Rotating speed control method of brush motor

Abstract

The invention provides a rotating speed control method for a brush motor, and relates to the technical field of data processing, and the method comprises the steps: collecting the voltage, current and rotating speed of the brush motor, calculating the change rates of the voltage, current and rotating speed at adjacent moments, constructing a corresponding change rate sequence, dividing the change rate sequence into a plurality of window intervals, and in each window interval, determining the rotating speed of the brush motor; calculating a delay amount group, judging whether the brush motor has response abrupt change or not, recording corresponding response abnormal moments, extracting rate evolution data corresponding to the response abnormal moments, calculating a weighted average rotating speed change rate, and obtaining a predicted rotating speed offset sequence; and according to a difference value between the predicted rotating speed offset sequence and the real-time rotating speed, calculating a compensation voltage increment, generating a compensation voltage signal, and ensuring that the rotating speed of the motor is stable. The rotating speed of the brush motor can be predicted, and the stability of the rotating speed is ensured through voltage correction.

Description

Technical Field

[0001] The present invention relates to the technical field of data processing, and in particular to a speed control method for a brushed motor. Background Art

[0002] Brushed motors are widely used in portable power tools, such as electric screwdrivers and drills, due to their simple structure and easy control. These tools typically use voltage regulation to control motor speed. For example, this involves indirectly controlling the voltage applied to the motor through thyristor voltage regulation or pulse-width modulation (PWM) signals, thereby adjusting the speed. This control method is low-cost and has relatively simple control logic, making it suitable for applications where precision is not a priority.

[0003] However, in environments where power tools are frequently started and stopped or where the load changes greatly, traditional voltage control methods may have defects in responding to sudden load changes. For example, when the power tool contacts hard materials and the load suddenly increases, the speed control system responds with a lag and may not be able to adjust the voltage compensation in time, causing the motor speed to drop instantaneously and causing a jamming phenomenon. Summary of the Invention

[0004] The object of the present invention is to provide a speed control method for a brushed motor, aiming to solve the problems mentioned in the background technology.

[0005] In order to solve the above technical problems, the technical solutions of the present invention are as follows:

[0006] A method for controlling the speed of a brushless motor, the method comprising:

[0007] Collect the voltage, current, and speed of the brushless motor and perform time alignment to obtain a three-element synchronized data set;

[0008] Based on the three-element synchronous data set, the change rates of voltage, current and speed at adjacent moments are calculated, and the corresponding change rate sequences are constructed to obtain the rate evolution data set;

[0009] According to the preset time window, the change rate sequence in the rate evolution data set is divided into multiple window intervals, and within each window interval, the delay amount group is calculated to obtain the response delay sequence;

[0010] By calculating the difference between the response delay sequence and the preset delay group, it is determined whether there is a sudden change in the response of the brushed motor, and the corresponding abnormal response time is recorded to obtain the sudden change identification sequence;

[0011] According to the mutation recognition sequence, the rate evolution data corresponding to each abnormal response moment is extracted, the weighted average speed change rate is calculated, and the predicted speed offset sequence is obtained;

[0012] According to the difference between the predicted speed offset sequence and the real-time speed, the compensation voltage increment is calculated to obtain the corrected voltage data;

[0013] Based on the corrected voltage data, a compensation voltage signal is generated and transmitted to the drive input of the brushed motor to ensure stable motor speed.

[0014] Furthermore, based on the three-element synchronous data set, the change rates of voltage, current, and speed at adjacent moments are calculated, and the corresponding change rate sequences are constructed to obtain the rate evolution data set, including:

[0015] The voltage change rate is calculated based on the difference between the current voltage value and the previous voltage value in the ternary synchronous data set, combined with the sampling interval time, to obtain the voltage change rate sequence;

[0016] According to the difference between the current value at the current moment and the current value at the previous moment in the ternary synchronous data set, combined with the sampling interval time, the current change rate is calculated to obtain the current change rate sequence;

[0017] According to the difference between the current speed value and the previous speed value in the ternary synchronous data set, and combined with the sampling interval time, the speed change rate is calculated to obtain the speed change rate sequence;

[0018] The rate evolution data set is composed according to the voltage change rate series, current change rate series and speed change rate series.

[0019] Furthermore, the change rate sequence in the rate evolution data set is divided into multiple window intervals according to the preset time window, and the delay amount group is calculated in each window interval to obtain the response delay sequence, including:

[0020] According to the length of the preset time window, the voltage change rate sequence, the current change rate sequence and the speed change rate sequence are divided into multiple window intervals in time order to obtain multiple rate windows;

[0021] In each rate window, the corresponding voltage change rate sequence and speed change rate sequence are extracted, sequence deviation matching is performed, and the minimum delay time of speed relative to voltage is calculated to obtain the voltage delay value;

[0022] In the same rate window, the current change rate sequence is extracted, the same sequence deviation matching is performed, and the minimum delay time of the speed relative to the current is calculated to obtain the current delay value;

[0023] According to the voltage delay value and the current delay value in each rate window, a delay amount group is formed and arranged in time sequence to obtain a response delay sequence.

[0024] Furthermore, within each rate window, the corresponding voltage change rate sequence and speed change rate sequence are extracted, sequence deviation matching is performed, and the minimum delay time of the speed relative to the voltage is calculated to obtain the voltage delay value, including:

[0025] According to the start and end time of the rate window, continuous data points of the voltage change rate sequence and the speed change rate sequence within the rate window are extracted respectively to obtain the voltage change rate window segment and the speed change rate window segment;

[0026] Keeping the position of the voltage change rate window segment unchanged, the speed change rate window segment is slid backward along the time axis by several sampling points within the current rate window to construct a first speed delay sequence;

[0027] Normalizing the voltage change rate window segments and the first speed delay sequence, scaling their numerical ranges to the interval [0, 1], and obtaining a first normalized segment set;

[0028] Calculate the mean absolute error between the voltage and the corresponding rotational speed according to the first normalized segment set to obtain voltage sliding offset value data;

[0029] According to the voltage sliding offset value data, the number of sliding sampling points corresponding to the minimum voltage sliding offset value is identified, and combined with the sampling interval time, the offset time of the speed relative to the voltage in the current rate window is determined to obtain the voltage delay value.

[0030] Furthermore, within the same rate window, the current change rate sequence is extracted, the same sequence deviation matching is performed, and the minimum delay time of the speed relative to the current is calculated to obtain the current delay value, including:

[0031] Within the same rate window, continuous data points of the current change rate sequence within the rate window are extracted to obtain a current change rate window segment;

[0032] Keeping the position of the current change rate window segment unchanged, the speed change rate window segment is slid backward along the time axis by several sampling points within the current rate window to construct a second speed delay sequence;

[0033] Normalizing the current change rate window segments and the second speed delay sequence, scaling their numerical ranges to the interval [0, 1], and obtaining a second normalized segment set;

[0034] Calculating the mean absolute error between the current and the corresponding rotational speed based on the second normalized segment set to obtain current sliding offset value data;

[0035] According to the current sliding offset value data, the number of sliding sampling points corresponding to the minimum current sliding offset value is identified, and combined with the sampling interval time, the offset time of the speed relative to the current in the current rate window is determined to obtain the current delay value.

[0036] Furthermore, by calculating the difference between the response delay sequence and the preset delay group, it is determined whether there is a sudden change in the response of the brushed motor, and the corresponding abnormal response time is recorded to obtain a sudden change identification sequence, including:

[0037] According to the voltage delay value and the current delay value of each rate window in the response delay sequence, the difference between them and the preset voltage delay reference value and the preset current delay reference value is calculated to obtain the voltage delay difference and the current delay difference;

[0038] Performing absolute value processing on the voltage delay difference and the current delay difference to obtain a non-negative delay offset value pair;

[0039] Determine whether any component of the non-negative delay offset value pair exceeds a preset offset threshold. If yes, a response mutation occurs within the rate window, and mark the start time of the rate window as the response abnormality moment.

[0040] Arrange all abnormal response moments in chronological order to obtain the mutation recognition sequence.

[0041] Furthermore, according to the mutation recognition sequence, the ternary synchronization data corresponding to each abnormal response moment is extracted, and the weighted average speed change rate is calculated to obtain the predicted speed offset sequence, including:

[0042] According to the abnormal response moment in the mutation recognition sequence, the speed change rate data, current change rate data, and voltage change rate data within a fixed prediction time length starting from any abnormal response moment are extracted from the rate evolution data set to obtain the abnormal response data set;

[0043] Calculate the weighted factors of the current change rate and the voltage change rate based on the response abnormality data set, and calculate the weighted average speed change rate at the moment of the response abnormality in combination with the speed change rate data;

[0044] The predicted speed offset is obtained according to the weighted average speed change rate and the fixed prediction time;

[0045] The predicted speed offsets corresponding to all abnormal response moments are arranged in chronological order to obtain a predicted speed offset sequence.

