Vehicle gear shifting method and device

Abstract

The present invention discloses a vehicle shifting method and device. The method comprises: when the current vehicle enters the gear shifting start mode, selecting a target start strategy; using the target start strategy to start the current vehicle, and obtaining the high-voltage motor state, actual operating gear and target gear of the current vehicle; determining the target shift type based on the high-voltage motor state, actual operating gear and target gear of the current vehicle; using the target shift type to control the current vehicle to start the engine during the gear shifting process. The present invention solves the technical problem in the related art that when the vehicle shifts gears, the gear shifting and the engine start cannot be coordinated and controlled, resulting in low vehicle driving smoothness and poor safety.

Description

Technical Field

[0001] The present invention relates to the field of automobile control technology, and in particular to a vehicle gear shifting method and device. Background Art

[0002] Hybrid vehicles have always been a hot topic for research by various automobile manufacturers due to their low energy consumption, especially in recent years. Hybrid vehicles also have the ability to drive purely on electric power. During pure electric driving, the engine needs to be started when the high-voltage battery capacity is insufficient or the driver's torque demand increases. However, due to the large transient changes during the engine startup process, poor control can cause the vehicle to experience impact during driving. For hybrid vehicles with multiple gears, the gear shifting process of the transmission is also a condition where vehicle smoothness is prone to problems. When the engine is started at the same time during the gear shifting process, the influencing factors of the two are superimposed. To meet the smoothness of the entire vehicle, there are huge challenges in the coordinated control of the two.

[0003] In the related technology, the content about the coordinated control of gear shifting and engine starting is to avoid the simultaneous execution of the two by some methods. By judging the state of the gear shift clutch, it is determined whether the gear shift process or the engine starting process is to be carried out first. If the gear shift starts first, the gear shift is completed before the engine is started. If the engine is started (that is, the generator is started) first, the engine is completed before the gear shift. Another implementation method is to reduce the frequency of clutch disengagement and engagement by maintaining the clutch state, so as to solve the problems of poor clutch service life and comfort; however, the disadvantages of these methods are that if the gear is shifted after the engine is started, the gear shift is delayed, the engine speed becomes higher during the gear shift, and in severe cases, it may exceed the speed limit, affecting the vehicle's smoothness / comfort / safety; if the engine is started after the gear shift is completed, the engine start time becomes late, and the engine cannot provide power in time, affecting the power and smoothness of the vehicle.

[0004] To address the above-mentioned problems, no effective solution has been proposed yet. Summary of the invention

[0005] The embodiment of the present invention provides a vehicle shifting method and device to at least solve the technical problem in the related art that when the vehicle shifts gears, the gear shifting and the engine start-up cannot be coordinated and controlled, resulting in low vehicle driving smoothness and poor safety.

[0006] According to one aspect of an embodiment of the present invention, a vehicle shifting method is provided, comprising: selecting a target starting strategy when a current vehicle enters a start mode during a gear shift; using the target starting strategy to start the current vehicle, and obtaining a high-voltage motor state, an actual operating gear, and a target gear of the current vehicle; determining a target gear shifting type based on the high-voltage motor state, the actual operating gear, and the target gear of the current vehicle; and using the target gear shifting type to control the current vehicle to start the engine during the gear shifting process.

[0007] Optionally, before the current vehicle enters the gear shift start mode, it also includes: obtaining the engine start / stop conditions of the current vehicle; judging whether to start the engine based on the engine start / stop conditions; judging whether the actual operating gear position of the transmission and the target gear position are consistent when the engine start / stop conditions determine that the engine is to be started; and determining to enter the gear shift start mode when the actual operating gear position of the transmission and the target gear position are inconsistent.

[0008] Optionally, the step of starting the current vehicle using the target starting strategy includes: using a low-voltage starter to drag the engine to rotate, and when the engine speed meets the injection and ignition conditions, the engine starts to inject fuel and ignite, and controls the engine speed to rush to the idle speed and maintain the idle operation state; controls the engine speed to the target speed, and at the same time controls the separation clutch to start filling with oil; after the engine speed reaches the target speed, controls the separation clutch to start engaging, so that the engine speed and the high-voltage motor speed are synchronized.

[0009] Optionally, based on the high-voltage motor state, actual operating gear and target gear of the current vehicle, the step of determining the target gear shift type includes: when the high-voltage motor state indicates that the torque of the high-voltage motor is greater than a first torque threshold and the target gear is greater than the actual operating gear, determining the target gear shift type as a power upshift starter; when the high-voltage motor state indicates that the torque of the high-voltage motor is greater than the first torque threshold and the target gear is less than the actual operating gear, determining the target gear shift type as a power downshift starter; when the high-voltage motor state indicates that the torque of the high-voltage motor is less than the first torque threshold and the target gear is greater than the actual operating gear, determining the target gear shift type as a coasting upshift starter; when the high-voltage motor state indicates that the torque of the high-voltage motor is less than the first torque threshold and the target gear is greater than the actual operating gear, determining the target gear shift type as a coasting downshift starter.

[0010] Optionally, in the case where the target shift type is a power upshift start or a coasting downshift start, the target shift type is used to control the steps of starting the engine of the current vehicle during the shifting process, including: controlling the oil filling of the shift clutch in the target gear; controlling the torque transfer of the transmission to switch from the shift clutch of the actual operating gear to the shift clutch of the target gear; controlling the motor speed, or controlling the speed of the motor and engine combination, from the transmission input shaft speed corresponding to the actual operating gear to the transmission input shaft speed corresponding to the target gear; when the transmission input shaft speed corresponding to the target gear is reached, determining that the current vehicle completes the power upshift shift operation or the coasting downshift shift operation; and controlling the engine to start smoothly during the process of the current vehicle completing the power upshift shift operation or the coasting downshift shift operation.

[0011] Optionally, during the process of the current vehicle completing the power upshift shift operation, the step of controlling the engine to start smoothly includes: upon receiving an engine start request, starting to control the low-voltage starter to start the engine to complete the first stage of engine starting, wherein, during the process of controlling the low-voltage starter to start the engine, the motor speed is controlled to reach the target speed with the closed-loop feedback torque of the motor; controlling the low-voltage starter to complete the first stage of engine starting to the third stage of separation clutch engagement; controlling the low-voltage starter to complete the fourth stage of power source torque switching from the third stage of separation clutch engagement, wherein the separation clutch in the third stage is engaged. After the third stage of separation clutch engagement is completed, the transmission input shaft speed corresponding to the actual operating gear is obtained plus the second speed deviation, the transmission input shaft speed corresponding to the target gear is obtained plus the second speed deviation, the transmission input shaft speed corresponding to the actual operating gear and the transmission input shaft speed corresponding to the target gear are obtained according to a preset transition curve plus the second speed deviation; the current vehicle is controlled to complete the fourth stage of power source torque switching, and the target speed of the motor is restored to a normal state, so that the engine can start smoothly, wherein, in the process of restoring to the normal state, the transmission input shaft speed corresponding to the target gear is controlled to be added with the first speed deviation.

[0012] Optionally, the steps of controlling the low-voltage starter from the completion of the first stage of engine starting to the engagement of the separation clutch in the third stage include: after controlling the low-voltage starter to complete the first stage of starting the engine, controlling the low-voltage starter to start the engine to enter the second stage of engine synchronization, and the target speed of the engine is equal to the motor speed plus a preset speed deviation; when the low-voltage starter starts the engine to enter the third stage of separation clutch engagement, controlling the target speed of the engine to reach the motor target speed in the process of motor speed control, and connecting the engine to the power transmission system as a power input source.

[0013] Optionally, the step of controlling the low-voltage starter to complete the power source torque switching from the third stage of separation clutch engagement to the fourth stage includes: after controlling the low-voltage starter to start the engine and the third stage of separation clutch engagement, controlling the engine torque to increase at a maximum rate to the driving request torque; determining a closed-loop feedback torque based on the driving request torque and the motor target speed during the speed control process of the shifting clutch, and controlling the motor speed to reach the motor target speed during the speed control process of the shifting clutch in combination with the closed-loop feedback torque.

[0014] Optionally, in the case where the target shift type is a power downshift to start or a coasting upshift to start, the target shift type is used to control the steps of starting the engine of the current vehicle during the shifting process, including: controlling the motor speed or the speed of the combination of the motor and the engine, from the transmission input shaft speed corresponding to the actual operating gear to the transmission input shaft speed corresponding to the target gear, and at the same time, controlling the oil filling of the target gear shift clutch; controlling the torque transfer of the transmission to switch from the actual operating gear shift clutch to the target gear clutch, so that the current vehicle completes the power downshift shift operation or the coasting upshift shift operation, and then controlling the engine to start smoothly.

[0015] According to another aspect of an embodiment of the present invention, a vehicle shifting device is also provided, including: a selection unit, used to select a target start-up strategy when a current vehicle enters a start-up mode during a gear shift; a processing unit, used to adopt the target start-up strategy to start the current vehicle, and obtain the high-voltage motor state, actual operating gear and target gear of the current vehicle; a first determination unit, used to determine a target gear shifting type based on the high-voltage motor state, actual operating gear and target gear of the current vehicle; and a control unit, used to adopt the target gear shifting type to control the current vehicle to start the engine during the gear shifting process.

[0016] Optionally, the vehicle's gear shifting device also includes: an acquisition unit for acquiring the engine start / stop condition of the current vehicle before the current vehicle enters the gear shifting start mode; a first judgment unit for judging whether to start the engine based on the engine start / stop condition; a second judgment unit for judging whether the actual operating gear position of the transmission and the target gear position are consistent when the engine start / stop condition determines that the engine is to be started; and a second determination unit for determining to enter the gear shifting start mode when the actual operating gear position of the transmission and the target gear position are inconsistent.

