Method for measuring output characteristics of engine electronic speed control on line

Abstract

The application discloses an output characteristic on-line measurement method of an engine electronic speed regulator, and belongs to the technical field of engine electronic speed regulator testing. The method comprises the following steps: injecting a group of excitation pulse signals with different duty cycles into the electronic speed regulator, and obtaining a driving current waveform; performing segmented analysis on the driving current waveform, and extracting a linear region response segment, a saturation region response segment and a transition region response segment; determining a linear driving gain based on the linear region response segment, determining a maximum output limiting value based on the saturation region response segment, and determining a response lag time based on the transition region response segment; generating an output characteristic envelope curve according to the linear driving gain and the maximum output limiting value, and taking the response lag time as a dynamic compensation parameter. The method can synchronously obtain the full-condition output characteristic parameters of the speed regulator on line, and form an envelope curve after dynamic compensation, thereby improving the measurement efficiency and the accuracy of the output characteristic description.

Description

Technical Field

[0001] This invention relates to the field of engine electronic speed governor testing technology, specifically to an online measurement method for the output characteristics of an engine electronic speed governor. Background Technology

[0002] The engine electronic speed controller receives speed commands in pulse-width modulation (PWM) form and converts them into current signals to drive the actuators. Its output characteristics determine the response quality of engine speed regulation. When establishing a control model for the speed controller or performing online fault diagnosis, it is necessary to obtain its linear drive gain, maximum output limit, and hysteresis time from command change to current response under different duty cycle commands.

[0003] Existing methods for measuring the output characteristics of electronic speed controllers typically follow a static calibration approach. This involves sequentially applying multiple DC levels or slowly varying signals with fixed duty cycles under offline conditions. Once the output current reaches a steady state, the corresponding amplitudes are recorded, and the input-output relationship curve is fitted using the steady-state data points. This measurement process only covers the static behavior of the controller in the linear and saturation regions, failing to reflect the dynamic process of the current transitioning from linear change to saturation, and also unable to obtain online information about the response hysteresis carried in the transition region. Measurements of hysteresis time often rely on independent step response tests, applying a step signal separately and calculating the time difference for the output current to reach a predetermined threshold. The resulting hysteresis parameters and static output characteristics belong to different test conditions, lacking a unified correspondence between them, making it difficult to integrate them into a complete output characteristic that simultaneously characterizes static limiting and dynamic delay.

[0004] While some online measurement schemes acquire the current time-domain waveform under continuous excitation, they treat the waveform as a whole for transfer function or nonlinear fitting, failing to distinguish and utilize the linear response segment, saturation response segment, and transient response segment contained within the waveform. This results in inaccurate extraction of linear gain and maximum amplitude limit values ​​under transient interference, and the response lag time cannot be directly correlated with the specific transition zone boundary. Consequently, it is difficult to generate dynamic compensation output characteristics that reflect both the envelope relationship from duty cycle to current and the delay differences at different frequencies. Due to this limitation, the output behavior of the speed controller under actual dynamic conditions of varying duty cycle and frequency cannot be accurately described online, affecting the real-time accuracy of feedforward compensation and speed regulation performance. Summary of the Invention

[0005] A method for online measurement of the output characteristics of an engine electronic speed controller is provided. This method can simultaneously extract the linear drive gain, maximum output limit value, and response lag time of the speed controller in a single online test and form an output characteristic envelope curve that includes dynamic compensation.

[0006] To achieve the above objectives, the present invention provides the following technical solution: The present invention provides an online measurement method for the output characteristics of an engine electronic speed controller. By directly injecting a set of excitation pulse signals with different duty cycles into the electronic speed controller and acquiring the drive current waveform, the output characteristics of the controller can be obtained online without removing the controller from the engine system. The method includes the following steps:

[0007] A set of excitation pulse signals with different duty cycles are injected into the electronic speed controller, and the drive current waveform of the electronic speed controller under the action of the excitation pulse signals is obtained.

[0008] The drive current waveform is segmented and analyzed to extract the linear region response segment, saturation region response segment, and transition region response segment.

[0009] The linear drive gain of the electronic speed controller is determined based on the linear response segment, the maximum output limit value of the electronic speed controller is determined based on the saturation response segment, and the response lag time of the electronic speed controller is determined based on the transition response segment.

[0010] The output characteristic envelope curve of the electronic speed controller is generated based on the linear drive gain and the maximum output limit value, and the response lag time is used as the dynamic compensation parameter of the output characteristic envelope curve.

[0011] Through the above steps, it is possible to accurately quantify the controller's key output characteristics, such as linear drive capability, maximum output limit, and dynamic response lag, under the condition that the engine is running continuously and the electronic speed controller is in a drive-by-wire state. The generated output characteristic envelope curve and dynamic compensation parameters can be directly used for online correction of the engine control strategy, effectively improving the accuracy and dynamic tracking performance of the engine speed closed-loop control.

