Engine rotating speed calculation method based on eTPU

Abstract

The invention provides an engine rotating speed calculation method, and belongs to the technical field of power control, and the method comprises the steps: collecting and coding the edges of a crankshaft and a camshaft at an eTPU end; fault diagnosis logic is introduced into each acquisition edge of a crankshaft and a camshaft, and acquisition results are divided into four conditions for encoding; crankshaft and camshaft tooth cycle data are collected at the eTPU end and transmitted to the main processor end. Four different rotating speed values are calculated according to the collected periodic data; calibration parameters are introduced, engine control software can flexibly select a rotating speed value calculation source by calibrating the parameters, and different rotating speed values are selected under different working conditions. Accuracy and stability of rotating speed calculation can be improved, and then working efficiency of an engine is improved. Theoretical analysis and experiments show that the rotating speed stability can be effectively improved by using the method, and the engine can still run stably under the condition that the single crankshaft / camshaft is lost suddenly.

Description

Technical Field

[0001] The present application relates to the field of power control, and in particular to an engine speed calculation method based on eTPU. Background Art

[0002] Speed ​​is involved in engine control and is a commonly controlled variable of the engine. It is also a very important parameter that affects the control efficiency and performance of the engine. In the field of power control, the control system has very high requirements for the speed calculation value. The speed value is involved in the control of multiple functional modules of the engine, and its calculation result directly affects the engine control efficiency. Therefore, the calculation of engine speed is of great significance to ensure the normal and efficient operation of the engine.

[0003] Currently, in engine control, the speed of a single crankshaft tooth is mostly used to represent the engine speed. The complex environment and complex state of engine operation are not considered. The speed value has low accuracy, which introduces large errors into engine control and affects engine control efficiency. Summary of the invention

[0004] In view of this, the present application provides an engine speed calculation method based on eTPU, which solves the problems in the prior art, can reasonably calculate the engine speed, improve the accuracy of the engine speed value, and thus improve the engine working efficiency and control accuracy.

[0005] The present application provides an engine speed calculation method based on eTPU using the following technical solution:

[0006] A method for calculating engine speed based on eTPU, comprising the following steps:

[0007] Collect engine position signals, crankshaft tooth cycle data, and camshaft tooth cycle data on the eTPU side;

[0008] The eTPU end transmits the crankshaft tooth cycle data and the camshaft tooth cycle data to the main processor end in the form of an array;

[0009] The main processor side calculates the engine speed EngineSpeedA with a single crankshaft tooth cycle, the main processor side calculates the engine speed EngineSpeedB with crankshaft N / CylinderN tooth cycles, the main processor side calculates the engine speed EngineSpeedC with a crankshaft cycle, and the main processor side calculates the engine speed EngineSpeedD with a camshaft cycle, where N is the total number of crankshaft teeth and CylinderN is the number of engine cylinders;

[0010] A calibration parameter EngineSpeedFlag is introduced. The value of EngineSpeedFlag corresponds to different working conditions. When EngineSpeedFlag=0, the engine speed value is EngineSpeedA; when EngineSpeedFlag=1, the engine speed value is EngineSpeedB; when EngineSpeedFlag=2, the engine speed value is EngineSpeedC; when EngineSpeedFlag=3, the engine speed value is EngineSpeedD. The engine control software selects the speed value calculation source through EngineSpeedFlag and selects different speed values ​​under different working conditions.

[0011] Optionally, fault diagnosis logic is introduced at each acquisition edge of the crankshaft and camshaft, and the eTPU end transmits the fault diagnosis code to the main processor end, and the main processor end determines whether the crankshaft and camshaft are abnormal through the fault diagnosis code.

[0012] Optionally, the eTPU transmits the fault diagnosis code to the main processor in the form of an array.

[0013] Optionally, the method for calculating the engine speed EngineSpeedA using a single crankshaft tooth period is: EngineSpeedA=TCRFreq*60 / CrankToothPeriodA*N, wherein TCRPreq is the acquisition clock frequency of the eTPU end, N is the total number of crankshaft teeth, and CrankToothPeriodA is the period of a single normal crankshaft tooth.

