Patent Description:
Resistance spot welding is a welding technique that includes joining metal surfaces together through the heat generated from electrical resistance as a result of running current through the two surfaces. Current may be routed to the metal surfaces through a first electrode and routed away from the metal surfaces through a second electrode. In some examples, two electrodes may execute a resistance spot weld (RSW) in an opposed weld configuration, where the two electrodes are substantially aligned on a single axis and approach each other (or one moving electrode approaches another relatively stationary electrode) to execute the weld to surfaces between the two electrodes. In other examples, two electrodes may execute a RSW in a parallel gap configuration where the two electrodes simultaneously approach and contact one or more components that define the metal surfaces along different adjacent parallel axes to execute the weld. In other examples, two electrodes may execute a RSW in a step weld configuration where the two electrodes simultaneously approach and contact one or more components that define the metal surfaces along different adjacent parallel axes to execute the weld, where one electrode contacts the one or more components at a relatively greater depth than the other electrode.

<CIT> according to its abstract describes a robot, which has a robot mechanism unit having a sensor and a control unit: The control unit includes a normal control unit that controls the operation of the robot mechanism unit, and a learning control unit hat, when the robot mechanism unit operated by a speed command that is given by multiplying a teaching speed designated in a task program by a speed change ratio, performs learning to calculate, from a detection result by the sensor, a learning correction amount for making the trajectory or position of the control target in the robot mechanism unit approach the target trajectory or target position, or for reducing the vibration of the control target, and performs processes so that the control target position of the robot mechanism unit moves along a fixed trajectory regardless of the speed change ratio.

An apparatus according to the present invention is defined in claim <NUM>, and comprises a resistance spot weld (RSW) head that defines a PGW configuration and an opposed welding configuration. The RSW head includes one or more processing circuits, a first electrode, and a second electrode. The first electrode and the second electrode are configured to execute a parallel gap RSW (hereinafter referred to as a PGW) on a first component secured to a first base when the RSW head is in the PGW configuration. The first electrode is configured to execute an opposed weld with a third electrode of a second base on a second component secured to the second base when the RSW head is in the opposed welding configuration. The RSW head includes an accelerometer securely attached to the first electrode at a location adjacent to the first electrode. The one or more processing circuits are configured to cause the accelerometer to gather a PGW set of acceleration data of the first electrode during the PGW and gather an opposed weld set of acceleration data of the first electrode during the opposed weld. In some examples, during the PGW, the RSW head may include a second accelerometer securely mounted to the second electrode that may collect a third set of acceleration data during the PGW. The one or more processing circuits are configured to determine that the PGW set of acceleration data gathered during the PGW when the RSW head is in the PGW configuration indicates a first welding defect by including at least one acceleration value outside of a threshold acceleration range. The one or more processing circuits are configured to determine that the opposed weld set of acceleration data gathered during the opposed weld when the RSW head is in the opposed welding configuration indicates a second welding defect by including at least one acceleration value outside of the threshold acceleration range.

Aspects of the disclosure are directed to a weld head configured to execute opposed and parallel gap resistance spot welding (RSW). The weld head may include two arms that each are configured to receive an electrode configured for executing RSW. The two electrodes of the two arms may be used to execute either parallel gap RSW (hereinafter referred to as PGW) to one or more components secured to a first base or step RSW (hereinafter referred to as a step weld) to one or more components that define contact points at two different depths as secured to the first base, while an electrode embedded in a second base may be used along with one of the electrodes of the weld head to execute an opposed RSW (hereinafter referred to as opposed welding or an opposed weld) to one or more components secured to the second base. The weld head may include at least one accelerometer secured adjacent one of the electrodes. The accelerometer may be configured to gather accelerometer data of the electrode as the electrode is executing a RSW. One or more processing circuits that are integrated into the weld head and/or integrated into a separate computing device may be configured to analyze the accelerometer data and determine if the RSW resulted in a welding defect. The processing circuits may be configured to determine that the accelerometer data indicates a defect when the accelerometer data includes data points satisfying one or more criteria, such as being out of a range threshold. For example, the processing circuits may be configured to determine that the acceleration data indicates a welding defect if one or more acceleration values are either greater than a maximum threshold or lower than a minimum threshold during a predetermined time window of the RSW during which the respective acceleration values occurred.

For example, when executing a PGW or step weld, the weld head may provide current to an electrode of one of the arms, such both electrodes may press down upon and weld together two metal surfaces resting upon a first base when the current flows through the surface to the other electrode. For another example, when executing an opposed weld, the current may be provided to either the electrode of one of the two arms that is executing the opposed weld or current may be provided to an electrode embedded of a second base, such that the current may pass from one of these two electrodes through two metal surfaces resting upon the second base and into the other respective electrode to weld the two surfaces together. A welding system may switch between executing PGW, step welding, and opposed welding by merely swapping out which base is secured to the welding station (e.g., a base without an electrode for PGW and/or step welds or a base with an electrode for opposed welding), swapping out an electrode secured to an arm (e.g., securing a relatively longer electrode that can extend to a relatively lower depth during the weld), and/or resecuring an arm to a different location on the weld head (e.g., a lower relative location to enable the same electrode to extend to a relatively lower depth during the weld) depending upon the application. Configuring a welding system to alternate between PGW, step welding, and opposed welding by only switching and/or resecuring a single component (e.g., the base, the electrode, or the arm location) may increase a speed at which the welding system may sequentially alternate between the configurations. Increasing a speed with which an operator may reconfigure a welding system to execute PGW, step welds, and/or opposed welds may enable the welding station to accommodate all three (or more) processes during production, reducing a need for additional stations to provide the alternative processes.

The two arms may each define an aperture configured to receive a securing mechanism such as a bolt. A securing mechanism may be inserted through one of the apertures of a respective arm and also inserted into an aperture of the weld head to secure the respective arm to the weld head. In some examples, each arm may define a plurality of apertures, such that the securing mechanism may be inserted through a different aperture of the arm to secure the respective electrode at a different location relative to the weld head. In this way, electrodes may be moved to different locations relative to the weld head in order to execute RSWs at different locations for different metal surfaces by securing respective arms to the weld head using different apertures. Similarly, as a result of securing mechanisms being receivable by a plurality of apertures at predetermined locations, a weld head may be configured to quickly be configured to execute a plurality of PGWs and/or step welds with different corresponding gaps between the electrodes (e.g., where a predetermined gap distance correlates to predetermined apertures).

<FIG> is a conceptual and schematic diagram of welding system <NUM> that includes weld head <NUM> configured to execute RSWs. <FIG> includes XYZ axes that are referenced herein for purposes of clarity, though weld systems <NUM> may have different orientations in different examples. Weld head <NUM> may include one or more arms 14A, 14B (collectively, "arms <NUM>") that each are configured to receive at least one electrode 16A, 16B (collectively, "electrodes <NUM>") that execute RSWs. As received by arms <NUM>, one or both electrodes <NUM> may be configured to execute a PGW, step weld, and an opposed weld as discussed herein.

