRIPTION 
       [0048]    The following discussion is directed to various embodiments of the invention. The embodiments disclosed should not be interpreted or otherwise used as limiting the scope of the disclosure. One skilled in the art will understand that the following description has broad application, and the discussion of any embodiment is meant only to be exemplary of that embodiment, and not intended to suggest that the scope of the disclosure, including the claims, is limited to that embodiment. 
         [0049]    Certain terms are used in the following description and claims to refer to particular features or components. As one skilled in the art will appreciate, different persons may refer to the same feature or component by different names. This document does not intend to distinguish between components or features that differ in name but not function. The drawing figures are not necessarily to scale. Certain features and components herein may be shown exaggerated in scale or in somewhat schematic form, and some details of conventional elements may not be shown in interest of clarity and conciseness. In addition, like or identical reference numerals may be used to identify common or similar elements. However, for clarity in the figures, not every similar or common element will be identified. 
         [0050]    In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . .” Also, the term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples or is coupled to a second device, that connection may be through a direct connection, or through an indirect connection via other devices, components, and connections. In addition, as used herein, the terms “axial” and “axially” generally mean along or parallel to a given axis (e.g., central axis of a body or a port), while the terms “radial” and “radially” generally mean perpendicular to the axis. For instance, an axial distance refers to a distance measured along or parallel to the axis, and a radial distance means a distance measured perpendicular to the axis. 
         [0051]    The terms “system,” “assembly,” and “sub-assembly” may refer to a collection of two or more components, or elements, that are associated with one another and that may be coupled together. Furthermore, a system, assembly, or sub-assembly may be comprised of a collection of other, lesser systems, assemblies, or sub-assemblies. The terms “proximal” and “distal” will refer to the intended mounting location of an object or feature relative to the location of the main body of a robot or relative to the location of another supporting device. As such, proximal will describe an object or feature located closer to the main body of a robot as compared to a distal object or feature. 
         [0052]      FIG. 1  illustrates an embodiment of robotic manipulator arm  1  comprising one or more segments, or joints,  5 . When arm  1  is formed from multiple joints  5 , each joint  5  may be selectively coupled to an adjacent joint  5  by an interchangeable connector called a universal mating adapter (UMA)  100 , which is alternatively called a universal mechanical-electrical coupling (UMEC). In  FIG. 1 , seven joints  5  are shown, but more or fewer joints  5  may be included in the configuration of a robotic manipulator arm like arm  1 . Examples of various types of joints  5  include a roll joint  20  and a pitch joint  60 , and will be explained in further detail in the disclosure below. The arm  1  may also include a UMA socket assembly  305 .  FIG. 2  illustrates an integrated system, called robot  10 , comprising mobile robot base  11 , an arm  1  with one or more UMA  100 , and a robot controller  12 . Robot controller  12  includes software to govern the performance of robot  10 , including arm  1  and a tool  14 . One of the UMA  100  (not visible) couples the robot main base  11  to one end of arm  1 . Another UMA  100  may attach a tool, also called an end-effector, to the other end of arm  1 . In the example of  FIG. 2 , gripping tool  14  is coupled to arm  1 . 
         [0053]    Another example of an end-effector is tool  85  in  FIG. 3 , which, in this embodiment, is a scoop configured to collect a soil sample or to perform similar tasks. In other embodiments, tool  85  may instead incorporate a drill, a gripper, a saw, cameras, or another capability. Reference to tool  85  throughout the disclosure will assume that tool  85  has any one or more of these capabilities. In  FIG. 3 , tool  85  is shown with a tri-lobe adapter plate  86 , which aids during removal and storage. Tool  85  may include sensors (not shown) to measure environmental conditions or tool performance or for diagnostics. If sensors are included in tool  85 , power and data signals can be exchanged with the robot controller  12  through manipulator arm  1 . 
         [0054]    UMA  100  is shown in  FIGS. 4 and 5 . As identified in the exploded view of  FIG. 6 , UMA  100  comprises two primary sub-assemblies: a first or proximal sub-assembly called a UMA socket assembly  305  and a second or distal sub-assembly called a UMA plug assembly  105 . 
         [0055]    Referring to  FIG. 6 , UMA plug assembly  105  comprises several components: a generally annular plug connector body  120  (also  FIG. 4 ), an internally threaded locking ring  160 , a power board  175  (also  FIG. 4 ), a control board  180  (also  FIG. 4 ), a mounting plate  190 , an o-ring  215 , an electrical plug interface board  220 , and a central axis  106 . Each component of plug assembly  105  will be explained in the following paragraphs. Subsequently, the assembly of these components will be explained. 
         [0056]    As shown in  FIGS. 7 and 8 , the generally annular plug connector body  120  of UMA plug assembly  105  comprises a central axis  106 , a first or proximal end  123 , second or distal end  124 , cylindrical outer surface  126 , cylindrical inner surface  127 , a circumferential outer flange  130 , an inner flange  135 , generally rectangular mechanical bosses  140 , countersunk through-holes  146 , and generally trapezoidal recesses  148 . Outer flange  130  is disposed at the proximal end  123  of plug body  120 . Outer flange  130  comprises a distal end  132  and a cylindrical outer surface  131 . Inner flange  135  is disposed axially near the center of the inner surface  127  and extends radially inward from inner surface  127 . Inner flange  135  is characterized by a proximal surface  136 , a cylindrical inner surface  138 , and a seal gland  139  adjacent to proximal surface  136 . Mechanical bosses  140  extend axially away from proximal end  123  and in some aspect define a continuation of inner surface  127 . In the disclosed embodiment, plug body  120  has four mechanical bosses  140 . Other embodiments may have a different number of bosses or may have bosses of different shapes but functionally similar to bosses  140 . The end of each mechanical boss  140  includes an engagement tab  142 , which extends radially outward and might not extend back to proximal surface  123 . The engagement tabs  142  are uniquely placed on bosses  140  so that if plug body  120  is rotated about its central axis  106 , the new position of engagement tabs  142  will only match their original position if the angle of rotation of plug body  120  is a multiple of 360 degrees. This angular limitation insures that mechanical bosses  140  and their corresponding engagement tabs  142  only allow UMA plug assembly  105  and UMA socket assembly  305  to engage in a single orientation relative to one another. The coupling of plug assembly  105  and socket assembly  305  will be described in more detail at a later point in this disclosure. 
         [0057]    Continuing with plug connector body  120  in  FIGS. 7 and 8 , countersunk through-holes  146  start at proximal end  123  and extend through distal end  124  to allow machine screws (not shown) to couple plug body  120 , and therefore all of UMA plug assembly  105 , to a joint  5  of robotic manipulator arm  1 . In depth, recesses  148  extend from proximal end  123  of plug body  120  to proximal surface  136  of inner flange  135 . In the radial direction, recesses  148  in plug body  120  extend outward from inner surface  127 . 