[0017] Optionally, the processing unit includes: a first processing sub-unit, used to use a low-voltage starter to drag the engine to rotate, when the engine speed meets the injection and ignition conditions, the engine starts to inject fuel and ignite, and controls the engine speed to rush to the idle speed to maintain the idle operation state; a first control sub-unit, used to control the engine speed to the target speed, and at the same time control the separation clutch to start filling with oil; a second control sub-unit, used to control the separation clutch to start engaging after the engine speed reaches the target speed, so as to synchronize the engine speed with the high-voltage motor speed.

[0018] Optionally, the first determination unit includes: a first determination subunit, used to determine that the target gear shift type is a power upshift start when the high-voltage motor state indicates that the torque of the high-voltage motor is greater than a first torque threshold and the target gear is greater than the actual operating gear; a second determination subunit, used to determine that the target gear shift type is a power downshift start when the high-voltage motor state indicates that the torque of the high-voltage motor is greater than the first torque threshold and the target gear is less than the actual operating gear; a third determination subunit, used to determine that the target gear shift type is a coasting upshift start when the high-voltage motor state indicates that the torque of the high-voltage motor is less than the first torque threshold and the target gear is greater than the actual operating gear; a fourth determination subunit, used to determine that the target gear shift type is a coasting downshift start when the high-voltage motor state indicates that the torque of the high-voltage motor is less than the first torque threshold and the target gear is less than the actual operating gear.

[0019] Optionally, the control unit also includes: a third control subunit, used to control the oil filling of the shift clutch under the target gear when the target shift type is a power upshift start or a coasting downshift start; a fourth control subunit, controlling the torque transmission of the transmission to switch from the shift clutch of the actual operating gear to the shift clutch of the target gear; a fifth control subunit, used to control the motor speed, or the speed of the motor and engine combination, from the transmission input shaft speed corresponding to the actual operating gear to the transmission input shaft speed corresponding to the target gear; a fifth determination subunit, used to determine that the current vehicle has completed a power upshift shift operation or a coasting downshift shift operation when the transmission input shaft speed corresponding to the target gear is reached; a sixth control subunit, used to control the engine to start smoothly during the process of the current vehicle completing a power upshift shift operation or a coasting downshift shift operation.

[0020] Optionally, the sixth control subunit further includes: a first control module, which is used to control the low-voltage starter to start the engine and complete the first stage of engine starting when receiving the engine start request, wherein, in the process of controlling the low-voltage starter to start the engine, the motor speed is controlled to reach the target speed with the closed-loop feedback torque of the motor; a second control module, which is used to control the low-voltage starter, from the completion of the first stage of engine starting to the engagement of the separation clutch in the third stage; a third control module, which is used to control the low-voltage starter, from the completion of the third stage of separation clutch engagement to the fourth stage of power source torque switching, wherein, in the third stage of separation clutch engagement completion After the separation clutch in the third stage is engaged, the transmission input shaft speed corresponding to the actual operating gear plus the second speed deviation is obtained, the transmission input shaft speed corresponding to the target gear plus the second speed deviation is obtained, and the transmission input shaft speed corresponding to the actual operating gear and the transmission input shaft speed corresponding to the target gear are obtained according to the preset transition curve plus the second speed deviation; the fourth control module is used to control the current vehicle to complete the power source torque switching of the fourth stage and restore the target speed of the motor to a normal state so that the engine can start smoothly, wherein, in the process of restoring to the normal state, the transmission input shaft speed corresponding to the target gear is controlled to be added with the first speed deviation.

[0021] Optionally, the second control module includes: a first processing submodule, used to control the low-voltage starter to start the engine and enter the second stage engine synchronization stage after controlling the low-voltage starter to complete the first stage of starting the engine, and the target speed of the engine is equal to the motor speed plus a preset speed deviation; a second processing submodule, used to control the target speed of the engine to reach the motor target speed in the motor speed control process when the low-voltage starter starts the engine and enters the third stage of separation clutch engagement, and connect the engine to the power transmission system as a power input source.

[0022] Optionally, the third control module includes: a first control submodule, used to control the engine torque to increase at a maximum rate to the driving request torque after the separation clutch of the third stage of controlling the low-voltage starter to start the engine is engaged; a determination submodule, used to determine the closed-loop feedback torque based on the driving request torque and the motor target speed during the speed control process of the shift clutch, and control the motor speed to reach the motor target speed during the speed control process of the shift clutch in combination with the closed-loop feedback torque.

[0023] Optionally, the control unit also includes: a seventh control subunit, which is used to control the motor speed or the speed of the combination of the motor and the engine, from the transmission input shaft speed corresponding to the actual operating gear to the transmission input shaft speed corresponding to the target gear, and at the same time, control the oil filling of the shift clutch of the target gear when the target shift type is power downshift start or coast upshift start, and an eighth control subunit, which is used to control the torque transfer of the transmission from the shift clutch of the actual operating gear to the target gear clutch, so as to enable the current vehicle to complete the power downshift shift operation or the coast upshift shift operation, and then control the engine to start smoothly.

[0024] In the present invention, when the current vehicle enters the start-up mode during gear shifting, the target start-up strategy is first selected, and then the target start-up strategy is adopted to start the current vehicle, and the high-voltage motor state, actual operating gear and target gear of the current vehicle are obtained. Then, based on the high-voltage motor state, actual operating gear and target gear of the current vehicle, the target gear shift type is determined, and finally, the target gear shift type is adopted to control the current vehicle to start the engine during the gear shifting process. In the present application, the start-up strategy is first selected, and then the gear shift type is determined according to the vehicle state and the target gear requirement, and the engine start is controlled according to the gear shift type, so as to achieve the purpose of coordinated control of gear shifting and engine start, thereby achieving the technical effect of improving the smoothness, comfort and safety of the vehicle during the gear shifting process, and thus solving the technical problem in the related art that when the vehicle shifts gears, the gear shifting and engine start cannot be coordinated and controlled, resulting in low smoothness and poor safety of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0026] Figure 1 is a flow chart of an optional vehicle shifting method according to an embodiment of the present invention;

[0027] Figure 2 is a flow chart of an optional method for controlling the start of the engine during gear shifting according to an embodiment of the present invention;

[0028] Figure 3 is a structural diagram of an optional P2-configuration hybrid vehicle shifting system according to an embodiment of the present invention;

[0029] Figure 4 is a flowchart of a starting process of an optional low-voltage starter starting method according to an embodiment of the present invention;

[0030] Figure 5is a flow chart of an optional power upshift shifting process according to an embodiment of the present invention;

[0031] Figure 6 is a flow chart of a control process of starting an engine with a low-voltage starter according to an embodiment of the present invention;

[0032] Figure 7 is a schematic diagram of the change of speed and torque during an optional power upshift starter control process according to an embodiment of the present invention;

[0033] Figure 8 is a schematic diagram of an optional power downshift and coasting upshift process according to an embodiment of the present invention;

[0034] Fig. 9 is a schematic diagram of an optional coasting downshift shifting process according to an embodiment of the present invention;

[0035] Fig.10 is a schematic diagram of an optional vehicle shifting device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0036] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0037] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0038] The present invention can be applied to various automatic driving systems, software and products, especially electric vehicles or hybrid vehicles mainly based on new energy vehicles. For example, a hybrid vehicle with a P2 configuration can realize a method of starting the engine during the gear shifting process of a hybrid vehicle, so that the engine start and the gear shifting are coordinated and controlled, so that the engine provides power in time according to the gear shifting requirements, thereby ensuring the smoothness / comfort / safety of the hybrid vehicle.

[0039] New energy vehicles consist of three parts: electric drive system, power supply system and auxiliary system. The electric drive system includes electronic controller, power converter, electric motor, mechanical transmission device and wheels; the power supply system includes power supply, energy management system and charger; the auxiliary system includes auxiliary power source, power steering system, navigation system, air conditioner, lighting and defrost device, wiper and radio, etc.

[0040] The present invention proposes a method for controlling the engine start during the gear shifting process of a vehicle. When a request to start the engine occurs during the gear shifting process, a suitable start mode is first selected. Secondly, the engine speed, motor speed, and transmission input shaft speed are used as control targets. Different control strategies are formulated according to different gear shifting types to achieve coordinated control of the engine start during the gear shifting process. The method is conducive to improving the smoothness of the whole vehicle when the engine is started during the gear shifting process, thereby improving the power comfort and safety performance of the whole vehicle, improving customer satisfaction with the whole vehicle product, and is conducive to improving the market competitiveness of the product.

[0041] The present invention is described in detail below in conjunction with various embodiments.

[0042] Embodiment 1

[0043] According to an embodiment of the present invention, a method embodiment of shifting gears of a vehicle is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0044] Figure 1 is a flow chart of an optional vehicle shifting method according to an embodiment of the present invention, such as Figure 1 As shown, the method comprises the following steps:

[0045] Step S101, when the current vehicle enters the mid-shift start mode, selecting a target start strategy;

[0046] Step S102, starting the current vehicle using a target startup strategy, and obtaining the high-voltage motor state, actual operating gear, and target gear of the current vehicle;

[0047] Step S103, determining a target gear shift type based on the current state of the high-voltage motor of the vehicle, the actual operating gear position and the target gear position;

[0048] Step S104, adopting the target gear shift type to control the current vehicle to start the engine during the gear shift process.

