Engine starting control method and system

Abstract

The invention provides an engine starting control method and system, and the method comprises the following steps: receiving an engine starting instruction; the state information of the engine is obtained, and an instruction is sent to an EVVT unit according to the state information to adjust the position of inlet valve timing; the actual position of the intake valve timing is compared with a preset target position; when the deviation is smaller than a preset threshold value, the engine is controlled to be started; when the deviation is larger than a preset threshold value, a controller of the EVVT unit is controlled to be powered off and restarted, the timing position of an inlet valve continues to be adjusted, and the number of times of power-off restarting of the controller is recorded; and when the timing position of the intake valve reaches a preset target position or the power-off restarting frequency of the controller is larger than a preset frequency, the engine is controlled to be started. According to the method, the control chip of the EVVT can be powered on and off again without powering off and powering on by a driver through a key, manual intervention of the driver is not needed, the starting process of the engine is optimized, and the operation experience of the driver is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile engines, and in particular to an engine starting control method and system. Background Art

[0002] With the development of hybrid vehicles, automobile manufacturers have launched Atkinson hybrid engines with high compression ratios to improve thermal efficiency and reduce fuel consumption. The intake VVT ​​(Variable Valve Timing) of the Atkinson cycle engine is used to adjust the position of the intake valve timing. When the intake valve timing is at the reference position (the default position when VVT does not work), because the intake valve timing closes too late, during the engine compression stroke, a large proportion of the intake air will flow back into the intake manifold through the intake valve timing, resulting in weak explosion pressure in the cylinder.

[0003] When the engine is started after being cold-soaked for 8 hours in an extremely cold environment (ambient temperature < -25°C), the engine oil resistance is large. If the intake valve timing is in the reference position, the explosion pressure in the cylinder is weak and cannot output enough torque to offset the low temperature resistance of the oil. The engine often has problems such as difficulty in starting, starting jitter, and starting failure. To solve this problem, the Atkinson cycle engine generally uses an EVVT (electric VVT) unit to replace the traditional hydraulic VVT. Compared with the traditional hydraulic VVT that cannot work at extremely low oil temperatures (oil temperature < -25°C), EVVT uses an electric motor as an actuator, which is not limited by oil temperature. As long as it is powered, it can quickly move the intake valve timing to the target position (open in advance) at extremely low temperatures, thereby increasing the explosion pressure in the engine cylinder and improving the engine starting torque output.

[0004] The EVVT unit mainly includes a controller and a motor. The control chip in the controller is a core component. If the control chip wakes up slowly after powering on or the control chip freezes abnormally (generally occurring at extremely cold temperatures or when the chip temperature is not within the allowable temperature range), the control chip will not be able to control the motor normally, resulting in occasional EVVT non-operation. Once the EVVT unit does not work, the above-mentioned intake valve timing will return to the reference position, and the explosion pressure in the cylinder will be weak. In the prior art, in response to this situation, manual intervention by the driver is generally required. The vehicle key is powered off and then on, and the main relay R1 is disconnected and then closed. The control chip is likely to restart and recover, and the EVVT unit returns to normal and restarts. This solution causes inconvenience to consumers and a poor experience. Summary of the invention

[0005] In view of the above defects of the prior art, the present invention provides an engine starting control method and system to solve the technical problem of inconvenient operation when a control chip of EVVT fails.

[0006] To achieve the above-mentioned purpose and other related purposes, the present invention provides an engine start control method, comprising the following steps: receiving an engine start command; obtaining status information of the engine, and issuing a command to the EVVT unit to adjust the position of the intake valve timing based on the status information; comparing the actual position of the intake valve timing with a preset target position: when the deviation is less than a preset threshold, controlling the engine to start; when the deviation is greater than the preset threshold, controlling the controller of the EVVT unit to power off and restart, continue to adjust the position of the intake valve timing, and record the number of power-off and restart times of the controller; until the position of the intake valve timing reaches the preset target position, or the number of power-off and restart times of the controller is greater than the preset number, controlling the engine to start.

[0007] In one embodiment of the present invention, the step of receiving an engine start command includes: receiving an engine start command; controlling the starter motor to start to drag the engine to rotate; and controlling the starter motor to stop when the controller of the EVVT unit is powered off and restarted.

