Method for determining a filter cut-off frequency and method for driving a motor control

Abstract

This disclosure provides a method for determining a filter cutoff frequency and a drive motor control method. The method for determining the filter cutoff frequency includes: calculating the theoretical phase current frequency based on the target speed of the drive motor in the current cycle, and calculating the estimated phase current frequency based on the estimated speed of the drive motor in the current cycle; calculating a theoretical frequency weighting coefficient and an estimated frequency weighting coefficient based on the theoretical phase current frequency and the estimated phase current frequency; and performing a weighted summation based on the theoretical phase current frequency, the estimated phase current frequency, the theoretical frequency weighting coefficient, and the estimated frequency weighting coefficient to obtain the filter cutoff frequency for the current cycle. The filter cutoff frequency determined by the aforementioned method is essentially based on predicting the actual speed of the drive motor. Therefore, the filter cutoff frequency better matches the actual speed characteristics of the drive motor, and can adaptively determine the filter cutoff frequency under speed fluctuations, thus optimizing filtering accuracy and filtering effect.

Description

Technical Field

[0001] This disclosure relates to the field of vehicle technology, specifically to a method for determining the filter cutoff frequency and a drive motor control method. Background Technology

[0002] Some vehicles use permanent magnet synchronous motors (PMSMs) as power sources for components such as water pumps and electric compressors. To reduce costs and motor weight, PMSMs used as power sources for water pumps and electric compressors employ a sensorless control strategy, calculating the rotor position based on electrical information such as voltage and current in the motor windings.

[0003] In practical applications, after estimating the flux linkage or back electromotive force of a permanent magnet synchronous motor using the aforementioned methods, a filter is needed to remove high-frequency jitter components to obtain a more accurate rotor position estimate. Currently, the industry uses a first-order low-pass filter (LPF). The filtering effect of a first-order low-pass filter is affected by the cutoff frequency. The current cutoff frequency can be determined based on either the phase current frequency corresponding to the motor's highest speed or the phase current frequency corresponding to the motor's current speed. However, using the phase current frequency corresponding to the motor's highest speed to determine the cutoff frequency results in a relatively large current sampling error in the low-speed range, leading to poor filtering performance. If the first-order low-pass filter cannot perform its filtering function effectively, it may directly cause incorrect position estimation, resulting in motor shutdown. If the phase current frequency corresponding to the motor's current speed is used to determine the cutoff frequency, the phase current frequency changes with the motor speed, causing the cutoff frequency to constantly change, increasing the filter's instability and the calculation error of the filter delay phase. In other words, the cutoff frequencies determined by the aforementioned two methods are not suitable for application scenarios at various motor speeds. Summary of the Invention

[0004] To address the aforementioned technical problems, this disclosure provides a method for determining the filter cutoff frequency and a method for controlling a drive motor.

[0005] In a first aspect, embodiments of this disclosure provide a method for determining a filter cutoff frequency, comprising:

[0006] The theoretical phase current frequency is calculated based on the target speed of the drive motor in the current cycle, and the estimated phase current frequency is calculated based on the estimated speed of the drive motor in the current cycle.

[0007] Calculate the theoretical frequency weighting coefficient and the estimated frequency weighting coefficient based on the theoretical phase current frequency and the estimated phase current frequency;

[0008] The filter cutoff frequency for the current cycle is obtained by weighting and summing the theoretical phase current frequency, the estimated phase current frequency, the theoretical frequency weighting coefficient, and the estimated frequency weighting coefficient.

[0009] Optionally, before calculating the theoretical phase current frequency based on the target speed of the drive motor in the current cycle, the method further includes:

[0010] Calculate the target speed for the current cycle based on the requested speed and the target speed in the previous cycle.

[0011] Optionally, calculating the target speed for the current cycle based on the requested speed and the target speed in the previous cycle includes:

[0012] Calculate the difference between the requested rotational speed and the target rotational speed in the previous cycle, and determine the rotational acceleration based on the difference;

[0013] The target rotational speed for the current cycle is calculated based on the target rotational speed in the previous cycle and the rotational acceleration.

[0014] Optionally, determining the rotational acceleration based on the difference includes:

[0015] If the difference is greater than 0, the first preset acceleration that is in the same direction as the target rotational speed in the previous cycle is taken as the rotational speed acceleration;

[0016] If the difference is less than 0, the second preset acceleration, which is opposite to the direction of the target rotational speed in the previous cycle, is taken as the rotational speed acceleration.