[0049] Through the above steps, when the current vehicle enters the gear shifting start mode, the target start strategy is first selected, and then the target start strategy is adopted to start the current vehicle, and the high-voltage motor state, actual operating gear and target gear of the current vehicle are obtained. Then, based on the high-voltage motor state, actual operating gear and target gear of the current vehicle, the target shift type is determined, and finally the target shift type is adopted to control the current vehicle to start the engine during the gear shifting process. In this embodiment, the start strategy is first selected, and then the gear shift type is determined according to the vehicle state and the target gear requirement, and the engine start is controlled according to the gear shift type, so as to achieve the purpose of coordinated control of gear shifting and engine start, thereby achieving the technical effect of improving the smoothness, comfort and safety of the vehicle during the gear shifting process, and thus solving the technical problem that when the vehicle shifts gears, the gear shifting and the engine start cannot be coordinated and controlled, resulting in low smoothness and poor safety of the vehicle in the related technology.

[0050] The embodiments of the present invention are described in detail below in combination with the above-mentioned implementation steps.

[0051] As an optional implementation of this embodiment, before the current vehicle enters the gear shift start mode, it also includes: obtaining the engine start and stop conditions of the current vehicle; based on the engine start and stop conditions, determining whether to start the engine; when the engine start and stop conditions determine that the engine is to be started, determining whether the actual operating gear position of the transmission is consistent with the target gear position; when the actual operating gear position of the transmission is inconsistent with the target gear position, determining to enter the gear shift start mode.

[0052] When the vehicle enters the gear shift start mode, the engine needs to be started when the high-voltage battery capacity is insufficient or the driver's required torque becomes larger during vehicle driving. That is, when the target gear selected by the driver is different from the actual gear, or when the driving vehicle is a pure electric vehicle or a hybrid vehicle and the battery capacity is insufficient, the engine can be started and the engine start and stop conditions of the current vehicle can be obtained. When the engine start and stop conditions determine that the engine needs to be started, it can be determined whether the actual operating gear of the transmission is consistent with the target gear. When the actual operating gear of the transmission is inconsistent with the target gear, it is determined to enter the gear shift start mode.

[0053] Step S101, when the current vehicle enters the mid-shift start mode, a target start strategy is selected.

[0054] Taking a P2 hybrid vehicle (a hybrid vehicle with the motor placed behind the clutch and before the gearbox) as an example, the starting strategy can include two starting methods, one is starting with a low-voltage starter and the other is starting with a high-voltage motor. For starting during the gear shifting process, in order to avoid the rapid changes in torque and speed during the engine drag and ignition process, which may lead to a deterioration in the vehicle's smoothness during the gear shifting process, a low-voltage starter can be used to start the engine. Since the separation clutch is in a disengaged state during the engine drag and ignition process, the transient impact during the engine starting process will not be transmitted to the wheel end, thereby ensuring the smoothness of the vehicle.

[0055] Step S102, starting the current vehicle using a target startup strategy, and obtaining the high-voltage motor state, actual operating gear, and target gear of the current vehicle.

[0056] Optionally, the steps of starting the current vehicle using a target starting strategy include: using a low-voltage starter to drag the engine to rotate, and when the engine speed meets the injection and ignition conditions, the engine starts to inject fuel and ignite, and controls the engine speed to rush to the idle speed and maintains the idle operation state; controls the engine speed to the target speed, and at the same time controls the separation clutch to start filling with oil; after the engine speed reaches the target speed, controls the separation clutch to start engaging, so that the engine speed and the speed of the high-voltage motor are synchronized.

[0057] During the process of starting the engine with a low-voltage starter, the control process can be divided into the following four processes:

[0058] a) Engine starting process: The low-voltage starter drives the engine to rotate. When the engine speed meets the fuel injection and ignition conditions, the engine starts to inject fuel and ignite, and the speed rises to the idle speed and maintains the idle running state;

[0059] b) Speed ​​synchronization process: The engine autonomously adjusts its speed to the target speed set based on the high-voltage motor speed, and at the same time the separation clutch begins to fill with oil to prepare for the next stage of the clutch engagement process.

[0060] c) Disengagement clutch engagement process: After the engine speed reaches the target speed, the separation clutch engages at a certain rate, ultimately achieving synchronization between the engine speed and the high-voltage motor speed.

[0061] d) Power source torque switching process: the process of switching power output from motor torque to engine torque.

[0062] Step S103, determining a target gear shift type based on the current state of the high-voltage motor of the vehicle, the actual operating gear position and the target gear position.

[0063] Optionally, based on the current vehicle's high-voltage motor state, actual operating gear and target gear, the step of determining the target gear shift type includes: when the high-voltage motor state indicates that the torque of the high-voltage motor is greater than a first torque threshold, and the target gear is greater than the actual operating gear, determining the target gear shift type as a power upshift start; when the high-voltage motor state indicates that the torque of the high-voltage motor is greater than the first torque threshold, and the target gear is less than the actual operating gear, determining the target gear shift type as a power downshift start; when the high-voltage motor state indicates that the torque of the high-voltage motor is less than the first torque threshold, and the target gear is greater than the actual operating gear, determining the target gear shift type as a coasting upshift start; when the high-voltage motor state indicates that the torque of the high-voltage motor is less than the first torque threshold, and the target gear is greater than the actual operating gear, determining the target gear shift type as a coasting downshift start.

[0064] The type of gear shift start control to be entered can be determined based on the state of the high-voltage motor, the actual gear position, and the target gear position. Specifically, when the torque of the high-voltage motor is greater than the first torque threshold and the target gear position is greater than the actual gear position, the power upshift start control is selected; when the torque of the high-voltage motor is greater than the first torque threshold and the target gear position is less than the actual gear position, the power downshift start control is selected; when the torque of the high-voltage motor is less than the first torque threshold and the target gear position is greater than the actual gear position, the coasting upshift start control is selected; when the torque of the high-voltage motor is less than the first torque threshold and the target gear position is less than the actual gear position, the coasting downshift start control is selected.

[0065] Optionally, when the target gear shift type is a power upshift start or a coast downshift start, the target gear shift type is adopted to control the steps of starting the engine of the current vehicle during the gear shift process, including: controlling the oil filling of the gear shift clutch in the target gear; controlling the torque transfer of the transmission to switch from the gear shift clutch of the actual operating gear to the gear shift clutch of the target gear; controlling the motor speed, or controlling the speed of the motor and engine combination, from the transmission input shaft speed corresponding to the actual operating gear to the transmission input shaft speed corresponding to the target gear; when the transmission input shaft speed corresponding to the target gear is reached, determining that the current vehicle completes the power upshift shift operation or the coast downshift shift operation; while the current vehicle completes the power upshift shift operation or the coast downshift shift operation, controlling the engine to start smoothly.

[0066] During the power upshift shift process, it can be divided into three steps: a) filling the shift clutch with oil: filling the shift clutch of the target gear with oil to prepare for the next stage of clutch torque switching; b) shift clutch torque switching: the torque transmission of the transmission is switched from the shift clutch of the actual gear to the clutch of the target gear to achieve the switching of the speed ratio; c) power source speed regulation: the motor speed (the separation clutch is in the separation state) or the speed of the motor and engine combination (the separation clutch is in the engagement state) changes from the transmission input shaft speed corresponding to the actual gear to the transmission input shaft speed corresponding to the target gear. When the transmission input shaft speed corresponding to the target gear is reached, it is determined that the current vehicle has completed the power upshift shift operation. During the process of the current vehicle completing the power upshift shift operation, the engine can be controlled to start smoothly, that is, the engine start control process during the power upshift shift process.

[0067] In the process of coasting downshift, the coasting downshift process is also divided into three steps: a) filling the shift clutch: filling the shift clutch of the target gear with oil to prepare for the next stage of clutch torque switching; b) shift clutch torque switching: the torque transmission of the transmission is switched from the shift clutch of the actual gear to the clutch of the target gear to achieve the switching of the speed ratio; c) power source speed regulation: the motor speed (the separation clutch is in the separation state) or the speed of the motor and engine combination (the separation clutch is in the engagement state) changes from the transmission input shaft speed corresponding to the actual gear to the transmission input shaft speed corresponding to the target gear. When the transmission input shaft speed corresponding to the target gear is reached, it is determined that the current vehicle has completed the coasting downshift operation. During the process of the current vehicle completing the coasting downshift operation, the engine can be controlled to start smoothly, that is, the engine start control process during the coasting downshift operation.

[0068] The function of the recovery process: After the start-up process is completed, the shift clutch slip speed is restored from the second speed deviation to the first speed deviation, and normal driving and shifting control are performed.

[0069] The engine start control process during the coasting downshift shifting process is the same as the engine start process during the coasting upshift shifting process described above, and the control content of each process is also the same.

[0070] The following is a detailed description of the steps for controlling the engine to start smoothly during the process of the current vehicle completing a power upshift shift operation.

[0071] An optional step of controlling the engine to start smoothly during the process of the current vehicle completing a power upshift shift operation includes: upon receiving an engine start request, starting to control the low-voltage starter to start the engine to complete the first stage of engine starting, wherein, during the process of controlling the low-voltage starter to start the engine, the motor speed is controlled to reach the target speed with the closed-loop feedback torque of the motor; controlling the low-voltage starter to complete the first stage of engine starting to the third stage of separation clutch engagement; controlling the low-voltage starter to complete the fourth stage of power source torque switching from the third stage of separation clutch engagement, wherein the separation clutch in the third stage is engaged. After the third stage of separation clutch engagement is completed, the transmission input shaft speed corresponding to the actual operating gear is obtained plus the second speed deviation, the transmission input shaft speed corresponding to the target gear is obtained plus the second speed deviation, the transmission input shaft speed corresponding to the actual operating gear and the transmission input shaft speed corresponding to the target gear are obtained according to a preset transition curve plus the second speed deviation; the current vehicle is controlled to complete the fourth stage of power source torque switching, and the target speed of the motor is restored to a normal state, so that the engine can start smoothly, wherein, in the process of restoring to the normal state, the transmission input shaft speed corresponding to the target gear is controlled to be added with the first speed deviation.

