Torque estimation method, device and automobile

Abstract

The application belongs to the technical field of torque estimation, and discloses a torque estimation method, device and automobile. The method comprises the following steps: acquiring a motor speed, and determining a torque estimation model based on the motor speed, wherein the torque estimation model comprises a current model and a power model; reading a target data section corresponding to the torque estimation model to obtain a preset number of torque estimation data; calculating the preset number of torque estimation data based on the torque estimation model to obtain a preset number of estimated torques; and performing mean value calculation on the preset number of estimated torques to obtain an estimated actual motor torque. Through the application, the estimation accuracy of the actual output torque of the vehicle can be improved, so that the occurrence of unexpected shutdown of the vehicle working condition is reduced, and the driving safety is further ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of motor control, and particularly relates to a torque estimation method and device and a vehicle. BACKGROUND

[0002] With the rapid popularization of new energy vehicles, the safety problems that follow are becoming more and more prominent. For pure electric vehicles, the main drive motor is the only torque output device. Abnormal torque output of the drive motor can cause unexpected acceleration or unexpected deceleration of the vehicle, which can lead to traffic accidents and pose a great safety hazard. Therefore, in order to ensure safety, it is necessary to monitor the safety of the motor output torque.

[0003] At present, most motor controllers with actual output torque function and meeting functional safety requirements implement the torque safety method in functional safety by comparing the output torque of the motor with the torque requested by the vehicle controller. Within a certain range, it is considered normal, otherwise it is considered that an abnormality affecting safety has occurred. On the main drive system, there is no torque sensor, so the actual output torque needs to be estimated by algorithm. However, the existing torque estimation method has low accuracy, which can easily lead to unexpected shutdown of the vehicle. After unexpected shutdown, the vehicle needs to be restarted to run, which is not good for user experience. SUMMARY

[0004] The present application provides a torque estimation method, device and vehicle, which can improve the estimation accuracy of the actual output torque of the vehicle, thereby reducing the occurrence of unexpected shutdown of the vehicle working condition, to further protect the safety of driving and riding.

[0005] In a first aspect, the embodiments of the present application provide a torque estimation method, which comprises:

[0006] Obtaining a motor speed and determining a torque estimation model based on the motor speed, wherein the torque estimation model comprises a current model and a power model;

[0007] Reading a target data segment corresponding to the torque estimation model to obtain a preset number of torque estimation data;

[0008] Calculating the preset number of torque estimation data based on the torque estimation model to obtain a preset number of estimated torques;

[0009] Performing mean value calculation on the preset number of estimated torques to obtain an estimated actual motor torque.

[0010] Further, the step of determining the torque estimation model based on the motor speed comprises:

[0011] Determining a preset numerical range in which the motor speed is located;

[0012] When it is determined that the motor speed is in a first preset value range, the torque estimation model is a current model;

[0013] When it is determined that the motor speed is in a second preset value range, the torque estimation model is a current model and a power model, wherein the lower limit value of the second preset value range is greater than the upper limit value of the first preset value range;

[0014] When it is determined that the motor speed is in a third preset value range, the torque estimation model is a power model, wherein the lower limit value of the third preset value range is greater than the upper limit value of the second preset value range.

[0015] Further, before the step of obtaining the motor speed and determining the torque estimation model based on the motor speed, the step includes:

[0016] Based on the collected sine and cosine signals of the motor resolver, the position data of the motor rotor is calculated;

[0017] The motor speed is calculated and determined based on the position data of the motor rotor.

[0018] Further, before the step of reading the target data segment corresponding to the torque estimation model to obtain the preset number of torque estimation data, the step includes:

[0019] The three-phase current values of the motor, the sine and cosine data of the motor resolver are taken as a group of data at a preset period, and are sequentially stored in the target data segment corresponding to the current model;

[0020] The three-phase current values of the motor, the sine and cosine data of the motor resolver, the voltage values of the motor controller DC bus, and the motor three-phase bridge arm switch state data are taken as a group of data at a preset period, and are sequentially stored in the target data segment corresponding to the power model.

[0021] Further, the length of the target data segment corresponding to the torque estimation model is at least double the preset number.

[0022] Further, the step of reading the target data segment corresponding to the torque estimation model to obtain the preset number of torque estimation data includes:

[0023] The data in the target data segment corresponding to the torque estimation model is sequentially and circularly read, and the data index value is incremented by one when each group of torque estimation data is read;

[0024] When the data index value reaches a preset threshold value, the preset number of torque estimation data is obtained, a flag bit indicating the end of the cycle is output, and the data index value is cleared.

