Calibration system and method for closed-loop self-calibration of motor

Abstract

The present application relates to the field of encoders, and specifically relates to a calibration system and method for closed-loop self-calibration of a motor. The system comprises an angle sensor and a controller. The angle sensor is used to detect a rotation angle of a motor; the angle sensor comprises an angle correction module, which outputs a real-time angle after correcting the rotation angle based on an angle correction parameter, and the angle correction module has a self-calibration function for the angle correction parameter, so as to perform self-calibration of the angle correction parameter on the basis of a preset calibration mode. The controller is configured to receive a real-time angle, generate a drive signal based on the real-time angle, and send the drive signal to a driver, the drive signal being used to control the driver to adjust at least one physical parameter, so as to adjust the rotation of the motor. The present application does not require stopping the motor, nor adding or removing additional equipment such as a reference encoder or a host computer, and can start and complete self-calibration of an angle correction parameter during normal operation of a closed-loop motor control process.

Description

A calibration system and method for motor closed-loop self-calibration TECHNICAL FIELD

[0001] The present application relates to the field of encoders, and in particular to a calibration system and method for motor closed-loop self-calibration. BACKGROUND

[0002] Angle sensors (encoders) play a key role in closed-loop control systems, but there are generally nonlinear errors. These errors can affect the stability of the system, often manifested as periodic fluctuations in speed.

[0003] Nonlinear error refers to the error caused by the nonlinear relationship between the encoder's measured output and the actual physical quantity. When the relationship between the encoder's output and the actual physical quantity is not a simple linear relationship, nonlinear error occurs. This error is usually caused by factors such as the nonlinear characteristics of the optical system, magnetic system, or mechanical structure during the design, manufacture, or installation of the encoder.

[0004] The relationship between the angle output by the encoder and the actual angle is not a simple linear relationship and cannot be expressed by a function. A lookup table must be created to record some key reference points and their angle correction parameters to map the encoder's output to the actual position or angle. The angles between key reference points can be fitted using a polynomial function in a local range to approximate the nonlinear output of the encoder. By finding the appropriate polynomial fit, the nonlinear error can be reduced throughout the measurement range. The order of the polynomial fit can be selected according to specific circumstances.

[0005] When the angle correction parameters need to be calibrated, a reference encoder (such as an optical encoder) can be used for calibration, and this method is called "torching".

[0006] Referring to FIG. 1, the system block diagram for calibrating a motor using the "torching" method is shown. The basic principle of torching is to superimpose an additional reference encoder on the actual output of the encoder to be calibrated. The purpose of this is to measure the actual output of the encoder to be calibrated and compare it with the accurate output of the reference encoder.

[0007] In the system block diagram shown in FIG. 1, the calibration system includes a motor, a driver driving the motor to operate, and a controller for controlling the driver. Among them, an additional reference encoder needs to be superimposed on the motor in addition to the installation of the angle sensor (i.e. the magnet and the encoder to be calibrated), and the reference encoder and the encoder to be calibrated are both used to detect the rotation angle of the motor; the reference encoder can be an encoder with higher measurement accuracy relative to the encoder to be calibrated, and an already calibrated optical encoder is generally selected to output accurate reference angle. At the same time, a computer host is also included, which is used to determine the angle error according to the reference angle sent by the reference encoder and the to-be-calibrated angle sent by the to-be-calibrated encoder, and to send the angle error to the to-be-calibrated encoder to complete the calibration. After the calibration is completed, the reference encoder and the computer host need to be removed, and then the motor operates by itself.

[0008] It can be seen that in the system of the above related technology, the inventors believe that the following problems exist: 1. It needs to be calibrated by comparison with the reference encoder, which increases additional equipment, 2. It needs to temporarily change the closed-loop system into an open-loop system, and calibrate the angle correction parameter in the non-working state of the motor running at a constant speed. That is, it needs to pause the normal working state, and after installing additional equipment such as reference encoder and host computer, it can only calibrate the angle correction parameter in the non-working state; after the calibration is completed, the additional equipment such as reference encoder and host computer needs to be removed before the normal working state can be restored. The normal working state and the non-working state cannot be converted in a non-sensing manner by internal instructions.

[0009] Therefore, there is a need for a calibration system that does not need to remove additional equipment and can automatically calibrate the angle correction parameter in the normal working state. SUMMARY

[0010] In order to be able to automatically calibrate the angle correction parameter in the normal working state, the present application provides a calibration system and method for motor closed-loop self-calibration.