Electrodes <NUM> may be many conductive elements, such as, e.g., class <NUM> copper, class <NUM> copper, or silica loaded copper. Electrodes may be any size consistent with the disclosure herein. For example, electrodes <NUM> may define a <NUM> millimeter x <NUM> millimeter cross section at a "top" portion (e.g., where electrodes <NUM> are secured to arms <NUM>) and a <NUM> millimeter x <NUM> millimeter cross-section at a "bottom" portion (e.g., where electrodes <NUM> contact components <NUM> as discussed herein). In some examples, electrodes <NUM> may define different cross-sectional shapes, such as circular, ovaloid, triangular, or the like.

Base <NUM> and weld head <NUM> may both be secured to a common location at a welding station. In some examples, weld head <NUM> may move towards base <NUM> to execute a PGW, step weld, and/or an opposed weld. For example, weld head <NUM> may be secured to a moving stage that can be lowered or otherwise moved along the Z axis toward a relatively stationary base <NUM>. Arms <NUM> may be configured to be moveable relative to weld head <NUM> when executing a PGW, step weld, and/or an opposed weld. For example, one or both electrodes <NUM> may be secured to weld head <NUM> partially through spring <NUM> that is configured to longitudinally condense along the Z axis when electrodes <NUM> contact components 22A, 22B (collectively, components "<NUM>") that are secured to base <NUM>.

Upon contacting components <NUM>, spring <NUM> may cause electrodes <NUM> to provide a physical force upon components <NUM>. Locknuts of welding system <NUM> can be adjusted to modify this physical force as described herein. One or more components of welding system <NUM> (e.g., such as a displacement sensor) may identify and capture a displacement reading that is equal to the amount that arms <NUM> and electrodes <NUM> move relative to weld head <NUM>. Control software (as stored within and executed upon computing device <NUM>) may monitor this physical force and displacement to determine when the linear stage should stop (e.g., when the physical force and/or displacement satisfy a threshold level. Once the control software identifies that the linear stage should stop, power source <NUM> fires current through one electrode <NUM> that passes through the components <NUM> and passes back to power source to execute the PGW, step weld, or opposed weld. At this point weld head <NUM> is retracted up Z-axis away from components <NUM> enabling spring <NUM> to stretch to a normal "resting" state and therein move arms <NUM> and electrodes <NUM> back to a "starting" state.

In other examples, arms <NUM> may be configured to move relative to weld head <NUM> to and base <NUM> to execute a PGW, step weld, and/or an opposed weld. For example, arms <NUM> may move along the Z axis away from weld head <NUM> to execute a PGW, step weld, or opposed weld. Weld head <NUM> may include one or more motors and/or drivers to move arms <NUM>. Arms <NUM> may move along Z axis toward base <NUM> upon which components 22A, 22B (collectively, components "<NUM>") are secured to execute the PGW, step weld, or opposed weld.

Both base <NUM> and weld head <NUM> may be secured to a single welding station on an assembly line. Base <NUM> may be secured to a common location through one or more bores <NUM> of base <NUM> while weld head <NUM> is secured to the common location through one or more bores <NUM>. For example, base <NUM> may be fixedly secured to a first shelf through a first set of securing mechanisms that are inserted into bores <NUM> while weld head <NUM> is fixedly secured to a second shelf with securing mechanisms inserted through at least a first bore <NUM> (e.g., securing mechanisms such as a bolt or pin). In other examples base <NUM> may be secured to common location through other means, such as using a clamp or the like the mechanically secure base <NUM> to a location adjacent weld head <NUM>. In certain examples, base <NUM> may be directly secured to weld head <NUM> (not depicted).

Base <NUM> may be one of a plurality of bases that are used in conjunction with weld head <NUM>, such that different examples of base <NUM> may be unsecured and interchanged for alternative applications as described herein. For example, one version of base 18A as depicted in <FIG> is configured for PGW, while another base <NUM> is configured is configured for step welding, while another base 18B as depicted in <FIG> is configured for opposed welding. In some examples, a same base (e.g., base 18A) may be used for both PGW and step welding, such that an operator may not need to switch base <NUM> between a PGW and a step weld (e.g., an operator may instead switch out an electrode <NUM> or reposition one arm <NUM> using the apertures as discussed herein). In some examples, an operator may only need to swap out a base (e.g., 18A or 18B) that is coupled to welding system <NUM> to switch between opposed weld and PGW/stepped weld functionality.

Electrodes <NUM> execute a RSW weld of surfaces 20A, 20B (collectively, "surfaces <NUM>") of components 22A, 22B (collectively, "components <NUM>") secured upon base <NUM>. Components <NUM> may include medical devices. For example, two medical devices components <NUM> may be stacked on each other as secured to base <NUM> such that respective surfaces <NUM> of the components <NUM> are substantially coplanar as they contact each other (e.g., such that the two surfaces 20A, 20B are substantially flush with each other once components <NUM> are secured to base <NUM>). The surfaces <NUM> may be planar with an XY plane as secured to base <NUM>.

While components <NUM> are depicted as having a visible height (e.g., as measured along Z axis) herein for purposes of clarity, components <NUM> may define a relatively small height that may not be visible to the naked eye. For example, components <NUM> may define a height between <NUM> and <NUM> millimeters, though components <NUM> may be other sizes in other examples. When components <NUM> are secured to or otherwise resting on base <NUM>, one or both electrodes <NUM> may be lowered toward surfaces <NUM> of components <NUM> as weld head <NUM> is lowered toward base <NUM>. Though two components <NUM> that each define respective surfaces <NUM> are depicted in <FIG> for purposes of clarity, in other examples electrodes <NUM> may be used to weld together two surfaces <NUM> of a single component, or execute a weld on a single surface of a single component, or weld together more than two surfaces <NUM> of more than two components <NUM>.

Weld head <NUM> includes accelerometer <NUM>. Accelerometer <NUM> is configured to gather acceleration data of at least one of electrodes <NUM> as electrodes <NUM> move during the execution of the PGW, step weld, or opposed weld. For example, accelerometer <NUM> may be configured to gather acceleration data while current is provided to one electrode of welding system <NUM> that flows throw both surfaces <NUM> to exit out another electrode of welding system <NUM>. Accelerometer <NUM> may gather motion of one or both electrodes <NUM> relative to weld head <NUM>, such motion being possible at least partially as a result of electrodes <NUM> being moveably attached to weld head <NUM> using springs <NUM> and slides (e.g., slide <NUM> of <FIG>) as discussed herein. Accelerometer <NUM> may be configured to be fixedly secured to weld head <NUM> at a position adjacent to electrode <NUM>, such that substantially each movement of electrode <NUM> along the Z axis may be substantially matched or otherwise measured by accelerometer <NUM>. For example, as depicted in <FIG>, both accelerometer <NUM> and electrode 16B may be secured to arm 14B of weld head <NUM>, such that both accelerometer <NUM> and electrode 16B move in conjunction as electrodes <NUM> executes RSWs as described herein.