[0012] As a technical solution of the present invention, when performing segmented analysis on the drive current waveform, a first-order difference operation is performed on the drive current waveform to obtain the current change rate sequence of the drive current waveform; the first stable current segment that is continuously below a preset change rate threshold is identified from the current change rate sequence, and this stable current segment is marked as the linear region response segment; the current flat-top segment that is continuously near zero at the end is identified from the current change rate sequence, and this flat-top segment is marked as the saturation region response segment; the waveform segment between the end of the linear region response segment and the beginning of the saturation region response segment is marked as the transition region response segment. This solution uses the current change rate to automatically segment the waveform, which can reliably distinguish the linear operating region, the saturation limiting region, and the transition process between the two of the controller response, avoiding subjective errors caused by manually setting the segmentation point.

[0013] As a technical solution of the present invention, the method for determining the linear drive gain based on the linear response segment is as follows: The current amplitude and corresponding excitation pulse duty cycle values ​​at multiple sampling points within the linear response segment are obtained; a first-order linear fit is performed on the current amplitude and the excitation pulse duty cycle values ​​to obtain the fitted straight line of the linear response segment; and the slope of the fitted straight line is calculated as the linear drive gain. Obtaining the gain value through multi-point linear fitting can effectively suppress the influence of measurement noise on the gain calculation, making the gain result more stable.

[0014] As a technical solution of the present invention, the method for determining the maximum output limit value based on the saturation response segment is as follows: The mean value of all current amplitude points within the saturation response segment is calculated to obtain the average current amplitude of the saturation response segment; the fluctuation amplitude of each current amplitude point within the saturation response segment relative to the average current amplitude is statistically analyzed; when the fluctuation amplitude is lower than a preset fluctuation threshold, the average current amplitude is used as the maximum output limit value. The limit value can only be confirmed when the fluctuation amplitude meets the threshold requirement, which can prevent misjudgments caused by detecting non-true saturation or abnormal current fluctuations, ensuring the reliability of the limit value extraction.

[0015] As a technical solution of the present invention, the method for determining the response lag time based on the transition region response segment is as follows: Within the linear region response segment, the time point with the largest current change rate is selected as the linear response peak point; within the transition region response segment, the time point where the current value begins to deviate from the linear region trend is selected as the nonlinear initiation point; the time difference between the linear response peak point and the nonlinear initiation point is calculated, and this time difference is taken as the response lag time. Using the time interval between the current change rate peak point and the nonlinear separation point to characterize the lag time allows for direct extraction of the controller's response delay to the excitation signal from the physical change law of the waveform, and the measurement results have clear physical meaning.

[0016] As a technical solution of the present invention, the method for generating the output characteristic envelope curve is as follows: A two-dimensional coordinate plane is established with the duty cycle of the excitation pulse signal as the abscissa and the current amplitude in the drive current waveform as the ordinate; the linear response segment is mapped to the two-dimensional coordinate plane to generate a linear straight line segment originating from the origin and having a slope equal to the linear drive gain; the saturation response segment is mapped to the two-dimensional coordinate plane to generate a horizontal straight line segment located at the maximum output limit value; the linear straight line segment and the horizontal straight line segment are connected through the curve segment corresponding to the transition response segment to form the output characteristic envelope curve. The envelope curve obtained in this way can intuitively and continuously describe the output behavior of the electronic speed controller across the entire operating range from linear adjustment to saturation limit, providing a clear basis for engine control parameter tuning.

[0017] Preferably, the set of excitation pulse signals with different duty cycles is constructed as follows: Multiple consecutive pulse width modulation (PWM) signals are generated by incrementing the duty cycle from the minimum to the maximum in preset steps; the frequency of each PWM signal is fixed at the rated operating frequency of the electronic speed controller; the multiple consecutive PWM signals are sequentially ordered according to their duty cycle values ​​to form an excitation pulse sequence. This sequence covers the complete excitation range from small to large duty cycles, ensuring that the drive current waveform can traverse the entire output range of the controller and avoid missing nonlinear inflection points.

[0018] Furthermore, when acquiring the drive current waveform, the output current data of the electronic speed controller is synchronously acquired during each pulse width modulation signal injection period of the excitation pulse sequence; a sliding window averaging filter is performed on the current data within each injection period to obtain the average current value corresponding to each injection period; the average current values ​​corresponding to multiple injection periods are spliced ​​together in chronological order to form a continuous drive current waveform. By acquiring and filtering the waveform sequentially by duty cycle, high-frequency interference is effectively removed while ensuring the integrity of the signal response, thus improving the quality of the current waveform.

[0019] As a technical solution of the present invention, the specific method of using the response lag time as a dynamic compensation parameter for the output characteristic envelope curve includes: recording multiple response lag times measured by the electronic speed controller under excitation pulse signals of different frequencies into a lag time table; adding a delay offset obtained by looking up the lag time table to each frequency point on the horizontal axis of the output characteristic envelope curve; and marking the output characteristic envelope curve with the added delay offset as the dynamically compensated output characteristic envelope curve. This dynamic compensation enables the envelope curve to automatically adapt to the response timing differences of the controller under different frequency excitations, which can significantly improve the phase consistency of the engine speed control system across the entire speed range.

[0020] Preferably, when constructing the lag time table, a two-dimensional array is generated using the frequency of the excitation pulse signal as the index and the corresponding response lag time as the value. Linear interpolation is then performed on the response lag times of adjacent frequency points in the two-dimensional array to fill in the blank items corresponding to the frequency intervals, resulting in a continuous lag time table. Linear interpolation ensures a smooth transition of the lag compensation amount when the frequency changes continuously, avoiding discontinuous fluctuations in the control amount caused by frequency jumps.

