A potentiometer resistance value automatic testing method, device and system

Abstract

The application relates to a potentiometer resistance value automatic testing method, device and system. The method comprises the following steps: calculating the coordinate dislocation point number tolerance according to the tolerance arc length of the potentiometer and the action radius of the transmission rotating shaft, controlling the potentiometer to perform a forward and reverse sweeping action, and collecting a voltage sequence; performing first-order difference calculation on each voltage sequence to obtain a voltage jump difference value sequence, intercepting a plurality of local voltage jump difference values with a preset length from each voltage jump difference value sequence according to the mutation center index; determining the value filled in the corresponding position of the deviation value two-dimensional matrix according to the comparison result of the index interval of the matching points and the coordinate dislocation point number tolerance, and solving to obtain a waveform alignment sequence; and performing quality evaluation on the potentiometer according to the difference between the local voltage jump difference values of each matching point in the waveform alignment sequence, the index interval of the matching points, and the frequency of the front and back reversal of the mapping relationship in the waveform alignment sequence. The application can improve the quality evaluation accuracy of the automatic equipment.

Description

Technical Field

[0001] This application relates to the field of automated testing technology, and in particular to an automatic testing method, apparatus and system for potentiometer resistance values. Background Technology

[0002] Electromechanical potentiometers are widely used in various industrial control components. During automated factory testing, the testing equipment typically controls a servo motor to drive the potentiometer shaft to perform forward and reverse sweeping motions, simultaneously acquiring the output voltage waveform. During testing, abrupt distortions in the voltage waveform are usually caused by two distinct mechanisms: the first is high-frequency brush stagnation and bouncing caused by tiny dust particles or transient friction unevenness on the carbon film surface, which is transient interference that can be addressed through retesting or degradation; the second is permanent structural damage such as breakage or deep scratches in the carbon film, which necessitates scrapping and removal.

[0003] Existing testing equipment typically uses a single threshold filter based on the absolute amplitude of voltage jumps, or employs conventional global filtering (such as cross-correlation algorithms or dynamic time warping) to align bidirectional waveforms. However, due to the inherent mechanical backlash of the transmission gears in the testing equipment, and the nonlinear phase compression and stretching of local waveforms caused by the resistance and bounce of the brushes in the forward and reverse time sequences, the aforementioned conventional pure mathematical alignment algorithms cannot handle this nonlinear local misalignment superimposed with electromechanical tolerances. This leads to the testing system, when judging based on the residual error after alignment, easily misjudging waveform misalignment caused by normal mechanical backlash and brush transient interference as permanent defects in the carbon film, thus significantly increasing the product misjudgment and scrap rate on automated mass production lines. Summary of the Invention

[0004] To address the aforementioned technical problems, the purpose of this application is to provide an automatic method, apparatus, and system for testing the resistance value of a potentiometer. The specific technical solution adopted is as follows:

[0005] Firstly, a method for automatically testing the resistance value of a potentiometer is provided, the method comprising:

[0006] Based on the potentiometer's tolerance arc length and the effective radius of the drive shaft, the coordinate misalignment tolerance is calculated, and the potentiometer is controlled to perform forward and reverse sweeping actions to acquire voltage sequences; the voltage sequences include forward voltage sequences and reverse voltage sequences;

[0007] For each voltage sequence, a first-order difference calculation is performed to obtain the corresponding voltage jump difference value sequence. Based on the mutation center index, multiple local voltage jump difference values ​​of a preset length are extracted from each voltage jump difference value sequence. The local voltage jump difference values ​​include positive local voltage jump difference values ​​and negative local voltage jump difference values.

[0008] A two-dimensional matrix of deviation cost is constructed. Based on the comparison between the index interval of the pairing points and the tolerance of the number of coordinate misalignment points, the values ​​to be filled into the corresponding positions of the two-dimensional matrix of deviation cost are determined. The two-dimensional matrix of deviation cost is then solved to obtain the waveform alignment sequence. The pairing points indicate the positive local voltage jump difference and the corresponding negative local voltage jump difference.

[0009] The quality of the potentiometer is evaluated based on the differences in local voltage jumps between paired points in the waveform alignment sequence, the index interval of the paired points, and the frequency of the mapping relationship being reversed in the waveform alignment sequence.

[0010] Optionally, the coordinate misalignment tolerance is calculated based on the potentiometer's tolerance arc length and the effective radius of the drive shaft, including:

[0011] The potentiometer's tolerance arc length is obtained by summing the deformation tolerance arc length of the potentiometer's cantilever beam and the mechanical backlash tolerance arc length of the machine tool's transmission gear. The deformation tolerance arc length characterizes the maximum offset arc length of the potentiometer's brush cantilever beam relative to the theoretical position of the drive shaft within the elastic deformation range. The mechanical backlash tolerance arc length characterizes the maximum arc length corresponding to the idling redundancy of the drive shaft when the machine tool's transmission gear switches from forward to reverse rotation.

[0012] Calculate the total clearance radian based on the ratio of the potentiometer's tolerance arc length to the effective radius of the transmission shaft, and convert the total clearance radian into the corresponding mechanical angle;

[0013] Obtain the single-step angular resolution during the potentiometer sweep process; where the single-step angular resolution characterizes the minimum angular displacement of the encoder of the machine tool under a single sampling pulse;

[0014] The coordinate misalignment tolerance is obtained by comparing the mechanical angle corresponding to the total gap radian with the single-step angular resolution; the coordinate misalignment tolerance characterizes the maximum number of misalignments allowed between the forward and reverse voltage sequences.

[0015] Optionally, the potentiometer is controlled to perform forward and reverse sweep operations to acquire voltage sequences, including:

[0016] The control potentiometer performs a forward sweep operation, records the forward time-domain voltage corresponding to the time index, and obtains the forward voltage sequence;

[0017] When the forward sweep reaches its end, the control potentiometer performs a reverse sweep, recording the inverse time-domain voltage corresponding to the time index, thus obtaining the inverse voltage sequence.

[0018] Optionally, a first-order difference calculation is performed on each voltage sequence to obtain the corresponding voltage jump difference sequence. Based on the abrupt change center index, multiple local voltage jump differences of a preset length are extracted from each voltage jump difference sequence, including:

[0019] Perform a first-order difference operation on the forward voltage sequence to obtain the corresponding forward voltage jump difference sequence, and perform a first-order difference operation on the reverse voltage sequence to obtain the corresponding reverse voltage jump difference sequence; wherein, the voltage jump difference sequence includes the forward voltage jump difference sequence and the reverse voltage jump difference sequence, and each element in the voltage jump difference sequence represents the voltage change between two adjacent sampling points;

[0020] The location of the data point in the forward voltage jump difference sequence that exceeds the preset contact impedance tolerance limit is determined as the forward mutation center index, and the location of the data point in the reverse voltage jump difference sequence that exceeds the preset contact impedance tolerance limit is determined as the reverse mutation center index; the mutation center index includes the forward mutation center index and the reverse mutation center index;

[0021] Based on the positive mutation center index, a fixed number of sampling points are extended along the left and right sides of the axis to extract multiple positive local voltage jump difference values ​​of a preset length from the positive voltage jump difference value sequence, and a positive local spatial index is assigned to the positive local voltage jump difference value.

[0022] Based on the reverse mutation center index, a fixed number of sampling points are extended along the left and right sides of the axis to extract multiple reverse local voltage jump differences of a preset length from the reverse voltage jump difference sequence, and a reverse local spatial index is assigned to the reverse local voltage jump difference.

[0023] Optionally, a two-dimensional matrix of deviation cost is constructed. Based on the comparison between the index interval of the paired points and the tolerance for the number of coordinate misalignments, the values ​​to be filled into the corresponding positions in the two-dimensional matrix of deviation cost are determined, including:

[0024] Construct a blank two-dimensional matrix; wherein the number of rows of the blank two-dimensional matrix is ​​equal to the number of multiple positive local voltage jump differences, the number of columns is equal to the number of multiple negative local voltage jump differences, and the number of multiple positive local voltage jump differences is equal to the number of multiple negative local voltage jump differences;

[0025] Use the forward local space index as the outer loop variable and the reverse local space index as the inner loop variable to traverse all paired points;

[0026] In each traversal, the absolute difference between the current positive local voltage jump difference and the corresponding negative local voltage jump difference is calculated to obtain the current local voltage jump deviation value, and the absolute value of the index interval between the current positive local space index and the corresponding negative local space index is calculated to obtain the current index interval of the pairing point.