[0046] Furthermore, based on the response abnormality data set, the weighted factors of the current change rate and the voltage change rate are calculated, and combined with the speed change rate data, the weighted average speed change rate at the time of the response abnormality is calculated, including:

[0047] Within the fixed prediction duration of any response abnormality moment, the current change rate of each sampling point in the response abnormality segment is read in sequence, and the current weight value is obtained based on its absolute value and the preset current adjustment value;

[0048] The voltage change rate of each sampling point in the same response abnormal segment is read in sequence, and the voltage weight value is obtained according to its absolute value and the preset voltage adjustment value;

[0049] The current weight value, voltage weight value and preset constant adjustment value corresponding to each sampling point are integrated to obtain a comprehensive weighting factor;

[0050] Multiply the speed change rate of each sampling point by its corresponding comprehensive weighting factor to obtain the weighted speed change rate;

[0051] All weighted speed change rates within the response abnormality segment are summed and divided by the sum of all comprehensive weighting factors within the response abnormality segment to obtain a weighted average speed change rate.

[0052] Furthermore, the compensation voltage increment is calculated based on the difference between the predicted speed offset sequence and the real-time speed to obtain the corrected voltage data, including:

[0053] According to the predicted speed offset sequence, the predicted speed offset at any abnormal response moment is extracted, and the real-time speed at the current moment is extracted;

[0054] The difference between the predicted speed offset and the real-time speed is calculated to obtain the speed compensation demand value;

[0055] Within the fixed prediction time of the abnormal response moment, the voltage change rate and the speed change rate are extracted, and the average corresponding ratio between the two is calculated to obtain the response conversion factor;

[0056] Calculate the compensation voltage increment according to the response conversion factor and the speed compensation requirement value;

[0057] The corrected voltage data is obtained according to the compensation voltage increment and the control voltage at the current moment.

[0058] Furthermore, a compensation voltage signal is generated based on the corrected voltage data and transmitted to the drive input of the brushed motor to ensure stable motor speed, including:

[0059] Calculate the change range between the correction voltage data and the control voltage at the previous moment to obtain the correction range;

[0060] When the correction amplitude exceeds the preset voltage adjustment threshold, the correction amplitude is limited to ensure that the correction amplitude does not exceed the preset voltage adjustment threshold;

[0061] Determine whether the corrected voltage data exceeds the brush motor voltage output range. If so, limit the corrected voltage data to within the brush motor voltage output range.

[0062] After the above restrictions, the restricted corrected voltage data is obtained, which is weighted averaged with the corrected voltage data to obtain the smoothed corrected voltage data;

[0063] According to the smoothed corrected voltage data, its value is converted into a voltage output instruction, a compensation voltage signal is generated, and it is transmitted to the drive input end of the brushed motor.

[0064] The above solution of the present invention includes at least the following beneficial effects:

[0065] This method converts raw synchronous data into a sequence of rate-of-change values for voltage, current, and speed, forming a rate-evolution dataset. This effectively introduces the dynamic expressive power of multivariate first-order differential features at the data processing level. Compared to traditional static sampling values, this evolutionary sequence more realistically reflects the trend changes, mutation tendencies, and inertial response characteristics of the system state. Through rate-of-change modeling, the motor system transitions from point sampling to continuous trajectory modeling. This rate-of-change modeling process is also more resistant to noise interference, making it easier to construct a prediction model in conjunction with a window mechanism, providing an accurate dynamic data foundation for the system.

[0066] The present invention divides the rate evolution data set into time windows and analyzes the local response characteristics in each window to achieve refined modeling of the system's short-term operating status. The characteristic parameters in each time window constitute a complete response unit, thereby avoiding the dilution problem of local abnormal behavior under the global feature extraction method. The processing mechanism has obvious data segmentation and sliding sampling characteristics, which significantly enhances the system's ability to detect local load mutations. By quantitatively modeling the local response offset, it can achieve rapid calibration of mutation behaviors and precise locking of target windows, providing clear boundary ranges and data entries for predictive control.

[0067] The present invention obtains the response delay sequence and performs differential analysis with the preset delay group to identify the mutation window, thereby constructing a dynamic coupling relationship identification mechanism between voltage and current changes and speed response, and realizing a full-chain data processing path from feature alignment to anomaly discrimination. The delay identification mechanism essentially uses time correlation to establish a hysteresis matching relationship between input and output, avoiding the false alarm or missed judgment problem caused by single variable fluctuation judgment, and can quickly lock the moment when the unexpected disturbance behavior occurs, providing a highly timely judgment criterion for predictive control.

[0068] The present invention extracts evolution data of a specific time period through a mutation recognition sequence, constructs a weighted average speed change rate, predicts future speed deviation trends, and generates a predicted speed deviation sequence. This mechanism integrates multiple modeling methods such as parameter collaborative analysis, voltage and current weight distribution, and time window integration, so that the prediction results have physical basis, trend rationality, and dynamic adaptability. This prediction mechanism can not only be used to design compensation strategies for sudden responses to load disturbances, but also to generate correction parameters in advance in continuous deviation trends, thereby enhancing the stability of the control system.

[0069] The present invention collects three types of operating parameters of the brushed motor, namely voltage, current and speed, and aligns them in the time dimension to form a ternary synchronous data set with high time resolution and high consistency, providing a basic guarantee for subsequent dynamic behavior modeling. This synchronous collection and alignment mechanism is significantly superior to the isolated sampling of each parameter in the existing technology, and can effectively suppress data misalignment problems caused by sensor delays, jitter or interruptions. This structured data model can ensure the traceability and real-time performance of analysis and calculation, and provide a stable data foundation for subsequent calculation links. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] Figure 1 This is a flow chart of a method for controlling the speed of a brushed motor provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0071] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0072] like Figure 1 As shown, an embodiment of the present invention provides a speed control method for a brushed motor, the method comprising:

[0073] Collect the voltage, current, and speed of the brushless motor and perform time alignment to obtain a three-element synchronized data set;

[0074] Based on the three-element synchronous data set, the change rates of voltage, current and speed at adjacent moments are calculated, and the corresponding change rate sequences are constructed to obtain the rate evolution data set;

[0075] According to the preset time window, the change rate sequence in the rate evolution data set is divided into multiple window intervals, and within each window interval, the delay amount group is calculated to obtain the response delay sequence;

[0076] By calculating the difference between the response delay sequence and the preset delay group, it is determined whether there is a sudden change in the response of the brushed motor, and the corresponding abnormal response time is recorded to obtain the sudden change identification sequence;

[0077] According to the mutation recognition sequence, the rate evolution data corresponding to each abnormal response moment is extracted, the weighted average speed change rate is calculated, and the predicted speed offset sequence is obtained;

[0078] According to the difference between the predicted speed offset sequence and the real-time speed, the compensation voltage increment is calculated to obtain the corrected voltage data;

[0079] Based on the corrected voltage data, a compensation voltage signal is generated and transmitted to the drive input end of the brushed motor to ensure stable motor speed.

[0080] In an embodiment of the present invention, the voltage, current and speed of the brushed motor are collected and time-aligned to obtain a ternary synchronous data set, ensuring that the three types of key operating data have time consistency and source synchronization, avoiding calculation errors or causal relationship confusion caused by time offset in the subsequent processing process, and providing accurate and stable original data support for the subsequent process; based on the ternary synchronous data set, the change rates of the voltage, current and speed at adjacent moments are calculated, and corresponding change rate sequences are constructed to obtain a rate evolution data set, which captures the response speed and sudden change behavior of the motor operating state on a microscopic time scale, and improves the sensitivity to sudden load interference and dynamic judgment ability; based on a preset time window, the change rate sequence in the rate evolution data set is divided into multiple window intervals, and in each window interval, the delay amount group is calculated to obtain a response delay sequence, and a hysteresis mapping relationship between the motor input and output is constructed, which effectively identifies the response offset trend in the local time period, and helps to quantify the degree of dynamic coupling from the time dimension.

[0081] By calculating the difference between the response delay sequence and the preset delay group, the system determines whether the brushed motor has a sudden change in response. The corresponding abnormal response moment is recorded to obtain a sudden change identification sequence, which is used to identify the statistical deviation of the response lag. This allows for early detection of system operating anomalies and local time-domain locking, accurately screening out periods of potential fault or load fluctuation risk. Based on the sudden change identification sequence, the rate evolution data corresponding to each abnormal response moment is extracted, and the weighted average speed change rate is calculated to obtain a predicted speed offset sequence. This enables advanced prediction of the motor's operating trend under abnormal conditions and generates a short-term control target, improving the control system's proactiveness and proactive correction capabilities. Based on the difference between the predicted speed offset sequence and the real-time speed, the compensation voltage increment is calculated to obtain the corrected voltage data, achieving a mapping from the predicted control variable to the executed voltage variable, ensuring that the voltage compensation has a quantitative basis, computational consistency, and dynamic adaptability. Based on the corrected voltage data, a compensation voltage signal is generated and transmitted to the brushed motor's drive input to ensure motor speed stability. This not only ensures the regulation effect, but also enhances the stability and security of the control system, providing a good terminal guarantee for achieving precise and flexible speed regulation.