[0014] Optionally, the method for calculating the engine speed EngineSpeedB using crankshaft N / CylinderN tooth periods is: EngineSpeedB=TCRFreq*60 / CrankToothPeriodB*CylinderN, wherein TCRPreq is the acquisition clock frequency of the eTPU end, CrankToothPeriodB is the period of crankshaft N / CylinderN teeth, and CylinderN is the number of engine cylinders.

[0015] Optionally, the method for calculating the engine speed EngineSpeedC based on the period of one crankshaft revolution is: EngineSpeedC=TCRFreq*60 / CrankToothPeriodC, wherein TCRPreq is the acquisition clock frequency of the eTPU end, and CrankToothPeriodC is the period of one crankshaft revolution.

[0016] Optionally, the method for calculating the engine speed EngineSpeedD using the camshaft period is: EngineSpeedD = 2*(TCRFreq*60 / CamToothPeriod*CylinderN), where TCRPreq is the acquisition clock frequency on the eTPU end, CamToothPeriod is the normal tooth period of the camshaft, and CylinderN is the number of engine cylinders.

[0017] In summary, this application includes the following beneficial technical effects:

[0018] By combining engine speed calculation, engine position system fault diagnosis and parameter calibration, the engine control software can flexibly select the speed value calculation source through EngineSpeedFlag, select different speed values ​​under different working conditions, and improve the stability of speed acquisition; and use the eTPU module to accurately collect and transmit engine position data, thereby improving the accuracy of engine speed values ​​and thus improving engine working efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 This is a logic diagram of the engine speed calculation method based on eTPU in this application;

[0021] Figure 2 This is a schematic diagram of the crankshaft and camshaft signals of a cylinder engine in an embodiment of the present application. DETAILED DESCRIPTION

[0022] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0023] The following describes the implementation methods of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present application.

[0024] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on the present application, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects described herein can be used to implement the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this device and / or practice this method.

[0025] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application. The illustrations only show the components related to the present application rather than being drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed at will, and the component layout may also be more complicated.

[0026] Additionally, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, it will be understood by those skilled in the art that the aspects described may be practiced without these specific details.

[0027] An embodiment of the present application provides an engine speed calculation method based on eTPU.

[0028] like Figure 1 and Figure 2 As shown, a method for calculating engine speed based on eTPU includes the following steps:

[0029] Collect engine position signals, crankshaft tooth cycle data and camshaft tooth cycle data on the eTPU side: Crankshaft and camshaft signals are collected on the eTPU side, and each tooth edge is encoded to confirm the unknown state of each tooth. The encoding method is: the first valid edge after the crankshaft missing tooth is numbered 1, the first valid edge after the camshaft marked tooth is 1, and then each valid edge is added by 1 in sequence until the last tooth of the crankshaft camshaft.

[0030] On the eTPU side, two eTPU channels are selected to access the crankshaft and camshaft signals for engine position acquisition. In addition, the crankshaft signal is connected to the TCRCLKA pin of the CPU as a reference signal to generate clock and angle clock signals. The engine position is acquired by acquiring the rising or falling edge of the crankshaft and camshaft edges.

[0031] like Figure 2As shown, in one embodiment, an 8-cylinder engine is taken as an example for explanation, the crankshaft has 58+2 teeth, and the camshaft has 8+1 teeth. The crankshaft and camshaft signals are collected at the eTPU end. The crankshaft missing tooth position is located according to the principle that the tooth period of the crankshaft missing tooth position is greater than the normal tooth period, and the first valid edge after the crankshaft missing tooth is numbered as 1. By analogy, the position of the 120 teeth of the crankshaft is located and numbered to achieve synchronization of the crankshaft signal; the camshaft marked tooth position is located according to the principle that the camshaft marked tooth period is less than the normal tooth period, and the first valid edge after the camshaft marked tooth is numbered as 1. By analogy, the position of the 9 teeth of the camshaft is located and numbered to achieve synchronization of the camshaft signal.

