CN108068659A - A kind of method, apparatus and system for inhibiting electric vehicle shake - Google Patents

Abstract

The application discloses a method, device and system for suppressing vibration of an electric vehicle, which are used to suppress the vibration of the electric vehicle and improve driving comfort. The method includes: acquiring the rotational speed signal of the motor; performing Fourier analysis on the rotational speed signal to obtain the frequency and amplitude of an effective component in the rotational speed signal that causes rotational speed jitter; the rotational speed jitter is the traction torque and resistance of the electric vehicle The jitter caused by the non-linear relationship between the moments; the parameters for suppressing the jitter of the speed are obtained according to the frequency and amplitude of the effective component that causes the jitter of the speed; the parameters for suppressing the jitter of the speed and the speed signal are passed through the differential inertia link and The compensation torque is obtained by the band-pass filtering link; and the compensation torque is superimposed on the given torque to suppress the speed jitter. Since the vibration of the electric vehicle is suppressed, the mechanical resonance generated during the vibration is reduced, thereby reducing the wear and tear of the hardware of the electric vehicle.

Description

A method, device and system for suppressing vibration of an electric vehicle

technical field

The present application relates to the technical field of electric vehicles, in particular to a method, device and system for suppressing shaking of electric vehicles.

Background technique

Electric vehicles have the advantages of high efficiency, energy saving, low noise and zero emissions, so electric vehicles are the development trend of new energy vehicles in the future. With the gradual improvement of people's awareness of environmental protection, electric vehicles are more and more popular.

Electric vehicles usually use a reducer to replace the gearbox of a traditional car. The motor and the reducer are connected by a spline, and the reducer and the wheels are connected by a universal joint. Because there is a certain connection gap and flexibility between the spline, reducer and universal joint.

The momentary jump in the output torque of the motor during the starting process of the electric vehicle will cause the elastic deformation of the transmission system, and there is a nonlinear relationship between the traction torque and the resistance torque, resulting in speed jitter. In addition, under certain working conditions of high-speed operation, mechanical resonance will occur in the power transmission system of the vehicle, which will also cause fluctuations in the output torque of the motor, resulting in speed jitter.

The speed jitter problem not only seriously affects the driving comfort of electric vehicles, but also reduces the working performance and life of the transmission system.

Therefore, how to suppress the speed jitter of electric vehicles and slow down the jitter of the whole vehicle has become an urgent problem in the field of motor drives.

Contents of the invention

The present application provides a method, device and system for suppressing vibration of an electric vehicle, which can effectively suppress the speed vibration of the electric vehicle, thereby improving driving comfort, and at the same time improving the working performance and life of the transmission system.

In a first aspect, there is provided a method for suppressing vibration of an electric vehicle, the method comprising:

Obtain the speed signal of the motor;

Perform Fourier analysis on the rotational speed signal to obtain the frequency and amplitude of an effective component in the rotational speed signal that causes rotational speed jitter; the rotational speed jitter is the jitter caused by the non-linear relationship between the traction torque and resistance torque of the electric vehicle ;

Obtaining parameters for suppressing rotational speed jitter according to the frequency and amplitude of the effective component causing rotational speed jitter;

obtaining the compensation torque through a differential inertia link and a band-pass filter link according to the parameters for suppressing rotational speed jitter and the rotational speed signal;

The compensation torque is superimposed with the given torque to suppress the speed jitter.

In a first possible implementation manner of the first aspect, Fourier analysis is performed on the rotational speed signal to obtain the frequency and amplitude of an effective component in the rotational speed signal that causes rotational speed jitter, specifically including:

performing Fourier analysis on the rotational speed signal to obtain the amplitude of each component in the rotational speed signal;

Take the component with the largest amplitude as the effective component that causes speed jitter;

Obtain the frequency and amplitude of the effective component causing rotational speed jitter.

In combination with the first aspect and any one of the above possible implementation manners, in the second possible implementation manner, superimposing the compensation torque with the given torque also includes:

limiting the compensation torque to obtain the limited compensation torque;

The superposition of the compensation torque and the given torque is specifically:

Superimpose the limited compensation torque with the given torque.

In combination with the first aspect and any of the above possible implementations, in the third possible implementation, the compensation rotation speed is obtained through the differential inertia link and the band-pass filter link according to the parameters for suppressing the rotation speed jitter and the rotation speed signal. moments, including:

The compensation torque is obtained by the following transfer function;

Among them, ω _n is the center frequency of the band-pass filter, ξ is the damping coefficient, T ₁ is the pass-band gain of the band-pass filter, T ₂ is the turning frequency of the differential inertia link; s is the Laplace variable;

Wherein, f ₁ ^* is the frequency of the effective component that causes speed jitter; A ₁ ^* is the amplitude of the effective component that causes speed jitter; a and b are coefficients used to adjust the on-state gain and the passband width, respectively .

In combination with the first aspect and any of the above possible implementation manners, in a fourth possible implementation manner, parameters for suppressing rotational speed jitter are obtained according to the frequency and amplitude of the effective component causing rotational speed jitter, specifically including:

The frequency f ₁ ^* and the amplitude A ₁ ^* of the effective component that will cause the speed jitter are obtained by the following formula to suppress the parameters of the speed jitter; the parameters for suppressing the speed jitter are respectively: the passband gain T ₁ of the band-pass filter, The corner frequency T ₂ of the differential inertia link, the center frequency ω _n and the damping coefficient ξ of the band-pass filter;

T ₁ =aA ₁

ω _n =2πf ₁ ^*

ξ=b

Among them, a and b are coefficients used to adjust the on-state gain and passband width, respectively.

In combination with the first aspect and any one of the above possible implementation manners, in a fifth possible implementation manner, it also includes:

Obtain the motor direct axis current deviation signal and the quadrature axis current deviation signal;

Performing Fourier analysis on the direct axis current deviation signal and the quadrature axis current deviation signal of the motor respectively to obtain the frequency and amplitude of the effective component that causes current jitter in the direct axis current and the quadrature axis AC;

Obtaining parameters for suppressing current jitter from the frequency and amplitude of the effective component causing current jitter;

Obtaining a direct-axis compensation voltage and a quadrature-axis compensation voltage through a resonance control link by using the parameter for suppressing current jitter, the direct-axis current deviation signal and the quadrature-axis current deviation signal;

The direct-axis compensation voltage and the quadrature-axis compensation voltage are respectively superimposed with the output direct-axis voltage, the output direct-axis voltage and the output quadrature-axis voltage, so as to suppress current jitter.

In combination with the first aspect and any of the above possible implementations, in a sixth possible implementation, perform Fourier analysis on the direct axis current deviation signal and the quadrature axis current deviation signal of the motor respectively to obtain the direct axis current The frequency and amplitude of the effective components that cause current jitter in the AC and quadrature axes, including:

performing Fourier analysis on the direct-axis current deviation signal and the quadrature-axis current deviation signal, respectively, to obtain the amplitudes of the respective components in the direct-axis current deviation signal and the quadrature-axis current deviation signal;

Take the component with the largest amplitude as the effective component that causes current jitter;

Obtaining the frequency and amplitude of effective components that cause current jitter in the direct-axis current and the quadrature-axis AC.

In combination with the first aspect and any of the above possible implementations, in a seventh possible implementation, the direct-axis compensation voltage and the quadrature-axis compensation voltage are respectively superimposed on the output direct-axis voltage and the output quadrature-axis voltage , which previously also included:

Limiting the direct-axis compensation voltage and the quadrature-axis compensation voltage to obtain the limited direct-axis compensation voltage and the limited quadrature-axis compensation voltage;

The direct-axis compensation voltage and the quadrature-axis compensation voltage are respectively superimposed on the output direct-axis voltage and the output quadrature-axis voltage, specifically:

The limited direct-axis compensation voltage and the limited quadrature-axis compensation voltage are respectively superimposed on the output direct-axis voltage and the output quadrature-axis voltage.

In combination with the first aspect and any of the above possible implementation manners, in an eighth possible implementation manner, using the parameters for suppressing current jitter, the direct-axis current deviation signal, and the quadrature-axis current deviation signal through The resonance control link obtains the direct axis compensation voltage and the quadrature axis compensation voltage, including:

The direct-axis compensation voltage and the quadrature-axis compensation voltage are obtained by the following transfer functions;

Wherein, ω _c is the preset bandwidth of the resonance control link, ω ₀ is the center frequency, k is the gain, and c is the preset coefficient for adjusting the gain; ω ₀ =2πf ₂ ^* , k=c·A ₂ ^* ; f ₂ ^* is the frequency of the effective component causing current jitter; A ₂ ^* is the amplitude of the effective component causing current jitter; s is a Laplace variable.

