A double-stator single-rotor brush hollow cup motor and an optimal control method

Abstract

The application discloses a double-stator single-rotor brush hollow cup motor and an optimal control method, relates to the technical field of motor control, and comprises the following steps: injecting a high-frequency detection pulse into a pulse driving sequence of an input motor to obtain a dynamic resistance change amount; acquiring a copper wire temperature coefficient of a rotor assembly to obtain a real-time virtual temperature value of the rotor assembly; judging whether the real-time virtual temperature value exceeds a preset thermal runaway boundary threshold value, amplifying a maximum allowable current parameter when the real-time virtual temperature value does not exceed the preset thermal runaway boundary threshold value, and smoothly reducing the maximum allowable current parameter when the real-time virtual temperature value exceeds the preset thermal runaway boundary threshold value; acquiring current rotating speed data of the motor to dynamically down-regulate a switching frequency parameter; and when both the maximum allowable current parameter and the switching frequency parameter are down-regulated, if the real-time virtual temperature value continuously rises, a sliding window with a duty ratio of zero is injected into the pulse driving sequence. The application has the effect of improving the operation safety and service life of the double-stator single-rotor brush hollow cup motor under complex high-load working conditions.

Description

Technical Field

[0001] This application relates to the technical field of motor control, and in particular to a dual-stator single-rotor brushed coreless motor and an optimized control method thereof. Background Technology

[0002] Dual-stator single-rotor brushed coreless motors, due to their unique structural design, possess extremely high air gap magnetic flux density and torque density. Furthermore, because the rotor has no iron core, its moment of inertia is extremely low, making them crucial in many high-precision and high-performance drive applications. Their superior physical characteristics directly determine the response speed and operational efficiency of related equipment.

[0003] In existing technologies, the drive control of brushed coreless motors typically employs a fixed maximum current limiting scheme and a constant frequency pulse drive. However, when faced with the strong magnetic field and high power output demands of a dual-stator motor, several problems arise. First, the coreless rotor lacks a core as a heat-absorbing substrate and is suspended in the narrow gap between the inner and outer stators, severely obstructing the heat dissipation path. Under high torque acceleration, it is highly susceptible to thermal runaway and burnout due to rapid transient temperature rise. Furthermore, it is impossible to implant physical temperature sensors inside the high-speed rotating thin-walled coreless rotor for real-time temperature monitoring, resulting in blind spots in temperature perception. Second, traditional fixed parameter control is too rigid. It cannot fully extract the maximum burst torque from the dual-stator structure when the motor is cold, and it cannot address the severe skin effect caused by high-frequency drive by implementing frequency conversion loss reduction. Moreover, it lacks a defense mechanism to provide transient heat dissipation respite for the motor under extreme conditions, severely limiting the motor's lifespan and ultimate performance.

[0004] Therefore, how to improve the temperature monitoring capability of a dual-stator single-rotor brushed coreless motor during operation, and how to dynamically optimize its control while ensuring operational safety, has become an urgent problem to be solved. Summary of the Invention

[0005] The purpose of this invention is to provide a dual-stator single-rotor brushed hollow cup motor and an optimized control method to solve the problems mentioned in the background art.

[0006] In a first aspect, this application provides an optimized control method for a dual-stator single-rotor brushed hollow cup motor, the method comprising: Inject high-frequency detection pulses into the pulse drive sequence of the input motor, extract the terminal voltage data and current response data of the rotor assembly, and obtain the dynamic resistance change based on the terminal voltage data and current response data; The temperature coefficient of the copper wire of the rotor assembly is obtained, and the dynamic resistance change is physically mapped to the temperature coefficient of the copper wire to obtain the real-time virtual temperature value of the rotor assembly. Determine whether the real-time virtual temperature value exceeds the preset thermal runaway boundary threshold. If it does not exceed the threshold, increase the maximum allowable current parameter. If it exceeds the threshold, smoothly reduce the maximum allowable current parameter. The current speed data of the motor is obtained, and the switching frequency parameter is dynamically adjusted by combining the current speed data with the real-time virtual temperature value. The maximum allowable current parameter and the switching frequency parameter are monitored. When both the maximum allowable current parameter and the switching frequency parameter are reduced, it is determined whether the real-time virtual temperature value increases. If the real-time virtual temperature value continues to increase, a sliding window with a duty cycle of zero is injected into the pulse drive sequence.

[0007] Preferably, the step of injecting high-frequency detection pulses into the pulse drive sequence of the input motor to extract the terminal voltage data and current response data of the rotor assembly specifically includes: Obtain the pulse drive sequence of the current input motor, extract the pulse duty cycle data in the pulse drive sequence, and determine the turn-off interval of the drive sequence based on the pulse duty cycle data; A high-frequency detection pulse is generated within the off interval and injected into the pulse drive sequence to obtain a hybrid drive sequence, which is then output to the rotor assembly. During the signal triggering period of the high-frequency detection pulse in the hybrid drive sequence, the transient voltage signal and transient current signal of the rotor assembly in the excited state are acquired. Discrete sampling and digitization processing are performed on the transient voltage signal and the transient current signal to obtain terminal voltage data and current response data with the same time scale.

[0008] Preferably, the step of obtaining the dynamic resistance change based on the terminal voltage data and current response data specifically includes: Extract the voltage amplitude parameter from the terminal voltage data, and extract the current amplitude parameter from the current response data; The real-time impedance value of the rotor assembly is calculated by dividing the voltage amplitude parameter by the current amplitude parameter. Obtain the reference impedance value of the rotor assembly under calibrated cold conditions, extract the impedance difference between the real-time impedance value and the reference impedance value, and use the impedance difference as the dynamic resistance change.