[0025] Further, when the torque estimation model is a current model, the step of calculating the preset number of torque estimation data based on the torque estimation model comprises:

[0026] calculating the position data of the motor rotor based on the sine and cosine data of the motor rotary transformer in each set of torque estimation data;

[0027] calculating the actual control current value on the d-axis and q-axis of the motor based on the three-phase current value of the motor and the position data of the motor rotor in each set of torque estimation data;

[0028] calculating the current vector and the included angle between the current vector and the motor rotor rotating coordinate system based on the actual control current value on the d-axis and q-axis of the motor;

[0029] obtaining the motor parameters, and calculating the actual output electromagnetic torque of the motor based on the motor parameters, the current vector and the included angle between the current vector and the motor rotor rotating coordinate system;

[0030] calculating the motor speed based on the position data of the motor rotor;

[0031] calculating the friction torque on the motor output shaft based on the motor speed;

[0032] obtaining the estimated torque corresponding to each set of torque estimation data based on the actual output electromagnetic torque of the motor and the friction torque on the motor output shaft.

[0033] Further, when the torque estimation model is a power model, the step of calculating the preset number of torque estimation data based on the torque estimation model comprises:

[0034] calculating the reconstructed three-phase voltage value based on the voltage value of the motor controller DC bus and the motor three-phase bridge arm switch state data in each set of torque estimation data;

[0035] calculating the output power of the motor controller based on the reconstructed three-phase voltage value and the three-phase current value of the motor in each set of torque estimation data;

[0036] calculating the position data of the motor rotor based on the sine and cosine data of the motor rotary transformer in each set of torque estimation data;

[0037] calculating the motor speed based on the position data of the motor rotor;

[0038] calculating the estimated torque corresponding to each set of torque estimation data based on the output power of the motor controller, the system efficiency and the motor speed.

[0039] In a second aspect, the present application further provides a torque estimation device, comprising:

[0040] a model determination module, configured to acquire a motor speed and determine a torque estimation model based on the motor speed, wherein the torque estimation model comprises a current model and a power model;

[0041] a data reading module, configured to read a target data segment corresponding to the torque estimation model to obtain a preset group of torque estimation data;

[0042] a first torque calculation module, configured to calculate the preset number of groups of torque estimation data based on the torque estimation model to obtain a preset number of estimated torques;

[0043] a second torque calculation module, configured to perform mean value calculation on the preset number of estimated torques to obtain an estimated actual motor torque.

[0044] Further, the model determination module is further configured to:

[0045] determine a preset numerical range in which the motor speed is located;

[0046] when it is determined that the motor speed is located in a first preset numerical range, the torque estimation model is the current model;

[0047] when it is determined that the motor speed is located in a second preset numerical range, the torque estimation model is the current model and the power model, wherein the lower limit value of the second preset numerical range is greater than the upper limit value of the first preset numerical range;

[0048] when it is determined that the motor speed is located in a third preset numerical range, the torque estimation model is the power model, wherein the lower limit value of the third preset numerical range is greater than the upper limit value of the second preset numerical range.

[0049] Further, the torque estimation device further comprises a speed calculation module, configured to:

[0050] calculate based on the acquired sine and cosine signals of the motor rotary transformer to obtain position data of a motor rotor;

[0051] determine the motor speed based on the position data of the motor rotor.

[0052] Further, the torque estimation device further comprises a storage module, configured to:

[0053] store, in sequence, three-phase current values of the motor and sine and cosine data of the motor rotary transformer as a group of data in a target data segment corresponding to the current model at a preset period;

[0054] The three-phase current value of the motor, the sine and cosine data of the motor rotary transformer, the voltage value of the motor controller DC bus, and the three-phase bridge arm switch state data of the motor are taken as a group of data with a preset period, and are sequentially stored in the target data segment corresponding to the power model.

[0055] Further, the length of the target data segment corresponding to the torque estimation model is at least double the preset number of groups.

[0056] Further, the data reading module is also specifically used for:

[0057] The data in the target data segment corresponding to the torque estimation model is sequentially read in a loop, and the data index value is incremented by one when each group of torque estimation data is read.

[0058] When the data index value reaches a preset threshold, the preset number of groups of torque estimation data are obtained, and a flag bit indicating the end of the loop is output, and the data index value is cleared.