In a second aspect, a device for suppressing vibration of an electric vehicle is provided, the device comprising:

The acquisition unit is used to acquire the rotational speed signal of the motor;

The effective component acquisition unit of the speed jitter is used to perform Fourier analysis on the speed signal to obtain the frequency and amplitude of the effective component in the speed signal that causes the speed jitter; the speed jitter is the traction torque and resistance of the electric vehicle Jitter caused by nonlinear relationship between moments;

A rotational speed jitter suppression parameter obtaining unit, configured to obtain a rotational speed jitter suppression parameter according to the frequency and amplitude of the effective component causing the rotational speed jitter;

A compensation torque obtaining unit, configured to obtain compensation torque through a differential inertia link and a band-pass filter link according to the parameters for suppressing rotational speed jitter and the rotational speed signal;

The rotational speed jitter suppression unit is configured to superimpose the compensation torque with a given torque to suppress the rotational speed jitter.

In a first possible implementation manner of the second aspect, the obtaining unit for the effective component of rotational speed jitter includes:

The rotation speed signal component obtaining subunit is used to perform Fourier analysis on the rotation speed signal to obtain the amplitude of each component in the rotation speed signal;

The effective component acquisition subunit of the rotational speed jitter is used to use the component with the largest amplitude as the effective component causing the rotational speed jitter;

The first obtaining subunit of frequency and amplitude is used to obtain the frequency and amplitude of the effective component that causes rotational speed jitter.

In combination with the second aspect and any one of the above possible implementation manners, in the second possible implementation manner, it further includes: a torque limiting unit;

The torque limiting unit is used to limit the compensation torque to obtain the limited compensation torque;

The rotational speed jitter suppression unit is used for superimposing the limited compensation torque and the given torque.

In combination with the second aspect and any of the above possible implementation manners, the third possible implementation manner further includes:

A current deviation signal obtaining unit, configured to obtain a motor direct-axis current deviation signal and a quadrature-axis current deviation signal;

The current jitter effective component acquisition unit is used to perform Fourier analysis on the direct axis current deviation signal and the quadrature axis current deviation signal of the motor respectively to obtain the frequency and amplitude of the effective component of the direct axis current and the quadrature axis AC that cause current jitter ;

A current jitter suppression parameter obtaining unit, configured to obtain a current jitter suppression parameter from the frequency and amplitude of the effective component causing current jitter;

A compensation voltage obtaining unit, configured to use the parameter for suppressing current jitter, the direct-axis current deviation signal and the quadrature-axis current deviation signal to obtain a direct-axis compensation voltage and a quadrature-axis compensation voltage through a resonance control link;

The current jitter suppression unit is configured to superimpose the direct-axis compensation voltage and the quadrature-axis compensation voltage with the output direct-axis voltage and the output quadrature-axis voltage respectively, so as to suppress the current jitter.

With reference to the second aspect and any one of the above possible implementation manners, in a fourth possible implementation manner, the current jitter effective component obtaining unit includes:

The current deviation signal component obtaining subunit is used to perform Fourier analysis on the direct-axis current deviation signal and the quadrature-axis current deviation signal respectively, and respectively obtain the amplitudes of the components in the direct-axis current deviation signal and the quadrature-axis current deviation signal ;

The current jitter effective component acquisition subunit is used to use the component with the largest amplitude as the effective component causing current jitter;

The frequency and amplitude second obtaining subunit is used to obtain the frequency and amplitude of the effective components in the direct-axis current and quadrature-axis AC that cause current jitter.

In combination with the second aspect and any one of the above possible implementation manners, in a fifth possible implementation manner, it further includes: a voltage limiting unit;

The voltage limiting unit is configured to limit the direct-axis compensation voltage and the quadrature-axis compensation voltage to obtain the limited direct-axis compensation voltage and the limited quadrature-axis compensation voltage;

The current jitter suppression unit is configured to superpose the limited direct-axis compensation voltage and the limited quadrature-axis compensation voltage with the output direct-axis voltage and the output quadrature-axis voltage respectively.

In the third aspect, a system for suppressing vibration of an electric vehicle is provided, the system is applied to control the motor of the electric vehicle, including: a speed sensor and a motor controller;

The rotational speed sensor is used to obtain the rotational speed signal of the motor;

The motor controller is used to perform Fourier analysis on the rotational speed signal to obtain the frequency and amplitude of the effective component in the rotational speed signal that causes rotational speed jitter; the rotational speed jitter is the traction torque and resistance torque of the electric vehicle The jitter caused by the non-linear relationship between them; the parameters for suppressing the speed jitter are obtained according to the frequency and amplitude of the effective component that causes the speed jitter; according to the parameters for suppressing the speed jitter and the speed signal through the differential inertia link and the band The compensation torque is obtained through the filtering link; the compensation torque is superimposed with the given torque to suppress the speed jitter.

In a first possible implementation manner of the third aspect, the motor controller is further configured to obtain a motor direct-axis current deviation signal and a quadrature-axis current deviation signal; Performing Fourier analysis on the deviation signal to obtain the frequency and amplitude of the effective component that causes current jitter in the direct-axis current and quadrature-axis AC; obtain the parameters for suppressing current jitter from the frequency and amplitude of the effective component that cause current jitter; Using the parameters for suppressing current jitter, the direct-axis current deviation signal and the quadrature-axis current deviation signal to obtain the direct-axis compensation voltage and the quadrature-axis compensation voltage through the resonance control link; the direct-axis compensation voltage and the quadrature-axis compensation The voltage is superimposed on the output direct-axis voltage and the output quadrature-axis voltage to suppress current jitter.

It can be seen from the above technical solutions that the embodiments of the present application have the following advantages:

This application provides a method for suppressing the jitter of an electric vehicle, which collects the motor speed and then obtains the corresponding speed signal, performs Fourier analysis on the obtained speed signal, and then obtains the frequency and amplitude of the effective component in the speed signal that causes the speed jitter , then according to the frequency and amplitude of the effective component that causes the speed jitter, the parameters for suppressing the speed jitter are obtained, and the parameters for suppressing the speed jitter and the speed signal are used to obtain the compensation torque through the differential inertia link and the band-pass filter link, and the compensation torque is combined with the given Superposition of constant torque can realize the suppression of electric vehicle speed jitter.

In the method for suppressing electric vehicle jitter provided by this application, when the working conditions of the electric vehicle change, the frequency of the effective component that causes the speed jitter obtained by Fourier analysis is also different, and then the suppression is obtained according to the frequency and amplitude of the effective component The parameters of speed jitter are also different, so that the parameters for suppressing speed jitter can be obtained in real time according to the working conditions of the electric vehicle, and there is no need to manually adjust the parameters for suppressing jitter according to the current working conditions of the electric vehicle. adaptability. In addition, in the method provided by this application, it is necessary to obtain the compensation torque according to the parameter of suppressing the vibration of the rotational speed and the rotational speed signal through the joint action of the differential inertial link and the bandpass filtering link, so as to solve the problem of extracting the rotational speed when the vehicle is running at an accelerated speed. There is a problem of direct bias in volatility. To sum up, the method for suppressing the shaking of electric vehicles provided by this application can more effectively suppress the shaking of electric vehicles, improve driving comfort, and reduce the mechanical resonance generated during shaking due to the suppression of shaking of electric vehicles , thereby reducing the wear and tear of electric vehicle hardware.

Description of drawings

Fig. 1 is a kind of structural diagram of the system of suppressing electric vehicle jitter;

Fig. 2 is the structural diagram of another kind of system that suppresses electric vehicle jitter;

FIG. 3 is a flowchart of a method for suppressing vibration of an electric vehicle provided in an embodiment of the present application;

FIG. 4 is a flow chart of another method for suppressing vibration of an electric vehicle provided in an embodiment of the present application;

FIG. 5 is a functional block diagram for suppressing speed jitter of an electric vehicle provided by an embodiment of the present application;

FIG. 6 is a specific implementation block diagram of suppressing the speed jitter of an electric vehicle provided by the embodiment of the present application;

FIG. 7 is a flow chart of a method for suppressing electric vehicle current jitter provided by an embodiment of the present application;

FIG. 8 is a functional block diagram of suppressing electric vehicle current jitter provided by the embodiment of the present application;

FIG. 9 is a specific implementation block diagram of suppressing electric vehicle current jitter provided by the embodiment of the present application;

FIG. 10 is a structural diagram of a device for suppressing vibration of an electric vehicle provided in an embodiment of the present application;

FIG. 11 is a structural diagram of another device for suppressing vibration of an electric vehicle provided in the embodiment of the present application;

FIG. 12 is a structural diagram of a device for suppressing electric vehicle current jitter provided by an embodiment of the present application;

FIG. 13 is a structural diagram of a device for suppressing electric vehicle current jitter provided by an embodiment of the present application;

FIG. 14 is a structural diagram of a system for suppressing vibration of an electric vehicle provided by an embodiment of the present application;

Fig. 15 is a schematic diagram of a system for suppressing vibration of an electric vehicle during specific implementation provided by the embodiment of the present application.

