Patent Description:
It is desirable to identify burrs on vehicle components, especially aerodynamic components (e.g., surfaces that are exposed to airflow) as such burrs can lead to suboptimal operation of the vehicle.

<CIT> in accordance with its abstract recites an induced vibration dynamic touch sensor comprising a compliant membrane adapted for sliding contact with an object so as to induce vibrations in the membrane, and a transducer assembly for converting the vibrations into electrical signals. The electrical signals are processed to produce a normalized spectral signature characteristic of the size and shape of the object, and the sizes and shapes and nature of its surface features. A pattern vector is extracted from the spectral signature and subjected to discriminant analysis to classify and recognize the object.

<CIT> in accordance with its abstract recites a system to detect the surface defect on a long size body by bringing wire bodies applied with tension into contact with the surface on the traveling long size body and detecting changes of the wire bodies generated when the wire bodies are caught on the surface defect on the long size body.

<CIT> in accordance with its abstract recites processes and systems for detecting surface anomalies in components which generally includes contacting a surface of the component with a detection apparatus, wherein the detection apparatus comprises at least one post, a wire extending from the post and a sensor in operative communication the wire; and sensing the surface anomaly as an increase in resistance of the wire across the surface.

Systems and methods are disclosed for burr detection. In a certain example, a burr detection system is disclosed and includes a test piece holder configured to hold a test piece, a robot arm, a test fabric held in a test fabric holder disposed on a first end of the robot arm and configured to hold the test fabric, wherein the test fabric comprises a plurality of fibers, and wherein the robot arm is configured to move the test fabric when the test fabric is contacting a surface of the test piece, a force sensor coupled to the robot arm and configured to output force data associated with a force required to move the test fabric when the test fabric is contacting the surface of the test piece, a surface scanner, and a controller configured to receive the force data and determine based on the force data a possible presence of a burr within an area of the test piece based on whether the force required to move the test fabric (<NUM>) within the area is a threshold percentage higher than a typical force required to move the test fabric on the test piece, wherein the controller (<NUM>) is further configured to store a location of the area (<NUM>), wherein the controller is further configured to cause the surface scanner to scan at least a portion of the location of the area to confirm the presence of the burr, wherein the fibers have a maximum thickness such that a burr with a minimum height of half of the maximum thickness can be detected by the system.

In certain other examples, a method is disclosed and includes holding a test fabric by a test fabric holder disposed on a first end of a robot arm, said test fabric comprising a plurality of fibers, moving the test fabric by the robot arm when the test fabric is contacting a surface of a test piece, outputting, by a force sensor coupled to the robot arm, a force required to move the test fabric when the test fabric is contacting the surface of the test piece, and determining, by a controller, a possible presence of a burr within an area of the test piece based on the determining the force required to move the test fabric comprising comprises determining whether the force required to move the test fabric (<NUM>) within the area is a threshold percentage higher than a typical force required to move the test fabric on the test piece, storing a location of the area (<NUM>), and scanning at least a portion of the location of the area to confirm the presence of the burr, wherein the fibers have a maximum thickness such that a burr with a minimum height of half of the maximum thickness can be detected by the system.

The scope of the disclosure is defined by the appended claims.

A more complete understanding of the disclosure will be afforded to those skilled in the art, as well as a realization of additional advantages thereof, by a consideration of the following detailed description of one or more implementations. Reference will be made to the appended sheets of drawings that will first be described briefly.

Examples of the disclosure and their advantages are best understood by referring to the detailed description that follows.

Various examples of a burr detection system are disclosed herein along with related methods. As an illustrative example, a burr detection system includes a test piece holder configured to hold a test piece, a robot arm, a test fabric holder disposed on a first end of the robot arm and configured to hold a test fabric, and a force sensor configured to detect a force required to move the test fabric when the test fabric is contacting the surface of the test piece. Data from the burr detection system (e.g., data from the force sensor) can be communicated to a controller. The controller can detect the presence of a burr on the test piece from the data.

