An engine start control method, device, engine and motor vehicle

Abstract

The application relates to an engine starting control method and device, an engine and a motor vehicle. A rotating speed signal and fault information during engine starting are acquired; when there is a crankshaft camshaft phase fault, a degraded starting mode is entered, the degraded starting mode being a trial injection mode or a trial ignition mode; when there is CAN communication fault information, a rotating speed rising trend is calculated according to the acquired engine rotating speed signal; when the rotating speed rising trend is greater than a preset threshold, injection or ignition is stopped, and the degraded starting mode is exited; if the rotating speed rising trend is not greater than the preset threshold, trial injection or trial ignition is continuously executed; when there is no CAN communication fault information, a motor is controlled to drag the engine to a set safe rotating speed according to a preset starting rotating speed and maintain the set safe rotating speed for a set time, and engine starting is completed through the degraded starting mode.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle control, in particular to an engine starting control method and device, an engine and a motor vehicle. BACKGROUND

[0002] The statements in this section merely provide background information related to the present application and do not necessarily constitute the prior art.

[0003] The new energy hybrid vehicle will start and run at low speed by motor reverse dragging the engine, which is different from the traditional vehicle that drags to a certain speed by starter, and then the engine phase is synchronized to make the speed rise to a certain value and then disconnects the starter. When the engine crankshaft and camshaft phase of the hybrid vehicle fails to synchronize, it will enter the test injection mode. In this mode, the accuracy of the test injection phase is generally judged by judging the rising trend of the engine speed, but since the hybrid vehicle engine is directly dragged by the motor according to the set speed, at this time, it cannot be determined whether the speed rise is caused by the motor dragging the engine or by the fuel combustion in the engine, so that the speed rising trend cannot truly reflect the accuracy of the test injection. If the injection is continued in this mode, it will cause the engine to be abnormal, and in severe cases, it will cause the engine to be abnormal, and in severe cases, it will cause the engine to be abnormal. SUMMARY

[0004] In order to solve the technical problems existing in the background art, the present application provides an engine starting control method, device, engine and motor vehicle, which cooperates with the engine ECU and the hybrid HCU to realize safe starting in the crankshaft camshaft phase fault mode.

[0005] In order to achieve the above purpose, the present application adopts the following technical scheme:

[0006] The first aspect of the present application provides an engine starting control method, comprising the following steps:

[0007] Obtaining the speed signal and fault information during engine starting;

[0008] When there is a crankshaft camshaft phase fault, enter the degraded starting mode, and the degraded starting mode is a test injection mode or a test ignition mode;

[0009] When there is a CAN communication fault information, according to the obtained engine speed signal, calculate the speed rising trend, when the speed rising trend is greater than a preset threshold, stop injection or stop ignition, and exit the degraded starting mode; if the speed rising trend is not greater than the preset threshold, continue to execute the test injection or test ignition;

[0010] When there is no CAN communication fault information, according to the preset starting speed, the motor drags the engine to the set safe speed and maintains the set time, and then the engine starting is completed through the degraded starting mode.

[0011] Further, when there is CAN communication fault information, whether the motor drags the engine is judged according to the speed rising trend, if yes, the injection is stopped or the ignition is stopped, and the degraded starting mode is exited.

[0012] Further, the speed acceleration calculated by the speed signal is used to reflect the speed rising trend.

[0013] Further, when there is CAN communication fault information, the ECU starting protection mode is triggered.

[0014] Further, in the ECU starting protection mode, the speed rising trend is calculated according to the obtained engine speed signal, and when the speed rising trend is greater than a preset threshold, the ECU reports a fault of "not allowed to drag start", the injection is stopped or the ignition is stopped, and the degraded starting mode is exited.

[0015] Further, when there is no CAN communication fault information, the ECU sends a "motor degraded drag allowed" instruction to the HCU.