[0032] The eTPU transmits the crankshaft tooth cycle data and camshaft tooth cycle data to the main processor in the form of an array. The eTPU collects edge and tooth cycle data, and the collected results are exchanged with the main processor in the form of an array, greatly improving the efficiency and accuracy of data exchange.

[0033] The main processor side calculates the engine speed EngineSpeedA based on a single crankshaft tooth cycle, the main processor side calculates the engine speed EngineSpeedB based on N / CylinderN crankshaft tooth cycles, the main processor side calculates the engine speed EngineSpeedC based on a crankshaft cycle, and the main processor side calculates the engine speed EngineSpeedD based on a camshaft cycle, wherein N is the total number of crankshaft teeth, CylinderN is the number of engine cylinders, and in this embodiment, N is 120, CylinderN is 8, and N / CylinderN is 15.

[0034] A calibration parameter EngineSpeedFlag is introduced. The value of EngineSpeedFlag corresponds to different working conditions. When EngineSpeedFlag = 0, the engine speed value is EngineSpeedA; when EngineSpeedFlag = 1, the engine speed value is EngineSpeedB; when EngineSpeedFlag = 2, the engine speed value is EngineSpeedC; when EngineSpeedFlag = 3, the engine speed value is EngineSpeedD. The engine control software selects the speed value calculation source through EngineSpeedFlag and selects different speed values ​​under different working conditions. This improves the accuracy and stability of speed calculation.

[0035] Specifically, the method for calculating the engine speed EngineSpeedA using a single crankshaft tooth period is: EngineSpeedA=TCRFreq*60 / CrankToothPeriodA*N, wherein TCRPreq is the acquisition clock frequency of the eTPU end, N is the total number of crankshaft teeth, and CrankToothPeriodA is the period of a single normal crankshaft tooth.

[0036] The method for calculating the engine speed EngineSpeedB using crankshaft N / CylinderN tooth periods is: EngineSpeedB=TCRFreq*60 / CrankToothPeriodB*CylinderN, where TCRPreq is the acquisition clock frequency on the eTPU side, CrankToothPeriodB is the period of crankshaft N / CylinderN teeth, and CylinderN is the number of engine cylinders.

[0037] The method for calculating the engine speed EngineSpeedC based on the period of one crankshaft revolution is: EngineSpeedC=TCRFreq*60 / CrankToothPeriodC, where TCRPreq is the acquisition clock frequency of the eTPU end, and CrankToothPeriodC is the period of one crankshaft revolution.

[0038] The method for calculating the engine speed EngineSpeedD using the camshaft period is: EngineSpeedD = 2*(TCRFreq*60 / CamToothPeriod*CylinderN), where TCRPreq is the acquisition clock frequency on the eTPU end, CamToothPeriod is the normal tooth period of the camshaft, and CylinderN is the number of engine cylinders.

[0039] Fault diagnosis logic is introduced at each acquisition edge of the crankshaft and camshaft. The eTPU transmits the fault diagnosis code to the main processor, which determines whether the crankshaft and camshaft are abnormal through the fault diagnosis code. The eTPU transmits the fault diagnosis code to the main processor in the form of an array. The details are as follows:

[0040] If the crankshaft and camshaft signals are both normal, the encoding synchronization state SyncState is 0; if the crankshaft signal is normal and the camshaft signal is abnormal, the encoding synchronization state SyncState is 2; if the camshaft signal is normal and the crankshaft signal is abnormal, the encoding synchronization state SyncState is 4; if both the crankshaft and camshaft signals are abnormal, the encoding synchronization state SyncState is 8. If the crankshaft and camshaft can enter the normal counting state, it is considered that their signal acquisition is normal, otherwise it is considered that the signal acquisition is abnormal.

[0041] By combining engine speed calculation, engine position system fault diagnosis and parameter calibration, the accuracy and stability of the engine speed value are improved, thereby improving the engine's operating efficiency.