[0021] The technical effects and advantages provided by the present invention in the above technical solution are as follows:

[0022] The drive current waveform is segmented and analyzed. A first-order difference operation is used to obtain the current rate of change sequence. Based on this, a stable current segment with a consistently low rate of change is identified as the linear response segment, a flat-top segment with a near-zero rate of change at the end is identified as the saturation response segment, and the waveform segment between the two is identified as the transition response segment. Within the linear response segment, a first-order linear fit is performed on the current amplitude at multiple sampling points and the corresponding excitation pulse duty cycle. The slope of the fitted line is used as the linear drive gain. Within the saturation response segment, the mean of all current amplitude points is calculated, and the fluctuation amplitude relative to the mean is statistically analyzed. When the fluctuation amplitude is lower than a preset fluctuation threshold, this mean is used as the maximum output limit. In the transition response segment, the time point with the largest current rate of change in the linear region is selected as the linear response peak point, and the time point when the current value begins to deviate from the linear trend in the transition region is selected as the nonlinear start point. The time difference between these two points is determined as the response hysteresis time. Based on the linear drive gain, a linear segment is generated in the duty cycle-current amplitude coordinate plane starting from the origin. A horizontal segment is generated at the maximum output limit value. The linear and horizontal segments are then connected by the curve segment corresponding to the transition region response segment, forming a complete output characteristic envelope curve. This process requires only a single continuous injection of excitation pulse signals with different duty cycles to simultaneously extract all characteristic parameters of the linear, saturation, and transition regions from the drive current waveform, directly generating a nonlinear envelope curve covering the static gain and limit. Compared to performing steady-state measurements point by point followed by separate step hysteresis tests, this method avoids parameter time mismatch caused by separate test conditions. The resulting envelope curve continuously reflects the complete transition of the controller output current from linear growth to saturation, resulting in better consistency and online applicability of the output characteristic parameters.

[0023] Multiple response lag times were measured under excitation pulse signals of different frequencies. A two-dimensional array was generated using the frequency of the excitation pulse signal as the index and the response lag time as the value. Linear interpolation was performed on the lag times of adjacent frequency points to obtain a continuous lag time table. On the horizontal axis of the output characteristic envelope curve, a delay offset obtained from the lag time table was added to each frequency point. The envelope curve with the added delay offset was used as the dynamically compensated output characteristic envelope curve. Thus, the envelope curve, which originally only reflected the static input-output mapping relationship, was endowed with frequency-related lag information, enabling real-time correction of the output current corresponding to the same duty cycle at different excitation frequencies. This dynamic compensation parameter is directly embedded in the envelope curve, eliminating the need for separate lag processing outside the controller model. This provides a more realistic description of the output characteristics of the speed control system under variable speed and load conditions, which is beneficial for improving the real-time matching accuracy of feedforward compensation. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0025] Figure 1 This is a flowchart of the online measurement method for the output characteristics of an engine electronic speed controller;

[0026] Figure 2 This is a flowchart of the method for determining linear drive gain;

[0027] Figure 3 It is a segmented waveform of the drive current and a linear fitting diagram. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] See Figure 1 This invention provides an online measurement method for the output characteristics of an engine electronic speed controller, comprising the following steps:

[0030] A set of excitation pulse signals with different duty cycles are injected into the electronic speed controller, and the drive current waveform of the electronic speed controller under the action of the excitation pulse signals is obtained.

[0031] Perform segmented analysis on the drive current waveform to extract the linear region response segment, saturation region response segment, and transition region response segment from the drive current waveform;

[0032] The linear drive gain of the electronic speed controller is determined based on the linear response segment, the maximum output limit value of the electronic speed controller is determined based on the saturation response segment, and the response lag time of the electronic speed controller is determined based on the transition response segment.

[0033] The output characteristic envelope curve of the electronic speed controller is generated based on the linear drive gain and the maximum output limit value, and the response lag time is used as the dynamic compensation parameter of the output characteristic envelope curve.

[0034] Example 1

[0035] In practice, a set of excitation pulse signals with different duty cycles is injected into the electronic speed controller. These excitation pulse signals are generated by increasing the duty cycle from minimum to maximum in a preset step increment, generating multiple continuous pulse width modulation signals. The minimum duty cycle, maximum duty cycle, and step increment are preset according to the specifications of the electronic speed controller.

[0036] In some implementations, the minimum duty cycle is set to 0%, the maximum duty cycle is set to 100%, and the step increment is set to 1%. In this case, 101 consecutive pulse width modulation signals are generated. The duty cycle of the first pulse width modulation signal is 0%, the duty cycle of the second pulse width modulation signal is 1%, and so on, until the duty cycle of the 101st pulse width modulation signal is 100%.

[0037] The frequency of each pulse width modulation signal is fixed at the rated operating frequency of the electronic speed controller. The rated operating frequency of the electronic speed controller can be obtained from the controller's technical manual or by reading parameters stored within the controller itself.

[0038] Multiple consecutive pulse width modulation (PWM) signals are sequentially ordered according to their duty cycle values ​​to form an excitation pulse sequence. In the excitation pulse sequence, the difference in the duty cycle between two adjacent PWM signals is equal to the step increment.

