Engine reverse rotation detection method in extended-range hybrid vehicle and readable storage medium

Abstract

According to the engine reverse rotation detection method and the readable storage medium provided by the invention, whether the engine is in a reverse rotation state or not is judged by detecting the rotation condition of the generator by utilizing the characteristic that the engine and the generator in an extended-range hybrid vehicle are mechanically connected; therefore, whether the engine is in the reverse rotation state or not can be judged no longer depending on a crankshaft position sensor, the crankshaft position sensor can also be a one-way crankshaft position sensor, and the purpose of reducing the cost of the whole vehicle can be achieved.

Description

Technical Field

[0001] The present invention relates to the field of vehicle technology, and in particular to a method for detecting engine reversal in an extended-range hybrid vehicle and a readable storage medium. Background Art

[0002] In recent years, with the rapid development of hybrid vehicles in China, hybrid technology has become more and more mature; and as the competition in the domestic hybrid vehicle market becomes increasingly fierce, major manufacturers are conducting in-depth research on reducing vehicle costs. This case is a solution to reduce the cost of a hybrid system.

[0003] Engine reversal detection is an indispensable logic in the EMS system (engine control system). When the engine reverses, the EMS system must shut down the fuel injection and ignition, otherwise it will cause the engine to backfire and cause engine damage.

[0004] At present, the EMS system determines the rotation position of the engine through the crankshaft signal of the crankshaft position sensor. There are generally two types of crankshaft position sensors: unidirectional and bidirectional. The ordinary (also called unidirectional) crankshaft position sensor is cheaper, but the accuracy of detecting engine reversal is poor; the bidirectional crankshaft position sensor is more expensive due to the large number of sensor elements, but its accuracy in detecting engine reversal is higher. In order to ensure the improvement of reversal detection accuracy, bidirectional crankshaft position sensors are generally used in extended-range hybrid vehicles, but at the same time it will also lead to an increase in the cost of the entire vehicle. Summary of the invention

[0005] The present invention aims to provide a method for detecting engine reversal in an extended-range hybrid vehicle to solve one or more problems in the prior art.

[0006] To achieve the above object, the present invention provides a method for detecting engine reversal in a range-extended hybrid vehicle, comprising:

[0007] Obtaining a speed feedback signal of the generator; and,

[0008] According to the speed feedback signal, it is determined whether the engine is in a reverse state.

[0009] Optionally, in the engine reversal detection method in the extended-range hybrid vehicle, the speed feedback signal is obtained by acquiring a high-frequency induction signal generated by a resolver sensor when the resolver sensor rotates with the generator under the action of an excitation signal.

[0010] Optionally, in the engine reversal detection method in the extended-range hybrid vehicle, the step of obtaining the speed feedback signal according to the high-frequency sensing signal includes:

[0011] The high-frequency induction signal is processed to obtain a sine signal or a cosine signal, and the sine signal and the cosine signal are analyzed to obtain the speed feedback signal.

[0012] Optionally, in the method for detecting engine reversal in a range-extended hybrid vehicle, the method further includes:

[0013] Acquiring a crankshaft signal from a crankshaft position sensor installed on the engine; and,

[0014] It is determined whether the engine is in a reverse rotation state according to the crankshaft signal.

[0015] Optionally, in the engine reversal detection method in the extended-range hybrid vehicle, after determining that the engine is in a reverse state based on any one of the speed feedback signal and the crankshaft signal, the engine is controlled to shut down fuel injection and ignition.

[0016] Optionally, in the engine reversal detection method in the extended-range hybrid vehicle, the crankshaft position sensor is a unidirectional crankshaft position sensor or a bidirectional crankshaft position sensor.

[0017] Optionally, in the engine reversal detection method in the extended-range hybrid vehicle, if the crankshaft position sensor is a bidirectional crankshaft position sensor, it is preferentially determined whether the engine is in a reverse state based on the crankshaft signal.

[0018] Optionally, in the engine reversal detection method in the extended-range hybrid vehicle, the unidirectional crankshaft position sensor has one contact that can sense the passage of the lower edge of the tooth, and the bidirectional crankshaft position sensor has three contacts that can sense the passage of the lower edge of the tooth.

