Vehicle mode switching method and system and vehicle

Abstract

The invention provides a vehicle mode switching method and system and a vehicle, and belongs to the technical field of vehicle control. According to the embodiment of the invention, under the condition that the vehicle meets the mode switching condition of switching from a power split mode to a direct drive mode, a clutch can be kept in a closed state, torque adjustment is conducted on an engine and a first motor, and therefore the mode switching speed is increased; therefore, when the first synchronizer meets the torque condition, the rotating speed of the first motor can be adjusted, and when the first synchronizer meets the rotating speed condition, the first synchronizer can be controlled to be switched to the combined gear from the power split gear, so that the vehicle is switched to the direct drive mode from the power split mode. According to the embodiment of the invention, the gear shifting operation of the first synchronizer can be smoothly completed on the premise that the clutch is not opened or closed, the mode switching time is shortened, meanwhile, the engine can quickly output torque, and the dynamic response performance of the vehicle in the mode switching process is improved.

Description

Technical Field

[0001] The present application relates to the technical field of vehicle control, and particularly to a vehicle mode switching method, system and vehicle. Background Art

[0002] With the rapid development of the automotive industry, traditional fuel vehicles are gradually moving towards hybrid vehicles. Hybrid vehicles usually have multiple driving modes including a direct drive mode and a power split mode to adapt to different road conditions and driving requirements. During the vehicle driving process, according to the changes in road conditions and driving requirements, the driving modes will switch to each other under certain conditions.

[0003] In the related art, during the process of the vehicle switching from the power split mode to the direct drive mode, usually the clutch needs to be opened first, and then the engine is subjected to torque reduction and speed regulation operations. After the torque reduction and speed regulation operations are completed, the clutch is re-closed to complete the mode switching. However, since this method has the process of opening and closing the clutch, there are problems such as a long mode switching time and untimely engine power response, which in turn affects the power response performance of the vehicle during the mode switching process. Summary of the Invention

[0004] The present application provides a vehicle mode switching method, device, system and vehicle to solve the problem of poor overall vehicle power response performance when a hybrid vehicle switches from the power split mode to the direct drive mode at present.

[0005] To solve the above problems, the present application adopts the following technical solutions:

[0006] In a first aspect, an embodiment of the present application provides a vehicle mode switching method. The vehicle includes an engine, a clutch, a first motor and a gearbox; the gearbox includes a power split mechanism, a first synchronizer and a gearbox input shaft. The engine is connected to a first input end of the power split mechanism through the clutch, the first motor is connected to a second input end of the power split mechanism, an output end of the power split mechanism is connected to the gearbox input shaft, and the first synchronizer is arranged between the first input end and the output end; the method includes:

[0007] When the vehicle meets the mode switching condition for switching from the power split mode to the direct drive mode, keep the clutch in a closed state, and perform torque adjustment on the engine and the first motor to make the first synchronizer meet the torque condition;

[0008] When the first synchronizer meets the torque condition, perform speed adjustment on the first motor to make the first synchronizer meet the speed condition;

[0009] When the first synchronizer meets the rotational speed condition, control the first synchronizer to switch from the power split gear to the engaged gear, so that the vehicle switches from the power split mode to the direct drive mode.

[0010] In an embodiment of the present application, the method further includes:

[0011] When the vehicle is in the power split mode, obtain the current remaining power of the power battery and determine whether the driver has a strong power demand;

[0012] When it is determined that the driver has the strong power demand and the current remaining power is greater than the power threshold, determine that the vehicle meets the mode switching condition for switching from the power split mode to the direct drive mode.

[0013] In an embodiment of the present application, the step of determining whether the driver has a strong power demand includes:

[0014] Obtain the current throttle opening and the current throttle opening change rate of the throttle pedal;

[0015] When the current throttle opening is greater than the opening threshold and the current throttle opening change rate is greater than the change rate threshold, determine that the driver has a strong power demand.

[0016] In an embodiment of the present application, the step of torque adjustment for the engine and the first motor includes:

[0017] Based on a preset torque adjustment gradient, control the current engine torque of the engine and the current motor torque of the first motor to follow a preset first target torque.

[0018] In an embodiment of the present application, the vehicle further includes a second motor, and the method further includes:

[0019] Based on the current engine torque and the current motor torque, determine the compensation torque of the second motor;

[0020] Based on the compensation torque and the current drive torque of the second motor, determine the target drive torque of the second motor;

[0021] During the process of torque adjustment for the engine and the first motor, based on the torque adjustment gradient, control the second motor to gradually increase from the current drive torque to the target drive torque.

[0022] In an embodiment of the present application, the method further includes:

[0023] When the first torque difference between the current engine torque and the first target torque is less than the first torque threshold, start timing for a first duration during which the first torque difference is less than the first torque threshold.

[0024] When the second torque difference between the current motor torque and the first target torque is less than the second torque threshold, start timing for a second duration during which the second torque difference is less than the second torque threshold.

[0025] When the first duration is greater than the first duration threshold and the second duration is greater than the second duration threshold, determine that the first synchronizer meets the torque condition.