[0008] In one embodiment of the present invention, the step of obtaining the status information of the engine and issuing an instruction to the EVVT unit to adjust the position of the intake valve timing based on the status information includes: obtaining the status information of the engine; judging the status information to determine whether the position of the intake valve timing needs to be adjusted: when the position of the intake valve timing needs to be adjusted, issuing an instruction to the EVVT unit to adjust the position of the intake valve timing; otherwise, directly controlling the engine to start.

[0009] In one embodiment of the present invention, the status information includes the number of starts in the current driving cycle and the ambient temperature; the step of judging the status information to determine whether the position of the intake valve timing needs to be adjusted includes: judging the number of starts in the current driving cycle and the ambient temperature; when the engine is started for the first time in the current driving cycle and the ambient temperature is less than a set temperature threshold, the position of the intake valve timing needs to be adjusted.

[0010] In one embodiment of the present invention, the step of obtaining the status information of the engine and issuing an instruction to the EVVT unit to adjust the position of the intake valve timing according to the status information includes: obtaining the position of the intake valve timing after a first preset time period.

[0011] In one embodiment of the present invention, when the position of the intake valve timing needs to be adjusted, the step of issuing a command to the EVVT unit to adjust the position of the intake valve timing includes: when the position of the intake valve timing needs to be adjusted, obtaining fault information of the motor of the EVVT unit, if the motor of the EVVT unit is faulty, directly controlling the engine to start, otherwise issuing a command to the EVVT unit to adjust the position of the intake valve timing.

[0012] In one embodiment of the present invention, the step of obtaining the status information of the engine and issuing an instruction to the EVVT unit to adjust the position of the intake valve timing based on the status information includes: obtaining the status information of the engine, and issuing an instruction to the EVVT unit to adjust the position of the intake valve timing after a second preset time period based on the status information, wherein the second preset time period starts from when the controller of the EVVT unit is powered on.

[0013] To achieve the above-mentioned purpose and other related purposes, the present invention also provides an engine starting control system, including: an EVVT unit, the EVVT unit including a controller and a motor, the controller driving the motor to rotate to adjust the position of the intake valve timing; a switch unit, used to independently control the power-on state of the controller of the EVVT unit; a control unit, the control unit is electrically connected to the EVVT unit and the switch unit, respectively, and is used to execute the engine starting control method as described above.

[0014] In one embodiment of the present invention, the switch unit is a normally closed relay, and the normally closed relay is connected in series between the main relay and the controller of the EVVT unit.

[0015] In one embodiment of the present invention, the control unit includes an ECU, which is communicatively connected to the EVVT unit; the ECU includes a first pin and a second pin, and the first pin and the second pin are respectively used to control the on and off of the main relay and the normally closed relay.

[0016] Beneficial effects of the invention: The invention proposes an engine starting control method and system, which adds a switch unit that independently controls the controller of the EVVT unit. When the control chip technology of the EVVT unit is immature and prone to freezing or other abnormal situations, the controller of the EVVT unit can be powered on and off again without the driver having to cut off and power on the key. The power-on and power-off operations of the controller of the EVVT unit are performed automatically without the need for manual intervention by the driver, thereby optimizing the engine starting process and improving the driver's operating experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1A flow chart of an engine starting control method provided by an embodiment of the present invention;

[0019] Figure 2 A power distribution architecture diagram of an EVVT unit provided in one embodiment of the present invention;

[0020] Figure 3 A block diagram of an engine starting control system provided by one embodiment of the present invention.

[0021] Description of reference numerals: 100, EVVT unit; 101, controller; 102, motor; 200, switch unit; 300, control unit. DETAILED DESCRIPTION

[0022] The following describes the embodiments of the present invention through specific specific embodiments, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. It should be noted that the following embodiments and the features in the embodiments can be combined with each other without conflict. In addition to the specific methods, equipment, and materials used in the embodiments, according to the technical personnel in this technical field's grasp of the prior art and the records of the present invention, any methods, equipment, and materials of the prior art that are similar or equivalent to the methods, equipment, and materials described in the embodiments of the present invention can also be used to implement the present invention.