         [0058]    Returning to  FIG. 6 , locking ring  160  includes a central axis  106 , a first or proximal end  163 , a second or distal end  164 , a cylindrical outer surface  166 , a cylindrical inner surface  168 , and a flange  170 . Additionally, threads  169  are cut into inner surface  168 . Flange  170  at distal end  164  extends radially inward and includes a generally smooth, inner proximal face  171  within ring  160 . Distal end  164  includes an external surface  165  that is perpendicular to central axis  106 . In the example of  FIG. 6 , flange  170  includes a portion of external surface  165 . The external surface  165  is generally smooth in at least one embodiment. In at least one embodiment, cylindrical outer surface  166  may have dimples, knurling, or another form of rough surface (not shown) to improve the ability of operators and equipment to grip surface  166 . 
         [0059]      FIGS. 9 and 10  present power board  175  and control board  180  of plug assembly  105 , which are coupled by threaded fasteners  177   a  and nuts  177   b , and are held at a fixed distance apart by spacers  178 . Power board  175  comprises a central axis  106  a first or proximal face  174 , a second or distal face  176 , one or more sets of power and data connector receptacles  179 , and a variety of multi-pin electrical connectors  184 . Receptacles  179  pass through power board  175 , extending beyond proximal face  174  and extending further beyond distal face  176 . Although not shown, power board  175  may also comprise power conditioning circuitry, fuses, internal circuitry, and other components to aid in routing electrical power and data signals to a coupled joint  5  or to a coupled tool  85 . 
         [0060]    Control board  180  comprises one or more integrated circuits and a variety of multi-pin electrical connectors  184 . Although not shown, control board  180  may also comprise fuses, internal circuitry, other integrated circuits, memory storage device(s), software, and other components to aid in managing a coupled joint  5  or a coupled tool  85 . When coupled to power board  175 , control board  180  is positioned nearest distal face  176 , and threaded fasteners  177 A extend beyond proximal face  174 . Some of the multi-pin electrical connectors  184  couple control board  180  to power board  175 . Other multi-pin electrical connectors  184  may couple with components, such as a motor or a sensor, of a joint  5  when a UMA plug assembly  105  is connected to a joint  5  or may couple to components of an end-effector tool (not shown). 
         [0061]    As indicated in  FIG. 6 , a mounting plate  190  or a derivative of plate  190  may be incorporated into either a UMA plug assembly  105  or a UMA socket assembly  305 . As illustrated in  FIGS. 11 and 12 , mounting plate  190  includes a central axis  106 , a first end  193 , a second end  194 , a first recessed face  195 , a second recessed face  196 , a generally cylindrical outer surface  198 , multiple external circumferentially-spaced tabs  202 , and a seal gland  204 . First end  193 , second end  194 , first recessed face  195 , and second recessed face  196  are perpendicular to central axis  106 . Seal gland  204  is radially disposed near first end  193  between the first recessed face  195  and outer surface  198 . More than one tab  202  is circumferentially-spaced along outer surface  198 . The exemplary embodiment of mounting plate  190  includes four tabs  202 . Each tab  202  includes a countersunk through-hole  203 , starting at first end  193  and extending through second end  194 . A generally rectangular recess  206  in face  195  is positioned off-center from central axis  106 . At least one through-hole  208  extends from recessed face  195  to recessed face  196 . In the example of plate  190 , four through-holes  208  are positioned towards the outer radial extent of recessed face  195 , approximately ninety degrees apart measured across axis  106 . At least one generally rectangular slot  210  extends from recessed face  195  through recessed face  196  as does at least one slot  212 . Slot  212  may be described as generally rectangular with the addition of wings, or smaller slots, that extend almost tangentially from either side of the primary slotted opening. In the example of plate  190 , two slots  210  are disposed on opposite sides of central axis  106 . Ninety degrees from these slots  210  are two of the slots  212 . 
         [0062]    Referring to  FIGS. 13 and 14 , electrical plug interface board  220  of UMA plug assembly  105  comprises a central axis  106 , a first or proximal face  223 , a second or distal face  224 , an cylindrical outer surface  226 , one or more standoffs  228 , one or more sets of internal power and data pins  230 , and one or more sets of power and data transfer pins  232 , and one or more spring-loaded axially-extendable pins P 13 , P 14 . In the exemplary embodiment shown, four standoffs  228  are fixedly attached to board  220  closer to outer surface  226  than to central axis  106  and spaced 90 degrees from each other about axis  106 . Standoffs  228  pass through faces  223 ,  224 , extending beyond proximal face  223  and extending further beyond distal face  224 . Two sets of power and data pins  230 , each with a plurality of pins, extend beyond face  224  on opposite sides of central axis  106 . Two sets of power and data transfer pins  232 , each with a plurality of pins, extend beyond face  223  on opposite sides of central axis  106  and displaced ninety degrees about axis  106  from the sets of pins  230 . Axially-extendable pins P 13 , P 14  are positioned on either side of one set of transfer pins  232 , extending beyond face  223  but not as far beyond face  223  as any of the pins  232  extend. When pins P 13  and P 14  engage a mating surface on a member of a UMA socket assembly  305 , power and data transfer between the mating plug assembly  105  and socket assembly  305  may be initiated. This coupling of plug assembly  105  and socket assembly  305  will be explained in more detail later in this disclosure. 
         [0063]    As arranged in  FIG. 6 , A UMA plug assembly  105  may be compiled from the following parts, arranged generally in the order listed from the most distal to the most proximal component (left to right in  FIG. 6 ): internally threaded locking ring  160 , plug connector body  120 , control board  180 , power board  175 , mounting plate  190 , O-ring  215 , and plug interface board  220 . In an assembly, locking ring  160  is positioned around a plug connector body  120  such that proximal face  171  of inner flange  170  on ring  160  ( FIG. 6 ) may abut the distal end  132  of outer flange  130  on plug body  120  ( FIG. 8 ). In this manner, locking ring  160  and plug connector body  120  are loosely engaged with axial and rotational degrees-of-freedom (DOF), i.e., the capability to move relative to one another in the stated directions. 
