Patent Description:
Some large workpieces need to be rotated during manufacture to have access to particular areas of an outer surface of the workpiece. During the manufacture of some workpieces, a work platform for workers is used so that multiple workers are able to stand on the work platform and access an outer surface of the workpiece. After work on a first portion of the outer surface is completed, the workpiece is rotated to allow the workers to access a second portion of the outer surface from the work platform. For some manufacturing processes during rotation of the workpiece, workers move off of slats of the work platform that extend to the workpiece, an access barrier is utilized to inhibit access to the slats, the slats are retracted away from the workpiece, and the workpiece is rotated. After rotation of the workpiece, the slats are extended toward the workpiece so that ends of the slats are within a separation distance range of the workpiece, and the access barrier is released to allow workers to move onto the slats of the work platform. A time for the rotation process can be more than <NUM> minutes and there may be over <NUM> rotation processes for one complete revolution of the workpiece, which can result in a significant amount of non-value added work time associated with time needed for rotation and resetting the slats to allow workers access to the workpiece.

Document <CIT>, with its abstract, discloses a mover system that moves a work platform relative to a target object. The mover system includes a drive vehicle configured to be attached to the work platform. Sensors are attached to the work platform that detect a distance between the sensors and the target object. Signals from the sensors are used to determine an alignment angle used for the operation of the drive vehicle to move the work platform into alignment and spacing relative to the work object.

Document <CIT>, with its abstract, discloses a universal platform and an assembly method of an aircraft using the same. The universal platform includes a plurality of scissor lifts arranged around an aircraft, wherein each of the plural scissor lifts includes a base frame, a support frame located above the base frame, a support table fixedly coupled to an upper portion of the support frame, a plurality of link members axially assembled to be mutually pivoted between the support frame and the base frame, a plurality of hydraulic cylinders coupled to the respective link members and the base frame so as to lift the support frame in upward and downward directions, and a slide member slidably coupled to the support table, and the slide member slides from the support table toward the aircraft so as to allow a worker to work according to height.

Document <CIT>, with its abstract, discloses an adjustable work platform comprising a fixed platform carrying a multiplicity of adjustable members designed to slide out of the fixed platform to variable lengths as needed. A large irregularly shaped object, such as an aircraft, may be driven into the interior of the platform with the adjustable members retracted. Once in place, the adjustable members are extended to form a heavy duty work platform conforming to the irregular shape of the exterior of the object.

Document <CIT>, with its abstract, discloses a portable aircraft maintenance stand including a frame assembly and a deck. The frame assembly has a base portion and an upper portion. The deck is mounted to the upper portion of the frame assembly and includes a cantilevered portion. The deck also has a gap configured to receive an engine of an aircraft such that the deck at least partially wraps around the engine. The cantilevered portion of the deck is configured to be positioned vertically above a wing of the aircraft while the base portion of the frame assembly is positioned vertically below the wing.

Document <CIT>, with its abstract, discloses an isolated human work platform for stabilized positioning of collaborative robotics. A base platform is provided, and a work platform is positioned above the base platform for supporting one or more humans. One or more robots are supported on the base platform independently of the work platform, so that movement of the work platform does not affect the robots' positions. The work platform is isolated from the robots for stabilized positioning of the robots, so that the base platform and work platform together provide a collaborative workspace for the robots and the humans.

The present disclosure relates to a system having the features described at claim <NUM>. The dependent claims outline advantageous forms of embodiments of the system.

Furthermore, the present disclosure relates to a method of adjusting extension lengths of slats of a work platform relative to a workpiece to accommodate rotation of the workpiece comprising the steps described at claim <NUM>. The dependent claims outline advantageous ways of carrying out the method.

The features, functions, and advantages described herein can be achieved independently in various implementations or may be combined in yet other implementations, further details of which can be found with reference to the following description and drawings, within the scope of the appended claims. The drawings are conceptual and not drawn to scale.

A workpiece on a workpiece transport is positioned in working relation to a work platform. The work platform is at an elevated height that enables workers standing on the work platform to access a portion of an outer surface of the workpiece. Workers stand on slats of the work platform. The slats are extended toward the workpiece so that a separation distance between ends of the slats and the workpiece is in a separation distance range that is not too close to the workpiece or too far away from the workpiece (e.g., based on safety and industrial hygiene tolerances). The workpiece is rotated to change the portion of the outer surface of the workpiece accessible to the workers. During rotation of the workpiece, a position of the outer surface of the workpiece changes relative to the work platform due to a shape of the workpiece, a rotational axis of the workpiece, or both. A controller receives operation data from sensors. The operation data includes first data corresponding to a position, and upcoming positions, of the outer surface of the workpiece at the height of the slats, and second data corresponding to rotation information associated with rotation of the workpiece (e.g., a rotation direction and a rotation rate). Based on the operation data, the controller provides signals to actuators of the work platform that cause one or more of the actuators to adjust extension lengths of the slats so that separation distances from the ends of the slats to the outer surface of the workpiece are in the separation distance range, cause one or more of the actuators to leave an extension length unchanged, or both. Adjusting the extension lengths of one or more of the slats, leaving the extension length of one or more slats unchanged, or both, during rotation of the workpiece enables workers to remain on the slats during rotation of the workpiece and avoids accumulation of a large amount of non-value added time for manufacture of the workpiece associated with waiting for rotation and repositioning of the slats when the workpiece is rotated.

