A multi-order vibration control method for powertrain active mount based on speed notch

Abstract

The present invention discloses a method for controlling multi-order vibrations in a powertrain active mount based on speed notching. The method comprises: step S1: padding the engine speed signal; step S2: digitally filtering the engine speed signal; step S3: estimating the engine vibration fundamental frequency using the engine speed signal and generating a multi-order reference signal; step S4: performing secondary channel identification; and step S5: applying the obtained engine speed signal and the multi-order reference signal to the FxLMS algorithm to enhance the FxLMS algorithm's ability to suppress multi-order vibrations. The present invention has the advantages of effectively reducing invalid fluctuations in the speed signal, optimizing reference signal generation, and enhancing the active control of multi-order vibrations.

Description

Technical Field

[0001] The present invention mainly relates to the technical field of engine control, and in particular to a multi-order vibration control method for active suspension of a powertrain based on speed notch. Background Art

[0002] An internal combustion engine is a thermal power machine characterized by reciprocating motion, consisting of a crank-connecting rod mechanism. Although other structural variations have been developed, such as rotary and cam-disc types, the crank-connecting rod mechanism is still the predominant mechanism currently in use. Its cyclical nature subjects components within the engine to periodic, variable forces. The various vibrations in an internal combustion engine are primarily driven by the gas pressure within the cylinder and the inertial forces generated by the motion of the main mechanism.

[0003] While traditional hydraulic and rubber mounts cannot fundamentally suppress engine vibration, active mounts, as a new type of active vibration isolation method, can significantly suppress engine vibration. However, the currently used active engine mount vibration isolation methods suffer from large engine speed fluctuations. These engine speed fluctuations adversely affect the quality of the reference signal generated, ultimately reducing the effectiveness of the active engine mount in suppressing engine vibration. This ineffective fluctuation reduces the quality of the reference signal and affects the call results of the secondary channel identification results, resulting in a decrease in the vibration control effect. Furthermore, current existing technologies only target the suppression of the engine's second-order vibration, resulting in a relatively limited vibration suppression effect. Therefore, in order to achieve better vibration suppression, multi-order vibration suppression of the engine should be considered.

[0004] For example, some practitioners have proposed "an FxLMS active suspension control method based on an expanded secondary channel" (Chinese patent application CN107972466A). The technical solution is: based on the original FxLMS data processing method, an expanded secondary channel design is proposed. The expanded secondary channel not only includes the transmission path from input voltage to transmission force of the traditional secondary channel, but also includes the electronic path in the sensor and controller, and the transmission path from transmission force to acceleration. The expanded secondary channel is identified by experimental methods and is finally embedded in the control method model in the form of an FIR filter or an amplitude and phase response table. This solution has the advantages of a simple and convenient identification method, which can greatly improve the robustness and following performance of the control method based on the FxLMS data processing method, and avoid the divergence of the FxLMS data processing method. Although the control algorithm adopted by this technical solution is the classic FxLMS algorithm, the main focus is on the expansion of the connotation of the secondary channel, that is, expanding the secondary channel from only the transmission path from input voltage to transmission force to an electronic path within the sensor and controller, as well as the transmission path from input voltage to transmission force from transmission force to acceleration. Summary of the Invention

[0005] The technical problem to be solved by the present invention is: in response to the technical problems existing in the prior art, the present invention provides a powertrain active suspension multi-order vibration control method based on speed notch, which can effectively reduce the invalid fluctuations of the speed signal, optimize the generation of the reference signal, and improve the active control effect of multi-order vibrations.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A multi-order vibration control method for a powertrain active mount based on speed notch, comprising:

[0008] Step S1: Compensate the engine speed signal;

[0009] Step S2: digitally filtering the engine speed signal;

[0010] Step S3: using the engine speed signal to estimate the engine vibration fundamental frequency and generate a multi-order reference signal;

[0011] Step S4: performing secondary channel identification;

[0012] Step S5: applying the obtained engine speed signal and the multi-order reference signal to the FxLMS algorithm to enhance the multi-order vibration suppression capability of the FxLMS algorithm.

[0013] As a further improvement of the method of the present invention: in step S1, the method of filling is to take the average of the data of the first several signal points.

[0014] As a further improvement of the method of the present invention: in step S2, the engine speed signal padded in step S1 is filtered using a Kalman filter to reduce invalid fluctuations in the engine speed signal.

[0015] As a further improvement of the method of the present invention: in step S2, the engine speed signal padded in step S1 is filtered by using a mean filter to reduce invalid fluctuations in the engine speed signal.

[0016] As a further improvement to the method of the present invention: in the step S3, the engine speed signal filtered in step S2 is used to obtain the p-order vibration frequency of the engine vibration, and the calculation formula for the p-order vibration frequency is f0=p·n / 60; and based on the p-order vibration frequency, a reference signal corresponding to the second-order vibration frequency and a reference signal corresponding to the fourth-order vibration frequency of the engine vibration are obtained by phase accumulation, and the two-order reference signals are added to obtain a fused reference signal.

