Patent Description:
Robotic tools for space manipulators fall into one of two categories: <NUM>) tools that are used to operate upon prepared interfaces (i.e. hardware that was designed together with the tools themselves, to facilitate the execution of robotic operations), and <NUM>) tools that are used to operate upon unprepared interfaces (i.e. hardware that was not specifically designed to accommodate robotic operations, and that may be designed in such a way that make robotic operations very difficult).

The Special Purpose Dextrous Manipulator, or Dextre, provided to the International Space Station (ISS) by the Canadian Space Agency (CSA), is equipped with tools targeted to prepared interfaces. Dextre's tools are described at the following link: http://www. ca/eng/iss/dextre/toolbox. They are described in greater detail below.

In addition to tools designed for ISS payloads, the Hubble Robotic Servicing Mission (http://www. com/job/hrsdm/hrsdm. htm) explored the development of Dextre compatible tools that could be used to service hardware that had been launched on the Hubble Space Telescope. The Hubble Space Telescope was designed for servicing by astronauts - it is not equipped with features to facilitate robotic servicing, such as grapple fixtures, visual cues, or a physical equipment layout that provides a generous robotic workspace envelope. A ground testbed version of Dextre was installed at Goddard Space Flight Center, and demonstrations of tool concept prototypes were performed on a full scale mockup of the Hubble telescope. Robotic tools developed for these unprepared interfaces included electrical connector tools and tools that were used to access and actuate door latch fasteners. Hubble interface designs made no accommodations for robotic operations - special tools had to be designed for these unprepared interfaces that allowed operators to perform operations remotely and reliably.

The Hubble Servicing Mission was eventually cancelled, but the development of tools for unprepared interfaces continued both at Goddard Space Flight Center and at MDA/CSA.

Other prepared, robotically compatible tool interfaces have been developed by the European Space Agency (ESA). The Compact Tool Exchange Device (CTED) is designed for Eurobot, a three arm robot concept that is being developed to perform extravehicular activities (EVA) on the ISS. A description of this interface can be found at the following link and paper: http://www. int/TEC/Robotics/SEMRIQNSP3F_0. html, A novel concept for a tool exchange device, <NPL>). CTED will enable the exchange of end effectors or tools, while allowing control signals and electrical power to pass from the arm to the tool. It consists of two types of components, one active unit, fixed to the robot arm, and several passive parts, fixed to the different tools and end effectors. Once the tool is positioned within reach of the arm, CTED is intended to automatically perform the attachment and release of the tool and the mating and de-mating of its electrical connectors. CTED provides alignment features that help guide the robot arm into the correct position and orientation for latching.

NASA has proposed a Robotic Refueling Mission (RRM) which is an external International Space Station experiment which is designed to demonstrate and test tools and methodologies required to refuel satellites in space, see <NPL>). This publication refers to tools to be tested including a Wire Cutter tool, Blanket Manipulation Tool, Multifunction Tool, the Safety Cap Removal Tool, and the Nozzle Tool. More details of these tools can be found at http://www. nasaspaceflight. com/<NUM>/<NUM>/sts-<NUM>-enabling-new-era-robotic-satellite-refuelling-space/.

Examining all of the existing robotic designs for handling multiple types of tools, a common feature is the use of a general robotic end-effector or hand which is capable of holding a tool which has its own source of motive power to apply force or torque. This is illustrated by the OTCM and CTED above. They are capable of grasping the tool and passing power to the motor(s) which provide actuation within the tool. However this means that for each tool held by the end-effector, it must possess its own single or multiple actuator. If the servicing mission requires a large number of powered tools, this will result in a large number of actuators being required in the overall robotic system to be capable of performing a variety of servicing functions. Generally, actuators are also required for grasping different tools and for adjusting the orientation of these tools.

Actuators add mass and complexity to the robotic device, and reduce robustness. Each additional actuator requires power, and necessitates the inclusion of redundancy schemes. As such, each additional actuator added to an end-effector increases the mass of that end-effector, and due to the need for more power and redundancy schemes, the mass increase is generally larger than the mass of the actuator itself. Additional mass added to the robot decreases the payload capacity of the robot, and in the case of space robotics, increases the cost of the overall mission.

<CIT>) discloses a robotic quick release assembly for releasably attaching and releasing a robotic gripper to a robotic arm.

<CIT>) discloses a device for interchanging tools on a mechanical manipulator which includes a male locking cone unit and a female receptacle cone unit along with a motor. The female receptacle cone unit is designed to carry the tools.

<CIT>) discloses a tool holder for use with machine tools configured for automatically changing tools according to a predetermined plan in which the tool holder containing a tool is transported from a tool rack to a spindle on the machine tool.

The present disclosure relates to a multifunctional tool with replaceable tool tips. The disclosed multifunctional tool may be used as an end-effector on a robotic arm in space. Each passive tool tip, when in the tool holder, is driven by a common actuator/motor. The same actuator/motor can also be used to control the orientation of the tool tip about an axis. The tool tips are replaceable in the tool holder by simple and robust means, resulting in a lighter and cheaper multifunctional tool. The tool tips can be variously adapted to perform a variety of functions, including cutting, grasping, drilling, driving, etc. Since the tool may be driven by only one actuator, and the single actuator may be used to drive both the tool and rotation of the tool, mass can be saved. Use of such a multifunctional tool also reduces overall system power requirements, and system complexity.

Thus, herein is disclosed a system comprising a multifunctional tool and a tool clip according to claim <NUM>.

A further understanding of the functional and advantageous aspects of the disclosure can be realized by reference to the following detailed description and drawings.