         [0064]    Another portion of plug assembly  105  will be considered next. As seen in  FIG. 10 , a control board  180  is coupled near the distal face  176  of a power board  175  by threaded fasteners  177 A and nuts  177 B, separated by an appropriate distance with spacers  178 . The proximal ends of these threaded fasteners  177 B are aligned and positioned in through-holes  208  of a mounting plate  190  ( FIG. 12 ). The alignment includes the passing of the receptacles  179  on power board  175  through the slots  210  of mounting plate  190 . An O-ring  215  ( FIG. 6 ) seats within seal gland  204  near first end  193  which is positioned as the proximal side of the stated mounting plate  190 . Once aligned and abutted, the distal face  224  of a plug interface board  220  ( FIG. 14 ) seals against O-ring  215  to inhibit the passage of liquid or gas. In other words, as configured, a hermetically sealed barrier may be formed. Alignment of plug interface board  220  includes that insertion and coupling of fasteners  177 B in standoffs  228 . This description refers to the portion of fasteners  177 B that pass through mounting plate  190 . Internal data and power pins  230  slidingly engage receptacles  179  on power board  175 , which are disposed within slots  210  of mounting plate  190 . 
         [0065]    As may be inferred from  FIG. 6 , tabs  202  of mounting plate  190  fit within recesses  148  of plug connector body  120  to be held by threaded fasteners (not shown) inserted through holes  203  and into body  120 . This arrangement forms a UMA plug assembly  105 . Power and data transfer pins  232  and axially-extendable pins P 13  and P 14  of interface board  220  extend from the proximal end of UMA plug assembly  105  as do mechanical bosses  140  of plug connector body  120 . These extending features ( 232 , P 13 , P 14 ,  140 ) are available for engagement with a UMA socket assembly  305 . 
         [0066]    UMA socket assembly  305  of UMA  100  in  FIG. 6  comprises multiple components: a generally annular socket connector body  320  (also  FIG. 4 ), a power board  360  (also  FIG. 4 ), a mounting plate  190 , an o-ring  215 , an electrical socket interface board  380 , and a central axis  306 . The components of socket assembly  305  will be explained in the following paragraphs. Subsequently, the assembly of these components will be explained. 
         [0067]    As shown in  FIGS. 15 and 16 , the generally annular socket connector body  320  comprises a central axis  306 , a first or proximal end  323 , a second or distal end  324 , a generally cylindrical outer surface  326 , a generally cylindrical inner surface  327 , external threads  330 , an inner flange  335 , more than one multifaceted recess  340 , countersunk through-holes  346 , and generally trapezoidal recesses  348 . Flange  335  extends radially inward from inner surface  327  with the exterior surface  336  flush at proximal end  323 . Inner flange  335  is also characterized by a cylindrical inner surface  338  and a seal gland  339  adjacent to distal surface  337 . In depth, multifaceted recesses  340  extend from distal end  324  of socket connector body  320  to distal surface  337  of inner flange  335 . At distal end  324 , multifaceted recesses  340  include chamfered portions  341 . In the radial direction, multifaceted recesses  340  extend outward from inner surface  327  and may be considered to be an extension of inner surface  327 . In the disclosed embodiment, socket connector body  320  has four multifaceted recesses  340 ; although, other embodiments may have a different number of recesses functionally similar to recesses  340 . Each multifaceted recess  340  is shaped to slidingly engage and capture a particular mechanical boss  140  and a corresponding engagement tab  142  on plug connector body  120  ( FIG. 7 ). This engagement limitation insures that a UMA plug assembly  105  and a UMA socket assembly  305  engage in a single orientation relative to one another. 
         [0068]    Continuing with socket connector body  320  in  FIGS. 15 and 16 , countersunk through-holes  346  start at distal end  324  and extend through proximal end  323  to allow machine screws (not shown) to coupled socket connector body  320 , and therefore all of UMA socket assembly  305 , to a joint  5  of robotic manipulator arm  1 . In depth, generally trapezoidal recesses  348  extend from distal end  324  of socket connector body  320  to distal surface  337  of inner flange  335 . In the radial direction, recesses  348  in socket connector body  320  extend outward from inner surface  327 . 
         [0069]      FIGS. 17 and 18  present power board  360  of socket assembly  305  comprises a central axis  306 , a first or proximal face  362 , a second or distal face  363  one or more sets of power and data connector receptacles  179 , a variety of multi-pin electrical connectors  184  and threaded fasteners  364 A and nuts  364 B. Although not shown, power board  360  may also comprise power conditioning circuitry, fuses, internal circuitry, electrical jumpers, and other components to aid in routing electrical power and data signals to a coupled joint  5  or to a coupled tool  85 . Receptacles  179  pass through power board  175 , extending beyond distal face  363  and extending further beyond proximal face  362 . Threaded fasteners  364 A extend beyond distal face  363 . Multi-pin electrical connectors  184  may couple components, such as a motor or a sensor, within a joint  5  when a UMA socket assembly  305  is connected to a joint  5 . 
         [0070]    Referring to  FIGS. 19 and 20 , electrical socket interface board  380  of UMA socket assembly  305  comprises a central axis  306 , a first or proximal face  383 , a second or distal face  384 , an cylindrical outer surface  386 , one or more standoffs  388 , one or more sets of internal power and data pins  390 , one or more sets of power and data transfer receptacles  392 , and one or more electrical contacts C 13 , C 14 . In the exemplary embodiment shown, four standoffs  388  are fixedly attached to board  380  closer to outer surface  386  than to central axis  106  and spaced 90 degrees from each other about axis  306 . Standoffs  388  pass through faces  383 ,  384 , extending beyond distal face  384  and extending further beyond proximal face  383 . Two sets of internal power and data pins  390 , each with a plurality of pins  390 , extend beyond face  383  on opposite sides of central axis  306 . Two sets of power and data transfer receptacles  392 , each with a plurality of pins  392  pass through faces  383 ,  384 , extending beyond distal face  384  and extending further beyond proximal face  383 . The two sets of receptacles  392  are positioned on opposite sides of central axis  106  from each other and displaced ninety degrees about axis  106  from the sets of pins  390 . Two electrical contacts C 13 , C 14  are positioned on either side of one set of transfer pins  392 . Electrical contacts C 13 , C 14  are coupled to and nearly flush with face  384 . When pins P 13  and P 14  of plug interface board  220  ( FIG. 14 ) engage contacts C 13 , C 14 , power and data transfer between the mating plug assembly  105  and socket assembly  305  may be initiated. The coupling of plug assembly  105  and socket assembly  305  will be explained in more detail later in this disclosure. 
         [0071]    Referring to the exploded view in  FIG. 6 , UMA socket assembly  305  may be compiled from the components previously described, arranged generally in the order listed next. The order proceeds from the most proximal to the most distal component, i.e., from right to left in  FIG. 6 . The components are: a socket connector body  320 , a power board  360 , a mounting plate  190 , an o-ring  215 , and a socket interface board  380 . To form a socket assembly  305 , the axes  306  for all components  320 ,  360 ,  190 , and  380  are aligned. As will be explained, other features dictate the necessary angular (rotational) alignment of components  320 ,  360 ,  190 , and  380 . The socket connector body  320  forms a foundation for the socket assembly  305 . The other referenced components coupled to the distal end  324  of body  320 . 