[0016] Further, according to the received "motor degraded drag allowed" instruction, the HCU sends an "engine drag starting" instruction to the motor using the preset drag speed and drag maintenance time, and the engine completes starting based on the trial injection mode or the trial ignition mode.

[0017] The second aspect of the application provides an engine starting control device, comprising an ECU (electronic control unit) and an HCU (hybrid vehicle controller);

[0018] The ECU is used to obtain a speed signal and fault information during engine starting, and when there is a crankshaft camshaft phase fault, the engine enters a degraded starting mode, and the degraded starting mode is a trial injection mode or a trial ignition mode.

[0019] When there is CAN communication fault information, the ECU starting protection mode is triggered, and in the ECU starting protection mode, the ECU calculates the speed rising trend according to the obtained engine speed signal, when the speed rising trend is greater than a preset threshold, the ECU reports a fault of "not allowed to drag start", the engine stops injection or stops ignition, and exits the degraded starting mode; if the speed rising trend is not greater than the preset threshold, the engine continues to perform trial injection or trial ignition.

[0020] When there is no CAN communication fault information, the ECU sends a command of "allowing the motor to be degraded to drag" to the HCU, the HCU sends a command of "engine drag start" to the motor by using a preset drag rotation speed and a drag maintenance time, and the engine completes starting based on a test injection mode or a test ignition mode.

[0021] A third aspect of the present application provides an engine, which is a hybrid engine and is installed with the engine start control device.

[0022] A fourth aspect of the present application provides a motor vehicle, which is installed with the engine.

[0023] Compared with the prior art, the above one or more technical solutions have the following beneficial effects:

[0024] When the hybrid engine has a crankshaft camshaft phase fault and the fault information of the crankshaft camshaft cannot be transmitted to the HCU, since it cannot be determined whether the rising trend of the rotation speed is caused by the motor dragging the engine or by the fuel combustion work in the engine, the start protection mode is triggered, and the engine starting is completed by the collaborative control of the HCU and the ECU; in the test injection or test ignition mode, the rising trend of the rotation speed is quite different from that in the motor drag mode, so after the start protection mode is triggered, whether the motor is dragging the engine at this moment is determined according to the rising trend of the rotation speed, if yes, the test injection or test ignition is stopped, and a fault information of "not allowing drag starting" is reported, thereby avoiding the safety hazard caused by the inaccuracy of the rising trend of the rotation speed reflecting the test injection or test ignition, and reducing or even avoiding the risk of cylinder pulling and top melting. When the fault information of the crankshaft camshaft can be transmitted to the HCU, the motor is controlled to drag the engine to complete starting according to the preset starting rotation speed. BRIEF DESCRIPTION OF DRAWINGS

[0025] The accompanying drawings, which form a part of the present application, are used to provide further understanding of the present application, and the illustrative embodiments of the present application and their description serve the purpose of explaining the present application, and do not constitute improper limitations on the present application.

[0026] Figure 1 is a hybrid vehicle engine start control schematic diagram provided by one or more embodiments of the present application. DETAILED DESCRIPTION

[0027] The present application will be further described below in conjunction with the drawings and embodiments.

[0028] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present application belongs.

[0029] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, elements, components, and / or groups thereof, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0030] Terminology:

[0031] ECU, Electronic Control Unit, is the comprehensive control device of the engine, which is responsible for receiving and analyzing information from various sensors of the engine, and issuing instructions to control the related actuators after precise operation through the built-in program, so as to ensure that the engine can maintain the best operating state under various working conditions.

[0032] HCU, Hybrid Control Unit, is responsible for managing the entire powertrain. HCU can sense the driver's operation intention, the vehicle's running state, and the working state of key components such as engine, transmission, motor, battery, etc. in real time, and accurately allocate the torque distribution of engine and motor, control the on-off of high-voltage circuit, and decide the start and stop of engine, activation of various accessories, etc.