[0027] Compare the index interval of the current pairing point with the tolerance of the number of coordinate misalignment points. If the index interval of the current pairing point is not greater than the tolerance of the number of coordinate misalignment points, then fill the current local voltage jump deviation value as the matrix element value into the current traversal position.

[0028] If the index interval of the current pairing point is greater than the tolerance for the number of coordinate misalignment points, then the preset blocking penalty value will be used as the matrix element value and filled into the current traversal position.

[0029] After the traversal is complete, a two-dimensional matrix of the fully assigned deviation costs is obtained.

[0030] Optionally, the two-dimensional matrix of deviation cost is solved to obtain the waveform alignment sequence, including:

[0031] The two-dimensional matrix of deviation cost is input into the allocation algorithm unit. The allocation algorithm unit establishes a one-to-one mapping relationship between the positive local voltage jump difference and the negative local voltage jump difference. The discrete mapping relationship set that minimizes the sum of the matrix element values ​​corresponding to all mapping relationships is solved to obtain the waveform alignment sequence.

[0032] Optionally, the potentiometer is evaluated for quality based on the differences in local voltage transitions between paired points in the waveform alignment sequence, the index interval of the paired points, and the frequency of inversion of the mapping relationship in the waveform alignment sequence, including:

[0033] The absolute differences between the local voltage jump differences at each pairing point in the waveform alignment sequence are summed to obtain the total local impedance deviation; the total local impedance deviation characterizes the degree of residual amplitude difference between the forward and reverse voltage sequences.

[0034] Calculate the index interval of each pairing point in the waveform alignment sequence, and determine the uniform coordinate translation gap based on the maximum index interval and the single-step angular resolution during the potentiometer sweep process; the uniform coordinate translation gap characterizes the overall lateral drift between the forward and reverse voltage sequences.

[0035] The frequency of the mapping relationship being reversed in the waveform alignment sequence is used to obtain the coordinate mapping cross-reverse sequence statistical value; the coordinate mapping cross-reverse sequence statistical value characterizes the degree of local phase jitter between the forward voltage sequence and the reverse voltage sequence;

[0036] The quality of the potentiometer is evaluated based on the sum of local impedance deviations, the uniform coordinate translation gap, and the statistical values ​​of the cross-reverse coordinate mapping.

[0037] Optionally, the potentiometer's quality is evaluated based on the sum of local impedance deviations, the uniform coordinate translation gap, and the statistical value of the coordinate mapping cross-reverse sequence, including:

[0038] The sum of local impedance deviations is compared with a preset local impedance deviation threshold to obtain the first comparison result;

[0039] The uniform coordinate translation gap is compared with the preset machine tool limit translation gap threshold to obtain the second comparison result;

[0040] The cross-reverse statistical values ​​of the coordinate mapping are compared with the preset values ​​to obtain the third comparison result;

[0041] The potentiometer is evaluated based on the first, second, and third comparison results.

[0042] Secondly, an automatic potentiometer resistance value testing device is provided, the device comprising:

[0043] The acquisition module is used to calculate the coordinate misalignment tolerance based on the potentiometer's tolerance arc length and the effective radius of the drive shaft, and to control the potentiometer to perform forward and reverse sweeping actions to acquire voltage sequences; the voltage sequences include forward voltage sequences and reverse voltage sequences;

[0044] The calculation module is used to perform first-order difference calculation on each voltage sequence to obtain the corresponding voltage jump difference value sequence. Based on the mutation center index, multiple local voltage jump difference values ​​of a preset length are extracted from each voltage jump difference value sequence. The local voltage jump difference values ​​include positive local voltage jump difference values ​​and negative local voltage jump difference values.

[0045] The module is used to construct a two-dimensional matrix of deviation cost. Based on the comparison between the index interval of the pairing points and the tolerance of the number of coordinate misalignment points, it determines the values ​​to be filled into the corresponding positions of the two-dimensional matrix of deviation cost and solves the two-dimensional matrix of deviation cost to obtain the waveform alignment sequence. The pairing points indicate the positive local voltage jump difference and the corresponding negative local voltage jump difference.

[0046] The evaluation module is used to evaluate the quality of the potentiometer based on the differences in local voltage jumps between each pairing point in the waveform alignment sequence, the index interval of the pairing points, and the frequency of the mapping relationship being reversed in the waveform alignment sequence.

[0047] Thirdly, an automatic testing system for potentiometer resistance values ​​is provided. The system includes a potentiometer and a control module, which are electrically connected. The control module is used to perform quality assessment on the potentiometer according to the method described in the first aspect.

[0048] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of this application.

[0049] This application offers the following advantages: it converts the potentiometer's tolerance arc length and the transmission shaft's effective radius into coordinate misalignment point tolerance, transforming physical hardware tolerances into rigid search boundaries for waveform matching algorithms. When constructing the two-dimensional deviation cost matrix, the matrix element values ​​are determined based on the comparison between the index interval of the pairing points and the coordinate misalignment point tolerance. Pairing points exceeding the tolerance range are penalized with blocking, thus accurately absorbing reasonable electromechanical errors caused by brush deformation and gear clearance during waveform alignment, avoiding misjudgments due to over-matching compensation. Solving the two-dimensional deviation cost matrix yields a waveform alignment sequence. Based on the differences in local voltage jumps between pairing points, the index interval of the pairing points, and the frequency of inverted mapping relationships in the waveform alignment sequence, it accurately decouples and independently quantifies three different types of defects in the potentiometer: resistive material inhomogeneity, mechanical transmission hysteresis, and brush contact jitter. This avoids the problem of mechanical and electrical errors masking each other in traditional testing, thereby achieving multi-dimensional, high-precision evaluation of potentiometer quality and accurate diagnosis of failure modes. By evaluating the quality of potentiometers using multidimensional features, transient interference and permanent structural defects in waveform distortion can be effectively decoupled. This solves the problem of misjudgment caused by local nonlinear misalignment in conventional testing and significantly improves the accuracy of quality evaluation for automated equipment. Attached Figure Description

[0050] To more clearly illustrate the technical solutions and advantages in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0051] Figure 1 This is a flowchart of an automatic testing method for potentiometer resistance value in one embodiment;

[0052] Figure 2 This is a schematic diagram of an automatic potentiometer resistance value testing device in one embodiment;

[0053] Figure 3 This is a schematic diagram of the structure of an electronic device in one embodiment. Detailed Implementation

[0054] To further illustrate the technical means and effects adopted by this application to achieve the intended inventive purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of an automatic potentiometer resistance value testing method, apparatus, and system proposed in this application. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0055] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0056] The following description, in conjunction with the accompanying drawings, details a specific scheme for an automatic potentiometer resistance value testing method provided in this application. For example... Figure 1 As shown, the method includes:

[0057] S11. Based on the potentiometer's tolerance arc length and the effective radius of the transmission shaft, calculate the coordinate misalignment tolerance, and control the potentiometer to perform forward and reverse sweeping actions to acquire voltage sequences.

[0058] The voltage sequence includes a forward voltage sequence and a reverse voltage sequence.

[0059] Before initiating the automated test sequence, electromechanical parameters related to the inherent hardware are first extracted from the test bench's configuration file, and these physical quantities are converted into digital constraint boundaries required for subsequent algorithm execution. The single-step angular resolution of the servo motor's coaxial absolute position encoder is then obtained. (For example, set to) The single-step angular resolution characterizes the minimum physical angular span between subsequent discrete sampling points. Simultaneously, a preset contact impedance tolerance limit is extracted. This limit, set according to the potentiometer product's factory inspection specifications, serves as a trigger threshold in subsequent steps to determine whether waveform jumps constitute abnormal abrupt changes.

[0060] In one embodiment, the tolerance for coordinate misalignment points is calculated based on the potentiometer's tolerance arc length and the effective radius of the drive shaft, including:

[0061] The potentiometer's tolerance arc length is obtained by summing the deformation tolerance arc length of the potentiometer's cantilever beam and the mechanical backlash tolerance arc length of the machine tool's transmission gear. The deformation tolerance arc length characterizes the maximum offset arc length of the potentiometer's brush cantilever beam relative to the theoretical position of the drive shaft within the elastic deformation range. The mechanical backlash tolerance arc length characterizes the maximum arc length corresponding to the idling redundancy of the drive shaft when the machine tool's transmission gear switches from forward to reverse rotation.

