A booming sound control system and control method of a vehicle back door

Abstract

The present application belongs to the technical field of vehicle noise cancellation, and particularly relates to a booming sound control system and control method for a rear back door of a vehicle. The control system comprises a data acquisition module, an adaptive filter unit and an error signal collection module. The data acquisition module is used to acquire a vibration reference signal generated by a chassis when the vehicle is running, and transmit the vibration reference signal to the adaptive filter unit. The error signal collection module is arranged on the rear back door, and is used to acquire a residual vibration signal of the rear back door and transmit the residual vibration signal to the adaptive filter unit. The adaptive filter unit is used to process the input vibration reference signal, so as to generate a counteracting vibration signal at the error signal collection module. The counteracting vibration signal at least partially counteracts the vibration of the chassis of the vehicle transmitted to the rear back door. The adaptive filter unit is also used to adjust a weight vector in the adaptive filter unit according to the received residual vibration signal by using a filter type least mean square error algorithm.

Description

Technical Field

[0001] This invention belongs to the field of vehicle noise reduction technology, specifically relating to a control system and method for controlling the rumbling noise of a vehicle's tailgate. Background Technology

[0002] Active road noise cancellation is an innovative noise control technology designed to reduce road noise generated by vehicles during operation, thereby improving in-vehicle comfort. Based on the concept of noise cancellation, it neutralizes the original road noise by generating sound waves with the opposite phase to the road noise, thus achieving noise reduction. Specifically, this technology uses multiple sensors (such as accelerometers and vibration sensors) and microphones installed on the vehicle to monitor and collect road noise signals in real time. These signals are then transmitted to the in-vehicle audio subsystem or a dedicated digital signal processor. The audio subsystem or digital signal processor calculates the inverse sound wave in real time based on the collected noise signals and plays it through the vehicle's speaker system to cancel out the road noise, thus achieving noise reduction.

[0003] As new energy vehicles have solved the powertrain noise problem of traditional gasoline vehicles, road noise, the most critical issue during daily low-to-medium speed driving, is becoming increasingly prominent. A significant factor contributing to road noise in new energy SUVs is the rear door's forward and backward movement or lateral rotation under road surface excitation. This compression of the air inside the vehicle and its modal coupling with the acoustic cavity generates a low-frequency booming sound around 100Hz. However, when applying existing active road noise cancellation technology to address the rear door booming sound problem in new energy SUVs, it can only superimpose and eliminate noise already generated inside the vehicle at the listener's ear, without controlling or reducing the noise generation process. Although noise at the listener's ear can be eliminated through reverse superposition of silencing sound waves, there is a technical problem where noise may actually increase in non-silencing locations not far from the listener's ear. For example, if passengers move their heads significantly or adopt non-standard sitting postures such as reclining, they may experience an increased perceived noise level when entering the noise-generating zone. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a vehicle tailgate noise control system and method. This addresses the issue that existing active road noise reduction technologies applied to solve the tailgate noise problem in new energy SUVs only superimpose and eliminate noise already generated inside the vehicle at the listener's ear, without controlling or reducing the noise generation process. While noise at the listener's ear can be eliminated through reverse superposition of sound-absorbing waves, there is a risk of increased noise at locations not far from the listener's ear. For example, significant head movements or non-standard sitting postures such as reclining can lead to a perceived increase in noise when entering the noise-generating zone.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows:

[0006] A noise control system for a vehicle's tailgate includes a data acquisition module, an adaptive filtering unit, and an error signal collection module.

[0007] The data acquisition module is used to acquire the vibration reference signal x(n) generated by the chassis when the vehicle is in motion, and transmit the vibration reference signal x(n) to the adaptive filtering unit;

[0008] The error signal collection module is installed on the rear door. The error signal collection module is used to collect the residual vibration signal e(n) of the rear door and transmit the residual vibration signal e(n) to the adaptive filtering unit.

[0009] The adaptive filtering unit is used to process the input vibration reference signal x(n) to generate a cancellation vibration signal y(n) at the error signal collection module; to at least partially cancel the vibration transmitted from the vehicle chassis to the tailgate; the adaptive filtering unit is also used to adjust the weight vector W in the adaptive filtering unit according to the received residual vibration signal e(n) using a filter-type minimum mean square error algorithm.

[0010] The vehicle tailgate noise control system provided by this invention innovatively improves upon existing active road noise reduction technology, shifting from actively reducing noise to actively reducing vibration. By actively controlling the amplitude of the tailgate's vibration, it controls the noise at the sound-generating end, effectively reducing overall vehicle interior noise and improving the interior noise environment. This solves the problem that existing active road noise reduction technologies applied to address the tailgate noise issue in new energy SUVs only superimpose and eliminate noise already generated inside the vehicle at the listener's ear, without controlling or reducing the noise generation process. While noise at the listener's ear can be eliminated through reverse superposition of silencing sound waves, there is a risk of increased noise at locations not far from the listener's ear. For example, significant head movements or non-standard sitting postures like reclining can lead to a perceived increase in noise when entering a noise-generating area.