[0009] Preferably, the step of obtaining the temperature coefficient of the copper wire of the rotor assembly and physically mapping the dynamic resistance change with the temperature coefficient of the copper wire to obtain the real-time virtual temperature value of the rotor assembly specifically includes: Obtain the preset material data of the rotor assembly, obtain the temperature coefficient of the copper wire of the rotor assembly based on the material data, and extract the calibration cold environment temperature value corresponding to the reference impedance value. Divide the dynamic resistance change by the reference impedance value to obtain the relative impedance drift ratio of the rotor assembly. Divide the relative impedance drift ratio by the temperature coefficient of the copper conductor to obtain the initial temperature rise quotient, and compare the initial temperature rise quotient with the preset physical melting temperature rise quotient. When it is determined that the initial temperature rise quotient is less than the physical melting temperature rise quotient, an effective temperature rise mark is generated. Based on the effective temperature rise marker, invalid jitter bits of the initial temperature rise quotient are removed, and the processed value is confirmed as the instantaneous temperature rise value of the rotor assembly. By combining the instantaneous temperature rise value with the calibrated cold ambient temperature value, the current operating temperature value of the rotor assembly is obtained, and the current operating temperature value is marked as the real-time virtual temperature value.

[0010] Preferably, the step of determining whether the real-time virtual temperature value exceeds a preset thermal runaway boundary threshold, increasing the maximum allowable current parameter when it does not exceed the threshold, and smoothly reducing the maximum allowable current parameter when it does exceed the threshold, specifically includes: Obtain the preset thermal runaway boundary threshold and the basic current limit, subtract the real-time virtual temperature value from the thermal runaway boundary threshold to obtain the temperature difference value, and identify the positive or negative value of the temperature difference value. Based on the positive or negative sign, determine whether the real-time virtual temperature value exceeds the thermal runaway boundary threshold; If it is determined that the real-time virtual temperature value does not exceed the thermal runaway boundary threshold, the basic current limit is multiplied by the preset overload scaling factor to generate the maximum allowable current parameter. If it is determined that the real-time virtual temperature value exceeds the thermal runaway boundary threshold, then overshoot temperature difference data is generated based on the temperature difference. The reduced maximum allowable current parameter is obtained by subtracting the product of the overshoot temperature difference data and the preset attenuation slope from the basic current limit.

[0011] Preferably, the step of acquiring the current motor speed data and dynamically adjusting the switching frequency parameter in combination with the current speed data and the real-time virtual temperature value specifically includes: Obtain the rotor pulse signal of the rotor assembly at the current time, extract the pulse signal sequence of the rotor pulse signal, and obtain the current speed data of the motor based on the pulse signal sequence; Configure the current rotation speed data as a reference operating parameter, and convert the real-time virtual temperature value into a corresponding dynamic adjustment coefficient. The benchmark operating parameters are proportionally multiplied according to the dynamic adjustment coefficient to generate the comprehensive thermal frequency stress value under the current operating load. Obtain a pre-constructed stress-frequency attenuation mapping table, use the comprehensive thermal-frequency stress value as an index parameter, index the stress-frequency attenuation mapping table to obtain the target data node, and extract the initial frequency deduction amount bound in the target data node. The initial frequency deduction amount is compared with the preset maximum allowable reduction parameter for boundary verification. The initial frequency deduction amount after verification is passed is taken as the target frequency deduction amount. The switching frequency parameter of the motor is dynamically adjusted according to the target frequency deduction amount.

[0012] Preferably, the step of constructing the stress-frequency attenuation mapping table is as follows: Obtain motor test sample records, and extract test speed data and test temperature data of the motor test sample records in a stable operating state; The test rotation speed data is multiplied proportionally according to the test temperature data to generate the corresponding sample's test thermal frequency stress value; Extract the limit stable switching frequency in the corresponding state from the motor test sample record, and calculate the difference between the limit stable switching frequency and the preset initial rated frequency. Use the difference as the test frequency deduction amount. The test thermal frequency stress value and the test frequency deduction amount are spliced ​​and encapsulated to generate independent mapping data nodes; By aggregating multiple mapping data nodes and arranging them in order of magnitude of the tested thermal frequency stress values, a stress-frequency attenuation mapping relationship table is generated.

[0013] Preferably, the maximum allowable current parameter and the switching frequency parameter are monitored. When both the maximum allowable current parameter and the switching frequency parameter are reduced, it is determined whether the real-time virtual temperature value increases. If the real-time virtual temperature value continues to increase, the step of injecting a sliding window with a zero duty cycle into the pulse drive sequence is as follows: The maximum allowable current parameter and the switching frequency parameter are monitored, and it is determined whether both the maximum allowable current parameter and the switching frequency parameter are reduced. If it is determined that both the maximum allowable current parameter and the switching frequency parameter have decreased, the real-time virtual temperature value is continuously collected within multiple sampling periods, and the difference between the real-time virtual temperature values ​​of adjacent periods is calculated to obtain a dynamic temperature difference sequence. Identify the positive or negative value of all temperature difference values ​​in the dynamic temperature difference sequence, and obtain the trend of the real-time virtual temperature value based on the positive or negative value. Determine whether the trend is upward; if it is, generate an intervention trigger command. Based on the intervention trigger command, the continuous conduction interval of the pulse drive sequence is identified, and zero duty cycle data is written into the continuous conduction interval. A sliding window with a zero duty cycle is injected into the pulse drive sequence.