[0082] The voltage, current, and speed of the brushless motor are collected and time-aligned to obtain a ternary synchronous data set, including:

[0083] First, a sensing device for real-time voltage, current, and speed measurement must be deployed within the motor system. Voltage sampling can be performed using a voltage divider circuit combined with a high-precision analog-to-digital converter (ADC), converting the instantaneous voltage between the motor terminals into a digital signal. Current acquisition typically utilizes a Hall current sensor or sampling resistor, converting the current changes in the motor power supply circuit into a voltage signal in real time before digitizing it via the ADC. The speed signal acquisition method varies depending on the motor structure. In typical portable power tools, speed estimation can be achieved using a photoelectric encoder, Hall position sensor, or sensorless algorithm based on back-EMF waveform analysis. The output value must be further smoothed by a filtering module to remove high-speed fluctuation noise, ultimately forming a speed sample value.

[0084] The signal sources of the three physical quantities (voltage, current, and speed) mentioned above differ, resulting in different latency characteristics in their sampling links, which can easily lead to data asynchrony on the timeline. By using a unified high-precision clock as the sampling trigger reference for the main control unit, the three sampling modules are uniformly scheduled, and DMA is used to read each data channel in parallel to avoid time jitter caused by CPU resource switching. In actual acquisition, the system triggers a synchronous read operation according to the set sampling period (for example, every 1 millisecond) and assigns a unique timestamp to each set of sampled values to ensure strict consistency in the time tags of the three data channels.

[0085] To further improve the accuracy of time alignment, linear or spline interpolation algorithms can be used to adjust samples that are slightly out of sync due to hardware delays. This involves using a particular data channel as a reference and interpolating the nearest neighboring values on its time axis on a linear scale to estimate the value of the other data channel at the corresponding moment, thereby forming paired data samples of the three quantities at the same time point. After the alignment operation is completed, the voltage, current, and speed values at each moment can be combined into a ternary vector data item, forming a ternary synchronized data sequence. The collection of consecutive sample points is the ternary synchronized data set.

[0086] In a preferred embodiment of the present invention, based on the ternary synchronous data set, the change rates of voltage, current and speed at adjacent moments are calculated, and corresponding change rate sequences are constructed to obtain a rate evolution data set, including:

[0087] The voltage change rate is calculated based on the difference between the current voltage value and the previous voltage value in the ternary synchronous data set, combined with the sampling interval time, to obtain the voltage change rate sequence;

[0088] According to the difference between the current value at the current moment and the current value at the previous moment in the ternary synchronous data set, combined with the sampling interval time, the current change rate is calculated to obtain the current change rate sequence;

[0089] According to the difference between the current speed value and the previous speed value in the ternary synchronous data set, and combined with the sampling interval time, the speed change rate is calculated to obtain the speed change rate sequence;

[0090] The rate evolution data set is composed according to the voltage change rate series, current change rate series and speed change rate series.

[0091] In an embodiment of the present invention, based on the difference between the voltage value at the current moment and the voltage value at the previous moment in the ternary synchronous data set, and in combination with the sampling interval, the voltage change rate is calculated to obtain a voltage change rate sequence, the voltage change trend on the time axis is extracted, and the actual input intensity of the control signal to the dynamic response of the motor is accurately described, providing a data basis with more dynamic characteristics for subsequent delay matching and mutation identification; based on the difference between the current value at the current moment and the current value at the previous moment in the ternary synchronous data set, and in combination with the sampling interval, the current change rate is calculated to obtain a current change rate sequence, and it is judged whether the motor is in normal acceleration, overload or mutation state; based on the difference between the speed value at the current moment and the speed value at the previous moment in the ternary synchronous data set, and in combination with the sampling interval, the speed change rate is calculated to obtain a speed change rate sequence, and through comparative analysis with the voltage change rate and the current change rate, the response efficiency and hysteresis characteristics between the input and output of the system are derived; based on the voltage change rate sequence, the current change rate sequence and the speed change rate sequence, a rate evolution data set is composed, which effectively enhances the linkage analysis capability between signals and lays a data foundation for dynamic correlation modeling and response trend reasoning.

[0092] The voltage change rate is calculated based on the difference between the current voltage value and the previous voltage value in the ternary synchronous data set, combined with the sampling interval, to obtain the voltage change rate sequence, which specifically includes:

[0093] First, the voltage signal sequence is extracted from the obtained ternary synchronous data set. The data sampling is performed at a fixed time interval to ensure that there is an equidistant time interval between any two adjacent sampling points in the sequence. Specifically, the sampling time interval is set to (unit is seconds), the voltage sequence can be recorded as ,in is the voltage value at the initial moment, is the voltage value of the next sampling period, and so on.

[0094] Then, for each pair of adjacent sampling points in the voltage sequence, a difference calculation operation is performed. time( ) as an example, the corresponding current voltage value is , the voltage value at the previous moment is The difference between the two reflects the change in voltage per unit sampling time. In order to normalize the change to unit time, the following calculation formula is used for normalization: ,in Indicates the The voltage change rate corresponding to the moment (unit is V / s), and are the voltage values of the current and previous sampling points respectively, is the preset sampling interval.

[0095] According to the above calculation method, the entire voltage sampling sequence is calculated one by one, and the length can be obtained. Voltage change rate series , where each item represents the dynamic change trend of voltage in the corresponding time period, and the resulting voltage change rate series will be input into the subsequent steps as part of the rate evolution dataset.

[0096] In a preferred embodiment of the present invention, the change rate sequence in the rate evolution data set is divided into multiple window intervals according to a preset time window, and within each window interval, a delay amount group is calculated to obtain a response delay sequence, including:

[0097] According to the length of the preset time window, the voltage change rate sequence, the current change rate sequence and the speed change rate sequence are divided into multiple window intervals in time order to obtain multiple rate windows;

[0098] In each rate window, the corresponding voltage change rate sequence and speed change rate sequence are extracted, sequence deviation matching is performed, and the minimum delay time of speed relative to voltage is calculated to obtain the voltage delay value;

[0099] Within the same rate window, the current change rate sequence is extracted, the same sequence deviation matching is performed, and the minimum delay time of the speed relative to the current is calculated to obtain the current delay value;

[0100] According to the voltage delay value and the current delay value in each rate window, a delay amount group is formed and arranged in time sequence to obtain a response delay sequence.

[0101] In an embodiment of the present invention, the voltage rate of change sequence, current rate of change sequence, and speed rate of change sequence are divided into multiple window intervals in chronological order according to the length of a preset time window, thereby obtaining multiple rate windows. This improves the ability to capture local mutation behavior and avoids the masking effect of local details in the global modeling process. Within each rate window, the corresponding voltage rate of change sequence and speed rate of change sequence are extracted, sequence deviation matching is performed, and the minimum delay time of speed relative to voltage is calculated to obtain a voltage delay value. This accurately quantifies the hysteresis effect of voltage change on speed response and eliminates shape errors caused by different amplitudes or disturbance morphologies. Within the same rate window, the current rate of change sequence is extracted, and the same sequence deviation matching is performed. The minimum delay time of speed relative to current is calculated to obtain a current delay value. This further establishes a dynamic response timing relationship between current input and speed response, revealing the hysteresis behavior of load response in the electromagnetic link. Based on the voltage delay values and current delay values within each rate window, delay groups are combined and arranged in chronological order to obtain a response delay sequence. This completes the process of abstracting the time response characteristics between input-output pairs into numerical indicators, which serves as a direct input basis for subsequent mutation identification and predictive control.

[0102] According to the length of the preset time window, the voltage change rate sequence, the current change rate sequence, and the speed change rate sequence are divided into multiple window intervals in chronological order to obtain multiple rate windows, specifically including:

[0103] First, a time window length parameter is preset, denoted as , whose unit is milliseconds or sampling points. The specific value can be set according to the system sampling frequency and response expectations. For example, it can be set to 100 sampling points in a high-frequency sampling scenario. On this basis, according to the time axis in the original rate evolution data set, the voltage change rate series, current change rate series, and speed change rate series are divided into equal lengths along the time dimension. The division method can adopt the fixed window division method, that is, setting the window starting point to , the end point is , followed by a sliding step Slide forward to generate the next window to , and so on, until the entire data sequence is covered.