Embodiments will now be described, by way of example only, with reference to the drawings, in which:.

Various embodiments and aspects of the disclosure will be described with reference to details discussed below. The following description and drawings are illustrative of the disclosure and are not to be construed as limiting the disclosure. Numerous specific details are described to provide a thorough understanding of various embodiments of the present disclosure. However, in certain instances, well-known or conventional details are not described in order to provide a concise discussion of embodiments of the present disclosure.

As used herein, the terms, "comprises" and "comprising" are to be construed as being inclusive and open ended, and not exclusive. Specifically, when used in this specification including claims, the terms, "comprises" and "comprising" and variations thereof mean the specified features, steps or components are included. These terms are not to be interpreted to exclude the presence of other features, steps or components.

As used herein, the terms "about" and "approximately", when used in conjunction with ranges of dimensions of particles, compositions of mixtures or other physical properties or characteristics, are meant to cover slight variations that may exist in the upper and lower limits of the ranges of dimensions so as to not exclude embodiments where on average most of the dimensions are satisfied but where statistically dimensions may exist outside this region. It is not the intention to exclude embodiments such as these from the present disclosure.

As used herein, the terms "axial movement" and "axially", when used to describe movement of an object in conjunction with a defined axis, means translation of that object along a vector substantially parallel to said defined axis.

As used herein, the terms "circumferential movement" and "circumferentially", when used to describe the movement of an object in conjunction with a defined axis, means movement of said object while maintaining substantially the same distance from said defined axis without moving axially.

As used herein, the terms "radial movement" and "radially", when used to describe the movement of an object in conjunction with a defined axis, means translation of said object substantially without moving axially and substantially without moving circumferentially. The terms "inward" and "inwardly", when used in conjunction with radial movement of an object, mean radial movement such that over the course of such movement, the distance between said object and said defined axis decreases. The terms "outward" and "outwardly", when used in conjunction with radial movement of an object, mean radial movement such that over the course of such movement, the distance between said object and said defined axis increases.

As used herein, the term "orthogonal", "perpendicular", and its variants, when used in conjunction with two geometrical entities, means that an angle between the two geometrical entities is about <NUM>°.

As used herein, the phrase "motive source" means a source of mechanical motion (e.g. a motor) and devices (e.g. as screws, mechanisms, levers, etc.) to transform the mechanical motion into other forms of desired motion (e.g. rotation, translation, scissoring motion, or combinations thereof).

Referring to <FIG> as used herein, the direction denoted by the terms "forward", "fore", and "ahead" is along the axis A, and generally away from the motor <NUM>, and towards an end of the tool holder <NUM> that accepts and holds the tool tip <NUM>. The direction denoted by the terms "back", and "backwards" is along the axis A and away from an end of the tool holder <NUM> that accepts and holds the tool tip <NUM>, and towards the motor <NUM>. Similarly, the term "front" denotes an end of the multifunctional tool <NUM> that accepts and holds the tool tip <NUM> (shown in <FIG>) while the term "rear" denotes an end of the multifunctional tool <NUM> that is opposite to an end of the multifunctional tool <NUM> that accepts and holds the tool tip <NUM>.

The multifunctional tool <NUM> comprises a tool holder <NUM> (shown in Figured 1d and <NUM>) and a tool tip <NUM> (shown in <FIG>). The tool holder <NUM> is capable of holding and driving a variety of tool tips <NUM>, each of which may provide a different function. The end of the tool tips <NUM> can be variously adapted to provide a variety of functions. The tool holder <NUM> comprises a motive source to power the tool tip <NUM>, and a tool tip locking mechanism to secure the tool tip <NUM> during operation. The locking mechanism can be engaged to secure the tool tip <NUM> to the tool holder <NUM>, or disengaged to allow for the insertion or removal of the tool tip <NUM>. The multifunctional tool <NUM> may also have a selector mechanism. This selector mechanism can be engaged to allow the motive source to rotate the entire tool tip <NUM> about axis A, in order to adjust the orientation of the tool tip <NUM> about axis A.

In a particular embodiment, multifunctional tool <NUM> is provided with a tilter mechanism that allows for the rotation of the multifunctional tool <NUM> about an axis B, which is perpendicular to the axis A (see <FIG> and <FIG>). An exemplary tilter mechanism is shown in <FIG> and <FIG>. In another embodiment, positioning the multifunctional tool <NUM> in a certain orientation about axis B engages the selector mechanism, allowing the motive source to rotate the tool tip <NUM> about axis A. In any other orientation about axis B, the motive source actuates the tool tip <NUM>.

<FIG>, <FIG>, <FIG> and <FIG> show various exploded views of the tilter mechanism, grapple fixture and associated brackets, clamps and housings of each of these components. Specifically, <FIG> shows an exploded view of the multifunction tool showing how the various detail assemblies relate to each other. <FIG> shows an exploded view of the structural chassis assembly <NUM> which comprises an upper mounting plate <NUM>, a grapple fixture <NUM>, an electrical connector assembly <NUM> and an electrical connector housing <NUM>.

<FIG> and <FIG> shows an exploded view of of the two halves of the tilter mechanism <NUM> forming part of the multifunction tool <NUM>. Tilter mechanism <NUM> includes housings 21R and <NUM> having a cam receiving housing section <NUM> for receiving therein cam <NUM>, a bearing housing section <NUM> for receiving a bearing <NUM> and bearing retainer <NUM>. <FIG> also shows shoe <NUM> and shoe mounting plate 22a that are attached to linear bearing <NUM> which runs on rail 24a. The cam <NUM> controls the motion of the sliding sleeve <NUM> via the cam follower <NUM>. The bearings <NUM> permit the multifunction tool <NUM> to rotate smoothly within the tilter mechanism <NUM> and are retained in the bearing housing section <NUM> by the bearing retainers <NUM>. The linear bearing <NUM> runs on rail 24a to allow the shoe <NUM> to move smoothly up and down to control the tilt of the multifunction tool <NUM>. Shoe mounting plate 22a structurally mounts the shoe <NUM> to the linear bearing <NUM>.