[0059] Further, when the torque estimation model is a current model, the first torque calculation module is also specifically used for:

[0060] Based on the sine and cosine data of the motor rotary transformer in each group of torque estimation data, the position data of the motor rotor is determined;

[0061] Based on the three-phase current value of the motor and the position data of the motor rotor in each group of torque estimation data, the actual control current value on the d-axis and q-axis of the motor is determined;

[0062] Based on the actual control current value on the d-axis and q-axis of the motor, the current vector and the included angle between the current vector and the motor rotor rotating coordinate system are calculated;

[0063] The motor parameters are obtained, and based on the motor parameters, the current vector, and the included angle between the current vector and the motor rotor rotating coordinate system, the actual output electromagnetic torque of the motor is calculated;

[0064] Based on the position data of the motor rotor, the motor speed is calculated;

[0065] Based on the motor speed, the friction torque on the motor output shaft is calculated;

[0066] Based on the actual output electromagnetic torque of the motor and the friction torque on the motor output shaft, the estimated torque corresponding to each group of torque estimation data is obtained.

[0067] Further, when the torque estimation model is a power model, the second torque calculation module is also specifically used for:

[0068] The reconstructed three-phase voltage value is calculated based on the voltage value of the motor controller DC bus and the motor three-phase bridge arm switch state data in each set of torque estimation data;

[0069] The output power of the motor controller is calculated based on the reconstructed three-phase voltage value and the three-phase current value of the motor in each set of torque estimation data;

[0070] The position data of the motor rotor is determined based on the sine and cosine data of the motor rotary transformer in each set of torque estimation data;

[0071] The motor speed is calculated based on the position data of the motor rotor;

[0072] The estimated torque corresponding to each set of torque estimation data is calculated based on the output power of the motor controller, the system efficiency, and the motor speed.

[0073] In a third aspect, the present application also provides an automobile, which comprises a processor, a memory, a torque estimation program stored in the memory and executable on the processor, and the processor implements the steps of the torque estimation method when executing the torque estimation program.

[0074] Compared with the prior art, the technical scheme provided by the embodiments of the present application has at least the following beneficial effects:

[0075] The torque estimation method, device, and automobile provided by the embodiments of the present application set a data segment comprising a plurality of sets of torque estimation data for each torque estimation model, and based on the determination of the model that needs to be used for torque estimation according to the different ranges of the motor speed to ensure the torque estimation accuracy, the preset number of estimated torques is obtained by reading and calculating the preset set of torque estimation data of the target data segment of the model, and the actual motor torque with higher accuracy is obtained by mean value calculation, so that the estimation accuracy of the actual output torque of the vehicle is improved, and the vehicle working condition that is unexpectedly shut down due to low estimation torque accuracy is reduced, so as to further ensure the driving safety. BRIEF DESCRIPTION OF DRAWINGS

[0076] Figure 1 The flowchart of the torque estimation method provided by an embodiment of the present application is shown.

[0077] Figure 2 The flowchart of the torque estimation method based on the current model to estimate the motor torque provided by another embodiment of the present application is shown.

[0078] Figure 3 The flowchart of the torque estimation method based on the power model to estimate the motor torque provided by another embodiment of the present application is shown.

[0079] Figure 4 A functional module schematic diagram of a torque estimation device provided for an embodiment of the present application is shown. DETAILED DESCRIPTION

[0080] The technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0081] Referring to Figure 1 The embodiments of the present application provide a torque estimation method, which specifically includes the following steps.

[0082] In step S10, the motor speed is obtained, and a torque estimation model is determined based on the motor speed, wherein the torque estimation model includes a current model and a power model.

[0083] In step S20, a target data segment corresponding to the torque estimation model is read to obtain a preset number of torque estimation data.

[0084] In step S30, the preset number of torque estimation data is calculated based on the torque estimation model to obtain a preset number of estimated torques.

[0085] In step S40, the preset number of estimated torques is subjected to mean value calculation to obtain an estimated actual motor torque.

[0086] In the embodiments, the calculation accuracy of different torque estimation models is different when the motor is in different speed ranges, and the torque estimation model includes a current model and a power model. The current model has higher estimation accuracy for torque when the motor speed is lower, and the power model has higher estimation accuracy for torque when the motor speed is higher. Therefore, in the torque estimation scheme of the present embodiment, the motor speed needs to be obtained first, and then the model for high-precision torque estimation is determined based on the motor speed, so as to ensure the accuracy of torque estimation.