[0017] When the difference is 0, the rotational acceleration is determined to be 0;

[0018] The magnitudes of the first preset acceleration and the second preset acceleration are preset.

[0019] Optionally, the calculation of the theoretical frequency weighting coefficient and the estimated frequency weighting coefficient based on the theoretical phase current frequency and the estimated phase current frequency includes:

[0020] Calculate the sum of the theoretical phase current frequency and the estimated phase current frequency;

[0021] The theoretical frequency weighting coefficient is determined based on the ratio of the theoretical phase current frequency to the sum, and the estimated frequency weighting coefficient is determined based on the ratio of the estimated phase current frequency to the sum.

[0022] Optionally, the step of obtaining the cutoff frequency by weighted summation based on the theoretical phase current frequency, the estimated phase current frequency, the theoretical frequency weighting coefficient, and the estimated frequency weighting coefficient includes:

[0023] use The cutoff frequency f is obtained. cutoff Where c is a value greater than 1, k1 is the theoretical frequency weighting coefficient, and f curr Let k1 be the theoretical phase current frequency, and k2 be the estimated frequency weighting coefficient. The estimated phase current frequency is given.

[0024] Secondly, embodiments of this disclosure provide a drive motor control method, including:

[0025] Obtain the motor flux linkage or back electromotive force of the drive motor; determine the filter cutoff frequency using the method described above, and construct a low-pass filter based on the filter cutoff frequency;

[0026] The low-pass filter is used to perform low-pass filtering on the motor flux linkage or the motor back electromotive force to obtain the filtered flux linkage or the filtered back electromotive force.

[0027] The rotor position of the drive motor is determined based on the filtered magnetic flux or the filtered back electromotive force.

[0028] Thirdly, embodiments of this disclosure provide a device for determining the filter cutoff frequency, comprising:

[0029] The frequency calculation unit is used to calculate the theoretical phase current frequency based on the target speed of the drive motor in the current cycle, and to calculate the estimated phase current frequency based on the estimated speed of the drive motor in the current cycle.

[0030] The weighting coefficient calculation unit is used to calculate the theoretical frequency weighting coefficient and the estimated frequency weighting coefficient based on the theoretical phase current frequency and the estimated phase current frequency;

[0031] The cutoff frequency determination unit is used to perform a weighted summation based on the theoretical phase current frequency, the estimated phase current frequency, the theoretical frequency weighting coefficient, and the estimated frequency weighting coefficient to obtain the filter cutoff frequency.

[0032] Fourthly, embodiments of this disclosure provide a drive motor control device, comprising:

[0033] Electromagnetic characteristic determination unit, used to obtain the motor flux linkage or back electromotive force of the drive motor;

[0034] A filter determination unit is used to determine the filter cutoff frequency using the method described above, and to construct a low-pass filter based on the filter cutoff frequency.

[0035] The filtering unit is used to perform low-pass filtering on the motor flux or the motor back electromotive force using the low-pass filter to obtain the filtered flux or the filtered back electromotive force.

[0036] The rotor position determination unit is used to determine the rotor position of the drive motor based on the filtered magnetic flux or the filtered back electromotive force.

[0037] Fifthly, this disclosure also provides a motor controller, including a processor and a memory, the memory being used to store a computer program; when the computer program is loaded by the processor, it causes the processor to execute the method described above.

[0038] The scheme for determining the filter cutoff frequency provided in this disclosure first determines the theoretical phase current frequency and the estimated phase current frequency of the drive motor in the current cycle. Then, it calculates the corresponding theoretical frequency weighting coefficient and estimated frequency weighting coefficient based on the theoretical and estimated phase current frequencies. Finally, it obtains the filter cutoff frequency for the current cycle by weighted summing of the theoretical and estimated phase current frequencies, the theoretical frequency weighting coefficient, and the estimated frequency weighting coefficient. The filter cutoff frequency determined by the aforementioned method is essentially based on predicting the actual speed of the drive motor. Therefore, the filter cutoff frequency better matches the actual speed characteristics of the drive motor, and can adaptively determine the filter cutoff frequency under speed fluctuations, thus optimizing the filtering accuracy and filtering effect. Attached Figure Description

[0039] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0040] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without any creative effort, wherein:

[0041] Figure 1 This is a flowchart of a method for determining the filter cutoff frequency provided in an embodiment of this disclosure;

[0042] Figure 2 This is a flowchart of the drive motor control method provided in the embodiments of this disclosure;

[0043] Figure 3 This is a schematic diagram of the structure of the filter cutoff frequency determination device provided in the embodiments of this disclosure;

[0044] Figure 4This is a schematic diagram of the structure of the motor controller provided in the embodiments of this disclosure. Detailed Implementation

[0045] Embodiments of this disclosure will now be described in more detail with reference to the accompanying drawings. While some embodiments of this disclosure are shown in the drawings, it should be understood that this disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this disclosure. It should be understood that the accompanying drawings and embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of protection of this disclosure.