[0011] In a first aspect, the application provides a calibration system for closed-loop self-calibration of an electric machine, which comprises: an angle sensor arranged on the electric machine and configured to detect a rotation angle of the electric machine, wherein the angle sensor comprises an angle correction module configured to correct the rotation angle according to an angle correction parameter and output a real-time angle, and the angle correction module has an angle correction parameter self-calibration function configured to self-calibrate the angle correction parameter according to a preset calibration mode; and a controller communicatively connected to the angle sensor, configured to receive the real-time angle, generate a driving signal according to the real-time angle, and send the driving signal to a driver configured to drive the electric machine to operate, wherein the driving signal is configured to control the driver to adjust at least one physical parameter to adjust the rotation of the electric machine.

[0012] In a further aspect, the angle correction module comprises a parameter calculator configured to receive the rotation angle, calculate the angle correction parameter according to the preset calibration mode and based on the rotation angle, and output a new angle correction parameter.

[0013] In a further aspect, the angle correction module further comprises an error corrector communicatively connected to the parameter calculator to receive the new angle correction parameter, correct the rotation angle according to the new angle correction parameter, and output the real-time angle; wherein the rotation angle is simultaneously input to an angle input end of the parameter calculator and an angle input end of the error corrector, an output end of the parameter calculator is connected to a parameter input end of the error corrector, and an output end of the error corrector is configured to output the real-time angle.

[0014] In a further aspect, the angle correction module further comprises a system stability monitor configured to receive the rotation angle, determine whether the system is stable according to the rotation angle, and enable the parameter calculator when the system is stable; wherein the rotation angle is first input to the system stability monitor and then input to the parameter calculator through the system stability monitor, and an output end of the system stability monitor is connected to an angle input end of the parameter calculator.

[0015] In a further aspect, the angle correction module further comprises a first timer configured to cyclically output a timing time and provide the timing time to the system stability monitor, and a trigger button configured to accept an input of an operator and trigger calibration of the angle correction parameter by manual operation in an initial state or an error state, and an output end of the trigger button is connected to the first timer or the parameter calculator.

[0016] Further, an output terminal of the trigger button is connected to the first timer and the parameter calculator.

[0017] Further, the angle correction module further comprises a non-volatile memory for storing the new angle correction parameter and providing the parameter calculator with the new angle correction parameter after system power-up.

[0018] Further, the controller further comprises an angle stabilizer for receiving the real-time angle, eliminating unstable jitter of the real-time angle, and providing the driving signal generator with the jitter-eliminated real-time angle.

[0019] Further, the angle stabilizer is a filter.

[0020] Further, the filter is a digital filter.

[0021] Further, the digital filter is a low-pass filter.

[0022] Further, the filter is an analog filter.

[0023] Further, the preset calibration mode comprises a timing calibration mode, and the calibration system for motor closed-loop self-calibration is configured to perform self-calibration of the angle correction parameter at a timing in a normal working state.

[0024] Further, a second timer is further provided for timing the start of the angle correction parameter self-calibration function.

[0025] Further, the first timer and the second timer are the same timer.

[0026] Further, an oscillator is further provided for providing the first timer or the second timer with a stable clock.

[0027] Further, the preset calibration mode comprises a real-time calibration mode, and the calibration system for motor closed-loop self-calibration is configured to perform self-calibration of the angle correction parameter in real time in a normal working state.

[0028] Further, the preset calibration mode comprises a single calibration mode, and the calibration system for motor closed-loop self-calibration is configured to perform self-calibration of the angle correction parameter in an initial state or an error state.

[0029] Further, the angle sensor is one of a magnetic angle sensor, an optical angle sensor, and a resistance angle sensor.

[0030] In a second aspect, the present application also provides a calibration method for motor closed-loop self-calibration, which adopts the following technical scheme: a calibration method for motor closed-loop self-calibration, comprising: arranging an angle sensor on a motor, the angle sensor being used to detect a rotation angle of the motor, wherein the angle sensor comprises an angle correction module, and the angle correction module has an angle correction parameter self-calibration function; performing self-calibration on the angle correction parameter according to a preset calibration mode; using the angle sensor to output a real-time angle after correcting the rotation angle according to the calibrated angle correction parameter; and communicatively connecting a controller to the angle sensor, the controller being configured to receive the real-time angle, generate a driving signal according to the real-time angle, and send the driving signal to a driver used to drive the motor to operate, the driving signal being used to control the driver to adjust at least one physical parameter to adjust the rotation of the motor.

[0031] In summary, the present application can start and complete the self-calibration of the angle correction parameter in the normal working state of the motor closed-loop control process without suspending the operation of the motor, and without the process of adding or removing a reference encoder, an upper computer and other additional equipment. BRIEF DESCRIPTION OF DRAWINGS

[0032] FIG. 1 is a system block diagram for realizing the "towing" calibration in the prior art.