Accelerometer <NUM> may be configured to transmit acceleration data to computing device <NUM> of welding system <NUM>. Computing device <NUM> may include one or more processing circuits that are configured to use acceleration data from accelerometer <NUM> to determine if a weld executed by electrodes <NUM> was defective. In some examples, computing device <NUM> may further control and/or cause weld head <NUM> to execute PGW, step weld, and/or opposed welding. For example, computing device <NUM> may cause current to be routed to one of electrodes <NUM> to execute an RSW, and/or computing device <NUM> may cause arms <NUM> to approach surfaces <NUM> in order to execute an RSW. Though in <FIG> computing device <NUM> is depicted as a discrete component in comparison to weld head <NUM>, in other examples one or more aspects of computing device <NUM> may be integrated into weld head <NUM>.

Where computing device <NUM> is physically separate from weld head <NUM> as depicted, accelerometer <NUM> may be directly coupled to computing device <NUM>. In other examples, accelerometer <NUM> may transmit data over a computing network, such as a private local area network (LAN) or wide area network (WAN), or a public network such as the internet. Once received, computing device <NUM> may be configured to determine if the acceleration data indicates a welding defect. For example, computing device <NUM> may determine if that acceleration data as gathered by accelerometer <NUM> indicates a welding defect if the acceleration data includes one or more acceleration data points that are outside of a predetermined threshold data range.

The acceleration data as gathered by accelerometer <NUM> and received by computing device <NUM> may include a plurality of acceleration data points. Accelerometer <NUM> may include a ceramic sensing element with a sensitivity of around <NUM> millivolts/(meter/second<NUM>), +<NUM>%. , a measurement range of (+<NUM> meters/second<NUM> peak, and a sampling rate of around <NUM>,<NUM> per/second.

Acceleration data points may include negative (e. g, in a first direction along the Z axis) and/or positive (e.g., in a second and opposite direction along the Z axis) values. Acceleration data points are discussed and depicted herein are in meters/second<NUM> (m/s<NUM>), though acceleration data may be recorded, received, or manipulated in any unit. Acceleration data points may be associated with a time during the weld at which the acceleration data was recorded. For example, a weld may take <NUM> seconds to execute, and accelerometer <NUM> may record a plurality of acceleration data points that occur during the <NUM> seconds, where each recorded acceleration data point is identified and stored as associated with the relative time (e.g., a time between <NUM> seconds and <NUM> seconds) during the weld at which point the acceleration data was recorded.

In some examples, the predetermined threshold data range as stored and/or accessed by computing device <NUM> may include different acceleration data ranges for one or more different time spans of an RSW. Put differently, a threshold data range for a given RSW may contain a plurality of upper and lower threshold values that correspond to different time periods of a weld such that the "envelope" of acceptable acceleration values may grow or shrink or encompass a different range of values at different points during a RSW. As the upper threshold increases and/or the lower threshold decreases, the number or range of acceptable acceleration values (e.g., values that are between the upper threshold and lower threshold) may increase, and similarly as the upper threshold decreases and/or the lower threshold increases the number or range of acceptable acceleration values may decrease. In this way, an acceleration data point that may be within the respective threshold range for the point in time during which the acceleration data point was gathered may be outside of (e.g., greater than upper threshold or lower than the lower threshold) the range for the other times of the weld.

Computing device <NUM> may send results to display <NUM> of welding system <NUM>. Computing device <NUM> may cause display <NUM> to provide a visual alert relating to detected welding defects. For example, computing device <NUM> may cause display <NUM> to present a red light that indicates the welding defect, or present the text "WARNING IMD WELD <NUM> FAILURE" or the like. Alternatively, or additionally, computing device <NUM> may maintain a record of detected welding defects for future use. For example, computing device <NUM> may compile a list of components <NUM> as potentially defective as computing device <NUM> analyzes data from accelerometer <NUM> and/or other sensors, subsequently providing a report on this complete list of components <NUM> (e.g., for an entire run of a plurality of components <NUM>). Computing device <NUM> may cause display <NUM> to provide the visual alert for the benefit of a human operator that may further inspect or otherwise actively fix or discard the device that underwent the potentially defective weld. Computing device <NUM> may additional cause display <NUM> to display a positive indication if no defect was detected from the acceleration data.

In some examples, computing device <NUM> may cause removal mechanism <NUM> of welding system <NUM> to remove components <NUM> of surfaces <NUM> that underwent the potentially defective weld from base <NUM>. Removal mechanism <NUM> may include a mechanical arm or the like that grasps, sweeps, or otherwise removes components <NUM> from base <NUM>. Removal mechanism <NUM> may remove components <NUM> from an assembly line that includes welding system <NUM> to a separate location. For example, removal mechanism <NUM> may deposit components <NUM> in a discrete location designated for defective components, or components that otherwise require further inspection.

Welding system <NUM> may include power source <NUM>. Power source <NUM> may be configured to provide current to one of electrodes <NUM> to execute PGW, step welds, and opposed welds as discussed herein. Power source <NUM> may be coupled to one or more leads 32A-32C (collectively "leads <NUM>"). For example, power source <NUM> may be coupled to lead 32A that is configured to provide current to electrodes of welding system <NUM> and power source <NUM> may be coupled to leads 32B, 32C that are configured to return current to power source <NUM> to complete a circuit. In this example, lead 32A may be coupled to electrode 16B that is used in each of PGWs, step welds, and opposed welds, while lead 32B is configured to be coupled to an electrode secured within base <NUM> (e.g., electrode <NUM> of <FIG>) that is configured to return current to power source <NUM> during opposed welds, while lead 32C is configured to be coupled to electrode 16A that is configured to return current to power source <NUM> during PGWs and/or step welds.

Weld head <NUM> may be substantially mirrored across central plane <NUM> of weld head <NUM>. For example, both arms <NUM> may be substantially mirrored across central plane <NUM> as secured to weld head <NUM>. Electrodes <NUM> may be on either side of central plane <NUM>.

In some examples, welding system <NUM> may include additional sensors with accelerometer <NUM>. For example, computing device <NUM> may detect and indicate a defective weld if any of a number of sensors of welding system <NUM> detects a failure. In other examples, computing device <NUM> may only detect and indicate a defective weld if two or more sensors (e.g., including accelerometer <NUM>) affirmatively identify a defective weld. For example, welding system may include a current sensor that detects a current running through electrodes <NUM>, a voltage sensor that detects voltage level across electrodes, a resistance sensor that detects resistance levels of electrodes, or a displacement sensor that detects displacement of electrodes <NUM>.