[0019] Optionally, in the engine reversal detection method in the extended-range hybrid vehicle, the speed feedback signal is transmitted via CAN communication.

[0020] The present invention also provides a readable storage medium, wherein the readable storage medium stores a computer program, and when the computer program is executed, the engine reversal detection method as described in any of the preceding items is implemented.

[0021] In summary, the engine reversal detection method and readable storage medium in the extended-range hybrid vehicle provided by the present invention utilize the characteristics of the mechanical connection between the engine and the generator in the extended-range hybrid vehicle to determine whether the engine is in a reverse state by detecting the rotation of the generator, so that the determination of whether the engine is in a reverse state no longer depends on the crankshaft position sensor. In this way, the crankshaft position sensor can also adopt a one-way crankshaft position sensor, thereby achieving the purpose of reducing the cost of the entire vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A flow chart of a method for detecting engine reversal in a range-extended hybrid vehicle provided by an embodiment of the present invention;

[0023] Figure 2 A schematic diagram of the composition of a hybrid power system in an embodiment of the present invention;

[0024] Figure 3 Schematic diagram of the working principle of position detection using a unidirectional crankshaft position sensor and a dual-axis crankshaft position sensor. DETAILED DESCRIPTION

[0025] In order to make the purpose, advantages and features of the present invention clearer, the present invention is described in detail in conjunction with the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In addition, the structure shown in the drawings is often a part of the actual structure. In particular, the emphasis of each drawing is different, and sometimes different proportions are used. It should also be understood that, unless otherwise specified or indicated, the terms "first", "second", "third", etc. in the specification are only used to distinguish the various components, elements, steps, etc. in the specification, and are not used to represent the logical relationship or sequential relationship between the various components, elements, steps, etc.

[0026] See also Figure 1 The embodiment of the present invention provides a method for detecting engine reversal in a range-extended hybrid vehicle, comprising the following steps:

[0027] S1, obtaining the speed feedback signal of the generator;

[0028] S2, judging whether the engine is in a reverse state according to the speed feedback signal.

[0029] For extended-range hybrid vehicles, the engine and generator are rigidly connected through physical means such as torsional dampers and reduction gears. In view of this, the present application uses the speed feedback signal of the generator to determine the forward and reverse rotation state of the engine. In this way, compared with the hybrid power system using a two-way crankshaft position sensor, the control effect is the same, but the system cost is reduced, meeting the needs of various vehicle manufacturers to reduce costs and increase efficiency.

[0030] The following combination Figure 2 and Figure 3 The engine reversal detection method provided in this application is further described.

[0031] Figure 2The figure shows the composition of the hybrid power system of the extended-range hybrid vehicle. The hybrid power system includes: a generator, a motor controller, a resolver sensor, an engine, a crankshaft sensor and an engine control system (EMS system). The generator and the engine are mechanically connected, the EMS system controls the engine, the crankshaft sensor is installed on the generator, the motor controller controls the generator and receives the feedback signal of the crankshaft sensor, the motor controller and the EMS system communicate via CAN, and the feedback signal from the crankshaft sensor received by the motor controller is transmitted to the EMS system in the form of CAN communication.

[0032] In step S1, the speed feedback signal can be obtained specifically through a resolver sensor. Specifically, the speed feedback signal is obtained by obtaining the high-frequency induction signal generated by the resolver sensor when the generator rotates under the action of the excitation signal. It can be understood that the speed of the generator mentioned in this application includes the speed size and direction. When the permanent magnet synchronous motor is working, the rotating magnetic field generated by the stator coil rotates synchronously with the rotor, and the rotating magnetic field poles and the rotor poles will maintain a certain angle, and the position and speed of the rotor are monitored by the resolver sensor. The resolver sensor is installed on the generator, specifically on the motor rotor. When the motor rotor rotates, the resolver sensor also rotates. After inputting a high-frequency sinusoidal signal (i.e., an excitation signal) to the motor rotor, the resolver sensor will feedback a high-frequency induction signal. According to the high-frequency induction signal fed back by the resolver sensor, the speed size and direction of the generator can be analyzed. In some other embodiments, other methods known to those skilled in the art can also be used to obtain the speed size and direction of the generator.