[0014] Secondly, this application provides a dual-stator single-rotor brushed hollow cup motor, comprising: Shaft, commutator, spool, brush, rear end cover, housing, inner magnetic ring, outer magnetic ring, and bearing; The shaft is located on the central axis of the housing. The inner magnetic ring and the outer magnetic ring are fixedly connected to the front end inside the housing. A gap is left between the inner magnetic ring and the outer magnetic ring. The bearing is fixedly connected inside the inner magnetic ring. The shaft passes through the outer magnetic ring and the inner magnetic ring and is fixedly connected to the inner wall of the bearing. The commutator is fixedly connected to the outer wall of the rear end of the shaft and is located inside the rear end of the housing. The spool is fixedly connected to the commutator and is located in the gap between the inner magnetic ring and the outer magnetic ring. When energized, the spool drives the shaft to rotate. The rear end cover is fixedly covered at the rear end of the housing. The rear end cover is provided with positive and negative terminals, which are connected to the brush plate. The brush plate is in contact with the commutator. The housing, the outer magnetic ring, the inner magnetic ring, and the bearing constitute a stator assembly; The shaft, the commutator, and the spool together form a rotor assembly. The brush and the rear cover together form the rear cover assembly.

[0015] In summary, this application includes at least one of the following beneficial technical effects: By injecting high-frequency detection pulses into the pulse drive sequence of the input motor, the terminal voltage and current response data of the rotor assembly are extracted, and the dynamic resistance change is obtained based on the terminal voltage and current response data. Then, the temperature coefficient of the copper wires of the rotor assembly is acquired, and the dynamic resistance change is physically mapped to the temperature coefficient of the copper wires to obtain the real-time virtual temperature value of the rotor assembly. Next, it is determined whether the real-time virtual temperature value exceeds a preset thermal runaway boundary threshold. If it does not exceed the threshold, the maximum allowable current parameter is amplified; if it does, the maximum allowable current parameter is smoothly reduced. Subsequently, the current speed data of the motor is acquired, and combined with the current speed data and the real-time virtual temperature value, the switching frequency parameter is dynamically adjusted downwards. Finally, the maximum allowable current parameter and the switching frequency parameter are monitored. When both are reduced and the real-time virtual temperature value continues to rise, a sliding window with a zero duty cycle is injected into the pulse drive sequence. This invention solves the problem of temperature measurement blind spots caused by the difficulty in installing temperature sensors inside coreless motors. While fully utilizing the maximum explosive performance of the motor, it effectively avoids the risk of thermal runaway and burnout under the strong magnetic field of dual stators, and improves the operational safety and service life of dual-stator single-rotor brushed coreless motors under complex high-load conditions. Attached Figure Description

[0016] Figure 1 This is a flowchart illustrating the steps of an optimized control method for a dual-stator single-rotor brushed hollow cup motor provided in an embodiment of this application. Figure 2 This is a structural diagram of a dual-stator single-rotor brushed hollow cup motor provided in an embodiment of this application.

[0017] Explanation of reference numerals in the attached diagram: 1. Shaft; 2. Commutator; 3. Coil; 4. Brush; 5. Rear end cover; 6. Housing; 7. Inner magnetic ring; 8. Outer magnetic ring; 9. Bearing. Detailed Implementation

[0018] The following is in conjunction with the appendix Figures 1-2 This application will be described in further detail, but the embodiments of the present invention are not limited thereto.

[0019] This application discloses a dual-stator single-rotor brushed hollow cup motor and an optimized control method.

[0020] In this embodiment, an optimized control method for a dual-stator single-rotor brushed hollow cup motor is provided, the method comprising: S100: Inject high-frequency detection pulses into the pulse drive sequence of the input motor, extract the terminal voltage data and current response data of the rotor assembly, and obtain the dynamic resistance change based on the terminal voltage data and current response data. S200: Obtain the temperature coefficient of the copper wire of the rotor assembly, physically map the dynamic resistance change to the temperature coefficient of the copper wire, and obtain the real-time virtual temperature value of the rotor assembly. S300: Determines whether the real-time virtual temperature value exceeds the preset thermal runaway boundary threshold. If it does not exceed the threshold, the maximum allowable current parameter is amplified. If it exceeds the threshold, the maximum allowable current parameter is smoothly reduced. S400: Obtain the current speed data of the motor, and dynamically adjust the switching frequency parameters by combining the current speed data with the real-time virtual temperature value. S500: Monitors the maximum allowable current parameter and switching frequency parameter. When both the maximum allowable current parameter and switching frequency parameter are reduced, it determines whether the real-time virtual temperature value is rising. If the real-time virtual temperature value continues to rise, it injects a sliding window with a zero duty cycle into the pulse drive sequence.

[0021] The steps for injecting high-frequency detection pulses into the pulse drive sequence of the input motor and extracting the terminal voltage data and current response data of the rotor assembly are as follows: Obtain the pulse drive sequence of the current input motor, extract the pulse duty cycle data from the pulse drive sequence, and determine the turn-off interval of the drive sequence based on the pulse duty cycle data; A high-frequency detection pulse is generated within the off interval and injected into the pulse drive sequence to obtain a hybrid drive sequence, which is then output to the rotor assembly. During the signal triggering period of the high-frequency detection pulse in the hybrid drive sequence, the transient voltage and transient current signals of the rotor assembly under excited state are acquired. The transient voltage and transient current signals are discretely sampled and digitized to obtain terminal voltage data and current response data with the same time scale.