<FIG> is a block diagram of a system <NUM> to adjust extension lengths of slats <NUM> of a work platform <NUM> relative to a workpiece <NUM>. The system <NUM> includes the work platform <NUM>, a workpiece transport <NUM> that supports the workpiece <NUM>, and a controller <NUM>. In particular implementations, components of the controller <NUM> are coupled to the work platform <NUM>, the workpiece transport <NUM>, or both.

The work platform <NUM> is a support for workers to stand on to access an outer surface <NUM> of the workpiece <NUM> at an elevated height so that the workers are able to ergonomically access a portion of the outer surface <NUM> of the workpiece <NUM>. For example, workers have the ability to access the workpiece <NUM> while standing without working at a height significantly above their shoulders or significantly below their waists for extended periods of time. In some implementations, the workers perform activities on the portion as the workpiece <NUM> is continuously rotated at a slow rate or is rotated by a particular amount after a passage of a time period. In other implementations, the workers perform the activities on the portion and, after completion of the activities, an input is provided to the controller <NUM> that causes the controller <NUM> to rotate the workpiece <NUM> by a particular amount to allow access to a next portion of the workpiece <NUM> to be worked on.

The work platform <NUM> includes at least one entryway <NUM>, fixed barriers <NUM> that define limits of the work platform <NUM>, the slats <NUM>, actuators <NUM> to extend or retract the slats <NUM>, side barriers <NUM>, an access barrier <NUM> to the slats <NUM>, and sensors <NUM>. The entryway <NUM> can be accessed by workers via stairs, a ladder, or a personnel lift system. The fixed barriers <NUM> are railings, one or more walls of a building, or both. <FIG> depicts six slats <NUM> and six actuators <NUM>. In other implementations, the system <NUM> includes fewer or more slats <NUM> and actuators <NUM> than the number of slats <NUM> and actuators depicted in <FIG>.

The work platform <NUM> is at an elevated height relative to a floor that supports the workpiece transport <NUM>. The controller <NUM> is provided with data that indicates a height of slat ends <NUM> of the slats <NUM> to facilitate determination of appropriate extension lengths of the slats <NUM>. In some implementations, the height of the work platform <NUM> above a floor that supports the workpiece transport <NUM> is greater than <NUM> meters, greater than <NUM> meters, or greater than <NUM> meters. In some implementations, the height of the work platform <NUM> above the floor is adjustable (e.g.. , by a hydraulic or mechanical lift system) to accommodate workpieces <NUM> of different sizes. When the height of the work platform <NUM> is adjustable, one or more sensors of the sensors <NUM> provide the controller <NUM> with data indicating the height of the work platform <NUM> at the slat ends <NUM> of the slats <NUM>.

The actuators <NUM> include housings that are fixed to the work platform <NUM> and include arms that are coupled to the slats <NUM>. One or more arms of one or more actuators <NUM> are coupled to each slat <NUM>. The arms of the actuators <NUM> are configured to extend the ends <NUM> of the slats <NUM> to particular distances in a range from a retracted position to a fully extended position. The slat ends <NUM> in the fully extended position can be a length of <NUM> meters beyond the retracted position or some other chosen length. The arms of the actuators <NUM> can be hydraulically driven, pneumatically driven, or mechanically driven.

The actuators <NUM> are electrically coupled to the controller <NUM> either by a wired connection or a wireless connection. Signals provided from the controller <NUM> to the actuators <NUM> are used by the actuators <NUM> to set lengths of the arms by extending or retracting portions of the arms relative to the housings, which sets extension lengths of the slats <NUM> relative to a side <NUM> of the work platform <NUM>. The housings of the actuators <NUM> and portions of the slats <NUM> are coupled to supports on an underside of the work platform <NUM>. In some implementations, portions of one or more of the supports include rollers to facilitate extension and retraction of the slats <NUM> by the arms of the actuators <NUM>.

In some implementations, the slat ends <NUM> include indicia (e.g., black and yellow striping) to visibly indicate the location of the slat ends <NUM>. In some implementations, the slat ends <NUM> include soft and deformable endpieces (e.g., foam endpieces) that inhibit damage to the workpiece <NUM> should one or more of the slat ends <NUM> contact the workpiece <NUM>.

The side barrier 122A includes a first portion that extends and retracts in accordance with extension and retraction of a first slat 102A to provide a barrier at a first side of the slats <NUM>. In an implementation, the first portion of the side barrier 122A is coupled to the first slat 102A and moves with the first slat 102A as the first slat 102A is extended or retracted by the arm(s) of the actuator(s) <NUM> coupled to the first slat 102A. A part of the first portion is configured to slide into a second portion of the side barrier 122A that is coupled to a floor <NUM> of the work platform <NUM>. The second portion of the side barrier 122A does not move toward and away from the workpiece <NUM>. Similarly, the side barrier 122B includes a first portion that extends and retracts in accordance with extension and retraction of a second slat 102F to provide a barrier at a second side of the slats <NUM>. In an implementation, the first portion of the side barrier 122B is affixed to the second slat 102F and moves with the second slat 102F as the second slat 102F is retracted or extended by the arm(s) of the actuator(s) <NUM> coupled to the second slat 102F. A part of the first portion of the side barrier 122B is configured to slide into a second portion of the side barrier 122B that is coupled to the floor <NUM> of the work platform <NUM>. The second portion of the side barrier 122B does not move toward and away from the workpiece <NUM>.