[0026] In an embodiment of the present application, the power split mechanism includes a ring gear, a sun gear, a plurality of planet gears meshing between the ring gear and the sun gear, and a planet carrier rotatably connected to the plurality of planet gears; the planet carrier is connected to the engine as the first input end, the sun gear is connected to the first motor as the second input end, the ring gear is connected to the transmission input shaft as the output end, and the first synchronizer is disposed between the planet carrier and the ring gear;

[0027] The steps of adjusting the speed of the first motor include:

[0028] When the current gear position of the first synchronizer is the power split gear position, determine that the transmission ratio between the planet carrier and the ring gear is the first transmission ratio;

[0029] Based on the current engine speed of the engine and the first transmission ratio, determine the target ring gear speed of the ring gear;

[0030] Based on the target ring gear speed and the second transmission ratio between the ring gear and the sun gear, determine the target motor speed of the first motor;

[0031] Control the current motor speed of the first motor to follow the target motor speed.

[0032] In an embodiment of the present application, the method further includes:

[0033] Based on the current motor speed and the second transmission ratio, determine the current ring gear speed of the ring gear;

[0034] Based on the current engine torque, determine the current planet carrier speed of the planet carrier;

[0035] When the speed difference between the current ring gear speed and the current planet carrier speed is less than the speed difference threshold, determine that the first synchronizer meets the speed condition.

[0036] In an embodiment of the present application, when the first synchronizer meets the rotational speed condition, the step of controlling the first synchronizer to switch from the power split gear to the engaged gear includes:

[0037] When the first synchronizer meets the rotational speed condition, determine the sum of the first target torque and the preset shift-in assist torque as the second target torque;

[0038] Control the current motor torque of the first motor to follow the second target torque to assist the first synchronizer to switch from the power split gear to the engaged gear.

[0039] In a second aspect, based on the same inventive concept, an embodiment of the present application provides a vehicle mode switching device. The vehicle includes an engine, a clutch, a first motor, and a transmission; the transmission includes a power split mechanism, a first synchronizer, and a transmission input shaft. The engine is connected to a first input end of the power split mechanism through the clutch, the first motor is connected to a second input end of the power split mechanism, an output end of the power split mechanism is connected to the transmission input shaft, and the first synchronizer is arranged between the first input end and the output end; the device includes:

[0040] A torque adjustment module, configured to keep the clutch in a closed state and perform torque adjustment on the engine and the first motor when the vehicle meets the mode switching condition for switching from the power split mode to the direct drive mode, so that the first synchronizer meets the torque condition;

[0041] A rotational speed adjustment module, configured to perform rotational speed adjustment on the first motor when the first synchronizer meets the torque condition, so that the first synchronizer meets the rotational speed condition;

[0042] A gear shift module, configured to control the first synchronizer to switch from the power split gear to the engaged gear when the first synchronizer meets the rotational speed condition, so that the vehicle switches from the power split mode to the direct drive mode.

[0043] In an embodiment of the present application, the vehicle mode switching device further includes:

[0044] An information acquisition sub-module, configured to acquire the current remaining power of the power battery and determine whether the driver has a strong power demand when the vehicle is in the power split mode;

[0045] A condition determination sub-module, configured to determine that the vehicle meets the mode switching condition for switching from the power split mode to the direct drive mode when it is determined that the driver has the strong power demand and the current remaining power is greater than the power threshold.

[0046] In an embodiment of the present application, the information acquisition sub-module includes:

[0047] A pedal information acquisition unit, configured to acquire the current throttle opening and the current throttle opening change rate of the throttle pedal;

[0048] A power demand determination unit, configured to determine that the driver has a strong power demand when the current throttle opening is greater than the opening threshold and the current throttle opening change rate is greater than the change rate threshold.

[0049] In an embodiment of the present application, the torque adjustment module includes:

[0050] A torque adjustment sub-module, configured to control the current engine torque of the engine and the current motor torque of the first motor to follow a preset first target torque based on a preset torque adjustment gradient.

[0051] In an embodiment of the present application, the vehicle further includes a second motor, and the vehicle mode switching device further includes:

[0052] A compensation torque determination module, configured to determine the compensation torque of the second motor based on the current engine torque and the current motor torque;

[0053] A drive torque determination module, configured to determine the target drive torque of the second motor based on the compensation torque and the current drive torque of the second motor;

[0054] A drive torque control module, configured to control the second motor to gradually increase from the current drive torque to the target drive torque based on the torque adjustment gradient during the process of adjusting the torques of the engine and the first motor.

[0055] In an embodiment of the present application, the vehicle mode switching device further includes:

[0056] A first timing module, configured to trigger timing for a first duration during which the first torque difference between the current engine torque and the first target torque is less than the first torque threshold;

[0057] A second timing module, configured to trigger timing for a second duration during which the second torque difference between the current motor torque and the first target torque is less than the second torque threshold;

[0058] A first condition determination module, configured to determine that the second synchronizer meets the first gear shifting condition when the first duration is greater than a first duration threshold and the second duration is greater than a second duration threshold.

[0059] In an embodiment of the present application, the power split mechanism includes a ring gear, a sun gear, a plurality of planet gears meshing between the ring gear and the sun gear, and a planet carrier rotatably connected to the plurality of planet gears; the planet carrier is connected to the engine as the first input end, the sun gear is connected to the first motor as the second input end, the ring gear is connected to the transmission input shaft as the output end, and the first synchronizer is arranged between the planet carrier and the ring gear; the speed regulation module includes:

[0060] A gear ratio determination sub-module, configured to determine that the gear ratio between the planet carrier and the ring gear is a first gear ratio when the current gear of the first synchronizer is the power split gear;

[0061] A target ring gear speed determination sub-module, configured to determine the target ring gear speed of the ring gear based on the current engine speed of the engine and the first gear ratio;

[0062] A motor speed determination sub-module, configured to determine the target motor speed of the first motor based on the target ring gear speed and a second gear ratio between the ring gear and the sun gear;

[0063] A motor speed control sub-module, configured to control the current motor speed of the first motor to follow the target motor speed.