[0046] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". Definitions of other terms will be given in the description below. It should be noted that the concepts of "first", "second", etc., used in this disclosure are only used to distinguish different devices, modules, or units, and are not intended to limit the order of functions performed by these devices, modules, or units or their interdependencies.

[0047] It should be noted that the terms "a" and "a plurality of" used in this disclosure are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0048] To address the problem that existing solutions, regardless of whether the phase current frequency corresponding to the highest speed or the phase current frequency corresponding to the current speed is used to determine the filter cutoff frequency, cannot achieve good overall filtering accuracy and filtering effect, this disclosure provides a new method for determining the filter cutoff frequency.

[0049] The filtering cutoff frequency method provided in this disclosure determines the filtering cutoff frequency based on the target speed characteristics and estimated speed characteristics of the drive motor, making the filtering cutoff frequency more consistent with the actual situation, thereby improving the filtering accuracy and filtering effect.

[0050] Figure 1 This is a flowchart of a method for determining the filter cutoff frequency provided in an embodiment of this disclosure. For example... Figure 1 As shown, the method for determining the filter cutoff frequency provided in this embodiment includes steps S110-S130.

[0051] In practical applications, since the speed control of the drive motor is implemented by the motor controller, and considering the real-time requirements of motor control, the method for determining the filter cutoff frequency in this embodiment is executed by the motor controller.

[0052] Of course, the method for determining the filter cutoff frequency is not limited to being executed by the motor controller; it can also be executed by a host computer system (such as the vehicle's infotainment system).

[0053] S110: Calculate the theoretical phase current frequency based on the target speed of the drive motor in the current cycle, and calculate the estimated phase current frequency based on the estimated speed of the drive motor in the current cycle.

[0054] In this embodiment of the present disclosure, the motor controller performs calculations according to a set execution frequency to determine the filter cutoff frequency of the current cycle in real time.

[0055] The target speed for the current cycle is the ideal speed that the drive motor should reach in the current cycle. In practical applications, drive motors used as power sources for water pumps and electric compressors often adjust their speed according to a set speed acceleration. After determining the target speed of the drive motor in the previous cycle, the target speed of the drive motor in the current cycle can be obtained by calculating based on the speed and speed acceleration of the previous cycle. Specifically, the target speed for the current cycle can be calculated using the following steps S111-S112.

[0056] S111: Calculate the difference between the requested rotational speed and the target rotational speed in the previous cycle, and determine the rotational speed acceleration based on the difference.

[0057] In one specific embodiment, the speed adjustment method of the drive motor can be based on a ramp function V. set (k)=V set (k-1)+a represents, where V set (k) represents the target speed of the drive motor in the current cycle, V set (k-1) represents the target speed of the drive motor in the previous cycle, and a represents the speed acceleration of the drive motor. a is related to the characteristic parameters of the electric drive motor itself and the actual control requirements, and is predetermined.

[0058] In practical applications, it is necessary to determine the required speed V of the drive motor. req and the target rotational speed V in the previous cycle set The difference of (k-1) determines the rotational acceleration specifically: if V set (k)>V set (k-1), then a is a predetermined first preset acceleration, which is the acceleration in the same direction as the target rotational speed of the current cycle; if V set (k) <V set (k-1), then a is a predetermined second preset acceleration, which is an acceleration opposite to the direction of the target rotational speed in the current cycle; and if V set (k)=V set If (k-1), then the value of a is 0.

[0059] S112: Calculate the target speed for the current cycle based on the target speed and speed acceleration of the previous cycle.

[0060] According to the aforementioned formula for the ramp function, after obtaining the target rotational speed and rotational acceleration of the previous cycle, adding the two together will yield the target rotational speed of the current cycle.