[0062] Calculate the total clearance radian based on the ratio of the potentiometer's tolerance arc length to the effective radius of the transmission shaft, and convert the total clearance radian into the corresponding mechanical angle;

[0063] Obtain the single-step angular resolution during the potentiometer sweep process; where the single-step angular resolution characterizes the minimum angular displacement of the encoder of the machine tool under a single sampling pulse;

[0064] The coordinate misalignment tolerance is obtained by comparing the mechanical angle corresponding to the total gap radian with the single-step angular resolution; the coordinate misalignment tolerance characterizes the maximum number of misalignments allowed between the forward and reverse voltage sequences.

[0065] Since the subsequent two-dimensional waveform matching algorithm must have boundary constraints to prevent infinite span matching, the elastic deformation capability of the potentiometer cantilever beam and the mechanical backlash of the test machine's transmission system need to be converted into specific digital scales. The deformation tolerance arc length (i.e., the maximum permissible deformation arc length) of the potentiometer cantilever beam under test is extracted, and the mechanical backlash tolerance arc length (i.e., the maximum mechanical backlash arc length) of the machine's transmission gears is extracted. The maximum permissible deformation arc length and the maximum mechanical backlash arc length are added together to calculate the tolerance arc length of the electromechanical system. The tolerance arc length characterizes the maximum offset arc length between the theoretical position and the actual contact position caused by the combined effect of the elastic deformation of the brush cantilever beam and the meshing clearance of the transmission gears during the potentiometer test. Subsequently, the effective radius of the test machine's transmission shaft is extracted simultaneously. Based on tolerance arc length and the radius of action of the rotating shaft. The ratio of the two values ​​yields the total clearance radian representing the electromechanical clearance.

[0066] After obtaining the total gap radius, in order to unify the physical dimensions, an angle conversion factor (i.e., multiplied by) is used. The total clearance in radians is then converted into the corresponding mechanical angle value. Finally, the following conversion operation is performed: the mechanical angle value corresponding to the total clearance in radians is divided by the single-step angular resolution. (Unit: degrees / pulse), and the calculation result is rounded down to generate a dimensionless, purely numerical variable—the coordinate misalignment tolerance. (That is, the maximum allowable number of coordinate misalignment points). Tolerance for the number of coordinate misalignment points. Persistently stored in system memory, its physical significance lies in defining the maximum number of sampling point offsets allowed for the bidirectional test waveform when mechanical deformation and gear backlash occur. Simultaneously, it sets a blocking penalty value. Blocking penalty value It is set to an extremely large fixed constant (e.g., pre-set to 100 times the maximum measurable voltage difference of the analog-to-digital converter in the test system) to forcibly block any span exceeding [a certain value] in subsequent two-dimensional matrix pairing. Illegal data mapping.

[0067] In one embodiment, controlling the potentiometer to perform forward and reverse sweep operations to acquire a voltage sequence includes:

[0068] The control potentiometer performs a forward sweep operation, records the forward time-domain voltage corresponding to the time index, and obtains the forward voltage sequence;

[0069] When the forward sweep reaches its end, the control potentiometer performs a reverse sweep, recording the inverse time-domain voltage corresponding to the time index, thus obtaining the inverse voltage sequence.

[0070] After parameter calibration is completed, the servo motor is controlled to drive the potentiometer under test to perform a complete forward and reverse scraping action, and the hardware timer is used to perform continuous equal-time data sampling.

[0071] Initialize a discrete global time index Global time index The value of is determined by The number of samples increases monotonically until the total number of samples is reached. In each time index As the value increases, the absolute mechanical angle of the test bench drive shaft at the current moment is recorded simultaneously. It should be noted that, due to the flexible frictional deformation of the potentiometer's brush contacts when scraping the carbon film, the actual physical contact position between the brush contacts and the carbon film differs from the absolute mechanical angle. There must be a dynamic, non-linear angular difference between them. Instead of forcibly locking this deformation angular difference at the hardware level, the absolute mechanical angle of the drive shaft is used. As a macroscopic alignment benchmark, this dynamic difference is extracted and quantified by subsequent waveform matching algorithms.

[0072] At the absolute mechanical angle of the driving brush When performing a forward sweep motion in an increasing direction, record and time index. Corresponding forward time domain voltage When the sweep reaches its end and the reverse drive brush performs a reverse sweep, this is also recorded with a time index. Corresponding inverse time domain voltage Thus, the continuously changing potentiometer analog output signal is completely converted into a discrete array set containing the timing sequence.

[0073] Retrieve the above with global time index A bidirectional time-domain voltage sequence. Due to the time index during reverse sweep... It is continuously increasing, but the corresponding absolute mechanical angle However, it gradually decreases over time. If the bidirectional arrays are directly compared side by side, it will cause a serious misalignment of the waveforms on the coordinate axis, with the beginning and end reversed.

[0074] Therefore, a coordinate reordering operation that completely removes the time attribute is performed. A global spatial index that is completely independent of the acquisition time sequence is established. Global spatial index The value of is determined by The numbers increase monotonically until they reach the total number of space points. .

[0075] For forward time domain voltage Since the angular coordinates during acquisition are inherently increasing, the internal voltage value sequence is extracted and directly mapped one-to-one to the global spatial index according to its original order. Above, a positive voltage sequence is generated. .

[0076] For inverse time domain voltage Extract the associated time-decreasing sequence of angle coordinates. Following a forced increasing order of absolute mechanical angle values ​​from smallest to largest, analyze the inverse time-domain voltage... All voltage data elements within the array are reordered by flipping their positions. After reordering, the data points that were originally acquired last in time are moved to the front of the array. The voltage array, now flipped and sorted, is then sequentially mapped to the same global index. This generates an inverse voltage sequence. .

[0077] The forward voltage sequence obtained through the above-described flip mapping based on the drive shaft angle With reverse voltage sequence By strictly sharing the same monotonically increasing mechanical angle coordinate axis, a basic data carrier is provided for subsequent comparison of morphological features in spatial dimensions.

[0078] S12. Perform first-order difference calculation on each voltage sequence to obtain the corresponding voltage jump difference sequence. Based on the mutation center index, extract multiple local voltage jump differences of a preset length from each voltage jump difference sequence.

[0079] The local voltage jump difference includes the positive local voltage jump difference and the negative local voltage jump difference.

[0080] In one embodiment, a first-order difference calculation is performed on each voltage sequence to obtain the corresponding voltage jump difference sequence. Based on the abrupt change center index, multiple local voltage jump differences of a preset length are extracted from each voltage jump difference sequence, including:

[0081] Perform a first-order difference operation on the forward voltage sequence to obtain the corresponding forward voltage jump difference sequence, and perform a first-order difference operation on the reverse voltage sequence to obtain the corresponding reverse voltage jump difference sequence; wherein, the voltage jump difference sequence includes the forward voltage jump difference sequence and the reverse voltage jump difference sequence, and each element in the voltage jump difference sequence represents the voltage change between two adjacent sampling points;

[0082] The location of the data point in the forward voltage jump difference sequence that exceeds the preset contact impedance tolerance limit is determined as the forward mutation center index, and the location of the data point in the reverse voltage jump difference sequence that exceeds the preset contact impedance tolerance limit is determined as the reverse mutation center index; the mutation center index includes the forward mutation center index and the reverse mutation center index;

[0083] Based on the positive mutation center index, a fixed number of sampling points are extended along the left and right sides of the axis to extract multiple positive local voltage jump difference values ​​of a preset length from the positive voltage jump difference value sequence, and a positive local spatial index is assigned to the positive local voltage jump difference value.

[0084] Based on the reverse mutation center index, a fixed number of sampling points are extended along the left and right sides of the axis to extract multiple reverse local voltage jump differences of a preset length from the reverse voltage jump difference sequence, and a reverse local spatial index is assigned to the reverse local voltage jump difference.

[0085] For shared global space index positive voltage sequence Expand the traversal operation. Perform a first-order difference operation on the forward voltage sequence and set the global space index. since Begin step-by-step traversal until the target is reached. End. In each iteration, extract the forward voltage value at the current coordinate position. It also extracts the forward voltage value of the immediately preceding coordinate position in space. Calculate the absolute value of the difference between the two forward voltage values ​​mentioned above, and assign this absolute value as the forward voltage jump difference value under the current coordinate. This yields the corresponding sequence of forward voltage jump differences.