[0017] As a further improvement of the method of the present invention: in step S3, the reference signal is generated by superimposing first-order vibration frequency sine and cosine waves.

[0018] As a further improvement of the method of the present invention: in step S4, secondary channel identification is performed, and the secondary channel identification result is called in the form of a phase-amplitude table and in a linear interpolation manner.

[0019] As a further improvement of the method of the present invention: in step S4, secondary channel identification can be performed by experimental means.

[0020] As a further improvement of the method of the present invention: in step S4, the secondary channel identification result is called in the form of weighted sine component-weighted cosine component.

[0021] Compared with the prior art, the advantages of the present invention are:

[0022] 1. The speed notch-based multi-order vibration control method for powertrain active mount of the present invention can effectively reduce invalid fluctuations in the engine speed signal, optimize the generation of reference signals and the call of secondary channel identification results, while taking into account the multi-order vibration control of the engine and improving the vibration suppression effect of the engine active mount.

[0023] 2. The present invention's speed-notching-based multi-order vibration control method for active powertrain mounts focuses on optimizing reference signal generation and controlling multi-order engine vibrations. Building on the existing FxLMS control algorithm for active powertrain mounts, this method improves reference signal generation for multi-order vibrations and notches the engine speed signal, further optimizing reference signal generation and improving vibration control effectiveness. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic flow diagram of the method of the present invention.

[0025] Figure 2 It is a schematic diagram of the control principle of the present invention in a specific application example.

[0026] Figure 3 The figure is a schematic diagram comparing engine speed signals before and after filtering in a specific application example of the present invention.

[0027] Figure 4 3 is a schematic diagram comparing the acceleration time domain signals of the passive end of the active mount before and after the method of the present invention is adopted in a specific application example of the present invention.

[0028] Figure 5 3 is a schematic diagram comparing frequency domain signals of the passive end of the active suspension before and after the method of the present invention is adopted in a specific application example of the present invention.

[0029] Figure 6 It is a schematic diagram comparing the time domain effects of the method of the present invention and the classic FxLMS algorithm in a specific application example of the present invention.

[0030] Figure 7 It is a schematic diagram comparing the frequency domain effects of the method of the present invention and the classic FxLMS algorithm in a specific application example of the present invention. DETAILED DESCRIPTION

[0031] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] like Figure 1 and Figure 2 As shown, a multi-order vibration control method for active suspension of a powertrain based on speed notch of the present invention comprises the following steps:

[0033] Step S1: Compensate the engine speed signal;

[0034] Since there is a missing tooth in the mechanical structure of the engine speed sensor, the signal corresponding to the missing tooth exists in the actual collected engine speed signal, which will cause the engine speed to suddenly drop. Therefore, in the invention, the engine speed signal is innovatively supplemented first.

[0035] In a specific application example, the method of filling in the gaps is to average the data of the first several signal points.

[0036] Step S2: digitally filtering the engine speed signal;

[0037] In this example, the engine speed signal padded in step S1 is filtered using a Kalman filter to reduce invalid fluctuations in the engine speed signal and make the engine speed change smoother.

[0038] In other embodiments, other digital filtering algorithms that can reduce invalid fluctuations in engine speed, such as mean filtering, may be adopted according to actual needs, and all of these should be within the scope of protection of the present invention.

[0039] Step S3: using the engine speed signal to estimate the engine vibration fundamental frequency and generate a multi-order reference signal;

[0040] In this example, the engine speed signal after filtering in step S2 is used to obtain the p-order vibration frequency of the engine vibration, and the calculation formula for the p-order vibration frequency is f0=p·n / 60; and based on the p-order vibration frequency, the reference signal corresponding to the second-order vibration frequency (p=2) and the reference signal corresponding to the fourth-order vibration frequency (p=4) of the engine vibration are obtained by phase accumulation, and the two-order reference signals are added to obtain the fused reference signal.

[0041] In other embodiments, other forms of reference signal generation methods may be used according to actual needs, such as a method of generating a reference signal by superimposing sine and cosine waves of a certain order of vibration frequency, which should be within the protection scope of the present invention.

[0042] Similarly, the generation of reference signals is not limited to reference signals corresponding to second-order and fourth-order vibration frequencies, but can also include reference signals corresponding to vibration frequencies of higher orders. The fusion of reference signals of different orders is not limited to simple addition, but also includes other readily conceivable fusion methods, all of which are within the scope of protection of the present invention.

[0043] Step S4: performing secondary channel identification;

[0044] Perform secondary channel identification and call the secondary channel identification results in the form of phase-amplitude table and linear interpolation.

[0045] In specific application examples, secondary channel identification can be performed using experimental methods, which will not be described in detail here.

[0046] In other embodiments, the secondary channel identification result may be called in the form of weighted sine component-weighted cosine component, which should all be within the protection scope of the present invention.