The systems and techniques disclosed herein allow for more accurate and efficient identification of burrs on a component. In certain situations, the presence of such burrs can lead to inefficient operation of the vehicle. For example, burrs that are present on aerodynamic surfaces of the vehicle (e.g., surfaces of components that are exposed to airflow such as wings, fuselages, tails, spoilers, flaps, stabilizers, nacelles, and other such components) can disrupt airflow and alter the aerodynamic performance of the vehicle. In certain examples, air can flow over a smooth aerodynamic surface as laminar flow. However, the presence of a burr on the aerodynamic surface can lead to laminar flow becoming turbulent flow. Turbulent flow decreases aerodynamic performance. However, such burrs can often be too small to be visible to the human eye. Accordingly, accurate identification of burrs is desirable.

Currently, identification of burrs on such vehicle components is a difficult and time consuming process. Existing systems to identify such burrs can only detect burrs within a small area and thus are not practical to be used on an entire vehicle component (e.g., on aircraft components with aerodynamic surfaces such as an engine nacelle or wing of an aircraft). The systems and techniques described herein allow for accurate and quick detection of burrs on such components.

<FIG> illustrates a burr detection system in accordance with an example of the disclosure. The burr detection system <NUM> of <FIG> includes a robot arm <NUM>, a test fabric holder <NUM>, a test fabric <NUM>, a force sensor <NUM>, a test piece holder <NUM>, a controller <NUM>, a test piece <NUM>, and a secondary sensor <NUM>.

The robot arm <NUM> can be a robot arm configured to robotically move the test fabric holder <NUM> and the test fabric <NUM> over a surface of the test piece <NUM>. The robot arm <NUM> can include one or more links and each such link can move in relation to and/or independently of one or more other links. As such, each of the links can rotate, translate, and/or otherwise move to perform one or more tasks. In certain examples, the links can be configured to allow the robot arm <NUM> to move in one or more degrees of freedoms. For example, each link of the robot arm <NUM> and/or the robot arm <NUM> in its entirety can be configured to move in one, two, three, four, five, or six degrees of freedom.

The test fabric holder <NUM> is disposed on a first end of the robot arm <NUM> and is configured to hold the test fabric <NUM>. The test fabric <NUM> can be disposed on the test fabric holder <NUM> through mechanical fastening (e.g., through clips, screws, and/or other fasteners), through adhesives (e.g., glue), and/or through other techniques for attaching the test fabric <NUM> to the test fabric holder <NUM>.

The test fabric <NUM> can be any sort of fabric that can be configured to detect the presence of burrs. In certain examples, the test fabric <NUM> can be cotton, wool, synthetic, microfiber, composite, and/or other types of fabrics. The test fabric <NUM> is composed of a plurality of fibers and has to be configured so that the thickness of the largest fiber is less than or equal to twice that of the minimum burr height that the burr detection system <NUM> is configured to detect. , if the smallest burr that the burr detection system <NUM> is configured to detect has a height of <NUM> inches (<NUM> micrometers), than the thickness of the largest fiber should be no more than <NUM> inches (<NUM> micrometers).

The robot arm <NUM> can be configured to move the test fabric holder <NUM> and, thus, the test fabric <NUM> at least when the test fabric <NUM> is contacting a surface of the test piece <NUM>. As the robot arm <NUM> moves the test fabric <NUM> along the surface of the test piece <NUM> held by the test piece holder <NUM>, fibers of the test fabric <NUM> can catch on burrs present on the test piece <NUM>. As the fibers catch the burrs, the force required to move the test fabric <NUM> can change. The force sensor <NUM> is coupled to the robot arm <NUM> and is configured to detect such changes in force required to move the test fabric <NUM>. The force sensor <NUM> can detect the force required to move the robot arm <NUM>, the test fabric holder <NUM>, and/or the test fabric <NUM>. In certain examples, the force sensor <NUM> can be disposed near the test fabric holder <NUM> and/or the test fabric <NUM>, but other examples can include the force sensor <NUM> disposed and/or coupled to other portions of the robot arm <NUM>.