[0072] The smooth engine starting process during the power upshift shifting process can be the four stages of the starting process of the low-voltage starter starting method, namely the first stage engine starting process, the second stage speed synchronization process, the third stage separation clutch engagement, and the fourth stage power source torque switching.

[0073] Specifically, it refers to the four control processes of starting the engine with a low-voltage starter according to the above starting mode selection, and realizing smooth power output of the whole vehicle through specific control of the shift clutch, high-voltage motor speed, and engine speed. Figure 6 FIG. 1 is a flow chart of a control process of starting an engine with a low-voltage starter according to an embodiment of the present invention. Figure 6 As shown, the power upshift gear change and start-up control process can be specifically divided into four control stages, which can be a pre-control process, a motor speed control process, a shift clutch speed control process, and a recovery process. Figure 7 is a schematic diagram of the speed and torque changes in an optional power upshift starter control process according to an embodiment of the present invention, combined with Figure 7 Effect of speed and torque changes during power upshift start control Figure 6 The four control stages in the process of starting the low-voltage starter and the four stages of the low-voltage starter are used to explain the steps of controlling the engine to start smoothly during the process of the current vehicle completing the power upshift shift operation:

[0074] a) Pre-control process: from receiving the engine start request to the low-voltage starter starting the engine, the first stage of engine start is completed, and the actions of each component are as follows: Engine: The low-voltage starter drags the engine to rotate. When the engine speed meets the injection ignition conditions, the engine starts to inject fuel and ignite, and after the speed rises to above the idle speed, it maintains the idle running state; Motor: Output torque according to the driving request torque; Shift clutch: Control the motor speed to reach the pre-control process motor target speed by using the motor torque as the feedforward torque and the closed-loop feedback torque of the difference between the motor speed and the pre-control process motor target speed, where the pre-control process motor target speed can specifically refer to the transmission input shaft speed corresponding to the actual gear plus the first speed deviation. The role of the above pre-control process: The engine is started by the low-voltage starter. Since the separation clutch is in a disengaged state, the factors affecting the engine starting process will not be transmitted to the 9-wheel end. Therefore, the shift clutch still maintains the control of the original shift process.

[0075] b) Motor speed control process: from the completion of the first stage of engine starting by the low-voltage starter to the completion of the engagement of the separation clutch in the third stage, the actions of each component are as follows: Engine: The engine performs autonomous speed control to make the engine speed reach the engine target speed of the motor speed control process; Motor: The motor speed is controlled to reach the motor target speed of the motor speed control process by using the driving request torque as the feedforward torque and the closed-loop feedback torque of the difference between the motor speed and the motor target speed of the motor speed control process; Shift clutch: Open-loop control is input based on the driving request torque as the clutch engagement torque.

[0076] c) Speed ​​control process of the gearshift clutch: from the completion of the engagement of the separation clutch in the third stage of starting the engine with the low-voltage starter to the completion of the torque switching of the fourth power source, the actions of the various components are as follows: Engine: The engine torque increases to the driving request torque at the maximum achievable rate; Motor: The motor torque is equal to the driving request torque minus the engine torque; The gearshift clutch: The motor speed is controlled to reach the motor target speed in the process of speed control by using the driving request torque as the feedforward torque and the closed-loop feedback torque of the difference between the motor speed and the motor target speed in the process of speed control by the gearshift clutch.

[0077] d) Recovery process: from the completion of the fourth power source torque switching to the recovery of the motor target speed to a normal state, wherein the motor target speed in the recovery process specifically refers to the target transmission input shaft speed in the speed regulation stage corresponding to the target gear plus the first speed deviation.

[0078] The function of the recovery process: After the start-up process is completed, the shift clutch slip speed is restored from the second speed deviation to the first speed deviation, and normal driving and shifting control are performed.

[0079] Optionally, the steps of controlling the low-voltage starter from the completion of the first stage of engine starting to the engagement of the separation clutch in the third stage include: after controlling the low-voltage starter to complete the first stage of starting the engine, controlling the low-voltage starter to start the engine to enter the second stage of engine synchronization, and the target speed of the engine is equal to the motor speed plus a preset speed deviation; when the low-voltage starter starts the engine to enter the third stage of separation clutch engagement, controlling the target speed of the engine to reach the motor target speed during the motor speed control process, and connecting the engine to the power transmission system as a power input source.

[0080] The target engine speed during the motor speed control process specifically refers to the engine speed synchronization stage in the second stage of starting the engine with a low-pressure starter, during which the target engine speed during the motor speed control process is equal to the motor speed plus the third speed deviation; during the separation clutch engagement stage in the third stage of starting the engine with a low-pressure starter, the target engine speed during the motor speed control process is equal to the motor target speed during the above-mentioned motor speed control process.

[0081] Optionally, the step of controlling the low-voltage starter to complete the power source torque switching from the third stage of separation clutch engagement to the fourth stage includes: after the third stage of separation clutch engagement is completed, controlling the engine torque to increase at a maximum rate to the driving request torque; determining the closed-loop feedback torque based on the driving request torque and the motor target speed during the speed control process of the shift clutch, and controlling the motor speed to reach the motor target speed during the speed control process of the shift clutch in combination with the closed-loop feedback torque, wherein the step of calculating the motor target speed during the speed control process of the shift clutch includes: obtaining the transmission input shaft speed corresponding to the actual operating gear plus the second speed deviation; obtaining the transmission input shaft speed corresponding to the target gear plus the second speed deviation; obtaining the transmission input shaft speed corresponding to the actual operating gear and the transmission input shaft speed corresponding to the target gear, and adding the second speed deviation according to a preset transition curve.

[0082] The above process is explained in conjunction with the various components of the driving car. From the completion of the engagement of the separation clutch in the third stage of starting the engine with a low-voltage starter to the completion of the torque switching of the fourth power source, the actions of the various components are as follows: Engine: The engine torque increases to the driving request torque at the maximum achievable rate; Motor: The motor torque is equal to the driving request torque minus the engine torque; Shift clutch: By using the driving request torque as the feedforward torque and the closed-loop feedback torque of the difference between the motor speed and the motor target speed in the process of shift clutch control speed, combined with the closed-loop feedback torque, the motor speed is controlled to reach the motor target speed in the process of shift clutch control speed, that is, by using the driving request torque as the feedforward torque and the closed-loop feedback torque of the difference between the motor speed and the motor target speed in the process of motor control speed, the motor speed is controlled to reach the motor target speed in the process of motor control speed.

[0083] The target speed of the motor during the speed control process of the gear shifting clutch may specifically refer to the addition of a second speed deviation to the transmission input shaft speed corresponding to the actual gear before the start of the power source speed regulation process of the third stage of the power upshift; the addition of a second speed deviation to the transmission input shaft speed corresponding to the target gear after the power source speed regulation process of the third stage of the power upshift is completed; and the addition of a second speed deviation to the transmission input shaft speed corresponding to the actual gear and the transmission input shaft speed corresponding to the target gear according to a preset transition curve during the power source speed regulation process of the third stage of the power upshift.

[0084] The role of the shift clutch speed control process: After the separation clutch is engaged, the power source torque is switched. Due to the different torque response characteristics of the engine and the motor, there may be an uneven output torque during the power source torque switching process. By maintaining a large speed difference between the input shaft of the power source and the transmission speed and using the driving demand torque as the feedforward torque of the shift clutch, the vehicle's smoothness can be ensured. Since the separation clutch has been engaged, the power source's rotational inertia has been re-determined, and the motor speed can be controlled by the shift clutch to reach the target speed, preparing for the shift process to return to normal.

[0085] Optionally, when the target gear shift type is a power downshift to start or a coast upshift to start, the target gear shift type is adopted to control the steps of starting the engine of the current vehicle during the gear shift process, including: controlling the motor speed or the speed of the combination of the motor and the engine, from the transmission input shaft speed corresponding to the actual operating gear to the transmission input shaft speed corresponding to the target gear, and at the same time, controlling the oil filling of the target gear shift clutch; controlling the torque transfer of the transmission to switch from the actual operating gear shift clutch to the target gear clutch, so that the current vehicle completes the power downshift shift operation or the coast upshift shift operation, and then controlling the engine to start smoothly.

[0086] The power downshift shift process is divided into two steps: a) power source speed regulation: the motor speed (the separation clutch is in the disengaged state) or the motor and engine combination speed (the separation clutch is in the engaged state) changes from the transmission input shaft speed corresponding to the actual gear to the transmission input shaft speed corresponding to the target gear; at the same time, the target gear shift clutch is filled with oil to prepare for the next stage of clutch torque switching; b) shift clutch torque switching: the transmission torque transmission is switched from the actual gear shift clutch to the target gear clutch to achieve the speed ratio switching. The engine start control process during the power downshift shift process is the same as the engine start process during the power upshift shift process, and the control content of each process is also the same.

[0087] In the process of coasting upshifting, the coasting upshifting process is divided into two steps: a) power source speed regulation: the motor speed (the separation clutch is in the disengaged state) or the motor and engine combination speed (the separation clutch is in the engaged state) changes from the transmission input shaft speed corresponding to the actual gear to the transmission input shaft speed corresponding to the target gear; at the same time, the shift clutch of the target gear is filled with oil to prepare for the next stage of clutch torque switching; b)

[0088] Shift clutch torque switching: The torque transmission of the transmission is switched from the shift clutch of the actual gear to the target gear clutch to achieve the speed ratio switching.