[0022] In application, a dual-stator single-rotor brushed coreless motor is taken as an example. To ensure accurate system judgment, the system acquires the pulse drive sequence of the current input motor. Next, the system extracts the pulse duty cycle data from the pulse drive sequence, for example, finding that the current duty cycle is 60%. Based on this pulse duty cycle data, the system determines the off-time interval of the drive sequence to be the remaining 40% idle period. Then, within this off-time interval, the system generates a high-frequency detection pulse with a frequency of 10 kHz. This high-frequency detection pulse is then injected into the original pulse drive sequence, resulting in a hybrid drive sequence, which is then output to the rotor assembly. When this hybrid drive sequence falls within the signal triggering period of the high-frequency detection pulse, the system begins to collect transient voltage and current signals from the rotor assembly under electrical signal stimulation. The system then performs discrete sampling on these transient voltage and current signals, for example, sampling 500 times per second. Finally, the system digitizes the sampling results. Finally, the system obtains terminal voltage data with the same time stamp, such as a voltage of 12 volts, and current response data with the same time stamp, such as a current of 1.5 amperes.

[0023] The steps for obtaining the dynamic resistance change based on the terminal voltage data and current response data are as follows: Extract the voltage amplitude parameter from the terminal voltage data, and extract the current amplitude parameter from the current response data; The real-time impedance value of the rotor assembly is calculated by dividing the voltage amplitude parameter by the current amplitude parameter. Obtain the reference impedance value of the rotor assembly under calibrated cold conditions, extract the impedance difference between the real-time impedance value and the reference impedance value, and use the impedance difference as the dynamic resistance change.

[0024] In this application, we take a dual-stator single-rotor brushed coreless motor as an example. To ensure the accuracy of subsequent calculations, after receiving the previously processed data, the system first extracts the voltage amplitude parameter from the terminal voltage data, for example, an extracted voltage amplitude parameter of 12.0 volts. Next, the system extracts the current amplitude parameter from the current response data, for example, an extracted current amplitude parameter of 1.5 amperes. Then, the system divides the 12.0 volt voltage amplitude parameter by the 1.5 ampere current amplitude parameter. Through this division, the system calculates that the current real-time impedance value of the rotor assembly is exactly 8.0 ohms. Then, the system retrieves the reference impedance value of the rotor assembly under calibrated cold-state conditions at 20 degrees Celsius from memory, for example, a reference impedance value measured before leaving the factory of 6.0 ohms. Next, the system extracts the impedance difference between the calculated 8.0 ohm real-time impedance value and the 6.0 ohm reference impedance value. The system subtracts 6.0 ohms from 8.0 ohms, obtaining an impedance difference of 2.0 ohms. Finally, the system uses this 2.0-ohm impedance difference as the actual dynamic resistance change. This simple and direct method allows the system to calculate the resistance change during motor operation, facilitating subsequent processing.

[0025] The steps for obtaining the temperature coefficient of the copper wires in the rotor assembly, and physically mapping the dynamic resistance change to the temperature coefficient of the copper wires to obtain the real-time virtual temperature value of the rotor assembly are as follows: Obtain the preset material data of the rotor assembly, obtain the temperature coefficient of the copper wire of the rotor assembly based on the material data, and extract the calibration cold environment temperature value corresponding to the reference impedance value. Divide the dynamic resistance change by the reference impedance value to obtain the relative impedance drift ratio of the rotor assembly. Divide the relative impedance drift ratio by the temperature coefficient of the copper conductor to obtain the initial temperature rise quotient. Compare the initial temperature rise quotient with the preset physical melting temperature rise quotient. When it is determined that the initial temperature rise quotient is less than the physical melting temperature rise quotient, an effective temperature rise mark is generated. Based on the effective temperature rise marker, invalid jitter bits in the initial temperature rise quotient are removed, and the processed value is confirmed as the instantaneous temperature rise value of the rotor assembly. By combining the instantaneous temperature rise value with the calibrated cold ambient temperature value, the current operating temperature value of the rotor assembly is obtained, and the current operating temperature value is marked as the real-time virtual temperature value.

[0026] In application, taking a dual-stator single-rotor brushed coreless motor as an example, the system acquires pre-stored rotor assembly material data. Based on this data, the system determines that the temperature coefficient of the copper conductor in the rotor assembly is 0.4% per degree Celsius. Then, the system extracts the calibration cold-state ambient temperature corresponding to the reference impedance value, for example, 25 degrees Celsius. Next, the system divides the previously calculated 2.0-ohm dynamic resistance change by the 6.0-ohm reference impedance value, obtaining a relative impedance drift ratio of 33%. Then, the system divides 33% by the 0.4% copper conductor temperature coefficient, calculating an initial temperature rise quotient of 82.5. The system then compares 82.5 with the preset physical melting temperature rise quotient of 200. The system determines that 82.5 is indeed less than 200, thus generating an effective temperature rise marker. Based on this effective temperature rise marker, the system removes the invalid decimal places from 82.5, resulting in the integer 82, which is then confirmed as the instantaneous temperature rise value of the rotor assembly. Finally, the system added the instantaneous temperature rise of 82 degrees Celsius to the calibrated cold ambient temperature of 25 degrees Celsius, calculating the current operating temperature of the rotor assembly to be exactly 107 degrees Celsius. The system directly marked 107 degrees Celsius as the real-time virtual temperature value.