Data from the force sensor <NUM> is communicated to the controller <NUM>. The controller <NUM> can include, for example, a single-core or multi-core processor or microprocessor, a microcontroller, a logic device, a signal processing device, non-transitory memory for storing executable instructions (e.g., software, firmware, or other instructions), and/or any elements to perform any of the various operations described herein. In various examples, the controller <NUM> and/or its associated operations can be implemented as a single device or multiple devices (e.g., communicatively linked through wired or wireless connections) to collectively constitute the controller <NUM>. Additionally, the controller <NUM> can be communicatively linked (e.g., communicatively linked through wired or wireless connections) to the robot arm <NUM>, the force sensor <NUM>, the secondary sensor <NUM>, and/or other components of the burr detection system <NUM> to receive signals from such components and/or provide control instructions to such components.

The controller <NUM> can include one or more memory components or devices to store data and information. The memory can include volatile and non-volatile memory. Examples of such memories include RAM (Random Access Memory), ROM (Read-Only Memory), EEPROM (Electrically-Erasable Read-Only Memory), flash memory, or other types of memory. In certain examples, the controller <NUM> can be adapted to execute instructions stored within the memory to perform various methods and processes described herein, including implementation and execution of control algorithms responsive to sensor and/or operator inputs.

The controller <NUM> is configured to detect the presence of burrs on the test piece <NUM> from, at least, the data from the force sensor <NUM>. When the test fabric <NUM> moves over a burr, one or more fibers of the test fabric <NUM> can snag the burr. The snagging of the burr can cause an increase in the amount of force required to move the test fabric <NUM>. The controller <NUM> can determine, from data from the force sensor <NUM>, the increase in force. If the increase in force exceeds a threshold increase, then the controller <NUM> determines that the test fabric <NUM> is passing over a burr. In certain examples, the threshold increase can be a magnitude increase (e.g., an increase of more than <NUM> Newton, <NUM> Newtons, or <NUM> Newtons or more of force), a percentage increase (e.g., an increase of at least <NUM>%, at least <NUM>%, at least <NUM>%, or more than <NUM>% of force over a baseline or typical force), and/or another type of increase and/or a combination of increases (e.g., both magnitude and percentage). The threshold increase may be an increase over a baseline or typical force, or may be an increase over a known force required to move the test fabric <NUM> over the test piece <NUM> when there is no burr present. As such, if <NUM> Newtons of force is typically required or is the average force required to move the test fabric <NUM> on the test piece <NUM>, and a <NUM>% increase over the typical or average force indicates the presence of a burr within the surface area covered by the test fabric <NUM> at the time of the force increase, the controller determines a possible presence of a burr within the area if data from the force sensor <NUM> indicates that <NUM> Newtons or higher of force is required to move the test fabric <NUM> on the test piece <NUM>.

The test piece holder <NUM> is configured to hold the test piece <NUM>. In certain examples, the test piece holder <NUM> can be configured to hold the test piece so that moving the test fabric <NUM> over the test piece <NUM> does not result in substantial movement of the test piece <NUM>. In certain such examples, the test piece <NUM> can, before a burr detection sequence is performed, be coupled to the test piece holder <NUM>. After the appropriate burr detection sequence has been performed, the test piece <NUM> can then be decoupled from the test piece holder <NUM> (e.g., to be used in manufacture of the vehicle and/or to be reworked).