[0064] In an embodiment of the present application, the vehicle mode switching device further includes:

[0065] A current ring gear speed determination module, configured to determine the current ring gear speed of the ring gear based on the current motor speed and the second gear ratio;

[0066] A current planet carrier speed determination module, configured to determine the current planet carrier speed of the planet carrier based on the current engine torque;

[0067] A second condition determination module, configured to determine that the first synchronizer meets the speed condition when the speed difference between the current ring gear speed and the current planet carrier speed is less than a speed difference threshold.

[0068] In an embodiment of the present application, the gear shifting module includes:

[0069] A target torque determination sub-module, configured to determine, when the first synchronizer meets the rotational speed condition, the sum of the first target torque and a preset shift-in assistance torque as the second target torque;

[0070] A gear shift sub-module, configured to control the current motor torque of the first motor to follow the second target torque, so as to assist the first synchronizer to shift from the power split gear to the engaged gear.

[0071] In a third aspect, based on the same inventive concept, an embodiment of the present application provides a vehicle mode switching system. The vehicle includes an engine, a clutch, a first motor, and a transmission. The transmission includes a power split mechanism, a first synchronizer, and a transmission input shaft. The engine is connected to a first input end of the power split mechanism through the clutch. The first motor is connected to a second input end of the power split mechanism. An output end of the power split mechanism is connected to the transmission input shaft. The first synchronizer is disposed between the first input end and the output end. The system includes a vehicle controller, a transmission controller, a motor controller, and an engine controller. Among them,

[0072] The vehicle controller is configured to send a clutch state holding request to the transmission controller, send an engine torque adjustment request to the engine controller, and send a motor torque adjustment request to the motor controller when the vehicle meets the mode switching condition for switching from the power split mode to the direct drive mode;

[0073] The transmission controller is configured to keep the clutch in a closed state in response to the clutch state holding request;

[0074] The engine controller is configured to perform torque adjustment on the engine in response to the engine torque adjustment request, and the motor controller is configured to perform torque adjustment on the first motor in response to the motor torque adjustment request, so that the first synchronizer meets the torque condition;

[0075] The vehicle controller is further configured to send a rotational speed adjustment request to the motor controller when the first synchronizer meets the rotational speed condition;

[0076] The motor controller is further configured to perform rotational speed adjustment on the first motor in response to the rotational speed adjustment request, so that the first synchronizer meets the rotational speed condition;

[0077] The vehicle controller is further configured to send a gear shift request to the transmission controller when the first synchronizer meets the rotational speed condition;

[0078] The transmission controller is further configured to control the first synchronizer to switch from the power split gear to the engaged gear in response to the gear shift request, so as to switch the vehicle from the power split mode to the direct drive mode.

[0079] Fourthly, based on the same inventive concept, an embodiment of the present application provides a vehicle, including the vehicle mode switching system proposed in the third aspect of the present application.

[0080] Compared with the prior art, the present application has the following advantages:

[0081] A vehicle mode switching method provided by an embodiment of the present application can keep the clutch in a closed state when the vehicle meets the mode switching condition for switching from the power split mode to the direct drive mode, and adjust the torques of the engine and the first motor, so that when the first synchronizer meets the torque condition, the speed of the first motor can be adjusted, and further when the first synchronizer meets the speed condition, the first synchronizer can be controlled to switch from the power split gear to the engaged gear, so as to switch the vehicle from the power split mode to the direct drive mode. By first adjusting the torques of the engine and the first motor and then adjusting the speed of the first motor, the embodiment of the present application enables the shifting operation of the first synchronizer to be smoothly completed without opening or closing the clutch during the vehicle mode switching process. In this way, the vehicle can more quickly and smoothly switch from the power split mode to the direct drive mode, effectively shortening the mode switching duration while enabling the engine to quickly output torque, thereby improving the power response performance of the vehicle during the mode switching process. Description of the Drawings

[0082] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention, and those of ordinary skill in the art can obtain other drawings based on these drawings without creative efforts.

[0083] Figure 1 It is a schematic structural diagram of a hybrid vehicle in an embodiment of the present application.

[0084] Figure 2 It is a step flowchart of a vehicle mode switching method in an embodiment of the present application.

[0085] Figure 3 It is a schematic functional module diagram of a vehicle mode switching device in an embodiment of the present application.

[0086] Figure 4 It is a schematic structural diagram of a vehicle mode switching system in an embodiment of the present application.

[0087] Figure 5 It is a schematic structural diagram of a vehicle in an embodiment of the present application. Detailed implementation manners

[0088] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0089] Referring to Figure 1 , a schematic structural diagram of a hybrid vehicle in an embodiment of the present application is shown. The hybrid vehicle is provided with an engine 101, a clutch 102, a first motor 103 and a gearbox on the front axle of the vehicle; the gearbox includes a power split mechanism 104, a gearbox input shaft 107, a gearbox output shaft 108, a first synchronizer 105 and a second synchronizer 106. The engine 101 is connected to the first input end of the power split mechanism 104 through the clutch 102, the first motor 103 is connected to the second input end of the power split mechanism 104, and the output end of the power split mechanism 104 is connected to the gearbox input shaft 107.