Detailed ways

The embodiments of the present application provide a method, device and system for suppressing the vibration of an electric vehicle, which are used to suppress the vibration of the electric vehicle, thereby improving driving comfort, and at the same time improving the working performance and life of the hardware structure in the vehicle transmission system.

The vibration of the electric vehicle during driving will affect the driving comfort of the electric vehicle, and the vibration of the electric vehicle will also have a certain impact on some hardware structures on the electric vehicle, which may cause damage to some hardware structures, thereby affecting its service life.

As shown in Fig. 1, it is a structural diagram of a system for suppressing speed jitter of an electric vehicle. Specifically, after the vehicle controller (VCU, Vehicle Control Unit) obtains the rotational speed signal, it calculates the deviation between the rotational speed signal and the given rotational speed signal, and looks up the table according to the calculated deviation to obtain the resistance capacitance (RC ) filter parameters, and filter the speed signal according to the RC filter parameters, wherein the RC filter is a circuit that uses a voltage source, a current source, and a resistor and a capacitor to operate. Then, according to the rotational speed signal obtained by filtering, look up the table and calculate the proportional integral derivative (PID, Proportional Integral Derivative) adjustment parameters. The PID parameters are proportional parameters, integral parameters and differential parameters. The corrected torque value is sent to the controller of the generator to realize the function of suppressing the vibration of the speed.

The inventors found that the method of suppressing the vibration of the electric vehicle speed corresponding to Fig. 1 has the following disadvantages:

Since the speed jitter is suppressed by the vehicle controller (VCU), the acquisition of the speed signal and the delivery of the torque command will be limited by the communication time between the vehicle controller (VCU) and the motor controller (IPU, Intelligence Processing Unit). Limitation will produce a large delay, and the suppression effect is limited, generally it can only be suppressed to within 90rpm/60ms. In addition, when the operating conditions change, the filter parameters are obtained by looking up the table according to the size of the speed deviation, and the adaptability of the control is poor.

In addition, there is another solution to suppress the vibration of electric vehicles, as shown in Figure 2, which is the structural diagram of the system. The system realizes the suppression of speed vibration on the side of the motor controller. Specifically, the expected torque is corrected through the speed feedback link, and the motor speed detection link detects the speed signal of the motor. After the detected speed signal passes through the low-pass filter, the motor speed differential, the inertial link and the output limiter, the torque compensation is obtained. value, superimpose the torque compensation value on the expected torque, and the speed vibration can be suppressed.

During the research process, the inventor found that the scheme for suppressing the speed jitter of the electric vehicle corresponding to Fig. 2 has the following disadvantages:

Since the values of control parameters such as filter coefficients and time parameters in the speed feedback link are fixed, only the jitter of a single frequency band can be effectively suppressed. In addition, when the vehicle is accelerating, using the low-pass filter, the motor speed differential link and the inertial link to obtain the torque compensation value will lead to the direct deviation of the extracted speed fluctuation, so that the actual given torque and There is a large deviation between the desired torques.

In summary, using the system corresponding to Fig. 1 or Fig. 2 to suppress the speed jitter of electric vehicles, there will be a delay in suppressing the speed jitter, the suppression effect is limited, and the control adaptability is poor. It can only suppress the torque jitter in a single frequency band And other shortcomings, and then can not effectively achieve the suppression of electric vehicle speed jitter.

This application provides a method for suppressing the jitter of an electric vehicle, which collects the motor speed and then obtains the corresponding speed signal, performs Fourier analysis on the obtained speed signal, and then obtains the frequency and amplitude of the effective component in the speed signal that causes the speed jitter , then according to the frequency and amplitude of the effective component that causes the speed jitter, the parameters for suppressing the speed jitter are obtained, and the parameters for suppressing the speed jitter and the speed signal are used to obtain the compensation torque through the differential inertia link and the band-pass filter link, and the compensation torque is combined with the given Superposition of constant torque can realize the suppression of electric vehicle speed jitter.

The method provided by this application can effectively suppress the shaking of the electric vehicle, thereby greatly improving the driving comfort. In addition, since the shaking of the electric vehicle is suppressed, the mechanical resonance generated during the shaking process is reduced, thereby reducing the impact on the electric vehicle. Damage to the hardware structure.

Method embodiment one

Referring to FIG. 3 , this figure is a flowchart of a method for suppressing vibration of an electric vehicle provided in this embodiment. The method includes:

Step 301: Obtain the rotational speed signal of the motor.

Specifically, when collecting the speed of the motor, a speed sensor such as a resolver can be used to collect the speed of the motor. After obtaining the analog signal of the speed, the analog signal is sent to the motor controller, and the motor controller converts the analog signal into a digital signal, and sends the The digital signal is decoded to obtain the corresponding speed signal.

Step 302: Perform Fourier analysis on the rotational speed signal to obtain the frequency and amplitude of the effective component in the rotational speed signal that causes the rotational speed jitter; the rotational speed jitter is the jitter caused by the non-linear relationship between the traction torque and resistance torque of the electric vehicle.

The essence of Fourier transform is to convert a time-domain waveform into the frequency domain for decomposition, and decompose it into the sum of sine waves of different frequencies. Therefore, using Fourier transform to analyze the speed signal can detect each frequency in the speed signal. The magnitude and phase information of the components.

The Fourier transform formula is as follows:

Among them, a ₀ is the DC component, A _n , f _n and are the amplitude, frequency and phase of the nth harmonic, respectively.

In the specific implementation, the time-domain sampling method can be used to perform fast Fourier transform on the speed signal to realize the Fourier analysis of the speed signal. The formula is as follows:

in, The input sequence x(n) has a length of N and satisfies N=2 ^L , where L is a positive integer.

The components of each frequency are obtained by performing Fourier analysis on the rotational speed signal, from which the frequency and amplitude of the effective component causing the rotational speed jitter are obtained.

Step 303: According to the frequency and amplitude of the effective component causing the speed jitter, the parameters for suppressing the speed jitter are obtained.

According to the frequency and amplitude of the effective component that causes the speed jitter obtained in step 302, the corresponding calculation is performed to obtain the parameters for suppressing the speed jitter. Specifically, the parameters for suppressing the speed jitter can be the passband gain of the band-pass filter, the differential The corner frequency of the inertial link, the center frequency of the bandpass filter and the damping coefficient.

Step 304: Obtain the compensation torque through the differential inertia link and the band-pass filter link according to the parameters for suppressing the speed vibration and the speed signal.

The parameters for suppressing the speed jitter obtained in step 303 are the corresponding parameters in the differential inertial link and the band-pass filter link. After the speed signal obtained in step 301 is processed by the differential inertia link and the band-pass filter link, the system can be obtained compensation torque.

Among them, the differential link can reflect the rate of change of the speed signal, and can effectively extract the fluctuation signal of the rotational speed, and then carry out jitter suppression. However, since the result obtained by the differential operation may fluctuate greatly, this embodiment further provides an inertial link, through which the result obtained by the differential operation of the rotational speed is smoothed, thereby obtaining a more stable result.

In addition, the speed jitter signal generally contains high-frequency components, and in the process of starting and accelerating the electric vehicle, there is still a large DC component in the speed signal processed by the differential link. Therefore, in order to prevent the extracted speed fluctuation from existing In the case of direct bias, the embodiment of the present application also provides a band-pass filter, which can realize effective signal extraction from the fluctuation signal of the rotational speed.

Step 305: superimpose the compensation torque and the given torque to suppress the vibration of the rotational speed.

By superimposing the compensation torque obtained in step 304 on the given torque, the suppression of the speed vibration of the electric vehicle can be realized.

In the method for suppressing the jitter of an electric vehicle provided in this embodiment, when the working conditions of the electric vehicle change, the frequency of the effective component that causes the speed jitter obtained by Fourier analysis is also different, and then the frequency and amplitude of the effective component are obtained according to the frequency and amplitude of the effective component. The parameters for suppressing speed jitter are also different, so that the parameters for suppressing speed jitter can be obtained in real time according to the working conditions of the electric vehicle, and there is no need to manually adjust the parameters for suppressing jitter according to the current working conditions of the electric vehicle. System adaptability. In addition, in the method provided by this embodiment, it is necessary to obtain the compensation torque according to the parameters of suppressing the speed vibration and the speed signal through the joint action of the differential inertia link and the band-pass filter link, so as to solve the problem of extracting There is a problem of direct deviation in the amount of rotational speed fluctuation. To sum up, the method for suppressing the shaking of electric vehicles provided by this application can more effectively suppress the shaking of electric vehicles, improve driving comfort, and reduce the mechanical resonance generated during shaking due to the suppression of shaking of electric vehicles , thereby reducing the wear and tear on the hardware on the electric vehicle.