[0061] In other embodiments, after determining the current speed and the required speed of the drive motor, the motor controller can determine the speed adjustment time based on the difference between the current speed and the required speed, as well as the speed acceleration of the drive motor. Then, during the speed adjustment time, the controller controls the drive motor to adjust its speed according to the speed acceleration. Correspondingly, based on the time difference between the current cycle and the initial cycle, the initial speed of the drive motor, and the aforementioned rotational acceleration, the target speed for the current cycle can also be determined.

[0062] After obtaining the target speed for the current cycle, the theoretical phase current frequency can be calculated based on the target speed for the current cycle. In specific implementation, the motor controller uses f curr =V set The theoretical phase current frequency f is obtained by calculation using p / 60. curr V set The target speed for the current cycle is given by p (in revolutions per minute), and p is the number of pole pairs of the motor.

[0063] The estimated speed of the drive motor in the current cycle is the motor speed estimated using a pre-selected motor speed estimation algorithm (e.g., a sensorless control algorithm). The specific motor speed estimation algorithm used will not be detailed here; please refer to relevant technical literature for details.

[0064] After obtaining the estimated rotational speed for the current cycle, the estimated phase current frequency can be calculated based on the estimated rotational speed for the current cycle. In specific implementations, the motor controller adopts... The theoretical phase current frequency was calculated. The target speed for the current cycle is given (in revolutions per minute), and p is the number of motor pole pairs mentioned earlier.

[0065] S120: Calculate the theoretical frequency weighting coefficient and the estimated frequency weighting coefficient based on the theoretical phase current frequency and the estimated phase current frequency.

[0066] In this embodiment of the disclosure, the theoretical frequency weighting coefficient and the estimated frequency weighting coefficient are calculated based on the theoretical phase current frequency and the estimated phase current frequency. The theoretical frequency weighting coefficient and the estimated frequency weighting coefficient are estimated according to a specific calculation method.

[0067] In some embodiments, the theoretical frequency weighting coefficient is k1, and the estimated frequency weighting coefficient is... Based on the aforementioned formula, the theoretical frequency weighting coefficient and the estimated frequency weighting coefficient can be calculated based on the theoretical phase current frequency and the estimated phase current frequency as follows: S121-S122.

[0068] S121: Calculate the sum of the theoretical phase current frequency and the estimated phase current frequency.

[0069] According to the aforementioned formula, the sum of the theoretical phase current frequency and the estimated phase current frequency is...

[0070] S122: Determine the theoretical frequency weighting coefficient based on the ratio of the theoretical phase current frequency and the sum of the values, and determine the estimated frequency weighting coefficient based on the ratio of the estimated phase current frequency and the sum of the values.

[0071] According to the aforementioned formula, if the theoretical phase current frequency is larger than the estimated phase current frequency, then the corresponding theoretical frequency weighting coefficient is larger, and the estimated frequency weighting coefficient is smaller; conversely, if the theoretical phase current frequency is smaller than the estimated phase current frequency, then the corresponding theoretical frequency weighting coefficient is smaller, and the estimated frequency weighting coefficient is larger. Furthermore, from the aforementioned formula, we know that k1 + k2 = 1.

[0072] In practical applications, besides using the aforementioned methods to calculate the theoretical and estimated frequency weighting coefficients, other methods can also be employed to determine them. For example, in some embodiments, after obtaining the theoretical and estimated phase current frequencies, the motor controller first calculates the ratio of the theoretical to the estimated phase current frequencies. Then, it uses this calculated ratio to look up the corresponding theoretical and estimated frequency weighting coefficients in a pre-defined data table. In practical applications, the sum of the paired theoretical and estimated frequency weighting coefficients stored in the data table can be 1 or not.

[0073] S130: The filter cutoff frequency for the current cycle is obtained by weighted summation based on the theoretical phase current frequency, the estimated phase current frequency, the theoretical frequency weighting coefficient, and the estimated frequency weighting coefficient.

[0074] After obtaining the theoretical and estimated frequency weighting coefficients, the filter cutoff frequency for the current cycle can be determined using a weighted summation method. Specifically, the motor controller can use... The filter cutoff frequency for the current cycle is calculated, where c is a preset value, typically set to 2-5.