[0027] The steps for determining whether the real-time virtual temperature value exceeds the preset thermal runaway boundary threshold, increasing the maximum allowable current parameter when it does not exceed the threshold, and smoothly reducing the maximum allowable current parameter when it does exceed the threshold are as follows: Obtain the preset thermal runaway boundary threshold and basic current limit, subtract the real-time virtual temperature value from the thermal runaway boundary threshold to obtain the temperature difference value, and identify the positive or negative value of the temperature difference value. The real-time virtual temperature value is determined based on whether it exceeds the thermal runaway boundary threshold; If it is determined that the real-time virtual temperature value does not exceed the thermal runaway boundary threshold, the base current limit is multiplied by the preset overload scaling factor to generate the maximum allowable current parameter. If it is determined that the real-time virtual temperature value exceeds the thermal runaway boundary threshold, then overshoot temperature difference data is generated based on the temperature difference. Subtract the product of the overshoot temperature difference data and the preset attenuation slope from the base current limit to obtain the reduced maximum allowable current parameter.

[0028] In application, taking a dual-stator, single-rotor brushed coreless motor as an example, the system acquires the machine's preset thermal runaway boundary threshold, for example, 100 degrees Celsius, and simultaneously acquires the basic current limit, for example, 5.0 amps. Next, the system subtracts the 100-degree Celsius thermal runaway boundary threshold from the previously calculated real-time virtual temperature value of 107 degrees Celsius. The system calculates the difference, obtaining a temperature difference of 7 degrees Celsius. Then, the system identifies the sign of this 7-degree Celsius value, directly finding it to be positive. Based on this positive result, the system determines that the current real-time virtual temperature value has exceeded the thermal runaway boundary threshold. If the system found the temperature difference to be negative, meaning it hadn't exceeded the threshold, it would multiply the 5.0-amp basic current limit by an overload scaling factor of 1.2, generating a maximum allowable current parameter of 6.0 amps. However, since the system now clearly determines that the threshold has been exceeded, it generates an overshoot temperature difference data equal to 7 based on the 7-degree Celsius temperature difference. Next, the system takes the 5.0 amp base current limit and subtracts the product of the 7 overshoot temperature difference and the 0.1 decay slope, which is a reduction of 0.7 amps. Finally, the system obtains the reduced maximum allowable current parameter, specifically 4.3 amps. Through these detailed steps, the current is controlled, ensuring the safety of the motor.

[0029] The steps for dynamically adjusting the switching frequency parameter by acquiring the current motor speed data and combining it with the real-time virtual temperature value are as follows: Obtain the rotor pulse signal of the rotor assembly at the current time, extract the pulse signal sequence of the rotor pulse signal, and obtain the current speed data of the motor based on the pulse signal sequence; Configure the current speed data as the reference operating parameter and convert the real-time virtual temperature value into the corresponding dynamic adjustment coefficient. The baseline operating parameters are proportionally multiplied according to the dynamic adjustment coefficient to generate the comprehensive thermal frequency stress value under the current operating load. Obtain the pre-built stress-frequency attenuation mapping table, use the comprehensive thermal-frequency stress value as the index parameter, index the stress-frequency attenuation mapping table to obtain the target data node, and extract the initial frequency deduction amount bound in the target data node; The initial frequency deduction is compared with the preset maximum allowable reduction parameter for boundary verification. The initial frequency deduction after verification is used as the target frequency deduction. The switching frequency parameter of the motor is dynamically adjusted according to the target frequency deduction.

[0030] In application, taking a dual-stator single-rotor brushed coreless motor as an example, the system acquires the rotor pulse signal emitted by the rotor assembly at the current time. Then, the system extracts the pulse signal sequence from this rotor pulse signal. Based on this pulse signal sequence, the system calculates the current motor speed as 10,000 revolutions per minute. The system then configures this current speed of 10,000 revolutions per minute as the baseline operating parameter. Simultaneously, the system converts the real-time virtual temperature value of 107 degrees Celsius into a corresponding dynamic adjustment coefficient. The system has a built-in baseline safe temperature threshold set at 70 degrees Celsius. At this point, the system first calculates the overshoot temperature rise by subtracting the baseline temperature of 70 degrees Celsius from the current temperature of 107 degrees Celsius, resulting in a rotor over-temperature of 37 degrees Celsius. Next, the system needs to convert this over-temperature physical quantity into a control coefficient. The system calls the internally preset temperature rise attenuation adjustment factor, which is a fixed constant of 74. The system divides the 37-degree Celsius overshoot temperature rise by the adjustment factor of 74, calculating that the contribution weight of temperature to the load factor is 0.5. This means that the current thermal state of the motor requires additional safety limits. Finally, the system adds a 0.5 temperature rise weight to the base coefficient of 1.0 during normal motor operation. Through simple addition, the system adds 1.0 and 0.5, ultimately obtaining a dynamic adjustment coefficient of 1.5. Then, the system proportionally multiplies the baseline operating parameter of 10,000 by the dynamic adjustment coefficient of 1.5, directly multiplying 10,000 by 1.5 to generate a comprehensive thermal-frequency stress value of 15,000 under the current operating load. Next, the system retrieves the pre-built stress-frequency attenuation mapping table from the machine. Then, the system uses the comprehensive thermal-frequency stress value of 15,000 as an index parameter and indexes its position in this table. The system successfully finds the target data node and then extracts the initial frequency deduction amount bound to the node, for example, 2000 Hz. The system then performs boundary size verification between 2000 Hz and the preset maximum allowable reduction parameter of 3000 Hz. Because the limit is not exceeded, the verification is successfully completed. Finally, the system uses 2000 Hz as the target frequency deduction and adjusts the motor switching frequency by 2000 Hz accordingly.