<FIG> shows a cross sectional view of a multifunctional tool <NUM>. <FIG> show different views, cross sections and an exploded view of tool <NUM>. With reference to <FIG>, and <FIG>, the tool tip <NUM> comprises a tool tip rotor <NUM> and a tool tip stator <NUM>, both of which may be disposed coaxial to an axis A. During operation of the tool tip <NUM>, the tool tip rotor <NUM> rotates about axis A while the tool tip stator <NUM> remains substantially stationary with respect to a collet <NUM> on the tool holder <NUM>. The rotor <NUM> is driven by the motive source and the stator <NUM> is held in place by the tool tip locker.

The tool tip rotor <NUM> is driven by a ball spline drive, which functions as follows. A motor <NUM> drives a motor shaft <NUM>, to which is keyed a rotor driver <NUM>. The motor shaft <NUM> and the rotor driver <NUM> are both disposed substantially coaxial to axis A, and rotate about axis A. The rotor driver <NUM> has an indentation <NUM> that engages a driving ball bearing <NUM>. The driving ball bearing <NUM> in turn engages the side of a recess <NUM> on the tool tip rotor <NUM>. Torque is transmitted from the motor shaft <NUM> to the rotor driver <NUM>, and through the driving ball bearing <NUM>, to the tool tip rotor <NUM>. The axial and circumferential movement of the driving ball bearing <NUM> is restricted by an appropriately sized hole <NUM> in a driving ball bearing retainer <NUM>. The recess <NUM> has an appropriate longitudinal slope such that the driving ball bearing <NUM> can easily slide into the recess <NUM> as the tool tip <NUM> is inserted axially into the tool holder <NUM>.

A person skilled in the art will appreciate that the ball spline drive may comprise a plurality of driving ball bearings <NUM> and a corresponding plurality of holes <NUM> in the driving ball bearing retainer <NUM>, both pluralities spaced substantially uniformly along the circumference of the tool holder <NUM>, at substantially the same radial position. The tool tip rotor <NUM> of the tool tip <NUM> will then have a plurality of recesses <NUM> spaced similarly around the circumference of the tool tip rotor <NUM> to be able to accept the plurality of driving ball bearings <NUM>. In a particular embodiment, the tool holder <NUM> is provided with six driving ball bearings <NUM> and six holes <NUM> in the driving ball bearing retainer <NUM> spaced substantially uniformly around the circumference of the tool holder <NUM>, and the tool tip <NUM> is provided with six corresponding recesses <NUM>.

A person skilled in the art will appreciate that the motor <NUM> may be a DC brushed motor, a DC brushless motor, an induction motor, or a stepper motor. There may also be a transmission placed between the motor <NUM> and the motor shaft <NUM> that transmit torques from the motor <NUM> to the motor shaft <NUM>. Such a transmission may include clutches, gearboxes, or gearheads. There may also be provided one or more sensors to detect variables associated with the motor <NUM>, such as angular position, angular velocity or angular acceleration. Such sensors may include resolvers or encoders. In a preferred embodiment shown in <FIG> and <FIG>, the motor <NUM> is a DC brushless motor coupled to a planetary gearhead <NUM> that transmits torque to the motor shaft <NUM>, monitored by a resolver <NUM> that measures the angular position of the motor shaft <NUM>.

The tool tip stator <NUM> is held in place by the collet <NUM>. The axial movement of the collet <NUM> is restricted with respect to a tool housing <NUM> by protrusions attached to the housing <NUM> that abut against distal ends of the collet <NUM>. The rotational movement of the collet <NUM> about axis A with respect to the housing <NUM> can be selectively restricted, by a collet locker described later. The axial movement of the entire tool tip <NUM> with respect to the tool holder <NUM> can be restricted by a tool tip locker, which functions as follows. The collet <NUM> has a hole <NUM> that holds a locking ball bearing <NUM>. The hole <NUM> is appropriately shaped such that it restricts the axial, circumferential, and inwardly radial movement of the locking ball bearing <NUM>. However, the hole <NUM> permits outwardly radial movement of the locking ball bearing <NUM>. In its most inwardly radial position (as permitted by the hole <NUM>), the locking ball bearing <NUM> engages an indentation <NUM> on the tool stator <NUM>. The locking ball bearing <NUM> is held in its most inwardly radial position, engaged to the indentation <NUM>, by an axially translatable spring-loaded locking sleeve <NUM>, which is biased forwards by a spring <NUM>. The indentation <NUM> is arranged such that when the locking ball bearing <NUM> is engaged therein, translation along all axes of the locking ball bearing <NUM> with respect to the tool stator <NUM> is restricted, thus locking the tool tip <NUM> to the tool holder <NUM>. The same locking mechanism, when engaged, also restricts the rotational movement about axis A of the tool rotor <NUM> with respect to the collet <NUM> due to the ball bearing <NUM> in hole <NUM>. A person skilled in the art will appreciate that the locking mechanism may comprise a plurality of locking ball bearings <NUM> spaced substantially uniformly along the circumference of the multifunctional tool <NUM>, in which case the collet <NUM> will have a corresponding number of similarly spaced holes <NUM>, and the tool tip stator <NUM> will have a plurality of indentations <NUM>. A person skilled in the art will also appreciate that the number of indentations <NUM> may be larger than the number of locking ball bearings <NUM>. In a particular embodiment, there are six locking ball bearings <NUM> spaced uniformly along the circumference of the multifunctional tool <NUM>, the collet <NUM> has six holes <NUM>, and the tool tip stator <NUM> has twelve indentations <NUM>. This allows for the tool tip stator <NUM> to be locked to the collet <NUM> in a number of discrete rotational orientations. As such, the tool tip <NUM> can be in a variety of orientations when being inserted into the tool holder <NUM>, and can tolerate variance in the orientation of the tool tip <NUM> during tool tip insertion. A person skilled in the art will also appreciate that there may be provided a plurality of springs <NUM> to bias the locking sleeve <NUM> forward. In a particular embodiment, there are six springs <NUM>. These springs may be coil springs.