[0104] In each time window, the voltage change rate sequence, current change rate sequence and speed change rate sequence within the current time range are extracted respectively, and recorded as ,in Indicates the windows. The number of data points in each window sequence is ,equal After the completion of this step, a set of rate windows with consistent time sequence, uniform sampling length and standardized data structure is obtained. Each rate window will serve as an independent analysis unit for subsequent sequence delay matching and feature recognition.

[0105] Among them, according to the voltage delay value and the current delay value in each rate window, a delay amount group is formed, and it is arranged in chronological order to obtain a response delay sequence, which specifically includes:

[0106] Within each constructed rate window, the delay matching operation between the voltage change rate sequence and the speed change rate sequence, as well as the delay matching operation between the current change rate sequence and the speed change rate sequence, are completed respectively. Specifically, the voltage (or current) sequence is kept stationary, and the corresponding speed change rate sequence slides along the time axis sampling point by sampling point within the window. A series of time-shifted speed sequences are constructed and compared one by one with the reference voltage (or current) sequence. The values are normalized so that they are all between [0,1]. The mean absolute error under each group of sliding correspondences is then calculated, and the number of sliding offset sampling points corresponding to the minimum error is selected. Combined with the sampling time interval, it is converted into a time value, which is used as the delay time of voltage relative to speed (i.e., voltage delay value) or the delay time of current relative to speed (i.e., current delay value) in the window.

[0107] Get the voltage delay value of each window and current delay value After that, they are encapsulated into a set of delay pairs, recorded as Repeat the above process, perform the above matching calculation operation on all rate windows in sequence, and finally arrange the delay groups of all windows in chronological order to form a complete response delay sequence ,This response delay sequence not only retains the hysteresis characteristics of the input-output response in each time window, but also provides dynamic timing input characteristics for subsequent operations such as identifying whether there is a sudden change in response, performing predictive modeling and voltage compensation control.

[0108] In a preferred embodiment of the present invention, within each rate window, the corresponding voltage change rate sequence and speed change rate sequence are extracted, sequence deviation matching is performed, and the minimum delay time of the speed relative to the voltage is calculated to obtain the voltage delay value, including:

[0109] According to the start and end time of the rate window, continuous data points of the voltage change rate sequence and the speed change rate sequence within the rate window are extracted respectively to obtain the voltage change rate window segment and the speed change rate window segment;

[0110] Keeping the position of the voltage change rate window segment unchanged, the speed change rate window segment is slid backward along the time axis by several sampling points within the current rate window to construct a first speed delay sequence;

[0111] Normalizing the voltage change rate window segments and the first speed delay sequence, scaling their numerical ranges to the interval [0, 1], and obtaining a first normalized segment set;

[0112] Calculate the mean absolute error between the voltage and the corresponding rotational speed according to the first normalized segment set to obtain voltage sliding offset value data;

[0113] According to the voltage sliding offset value data, the number of sliding sampling points corresponding to the minimum voltage sliding offset value is identified, and combined with the sampling interval time, the offset time of the speed relative to the voltage in the current rate window is determined to obtain the voltage delay value.

[0114] In an embodiment of the present invention, according to the start and end time of the rate window, continuous data points of the voltage change rate sequence and the speed change rate sequence in the rate window are extracted respectively to obtain the voltage change rate window fragment and the speed change rate window fragment, thereby ensuring that the voltage and the speed are matched and analyzed in the same time interval and maintaining time consistency, which is the basis for subsequent time delay calculation; the position of the voltage change rate window fragment is kept unchanged, and the speed change rate window fragment is slid backward along the time axis by several sampling points in the current rate window to construct a first speed delay sequence, and multiple lagged versions of the speed fragment are generated by sliding, thereby providing multiple candidate combinations for subsequent error comparison with the voltage fragment; the voltage change rate window fragment and the first speed delay sequence are normalized to scale their numerical ranges to The first normalized segment set is obtained based on the interval [0,1], eliminating the deviation caused by dimensional differences between different data sources and ensuring that the voltage and speed segments have the same comparison benchmark. Based on the first normalized segment set, the mean absolute error between the voltage and its corresponding speed is calculated to obtain voltage sliding offset value data. Error analysis is used to quantify the voltage-speed delay coupling relationship and avoid errors caused by subjective experience. Based on the voltage sliding offset value data, the number of sliding sampling points corresponding to the minimum voltage sliding offset value is identified. Combined with the sampling interval time, the offset time of the speed relative to the voltage within the current rate window is determined to obtain the voltage delay value. The minimum error matching result is converted into a physically meaningful time delay value, realizing the mapping from data differences to response characteristic indicators.

[0115] The voltage change rate window segment position is kept unchanged, and the speed change rate window segment is slid backward along the time axis by several sampling points within the current rate window to construct a first speed delay sequence, specifically including:

[0116] First, the voltage change rate window segment has been extracted from the rate window. Its data is a set of equally spaced change rate values, recorded as At the same time, the original speed window segment extracted from the speed change rate sequence is , whose initial position is aligned with the voltage segment. To simulate the delayed effect of voltage change on the speed response, in this step, the position of the voltage change rate window segment is not changed; it remains fixed at the original rate window starting point. Instead, the speed window segment is slid backward along the time axis point by point to construct multiple speed sequence copies with different time delays. For example, the speed segment is slid backward from the original point by 1, 2, 3, and so on. sampling points, forming new sequence: Until ,These constitute the first set of speed delay sequences, each of which represents a speed response pattern with a specific lag time (i.e., number of sliding steps × sampling interval).

[0117] The method of calculating the mean absolute error between the voltage and the corresponding rotational speed based on the first normalized segment set to obtain the voltage sliding offset value data specifically includes:

[0118] Each speed delay segment and voltage change rate window segment is normalized. The normalization process uses a linear scaling method to map the minimum value of each segment to 0 and the maximum value to 1. The remaining points are calculated according to the linear ratio so that they all fall within the [0,1] interval, thereby eliminating the dimension effect of the original data. After the normalization is completed, the normalized voltage segment is set to , normalized The speed delay segment is Next, the absolute error calculation is performed point by point for each speed delay segment and voltage segment, that is, the calculation ,in The value range is 0 to , is the sliding step index. After completing this calculation, a voltage sliding offset value data array can be obtained, which is recorded as , which is used to determine the error level of the speed response to voltage under different delay states. The smaller the error value, the higher the degree of matching.

[0119] Among them, according to the voltage sliding offset value data, the number of sliding sampling points corresponding to the minimum voltage sliding offset value is identified, and combined with the sampling interval time, the offset time of the speed relative to the voltage in the current rate window is determined to obtain the voltage delay value, which specifically includes:

[0120] After obtaining the above voltage sliding offset value data, it is traversed and searched to identify the minimum value and its corresponding index position. is the minimum error value, This is the number of sliding sampling points corresponding to the optimal match between voltage and speed. ), the sliding steps and By multiplying, the time delay of the speed response relative to the voltage change can be calculated. ,Right now This value, denoted as voltage delay, is a crucial indicator for describing the dynamic relationship between voltage changes and speed response. This delay value is then recorded in the response delay sequence and compared with the preset delay group to determine if there are any sudden changes in response. It also serves as a timing benchmark for subsequent response modeling and offset prediction, ensuring strong logical consistency and temporal stability in the control system.

[0121] In a preferred embodiment of the present invention, within the same rate window, a current change rate sequence is extracted, the same sequence deviation matching is performed, and the minimum delay time of the speed relative to the current is calculated to obtain the current delay value, including:

[0122] Within the same rate window, continuous data points of the current change rate sequence within the rate window are extracted to obtain a current change rate window segment;

[0123] Keeping the position of the current change rate window segment unchanged, the speed change rate window segment is slid backward along the time axis by several sampling points within the current rate window to construct a second speed delay sequence;

[0124] Normalizing the current change rate window segments and the second speed delay sequence, scaling their numerical ranges to the interval [0, 1], and obtaining a second normalized segment set;

[0125] Calculating the mean absolute error between the current and the corresponding rotational speed based on the second normalized segment set to obtain current sliding offset value data;

[0126] According to the current sliding offset value data, the number of sliding sampling points corresponding to the minimum current sliding offset value is identified, and combined with the sampling interval time, the offset time of the speed relative to the current in the current rate window is determined to obtain the current delay value.

[0127] In an embodiment of the present invention, within the same rate window, continuous data points of the current change rate sequence within the rate window are extracted to obtain a current change rate window segment, and the dynamic signal of the current change rate is subjected to time localization processing, so that the subsequent matching analysis focuses on the local response characteristics, reducing the probability of misjudgment affected by global interference or inertia of historical data; keeping the position of the current change rate window segment unchanged, the speed change rate window segment is slid backward along the time axis for several sampling points within the current rate window to construct a second speed delay sequence, simulating the speed response delay behavior under various hypothetical conditions, and providing a basis for subsequent error matching; the current change rate window segment and the second speed delay sequence are normalized to be The numerical range is scaled to the interval [0,1] to obtain the second normalized segment set, ensuring that the comparison benchmarks of current and speed are consistent, avoiding error judgment deviations caused by different sampling amplitudes; based on the second normalized segment set, the mean absolute error between the current and its corresponding speed is calculated to obtain the current sliding offset value data, which effectively reflects the offset strength between the speed response and the current change; based on the current sliding offset value data, the number of sliding sampling points corresponding to the minimum current sliding offset value is identified, and combined with the sampling interval time, the offset time of the speed relative to the current in the current rate window is determined to obtain the current delay value, quantify the minimum delay time of the speed relative to the current response, and reflect the actual response mechanism of the motor system.