[0075] The method for determining the filter cutoff frequency provided in this embodiment first determines the theoretical phase current frequency and the estimated phase current frequency of the drive motor in the current cycle. Then, based on the theoretical and estimated phase current frequencies, the corresponding theoretical and estimated frequency weighting coefficients are calculated. Finally, the filter cutoff frequency for the current cycle is obtained by weighted summation of the theoretical and estimated phase current frequencies, the theoretical and estimated frequency weighting coefficients. The filter cutoff frequency determined by the aforementioned method is essentially based on predicting the actual speed of the drive motor. Therefore, the filter cutoff frequency better matches the actual speed characteristics of the drive motor and can adaptively determine the filter cutoff frequency under speed fluctuations, thus optimizing filtering accuracy and effect.

[0076] In addition to providing the aforementioned method for determining the filter cutoff frequency, this disclosure also provides a drive motor control method. Figure 2 This is a flowchart of a drive motor control method provided in an embodiment of this disclosure. Figure 2 As shown, the drive motor control method provided in this embodiment includes S210-S260.

[0077] S210: Calculate the theoretical phase current frequency based on the target speed of the drive motor in the current cycle, and calculate the estimated phase current frequency based on the estimated speed of the drive motor in the current cycle.

[0078] S220: Calculate the theoretical frequency weighting coefficient and the estimated frequency weighting coefficient based on the theoretical phase current frequency and the estimated phase current frequency.

[0079] S230: The filter cutoff frequency for the current cycle is obtained by weighted summation based on the theoretical phase current frequency, the estimated phase current frequency, the theoretical frequency weighting coefficient, and the estimated frequency weighting coefficient.

[0080] The specific implementation process of S210-S230 is the same as the steps of S110-S130 in the previous embodiment, and will not be repeated here. For details, please refer to the previous description.

[0081] S240: Construct a low-pass filter based on the filter cutoff frequency.

[0082] In some embodiments of this disclosure, the low-pass filter constructed based on the filter medium frequency can be a first-order low-pass filter, characterized by U. o (k)=U o (k-1) / (1+ω c T)+ω c T·U i (k) / (1+ω c T), where ω c =2πf cutoffIt is conceivable that, in the scheme of this embodiment, the low-pass filter is based on the output U of the filter obtained in the previous period. o (k-1) and the input U of the current periodic filter i (k) Determine the output U of the low-pass filter o (k).

[0083] Of course, the low-pass filter constructed based on the filter cutoff frequency in this embodiment is not limited to the aforementioned first-order low-pass filter, but can also be a higher-order low-pass filter.

[0084] S250: Determine the motor flux linkage or back electromotive force of the drive motor.

[0085] Based on the principles of motor operation, a motor controller can detect flux linkage using a flux sensor installed in the motor, or measure voltage using a voltmeter installed in the circuit, and determine the motor flux linkage or back electromotive force (EMF) of the drive motor using a pre-set calculation method. It can be assumed that the magnitude of the motor flux linkage and back EMF are positively correlated with the motor speed.

[0086] In practice, the motor controller can use the sliding mode observer method, the nonlinear flux observer method, or the virtual coordinate axis method to determine the motor flux or back electromotive force of the drive motor.

[0087] S260: A low-pass filter is used to perform low-pass filtering on the motor flux linkage or motor back EMF to obtain the filtered flux linkage or filtered back EMF.

[0088] Following the aforementioned first-order low-pass filter configuration, the motor magnetoelectric flux or back EMF is low-pass filtered to obtain the filtered flux linkage or back EMF. This is achieved by inputting the motor flux linkage or back EMF predicted in the current cycle into the low-pass filter. A first weighting coefficient, determined based on the filter cutoff frequency, is used to process the input motor flux linkage or back EMF, resulting in first weighted data. This first weighted data is then added to a second weighted data set to obtain the filtered flux linkage or back EMF. The second weighted data is determined by multiplying the motor flux linkage or back EMF output from the previous cycle by a second weighting coefficient determined based on the filter frequency.

[0089] S270: Determine the rotor position of the drive motor based on the filter flux linkage or the filter back electromotive force.

[0090] After determining the filter flux linkage or filter back EMF, the rotor position of the drive motor is then estimated based on the motor model. In practice, the rotor position of the drive motor can be estimated using a flux linkage / back EMF estimation method based on the motor's fundamental frequency model.

[0091] After determining the rotor position of the drive motor using the aforementioned method, the real-time rotational speed of the rotor can be estimated based on the position of the rotor in the next cycle. The speed of the drive motor can then be determined to meet the required speed based on the real-time rotational speed, thereby determining how to perform subsequent motor rotation control.