         [0072]    The threaded fasteners  364 A extending from the distal face  363  of power board  360  ( FIG. 17 ) are configured to pass through the holes  208  of mounting plate  190  ( FIG. 11 ) and couple with standoffs  388  on socket interface board  380  ( FIG. 20 ). Additional alignment interactions will now be described. When a sub-assembly is coupled as just described, second end  194  of mounting plate  190  ( FIG. 11 ) faces distal face  363  of power board  360 , making second end  194  the proximal end for the plate  190  in a socket assembly  305 , which is the opposite of a plate  190  in a plug assembly  105  ( FIG. 6 ). Correspondingly, first end  193  ( FIG. 12 ) is positioned toward the most distal component, the socket interface board  380 . An O-ring  215  ( FIG. 6 ) seats within seal gland  204  on mounting plate  190 , facing socket interface board  380 . Once aligned and abutted, proximal face  383  of a socket interface board  380  ( FIG. 20 ) seals against the o-ring  215  to inhibit the passage of liquid or gas. In other words, as configured, a hermetically sealed barrier may be formed. Additionally, receptacles  179  on power board  360  extend through the slots  210  of mounting plate  190  without contacting slot  210  and slidingly engage the internal power and data pins  390  extending from proximal face  383  on socket interface board  380 . Power and data transfer receptacles  392  pass into slots  212  on mounting plate  190  without contacting slot  212  and without contacting power board  360 . 
         [0073]    With power board  360  and socket interface board  380  mutually coupled to mounting plate  190 , tabs  202  of plate  190  ( FIG. 12 ) fit within recesses  348  of socket connector body  320  ( FIG. 15 ) to be held by threaded fasteners (not shown) inserted through holes  203  and into body  320 . This arrangement forms a UMA socket assembly  305 . Power and data transfer receptacles  392 , electrical contacts C 13 , C 14 , and multifaceted recesses  340  of the distal face  384  of socket interface board  380  are available for engagement with a UMA plug assembly  105  as are external threads  330  of connector body  320 . 
         [0074]    Referring to  FIGS. 5 and 6 , the universal mating adapter (UMA)  100  comprises a UMA plug assembly  105  and UMA socket assembly  305 . In some embodiments, assemblies  105  and  305  are coupled. In other embodiments, assemblies  105  and  103  are not coupled. To couple assemblies  105  and  305 , axes  106  and  306  are aligned, and each mechanical boss  140  on plug connector body  120  ( FIG. 7 ) is aligned with a prescribed multifaceted recess  340  on socket connector body  320  ( FIG. 15 ). Assemblies  105  and  305  are moved axially toward one another. In the early stages of contact between  105  and  305 , minor misalignment between bosses  140  and recesses  340  may be corrected by the chamfered portions  341  at the edge of recesses  340 , which are configured to guide the entry of bosses  140 . When mechanical bosses  140  are aligned with and are partially within recesses  340 , power and data transfer receptacles  392  on socket interface board  380  ( FIG. 19 ) slidingly receive power and data transfer pins  232  on interface board  220  ( FIG. 14 ) of plug assembly  105 . Therefore, bosses  140  and recesses  340  have a self-aligning, self-correcting capability to protect pins  232  from being bent during the coupling of a UMA. When plug assembly  105  and socket assembly  305  are axially closer and have greater contact between receptacles  392  and pins  232 , then axially-extendable pins P 13 , P 14  ( FIG. 14 ) touch electrical contacts C 13 , C 14  ( FIG. 19 ), respectively, to form a combined and operative electrical interface between the electrical interfaces  220 ,  380 . 
         [0075]    If plug assembly  105  or socket assembly  305  is energized during the coupling process, the receptacles  392  and the mating pins  232  are inactive until pins P 13 , P 14  connect with electrical contacts C 13 , C 14 . The contact of pins P 13 , P 14  with electrical contacts C 13 , C 14  may initiate power and data transfer between receptacles  392  and mating pins  232 . Similarly for de-coupling or disconnecting, a plug assembly  105  and socket assembly  305  of a coupled UMA  100  are configured to be de-energized when disconnection is initiated. So, during disconnection and while disconnected, the plug assembly  105  and socket assembly  305  pair are de-energized. In this scenario, power and data transfer between receptacles  392  and the mating pins  232  will cease when pins P 13 , P 14  cease to mate with electrical contacts C 13 , C 14 , which will occur before the receptacles  392  and the mating pins  232  disconnect. As a consequence of these characteristics, UMA  100  is “hot swappable,” meaning a plug assembly  105  and a socket assembly  305  may be connected or disconnected while one or both assemblies  105 ,  305  is energized. 
         [0076]    When assembled as shown in  FIGS. 4 and 5 , the universal mating adapter (UMA)  100  is configured to transfer force and torque loads between an external object connected to plug connector body  120 , and an another external object connected to socket connector body  320 . One or more of the external objects may be a joint  5 . UMA  100  is also configured to transfer power and data signals between the power board  360  and the pair that includes control board  180  and power board  175 . Power board  360  may also couple and exchange power and data signals with an external object, such as one of the previously referenced joints  5 . Control board  180  and power board  175  may individually or collectively couple and exchange power and data signals with an external object, such as a joint  5 . 
         [0077]    As introduced earlier in relation to  FIG. 1 , robotic manipulator arm  1  comprises a series of joints  5 , each configured to be selectively coupled to an adjacent joint  5  with a UMA  100 . That is to say the plug assembly  105  on a first joint  5  is configured to couple to the socket assembly  305  of a second, adjacent joint  5 . The locking ring  160  of the plug assembly  105  is configured to engage threadingly with the socket connector body  320  of the socket assembly  305  and thereby to hold firmly together (i.e., to lock) the assemblies  105 ,  305  and the accompanying joints  5 . 
         [0078]    The embodiment of  FIG. 1  includes two types of joints  5  in manipulator arm  1 , named according to the type of motion each one is configured to perform. The first type of joint, the roll joint  20 , is illustrated in greater detail in  FIG. 21 . The second type of joint, the pitch joint  60 , is illustrated in greater detail in  FIGS. 26 and 27 . Various other embodiments include one type of joint  5  or more than two types of joints  5 . Thus, other embodiments of manipulator arm  1  may include other types of joints  5 , such as a joint configured for linear extension or retraction. Some embodiments may include a joint that is configured as a combination of or a variation of roll joint  20  and pitch joint  60 . 