<FIG> is a functional block diagram illustrating components of computing device <NUM> of <FIG>. Computing device <NUM> includes interfaces <NUM>, processing circuits <NUM>, and memory <NUM>. Computing device <NUM> may include any number of interfaces <NUM>, processing circuits <NUM>, and memory <NUM> components. Interfaces <NUM> may enable computing device <NUM> to communicate with one or more external components, such as weld head <NUM>, accelerometer <NUM>, display <NUM>, and/or removal mechanism <NUM>. Though weld head <NUM>, accelerometer <NUM>, computing device <NUM>, display <NUM>, and removal mechanism <NUM> are all depicted in <FIG> as separate and discrete components, in some examples one or more of weld head <NUM>, accelerometer, display <NUM>, and/or removal mechanism <NUM> may be directly coupled to or incorporated within computing device <NUM> and accessed using interfaces <NUM>. Interfaces <NUM> may include one or more network interface cards, such as Ethernet cards, and/or any other types of interface devices that can send and receive information. Any suitable number of interfaces <NUM> may be used to perform the described functions according to particular needs.

Computing device <NUM> may include one or more processing circuits <NUM> configured to implement functionality and/or process instructions as described herein. For example, processing circuits <NUM> may be configured to execute instructions as stored in memory <NUM>. Processing circuits <NUM> may include, for example, microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), and/or equivalent discrete or integrated logic circuitry. Though in <FIG> processing circuits <NUM> are depicted as separate from memory <NUM>, in other examples one or more elements or portions of memory <NUM> may include one or more processing circuits <NUM>, or instructions stored in memory <NUM> as described herein may be hard-coded into one or more processing circuits <NUM> (e.g., such that no instructions of identifying weld defects as described herein are stored within memory <NUM> of computing device <NUM>).

Computing device <NUM> may include memory <NUM> configured to store information within computing device <NUM>. Memory <NUM> may include a computer-readable storage medium or computer-readable storage device. In some examples, memory <NUM> may include one or more of a short-term memory or a long-term memory. Memory <NUM> may include, for example, random access memories (RAM), dynamic random-access memories (DRAM), static random-access memories (SRAM), magnetic hard discs, optical discs, floppy discs, flash memories, or forms of electrically programmable memories (EPROM), or electrically erasable and programmable memories (EEPROM). In some examples, memory <NUM> may store logic (e.g., logic of identifying weld defects using acceleration data as discussed herein) for execution by one or more processing circuits <NUM>. In further examples, memory <NUM> may be used by computing device <NUM> to temporarily or pseudo-permanently store information during program execution. For example, computing device <NUM> may store one or more threshold ranges <NUM> and/or defect data <NUM> in memory <NUM>. In other examples computing device <NUM> may store more or less data in memory <NUM>, or may store the same data in a different structure or organization.

Memory <NUM> may include defect controller <NUM>. Defect controller <NUM> may include instructions to be executed by one or more processing circuits <NUM> of computing device <NUM> to perform the functions of computing device <NUM> as described herein. For example, as described herein, defect controller <NUM> may be configured to identify weld defects using acceleration data as gathered by accelerometer <NUM>. Defect controller <NUM> may receive acceleration data and determine whether or not the acceleration data is within threshold ranges <NUM>. Defect controller <NUM> may determine a particular threshold range <NUM> that is applicable to the respective weld. For example, defect controller <NUM> may identify whether weld head <NUM> executed an RSW in opposed weld, step weld, or PGW configuration. Defect controller <NUM> may determine whether or not weld head <NUM> executed an RSW in opposed weld, step weld, or PGW configuration by detecting where current flows during an RSW weld (e.g., from electrode <NUM> of weld head <NUM> to an electrode of base <NUM> or from one electrode 16A of weld head <NUM> to another electrode 16B of weld head <NUM>). Further, defect controller <NUM> may identify and utilize different threshold ranges <NUM> based on a set of apertures used to secure arms <NUM> to weld head <NUM> and/or a detected type of electrode <NUM> secured to weld head <NUM> as described herein. In other examples defect controller <NUM> may use other variables or factors to identify and utilize one or more threshold ranges <NUM> as stored in memory <NUM>.

For example, <FIG> depict conceptual and schematic diagram of PGW configuration <NUM>, step configuration <NUM>, and opposed weld configuration <NUM>, respectively. As depicted in <FIG>, PGW configuration <NUM> may include both electrodes 16A, 16B contacting component 22B as stacked on component 22A as secured to first base 18A. Surfaces <NUM> of components <NUM> to be welded may be facing and contacting each other as stacked on base 18A. While components <NUM> are depicted as offset as stacked on base <NUM> for purposes of depicting both surfaces <NUM>, it is to be understood that components <NUM> may be substantially aligned in other examples. As depicted, electrodes <NUM> may be on either side of central plane <NUM>. For example, locations of both electrodes <NUM> may define a small distance along X axis between itself and central plane <NUM>, therein defining a distance between both electrodes <NUM> along X axis.

As discussed above, welding system <NUM> may include a first lead 32A coupled to electrode 16B and a second lead 32C coupled to electrode 16A. Both leads 32A, 32C may be coupled to power source <NUM>. In this way, when you "fire" the welding power source <NUM>, current may flow in the form of electrons from first lead 32A to electrode 16B to both components <NUM> to weld both surfaces <NUM> together, upon which electrons/current may exit components <NUM> through electrode 16A to return to power source <NUM> via second lead 32C.

Alternatively, as depicted in <FIG>, step weld configuration <NUM> may include one electrode 16A contacting component 22A and another electrode 16B contacting a second component 22C that is stacked on component 22A. In some examples, as depicted, second component 22C may be relatively smaller than component 22A, such that electrode 16A extends past second component 22C along Z axis to contact component 22A while electrode 16B contacts second component 22C. In other examples (not depicted), second component 22C may be a substantially similar size as component 22A but may simply be stacked offset such that electrode 16A extends further along Z axis than electrode 16B. Arm 14A securing electrode 16A may be configured to extend further along Z axis than arm 14B securing electrode 16B to move into step weld configuration <NUM>. For example, one or more lock nuts (e.g., lock nuts <NUM> of <FIG>), spring <NUM>, and/or motors or drivers configured to move arms <NUM> may be configured to move arm 14A relatively further along Z axis than 14B. Alternatively, electrode 16A may be relatively longer than electrode 16B (e.g., as depicted between electrodes <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM> of <FIG>), such that arms <NUM> may both be configured to move a similar distance along Z-axis to result in electrode 16A reaching further along Z axis relative to electrode 16B.

Both component 22A and component 22C may be secured to first base 18A. Surfaces 20A, 20C of components 22A, 22C to be welded may be facing and contacting each other as stacked on base 18A. While components 22A, 22C are depicted as offset on a right side as stacked on base 18A for purposes of depicting surface 20C, it is to be understood that components <NUM> may be substantially aligned such that an end of smaller component 22C is aligned with an end of relatively larger component 22A in other examples. As depicted, electrodes <NUM> may be on either side of central plane <NUM>. For example, locations of both electrodes <NUM> may define a small distance along X axis between itself and central plane <NUM>, therein defining a distance between both electrodes <NUM> along X axis.