[0011] Furthermore, the adaptive filtering unit includes a main path module, a secondary path module, a secondary path estimation module, a momentum FxLMS algorithm module, and an adaptive filter;

[0012] The main path module is used to transmit the vibration reference signal x(n) generated by the chassis to the error signal collection module to generate the vibration expectation signal d(n);

[0013] The secondary path estimation module is used to calculate the received vibration reference signal x(n) based on the secondary path estimation transfer function G1(z) to obtain the first filtered signal x′(n), and input the obtained first filtered signal x′(n) to the adaptive filter and the momentum FxLMS algorithm module as reference coefficients;

[0014] The adaptive filter is used to filter the received vibration reference signal x(n), and uses the received first filtered signal x′(n) as a reference coefficient to obtain a second filtered signal u(n), and transmits the obtained second filtered signal u(n) to the secondary path module.

[0015] The secondary path module is used to process the received second filtered signal u(n) according to the secondary path transfer function G(z) to generate a canceling vibration signal y(n) at the error signal collection module;

[0016] The momentum FxLMS algorithm module is used to adjust the weight vector W in the adaptive filter based on the received residual vibration signal e(n) and the input first filtered signal x′(n), using a filter-type minimum mean square error algorithm, so as to adjust the second filtered signal u(n) obtained by the adaptive filter.

[0017] Furthermore, the secondary path module includes a secondary path calculation submodule, a controller, and a vibration component;

[0018] The secondary path calculation submodule is used to calculate the received second filtered signal u(n) according to the secondary path transfer function G(z) and output a control signal to the controller; the controller is used to control the vibration component to generate the canceling vibration signal y(n) at the error signal collection module according to the received control signal.

[0019] Furthermore, the vibration mechanism includes multiple vibration components, each of which includes a neodymium magnet, a driving component, and an electromagnetic coil;

[0020] Both the neodymium magnet and the driving component are installed in a first mounting hole on the left or right side of the rear door. The neodymium magnet can slide linearly back and forth in the first mounting hole along its axial direction. The driving component is used to drive the neodymium magnet to extend out of the first mounting hole and insert it into a second mounting hole on the left or right inner side of the rear door frame corresponding to the first mounting hole, or to drive the neodymium magnet to retract into the first mounting hole. The electromagnetic coil is fixedly installed inside the rear door frame and surrounds the outside of the corresponding second mounting hole.

[0021] Multiple neodymium magnets are symmetrically arranged on the left and right sides of the rear door;

[0022] The controller is used to control the current amplitude and phase of each of the electromagnetic coils according to the received control signal, so as to generate the anti-vibration signal y(n) at the error signal collection module.

[0023] By using the driving component to drive the neodymium magnet to extend out of the first mounting hole and insert it into the second mounting hole corresponding to the first mounting hole on the left or right inner side of the tailgate frame, or by driving the neodymium magnet to retract into the first mounting hole, an unlockable connection between the tailgate and the tailgate frame can be achieved. This allows the neodymium magnet to extend out of the first mounting hole and insert into the corresponding second mounting hole when the vehicle is in motion and the tailgate is closed. The controller then controls the current amplitude and phase of each electromagnetic coil according to the received control signal, generating the anti-vibration signal y(n) at the error signal collection module to at least partially cancel the vibration transmitted from the vehicle chassis to the tailgate. Alternatively, after the vehicle stops, the neodymium magnet can be driven to retract into the first mounting hole, disconnecting the tailgate and tailgate frame and preventing the vibration mechanism from affecting the normal opening of the tailgate. Furthermore, the vibration mechanism is lightweight and has a simple structure.

[0024] Furthermore, the vibration mechanism includes four of the aforementioned vibration components;

[0025] Two of the neodymium magnets are respectively arranged on the upper part of the left side and the lower part of the left side of the rear door, and the other two neodymium magnets are respectively arranged on the upper part of the right side and the lower part of the right side of the rear door.

[0026] Based on the vehicle tailgate noise control system provided by this invention, this invention also provides a vehicle tailgate noise control method, the control method comprising:

[0027] The vehicle has started moving and the rear door of the vehicle is closed;

[0028] The data acquisition module of the vehicle tailgate noise control system acquires the vibration reference signal x(n) generated by the chassis when the vehicle is in motion, and transmits the vibration reference signal x(n) to the adaptive filtering unit of the vehicle tailgate noise control system.