[0033] The step of obtaining the speed feedback signal according to the high-frequency sensing signal includes: processing the high-frequency sensing signal to obtain a sine signal or a cosine signal, and analyzing the sine signal and the cosine signal to obtain the speed feedback signal.

[0034] The engine reverse rotation detection method provided in the embodiment of the present invention may also be detected by using a crankshaft position sensor, that is, the engine reverse rotation detection method provided in the embodiment of the present invention may also include:

[0035] Step S3, obtaining a crankshaft signal from a crankshaft position sensor installed on the engine; and, based on the crankshaft signal, determining whether the engine is in a reverse rotation state.

[0036] From the above description, it can be seen that there are two ways for the extended-range hybrid vehicle engine management system provided by the embodiment of the present invention to determine whether the engine is in a reverse state. One is to determine based on the speed feedback signal of the generator, and the other is to determine based on the crankshaft signal of the crankshaft position sensor. Therefore, further, the engine reverse detection method provided by the embodiment of the present invention also includes:

[0037] Step S4, when it is determined according to any one of them that the engine is in a reverse state, the engine is controlled to shut down fuel injection and ignition.

[0038] Optionally, the crankshaft position sensor adopts a unidirectional crankshaft position sensor (unidirectional DG) or a bidirectional crankshaft position sensor (bidirectional DG).

[0039] See also Figure 3 The one-way crankshaft position sensor has a contact that can sense the passing of the lower edge of the tooth. When the falling edge of the tooth passes, it can only recognize that there is a falling edge passing and generate a pulse signal. Therefore, it cannot accurately determine whether the engine is in the forward or reverse state. The two-way crankshaft position sensor has three contacts that can sense the passing of the lower edge of the tooth. When the falling edge of the tooth passes, it can not only generate a pulse signal, but also calculate the time difference between the falling edge of the same tooth passing through two adjacent contacts, that is, Figure 3 By comparing t1 and t2 in the figure with the value 1, it is possible to accurately identify whether the engine is in the forward rotation state or the reverse rotation state.

[0040] The engine reversal detection method provided by the present application can also use the speed feedback signal of the generator to detect whether the engine is in a reversal state. Even if the crankshaft position sensor adopts a one-way crankshaft position sensor, it can accurately determine whether the engine is in a reversal state, thereby ensuring the control accuracy while reducing the cost of the whole vehicle. Of course, without considering the cost of the whole vehicle, the crankshaft position sensor can also adopt a two-way crankshaft position sensor.

[0041] If the crankshaft position sensor adopts a bidirectional crankshaft position sensor, it is preferred to give priority to judging whether the engine is in a reverse state based on the crankshaft signal. In the automobile hybrid system, the motor controller and the engine control system (i.e., the EMS system) communicate via CAN. The speed feedback signal is transmitted to the EMS system via CAN communication, and the EMS system can process the speed feedback signal. The crankshaft signal of the crankshaft position sensor is directly sent to the EMS system. Therefore, the rate at which the crankshaft signal is transmitted to the EMS system is greater than the rate at which the speed feedback signal is transmitted to the EMS system. In the case where a high-precision detection result can be obtained based on both signals, the crankshaft signal is used first to judge whether the engine is in a reverse state. The EMS system can shut down the injection and ignition more quickly, thereby being more effective in protecting the engine.

[0042] An embodiment of the present invention further provides a readable storage medium, wherein the readable storage medium stores a computer program, and when the computer program is executed, the engine reversal detection method provided in the embodiment of the present invention is implemented.

[0043] The readable storage medium can be a tangible device that can hold and store instructions used by an instruction execution device, such as but not limited to an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination thereof. The computer program described herein can be downloaded from the readable storage medium to each computing / processing device, or downloaded to an external computer or external storage device via a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. In addition, the computer program for performing the operation of the present invention can be an assembly instruction, an instruction set architecture (ISA) instruction, a machine instruction, a machine-related instruction, a microcode, a firmware instruction, a state setting data, or a source code or object code written in any combination of one or more programming languages. The computer program can be executed completely on a user's computer, partially on a user's computer, executed as an independent software package, partially on a user's computer, partially on a remote computer, or completely on a remote computer or server. In some embodiments, by utilizing the state information of a computer program to personalize an electronic circuit, such as a programmable logic circuit, a field programmable gate array (FPGA), or a programmable logic array (PLA), the electronic circuit can execute computer-readable program instructions, thereby realizing various aspects of the present invention.

