Engine knock recognition signal processing method, device, equipment and storage medium

Abstract

The application relates to an engine knock identification signal processing method and device, equipment and a storage medium, and relates to the technical field of engines. The method comprises the following steps: obtaining a target knock signal by intercepting an acquired knock signal according to a target starting position and a target length; determining an ordinary knock signal window with a first starting position and a first length and a super knock signal window with a second starting position and a second length based on the real-time speed of an engine, the real-time torque of the engine and preset first and second mapping relationships; intercepting the target knock signal based on the ordinary knock signal window to obtain an ordinary knock signal, and intercepting the target knock signal based on the super knock signal window to obtain a super knock signal. According to the application, the knock signal sampling window can be set according to the specific working condition of the engine, so that the signals of ordinary knock and super knock can be accurately distinguished and processed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of engines, and in particular to an engine knock identification signal processing method and device, an engine knock identification signal processing apparatus, an engine knock identification signal processing equipment and a storage medium. BACKGROUND

[0002] Knock is a phenomenon caused by abnormal combustion of an engine. When the engine knocks, the engine has poor emissions, fuel economy and drivability, and in particular, when super-knock occurs, mechanical damage can even occur. Therefore, effective detection of knock is needed to take appropriate knock suppression actions. Among them, knock signal processing is one of the necessary technologies for effective detection of knock.

[0003] Among them, knock includes ordinary knock and super-knock, ordinary knock occurs after ignition, and super-knock occurs before ignition; because the processing methods after ordinary knock and super-knock are different, and the signal frequency and intensity of ordinary knock and super-knock are also different, it is necessary to distinguish the knock signals of ordinary knock and super-knock in order to better control engine knock. However, the processing of the knock signal in the prior art is only used for the signal processing of ordinary knock, and the signal of super-knock is not processed. Therefore, how to distinguish and process the signals of ordinary knock and super-knock is a problem that needs to be solved at present. SUMMARY

[0004] The present application provides an engine knock identification signal processing method, device, equipment and storage medium to solve the problem that the signals of ordinary knock and super-knock cannot be distinguished and processed in related technologies.

[0005] In a first aspect, an engine knock identification signal processing method is provided, comprising the following steps:

[0006] The acquired knock signal is intercepted according to the target starting position and the target length to obtain a target knock signal;

[0007] Based on the real-time speed of the engine, the real-time torque of the engine, and the preset first mapping relationship and second mapping relationship, an ordinary knock signal window with a first starting position and a first length and a super-knock signal window with a second starting position and a second length are determined;

[0008] The target knock signal is intercepted based on the ordinary knock signal window to obtain an ordinary knock signal, and the target knock signal is intercepted based on the super-knock signal window to obtain a super-knock signal.

[0009] In some embodiments, after the step of intercepting the acquired knock signal according to the target starting position and the target length to obtain the target knock signal, the method further comprises:

[0010] storing the target knock signal into a storage space with a preset capacity;

[0011] judging whether a real-time rotating speed of the engine is greater than or equal to a rotating speed threshold value;

[0012] if yes, determining that the target knock signal in the storage space is a valid knock signal, and performing a step of determining a normal knock signal window with a first starting position and a first length and a super knock signal window with a second starting position and a second length based on the real-time rotating speed of the engine, a real-time torque of the engine, and preset first mapping relationship and second mapping relationship respectively;

[0013] if no, determining that the target knock signal in the storage space is an invalid knock signal, and re-acquiring a new target knock signal.

[0014] In some embodiments, before the step of storing the target knock signal into a storage space with a preset capacity, the method further comprises:

[0015] calculating a sampling sample number according to a maximum identification frequency of the knock sensor, a minimum rotating speed at which the engine knocks, and a maximum knock crank angle length, the maximum knock crank angle length being a maximum value in all knock crank angle lengths corresponding to all piston cylinders, the knock crank angle length being a difference between a maximum value and a minimum value in all crank angles corresponding to the piston cylinder when the piston cylinder knocks under different working conditions;

[0016] taking the sampling sample number as the capacity of the storage space.

[0017] In some embodiments, before the step of judging whether the real-time rotating speed of the engine is greater than or equal to the rotating speed threshold value, the method further comprises:

[0018] when the engine is not cold started, taking a minimum value in a rotating speed range corresponding to when the engine knocks as the rotating speed threshold value;

[0019] when the engine is cold started, determining a target rotating speed offset value according to a mapping relationship between a preset water temperature and rotating speed offset value and a real-time cooling water temperature of the engine, and taking a sum of the target rotating speed offset value and a minimum value in a rotating speed range corresponding to when the engine knocks as the rotating speed threshold value.

[0020] In some embodiments, the first mapping relationship comprises a mapping relationship between rotating speed-torque and a starting position of the normal knock signal window and a mapping relationship between rotating speed-torque and a length of the normal knock signal window, and the second mapping relationship comprises a mapping relationship between rotating speed-torque and a starting position of the super knock signal window and a mapping relationship between rotating speed-torque and a length of the super knock signal window.

[0021] In some embodiments, after the step of determining the normal knock signal window with the first start position and the first length and the super knock signal window with the second start position and the second length based on the real-time engine speed, the real-time engine torque, and the preset first mapping relationship and second mapping relationship, the method further comprises:

[0022] Offsetting and correcting the first start position, the first length, the second start position, and the second length based on the EGR valve opening degree of the engine and the VVT state.