The secondary sensor <NUM> is an additional sensor for detection of burrs on the test piece <NUM>. For example, the secondary sensor <NUM> is a surface scanner that can scan an area. In certain examples, the secondary sensor <NUM> can be used to detect burrs within a targeted area. Certain such examples detect the presence of burrs within an area covered by the test fabric <NUM> (e.g., the area that the test fabric <NUM> covers when an increase in force required to move the test fabric <NUM> is detected), and utilize the secondary sensor <NUM> to, for example, scan the area to further detect and confirm the presence of the burr. As such, such systems use the test fabric <NUM> to determine a possible presence of a burr within an area and then use the secondary sensor <NUM> to confirm the presence of the burr within the area.

While <FIG> illustrates the burr detection system <NUM> that can perform the techniques described herein, other examples can perform the burr detection techniques with other systems (e.g., other automatically operated robotic systems, with a user operated system, and/or by hand with one or more gloves constructed of test fabric).

<FIG> illustrates an example of using the burr detection system in accordance with an example of the disclosure. Example <NUM> of <FIG> illustrates a test fabric <NUM> contacting a test piece through an area <NUM> that contains burrs <NUM> and <NUM>.

The test fabric <NUM> can be configured to move in one or more directions. For example, the test fabric <NUM> can translate in directions <NUM>, <NUM>, <NUM>, and/or <NUM>. Certain other examples can have the test fabric <NUM> rotate in one or more directions. In certain such examples, the robot arm <NUM> can translate and/or rotate the test fabric <NUM> in a plurality of directions in order to increase the likelihood of detecting the burr. As such, the robot arm <NUM> can both translate and rotate the test fabric <NUM> in one or more directions.

When the test fabric <NUM> is translated and/or rotated in a direction, fibers of the test fabric <NUM> can catch on any burrs present on the test piece <NUM>. When the fiber catches on the burr, the force required to move the test fabric <NUM> over the test piece <NUM> can increase. As explained above, if the increase in force exceeds a threshold increase, the controller <NUM> can then determine a possible presence of a burr within the area <NUM> covered by the test fabric <NUM>.

In <FIG>, the area <NUM> can include burrs <NUM> and <NUM>. As the test fabric <NUM> moves over the area <NUM> of the test piece <NUM>, fibers of the test fabric <NUM> can catch on the burrs <NUM> and/or <NUM>. Catching the burrs <NUM> and/or <NUM> with the fibers of the test fabric <NUM> can lead to an increase in the force required to move the test fabric <NUM> on the surface of the test piece <NUM> and allow for the controller <NUM> to determine a possible presence of the burrs <NUM> and/or <NUM> within the area <NUM>. Additionally, fibers <NUM> and <NUM> can catch on the burrs <NUM> and <NUM>, respectively, and be left behind close to the position of the burrs. Such left behind fibers <NUM> and <NUM> can allow for the burrs to be more easily identified through visual scanning. As such, in certain examples, the fibers of the test fabric <NUM> can be a color different from the color of the test piece <NUM> to allow for easier identification of the burrs. In certain examples, the secondary sensor <NUM> can then further inspect the area.

In other examples not part of the present invention, the burr detection system <NUM> can be configured to determine the presence of the burr from just passing the test fabric <NUM> over the area of the test piece <NUM>. In certain such examples, the burr detection system <NUM> can determine that the area covered by the test piece <NUM> should be reworked (e.g., smoothed out) and/or refinished when the presence of the burr is detected to remove such burr.

The test fabric <NUM> can be moved in a plurality of directions (e.g., by the robot arm <NUM>) over the area <NUM>. For example, the test fabric <NUM> can be moved in two or more of directions <NUM>, <NUM>, <NUM>, and <NUM> and/or rotated in addition to being translated. Certain examples can move the test fabric <NUM> in any combination of translational and/or rotational directions. Burrs present on the test piece <NUM> can be oriented so that the each burr will catch fiber(s) only when the test fabric <NUM> is moved over the burr in certain directions. Moving the test fabric <NUM> in a plurality of directions can allow for fibers of the test fabric <NUM> to catch on more burrs present on the test piece <NUM>. As illustrated in <FIG>, burrs <NUM> and <NUM> are in different orientations (e.g., the burr <NUM> is in a first orientation and the burr <NUM> is in a second orientation). The test fabric <NUM> can catch on the burr <NUM> when moving in direction <NUM> and can catch on the burr <NUM> when moving in direction <NUM>. Accordingly, moving the test fabric <NUM> in directions <NUM> and/or <NUM> might lead to the test fabric <NUM> not catching on burrs <NUM> and/or <NUM> and, thus, moving in a plurality of directions can lead to detection of more burrs and/or lead to increased likelihood of detection of burrs.