The working end of the tool tip rotor <NUM> may be variously adapted to perform a variety of functions. For example, it may comprise one of a variety of rotational bits such as drills, sockets, screwdrivers, etc. The tool tip <NUM> may be used to fasten and unfasten a variety of rotational fasteners including slotted and Phillips screws, internal and external hex screws, ¼ turn fasteners. A particular embodiment shown in <FIG> comprises a hex socket <NUM> attached directly to the tool tip rotor <NUM>. The embodiment in <FIG> also includes a clamp <NUM> attached to the locking sleeve <NUM> for locally reacting torques produced by the action of rotational bits such as the hex socket <NUM>. The clamp <NUM> grounds the multifunctional tool <NUM> to whatever object the multifunctional tool <NUM> is acting upon.

The tool tip <NUM> may be adapted to transform the rotational motion of the tool tip rotor <NUM> into other forms of motion. For example, the tool tip <NUM> in <FIG>, <FIG> has been adapted to transform the rotational motion of the tool tip rotor <NUM> about axis A into linear motion of a pushrod <NUM> by means of a screw assembly. The interior of the tool tip rotor <NUM> is hollow, and the inside surface of the tool tip rotor <NUM> is threaded such that the thread engages a screw <NUM> on the pushrod <NUM>. As the tool tip rotor <NUM> rotates, the screw mechanism <NUM> converts the rotational motion of the tool tip rotor <NUM> into linear motion of the pushrod <NUM>. The pushrod <NUM> may be further coupled to other mechanical devices for transforming the linear motion of the pushrod <NUM> into other kinds of motions and performing a variety of mechanical actions, such as cutting, grasping, gripping, etc. In a set of embodiments, the pushrod <NUM> is coupled to a lever tool. Such a lever tool may be, for example, pliers, scissors, cutters, grippers, or handlers.

<FIG> shows an embodiment of a tool tip <NUM> configured to transform the actuation of the motive source into both rotation and translation of the hex driver <NUM>. The rate at which the hex key <NUM> advances or retracts can be tuned by modifying the pitch of the translating threads <NUM> between the translating socket <NUM> and the stationary collar <NUM>. The power may be transmitted from the socket drive <NUM> to the translating socket <NUM> by any number of means, e.g. spline, hex drive, square drive, sliding Woodruff key, etc..

<FIG> and <FIG> shows an example of a tool tip <NUM> that has a lever tool adapted to cut wires. The tool tip <NUM> has been adapted to transform the rotational motion of the tool tip rotor <NUM> into linear motion of the push rod <NUM>. The tool tip <NUM> in <FIG> comprises a series of mechanical linkages to transform the linear motion of the pushrod <NUM> into a scissoring motion of two members <NUM> and <NUM>' about a pivot <NUM>, which operates about an axis perpendicular to the axis A. The pivot <NUM> may be implemented a pin that passes through the two members <NUM> and <NUM>', as well as a member that is affixed to the tool tip stator <NUM>. As the pushrod <NUM> translates forwards, the mechanical linkages <NUM> and <NUM>' rotate about the pivot <NUM>, which rotates the members <NUM> and <NUM>' about the pivot <NUM>. The ends of the members <NUM> and <NUM>' may be variously adapted to perform a variety of functions. In the embodiment shown in <FIG>, the ends of the members <NUM> and <NUM>' are serrated blades, adapted for cutting wires. In other applications, these may be replaced with any number of end tools that require a scissoring motion about a common pivot such as wire cutters, grasping members, pliers, pincers, scissors, etc. The tool tip <NUM> may be used to perform any one of the following tasks: cutting electrical wire, thermal blankets, lock wire, and metals; gripping; clamping; and operating buttons, thermal blankets, latches, and handles. The tool tip <NUM> may also be adapted to strip and dispose of wire insulation, remove and dispose of fastener safety caps, apply adhesive tapes, suture thermal blankets together, or be used as a pry bar. The tool tip <NUM> may be equipped with expanding jaws for prying apart material, or be used as a nut splitter. <FIG> shows a tool tip <NUM> wherein the ends of the members <NUM> and <NUM>' are flat and elongate, and adapted for grasping material. A particular embodiment has the ends of the members <NUM> and <NUM>' adapted to grasping thermal blankets.

Tool tips <NUM> that have a levering tool generally operate about an axis perpendicular to axis A, which is fixed with respect to the tool tip stator <NUM>. In order to change the axis about which such tools operate, the tool tip <NUM> can be rotated about one or more of (i) axis A and (ii) axis B, which is substantially perpendicular to axis A as shown in <FIG> and <FIG>.