[0023] In some embodiments, before the step of obtaining the target knock signal by intercepting the obtained knock signal according to the target start position and the target length, the method further comprises:

[0024] Taking the minimum value of all the minimum crankshaft angles corresponding to the super knock of all the piston cylinders under different working conditions as the target start position.

[0025] Taking the maximum knock crankshaft angle length as the target length, the maximum knock crankshaft angle length being the maximum value of all the knock crankshaft angle lengths corresponding to all the piston cylinders, and the knock crankshaft angle length being the difference between the maximum value and the minimum value of all the crankshaft angles corresponding to the knock of the piston cylinder under different working conditions.

[0026] In a second aspect, an engine knock identification signal processing device is provided, comprising:

[0027] A first intercepting unit configured to intercept the obtained knock signal according to the target start position and the target length to obtain a target knock signal.

[0028] A window determining unit configured to determine a normal knock signal window with a first start position and a first length and a super knock signal window with a second start position and a second length based on the real-time engine speed, the real-time engine torque, and the preset first mapping relationship and second mapping relationship.

[0029] A second intercepting unit configured to intercept the target knock signal based on the normal knock signal window to obtain a normal knock signal and intercept the target knock signal based on the super knock signal window to obtain a super knock signal.

[0030] In a third aspect, an engine knock identification signal processing device is provided, comprising a memory and a processor, the memory storing at least one instruction, the at least one instruction being loaded and executed by the processor to implement the engine knock identification signal processing method described above.

[0031] In a fourth aspect, a computer readable storage medium is provided, which stores a computer program. When the computer program is executed by a processor, the engine knock identification signal processing method described above is implemented.

[0032] The application provides an engine knock identification signal processing method and device, equipment and a storage medium. The method comprises: obtaining a target knock signal by intercepting an acquired knock signal according to a target start position and a target length; determining a normal knock signal window with a first start position and a first length and a super knock signal window with a second start position and a second length based on a real-time speed of the engine, a real-time torque of the engine and preset first and second mapping relationships; intercepting the target knock signal based on the normal knock signal window to obtain a normal knock signal and intercepting the target knock signal based on the super knock signal window to obtain a super knock signal. According to the application, the knock signal sampling window can be set according to the specific working condition of the engine, so that the signals of normal knock and super knock can be accurately distinguished and processed. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative effort.

[0034] Figure 1 A flowchart of an engine knock identification signal processing method provided by an embodiment of the application is shown in the figure.

[0035] Figure 2 A specific processing flowchart of the knock identification signal provided by an embodiment of the application is shown in the figure.

[0036] Figure 3 A crankshaft rotation angle in-cylinder pressure curve diagram of a single piston cylinder provided by an embodiment of the application is shown in the figure.

[0037] Figure 4 A flowchart for judging the effectiveness of the knock signal provided by an embodiment of the application is shown in the figure.

[0038] Figure 5 A flowchart for calculating the start position of the normal knock signal window provided by an embodiment of the application is shown in the figure.

[0039] Figure 6 A structural diagram of an engine knock identification signal processing device provided by an embodiment of the application is shown in the figure. DETAILED DESCRIPTION

[0040] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0041] This application provides an engine knock identification signal processing method, apparatus, device, and storage medium, which can solve the problem in related technologies that cannot distinguish and process ordinary knock and super knock signals.

[0042] Figure 1 This application provides an embodiment of an engine knock detection signal processing method, which includes the following steps:

[0043] Step S10: Extract the acquired detonation signal based on the target's starting position and length to obtain the target detonation signal.

[0044] In this embodiment, before the step of truncating the acquired detonation signal according to the target starting position and target length to obtain the target detonation signal, the method further includes:

[0045] The minimum value of all minimum crankshaft rotation angles corresponding to the occurrence of super knocking in all piston cylinders under different operating conditions is taken as the target starting position;

[0046] The maximum knock crankshaft angle length is taken as the target length. The maximum knock crankshaft angle length is the maximum value among all knock crankshaft angle lengths corresponding to all piston cylinders. The knock crankshaft angle length is the difference between the maximum and minimum values ​​among all crankshaft angles corresponding to the piston cylinder when knock occurs under different operating conditions.

[0047] As an example, this embodiment first processes the voltage signal acquired by the detonation sensor to obtain the detonation signal. Specifically, an analog-to-digital circuit with a sampling frequency of f1 can be used to convert the voltage signal acquired by the detonation sensor into a digital signal, which is the detonation digital signal. Then, the obtained detonation digital signal is subjected to low-pass filtering to obtain the first filtered detonation digital signal, at which point the signal frequency is f2. Finally, the first filtered detonation digital signal is subjected to band-pass filtering to obtain the detonation signal, at which point the detonation signal frequency is f. s The unit of all the above signals is Hertz (Hz).

[0048] It should be noted that the frequencies of the above signals should meet the following requirements: That is, the signal frequency f1 must be much greater than f2, and f2 must be greater than fs , and f2 is greater than the maximum value of the identification frequency of the knock sensor. It should be understood that the current setting of the band-pass filtering frequency is relatively single, which only considers the frequency range when the ordinary knock and no knock occur; and in the embodiment, when the band-pass filtering is performed, the maximum boundary of the frequency of the band-pass filtering is set to be greater than the maximum frequency f max , i.e. , i.e. not only the frequency when the ordinary knock and no knock occur is considered, but also the frequency when the super knock occurs.