[0086] Synchronously, for the reverse voltage sequence It employs a completely consistent traversal and subtraction operation logic. A first-order difference operation is performed on the inverse voltage sequence to extract the inverse voltage value at the current coordinate position. And extract the reverse voltage value of its spatially adjacent preceding coordinate position. Calculate the absolute value of the difference between the two reverse voltage values ​​mentioned above, and assign this absolute value as the reverse voltage jump difference value. This yields the corresponding reverse voltage jump difference sequence.

[0087] Through the first-order spatial difference operation described above, the original gradually changing voltage sequence with a macroscopic slope is transformed into a discrete difference sequence that purely characterizes the amplitude of local abrupt changes. The closer the value in the voltage jump difference sequence is to zero, the smoother the waveform at that location; the larger the value, the more obvious the abrupt change at that location.

[0088] To completely block the interference of global redundant coordinates on the subscripts of the subsequent local matrix matching algorithm, and to ensure that the forward and reverse array sets participating in the cross operation have completely equal data lengths, a local truncation operation based on a fixed data window is performed.

[0089] The generated voltage jump difference sequence is read sequentially, and each value is compared with a preset contact impedance tolerance limit. When a sudden data point exceeding the contact impedance tolerance limit is detected in the forward voltage jump difference sequence, its global spatial location is recorded and marked as the forward jump center index. When a sudden data point exceeding the contact impedance tolerance limit is detected in the reverse voltage jump difference sequence, its global spatial location is recorded and marked as the reverse jump center index. When multiple consecutive data points exceed the contact impedance tolerance limit, the index of the data point with the largest absolute value in the consecutive data segment is selected as the unique jump center index.

[0090] It should be noted that if the maximum value in the entire first-order voltage jump difference sequence is less than the preset contact impedance tolerance limit, the matrix construction and solution steps are skipped directly, and the potentiometer is judged to be "qualified" or "without transient interference and defects".

[0091] Taking the positive mutation center index as an example, based on the positive mutation center index index along the global space The horizontal axis decreases to the left and increases to the right, with each extension having a preset fixed number of sampling points. (For example, based on experience with conventional interference waveform widths, preset) In global spatial coordinates, extract from... From, to A continuous data segment is formed by extracting multiple forward local voltage jump differences of a predetermined length from the forward voltage jump difference sequence. The total length of this continuous data segment is constant. Its calculation formula is Similarly, using the reverse mutation center index as a reference, a predetermined number of fixed sampling points are extended along the left and right sides of the axis to extract multiple reverse local voltage jump differences of a predetermined length from the reverse voltage jump difference sequence. If the index obtained from the extended calculation is less than 1 or greater than the total sampling length, the excess part is filled with constant values ​​from the endpoints of the sequence, or mirror padding is used to force the truncation length to reach 2L+1.

[0092] To prevent array out-of-bounds errors or forced triggering of blocking penalties (leading to deadlock and crash) in subsequent two-dimensional matrix matching algorithms when processing normal waveform phase drift, the above-mentioned fixed number of sampling points is set. At this time, strict mathematical anti-crash constraints are introduced: ensuring the total length of the generated continuous data segments. Strictly greater than twice the tolerance for coordinate misalignment points (Right now This constraint ensures that the extracted local data segment window is wide enough so that the edge data points can be processed within a maximum span of [value missing]. Even during pairing searches, there is still ample redundancy for pairing without penalty.

[0093] After truncation, local index reallocation is performed on the truncated forward continuous data segments and reverse data segments. For each truncated forward continuous data segment, an independent dimension identifier is created, and a forward local spatial index is allocated. The positive local space index The value of is determined by Monotonically increasing to a constant The extracted values ​​at the corresponding locations are recorded as positive local voltage jump differences. Simultaneously, for the extracted reverse continuous data segments, a reverse local space index is assigned to them. Inverse local space index The value also depends on Monotonically increasing to a constant The extracted values ​​at the corresponding locations are recorded as the reverse local voltage jump difference values. .

[0094] The positive local voltage jump difference is entirely driven by the aforementioned local index. Difference between reverse local voltage jump value The data are combined and packaged. After packaging, two sets of local voltage jump data segments with absolutely equal length, symmetrical structure, and focused on the abnormal change region are output, which are directly used as the input data source for the two-dimensional matrix operation of the deviation cost.

[0095] S13. Construct a two-dimensional matrix of deviation cost. Based on the comparison results of the index interval of the pairing points and the tolerance of the number of misaligned coordinate points, determine the values ​​to be filled into the corresponding positions of the two-dimensional matrix of deviation cost, and solve the two-dimensional matrix of deviation cost to obtain the waveform alignment sequence.

[0096] In this context, a pairing point indicates the forward local voltage jump difference value and its corresponding reverse local voltage jump difference value. For each extracted sequence of forward local voltage jump differences, a forward local spatial index *i* is assigned. The value of *i* starts from 1 and monotonically increases until the total length *N* of the sequence. Similarly, for each extracted sequence of reverse local voltage jump differences, a reverse local spatial index *j* is assigned. Likewise, the value of *j* also starts from 1 and monotonically increases until the total length *N* of the sequence. A pairing point indicates that the data point with the forward local spatial index *i* is combined with the data point with the reverse local spatial index *j* to form a correspondence, where *i* is any forward local spatial index and *j* is any reverse local spatial index.

[0097] In one embodiment, a two-dimensional matrix of deviation cost is constructed. Based on a comparison between the index interval of paired points and the tolerance for the number of coordinate misalignments, the values ​​to be filled into the corresponding positions in the two-dimensional matrix of deviation cost are determined, including:

[0098] Construct a blank two-dimensional matrix; wherein the number of rows of the blank two-dimensional matrix is ​​equal to the number of multiple positive local voltage jump differences, the number of columns is equal to the number of multiple negative local voltage jump differences, and the number of multiple positive local voltage jump differences is equal to the number of multiple negative local voltage jump differences;

[0099] Use the forward local space index as the outer loop variable and the reverse local space index as the inner loop variable to traverse all paired points;

[0100] In each traversal, the absolute difference between the current positive local voltage jump difference and the corresponding negative local voltage jump difference is calculated to obtain the current local voltage jump deviation value, and the absolute value of the index interval between the current positive local space index and the corresponding negative local space index is calculated to obtain the current index interval of the pairing point.

[0101] Compare the index interval of the current pairing point with the tolerance of the number of coordinate misalignment points. If the index interval of the current pairing point is not greater than the tolerance of the number of coordinate misalignment points, then fill the current local voltage jump deviation value as the matrix element value into the current traversal position.

[0102] If the index interval of the current pairing point is greater than the tolerance for the number of coordinate misalignment points, then the preset blocking penalty value will be used as the matrix element value and filled into the current traversal position.

[0103] After the traversal is complete, a two-dimensional matrix of the fully assigned deviation costs is obtained.

[0104] Since unrestricted cross-pairing of data points will force the merging of waveform features that are far apart and have no relation, thus introducing incorrect morphological mapping relationships, it is necessary to impose strict boundary constraints on the pairing range of waveform data points based on the actual physical deformation limits of the electromechanical structure.

[0105] For including Positive local voltage jump difference at each data point and contain Reverse local voltage jump difference at each data point First, initialize a size of A blank two-dimensional matrix is ​​given, and this matrix is ​​named the deviation cost two-dimensional matrix. Values ​​are assigned to all elements in this matrix, and a double-nested traversal calculation operation is performed.

[0106] Set the outer loop variable as a positive local space index. ,in The value of is determined by Monotonically increasing to Indexing in the forward local space For each fixed value, the inner loop variable is set to the inverse local space index. ,in The value also depends on Monotonically increasing to In every and In the iterative loop of the combination, the following pairwise substitution value calculation and boundary penalty logic are executed:

[0107] Extract the positive local voltage jump difference corresponding to the current loop position. Difference between reverse local voltage jump value Calculate the absolute difference between the two values ​​mentioned above and label it as the current local voltage jump deviation value. The smaller the difference, the stronger the positive first... The waveform feature point and the reversed first The more similar the waveform feature points are in terms of shape and amplitude, the better.