[0039] The method for obtaining the drive current waveform of the electronic speed controller under the action of the excitation pulse signal is as follows: during each pulse width modulation signal injection period of the excitation pulse sequence, the output current data of the electronic speed controller is collected synchronously.

[0040] In practical implementation, the pulse width modulation (PWM) signal injection period refers to the time interval during which a single PWM signal continuously acts on the electronic speed controller. The duration of each PWM signal injection period is equal and longer than the time required for the electronic speed controller output response to reach steady state.

[0041] When synchronously acquiring the output current data of the electronic speed controller, the sampling frequency is greater than 10 times the frequency of the pulse width modulation signal.

[0042] A sliding window average filter is applied to the current data for each injection period to obtain the average current value for each injection period.

[0043] In some implementations, the formula for calculating the sliding window average filter is:

[0044] ;

[0045] in, Indicates the first The average current value of the sliding window corresponding to each sampling point. This represents the width of the sliding window. The value of is the integer part of the quotient obtained by dividing the sampling frequency by the pulse width modulation signal frequency. Indicates the first The original current values ​​collected at each sampling point The range of values ​​is to , The range of values ​​is The total number of sampling points during the injection period.

[0046] Slide window width The value of is based on the fact that when the width of the sliding window is equal to the ratio of the sampling frequency to the frequency of the pulse width modulation signal, the sliding window just covers all the sampling points within a complete pulse width modulation signal cycle, thereby effectively filtering out the current ripple introduced by the periodic switching action of the pulse width modulation signal.

[0047] For each injection period, the average current value of the sliding window corresponding to the end of the injection period is taken as the average current value of the injection period.

[0048] The average current values ​​corresponding to multiple injection periods are stitched together in chronological order to form a continuous drive current waveform. The chronological order refers to the injection sequence of each pulse width modulation signal in the excitation pulse sequence. The drive current waveform is plotted with time on the horizontal axis and the average current value on the vertical axis.

[0049] Example 2

[0050] In practice, the process of performing segmented analysis on the drive current waveform starts with performing a first-order difference operation on the drive current waveform to obtain the current change rate sequence of the drive current waveform.

[0051] When performing a first-order differential operation on the drive current waveform, the difference between the average current value corresponding to each sampling point and the average current value corresponding to the previous sampling point is divided by the time interval between two adjacent sampling points to obtain the current change rate corresponding to each sampling point. The current change rates corresponding to all sampling points are arranged in order of sampling time to form a current change rate sequence.

[0052] In some implementations, the first in the current change rate sequence The formula for calculating the rate of change of current corresponding to each sampling point is:

[0053] ;

[0054] in, Represents the first in the current change rate sequence The rate of change of current corresponding to each sampling point The value of is an integer greater than or equal to 2. Indicating the first [waveform] in the drive current waveform The average current value corresponding to each sampling point Indicating the first [waveform] in the drive current waveform The average current value corresponding to each sampling point This represents the time interval between two adjacent sampling points. The value is the reciprocal of the sampling frequency.

[0055] Identify the first stable current segment in the current change rate sequence that is consistently below a preset change rate threshold, and mark the stable current segment as the linear response segment.

[0056] In practice, the preset rate of change threshold is calculated by dividing 1% of the rated output current of the electronic speed controller by the rated response time. The rated output current and rated response time of the electronic speed controller are obtained from its technical manual.

[0057] In the current rate of change sequence, starting from the first sampling point and traversing backwards, segments where the current rate of change corresponding to multiple consecutive sampling points is less than or equal to a preset rate of change threshold, and the number of such consecutive sampling points is greater than or equal to a preset stable sampling point threshold, are identified as current stable segments. The preset stable sampling point threshold is set based on 10% of the total number of sampling points during the injection period of a single pulse width modulation signal in the excitation pulse sequence.

[0058] The first current-stable segment that meets the conditions is marked as the linear response segment.

[0059] Identify the current plateau segment that is continuously near zero at the end of the current change rate sequence and mark the current plateau segment as the saturation response segment.

[0060] The range near zero is defined by a preset zero threshold, which is calculated by dividing 0.5% of the rated output current of the electronic speed controller by the rated response time.

[0061] In the current rate of change sequence, starting from the last sampling point and traversing backwards, segments where the absolute value of the current rate of change corresponding to multiple consecutive sampling points is less than or equal to a preset zero threshold and the number of such consecutive sampling points is greater than or equal to a preset flat-top sampling point number threshold are identified as current flat-top segments. The preset flat-top sampling point number threshold is set according to 15% of the total number of sampling points during the injection period of a single pulse width modulation signal in the excitation pulse sequence.

[0062] The identified flat-top current segment is marked as the saturation response segment.

[0063] The waveform segment between the end of the linear response segment and the beginning of the saturation response segment is marked as the transition response segment.

[0064] The end point of the linear response segment refers to the sampling point with the longest sampling time within the linear response segment. The start point of the saturation response segment refers to the sampling point with the shortest sampling time within the saturation response segment. In the drive current waveform, all sampling points whose sampling time is greater than the sampling time corresponding to the end point of the linear response segment and less than the sampling time corresponding to the start point of the saturation response segment are selected to form the transition response segment.