To achieve rotation of the tool tip <NUM> about axis B, the entire multifunctional tool <NUM> can be tilted about axis B using the following mechanism, shown in <FIG>. The multifunctional tool <NUM> is rotatably attached to housing sections 21R and <NUM> using a pivot <NUM> disposed substantially coaxial to axis B. To the housing <NUM> is affixed a linear bearing <NUM>. On the linear bearing <NUM> is provided a shoe <NUM>, which is translatably actuatable along the linear bearing <NUM>. Such actuation is provided by the rotation of a shaft <NUM> about its longitudinal axis. A suitable transmission system can be provided within the shoe <NUM> that transforms the rotational motion of the shaft <NUM> into linear motion of the shoe <NUM> along the linear bearing <NUM>. Such transmission systems are known in the art, and may include a worm gear engaged to a rack-and-pinion assembly.

Suitable actuators may be used to drive the rotation of the shaft <NUM>. Such actuators may include DC brushed motors, DC brushless motors, AC motors or stepper motors. Such actuators may also include suitable a transmission to transmit torque from the motor to the shaft <NUM>, and suitable sensors to measure the angular position or velocity of the rotational shaft <NUM>. In a particular embodiment, such actuators comprise a DC brushless motor coupled to a gearbox, monitored by a resolver. To the shoe <NUM> is rotatably attached a yoke <NUM> using a pivot <NUM>. The pivot <NUM> allows rotation of the yoke <NUM> about an axis that is substantially parallel to axis B.

The yoke <NUM> is rotatably attached to a sliding sleeve <NUM> through a pivot <NUM>. The pivot <NUM> allows rotation of the yoke <NUM> with respect to the sliding sleeve <NUM> about an axis substantially parallel to axis B. The sliding sleeve <NUM> is linearly translatable along the body of the multifunctional tool <NUM>. Also rotatably attached to the yoke <NUM> about the pivot <NUM> is a cam follower <NUM>, which can move along cams <NUM> affixed to the housings 21R and <NUM>. Rotation of the shaft <NUM> causes the shoe <NUM> to translate along the linear bearing <NUM>. The movement of the shoe <NUM> urges the yoke <NUM> to rotate about the pivot <NUM>, and move the cam follower <NUM> along the cam <NUM>. The cam <NUM> is shaped such that motion of the cam follower <NUM> along the cam <NUM> causes the sliding sleeve <NUM> to translate along the body of the multifunctional tool <NUM>. Since the yoke <NUM> is rotatably attached to both the shoe <NUM> at pivot <NUM> and to the sliding sleeve <NUM> at pivot <NUM>, such motion results in the rotation of the multifunctional tool <NUM> about axis B. Note that such rotation results in the reorientation of axis A, which remains fixed to the motor <NUM>.

Referring again to <FIG>, the sliding sleeve <NUM> also is a part of a collet locker that locks and unlocks the collet <NUM> to a tool housing <NUM> that is affixed to the motor <NUM>. When the collet <NUM> is locked to the tool housing <NUM>, the motor <NUM> drives the tool tip <NUM> as discussed above. When the collet <NUM> is unlocked from the tool housing <NUM>, it is freely rotatable with respect to the tool housing <NUM> and can be rotated about axis A by the motive source in the following manner. The collet <NUM> is unlocked from the tool housing <NUM>, and the motive source drives the tool tip rotor <NUM>, as described above, until the lever tool reaches an extent of its movement and the pushrod <NUM> cannot be translated further forward. Thus, the tool tip rotor <NUM> is locked to the tool tip stator <NUM>. Any further actuation by the motive source results in rotation of the entire tool tip <NUM> about axis A, including the tool tip stator <NUM>, as well as the collet <NUM> (which may be engaged to the tool tip stator <NUM>). The selective locking of the collet <NUM> to the tool housing <NUM> is achieved using a mechanism similar to the locking mechanism used to hold the tool tip stator <NUM> connected to the collet <NUM>, as described above. The collet locker works in the following manner. A collet-locking ball bearing <NUM>, shown in <FIG> and <FIG> has its axial, circumferential, and inwardly radial movement restricted by a hole <NUM> in the tool housing <NUM>. In its most inwardly radial position, the collet-locking ball bearing <NUM> engages an indentation <NUM> in the collet <NUM>, restricting the rotational movement about axis A of the collet <NUM> with respect to the tool housing <NUM>. When in a certain range of positions along the multifunctional tool <NUM>, the sliding sleeve <NUM> holds the collet bearing <NUM> in its most inwardly radial position, engaged to the indentation <NUM>, thus locking the collet <NUM> to the tool housing <NUM>. Since each position of the sliding sleeve <NUM> along the multifunctional tool <NUM> corresponds to an angular position of the multifunctional tool <NUM> about axis B, there is a certain range of orientations of the multifunctional tool <NUM> about axis B in which the collet <NUM> is held substantially affixed to the tool housing <NUM>. When the multifunctional tool <NUM> is not within this certain range, the collet <NUM> is rotationally uncoupled (unlocked) from the tool housing <NUM>: a recess <NUM> in the sliding sleeve <NUM> allows the collet-locking ball bearing <NUM> to become disengaged from the indentation <NUM> in the collet <NUM>, allowing the collet <NUM> to rotate about axis A independent of the tool housing <NUM>.

Thus, when the multifunctional tool <NUM> is in a certain position about axis B, the motor <NUM> is capable of driving the rotation of the tool tip collet <NUM> (and all other parts that are affixed to tool tip collet <NUM> at that point in time, which may include the tool tip <NUM>).