[0087] Considering that the current model and the power model in the prior art both need to run in an interrupt at the same frequency as the motor control, and the fusion output based on the two torque estimation models needs to run in a periodic task, and there are several interrupts running protective programs, the vehicle software architecture implementing the torque estimation method is not conducive to meeting the functional safety requirements. In the embodiment, a data segment is set for each torque estimation model, and the original signal data required by the torque estimation model is periodically collected and stored in the target data segment corresponding to the torque estimation model. The target data segment includes several groups of torque estimation data. By setting the data cache data segment, the software of the entire safety layer only has one main task with a fixed period, reducing the complexity of the software.

[0088] After determining the model that needs to perform torque estimation based on the motor speed, the target data segment corresponding to the torque estimation model can be read to obtain a preset number of torque estimation data, so as to avoid that the estimation data is single data of short-time fluctuation of the motor, thereby ensuring the robustness of the data and further improving the accuracy of torque estimation. After obtaining the preset number of torque estimation data, the preset number of torque estimation data is calculated based on the determined torque estimation model, and a preset number of estimated torques can be obtained. At this time, the mean value of the preset number of estimated torques is calculated to obtain the estimated actual motor torque. The actual motor torque estimated by the mean value calculation has high accuracy, and the vehicle working condition caused by the low accuracy of the estimated torque and the mis-triggered shutdown is reduced. The mean value calculation of the current model is as follows The mean value calculation of the power model is as follows The mean value calculation of the fusion of the current model and the power model is as follows Wherein, i represents the cache order bit of a group of data in the target data segment in the cache area; N represents the total number of reading cache data at a time, that is, the preset number; represents the i-th estimated torque calculated by the current model based on the i-th group of cache data; represents the actual motor torque estimated by the current model based on N groups of cache data; represents the i-th estimated torque calculated by the power model based on the i-th group of cache data; represents the actual motor torque estimated by the power model based on N groups of cache data, represents the actual motor torque estimated by the fusion of the current model and the power model after the mean value calculation.

[0089] Further, in an embodiment, the step of determining the torque estimation model based on the motor speed comprises:

[0090] determining a preset numerical range of the motor speed;

[0091] When it is determined that the motor speed is in a first preset value range, the torque estimation model is a current model;

[0092] When it is determined that the motor speed is in a second preset value range, the torque estimation model is a current model and a power model, wherein a lower limit value of the second preset value range is greater than an upper limit value of the first preset value range;

[0093] When it is determined that the motor speed is in a third preset value range, the torque estimation model is a power model, wherein a lower limit value of the third preset value range is greater than an upper limit value of the second preset value range.

[0094] In the embodiment, in order to guarantee the accuracy of torque estimation, different torque estimation models are used for the motor in different speed ranges. The current model has higher estimation accuracy when the motor speed is low, the power model has higher estimation accuracy when the motor speed is high, and when the motor speed is in an intermediate value, the estimation accuracy of the current model or the power model is not much different, so the characteristics of the two torque estimation models can be comprehensively used in the intermediate value. Based on the above consideration, the embodiment scheme pre-sets three value ranges, the values of the three value ranges are determined based on a limited number of tests or the actual experience of the technical personnel to compare the torque estimation accuracy, and then corresponding calibration is performed. After the motor speed is obtained, the value range in which the motor speed is located is determined, and then the model used for subsequent torque estimation is determined. The lower limit value of the second preset value range is greater than the upper limit value of the first preset threshold, and the lower limit value of the third preset value range is greater than the upper limit value of the second preset value range. When the motor speed is in the first preset value range, the torque estimation model is the current model. When the motor speed is in the second preset value range, the torque estimation model is the current model and the power model. When the motor speed is in the third preset value range, the torque estimation model is the power model. Through the above distribution of the torque estimation model, the accuracy of the torque estimation can be further improved, and the high torque estimation accuracy in the whole working speed range is guaranteed.

[0095] Further, an embodiment includes, before the step S10:

[0096] The position data of the motor rotor is obtained based on the collected sine and cosine signals of the motor resolver;

[0097] The motor speed is determined based on the position data of the motor rotor.

[0098] In this embodiment, before obtaining the motor speed, the motor speed needs to be calculated first. Compared with the prior art, the motor rotor position data is determined based on the set hardware chip decoding, and then the motor speed is calculated based on the motor rotor position data. In this embodiment, the motor rotor position data can be calculated based on the collected sine and cosine signals of the motor resolver, and then the motor speed is calculated based on the motor rotor position data. By this method, the hardware chip can be saved, and the cost of the motor controller system is further reduced.