[0033] FIG. 2 is a calibration system block diagram for motor closed-loop self-calibration according to the present application.

[0034] FIG. 3 is an internal structure block diagram of an angle correction module according to an embodiment of the present application.

[0035] FIG. 4 is an internal structure block diagram of an angle correction module according to another embodiment of the present application.

[0036] FIG. 5 is an internal structure block diagram of an angle correction module according to still another embodiment of the present application. DETAILED DESCRIPTION

[0037] It should be noted that the terms "first", "second" are only used for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features.

[0038] The embodiments of the present application will be described below in conjunction with the accompanying drawings of the present application, but the embodiments should not be understood as limiting the present application.

[0039] Referring to FIG. 2, FIG. 2 is a calibration system block diagram for motor closed-loop self-calibration according to the present application. The embodiments of the present application provide a calibration system for motor closed-loop self-calibration, comprising an angle sensor and a controller.

[0040] The driver is configured to drive the motor to operate, the controller is communicatively connected to the angle sensor, the controller is configured to receive the real-time angle, generate a driving signal (for example, in some embodiments, the driving signal can be a driving current value) according to the real-time angle, and send the driving signal to the driver, the driving signal is used to control the driver to adjust at least one physical parameter to adjust the rotation of the motor. For example, the driver can adjust the motor operating current, voltage, etc. to adjust the rotation speed of the motor. In the driver of the motor system, the controller, the driver, the driving tube, etc. can be integrated on the same PCB board, or can be separately arranged, and the application does not limit.

[0041] The angle sensor can be a magnetic angle sensor, an optical angle sensor, a resistance angle sensor, etc. The physical quantity sensed by the sensor is not limited. For convenience of description, the magnetic angle sensor (i.e. magnetic encoder) is used for specific introduction in the embodiments of the application. The magnetic encoder is fixedly arranged on the motor rotor or stator. In the embodiments of the application, the magnetic encoder is fixed relative to the stator of the motor, and the rotating shaft of the motor is provided with a magnet. The magnet rotates synchronously with the rotating shaft, and the magnetic encoder is used to detect the rotation angle of the magnet. In other embodiments of the application, an optical encoder can also be used to achieve, for example, the optical encoder can be fixed relative to the stator of the motor, and the rotating shaft of the motor is provided with an optical grating. The optical grating rotates synchronously with the rotating shaft, and the optical encoder is used to detect the rotation angle of the magnet.

[0042] Regarding the position of the magnetic encoder relative to the magnet, the magnetic encoder can adopt an on-axis detection scheme or an off-axis detection scheme. On-axis detection and off-axis detection are two different ways of magnetic induction detection in the art. It can be understood that the magnetic encoder provided by the application adopts the on-axis detection scheme, and the magnetic encoder is located on the side of the magnet along the axial direction of the output shaft of the motor, so as to obtain higher angle detection accuracy.

[0043] It can be understood that in the embodiments of the application, the angle sensor comprises an angle correction module, the angle correction module has an angle correction parameter self-calibration function, is used to correct the rotation angle according to the angle correction parameter and output the real-time angle, and is used to self-calibrate the angle correction parameter according to the preset calibration mode.

[0044] In the normal working state of the embodiments of the application, the angle sensor detects the rotation angle of the motor in real time, and sends the real-time angle generated according to the rotation angle to the controller. The controller generates a driving signal according to the real-time angle, and sends the driving signal to the driver. The driver adjusts the rotation of the motor in real time according to the driving signal.

[0045] Wherein, when generating the real-time angle according to the rotation angle, it can be judged whether the angle correction parameter needs to be self-calibrated according to a preset calibration mode. When the angle correction parameter does not need to be self-calibrated, the angle correction module will correct the rotation angle according to the set angle correction parameter and output the real-time angle; when the angle correction parameter needs to be self-calibrated, the angle correction module will calculate the set angle correction parameter according to the rotation angle and the set angle correction parameter and output a new angle correction parameter, and the angle correction module will correct the rotation angle according to the new angle correction parameter and output the real-time angle, wherein the new angle correction parameter will replace the set angle correction parameter, and thus continuously update, so as to obtain more and more accurate angle correction parameters, and realize the self-calibration function of the angle correction parameter.