[0090] The first synchronizer 105 is arranged between the first input end and the output end and is used to engage or disengage the first input end and the output end. Specifically, when the first synchronizer 105 is in the engaged gear, the first synchronizer 105 is used to engage the first input end and the output end; when the first synchronizer 105 is in the power split gear, the first synchronizer 105 is used to disengage the first input end and the output end. It should be noted that the first synchronizer 105 is used to control the vehicle to switch between the power split mode and other modes. That is, when the first synchronizer 105 is in the power split gear, the vehicle can be in the power split mode; when the first synchronizer 105 is in the engaged gear, the vehicle can be in other modes outside the power split mode, for example, direct drive mode, series mode or pure electric four-wheel drive mode, etc.

[0091] The second synchronizer 106 is arranged between the gearbox input shaft 107 and the gearbox output shaft 108 and is used to engage or disengage the gearbox input shaft 107 and the gearbox output shaft 108. Specifically, when the second synchronizer 106 is in gear, the second synchronizer 106 is used to engage the gearbox input shaft 107 and the gearbox output shaft 108; when the second synchronizer 106 is in neutral, the second synchronizer 106 is used to disengage the gearbox input shaft 107 and the gearbox output shaft 108.

[0092] Furthermore, the transmission output shaft 108 is also connected to the front axle wheels through the front axle differential 109, and is used to transmit power to the front axle wheels through the front axle differential 109 to drive the front axle of the vehicle; the hybrid vehicle is also provided with a second motor (not shown in the figure) at the rear axle of the vehicle, and the second motor is used to transmit power to the rear axle wheels through the rear axle differential (not shown in the figure) to drive the rear axle of the vehicle.

[0093] Due to the configuration of the power split mechanism 104 in the hybrid vehicle with the above architecture, and the power split mechanism 104 is simultaneously connected to the engine 101, the first motor 103 and the transmission input shaft 107, the vehicle can have multiple driving modes including a direct drive mode and a power split mode. Furthermore, by changing the gear state of the first synchronizer 105, the switching between different driving modes of the vehicle can be achieved. Specifically:

[0094] In the power split mode, the first synchronizer 105 is in the power split gear position. At this time, the first synchronizer is in the disengaged state, used to disconnect the first input end and the output end. The second synchronizer 106 is in the engaged state, the engine 101 is in the driving state, the clutch 102 is in the closed state, the first motor 103 is in the power generation state, and the second motor is in the driving state. At this time, the driving force output by the engine 101 is transmitted to the power split mechanism 104 through the clutch 102 and the first input end. The power split mechanism 104 then transmits a part of the driving force to the first motor 103 through the second input end to drive the first motor 103 to generate electricity (at this time, the first motor 103 outputs negative torque), and the generated electric energy is provided to the power battery for charging; the power split mechanism 104 also transmits another part of the driving force to the transmission input shaft 107 through the output end, and the transmission input shaft 107 sequentially transmits this part of the driving force to the front axle of the vehicle through the second synchronizer 106, the transmission output shaft 108 and the front axle differential 109 to drive the vehicle to travel. Among them, the distribution ratio of the driving force can be set according to actual needs. That is to say, in the power split mode, a part of the output power of the engine 101 is used to drive the first motor 103 to charge the power battery, and the other part of the output power is used to directly drive the vehicle to travel.

[0095] In the direct drive mode, the first synchronizer 105 is in the engaged gear, the second synchronizer 106 is in the in-gear state, the engine 101 is in the driving state, the clutch 102 is in the closed state, the first motor 103 is usually in the driving state, and the second motor is in the driving state. At this time, the driving force output by the engine 101 will be transmitted to the transmission input shaft 107 through the first input end, the first synchronizer 105 and the output end of the power split mechanism in sequence. The driving force output by the first motor 103 will be transmitted to the transmission input shaft 107 through the second input end and the output end of the power split mechanism, and this part of the driving force will be transmitted to the vehicle front axle by the transmission input shaft 107 through the second synchronizer 106, the transmission output shaft 108 and the front axle differential 109 in sequence to drive the vehicle to travel. Since the engine 101 and the first motor 103 can jointly drive the vehicle front axle in the direct drive mode, the overall vehicle driving force in the direct drive mode is usually greater than that in the power split mode.

[0096] It can be seen that when the vehicle switches from the power split mode to the direct drive mode, it is necessary to switch the first synchronizer 105 from the power split gear to the engaged gear.

[0097] In the related art, during the process of the vehicle switching from the power split mode to the direct drive mode, it is usually necessary for the vehicle to first open the clutch 102, then perform torque reduction and speed regulation operations on the engine 101. After the torque reduction and speed regulation operations are completed, the first synchronizer 105 is switched from the power split gear to the engaged gear, and the clutch 102 is re-closed to complete the mode switch. However, in this method during the mode switch process, it is necessary to additionally control the opening or closing of the clutch 102. On the one hand, it will also result in a longer switching link and a longer mode switch time. On the other hand, the engine 101 needs to wait until the clutch 102 is re-closed before it can output torque, resulting in untimely power response of the engine 101, thereby affecting the overall vehicle power response performance during the mode switch process.