[0023] It should be understood that the terms used in the embodiments of the present invention are for describing specific embodiments rather than for limiting the scope of protection of the present invention. Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as those generally understood by those skilled in the art.

[0024] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions under which the present invention can be implemented, so they have no substantive technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. In addition, the drawings only show the components related to the present invention rather than the number, shape, and size of the components in actual implementation. The type, quantity, and proportion of each component in actual implementation can be changed arbitrarily, and the component layout type may also be more complicated.

[0025] In the following description, numerous details are discussed to provide a more thorough explanation of the embodiments of the present invention. However, it is obvious to those skilled in the art that the embodiments of the present invention can be implemented without these specific details. In some of the embodiments, well-known structures and devices are shown in the form of block diagrams rather than in detail to avoid making the embodiments of the present invention difficult to understand.

[0026] The flowchart and block diagram in the accompanying drawings illustrate the system architecture, functions and operations that may be implemented according to the methods and computer program products of various embodiments disclosed in the present invention. In this regard, each box in the flowchart or block diagram can represent a module, a program segment, or a part of a code, and the module, the program segment, or a part of the code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or the flowchart, and the combination of the boxes in the block diagram and / or the flowchart can be implemented with a dedicated hardware-based system that performs the specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0027] See also Figure 1 , Figure 1 An engine start control method provided in an embodiment of the present invention comprises the following steps: S100, receiving an engine start command, which is generally from a driver turning a key to start the vehicle, or a vehicle controller of a hybrid vehicle requesting to start the vehicle. The engine start control method in this embodiment is aimed at the engine start process, and therefore, subsequent steps are executed only after receiving the engine start command.

[0028] like Figure 2 As shown, after receiving the engine start command, the engine control unit (ECU) will control the main relay R1 to close. Of course, in the control logic of some vehicles, before receiving the engine start command, for example, when the vehicle is powered on, or when the door is opened, or when the vehicle is unlocked, the main relay R1 is already controlled to close. Regardless of the control logic, after executing step S100, the main relay R1 is already closed, and the normal operation of related components (such as LIN communication, CAN communication, ECU main chip power supply, etc.) can be maintained. The switch unit 200 can be, for example, Figure 2 The normally closed relay R2 in the engine, when the main relay R1 is closed, the EVVT unit 100 will also be powered and awakened, and adjust the position of the intake valve timing as needed.

[0029] The engine start control method also includes the following steps: S200, obtaining the state information of the engine, and sending a command to the EVVT unit 100 to adjust the position of the intake valve timing according to the state information. The EVVT unit is also called an electric variable valve timing mechanism. The state information of the engine is used to determine whether the intake valve timing needs to move from a reference position to a target position. The reference position is the default position when the intake VVT ​​is not working, and is also the position where the intake VVT ​​is at the mechanical dead point. The target position is a position where the explosion pressure in the cylinder is strong, the starting torque is good, and the torque is large.

[0030] In a specific embodiment of the present invention, step S200 includes: obtaining the state information of the engine; judging the state information to determine whether the position of the intake valve timing needs to be adjusted: when the position of the intake valve timing needs to be adjusted, sending a command to the EVVT unit 100 to adjust the position of the intake valve timing; otherwise, directly controlling the engine to start. When the position of the intake valve timing does not need to be adjusted, the EVVT unit 100 does not need to adjust the position of the intake valve timing, and the engine can be started directly.

[0031] In a specific embodiment of the present invention, the state information includes the number of starts in the current driving cycle and the ambient temperature; the step of judging the state information to determine whether the position of the intake valve timing needs to be adjusted includes: judging the number of starts in the current driving cycle and the ambient temperature; when the engine is started for the first time in the current driving cycle and the ambient temperature is less than the set temperature threshold, the position of the intake valve timing needs to be adjusted. Here, the following two conditions need to be judged: (1) the engine is started for the first time in the current driving cycle; (2) the ambient temperature is less than the set temperature threshold, which is a calibration value and can be set according to actual conditions. If these two conditions are met at the same time, it is considered that the low-temperature start of the Atkinson engine in the current working condition requires the intake valve timing to move from the reference position to the target position, so it is necessary to send a command to the EVVT unit 100 to adjust the position of the intake valve timing. If any of these two conditions is not met, it is considered that there is no risk of low-temperature start jitter or failure in the start of the engine, and the engine can be controlled to start directly when the intake valve timing is at the reference position.