         [0079]    The various joints  5  may vary in size depending on the task or location of the joint. A joint  5  that is coupled directly to a robot or is mounted in a more proximal location to the robot may be larger and stronger than other joints  5  that are more distal. A more proximal joint  5  must be configured to support the weight, force, and torque loads of any joints  5  that may be mounted beyond the proximal joint  5 . A distal joint  5  has less load to support than a more proximal joint  5 , and so the distal joint  5  may be sized smaller, if appropriate for the intended task. This disclosed size variation may be implemented for joints  20 ,  60  or any other type of joint  5  that is used. Depending on the location, size, or intended purpose of particular a joint  5 ,  20 ,  60 , the joint may be described as a shoulder, elbow, wrist, or base joint  5 ,  20 ,  60 . Such a designation is intended for convenience when discussing a joint and is not intended to describe a limitation of the joint. 
         [0080]    UMA  100  is configured as a common connector to couple the various pairs of adjacent joints  5 ,  20 ,  60  in manipulator arm  1 , whether the multiple joints  5 ,  20 ,  60  are similar in size or differ in size. A plug assembly  105  connects to the proximal end, and a socket assembly  305  connects to the distal end of each joint  5 ,  20 ,  60 . 
         [0081]    With the inclusion of a UMA  100 , two joints may be coupled or uncoupled manually without tools, i.e., in a tool-free manner, and without an external power source. Because all joints use the same connector, i.e., UMA  100 , the order of the joints  5 ,  20 ,  60  in a manipulator arm  1  may be rearranged, and the number of joints  5 ,  20 ,  60  can be changed as compared to  FIG. 1 , making manipulator arm  1  reconfigurable and scalable. Within the plug assembly  105  of the UMA  100  coupled to each joint  5 ,  20 ,  60 , the control board  180  is configured to exchange configuration parameters and other data with the control boards  180  coupled to adjoining joint(s)  5 ,  20 ,  60 . The exchanged parameters from each joint may include the type of joint, range of motion, gear transmission ratio, length of joint, mass of joint, the zero angular location (“home”) of the joint, sensor information, and possibly other pertinent information. The parameters and other data may also be exchanged with a controller, such as robot controller  12  in  FIG. 2 . Power boards  175  and  360  in each UMA  100  pass power and aid with the parameter and data exchange to and from joints  5 ,  20 ,  60 . Power, parameters, and data may also be transmitted for an end-effector, such as gripping tool  14  or and embodiment of tool  85 . The exchange of these parameters and data facilitates the capability to remove joints from, to add joints to, and to rearrange the sequence of joints within arm  1  without reprogramming or recompiling the software running in control boards  180  or the software running in controller  12 . Controller  12  is configured to automatically recognize and control one or more joints  5 ,  20 ,  60  even after the quantity or sequence of joints has been altered. 
         [0082]    Next, the specifications for a roll joint  20  and for a pitch joint  60  will be explained. In the descriptions, reference will be given to a base section and to a rotatable or movable section of the joint  20 ,  60 . The base section is intended to be coupled more proximal the robot  10  or another mounting device than is the rotatable section of the same joint  20 ,  60 . Thus, the base section refers to the portion of a joint  20  or  60  that is intended couple to the robot directly or to couple to the robot indirectly through one or more joints more proximal. The rotatable section is attached to the base section and is the portion of the joint that is configured to be moved relative to the base section. For example, for a joint  20 ,  60  that is directly coupled to the robot, the base section of that joint is configured to remain stationary relative to the robot when the joint operates to move the other, rotatable section. For joints  20 ,  60  that couple indirectly to the robot by means of intervening joints, the base section remains stationary relative to the robot if all intervening joints remain stationary. However, in some situations, it is possible for a base section to move while the corresponding rotatable section remains stationary. In general, the base section and the rotatable section of a joint are configured to move relative to each other. More generally, one or both sections of a joint  20 ,  60  on an arm  1  are configured to move relative to a fixed coordinate system (not shown) due to the movement of one or more joints  5  in the manipulator arm  1 , due to the movement of robot  10  when coupled to arm  1 , or due to outside forces. 
         [0083]    A cross-sectional view of a roll joint  20  is illustrated in  FIG. 21 . Roll joint  20  comprises a central axis  21 , a first or proximal end  23 , a second or distal end  24 , a base section  25 , a rotatable section  35 , a motor  40 , a gear mechanism, such as harmonic drive  45 , a brake assembly  50 , one or more rotational bearings  56 , and a central wiring tube  58 . Base section  25  includes an external shell  26 , an internal shell  28 , and a proximal end cap  30 . End cap  30  is configured to couple a UMA plug assembly  105  at the proximal end  23  of joint  20 , as exemplified on the right side of  FIG. 21 . Views of end cap  30  are shown in  FIGS. 22 and 23 . On the outer surface of external shell  26 , an external recess  27  offers a location to insert a removable magnet  53  to release the grip of brake assembly  50 . The location for recess  27  shown in  FIG. 21  is one of many possible locations within base section  25 . Rotatable section  35  includes an external shell  36  and a distal end cap  38 . End cap  38  is configured to couple with a UMA socket assembly  305  at the second or distal end  24  of joint  20 , as exemplified on the left side of  FIG. 21 . Views of end cap  38  are shown in  FIGS. 24 and 25 . 
         [0084]    Hollow-core motor  40 , which may be a brushless direct current (DC) motor, comprises a generally annular stator  44  surrounding a generally annular rotor  42 , which is mounted on a hollow-core rotor coupling  43 . Motor axis  41  is aligned with central axis  21 . At one end, bearing  56 A rotationally couples rotor coupling  43  to external shell  26  of base section  25 . The other end of rotor coupling  43  is coupled to an annular, elliptically-shaped wave generator  46  of harmonic drive  45 . Continuing to explain harmonic drive  45 , wave generator  46  may rotate and may induce rotational motion in bearing  56 C and may cause the external gear teeth  47 G on a flexspline  47  to movably mesh against a small number of the internal gear teeth  48 G on stationary circular spline  48 . Circular spline  48  is fixed to internal shell  28  of base section  25 . Therefore, when wave generator  46  rotates, the rotation induces a slower rotation in flexspline  47  with respect to stationary circular spline  48 . Flexspline  47  is fixed to section  35  of joint  20  by fasteners (not shown) located in through-holes  39 . Therefore, if flexspline  47  rotates, section  35  also rotates. In addition, section  35  is rotationally coupled to base section  25  by one or more bearings  56 B. With this configuration, section  35  may rotate about axis  21  and move relative to section  25  with or without the energized aid of motor  40 . 