In certain other such examples, the robot arm <NUM>, the test fabric holder <NUM>, and/or the test fabric <NUM> can include one or more force sensors (e.g., force sensors additional to the force sensor <NUM>) to determine local resistance to movement to the test fabric <NUM>. For example, such sensors can detect force pulling the test fabric <NUM> against its direction of movement (e.g., resistance to movement of the test fabric <NUM>). In an exemplary system, such sensors can be disposed on the test fabric holder <NUM> and be coupled to at least a portion of the test fabric <NUM> when the test fabric <NUM> is mounted on the test fabric holder <NUM>. In systems with a plurality of such sensors, the sensors can form a grid and each sensor can be used to detect localized resistance force for a portion of the test fabric <NUM>. If such force is higher than a threshold force, then that portion of the test piece <NUM> covered by the test fabric <NUM> (e.g., the area covered by the portion of the test fabric <NUM> that the sensor is configured to detect the movement force of) can include one or more burrs. Such a system can allow for a larger test fabric <NUM> while reducing and/or eliminating the need for secondary review of the area covered by the test fabric <NUM> as well as increasing the precision of determinations of the location of burrs.

<FIG> illustrates an example of burr detection in accordance with an example of the disclosure. <FIG> illustrates a fiber <NUM> of a test fabric contacting a burr <NUM>. Fiber <NUM> can be a circular shaped fiber. As shown in <FIG>, fiber <NUM> has a thickness <NUM> and the burr <NUM> has a height <NUM>. The thickness <NUM> is twice or less than twice that of height <NUM>. Thus, fiber <NUM> can catch on burr <NUM> and lead to increased resistance to movement of the test fabric and/or can snag on the burr <NUM> and be left behind on the test piece as a visual indicator of the location of the burr <NUM>.

In certain examples, the height <NUM> can be a minimum height of a burr that the test fabric <NUM> is configured to detect. To consistently detect burrs of height <NUM> or greater, the fibers of the test fabric <NUM> is a maximum thickness that is twice that of height <NUM>. Thus, the thickness <NUM> of fiber <NUM> is at most twice that of height <NUM>.

The test piece surface also includes a plurality of other microscopic protrusions, but such protrusions are of a height less than half that of the thickness <NUM> of the fiber <NUM> and so does not catch the fiber <NUM>. Additionally, such protrusions can be of a size that does not cause a decrease in aerodynamic performance of the test piece. Accordingly, the fiber <NUM> of the test fabric can be sized to not detect such protrusions to reduce the amount of false positives detected by the burr detection system <NUM>.

<FIG> illustrates a further example burr detection in accordance with an example of the disclosure. <FIG> illustrates a fiber <NUM> of a test fabric contacting a burr <NUM>. Fiber <NUM> can be a rectangular shaped fiber. As shown in <FIG>, fiber <NUM> has a thickness <NUM> that is twice or less than twice height <NUM> of the burr <NUM>. Thus, fiber <NUM> can catch on burr <NUM> and lead to increased resistance to movement of the test fabric and/or can snag on the burr <NUM> and be left behind on the test piece as a visual indicator of the location of the burr <NUM>. Though <FIG> and <FIG> are directed to circular and rectangular shaped fibers of test fabrics, other examples can include fibers of other shapes or of irregular shapes (e.g., the shape is different at one portion of the fiber as compared to another portion of the fiber).