[0044] As can be seen from the foregoing description, when the computer program is executed, the above step S1 is completed by controlling the generator controller, involving the communication interaction between the generator controller and the resolver sensor and the generator, and the above steps S2 to S4 are completed by controlling the EMS system, step S2 involves the communication interaction between the EMS system and the generator controller, step S3 involves the communication interaction between the EMS system and the crankshaft position sensor, and step S4 involves the communication interaction between the EMS system and the engine. The specific control logic should be understood by those skilled in the art, and will not be described in detail here.

[0045] In summary, the engine reversal detection method and readable storage medium in the extended-range hybrid vehicle provided by the embodiments of the present invention utilize the characteristics of the mechanical connection between the engine and the generator in the extended-range hybrid vehicle to determine whether the engine is in a reverse state by detecting the rotation of the generator, so that the determination of whether the engine is in a reverse state no longer depends on the crankshaft position sensor. In this way, the crankshaft position sensor can also adopt a one-way crankshaft position sensor, thereby achieving the purpose of reducing the cost of the entire vehicle.

[0046] In addition, it should be recognized that although the present invention has been disclosed as a preferred embodiment, the above embodiment is not intended to limit the present invention. For any technician familiar with the art, without departing from the scope of the technical solution of the present invention, the technical content disclosed above can be used to make many possible changes and modifications to the technical solution of the present invention, or modified into equivalent embodiments of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still belongs to the scope of protection of the technical solution of the present invention.

Claims

1. A method for detecting engine reversal in a range-extended hybrid vehicle, characterized in that: include: Obtain the speed feedback signal of the generator; as well as, According to the speed feedback signal, it is determined whether the engine is in a reverse state.

2. The method for detecting engine reverse rotation in a range-extended hybrid vehicle according to claim 1, characterized in that: The speed feedback signal is obtained by acquiring a high-frequency induction signal generated when the resolver sensor rotates with the generator under the action of the excitation signal.

3. The method for detecting engine reverse rotation in a range-extended hybrid vehicle according to claim 2, characterized in that: The step of obtaining the speed feedback signal according to the high-frequency induction signal comprises: The high-frequency induction signal is processed to obtain a sine signal or a cosine signal, and the sine signal and the cosine signal are analyzed to obtain the speed feedback signal.

4. The method for detecting engine reverse rotation of an extended-range hybrid vehicle according to claim 1, characterized in that: Also includes: Acquire a crankshaft signal from a crankshaft position sensor installed on the engine; as well as, It is determined whether the engine is in a reverse rotation state according to the crankshaft signal.

5. The method for detecting engine reverse rotation of an extended-range hybrid vehicle according to claim 4, characterized in that: Also includes: After determining that the engine is in a reverse state based on any one of the speed feedback signal and the crankshaft signal, the engine is controlled to shut down fuel injection and ignition.

6. The method for detecting engine reverse rotation of an extended-range hybrid vehicle according to claim 4, characterized in that: The crankshaft position sensor is a unidirectional crankshaft position sensor or a bidirectional crankshaft position sensor.

7. The method for detecting engine reverse rotation of an extended-range hybrid vehicle according to claim 6, characterized in that: If the crankshaft position sensor is a bidirectional crankshaft position sensor, it is preferred to determine whether the engine is in a reverse rotation state based on the crankshaft signal.

8. The method for detecting engine reverse rotation of an extended-range hybrid vehicle according to claim 6, characterized in that: The one-way crankshaft position sensor has one contact point capable of sensing the passage of the lower edge of the tooth, and the two-way crankshaft position sensor has three contacts capable of sensing the passage of the lower edge of the tooth.

9. The method for detecting engine reverse rotation of an extended-range hybrid vehicle according to claim 1, characterized in that: The transmission of the speed feedback signal is via CAN communication.

10. A readable storage medium, characterized in that: The readable storage medium stores a computer program, and when the computer program is executed, the engine reversal detection method according to any one of claims 1 to 9 is implemented.

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