[0098] Aiming at the problem of poor overall vehicle power response performance when the current hybrid vehicle switches from the power split mode to the direct drive mode. This application aims to provide a vehicle mode switching method. By first performing torque adjustment on the engine 101 and the first motor 103, and then performing speed adjustment on the first motor 103, it is possible to complete the shifting operation of the first synchronizer 105 without opening or closing the clutch 102 during the vehicle mode switch process. In this way, the vehicle can switch from the power split mode to the direct drive mode more quickly and smoothly, effectively shortening the mode switch duration while enabling the engine 101 to quickly output torque, thereby improving the power response performance of the vehicle during the mode switch process.

[0099] Refer to Figure 2, which shows a vehicle mode switching method of the present application, applied to a hybrid vehicle adopting the above architecture. The method may include the following steps:

[0100] S201: When the vehicle meets the mode switching condition for switching from the power split mode to the direct drive mode, keep the clutch 102 in the closed state, and adjust the torques of the engine 101 and the first motor 103 so that the first synchronizer 105 meets the torque condition.

[0101] It should be noted that the execution subject of this embodiment may be a computing service device with data processing, network communication, and program running functions, or an electronic device with the above functions such as an on-board computer or a vehicle computer, such as an ECU (Electronic Control Unit), an HCU (Hybrid Control Unit), etc. This embodiment will be described with the HCU as the execution subject. It should be noted that this embodiment does not make specific restrictions on the execution subject of the vehicle.

[0102] In this embodiment, the HCU can obtain the vehicle condition information and the driver operation information, and then determine whether the vehicle needs to switch from the power split mode to the direct drive mode based on the vehicle condition information and the driver operation information, so as to realize the intelligent switching of the vehicle mode.

[0103] In this embodiment, after the HCU determines that the vehicle meets the mode switching condition for switching from the power split mode to the direct drive mode, it will send a clutch state holding request to the transmission controller, so that the transmission controller responds to the clutch state holding request and keeps the clutch 102 in the closed state; at the same time, it sends an engine torque adjustment request to the engine controller, so that the engine controller responds to the engine torque adjustment request and adjusts the torque of the engine 101; at the same time, it also sends a motor torque adjustment request to the motor controller, so that the motor controller responds to the motor torque adjustment request and adjusts the torque of the first motor 103.

[0104] It should be noted that when the vehicle switches from the power split mode to the direct drive mode, the first synchronizer 105 needs to be shifted from the power split gear to the engaged gear. If the torque applied to the first synchronizer 105 is too large when the first synchronizer 105 is shifted, it may cause the first synchronizer 105 to fail to shift or be damaged during shifting.

[0105] In this embodiment, to prevent the first synchronizer 105 from failing to engage gears smoothly, torque adjustment will be performed on the engine 101 and the first motor 103, such that the torque jointly acting on the first synchronizer 105 by the engine 101 and the first motor 103 through the power split mechanism 104 is a relatively small value, preferably zero. In this way, the torque at the first synchronizer 105 can be reduced to the torque required for gear engagement without disengaging the clutch 102, thereby enabling the first synchronizer 105 to meet the torque condition.

[0106] It should be noted that the torque condition is used to characterize the condition under which the first synchronizer 105 can shift from the power split gear to the engaged gear in terms of torque.

[0107] S202: When the first synchronizer 105 meets the torque condition, the rotational speed of the first motor 103 is adjusted to enable the first synchronizer 105 to meet the rotational speed condition.

[0108] In this embodiment, after the HCU determines that the first synchronizer 105 meets the torque condition, it will trigger the rotational speed adjustment of the first motor 103 and send a rotational speed adjustment request including the target motor rotational speed to the motor controller, so that the motor controller responds to the rotational speed adjustment request and adjusts the current motor rotational speed of the first motor 103 to enable the first synchronizer 105 to meet the rotational speed condition.

[0109] It should be noted that the first synchronizer 105 is arranged between the first input end and the output end of the power split mechanism 104 and is used to adjust the gear ratio between the first input end of the power split mechanism 104 and the transmission input shaft 107.

[0110] In the power split mode, the first synchronizer 105 is in the power split gear. At this time, the gear ratio between the first input end of the power split mechanism 104 and the transmission input shaft 107 is usually set to a value greater than 1, such as 2:1. When the vehicle switches from the power split mode to the direct drive mode, the first synchronizer 105 needs to shift to the engaged gear. At this time, the first input end and the output end of the power split mechanism 104 are in a locked state, and the output end is connected to the transmission input shaft 107, so that the gear ratio between the first input end and the transmission input shaft 107 is 1:1. To prevent the first synchronizer 105 from being damaged during gear engagement, it is required that the rotational speed difference at both ends of the first synchronizer 105 is a relatively small value, ideally zero.

[0111] In this embodiment, considering that the first motor 103 is connected to the power split mechanism 104, and the torque balance at the first synchronizer 105 has been achieved through the engine 101 and the first motor 103, therefore, by adjusting the speed of the first motor 103, it is also possible to adjust the speeds at both ends of the first synchronizer 105 while keeping the clutch 102 closed, so that the first synchronizer 105 meets the speed condition.