[0031] The steps for constructing a stress-frequency attenuation mapping table are as follows: Obtain motor test sample records and extract test speed data and test temperature data of motors in stable operating conditions from the motor test sample records; The test rotation speed data is multiplied proportionally according to the test temperature data to generate the corresponding sample's test thermal frequency stress value; Extract the limit stable switching frequency in the corresponding state from the motor test sample record, and calculate the difference between the limit stable switching frequency and the preset initial rated frequency. Use the difference as the test frequency deduction amount. The test thermal stress value and the test frequency deduction are spliced ​​and encapsulated to generate independent mapping data nodes. Multiple mapping data nodes are aggregated and arranged in order of magnitude of the tested thermal frequency stress values ​​to generate a stress-frequency attenuation mapping table.

[0032] In application, taking a dual-stator, single-rotor brushed coreless motor as an example, the system first acquires the internal motor test sample record. Next, the system extracts the test speed data (e.g., 12000 rpm) and test temperature data (e.g., 100 degrees Celsius) from a sample of the motor test samples. Then, the system proportionally multiplies the 12000 rpm test speed data by the 100 degrees Celsius conversion parameter, generating the corresponding thermal frequency stress value for the sample (e.g., 16200). Next, the system extracts the limiting stable switching frequency (e.g., 18000 Hz) from this sample of the motor test samples under the current state. Then, the system performs a simple numerical difference between the limiting stable switching frequency and the preset initial rated frequency of 20000 Hz. The system subtracts 18000 from 20000, using the calculated 2000 Hz difference as the test frequency deduction. Next, the system concatenates and encapsulates the 16200 Hz test thermal stress value and the 2000 Hz test frequency deduction, directly generating an independent mapping data node. The system then repeats this process, aggregating numerous such mapping data nodes. Finally, the system arranges these nodes neatly according to the numerical order of the test thermal stress values, successfully generating a stress-frequency attenuation mapping table for easy system retrieval.

[0033] The maximum allowable current parameter and switching frequency parameter are monitored. When both the maximum allowable current parameter and switching frequency parameter are reduced, it is determined whether the real-time virtual temperature value increases. If the real-time virtual temperature value continues to rise, a sliding window with a zero duty cycle is injected into the pulse drive sequence. Specifically: Monitor the maximum allowable current parameter and the switching frequency parameter, and determine whether both the maximum allowable current parameter and the switching frequency parameter have been reduced; If it is determined that both the maximum allowable current parameter and the switching frequency parameter have decreased, then the real-time virtual temperature values ​​in multiple sampling periods are continuously collected, and the difference between the real-time virtual temperature values ​​in adjacent periods is calculated to obtain a dynamic temperature difference sequence. Identify the positive or negative value of all temperature difference values ​​in the dynamic temperature difference sequence, and obtain the trend of the real-time virtual temperature value based on the positive or negative value. Determine whether the trend is upward. If it is determined to be upward, generate an intervention trigger command. Based on the intervention trigger command, the continuous conduction interval of the pulse drive sequence is identified, and zero duty cycle data is written into the continuous conduction interval. A sliding window with zero duty cycle is injected into the pulse drive sequence.

[0034] In application, taking a dual-stator, single-rotor brushed coreless motor as an example, the system monitors the maximum allowable current parameter of 4.3 amps and the switching frequency parameter of 18000 Hz in real time. The system then determines that both the maximum allowable current parameter and the switching frequency parameter have been reduced. Since both parameters have been determined to be decreasing, the system begins to continuously collect real-time virtual temperature values ​​over five sampling periods, such as 107, 108, and 109 degrees Celsius. Next, the system calculates the difference between the real-time virtual temperature values ​​of adjacent periods, finding that each difference increases by 1 degree Celsius, resulting in a dynamic temperature difference sequence consisting entirely of positive 1s. The system then identifies the sign of all temperature difference values ​​in the dynamic temperature difference sequence. Finding that all values ​​are positive, the system concludes that the real-time virtual temperature value trend is increasingly hot. The system then definitively determines that this trend is upward. Because the trend is determined to be upward, the system immediately generates an intervention trigger command. Finally, based on the intervention trigger command, the system accurately identifies the continuous conduction interval in the pulse drive sequence that is normally used for power supply. To avoid overheating, the system directly writes 0 duty cycle data into this continuous conduction interval, which is equivalent to injecting a sliding window with a 0 duty cycle into the pulse drive sequence, allowing the motor to rest and cool down.