[0099] Further, in an embodiment, the step S20 comprises the following steps before the step S20:

[0100] The three-phase current values of the motor, the sine and cosine data of the motor resolver are taken as a group of data at a preset period, and are sequentially stored in the target data segment corresponding to the current model.

[0101] The three-phase current values of the motor, the sine and cosine data of the motor resolver, the voltage values of the motor controller DC bus, and the motor three-phase bridge arm switch state data are taken as a group of data at a preset period, and are sequentially stored in the target data segment corresponding to the power model.

[0102] In this embodiment, the data segment corresponding to the current model contains several groups of data, wherein one group of data contains the three-phase current values of the motor detected by the phase current detection device and the continuous sine and cosine signal data output by the resolver based on the periodic excitation signal detected by the resolver detection device. The data segment corresponding to the power model contains several groups of data, wherein one group of data contains the voltage on the DC bus detected by the bus voltage detection device, the motor three-phase bridge arm switch state data including the instantaneous phase voltage duty cycle of the three power tubes of the upper half bridge in a period detected by the PWM detection device, the three-phase current values of the motor detected by the phase current detection device, and the continuous sine and cosine signal data output by the resolver based on the periodic excitation signal detected by the resolver detection device. The above data is stored in the target data segment corresponding to the current model and the power model in the order of detection and collection, for subsequent torque estimation.

[0103] Further, in an embodiment, the length of the target data segment corresponding to the torque estimation model is at least double the preset number of groups.

[0104] In the embodiment, the data in the target data segment of the cache area is subjected to the processes of collection, caching, reading, calculation and updating. In order to guarantee the integrity of the original data during calculation, when reading the preset number of groups of data in the target data segment, the preset number of groups of data in the target data segment is required to be able to be subjected to caching of newly collected data, and therefore the length of the target data segment corresponding to each torque estimation model is at least double the preset number of groups, wherein the preset number of groups is the maximum allowed array size for single reading calculation.

[0105] Further, in an embodiment, the step S20 comprises:

[0106] The data in the target data segment corresponding to the torque estimation model is read in sequence and in a loop, and the data index value is incremented by one when each group of torque estimation data is read;

[0107] When the data index value reaches a preset threshold value, the preset number of groups of torque estimation data is obtained, and a flag bit indicating the end of the loop is output, and the data index value is cleared.

[0108] In the embodiment, the data in the target data segment corresponding to the torque estimation model is read in a loop according to the order in which the data enters the cache area, and the end condition of the loop reading is that the preset number of groups of torque estimation data is obtained. Therefore, when the data in the target data segment is read in a loop, the data index value of the cache data counter is incremented by one for each group of data read. The preset threshold value corresponds to the value of the preset number of groups, and when the data index value reaches the preset threshold value, the flag bit indicating the end of the loop can be output, the caching of the target cache area is ended, and the data index value is cleared for counting when the data is read next time. At the same time, since the preset number of groups of data has been read, the positions of the preset number of groups of data can be emptied for updating the new collected data.

[0109] Further, in an embodiment, when the torque estimation model is a current model, the step S30 comprises:

[0110] The position data of the motor rotor is determined based on the sine and cosine data of the motor rotary transformer in each group of torque estimation data;

[0111] The actual control current values on the d-axis and q-axis of the motor are determined based on the three-phase current values of the motor and the position data of the motor rotor in each group of torque estimation data;

[0112] The current vector and the included angle between the current vector and the motor rotor rotating coordinate system are obtained based on the actual control current values on the d-axis and q-axis of the motor;

[0113] The motor parameters are obtained, and the actual output electromagnetic torque of the motor is obtained based on the motor parameters, the current vector and the included angle between the current vector and the motor rotor rotating coordinate system;

[0114] The motor speed is calculated based on the position data of the motor rotor;

[0115] The frictional torque on the motor output shaft is calculated based on the motor speed.

[0116] Based on the actual electromagnetic torque output by the motor and the frictional torque on the motor output shaft, the estimated torque corresponding to each set of torque estimation data is obtained.