In addition, temporary barriers can be placed on the slats <NUM> if needed. For example, if a protrusion from the outer surface <NUM> of the workpiece <NUM> causes retraction of two slats 102D, 102E next to extended slats 102C, 102F such that a large gap is present between one or both of the extended slats 102C, 102F and the protrusion from the outer surface <NUM>, one or more temporary barriers can be coupled to one or both of the extended slats 102C, 102F to form a barrier on the sides and in front of the large gap. The one or more temporary barriers can be removed after the retracted slats 102D, 102E are extended such that the large gap is eliminated.

The access barrier <NUM> is used to allow or inhibit worker access to the slats <NUM>. The access barrier <NUM> is coupled to the floor <NUM> of the work platform <NUM> near to, or at, an interface with the slats <NUM>. When a workpiece <NUM> is positioned in working relation to the work platform <NUM> and the slats <NUM> are extended to within a separation distance range of the workpiece <NUM>, the controller <NUM> places the access barrier <NUM> in an open status that causes opening of one or more gates in the access barrier <NUM> or removal (e.g., retraction) of all or a portion of the access barrier <NUM>. When the access barrier <NUM> is in the open status, workers can move onto or off of the slats <NUM> and the workpiece <NUM> is a barrier in front of the slat ends <NUM>. When a workpiece <NUM> is not positioned in working relation to the work platform <NUM> or the slats <NUM> are not extended to within the separation range of the workpiece <NUM>, the controller <NUM> places the access barrier <NUM> in a closed status that causes the access barrier <NUM> to inhibit worker access to the slats <NUM>.

In an implementation, usage data is provided from one or more usage sensors of the sensors <NUM> (e.g., cameras, load sensors, etc.) to the controller <NUM>. Based on the usage data, the controller <NUM> prevents a change in access barrier status from the open status to the closed status when the usage data indicates one or more workers are on the slats <NUM>. The controller <NUM> prevents a change of the access barrier status from the closed status to the open status when there is no workpiece <NUM> positioned in front of the work platform <NUM> with the slats <NUM> of the work platform <NUM> extended to within the separation distance of the workpiece <NUM>. The controller <NUM> can also be configured to inhibit movement of the workpiece transport <NUM> towards or away from the work platform <NUM> when the access barrier <NUM> has the open status.

The sensors <NUM> are coupled to the controller <NUM> and provide data to the controller <NUM>. The sensors <NUM> can be coupled to the controller <NUM> by wireless or wired connections. The platform sensors <NUM> can include distance sensors in one or more of the slats that provide distance data to an object (e.g., the workpiece <NUM>) in front of the slats <NUM>, one or more sensors that detect whether the slat ends <NUM> are positioned in front of a groove in the workpiece, one or more distance sensors that provide distance data to indicia of the workpiece <NUM> that indicates information associated with the outer surface <NUM> of the workpiece <NUM>, the one or more usage sensors, one or more sensors that provide data associated with a height of the work platform <NUM> when the height of the work platform <NUM> is adjustable, other sensors, or combinations thereof.

The distance data from the distance sensors in one or more of the slats <NUM> can be used by the controller <NUM> to determine whether a workpiece <NUM> is positioned in working relation to the work platform <NUM>. In some implementations, the distance data from the distance sensors in one or more of the slats <NUM> and other sensor data is used by the controller <NUM> to inhibit extension of the slat ends <NUM> into openings or grooves in the workpiece <NUM> and can be used by the controller <NUM> to set initial extension lengths of the slats <NUM> when the slats <NUM> are initially extended from retracted positions toward the workpiece <NUM>.

The workpiece <NUM> is a large object (e.g., a mandrel for forming a portion of a fuselage of a passenger aircraft) that is rotated about a longitudinal axis to enable workers to access the outer surface <NUM> of the workpiece <NUM> at an elevated height relative to the floor that supports the workpiece transport <NUM>. In some implementations, the workpiece <NUM> has a substantially circular, elliptical, or other cross-sectional shape. The outer surface <NUM> can have surface irregularities (e.g., indentations, openings, protrusions, flat sections, etc.). When the workpiece <NUM> is rotated, a location of the outer surface <NUM> at a height of the slats <NUM> of the work platform <NUM> changes so that extension lengths the slats <NUM> relative to the side <NUM> of the work platform <NUM> need to be adjusted by the controller <NUM> to prevent damage to one or more of the slats <NUM>, the workpiece <NUM>, or both, due to contact of the workpiece <NUM> and the one or more slats <NUM> during rotation of the workpiece <NUM>. Adjustment of the extension lengths of the slats <NUM> by the controller <NUM> is also performed to prevent too large a gap from forming between ends of the slats <NUM> and the workpiece <NUM>. A workpiece <NUM> that has surface irregularities, a workpiece <NUM> with a non-circular cross-sectional shape, a workpiece <NUM> with a substantially circular cross-sectional shape that is not rotated about the central axis of the workpiece <NUM>, or combinations thereof, can make basing the extension lengths of the slats <NUM> based on sensor data that directly measures one or more distances to the outer surface <NUM> of the workpiece <NUM> impractical.

The gap between the slat ends <NUM> and an effective location of the workpiece surface (e.g., locations of the outer surface <NUM> or where the outer surface would be without consideration of recesses or openings in the outer surface <NUM>) is maintained by the controller <NUM> in a separation distance range as the workpiece <NUM> rotates. The separation distance range can be a range that is close to the effective location of the workpiece surface (e.g., greater than <NUM> away from the effective location of the workpiece <NUM>) up to a second distance (e.g., up to <NUM> or more) but large enough to accommodate layers of a composite layup or other material added onto the outer surface. For example, the separation distance range from the effective location of the workpiece surface can be from <NUM> to <NUM>, <NUM> to <NUM>, or some other selected range. In some implementations, the second distance is less than a width associated with an average person's shoe in order to inhibit a likelihood of any portion of a leg of a worker from being positioned below an upper surface of the slats <NUM> and in order to inhibit items (e.g., tools) from falling through the gap between the slats <NUM> and the workpiece <NUM>.