[0065] Example 3

[0066] In specific implementation, please refer to Figure 2 The process of determining the linear drive gain of the electronic speed controller based on the linear response segment begins with obtaining the current amplitude and corresponding excitation pulse duty cycle values ​​at multiple sampling points within the linear response segment.

[0067] The linear response segment contains multiple sampling points, each corresponding to a sampling time and a current amplitude. The duty cycle value of the excitation pulse corresponding to each sampling point is determined according to the pulse width modulation signal injection period to which the sampling point belongs. Specifically, the duty cycle value of the pulse width modulation signal injected during the pulse width modulation signal injection period is obtained from the excitation pulse sequence and used as the excitation pulse duty cycle value corresponding to the sampling point.

[0068] In some implementations, all sampling points within the linear response segment are selected for subsequent calculations.

[0069] A first-order linear fit is performed on the current amplitude and the duty cycle of the excitation pulse to obtain the fitted straight line of the linear response segment.

[0070] First-order linear fitting employs the least squares method. When performing first-order linear fitting, the current amplitude corresponding to each sampling point within the linear response segment is used as the dependent variable, and the duty cycle value of the excitation pulse corresponding to each sampling point is used as the independent variable. The linear equation parameters that minimize the sum of squared residuals are then solved.

[0071] In some implementations, the expression for the fitted straight line of the linear response segment is:

[0072] ;

[0073] in, Indicates the first segment of the linear response region The fitted current amplitude corresponding to each sampling point The value ranges from 1 to integers, This represents the total number of sampling points within the linear response region. This represents the slope of the fitted line. Indicates the first segment of the linear response region The duty cycle value of the excitation pulse corresponding to each sampling point This represents the intercept of the fitted line.

[0074] slope and intercept The solution is obtained using the least squares method, specifically by finding the solution that makes the sum of squared residuals equal. When taking the minimum value and Value, of which Indicates the first segment of the linear response region The actual current amplitude corresponding to each sampling point.

[0075] The slope of the fitted straight line is calculated as the linear drive gain of the electronic speed controller. In specific implementations, the slope obtained by the least squares method is used. The numerical value is assigned to the linear drive gain. The physical dimension of the linear drive gain is current units divided by duty cycle units, representing the change in the output current amplitude of the electronic speed controller caused by each unit change in the duty cycle value of the excitation pulse.

[0076] See Figure 3 In the figure, the horizontal axis represents the excitation pulse duty cycle, ranging from 0% to 100%; the vertical axis represents the drive current amplitude, in amperes (A), ranging from 0 to 12A. The figure shows the response characteristic curve of the electronic speed controller's output drive current relative to the excitation pulse duty cycle. The data points are classified and labeled according to the method described in Example 3, combined with the segmented analysis results of the drive current waveform.

[0077] In the figure, the dots represent sampling points in the linear response segment, showing a linear growth trend of the drive current amplitude with the duty cycle of the excitation pulse. The fitted line closely matches these sampling points, indicating that the linear drive gain obtained through least-squares fitting accurately reflects the output characteristics of this segment. The linear segment begins at approximately 0% duty cycle and 0A current amplitude, and ends at approximately 80% duty cycle and 10A current amplitude, clearly defining the linear gain range of the electronic speed controller.

[0078] The triangular points represent sampling points in the transition response segment, located in the range of approximately 80% to 90% duty cycle. Within this range, the current amplitude tends to saturate but has not yet reached complete stability. The curve exhibits nonlinear transition characteristics, reflecting the change in the controller's response from linear drive to saturated output.

[0079] The square points represent sampling points in the saturation response segment, located within a duty cycle of approximately 90% to 100%. The current amplitude remains at a high level close to 10A, reflecting the maximum output limiting characteristic. The current amplitude fluctuation in this segment is relatively small, meeting the criteria for determining the maximum output limiting value and fluctuation amplitude in Example 4.

[0080] Example 4

[0081] In practice, the process of determining the maximum output limit of the electronic speed controller based on the saturation response segment begins with calculating the average value of all current amplitude points within the saturation response segment.

[0082] The saturation response segment contains multiple sampling points, each corresponding to a current amplitude. When performing the mean calculation, the current amplitudes of all sampling points within the saturation response segment are accumulated, and then the accumulated result is divided by the total number of sampling points within the saturation response segment to obtain the average current amplitude of the saturation response segment.

[0083] In some implementations, the formula for calculating the average current amplitude in the saturation response segment is:

[0084] ;

[0085] in, This represents the average current amplitude in the saturation response region. This represents the total number of sampling points within the saturation response range. The value ranges from 1 to integers, Indicates the first response segment within the saturation region The current amplitude corresponding to each sampling point.

[0086] The fluctuation range of each current amplitude point relative to the average current amplitude within the saturation response range is statistically analyzed. For each sampling point within the saturation response range, the absolute value of the difference between the current amplitude corresponding to the sampling point and the average current amplitude is taken as the fluctuation range corresponding to that sampling point.

[0087] In practice, all sampling points within the saturated response segment are traversed, and the fluctuation amplitude corresponding to each sampling point is calculated to obtain a set of fluctuation amplitudes that correspond one-to-one with the sampling points within the saturated response segment.