[0042] When the engine position fault code SyncState is 0, the corresponding speed value is calculated according to the value of EngineSpeedFlag, and the speed value source can be the crankshaft or camshaft; when the engine position fault code SyncState is 2, the corresponding speed value is calculated according to the value of EngineSpeedFlag, and the speed value source can only be the crankshaft; when the engine position fault code SyncState is 4, the corresponding speed value is calculated according to the value of EngineSpeedFlag, and the speed value source can only be the camshaft; when the engine position fault code SyncState is 8, the speed value is set to 0, and the engine position signal needs to be collected again.

[0043] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. An engine speed calculation method based on eTPU, characterized in that: The steps include: Collect engine position signals, crankshaft tooth cycle data, and camshaft tooth cycle data on the eTPU side; The eTPU end transmits the crankshaft tooth cycle data and the camshaft tooth cycle data to the main processor end in the form of an array; The main processor side calculates the engine speed EngineSpeedA with a single crankshaft tooth cycle, the main processor side calculates the engine speed EngineSpeedB with crankshaft N / CylinderN tooth cycles, the main processor side calculates the engine speed EngineSpeedC with a crankshaft cycle, and the main processor side calculates the engine speed EngineSpeedD with a camshaft cycle, where N is the total number of crankshaft teeth and CylinderN is the number of engine cylinders; A calibration parameter EngineSpeedFlag is introduced. The value of EngineSpeedFlag corresponds to different working conditions. When EngineSpeedFlag=0, the engine speed value is EngineSpeedA; when EngineSpeedFlag=1, the engine speed value is EngineSpeedB; when EngineSpeedFlag=2, the engine speed value is EngineSpeedC; when EngineSpeedFlag=3, the engine speed value is EngineSpeedD. The engine control software selects the speed value calculation source through EngineSpeedFlag and selects different speed values ​​under different working conditions.

2. The engine speed calculation method based on eTPU according to claim 1, characterized in that: Fault diagnosis logic is introduced at each acquisition edge of the crankshaft and camshaft. The eTPU transmits the fault diagnosis code to the main processor, and the main processor determines whether the crankshaft and camshaft are abnormal based on the fault diagnosis code.

3. The engine speed calculation method based on eTPU according to claim 1, characterized in that: The eTPU transmits the fault diagnosis code to the main processor in the form of an array.

4. The engine speed calculation method based on eTPU according to claim 1, characterized in that: The method for calculating the engine speed EngineSpeedA using a single crankshaft tooth period is: EngineSpeedA=TCRFreq*60 / CrankToothPeriodA*N, where TCRPreq is the eTPU acquisition clock frequency, N is the total number of crankshaft teeth, and CrankToothPeriodA is the period of a single normal crankshaft tooth.

5. The engine speed calculation method based on eTPU according to claim 1, characterized in that: The method for calculating the engine speed EngineSpeedB using crankshaft N / CylinderN tooth periods is: EngineSpeedB=TCRFreq*60 / CrankToothPeriodB*CylinderN, where TCRPreq is the acquisition clock frequency on the eTPU side, CrankToothPeriodB is the period of crankshaft N / CylinderN teeth, and CylinderN is the number of engine cylinders.

6. The engine speed calculation method based on eTPU according to claim 1, characterized in that: The method for calculating the engine speed EngineSpeedC based on the period of one crankshaft revolution is: EngineSpeedC=TCRFreq*60 / CrankToothPeriodC, where TCRPreq is the acquisition clock frequency of the eTPU end, and CrankToothPeriodC is the period of one crankshaft revolution.

7. The engine speed calculation method based on eTPU according to claim 1, characterized in that: The method for calculating the engine speed EngineSpeedD using the camshaft period is: EngineSpeedD = 2*(TCRFreq*60 / CamToothPeriod*CylinderN), where TCRPreq is the acquisition clock frequency of the eTPU end, CamToothPeriod is the normal tooth period of the camshaft, and CylinderN is the number of engine cylinders.

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