In some implementations, the workpiece <NUM> includes a broadening taper from a first particular length of the workpiece <NUM>, a narrowing taper for a second particular length of the workpiece <NUM>, a curved portion extending for a third particular length of the workpiece <NUM>, or combinations thereof. One or more of the slat ends <NUM> can be shaped (e.g., slanted or curved) to correspond to lengths of the workpiece <NUM> that taper or curve.

In a particular implementation, the workpiece <NUM> is a fuselage, or a portion of a fuselage, of an aircraft that has a substantially elliptical cross-sectional shape with one or more outer surface irregularities to accommodate stringers (e.g., longitudinal grooves), landing gear, windows, wings, etc. During a manufacturing process, workers access the outer surface <NUM> to perform operations on the fuselage. For example, workers place stringers, which are long strengthening members that include uncured polymer material, in corresponding longitudinal grooves in the fuselage, and cover the fuselage with a plastic covering that is sealed to the fuselage. After the stringers are placed in corresponding indentations on the fuselage around the fuselage, the fuselage and stringers are subjected to a curing process to integrate the stringers with the fuselage. Subsequently, the plastic covering is removed and additional manufacturing processing is performed on the fuselage.

The workpiece transport <NUM> supports the workpiece <NUM> and allows the workpiece <NUM> to be moved to a position in working relation to the work platform <NUM>. The workpiece transport <NUM> includes a rotation mechanism <NUM> and sensors <NUM>. In some implementations, the workpiece transport <NUM> includes a drive to move the workpiece transport <NUM> relative to the work platform <NUM> to a desired position. In other implementations, a separate vehicle or drive system is used to move the workpiece transport <NUM> to the desired position relative to the work platform <NUM>. In some implementations, when the workpiece transport <NUM> is located in the desired position, the workpiece transport <NUM> is locked in position to prevent unintentional movement of the workpiece transport <NUM>.

The rotation mechanism <NUM> of the workpiece transport <NUM> enables rotation of the workpiece <NUM> about a longitudinal axis of the workpiece <NUM>. In some implementations, the longitudinal axis is a central longitudinal axis of the workpiece <NUM>. In other implementations, the longitudinal axis is offset from the central longitudinal axis of the workpiece <NUM>. The rotation mechanism <NUM> includes workpiece supports <NUM>, endpieces <NUM> coupled to the workpiece <NUM>, and a rotation drive <NUM>. The endpieces <NUM> are rotationally coupled to the workpiece supports <NUM> of the workpiece transport <NUM>. In some implementations, additional workpiece supports <NUM> (e.g., rollers) of the workpiece transport <NUM> are used to support the workpiece <NUM> at one or more locations along a length of the workpiece <NUM>.

One or both of the endpieces <NUM> include a first portion that corresponds to and is securely coupled to the workpiece <NUM> such that rotation of the endpieces <NUM> by the rotation mechanism <NUM> rotates the workpiece <NUM>, a second portion with a circular cross-sectional shape that includes gear portions <NUM> (e.g., gear teeth to fit in corresponding gear teeth of a drive gear or links of a drive chain, or recesses configured to receive gear teeth of a drive gear) that are engaged by corresponding gear portions coupled to the rotation drive <NUM>, and a third portion that is a transition between the first portion and the second portion. In some implementations, one or both endpieces <NUM> are permanently coupled to the workpiece <NUM> (e.g., welded to one or more support members of the workpiece <NUM>); while in other implementations, one or both of the endpieces <NUM> are removably coupled to the workpiece <NUM> (e.g., bolted to one or more support members of the workpiece <NUM>) to enable reuse of one or both of the endpieces <NUM>. Attaching the endpieces <NUM> to the workpiece <NUM> enables the controller <NUM> to determine extension distances of the slats <NUM> of the work platform <NUM> based on an angular position of one or both endpieces <NUM> that are coupled to the workpiece supports <NUM> of the workpiece transport <NUM>.

Indicia <NUM> are formed in one or more surfaces of one or both of the endpieces <NUM>, printed on one or more surfaces of one or both of the endpieces <NUM>, coupled to one or more surfaces of one or both of the endpieces <NUM>, or combinations thereof. In an alternate implementation, the indicia <NUM> are formed or printed on a portion of the workpiece <NUM> without significant surface irregularities. The indicia <NUM> are read by one or more position sensors of the sensors <NUM>, the sensors <NUM>, or both, and data from the one or more position sensors is used by the controller <NUM> to determine extension lengths of the slats <NUM> of the work platform <NUM>. In some implementations, the indicia <NUM> are on a circumferential portion of the second portion of one or both of the endpieces <NUM>, on a circumferential portion of the workpiece <NUM>, or combinations thereof. In some implementations, the indicia <NUM> are on a front face or back face of the second portion.

In an implementation, the indicia <NUM> include separate indicia <NUM> for each slat <NUM> of the slats <NUM> on a circumferential portion of the second portion of one or both endpieces <NUM> or on a circumferential portion of the workpiece <NUM>. The indicia <NUM> are read by a plurality of contour sensors of the contour sensors of the sensors <NUM>, the sensors <NUM>, or both, for each separate indicia. For some implementations, a particular separate indicia <NUM> of the separate indicia can be associated with more than one slat <NUM>.