[0049] After obtaining the knock signal, the knock signal is intercepted to obtain the effective target knock signal. However, the current interception of the knock signal is only to set the sampling window according to the preset crank angle, but the engine working condition changes greatly, and it is impossible to include all the crank angle ranges corresponding to the occurrence of the knock, and if a too large crank angle range is set, it will lead to a large amount of knock signal data collected at low speed of the engine, so as to occupy the computing resources. In the embodiment, the determination of the knock sampling window is performed according to the engine working condition, and then the starting position and length of the knock sampling window are determined, so that the size of the knock sampling window is more reasonable, so as to avoid too much knock identification signal collected, thereby effectively reducing the occupation of the computing resources.

[0050] In the embodiment, the minimum value of all the minimum crank angles corresponding to the occurrence of the super knock in the multiple piston cylinders of the engine under all the working conditions of the engine in which the knock occurs is taken as the starting position of the knock sampling window. For example, it is assumed that the engine includes piston cylinder 1 to piston cylinder 3, when the engine is in the working condition of the speed A1 and the torque B1, the minimum crank angle corresponding to the occurrence of the super knock in the piston cylinder 1 is C1, the minimum crank angle corresponding to the occurrence of the super knock in the piston cylinder 2 is D1, and the minimum crank angle corresponding to the occurrence of the super knock in the piston cylinder 3 is E1; when the engine is in the working condition of the speed A2 and the torque B2, the minimum crank angle corresponding to the occurrence of the super knock in the piston cylinder 1 is C2, the minimum crank angle corresponding to the occurrence of the super knock in the piston cylinder 2 is D2, and the minimum crank angle corresponding to the occurrence of the super knock in the piston cylinder 3 is E2; if the minimum value among C1, D1, E1, C2, D2 and E2 is E1, then E1 is taken as the target starting position of the knock sampling window.

[0051] For the length of the knock sampling window, firstly, the maximum value and the minimum value of the crank angle corresponding to the occurrence of the knock (including the ordinary knock and the super knock) in each piston cylinder under all the working conditions of the engine in which the knock occurs (i.e. different speeds and torques) are determined, and the difference between the maximum value and the minimum value of the crank angle is the length of the knock crank angle, and then the maximum value among the lengths of the knock crank angles corresponding to the multiple piston cylinders is taken as the target length of the knock sampling window .

[0052] For example, when the engine is in the working condition of the speed A1 and the torque B1, the minimum crank angle of the piston cylinder 1 is C2 and the maximum crank angle is C3 when knock occurs, the knock crank angle length is X1=C3-C2, the minimum crank angle of the piston cylinder 2 is D3 and the maximum crank angle is D5 when knock occurs, the knock crank angle length is Y1=D5-D3, the minimum crank angle of the piston cylinder 3 is E1 and the maximum crank angle is E4 when knock occurs, the knock crank angle length is Z1=E4-E1;

[0053] When the engine is in the working condition of the speed A2 and the torque B2, the minimum crank angle of the piston cylinder 1 is C1 and the maximum crank angle is C3 when knock occurs, the knock crank angle length is X2=C3-C1, the minimum crank angle of the piston cylinder 2 is D4 and the maximum crank angle is D2 when knock occurs, the knock crank angle length is Y2=D4-D2, the minimum crank angle of the piston cylinder 3 is E2 and the maximum crank angle is E3 when knock occurs, the knock crank angle length is Z2=E3-E2; if the maximum value of X1, Y1, Z1, X2, Y2 and Z2 is Z1, then Z1 is taken as the target length of the knock sampling window.

[0054] After the target starting position and the target length of the knock sampling window are determined, the target knock signal can be obtained by intercepting the knock signal according to the target starting position and the target length.

[0055] Further, before the step of storing the target knock signal into the storage space with a preset capacity, the method further comprises:

[0056] The number of sampling samples is calculated according to the maximum identification frequency of the knock sensor, the minimum speed of the engine when knock occurs and the maximum knock crank angle length, the maximum knock crank angle length being the maximum value of all knock crank angle lengths corresponding to all piston cylinders, the knock crank angle length being the difference between the maximum value and the minimum value of all crank angles corresponding to the piston cylinder when knock occurs under different working conditions.

[0057] The number of sampling samples is taken as the capacity of the storage space.

[0058] It is to be noted that the number of effective knock signals for sampling is not determined in a guided manner, i.e. too small number of knock signals will cause that the larger sampling window has no practical significance, and too large number of knock signals will waste the calculation resources. In the embodiment, the number of effective knock signals for sampling for subsequent knock judgment feature value calculation is determined to set a more reasonable number of effective knock signals for sampling, thereby saving the calculation resources. determined to set a more reasonable number of effective knock signals for sampling, thereby saving the calculation resources.

[0059] Specifically, the required detonation signal frequency f is first determined based on the detonation sensor's recognition capability. s Of course, in order to more accurately determine the detonation signal frequency f s Furthermore, the detonation signal frequency f can be determined by combining it with subsequent methods used to calculate detonation characteristic values. s For example, if the subsequent method used to calculate the detonation characteristic value is the integral method, then only the maximum frequency value within the frequency range recognized by the detonation sensor is taken as the detonation signal frequency f. s For example, if the detection frequency range of a knock sensor is 0~25kHz, then f s =25kHz; However, if the subsequent method used to calculate the detonation characteristic value is FFT (Fast Fourier Transform), due to the picket fence effect, a certain frequency needs to be set to avoid the picket fence effect. That is, the sampling frequency in the time domain needs to be 3-4 times the maximum value of the frequency to be analyzed (i.e., the maximum frequency value in the frequency range that the detonation sensor can identify) in order to effectively perform frequency domain analysis on the data in the time domain. Therefore, the detonation signal frequency f can be set at this time. s Set to 100kHz.