[0032] The steps of directly starting the engine when the intake valve timing is at the reference position are as follows: First, the starter motor needs to be controlled to start to drive the engine to rotate. The starter motor can be, for example, an ISG motor. The ISG motor is an integrated starter generator, which is directly integrated on the main shaft of the engine and has the dual functions of starting the engine and generating electricity. When the engine control system (EMS) detects the engine speed, it releases the engine start injection ignition command to complete the engine start.

[0033] The EVVT unit 100 adjusts the position of the intake valve timing through the motor 102. In a specific embodiment of the present invention, when the position of the intake valve timing needs to be adjusted, the step of issuing a command to the EVVT unit 100 to adjust the position of the intake valve timing includes: when the position of the intake valve timing needs to be adjusted, obtaining the fault information of the motor 102 of the EVVT unit 100, if the motor 102 of the EVVT unit 100 is faulty, directly controlling the engine to start, otherwise issuing a command to the EVVT unit 100 to adjust the position of the intake valve timing. When the motor 102 of the EVVT unit 100 fails, even if a command is issued to the EVVT unit 100 to adjust the position of the intake valve timing, it cannot be executed, so the step adds the judgment of the fault information of the motor 102 of the EVVT unit 100 to make the entire control process more perfect.

[0034] When the motor 102 of the EVVT unit 100 fails, the EVVT unit 100 cannot adjust the intake valve timing to the target position, and the engine can be directly started when the intake valve timing is at the reference position. The specific steps of this process can be found in the description above. The start at this time can be considered as an emergency mode, and there may be a risk of starting failure or starting jitter. When the motor 102 of the EVVT unit 100 is not faulty, it means that the EVVT unit 100 can adjust the position of the intake valve timing, so an action instruction can be directly issued to the EVVT unit 100.

[0035] The engine start control method also includes the following steps: S300, comparing the actual position of the intake valve timing with the preset target position: when the deviation is less than the preset threshold, controlling the engine to start; when the deviation is greater than the preset threshold, controlling the controller 101 of the EVVT unit 100 to power off and restart, continue to adjust the position of the intake valve timing, and record the number of power-off and restart times of the controller 101; until the position of the intake valve timing reaches the preset target position, or the number of power-off and restart times of the controller 101 is greater than the preset number, controlling the engine to start. In step S200, after issuing an instruction to the EVVT unit 100, the controller 101 of the EVVT unit 100 will control the motor 102 of the EVVT unit 100 to operate in the absence of abnormalities, thereby adjusting the position of the intake valve timing from the reference position to the target position. The working state of the EVVT unit 100 can be obtained, for example, through the feedback signal of the EVVT unit 100, and the feedback signal can be, for example, a fault signal, a speed signal, a rotation direction signal, and the like. If there is an abnormality in the controller 101 of the EVVT unit 100, which makes it unable to control the action of the motor 102 of the EVVT unit 100, and naturally unable to adjust the position of the intake valve timing, the controller 101 of the EVVT unit 100 can be controlled to power off and restart to restore it to normal.

[0036] The preset threshold is a pre-set calibration value, which can be recorded as C1. It is the allowable deviation value of the position of the intake valve timing. When the deviation is greater than C1, it can be considered that the controller 101 of the current EVVT unit 100 is abnormal and cannot accurately control the motor 102 of the EVVT unit 100. At this time, due to the drag of the engine, the intake valve timing may move to the reference position (i.e., the mechanical dead point) and cannot meet the starting requirements. When the deviation is less than C1, it is considered that the intake valve timing has moved to the starting target position, and it can be considered that the current EVVT unit 100 is working normally.

[0037] When the controller 101 of the EVVT unit 100 is abnormal, the controller 101 can be powered off and then powered on again through the switch unit 200. For example, when the switch unit 200 is a normally closed relay R2, as long as the normally closed relay R2 is controlled to be disconnected for a period of time and then closed again, the controller 101 can be powered off and restarted, thereby realizing the electrical restart of the control chip. This process is automatically executed when the controller 101 is abnormal, and the driver does not need to power off and then power on the vehicle key, thereby optimizing the engine start control process, simplifying the driver's operation, and optimizing the driving experience.