The plurality of contour sensors associated with the particular separate indicia include a first contour sensor that provides data associated with a current position of slat end <NUM> of a corresponding slat, a second contour sensor that provides data associated with where the slat end <NUM> of the corresponding slat will be due to rotation of the workpiece <NUM> in a first direction, and a third contour sensor that provides data associated with where the slat end <NUM> will be due to rotation of the workpiece <NUM> in a second direction opposite to the first direction. The contour sensors can include or correspond to, for example, optical sensors or contact sensors. The optical sensors optically determine the contours of the indicia <NUM> based on return optical signals corresponding to optical signals sent to the indicia. The contact sensors include sensor heads that contact the indicia <NUM>, The sensor heads are coupled to arms and the contact sensors provide data to the controller <NUM> corresponding to an amount of extension or retraction of the arms as the workpiece <NUM> rotates. When the workpiece <NUM> is rotated, the controller <NUM> receives second data from the rotation mechanism <NUM> that indicates a rotation direction (i.e., the first direction or the second direction), a rotation rate of the workpiece, or both. Based on the rotation direction, the controller <NUM> acquires data from an appropriate contour sensor (e.g., the second contour sensor or the third contour sensor) and from the first contour sensor.

In a particular aspect, each separate indicia <NUM> around a circumference of the second portion includes raised portions, recesses, or both, that indicate an approximate contour of the outer surface <NUM> of the workpiece <NUM> at a height of a corresponding slat(s) <NUM>. The approximation of the contour ignores some surface irregularities in the outer surface <NUM> of the workpiece <NUM> (e.g., openings or grooves in the outer surface <NUM> of the workpiece <NUM>). For a first indicia <NUM> that corresponds to the first slat 102A controlled by a first actuator 120A, when the workpiece <NUM> is rotating in the first direction at a particular rotation rate, data from the first contour sensor and the second contour sensor are used to generate a contour map of the indicia <NUM> that corresponds to changes in the location of the outer surface <NUM> of the workpiece <NUM> due to the rotation of the workpiece <NUM> in the first direction at the rotation rate. The controller <NUM> uses the information of where the outer surface will be to generate signals for the actuator 120A that cause the actuator to adjust the extension length of the slat 102A, or leave the extension length of the slat 102A unchanged, to maintain the separation distance between the slat end <NUM> and the workpiece <NUM> in the separation distance range.

For example, the first contour sensor associated with the first slat 102A provides first data to the controller <NUM> that indicates the first distance from the first contour sensor to the first indicia <NUM> is <NUM>. The contour map determined with data from the second contour sensor and the rotation rate enables the controller <NUM> to determine that in a particular amount of time (e.g., <NUM> seconds) the first distance from the first contour sensor to the first indicia will be <NUM>. Based on the negative difference (i.e., -<NUM>), the controller <NUM> generates a signal for the first actuator 120A that causes the first actuator 120A to extend the first slat 102A by a particular distance directly proportional to the negative difference during rotation of the workpiece <NUM> so that at the particular time, the slat end <NUM> of the first slat 102A is within the separation distance range from the workpiece <NUM>. In an alternate implementation, the negative difference causes the controller <NUM> to generate a signal for the first actuator 120A that causes the first actuator 120A to retract the first slat 102A by a particular distance directly proportional to the negative difference during rotation of the workpiece <NUM> so that at the particular time, the slat end <NUM> of the first slat 102A is within the separation distance range from the workpiece <NUM>.

In another implementation, a position sensor of the sensors <NUM>, sensors <NUM>, or both, provides data that corresponds to the indicia <NUM> on one of the endpieces <NUM> to the controller <NUM>. Based on the data, the controller <NUM> determines an identifier associated with particular indicia read by the position sensor and accesses a table based on the identifier to find information that enables determination of signals to send to the actuators <NUM> to set the extension lengths of the slats <NUM> relative to the side <NUM> of the work platform <NUM> at the height of the slats <NUM>. In another implementation, the controller <NUM> receives angular position data from one or more sensors of the sensors <NUM> corresponding to an angular position of the workpiece <NUM> relative to a reference position (e.g., an angle from a center of rotation designated as zero degrees or zero radians). Based on the angular position data, the controller <NUM> determines an identifier associated with a particular angular position corresponding to the data and accesses the table based on the identifier to find information that enables determination of signals to send to the actuators <NUM> to set the extension lengths of the slats <NUM> relative to the side <NUM> of the work platform <NUM> at the height of the slats <NUM>.

Each identifier corresponds to a row in the table, and columns in the table include information associated with the slats <NUM>. A first column associated with a particular slat indicates a horizontal distance of the outer surface of the workpiece <NUM> from a reference position of the workpiece transport <NUM>. A second column associated with the particular slat indicates a rate of change for the position of the slat to maintain the slat within the separation range during rotation of the workpiece <NUM> in the first direction at a reference rotation rate from the current position to a position associated with the next row of the table, or the first row if the present row is the last row of the table. A third column associated with the particular slat indicates a rate of change for the position of the slat to maintain the slat within the separation range during rotation of the workpiece <NUM> in the second direction at the reference rotation rate from the current position to a position associated with the previous row of the table, or the last row if the present row is the first row of the table.