[0108] Calculate the index interval of the current pairing point This refers to the absolute value of the spatial span between indices within a pair of points. The calculated index interval... Tolerance for the number of coordinate misalignment points Then, compare the numerical values. 1. When the comparison result is... At this time, it is determined that the current pairing coordinate offset is still within the allowable mechanical tolerance range of the brush cantilever beam and gear clearance. The current local voltage jump deviation value obtained from the above normal calculation is then used. Directly input into the two-dimensional matrix of deviation cost Within the coordinate cells; 2. When the comparison result is At this point, it is determined that the spatial span between the two data points currently being attempted to be paired has physically exceeded the maximum deformation and gap limits that the electromechanical equipment hardware materials can produce. Forcing a match would constitute excessive algorithmic compensation detached from physical reality, and would result in the default blocking penalty value being applied. Forced input into the two-dimensional matrix of deviation cost Within the coordinate cell.

[0109] After the double-nested traversal is completed, a two-dimensional matrix of the fully assigned deviation costs is output. This matrix possesses a very clear hardware-software co-operation characteristic: its width is [missing information] on both sides of the main diagonal. Within the banded region, the matrix is ​​filled with cost values ​​reflecting the differences in the true shape of the waveform; while in the far space outside the banded region, the matrix is ​​subject to a significant blocking penalty value. This fills the gap, thus erecting an insurmountable physical boundary wall at the algorithm's underlying level.

[0110] In one embodiment, solving the two-dimensional matrix of deviation cost yields a waveform alignment sequence, including:

[0111] The two-dimensional matrix of deviation cost is input into the allocation algorithm unit. The allocation algorithm unit establishes a one-to-one mapping relationship between the positive local voltage jump difference and the negative local voltage jump difference. The discrete mapping relationship set that minimizes the sum of the matrix element values ​​corresponding to all mapping relationships is solved to obtain the waveform alignment sequence.

[0112] After generating a two-dimensional matrix with rigid boundary constraints, it is necessary to find the optimal alignment path that runs through the forward and reverse data sequences. Since local nonlinear waveform distortion can cause complex misalignment of multiple data points within the same time window, exhaustively searching through all combinations would lead to an exponential explosion in computational power consumption. Therefore, a polynomial-time allocation algorithm (such as the Hungarian Algorithm for bipartite graphs) is introduced to solve for the globally optimal path.

[0113] The generated two-dimensional matrix of deviation costs is used as input parameters and passed to a pre-defined allocation algorithm unit. The allocation algorithm unit, based on the numerical value of each cell within the matrix, allocates values ​​in rows (positive local space index). ) and columns (reverse local spatial index) It performs a one-to-one mapping assignment calculation between () and (). The core operational logic of the algorithm is to find a set that covers all The independent pairing of data points minimizes the sum of the matrix cell values ​​corresponding to the selected pairing. Finally, a discrete set of mapping relationships that minimizes the overall waveform morphology difference is obtained and output as a waveform alignment sequence. It needs to be clarified that this waveform alignment sequence It does not represent an absolute entity mapping at the level of physical particles, but rather a time-warped sequence characterizing the optimal overlap of waveform morphology in forward and reverse local voltage jump data segments under tolerance boundary constraints. The allocation algorithm, used to extract the optimal matching path for the bidirectional waveform morphology within the tolerance boundary, is a data-driven feature extraction mathematical model. The resulting reversed mapping relationship (cross-reverse order) does not represent time reversal, but rather serves as a statistical feature parameter specifically used to mathematically quantify the degree of nonlinear phase distortion (i.e., high-frequency jitter of the brushes) in the local waveform.

[0114] Waveform Alignment Sequence Include The discrete mapping elements, where the first... The elements are denoted as The specific value of this element represents the value of the first element in the forward sequence under the constraint of minimizing the overall waveform difference. The data point is assigned and aligned with the first data point in the reverse sequence. Data points. Alignment sequence for the output waveform. Execution based on blocking penalty value Error screening and mistake-proofing procedures. Sequentially extract waveform alignment sequences. middle The original matrix values ​​corresponding to each mapping position, i.e., reading The value of .

[0115] Determine whether the extracted set of values ​​contains a value equal to the blocking penalty value. The elements. 1. When the judgment result is true, it indicates that even if the globally optimal algorithm is used, it is impossible to find the legal mechanical capacitance difference boundary (width). Within the range, the algorithm is forced to choose a far-end out-of-bounds point for matching because it cannot find an alignment point sufficient to stitch together the bidirectional waveform. This physically means that the macroscopic fault misalignment of the current waveform has fundamentally broken through the normal structural connection state of the component. At this point, it is determined that the cantilever beam metal spring of the potentiometer has suffered severe bending or breakage, directly interrupting all subsequent complex feature statistical processes and triggering a structural failure alarm to the peripheral automated control unit of the test bench. 2. When the judgment result is false, it indicates that the set of forward and reverse abrupt waveforms can complete morphological reconstruction and stitching within the deformation range allowed by the electromechanical hardware. In response to this judgment, based on the acquired waveform alignment sequence... Continue propagating to perform quantification and statistics of secondary dynamic interference characteristics.

[0116] S14. Evaluate the quality of the potentiometer based on the differences in local voltage jumps between each pairing point in the waveform alignment sequence, the index interval of the pairing points, and the frequency of the mapping relationship being reversed in the waveform alignment sequence.

[0117] In one embodiment, the potentiometer is quality evaluated based on the differences in local voltage transitions between paired points in the waveform alignment sequence, the index interval of the paired points, and the frequency of reversals in the mapping relationship in the waveform alignment sequence, including:

[0118] The absolute differences between the local voltage jump differences at each pairing point in the waveform alignment sequence are summed to obtain the total local impedance deviation; the total local impedance deviation characterizes the degree of residual amplitude difference between the forward and reverse voltage sequences.

[0119] Calculate the index interval of each pairing point in the waveform alignment sequence, and determine the uniform coordinate translation gap based on the maximum index interval and the single-step angular resolution during the potentiometer sweep process; the uniform coordinate translation gap characterizes the overall lateral drift between the forward and reverse voltage sequences.

[0120] The frequency of the mapping relationship being reversed in the waveform alignment sequence is used to obtain the coordinate mapping cross-reverse sequence statistical value; the coordinate mapping cross-reverse sequence statistical value characterizes the degree of local phase jitter between the forward voltage sequence and the reverse voltage sequence;

[0121] The quality of the potentiometer is evaluated based on the sum of local impedance deviations, the uniform coordinate translation gap, and the statistical values ​​of the cross-reverse coordinate mapping.

[0122] Specifically, the potentiometer's quality is evaluated based on the sum of local impedance deviations, the uniform coordinate translation gap, and the statistical value of the coordinate mapping cross-reverse sequence, including:

[0123] The sum of local impedance deviations is compared with a preset local impedance deviation threshold to obtain the first comparison result;

[0124] The uniform coordinate translation gap is compared with the preset machine tool limit translation gap threshold to obtain the second comparison result;

[0125] The cross-reverse statistical values ​​of the coordinate mapping are compared with the preset values ​​to obtain the third comparison result;

[0126] The potentiometer is evaluated based on the first, second, and third comparison results.

[0127] The uniform coordinate translation gap characterizes the overall lateral drift between the forward and reverse voltage sequences. It can be understood that the uniform coordinate translation gap characterizes the combined equivalent offset of the machine tool mechanical hysteresis and the local slippage of the brush within the intercepted window.

[0128] Based on the acquired waveform alignment sequence Calculate the sum of local impedance deviations used to characterize the inability to eliminate differences in the longitudinal amplitude of the waveform. Specifically, a two-dimensional matrix of deviation cost is extracted, and the alignment sequence is based on the waveform. The row and column index mapping relationship recorded in the middle (i.e., the first row in the forward sequence) The nth point is mapped to the nth point in the reverse sequence. (points), read the corresponding matrix cell values ​​one by one, the deviation cost is the value of each cell in the two-dimensional matrix is Set the iterator since Monotonically increasing until the total length of the data segment. In each iteration, a cumulative summation algorithm is used to calculate all... The normal voltage jump deviation values ​​at each mapped location are summed, and the specific extraction formula is as follows:

[0129] ;

[0130] in, Let be the sum of local impedance deviations, and let i be the iterative variable for the positive local space index. This represents the total number of points in the continuous data segment that participated in the extraction and matrix operations. This represents two data points mapped according to the waveform alignment sequence. and The local voltage jump deviation value, that is, the absolute difference between the local voltage jump differences at each paired point in the waveform alignment sequence, is summed in terms of the term. Implement the capture of all content within the window. The residual amplitude difference of each discrete mapping point is integrated to eliminate the influence of accidental fluctuations in individual local data points.