<FIG> is a flowchart detailing a method of burr detection in accordance with an example of the disclosure. In block <NUM>, a test piece <NUM> is mounted on a test piece holder <NUM>. The test piece <NUM> can be any manufactured component, such as a vehicle component that includes an aerodynamic surface.

In block <NUM>, the test fabric <NUM> is held by the test fabric holder <NUM>. In certain examples, the test fabric <NUM> can be coupled to the test fabric holder <NUM> in block <NUM>, but other examples can include the test fabric <NUM> having been previously coupled to the test fabric holder <NUM> prior to block <NUM>.

In block <NUM>, the robot arm <NUM> can move so that the test fabric <NUM> contacts the test piece <NUM>. In certain examples, the robot arm <NUM> can detect when the test fabric <NUM> has contacted the test piece <NUM>. The robot arm <NUM> can then move the test fabric <NUM> on the test piece <NUM>.

In block <NUM>, the force required to move the test fabric <NUM> on the test piece <NUM> is determined by the force sensor <NUM> and outputted to the controller <NUM>. The controller <NUM> can then determine the force required to move the test fabric <NUM> on the portion of the test piece <NUM> via, for example, the force sensor <NUM> as well as one or more other sensors (e.g., sensors coupled to the test fabric as described herein).

In certain examples, the controller <NUM> can be programmed, can be inputted, or can be configured to first determine a baseline or typical force to move the test fabric <NUM> on the test piece <NUM> (e.g., force required to move the test fabric <NUM> on the test piece <NUM> when no burrs are present). Such a determination can be made by, for example, moving the test fabric <NUM> on a baseline test piece confirmed to not include burrs. Such baseline test pieces can include a shape similar to the shape of production components to be tested, or can just include a similar surface (e.g., the baseline is made of the same material and/or finish as that of production components).

In block <NUM>, the possible presence of a burr can be determined from the force required to move the test fabric <NUM>. In certain examples, the possible presence of the burr can be determined from an increase in force required to move the test fabric <NUM>. Additionally or alternatively, the possible presence of the burr can be determined from fibers caught on such burrs. In certain examples, the presence of the burr can be determined directly in block <NUM> from force data, but other examples can proceed to block <NUM> to confirm the presence of the burr.

In block <NUM>, the presence of the burr can be confirmed. For example, one or more secondary sensors <NUM> can scan an area identified to possibly include a burr. Additionally, other examples can include visual and/or manual (hand) inspections. Hand inspections can be conducted with one or more gloves constructed of test fabric, moving and/or rotating in a plurality of directions in order to increase the likelihood of detecting the burr. After the burr has been confirmed, the test piece <NUM> can then be reworked and/or refinished to remove such burrs.

Claim 1:
A system comprising:
a test piece holder (<NUM>) configured to hold a test piece (<NUM>);
a robot arm (<NUM>);
a test fabric (<NUM>) held in a test fabric holder (<NUM>) disposed on a first end of the robot arm and configured to hold the test fabric (<NUM>), wherein the test fabric comprises a plurality of fibers (<NUM>, <NUM>), and wherein the robot arm is configured to move the test fabric when the test fabric is contacting a surface of the test piece;
a force sensor (<NUM>) coupled to the robot arm and configured to output force data associated with a force required to move the test fabric when the test fabric is contacting the surface of the test piece;
a surface scanner (<NUM>); and
a controller (<NUM>) configured to receive the force data and determine, based on the force data, a possible presence of a burr within an area (<NUM>) of the test piece based on whether the force required to move the test fabric (<NUM>) within the area is a threshold percentage higher than a typical force required to move the test fabric on the test piece, wherein the controller (<NUM>) is further configured to store a location of the area (<NUM>), wherein the controller is further configured to cause the surface scanner to scan at least a portion of the location of the area to confirm the presence of the burr;
wherein the fibers (<NUM>, <NUM>) have a maximum thickness such that a burr with a minimum height of half of the maximum thickness can be detected by the system.