[0089] The engine start control process during the coasting upshift. The engine start control process during the coasting upshift is the same as the engine start process during the above-mentioned power upshift, but there are differences in the calculation of the target speed in the control content. The differences are as follows: a) The difference in the pre-control process: During the engine start control process during the coasting upshift, the motor target speed of the pre-control process specifically refers to the transmission input shaft speed corresponding to the actual gear position minus the first speed deviation. b) The difference in the motor speed control process: During the engine start control process during the coasting upshift, the motor target speed of the motor control process specifically refers to the transmission input shaft speed corresponding to the actual gear position minus the second speed deviation.

[0090] The target engine speed during the motor speed control process specifically refers to the engine synchronization stage of the second stage of the low-voltage starter starting the engine, the target engine speed during the motor speed control process is equal to the motor speed minus the third speed deviation. During the separation clutch engagement stage of the third stage of the low-voltage starter starting the engine, the target engine speed during the motor speed control process is equal to the motor target speed during the above-mentioned motor pre-control process;

[0091] The role of the motor speed control process: The engine speed synchronization and clutch engagement process is to connect the engine as a power input source to the power transmission system. In order to avoid affecting the vehicle wheel end, the target speed control method of engine speed < motor speed < transmission input shaft speed is used to ensure the torque transmission direction, and the open-loop control method of the shift clutch torque only uses the driving request torque as input to ensure that the torque transmitted to the wheel end is smooth, thereby ensuring the smoothness of the vehicle.

[0092] Step S104, adopting the target gear shift type to control the current vehicle to start the engine during the gear shift process.

[0093] The engine start control method during the gear shifting process proposed in this embodiment is that when a request to start the engine appears during the gear shifting process, firstly, a suitable start mode is selected, and then, the engine speed, motor speed, and transmission input shaft speed are used as control targets. Different control strategies are formulated according to different gear shifting types to achieve coordinated control of the engine start during the gear shifting process. This is conducive to improving the smoothness of the whole vehicle when the engine is started during the gear shifting process, thereby improving the power comfort of the whole vehicle.

[0094] The present invention is described below in conjunction with another optional embodiment.

[0095] Embodiment 2

[0096] The embodiment of the present invention, in combination with a schematic hybrid vehicle architecture, illustrates another optional vehicle shifting method, which can start control during the shifting process, that is, start control of the engine during the shifting process. Figure 2 FIG. 1 is a flow chart of an optional method for controlling the start of the engine during a gear shift according to an embodiment of the present invention. Figure 2 As shown in the figure, the control process of starting the engine during gear shifting is as follows:

[0097] (1) Determination of the start-up condition during gear shifting: Whether to enter the start-up control mode during gear shifting can be determined based on the actual gear position, target gear position and start-up request;

[0098] (2) Start mode selection: After entering the mid-shift start control mode, select a specific start mode;

[0099] (3) After determining the starting mode, determine the gear shift type: determine which type of gear shift to enter in the starting control process according to the state of the high-voltage motor, the actual gear position, and the target gear position, wherein the gear shift type can be a power upshift, a power downshift, a coasting upshift, or a coasting downshift.

[0100] (4) According to the gear shift type, the start control process corresponding to the gear shift type is entered: the start control mode can be power upshift start control, power downshift start control, coasting upshift start control, coasting downshift start control, wherein,

[0101] Power upshift start control: it can be the engine start control process during the power upshift shift process;

[0102] Power downshift start control: it can be the engine start control process during the power downshift shift process;

[0103] Coasting upshift start control: it can be the engine start control process during the coasting upshift shifting process;

[0104] Coasting downshift start control: it can be the engine start control process during the coasting downshift shifting process.

[0105] This embodiment provides an engine start control method during vehicle gear shifting, which can be used in a hybrid vehicle with a P2 configuration, and can also be used in other types of hybrid vehicles or electric vehicles. Figure 3 is a structural diagram of an optional P2 configuration hybrid vehicle shifting system according to an embodiment of the present invention, such as Figure 3 As shown:

[0106] First, the meaning of the numbers and the structures corresponding to the numbers in the figure are explained:

[0107] In the figure: 1- low-voltage starter; 2- engine; 3- separation clutch; 4- high-voltage motor; 5- shift clutch; 6- transmission input shaft; 7- transmission; 8- transmission output shaft; 9- wheel.

[0108] The shift clutch refers to the clutch mechanism between the transmission and the power input source, not a specific clutch. For example, for a DCT transmission (Dual-clutch Transmission), the shift clutch represents the two clutches of the odd-numbered shaft and the even-numbered shaft; for an AT transmission (Automatic Transmission), the shift clutch represents the combination of the clutch and brake of the planetary gear mechanism to achieve different speed ratios and the torque converter and its locking clutch; for an AMT transmission (Automated Manual Transmission), the shift clutch represents a single clutch in the transmission; for a CVT transmission (Continuously Variable Transmission), the shift clutch represents the torque converter and its locking clutch.

[0109] The transmission input shaft refers to the transmission input shaft calculated based on the transmission output shaft speed and gear ratio, and does not represent a specific physical shaft. For example: the transmission target gear input shaft speed is equal to the transmission output shaft speed multiplied by the target gear ratio; the transmission actual gear input shaft speed is equal to the transmission output shaft speed multiplied by the actual gear ratio.

[0110] There are two main starting methods for P2 hybrid vehicles: one is to use a low-voltage starter, and the other is to use a high-voltage motor. For starting during the gear shift process, in order to avoid the rapid changes in torque and speed during the engine drag and ignition process, which will lead to a deterioration in the vehicle's smoothness during the gear shift process, a low-voltage starter is used to start the engine. Since the separation clutch is in a disengaged state during the engine drag and ignition process, the transient impact during the engine start process will not be transmitted to the wheel end, thereby ensuring the smoothness of the vehicle.

[0111] The following is a detailed description of each step of the engine start control process during gear shifting.

[0112] 1. Determine the engine starting condition during gear shifting.

[0113] During the judgment of the start-up process during gear shifting, it is determined whether to enter the start-up control mode during gear shifting based on the actual gear position, target gear position and start request. Specifically, when the vehicle control unit decides to start the engine based on the engine start-stop conditions, it determines whether the actual gear position of the transmission and the target gear position are consistent. If they are inconsistent, the start-up control mode during gear shifting is entered.

[0114] 2. Select the startup method.

[0115] In the starting mode selection, a specific starting mode is selected, which may specifically refer to a starting mode of using a low-voltage starter to start the engine. Figure 4 FIG. 1 is a flowchart of a starting process of an optional low-voltage starter starting method according to an embodiment of the present invention. The starting method of the low-voltage starter starting the engine has a control process divided into the following four processes, such as Figure 4 As shown:

[0116] 1) Engine starting process: The low-voltage starter drives the engine to rotate. When the engine speed meets the fuel injection and ignition conditions, the engine starts to inject fuel and ignite, and the speed rises to the idle speed and maintains the idle running state;

[0117] 2) Speed ​​synchronization process: The engine autonomously adjusts its speed to the target speed set based on the high-voltage motor speed. At the same time, the clutch begins to fill with oil to prepare for the next stage of the clutch engagement process.

[0118] 3) Disengagement clutch engagement process: After the engine speed reaches the target speed, the separation clutch engages at a certain rate, ultimately achieving synchronization between the engine speed and the high-voltage motor speed.

[0119] 4) Power source torque switching process: the process of switching the power output from motor torque to engine torque.

[0120] 3. Determine the gear shift type.

[0121] In determining the gear shift type, the type of gear shift start control to be entered is determined based on the state of the high-voltage motor, the actual gear position, and the target gear position. Specifically, when the torque of the high-voltage motor is greater than the first torque threshold and the target gear position is greater than the actual gear position, the power upshift start control is selected; when the torque of the high-voltage motor is greater than the first torque threshold and the target gear position is less than the actual gear position, the power downshift start control is selected; when the torque of the high-voltage motor is less than the first torque threshold and the target gear position is greater than the actual gear position, the coasting upshift start control is selected; when the torque of the high-voltage motor is less than the first torque threshold and the target gear position is greater than the actual gear position, the coasting downshift start control is selected.

[0122] 4. According to the gear shift type determined in the gear shift type determination, the start-up control process of the gear shift type is entered.

[0123] The following is a detailed description of the mid-shift start control for each shift type.

[0124] 4.1 Power shift up and start control.

[0125] 1) Power upshift shifting process. Figure 5 FIG. 1 is a flow chart of an optional power upshift shifting process according to an embodiment of the present invention. Figure 5 As shown in the figure, the power upshift shift process is divided into three steps:

[0126] a) Shift clutch oil filling: The shift clutch of the target gear is filled with oil to prepare for the next stage of clutch torque switching;

[0127] b) Shift clutch torque switching: The torque transmission of the transmission is switched from the shift clutch of the actual gear to the clutch of the target gear to achieve the speed ratio switching;

[0128] c) Power source speed regulation: The motor speed (the disconnect clutch is in the disconnected state) or the speed of the motor and engine combination (the disconnect clutch is in the engaged state) changes from the transmission input shaft speed corresponding to the actual gear to the transmission input shaft speed corresponding to the target gear.