[0035] This invention provides a dual-stator single-rotor brushed coreless motor, using any of the above-described optimized control methods for a dual-stator single-rotor brushed coreless motor, including the following: Shaft 1, commutator 2, spool 3, brush 4, rear end cover 5, housing 6, inner magnetic ring 7, outer magnetic ring 8, and bearing 9; Shaft 1 is set on the central axis of housing 6. Inner magnetic ring 7 and outer magnetic ring 8 are fixedly connected to the front end of housing 6. There is a gap between inner magnetic ring 7 and outer magnetic ring 8. Bearing 9 is fixedly connected inside inner magnetic ring 7. Shaft 1 passes through outer magnetic ring 8 and inner magnetic ring 7 and is fixedly connected to the inner wall of bearing 9. Commutator 2 is fixedly connected to the outer wall of the rear end of shaft 1 and is located inside the rear end of housing 6. Coil 3 is fixedly connected to commutator 2 and is located in the gap between inner magnetic ring 7 and outer magnetic ring 8. When energized, coil 3 drives shaft 1 to rotate. The rear cover 5 is fixedly covered at the rear end of the housing 6. The rear cover 5 is provided with positive and negative terminals, which are connected to the brush plate 4. The brush plate 4 is in contact with the commutator 2. The stator assembly consists of the housing 6, the outer magnetic ring 8, the inner magnetic ring 7, and the bearing 9; Shaft 1, commutator 2, and spool 3 constitute the rotor assembly; The brush plate 4 and the rear cover 5 together form the rear cover assembly.

[0036] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. An optimized control method for a dual-stator single-rotor brushed hollow cup motor, characterized in that, include: Inject high-frequency detection pulses into the pulse drive sequence of the input motor, extract the terminal voltage data and current response data of the rotor assembly, and obtain the dynamic resistance change based on the terminal voltage data and current response data; The temperature coefficient of the copper wire of the rotor assembly is obtained, and the dynamic resistance change is physically mapped to the temperature coefficient of the copper wire to obtain the real-time virtual temperature value of the rotor assembly. Determine whether the real-time virtual temperature value exceeds the preset thermal runaway boundary threshold. If it does not exceed the threshold, increase the maximum allowable current parameter. If it exceeds the threshold, smoothly reduce the maximum allowable current parameter. The current speed data of the motor is obtained, and the switching frequency parameter is dynamically adjusted by combining the current speed data with the real-time virtual temperature value. The maximum allowable current parameter and the switching frequency parameter are monitored. When both the maximum allowable current parameter and the switching frequency parameter are reduced, it is determined whether the real-time virtual temperature value increases. If the real-time virtual temperature value continues to increase, a sliding window with a duty cycle of zero is injected into the pulse drive sequence.

2. The optimized control method for a dual-stator single-rotor brushed hollow cup motor according to claim 1, characterized in that, The steps for injecting high-frequency detection pulses into the pulse drive sequence of the input motor and extracting the terminal voltage data and current response data of the rotor assembly are as follows: Obtain the pulse drive sequence of the current input motor, extract the pulse duty cycle data in the pulse drive sequence, and determine the turn-off interval of the drive sequence based on the pulse duty cycle data; A high-frequency detection pulse is generated within the off interval and injected into the pulse drive sequence to obtain a hybrid drive sequence, which is then output to the rotor assembly. During the signal triggering period of the high-frequency detection pulse in the hybrid drive sequence, the transient voltage signal and transient current signal of the rotor assembly in the excited state are acquired. The transient voltage signal and the transient current signal are discretely sampled and digitized to obtain terminal voltage data and current response data with the same time scale.

3. The optimized control method for a dual-stator single-rotor brushed hollow cup motor according to claim 2, characterized in that, The steps for obtaining the dynamic resistance change based on the terminal voltage data and current response data are as follows: Extract the voltage amplitude parameter from the terminal voltage data, and extract the current amplitude parameter from the current response data; The real-time impedance value of the rotor assembly is calculated by dividing the voltage amplitude parameter by the current amplitude parameter. Obtain the reference impedance value of the rotor assembly under calibrated cold conditions, extract the impedance difference between the real-time impedance value and the reference impedance value, and use the impedance difference as the dynamic resistance change.

4. The optimized control method for a dual-stator single-rotor brushed hollow cup motor according to claim 3, characterized in that, The steps of obtaining the temperature coefficient of the copper wires of the rotor assembly, and physically mapping the dynamic resistance change to the temperature coefficient of the copper wires to obtain the real-time virtual temperature value of the rotor assembly are as follows: Obtain the preset material data of the rotor assembly, obtain the temperature coefficient of the copper wire of the rotor assembly based on the material data, and extract the calibration cold environment temperature value corresponding to the reference impedance value. Divide the dynamic resistance change by the reference impedance value to obtain the relative impedance drift ratio of the rotor assembly. Divide the relative impedance drift ratio by the temperature coefficient of the copper conductor to obtain the initial temperature rise quotient, and compare the initial temperature rise quotient with the preset physical melting temperature rise quotient. When it is determined that the initial temperature rise quotient is less than the physical melting temperature rise quotient, an effective temperature rise mark is generated. Based on the effective temperature rise marker, invalid jitter bits of the initial temperature rise quotient are removed, and the processed value is confirmed as the instantaneous temperature rise value of the rotor assembly. By combining the instantaneous temperature rise value with the calibrated cold ambient temperature value, the current operating temperature value of the rotor assembly is obtained, and the current operating temperature value is marked as the real-time virtual temperature value.