[0038] It is understandable that when the controller 101 of the EVVT unit 100 is powered off and restarted, the controller 101 may return to normal and adjust the intake valve timing to the target position. At this time, the engine can be started according to the normal engine starting process.

[0039] It can be understood that when the number of times the controller 101 of the EVVT unit 100 is powered off and restarted reaches a preset number N, it is determined that the controller 101 of the EVVT unit 100 is irreversibly damaged and cannot be solved by re-distributing power. At this time, re-distribution of power is no longer performed, and the engine can be controlled to start when the intake valve is in the reference position. N is a preset value, which is the upper limit of the number of times the EVVT unit 100 is reset, and can be set based on experience.

[0040] In the above embodiment, a switch unit 200 is added for independently controlling the controller 101 of the EVVT unit 100. When an abnormal situation occurs in the controller 101 of the EVVT unit 100, the driver does not need to power on and off by using the key. The driver only needs to control the switch unit 200 to power off the controller 101 and then power it on again to power the controller 101 of the EVVT unit 100 on and off again. The power-on and power-off operations of the controller 101 of the EVVT unit 100 are all performed automatically without manual intervention by the driver, thereby optimizing the engine starting process and improving the driver's operating experience.

[0041] In a specific embodiment of the present invention, step S100 includes the following steps: receiving an engine start command; controlling the starter motor to start to drive the engine to rotate. In most cases, the EVVT unit 100 does not need to adjust the position of the intake valve timing, or the position of the intake valve timing needs to be adjusted and the EVVT unit 100 can work normally. Therefore, in order to start the engine as soon as possible, the starter motor can be controlled to start immediately after receiving the engine start command. The starter motor can be, for example, the above-mentioned ISG motor.

[0042] In a specific embodiment of the present invention, in order to further improve the efficiency of the engine, the starter motor can be controlled to start after the EVVT unit 100 is awakened. In this case, the efficiency of the engine is higher, but correspondingly, the starting time is slightly extended.

[0043] In a specific embodiment of the present invention, after receiving the engine start command, the starter motor is controlled to start to drive the engine to rotate. When the controller 101 of the EVVT unit 100 is abnormal, the engine can only be started after the fault needs to be eliminated or the fault is determined to be unable to be eliminated. During this period, the engine does not meet the starting conditions. Therefore, when the controller 101 of the EVVT unit 100 is powered off and restarted, the starter motor is controlled to stop.

[0044] In a specific embodiment of the present invention, in step S200, after the step of issuing an instruction to the EVVT unit 100 to adjust the position of the intake valve timing according to the state information, the following steps are included: after a first preset time, the position of the intake valve timing is obtained. It can be understood that when the instruction is issued to the EVVT unit 100, the controller 101 of the EVVT unit 100 needs to respond to the instruction and control the motor 102 of the EVVT unit 100 to operate, and after a certain period of time, the position of the intake valve timing will move from the reference position to the target position. This process has a certain time difference. In order to ensure that the position of the intake valve timing obtained is sufficiently accurate, the first preset time T1 is introduced in this embodiment.

[0045] In a specific embodiment of the present invention, the first preset time length T1 can also be a fixed value, or set to different time lengths according to different ambient temperatures. When setting the first preset time length T1, it should be ensured that within this time, the EVVT unit 100 can complete the entire process from responding to the command to the intake valve timing action to the target position.

[0046] In a specific embodiment of the present invention, step S200 includes: obtaining the state information of the engine, and according to the state information, after a second preset time, issuing an instruction to the EVVT unit to adjust the position of the intake valve timing, the second preset time starts from the time when the controller of the EVVT unit is powered on. It can be understood that when issuing an instruction to the EVVT unit 100 to adjust the position of the intake valve timing, it is necessary to ensure that the EVVT unit 100 has been awakened, otherwise the issued instruction cannot be effectively executed. In order to accurately determine whether the EVVT unit 100 has completed the awakening, for example, the timer can start timing after the EVVT unit 100 is powered on, and the time is recorded as t. After the second preset time T2 (i.e., t>T2), it is considered that the EVVT unit 100 has completed the awakening, and then an instruction is issued to the EVVT unit 100 to adjust the position of the intake valve timing. The second preset time T2 is also a calibration value, which represents the time required for the controller 101 of the EVVT unit 100 to wake up after power distribution. This time can be set to a fixed value, or it can be set to different durations according to different ambient temperatures.