[0129] 2) Engine start control process during power upshift: Specifically refers to the four control processes of starting the engine with a low-voltage starter according to the above starting mode selection, through the specific control of the shift clutch, high-voltage motor speed, and engine speed, to achieve smooth power output of the whole vehicle, Figure 6 FIG. 1 is a flow chart of a control process of starting an engine with a low-voltage starter according to an embodiment of the present invention. Figure 6 As shown, it can be specifically divided into four control stages, which can be a pre-control process, a motor speed control process, a gear shift clutch speed control process, and a recovery process. Figure 7 FIG. 1 is a schematic diagram of the speed and torque changes during an optional power upshift starter control process according to an embodiment of the present invention, such as Figure 7 As shown, the shift start control includes four stages (embodied in Figure 7 The top of the diagram): pre-control process, motor speed control process, shift clutch speed control process, recovery process; the start process includes: engine start, speed synchronization, separation clutch engagement and power source torque switching; Figure 7 The left side of the diagram shows the rotation speed (e.g. Figure 7 The first speed difference, the second speed difference and the third speed difference, the high-voltage motor speed and the engine speed at different stages as shown in FIG. 1 ), the change states of the two reference quantities of torque and the shift clutch; Figure 7 The bottom of the figure shows the shifting process, including: filling the shift clutch, torque exchange of the shift clutch, and speed adjustment of the power source; Figure 7 The far right side shows the shift reference quantities for different stages, including: actual gear transmission input shaft speed, target gear transmission input shaft speed, release clutch torque, engine torque, high-voltage motor torque, target gear shift clutch torque and actual gear shift clutch torque.

[0130] Combine the following Figure 7 Effect of speed and torque changes during power upshift start control Figure 6 The four control stages in are described as follows:

[0131] a) Pre-control process:

[0132] From the receipt of the engine start request to the completion of the first stage of engine starting by the low-voltage starter, the actions of each component are as follows:

[0133] Engine: The low-voltage starter drives the engine to rotate. When the engine speed meets the fuel injection and ignition conditions, the engine starts to inject fuel and ignite. After the speed rises to above the idle speed, it maintains the idle running state.

[0134] Motor: Outputs torque according to driving request torque;

[0135] Shift clutch: By using the motor torque as the feedforward torque and the closed-loop feedback torque of the difference between the motor speed and the motor target speed of the pre-control process, the motor speed is controlled to reach the motor target speed of the pre-control process, wherein the motor target speed of the pre-control process may specifically refer to the transmission input shaft speed corresponding to the actual gear position plus the first speed deviation.

[0136] The effect of the above pre-control process is as follows: the engine is started by a low-voltage starter. Since the separation clutch is in a disengaged state, the influencing factors of the engine starting process will not be transmitted to the wheel end. Therefore, the shift clutch still maintains the control of the original shift process.

[0137] b) Motor speed control process.

[0138] From the completion of the first stage of engine starting by the low-pressure starter to the completion of the separation clutch engagement in the third stage, the actions of the various components are as follows:

[0139] Engine: The engine performs autonomous speed control to make the engine speed reach the target speed of the engine during the motor speed control process;

[0140] Motor: The motor speed is controlled to reach the motor target speed during the motor speed control process by using the driving request torque as the feedforward torque and the closed-loop feedback torque as the difference between the motor speed and the motor target speed during the motor speed control process;

[0141] Shift clutch: open loop control based on driving request torque as clutch engagement torque input;

[0142] The target speed of the motor during the motor speed control process specifically refers to the transmission input shaft speed corresponding to the actual gear position plus the second speed deviation, and the value of the second speed deviation is greater than the first speed deviation.

[0143] The target engine speed during the motor speed control process refers specifically to the second stage of engine synchronization during the low-voltage starter starting the engine (corresponding to the Figure 7 Speed ​​synchronization in the process), the target speed of the engine during the motor speed control process is equal to the motor speed plus the third speed deviation; in the separation clutch engagement stage of the third stage of starting the engine with a low-pressure starter, the target speed of the engine during the motor speed control process is equal to the motor target speed during the above-mentioned motor speed control process.

[0144] The role of the motor speed control process: The engine speed synchronization and clutch engagement process is to connect the engine as a power input source to the power transmission system. In order to avoid affecting the vehicle wheel end, the target speed control method of engine speed> motor speed> transmission input shaft speed is used to ensure the torque transmission direction, and the open-loop control method of the shift clutch torque only uses the driving request torque as input to ensure that the torque transmitted to the wheel end is smooth, thereby ensuring the smoothness of the vehicle.

[0145] c) Shift clutch speed control process:

[0146] From the completion of the third stage of the separation clutch engagement when the low-voltage starter starts the engine to the completion of the fourth stage of the power source torque switching, the actions of each component are as follows:

[0147] Engine: Engine torque increases at the maximum achievable rate to the driver's requested torque;

[0148] Motor: Motor torque is equal to the driving request torque minus the engine torque;

[0149] Shifting clutch: The motor speed is controlled to reach the motor target speed during the shifting clutch speed control process by using the driving request torque as the feedforward torque and the closed-loop feedback torque as the difference between the motor speed and the motor target speed during the shifting clutch speed control process. Among them, the motor target speed during the shifting clutch speed control process specifically refers to the transmission input shaft speed corresponding to the actual gear plus the second speed deviation before the start of the power source speed regulation process in the third stage of power upshift; after the power source speed regulation process in the third stage of power upshift is completed, the transmission input shaft speed corresponding to the target gear plus the second speed deviation; during the power source speed regulation process in the third stage of power upshift; the transmission input shaft speed corresponding to the actual gear and the transmission input shaft speed corresponding to the target gear are taken according to the preset transition curve and then added with the second speed deviation.

[0150] The role of the shift clutch speed control process: After the separation clutch is engaged, the power source torque is switched. Due to the different torque response characteristics of the engine and the motor, there may be an uneven output torque during the power source torque switching process. By maintaining a large speed difference between the input shaft of the power source and the transmission speed and using the driving demand torque as the feedforward torque of the shift clutch, the vehicle's smoothness can be ensured. Since the separation clutch has been engaged, the power source's rotational inertia has been re-determined, and the motor speed can be controlled by the shift clutch to reach the target speed, preparing for the shift process to return to normal.

[0151] d) Recovery process: From the completion of the fourth stage power source torque switching to the recovery of the motor target speed to the normal state, the actions of each component are as follows:

[0152] Engine: The engine torque outputs torque according to the hybrid strategy request;

[0153] Motor: The motor torque outputs torque according to the hybrid strategy request;

[0154] Shift clutch: By using the driving request torque as the feedforward torque and the closed-loop feedback torque as the difference between the target speed of the motor in the recovery process, the motor speed is controlled to reach the target speed of the motor in the recovery process, wherein the target speed of the motor in the recovery process specifically refers to the target transmission input shaft speed in the speed regulation stage corresponding to the target gear plus the first speed deviation.

[0155] The function of the recovery process: After the start-up process is completed, the shift clutch slip speed is restored from the second speed deviation to the first speed deviation, and normal driving and shifting control are performed.

[0156] 4.2 Power downshift start control.

[0157] 1) Power downshift shifting process. Figure 8 is a schematic diagram of an optional power downshift and coasting upshift process according to an embodiment of the present invention, such as Figure 8 As shown in the figure, the power downshift shifting process is divided into two steps:

[0158] a) Speed ​​regulation of power source: the motor speed (the separation clutch is in the disengaged state) or the motor and engine combination speed (the separation clutch is in the engaged state) changes from the transmission input shaft speed corresponding to the actual gear to the transmission input shaft speed corresponding to the target gear; at the same time, the shift clutch of the target gear is filled with oil to prepare for the next stage of clutch torque switching;

[0159] b) Shift clutch torque switching: The torque transmission of the transmission is switched from the shift clutch of the actual gear to the target gear clutch to achieve the speed ratio switching.

[0160] 2) The engine start control process during the power downshift is the same as the engine start process during the power upshift, and the control content of each process is also the same, which will not be repeated here.

[0161] 4.3 Coasting upshift start control.

[0162] 1) The process of coasting upshift.

[0163] Figure 8 1 is a schematic diagram of an optional power downshift and coasting upshift process according to an embodiment of the present invention. In the coasting upshift start control, the coasting upshift process is divided into two steps, such as Figure 8 :

[0164] a) Speed ​​regulation of power source: the motor speed (the separation clutch is in the disengaged state) or the motor and engine combination speed (the separation clutch is in the engaged state) changes from the transmission input shaft speed corresponding to the actual gear to the transmission input shaft speed corresponding to the target gear; at the same time, the shift clutch of the target gear is filled with oil to prepare for the next stage of clutch torque switching;

[0165] b) Shift clutch torque switching: The torque transmission of the transmission is switched from the shift clutch of the actual gear to the target gear clutch to achieve the speed ratio switching.

[0166] 2) Engine start control process during coasting upshift.

[0167] The engine start control process during the coasting upshift is the same as the engine start process during the power upshift, but the calculation of the target speed in the control content is different. The differences are as follows:

[0168] a) Differences in pre-control process:

[0169] During the engine start control process during the coasting upshift, the motor target speed is pre-controlled, specifically referring to the transmission input shaft speed corresponding to the actual gear position minus the first speed deviation.

[0170] b) Differences in the motor speed control process:

[0171] During the engine start control process during the coasting upshift, the motor target speed during the motor speed control process specifically refers to the transmission input shaft speed corresponding to the actual gear position minus the second speed deviation.

[0172] The target engine speed during the motor speed control process specifically refers to the engine synchronization stage of the second stage of the low-voltage starter starting the engine, the target engine speed during the motor speed control process is equal to the motor speed minus the third speed deviation. During the separation clutch engagement stage of the third stage of the low-voltage starter starting the engine, the target engine speed during the motor speed control process is equal to the motor target speed during the above-mentioned motor pre-control process;

[0173] The role of the motor speed control process: The engine speed synchronization and clutch engagement process is to connect the engine as a power input source to the power transmission system. In order to avoid affecting the vehicle wheel end, the target speed control method of engine speed < motor speed < transmission input shaft speed is used to ensure the torque transmission direction, and the open-loop control method of the shift clutch torque only uses the driving request torque as input to ensure that the torque transmitted to the wheel end is smooth, thereby ensuring the smoothness of the vehicle.