[0033] Trial injection mode: This mode refers to the form of trial injection to a certain cylinder when the phase fault of the engine crankshaft and camshaft cannot be synchronized, and whether the corresponding cylinder after injection meets the preset conditions by detecting the trend of engine speed change to determine whether the cylinder is injected correctly. If not, it will be turned over 360 degrees and the symmetric cylinder will be trial injected to determine the phase.

[0034] If the hybrid vehicle is equipped with a spark-ignition engine instead of a compression-ignition engine, it is in the form of trial ignition. Trial ignition and trial injection are the same in principle, except that the process of spark plug ignition is added.

[0035] Crankshaft camshaft phase fault refers to the phase relationship between the crankshaft and the camshaft, which has errors in signal synchronization or physical position, for example, the relative position between the crankshaft and the camshaft deviates, which may be caused by loosening, wear or improper installation of the timing belt or chain. When this deviation exceeds a certain range, it will trigger the engine fault code.

[0036] CAN communication failure refers to a problem in data communication between an engine control unit (ECU) and other related controllers or sensors through a CAN bus, which causes the ECU to fail to send information to other related controllers or sensors or the ECU to fail to receive information sent by other related controllers or sensors, thereby causing the ECU to fail to identify some potential problems.

[0037] As introduced in the background, when a traditional vehicle starts, the starter motor drags the engine to a certain speed, the engine phase synchronizes, and then the engine does work by combustion, so that the speed rises to a certain value, and then the engine is disconnected from the starter motor, and the engine completes the starting process.

[0038] In a hybrid vehicle, there is no special starter motor, but the motor originally responsible for power output drags the engine to start and run at low speed.

[0039] When the engine crankshaft and camshaft of the hybrid vehicle cannot be synchronized due to a phase fault, the engine enters a trial injection mode. The trial injection mode determines whether the trial injection phase is accurate by judging the rising trend of the engine speed. However, since the engine of the hybrid vehicle is directly dragged by the motor according to the set speed, it is not possible to determine whether the rising trend of the speed is caused by the motor dragging the engine or by the fuel combustion in the engine, which causes the rising trend of the speed to not truly reflect the accuracy of the trial injection. If the injection and work continue in this mode, the engine will be abnormal, and in severe cases, the engine will be severely damaged.

[0040] Therefore, the following embodiments provide an engine starting control method, device, engine, and motor vehicle, which cooperates with the engine ECU and the hybrid HCU to achieve safe starting in the crankshaft camshaft phase fault mode.

[0041] Embodiment one:

[0042] An engine starting control method, comprising the following steps:

[0043] Obtaining a speed signal and fault information during engine starting;

[0044] When there is a crankshaft camshaft phase fault, a degraded starting mode is entered, and the degraded starting mode is a trial injection mode or a trial ignition mode;

[0045] When there is a CAN communication fault information, a starting protection mode is triggered. In the starting protection mode, the rising trend of the speed is calculated according to the obtained engine speed signal. When the rising trend of the speed is greater than a preset threshold, the injection or ignition is stopped, and the degraded starting mode is exited. If the rising trend of the speed is not greater than the preset threshold, the trial injection or trial ignition is continued;

[0046] When there is no CAN communication fault information, the motor drags the engine to a set safe speed according to a preset starting speed, and then the starting is completed through a degraded starting mode.

[0047] In this embodiment, as shown in FIG. 1, the ECU obtains the real-time speed signal of the engine, the fault information related to the phase of the crankshaft and the camshaft, and the fault information related to CAN communication during the T15 power-on and the dragging process. Figure 1

[0048] When there is a phase fault of the crankshaft and the camshaft, the engine enters a degraded starting mode, and the degraded starting mode in this embodiment is a trial injection mode.

[0049] It is judged whether the ECU has a fault affecting CAN communication at this time.