[0047] In other embodiments, the secondary channel identification results are not limited to being called using the linear interpolation method, but can also be called using other interpolation methods, all of which should be within the scope of protection of the present invention.

[0048] Step S5: applying the obtained engine speed signal and the multi-order reference signal to the FxLMS algorithm to enhance the multi-order vibration suppression capability of the FxLMS algorithm.

[0049] In the method of the present invention, the FxLMS algorithm is one of the algorithms widely used in active vibration noise control. Its advantages are simple implementation and small computational complexity. It is derived from the LMS algorithm proposed by Widrow. On the basis of the LMS algorithm, the reference signal is filtered using a secondary channel, thereby improving the active vibration noise control effect.

[0050] like Figure 2Figure 2 shows the control principle for this example. Engine vibration propagates through the primary channel to the vibration measurement point. The goal of this example is to eliminate primary engine vibration. First, a digital filtering algorithm filters the engine speed to eliminate engine speed fluctuations. The filtered engine speed information is used to obtain the current second- and fourth-order engine vibration frequencies. A phase accumulation method is used to calculate the second- and fourth-order reference signals, respectively. These signals are then fused using an algorithm. The fused signals are then combined with the weights obtained from the LMS algorithm to generate the actuator control signal, which is then input into the actuator to control primary vibration. The LMS algorithm weights are then obtained by filtering the second- and fourth-order reference signals using the secondary channel. The filtered reference signals, combined with the error sensor signal, are then iterated and fed into the LMS algorithm to obtain the final LMS algorithm weights.

[0051] In this invention, based on the original approach focused solely on second-order vibration, a phase accumulation method is used to generate second-order and fourth-order reference signals. These two reference signals are generated in the same manner, differing in the vibration frequency derived from the rotational speed information. After generating the second-order and fourth-order reference signals, they are filtered using secondary channels in the FxLMS algorithm. After obtaining the filtered second-order and fourth-order reference signals, the reference signals are fused using the algorithm. The fused reference signals are input into the LMS algorithm and, combined with the error sensor signal, LMS weight iteration is performed to ultimately obtain LMS weights suitable for multi-order vibration control, ultimately resulting in the actuator control signal.

[0052] In a specific application example, the engine speed signal before and after filtering is compared. Figure 3 As shown in the figure, the time domain signal and frequency domain signal comparison of the passive end acceleration of the active mount before and after using this algorithm are shown in the figure. Figure 4 and 5 As shown in the figure, the time domain and frequency domain effects of this algorithm are compared with those of the classic FxLMS algorithm. Figure 6 and 7 shown.

[0053] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions based on the principles of the present invention are within the scope of protection of the present invention. It should be noted that for those skilled in the art, various improvements and modifications that do not depart from the principles of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A multi-order vibration control method for active suspension of powertrain based on speed notch, characterized in that: include: Step S1: Compensate the engine speed signal; In step S1, the method of filling is to take the average of the data of the first several signal points; Step S2: digitally filtering the padded engine speed signal; Step S3: Use the filtered engine speed signal to estimate the engine vibration fundamental frequency and generate a multi-order reference signal; use the filtered engine speed signal in step S2 to obtain the p-order vibration frequency of the engine vibration. The p-order vibration frequency calculation formula is: ; Based on the p-order vibration frequency, a reference signal corresponding to the second-order vibration frequency and a reference signal corresponding to the fourth-order vibration frequency of the engine vibration are obtained by phase accumulation, and the two-order reference signals are added to obtain a fused reference signal; Step S4: performing secondary channel identification; Step S5: applying the obtained engine speed signal and the multi-order reference signal to the FxLMS algorithm to enhance the multi-order vibration suppression capability of the FxLMS algorithm.

2. The multi-order vibration control method for active suspension of powertrain based on speed notch according to claim 1, characterized in that: In step S2, the engine speed signal padded in step S1 is filtered using a Kalman filter to reduce invalid fluctuations in the engine speed signal.

3. The multi-order vibration control method for active suspension of powertrain based on speed notch according to claim 1, characterized in that: In step S2, the engine speed signal padded in step S1 is filtered using a mean filter to reduce invalid fluctuations in the engine speed signal.

4. The multi-order vibration control method for active suspension of powertrain based on speed notch according to claim 1, 2 or 3, characterized in that: In step S3, a reference signal is generated by superimposing first-order vibration frequency sine and cosine waves.

5. The multi-order vibration control method for active suspension of powertrain based on speed notch according to claim 1, 2 or 3, characterized in that: In step S4, secondary channel identification is performed, and the secondary channel identification result is called in the form of a phase-amplitude table and a linear interpolation method.

6. The multi-order vibration control method for active suspension of powertrain based on speed notch according to claim 1, 2 or 3, characterized in that: In step S4, secondary channel identification is performed by experiment.

7. The multi-order vibration control method for active suspension of powertrain based on speed notch according to claim 1, 2 or 3, characterized in that: In step S4, the secondary channel identification result is called in the form of weighted sine component-weighted cosine component.

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