[0029] The adaptive filtering unit processes the input vibration reference signal x(n) to generate a cancellation vibration signal y(n) at the error signal collection module of the vehicle tailgate noise control system located on the tailgate, so as to at least partially cancel the vibration transmitted from the vehicle chassis to the tailgate.

[0030] The error signal collection module acquires the residual vibration signal e(n) of the rear door and transmits the residual vibration signal e(n) to the adaptive filtering unit;

[0031] The adaptive filtering unit adjusts the weight vector W in the adaptive filtering unit according to the received residual vibration signal e(n) using a filtering-type minimum mean square error algorithm.

[0032] Furthermore, the adaptive filtering unit processes the input vibration reference signal x(n) to generate a cancellation vibration signal y(n) at the error signal collection module of the vehicle tailgate noise control system located on the tailgate to at least partially cancel the vibration transmitted from the vehicle chassis to the tailgate. The method includes:

[0033] The secondary path estimation module of the adaptive filtering unit calculates the received vibration reference signal x(n) based on the secondary path estimation transfer function G1(z) to obtain the first filtered signal x′(n), and inputs the obtained first filtered signal x′(n) into the adaptive filter as a reference coefficient.

[0034] The adaptive filter of the adaptive filtering unit filters the received vibration reference signal x(n), and uses the received first filtered signal x′(n) as a reference coefficient to obtain the second filtered signal u(n), and transmits the obtained second filtered signal u(n) to the secondary path module of the adaptive filtering unit.

[0035] The secondary path module processes the received second filtered signal u(n) according to the secondary path transfer function G(z) to generate a canceling vibration signal y(n) at the error signal collection module;

[0036] The vibration cancellation signal y(n) and the vibration reference signal x(n) generated by the chassis are combined and transmitted to the error signal collection module via the main path module of the adaptive filtering unit to generate the vibration expectation signal d(n) to at least partially cancel the vibration transmitted from the chassis of the vehicle to the tailgate.

[0037] Furthermore, the method for adjusting the weight vector W in the adaptive filtering unit includes:

[0038] The secondary path estimation module of the adaptive filtering unit calculates the received vibration reference signal x(n) based on the secondary path estimation transfer function G1(z) to obtain the first filtered signal x′(n), and inputs the obtained first filtered signal x′(n) to the momentum FxLMS algorithm module as a reference coefficient.

[0039] The error signal collection module acquires the residual vibration signal e(n) of the rear door and transmits the residual vibration signal e(n) to the momentum FxLMS algorithm module;

[0040] The momentum FxLMS algorithm module adjusts the weight vector W in the adaptive filter using a filter-type minimum mean square error algorithm based on the received residual vibration signal e(n) and the input first filtered signal x′(n).

[0041] Furthermore, the momentum FxLMS algorithm module adjusts the weight vector W in the adaptive filter using a filter-type minimum mean square error algorithm based on the residual vibration signal e(n) and the first filtered signal x′(n), including:

[0042] The momentum FxLMS algorithm module continuously updates the weight vector W by minimizing the objective function J(n) based on the received residual vibration signal e(n) and the input first filtered signal x′(n).

[0043] Furthermore, the objective function is the minimum mean square error function J(n), specifically:

[0044] J(n)=E[e 2 (n)]=E[d 2 (n)]―2E[d(n)X′ T (n)]W+W T E[X′(n)X′ T (n)]W

[0045] Where E is the mathematical expectation; e(n) is the residual vibration signal; d(n) is the vibration expectation signal; x′(n) is the first filtered signal; X′ T (n) is the transpose of the first filtered signal; W is the weight vector; W T This is the transpose of the weight vector.

[0046] There are multiple methods for obtaining the vibration expectation signal d(n) in the above function, including but not limited to obtaining the mapping relationship between the second filtered signal u(n) received by the secondary path module and the cancellation vibration signal y(n) generated by the secondary path module at the error signal collection module through calibration test in advance; using the mapping relationship, while the second filtered signal u(n) is received by the secondary path module, the corresponding cancellation vibration signal y(n) is obtained, and the obtained cancellation vibration signal y(n) is also sent to the momentum FxLMS algorithm module. Then, according to the fact that the residual vibration signal e(n) is generated by the combination of the cancellation vibration signal y(n) and the vibration expectation signal d(n), that is, e(n) = d(n) + y(n), the vibration expectation signal d(n) can be obtained.

[0047] Furthermore, the method for obtaining the secondary path transfer function G(z) includes:

[0048] The noise control system based on the vehicle's rear door uses a random vibration signal or a swept-frequency sinusoidal vibration signal with uniform power spectral density as the excitation source, and employs random white noise method to model and obtain the secondary path.

[0049] The specific method of using random white noise to model secondary paths and obtain the transfer function of secondary paths is a conventional technique in this technical field. The difference in this invention is that the input excitation source is a vibration signal, so it will not be described in detail here.