[0131] Sum of local impedance deviations This reflects the irreparable voltage amplitude difference that still exists in the forward and reverse waveforms after optimal morphological alignment (i.e., exhausting all spatial misalignment compensations not exceeding the deformation limit). The larger the value of this calculation result, the more severe the difference in the longitudinal amplitude characteristics of the waveform. In physical terms, this indicates a more severe permanent carbon film defect in the test area that cannot be explained by simple phase shift (e.g., a sharp reduction in the forward and reverse contact area caused by deep scratches).

[0132] Based on the same waveform alignment sequence Calculate the uniform coordinate translation gap used to characterize the overall lateral drift of the waveform. .

[0133] Extracting waveform alignment sequence Spatial index of all mapping point pairs recorded in the middle and Set the iterator since Monotonically increasing to Calculate the absolute position offset within each mapping pair, i.e., calculate The value will be calculated. Each absolute position offset is used to construct a discrete set of offset values. A maximum search algorithm (such as the Max function) is called to traverse, compare, and filter this set of offset values, extracting the offset point with the largest value. Since this offset point number is a pure numerical index difference without actual physical length units, it is multiplied by the single-step angular resolution. (Unit: degrees / pulse), thus outputting a uniform coordinate translation gap with actual angular length dimensions. Uniform coordinate translation gap The extraction formula is as follows:

[0134] ;

[0135] in, This represents the uniform coordinate translation gap, in degrees. Let $\frac{i}{i}$ be the index interval between the paired points, which is the absolute distance between the $i$-th data point in the forward direction and the $π(i)$-th data point in the reverse direction on the spatial index axis. By subtracting the two data points and taking their absolute values, the lateral drift span of a single-point pairing on the discrete spatial coordinate axis can be calculated. To obtain the maximum value, the maximum horizontal drift span occurring within the entire capture window is extracted.

[0136] Uniform coordinate translation gap The larger the calculated value, the more significant the overall lateral translation of the forward and reverse waveforms within the entire waveform anomaly capture window. In actual test physical scenarios, this value equivalently reflects the mechanical backlash and macroscopic hysteresis caused by the machine tool transmission mechanism (gear backlash). Extracting the uniform coordinate translation clearance. This is used to verify in subsequent steps whether the overall drift of the waveform is within a reasonable range of mechanical float.

[0137] After extracting the macroscopic translation and residual amplitude, it is necessary to further quantify the high-frequency hysteresis and bouncing phenomena caused by the brush crossing carbon film particles. Because hysteresis and bouncing cause local nonlinear compression (jamming) and stretching (slippage and rebound) in the originally continuous and smooth time-series waveform, this local distortion affects the optimal waveform alignment sequence. In this process, the originally ordered data point mappings become densely intersecting and reversed. By performing a two-level traversal comparison, the frequency of intersections within the sequence is statistically analyzed, thereby quantifying the dynamic transient interference characteristics.

[0138] For the acquired waveform alignment sequence Initialize an integer counter variable and name it "Coordinate Mapping Cross Reverse Statistic". And assign its initial starting point to zero. Align the waveform sequence. Expand the nested loop used to determine if the order is reversed, and set the outer comparison pointer. This makes it start from the index of the sequence. Initially, it monotonically increases to... End. Compare pointers on the outer layer. For each current fixed value, set the inner comparison pointer. So that it moves from the position immediately following it. Initially, the sequence monotonically increases until the index at the end of the sequence. End. This double loop setup ensures the outer pointer... The corresponding data points always precede the inner pointer in the original forward timing sequence. The corresponding data point occurs.

[0139] In every and In the combined comparison iteration, the following size judgment and counting logic are executed sequentially: extract the positive prior position. The corresponding target allocation index in the reverse sequence Simultaneously extract the positive posterior position. The corresponding target allocation index in the reverse sequence Use the greater than sign ( A rigorous comparison and judgment is performed on the two extracted index values. The target index is then determined. Is the value strictly greater than the target allocation index? The numerical value. Its logical expression is as follows:

[0140] ;

[0141] in, and Represents the relative timing sequence position on the positive waveform (and satisfies) ), and These represent the timing positions of the inverse waveforms to which the two positions are assigned and bound when the two positions are optimally aligned. This expresses a reversal of the time sequence: that is, the characteristic peak (position) that originally occurred first in the forward sweep. In the reverse sweep waveform, a characteristic peak (position) that occurred later was matched. Further ahead (with larger values), the coordinate mapping cross-reverse statistics are... ,in, The instruction responds to each event that triggers the inverted inequality to be true by performing an accumulation with a step size of one.

[0142] After the double loop traversal is completed, output the final coordinate mapping cross-inversion statistics. The larger the calculated statistical value, the denser the occurrence of misalignment and intersection of the optimal alignment mapping points in both directions within the entire waveform capture window. This dense intersection reflects a drastic nonlinear phase deformation in the local waveform, directly and equivalently representing the frequent dynamic hindrance and instantaneous slippage and bouncing actions encountered by the brush when passing through this coordinate region. This extraction process allows the system to separate the transient interference state of the brush solely based on the voltage waveform sequence without adding any external high-frequency acoustic or vibration sensors, forming the core data tool for distinguishing between physical defects and pseudo-defects in this case.

[0143] Extract the preset local impedance deviation threshold To ensure the scientific validity and feasibility of this threshold, a preset local impedance deviation threshold is established. This is not a subjective assumption, but rather a process that involves pre-collecting the forward and reverse transition waveforms of several known, qualified standard gold components (potentiometer entities that are undamaged but allow for reasonable microscopic scratches), extracting the average value of the sum of the residual local impedance deviations of these standard samples after performing optimal morphological alignment, and then adding a preset positive allowance factor (e.g., multiplied by) to this average value. The empirical constant obtained after calculation is used. This parameter sets the upper limit of the maximum voltage amplitude difference that the waveform can tolerate after exhaustive morphological compensation.

[0144] Then extract the preset machine tool limit translation gap threshold. The preset limit of machine tool translation clearance. This is a mechanical distance constant obtained by offline calibration of the test gear during the switch from forward to reverse rotation under no-load conditions. This parameter characterizes the inherent reasonable mechanical backlash of the test bench itself.

[0145] Using a multi-branch Boolean logic decision structure, the received local impedance deviations are summed. Uniform coordinate translation gap and coordinate mapping cross-reverse statistics As the parameter to be evaluated, its value is compared item by item with the aforementioned benchmark limit. Based on the judgment results of three different combination states, corresponding flow control commands are issued to the testing machine:

[0146] 1. Perform an AND logic comparison containing three independent conditions. First, compare to confirm the total local impedance deviation. Strictly less than the local impedance deviation threshold Next, the translation gap of the uniform coordinates was compared and confirmed. Less than or equal to the preset machine tool limit translation clearance threshold (i.e., within a reasonable range of mechanical backlash fluctuation, for example, less than or equal to the machine tool limit translation clearance threshold). (Including reasonable allowable floating tolerances). Finally, compare and confirm the coordinate mapping cross-inversion statistics. The value is strictly greater than the preset value, where the preset value can be 0.

[0147] When all three conditions are met, the transient interference judgment process is triggered. In this state, the residual voltage deviation does not exceed the limit, indicating that the carbon film has not undergone substantial deep damage or thinning; the macroscopic translation is within a reasonable range, confirming the normal backlash of the transmission gears; and the generation of cross-reverse frequency necessarily corresponds to the timing reversal and phase deformation occurring within the optimal alignment sequence. This tight combination of three indicators uniquely characterizes, in terms of physical mechanism, the transient high-frequency jumps and elastic deformation recovery caused by uneven friction when the brush normally glides over the microscopic particles on the carbon film surface. Therefore, the waveform jump characteristics captured in this test are judged as non-fatal transient interference. An exemption record operation for the abnormal alarm is executed in the test result database, and a specific process flow instruction for the product is issued to the production line's underlying programmable logic controller (PLC) (e.g., allowing it to proceed to the next process, or marking it as a downgraded product that allows retesting).

[0148] 2. Perform a single impedance over-limit comparison. When the comparison confirms the total local impedance deviation... Greater than or equal to the local impedance deviation threshold At that time, regardless of the state of the other two indicators, the physical defect determination process will be triggered immediately.