For these implementations, the workpiece <NUM> is initially rotated by the rotation mechanism <NUM> until the position sensor is aligned with one of the indicia <NUM> corresponding to a particular identifier in the table or until the angular position data provided by the angular position sensor indicates that a current angular position corresponds to a particular identifier in the table. The controller <NUM> determines initial signals to adjust the slats <NUM> from retracted positions to extended positions in the separation distance range based on the data from the sensor and sends the initial signals to the actuators <NUM> to cause the actuators <NUM> to extend the slats <NUM> toward the workpiece <NUM>. The controller <NUM> determines the initial signals based on information in the table from the row corresponding to the particular identifier and the first columns corresponding to the individual slats <NUM>, based on position data associated with the workpiece transport <NUM>, and position data associated with the work platform <NUM>.

After the positions of the slats <NUM> are set based on the initial signals, the controller <NUM> receives a command to rotate the workpiece <NUM> continuously or in increments. For example, the controller <NUM> receives a command to rotate the workpiece <NUM> in the second direction at a first rate. In response to the command, the controller <NUM> generates first signals that are sent to the actuators <NUM> to cause the actuators <NUM> to set an extension rate, or a retraction rate, of corresponding slats <NUM> by the corresponding actuators <NUM> for a period time during rotation of the workpiece <NUM>. The first signals are based on the information in the table from the third columns associated with the slats <NUM> for the row corresponding to the particular identifier adjusted for any difference between the first rate and the reference rate. When the position sensor provides data to the controller <NUM> indicating detection of the next identifier, or when the controller <NUM> determines that the angular position corresponds to the next identifier, the controller <NUM> determines the first signals based on the information in the table corresponding to the next identifier and provides the first signals to the actuators <NUM> to cause the actuators <NUM> to set the extension rate, or the retraction rate, of corresponding slats <NUM> to values indicated by the first signal. The extension rate or retraction rate included in a particular signal for a particular slat <NUM> can be zero, which causes the actuator <NUM> associated with the slat <NUM> to maintain a current extension length of the particular slat <NUM>.

The controller <NUM> includes one or more processors <NUM> and a memory <NUM>. The memory <NUM> is a non-transitory memory. The memory <NUM> includes instructions <NUM> that are executable by the processor(s) <NUM> to perform operations to send signals to the actuators <NUM> that cause the actuators <NUM> to adjust extension length of one or more of the slats <NUM>, maintain the extension length of one or more slats <NUM>, or both, to maintain the separation distance between the slat ends <NUM> and the workpiece <NUM> in the separation range during rotation of the workpiece <NUM>. The memory <NUM> includes input data <NUM>, position data <NUM>, rotation data <NUM>, access barrier data <NUM>, output data <NUM>, other data, or combinations thereof.

The input data <NUM> includes data from one or more input devices, data from the sensors <NUM>, data from the sensors <NUM>, other data, or combinations thereof. The processor(s) <NUM> generates the position data <NUM>, the rotation data <NUM>, the access barrier data <NUM>, and the output data <NUM> based on the input data <NUM>.

The position data <NUM> indicates positions of the workpiece transport <NUM> and the work platform <NUM>. The positions include locations of the workpiece transport <NUM> when the workpiece transport <NUM> is in a working relation to the work platform <NUM>, a location of the work platform <NUM>, a height of the slats <NUM>, other position information, or combinations thereof. The rotation data <NUM> includes information regarding rotation of the workpiece <NUM> by the rotation mechanism <NUM>. The rotation information includes a rotation direction, a rotation rate, rotation drive status (e.g., is the rotation drive on or off), an interval between rotations when the rotation mechanism <NUM> operates at periodic intervals, other information, or combinations thereof. The access barrier data <NUM> includes status of the access barrier <NUM>, rules associated with a change in the status of the access barrier <NUM>, other information, or combinations thereof.

The output data <NUM> includes output generated based on the position data <NUM>, the rotation data <NUM>, the access barrier data <NUM>, other data, or combinations thereof. The output data <NUM> includes information provided to one or more display devices and signals provided to one or more devices (e.g., the actuators <NUM>). The signals include control signals that cause or stop operation of the rotation mechanism <NUM>; signals that enable or inhibit movement of the workpiece transport <NUM> toward or away from the work platform <NUM>; access barrier signals associated with operation of the access barrier <NUM>; and signals provided to the actuators <NUM> that cause adjustment of extension lengths of one or more of the slats <NUM>, cause an extension length of one or more slats to be maintained, or both.

The system <NUM> of <FIG> enables reduction of non-value added time of a workpiece <NUM>. For example, the system <NUM> eliminates or reduces idle time during rotation of a workpiece to a new position by ensuring worker safety without requiring workers to leave the work area around the slats <NUM>. For example, without the system <NUM>, during rotation of the workpiece <NUM>, workers may need to move off of slats <NUM> to retract the slats <NUM>, rotate of the workpiece <NUM>, and re-extend the slats <NUM> to a safe position, all of which is non-value added time. Use of the system <NUM> reduces the non-value time by enabling the workers to safely remain on the slats <NUM> and continue to perform value added work (e.g., placement of stringers on a fuselage of an aircraft) as the workpiece <NUM> is rotated.

<FIG> depicts a side view representation of a workpiece <NUM> coupled to a workpiece transport <NUM> that supports the workpiece <NUM>. The workpiece supports <NUM> include bases <NUM> and one or more arcuate portions <NUM>. The one or more arcuate portions <NUM> have surfaces configured to complement outer surfaces of the cylindrical portions of the endpieces <NUM> of the workpiece <NUM> including gear portions <NUM> and contour changes of indicia <NUM> and configured to accommodate coupling of a gear portion coupled to the rotation drive <NUM> for the endpiece 138A that is rotated by the rotation drive <NUM>.