As discussed above, welding system <NUM> may include a first lead 32A coupled to electrode 16B and a second lead 32C coupled to electrode 16A. Both leads 32A, 32C may be coupled to power source <NUM>. In this way, when welding power source <NUM> is fired, current may flow in the form of electrons from first lead 32A to electrode 16B to component 22C through surfaces 20C and 20A to weld both surfaces 20A, 20C together, upon which electrons/current may exit component 22A through electrode 16A to return to power source <NUM> via second lead 32C.

As depicted in <FIG>, opposed weld configuration <NUM> includes electrode 16B and electrode <NUM> that is secured to second base 18B. Second base 18B is different than first base 18A in that second base 18B includes electrode <NUM>. Though electrode <NUM> is depicted as structurally similar to electrodes <NUM> for purposes of illustration, electrode <NUM> may be a different shape in other examples. For example, electrode <NUM> may be substantially larger than electrodes <NUM>, such that electrode <NUM> defines a cross-sectional shape that is <NUM> millimeters by <NUM> millimeters or larger. As secured to welding system <NUM>, electrode <NUM> may be aligned along Z axis with electrode 16B. In some examples, in opposed weld configuration <NUM> component 22B may be stacked on component 22A as secured to first base 18A directly over electrode <NUM> and directly under electrode 16B. Surfaces <NUM> of components <NUM> to be welded may be facing and contacting each other as stacked on base 18A and between electrode 16B and electrode <NUM>.

In some examples, electrode <NUM> may be external to base 18B, such that at least a tip of electrode <NUM> that is configured to contact components <NUM> is visible. In other examples, electrode <NUM> may be partially or substantially entirely enclosed within base 18B, such that the tip of electrode <NUM> is substantially flush with an outer surface of base 18B to contact or otherwise receive current from components <NUM> (e.g., as provided to components <NUM> by electrode 16B). In some examples, as depicted, electrode 16A may be removed from weld head <NUM> in opposed weld configuration <NUM>. In other examples, weld head <NUM> may be configured to only lower electrode 16B in opposed weld configuration <NUM>, such that electrode 16A is raised higher along axis Z than electrode 16B. In yet other examples, both electrodes <NUM> may be lowered along Z axis to components <NUM>, but current may only be provided to lead 32A and therein to one electrode 16B (e.g., the electrode that is aligned with electrode <NUM> of base 18B), and further current may only be allowed to return to power source <NUM> through lead 32B that is coupled with electrode <NUM> secured to base 18B. For example, lead 32B may be manually or automatically (e.g., as caused by computing device <NUM>) decoupled from power source <NUM> and/or decoupled from electrode 16A.

<FIG> depicts a conceptual and schematic diagram of weld head <NUM>, arms <NUM>, and base <NUM> in a partially assembled state. For example, as depicted, arm 14B is removed from weld head <NUM> along axis <NUM> that is aligned with X axis. As removed, input port <NUM> of arm 14B is depicted. Input port <NUM> may be configured to receive lead 32A, such that upon receiving lead <NUM> electrode 16B of arm 14B is electrically coupled to lead 32A and therein power source <NUM>. Arm 14B may be re-secured to weld head <NUM> by moving arm 14B back along axis <NUM> and inserting a securing mechanism (e.g., a pin or bolt or the like) through an aperture of arm 14B and aperture <NUM> of weld head <NUM>.

Further, arm 14B is depicted as both removed from weld head <NUM> and rotated <NUM>° on an XY plane relative to Z axis. As depicted, welding system <NUM> may include two accelerometers 24A, 24B. Both accelerometers 24A, 24B may be secured to respective arms 14A, 14B, such that accelerometers 24A, 24B may substantially move when electrodes 16A, 16B move. Put differently, accelerometers 24A, 24B may be configured to move along Z axis in conjunction with electrodes 16A, 16B when electrode 16B is providing current to components <NUM> to execute a RSW. In this way, welding system <NUM> may include two accelerometers 24A, 24B gathering acceleration data.

In some examples, computing device <NUM> may analyze accelerometer data as gathered from accelerometers 24A, 24B independently, such that each set of acceleration data is analyzed to see if the acceleration data indicates a welding defect. In such examples, welding system <NUM> may increase an opportunity for accelerometers 24A, 24B to gather evidence that indicates welding defect. In other examples, computing device <NUM> may average together acceleration data as gathered from both accelerometers 24A, 24B. Averaging together acceleration data across two or more accelerometers 24A, 24B may decrease a possibility of false negatives in indicating a weld was defective (e.g., where one accelerometer gathers acceleration data that incorrectly suggests that a weld was defective, while the other accelerometer gathers data that correctly indicates that a weld was acceptable).

depicts feedback wires 84A, 84B (collectively, "feedback wires <NUM>") extending from arms <NUM>. As depicted, feedback wires <NUM> extend straight out such that both feedback wires <NUM> are substantially stiff, though feedback wires <NUM> may be relatively flexible to allow feedback wires <NUM> to be routed between components. Feedback wires <NUM> may be coupled to computing device <NUM> and/or other devices. Feedback wires <NUM> may provide weld data to computing device <NUM>. For example, feedback wires <NUM> may provide voltage feedback information from weld head <NUM> to computing device <NUM>. Voltage feedback may include information about the weld pulse delivered to components <NUM> when current is provided through one electrode <NUM> to weld components <NUM>. In some examples, computing device <NUM> may gather acceleration data from one or both accelerometers 24A, 24B using feedback wires <NUM>. Further, arms <NUM> and/or weld head <NUM> may send other sensor data using feedback wires <NUM>. For example, displacement data, visual data, and the like may be sent over feedback wires <NUM> to computing device <NUM>.

depicts an exploded conceptual and schematic diagram exploded view of weld arm <NUM>. Weld arm <NUM> may include a plurality of securing mechanisms 100A-100D (collectively, "securing mechanism <NUM>") configured to secure arm <NUM> together in an assembled state. For example, securing mechanisms <NUM> may include a variety of bolts, dowels, pins, or the like. Securing mechanisms <NUM> may be configured to removably or reversibly secure arm <NUM> into an assembled state, such that it may be possible to disassemble arm <NUM> by removing securing mechanisms <NUM> without damaging arm <NUM> or securing mechanisms <NUM>.

Arm <NUM> may include a plurality of body components 102A-102D (collectively, body components <NUM>"). Body components <NUM> may be cast, machined, or otherwise manufactured into their depicted shape. Body components <NUM> may be configured to be secured together to hold other components and/or define shapes that may be secured to weld head <NUM>. For example, body components 102A, 102C may be secured together to hold load cell <NUM> that weld head <NUM> may use to collect weld data during RSWs as described herein.