[0088] When the fluctuation amplitude is lower than the preset fluctuation threshold, the average current amplitude is used as the maximum output limit. The preset fluctuation threshold is set based on 2% of the rated output current of the electronic speed controller. The rated output current of the electronic speed controller can be obtained from the electronic speed controller's technical manual.

[0089] Each fluctuation amplitude in the fluctuation amplitude set is compared with a preset fluctuation threshold. It is determined whether all fluctuation amplitudes are below the preset fluctuation threshold. If so, the average current amplitude of the saturation response segment is assigned to the maximum output limit. If any fluctuation amplitude in the fluctuation amplitude set is greater than or equal to the preset fluctuation threshold, it is determined that the current waveform within the saturation response segment has not reached a sufficiently stable state. In this case, the average current amplitude is not used as the maximum output limit, and a warning message is issued.

[0090] The process of determining the response lag time of an electronic speed controller based on the transition region response segment begins by selecting the time point with the largest current change rate within the linear region response segment as the peak point of the linear response.

[0091] In practical implementation, each sampling point within the linear response region corresponds to a current change rate. The current change rates corresponding to all sampling points within the linear response region are iterated through, and the current change rate with the largest value is identified. The sampling time of the sampling point corresponding to this largest current change rate is taken as the peak point of the linear response.

[0092] Within the transition response zone, the point at which the current value begins to deviate from the linear trend is selected as the nonlinear initiation point. The method for determining when the current value begins to deviate from the linear trend is as follows: using the fitted straight line of the linear response zone, the deviation between the fitted current amplitude and the actual collected current amplitude at each sampling point within the transition response zone is calculated, and the sampling time of the sampling point where the deviation first exceeds the preset deviation threshold is taken as the nonlinear initiation point.

[0093] The preset deviation threshold is set at 3% of the rated output current of the electronic speed controller.

[0094] In some implementations, starting with the sampling point with the shortest sampling time within the transition response segment, each sampling point is processed sequentially in the direction of increasing sampling time. For the first sampling point within the transition response segment... The sampling point is used to calculate the th sampling point within the transition region response segment based on the fitted linear equation of the linear region response segment. The fitted current amplitude corresponding to the sampling point is compared with the fitted current amplitude within the transition region response segment. Subtract the actual current amplitude corresponding to the sampling point and take the absolute value to obtain the first sampling point within the transition zone response segment. The deviation value corresponding to the sampling point. The first sampling point within the transition zone response segment. The deviation value corresponding to the sampling point is compared with the preset deviation threshold. When the first sampling point in the transition zone response segment... When the deviation value corresponding to the sampling point first exceeds the preset deviation threshold, the response segment of the transition zone will be... The sampling time of each sampling point is used as the nonlinear start point, and the traversal stops. If no sampling point with a deviation value greater than the preset deviation threshold is found after traversing all sampling points in the transition zone response segment, the sampling time of the sampling point with the longest sampling time in the transition zone response segment is used as the nonlinear start point.

[0095] The time difference between the peak point of the linear response and the nonlinear start-up point is calculated and used as the response lag time. The response lag time is calculated by subtracting the sampling time corresponding to the peak point of the linear response from the sampling time corresponding to the nonlinear start-up point; the difference is the response lag time. The physical dimension of the response lag time is time units, representing the length of time elapsed from the moment the electronic speed controller reaches its maximum response speed in the linear region to the moment the output current begins to leave the linear region and enter the transition region.

[0096] Example 5

[0097] In practice, the process of generating the output characteristic envelope curve of the electronic speed controller based on the linear drive gain and the maximum output limit value begins with establishing a two-dimensional coordinate plane.

[0098] A two-dimensional coordinate plane is established with the duty cycle of the excitation pulse signal as the abscissa and the current amplitude in the driving current waveform as the ordinate. The physical dimension of the abscissa is percentage, ranging from 0% to 100%. The physical dimension of the ordinate is current unit, ranging from zero to 1.2 times the maximum output limit value.

[0099] The linear response segment is mapped to a two-dimensional coordinate plane, generating a linear straight line originating from the origin with a slope equal to the linear drive gain. In specific implementations, the starting point of the linear straight line is the origin of the two-dimensional coordinate plane, with coordinates (0,0). The equation of the linear straight line is determined by the linear drive gain. In the two-dimensional coordinate plane, the ordinate of any point on the linear straight line is equal to the product of its abscissa and the linear drive gain. The abscissa of the endpoint of the linear straight line is determined based on the boundary between the linear response segment and the transition response segment. Specifically, the duty cycle value of the excitation pulse corresponding to the endpoint of the linear response segment is used as the abscissa of the endpoint of the linear straight line, and the product of the abscissa of the endpoint of the linear straight line and the linear drive gain is used as the ordinate of the endpoint of the linear straight line.

[0100] The saturation response segment is mapped to a two-dimensional coordinate plane, generating a horizontal straight line located at the maximum output limit. The ordinate of the horizontal straight line is always equal to the maximum output limit. The starting abscissa of the horizontal straight line is determined based on the boundary between the transition response segment and the saturation response segment; specifically, the duty cycle value of the excitation pulse corresponding to the starting point of the saturation response segment is used as the starting abscissa of the horizontal straight line. The ending abscissa of the horizontal straight line is 100%.