<FIG> depicts a top view representation of a workpiece <NUM> on a workpiece transport <NUM> positioned in working relation to a work platform <NUM>. The endpieces <NUM> that are coupled to the workpiece <NUM> are positioned on workpiece supports <NUM>. The gear portion <NUM> of the endpiece 138A enables rotation of the endpieces <NUM> and the workpiece <NUM> by the workpiece transport <NUM>.

A contour sensor <NUM> coupled to the work platform <NUM> is positioned to read contours of indicia <NUM> of the endpiece 138B. The contour sensor <NUM> sends data associated with the contours of the indicia <NUM> to the controller <NUM>. The data is used by the controller <NUM> to adjust or maintain extension lengths of the slats <NUM> as the workpiece <NUM> rotates to maintain a separation distance between slat ends <NUM> of the slats <NUM> and the outside surface <NUM> of the workpiece in a separation distance range. In the depiction of <FIG>, the slats <NUM> are extended toward the workpiece <NUM> and are positioned within the separation distance range of the outside surface <NUM> of the workpiece <NUM>. Side barriers <NUM> are positioned on each side of the slats <NUM> and an access barrier <NUM> is open to allow worker access to the slats <NUM>.

<FIG> is a flow chart of a method <NUM> of adjusting extension lengths of slats <NUM> of a work platform <NUM> to maintain a separation distance between ends <NUM> of the slats <NUM> and an outer surface <NUM> of the workpiece <NUM> in a separation distance range during rotation of the workpiece <NUM>. The method <NUM>, at block <NUM>, includes coupling the workpiece <NUM> to a workpiece transport <NUM>. During coupling of the workpiece <NUM> to the workpiece transport <NUM>, the workpiece <NUM> with a first endpiece <NUM> coupled to a first end of the workpiece <NUM> is positioned on the workpiece transport <NUM> such that the first endpiece <NUM> is positioned in a workpiece support <NUM> so that a gear portion <NUM> on the first endpiece <NUM> is coupled to a rotation drive <NUM> of the workpiece transport <NUM>. When the first endpiece 138A is positioned in the workpiece support <NUM>, a second endpiece 138B coupled to a second end of the workpiece <NUM> is positioned in a second workpiece support <NUM>. In some implementations a crane is used during the positioning of the workpiece <NUM> with the endpieces <NUM> on the workpiece transport <NUM>.

The method <NUM>, at block <NUM>, includes positioning the workpiece <NUM> on the workpiece transport <NUM> in working relation to the work platform <NUM>. When the workpiece <NUM> is positioned in working relation to the work platform <NUM>, the position of the workpiece transport <NUM> can be locked to prevent unintentional movement of the workpiece transport <NUM>. Sensors <NUM>, <NUM> provide position data to a controller <NUM> to enable the controller <NUM> to determine the position of an outer surface <NUM> of the workpiece <NUM> at the height of slat ends <NUM> of the slats <NUM>.

The method <NUM>, at block <NUM>, includes setting initial extension lengths of the slats <NUM> from a retracted position of the slats <NUM>. Setting the initial extension lengths of the slats <NUM> includes providing slat end position data to the controller <NUM> from the sensors <NUM>, <NUM>. Based on the slat end position data, the controller <NUM> generates signals sent to actuators <NUM>. The signals cause the actuators <NUM> to extend the slats <NUM> toward the workpiece <NUM> to positions in the separation distance range. In some implementations, the workpiece <NUM> is rotated to a particular position, and the signals are generated based on the particular position. When the slats <NUM> are positioned in the separation distance range, the controller <NUM> provides a signal to an access barrier <NUM> that causes the access barrier <NUM> to open a gate(s) in the access barrier <NUM> or retract all or a portion of the access barrier <NUM> to enable workers to walk onto the slats <NUM>.

The method <NUM>, at block <NUM>, includes obtaining operation data at the controller. The operation data includes first data associated with a position of an outer surface <NUM> of the workpiece <NUM> at a height of the slat ends <NUM> and second data associated with rotation of the workpiece <NUM>. The operation data is provided to the controller <NUM> by the sensors <NUM>, <NUM>, by components of a rotation mechanism <NUM> used to rotate the workpiece <NUM>, or both. The second data includes a rotation direction of the workpiece <NUM>, a rotation rate of the workpiece <NUM>, other information, or combinations thereof.

The method <NUM>, at block <NUM>, includes sending signals based on the operation data from the controller <NUM> to one or more of the actuators <NUM> of the work platform <NUM> during rotation of the workpiece <NUM>. The signals cause one or more of the actuators <NUM> to adjust extension lengths of the one or more slats <NUM> relative to the workpiece <NUM>, cause one or more of the actuators to maintain a particular extension length, or both.

During work on the workpiece <NUM>, one or more of the slat ends <NUM> can be set at a position outside of the separation distance range. For example, one or more slat ends <NUM> can become too close to the workpiece <NUM> or too far away from the workpiece <NUM> during rotation of the workpiece <NUM>. The method <NUM>, at block <NUM>, includes receiving third data at the controller from the sensors <NUM>, <NUM> associated with the slats <NUM>. The third data indicates that the separation distance between one or more slats <NUM> and the workpiece <NUM> is outside of the separation distance range for over a particular amount of time.