[0128] Among them, according to the current sliding offset value data, the number of sliding sampling points corresponding to the minimum current sliding offset value is identified, and combined with the sampling interval time, the offset time amount of the speed relative to the current in the current rate window is determined to obtain the current delay value, which specifically includes:

[0129] First, the sliding error data is analyzed. The constructed sliding offset data is essentially a sequence of mean absolute errors corresponding to different sliding sampling points. This sequence reflects the degree of match between the speed change rate segments and the current change rate segments under different assumed delay conditions. The smaller the error, the more consistent the response trends of the two under the sliding condition. Therefore, based on this sliding offset data, the system uses the global minimum error criterion to locate the point with the smallest error among the sliding sampling points. This sliding point is the speed response position under the optimal alignment state, indicating the actual response delay of the speed relative to the current.

[0130] Next, the number of sliding sampling points corresponding to the minimum offset value is recorded as , which represents the number of sampling cycles that the speed response needs to lag relative to the current change within the current window. Since the sliding process is based on discrete sampling points, it is still necessary to combine the sampling interval time set in the system. The time scale of the offset points is mapped, that is, by The discrete sampled displacement is converted into a continuous time delay value. This current delay value represents the minimum response time required for the motor speed to remain within the window after the current signal changes. It is an empirical quantitative result of the motor's internal dynamic characteristics and response inertia.

[0131] In a preferred embodiment of the present invention, by calculating the difference between the response delay sequence and the preset delay group, it is determined whether there is a sudden change in the response of the brushed motor, and the corresponding abnormal response time is recorded to obtain a sudden change identification sequence, including:

[0132] According to the voltage delay value and the current delay value of each rate window in the response delay sequence, the difference between them and the preset voltage delay reference value and the preset current delay reference value is calculated to obtain the voltage delay difference and the current delay difference;

[0133] Performing absolute value processing on the voltage delay difference and the current delay difference to obtain a non-negative delay offset value pair;

[0134] Determine whether any component of the non-negative delay offset value pair exceeds a preset offset threshold. If yes, a response mutation occurs within the rate window, and mark the start time of the rate window as the response abnormality moment.

[0135] Arrange all abnormal response moments in chronological order to obtain the mutation recognition sequence.

[0136] In an embodiment of the present invention, the voltage delay value and current delay value of each rate window in the response delay sequence are differentially calculated with preset voltage delay reference values and preset current delay reference values, respectively, to obtain voltage delay difference and current delay difference values. By using the differential calculation method with the reference values, the offset between the actual response delay and the expected response state is clearly quantified, forming a continuous and comparable data sequence, facilitating the subsequent unified standard for abnormal situation judgment. Absolute value processing is performed on the voltage delay difference and the current delay difference to obtain non-negative delay offset value pairs, removing positive and negative interference and facilitating the setting of a unified mutation judgment threshold. A determination is made as to whether any component of the non-negative delay offset value pair exceeds a preset offset threshold. If the result is yes, a response mutation occurs within the rate window, and the start time of the rate window is marked as the response abnormality moment. This achieves discrete identification of abnormal response windows, effectively resolving the problem of false alarms under the influence of multi-parameter coupling. All response abnormality moments are arranged in chronological order to obtain a mutation identification sequence. The data path from the perception layer to the execution layer has a clear transmission structure and a unified format, providing a time anchor for subsequent predictive modeling and voltage correction and compensation control modules.

[0137] Among them, the preset delay group includes a preset voltage delay reference value and a preset current delay reference value, which serve as reference standards for judging whether there is a sudden response change in the motor operating state. Both are set based on the actual operating characteristics of the brushed motor and a large amount of measured data under stable load conditions, combined with statistical analysis methods and engineering experience. It is necessary to ensure that there is no false alarm under normal working conditions, and to have the ability to respond in time under abnormal circumstances.

[0138] The preset voltage delay reference value reflects the minimum time offset required for the voltage rate of change sequence to respond to the speed rate of change sequence during stable operation under normal load. Specifically, multiple operating cycles under typical load conditions are selected, and the delay value corresponding to the position of the minimum sliding error between the voltage rate of change and the speed rate of change within each cycle is extracted. After multi-window and multi-sample statistics, the mean or mode is taken as the voltage response delay reference in the stable state. For example, when an electric screwdriver is operating under no-load or light-load conditions, voltage regulation typically causes a noticeable speed change within 1-2 sampling intervals. If the sampling period is 2ms, the reference value can be set between 2-4ms, that is, 1-2 time steps.

[0139] The preset current delay reference value reflects the time coupling delay between the internal electromagnetic response characteristics of the motor and the current feedback of the load change. Under static load or constant torque, the current changes are usually faster, so its reference value should be smaller than the voltage delay reference value. By sampling and analyzing the time difference between the current change rate and the speed response under a large number of normal operating conditions, the most common or average minimum delay time is statistically obtained as the set value. This value can be set at around 1-2ms. In some high-speed response systems, it can even be set to within 1 sampling point (i.e., 2ms).

[0140] The values of the two should not be fixed to a certain constant, but should have parameterizable adjustment capabilities. In actual deployment, they can be automatically calibrated through preset curves or system identification algorithms based on different motor models, control frequencies, load inertias, and sensor response times.

[0141] The absolute value processing of the voltage delay difference and the current delay difference is performed to obtain a non-negative delay offset value pair, specifically including:

[0142] For each time window, the voltage delay difference and current delay difference corresponding to the window are transformed into absolute values respectively. The mathematical expression is: , the voltage delay difference Transformed into , current delay difference Transformed into , these two values represent the absolute degree of voltage response delay and current response delay offset, respectively, without considering the offset direction. Finally, these two non-negative values are combined into an ordered number pair to form the non-negative delay offset value pair corresponding to the window.

[0143] In a preferred embodiment of the present invention, according to the mutation recognition sequence, the ternary synchronization data corresponding to each abnormal response moment is extracted, and the weighted average speed change rate is calculated to obtain the predicted speed offset sequence, including:

[0144] According to the abnormal response moment in the mutation recognition sequence, the speed change rate data, current change rate data, and voltage change rate data within a fixed prediction time length starting from any abnormal response moment are extracted from the rate evolution data set to obtain the abnormal response data set;

[0145] Calculate the weighted factors of the current change rate and the voltage change rate based on the response abnormality data set, and calculate the weighted average speed change rate at the moment of the response abnormality in combination with the speed change rate data;

[0146] The predicted speed offset is obtained according to the weighted average speed change rate and the fixed prediction time;

[0147] The predicted speed offsets corresponding to all abnormal response moments are arranged in chronological order to obtain a predicted speed offset sequence.

[0148] In an embodiment of the present invention, according to the response abnormality moment in the mutation identification sequence, the speed change rate data, current change rate data and voltage change rate data within a fixed prediction time length starting from any response abnormality moment are extracted from the rate evolution data set to obtain the response abnormality data set, which accurately focuses on the local dynamic process when the motor state suddenly changes, ensures that the predicted input data is consistent in time and physical correlation, and lays a high-fidelity data foundation for the subsequent calculation of the speed change trend; according to the response abnormality data set, the weighted factors of the current change rate and the voltage change rate are calculated, and combined with the speed change rate data, the weighted average speed change rate at the response abnormality moment is calculated to reflect the voltage and current transients. The real force intensity of time-varying effects on the motor response solves the problem of easy distortion of single-parameter driven speed response in traditional methods; the predicted speed offset is obtained based on the weighted average speed change rate and the fixed prediction time, ensuring that the predicted value has a reasonable source, data-driven logic and time domain validity, effectively supporting the quantitative basis required for the next step of compensation calculation; the predicted speed offsets corresponding to all abnormal response moments are arranged in chronological order to obtain a predicted speed offset sequence, realizing the transformation from discrete prediction points to continuous compensation control trajectory, ensuring that the control system has a responsive prediction reference at each key disturbance node, and also providing quantitative support for the design of smooth control strategies.

[0149] The calculation formula of the predicted speed offset is: ,

[0150] in, For the The predicted speed deviation at the time of abnormal response, To respond to the index of the abnormal moment, For a fixed prediction duration, is the total number of sampling points within a fixed prediction time, is the index of the sampling point within the fixed prediction duration, For the The current change rate of each sampling point is For the The current change rate of each sampling point is For the After the abnormal response time The speed change rate of each sampling point, is the preset current adjustment value, is the preset voltage adjustment value, is the preset constant adjustment value, is the coefficient.