The tool tip <NUM> is insertable into and removable from the tool holder <NUM>. The tool tip <NUM> is inserted into the tool holder <NUM> as follows. The locking sleeve <NUM> is translated backwards with respect to the tool tip collet <NUM>, creating a space <NUM>. This may be performed by the robotic arm pushing sleeve <NUM> against another object. As the tool tip <NUM> is inserted into the tool holder <NUM>, the tool tip stator <NUM> moves the locking ball bearing <NUM> into the space <NUM>, and the sloped end of the recess <NUM> of the tool tip rotor <NUM> accepts the driving ball bearing <NUM>. The axial movement of the tool tip <NUM> is continued until the locking ball bearing <NUM> is aligned with the indentation <NUM> in the tool tip stator <NUM>. At this point in time, the locking sleeve <NUM> is allowed to translate axially forward through the action of the spring <NUM>, thus engaging the locking ball bearing <NUM> into the indentation <NUM> (as described above) and locking the tool tip <NUM> to the tool tip collet <NUM>.

The reverse process is carried out to remove the tool tip <NUM> from the tool holder <NUM>. The locking sleeve <NUM> is translated axially backwards, creating a space <NUM>. This may be performed by the robotic arm pushing sleeve <NUM> against another object. As the tool tip <NUM> is moved axially forwards, the tool tip stator <NUM> moves the locking ball bearing <NUM> into this space <NUM>, disengaging the locking ball bearing <NUM> from the indentation <NUM>. This allows for the entire tool tip <NUM> to be removed from the tool holder <NUM> by moving it axially forwards.

A variety of means may be employed to insert and remove the tool tip <NUM> from the tool holder <NUM>. <FIG> and <FIG> shows an example of a tool clip <NUM> that includes structures to assist in the insertion and removal of the tool tip <NUM> from the tool holder <NUM>, and also stores tool tips <NUM> when they are not engaged to the tool holder <NUM>. To remove the tool tip <NUM>, the tool tip <NUM> is slotted into the tool clip <NUM>. As the tool tip <NUM> is slotted into the tool clip <NUM>, a groove <NUM> on the tool tip stator <NUM> engages a retainer <NUM> on the tool clip <NUM>. The tool tip <NUM> is moved along the tool clip <NUM>, and a spacer <NUM> engenders a separation between the retainer <NUM> (to which the tool tip <NUM> is engaged) and a push plate <NUM>. This separation causes the push plate <NUM> to push against the locking sleeve <NUM>, pushing it backwards, and unlocking the tool tip <NUM> from the tool holder <NUM> as described above. As the multifunctional tool <NUM> is translated axially away from the tool clip <NUM>, the groove <NUM> on the tool tip <NUM> remains engaged to the retainer <NUM>, holding the tool tip <NUM> in the tool clip <NUM> while the tool tip <NUM> slides out of the tool holder <NUM>. The tool clip <NUM> is provided with a spring tab <NUM> to grasp and hold the tool tip <NUM> securely in place. The tool tip <NUM> remains in the tool clip <NUM> until it is required again.

The process of inserting a tool tip <NUM> being held by a tool clip <NUM> into the tool holder <NUM> is as follows. The tool holder <NUM> approaches the tool tip <NUM> from the rear, and the tool tip <NUM> is slid into the tool holder <NUM>. As the locking sleeve <NUM> contacts the push plate <NUM>, the locking sleeve <NUM> is translated axially backwards with respect to the tool tip collet <NUM>, opening up a space <NUM>. The locking ball bearing <NUM> is moved into that space <NUM> by the tool tip stator <NUM> as the tool tip <NUM> is slid further into the tool holder <NUM>. The multifunctional tool <NUM> is moved along the tool clip <NUM> and away from the spacer <NUM>, and the separation between the retainer <NUM> and the push plate <NUM> decreases. This allows the locking sleeve <NUM> to translate axially forwards with respect to the tool tip collet <NUM>, locking the tool tip <NUM> in the tool holder <NUM> as described above.

In a particular embodiment, there is provided a tool caddy comprising a plurality of tool clips <NUM>, each holding a distinct tool tip <NUM> arranged in close proximity. The tool holder <NUM> may be connected to a robotic arm, and act as an end-effector for the robotic arm. The necessary movement of the tool holder <NUM> in order to insert or remove tool tips <NUM> may be achieved by actuating the robotic arm. In such an embodiment, the robotic arm would be able to pick up a tool tip <NUM> from a tool caddy by inserting it into the tool holder <NUM>, perform a task with the tool tip <NUM>, return the tool tip <NUM> to the caddy, and pick up one or more additional tool tip <NUM> from the tool caddy in order to perform a second task. Such a system would be highly advantageous since it would allow a single robotic arm with a single end-effector (i.e. the tool holder <NUM>) and a single drive system to perform a variety of tasks by using a appropriate tool tips <NUM>.

<FIG> shows an alternative embodiment to the tool tip clip of <FIG> and <FIG>. In this embodiment, the pusher plate <NUM> and the retainer <NUM> are integrally formed to produce one piece. During insertion of the tool tip <NUM>, the tool tip <NUM> locks into a slot <NUM>. Instead of the spacer <NUM> in <FIG> and <FIG>, the retainer <NUM> has a wedge shape that compresses the locking sleeve <NUM> backwards. This embodiment also comprises a spring tab <NUM> that holds and retains the tool tip <NUM>. The steps required for the insertion and removal of a tool tip <NUM> from this tool tip clip <NUM> are the same as described above for the embodiment shown in <FIG> and <FIG>.