[0117] In this embodiment, when the torque estimation model is a current model, each set of torque estimation data includes the three-phase current values ​​of the motor detected by the phase current detection device. And a rotary transformer testing device for detecting rotary transformers based on periodic excitation signal Exc i Output continuous sine and cosine signal data (ResSin i ResCos i ). Specifically, refer to Figure 2 The rotor calculation module will use the sine and cosine data of the motor resolver in each set of torque estimation data (ResinSin) i ResCos i Calculate and determine the position data θ of the motor rotor. i =arctan(ResSin i / ResCos i The current coordinate transformation module will then, based on the determined motor rotor position data θ,... i Three-phase current values ​​of the motor Perform coordinate transformation to convert the values ​​into actual control current values ​​on the d-axis and q-axis of the motor. The current vector calculation module calculates the actual control current values ​​on the d-axis and q-axis. Calculate the current vector and the angle δ between it and the rotating coordinate system of the motor rotor i The actual electromagnetic torque calculation module of the motor will obtain the motor parameters from the vehicle parameter storage area. The motor parameters include the number of motor pole pairs P and the motor rotor flux λ. m Motor d-axis inductance L d Motor q-axis inductance L q Then based on the motor parameters (P, λ) m L d L q ), Current vector I si and the angle δ between the current vector and the rotating coordinate system of the motor rotor. i Calculations are performed to obtain the actual electromagnetic torque output by the motor. The motor speed calculation module will use the motor rotor position data θ determined by the rotor solution module. i Calculate and determine the motor speed ω i; friction resistance calculation module calculates friction torque on the output shaft of the main drive motor based on motor speed ω i current model corresponding motor actual output torque calculation module, based on electromagnetic torque and friction torque on the output shaft of the motor Each set of torque estimation data corresponding to the estimated torque of the motor can be calculated

[0118] Further, in an embodiment, when the torque estimation model is a power model, the step S30 comprises:

[0119] Based on the voltage value of the motor controller DC bus in each set of torque estimation data and the motor three-phase bridge arm switch state data, the reconstructed three-phase voltage value is calculated;

[0120] Based on the reconstructed three-phase voltage value and the three-phase current value of the motor in each set of torque estimation data, the output power of the motor controller is calculated;

[0121] Based on the sine and cosine data of the motor rotary transformer in each set of torque estimation data, the position data of the motor rotor is determined;

[0122] Based on the position data of the motor rotor, the motor speed is calculated;

[0123] Based on the output power of the motor controller, the system efficiency and the motor speed, the estimated torque corresponding to each set of torque estimation data is calculated.

[0124] In this embodiment, when the torque estimation model is a power model, each set of torque estimation data includes the three-phase current value of the motor The sine and cosine data (ResSin i , ResCos i ) of the motor rotary transformer, the voltage value V dc of the motor controller DC bus and the motor three-phase bridge arm switch state data. Specifically, referring to Figure 3 , the inverter output phase voltage reconstruction calculation module calculates the reconstructed U\V\W phase voltage based on the instantaneous phase voltage duty cycle given by the three power tubes of the upper half bridge in one period contained in the motor three-phase bridge arm switch state data bus voltage V dc The inverter AC side power calculation module calculates the output power of the motor controller based on the read three-phase current value and the reconstructed U\V\W phase voltage ​​​The rotor resolving module calculates the position data θ of the motor rotor based on the sine and cosine data (ResSin i , ResCos i ) of the motor resolver in each set of torque estimation data. i The motor speed calculating module calculates the motor speed ω based on the position data θ of the motor rotor determined by the rotor resolving module. i i The motor actual output torque calculating module calculates the motor estimation torque corresponding to each set of torque estimation data based on the output power of the motor controller , the system efficiency η, and the motor speed ω i .

[0125] The application also provides a torque estimation device.

[0126] Referring to Figure 4 , a schematic diagram of the functional modules of the first embodiment of the torque estimation device.

[0127] In this embodiment, the torque estimation device comprises:

[0128] a model determining module 10 configured to obtain the motor speed and determine a torque estimation model based on the motor speed, wherein the torque estimation model comprises a current model and a power model;

[0129] a data reading module 20 configured to read a target data segment corresponding to the torque estimation model to obtain a preset set of torque estimation data;

[0130] a first torque calculating module 30 configured to calculate a preset number of sets of torque estimation data based on the torque estimation model to obtain a preset number of estimation torques;

[0131] a second torque calculating module 40 configured to perform mean value calculation on the preset number of estimation torques to obtain an estimated actual motor torque.