[0050] If there is a fault in CAN communication, the ECU cannot send the fault information of the crankshaft and the camshaft to the HCU at this time, in order to prevent the engine from being dragged by the motor at this time, causing the engine to be cylinder-pulled or top-melted, it is necessary to judge whether there is a motor dragging condition at this time according to the speed acceleration, if there is, stop injection, and report a fault of not allowing dragging starting; specifically:

[0051] If there is a fault in CAN communication, the ECU starting protection mode is triggered, and the ECU starting protection mode calculates the speed rising trend according to the obtained engine speed signal, and the speed acceleration is selected in this embodiment to reflect the speed rising trend; when the speed rising trend is greater than a preset threshold, the ECU reports a fault of “not allowing dragging starting”, stops injection and exits the trial injection mode; if it is not greater than the preset threshold, the trial injection mode is continued.

[0052] If there is no fault related to CAN communication, the ECU sends an instruction allowing the HCU to degrade the dragging, at this time the motor acts as a starter role, the HCU drags the engine to a certain safe speed based on a preset starting speed, and the engine enters a trial injection mode to perform degraded starting by itself. Specifically:

[0053] If there is no fault related to CAN communication, the ECU sends an instruction allowing the HCU to degrade the dragging, the HCU sends an instruction of “engine reverse dragging starting” to the motor based on the degraded dragging state, the preset dragging speed and the dragging maintenance time, and the engine completes the starting based on the trial injection mode.

[0054] In the above process, through the cooperation of the ECU and the HCU of the engine, when the hybrid engine has a phase fault of the crankshaft and the camshaft, and the HCU can reliably receive the fault information of the crankshaft and the camshaft, the motor drags the engine to complete the starting according to a preset starting speed.

[0055] ​Since there is a big difference between the rising trend of the rotation speed in the normal test injection mode and the rising trend of the rotation speed in the motor drag mode, when the HCU cannot receive the fault information of the crankshaft camshaft, the ECU triggers the starting protection mode, and according to the rising trend of the rotation speed, it is judged whether the motor drags the engine at this time, if so, it stops, exits the test injection mode, and reports the fault information that the drag starting is not allowed, to avoid the safety hazard caused by the fact that the rising trend of the rotation speed cannot truly reflect the accuracy of the test injection, and to reduce or even avoid the risk of cylinder pulling and top melting.

[0056] Embodiment Two

[0057] The embodiment provides an engine starting control device, which comprises an ECU (Electronic Control Unit) and an HCU (Hybrid Vehicle Controller);

[0058] The ECU is used for acquiring a rotation speed signal and fault information during engine starting; when there is a crankshaft camshaft phase fault, the engine enters a degraded starting mode, and the degraded starting mode is a test injection mode or a test ignition mode;

[0059] When there is CAN communication fault information, the ECU triggers the starting protection mode, and in the ECU starting protection mode, the ECU calculates the rising trend of the rotation speed according to the acquired engine rotation speed signal, when the rising trend of the rotation speed is greater than a preset threshold, the ECU reports the fault that the drag starting is not allowed, the engine stops injection or stops ignition, and exits the degraded starting mode; if the rising trend of the rotation speed is not greater than the preset threshold, the engine continues to perform the test injection or the test ignition;

[0060] When there is no CAN communication fault information, the ECU sends a "motor degraded drag allowed" instruction to the HCU, the HCU sends an "engine drag starting" instruction to the motor by using a preset drag rotation speed and a drag maintenance time, and the engine completes starting based on the test injection mode or the test ignition mode.

[0061] When the hybrid engine has a crankshaft camshaft phase fault, and the fault information of the crankshaft camshaft cannot be transmitted to the HCU, since it cannot be determined whether the rising trend of the rotation speed is caused by the motor dragging the engine or by the fuel combustion work in the engine, the starting protection mode is triggered, in which mode, according to the rising trend of the rotation speed, it is judged whether the motor drags the engine at this time, if so, the test injection or the test ignition is stopped, and the fault information that the drag starting is not allowed is reported, to avoid the safety hazard caused by the fact that the rising trend of the rotation speed cannot reflect the accuracy of the test injection or the test ignition, and to reduce or even avoid the risk of cylinder pulling and top melting. When the fault information of the crankshaft camshaft can be transmitted to the HCU, the motor drags the engine to complete starting according to the preset starting rotation speed.