[0101] The linear segment and the horizontal segment are connected by the curve segment corresponding to the transition zone response segment to form the output characteristic envelope curve. The curve segment corresponding to the transition zone response segment is generated in the two-dimensional coordinate plane as follows: the duty cycle value of the excitation pulse corresponding to each sampling point within the transition zone response segment is used as the abscissa value, and the current amplitude corresponding to each sampling point within the transition zone response segment is used as the ordinate value. The coordinates of all sampling points within the transition zone response segment are marked on the two-dimensional coordinate plane. Cubic spline interpolation is used to sequentially connect the endpoint of the linear segment, the coordinates of all sampling points within the transition zone response segment, and the starting point of the horizontal segment, generating a smooth curve, which serves as the curve segment corresponding to the transition zone response segment. The linear segment, the curve segment corresponding to the transition zone response segment, and the horizontal segment are then connected end-to-end to form a continuous curve extending from the origin to 100% of the abscissa value; this continuous curve is the output characteristic envelope curve.

[0102] The method of using response lag time as a dynamic compensation parameter for the output characteristic envelope curve began by recording multiple response lag times measured by the electronic speed controller under excitation pulse signals of different frequencies into a lag time table.

[0103] In practical implementation, when generating the excitation pulse sequence, the frequency of each pulse width modulation signal in each excitation pulse sequence is set to the same value. By changing the frequency value, the steps of injecting a set of excitation pulse signals with different duty cycles into the electronic speed controller, performing segmented analysis on the drive current waveform, and determining the response lag time based on the transition region response segment are repeated to obtain multiple response lag times measured by the electronic speed controller under excitation pulse signals of different frequencies.

[0104] A two-dimensional array is generated, indexed by the frequency of the excitation pulse signal and delimited by the corresponding response lag time. The first dimension of the two-dimensional array stores the frequency values, and the second dimension stores the corresponding response lag time values. Each element in the two-dimensional array contains a correspondence between a frequency value and a response lag time value.

[0105] In some implementations, the frequency value is selected within a range of 50% to 150% of the rated operating frequency of the electronic speed controller. A preset number of frequency points are selected within this frequency range for measurement. The preset number is set according to the actual accuracy requirements; the larger the preset number, the more precise the generated lag time.

[0106] Linear interpolation is performed on the response lag times of adjacent frequency points in a two-dimensional array to fill in the blank terms corresponding to the frequency intervals, resulting in a continuous lag time table. The linear interpolation process is as follows: for any two adjacent frequency points in the two-dimensional array, the frequency point with the smaller frequency value is denoted as... The frequency point with a larger frequency value is , The corresponding response lag time is , The corresponding response lag time is ,exist and any unmeasured frequency point between Corresponding response lag time The calculation formula is:

[0107] ;

[0108] in, Indicates unmeasured frequency points The corresponding response lag time, Indicates the frequency point with a smaller frequency value. The corresponding response lag time, Indicates frequency points with larger frequency values The corresponding response lag time, Indicates that it is located at and The frequency value of any unmeasured frequency point between them. This represents the frequency point with the smaller frequency value among two adjacent frequency points in a two-dimensional array. This represents the frequency point with the larger frequency value among two adjacent frequency points in a two-dimensional array.

[0109] In practice, all frequency points are generated within the frequency range using a preset frequency step value. For each frequency point, it is determined whether the frequency point exists in the first dimension of the two-dimensional array. If it exists, the corresponding response lag time value in the two-dimensional array is directly taken; otherwise, the response lag time value corresponding to the frequency point is calculated using a linear interpolation formula. All frequency points and their corresponding response lag time values ​​are summarized to obtain a continuous lag time table. The continuous lag time table covers all frequency points within the range of 50% to 150% of the rated operating frequency of the electronic speed controller, and the interval between adjacent frequency points is equal to the preset frequency step value.

[0110] On the horizontal axis of the output characteristic envelope curve, a delay offset obtained from a lag time table is added to each frequency point. In specific implementation, based on the frequency value of the current excitation pulse signal, the corresponding response lag time value is looked up in the lag time table, and the found response lag time value is used as the delay offset. The delay offset is added to the horizontal axis of the output characteristic envelope curve by shifting the horizontal coordinate value of each point on the output characteristic envelope curve along the positive direction of the horizontal axis, and the shift amount is equal to the delay offset.

[0111] The output characteristic envelope curve with the added delay offset is labeled as the dynamically compensated output characteristic envelope curve. The x-coordinate of any point on the dynamically compensated output characteristic envelope curve is the sum of the x-coordinate of the corresponding point on the original output characteristic envelope curve and the delay offset, while the y-coordinate remains unchanged.

[0112] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A method for online measurement of the output characteristics of an engine electronic speed controller, characterized in that, Includes the following steps: A set of excitation pulse signals with different duty cycles are injected into the electronic speed controller, and the drive current waveform of the electronic speed controller under the action of the excitation pulse signals is obtained. Perform segmented analysis on the drive current waveform to extract the linear region response segment, saturation region response segment, and transition region response segment from the drive current waveform; The linear drive gain of the electronic speed controller is determined based on the linear response segment, the maximum output limit value of the electronic speed controller is determined based on the saturation response segment, and the response lag time of the electronic speed controller is determined based on the transition response segment. The output characteristic envelope curve of the electronic speed controller is generated based on the linear drive gain and the maximum output limit value, and the response lag time is used as the dynamic compensation parameter of the output characteristic envelope curve.