[0151] in, is the weight coefficient, and its sum is 1.

[0152] In scenarios where the load disturbance is mainly manifested as a sudden change in the mechanical impedance on the output side (for example, when an electric screwdriver hits a steel plate), the current signal, as the first characteristic parameter of the load response, has the strongest sudden change, reflecting the sudden increase in the back electromotive force required by the rotor magnetic field. Therefore, in such high mechanical inertia conditions, the current weight coefficient should be increased. The proportion of The values of are 0.55, 0.25 and 0.2 respectively, which ensure that the prediction model is more sensitive to the coupling relationship between current and speed, and is especially suitable for medium and high speed gear impact load situations.

[0153] In applications where voltage disturbances significantly dominate the response characteristics (such as small electric drills with frequent PWM duty cycle adjustments or motor control strategy switching), the voltage fluctuation at the drive end often determines the rate of change of energy input. In this case, more attention should be paid to the voltage-speed coupling characteristics. The values of are 0.3, 0.5 and 0.2 respectively. At this time, the model is more sensitive to the fluctuation of the input side signal, and the prediction results focus more on the modeling performance of the response speed of the energy supply end, which is suitable for high-frequency control or soft start-stop scenarios.

[0154] In some working conditions that are sensitive to the balanced response of both supply and demand but the fluctuation range is not drastic, such as low-power daily power tools or systems with partial speed stabilization capabilities, a relatively neutral and balanced weight distribution can be adopted. The values of are 0.4, 0.4 and 0.2 respectively, which can maintain the stability of predictive modeling when the system parameter changes do not show dominant variables, reduce the abnormal prediction offset caused by extreme weight error amplification, and make the control logic more robust.

[0155] No matter what the scenario, The proportion of the constant adjustment item is generally maintained in the range of 0.15-0.25. Its function is to provide a minimum benchmark response when the mutation signal is not significant or the fluctuations of the two signals are close to zero, so as to avoid the situation where the denominator approaches 0 in the weighting process, thereby ensuring the numerical stability of the system and the completeness in the mathematical sense. The final weight value should be based on the historical operating condition data of the application equipment and tuned through experimental sampling or online learning.

[0156] In a preferred embodiment of the present invention, based on the response abnormality data set, the weighted factors of the current change rate and the voltage change rate are calculated, and combined with the speed change rate data, the weighted average speed change rate at the time of the response abnormality is calculated, including:

[0157] Within the fixed prediction duration of any response abnormality moment, the current change rate of each sampling point in the response abnormality segment is read in sequence, and the current weight value is obtained based on its absolute value and the preset current adjustment value;

[0158] The voltage change rate of each sampling point in the same response abnormal segment is read in sequence, and the voltage weight value is obtained according to its absolute value and the preset voltage adjustment value;

[0159] The current weight value, voltage weight value and preset constant adjustment value corresponding to each sampling point are integrated to obtain a comprehensive weighting factor;

[0160] Multiply the speed change rate of each sampling point by its corresponding comprehensive weighting factor to obtain the weighted speed change rate;

[0161] All weighted speed change rates within the response abnormality segment are summed and divided by the sum of all comprehensive weighting factors within the response abnormality segment to obtain a weighted average speed change rate.

[0162] In an embodiment of the present invention, within a fixed prediction duration of any abnormal response moment, the current change rate of each sampling point in the abnormal response segment is read in sequence, and the current weight value is obtained based on its absolute value and the preset current adjustment value, thereby effectively identifying the dominant influence of the current change on the speed during the mutation period; the voltage change rate of each sampling point in the same abnormal response segment is read in sequence, and the voltage weight value is obtained based on its absolute value and the preset voltage adjustment value, thereby ensuring that the system fully considers the incentive effect of the energy supply side in the abnormal response judgment; the current weight value, voltage weight value and preset constant adjustment value corresponding to each sampling point are fused to obtain a comprehensive weighting factor, thereby achieving the goal of abnormal response judgment. The organic unification of the influence of multiple source variables overcomes the problem that a single weight may cause deviation amplification; the speed change rate of each sampling point is multiplied by its corresponding comprehensive weighting factor to obtain the weighted speed change rate, so that each data point is no longer treated equivalently, but is differentially mapped based on the response capability, which suppresses the system's overfitting to irrelevant changes; all weighted speed change rates in the response abnormality segment are summed and divided by the sum of all comprehensive weighting factors in the response abnormality segment to obtain the weighted average speed change rate. While filtering out the influence of random disturbances, the key components that truly affect the system speed evolution are retained, avoiding the risk of single-point values dominating the prediction.

[0163] Among them, the preset current adjustment value, preset voltage adjustment value and preset constant adjustment value respectively correspond to the adjustment control of the current change rate, voltage change rate and system basic balance factor, and are important weight benchmarks for constructing the multi-parameter response influence distribution.

[0164] Preset current adjustment value It is mainly used to normalize the absolute value of the current change rate. Its purpose is to enable the current response degree to establish a standard scale for relative comparison between different sampling points. By comparing the current change rate at a certain moment with the preset value, the current weight is calculated, and the system can determine whether the current fluctuation at the sampling point is significant. If the current response is too intense and the preset current adjustment value is too small, the weight will be too high, thereby amplifying the influence of the current in the model. If the preset current adjustment value is set too large, the contribution of the current change to the weighted speed change rate will be weakened. Therefore, the specific value of the preset current adjustment value should be set in combination with the motor current fluctuation range under typical loads. For example, in a conventional electric screwdriver, the current change range per unit time is usually ±1.5A. The preset current adjustment value can be set to 1A, which not only ensures that normal operating fluctuations are covered, but also has good resolution for sudden mutations.

[0165] Preset voltage adjustment value This serves the same purpose as the preset current adjustment value when calculating voltage weights. It normalizes the absolute value of the voltage rate of change to assess the degree of dominance of the voltage application terminal during a sudden change response. As a normalization factor, the preset voltage adjustment value should reflect the effective response range of the average voltage fluctuation in motor speed control. In PWM speed control systems, the voltage rate of change is typically around ±2V / ms. Therefore, a preset voltage adjustment value of approximately 1.5V / ms can be selected to ensure objectivity and stability in determining voltage dominance within the sudden change identification window.

[0166] Preset constant adjustment value The main function of is to introduce a reference coefficient that provides a basic control weight even when voltage and current fluctuations are not significant. This is used to balance the model's output stability in scenarios with weak signal fluctuations. This constant adjustment value can be set to a constant between the normalized voltage and current weights. The recommended initial value is 1, which allows for a consistent reference value with the other normalized ratios. In actual control, dynamic adjustment can also be used to appropriately correct the frequency of the sudden change, thereby avoiding prediction errors caused by over-reliance on voltage or current changes.

[0167] In summary, the functions of these three preset values are to provide a normalized reference for the current and voltage change rates, and to provide a stable benchmark for the construction of weighting factors. Their values are mainly based on the statistical analysis of the measured data range of motor operation, the power supply regulation mechanism, and the algorithm tolerance design. Experimental correction and parameter calibration are required before system integration to adapt to the actual operating characteristics of specific motor models and load types.

[0168] in, For the The weighted average speed change rate of the sampling points, and Respectively The current weight value and voltage weight value of each sampling point, For the The comprehensive weighting factor of the sampling points, For the The weighted speed change rate of each sampling point.

[0169] In a preferred embodiment of the present invention, the compensation voltage increment is calculated based on the difference between the predicted speed offset sequence and the real-time speed to obtain the corrected voltage data, including:

[0170] According to the predicted speed offset sequence, the predicted speed offset at any abnormal response moment is extracted, and the real-time speed at the current moment is extracted;

[0171] The difference between the predicted speed offset and the real-time speed is calculated to obtain the speed compensation demand value;

[0172] Within the fixed prediction time of the abnormal response moment, the voltage change rate and the speed change rate are extracted, and the average corresponding ratio between the two is calculated to obtain the response conversion factor;

[0173] Calculate the compensation voltage increment according to the response conversion factor and the speed compensation requirement value;

[0174] The corrected voltage data is obtained according to the compensation voltage increment and the control voltage at the current moment.