For another example, body components 102B, 102C may be secured together to hold any of electrodes <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM> in arm <NUM>, each of which may both be substantially similar to electrodes <NUM> described herein. As depicted electrode <NUM>-<NUM> may be substantially longer along Z axis than electrode <NUM>-<NUM>, which may be substantially longer along Z-axis than electrode <NUM>-<NUM>. An operator may secure one of electrodes <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM> to arm <NUM> and therein weld head <NUM> depending upon a specific welding application that welding system <NUM> is to be used for. Knob <NUM> may be used to remove securing mechanism 100B that is secured one of electrodes <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM> within body compartments 102B, 102C. As such, when switching between different welding applications, an operator may be able to modify weld system by simply turning knob <NUM> to loosen securing mechanism 100B in order to functionally replace one electrode with another. Configuring weld system <NUM> such that electrode position along the Z-axis may be altered by switching electrodes with different lengths may increase a functionality of weld system <NUM> and decrease an amount of time required to alter functionality of weld system <NUM>.

In some examples, accelerometer <NUM> may be secured to weld arm <NUM> through magnets <NUM>. Magnets <NUM> may securely affix accelerometer <NUM> to weld arm <NUM> such that accelerometer may move along each axis in conjunction with electrode <NUM>. In some examples, magnets <NUM> may secure accelerometer <NUM> to the same body component 102C that encloses electrode <NUM> to improve an ability of accelerometer <NUM> to track movement of electrode <NUM>. Magnets <NUM> may have a sufficient strength that accelerometer <NUM> does not move relative to arm <NUM> as RSW is executed. Magnets <NUM> may further be weak enough that an operator may remove accelerometer <NUM> from arm <NUM> without damaging either accelerometer <NUM>, arm <NUM>, or magnets <NUM>. Configuring weld arm <NUM> such that accelerometer <NUM> is securely affixed at arm <NUM> such that accelerometer <NUM> is both configured to move with electrode <NUM> but also be removable may increase an ability of accelerometer <NUM> to be replaced easily and quickly.

Arms <NUM> may be configured to be secured to weld head <NUM>. Arms <NUM> may define a plurality of apertures 114A, 114B (collectively, "apertures <NUM>") that may be used to secure arms <NUM> to weld head <NUM>. For example, arms <NUM> may be secured to weld head <NUM> using one or more pins, bolts, dowels, or the like that are configured to extend through apertures <NUM> and be securely mechanically received by weld head <NUM>. As depicted, securing members 100C are configured to be received by apertures <NUM> to secure arm <NUM> to weld head <NUM>. Though arm 14A is depicted in <FIG> as defining all apertures <NUM> centered on one XZ plane, in other examples arms <NUM> may define apertures <NUM> at a plurality of different relative locations (e.g., different locations along Y axis). In some examples, different apertures <NUM> may be used to secure arms <NUM> to weld head <NUM> in different relative locations. For example, aperture 114A may be used to secure arm 14A to weld head <NUM> to define relatively more distance and/or space between arm 14A and arm 14B along X axis, while aperture 114B may be used to secure arm 14A to weld head <NUM> to define relatively less space between arm 14A and arm 14B along X axis. In this way, a subset (e.g., less than all) of apertures <NUM> are used to secure arms <NUM> at any one relative location to weld head <NUM>.

In some examples, all apertures <NUM> relate to predetermined configurations. For example, weld head <NUM> may be used to execute RSWs for a finite number of predetermined devices, such that each of the different RSWs are to be executed at predetermined locations. In this example, each of apertures <NUM> may relate to one or more of these predetermined locations. In this way, arms <NUM> may be moved to different relative locations on weld head <NUM> by switching which of apertures <NUM> are used to secure arms <NUM> to weld head <NUM>.

Arm <NUM> may include other components that improve an accuracy and robustness of weld system <NUM>. For example, arm may include bushing and linear race set <NUM> that is configured to prevent twisting of weld head <NUM> load cells <NUM>. Put differently, bushing and linear race set <NUM> may prevent side loading of load cells <NUM>. Bushing and linear race set <NUM> may alternatively/additionally improve the force measurement during the welding process. As depicted in <FIG>, one set of bushing and linear race set <NUM> may terminate in a hard stop used for reference in evaluating force measurements (e.g., to set up and check weld system <NUM> during an initialization protocol) and the other set of bushing and linear race set <NUM> terminates in spring <NUM> and measurement load cell <NUM>.

depicts a conceptual and schematic diagram exploded view of weld head <NUM>. Weld arm <NUM> may include a plurality of securing mechanisms 120A-<NUM> (collectively, "securing mechanism <NUM>") configured to secure weld head <NUM> in an assembled state. For example, securing mechanisms <NUM> may include a variety of bolts, dowels, pins, studs, or the like. Securing mechanisms <NUM> may be configured to removably or reversibly secure weld head <NUM>, such it may be possible to disassemble weld head <NUM> by removing securing mechanisms <NUM> without damaging weld head <NUM> or securing mechanisms <NUM>.

Arm <NUM> may include a plurality of body components 122A-122D (collectively, "weld head body components <NUM>"). Body components <NUM> may be cast, machined, or otherwise manufactured into their shape. Body components <NUM> may be configured to be secured together to hold other components and/or define shapes that may be secured to weld head <NUM>. For example, body components 122C, 122D may be secured together to hold displacement gauge <NUM> (e.g., for sensing displacement values as discussed herein) in place. Body components may also be secured together to define apertures or bores of weld head <NUM>. For example, body components 122A, 122B may be secured together to define bore 38A as described herein.

Weld head <NUM> may include sliding components <NUM> to which arms <NUM> may be coupled. Sliding components <NUM> may include a plate <NUM> that is configured to be fixedly secured to weld head <NUM> body component 120D using securing mechanisms 120B. Sliding components <NUM> may also define slide <NUM> that is configured to slide relative to plate <NUM>. Arms <NUM> may be configured to be fixedly secured to slide <NUM> such that arms <NUM> may move relative to weld head <NUM>. Arms <NUM> may be fixedly secured to slide <NUM> using securing mechanisms 100C that extend through apertures <NUM> of arms <NUM>. As a result of slide <NUM> and springs <NUM>, arms <NUM> may be able to move relative to weld head <NUM>, e.g., when respective electrodes <NUM> contact components <NUM> to execute a RSW as described herein.

Weld head <NUM> may include other components that improve an accuracy and robustness of weld system <NUM>. For example, weld head <NUM> may include pin <NUM> along which locking nuts <NUM> may be moved up and down along Z-axis. In some examples, pin <NUM> may include external threads along a portion of an external surface to facilitate locking nuts <NUM> moving up and down along Z-axis. As a result of moving locking nuts <NUM> along Z-axis, a spring tension of spring <NUM> may be increased or decreased. Altering a spring tension of spring <NUM> may alter a weld force imparted by electrodes <NUM> upon components <NUM> during a weld as described herein.