2. The online measurement method for the output characteristics of an engine electronic speed controller according to claim 1, characterized in that, The step of performing segmented analysis on the drive current waveform includes: Perform a first-order difference operation on the driving current waveform to obtain the current change rate sequence of the driving current waveform; Identify the first stable current segment that is consistently below a preset rate of change threshold from the current change rate sequence, and mark this stable current segment as the linear region response segment; Identify the current flat-top segment whose end is continuously near zero from the current change rate sequence, and mark the current flat-top segment as the saturation region response segment; The waveform segment between the end of the linear response segment and the beginning of the saturation response segment is marked as the transition response segment.

3. The online measurement method for the output characteristics of the engine electronic speed controller according to claim 2, characterized in that, Determining the linear drive gain of the electronic speed controller based on the linear response segment includes: Obtain the current amplitude and corresponding excitation pulse duty cycle values ​​at multiple sampling points within the linear response segment; Perform a first-order linear fit on the current amplitude and the duty cycle of the excitation pulse to obtain the fitted straight line of the response segment in the linear region; The slope of the fitted straight line is calculated as the linear drive gain.

4. The online measurement method for the output characteristics of an engine electronic speed controller according to claim 2, characterized in that, Determining the maximum output limit value of the electronic speed controller based on the saturation response segment includes: The mean value of the current is calculated for all current amplitude points within the saturation response segment to obtain the average current amplitude of the saturation response segment. The fluctuation range of each current amplitude point relative to the average current amplitude within the saturation response segment is statistically analyzed. When the fluctuation amplitude is lower than the preset fluctuation threshold, the average current amplitude is used as the maximum output limit value.

5. The online measurement method for the output characteristics of an engine electronic speed controller according to claim 2, characterized in that, Determining the response lag time of the electronic speed controller based on the transition zone response segment includes: Within the linear response region, the time point with the largest rate of change of current is selected as the peak point of the linear response. Within the transition region response segment, the point at which the current value begins to deviate from the linear region trend is selected as the nonlinear initiation point. Calculate the time difference between the peak point of the linear response and the nonlinear starting point, and use this time difference as the response lag time.

6. The online measurement method for the output characteristics of an engine electronic speed controller according to claim 1, characterized in that, The step of generating the output characteristic envelope curve of the electronic speed controller based on the linear drive gain and the maximum output limit value includes: A two-dimensional coordinate plane is established with the duty cycle of the excitation pulse signal as the horizontal axis and the current amplitude in the driving current waveform as the vertical axis. The linear response segment is mapped onto the two-dimensional coordinate plane to generate a linear straight line segment originating from the origin and having a slope equal to the linear drive gain. The saturation region response segment is mapped onto the two-dimensional coordinate plane to generate a horizontal straight line segment located at the maximum output limit value; The linear segment and the horizontal segment are connected by the curve segment corresponding to the transition zone response segment to form the output characteristic envelope curve.

7. The online measurement method for the output characteristics of an engine electronic speed controller according to claim 1, characterized in that, The set of excitation pulse signals with different duty cycles includes: Multiple consecutive pulse width modulation signals are generated by incrementing the duty cycle from the minimum to the maximum in preset step increments. The frequency of each pulse width modulation signal is fixed at the rated operating frequency of the electronic speed controller; The multiple consecutive pulse width modulation signals are sorted sequentially according to their duty cycle values ​​to form an excitation pulse sequence.

8. The online measurement method for the output characteristics of an engine electronic speed controller according to claim 7, characterized in that, The step of acquiring the drive current waveform of the electronic speed controller under the action of the excitation pulse signal includes: During each pulse width modulation signal injection period of the excitation pulse sequence, the output current data of the electronic speed controller is synchronously acquired; A sliding window average filter is applied to the current data within each injection period to obtain the average current value corresponding to each injection period. The average current values ​​corresponding to the multiple injection periods are spliced ​​together in chronological order to form a continuous drive current waveform.

9. The online measurement method for the output characteristics of an engine electronic speed controller according to claim 1, characterized in that, The step of using the response lag time as a dynamic compensation parameter for the output characteristic envelope curve includes: The multiple response lag times of the electronic speed controller measured under excitation pulse signals of different frequencies were recorded in a lag time table; On the horizontal axis of the output characteristic envelope curve, a delay offset obtained by looking up the hysteresis time table is added to each frequency point; The output characteristic envelope curve with the added delay offset is marked as the dynamically compensated output characteristic envelope curve.

10. The online measurement method for the output characteristics of an engine electronic speed controller according to claim 9, characterized in that, The process of recording multiple response lag times measured by the electronic speed controller under excitation pulse signals of different frequencies into a lag time table includes: A two-dimensional array is generated using the frequency of the excitation pulse signal as the index and the corresponding response lag time as the value. Linear interpolation is performed on the response lag time of adjacent frequency points in the two-dimensional array to fill in the blank items corresponding to the frequency interval, thereby obtaining a continuous lag time table.

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