[0050] The vehicle tailgate noise control system and method provided by this invention have at least the following technical effects or advantages:

[0051] 1. The vehicle tailgate noise control system provided by this invention innovatively improves upon existing active road noise reduction technology, shifting from actively reducing noise to actively reducing vibration. By actively controlling the amplitude of the tailgate's vibration, it controls the noise at the sound-generating end, effectively reducing overall vehicle interior noise and improving the interior noise situation. This solves the problem that existing active road noise reduction technology, when applied to address the tailgate noise issue in new energy SUVs, only superimposes and eliminates noise already generated inside the vehicle at the listener's ear, without controlling or reducing the noise generation process. Although it can eliminate noise at the listener's ear through reverse superposition of silencing sound waves, there is a risk of increased noise at non-silencing locations not far from the listener's ear. For example, if passengers move their heads significantly or adopt non-standard sitting postures such as reclining, they may experience an increased noise level when entering the noise-generating area.

[0052] 2. By using the driving component to drive the neodymium magnet to extend out of the first mounting hole and insert it into the second mounting hole corresponding to the first mounting hole on the left or right inner side of the tailgate frame, or by driving the neodymium magnet to retract into the first mounting hole, an unlockable connection between the tailgate and the tailgate frame can be achieved. This allows the neodymium magnet to extend out of the first mounting hole and insert into the corresponding second mounting hole when the vehicle is in motion and the tailgate is closed. The controller then controls the current amplitude and phase of each electromagnetic coil according to the received control signal to generate the anti-vibration signal y(n) at the error signal collection module, so as to at least partially cancel the vibration transmitted from the vehicle chassis to the tailgate. Alternatively, the neodymium magnet can be driven to retract into the first mounting hole after the vehicle stops, disconnecting the tailgate and the tailgate frame and preventing the vibration mechanism from affecting the normal opening of the tailgate. The vibration mechanism also has the advantages of being lightweight and having a simple structure. Attached Figure Description

[0053] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0054] Figure 1 This is a schematic diagram of the noise control system for the vehicle's rear door in Example 1;

[0055] Figure 2 This is a schematic diagram of the vibration mechanism in Example 1;

[0056] 1—Rear door, 2—Rear door frame, 3—Neodyne magnet, 4—Drive component, 5—Electromagnetic coil. Detailed Implementation

[0057] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0058] Example 1:

[0059] like Figure 1 As shown, Embodiment 1 provides a noise control system for the tailgate of a vehicle, including a data acquisition module, an adaptive filtering unit, and an error signal collection module;

[0060] The data acquisition module is used to acquire the vibration reference signal x(n) generated by the chassis when the vehicle is in motion, and transmit the vibration reference signal x(n) to the adaptive filtering unit;

[0061] An error signal collection module is installed on the rear door. The error signal collection module is used to collect the residual vibration signal e(n) of the rear door and transmit the residual vibration signal e(n) to the adaptive filtering unit.

[0062] The adaptive filtering unit is used to process the input vibration reference signal x(n) to generate a cancellation vibration signal y(n) at the error signal collection module; to at least partially cancel the vibration transmitted from the vehicle chassis to the tailgate; the adaptive filtering unit is also used to adjust the weight vector W in the adaptive filtering unit according to the received residual vibration signal e(n) using a filter-type minimum mean square error algorithm.

[0063] The vehicle tailgate noise control system provided by this invention innovatively improves upon existing active road noise reduction technology, shifting from actively reducing noise to actively reducing vibration. By actively controlling the amplitude of the tailgate's vibration, it controls the noise at the sound-generating end, effectively reducing overall vehicle interior noise and improving the interior noise environment. This solves the problem that existing active road noise reduction technologies applied to address the tailgate noise issue in new energy SUVs only superimpose and eliminate noise already generated inside the vehicle at the listener's ear, without controlling or reducing the noise generation process. While noise at the listener's ear can be eliminated through reverse superposition of silencing sound waves, there is a risk of increased noise at locations not far from the listener's ear. For example, significant head movements or non-standard sitting postures like reclining can lead to a perceived increase in noise when entering a noise-generating area.

[0064] In one embodiment, such as Figure 1 As shown, the adaptive filtering unit includes a main path module, a secondary path module, an estimation secondary path module, a momentum FxLMS algorithm module, and an adaptive filter;

[0065] The main path module is used to transmit the vibration reference signal x(n) generated by the chassis to the error signal collection module to generate the vibration expectation signal d(n);

[0066] The secondary path estimation module is used to calculate the received vibration reference signal x(n) based on the secondary path estimation transfer function G1(z) to obtain the first filtered signal x′(n), and input the obtained first filtered signal x′(n) to the adaptive filter and momentum FxLMS algorithm module as reference coefficients;

[0067] An adaptive filter is used to filter the received vibration reference signal x(n), and the received first filtered signal x′(n) is used as a reference coefficient to obtain the second filtered signal u(n), and the obtained second filtered signal u(n) is transmitted to the secondary path module.