In actual application, in order to facilitate the implementation of the method for suppressing the shaking of an electric vehicle in the first method embodiment, this embodiment provides a more specific implementation solution.

Method embodiment two

Referring to Fig. 4, the method for suppressing electric vehicle shaking provided by this embodiment includes:

Step 401: Collect the motor speed to obtain a corresponding speed signal.

The implementation method of step 401 is the same as the implementation method of step 301 in the first method embodiment, and will not be repeated here.

Step 402: Perform Fourier analysis on the rotational speed signal to obtain the amplitude of each component in the rotational speed signal.

Perform Fourier analysis on the speed signal obtained in step 401. The essence of Fourier transform is to convert a time-domain waveform into the frequency domain for decomposition, and decompose it into the sum of sine waves of different frequencies. Therefore, using Fourier The transformation analyzes the rotational speed signal, and can detect the amplitude and phase information of each frequency component in the rotational speed signal.

The Fourier transform formula is as follows:

Among them, a ₀ is the DC component, A _n , f _n and are the amplitude, frequency and phase of the nth harmonic, respectively.

In the specific implementation, the time-domain sampling method is used to perform fast Fourier transform on the speed signal to realize the Fourier analysis of the speed signal. The formula is as follows:

in, The input sequence x(n) has a length of N and satisfies N=2L, where L is a positive integer.

That is, by performing Fourier analysis on the rotational speed signal, the components of different frequencies in the rotational speed signal are obtained, and at the same time, the amplitude of each frequency component is obtained.

Step 403: Take the component with the largest amplitude as the effective component causing the speed jitter.

Step 404: Obtain the frequency and amplitude of the effective component causing the rotational speed jitter.

Select the component with the largest amplitude among the various frequency components, and use this component as the effective component that causes speed jitter. Furthermore, the frequency and amplitude of the effective component causing the rotational speed jitter are obtained.

Step 405: Obtain the parameters for suppressing the rotational speed jitter from the frequency and amplitude of the effective component causing the rotational speed jitter.

Specifically, input f(T ₁ , T ₂ , ω _n , ξ)=f(f*,A*) to the frequency f ₁ * and amplitude A ₁ * of the effective component that causes speed jitter obtained in step 302 , to obtain the parameters for suppressing speed jitter. The parameters for suppressing speed jitter are the passband gain T ₁ of the bandpass filter, the corner frequency T ₂ of the differential inertia link, the center frequency ω _n of the bandpass filter, and the damping coefficient ξ.

Specifically, the formulas for obtaining various parameters for suppressing speed jitter are as follows:

T ₁ =aA ₁ ^*

ω _n =2πf ₁ ^*

ξ=b

Wherein, a and b are coefficients for adjusting on-state gain and passband width respectively, which can be set according to actual conditions, and are not specifically limited in this embodiment. For example, different car models have different requirements.

Step 406: Obtain the compensation torque through the differential inertia link and the band-pass filter link by using the parameters for suppressing the vibration of the rotational speed and the rotational speed signal.

The compensation torque is obtained by the following transfer function;

Among them, ω _n is the center frequency of the band-pass filter, ξ is the damping coefficient, T ₁ is the pass-band gain of the band-pass filter, T ₂ is the turning frequency of the differential inertia link; s is the Laplace variable.

During specific implementation, a differential inertial link and a band-pass filter link can be set in the jitter suppression regulator, and the rotational speed signal corresponding to the motor speed collected in step 401 is input into the jitter suppression regulator, and each obtained in step 405 The parameters T ₁ , T ₂ , ω _n and ξ for suppressing speed jitter are also input into the jitter suppression regulator. Using each parameter for suppressing speed jitter, differential inertia processing and band-pass filtering are performed on the speed signal to obtain compensation torque .

In the specific implementation, the above formula is discretized, and after discretization, the difference equations of the differential inertia link and the band-pass filter link can be obtained as follows:

in,

Wherein, T ₁ , T ₂ , ω _n and ξ are the parameters obtained in step 303 for suppressing speed vibration, and s is a Laplace variable.

Since the band-pass gain T ₁ and the damping coefficient ξ of the band-pass filter can be adjusted online through coefficient a and coefficient b respectively, the corner frequency T ₂ of the differential inertial link and the center frequency ω _n of the band-pass filter are both obtained by Fourier analysis The frequency of the effective component that causes the speed jitter is calculated. Therefore, the defect of the narrow frequency adaptation range of the filtering scheme in the prior art is overcome, and the good filtering effect can still be maintained when the speed jitter changes in a wide range.

Step 407: Limit the compensation torque to obtain the limited compensation torque.

Specifically, the compensation torque is limited according to the following formula, and the compensation torque is limited within a controllable range.

Among them, ΔT' is the limit output of the torque compensation amount, ΔT is the torque compensation amount, ΔT _UpLimit is the upper limit of the torque compensation amount, and ΔT _DnLimit is the lower limit of the torque compensation amount.

The compensation torque obtained in step 406 is about to be subjected to limiting processing, specifically, when the compensation torque is greater than the upper limit of the torque compensation amount, the value of the compensation torque is replaced by the value of the upper limit of the torque compensation amount; when the compensation torque When it is between the lower limit of the torque compensation amount and the upper limit of the torque compensation amount, the value of the compensation torque does not change; when the compensation torque is less than the lower limit of the torque compensation amount, the value of the compensation torque is replaced by the value of the lower limit of the torque compensation amount value.

Step 408: Superimpose the limited compensation torque and the given torque to suppress the vibration of the rotational speed.

The speed jitter of electric vehicles can be suppressed by superimposing the limited compensation torque with the given torque.

The method provided in this embodiment can be implemented in the form of a rotational speed jitter suppression module, and the functional block diagram of this module is shown in FIG. 5 .

As shown in Figure 5, the Fourier analysis of the collected rotational speed signal n is implemented in the form of an FFT unit. By performing Fourier analysis on the rotational speed signal, the frequency f ₁ ^* and the amplitude A of the effective component that causes rotational speed jitter are obtained ₁ ^* , input the frequency f ₁ ^* and amplitude A ₁ ^* of the effective component that causes speed jitter into the parameter adaptive unit, and the parameter adaptive unit is based on the frequency f ₁ ^* and amplitude A ₁ of the effective component that causes speed jitter ^* , get the parameters T ₁ , T ₂ , ω _n , ξ to suppress the speed jitter. The parameters to suppress the speed jitter are the parameters in the transfer function of the speed jitter suppression regulator. The speed signal passes through the transfer function of the speed jitter suppression regulator. The compensation torque ΔT is obtained, and the compensation torque ΔT is subjected to output limiting processing, so that it can be superimposed with the given torque, so as to suppress the speed jitter of the electric vehicle. FIG. 6 is a block diagram of a specific implementation corresponding to FIG. 5 .

The method for suppressing the vibration of an electric vehicle provided in this embodiment is specific to the method for suppressing the vibration of an electric vehicle provided in Method Embodiment 1, that is, a more specific method is provided to suppress the speed vibration of an electric vehicle. The method provided by this implementation can also effectively suppress the vibration of the speed of the electric vehicle and improve the driving comfort, and because the vibration of the electric vehicle is suppressed, the mechanical resonance generated during the vibration is reduced, thereby reducing the impact on the hardware of the electric vehicle. wear and tear.

When the electric vehicle works in the high-frequency band, current jitter is prone to occur, and the current jitter will cause the torque to jitter, which will also affect the driving comfort of the electric vehicle, and will cause a certain degree of damage to the internal hardware structure of the electric vehicle. In order to further ensure that the jitter of the electric vehicle is suppressed, this embodiment further provides a current jitter suppression method, on the basis of the speed jitter suppression method provided in the method embodiment 1, the current jitter suppression is further added, In order to achieve a better effect on the vibration suppression of electric vehicles.

It should be noted that the current jitter suppression method provided in this embodiment and the rotational speed jitter suppression method provided in Method Embodiment 1 are two independent methods, and the order in which the two methods are used is not fixed.

Method embodiment three

Referring to FIG. 7 , it is a flow chart of the method for suppressing the increased current jitter based on the speed jitter suppression method.

Step 701: Obtain a direct-axis current deviation signal and a quadrature-axis current deviation signal of the motor.