[0047] It can be understood that since the first preset time length T1 starts from the time when the instruction is issued to the EVVT unit 100, if the above scheme is adopted (i.e., the timer starts timing after the EVVT unit 100 is powered on), it can be determined whether the first preset time length T1 has passed by judging whether t is greater than T1+T2.

[0048] It should be noted that the steps of the above methods are divided only for the purpose of clear description. When implemented, they can be combined into one step or some steps can be split and decomposed into multiple steps. As long as they contain the same logical relationship, they are all within the scope of protection of this patent; adding insignificant modifications or introducing insignificant designs to the algorithm or process, but not changing the core design of the algorithm and process, are all within the scope of protection of this patent. In addition, the numbering of the above steps is only to distinguish and explain the steps, and does not limit these steps to be executed in the order of the numbers, and can also be executed in other steps.

[0049] See also Figure 3 , Figure 3An engine starting control system provided for one embodiment of the present invention includes: an EVVT unit 100, wherein the EVVT unit 100 includes a controller 101 and a motor 102, wherein the controller 101 drives the motor 102 to rotate to adjust the position of the intake valve timing; a switch unit 200, which is used to independently control the power-on state of the controller 101 of the EVVT unit 100; and a control unit 300, wherein the control unit 300 is electrically connected to the EVVT unit 100 and the switch unit 200, respectively, and is used to execute any of the above engine starting control method embodiments. In the engine starting control system, the independent control of the power-on state of the controller 101 of the EVVT unit 100 is achieved by connecting the switch unit 200, so that when an abnormality occurs in the controller 101, the controller 101 can be powered off and restarted by controlling the on and off of the switch unit 200.

[0050] In a specific embodiment of the present invention, the switch unit 200 is a normally closed relay R2, which is connected in series between the main relay R1 and the controller 101 of the EVVT unit 100. In this way, when the engine start command is received, the main relay R1 will be energized, and the normally closed relay R2 will be in a closed state under normal conditions, so the controller 101 of the EVVT unit 100 will be powered. When the controller 101 of the EVVT unit 100 is abnormal, it is only necessary to control the normally closed relay R2 to be disconnected and then closed after a period of time, so that the controller 101 of the EVVT unit 100 can be re-powered.

[0051] In a specific embodiment of the present invention, the control unit 300 includes an ECU, which is connected to the EVVT unit 100 for communication; the ECU includes a first pin and a second pin, which are used to control the on and off of the main relay and the normally closed relay respectively. Figure 2 The main relay control PIN in the second pin corresponds to Figure 2 The functions of the control unit 300 are realized by the ECU, and there is no need to set up an additional control unit 300, which can reduce the cost of the system.

[0052] In another specific embodiment of the present invention, the opening and closing of the switch unit 200 may not be controlled by the ECU, but the ECU may send a control signal to realize power-off and power-distribution of the controller 101 of the EVVT unit 100 through other circuit control methods.

[0053] In general, the present technical solution adds a normally closed relay R2 to the power supply end of the controller 101 of the EVVT unit 100, and controls the opening and closing of the normally closed relay R2 through a specific control PIN of the ECU, thereby realizing the control of the EMS on the power supply of the controller 101 of the EVVT unit 100, which brings many benefits: (1) During the starting stage, if there is an abnormality in the controller 101 of the EVVT unit 100, the controller 101 of the EVVT unit 100 can be powered on and off again without the driver having to power on and off the key; (2) By setting a delay time during the wake-up period of the controller 101, the controller 101 is sent to the EVVT unit 100 to adjust the position of the intake valve timing after the controller 101 is awakened. The delay time can be calibrated, so that different calibration data can be set, thereby being able to adapt well to the wake-up time of the controller 101 of different manufacturers, different working conditions, and different EVVT units 100, thereby avoiding problems such as difficulty in starting the engine when the EVVT unit 100 is not awakened, and NVH noise caused by too long start-up and dragging time. (3) When the controller 101 of the EVVT unit 100 is immature and prone to crash, the automatic power-off and power distribution strategy proposed in the present invention can effectively prevent many problems such as start failure, start jitter, start NVH, etc. caused by the crash of the control chip.