[0112] It should be noted that the speed condition is used to characterize the condition under which the first synchronizer 105 can shift from the power split gear to the engaged gear in terms of speed.

[0113] S203: When the first synchronizer 105 meets the speed condition, control the first synchronizer 105 to switch from the power split gear to the engaged gear, so that the vehicle switches from the power split mode to the direct drive mode.

[0114] In this embodiment, since the first synchronizer 105 has already met the torque condition in advance, therefore, after the HCU detects that the first synchronizer 105 also meets the speed condition, it will send a gear shift request indicating that the target gear is the engaged gear to the transmission controller, so that the transmission controller responds to the gear shift request and controls the first synchronizer 105 to switch from the power split gear to the engaged gear.

[0115] In this embodiment, by first adjusting the torques of the engine 101 and the first motor 103, and then adjusting the speed of the first motor 103, the first synchronizer 105 can complete the gear shifting operation while meeting both the torque condition and the speed condition, thereby effectively ensuring the gear shifting safety of the first synchronizer 105.

[0116] In this embodiment, after the HCU determines that the first synchronizer 105 has been switched to the engaged gear, it will set the current driving mode of the vehicle from the power split mode to the direct drive mode, and then control the engine 101, the first motor 103 and the second motor to output torques according to the torque distribution strategy in the direct drive mode.

[0117] Specifically, the torque distribution strategy includes the front axle torque distribution strategy and the rear axle torque output strategy. Among them, the HCU is used to execute the front axle torque distribution strategy, control the engine 101 to output the first torque, and control the first motor 103 to output the second torque to jointly drive the front axle of the vehicle; at the same time, the HCU is also used to execute the rear axle torque output strategy, control the second motor to output the third torque to drive the rear axle of the vehicle.

[0118] It should be noted that the second torque output by the first motor 103 can be a positive torque or a negative torque. For example, when the driver's required torque is large and the engine 101 and the second motor cannot effectively meet the user's power demand, the first motor 103 can output a positive torque to ensure the vehicle's power performance; when the driver's required torque is small, the first motor 103 can output a negative torque to adjust the operating point of the engine 101 so that the engine 101 can operate in the optimal economic range.

[0119] A vehicle mode switching method provided by an embodiment of the present application first adjusts the torques of the engine 101 and the first motor 103, and then adjusts the speed of the first motor 103, so that during the vehicle mode switching process, the shifting operation of the first synchronizer 105 can be successfully completed without opening or closing the clutch 102. In this way, the vehicle can switch from the power split mode to the direct drive mode more quickly and smoothly, effectively shortening the mode switching duration while enabling the engine 101 to quickly output torque, thereby improving the vehicle's dynamic response performance during the mode switching process.

[0120] In a feasible implementation, the vehicle mode switching method may further include the following steps:

[0121] S301: When the vehicle is in the power split mode, obtain the current remaining power of the power battery and determine whether the driver has a strong power demand.

[0122] In this implementation, when the vehicle is in the power split mode, the HCU will continuously obtain the vehicle's operating condition information and driver operation information to determine whether to control the vehicle to switch from the power split mode to the direct drive mode. Among them, the operating condition information may specifically include the current SOC (State of Charge) of the power battery, also known as the remaining power.

[0123] In this implementation, by detecting the current remaining power of the power battery, it is possible to effectively determine whether the power battery has sufficient remaining power to support the vehicle to operate in the direct drive mode. At the same time, by detecting the driver operation information, it is possible to effectively determine whether the driver has a strong power demand.

[0124] In a specific implementation, the driver operation information may specifically include the current throttle opening of the throttle pedal and the current throttle opening change rate. Furthermore, when the HCU detects that the current throttle opening is greater than the opening threshold and the current throttle opening change rate is greater than the change rate threshold, it will be determined that the driver has a strong power demand.

[0125] In this embodiment, by comprehensively considering the current throttle opening change rate on the basis of the current throttle opening, the strong power demand of the driver can be more accurately identified, thereby effectively avoiding the phenomenon of incorrect mode switching.

[0126] S302: When it is determined that the driver has a strong power demand and the current remaining power is greater than the power threshold, it is determined that the vehicle meets the mode switching condition for switching from the power split mode to the direct drive mode.

[0127] In this embodiment, if the HCU detects that the driver has a strong power demand and the current remaining power is greater than the power threshold at the same time, it will automatically control the vehicle to switch from the power split mode to the direct drive mode to achieve automatic switching of the vehicle mode, thereby quickly and effectively meeting the power demand of the driver.

[0128] In a feasible embodiment, the step of adjusting the torques of the engine 101 and the first motor 103 in S201 may specifically include the following sub-steps:

[0129] S201-1: Based on a preset torque adjustment gradient, control the current engine torque of the engine 101 and the current motor torque of the first motor 103 to follow a preset first target torque.

[0130] It should be noted that the first target torque represents the torque at which the first synchronizer 105 can shift from the power split gear to the engaged gear. Specifically, the first target torque can be set according to actual shifting requirements. For example, to maximize the service life of the first synchronizer 105, the first target torque can be set to zero; or to maximize the shifting speed, the first target torque can be set to the maximum torque that can achieve gear engagement; or the first target torque can be set to a torque between zero and the maximum torque, thereby to a certain extent improving the shifting speed while ensuring the service life of the first synchronizer 105.