[0060] Determine the engine speed range where knocking (including normal knocking and severe knocking) occurs, and then take the minimum value of the engine speed range where knocking occurs, i.e., the minimum speed n. spe_min Next, under all operating conditions where engine knocking occurs, the maximum knock crankshaft angle length is determined. Due to the maximum knock crankshaft rotation angle length The principle for determining the target length is the same as that for determining the target length mentioned above, and will not be repeated here for the sake of simplicity.

[0061] After obtaining the above data, the number of samples for the effective knock signal can be calculated using the following formula. To confirm:

[0062] (1)

[0063] in, This is the sampling coefficient correction factor, and its value is greater than or equal to 1. It should be noted that since the number of valid detonation signals is an integer, the number of sampled data needs to be adjusted. Rounding is performed. Understandably, subsequent adjustments will be made based on the number of samples collected. To obtain a valid knock signal, the number of samples is... This serves as a preset capacity for storage space, allowing for a more reasonable and effective number of detonation signal samples, thereby saving computational resources. Specifically, if the number of captured target detonation signals exceeds the number of sampled data... , which indicates that the number of the intercepted target knock signals is too large to be used for subsequent calculation.

[0064] Further, after the step of intercepting the acquired knock signals according to the target start position and the target length to obtain the target knock signals, the method further comprises:

[0065] storing the target knock signals into a storage space with a preset capacity;

[0066] judging whether the real-time speed of the engine is greater than or equal to a speed threshold;

[0067] if yes, determining that the target knock signals in the storage space are valid knock signals, and performing the next step;

[0068] if no, determining that the target knock signals in the storage space are invalid knock signals, and re-acquiring new target knock signals.

[0069] In an exemplary embodiment, the intercepted target knock signals are sequentially and continuously placed in the storage space (such as a chip storage area) from left to right, and the storage space is provided with an interval for storing the target knock signals, and the number of data that can be stored in the interval is If the number of the intercepted target knock signals exceeds the number of the data that can be stored, the start position of the storage space is returned to, and the existing data is sequentially overwritten from the start position.

[0070] Since the number of the intercepted target knock signals can be greater than or much smaller than , the target knock signals corresponding to the two cases are both invalid. Therefore, the validity of the intercepted target knock signals needs to be judged, that is, whether the target knock signals are valid knock signals can be further judged by the real-time speed of the engine corresponding to the intercepted target knock signals. Specifically, if the real-time speed of the engine is greater than or equal to a preset speed threshold, it is considered that the intercepted data is valid and can be used for subsequent calculation; and if the speed of the engine is less than the speed threshold, it is considered that the intercepted data is invalid and cannot be used for subsequent calculation, and new target knock signals are re-acquired.

[0071] It should be noted that after the interception and validity judgment of the target knock signals are completed, the target knock signals also need to be marked. The specific marking information can include the validity of the target knock signals, the cylinder number of the engine corresponding to the target knock signals, and the start position and end position of the target knock signals in the storage space, so that the corresponding target knock signal data can be selected according to the marking information for the calculation of the knock characteristic value and the determination of the piston cylinder where the knock occurs.

[0072] Further, before the step of judging whether the real-time engine speed is greater than or equal to the speed threshold, the method further comprises:

[0073] When the engine is not cold-start, the minimum value of the speed range corresponding to the engine knock is taken as the speed threshold;

[0074] When the engine is cold-start, a target speed offset value is determined according to the real-time cooling water temperature of the engine and a preset mapping relationship between the water temperature and the speed offset value, and the sum of the target speed offset value and the minimum value of the speed range corresponding to the engine knock is taken as the speed threshold.

[0075] Exemplarily, since the occurrence of knock is related to the cooling water temperature and the engine speed, in the embodiment, the speed threshold of the engine is determined according to the cooling water temperature of the engine and the minimum speed n spe_min of the engine when the engine knock occurs. Specifically, if the engine is not cold-start, the minimum speed corresponding to the engine knock is directly taken as the speed threshold; if the engine is cold-start, a target speed offset value is determined according to the real-time cooling water temperature of the engine and a preset mapping relationship between the water temperature and the speed offset value, and the sum of the target speed offset value and the minimum value of the speed range corresponding to the engine knock is taken as the speed threshold.

[0076] The mapping relationship between the water temperature and the speed offset value can be determined by experiment calibration or according to experience values, which is not limited herein. It can be understood that the engine is not prone to knock when the engine is cold-start, and therefore, to save computing resources, the speed threshold of the engine can be set to be greater than n spe_min , and at the same time, the number of effective target knock signals is ensured not to exceed the number of data that can be stored in the storage space.

[0077] Step S20: determining an ordinary knock signal window with a first starting position and a first length and a super knock signal window with a second starting position and a second length based on the real-time engine speed, the real-time engine torque, and a preset first mapping relationship and a second mapping relationship; the first mapping relationship includes a mapping relationship between the speed-torque and the starting position of the ordinary knock signal window and a mapping relationship between the speed-torque and the length of the ordinary knock signal window; the second mapping relationship includes a mapping relationship between the speed-torque and the starting position of the super knock signal window and a mapping relationship between the speed-torque and the length of the super knock signal window.