[0046] Referring to FIG. 3, FIG. 3 is an internal structure block diagram of the angle correction module according to an embodiment of the present application. The angle correction module can include a parameter calculator and an error corrector. As shown in the figure, the rotation angle is input to the angle input end of the parameter calculator and the angle input end of the error corrector at the same time, the output end of the parameter calculator is connected to the parameter input end of the error corrector, and the output end of the error corrector is used to output the real-time angle. Wherein, the parameter calculator is used to receive the rotation angle, and calculate the new angle correction parameter according to the preset calibration mode and based on the rotation angle. The error corrector is communicatively connected to the parameter calculator to receive the new angle correction parameter, and correct the rotation angle according to the new angle correction parameter to output the real-time angle.

[0047] Wherein, the rotation angle is input to the angle input end of the parameter calculator and the angle input end of the error corrector at the same time, the output end of the parameter calculator is connected to the parameter input end of the error corrector, and the output end of the error corrector is used to output the real-time angle.

[0048] For the implementation of the parameter calculator and the error corrector, please refer to the description of FIG. 4.

[0049] Referring to FIG. 4, FIG. 4 is an internal structure block diagram of the angle correction module according to another embodiment of the present application. In this embodiment, the angle correction module includes a parameter calculator, an error corrector, a system stability monitor, a non-volatile memory, a timer (in this embodiment, the first timer and the second timer are the same), an oscillator (such as a crystal oscillator or an oscillator made inside a cmos chip), and a trigger button.

[0050] With reference to FIG. 4, in the embodiment, the rotation angle is input to the input end of the system stability monitor and the angle input end of the error corrector, the output end of the system stability monitor is connected to the angle input end of the parameter calculator, the system stability monitor is used to receive the rotation angle, judge whether the system is stable according to the rotation angle, and enable the parameter calculator when the system is stable. The output end of the parameter calculator is connected to the parameter input end of the error corrector, the parameter calculator is used to receive the rotation angle, calculate the angle correction parameter according to the preset calibration mode and based on the rotation angle, and output a new angle correction parameter. The error corrector is used to receive the rotation angle, correct the rotation angle according to the new angle correction parameter, and output a real-time angle. The parameter calculator and the non-volatile memory are in bidirectional communication, the parameter calculator can write the new angle correction parameter into the non-volatile memory, or read the stored angle correction parameter from the non-volatile memory. The output end of the trigger button can be connected to the trigger end of the timer, used to trigger the start of the timer, so that a more professional judgment of whether to start the system stability monitoring can be made by professionals according to different use environments and conditions, and this judgment can also indirectly trigger whether to perform self-calibration of the angle correction parameter and / or whether to perform error correction of the rotation angle. The output end of the trigger button can also be connected to the trigger end of the parameter calculator, used to trigger the parameter calculator to calculate the angle correction parameter to complete self-calibration, so that in some scenes where the calibration error is too large, this function can be manually turned off, and the angle correction parameter stored by the system previously is used to correct the error of the rotation angle output by the magnetic encoder; it can also be used to indirectly trigger whether to perform error correction of the rotation angle; it can also be used to trigger the parameter calculator to write the new angle correction parameter into the non-volatile memory or read the stored angle correction parameter from the non-volatile memory, which can be determined by professionals according to the current correction effect whether to read or store the angle correction parameter. The timer outputs the timing time cyclically, and the oscillator (such as a crystal oscillator or an oscillator made inside a cmos chip) provides a stable clock for the timer. At the same time, in the embodiment including the system stability monitor, if the system stability monitor is implemented by using the method of judging the stability of the magnetic encoder based on the timestamp register, a stable clock source can also be provided for the timestamp register in the method.

[0051] The implementation of the system stability monitor has many ways, which can adopt the speed stability detection sensor commonly used in the art, or can adopt the self-detection method disclosed in the patent with publication number CN116892970A to realize the detection of speed stability. The specific method is as follows. N angle reference points {ref[0], ref[1]…ref[n-1], ref[n]…ref[N-1]} are sequentially arranged on 0-360 degrees, and the time points {TS[0], TS[1]…TS[n-1], TS[n]…TS[N-1]} of the angle output value of the magnetic encoder passing through each angle reference point are recorded. These time points are called time stamps. For the angle reference point ref[n], the qth period of the shaft passing through ref[n] is recorded as Pq. The period of the shaft is measured and recorded multiple times for ref[n] to form a period data set: {P1, P2…Pq-1, Pq…PQ}. Taking ref[n] as an example, the time length of the angle output value of the magnetic encoder passing through ref[n] for the second time and the first time is the period P1 of the shaft measured by ref[n]; the time length of the angle output value of the magnetic encoder passing through ref[n] for the third time and the second time is the period P2 of the shaft measured by ref[n]; and so on. Then, the period set {P1, P2…Pq-1, Pq…PQ} is calculated to obtain the average period P of the shaft. The system can also take the average period P of the shaft as an index to judge the stability of the magnetic encoder. Then, whether the system meets the premise of entering the stable state can be judged according to one of the following methods: (1) whether the absolute value of the difference between the current period Pq and the last period Pq-1 is less than a first preset value Rlim1, that is, whether the judgment formula |Pq-Pq-1|<Rlim1 is established; (2) judging through the difference between the time stamps TS[n] and TS[n-1] of the adjacent two reference points ref[n] and ref[n-1] and the relationship between the angle values of the two reference points ref[n] and ref[n-1], that is, whether the judgment formula is established; (3) whether the absolute value of the difference between the current period Pq and P is less than a third preset value Rlim3, that is, whether the judgment formula |Pq-P|<Rlim3 is established. When the corresponding formula is established according to one of the above methods (judging that the system meets the premise of entering the stable state), and the formula continuously established for a certain number of times, it is judged that the system enters the stable state.