[0132] Further, the model determining module 10 is further configured to:

[0133] determine a preset numerical range in which the motor speed is located;

[0134] when it is determined that the motor speed is located in a first preset numerical range, the torque estimation model is a current model;

[0135] when it is determined that the motor speed is located in a second preset numerical range, the torque estimation model is a current model and a power model, wherein the lower limit value of the second preset numerical range is greater than the upper limit value of the first preset numerical range;

[0136] ​When it is determined that the motor speed is in a third preset value range, the torque estimation model is a power model, wherein a lower limit value of the third preset value range is greater than an upper limit value of the second preset value range.

[0137] Further, in an embodiment, the torque estimation device further comprises a speed calculation module, configured to:

[0138] Based on the collected sine and cosine signals of the motor rotary transformer, position data of the motor rotor is obtained;

[0139] The motor speed is determined based on the position data of the motor rotor.

[0140] Further, in an embodiment, the torque estimation device further comprises a storage module, configured to:

[0141] The three-phase current values of the motor, the sine and cosine data of the motor rotary transformer are taken as a group of data at a preset period, and are sequentially stored in the target data section corresponding to the current model;

[0142] The three-phase current values of the motor, the sine and cosine data of the motor rotary transformer, the voltage value of the motor controller DC bus, and the motor three-phase bridge arm switch state data are taken as a group of data at a preset period, and are sequentially stored in the target data section corresponding to the power model.

[0143] Further, in an embodiment, the length of the target data section corresponding to the torque estimation model is at least double the preset number of groups.

[0144] Further, in an embodiment, the data reading module 20 is further specifically configured to:

[0145] The data in the target data section corresponding to the torque estimation model is sequentially and circularly read, and the data index value is incremented by one when each group of torque estimation data is read;

[0146] When the data index value reaches a preset threshold value, the preset number of groups of torque estimation data are obtained, and a flag bit indicating the end of the cycle is output, and the data index value is cleared.

[0147] Further, in an embodiment, when the torque estimation model is the current model, the first torque calculation module 30 is further specifically configured to:

[0148] The position data of the motor rotor is determined based on the sine and cosine data of the motor rotary transformer in each group of torque estimation data;

[0149] The actual control current values on the d-axis and the q-axis of the motor are determined based on the three-phase current values of the motor and the position data of the motor rotor in each group of torque estimation data;

[0150] The current vector and the included angle between the current vector and the motor rotor rotating coordinate system are obtained by calculating based on the actual control current values on the d-axis and the q-axis of the motor;

[0151] The motor actual output electromagnetic torque is obtained by calculating based on the motor parameters, the current vector and the included angle between the current vector and the motor rotor rotating coordinate system;

[0152] The motor speed is obtained by calculating based on the position data of the motor rotor;

[0153] The friction torque on the motor output shaft is obtained by calculating based on the motor speed;

[0154] The estimated torque corresponding to each set of torque estimation data is obtained based on the motor actual output electromagnetic torque and the friction torque on the motor output shaft.

[0155] Further, in an embodiment, when the torque estimation model is a power model, the first torque calculation module 30 is further configured to:

[0156] The reconstructed three-phase voltage values are obtained by calculating based on the voltage values of the motor controller direct-current bus and the motor three-phase bridge arm switch state data in each set of torque estimation data;

[0157] The output power of the motor controller is obtained by calculating based on the reconstructed three-phase voltage values and the three-phase current values of the motor in each set of torque estimation data;

[0158] The position data of the motor rotor is determined by calculating based on the sine and cosine data of the motor rotary transformer in each set of torque estimation data;

[0159] The motor speed is obtained by calculating based on the position data of the motor rotor;

[0160] The estimated torque corresponding to each set of torque estimation data is obtained based on the output power of the motor controller, the system efficiency and the motor speed.

[0161] The functions of the modules in the torque estimation device correspond to the steps in the torque estimation method, and the functions and implementation processes will not be repeated here.

[0162] An automobile is provided in an embodiment of the application, and the automobile includes a processor, a memory, and a torque estimation program stored in the memory and executable on the processor. The processor can call the stored torque estimation program and execute the steps of the torque estimation method provided in the embodiment of the application.

[0163] The method implemented when the torque estimation program is executed can refer to the embodiments of the torque estimation method of the application, and will not be repeated here.

[0164] Any combination of the technical features in the above embodiments can be made. For the sake of brevity, the foregoing description has not described all possible combinations of the technical features in the above embodiments. However, as long as the combination of the technical features does not contradict, it should be considered within the scope of the present disclosure.