[0068] The secondary path module is used to process the received second filtered signal u(n) according to the secondary path transfer function G(z) to generate a canceling vibration signal y(n) at the error signal collection module;

[0069] The momentum FxLMS algorithm module is used to adjust the weight vector W in the adaptive filter based on the received residual vibration signal e(n) and the input first filtered signal x′(n), using a filter-type minimum mean square error algorithm, so as to adjust the second filtered signal u(n) obtained by the adaptive filter.

[0070] Specifically, in this embodiment 1, as follows Figure 1 As shown, the secondary path module includes a secondary path calculation submodule, a controller, and a vibration component;

[0071] The secondary path calculation submodule is used to calculate the received second filtered signal u(n) according to the secondary path transfer function G(z) and output a control signal to the controller; the controller is used to control the vibration component to generate a cancellation vibration signal y(n) at the error signal collection module according to the received control signal.

[0072] Specifically, in this embodiment 1, as follows Figure 2 As shown, the vibration mechanism includes multiple vibration components, including a neodymium magnet 3, a driving component 4, and an electromagnetic coil 5;

[0073] Both the neodymium magnet 3 and the driving component 4 are installed in the first mounting hole opened on the left or right side of the rear door 1. The neodymium magnet 3 can slide back and forth linearly along its axis in the first mounting hole. The driving component 4 is used to drive the neodymium magnet 3 to extend out of the first mounting hole and insert into the second mounting hole opened on the left or right inner side of the rear door frame 2 corresponding to the first mounting hole, or to drive the neodymium magnet 3 to retract into the first mounting hole. The electromagnetic coil 5 is fixedly installed in the rear door frame 2 and surrounds the outside of the corresponding second mounting hole.

[0074] Multiple neodymium magnets 3 are symmetrically arranged on the left and right sides of the rear door 1;

[0075] The controller is used to control the current amplitude and phase of each input electromagnetic coil 5 according to the received control signal, so as to generate a vibration cancellation signal y(n) at the error signal collection module.

[0076] By using the driving component 4 to drive the neodymium magnet 3 to extend out of the first mounting hole and insert it into the second mounting hole corresponding to the first mounting hole on the left or right inner side of the tailgate frame 2, or by driving the neodymium magnet 3 to retract into the first mounting hole, an unlockable connection between the tailgate 1 and the tailgate frame 2 can be achieved. This allows the neodymium magnet 3 to extend out of the first mounting hole and insert into the corresponding second mounting hole when the vehicle is in motion and the tailgate 1 is closed. The controller then controls the current amplitude and phase of each electromagnetic coil 5 according to the received control signal, generating a vibration cancellation signal y(n) at the error signal collection module to at least partially cancel the vibration transmitted from the vehicle chassis to the tailgate 1. Alternatively, after the vehicle stops, the neodymium magnet 3 can be driven to retract into the first mounting hole, disconnecting the tailgate 1 and the tailgate frame 2 and preventing the vibration mechanism 4 from affecting the normal opening of the tailgate 1. The vibration mechanism also has the advantages of being lightweight and having a simple structure.

[0077] In one embodiment, preferably, the vibration mechanism includes four vibration components;

[0078] Two neodymium magnets 3 are respectively arranged on the upper part of the left side and the lower part of the left side of the rear door 1, and the other two neodymium magnets 3 are respectively arranged on the upper part of the right side and the lower part of the right side of the rear door 1.

[0079] Example 2:

[0080] Based on the vehicle tailgate noise control system provided in Embodiment 1, Embodiment 2 provides a vehicle tailgate noise control method, the control method including:

[0081] The vehicle has started moving and the rear door is closed;

[0082] The data acquisition module of the vehicle tailgate noise control system collects the vibration reference signal x(n) generated by the chassis when the vehicle is driving, and transmits the vibration reference signal x(n) to the adaptive filtering unit of the vehicle tailgate noise control system.

[0083] The adaptive filtering unit processes the input vibration reference signal x(n) to generate a cancellation vibration signal y(n) at the error signal collection module of the vehicle tailgate noise control system located on the tailgate, so as to at least partially cancel the vibration transmitted from the vehicle chassis to the tailgate.

[0084] The error signal collection module acquires the residual vibration signal e(n) of the rear door and transmits the residual vibration signal e(n) to the adaptive filtering unit;

[0085] The adaptive filtering unit adjusts the weight vector W in the adaptive filtering unit according to the received residual vibration signal e(n) using a filtering-type minimum mean square error algorithm.