[0052] CN116892970A patent discloses the above method, mainly by calculating the difference between each cycle to determine the rotational speed of the rotating shaft value is stable, so as to realize the detection of speed stability, at the same time overcome the influence of noise on the magnetic encoder angle output value jitter. The skilled person in the art under the guidance of this method, it is easy to adjust the method, thus designing other self detection method with consistent principle but different specific operation steps, for example, the variance of cycle or speed can be calculated, when the variance of cycle or speed is less than a certain preset value for a certain number of times, the system is judged to be in stable state; Or, the cycle data set of each angle reference point ref[n] can be calculated respectively, and the cycle data calculated by each angle reference point ref[n] is considered when judging whether the system enters stable state by using method (1) to (3); Or, after judging that the corresponding formula is established (judging that the system meets the premise of entering stable state) according to one of methods (1) to (3), although the formula cannot be continuously established for a certain number of times, the system is also judged to be in stable state under certain conditions. The skilled person in the art can also use non self calibration method to judge whether the rotating speed is stable, for example, a signal source is arranged on the motor rotor or stator, and a signal source detection device is arranged on the other end of the rotor or stator, the relative position between the signal source and the detection device is detected to calculate the motor rotating cycle or speed, and the rotating speed is calculated to judge whether the rotating speed is stable. The present application does not limit this.

[0053] There are many implementation methods of parameter calculator, for example, patent application CN117168530A discloses a self calibration method of magnetic encoder, which is as follows. For example, in order to obtain the angle correction parameter in the present application, N angle reference points are arranged on 0-360 degrees, and the initial values of N nonlinear angle error reference values are arranged correspondingly. The time point when the angle output value of the magnetic encoder passes through each angle reference point is recorded, which is called time stamp. This time point is actually affected by noise and is not stable, but noise is suppressed through subsequent multiple iteration average filtering calculation (such as low pass filtering calculation introduced later). Then, it is judged whether the rotating shaft is in uniform rotating state, if yes, the N nonlinear angle error reference values are iterated, which is based on the difference between the time stamps of the previous angle reference point ANG[n-x] and the subsequent angle reference point ANG[n], the rotating cycle P of the rotating shaft, and the nonlinear angle error reference value corresponding to the previous angle reference point, to calculate the nonlinear angle error reference value of the subsequent angle reference point. For example, the actual angle ANG turned by the rotating shaft from the previous angle reference point to the subsequent angle reference point is calculated first using n-x→n , and then the nonlinear angle error reference value of the subsequent angle reference point is calculated using A new nonlinear angle error reference value corresponding to the latter angle reference point ANG[n] is calculated, where TS[n] is the time stamp corresponding to the former angle reference point, TS[n-x] is the time stamp corresponding to the latter angle reference point, and P is the period of the rotating shaft, the calculation method of which is described later in this patent application. Then, the nonlinear angle error reference values obtained in the foregoing are filtered, for example, using a low-pass filter, to obtain filtered nonlinear angle error reference values, and this operation is performed for all angle reference points. For example, the low-pass filter calculation can be specifically implemented as ref[n] <= ref[n] + K ref (ref new [n] - ref[n]), where ref`[n] is the filtered value of ref new [n], ref[n] is the nonlinear angle error reference value obtained last time corresponding to the angle reference point ANG[n], and ref new [n] is the new nonlinear angle error reference value corresponding to the angle reference point ANG[n], K ref is the low-pass filter coefficient, and 0 < K ref ≤ 1. Then, the average of the filtered nonlinear angle error reference values of all angle reference points is calculated, which is specifically calculated as Then, each filtered nonlinear angle error reference value is subtracted by the average, which is specifically calculated as ref out [i] = ref[i] - ref mean , i = 0, 1, 2,..., N-1, so as to eliminate the zero-point offset of the nonlinear angle error reference values. The filtered nonlinear angle error reference values ref out [i] after the subtraction of the average are taken as the final output nonlinear angle error reference values (equivalent to the “angle correction parameter” in this application).