Specifically, the deviation signal of the direct-axis current and the deviation signal of the quadrature-axis current of the motor may be obtained through a current sensor such as a Hall element.

Step 702: Perform Fourier analysis on the motor direct-axis current deviation signal and the quadrature-axis current deviation signal respectively to obtain the frequency and amplitude of the effective components in the direct-axis current and the quadrature-axis current that cause current jitter.

The Fourier analysis is performed on the direct axis current deviation signal and the quadrature axis current deviation signal respectively, and the amplitudes of each component in the direct axis current deviation signal and the quadrature axis current deviation signal are respectively obtained.

Take the component with the largest amplitude as the effective component that causes current jitter.

Obtains the frequency and magnitude of the effective components of the d-axis and quadrature-axis currents that cause current jitter.

During specific implementation, the Fourier analysis of the direct-axis current deviation signal and the quadrature-axis current deviation signal can be implemented in the form of an FFT unit. The essence of Fourier transform is to convert a time-domain waveform into the frequency domain for decomposition, and decompose it into the sum of sine waves of different frequencies. After analysis, the amplitude and phase information of each frequency component in the motor direct axis current deviation signal and the quadrature axis current deviation signal can be detected.

Among them, a ₀ is the DC component, A _n , f _n , For the amplitude, frequency and phase of the nth harmonic.

In the specific implementation, the time-domain sampling method is used to perform fast Fourier transformation on the motor direct axis current deviation signal and the quadrature axis current deviation signal, so as to realize the Fourier analysis of the motor direct axis current deviation signal and the quadrature axis current deviation signal , the formula is as follows:

in, The input sequence x(n) has a length of N and satisfies N=2 ^L , where L is a positive integer.

Screen the various frequency components obtained by Fourier analysis, specifically, select the component with the largest amplitude among the various frequency components of the direct-axis current deviation signal as the effective component that causes current jitter in the direct-axis current; Among the various frequency components of the current deviation signal, the component with the largest amplitude is selected as the effective component in the quadrature axis current that causes current jitter. The frequencies and amplitudes of the effective components causing current jitter in the direct-axis current and the quadrature-axis current are respectively obtained as the frequencies and amplitudes of the effective components in the direct-axis current and the quadrature axis current that cause current jitter.

Step 703: Obtain parameters for suppressing current jitter from the frequency and amplitude of the effective component causing current jitter.

During specific implementation, the parameter for suppressing current jitter can be obtained in the form of a parameter adaptive unit. Input the frequency and amplitude of the effective component that causes current jitter obtained in the FFT analysis unit into f(ω ₀ ,k)=f(f ^* ,A ^* ) in the parameter adaptive unit to obtain the parameters for suppressing current jitter , the parameters to suppress current jitter are center frequency ω ₀ and gain k respectively.

Specifically, the formula for obtaining parameters for suppressing direct-axis current jitter is as follows:

ω ₀ =2πf ₂ ^*

k＝a·A ₂ ^*

Among them, ω ₀ is the center frequency, k is the gain, and a is the adjustment coefficient. f ₂ ^* is the frequency of the effective component that causes direct-axis current jitter, and A ₂ ^* is the amplitude of the effective component that causes direct-axis current jitter.

The formula for obtaining the parameters for suppressing quadrature-axis current jitter is as follows:

ω ₀ '=2πf ₃ ^*

k'＝a·A ₃ ^*

Among them, ω ₀ ' is the center frequency, k' is the gain, and a is the adjustment coefficient. f ₃ ^* is the frequency of the effective component that causes quadrature axis current jitter, and A ₃ ^* is the amplitude of the effective component that causes quadrature axis current jitter.

Step 704: Obtain the direct-axis compensation voltage and the quadrature-axis compensation voltage through the resonance control link by using the parameters for suppressing current jitter, the direct-axis current deviation signal and the quadrature-axis current deviation signal.

The direct-axis compensation voltage and the quadrature-axis compensation voltage are obtained by the following transfer functions;

Wherein, ω _c is the preset bandwidth of the resonance control link, ω ₀ is the center frequency, k is the gain, c is the preset coefficient for adjusting the gain; s is the Laplace variable.

In specific implementation, a resonance control link can be set in the current jitter suppression regulator, and the direct-axis current deviation signal and the quadrature-axis current deviation signal collected in step 701 are input into the current jitter suppression regulator, and the obtained in step 703 Various parameters for suppressing direct-axis and quadrature-axis current jitter are also input to the current jitter suppression regulator. Using each parameter to suppress the dithering of the direct-axis current, carry out resonance control processing on the direct-axis current deviation signal to obtain the direct-axis compensation voltage; use each parameter to suppress the quadrature-axis current dithering to perform resonant control processing on the quadrature-axis current deviation signal to obtain Obtain the quadrature axis compensation voltage.

Among them, the resonance control link can realize zero-steady-state non-difference control for the sinusoidal signal whose frequency is the same as its resonance frequency. In actual implementation, a quasi-resonant controller can be used in the resonance control link. When a quasi-resonant controller is used, it can not only achieve a larger gain in the resonance control link, but also effectively reduce the influence of the fundamental frequency offset.

The system transfer function is as follows:

In the specific implementation, the above-mentioned system transfer function is discretized, and the difference equation of the resonance control link is obtained after discretization as follows:

in, D= _2ωcT , E= _-2ωcT .

Among them, ω _c is the bandwidth, ω ₀ is the center frequency, k is the gain, c is the coefficient for adjusting the gain, and s is the Laplace variable.

Since the center frequency _ω0 is calculated according to the frequency of the effective component that causes current jitter obtained by Fourier analysis, it overcomes the defect that the frequency adaptation range in the existing control method is narrow, and in the case of a wide jitter frequency, The effect of resonance control can still be maintained.

Step 705: Superpose the direct-axis compensation voltage and the quadrature-axis compensation voltage with the output direct-axis voltage and the output quadrature-axis voltage respectively, so as to suppress the current jitter.

Before superimposing the direct-axis compensation voltage and the quadrature-axis compensation voltage with the output direct-axis voltage and the output quadrature-axis voltage respectively, limit the direct-axis compensation voltage and the quadrature-axis compensation voltage to obtain the limited direct-axis compensation voltage and limit The quadrature-axis compensation voltage after amplitude, that is, both the direct-axis compensation voltage and the quadrature-axis compensation voltage are limited within a controllable range.

Wherein, the output direct-axis voltage and the output AC voltage are output after performing PI adjustment on the direct-axis current and the quadrature-axis current respectively.

Specifically, the direct-axis compensation voltage and the quadrature-axis compensation voltage are clipped according to the following formula to obtain the clipped direct-axis compensation voltage and quadrature-axis compensation voltage.

Among them, Δu' is the compensation voltage limiter output, Δu is the d and q axis voltage compensation amount, Δu _UpLimit is the upper limit of the compensation voltage, and Δu _DnLimit is the lower limit of the compensation voltage.

During specific implementation, the direct-axis compensation voltage obtained in step 704 is limited. Specifically, when the direct-axis compensation voltage is greater than the upper limit of the compensation voltage, the value of the direct-axis compensation voltage is replaced by the value of the upper limit of the compensation voltage; when the direct-axis When the compensation voltage is between the lower limit of the compensation voltage and the upper limit of the compensation voltage, the value of the direct axis compensation voltage does not change; when the value of the direct axis compensation voltage is less than the value of the lower limit of the compensation voltage, the value of the direct axis compensation voltage is replaced by the value of the lower limit of the compensation voltage .

It should be noted that the method of clipping the quadrature-axis compensation voltage is the same as the above-mentioned method of clipping the direct-axis compensation voltage, and will not be repeated here.

By superimposing the limited direct-axis compensation voltage and the output direct-axis voltage, the direct-axis current jitter can be suppressed; by superposing the limited quadrature-axis compensation voltage and the output quadrature-axis voltage, the AC Shaft current jitter is suppressed.

The method provided in this embodiment can be implemented in the form of a current jitter suppression module, and a functional block diagram of the module is shown in FIG. 8 .