[0062] Embodiment Three

[0063] The present embodiment provides a hybrid engine to which the above-described start control device is installed.

[0064] Embodiment Four

[0065] The present embodiment provides a motor vehicle having a hybrid engine to which the above-described start control device is installed.

[0066] The above only a preferred embodiment of the present application, and is not intended to limit the present application, for those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application, should be included in the protection scope of the present application.

Claims

1. A hybrid engine start control method characterized by comprising: The method comprises the following steps: acquiring a rotation speed signal and fault information during engine starting; when there is a crankshaft camshaft phase fault, entering a degraded starting mode, which is a trial injection mode or a trial ignition mode; when there is CAN communication fault information, calculating a rotation speed rising trend according to the acquired engine rotation speed signal, stopping injection or stopping ignition when the rotation speed rising trend is greater than a preset threshold, and exiting the degraded starting mode; if the rotation speed rising trend is not greater than the preset threshold, continuing to perform trial injection or trial ignition; when there is no CAN communication fault information, controlling the motor to drag the engine to a set safe rotation speed according to a preset starting rotation speed and maintaining the set rotation speed for a set time, and completing engine starting through the degraded starting mode.

2. The hybrid engine start control method according to claim 1, characterized by, when there is CAN communication fault information, judging whether there is a motor dragging engine condition according to the rotation speed rising trend, stopping injection or stopping ignition if there is, and exiting the degraded starting mode.

3. The hybrid engine start control method of claim 1, wherein The rotation speed acceleration calculated by using the rotation speed signal reflects the rotation speed rising trend.

4. The hybrid engine start control method of claim 1, wherein when there is CAN communication fault information, triggering an ECU starting protection mode.

5. The hybrid engine start control method of claim 1, wherein In the ECU starting protection mode, calculating a rotation speed rising trend according to the acquired engine rotation speed signal, and reporting a "not allowed to drag start" fault, stopping injection or stopping ignition, and exiting the degraded starting mode when the rotation speed rising trend is greater than a preset threshold.

6. The hybrid engine start control method of claim 1, wherein when there is no CAN communication fault information, the ECU sends a "motor degraded dragging allowed" instruction to a hybrid vehicle controller HCU.

7. The hybrid engine start control method according to claim 6, characterized by, The HCU sends an "engine dragging start" instruction to the motor according to the received "motor degraded dragging allowed" instruction, and the engine completes starting based on the trial injection mode or the trial ignition mode.

8. A hybrid engine start control device that implements the hybrid engine start control method according to any one of claims 1 to 7, characterized by The method comprises an ECU and a hybrid vehicle controller HCU. The ECU is used to acquire a rotation speed signal and fault information during engine starting, and when there is a crankshaft camshaft phase fault, the engine enters a degraded starting mode, which is a trial injection mode or a trial ignition mode. when there is CAN communication fault information, triggering an ECU starting protection mode, in which the ECU calculates a rotation speed rising trend according to the acquired engine rotation speed signal, reports a "not allowed to drag start" fault when the rotation speed rising trend is greater than a preset threshold, stops injection or stops ignition, and exits the degraded starting mode; if the rotation speed rising trend is not greater than the preset threshold, the engine continues to perform trial injection or trial ignition. when there is no CAN communication fault information, the ECU sends a "motor degraded dragging allowed" instruction to the HCU, the HCU sends an "engine dragging start" instruction to the motor according to a preset dragging rotation speed and a dragging maintenance time, and the engine completes starting based on the trial injection mode or the trial ignition mode.

9. A hybrid engine characterized by, The hybrid engine starting control device has the ECU.

10. Motor vehicle, characterised in that The hybrid engine has the ECU.

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