[0054] In the above method disclosed in CN117168530A, the calculation method of the rotation period P is as follows: first, calculate the difference between the two time stamps of the adjacent two rotations of the same angle reference point. If the difference is greater than a certain threshold Pmin (due to noise, there is a small probability that the signal will rapidly fluctuate left and right near the angle reference point, for example, near 22.5 degrees. This may result in the time of passing through 22.5 degrees twice being recorded, but the interval between the two times is very small and is not a period. In order to exclude this situation, a minimum threshold Pmin is set according to the maximum speed that may be encountered in actual use of the motor. Only when the time of passing through a certain angle reference value twice is greater than Pmin, the difference between the two times is considered as the rotation period based on the angle reference point, so as to exclude the influence of excessive noise on the calculation result. The rotation period can be taken as the period of the next rotation, or the rotation periods based on multiple angle reference points can be averaged or processed in other ways to obtain the period of the next rotation. Then, the periods obtained from the previous rotations are low-pass filtered to obtain the filtered period, which is the final calculated output rotation period P.

[0055] For example, patent application CN115355937A also discloses a self-calibration method for a magnetic encoder, which is as follows. For example, in order to obtain the angle correction parameter in the present application, the angle value θdet(ij) output by the i th rotation of the magnetic encoder j times is low-pass filtered to improve the linearity of the detection data; the filtered value θfilt(ij) obtained after filtering is regarded as the result of linearity correction of the detection value θdet(ij). N reference points θref(n) are set within 0-360 degrees, the detection value θdet(ij) closest to each reference point θref(n) is selected, and θcal(i-n) = θfilt(ij)- θdet(ij) is taken as the difference between the correction result and the measurement result, which is used as the adjustment value of the i th period of the reference point θref(n). For each reference point, there are p corresponding adjustment values for p periods. The p adjustment values are averaged to obtain a more accurate target adjustment value θcal(n). Thus, each reference point can obtain a corresponding target adjustment value θcal(n), thereby forming an adjustment reference table (equivalent to the "angle correction parameter" in the present application).

[0056] For example, the parameter calculator can also perform Z transform on the angle error to calculate the harmonic component coefficients, so that each harmonic component coefficient is used in the error corrector to compensate the input angle, so as to obtain the corrected real-time angle value.

[0057] It can be understood that the preset calibration mode includes a timing calibration mode, a real-time calibration mode and a single calibration mode, and the parameter calculator calculates the angle correction parameter according to the preset calibration mode and based on the rotation angle, and outputs a new angle correction parameter, which can be specifically divided into the following cases according to different preset calibration modes adopted.

[0058] When the timing calibration mode is adopted, the calibration system for motor closed-loop self-calibration calibrates the angle correction parameter in a normal working state in a timing manner. In this embodiment, a timer can be added to the calibration system for motor closed-loop self-calibration, which outputs a timing time in a cycle. In the embodiment including the system stability monitor, the timer is a first timer, and the timing time can be provided to the system stability monitor to start the system stability detection in a timing manner, and the parameter calculator is automatically started to perform the angle correction parameter self-calibration function after the system is stable. In the embodiment not including the system stability monitor, for example, referring to FIG. 5, the timer is a second timer, and the timing time can be provided to the parameter calculator to start the angle correction parameter self-calibration function in a timing manner. Of course, in the embodiment including the system stability monitor, the first timer and the second timer can be included at the same time, and the first timer and the second timer can also be the same timer.

[0059] When the real-time calibration mode is adopted, the calibration system for motor closed-loop self-calibration calibrates the angle correction parameter in a normal working state in a real-time manner. It can be understood that in most use scenarios, the timing calibration mode can solve the problem, but if the actual use environment has a greater impact on the system, the real-time calibration mode can be adopted to keep the angle correction parameter in the latest state. It can be understood that in the real-time calibration mode, the system stability monitor is used to judge the stability of the system, and the self-calibration is performed when the system is stable, which is a better way.

[0060] When the single calibration mode is adopted, the calibration system for motor closed-loop self-calibration can calibrate the angle correction parameter in an initial state or an error state. A trigger button is used to manually trigger the calibration of the angle correction parameter in the initial state or the error state. The trigger button output end can be connected to the trigger end of the first timer to trigger the start of the first timer, so as to trigger the system stability monitor.