[0054] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. An engine starting control method, characterized in that: The steps include: receiving an engine start command; Acquiring state information of the engine, and sending a command to the EVVT unit to adjust the position of the intake valve timing according to the state information; The actual position of the intake valve timing is compared with the preset target position: When the deviation is less than a preset threshold, controlling the engine to start; When the deviation is greater than a preset threshold, the controller of the EVVT unit is controlled to power off and restart, the position of the intake valve timing is continued to be adjusted, and the number of power-off and restart times of the controller is recorded; The engine is controlled to start until the position of the intake valve timing reaches a preset target position, or the number of power-off restarts of the controller is greater than a preset number.

2. The engine starting control method according to claim 1, characterized in that: The step of receiving the engine start command comprises: receiving an engine start command; Controlling the starter motor to start so as to drive the engine to rotate; When the controller of the EVVT unit is powered off and restarted, the starter motor is controlled to stop.

3. The engine starting control method according to claim 1, characterized in that: The step of obtaining the state information of the engine and issuing a command to the EVVT unit to adjust the position of the intake valve timing according to the state information comprises: Acquiring status information of the engine; Judging the state information to determine whether the position of the intake valve timing needs to be adjusted: When the position of the intake valve timing needs to be adjusted, sending a command to the EVVT unit to adjust the position of the intake valve timing; Otherwise, the engine is directly controlled to start.

4. The engine startup control method according to claim 3, characterized in that: The state information includes the number of starts in the current driving cycle and the ambient temperature; the step of judging the state information to determine whether the position of the intake valve timing needs to be adjusted includes: Determining the number of starts of the current driving cycle and the ambient temperature; When the engine is started for the first time in the current driving cycle and the ambient temperature is less than a set temperature threshold, the position of the intake valve timing needs to be adjusted.

5. The engine starting control method according to claim 1, characterized in that: The step of obtaining the state information of the engine and issuing a command to the EVVT unit to adjust the position of the intake valve timing according to the state information includes: After a first preset time period has passed, the position of the intake valve timing is obtained.

6. The engine starting control method according to claim 3, characterized in that: When the position of the intake valve timing needs to be adjusted, the step of sending a command to the EVVT unit to adjust the position of the intake valve timing includes: When the position of the intake valve timing needs to be adjusted, the fault information of the motor of the EVVT unit is obtained. If the motor of the EVVT unit is faulty, the engine is directly controlled to start; otherwise, a command is sent to the EVVT unit to adjust the position of the intake valve timing.

7. The engine starting control method according to claim 1, characterized in that: The step of obtaining the state information of the engine and issuing a command to the EVVT unit to adjust the position of the intake valve timing according to the state information comprises: The state information of the engine is obtained, and based on the state information, a command is sent to the EVVT unit to adjust the position of the intake valve timing after a second preset time period, wherein the second preset time period starts from when the controller of the EVVT unit is powered on.

8. An engine starting control system, characterized in that: include: An EVVT unit, the EVVT unit comprising a controller and a motor, the controller driving the motor to rotate to adjust the position of the intake valve timing; A switch unit, used to independently control the power-on state of the controller of the EVVT unit; A control unit, wherein the control unit is electrically connected to the EVVT unit and the switch unit, respectively, and is used to execute the engine start control method according to any one of claims 1 to 7.

9. The engine starting control system according to claim 8, characterized in that: The switch unit is a normally closed relay, which is connected in series between a main relay and a controller of the EVVT unit.

10. The engine starting control system according to claim 9, characterized in that: The control unit includes an ECU, and the ECU is communicatively connected with the EVVT unit; the ECU includes a first pin and a second pin, and the first pin and the second pin are respectively used to control the on and off of the main relay and the normally closed relay.

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