[0175] In an embodiment of the present invention, based on a sequence of predicted speed offsets, the predicted speed offset at any moment of response anomaly is extracted, and the real-time speed at the current moment is extracted, which helps to form a quantitative description of the system state offset under the same time reference and provides a basic judgment basis for the subsequent error-driven compensation mechanism; the predicted speed offset and the real-time speed are differentially calculated to obtain a speed compensation demand value, effectively avoiding the risk of misadjustment due to local fluctuations; within a fixed prediction duration at the moment of response anomaly, the voltage change rate and the speed change rate are extracted, and the average corresponding ratio between the two is calculated to obtain a response conversion factor, and a nonlinear coefficient mapping from speed error to voltage increment is constructed; based on the response conversion factor and the speed compensation demand value, the compensation voltage increment is calculated, and the dynamic conversion of speed offset-voltage compensation is achieved through parameter coupling, forming a direct path from the predicted trend to the voltage correction amount; based on the compensation voltage increment and the control voltage at the current moment, the corrected voltage data is obtained, and the organic combination of steady-state adjustment and sudden intervention is achieved through this correction value, effectively maintaining the stable operating state of the brushed motor speed.

[0176] The calculation formula of the compensation voltage increment is: ,

[0177] in, For the The compensation voltage increment at the moment of abnormal response, For the The predicted speed deviation at the time of abnormal response, For the The real-time speed of the response abnormal moment, is the number of sampling points within a fixed prediction time, is the index of the sampling point within the fixed prediction duration, For the The current change rate of each sampling point is For the The voltage change rate of each sampling point is For the The speed change rate of each sampling point, is the preset current adjustment value, is the preset voltage adjustment value, is a constant, is the coefficient.

[0178] in, is a minimum constant used to avoid division by zero errors, set to . is the weight coefficient, and its sum is 1.

[0179] In the working conditions applicable to most power tools where the load amplitude is not extreme but fluctuates, current is the most sensitive indicator of load change. It usually first shows peak fluctuation at the moment of sudden change on the mechanical end, so it should be given the highest weight. Voltage is the main means for the control system to apply the drive signal. Its change directly reflects the adjustment intention, but its response speed is slightly slower than that of current, so its weight is moderate. Constant term The introduction of is to retain a certain response basis when the voltage and current signals tend to be stable or close to zero rate of change, ensuring that even if the system is in a perturbation or quasi-steady state, it can generate a moderate compensation signal. The values are 0.5, 0.3 and 0.2 respectively.

[0180] When the controlled object is in a typical impact scenario with a sudden and drastic load change, such as an electric impact drill or hammer drill, the system's sensitivity to current response should be significantly enhanced, enabling faster judgment and adjustment under high dynamic characteristics. At the same time, the weight of the voltage change rate should be appropriately lowered to avoid overly aggressive adjustments that cause voltage jitter, and the constant bias should be slightly reduced to improve the resolution of the judgment threshold, making the compensation process more compact and the response more decisive. The values are 0.6, 0.25 and 0.15 respectively.

[0181] In scenarios where steady-state operation accuracy is required to be high but the load changes slowly, such as micro electric actuators and precision servo control systems, more reliance is placed on fine-tuning to maintain a constant speed state, and current fluctuations are not severe, thus reducing its dominant position; and regulation is more achieved through high-frequency voltage PWM fine-tuning, so the voltage is given a higher weight; the constant term becomes a key factor in this scenario, used to enhance the system's adjustment sensitivity in the perturbation stage, thereby preventing the static point dull zone and error accumulation, so The values are 0.3, 0.4 and 0.3 respectively.

[0182] In a preferred embodiment of the present invention, a compensation voltage signal is generated based on the corrected voltage data and transmitted to the drive input terminal of the brushed motor to ensure the stability of the motor speed, including:

[0183] Calculate the change range between the correction voltage data and the control voltage at the previous moment to obtain the correction range;

[0184] When the correction amplitude exceeds the preset voltage adjustment threshold, the correction amplitude is limited to ensure that the correction amplitude does not exceed the preset voltage adjustment threshold;

[0185] Determine whether the corrected voltage data exceeds the voltage output range of the brushed motor. If so, limit the corrected voltage data to within the voltage output range of the brushed motor.

[0186] After the above restrictions, the restricted corrected voltage data is obtained, which is weighted averaged with the corrected voltage data to obtain the smoothed corrected voltage data;

[0187] According to the smoothed corrected voltage data, its value is converted into a voltage output instruction, a compensation voltage signal is generated, and it is transmitted to the drive input end of the brushed motor.

[0188] In an embodiment of the present invention, the change amplitude between the corrected voltage data and the control voltage at the previous moment is calculated to obtain the corrected amplitude, and the output adjustment amplitude of the controller in the current control cycle is quantified to facilitate the identification of whether there is a voltage mutation behavior; when the corrected amplitude exceeds the preset voltage adjustment threshold, the corrected amplitude is limited to ensure that the corrected amplitude does not exceed the preset voltage adjustment threshold, effectively suppressing the impact of instantaneous large-amplitude voltage changes on the motor winding or drive circuit, and avoiding the motor overshoot caused by excessive control; it is judged whether the corrected voltage data exceeds the voltage output range of the brush motor. If the result is yes, the corrected voltage data is limited to the voltage output range of the brush motor. Ensure that the control output is within the electrical range physically allowed by the equipment to prevent the controller output from going out of bounds due to inaccurate prediction or adjustment; after the above restrictions, the restricted corrected voltage data is obtained, and the restricted corrected voltage data is weighted averaged with the corrected voltage data to obtain the smoothed corrected voltage data, which can eliminate the voltage fluctuations caused by disturbance estimation deviation or transient prediction error, and effectively avoid sudden changes in the voltage output signal; according to the smoothed corrected voltage data, its numerical value is converted into a voltage output instruction, and a compensation voltage signal is generated, which is transmitted to the drive input end of the brushed motor, ensuring the response consistency from data calculation to actual physical action, and effectively realizing active intervention in speed fluctuations and dynamic voltage stabilization.

[0189] When the correction amplitude exceeds the preset voltage adjustment threshold, the correction amplitude is limited to ensure that the correction amplitude does not exceed the preset voltage adjustment threshold, specifically including:

[0190] In each control cycle, the corrected voltage data at the current moment and the control voltage data at the previous moment are obtained, and the difference between the two is calculated to obtain the correction amplitude; then, a preset voltage adjustment threshold is set to represent the maximum allowable adjustment range of the voltage per unit time. If the absolute value of the correction amplitude is greater than the preset threshold, it indicates that the current voltage changes too fast or too large, which may cause the motor system response overshoot or driver output abnormality. Therefore, the correction amplitude is limited, that is, the correction amplitude is adjusted to a correction value with the sign unchanged and the absolute value equal to the preset voltage adjustment threshold, thereby obtaining a limited voltage correction result to ensure that the correction amplitude is within the system safety adjustment range; if the absolute value of the correction amplitude does not exceed the preset voltage adjustment threshold, the original corrected voltage data is kept unchanged, thereby completing the dynamic control suppression of the rapid voltage fluctuation behavior.

[0191] The process of determining whether the corrected voltage data exceeds the voltage output range of the brushed motor is as follows: if so, limiting the corrected voltage data to within the voltage output range of the brushed motor is performed. Specifically, the process includes:

[0192] Get the voltage value after the above limit processing Then, based on the rated operating range of the brushed motor used, set the minimum acceptable operating voltage of the motor. and maximum operating voltage ,in Used to limit the motor starting failure or insufficient output torque caused by low voltage. It is used to prevent the risk of motor insulation damage, winding overheating or driver breakdown caused by excessive voltage; in actual operation, it is more and and relationship, if Less than , then Adjust to ;like Greater than , then Adjust to ;like If it is within this range, it remains unchanged, and the voltage correction data after output limitation is finally obtained. , ensuring that the voltage value is always within the physical range allowed for normal operation of the brushed motor.

[0193] After the above restrictions, the restricted corrected voltage data is obtained, and the restricted corrected voltage data is weighted averaged with the corrected voltage data to obtain the smoothed corrected voltage data, which specifically includes:

[0194] After obtaining the above range limit, the corrected voltage and the initial correction voltage Afterwards, a weighted average strategy is used to generate the smooth correction voltage that is ultimately used to control the output Specifically, set a smoothing factor , The value range of is 0-1, and is usually selected between 0.7 and 0.95 to achieve a trade-off between response sensitivity and control stability; and Perform weighted fusion to obtain the smoothed corrected voltage calculation expression: ; Among them, if the current limit is small, and Close, then and The phase difference is small, which can maintain high system responsiveness; if the limit amplitude is large, the smooth output will effectively suppress input jumps, achieve continuous voltage transition, and improve the driving stability under dynamic conditions of the motor.