[0086] Specifically, in this embodiment 2, the adaptive filtering unit processes the input vibration reference signal x(n) to generate a cancellation vibration signal y(n) at the error signal collection module of the vehicle tailgate noise control system located on the tailgate, in order to at least partially cancel the vibration transmitted from the vehicle chassis to the tailgate. The method includes:

[0087] The secondary path estimation module of the adaptive filtering unit calculates the received vibration reference signal x(n) based on the secondary path estimation transfer function G1(z) to obtain the first filtered signal x′(n), and inputs the obtained first filtered signal x′(n) into the adaptive filter as a reference coefficient;

[0088] The adaptive filter of the adaptive filter unit filters the received vibration reference signal x(n), and uses the received first filtered signal x′(n) as a reference coefficient to obtain the second filtered signal u(n), and transmits the obtained second filtered signal u(n) to the secondary path module of the adaptive filter unit.

[0089] The secondary path module processes the received second filtered signal u(n) according to the secondary path transfer function G(z) to generate a canceling vibration signal y(n) at the error signal collection module;

[0090] The vibration signal y(n) is canceled, and the vibration reference signal x(n) generated by the chassis is transmitted to the error signal collection module through the main path module of the adaptive filtering unit to generate the vibration expectation signal d(n), so as to at least partially cancel the vibration transmitted from the vehicle chassis to the tailgate.

[0091] Specifically, in this embodiment 2, the method for adjusting the weight vector W in the adaptive filtering unit includes:

[0092] The secondary path estimation module of the adaptive filtering unit calculates the received vibration reference signal x(n) based on the secondary path estimation transfer function G1(z) to obtain the first filtered signal x′(n), and inputs the obtained first filtered signal x′(n) into the momentum FxLMS algorithm module as a reference coefficient;

[0093] The error signal collection module collects the residual vibration signal e(n) of the rear door and transmits the residual vibration signal e(n) to the momentum FxLMS algorithm module;

[0094] The momentum FxLMS algorithm module adjusts the weight vector W in the adaptive filter using a filter-type minimum mean square error algorithm based on the received residual vibration signal e(n) and the input first filtered signal x′(n).

[0095] Specifically, in this embodiment 2, the momentum FxLMS algorithm module adjusts the weight vector W in the adaptive filter using a filter-type minimum mean square error algorithm based on the residual vibration signal e(n) and the first filtered signal x′(n). The method includes:

[0096] The momentum FxLMS algorithm module continuously updates the weight vector W by minimizing the objective function J(n) based on the received residual vibration signal e(n) and the input first filtered signal x′(n).

[0097] Specifically, in this embodiment 2, the objective function is the minimum mean square error function J(n), which is as follows:

[0098] J(n)=E[e 2 (n)]=E[d 2 (n)]―2E[d(n)X′ T (n)]W+W T E[X′(n)X′ T (n)]W

[0099] Where E is the mathematical expectation; e(n) is the residual vibration signal; d(n) is the vibration expectation signal; x′(n) is the first filtered signal; X′ T (n) is the transpose of the first filtered signal; W is the weight vector; W T This is the transpose of the weight vector.

[0100] There are multiple methods to obtain the vibration expectation signal d(n) in the above function, including but not limited to obtaining the mapping relationship between the second filtered signal u(n) received by the secondary path module and the cancellation vibration signal y(n) generated by the secondary path module at the error signal collection module through calibration test in advance; using the mapping relationship, at the same time as the second filtered signal u(n) received by the secondary path module, the corresponding cancellation vibration signal y(n) is obtained, and the obtained cancellation vibration signal y(n) is also sent to the momentum FxLMS algorithm module. Then, according to the fact that the residual vibration signal e(n) is generated by the combination of the cancellation vibration signal y(n) and the vibration expectation signal d(n), that is, e(n) = d(n) + y(n), the vibration expectation signal d(n) can be obtained.

[0101] Specifically, in this embodiment 2, the method for obtaining the secondary path transfer function G(z) includes:

[0102] The noise control system based on the vehicle's tailgate uses a random vibration signal or a swept-frequency sinusoidal vibration signal with uniform power spectral density as the excitation source, and employs random white noise method to model and obtain the secondary path.

[0103] The specific method of using random white noise to model secondary paths and obtain the transfer function of secondary paths is a conventional technique in this technical field. The difference in this invention is that the input excitation source is a vibration signal, so it will not be described in detail here.

[0104] The vehicle tailgate noise control system and method provided by this invention have at least the following technical effects or advantages:

[0105] 1. The vehicle tailgate noise control system provided by this invention innovatively improves upon existing active road noise reduction technology, shifting from actively reducing noise to actively reducing vibration. By actively controlling the amplitude of the tailgate's vibration, it controls the noise at the sound-generating end, effectively reducing overall vehicle interior noise and improving the interior noise situation. This solves the problem that existing active road noise reduction technology, when applied to address the tailgate noise issue in new energy SUVs, only superimposes and eliminates noise already generated inside the vehicle at the listener's ear, without controlling or reducing the noise generation process. Although it can eliminate noise at the listener's ear through reverse superposition of silencing sound waves, there is a risk of increased noise at non-silencing locations not far from the listener's ear. For example, if passengers move their heads significantly or adopt non-standard sitting postures such as reclining, they may experience an increased noise level when entering the noise-generating area.