[0078] Exemplarily, in the embodiment, the normal knock signal window and the super knock signal window of each piston cylinder of the engine are set according to the engine working condition, and specifically, the engine speed and the engine torque can be selected as the engine working condition to respectively give the start position and the length of the normal knock window and the super knock window. It should be noted that the mapping relationship between the speed-torque and the start position and the length of the normal knock effective signal (i.e. the normal knock signal window) and the mapping relationship between the speed-torque and the start position and the length of the super knock effective signal (i.e. the super knock signal window) can be constructed by experiment calibration or according to empirical values.

[0079] Taking the first mapping relationship corresponding to the normal knock as an example, it is assumed that when the engine speed is A1 and the torque is B1, the corresponding start position is G1 and the length is L1, and when the engine speed is A2 and the torque is B2, the corresponding start position is G2 and the length is L2.

[0080] Therefore, after the real-time speed of the engine and the real-time torque of the engine are obtained, the first start position and the first length corresponding to the real-time speed and the real-time torque can be screened from the first mapping relationship, and the first start position and the first length are taken as the start position and the length of the normal knock signal window, that is, as the start position and the length of the normal knock effective signal; then the second start position and the second length corresponding to the real-time speed and the real-time torque are screened from the second mapping relationship, and the second start position and the second length are taken as the start position and the length of the super knock signal window, that is, as the start position and the length of the super knock effective signal. As can be seen, the embodiment accurately distinguishes the normal knock signal and the super knock signal by the different working conditions of the engine.

[0081] Further, after the step of determining the normal knock signal window with the first start position and the first length and the super knock signal window with the second start position and the second length based on the real-time speed of the engine, the real-time torque of the engine, and the preset first mapping relationship and second mapping relationship, the method further comprises:

[0082] Based on the EGR valve opening degree of the engine and the variable valve timing (VVT) state, the first start position, the first length, the second start position, and the second length are offset corrected.

[0083] Exemplarily, in the embodiment, in order to more accurately obtain the starting position and length of the normal knock signal window and the super knock signal window, the variables influencing the engine combustion, such as the actual EGR (Exhaust Gas Recirculation) valve opening and VVT (Variable Valve Timing) state, are used to offset correct the normal knock window and the super knock window of each piston cylinder, that is, offset correct the basic starting position (that is, the first starting position and the second starting position) and the basic length (that is, the first length and the second length) to obtain the final normal knock window and super knock window of each piston cylinder. It should be noted that the third mapping relationship between the EGR valve opening-VVT state and the starting position correction value and the length correction value of the normal knock signal window and the fourth mapping relationship between the EGR valve opening-VVT state and the starting position correction value and the length correction value of the super knock signal window can be constructed by experimental calibration or according to empirical values.

[0084] Specifically, after the first starting position, the first length, the second starting position and the second length are calculated, the real-time EGR valve opening and the real-time VVT state of the engine are obtained, and the starting position correction value and the length correction value corresponding to the real-time EGR valve opening and the real-time VVT state are obtained from the third mapping relationship to correct the first starting position and the first length respectively; similarly, the starting position correction value and the length correction value corresponding to the real-time EGR valve opening and the real-time VVT state are obtained from the fourth mapping relationship to correct the second starting position and the second length respectively.

[0085] Step S30: intercepting the target knock signal based on the normal knock signal window to obtain a normal knock signal, and intercepting the target knock signal based on the super knock signal window to obtain a super knock signal.

[0086] Exemplarily, in the embodiment, when the validity of the target knock signal is valid, the target knock signal is intercepted by the normal knock signal window and the super knock signal window obtained in step S20 respectively, which can accurately and effectively distinguish the super knock and the normal knock of each piston cylinder, and further obtain the normal knock identification signal and the super knock identification signal. As can be seen, the embodiment not only can set the knock signal sampling window according to the specific working condition of the engine, effectively distinguish the normal knock signal and the super knock signal, provide effective and accurate knock identification signals for subsequent knock judgment and analysis, but also can guide the determination of the number of knock signal samples to effectively avoid the waste of computing resources.

[0087] Taking an engine and a knock sensor with the parameters shown in Table 1 as an example and combining the above description Figures 2 to 5The following example illustrates the processing procedure for the detonation identification signal in this embodiment.

[0088] Table 1. Schematic diagram of engine and knock sensor parameters

[0089]

[0090] First, a voltage signal is acquired using a detonation sensor. Then, taking the conversion of the time-domain detonation identification signal to a frequency-domain signal using FFT in the calculation of detonation characteristic values ​​as an example, due to the picket-fence effect of FFT, the sampling frequency in the time domain needs to be 3-4 times the maximum value of the frequency to be analyzed in order to effectively perform frequency-domain analysis on the time-domain data. Therefore, the detonation signal frequency f... s The frequency is set to 100kHz; because the sampling frequency f1 of the analog-to-digital conversion is much greater than the frequency f2 of the detonation digital signal after the first filtering process following the low-pass filtering, and the frequency f2 of the detonation digital signal after the first filtering process following the low-pass filtering is greater than the frequency f of the detonation signal. s Therefore, the analog-to-digital sampling frequency f1 can be set to 20MHz, and the frequency f2 of the detonation digital signal after the first filtering after low-pass filtering can be set to 400kHz.