As shown in Figure 8, the Fourier analysis of the collected direct-axis current deviation signal Δi _d and quadrature-axis current deviation signal Δi _q is realized in the form of an FFT analysis unit. By analyzing the direct-axis current deviation signal Δi _d and the quadrature-axis current The deviation signal Δi _q is subjected to Fourier analysis to obtain the frequency f * and amplitude A ^* of the effective component that causes current jitter in the direct axis current and the quadrature axis current, and the frequency f ^* and amplitude A ^* of the effective component that cause current jitter A ^* Input the parameter adaptive unit, through the processing of the parameter adaptive unit, obtain the parameters ω ₀ and k for suppressing current jitter, the parameters for suppressing current jitter are the parameters in the transfer function of the current jitter suppression regulator, the direct axis The current deviation signal and the quadrature axis current deviation signal are processed by the transfer function in the current jitter suppression regulator to obtain the direct axis compensation voltage Δu _d and the quadrature axis compensation voltage Δu _q , and the direct axis compensation voltage Δu _d and the quadrature axis compensation voltage Δu _q After being processed by the output limiting unit, the limited direct-axis compensation voltage Δu' _d and quadrature-axis compensation voltage Δu' _q are obtained. Correspondingly, the limited direct-axis compensation voltage and quadrature-axis compensation voltage are respectively compared with the output direct axis The current jitter suppression can be achieved by superimposing the shaft voltage and the output quadrature shaft voltage. FIG. 9 is a block diagram of a specific implementation corresponding to FIG. 8 .

The current jitter suppression method provided in this embodiment further suppresses the current jitter generated when the electric vehicle operates at a high frequency on the basis of suppressing the rotational speed jitter, so that the electric vehicle can ensure driving comfort when it operates at any frequency , and can always protect the hardware structure inside the car.

Based on a method for suppressing vibration of an electric vehicle introduced in the method embodiment, an embodiment of the present application further provides a device for suppressing vibration of an electric vehicle, which will be described in detail below with reference to the accompanying drawings.

Device embodiment one

Referring to FIG. 10 , it is a structural diagram of a device for suppressing vibration of an electric vehicle provided in this embodiment. The device for suppressing vibration of an electric vehicle includes:

The collection unit 1001 is used to collect the rotation speed of the motor to obtain a corresponding rotation speed signal.

The effective component acquisition unit 1002 of the rotational speed jitter is configured to perform Fourier analysis on the rotational speed signal to obtain the frequency and amplitude of the effective component in the rotational speed signal that causes the rotational speed jitter.

The rotation speed vibration suppression parameter obtaining unit 1003 is used to obtain the rotation speed vibration suppression parameter from the frequency and amplitude of the effective component causing the rotation speed vibration.

The compensation torque obtaining unit 1004 is used to obtain the compensation torque through the differential inertia link and the band-pass filter link by using the parameters for suppressing the vibration of the rotational speed and the rotational speed signal.

The rotational speed vibration suppression unit 1005 is configured to superimpose the compensation torque and the given torque, so as to suppress the rotational speed vibration.

Wherein, as shown in FIG. 11 , the effective component obtaining unit 1002 of rotational speed jitter includes:

The rotation speed signal component obtaining subunit 1101 is used to perform Fourier analysis on the rotation speed signal to obtain the amplitude of each component in the rotation speed signal.

The subunit 1102 for obtaining effective components of rotational speed jitter is configured to use the component with the largest amplitude as the effective component causing the rotational speed jitter.

The frequency and amplitude first obtaining subunit 1103 is used to obtain the frequency and amplitude of the effective component that causes the rotational speed jitter.

As shown in Figure 11, the device further includes:

The torque limiting unit 1104 is used to limit the compensation torque to obtain the limited compensation torque.

The rotational speed jitter suppression unit 1005 is configured to superimpose the limited compensation torque with the given torque.

In the device for suppressing the jitter of an electric vehicle provided in this embodiment, when the working conditions of the electric vehicle change, the frequency of the effective component that causes the speed jitter obtained by Fourier analysis is also different, and then obtained according to the frequency and amplitude of the effective component The parameters for suppressing speed jitter are also different, so that the parameters for suppressing speed jitter can be obtained in real time according to the working conditions of the electric vehicle, and there is no need to manually adjust the parameters for suppressing jitter according to the current working conditions of the electric vehicle. System adaptability. In addition, in the device provided by this embodiment, it is necessary to obtain the compensation torque according to the parameters and the speed signal for suppressing the speed vibration through the joint action of the differential inertia link and the band-pass filter, so as to solve the problem of extracting There is a problem of direct deviation in the amount of rotational speed fluctuation. To sum up, the method for suppressing the shaking of electric vehicles provided by this application can more effectively suppress the shaking of electric vehicles, improve driving comfort, and reduce the mechanical resonance generated during shaking due to the suppression of shaking of electric vehicles , thereby reducing the wear and tear on the hardware on the electric vehicle.

Based on the method for suppressing the electric vehicle current jitter introduced in the third method embodiment, this embodiment also provides a device for suppressing the electric vehicle current jitter on the basis of the device for suppressing the electric vehicle jitter provided in the first device embodiment. A detailed introduction will be made below in conjunction with the accompanying drawings.

Device embodiment two

Referring to Figure 12, it is a structural diagram of a device for suppressing electric vehicle current jitter provided by this embodiment on the basis of device embodiment 1. The device includes:

The current deviation signal obtaining unit 1201 is used to obtain the direct axis current deviation signal and the quadrature axis current deviation signal of the motor.

The current jitter effective component obtaining unit 1202 is used to perform Fourier analysis on the motor direct axis current deviation signal and the quadrature axis current deviation signal respectively to obtain the frequency and amplitude of the effective component of the direct axis current and the quadrature axis AC that cause current jitter.

The current jitter suppression parameter obtaining unit 1203 is configured to obtain the current jitter suppression parameter from the frequency and amplitude of the effective component causing the current jitter.

A compensation voltage obtaining unit 1204, configured to use the parameters for suppressing current jitter, the direct-axis current deviation signal and the quadrature-axis current deviation signal to obtain the direct-axis compensation voltage and the quadrature-axis compensation voltage through the resonance control link;

The current jitter suppression unit 1205 is configured to superimpose the direct-axis compensation voltage and the quadrature-axis compensation voltage with the output direct-axis voltage and the output quadrature-axis voltage respectively, so as to suppress the current jitter.

As shown in FIG. 13, the current jitter effective component obtaining unit 1202 includes:

The current deviation signal component obtaining subunit 1301 is configured to perform Fourier analysis on the direct-axis current deviation signal and the quadrature-axis current deviation signal respectively, and obtain the amplitudes of the respective components in the direct-axis current deviation signal and the quadrature-axis current deviation signal.

The current jitter effective component obtaining subunit 1302 is configured to use the component with the largest amplitude as the effective component causing the current jitter.

The frequency and amplitude second obtaining subunit 1303 is configured to obtain the frequency and amplitude of the effective component that causes current jitter in the direct axis current and the quadrature axis AC.

As shown in Figure 13, the device also includes:

The voltage limiting unit 1304 is configured to limit the direct-axis compensation voltage and the quadrature-axis compensation voltage to obtain the limited direct-axis compensation voltage and the limited quadrature-axis compensation voltage.

The current jitter suppression unit 1205 is configured to superpose the limited direct-axis compensation voltage and the limited quadrature-axis compensation voltage with the output direct-axis voltage and the output quadrature-axis voltage respectively.

The current jitter suppression device provided in this embodiment further suppresses the current jitter generated when the electric vehicle operates at a high frequency on the basis of suppressing the rotational speed jitter, so that the electric vehicle can ensure driving comfort when it operates at any frequency , and can always protect the hardware structure inside the car.

Based on the method and device for suppressing the shaking of an electric vehicle introduced in the above method embodiments, this implementation provides a system for suppressing the shaking of an electric vehicle, which will be described in detail below with reference to the accompanying drawings.

System embodiment

Referring to FIG. 14 , it is a structural diagram of a system for suppressing vibration of an electric vehicle provided in this embodiment.

The speed sensor 1401 is used to collect the motor speed to obtain the corresponding speed signal.

The motor controller 1402 is configured to perform Fourier analysis on the rotational speed signal to obtain the frequency and amplitude of the effective component that causes rotational speed jitter in the rotational speed signal; obtain the suppressed rotational speed from the frequency and amplitude of the effective component that causes rotational speed jitter vibration parameters; using the parameters for suppressing speed vibration to obtain compensation torque through a differential inertia link and a band-pass filter link; superimposing the compensation torque and a given torque to suppress speed vibration.

Specifically, a speed sensor such as a resolver can be used to measure the rotational speed of the motor, and an analog signal corresponding to the rotational speed of the motor can be obtained, and the analog signal can be sent to the motor controller 1402, and the motor controller 1402 can convert the analog signal into a corresponding The digital signal of the motor can be decoded to obtain the speed signal of the motor.

The motor controller 1402 implements the suppression of the vibration of the motor speed according to the method from step 302 to step 305 in the first method embodiment.