[0061] It can be understood that in many cases, we only need to adopt a single calibration mode, and calibrate the angle correction parameter in the initial state or error state. It should be noted that the single calibration mode of the embodiment of the application is also carried out in the normal working state of the calibration system for motor closed-loop self-calibration, without the need to suspend the motor operation, and more without the need to add or remove reference encoders, host computers and other additional devices and other processes, so as to start and complete the self-calibration of the angle correction parameter in the normal working state of the motor closed-loop control process.

[0062] In the embodiment of the application, the system stability monitor is used to monitor the stability of the system, to ensure that calibration is only carried out when the system is stable, thereby reducing the storage or use of incorrect or more error angle correction parameters as new angle correction parameters when the system is unstable.

[0063] It can be understood that when the system runs stably for a period of time, the new angle correction parameter continuously calculated by the parameter calculator (i.e. self-calibration) is a relatively good parameter that conforms to the current use environment and system, however, when the system is powered off, the above-mentioned good parameter will be lost, and the system needs to continuously calculate (i.e. self-calibration) again to obtain the good parameter again. In order to reduce the loss of the good parameter, a non-volatile memory is added, which is used to store the new angle correction parameter (good parameter) and provide it to the parameter calculator after the system is powered on again.

[0064] It can be understood that in the motor system, especially in the high-speed motor system, when the high-speed motor is in the normal working state, it is difficult for the high-speed motor to be in an unstable state, and therefore, it can be considered whether to add a system stability monitor in this use scenario.

[0065] It can be understood that the system stability monitor, non-volatile memory, timer (including first timer and second timer), oscillator (such as crystal oscillator or oscillator made inside cmos chip), trigger button and other devices in the embodiment can be selected according to the actual use environment, and the application does not make any limitation. For example, it can be selected to include the system stability monitor and the non-volatile memory, it can be selected to include the system stability monitor, the timer and the crystal oscillator, it can be selected to include the system stability monitor, the timer and the trigger button, it can be selected to include the system stability monitor and the trigger button, and it can be selected to include the non-volatile memory and the trigger button, and other different combinations.

[0066] In actual application of the embodiments of the present application, due to the influence of environmental factors and the like, the real-time angle information sent by the motor to the controller often has certain fluctuation, and sometimes the fluctuation is relatively large, which is easy to introduce certain error in the subsequent generation of the driving signal. In order to reduce such error, the controller can further include an angle stabilizer (see also FIG. 2) for receiving the real-time angle, eliminating the unstable jitter of the real-time angle, and providing the real-time angle after eliminating the jitter to the driving signal generator. The angle stabilizer is essentially a filter for filtering high frequency, which can be a digital filter or an analog filter. When the motor sends a digital signal, a digital filter such as a low-pass filter can be used; when the motor sends an analog signal, an analog filter such as an active filter or a passive filter can be used.

[0067] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above functional modules is taken as an example for illustration, and in actual application, the above functions can be completed by different functional modules according to needs, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. The specific working process of the system, device and unit described above can refer to the corresponding process in the foregoing method embodiments, which will not be repeated here.

[0068] In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other ways. When the integrated unit is realized in the form of a software function unit and sold or used as a separate product, it can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or the part that makes contributions to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to make a computer device or a processor execute all or part of the steps of the methods described in the embodiments of the present application.

[0069] The above embodiments are only used to specifically describe the technical solutions of the present application, and the above embodiment descriptions are only used to help understand the method of the present application and its core idea, and should not be understood as a limitation of the present application. Those skilled in the art can easily think of changes or replacements within the technical range disclosed in the present application, which should be covered within the protection scope of the present application.

Claims

1. A calibration system for closed loop self-calibration of an electric machine, characterized in that, The application relates to an angle sensor, a controller and a motor control system. The angle sensor is arranged on a motor and used for detecting a rotation angle of the motor, wherein the angle sensor comprises an angle correction module, the angle correction module is used for correcting the rotation angle according to an angle correction parameter and outputting a real-time angle, and the angle correction module has an angle correction parameter self-calibration function, so as to self-calibrate the angle correction parameter according to a preset calibration mode. The controller is communicatively connected to the angle sensor, the controller is configured to receive the real-time angle, generate a driving signal according to the real-time angle, and send the driving signal to a driver used for driving the motor to operate, and the driving signal is used for controlling the driver to adjust at least one physical parameter to adjust rotation of the motor. The angle correction module comprises a parameter calculator and a system stability monitor. The parameter calculator is used for receiving the rotation angle, calculating the angle correction parameter according to the preset calibration mode and based on the rotation angle, and outputting a new angle correction parameter. The system stability monitor is used for receiving the rotation angle, judging whether the system is stable according to the rotation angle, and enabling the parameter calculator when the system is stable. The controller further comprises an angle stabilizer, which is used for receiving the real-time angle, eliminating unstable jitter of the real-time angle, and providing the real-time angle after the jitter is eliminated to a driving signal generator.