[0091] Next, the voltage signal of the detonation sensor is acquired according to the set analog-to-digital conversion sampling frequency of 20MHz to obtain the detonation digital signal; the frequency of the detonation digital signal obtained by the first filtering through low-pass filtering is converted to 400kHz, and the frequency of the detonation signal obtained by band-pass filtering is converted to 100kHz.

[0092] The minimum speed n is determined based on the speed range at which engine knock occurs. spe_min The maximum detonation crankshaft angle length is calculated based on the aforementioned principle for determining the maximum detonation crankshaft angle length, which is 800 rpm. Then the detonation signal frequency f s n spe_min and Substitute into formula (1) to calculate the number of samples for the detonation signal. The number is 2292, and 2292 is used as the capacity of the chip's storage area, that is, the range used to store the intercepted data.

[0093] After obtaining the knock signal, it is truncated to obtain the target knock signal. The truncated knock signal window is triggered and terminated by the crankshaft angle. The target knock signal truncating process is illustrated using the crankshaft angle and cylinder pressure curve of a single piston cylinder. Figure 3As shown: for a single piston cylinder, the top dead center before ignition is defined as 0, the knock occurring when the crank angle is negative is super knock, and the knock occurring when the crank angle is positive is normal knock; the starting position of the knock signal interception window is determined according to the target starting position calculation method, which is the minimum angle corresponding to the super knock, such as -20 CA; the length of the knock signal interception is determined according to the target length calculation method, such as in one working condition, the minimum value is -20 CA, and the maximum value is 90 CA, so the maximum knock crank angle length should be 110 CA; if the above -20 CA is the minimum value of the minimum angle corresponding to the super knock of multiple piston cylinders in the engine, and 110 CA is the maximum value of the knock crank angle length corresponding to multiple piston cylinders in the engine, then the starting position of the knock signal interception window is determined as -20 CA, and the length is 110 CA.

[0094] The target knock signal intercepted by the starting position and the length of the knock signal interception window is sequentially and continuously placed in the interval for storing the intercepted data in the chip storage area, and the number of data that can be stored in the interval is 2292.

[0095] Then the target knock signal is judged and marked for effectiveness, and the marking information includes the effectiveness of the intercepted target knock signal data, the engine cylinder number corresponding to the intercepted target knock signal data, and the starting position and end position of the intercepted target knock signal data in the chip storage area.

[0096] Among them, the effectiveness judgment of the intercepted target knock signal data is as shown in Figure 4 As shown: first, it is judged whether the engine is cold started, if the engine is not cold started, the engine speed threshold is set as Espe2, and the minimum value of the engine speed range when the engine knocks is preferably taken as Espe2; if the engine is cold started, the engine speed offset value is given according to the engine cooling water temperature, and the engine speed threshold Espe1 during cold start is obtained by adding the engine speed offset value to Espe2; then it is judged whether the real-time speed of the engine is greater than or equal to the speed threshold to judge the effectiveness of the target knock signal, that is, if the real-time speed is greater than or equal to the speed threshold, it is determined that the target knock signal is effective, otherwise it is determined that the target knock signal is invalid.

[0097] After obtaining the effective target knock signal, the effective target knock signal is intercepted to distinguish the normal knock signal and the super knock signal. Among them, the calculation of the starting position of the interception window of the normal knock signal is as shown in Figure 5It is shown that: first, the basic starting position and basic length of the common knock signal are given by the real-time speed and real-time torque of the engine and the preset mapping relationship, then the basic starting position and basic length of the common knock signal are offset and corrected according to the actual opening of the EGR and the state of the VVT, to obtain the final starting position and length of the common knock signal, and the final starting position and length of the super knock signal are obtained in the same way, and then the common knock signal window and the super knock signal window are obtained. Finally, the above common knock window and super knock window are used to intercept the effective target knock signal respectively, to obtain the common knock signal and the super knock signal respectively.

[0098] It should be noted that the step numbers of the steps in the embodiments of the present application do not limit the order of operations in the technical solutions of the present application.

[0099] The embodiments of the present application also provide an engine knock identification signal processing device, comprising:

[0100] A first intercepting unit is configured to intercept the acquired knock signal according to the target starting position and the target length to obtain a target knock signal;

[0101] A window determining unit is configured to determine a common knock signal window with a first starting position and a first length and a super knock signal window with a second starting position and a second length based on the real-time speed of the engine, the real-time torque of the engine, and preset first and second mapping relationships respectively;

[0102] A second intercepting unit is configured to intercept the target knock signal based on the common knock signal window to obtain a common knock signal, and intercept the target knock signal based on the super knock signal window to obtain a super knock signal.

[0103] Further, the device further comprises a data processing unit configured to:

[0104] store the target knock signal in a storage space with a preset capacity;

[0105] determine whether the real-time speed of the engine is greater than or equal to a speed threshold;

[0106] If yes, determine that the target knock signal in the storage space is an effective knock signal, and perform the step of determining the common knock signal window with the first starting position and the first length and the super knock signal window with the second starting position and the second length based on the real-time speed of the engine, the real-time torque of the engine, and preset first and second mapping relationships respectively;

[0107] If not, it is determined that the target knock signal in the storage space is an invalid knock signal, and a new target knock signal is re-acquired.

[0108] Further, the data processing unit is further configured to:

[0109] According to the maximum identification frequency of the knock sensor, the minimum rotating speed of the engine when knock occurs, and the maximum knock crank angle length, the number of sampling samples is calculated, the maximum knock crank angle length is the maximum value in all knock crank angle lengths corresponding to all piston cylinders, and the knock crank angle length is the difference between the maximum value and the minimum value in all crank angles corresponding to the piston cylinder when knock occurs under different working conditions.