In addition, the motor controller 1402 is also used to obtain the motor direct-axis current deviation signal and the quadrature-axis current deviation signal; respectively perform Fourier analysis on the motor direct-axis current deviation signal and the quadrature-axis current deviation signal to obtain the direct-axis current and the quadrature-axis current deviation signal. The frequency and amplitude of the effective component that causes current jitter in quadrature-axis AC; the parameters for suppressing current jitter are obtained from the frequency and amplitude of the effective component that cause current jitter; the parameters for suppressing current jitter are obtained through the resonance control link A direct-axis compensation voltage and a quadrature-axis compensation voltage; the direct-axis compensation voltage and the quadrature-axis compensation voltage are respectively superimposed on the output direct-axis voltage and the output quadrature-axis voltage, so as to suppress current jitter.

Specifically, the motor controller 1402 may further suppress current jitter according to the method introduced in the second method embodiment.

As shown in Fig. 15, it is a system topology diagram for suppressing vibration of electric vehicles during specific implementation.

Wherein, the speed jitter suppression module 1501 is the speed jitter suppression module in FIG. 5 , and the current jitter suppression module 1502 is the current jitter suppression module in FIG. 7 .

In the system for suppressing electric vehicle jitter provided by this embodiment, when the working conditions of the electric vehicle change, the frequency of the effective component that causes the speed jitter obtained by Fourier analysis is also different, and then the frequency and amplitude of the effective component are obtained according to the frequency and amplitude of the effective component. The parameters for suppressing speed jitter are also different, so that the parameters for suppressing speed jitter can be obtained in real time according to the working conditions of the electric vehicle, and there is no need to manually adjust the parameters for suppressing jitter according to the current working conditions of the electric vehicle. System adaptability. In addition, in the system provided by this embodiment, it is necessary to obtain the compensation torque according to the parameters for suppressing the vibration of the rotational speed and the rotational speed signal through the joint action of the differential inertial link and the band-pass filtering link, so as to solve the problem of extracting There is a problem of direct deviation in the amount of rotational speed fluctuation. To sum up, the method for suppressing the shaking of electric vehicles provided by this application can more effectively suppress the shaking of electric vehicles, improve driving comfort, and reduce the mechanical resonance generated during shaking due to the suppression of shaking of electric vehicles , thereby reducing the wear and tear on the hardware on the electric vehicle.

In addition, the system for suppressing electric vehicle jitter provided by this embodiment further suppresses the current jitter generated when the electric vehicle operates at a high frequency on the basis of suppressing the speed jitter, so that when the electric vehicle operates at any frequency, it can ensure Driving comfort, and can always protect the hardware structure inside the car.

In addition, since in the embodiment of the present application, the motor controller directly suppresses the speed jitter and the current jitter, rather than the vehicle controller, therefore, in this embodiment, there is no control by the vehicle controller as shown in FIG. 2 . The signal delay problem of jitter suppression.

As mentioned above, the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still understand the foregoing The technical solutions described in each embodiment are modified, or some of the technical features are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the application.

Claims (17)