<FIG> depicts a charts of acceleration data that indicated a defective weld <NUM> (said acceleration data hereinafter referred to as "defective acceleration data <NUM>") and acceleration data that indicated a successful weld <NUM> (said acceleration data hereinafter referred to as "successful acceleration data <NUM>") in comparison to upper and lower threshold ranges 154A, 154B (collectively "threshold range <NUM>"). Defective acceleration data <NUM> and successful acceleration data <NUM> may include "raw" acceleration data such that neither first set nor second set of acceleration data <NUM>, <NUM> have had data manipulated prior to depiction in <FIG>. As depicted, threshold range <NUM> may be different at different times of the respective welds.

As depicted, successful acceleration data <NUM> may be entirely within upper and lower threshold ranges <NUM>, such that computing device <NUM> determines that successful acceleration data <NUM> resulted in a successful weld. Alternatively, defective acceleration data <NUM> may be include extreme acceleration data points 156A, 156B (collectively "extreme data points <NUM>") that are outside of both upper threshold range 154A and lower threshold range 154B, respectively. Welding system <NUM> may detect that defective acceleration data <NUM> includes one or more extreme data points <NUM> that are outside of upper and lower threshold ranges <NUM>. In some examples, welding system <NUM> may identify defective acceleration data <NUM> as indicating a weld defect as a result of only a single extreme data point being outside upper and lower threshold ranges <NUM>. In other examples, welding system <NUM> may identify defective acceleration data <NUM> as indicating a weld defect as a result of defective acceleration data <NUM> having more than a threshold number of extreme data points <NUM> that are outside of data ranges <NUM>.

In some examples, computer device <NUM> may identify and isolate certain portions of acceleration data that are relatively prognosticative of welding defects. For example, computing device <NUM> may identify first portion <NUM> of acceleration data as prognosticative. First portion <NUM> of acceleration data may include a portion of acceleration data that includes the first <NUM> seconds of an RSW (e.g., the first <NUM> seconds during which electrodes <NUM> are creating a circuit by running a current through surfaces <NUM>). For example, in first portion <NUM>, upper and lower threshold ranges <NUM> may include a relatively narrow band of acceptable ranges, such that successful acceleration data <NUM> is within upper and lower threshold ranges <NUM>. However, as depicted, defective acceleration data <NUM> may be outside upper and lower threshold ranges <NUM> in first portion. In some examples, defective acceleration data <NUM> may be outside lower and upper threshold range <NUM> in first portion <NUM> but within lower and upper threshold range <NUM> in second portion <NUM>.

In some examples, defective acceleration data <NUM> may be substantially similar (e.g., statistically similar over a statistically significant amount of RSWs) to successful acceleration data <NUM> across second portion <NUM>. Put differently, acceleration data may substantially only indicate a defective weld within first portion <NUM> of acceleration data. Further, in some examples, only a second amount of first portion <NUM> of weld may be prognostic. For example, initializing portion <NUM> may include the first <NUM> seconds of a weld, while prognostic portion <NUM> of acceleration data may include the time between <NUM> and <NUM> seconds of a weld. Initializing portion <NUM> may include substantially nominal acceleration data, such that prognostic portion <NUM> of acceleration data may be the portion of the data that has the highest correlation with correctly identifying defective welds. Accordingly, in some examples computing device <NUM> may begin a process of analyzing acceleration data by truncating acceleration data to only include prognostic portion <NUM>.

In other examples the total time of the weld may be different, such that first portion <NUM> of weld may include a different subset of time. For example, in some instances a full weld may complete in approximately <NUM> seconds. In such examples, first portion <NUM> may include the first <NUM> seconds of weld, such that second portion <NUM> includes between <NUM> and <NUM> seconds of weld. Other examples consistent with the disclosure herein are possible in other applications.

In some examples computing device <NUM> may execute one or more mathematical operations on acceleration data. Computing device <NUM> may execute mathematical operations in order to increase an ability of acceleration data to indicate defective welds. For example, computing device <NUM> may determine a first derivative of the acceleration data to determine the rate of change of the acceleration data (i.e., to determine the jerk of one or more respective electrodes <NUM>). <FIG> depicts a chart of such derivative acceleration data of an acceptable and defective weld in comparison to threshold ranges.

<FIG> includes defective derived data set <NUM> and successful derived data set <NUM>. Defective derived data set <NUM> may include data indicative of a defective RSW. Successful derived data set <NUM> may include data indicative of a successful RSW. Data points of defective and successful derived data sets <NUM>, <NUM> are provided for purposes of illustration, such that other data points consistent with the discussion herein may be included in derived data sets are indicative of defective or successful RSWs. <FIG> may also include upper threshold range 174A and lower threshold range 174B (collectively, "threshold ranges <NUM>"), as well as first portion <NUM>, second portion <NUM>, initializing portion <NUM>, and prognostic portion <NUM> of <FIG>, which may relate to substantially the same time ranges of <FIG>.

As depicted, after a first derivative first portion <NUM> of second derived data set <NUM> (e.g., the data set indicative of a successful RSW) may flatten to a substantially flat line. In some examples, derived data sets of successful RSWs may reliably flatten to a substantially flat line, such that upper and lower threshold ranges <NUM> are relatively close to this predicted flat line. As such, relatively mild deviations from this flat line may be identified as indicative of a defective RSW. For example, first derived data set <NUM> may include plurality of data points 176A, 176B (collectively "data points <NUM>") outside of upper and lower threshold ranges <NUM>.

In some examples, initial unmodified acceleration data may show a statistically insignificant amount of deviation, but acceleration data following a first derivative may identify a spike that is outside of upper and/or lower threshold ranges <NUM>. In this way, in some examples, computing device <NUM> may first determine that acceleration data as gathered by accelerometer <NUM> is within upper and lower threshold ranges <NUM>, after which computing device <NUM> may determine that derived acceleration data includes some extreme data points <NUM> outside of upper and/or lower threshold ranges <NUM>. In this way, computing device <NUM> may be configured to increase an ability of welding system <NUM> to detect a welding defect.

<FIG> depicts a conceptual flowchart of a method of executing and monitoring a weld using the weld system of <FIG>. Though <FIG> is discussed referencing the reference numerals of <FIG>, it is to be understood that the method of <FIG> may be executed using any weld system consistent with the disclosure herein. Further, in other examples the method of <FIG> may be executed with one or more operations in a different order, or may be executed skipping or adding in one or more operations.

Apertures <NUM> may be used to secure arms <NUM> to weld head <NUM> of welding system <NUM> (<NUM>). One or more securing components may be used for each of the one or more apertures <NUM>. For example, a single bolt or pin may be inserted into each of the one or more apertures <NUM> to secure the arms <NUM> to weld head <NUM>. Apertures <NUM> may be selected based on the planned use of welding system <NUM>. For example, securing mechanisms may be inserted into a predetermined plurality of apertures <NUM> to secure arms <NUM> at a predetermined relative location to weld head <NUM> in response to components <NUM> that welding system <NUM> will be welding.