[0174] c) Differences in the speed control process of the shift clutch:

[0175] During the engine start-up control process during the coasting upshift shifting process, the shift clutch controls the speed process and the motor target speed, specifically refers to before the start of the third stage power source speed regulation process of the power upshift, the transmission input shaft speed corresponding to the actual gear minus the second speed deviation; after the third stage power source speed regulation process of the power upshift is completed, the transmission input shaft speed corresponding to the target gear minus the second speed deviation; in the third stage power source speed regulation process of the power upshift; take the transmission input shaft speed corresponding to the actual gear and the transmission input shaft speed corresponding to the target gear according to the preset transition curve minus the second speed deviation.

[0176] d) Differences in the recovery process:

[0177] During the engine start control process during the coasting upshift, the motor target speed is restored, specifically referring to the transmission input shaft speed corresponding to the target gear position minus the first speed deviation.

[0178] 4.3 Coasting downshift start control.

[0179] 1) Coasting downshift process. Fig. 9 is a schematic diagram of an optional coasting downshift shifting process according to an embodiment of the present invention. In the coasting downshift start control, the coasting downshift shifting process is divided into three steps, such as Fig. 9 As shown:

[0180] a) Shift clutch oil filling: The shift clutch of the target gear is filled with oil to prepare for the next stage of clutch torque switching;

[0181] b) Shift clutch torque switching: The torque transmission of the transmission is switched from the shift clutch of the actual gear to the clutch of the target gear to achieve the speed ratio switching;

[0182] c) Power source speed regulation: The motor speed (the disconnect clutch is in the disconnected state) or the speed of the motor and engine combination (the disconnect clutch is in the engaged state) changes from the transmission input shaft speed corresponding to the actual gear to the transmission input shaft speed corresponding to the target gear.

[0183] The engine start control process during the coasting downshift shifting process is the same as the engine start process during the coasting upshift shifting process mentioned above, and the control content of each process is also the same, which will not be repeated here.

[0184] The present embodiment proposes a method for controlling the engine start during the gear shifting process of a vehicle. When a request to start the engine occurs during the gear shifting process, firstly, a suitable start mode is selected, and secondly, different control strategies are formulated according to different gear shifting types with the engine speed, motor speed, and transmission input shaft speed as control targets to achieve coordinated control of the engine start during the gear shifting process. This is beneficial to improving the smoothness of the entire vehicle when the engine is started during the gear shifting process, thereby improving the power comfort of the entire vehicle.

[0185] The present invention is described below in conjunction with another optional embodiment.

[0186] Embodiment 3

[0187] This embodiment provides an optional vehicle shifting device, and each implementation unit included in the shifting device corresponds to each implementation step in the above embodiment.

[0188] It should be noted that the vehicle shifting device according to the embodiment of the present invention can be used to execute the vehicle shifting method according to the embodiment of the present invention. The vehicle shifting device according to the embodiment of the present invention is introduced below.

[0189] Fig.10 is a schematic diagram of an optional vehicle shifting device according to an embodiment of the present invention, such as Fig.10 As shown, it includes: a selection unit 111, a processing unit 112, a first determination unit 113, and a control unit 114, wherein:

[0190] A selection unit 111 is used to select a target start strategy when the current vehicle enters a start mode during gear shifting;

[0191] The processing unit 112 is used to start the current vehicle using a target startup strategy and obtain the high-voltage motor state, actual operating gear position and target gear position of the current vehicle;

[0192] A first determining unit 113, configured to determine a target gear shift type based on a current state of a high-voltage motor of the vehicle, an actual operating gear position, and a target gear position;

[0193] The control unit 114 is used to control the current vehicle to start the engine during the gear shifting process by adopting the target gear shifting type.

[0194] The gear shifting device of the above-mentioned vehicle can first select the target start-up strategy through the selection unit 111 when the current vehicle enters the gear shifting start-up mode, then use the target start-up strategy through the processing unit 112 to start the current vehicle, and obtain the high-voltage motor state, actual operating gear and target gear of the current vehicle, and then determine the target gear shift type based on the high-voltage motor state, actual operating gear and target gear of the current vehicle through the first determination unit 113, and finally use the target gear shift type through the control unit 114 to control the current vehicle to start the engine during the gear shifting process. In this embodiment, by first selecting the start-up strategy, and then determining the gear shift type according to the vehicle state and the target gear requirement, and controlling the engine start according to the gear shift type, the purpose of coordinated control of gear shifting and engine start is achieved, thereby achieving the technical effect of improving the smoothness, comfort and safety of the vehicle during the gear shifting process, thereby solving the technical problem that when the vehicle shifts, the gear shifting and the engine start cannot be coordinated and controlled, resulting in low smoothness and poor safety of the vehicle in the related art.

[0195] Optionally, the vehicle's gear shifting device also includes an acquisition unit for acquiring the engine start / stop conditions of the current vehicle before the current vehicle enters the gear shifting start mode; a first judgment unit for judging whether to start the engine based on the engine start / stop conditions; a second judgment unit for judging whether the actual operating gear position of the transmission and the target gear position are consistent when the engine start / stop conditions determine that the engine is to be started; and a second determination unit for determining to enter the gear shifting start mode when the actual operating gear position of the transmission and the target gear position are inconsistent.

[0196] Optionally, the processing unit includes: a first processing sub-unit, used to use a low-voltage starter to drag the engine to rotate, when the engine speed meets the injection and ignition conditions, the engine starts to inject fuel and ignite, and controls the engine speed to rush to the idle speed to maintain the idle operation state; a first control sub-unit, used to control the engine speed to the target speed, and at the same time control the separation clutch to start filling with oil; a second control sub-unit, used to control the separation clutch to start engaging after the engine speed reaches the target speed, so as to synchronize the engine speed with the speed of the high-voltage motor.

[0197] Optionally, the first determination unit includes: a first determination subunit, used to determine that the target gear shift type is a power upshift start when the high-voltage motor state indicates that the torque of the high-voltage motor is greater than a first torque threshold and the target gear is greater than the actual operating gear; a second determination subunit, used to determine that the target gear shift type is a power downshift start when the high-voltage motor state indicates that the torque of the high-voltage motor is greater than the first torque threshold and the target gear is less than the actual operating gear; a third determination subunit, used to determine that the target gear shift type is a coasting upshift start when the high-voltage motor state indicates that the torque of the high-voltage motor is less than the first torque threshold and the target gear is greater than the actual operating gear; a fourth determination subunit, used to determine that the target gear shift type is a coasting downshift start when the high-voltage motor state indicates that the torque of the high-voltage motor is less than the first torque threshold and the target gear is less than the actual operating gear.

[0198] Optionally, the control unit also includes: a third control subunit, used to control the oil filling of the shift clutch in the target gear when the target shift type is a power upshift start or a coasting downshift start; a fourth control subunit, used to control the torque transmission of the transmission to switch from the shift clutch of the actual operating gear to the shift clutch of the target gear; a fifth control subunit, used to control the motor speed, or the speed of the motor and engine combination, from the transmission input shaft speed corresponding to the actual operating gear to the transmission input shaft speed corresponding to the target gear; a fifth determination subunit, used to determine that the current vehicle has completed a power upshift shift operation or a coasting downshift shift operation when the transmission input shaft speed corresponding to the target gear is reached; a sixth control subunit, used to control the engine to start smoothly during the process of the current vehicle completing a power upshift shift operation or a coasting downshift shift operation.

[0199] Optionally, the sixth control subunit also includes: a first control module, which is used to control the low-voltage starter to start the engine and complete the first stage of engine starting when receiving the engine start request, wherein, in the process of controlling the low-voltage starter to start the engine, the motor speed is controlled to reach the target speed with the closed-loop feedback torque of the motor; a second control module, which is used to control the low-voltage starter, from the completion of the first stage of engine starting to the engagement of the separation clutch in the third stage; a third control module, which is used to control the low-voltage starter, from the completion of the third stage of separation clutch engagement to the fourth stage of power source torque switching, wherein, in the third stage, the separation clutch engagement is completed After the separation clutch in the third stage is engaged, the transmission input shaft speed corresponding to the actual operating gear plus the second speed deviation is obtained, the transmission input shaft speed corresponding to the target gear plus the second speed deviation is obtained, and the transmission input shaft speed corresponding to the actual operating gear and the transmission input shaft speed corresponding to the target gear are obtained according to the preset transition curve plus the second speed deviation; the fourth control module is used to control the current vehicle to complete the power source torque switching of the fourth stage and restore the target speed of the motor to a normal state so that the engine can start smoothly, wherein, in the process of restoring to the normal state, the transmission input shaft speed corresponding to the target gear is controlled to be added with the first speed deviation.

[0200] Optionally, the second control module includes: a first processing sub-module, used to control the low-voltage starter to start the engine and enter the second stage engine synchronization stage after controlling the low-voltage starter to complete the first stage of starting the engine, and the target speed of the engine is equal to the motor speed plus a preset speed deviation; a second processing sub-module, used to control the target speed of the engine to reach the motor target speed in the process of motor speed control when the low-voltage starter starts the engine and enters the third stage of separation clutch engagement, and connect the engine to the power transmission system as a power input source.

[0201] Optionally, the third control module includes: a first control submodule, used to control the engine torque to increase at a maximum rate to the driving request torque after the third stage of the separation clutch engagement is completed; a determination submodule, used to determine the closed-loop feedback torque based on the driving request torque and the motor target speed during the gear shift clutch speed control process, and control the motor speed to reach the motor target speed during the gear shift clutch speed control process in combination with the closed-loop feedback torque.