         [0085]    Continuing to refer to roll joint  20  in  FIG. 21 , hollow-core brake assembly  50  comprises a brake rotor  54 A and a brake stator  54 B. In at least one embodiment, brake assembly  50  is equivalent to Kendrion model 86-61104H00. Brake rotor  54 A is affixed to rotor coupling  43 . Brake stator  54 B is affixed to proximal end cap  30  of base section  25 . In the disclosed embodiment, brake assembly  50  is electrically actuatable and is configured for fail-safe operation. The fail-safe configuration means that the brake engages and inhibits rotation of rotor  54 A relative to stator  54 B when electrical power is removed or lost. The brake  50  may also be engaged when power is supplied and commanded to engage. For the brake  50  to engage, a portion of rotor  54 A would move toward and contact stator  54 B, developing friction. When brake  50  engages, rotor coupling  43 , harmonic drive  45 , rotatable section  35 , and any other connected components achieve a less movable configuration with respect to base section  25 . The less movable configuration may result in a slower rotational speed or a fixed, non-moving condition. For section  35  to rotate relative to section  25  of pitch joint  20 , brake  50  is energized and activated to release the frictional engagement of rotor  54 A and stator  54 B. 
         [0086]    Another feature is the inclusion of magnetic brake release switch  51 , which is distinct from brake  50  but is functionally coupled to the brake  50 . Brake release switch  51  is configured with the ability to release the hold of brake assembly  50  when joint  20  is appropriately energized. As stated, releasing the engagement of brake  50  allows section  35  of joint  20  to move relative to base section  25 . Release switch  51  is located inside base section  25  near external recess  27  of proximal outer shell  26 . 
         [0087]    A method for actuating switch  51  to release the hold of brake assembly  50  is to place a removable magnet  53  in external recess  27 . A ferrous metal member  52  located near switch  51  holds magnet  53  in place and concentrates the lines of magnetic flux of magnet  53 , making it more effective in activating switch  51 . Other braking mechanisms with similar functionality may be employed in joint  20  or any joint  5 ,  60 . 
         [0088]    Within roll joint  20 , central wiring tube  58  is coaxial with axis  21  and extends through the hollow cores of motor  40 , harmonic drive  45 , brake assembly  50 , rotator coupling  43 , and various other annular features (e.g., bearings  56 ) without hindering the rotation of the stated features. Central wiring tube  58  provides a place for installing electrical wires and other elongate features (not shown) that may extend between base section  25  and rotatable section  35  without being disturbed by the multiple revolutions of the motor  40 , harmonic drive  45 , brake assembly  50 , or other annular features. Any of the electrical wires and other elongate features contained in tube  58  may extend between a UMA plug assembly  105  and a UMA socket assembly  305  for power and data exchange. Electrical wires and other elongate features in tube  58  facilitate the exchange of parameters and data between base section  25  and rotatable section  35  of a single joint  20  or between any combination of joints  5 ,  20 ,  60 , a tool  85 , robot controller  12 , or similarly connected components. 
         [0089]    A pitch joint  60  is illustrated in  FIG. 26 . A cross-section of pitch joint  60  is presented in  FIG. 27 . Pitch joint  60  comprises a joint axis  61 , a first or proximal end  63 , a second or distal end  64 , a base section  65 , a rotatable section  75 , a motor  40 , a gear mechanism, such as harmonic drive  45 , a brake assembly  50 , one or more rotational bearings  56 , and a central wiring tube  84 . Base section  65  includes an external shell  68  an internal shell  70 , an end cover  71 , and a side cover  72 . Covers  71 ,  72  are removable to provide access for maintenance. Internal shell  70  is affixed to external shell  68 . Base section  65  also includes a first or proximal mounting axis  66 , which is perpendicular to joint axis  61 . As exemplified on the bottom of  FIGS. 26 and 27 , base section  65  is configured to couple a UMA plug assembly  105  at the proximal end  63  of pitch joint  60 , having the central axis  106  aligned with the proximal mounting axis  66 . On the outer surface of base section  65 , external recess  69  offers a location to insert a removable magnet  53  to release the grip of brake assembly  50 . One possible location for recess  69  is shown in  FIG. 27 . Rotatable section  75  includes an external shell  78 , an end cover  81 , and a side cover  82 . Covers  81 ,  82  provide access for maintenance. Rotatable section  75  also includes a second or distal mounting axis  76 , which is perpendicular to joint axis  61 . As exemplified on the top of  FIGS. 26 and 27 , rotatable section  75  is configured to couple a UMA socket assembly  305  at the distal end  64  of pitch joint  60 , having the central axis  306  aligned with the distal mounting axis  76 . 
         [0090]    Continuing to reference  FIG. 27 , within pitch joint  60 , the a hollow-core motor  40  is coupled to internal shell  70  and is coupled to rotatable section  75  through a harmonic drive  45  in a similar fashion and for a similar function as another motor  40  is installed within a roll joint  20 , as previously described in reference to  FIG. 21 . Returning to  FIG. 27 , motor axis  41  is aligned with joint axis  61 . In addition, section  75  is rotationally coupled to base section  65  by one or more bearings  56 B. With this configuration, section  75  may rotate about joint axis  61  and thereby move relative to section  65  with or without the energized aid of the motor  40 . 
         [0091]    A fail-safe brake assembly  50  within pitch joint  60  couples base section  65  and rotational section  75  in a similar fashion and for a similar function as brake assembly  50  within roll joint  20 . When brake  50  engages rotatable section  75  and any other connected components of pitch joint  60 , rotatable section  75  achieves a less movable configuration with respect to base section  65 . The less movable configuration may result in a slower rotational speed or a fixed, non-moving condition. Brake  50  may be energized and activated to release section  75  to rotate relative to section  65 . Other features and functions of a brake assembly  50 , a release switch  51 , a ferrous metal member  52 , and a removable magnet  53  were explained previously in relation to roll joint  20  and may be similarly applied to pitch joint  60 . 
         [0092]    Within pitch joint  60 , central wiring tube  84  is coaxial with axis  21  and extends through the hollow cores of motor  40 , harmonic drive  45 , brake assembly  50 , and various other annular features (e.g., rotor coupling  43 , bearings  56 ) without hindering the rotation of the stated features. Central wiring tube  84  provides a place for installing electrical wires and other elongate features (not shown) that may extend between base section  65  and rotatable section  75  without being disturbed by the multiple revolutions of the motor  40 , harmonic drive  45 , brake assembly  50 , or other annular features. Any of the electrical wires and other elongate features contained in tube  58  may extend between a UMA plug assembly  105  and a UMA socket assembly  305  for power and data exchange. Electrical wires and other elongate features in tube  58  facilitate the exchange of parameters and data between base section  65  and rotatable section  75  of a single joint  60  or between any combination of joints  5 ,  20 ,  60 , a tool  85 , robot controller  12 , or similarly connected components. 