Similarly, in some examples an operator may determine a specific electrode <NUM> for the respective application. For example, an operator may determine a relatively shorter or longer electrode <NUM> (e.g., electrode <NUM>-<NUM> vs electrode <NUM>-<NUM> vs electrode <NUM>-<NUM> as depicted in <FIG>) depending upon a particular application. An operator may turn a knob (e.g., knob <NUM> of <FIG>) of a respective arm <NUM> to unsecure a respective electrode <NUM> and insert an alternate electrode <NUM>. Upon inserting the alternate electrode <NUM>, the operator may turn the knob in the opposite direction to secure the alternate electrode <NUM> in the respective arm <NUM>.

Welding system <NUM> may be configured to execute a PGW, a step weld, and/or an opposed weld (<NUM>). In some examples, configuring welding system <NUM> for either PGW or an opposed weld may include no more than switching base <NUM> of welding system <NUM>, though in other examples switching between PGW and opposed welding may additionally include adding or removing one weld arm <NUM>. For example, welding system <NUM> may be configured for PGW by securing PGW base 18A to welding system <NUM> (<NUM>). PGW base 18A may not include an electrode. Once PGW base 18A is secure to welding system <NUM>, welding system <NUM> will provide current to one of electrode <NUM> of arms <NUM> (<NUM>). For example, computing device <NUM> may cause current to be routed to one of electrodes <NUM> of arms <NUM> through one lead <NUM>. In some examples, the instructions to provide the current may be received using feedback wires (e.g., feedback wires <NUM> of <FIG>). System <NUM> may provide current to an electrode 16A to and let current return through electrode 16B to execute PGW to surfaces <NUM> below electrodes <NUM>.

Alternatively, where welding system <NUM> is to execute a step weld, a relatively longer electrode <NUM> may be secured to one arm <NUM> of welding system <NUM> (<NUM>). A knob (e.g., knob <NUM> of <FIG>) may be unsecured to remove an existing electrode <NUM> and insert the relatively longer electrode <NUM>. A step weld base 18A which may be substantially similar to a PGW base 18A may be secured to weld system <NUM>. System <NUM> may then provide current to one electrode 16A of weld head <NUM> using lead <NUM> such that current runs through both components <NUM> and exits through another electrode 16B of weld head <NUM> back through another respective lead <NUM> to power source <NUM> (<NUM>). System <NUM> may provide current to first electrode 16A to create a circuit between power source <NUM>, first electrode 16A, second electrode 16B, and components <NUM>.

Alternatively, where welding system <NUM> is to execute an opposed weld, opposed base 18B may be secured to welding system <NUM> (<NUM>). Opposed base 18B may include electrode <NUM> that is configured to align with one electrode <NUM> of weld head <NUM> once secured to system. System <NUM> may then provide current to top electrode <NUM> using lead <NUM> such that current runs through both components <NUM> and exits through electrode <NUM> of opposed base 18B back through another respective lead <NUM> to power source <NUM> (<NUM>). System <NUM> may provide current to top electrode <NUM> to create a circuit between power source <NUM>, top electrode <NUM>, bottom electrode <NUM>, and components <NUM>.

Accelerometer <NUM> may gather acceleration data of the weld (<NUM>). Accelerometer <NUM> may gather acceleration data whether or not the weld was an opposed weld, a PGW, or a step weld. In some examples, only one accelerometer <NUM> may gather acceleration data. For example, where RSW is an opposed weld, accelerometer <NUM> may be attached to arm <NUM> that holds electrode <NUM> that is opposed to electrode <NUM> of opposed base 18B. In other examples, system <NUM> may gather acceleration data from two accelerometers (e.g., accelerometers 24A, 24B of <FIG>). In some examples, computing device <NUM> may calculate a first derivative of the gathered acceleration data.

Computing device <NUM> may identify a prognostic portion (e.g., prognostic portion <NUM> of <FIG>) of the acceleration data (<NUM>). The prognostic portion may include a predetermined time period of the weld. For example, the prognostic portion may include a period of the weld that is subsequent to an initial instantiating portion (e.g., instantiating portion <NUM> of <FIG>) and a period of the weld that is prior to the greatest acceleration data points (e.g., second portion <NUM> of <FIG>).

Computing device <NUM> may determine whether the prognostic portion of the acceleration data (<NUM>). Computing device <NUM> may determine that the prognostic portion of the acceleration data is indicative of a welding defective if the prognostic portion of acceleration data includes data points (e.g., data points <NUM> of <FIG>, or data points <NUM> of <FIG>). Accordingly, if computing device <NUM> determines that the prognostic portion indicates that the weld is defective, computing device <NUM> may provide an indication of the defective weld (<NUM>). For example, computing device <NUM> may provide a visual indication using display <NUM>, such that a human operator may further inspect or otherwise address components <NUM> that underwent the respective weld. Additionally, or alternatively, computing device <NUM> may cause a removal mechanism <NUM> to remove the components <NUM> that underwent the weld to a predetermined location for further inspection or disposal.

Alternatively, if computing device <NUM> determines that the prognostic portion indicates that the weld is successful, computing device <NUM> may provide an indication of the successful weld (<NUM>). For example, computing device <NUM> may provide the indication to the display <NUM>. Further, in some examples, computing device <NUM> may store the successful weld in a pseudo-permanent log.

Claim 1:
An apparatus comprising:
a resistance spot weld (RSW) head (<NUM>) configured to define a parallel gap RSW (PGW) configuration and an opposed welding configuration, the RSW head comprising:
one or more processing circuits (<NUM>); and
a first electrode and a second electrode,
the apparatus further comprising a third electrode (<NUM>), a first base (18A) and a second base (18B), wherein the second base (18B) comprises the third electrode (<NUM>),
wherein the first electrode and the second electrode are configured to execute a parallel gap RSW (PGW) on a first set of components (22A) secured to the first base (18A) when the RSW head is in the PGW configuration, wherein the first electrode is configured to execute an opposed RSW (opposed weld) with the third electrode of the second base (18B) on a second set of components (22B) secured to the second base when the RSW head is in the opposed welding configuration, and
the RSW head (<NUM>) further comprising an accelerometer (<NUM>) securely attached to the first electrode at a location adjacent to the first electrode, wherein the one or more processing circuits are configured to cause the accelerometer to gather a PGW set of acceleration data of the first electrode during the PGW and gather an opposed weld set of acceleration data of the first electrode during the opposed weld,
wherein the one or more processing circuits are configured to determine that the PGW set of acceleration data indicates a first welding defect based on the PGW set of acceleration data including at least one acceleration value outside of a first threshold acceleration range, and
wherein the one or more processing circuits are configured to determine that the opposed weld set of acceleration data indicates a second welding defect based on the opposed weld set of acceleration data including at least one acceleration value outside of a second threshold acceleration range.