2. The calibration system for closed loop self-calibration of electric machines of claim 1, wherein, The angle correction module comprises a parameter calculator. The parameter calculator is used for receiving the rotation angle, calculating the angle correction parameter according to the preset calibration mode and based on the rotation angle, and outputting a new angle correction parameter.

3. The calibration system for closed loop self-calibration of electric machines of claim 2, wherein, The angle correction module further comprises an error corrector. The error corrector is communicatively connected to the parameter calculator to receive the new angle correction parameter, correct the rotation angle according to the new angle correction parameter, and output the real-time angle. The rotation angle is simultaneously input to an angle input end of the parameter calculator and an angle input end of the error corrector, an output end of the parameter calculator is connected to a parameter input end of the error corrector, and an output end of the error corrector is used for outputting the real-time angle.

4. The calibration system for closed loop self-calibration of electric machines of claim 3, wherein, The rotation angle is first input to the system stability monitor and then input to the parameter calculator through the system stability monitor, and an output end of the system stability monitor is connected to an angle input end of the parameter calculator.

5. The calibration system for closed loop self-calibration of electric machines of claim 1, wherein, The angle correction module further comprises a first timer and a trigger button. The first timer is used for cyclically outputting a timing time and providing the timing time to the system stability monitor. The trigger button is used for manually triggering calibration of the angle correction parameter in an initial state or an error state, and an output end of the trigger button is connected to the first timer or the parameter calculator.

6. The calibration system for closed loop self-calibration of electric machines of claim 5, wherein, The output end of the trigger button is simultaneously connected to the first timer and the parameter calculator.

7. The calibration system for closed loop self-calibration of electric machines of claim 1, wherein, The angle correction module further comprises a nonvolatile memory. The angle stabilizer is a filter.

8. The calibration system for closed loop self-calibration of electric machines of claim 1, wherein, The filter is a digital filter.

9. The calibration system for closed loop self-calibration of electric machines of claim 8, wherein, ​ 10. The calibration system for closed loop self-calibration of electric machines of claim 9, wherein, The digital filter is a low-pass filter.

11. The calibration system for closed loop self-calibration of electric machines of claim 8, wherein, The filter is an analog filter.

12. The calibration system for closed loop self-calibration of electric machines of any of claims 1-11, characterized in that: The preset calibration mode includes a timing calibration mode, and the calibration system for motor closed-loop self-calibration performs self-calibration on the angle correction parameter in a normal working state.

13. The calibration system for closed loop self-calibration of electric machines of claim 12, wherein: A second timer is further included for timing the start of the angle correction parameter self-calibration function.

14. The calibration system for closed loop self-calibration of electric machines of claim 13, wherein: When the angle correction module further includes a first timer, the first timer and the second timer are the same timer.

15. The calibration system for closed loop self-calibration of electric machines of claim 14, wherein: An oscillator is further included for providing a stable clock for the first timer or the second timer.

16. The calibration system for closed loop self-calibration of electric machines of any of claims 1-11, characterized in that: The preset calibration mode includes a real-time calibration mode, and the calibration system for motor closed-loop self-calibration performs self-calibration on the angle correction parameter in a normal working state.

17. The calibration system for closed loop self-calibration of electric machines of any of claims 1-11, wherein: The preset calibration mode includes a single calibration mode, and the calibration system for motor closed-loop self-calibration performs self-calibration on the angle correction parameter in an initial state or an error state.

18. The calibration system for closed loop self-calibration of electric machines of any of claims 1-11, wherein: The angle sensor is one of a magnetic angle sensor, an optoelectronic angle sensor, and a resistance angle sensor.

19. A calibration method for closed loop self-calibration of an electrical machine, characterized in that, The angle sensor is disposed on the motor, and is configured to detect a rotation angle of the motor. The angle sensor is disposed on the motor, and is configured to detect a rotation angle of the motor. The angle sensor is disposed on the motor, and is configured to detect a rotation angle of the motor. The angle sensor is disposed on the motor, and is configured to detect a rotation angle of the motor. The angle sensor is disposed on the motor, and is configured to detect a rotation angle of the motor. The angle sensor is disposed on the motor, and is configured to detect a rotation angle of the motor. The angle sensor is disposed on the motor, and is configured to detect a rotation angle of the motor. The angle sensor is disposed on the motor, and is configured to detect a rotation angle of the motor. 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