         [0093]    Pitch joint  60  has a symmetric range of motion in both directions. For example, rotatable section  75  may start in the un-bent, “home” position shown in  FIG. 26  and rotate about joint axis  61  and relative to base section  65 , rotating through an angle in one direction (for example, clockwise) to the maximum extent that section  75  is configured to travel. Next, section  75  may return to the “home” position and rotate through an angle in the opposite, counter-clockwise direction to the maximum extent that section  75  is configured to travel. Because pitch joint  60  is configured with a symmetric range of motion, the maximum angle travelled in the clockwise direction will equal or nearly equal the maximum angle travelled in the counter-clockwise direction. The symmetric configuration of pitch joint  60  may permit a closed-form solution for the inverse kinematics when planning a path of motion for robotic arm  1  and may reduce the need to unwind the joints  5  when traveling along certain trajectories, i.e., paths of travel. Similarly, roll joint  20  may be configured with a symmetric range of motion in both directions. 
         [0094]    Some embodiments of the disclosed equipment may include sensors to evaluate and respond to force feedback, environmental conditions, joint rotation, joint extension, sense of touch, or other conditions. The sensors may include hall-effect sensors, rotational encoders, strain gauges, or other sensing components. The sensors may be coupled to a joint  5  or to a tool  85 . 
         [0095]    Referring now to  FIGS. 21 and 27 , within each joint  20 ,  60 , an optical encoder and rotating disc pair  530  is axially aligned with a motor  40  and one or more axes  21 ,  61 ,  41  and configured to track the rotational position and speed of rotor  42  and rotor coupling  43  with respect to a base section  25 ,  65 . Each joint  20 ,  60  includes a position sensor assembly  500  and a position-indicating label  520  configured to track the rotational position and, if desired, the speed of rotatable section  35 ,  75  with respect to base section  25 ,  65 . More clearly seen in  FIG. 31 , position sensor assembly  500  comprises an angular position sensor  505 , a home sensor  510 , an electrical coupling  512 , stand-off legs  514 , and a mounting pad  516 . Sensors  505 ,  510  are mounted to one surface of pad  516  and the legs  514  are attached to the opposite surface of pad  516 . Returning to  FIGS. 21 and 27 , the legs  514  of position sensor assembly  500  may be attached to the cylindrical outer surface of an internal shell  28 ,  70  of a base section  25 ,  65 , respectively. In this location, sensors  505 ,  510  are near the inner surface of an external shell  36 ,  78  of a rotatable section  35 ,  75 , respectively, where position-indicating label  520  is affixed, facing toward sensors  505 ,  510 . An embodiment of label  520  is shown  FIG. 32 . The gradient-shaded region  522  extends the entire length of label  520  and therefore may encompass the entire inner circumference of an external shell  36 ,  78 . When installed, gradient-shaded region  522  is intended to be aligned with angular position sensor  505 . The single stripe, i.e., solid line,  523  on label  520  is intended to be aligned with home sensor  510 . The other linear markings on label  520  may be used to align the label during installation. 
         [0096]    Referring to  FIGS. 31 and 32 , home sensor  510  may be an optical emitter-sensor pair capable of generating a change in electrical output when the light intensity reflected from an adjacent surface changes by a prescribed threshold. Sensor  510  is configured to generate one level of signal for a light-colored region (e.g., white) and a second signal level for a darker region (e.g., black) such as solid line  523 . In some embodiments, home sensor  510  is a digital optical sensor. If a joint  20 ,  60  is energized and activated, sensor  510  may indicate the one particular angular position of a rotatable section  35 ,  75  with respect to a base section  25 ,  65 , respectively, wherein solid line  523  is adjacent to sensor  510 . This particular angular position may be described as the “home position” of the joint. For a pitch joint  60 , as an example, the home position may be configured to be the position in which the distal mounting axis  76  of section  75  is aligned with proximal mounting axis  66  of section  65 . 
         [0097]    Referring still to  FIGS. 31 and 32 , angular position sensor  505  may be an optical emitter-sensor pair capable of generating an electrical output proportional to a varying intensity of light reflected from an adjacent surface, such as gradient-shaded region  522 . Therefore, if a joint  20 ,  60  is energized and activated, sensor  505  may indicate the angular position of a rotatable section  35 ,  75  with respect to a base section  25 ,  65 , respectively. In some embodiments sensor  505  is an analog optical sensor. The range of sensitivity of sensor  505  and the shading spectrum of region  522  on label  520  are configured to give a unique output signal for any angular configuration of joint  20 ,  60 ; therefore, sensor  505  may be described as an absolute position sensor. As an absolute sensor, sensor  505  may not require calibration or confirmation each time the joint  20 ,  60  is initially energized and activated. However, the home signal from home sensor  510  may be used as a redundant confirmation or as an extra calibration aid for angular position sensor  505  if desired. 
         [0098]    In other embodiments, position sensor  505  and home sensor  510  may be implemented using another principle for generating and detecting variable or discretely (i.e., distinctly) changing signals based on the relative angular position of two rotatably coupled members, such as, for example, sections  25  and  35  of joint  20  or sections  65  and  75  of joint  60 . For example, sensor  505  may respond to a variation in capacitance induced from a position-indication label that has a dielectric strip of varying width in place of the gradient-shaded region  522  of label  520 . Similarly, as an example, home sensor  510  may be a capacitance sensor with a one or more discrete dielectric elements configured to pass within range of sensor  510 . 
         [0099]      FIGS. 28 ,  29 , and  30  illustrate an embodiment of an auto-detach/attach mechanism (ADAM)  600  that may couple a tool  85 , also called an end-effector, with the distal end, e.g., end  24 ,  64 , of the most distal joint, which may be a joint  5 ,  20 ,  60 , of a manipulator arm  1 . ADAM  600  includes two portions  605 ,  625  that may be coupled or decoupled. First portion  605  includes a modified end cap  610  for a socket and a UMA socket assembly  305 . Second portion  605  includes a modified end cap  630  for a plug and a UMA plug assembly  105 . Modified end cap  610  is generally cylindrical and comprises a central axis  611 , a cylindrical outer surface  612 , a first or proximal end  613 , a second or distal end  614 , one or more wheel assemblies  615 , and one or more motors  624 . Modified end cap  610  may be a modified version of an end cap  38  ( FIG. 24 ) for the distal end  24  of a roll joint  20 , or modified end cap  610  may be configured for the distal end  64  of a pitch joint  60 . When an ADAM  600  attaches to a roll joint  20 , the modified end cap  610  replaces or obviates the use of an end cap  38 . 