[0195] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for controlling the speed of a brushless motor, characterized in that: The method comprises: Collect the voltage, current, and speed of the brushless motor and perform time alignment to obtain a three-element synchronized data set; Based on the three-element synchronous data set, the change rates of voltage, current and speed at adjacent moments are calculated, and the corresponding change rate sequences are constructed to obtain the rate evolution data set; According to the preset time window, the change rate sequence in the rate evolution data set is divided into multiple window intervals, and within each window interval, the delay amount group is calculated to obtain the response delay sequence; By calculating the difference between the response delay sequence and the preset delay group, it is determined whether there is a sudden change in the response of the brushed motor, and the corresponding abnormal response time is recorded to obtain the sudden change identification sequence; According to the mutation recognition sequence, the rate evolution data corresponding to each abnormal response moment is extracted, the weighted average speed change rate is calculated, and the predicted speed offset sequence is obtained; According to the difference between the predicted speed offset sequence and the real-time speed, the compensation voltage increment is calculated to obtain the corrected voltage data; Based on the corrected voltage data, a compensation voltage signal is generated and transmitted to the drive input of the brushed motor to ensure stable motor speed.

2. The speed control method of a brushed motor according to claim 1, characterized in that: Based on the three-element synchronous data set, the change rates of voltage, current, and speed at adjacent moments are calculated, and the corresponding change rate sequences are constructed to obtain the rate evolution data set, including: The voltage change rate is calculated based on the difference between the current voltage value and the previous voltage value in the ternary synchronous data set, combined with the sampling interval time, to obtain the voltage change rate sequence; According to the difference between the current value at the current moment and the current value at the previous moment in the ternary synchronous data set, combined with the sampling interval time, the current change rate is calculated to obtain the current change rate sequence; According to the difference between the current speed value and the previous speed value in the ternary synchronous data set, and combined with the sampling interval time, the speed change rate is calculated to obtain the speed change rate sequence; The rate evolution data set is composed according to the voltage change rate series, current change rate series and speed change rate series.

3. The speed control method of a brushed motor according to claim 2, characterized in that: According to the time window, the change rate sequence in the rate evolution data set is divided into multiple window intervals, and within each window interval, the delay amount group is calculated to obtain the response delay sequence, including: According to the length of the preset time window, the voltage change rate sequence, the current change rate sequence and the speed change rate sequence are divided into multiple window intervals in time order to obtain multiple rate windows; In each rate window, the corresponding voltage change rate sequence and speed change rate sequence are extracted, sequence deviation matching is performed, and the minimum delay time of speed relative to voltage is calculated to obtain the voltage delay value; In the same rate window, the current change rate sequence is extracted, the same sequence deviation matching is performed, and the minimum delay time of the speed relative to the current is calculated to obtain the current delay value; According to the voltage delay value and the current delay value in each rate window, a delay amount group is formed and arranged in time sequence to obtain a response delay sequence.

4. The method for controlling the speed of a brushed motor according to claim 3, wherein: In each rate window, the corresponding voltage change rate sequence and speed change rate sequence are extracted, sequence deviation matching is performed, and the minimum delay time of speed relative to voltage is calculated to obtain the voltage delay value, including: According to the start and end time of the rate window, continuous data points of the voltage change rate sequence and the speed change rate sequence within the rate window are extracted respectively to obtain the voltage change rate window segment and the speed change rate window segment; Keeping the position of the voltage change rate window segment unchanged, the speed change rate window segment is slid backward along the time axis by several sampling points within the current rate window to construct a first speed delay sequence; Normalizing the voltage change rate window segments and the first speed delay sequence, scaling their numerical ranges to the interval [0, 1], and obtaining a first normalized segment set; Calculate the mean absolute error between the voltage and the corresponding rotational speed according to the first normalized segment set to obtain voltage sliding offset value data; According to the voltage sliding offset value data, the number of sliding sampling points corresponding to the minimum voltage sliding offset value is identified, and combined with the sampling interval time, the offset time of the speed relative to the voltage in the current rate window is determined to obtain the voltage delay value.

5. The method for controlling the speed of a brushed motor according to claim 4, wherein: Within the same rate window, extract the current change rate sequence, perform the same sequence deviation matching, calculate the minimum delay time of the speed relative to the current, and obtain the current delay value, including: Within the same rate window, continuous data points of the current change rate sequence within the rate window are extracted to obtain a current change rate window segment; Keeping the position of the current change rate window segment unchanged, the speed change rate window segment is slid backward along the time axis by several sampling points within the current rate window to construct a second speed delay sequence; Normalizing the current change rate window segments and the second speed delay sequence, scaling their numerical ranges to the interval [0, 1], and obtaining a second normalized segment set; Calculating the mean absolute error between the current and the corresponding rotational speed based on the second normalized segment set to obtain current sliding offset value data; According to the current sliding offset value data, the number of sliding sampling points corresponding to the minimum current sliding offset value is identified, and combined with the sampling interval time, the offset time of the speed relative to the current in the current rate window is determined to obtain the current delay value.

6. The method for controlling the speed of a brushed motor according to claim 5, wherein: By calculating the difference between the response delay sequence and the preset delay group, it is determined whether there is a sudden change in the response of the brushed motor, and the corresponding abnormal response time is recorded to obtain the sudden change identification sequence, including: According to the voltage delay value and the current delay value of each rate window in the response delay sequence, the difference between them and the preset voltage delay reference value and the preset current delay reference value is calculated to obtain the voltage delay difference and the current delay difference; Performing absolute value processing on the voltage delay difference and the current delay difference to obtain a non-negative delay offset value pair; Determine whether any component of the non-negative delay offset value pair exceeds a preset offset threshold. If yes, a response mutation occurs within the rate window, and mark the start time of the rate window as the response abnormality moment. Arrange all abnormal response moments in chronological order to obtain the mutation recognition sequence.

7. The method for controlling the speed of a brushed motor according to claim 6, wherein: According to the mutation recognition sequence, the ternary synchronization data corresponding to each abnormal response moment is extracted, and the weighted average speed change rate is calculated to obtain the predicted speed offset sequence, including: According to the abnormal response moment in the mutation recognition sequence, the speed change rate data, current change rate data, and voltage change rate data within a fixed prediction time length starting from any abnormal response moment are extracted from the rate evolution data set to obtain the abnormal response data set; Calculate the weighted factors of the current change rate and the voltage change rate based on the response abnormality data set, and calculate the weighted average speed change rate at the moment of the response abnormality in combination with the speed change rate data; The predicted speed offset is obtained according to the weighted average speed change rate and the fixed prediction time; The predicted speed offsets corresponding to all abnormal response moments are arranged in chronological order to obtain a predicted speed offset sequence.

8. The method for controlling the speed of a brushed motor according to claim 7, wherein: Based on the response abnormality data set, the weighted factors of the current change rate and the voltage change rate are calculated. Combined with the speed change rate data, the weighted average speed change rate at the moment of the response abnormality is calculated, including: Within the fixed prediction duration of any response abnormality moment, the current change rate of each sampling point in the response abnormality segment is read in sequence, and the current weight value is obtained based on its absolute value and the preset current adjustment value; The voltage change rate of each sampling point in the same response abnormal segment is read in sequence, and the voltage weight value is obtained according to its absolute value and the preset voltage adjustment value; The current weight value, voltage weight value and preset constant adjustment value corresponding to each sampling point are integrated to obtain a comprehensive weighting factor; Multiply the speed change rate of each sampling point by its corresponding comprehensive weighting factor to obtain the weighted speed change rate; All weighted speed change rates within the response abnormality segment are summed and divided by the sum of all comprehensive weighting factors within the response abnormality segment to obtain a weighted average speed change rate.

9. The method for controlling the speed of a brushed motor according to claim 8, wherein: According to the difference between the predicted speed offset sequence and the real-time speed, the compensation voltage increment is calculated to obtain the corrected voltage data, including: According to the predicted speed offset sequence, the predicted speed offset at any abnormal response moment is extracted, and the real-time speed at the current moment is extracted; The difference between the predicted speed offset and the real-time speed is calculated to obtain the speed compensation demand value; Within the fixed prediction time of the abnormal response moment, the voltage change rate and the speed change rate are extracted, and the average corresponding ratio between the two is calculated to obtain the response conversion factor; Calculate the compensation voltage increment according to the response conversion factor and the speed compensation requirement value; The corrected voltage data is obtained according to the compensation voltage increment and the control voltage at the current moment.

10. The method for controlling the speed of a brushed motor according to claim 9, wherein: Generate a compensation voltage signal based on the corrected voltage data and transmit it to the drive input of the brushed motor to ensure stable motor speed, including: Calculate the change range between the correction voltage data and the control voltage at the previous moment to obtain the correction range; When the correction amplitude exceeds the preset voltage adjustment threshold, the correction amplitude is limited to ensure that the correction amplitude does not exceed the preset voltage adjustment threshold; Determine whether the corrected voltage data exceeds the brush motor voltage output range. If so, limit the corrected voltage data to within the brush motor voltage output range. After the above restrictions, the restricted corrected voltage data is obtained, which is weighted averaged with the corrected voltage data to obtain the smoothed corrected voltage data; According to the smoothed corrected voltage data, its value is converted into a voltage output instruction, a compensation voltage signal is generated, and it is transmitted to the drive input end of the brushed motor.

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