1. A method for suppressing electric vehicle jitter, characterized in that, comprising: Obtain the speed signal of the motor; Perform Fourier analysis on the rotational speed signal to obtain the frequency and amplitude of an effective component in the rotational speed signal that causes rotational speed jitter; the rotational speed jitter is the jitter caused by the non-linear relationship between the traction torque and resistance torque of the electric vehicle ; Obtaining parameters for suppressing rotational speed jitter according to the frequency and amplitude of the effective component causing rotational speed jitter; obtaining the compensation torque through a differential inertia link and a band-pass filter link according to the parameters for suppressing rotational speed jitter and the rotational speed signal; The compensation torque is superimposed with the given torque to suppress the speed jitter. 2. The method for suppressing the jitter of an electric vehicle according to claim 1, characterized in that, Fourier analysis is carried out to the rotational speed signal to obtain the frequency and the amplitude of the effective component causing rotational speed jitter in the rotational speed signal, specifically include: performing Fourier analysis on the rotational speed signal to obtain the amplitude of each component in the rotational speed signal; Take the component with the largest amplitude as the effective component that causes speed jitter; Obtain the frequency and amplitude of the effective component causing rotational speed jitter. 3. The method for suppressing electric vehicle jitter according to claim 1, characterized in that, superimposing the compensation torque with a given torque, also includes before: limiting the compensation torque to obtain the limited compensation torque; The superposition of the compensation torque and the given torque is specifically: Superimpose the limited compensation torque with the given torque. 4. The method for suppressing the jitter of an electric vehicle according to claim 2, wherein the compensation torque is obtained through a differential inertial link and a band-pass filter link according to the parameter for suppressing rotational speed jitter and the rotational speed signal, specifically comprising: The compensation torque is obtained by the following transfer function; <mrow><msub><mi>G</mi><mi>n</mi></msub><mrow><mo>(</mo><mi>s</mi><mo>)</mo></mrow><mo>=</mo><mfrac><mrow><msub><mi>T</mi><mn>1</mn></msub><msubsup><mi>&amp;omega;</mi><mi>n</mi><mn>2</mn></msubsup><msup><mi>s</mi><mn>2</mn></msup></mrow><mrow><msub><mi>T</mi><mn>3</mn></msub><msup><mi>s</mi><mn>3</mn></msup><mo>+</mo><mrow><mo>(</mo><mn>2</mn><msub><mi>&amp;xi;&amp;omega;</mi><mi>n</mi></msub><msub><mi>T</mi><mn>2</mn></msub><mo>+</mo><mn>1</mn><mo>)</mo></mrow><msup><mi>s</mi><mn>2</mn></msup><mo>+</mo><mrow><mo>(</mo><msub><mi>T</mi><mn>2</mn></msub><msubsup><mi>&amp;omega;</mi><mi>n</mi><mn>2</mn></msubsup><mo>+</mo><mn>2</mn><msub><mi>&amp;xi;&amp;omega;</mi><mi>n</mi></msub><mo>)</mo></mrow><mi>s</mi><mo>+</mo><msubsup><mi>&amp;omega;</mi><mi>n</mi><mn>2</mn></msubsup></mrow></mfrac></mrow> Among them, ω _n is the center frequency of the band-pass filter, ξ is the damping coefficient, T ₁ is the pass-band gain of the band-pass filter, T ₂ is the turning frequency of the differential inertia link; s is the Laplace variable; <mrow><msub><mi>T</mi><mn>1</mn></msub><mo>=</mo><msup><msub><mi>aA</mi><mn>1</mn></msub><mo>*</mo></msup><mo>,</mo><msub><mi>T</mi><mn>2</mn></msub><mo>=</mo><mfrac><mn>1</mn><mrow><mn>10</mn><msup><msub><mi>f</mi><mn>1</mn></msub><mo>*</mo></msup></mrow></mfrac><mo>,</mo><msub><mi>&amp;omega;</mi><mi>n</mi></msub><mo>=</mo><mn>2</mn><msup><msub><mi>&amp;pi;f</mi><mn>1</mn></msub><mo>*</mo></msup><mo>,</mo><mi>&amp;xi;</mi><mo>=</mo><mi>b</mi><mo>;</mo></mrow> Wherein, f ₁ ^* is the frequency of the effective component that causes speed jitter; A ₁ ^* is the amplitude of the effective component that causes speed jitter; a and b are coefficients used to adjust the on-state gain and the passband width, respectively . 5. The method for suppressing the vibration of an electric vehicle according to claim 1, wherein the parameters for suppressing the vibration of the rotational speed are obtained according to the frequency and amplitude of the effective component causing the vibration of the rotational speed, specifically comprising: The frequency f ₁ ^* and the amplitude A ₁ ^* of the effective component that will cause the speed jitter are obtained by the following formula to suppress the parameters of the speed jitter; the parameters for suppressing the speed jitter are respectively: the passband gain T ₁ of the band-pass filter, The corner frequency T ₂ of the differential inertia link, the center frequency ω _n and the damping coefficient ξ of the band-pass filter; T ₁ =aA ₁ ^* <mrow><msub><mi>T</mi><mn>2</mn></msub><mo>=</mo><mfrac><mn>1</mn><mrow><mn>10</mn><msup><msub><mi>f</mi><mn>1</mn></msub><mo>*</mo></msup></mrow></mfrac></mrow> ω _n =2πf ₁ ^* ξ=b Among them, a and b are coefficients used to adjust the on-state gain and passband width, respectively. 6. The method for suppressing electric vehicle jitter according to claim 1, further comprising: Obtain the motor direct axis current deviation signal and the quadrature axis current deviation signal; Performing Fourier analysis on the direct axis current deviation signal and the quadrature axis current deviation signal of the motor respectively to obtain the frequency and amplitude of the effective component that causes current jitter in the direct axis current and the quadrature axis AC; Obtaining parameters for suppressing current jitter from the frequency and amplitude of the effective component causing current jitter; Obtaining a direct-axis compensation voltage and a quadrature-axis compensation voltage through a resonance control link by using the parameter for suppressing current jitter, the direct-axis current deviation signal and the quadrature-axis current deviation signal; The direct-axis compensation voltage and the quadrature-axis compensation voltage are respectively superimposed with the output direct-axis voltage, the output direct-axis voltage and the output quadrature-axis voltage, so as to suppress current jitter. 7. The method for suppressing electric vehicle jitter according to claim 6, characterized in that, performing Fourier analysis on the direct-axis current deviation signal and the quadrature-axis current deviation signal of the motor respectively to obtain the direct-axis current and the quadrature-axis AC center The frequency and magnitude of the active components that cause current jitter, including: performing Fourier analysis on the direct-axis current deviation signal and the quadrature-axis current deviation signal, respectively, to obtain the amplitudes of the respective components in the direct-axis current deviation signal and the quadrature-axis current deviation signal; Take the component with the largest amplitude as the effective component that causes current jitter; Obtaining the frequency and amplitude of effective components that cause current jitter in the direct-axis current and the quadrature-axis AC. 8. The method for suppressing the jitter of an electric vehicle according to claim 6, wherein the direct-axis compensation voltage and the quadrature-axis compensation voltage are respectively superimposed on the output direct-axis voltage and the output quadrature-axis voltage, and the method also includes: Limiting the direct-axis compensation voltage and the quadrature-axis compensation voltage to obtain the limited direct-axis compensation voltage and the limited quadrature-axis compensation voltage; The direct-axis compensation voltage and the quadrature-axis compensation voltage are respectively superimposed on the output direct-axis voltage and the output quadrature-axis voltage, specifically: The limited direct-axis compensation voltage and the limited quadrature-axis compensation voltage are respectively superimposed on the output direct-axis voltage and the output quadrature-axis voltage. 9. The method for suppressing electric vehicle jitter according to claim 7, characterized in that, using the parameters for suppressing current jitter, the direct-axis current deviation signal and the quadrature-axis current deviation signal to obtain the direct current deviation signal through the resonance control link Axis compensation voltage and quadrature axis compensation voltage, including: The direct-axis compensation voltage and the quadrature-axis compensation voltage are obtained by the following transfer functions; <mrow><msub><mi>G</mi><mi>i</mi></msub><mrow><mo>(</mo><mi>s</mi><mo>)</mo></mrow><mo>=</mo><mfrac><mrow><msub><mi>k&amp;omega;</mi><mi>c</mi></msub><mi>s</mi></mrow><mrow><msup><mi>s</mi><mn>2</mn></msup><mo>+</mo><msub><mi>&amp;omega;</mi><mi>c</mi></msub><mi>s</mi><mo>+</mo><msubsup><mi>&amp;omega;</mi><mn>0</mn><mn>2</mn></msubsup></mrow></mfrac></mrow> Wherein, ω _c is the preset bandwidth of the resonance control link, ω ₀ is the center frequency, k is the gain, and c is the preset coefficient for adjusting the gain; ω ₀ =2πf ₂ ^* , k=c·A ₂ ^* ; f ₂ ^* is the frequency of the effective component causing current jitter; A ₂ ^* is the amplitude of the effective component causing current jitter; s is a Laplace variable. 10. A device for suppressing electric vehicle shaking, characterized in that it comprises: The acquisition unit is used to acquire the rotational speed signal of the motor; The effective component acquisition unit of the speed jitter is used to perform Fourier analysis on the speed signal to obtain the frequency and amplitude of the effective component in the speed signal that causes the speed jitter; the speed jitter is the traction torque and resistance of the electric vehicle The jitter caused by the non-linear relationship between moments; A rotational speed jitter suppression parameter obtaining unit, configured to obtain a rotational speed jitter suppression parameter according to the frequency and amplitude of the effective component causing the rotational speed jitter; A compensation torque obtaining unit, configured to obtain compensation torque through a differential inertia link and a band-pass filter link according to the parameters for suppressing rotational speed jitter and the rotational speed signal; The rotational speed jitter suppression unit is configured to superimpose the compensation torque with a given torque to suppress the rotational speed jitter. 11. The device for suppressing electric vehicle jitter according to claim 10, characterized in that, the acquisition unit of the effective component of rotational speed jitter comprises: The rotation speed signal component obtaining subunit is used to perform Fourier analysis on the rotation speed signal to obtain the amplitude of each component in the rotation speed signal; The effective component acquisition subunit of the rotational speed jitter is used to use the component with the largest amplitude as the effective component causing the rotational speed jitter; The first obtaining subunit of frequency and amplitude is used to obtain the frequency and amplitude of the effective component that causes rotational speed jitter. 12. The device for suppressing electric vehicle shaking according to claim 10, further comprising: a torque limiting unit; The torque limiting unit is used to limit the compensation torque to obtain the limited compensation torque; The rotational speed jitter suppression unit is used for superimposing the limited compensation torque and the given torque. 13. The device for suppressing electric vehicle shaking according to claim 10, further comprising: A current deviation signal obtaining unit, configured to obtain a motor direct-axis current deviation signal and a quadrature-axis current deviation signal; The current jitter effective component acquisition unit is used to perform Fourier analysis on the direct axis current deviation signal and the quadrature axis current deviation signal of the motor respectively to obtain the frequency and amplitude of the effective component of the direct axis current and the quadrature axis AC that cause current jitter ; A current jitter suppression parameter obtaining unit, configured to obtain a current jitter suppression parameter from the frequency and amplitude of the effective component causing current jitter; A compensation voltage obtaining unit, configured to use the parameter for suppressing current jitter, the direct-axis current deviation signal and the quadrature-axis current deviation signal to obtain a direct-axis compensation voltage and a quadrature-axis compensation voltage through a resonance control link; The current jitter suppression unit is configured to superimpose the direct-axis compensation voltage and the quadrature-axis compensation voltage with the output direct-axis voltage and the output quadrature-axis voltage respectively, so as to suppress the current jitter. 14. The device for suppressing electric vehicle jitter according to claim 13, wherein the current jitter effective component obtaining unit comprises: The current deviation signal component obtaining subunit is used to perform Fourier analysis on the direct-axis current deviation signal and the quadrature-axis current deviation signal respectively, and respectively obtain the amplitudes of the components in the direct-axis current deviation signal and the quadrature-axis current deviation signal ; The current jitter effective component acquisition subunit is used to use the component with the largest amplitude as the effective component causing current jitter; The frequency and amplitude second obtaining subunit is used to obtain the frequency and amplitude of the effective components in the direct-axis current and quadrature-axis AC that cause current jitter. 15. The device for suppressing electric vehicle jitter according to claim 13, further comprising: a voltage limiting unit; The voltage limiting unit is configured to limit the direct-axis compensation voltage and the quadrature-axis compensation voltage to obtain the limited direct-axis compensation voltage and the limited quadrature-axis compensation voltage; The current jitter suppression unit is configured to superpose the limited direct-axis compensation voltage and the limited quadrature-axis compensation voltage with the output direct-axis voltage and the output quadrature-axis voltage respectively. 16. A system for suppressing the vibration of an electric vehicle, characterized in that it is applied to control the motor of the electric vehicle, including: a speed sensor and a motor controller; The rotational speed sensor is used to obtain the rotational speed signal of the motor; The motor controller is used to perform Fourier analysis on the rotational speed signal to obtain the frequency and amplitude of the effective component in the rotational speed signal that causes rotational speed jitter; the rotational speed jitter is the traction torque and resistance torque of the electric vehicle The jitter caused by the non-linear relationship between them; the parameters for suppressing the speed jitter are obtained according to the frequency and amplitude of the effective component that causes the speed jitter; according to the parameters for suppressing the speed jitter and the speed signal through the differential inertia link and the band The compensation torque is obtained through the filtering link; the compensation torque is superimposed with the given torque to suppress the speed jitter. 17. The system for suppressing electric vehicle jitter according to claim 16, wherein the motor controller is also used to obtain a motor direct-axis current deviation signal and a quadrature-axis current deviation signal; for the motor direct-axis current The deviation signal and the quadrature-axis current deviation signal are respectively subjected to Fourier analysis to obtain the frequency and amplitude of the effective component causing current jitter in the direct-axis current and quadrature-axis AC; obtained from the frequency and amplitude of the effective component causing current jitter A parameter for suppressing current jitter; using the parameter for suppressing current jitter, the direct-axis current deviation signal and the quadrature-axis current deviation signal to obtain a direct-axis compensation voltage and a quadrature-axis compensation voltage through a resonance control link; The compensation voltage and the quadrature-axis compensation voltage are respectively superimposed on the output direct-axis voltage and the output quadrature-axis voltage to suppress current jitter.