[0092] The drive motor control method provided in this embodiment can optimize the method for determining the filter cutoff frequency, improve the filtering accuracy, and thus optimize the rotor position estimation accuracy and the overall control stability.

[0093] In addition to providing the aforementioned method for determining the filter cutoff frequency, this disclosure also provides a filter cutoff frequency determination device 300. Figure 3 This is a schematic diagram of the structure of the filter cutoff frequency determination device 300 provided in an embodiment of this disclosure. Figure 3 As shown, the filter cutoff frequency determination device 300 includes a frequency calculation unit 301, a weighting coefficient calculation unit 302, and a cutoff frequency determination unit 303.

[0094] The frequency calculation unit 301 is used to calculate the theoretical phase current frequency based on the target speed of the drive motor in the current cycle, and to calculate the estimated phase current frequency based on the estimated speed of the drive motor in the current cycle.

[0095] The weighting coefficient calculation unit 302 is used to calculate the theoretical frequency weighting coefficient and the estimated frequency weighting coefficient based on the theoretical phase current frequency and the estimated phase current frequency.

[0096] The cutoff frequency determination unit 303 is used to perform a weighted summation based on the theoretical phase current frequency, the estimated phase current frequency, the theoretical frequency weighting coefficient, and the estimated frequency weighting coefficient to obtain the filter cutoff frequency.

[0097] In some embodiments, before the frequency calculation unit 301 calculates the theoretical phase current frequency based on the target speed of the drive motor in the current cycle, the frequency calculation unit 301 also calculates the target speed of the current cycle based on the requested speed and the target speed in the previous cycle.

[0098] In some embodiments, the frequency calculation unit 301 first calculates the difference between the requested rotational speed and the target rotational speed in the previous cycle, and determines the rotational speed acceleration based on the difference; then it calculates the target rotational speed of the current cycle based on the target rotational speed and rotational speed acceleration in the previous cycle.

[0099] In some embodiments, when the difference is greater than 0, the frequency calculation unit 301 takes the first preset acceleration that is in the same direction as the target rotational speed in the previous cycle as the rotational speed acceleration; when the difference is less than 0, the frequency calculation unit 301 takes the second preset acceleration that is opposite to the target rotational speed in the previous cycle as the rotational speed acceleration; when the difference is 0, the frequency calculation unit 301 determines that the rotational speed acceleration is 0; wherein the magnitudes of the first preset acceleration and the second preset acceleration are preset.

[0100] In some embodiments, the weighting coefficient calculation unit 302 first calculates the sum of the theoretical phase current frequency and the estimated phase current frequency, then determines the theoretical frequency weighting coefficient based on the ratio of the theoretical phase current frequency and the sum, and determines the estimated frequency weighting coefficient based on the ratio of the estimated phase current frequency and the sum.

[0101] In some embodiments, the cutoff frequency determination unit 303 employs Obtain the cutoff frequency f cutoff Where c is a value greater than 1, k1 is the theoretical frequency weighting coefficient, and f curr k is the theoretical phase current frequency, and k2 is the estimated frequency weighting coefficient. To estimate the phase current frequency.

[0102] This disclosure also provides a drive motor control device. The drive motor control device includes an electromagnetic characteristic determination unit, a filter determination unit, a filter unit, and a rotor position determination unit. The electromagnetic characteristic determination unit is used to obtain the motor flux linkage or motor back electromotive force of the drive motor.

[0103] The filter determination unit is used to determine the filter cutoff frequency using the previously described method, and to construct a low-pass filter based on the filter cutoff frequency.

[0104] The filtering unit is used to perform low-pass filtering on the motor flux or motor back EMF to obtain the filtered flux or filtered back EMF.

[0105] The rotor position determination unit is used to determine the rotor position of the drive motor based on the filtered flux linkage or the filtered back electromotive force.

[0106] This disclosure also provides a motor controller for implementing the aforementioned method. Figure 4 This is a schematic diagram of the structure of the motor controller provided in an embodiment of this disclosure. See below for details. Figure 4 It shows a structural schematic diagram suitable for implementing the motor controller 400 in the embodiments of this disclosure. Figure 4 The motor controller shown is merely an example and should not be construed as limiting the functionality and scope of the embodiments disclosed herein.

[0107] like Figure 4 As shown, the motor controller 400 may include a processing device (e.g., a central processing unit, a graphics processing unit, etc.) 401, which can perform various appropriate actions and processes according to a program stored in a read-only memory ROM 402 or a program loaded from a storage device 408 into a random access memory RAM 403. The RAM 403 also stores various programs and data required for the operation of the motor controller 400. The processing device 401, ROM 402, and RAM 403 are interconnected via a bus 404. An input / output (I / O) interface 405 is also connected to the bus 404.