The multifunctional tool may also be provided with a vision system which may include one or more of imagers that capture a view of the operations of the multifunctional tool <NUM>. Such imagers may comprise video cameras, still cameras, and stereoscopic cameras. <FIG> shows a multifunctional tool <NUM> outfitted with four video cameras <NUM> which constitute a vision system. It is noted the vision system may have more or less cameras than four (<NUM>) and may use alternatively, or additionally other types of sensors to give the same information. The imagery captured by such imagers may be transmitted to a human operator or to a computer-controlled guidance-and-control system. The imagers may be rigidly attached to the housings <NUM>. In a particular embodiment, the imagers comprise four cameras mounted to the multifunctional tool <NUM> using yoke <NUM>.

<FIG> shows a partial exploded view of the assembly of <FIG> absent the video cameras on the left hand side of the <FIG>. In this embodiment, yoke <NUM> is used to support the cameras <NUM> and provide a stable location to support the multipurpose tool <NUM> on the spacecraft <NUM> via an interface socket <NUM>.

<FIG> shows an exploded view of the structural chassis assembly <NUM> which comprises upper mounting plate <NUM>, a grapple fixture <NUM>, an electrical connector assembly <NUM>, and an electrical connector housing <NUM>. The upper mounting plate <NUM> provides the structural chassis for the tool <NUM> to which the grapple fixture <NUM> is bolted to allow structural loads to be passed from the tool work site through the robotic arm <NUM> to the servicing spacecraft or satellite <NUM>. The electrical connector assembly <NUM> holds the electrical and video connectors necessary to pass signals and data to and from the control system <NUM> in the spacecraft <NUM> to the tool motor <NUM> and the cameras <NUM>. The connectors are designed to permit robotic engagement to mating connectors on the end effector <NUM>. The electrical connector housing <NUM> provides a mechanical shield for the electrical connector assembly <NUM> and the wires the exit from it.

One application of the multifunctional tool <NUM> is in the field of space robotics. In a particular embodiment, the multifunctional tool <NUM> is provided with a mechanical and an electrical interface where a robotic arm may make a mechanical attachment and an electrical attachment, respectively. Such interfaces may be affixed to the upper mounting plate <NUM>. The mechanical interface <NUM> would allow the multifunctional tool <NUM> to be releasably affixed to an end of a robotic arm, and the electrical interface <NUM> would allow the multifunctional tool <NUM> to receive power and control signals, and to output telemetry and video data. Such mechanical interfaces are known in the art, and may comprise a graspable member rigidly attached to the upper mounting plate <NUM>, wherein an end of the robotic arm (end effector) <NUM> can grasp said graspable member. Electrical interfaces for use herein are also known in the art, and may comprise a socket assembly <NUM> to which can be attached a corresponding plug at an end of the robotic arm. In a particular embodiment, the mechanical and electrical interfaces are placed in close proximity, forming a combined electromechanical interface for attaching to an end-effector of a robotic arm. In another embodiment, such a robotic arm is attached to a spacecraft, and is operable is space. <FIG> shows a multifunctional tool with a grapple fixture <NUM> that can be used by a robotic arm to grasp the multifunctional tool.

Thus, as depicted in <FIG>, the multifunction tool disclosed herein may form part of a system for remote robotic servicing located on a spacecraft or satellite <NUM> which comprises a vision system, a robotic arm <NUM> having an end-effector <NUM>, a multifunction tool <NUM> configured to be releasably grasped by the end-effector <NUM>. The multifunction tool <NUM> comprising tool holder <NUM> is configured to releasably grasp a plurality of tool tips <NUM>, and the multifunction tool <NUM> includes a motive source configured to activate the tool tip <NUM> when the motive source is activated.

Referring now to <FIG> and <FIG>, an example computing system for performing the aforementioned methods is illustrated. The system includes a computer control system <NUM> configured, and programmed to control movement of the robotic arm <NUM> and the motive source of the multifunction tool <NUM>. Computer control system <NUM> is interfaced with vision system <NUM>, and robotic arm <NUM>. A communication system <NUM> is provided which is interfaced with the robotic arm <NUM> and configured to allow remote operation (from the Earth <NUM> or from any other suitable location) of the vision system (which may include one or more cameras <NUM>), the robotic arm <NUM> and the multifunction tool <NUM>. A system of this type is very advantageous particularly for space based systems needing remote control. By providing a suite of tool tips <NUM> in a tool caddy <NUM> that are configured to be activated by a single motive source on the multifunction tool <NUM> such that they do not need their own power sources provides an enormous saving in weight which is a premium on every launch.

Some aspects of the present disclosure can be embodied, at least in part, in software. That is, the techniques can be carried out in a computer system or other data processing system in response to its processor, such as a microprocessor, executing sequences of instructions contained in a memory, such as ROM, volatile RAM, non-volatile memory, cache, magnetic and optical disks, or a remote storage device. Further, the instructions can be downloaded into a computing device over a data network in a form of compiled and linked version. Alternatively, the logic to perform the processes as discussed above could be implemented in additional computer and/or machine readable media, such as discrete hardware components as large-scale integrated circuits (LSI's), application-specific integrated circuits (ASIC's), or firmware such as electrically erasable programmable read-only memory (EEPROM's).

<FIG> provides an exemplary, non-limiting implementation of computer control system <NUM>, which includes one or more processors <NUM> (for example, a CPU/microprocessor), bus <NUM>, memory <NUM>, which may include random access memory (RAM) and/or read only memory (ROM), one or more internal storage devices <NUM> (e.g. a hard disk drive, compact disk drive or internal flash memory), a power supply <NUM>, one more communications interfaces <NUM>, and various input/output devices and/or interfaces <NUM>.

Although only one of each component is illustrated in <FIG>, any number of each component can be included computer control system <NUM>. For example, a computer typically contains a number of different data storage media. Furthermore, although bus <NUM> is depicted as a single connection between all of the components, it will be appreciated that the bus <NUM> may represent one or more circuits, devices or communication channels which link two or more of the components. For example, in personal computers, bus <NUM> often includes or is a motherboard.