         [0100]    Each wheel assembly  615  includes an axis  616 , a wheel bracket  617 , a rotatable shaft coupling  618 , which may be a ball-bearing assembly, a shaft  620 , and a wheel  622 . The rotatable shaft coupling  618 , shaft  620 , and wheel  622  are aligned along the common axis  616 . Wheel  622  is rotationally fixed to one end of shaft  620 . Shaft  620  is inserted and axially fixed inside rotatable shaft coupling  618 , which is affixed to wheel bracket  617 . In this configuration, wheel  622  and shaft  620  are free to rotate together relative to wheel bracket  617  as allowed by rotatable shaft coupling  618 . 
         [0101]    The example of  FIGS. 28 and 29  illustrates an ADAM  600  with three wheel assemblies  615  and one motor  624 . The three wheel assemblies  615  are coupled to and evenly spaced around the circumference of outer surface  612  at the distal end  614  of modified end cap  610 . More specifically, wheel brackets  617  are coupled to the modified end cap  610  and may extend inside the outer surface  612  to facilitate the coupling. The wheel assembly axes  616 , and consequently shafts  620 , are aligned with central axis  611  of modified end cap  610 . The shaft (not independently numbered) of motor  624  is coupled to the shaft  620  of one wheel assembly  615 , or the motor  624  shaft is integral with the shaft  620  of one wheel assembly  615 . In this configuration, motor  624  may drive the coupled wheel  622 , which is also called the driven-wheel  622 A. The outer surface of driven-wheel  622 A is called the motor-driven surface  623 A. The wheels  622  on the wheel assemblies  615  that have no motor may rotate when contacted by a moving object. These wheels with no coupled motor are called idler wheels  622 B. 
         [0102]    As best seen in  FIG. 29 , in the first portion  605 , a UMA socket assembly  305  is coupled to the distal end  614  of modified end cap  610 . Central axis  306  of assembly  305  is aligned and collinear with central axis  611 . Wheels  622  extend beyond the end  614 . A portion of the outer, contact surface of wheels  622  is axially aligned with external threads  330  on socket assembly  305 . The remainder of the contact surface of wheels  622  extends a distance “X” beyond threads  330 . 
         [0103]    Referring still to  FIG. 29 , the second portion  625  of ADAM  600  comprises a UMA plug assembly  105  coupled to the proximal end  633  of a modified end cap  630 . Modified end cap  630  is generally cylindrical and comprises a central axis  631 , a first or proximal end  633 , a second or distal end  634 , and a plurality of spring-loaded engagement pins  636 . Modified end cap  630  may be a modified version of a proximal end cap  30  ( FIG. 22 ) as used at the proximal end  23  of a roll joint  20 , or modified end cap  630  may be configured uniquely to match the requirements of a particular tool  85  that may couple at distal end  634 . Engagement pins  636  are circumferentially spaced around proximal end  633 . Pins  636  are configured to press against and slidingly contact the smooth, external surface  165  of the locking ring  160  in UMA plug assembly  105 . 
         [0104]    As exemplified in  FIG. 30 , ADAM  600  is configured to couple an end-effector, such as a tool  85 , to a manipulator arm  1  at the most distal joint, which, for example, may be a joint  20 . In general, another type of joint  5 ,  20 ,  60  may be used, and the joint may be alone, not connected to a complete manipulator arm. A coupling process will be described, but the process is only exemplary of the performance of ADAM  600 . The components are not required to be coupled to constitute an ADAM  600 . In the example of  FIG. 30 , the two portions  605 ,  625  of ADAM  600  are contacting one another or are coupled. A tool  85  couples the distal end  634  of modified end cap  630  while a joint  20  couples the proximal end  613  of modified end cap  610 . To achieve this configuration, axis  611  is first aligned with axis  631 . Plug connector body  120  ( FIG. 7 ) axially engages socket connector body  320  ( FIG. 15 ). This action brings locking ring  160  in proximity to the external threads  330  of body  320  and in proximity to wheels  622 , including motor-driven surface  623 A. Engagement pins  636  push ring  160  toward threads  330 . When motor  624  is activated, motor-driven surface  623 A engages ring  160  causing ring  160  to rotate around axis  611 . Consequently, ring  160  may rotate idler wheels  622 B. Idler wheels  622 B are configured to supply radial, reactive forces to keep ring  160  centered on axis  611  and threads  330 . The rotating action engages threads  169  ( FIG. 6 ) of locking ring  160  with threads  330 , driving ring  160  upward (in the view of  FIG. 30 ) toward modified end cap  610  and joint  20 . The coupling of a tool  85  (representing any compatible end-effector) to the end of a joint  20  may be accomplished automatically, without human interaction, when using an ADAM  600  augmented by a tool holder, such as tool holder  90  that grips tri-lobe adapter plate  86  on tool  85 . With an ADAM  600 , tool  85  may also be manually installed or removed without activating motor  624 S. Alternatively, tool  85  may be manually coupled to a joint  5 ,  20 ,  60  by standard end caps  30 ,  38  (or an equivalent interconnection) and a UMA  100 . 
         [0105]    Although the disclosed embodiment includes a motor-driven surface  623 A as part of a driven-wheel  622 A, in other embodiments, motor-driven surface  623 A may be part of a rotating belt, a reciprocating arm, the teeth of a ratchet, or another member that engages ring  160 . 
         [0106]    While disclosed embodiments have been shown and described, modifications thereof may be made by one skilled in the art without departing from the scope or teachings herein. The embodiments described herein are exemplary only and are not limiting. Many variations and modifications of the systems, apparatus, and processes described herein are possible and are within the scope of the invention. For example, the relative dimensions of various parts, the materials from which the various parts are made, and other parameters may be varied. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims that follow, the scope of which shall include all equivalents of the subject matter of the claims. 
         [0107]    The arrangement and features of UMA  100  components may be modified in some embodiments. As exemplified in  FIG. 6 , one or more embodiments have been disclosed in which a plug assembly  105  is located on the distal end of a UMA  100  and a socket assembly  305  is on the proximal end. In these embodiments, for example  FIG. 21  and  FIG. 26 , a plug assembly  105  would be installed at the proximal end of joint  5 ,  20 ,  60 , and a socket assembly  305  would be installed at the distal end of each joint  5 ,  20 ,  60 . In other embodiments, some components of plug assembly  105  or an entire a plug assembly similar to assembly  105  may be arranged to be at the proximal end of a UMA  100 , and some components of socket assembly  305  or an entire a socket assembly similar to assembly  305  may be arranged to be at the distal end of a UMA  100 . The relative locations of assemblies  105 ,  305  on adjacent joints  5 ,  20 ,  60  would be swapped accordingly.