[0106] 2. By using the driving component 4 to drive the neodymium magnet 3 to extend out of the first mounting hole and insert it into the second mounting hole corresponding to the first mounting hole on the left or right inner side of the tailgate frame 2, or by driving the neodymium magnet 3 to retract into the first mounting hole, an unlockable connection between the tailgate 1 and the tailgate frame 2 can be achieved. This allows the neodymium magnet 3 to extend out of the first mounting hole and insert into the corresponding second mounting hole when the vehicle is in motion and the tailgate 1 is closed. The controller then controls the current amplitude and phase of each electromagnetic coil 5 according to the received control signal, generating a vibration cancellation signal y(n) at the error signal collection module to at least partially cancel the vibration transmitted from the vehicle chassis to the tailgate 1. Alternatively, the neodymium magnet 3 can be driven to retract into the first mounting hole after the vehicle has stopped, disconnecting the tailgate 1 and the tailgate frame 2 and preventing the vibration mechanism 4 from affecting the normal opening of the tailgate 1. The vibration mechanism also has the advantages of being lightweight and having a simple structure.

[0107] The above are merely specific application examples of the present invention and do not constitute any limitation on the scope of protection of the present invention. All technical solutions formed by equivalent transformation or equivalent substitution fall within the scope of protection of the present invention.

Claims

1. A noise control system for a vehicle's tailgate, characterized in that, It includes a data acquisition module, an adaptive filtering unit, and an error signal collection module; The data acquisition module is used to acquire the vibration reference signal x(n) generated by the chassis when the vehicle is in motion, and transmit the vibration reference signal x(n) to the adaptive filtering unit; The error signal collection module is installed on the rear door. The error signal collection module is used to collect the residual vibration signal e(n) of the rear door and transmit the residual vibration signal e(n) to the adaptive filtering unit. The adaptive filtering unit is used to process the input vibration reference signal x(n) to generate a cancellation vibration signal y(n) at the error signal collection module; to at least partially cancel the vibration transmitted from the vehicle chassis to the tailgate; the adaptive filtering unit is also used to adjust the weight vector W in the adaptive filtering unit according to the received residual vibration signal e(n) using a filter-type minimum mean square error algorithm. The adaptive filtering unit includes a main path module, a secondary path module, an estimation secondary path module, a momentum FxLMS algorithm module, and an adaptive filter; The main path module is used to transmit the vibration reference signal x(n) generated by the chassis to the error signal collection module to generate the vibration expectation signal d(n); The secondary path estimation module is used to calculate the received vibration reference signal x(n) based on the secondary path estimation transfer function G1(z) to obtain the first filtered signal x′(n), and input the obtained first filtered signal x′(n) to the adaptive filter and the momentum FxLMS algorithm module as reference coefficients; The adaptive filter is used to filter the received vibration reference signal x(n), and uses the received first filtered signal x′(n) as a reference coefficient to obtain a second filtered signal u(n), and transmits the obtained second filtered signal u(n) to the secondary path module. The secondary path module is used to process the received second filtered signal u(n) according to the secondary path transfer function G(z) to generate a canceling vibration signal y(n) at the error signal collection module; The momentum FxLMS algorithm module is used to adjust the weight vector W in the adaptive filter based on the received residual vibration signal e(n) and the input first filtered signal x′(n), using a filter-type minimum mean square error algorithm, so as to adjust the second filtered signal u(n) obtained by the adaptive filter.

2. The vehicle tailgate noise control system according to claim 1, characterized in that: The secondary path module includes a secondary path calculation submodule, a controller, and a vibration component; The secondary path calculation submodule is used to calculate the received second filtered signal u(n) according to the secondary path transfer function G(z) and output a control signal to the controller; The controller is used to control the vibration component to generate the canceling vibration signal y(n) at the error signal collection module according to the received control signal.

3. The vehicle tailgate noise control system according to claim 2, characterized in that: The vibration mechanism includes multiple vibration components, each of which includes a neodymium magnet, a driving component, and an electromagnetic coil. Both the neodymium magnet and the driving component are installed in a first mounting hole on the left or right side of the rear door. The neodymium magnet can slide linearly back and forth in the first mounting hole along its axial direction. The driving component is used to drive the neodymium magnet to extend out of the first mounting hole and insert it into a second mounting hole on the left or right inner side of the rear door frame corresponding to the first mounting hole, or to drive the neodymium magnet to retract into the first mounting hole. The electromagnetic coil is fixedly installed inside the rear door frame and surrounds the outside of the corresponding second mounting hole. Multiple neodymium magnets are symmetrically arranged on the left and right sides of the rear door; The controller is used to control the current amplitude and phase of each of the electromagnetic coils according to the received control signal, so as to generate the anti-vibration signal y(n) at the error signal collection module.