[0165] The above embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the patent scope of the present application. It should be pointed out that, for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

Claims

1. A torque estimation method characterized by, The method comprises: acquiring the motor speed and determining a torque estimation model based on the motor speed, wherein the torque estimation model comprises a current model and a power model; specifically comprising: determining the preset numerical range in which the motor speed is located, when it is determined that the motor speed is in the first preset numerical range, the torque estimation model is the current model; when it is determined that the motor speed is in the second preset numerical range, the torque estimation model is the current model and the power model, wherein the lower limit value of the second preset numerical range is greater than the upper limit value of the first preset numerical range; when it is determined that the motor speed is in the third preset numerical range, the torque estimation model is the power model, wherein the lower limit value of the third preset numerical range is greater than the upper limit value of the second preset numerical range; the three-phase current value of the motor, the sine and cosine data of the motor rotary transformer are taken as a group of data at a preset period, and are sequentially stored in the target data segment corresponding to the current model; the three-phase current value of the motor, the sine and cosine data of the motor rotary transformer, the voltage value of the motor controller DC bus and the motor three-phase bridge arm switch state data are taken as a group of data at a preset period, and are sequentially stored in the target data segment corresponding to the power model; sequentially and circularly reading the data in the target data segment corresponding to the torque estimation model, and when each group of torque estimation data is read, the data index value is increased by one, when the data index value reaches a preset threshold, a preset number of torque estimation data are obtained, and a flag bit indicating the end of the cycle is output, and the data index value is cleared; based on the torque estimation model, the preset number of torque estimation data are calculated to obtain a preset number of estimated torques; when the torque estimation model is the current model, the position data of the motor rotor is calculated based on the sine and cosine data of the motor rotary transformer in each group of torque estimation data; the actual control current value on the d-axis and q-axis of the motor is determined based on the three-phase current value of the motor and the position data of the motor rotor in each group of torque estimation data; the current vector and the included angle between the current vector and the motor rotor rotating coordinate system are obtained based on the actual control current value on the d-axis and q-axis of the motor; the motor parameters are acquired, and the actual output electromagnetic torque of the motor is obtained based on the motor parameters, the current vector and the included angle between the current vector and the motor rotor rotating coordinate system; the motor speed is calculated based on the position data of the motor rotor; the friction torque on the motor output shaft is calculated based on the motor speed; the estimated torque corresponding to each group of torque estimation data is obtained based on the actual output electromagnetic torque of the motor and the friction torque on the motor output shaft; the mean value of the preset number of estimated torques is calculated to obtain the estimated actual motor torque.

2. The torque estimation method according to claim 1, characterized by, Before the step of acquiring the motor speed and determining the torque estimation model based on the motor speed, the method comprises: calculating the position data of the motor rotor based on the collected sine and cosine signals of the motor rotary transformer; calculating the motor speed based on the position data of the motor rotor.

3. The torque estimation method according to claim 1, characterized by: The length of the target data segment corresponding to the torque estimation model is at least double the preset number.

4. The torque estimation method according to claim 1, characterized by, When the torque estimation model is a power model, the step of calculating the preset number of torque estimation data based on the torque estimation model comprises: Based on the voltage value of the motor controller DC bus and the motor three-phase bridge arm switch state data in each group of torque estimation data, the reconstructed three-phase voltage value is calculated; Based on the reconstructed three-phase voltage value and the three-phase current value of the motor in each group of torque estimation data, the output power of the motor controller is calculated; Based on the sine and cosine data of the motor rotary transformer in each group of torque estimation data, the position data of the motor rotor is determined; Based on the position data of the motor rotor, the motor speed is calculated; Based on the output power of the motor controller, the system efficiency and the motor speed, the estimated torque corresponding to each group of torque estimation data is calculated.

5. A torque estimation device characterized by comprising: The device for performing the steps of the torque estimation method according to any one of claims 1 to 4 comprises: a model determination module for obtaining the motor speed and determining the torque estimation model based on the motor speed, wherein the torque estimation model comprises a current model and a power model; a data reading module for reading the target data segment corresponding to the torque estimation model to obtain the preset group of torque estimation data; a first torque calculation module for calculating the preset number of torque estimation data based on the torque estimation model to obtain the preset number of estimated torques; a second torque calculation module for performing mean value calculation on the preset number of estimated torques to obtain the estimated actual motor torque.

6. An automobile characterized by comprising: The automobile comprises a processor, a memory, a torque estimation program stored on the memory and executable on the processor, and the processor executes the torque estimation program to implement the steps of the torque estimation method according to any one of claims 1 to 4.

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