[0108] Typically, the following devices can be connected to I / O interface 405: input devices 405 including, for example, touchscreens, touchpads, cameras, microphones, accelerometers, gyroscopes, etc.; output devices 407 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; storage devices 408 including, for example, magnetic tapes, hard disks, etc.; and communication devices 409. Communication device 409 allows motor controller 400 to communicate wirelessly or wiredly with other devices to exchange data. Although Figure 4 A motor controller 400 with various devices is shown; however, it should be understood that implementation or possession of all the devices shown is not required. More or fewer devices may be implemented alternatively.

[0109] In particular, according to embodiments of this disclosure, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of this disclosure include a computer program product comprising a computer program carried on a non-transitory computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via communication device 409, or installed from storage device 408, or installed from ROM 402. When the computer program is executed by processing device 401, it performs the functions defined in the methods of embodiments of this disclosure.

[0110] It should be noted that the computer-readable medium described in this disclosure can be a computer-readable signal medium or a computer-readable storage medium, or any combination thereof. A computer-readable storage medium can be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this disclosure, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in connection with an instruction execution system, apparatus, or device. In this disclosure, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium can be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to: wires, optical fibers, RF (radio frequency), etc., or any suitable combination thereof.

[0111] In some implementations, clients and servers can communicate using any currently known or future-developed network protocol such as HTTP (Hypertext Transfer Protocol) and can interconnect with digital data communication (e.g., communication networks) of any form or medium. Examples of communication networks include local area networks (“LANs”), wide area networks (“WANs”), the Internet (e.g., the Internet of Things), and peer-to-peer networks (e.g., ad hoc peer-to-peer networks), as well as any currently known or future-developed networks.

[0112] The aforementioned computer-readable medium may be included in the aforementioned motor controller; or it may exist independently and not assembled into the motor controller. The aforementioned computer-readable medium carries one or more programs that, when executed by the motor controller, cause the motor controller to: calculate the theoretical phase current frequency based on the target speed of the drive motor in the current cycle, and calculate the estimated phase current frequency based on the estimated speed of the drive motor in the current cycle; calculate the theoretical frequency weighting coefficient and the estimated frequency weighting coefficient based on the theoretical phase current frequency and the estimated phase current frequency; and perform a weighted summation based on the theoretical phase current frequency, the estimated phase current frequency, the theoretical frequency weighting coefficient, and the estimated frequency weighting coefficient to obtain the filter cutoff frequency for the current cycle.

[0113] Computer program code for performing the operations of this disclosure can be written in one or more programming languages ​​or a combination thereof, including but not limited to object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as the "C" language or similar programming languages. The program code can be executed entirely on the tester's computer, partially on the tester's computer, as a standalone software package, partially on the tester's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the tester's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0114] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, may be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0115] The units described in the embodiments of this disclosure can be implemented in software or hardware. The names of the units are not, in some cases, intended to limit the specific unit.

[0116] The functions described above in this document can be performed, at least in part, by one or more hardware logic components. For example, exemplary types of hardware logic components that can be used, without limitation, include: Field Programmable Gate Arrays (FPGAs), Application-Specific Integrated Circuits (ASICs), Application Standard Products (ASSPs), System-on-Chip (SoCs), Complex Programmable Logic Devices (CPLDs), and so on.

[0117] In the context of this disclosure, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium can be, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include, based on electrical connections of one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0118] This disclosure also provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it can implement the methods of any of the above method embodiments. The execution method and beneficial effects are similar, and will not be described again here.

[0119] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0120] The above are merely specific embodiments of this disclosure, enabling those skilled in the art to understand or implement this disclosure. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not to be limited to the embodiments described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for determining the filter cutoff frequency, characterized in that, include: The theoretical phase current frequency is calculated based on the target speed of the drive motor in the current cycle, and the estimated phase current frequency is calculated based on the estimated speed of the drive motor in the current cycle. Calculate the theoretical frequency weighting coefficient and the estimated frequency weighting coefficient based on the theoretical phase current frequency and the estimated phase current frequency; The filter cutoff frequency for the current cycle is obtained by weighting and summing the theoretical phase current frequency, the estimated phase current frequency, the theoretical frequency weighting coefficient, and the estimated frequency weighting coefficient. The calculation of the theoretical frequency weighting coefficient and the estimated frequency weighting coefficient based on the theoretical phase current frequency and the estimated phase current frequency includes: Calculate the sum of the theoretical phase current frequency and the estimated phase current frequency; The theoretical frequency weighting coefficient is determined based on the ratio of the theoretical phase current frequency to the sum, and the estimated frequency weighting coefficient is determined based on the ratio of the estimated phase current frequency to the sum.