4. The vehicle tailgate noise control system according to claim 3, characterized in that: The vibration mechanism includes four vibration components; Two of the neodymium magnets are respectively arranged on the upper part of the left side and the lower part of the left side of the rear door, and the other two neodymium magnets are respectively arranged on the upper part of the right side and the lower part of the right side of the rear door.

5. A method for controlling the humming sound of a vehicle's tailgate, characterized in that, This is achieved using a vehicle tailgate noise control system as described in any one of claims 1-4, wherein the control method includes: The vehicle has started moving and the rear door of the vehicle is closed; The data acquisition module of the vehicle tailgate noise control system acquires the vibration reference signal x(n) generated by the chassis when the vehicle is in motion, and transmits the vibration reference signal x(n) to the adaptive filtering unit of the vehicle tailgate noise control system. The adaptive filtering unit processes the input vibration reference signal x(n) to generate a cancellation vibration signal y(n) at the error signal collection module of the vehicle tailgate noise control system located on the tailgate, so as to at least partially cancel the vibration transmitted from the vehicle chassis to the tailgate. The error signal collection module acquires the residual vibration signal e(n) of the rear door and transmits the residual vibration signal e(n) to the adaptive filtering unit; The adaptive filtering unit adjusts the weight vector W in the adaptive filtering unit according to the received residual vibration signal e(n) using a filtering-type minimum mean square error algorithm.

6. The method for controlling the rumbling noise of a vehicle's tailgate according to claim 5, characterized in that: The adaptive filtering unit processes the input vibration reference signal x(n) to generate a cancellation vibration signal y(n) at the error signal collection module of the vehicle tailgate noise control system located on the tailgate, so as to at least partially cancel the vibration transmitted from the vehicle chassis to the tailgate. The method includes: The secondary path estimation module of the adaptive filtering unit calculates the received vibration reference signal x(n) based on the secondary path estimation transfer function G1(z) to obtain the first filtered signal x′(n), and inputs the obtained first filtered signal x′(n) into the adaptive filter as a reference coefficient. The adaptive filter of the adaptive filtering unit filters the received vibration reference signal x(n), and uses the received first filtered signal x′(n) as a reference coefficient to obtain the second filtered signal u(n), and transmits the obtained second filtered signal u(n) to the secondary path module of the adaptive filtering unit. The secondary path module processes the received second filtered signal u(n) according to the secondary path transfer function G(z) to generate a canceling vibration signal y(n) at the error signal collection module; The vibration cancellation signal y(n) and the vibration reference signal x(n) generated by the chassis are combined and transmitted to the error signal collection module via the main path module of the adaptive filtering unit to generate the vibration expectation signal d(n) to at least partially cancel the vibration transmitted from the chassis of the vehicle to the tailgate.

7. The method for controlling the noise of a vehicle's tailgate according to claim 5, characterized in that: The method for adjusting the weight vector W in the adaptive filtering unit includes: The secondary path estimation module of the adaptive filtering unit calculates the received vibration reference signal x(n) based on the secondary path estimation transfer function G1(z) to obtain the first filtered signal x′(n), and inputs the obtained first filtered signal x′(n) to the momentum FxLMS algorithm module as a reference coefficient. The error signal collection module acquires the residual vibration signal e(n) of the rear door and transmits the residual vibration signal e(n) to the momentum FxLMS algorithm module; The momentum FxLMS algorithm module adjusts the weight vector W in the adaptive filter using a filter-type minimum mean square error algorithm based on the received residual vibration signal e(n) and the input first filtered signal x′(n).

8. The method for controlling the noise of a vehicle's tailgate according to claim 7, characterized in that: The momentum FxLMS algorithm module adjusts the weight vector W in the adaptive filter using a filter-type minimum mean square error algorithm based on the residual vibration signal e(n) and the first filtered signal x′(n). The method includes: The momentum FxLMS algorithm module continuously updates the weight vector W by minimizing the objective function J(n) based on the received residual vibration signal e(n) and the input first filtered signal x′(n).

9. The method for controlling the rumbling noise of a vehicle's tailgate according to claim 6, characterized in that: The method for obtaining the secondary path transfer function G(z) includes: The noise control system based on the vehicle's rear door uses a random vibration signal or a swept-frequency sinusoidal vibration signal with uniform power spectral density as the excitation source, and employs random white noise method to model and obtain the secondary path.

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