The method, at block <NUM>, includes stopping rotation of the workpiece <NUM> based on the third data. When the controller <NUM> stops rotation of the workpiece <NUM> based on the third data, the controller <NUM> sends information regarding the stoppage to one or more display devices, sounds an alarm, provides a visual indicator of a problem (e.g., a flashing yellow light if one or more of the slat ends <NUM> are too close to the workpiece <NUM> and a flashing red light if one or more of the slats <NUM> are too far away from the workpiece <NUM>). The information provided to the one or more displays informs workers of a reason for the stoppage (e.g., ends of identified slats <NUM> are too close or too far away from the workpiece <NUM>) and provides corrective information regarding one or more steps to be performed to allow continued rotation of the workpiece <NUM>. A particular sound of the alarm, the particular visual alert, or both, inform workers if the workers need to walk off of the slats <NUM> to the floor <NUM> of the work platform <NUM> (e.g., a first alarm sound and a red flashing visual indicator) or if the workers can remain on the slats <NUM> (e.g., a second alarm sound and a yellow flashing visual indicator). The method <NUM>, at block <NUM>, includes resuming rotation of the workpiece <NUM> after completion of one or more corrective actions to reposition the slat ends <NUM> relative to the workpiece <NUM> in the separation distance range.

The method <NUM>, at block <NUM>, includes sending a signal to the access barrier <NUM> to block access to the slats <NUM> and moving the workpiece transport <NUM> away from the work platform <NUM> in response to input data that a work phase for the workpiece <NUM> is completed. The input data can be data entered via an interface of the controller <NUM> from a worker associated with the work phase. Responsive to the input data, the controller <NUM> sends a close signal to the access barrier <NUM> to close the access barrier <NUM> when no workers are on the slats <NUM>, retracts the slats <NUM> to a retracted position, and provides output that enables the workpiece transport <NUM> to move the workpiece <NUM> away from the work platform <NUM>.

<FIG> is an illustration of a block diagram of a computing environment <NUM> including a general purpose computing device <NUM> configured to support implementations of computer-implemented methods and computer-executable program instructions (or code) according to the present disclosure. For example, the computing device <NUM>, or portions thereof, may execute instructions to perform, or cause equipment to perform, operations described with reference to <FIG>. In an implementation, the computing device <NUM> is, or is a component of, the controller <NUM>.

The computing device <NUM> includes a processor <NUM>. The processor <NUM> communicates with a system memory <NUM>, one or more storage devices <NUM>, one or more input/output interfaces <NUM>, one or more communications interfaces <NUM>, or a combination thereof. The system memory <NUM> includes non-transitory computer readable media, including volatile memory devices (e.g., random access memory (RAM) devices), nonvolatile memory devices (e.g., read-only memory (ROM) devices, programmable read-only memory, and flash memory), or both. The system memory <NUM> includes an operating system <NUM>, which may include a basic input/output system for booting the computing device <NUM> as well as a full operating system to enable the computing device <NUM> to interact with users, other programs, and other devices. The system memory <NUM> includes one or more applications <NUM> (e.g., instructions) which are executable by the processor <NUM>.

The processor <NUM> communicates with the one or more storage devices <NUM>. For example, the one or more storage devices <NUM> are non-transitory computer readable media that can include nonvolatile storage devices, such as magnetic disks, optical disks, or flash memory devices. The storage devices <NUM> can include both removable and non-removable memory devices. The storage devices <NUM> can be configured to store an operating system, images of operating systems, applications, and program data. In particular implementations, the system memory <NUM>, the storage devices <NUM>, or both, include tangible computer-readable media incorporated in hardware and which are not signals.

The processor <NUM> communicates with the one or more input/output interfaces <NUM> that enable the computing device <NUM> to communicate with one or more input/output devices <NUM> to facilitate user interaction. The input/output interfaces <NUM> can include serial interfaces (e.g., universal serial bus (USB) interfaces or Institute of Electrical and Electronics Engineers (IEEE) <NUM> interfaces), parallel interfaces, display adapters, audio adapters, and other interfaces. The input/output devices <NUM> can include keyboards, pointing devices, displays, speakers, microphones, touch screens, and other devices. The processor <NUM> detects interaction events based on user input received via the input/output interfaces <NUM>. Additionally, the processor <NUM> sends a display to a display device via the input/output interfaces <NUM>.

Claim 1:
A system (<NUM>) comprising a work platform (<NUM>) including slats (<NUM>), the system (<NUM>) being configured to adjust extension lengths of the slats (<NUM>) of the work platform (<NUM>) relative to an outer surface (<NUM>) of a rotatable workpiece (<NUM>) positioned in working relation to the work platform (<NUM>), the system (<NUM>) further comprising:
one or more sensors (<NUM>, <NUM>) configured to collect first data associated with a position of the outer surface (<NUM>) of the workpiece (<NUM>) at a height of the slats (<NUM>);
actuators (<NUM>) configured to extend or retract the slats (<NUM>); and
a controller (<NUM>) coupled to the one or more sensors (<NUM>, <NUM>) and to the actuators (<NUM>), wherein the controller (<NUM>) is configured to receive the first data and second data associated with rotation of the workpiece (<NUM>) from the one or more sensors (<NUM>), wherein the controller (<NUM>) is configured to provide signals to the actuators (<NUM>) based on the first data and the second data, and wherein the signals cause the actuators (<NUM>) to adjust or maintain extension lengths of the slats (<NUM>) of the work platform (<NUM>) to maintain separation distances between ends of the slats (<NUM>) and the outer surface (<NUM>) of the workpiece (<NUM>) within a separation distance range as the workpiece (<NUM>) rotates.