5. The optimized control method for a dual-stator single-rotor brushed hollow cup motor according to claim 4, characterized in that, The steps of determining whether the real-time virtual temperature value exceeds a preset thermal runaway boundary threshold, increasing the maximum allowable current parameter when it does not exceed the threshold, and smoothly reducing the maximum allowable current parameter when it does exceed the threshold are as follows: Obtain the preset thermal runaway boundary threshold and the basic current limit, subtract the real-time virtual temperature value from the thermal runaway boundary threshold to obtain the temperature difference value, and identify the positive or negative value of the temperature difference value. Based on the positive or negative sign, determine whether the real-time virtual temperature value exceeds the thermal runaway boundary threshold; If it is determined that the real-time virtual temperature value does not exceed the thermal runaway boundary threshold, the basic current limit is multiplied by the preset overload scaling factor to generate the maximum allowable current parameter. If it is determined that the real-time virtual temperature value exceeds the thermal runaway boundary threshold, then overshoot temperature difference data is generated based on the temperature difference. The reduced maximum allowable current parameter is obtained by subtracting the product of the overshoot temperature difference data and the preset attenuation slope from the basic current limit.

6. The optimized control method for a dual-stator single-rotor brushed hollow cup motor according to claim 5, characterized in that, The steps for acquiring the current motor speed data and dynamically adjusting the switching frequency parameter based on the current speed data and the real-time virtual temperature value are as follows: Obtain the rotor pulse signal of the rotor assembly at the current time, extract the pulse signal sequence of the rotor pulse signal, and obtain the current speed data of the motor based on the pulse signal sequence; Configure the current rotation speed data as a reference operating parameter, and convert the real-time virtual temperature value into a corresponding dynamic adjustment coefficient. The benchmark operating parameters are proportionally multiplied according to the dynamic adjustment coefficient to generate the comprehensive thermal frequency stress value under the current operating load. Obtain a pre-constructed stress-frequency attenuation mapping table, use the comprehensive thermal-frequency stress value as an index parameter, index the stress-frequency attenuation mapping table to obtain the target data node, and extract the initial frequency deduction amount bound in the target data node. The initial frequency deduction amount is compared with the preset maximum allowable reduction parameter for boundary verification. The initial frequency deduction amount after verification is passed is taken as the target frequency deduction amount. The switching frequency parameter of the motor is dynamically adjusted according to the target frequency deduction amount.

7. The optimized control method for a dual-stator single-rotor brushed hollow cup motor according to claim 6, characterized in that, The steps for constructing a stress-frequency attenuation mapping table are as follows: Obtain motor test sample records, and extract test speed data and test temperature data in stable operating state from the motor test sample records; The test rotation speed data is multiplied proportionally according to the test temperature data to generate the corresponding sample's test thermal frequency stress value; Extract the limit stable switching frequency in the corresponding state from the motor test sample record, and calculate the difference between the limit stable switching frequency and the preset initial rated frequency. Use the difference as the test frequency deduction amount. The test thermal frequency stress value and the test frequency deduction amount are spliced ​​and encapsulated to generate independent mapping data nodes; By aggregating multiple mapping data nodes and arranging them in order of magnitude of the tested thermal frequency stress values, a stress-frequency attenuation mapping relationship table is generated.

8. The optimized control method for a dual-stator single-rotor brushed hollow cup motor according to claim 7, characterized in that, The maximum allowable current parameter and the switching frequency parameter are monitored. When both the maximum allowable current parameter and the switching frequency parameter are reduced, it is determined whether the real-time virtual temperature value increases. If the real-time virtual temperature value continues to increase, the step of injecting a sliding window with a zero duty cycle into the pulse drive sequence is as follows: The maximum allowable current parameter and the switching frequency parameter are monitored, and it is determined whether both the maximum allowable current parameter and the switching frequency parameter are reduced. If it is determined that both the maximum allowable current parameter and the switching frequency parameter have decreased, the real-time virtual temperature value is continuously collected within multiple sampling periods, and the difference between the real-time virtual temperature values ​​of adjacent periods is calculated to obtain a dynamic temperature difference sequence. Identify the positive or negative value of all temperature difference values ​​in the dynamic temperature difference sequence, and obtain the trend of the real-time virtual temperature value based on the positive or negative value. Determine whether the trend is upward; if it is, generate an intervention trigger command. Based on the intervention trigger command, the continuous conduction interval of the pulse drive sequence is identified, and zero duty cycle data is written into the continuous conduction interval. A sliding window with a zero duty cycle is injected into the pulse drive sequence.

9. A dual-stator single-rotor brushed coreless motor, applied to the optimized control method of the dual-stator single-rotor brushed coreless motor as described in any one of claims 1-8, characterized in that, include: Shaft, commutator, spool, brush, rear end cover, housing, inner magnetic ring, outer magnetic ring, and bearing; The shaft is located on the central axis of the housing. The inner magnetic ring and the outer magnetic ring are fixedly connected to the front end inside the housing. A gap is left between the inner magnetic ring and the outer magnetic ring. The bearing is fixedly connected inside the inner magnetic ring. The shaft passes through the outer magnetic ring and the inner magnetic ring and is fixedly connected to the inner wall of the bearing. The commutator is fixedly connected to the outer wall of the rear end of the shaft and is located inside the rear end of the housing. The spool is fixedly connected to the commutator and is located in the gap between the inner magnetic ring and the outer magnetic ring. When energized, the spool drives the shaft to rotate. The rear end cover is fixedly covered at the rear end of the housing. The rear end cover is provided with positive and negative terminals, which are connected to the brush plate. The brush plate is in contact with the commutator. The housing, the outer magnetic ring, the inner magnetic ring, and the bearing constitute a stator assembly; The shaft, the commutator, and the spool together form a rotor assembly. The brush and the rear cover together form the rear cover assembly.

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