[0110] The number of sampling samples is used as the capacity of the storage space.

[0111] Further, the data processing unit is further configured to:

[0112] When the engine is not cold start, the minimum value of the rotating speed range corresponding to the engine when knock occurs is used as the rotating speed threshold;

[0113] When the engine is cold start, the target rotating speed offset value is determined according to the real-time cooling water temperature of the engine and the mapping relationship between the preset water temperature and rotating speed offset value, and the sum of the target rotating speed offset value and the minimum value of the rotating speed range corresponding to the engine when knock occurs is used as the rotating speed threshold.

[0114] Further, the first mapping relationship includes the mapping relationship between the rotating speed-torque and the starting position of the ordinary knock signal window, and the mapping relationship between the rotating speed-torque and the length of the ordinary knock signal window; the second mapping relationship includes the mapping relationship between the rotating speed-torque and the starting position of the super knock signal window, and the mapping relationship between the rotating speed-torque and the length of the super knock signal window.

[0115] Further, the window determination unit is further configured to:

[0116] Based on the EGR valve opening degree and the variable valve timing VVT state of the engine, the first starting position, the first length, the second starting position and the second length are offset corrected.

[0117] Further, the data processing unit is further configured to:

[0118] The minimum value of all minimum crank angles corresponding to all piston cylinders when super knock occurs under different working conditions is used as the target starting position.

[0119] The maximum knock crank angle length is taken as the target length, the maximum knock crank angle length being the maximum value in all knock crank angle lengths corresponding to all piston cylinders, and the knock crank angle length being the difference between the maximum value and the minimum value in all crank angles corresponding to the piston cylinder when knock occurs under different working conditions.

[0120] It should be noted that, for the convenience and brevity of description, the specific working processes of the apparatus and each unit described above can be understood by the person skilled in the art, and the corresponding processes in the foregoing engine knock identification signal processing method embodiments are referred to, which will not be described here.

[0121] The engine knock identification signal processing apparatus provided in the foregoing embodiments can be implemented in the form of a computer program, which can run on an engine knock identification signal processing device as shown in the foregoing engine knock identification signal processing device. Figure 6 The engine knock identification signal processing device is shown in the foregoing engine knock identification signal processing device.

[0122] The embodiments of the present application also provide an engine knock identification signal processing device, which comprises a memory, a processor and a network interface connected through a system bus, the memory storing at least one instruction, and the at least one instruction being loaded and executed by the processor to implement all or part of the steps of the foregoing engine knock identification signal processing method.

[0123] The network interface is configured to perform network communication, such as sending the assigned tasks. Figure 6 The structure shown in the foregoing engine knock identification signal processing device is only a block diagram of part of the structure related to the scheme of the present application, and does not constitute a limitation on the computer device to which the scheme of the present application is applied, and the specific computer device can comprise more or fewer components than those shown in the figure, or combine certain components, or have a different component arrangement.

[0124] The processor can be a CPU, and can also be other general-purpose processors, DSPs (Digital Signal Processors), ASICs (Application Specific Integrated Circuits), FPGAs (Field Programmable Gate Arrays) or other programmable logic devices, discrete gate or transistor logic discrete hardware components, etc. The general-purpose processor can be a microprocessor, or the processor can also be any conventional processor, etc. The processor is the control center of the computer device, and connects all parts of the computer device through various interfaces and lines.

[0125] The memory can be used to store computer programs and / or modules, and the processor realizes various functions of the computer device by running or executing the computer programs and / or modules stored in the memory, and calling data stored in the memory. The memory can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, at least one application required by a function, and the like; and the data storage area can store data created according to the use of the system, and the like. In addition, the memory can include a high-speed random access memory, and can also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, an SMC (Smart Media Card), an SD (Secure digital) card, a flash card, at least one disk storage device, a flash storage device, or other volatile solid-state storage devices.

[0126] The embodiment of the present application also provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to realize all steps or part of steps of the engine knock identification signal processing method.

[0127] The embodiment of the present application realizes all or part of the foregoing processes, and can also be completed by instructing related hardware through a computer program. The computer program can be stored in a computer readable storage medium, and the computer program can realize the steps of the above-mentioned methods when executed by a processor. The computer program includes computer program code, which can be in the form of source code, object code, an executable file, or some intermediate form. The computer readable medium can include any entity or device capable of carrying computer program code, a recording medium, a U disk, a mobile hard disk, a magnetic disk, an optical disk, a computer memory, a ROM (Read-Only memory), a RAM (Random Access memory), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc.

[0128] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, a server or a computer program product. Therefore, the present application can adopt a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer usable storage media (including but not limited to disk storage and optical storage, etc.) containing computer usable program code.

[0129] It has to be understood that the terms "including", "containing" or any other

[0130] The computer program instructions can also be loaded onto a computer, other programmable data processing apparatus, or other processing device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other processing device to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions of the flowchart block(s) or step(s) of the flowchart block(s). Figure 1 The flowchart and / or block diagram in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments. In this regard, each flowchart block and / or block in the Figures can represent a module, segment, or portion of code, which comprises one or more executable Figure 1 The means can comprise any hardware and / or software for implementing the function specified in the flow(s) or block(s) and / or combination of flow(s) and / or block(s).