In one embodiment, computer control system <NUM> may be, or include, a general purpose computer or any other hardware equivalents configured for operation in space. Computer control system <NUM> may also be implemented as one or more physical devices that are coupled to processor <NUM> through one of more communications channels or interfaces. For example, computer control system <NUM> can be implemented using application specific integrated circuits (ASIC). Alternatively, computer control system <NUM> can be implemented as a combination of hardware and software, where the software is loaded into the processor from the memory or over a network connection.

Computer control system <NUM> may be programmed with a set of instructions which when executed in the processor causes the system to perform one or more methods described in the disclosure. Computer control system <NUM> may include many more or less components than those shown.

While some embodiments have been described in the context of fully functioning computers and computer systems, those skilled in the art will appreciate that various embodiments are capable of being distributed as a program product in a variety of forms and are capable of being applied regardless of the particular type of machine or computer readable media used to actually effect the distribution.

A computer readable medium can be used to store software and data which when executed by a data processing system causes the system to perform various methods. The executable software and data can be stored in various places including for example ROM, volatile RAM, non-volatile memory and/or cache. Portions of this software and/or data can be stored in any one of these storage devices. In general, a machine readable medium includes any mechanism that provides (i.e., stores and/or transmits) information in a form accessible by a machine (e.g., a computer, network device, personal digital assistant, manufacturing tool, any device with a set of one or more processors, etc.).

Examples of computer-readable media include but are not limited to recordable and non-recordable type media such as volatile and non-volatile memory devices, read only memory (ROM), random access memory (RAM), flash memory devices, floppy and other removable disks, magnetic disk storage media, optical storage media (e.g., compact discs (CDs), digital versatile disks (DVDs), etc.), among others. The instructions can be embodied in digital and analog communication links for electrical, optical, acoustical or other forms of propagated signals, such as carrier waves, infrared signals, digital signals, and the like.

The present system is configured specifically to operate a plurality of tool tips all configured to be graspable by the multifunction tool. In addition to the tools illustrated in the Figures, the tool tips can be designed for any operation imaginable. A non-limiting and non-exhaustive list of tool tips for servicing tasks for the present multifunction tool on a spacecraft include, but are not limited to, fastening and unfastening of rotating fasteners: slotted and Phillips screw, internal and external hex screw, ¼ turn fasteners, scissors or saws for cutting of electrical wires, thermal blankets, lock wire, metal. Tool tips may be included for handling/clamping such as thermal blanket handling, general gripping, and static clamping. Tool tips may be included for mechanism operation: generic ground-type mechanisms such as buttons, latches, handles, manned EVA mechanisms via standard interfaces, electrical connector installation and removal. Tool tips may be included which are configured for the removal of components: fastener safety cap removal and disposal, wire insulation stripping and disposal. Tool tips may be included which are configured for leverage operations such as pry bar, expanding jaws, and a nut splitter to mention a few. Tool tips for any number of multiple miscellaneous operations may be included, for example for application of fluids via hypodermic, compression of springs, application of adhesive tapes, suturing thermal blankets together.

The multifunction tool disclosed herein may be part of a larger system for refueling satellites in orbit and may be mounted on a dedicated refueling satellite launched directly from earth on which the refueling apparatus including a tool caddy, robotic arm and various tool tips are mounted. Such a dedicated satellite may include a spacecraft docking mechanism such as that disclosed in <CIT>. The apparatus may be retrofitted onto any suitable satellite to be used as a servicer satellite for refueling. The refueling satellite with the refueling apparatus mounted thereon could be carried on a larger "mother ship" and launched from there or stored on an orbiting space station and launched from there when needed. The system may be under teleoperation by a remotely located operator, for example located on earth, in the "mother ship" or in an orbiting space station. The system may also be autonomously controlled by a local Mission Manager with some levels of supervised autonomy so that in addition to being under pure teleoperation there may be mixed teleoperation/supervised autonomy.

Claim 1:
A system comprising a multifunctional tool (<NUM>) and a tool clip (<NUM>), comprising:
I) a tool tip (<NUM>), said tool tip (<NUM>) comprising
a) a tool tip stator (<NUM>), and
b) a tool tip rotor (<NUM>) rotatable about a first axis (A) relative to said tool tip stator (<NUM>); and
II) a tool holder (<NUM>) capable of removably engaging said tool tip (<NUM>), said tool holder (<NUM>) comprising
a collet (<NUM>),
a tool tip locker,
a motive source;
a selector mechanism,
wherein when said tool holder (<NUM>) engages said tool tip (<NUM>),
i) said tool tip locker comprises a locking sleeve (<NUM>), and wherein said locking sleeve (<NUM>) of said tool tip locker restricts rotational and axial movement about said first axis (A) of said tool tip stator (<NUM>) relative to said collet (<NUM>),
ii) said motive source is capable of rotating said tool tip rotor (<NUM>) about said first axis (A) relative to said tool tip stator (<NUM>), and
iii) said selector mechanism can be engaged to allow the motive source to rotate the entire tool tip (<NUM>) about said first axis (A) relative to said tool tip stator or to actuate the tool tip (<NUM>), and
III) the tool clip (<NUM>), wherein said tool clip (<NUM>) is suitable for storing the tool tip (<NUM>) when said tool tip (<NUM>) is not engaged to the tool holder (<NUM>), said tool clip (<NUM>) comprises structures to assist in the insertion and removal of the tool tip (<NUM>) from the tool holder (<NUM>).