2. The method according to claim 1, characterized in that, Before calculating the theoretical phase current frequency based on the target speed of the drive motor in the current cycle, the method further includes: The target speed for the current cycle is calculated based on the requested speed and the target speed in the previous cycle.

3. The method according to claim 2, characterized in that, The step of calculating the target speed for the current cycle based on the requested speed and the target speed in the previous cycle includes: Calculate the difference between the requested rotational speed and the target rotational speed in the previous cycle, and determine the rotational acceleration based on the difference; The target rotational speed for the current cycle is calculated based on the target rotational speed in the previous cycle and the rotational acceleration.

4. The method according to claim 3, characterized in that, The determination of rotational acceleration based on the difference includes: If the difference is greater than 0, the first preset acceleration that is in the same direction as the target rotational speed in the previous cycle is taken as the rotational speed acceleration; If the difference is less than 0, the second preset acceleration, which is opposite to the direction of the target rotational speed in the previous cycle, is taken as the rotational speed acceleration. When the difference is 0, the rotational acceleration is determined to be 0; The magnitudes of the first preset acceleration and the second preset acceleration are preset.

5. The method according to claim 1, characterized in that, The step of obtaining the cutoff frequency by weighted summation based on the theoretical phase current frequency, the estimated phase current frequency, the theoretical frequency weighting coefficient, and the estimated frequency weighting coefficient includes: use The cutoff frequency is obtained. ,in For values ​​greater than 1, These are the theoretical frequency weighting coefficients. The theoretical phase current frequency is... The estimated frequency weighting coefficients are... The estimated phase current frequency is given.

6. A method for controlling a drive motor, characterized in that, include: Obtain the motor flux linkage or back electromotive force of the drive motor; The filter cutoff frequency is determined by the method described in any one of claims 1-5, and a low-pass filter is constructed based on the filter cutoff frequency; The low-pass filter is used to perform low-pass filtering on the motor flux linkage or the motor back electromotive force to obtain the filtered flux linkage or the filtered back electromotive force. The rotor position of the drive motor is determined based on the filtered magnetic flux or the filtered back electromotive force.

7. A device for determining the filter cutoff frequency, characterized in that, include: The frequency calculation unit is used to calculate the theoretical phase current frequency based on the target speed of the drive motor in the current cycle, and to calculate the estimated phase current frequency based on the estimated speed of the drive motor in the current cycle. The weighting coefficient calculation unit is used to calculate the theoretical frequency weighting coefficient and the estimated frequency weighting coefficient based on the theoretical phase current frequency and the estimated phase current frequency; The cutoff frequency determination unit is used to perform a weighted summation based on the theoretical phase current frequency, the estimated phase current frequency, the theoretical frequency weighting coefficient, and the estimated frequency weighting coefficient to obtain the filter cutoff frequency; The weighting coefficient calculation unit is used to calculate the sum of the theoretical phase current frequency and the estimated phase current frequency. The theoretical frequency weighting coefficient is determined based on the ratio of the theoretical phase current frequency to the sum, and the estimated frequency weighting coefficient is determined based on the ratio of the estimated phase current frequency to the sum.

8. A drive motor control device, characterized in that, include: Electromagnetic characteristic determination unit, used to obtain the motor flux linkage or back electromotive force of the drive motor; A filter determination unit is configured to determine a filter cutoff frequency using the method described in any one of claims 1-5, and to construct a low-pass filter based on the filter cutoff frequency; The filtering unit is used to perform low-pass filtering on the motor flux or the motor back electromotive force using the low-pass filter to obtain the filtered flux or the filtered back electromotive force. The rotor position determination unit is used to determine the rotor position of the drive motor based on the filtered magnetic flux or the filtered back electromotive force.

9. A motor controller, characterized in that, Includes a processor and a memory, the memory being used to store computer programs; When the computer program is loaded by the processor, it causes the processor to perform the method as described in any one of claims 1-6.

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