[0131] The above description is that of current embodiments of the application. Various modifications and changes can be made thereto without departing from the spirit and scope of the application as set forth. The scope of the application is not to be limited to the embodi ments disclosed in the specification, but is intended to cover prior art falling within the scope of the application as well as later lying within the scope of the application.

Claims

1. A method for processing engine knock detection signals, characterized in that, Includes the following steps: The acquired detonation signal is truncated based on the target's starting position and length to obtain the target detonation signal; Based on the engine's real-time speed, engine's real-time torque, and preset first and second mapping relationships, a normal knock signal window with a first starting position and a first length and a super knock signal window with a second starting position and a second length are determined respectively. The target detonation signal is extracted based on the ordinary detonation signal window to obtain an ordinary detonation signal, and the target detonation signal is extracted based on the super detonation signal window to obtain a super detonation signal. Prior to the step of truncating the acquired detonation signal based on the target's starting position and length to obtain the target detonation signal, the method further includes: The minimum value of all minimum crankshaft rotation angles corresponding to the occurrence of super knocking in all piston cylinders under different operating conditions is taken as the target starting position; The maximum knock crankshaft angle length is taken as the target length. The maximum knock crankshaft angle length is the maximum value among all knock crankshaft angle lengths corresponding to all piston cylinders. The knock crankshaft angle length is the difference between the maximum and minimum values ​​among all crankshaft angles corresponding to the piston cylinder when knock occurs under different operating conditions.

2. The engine knock detection signal processing method as described in claim 1, characterized in that, After the step of truncating the acquired detonation signal based on the target's starting position and length to obtain the target detonation signal, the method further includes: The target detonation signal is stored in a storage space with a preset capacity; Determine whether the engine's real-time speed is greater than or equal to the speed threshold; If so, the target detonation signal in the storage space is determined to be a valid detonation signal, and the steps of determining a normal detonation signal window with a first starting position and a first length and a super detonation signal window with a second starting position and a second length based on the engine's real-time speed, the engine's real-time torque and the preset first mapping relationship and second mapping relationship are executed respectively. If not, the target detonation signal in the storage space is determined to be an invalid detonation signal, and a new target detonation signal is acquired.

3. The engine knock detection signal processing method as described in claim 2, characterized in that, Before the step of storing the target detonation signal into a storage space with a preset capacity, the method further includes: The number of samples is calculated based on the maximum recognition frequency of the knock sensor, the minimum speed at which engine knock occurs, and the maximum knock crankshaft angle length. The maximum knock crankshaft angle length is the maximum value among all knock crankshaft angle lengths corresponding to all piston cylinders. The knock crankshaft angle length is the difference between the maximum and minimum values ​​among all crankshaft angles corresponding to the piston cylinders when knock occurs under different operating conditions. The number of samples is used as the storage capacity.

4. The engine knock detection signal processing method as described in claim 2, characterized in that, Before the step of determining whether the real-time engine speed is greater than or equal to the speed threshold, the method further includes: When the engine is not cold-started, the minimum value of the speed range corresponding to the engine knocking is used as the speed threshold. When the engine is cold-started, the target speed offset value is determined based on the engine's real-time coolant temperature and the preset mapping relationship between coolant temperature and speed offset value. The sum of the target speed offset value and the minimum value of the speed range corresponding to the engine knocking is used as the speed threshold.

5. The engine knock detection signal processing method as described in claim 1, characterized in that: The first mapping relationship includes the mapping relationship between speed-torque and the starting position of the ordinary knock signal window, and the mapping relationship between speed-torque and the length of the ordinary knock signal window; the second mapping relationship includes the mapping relationship between speed-torque and the starting position of the super knock signal window, and the mapping relationship between speed-torque and the length of the super knock signal window.

6. The engine knock detection signal processing method as described in claim 1, characterized in that, After determining the ordinary knock signal window with a first starting position and a first length and the super knock signal window with a second starting position and a second length based on the engine's real-time speed, engine's real-time torque, and preset first and second mapping relationships, the method further includes: The offset corrections for the first starting position, first length, second starting position, and second length are performed based on the engine's EGR valve opening and VVT state.

7. An engine knock detection signal processing device, characterized in that, include: The data processing unit is used as the target starting position by taking the minimum value of all minimum crankshaft angles corresponding to the occurrence of super knocking in all piston cylinders under different operating conditions. The maximum knock crankshaft angle length is taken as the target length. The maximum knock crankshaft angle length is the maximum value among all knock crankshaft angle lengths corresponding to all piston cylinders. The knock crankshaft length is the difference between the maximum and minimum values ​​among all crankshaft angles corresponding to the piston cylinder when knock occurs under different working conditions. The first interception unit is used to intercept the acquired detonation signal according to the target's starting position and target length to obtain the target detonation signal; The window determination unit is used to determine, based on the engine's real-time speed, the engine's real-time torque, and preset first and second mapping relationships, a normal knock signal window with a first starting position and a first length, and a super knock signal window with a second starting position and a second length, respectively. The second interception unit is used to intercept the target detonation signal based on the ordinary detonation signal window to obtain an ordinary detonation signal, and to intercept the target detonation signal based on the super detonation signal window to obtain a super detonation signal.

8. An engine knock detection signal processing device, characterized in that, include: A memory and a processor, wherein the memory stores at least one instruction, which is loaded and executed by the processor to implement the engine knock detection signal processing method according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program that, when executed by a processor, implements the engine knock detection signal processing method according to any one of claims 1 to 6.

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