[0202] Optionally, the control unit also includes: a seventh control subunit, which is used to control the motor speed or the speed of the combination of the motor and the engine, from the transmission input shaft speed corresponding to the actual operating gear to the transmission input shaft speed corresponding to the target gear, and at the same time, control the oil filling of the shift clutch of the target gear when the target gear shift type is power downshift start or coast upshift start, and an eighth control subunit, which is used to control the torque transfer of the transmission from the shift clutch of the actual operating gear to the target gear clutch, so as to enable the current vehicle to complete the power downshift shift operation or the coast upshift shift operation, and then control the engine to start smoothly.

[0203] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0204] In the above embodiments of the present invention, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0205] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0206] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed over multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0207] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0208] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk and other media that can store program codes.

[0209] The above are only preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A vehicle shifting method, characterized in that: include: When the current vehicle enters the gear shift start mode, select the target start strategy; Starting the current vehicle using the target startup strategy, and obtaining a high-voltage motor state, an actual operating gear, and a target gear of the current vehicle; Determining a target gear shift type based on the current state of the high-voltage motor of the vehicle, the actual operating gear, and the target gear; Using the target gear shift type, controlling the current vehicle to start the engine during the gear shift process; In the case where the target shift type is a power upshift start or a coasting downshift start, the target shift type is adopted to control the steps of starting the engine of the current vehicle during the shift process, including: controlling the oil filling of the shift clutch at the target gear; controlling the torque transmission of the transmission to switch from the shift clutch of the actual operating gear to the shift clutch of the target gear; controlling the motor speed, or the speed of the motor and the engine combination, from the transmission input shaft speed corresponding to the actual operating gear to the transmission input shaft speed corresponding to the target gear; when the transmission input shaft speed corresponding to the target gear is reached, determining that the current vehicle completes the power upshift shift operation or the coasting downshift shift operation; in the process of the current vehicle completing the power upshift shift operation or the coasting downshift shift operation, controlling the engine to start smoothly; During the process of the current vehicle completing the power upshift shift operation, the step of controlling the engine to start smoothly includes: upon receiving an engine start request, controlling the low-voltage starter to start the engine to complete the first stage of engine starting, wherein, during the process of controlling the low-voltage starter to start the engine, the motor speed is controlled to reach the target speed with the closed-loop feedback torque of the motor; controlling the low-voltage starter to complete the first stage of engine starting to the third stage of separation clutch engagement; controlling the low-voltage starter to complete the fourth stage of power source torque switching from the third stage of separation clutch engagement, wherein, after the third stage of separation clutch engagement is completed, the transmission input shaft speed corresponding to the actual operating gear position is obtained plus the speed of the first stage of separation clutch engagement. Two speed deviations, obtain the transmission input shaft speed corresponding to the target gear plus the second speed deviation, obtain the transmission input shaft speed corresponding to the actual operating gear and the transmission input shaft speed corresponding to the target gear according to a preset transition curve plus the second speed deviation; control the current vehicle to complete the fourth stage of power source torque switching, and restore the target speed of the motor to a normal state, so that the engine can start smoothly, wherein, in the process of restoring to the normal state, the transmission input shaft speed corresponding to the target gear is controlled to be added with the first speed deviation, the second speed deviation and the first speed deviation refer to the difference between the high-voltage motor speed and the transmission input shaft speed corresponding to the actual operating gear, and the value of the second speed deviation is greater than the first speed deviation.

2. The shifting method according to claim 1, characterized in that: Before the current vehicle enters the gear shift start mode, it also includes: Acquiring an engine start / stop condition of the current vehicle; Based on the engine start / stop condition, determining whether to start the engine; When the engine start-stop condition determines that the engine is to be started, determining whether the actual operating gear position of the transmission is consistent with the target gear position; When the actual operating gear position of the transmission is inconsistent with the target gear position, it is determined to enter the mid-shift start mode.

3. The shifting method according to claim 1, characterized in that: The step of starting the current vehicle using the target startup strategy includes: A low-voltage starter is used to drive the engine to rotate. When the engine speed meets the fuel injection and ignition conditions, the engine starts fuel injection and ignition, and controls the engine speed to rush up to the idle speed to maintain the idle running state; Controlling the engine speed to a target speed and controlling the separation clutch to start oil filling; After the engine speed reaches the target speed, the separation clutch is controlled to start engaging so that the speed of the engine is synchronized with the speed of the high-voltage motor.

4. The shifting method according to claim 1, characterized in that: The step of determining a target gear shift type based on the current state of the high-voltage motor of the vehicle, the actual operating gear, and the target gear comprises: When the high-voltage motor state indicates that the torque of the high-voltage motor is greater than a first torque threshold, and the target gear position is greater than the actual operating gear position, determining the target gear shift type to be a power upshift start; When the high-voltage motor state indicates that the torque of the high-voltage motor is greater than a first torque threshold, and the target gear position is less than the actual operating gear position, determining the target gear shift type to be a power downshift start; When the high-voltage motor state indicates that the torque of the high-voltage motor is less than a first torque threshold, and the target gear position is greater than the actual operating gear position, determining the target gear shift type to be a coasting upshift start; When the high-voltage motor state indicates that the torque of the high-voltage motor is less than a first torque threshold, and the target gear is less than the actual operating gear, the target gear shift type is determined to be a coasting downshift start.

5. The shifting method according to claim 1, characterized in that: The steps of controlling the low-pressure starter from the first stage of engine starting to the third stage of separation clutch engagement include: After the low-voltage starter is controlled to complete the first stage of starting the engine, the low-voltage starter is controlled to start the engine to enter the second stage of engine synchronization, and the target speed of the engine is equal to the motor speed plus a preset speed deviation; When the low-voltage starter starts the engine and enters the third stage of the separation clutch engagement phase, the target speed of the engine is controlled to reach the motor target speed during the motor speed control process, and the engine is connected to the power transmission system as a power input source.

6. The shifting method according to claim 1, characterized in that: The steps of controlling the low-voltage starter, from the third stage of separation clutch engagement to the fourth stage of power source torque switching, include: After controlling the separation clutch of the low-pressure starter to start the engine in the third stage to engage, controlling the engine torque to increase to the driving request torque at a maximum rate; Based on the driving request torque and the motor target speed during the clutch shift speed control process, a closed-loop feedback torque is determined, and the motor speed is controlled to reach the motor target speed during the clutch shift speed control process in combination with the closed-loop feedback torque.

7. The shifting method according to claim 4, characterized in that: When the target shift type is power downshift start or coast upshift start, the step of using the target shift type to control the current vehicle to start the engine during the shift process includes: Controlling the speed of the motor or the combination of the motor and the engine from the speed of the transmission input shaft corresponding to the actual operating gear to the speed of the transmission input shaft corresponding to the target gear, and at the same time, controlling the oil filling of the shift clutch of the target gear; Control the torque transfer of the transmission to switch from the shift clutch of the actual operating gear to the target gear clutch, so that the current vehicle completes the power downshift shift operation or the coasting upshift shift operation, and then controls the engine to start smoothly.

8. A gear shifting device for a vehicle, characterized in that: include: A selection unit, used to select a target start strategy when the current vehicle enters a start mode during gear shifting; A processing unit, configured to start the current vehicle using the target startup strategy, and obtain a high-voltage motor state, an actual operating gear, and a target gear of the current vehicle; A first determining unit, configured to determine a target gear shift type based on a current state of a high-voltage motor of the vehicle, an actual operating gear position, and a target gear position; A control unit, configured to adopt the target gear shift type to control the current vehicle to start the engine during the gear shift process; The control unit further includes: a third control subunit, for controlling the oil filling of the shift clutch at the target gear position when the target shift type is a power upshift start or a coasting downshift start; a fourth control subunit, for controlling the torque transmission of the transmission to switch from the shift clutch of the actual operating gear position to the shift clutch of the target gear position; a fifth control subunit, for controlling the motor speed, or the speed of the motor and engine combination, from the transmission input shaft speed corresponding to the actual operating gear position to the transmission input shaft speed corresponding to the target gear position; a fifth determination subunit, for determining that the current vehicle completes the power upshift shift operation or the coasting downshift shift operation when the transmission input shaft speed corresponding to the target gear position is reached; a sixth control subunit, for controlling the engine to start smoothly during the process of the current vehicle completing the power upshift shift operation or the coasting downshift shift operation; The sixth control subunit also includes: a first control module, which is used to control the low-voltage starter to start the engine and complete the first stage of engine starting when receiving the engine start request, wherein, in the process of controlling the low-voltage starter to start the engine, the motor speed is controlled to reach the target speed with the closed-loop feedback torque of the motor; a second control module, which is used to control the low-voltage starter, from the completion of the first stage of engine starting to the engagement of the separation clutch in the third stage; a third control module, which is used to control the low-voltage starter, from the completion of the separation clutch engagement in the third stage to the power source torque switching in the fourth stage, wherein, after the separation clutch engagement in the third stage completes the separation clutch engagement in the third stage, the transmission input shaft speed corresponding to the actual operating gear is obtained plus the second Speed ​​deviation, obtain the transmission input shaft speed corresponding to the target gear plus the second speed deviation, obtain the transmission input shaft speed corresponding to the actual operating gear and the transmission input shaft speed corresponding to the target gear according to the preset transition curve plus the second speed deviation; the fourth control module is used to control the current vehicle to complete the fourth stage of power source torque switching, and restore the target speed of the motor to a normal state so that the engine can start smoothly, wherein, in the process of restoring to the normal state, the transmission input shaft speed corresponding to the target gear is controlled to be added with the first speed deviation, the second speed deviation and the first speed deviation refer to the difference between the high-voltage motor speed and the transmission input shaft speed corresponding to the actual operating gear, and the value of the second speed deviation is greater than the first speed deviation.

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