[0149] In this state, the total high local impedance deviation This means that no matter how many times the forward and reverse waveforms are reconstructed within the capacitance difference boundary, a significant residual voltage difference will still exist between them. Physically, this is directly equivalent to irreversible deep carbon film peeling, hard scratches, or exposed metal substrate defects on the potentiometer contact surface. Since this type of damage cannot heal itself and severely affects electrical life, the potentiometer under test is determined to be a defective product, and a rejection instruction is directly issued to the production line's programmable logic controller.

[0150] 3. Perform a logical comparison that includes two independent conditions. When the comparison confirms the sum of local impedance deviations... Strictly less than the local impedance deviation threshold However, at the same time, the cross-reverse statistics of coordinate mapping were confirmed. When the value is zero, the rigid short-circuit judgment process is triggered.

[0151] In this state, although the waveform amplitude difference is within the tolerance range and local voltage anomalies exceeding the normal baseline have been captured, no crossover occurs within the mapping sequence. This indicates that when the brush crosses this abrupt change region, the waveform undergoes only a pure amplitude shift, without any nonlinear lag or bouncing accompanied by high-frequency jitter. This absolute rigidity abrupt change without bouncing corresponds to instantaneous short circuits or parallel resistance reduction phenomena caused by rigid assembly defects such as metal burrs, conductive adhesive overflow, etc., inside the potentiometer. Since such assembly foreign objects may fall off at any time and cause fatal failures, the potentiometer under test is determined to be a defective product with potential defects, and a defective product rejection instruction is also issued to the programmable logic controller.

[0152] The peripheral cylinders or robotic arms of the testing machine perform standard sorting actions based on the received transient interference flow instructions or defective product rejection instructions, and then complete the closed-loop automatic testing and quality identification of a single potentiometer.

[0153] It should be understood that, although Figure 1 The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figure 1At least some of the steps in the process may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps.

[0154] This application also provides an automatic potentiometer resistance value testing device, such as... Figure 2 As shown, the device includes:

[0155] The acquisition module 21 is used to calculate the coordinate misalignment tolerance based on the potentiometer's tolerance arc length and the effective radius of the transmission shaft, and to control the potentiometer to perform forward and reverse sweeping actions to acquire voltage sequences; the voltage sequences include forward voltage sequences and reverse voltage sequences;

[0156] The calculation module 22 is used to perform first-order difference calculation on each voltage sequence to obtain the corresponding voltage jump difference value sequence. According to the mutation center index, it extracts multiple local voltage jump difference values ​​of a preset length from each voltage jump difference value sequence. The local voltage jump difference values ​​include positive local voltage jump difference values ​​and negative local voltage jump difference values.

[0157] Module 23 is used to construct a two-dimensional matrix of deviation cost. Based on the comparison result of the index interval of the pairing points and the tolerance of the number of coordinate misalignment points, the value of the corresponding position to be filled into the two-dimensional matrix of deviation cost is determined, and the two-dimensional matrix of deviation cost is solved to obtain the waveform alignment sequence; the pairing points indicate the positive local voltage jump difference value and the corresponding reverse local voltage jump difference value.

[0158] Evaluation module 24 is used to evaluate the quality of the potentiometer based on the differences between the local voltage jump differences of each pairing point in the waveform alignment sequence, the index interval of the pairing points, and the frequency of the mapping relationship being reversed in the waveform alignment sequence.

[0159] For the device embodiments, since they basically correspond to the method embodiments, the relevant parts can be referred to in the description of the method embodiments. The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this application according to actual needs.

[0160] This application also provides an automatic potentiometer resistance value testing system, the system including a potentiometer and a control module, the potentiometer and the control module being electrically connected, and the control module being used to perform quality assessment on the potentiometer according to any of the above embodiments.

[0161] Figure 3 This is a schematic diagram of the structure of an electronic device according to an example embodiment of this application. The electronic device includes a memory, a processor, and a computer program stored in the memory and used to run on the processor. When the processor executes the computer program, it implements the method described in any of the above embodiments. Figure 3 The electronic device 30 shown is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of this application.

[0162] like Figure 3 As shown, the electronic device 30 can be manifested as a general-purpose computing device, such as a server device. The components of the electronic device 30 may include, but are not limited to: at least one processor 31, at least one memory 32, and a bus 33 connecting different system components (including memory 32 and processor 31).

[0163] Bus 33 includes a data bus, an address bus, and a control bus.

[0164] The memory 32 may include volatile memory, such as random access memory (RAM) 321 and / or cache memory 322, and may further include read-only memory (ROM) 323.

[0165] The memory 32 may also include a program tool 325 (or utility) having a set (at least one) program module 324, such program module 324 including but not limited to: an operating system, one or more application programs, other program modules and program data, each or some combination of these examples may include an implementation of a network environment.

[0166] The processor 31 executes various functional applications and data processing, such as the methods provided in any of the above embodiments, by running computer programs stored in the memory 32.

[0167] Electronic device 30 can also communicate with one or more external devices 34 (e.g., keyboard, pointing device, etc.). This communication can be performed via input / output (I / O) interface 35. Furthermore, electronic device 30 can also communicate with one or more networks (e.g., local area network (LAN), wide area network (WAN), and / or public network, such as the Internet) via network adapter 36. As shown, network adapter 36 communicates with other modules of electronic device 30 via bus 33. It should be understood that, although not shown in the figure, other hardware and / or software modules can be used in conjunction with electronic device 30, including but not limited to: microcode, device drivers, redundant processors, external disk drive arrays, RAID (disk array) systems, tape drives, and data backup storage systems.

[0168] It should be noted that although several units / modules or sub-units / modules of the electronic device have been mentioned in the detailed description above, this division is merely exemplary and not mandatory. In fact, according to the embodiments of this application, the features and functions of two or more units / modules described above can be embodied in one unit / module. Conversely, the features and functions of one unit / module described above can be further divided and embodied by multiple units / modules.

[0169] This application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method provided in any of the above embodiments.

[0170] The readable storage medium may be more specifically adopted, including but not limited to: portable disk, hard disk, random access memory, read-only memory, erasable programmable read-only memory, optical storage device, magnetic storage device, or any suitable combination thereof.

[0171] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0172] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the method described in any of the above embodiments.

[0173] The program code for executing the computer program product of this application can be written in any combination of one or more programming languages. The program code can be executed entirely on the user device, partially on the user device, as a standalone software package, partially on the user device and partially on a remote device, or entirely on a remote device.

[0174] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0175] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application.

[0176] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

Claims

1. An automatic method for testing the resistance value of a potentiometer, characterized in that, The method includes: Based on the potentiometer's tolerance arc length and the effective radius of the drive shaft, the coordinate misalignment tolerance is calculated, and the potentiometer is controlled to perform forward and reverse sweeping actions to acquire voltage sequences; the voltage sequences include forward voltage sequences and reverse voltage sequences; For each voltage sequence, a first-order difference calculation is performed to obtain the corresponding voltage jump difference value sequence. Based on the mutation center index, multiple local voltage jump difference values ​​of a preset length are extracted from each voltage jump difference value sequence. The local voltage jump difference values ​​include positive local voltage jump difference values ​​and negative local voltage jump difference values. A two-dimensional matrix of deviation cost is constructed. Based on the comparison between the index interval of the pairing points and the tolerance of the number of coordinate misalignment points, the values ​​to be filled into the corresponding positions of the two-dimensional matrix of deviation cost are determined. The two-dimensional matrix of deviation cost is then solved to obtain the waveform alignment sequence. The pairing points indicate the positive local voltage jump difference and the corresponding negative local voltage jump difference. The quality of the potentiometer is evaluated based on the differences in local voltage jumps between paired points in the waveform alignment sequence, the index interval of the paired points, and the frequency of the mapping relationship being reversed in the waveform alignment sequence.