[0131] In this embodiment, after the HCU determines the first target torque, it will activate the torque control mode of the motor controller so that the motor controller adjusts the current motor torque of the first motor 103 to the first target torque; at the same time, the HCU will also activate the torque control mode of the engine controller so that the engine controller adjusts the current engine torque of the engine 101 to the first target torque.

[0132] In specific implementation, according to a preset torque adjustment gradient, the current engine torque of the engine 101 and the current motor torque of the first motor 103 gradually reach the first target torque. Among them, the torque adjustment gradient represents the change amount of torque per unit time. For example, it can be set to 200 N·m / s.

[0133] In this embodiment, by adjusting the torques of the engine 101 and the first motor 103 according to the torque adjustment gradient, it is possible to avoid drastic torque changes that may affect the driving smoothness of the vehicle.

[0134] In a feasible embodiment, the vehicle further includes a second motor, and the vehicle mode switching method may further include the following steps:

[0135] S401: Determine the compensation torque of the second motor based on the current engine torque and the current motor torque.

[0136] In this embodiment, considering that during the process of adjusting the torques of the engine 101 and the first motor 103, the front axle torque will continuously decrease. To ensure the power demand of the whole vehicle during mode switching, torque compensation will be performed by the second motor.

[0137] In this embodiment, since the current motor torque is a negative torque and is used to offset a part of the positive torque of the current engine torque, the HCU can determine the sum of the current engine torque and the current motor torque as the compensation torque of the second motor.

[0138] Exemplarily, before adjusting the torques of the engine 101 and the first motor 103, if the current engine torque is 800 N·m and the current motor torque is -300 N·m, then the compensation torque of the second motor is 500 N·m.

[0139] S402: Determine the target drive torque of the second motor based on the compensation torque and the current drive torque of the second motor.

[0140] In this embodiment, the HCU will further superimpose the compensation torque on the basis of the current drive torque of the second motor to obtain the target drive torque of the second motor. Then, the second motor can supplement the reduced torque of the vehicle front axle at the vehicle rear axle.

[0141] S403: During the process of adjusting the torques of the engine 101 and the first motor 103, control the second motor to gradually increase from the current drive torque to the target drive torque based on the torque adjustment gradient.

[0142] In this embodiment, during the process of adjusting the torques of the engine 101 and the first motor 103 according to the torque adjustment gradient, the HCU will also synchronously control the second motor to perform torque compensation according to the same torque adjustment gradient.

[0143] In one example, the torque adjustment gradient is set to 200 N·m / s, and the first target torque is set to 0 N·m. If the HCU detects that the engine 101 outputs 800 N·m, the first motor 103 outputs -300 N·m, and the second motor outputs 400 N·m, then after detecting that the vehicle meets the mode switching request, the HCU will control the engine 101 to gradually decrease from 800 N·m to 0 N·m at a torque adjustment gradient of 200 N·m / s, and control the first motor 103 to gradually increase from -300 N·m to 0 N·m; meanwhile, it is calculated that the compensation torque of the second motor is 500 N·m, and the target driving torque is 900 N·m, and then synchronously control the second motor to gradually increase from 400 N·m to 900 N·m at a torque adjustment gradient of 200 N·m / s.

[0144] In this embodiment, torque compensation is performed by the second motor, so that during the mode switching process, the vehicle power performance can be kept consistent, effectively meeting the driver's power demand during the mode switching process, and at the same time avoiding phenomena such as abnormal deceleration or jerks of the vehicle.

[0145] In a feasible embodiment, the vehicle mode switching method may further include the following steps:

[0146] S501: When the first torque difference between the current engine torque and the first target torque is less than the first torque threshold, trigger the timing for the first duration during which the first torque difference is less than the first torque threshold.

[0147] In this embodiment, during the process of the HCU adjusting the torque of the engine 101, the HCU will obtain the current engine torque real-time feedback by the engine controller, and then when detecting that the first torque difference between the current engine torque and the first target torque is less than the first torque threshold, trigger the cumulative timing for the first duration by the first timer, and then based on the first duration, determine whether the engine 101 is stably operating at the first target torque.

[0148] S502: When the second torque difference between the current motor torque and the first target torque is less than the second torque threshold, trigger the timing for the second duration during which the second torque difference is less than the second torque threshold.

[0149] In this embodiment, during the process of the HCU adjusting the torque of the first motor 103, the HCU will obtain the current motor torque of the first motor 103 real-time feedback by the motor controller, and then when detecting that the second torque difference between the current motor torque and the first target torque is less than the second torque threshold, trigger the cumulative timing for the second duration by the second timer, and then based on the second duration, determine whether the first motor 103 is stably operating at the first target torque.

[0150] S503: When the first duration is greater than the first duration threshold and the second duration is greater than the second duration threshold, it is determined that the first synchronizer 105 meets the torque condition.

[0151] In this embodiment, if the HCU detects that both the first duration and the second duration are greater than their respective corresponding duration thresholds, it is considered that both the engine 101 and the first motor 103 are stably operating at the first target torque, and then it is determined that the first synchronizer 105 has met the torque condition.

[0152] In this embodiment, by monitoring the first duration and the second duration, it is possible to effectively avoid controlling the first synchronizer 105 to perform a gear shifting operation in the case of abnormal torque fluctuations in the engine 101 or the first motor 103, thereby ensuring the shifting safety of the first synchronizer 105.