2. The automatic testing method for potentiometer resistance value as described in claim 1, characterized in that, The calculation of the coordinate misalignment tolerance based on the potentiometer's tolerance arc length and the transmission shaft's effective radius includes: The potentiometer's tolerance arc length is obtained by summing the deformation tolerance arc length of the potentiometer's cantilever beam and the mechanical backlash tolerance arc length of the machine tool's transmission gear. The deformation tolerance arc length characterizes the maximum offset arc length of the potentiometer's brush cantilever beam relative to the theoretical position of the drive shaft within the elastic deformation range. The mechanical backlash tolerance arc length characterizes the maximum arc length corresponding to the idling redundancy of the drive shaft when the machine tool's transmission gear switches from forward to reverse rotation. Calculate the total clearance radian based on the ratio of the potentiometer's tolerance arc length to the effective radius of the transmission shaft, and convert the total clearance radian into the corresponding mechanical angle; Obtain the single-step angular resolution during the potentiometer sweep process; where the single-step angular resolution characterizes the minimum angular displacement of the encoder of the machine tool under a single sampling pulse; The coordinate misalignment tolerance is obtained by comparing the mechanical angle corresponding to the total gap radian with the single-step angular resolution; the coordinate misalignment tolerance characterizes the maximum number of misalignments allowed between the forward and reverse voltage sequences.

3. The automatic testing method for potentiometer resistance value as described in claim 2, characterized in that, The control potentiometer performs forward and reverse sweep operations to acquire voltage sequences, including: The control potentiometer performs a forward sweep operation, records the forward time-domain voltage corresponding to the time index, and obtains the forward voltage sequence; When the forward sweep reaches its end, the control potentiometer performs a reverse sweep, recording the inverse time-domain voltage corresponding to the time index, thus obtaining the inverse voltage sequence.

4. The automatic testing method for potentiometer resistance value as described in claim 1, characterized in that, The first-order difference calculation is performed on each voltage sequence to obtain the corresponding voltage jump difference sequence. Based on the abrupt change center index, multiple local voltage jump differences of a preset length are extracted from each voltage jump difference sequence, including: Perform a first-order difference operation on the forward voltage sequence to obtain the corresponding forward voltage jump difference sequence, and perform a first-order difference operation on the reverse voltage sequence to obtain the corresponding reverse voltage jump difference sequence; wherein, the voltage jump difference sequence includes the forward voltage jump difference sequence and the reverse voltage jump difference sequence, and each element in the voltage jump difference sequence represents the voltage change between two adjacent sampling points; The location of the data point in the forward voltage jump difference sequence that exceeds the preset contact impedance tolerance limit is determined as the forward mutation center index, and the location of the data point in the reverse voltage jump difference sequence that exceeds the preset contact impedance tolerance limit is determined as the reverse mutation center index; the mutation center index includes the forward mutation center index and the reverse mutation center index; Based on the positive mutation center index, a fixed number of sampling points are extended along the left and right sides of the axis to extract multiple positive local voltage jump difference values ​​of a preset length from the positive voltage jump difference value sequence, and a positive local spatial index is assigned to the positive local voltage jump difference value. Based on the reverse mutation center index, a fixed number of sampling points are extended along the left and right sides of the axis to extract multiple reverse local voltage jump differences of a preset length from the reverse voltage jump difference sequence, and a reverse local spatial index is assigned to the reverse local voltage jump difference.

5. The automatic testing method for potentiometer resistance value as described in claim 4, characterized in that, The construction of the two-dimensional deviation cost matrix involves determining the values ​​to be filled into the corresponding positions of the two-dimensional deviation cost matrix based on the comparison results between the index interval of the paired points and the tolerance of the number of coordinate misalignment points. This includes: Construct a blank two-dimensional matrix; wherein the number of rows of the blank two-dimensional matrix is ​​equal to the number of multiple positive local voltage jump differences, the number of columns is equal to the number of multiple negative local voltage jump differences, and the number of multiple positive local voltage jump differences is equal to the number of multiple negative local voltage jump differences; Use the forward local space index as the outer loop variable and the reverse local space index as the inner loop variable to traverse all paired points; In each traversal, the absolute difference between the current positive local voltage jump difference and the corresponding negative local voltage jump difference is calculated to obtain the current local voltage jump deviation value, and the absolute value of the index interval between the current positive local space index and the corresponding negative local space index is calculated to obtain the current index interval of the pairing point. Compare the index interval of the current pairing point with the tolerance of the number of coordinate misalignment points. If the index interval of the current pairing point is not greater than the tolerance of the number of coordinate misalignment points, then fill the current local voltage jump deviation value as the matrix element value into the current traversal position. If the index interval of the current pairing point is greater than the tolerance for the number of coordinate misalignment points, then the preset blocking penalty value will be used as the matrix element value and filled into the current traversal position. After the traversal is complete, a two-dimensional matrix of the fully assigned deviation costs is obtained.

6. The automatic testing method for potentiometer resistance value as described in claim 5, characterized in that, Solving the two-dimensional matrix of deviation cost yields the waveform alignment sequence, including: The two-dimensional matrix of deviation cost is input into the allocation algorithm unit. The allocation algorithm unit establishes a one-to-one mapping relationship between the positive local voltage jump difference and the negative local voltage jump difference. The discrete mapping relationship set that minimizes the sum of the matrix element values ​​corresponding to all mapping relationships is solved to obtain the waveform alignment sequence.

7. The automatic method for testing the resistance value of a potentiometer as described in claim 1, characterized in that, The potentiometer quality assessment is performed based on the differences in local voltage jumps between paired points in the waveform alignment sequence, the index interval of the paired points, and the frequency of inversion of the mapping relationship in the waveform alignment sequence, including: The absolute differences between the local voltage jump differences at each pairing point in the waveform alignment sequence are summed to obtain the total local impedance deviation; the total local impedance deviation characterizes the degree of residual amplitude difference between the forward and reverse voltage sequences. Calculate the index interval of each pairing point in the waveform alignment sequence, and determine the uniform coordinate translation gap based on the maximum index interval and the single-step angular resolution during the potentiometer sweep process; the uniform coordinate translation gap characterizes the overall lateral drift between the forward and reverse voltage sequences. The frequency of the mapping relationship being reversed in the waveform alignment sequence is used to obtain the coordinate mapping cross-reverse sequence statistical value; the coordinate mapping cross-reverse sequence statistical value characterizes the degree of local phase jitter between the forward voltage sequence and the reverse voltage sequence; The quality of the potentiometer is evaluated based on the sum of local impedance deviations, the uniform coordinate translation gap, and the statistical values ​​of the cross-reverse coordinate mapping.

8. The automatic testing method for potentiometer resistance value as described in claim 7, characterized in that, The quality assessment of the potentiometer based on the sum of local impedance deviations, the uniform coordinate translation gap, and the statistical value of the coordinate mapping cross-reverse order includes: The sum of local impedance deviations is compared with a preset local impedance deviation threshold to obtain the first comparison result; The uniform coordinate translation gap is compared with the preset machine tool limit translation gap threshold to obtain the second comparison result; The cross-reverse statistical values ​​of the coordinate mapping are compared with the preset values ​​to obtain the third comparison result; The potentiometer is evaluated based on the first, second, and third comparison results.

9. An automatic potentiometer resistance value testing device, characterized in that, The device includes: The acquisition module is used to calculate the coordinate misalignment tolerance based on the potentiometer's tolerance arc length and the effective radius of the drive shaft, and to control the potentiometer to perform forward and reverse sweeping actions to acquire voltage sequences; the voltage sequences include forward voltage sequences and reverse voltage sequences; The calculation module is used to perform first-order difference calculation on each voltage sequence to obtain the corresponding voltage jump difference value sequence. Based on the mutation center index, multiple local voltage jump difference values ​​of a preset length are extracted from each voltage jump difference value sequence. The local voltage jump difference values ​​include positive local voltage jump difference values ​​and negative local voltage jump difference values. The module is used to construct a two-dimensional matrix of deviation cost. Based on the comparison between the index interval of the pairing points and the tolerance of the number of coordinate misalignment points, it determines the values ​​to be filled into the corresponding positions of the two-dimensional matrix of deviation cost and solves the two-dimensional matrix of deviation cost to obtain the waveform alignment sequence. The pairing points indicate the positive local voltage jump difference and the corresponding negative local voltage jump difference. The evaluation module is used to evaluate the quality of the potentiometer based on the differences in local voltage jumps between each pairing point in the waveform alignment sequence, the index interval of the pairing points, and the frequency of the mapping relationship being reversed in the waveform alignment sequence.

10. An automatic potentiometer resistance value testing system, characterized in that, The system includes a potentiometer and a control module, the potentiometer and the control module being electrically connected, and the control module being used to perform a quality assessment of the potentiometer according to any one of claims 1-8.

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