[0153] In a feasible embodiment, with continued reference to Figure 1 , the power split mechanism 104 may specifically include a ring gear 1041, a sun gear 1042, a plurality of planet gears 1043 meshing between the ring gear 1041 and the sun gear 1042, and a planet carrier 1044 rotatably connected to the plurality of planet gears 1043; the planet carrier 1044 is connected to the engine 101 as the first input end of the power split mechanism 104, the sun gear 1042 is connected to the first motor 103 as the second input end of the power split mechanism 104, the ring gear 1041 is connected to the transmission input shaft 107 as the output end of the power split mechanism 104, and the first synchronizer 105 is disposed between the planet carrier 1044 and the ring gear 1041.

[0154] It should be noted that in the power split mode, the first synchronizer 105 is in the power split gear position. At this time, the planet carrier 1044 and the ring gear 1041 are in a disconnected state. The driving force output by the engine 101 will be transmitted to the planet carrier 1044 through the clutch 102, and the planet carrier 1044 will transmit a part of the driving force to the first motor 103 through the plurality of planet gears 1043 and the sun gear 1042 in sequence to drive the first motor 103 to charge the power battery; at the same time, the planet carrier 1044 will transmit another part of the driving force to the vehicle front axle through the plurality of planet gears 1043, the ring gear 1041, the transmission input shaft 107, the second synchronizer 106, the transmission output shaft 108, and the front axle differential 109 in sequence to drive the vehicle to travel.

[0155] In the direct drive mode, the first synchronizer 105 is in the engaged gear. At this time, the planet carrier 1044 and the ring gear 1041 are in the locked state. The driving force output by the engine 101 will be transmitted to the transmission input shaft 107 through the planet carrier 1044, the first synchronizer 105 and the ring gear 1041 in sequence. And the driving force output by the first motor 103 will be transmitted to the transmission input shaft 107 through the sun gear 1042, multiple planet gears 1043 and the ring gear 1041. That is, the engine 101 and the first motor 103 transmit the driving force to the transmission input shaft 107 together through two different power paths, and then the transmission input shaft 107 transmits this part of the driving force to the vehicle front axle through the second synchronizer 106, the transmission output shaft 108 and the front axle differential 109 in sequence to drive the vehicle to travel.

[0156] Based on the above structure, the step of adjusting the speed of the first motor 103 in S202 may specifically include the following sub-steps:

[0157] S202-1: When the current gear of the first synchronizer 105 is the power split gear, determine that the transmission ratio between the planet carrier 1044 and the ring gear 1041 is the first transmission ratio.

[0158] It should be noted that since the first synchronizer 105 is arranged between the planet carrier 1044 and the ring gear 1041, therefore, it is necessary to adjust the speeds between the planet carrier 1044 and the ring gear 1041 so that the speed difference between both ends of the first synchronizer 105 is less than the preset speed difference threshold. And since the planet carrier 1044 is connected to the engine 101, the speed of the planet carrier 1044 is the engine speed. Also, since the ring gear 1041 is connected through multiple planet gears 1043, the sun gear 1042 and the first motor 103, the speed of the ring gear 1041 can be converted with the speed of the first motor 103. In this way, on the premise of keeping the engine speed unchanged, only by adjusting the speed of the first motor 103, the speeds at both ends of the first synchronizer 105 can be adjusted so that the first synchronizer 105 meets the speed conditions.

[0159] In this embodiment, considering that the transmission ratio between the planet carrier 1044 and the ring gear 1041 is different in different gears of the first synchronizer 105, therefore, it will first be determined that the transmission ratio between the planet carrier 1044 and the ring gear 1041 is the first transmission ratio based on the current gear of the first synchronizer 105.

[0160] S202-2: Based on the current engine speed of the engine 101 and the first transmission ratio, determine the target ring gear speed of the ring gear 1041.

[0161] In this embodiment, the HCU uses the current engine speed of the engine 101 as the speed regulation reference to achieve the speed of the first motor 103. Thus, it is not necessary to adjust the engine speed. Furthermore, based on the current engine speed of the engine 101 and the first gear ratio, the target ring gear speed of the ring gear 1041 can be determined.

[0162] S202-3: Based on the target ring gear speed and the second gear ratio between the ring gear 1041 and the sun gear 1042, determine the target motor speed of the first motor 103.

[0163] In this embodiment, according to the second gear ratio between the ring gear 1041 and the sun gear 1042, the target ring gear speed can be further converted into the target motor speed required by the first motor 103.

[0164] In a specific implementation, the target motor speed can be calculated according to the following formula:

[0165] n1 = n0 × i1 × i2 (1);

[0166] Wherein, n1 represents the target motor speed of the first motor 103, n0 represents the current engine speed of the engine 101, i1 represents the first gear ratio, and this first gear ratio represents the gear ratio between the planet carrier 1044 and the ring gear 1041 when the first synchronizer 105 is in the power split gear, and i2 represents the second gear ratio between the ring gear 1041 and the sun gear 1042.

[0167] S202-4: Control the current motor speed of the first motor 103 to follow the target motor speed.

[0168] In this embodiment, when the HCU sends a speed control request including the target motor speed to the motor controller, it will also send a speed control flag bit to the motor controller, so that the motor controller controls the first motor 103 to switch from the torque control mode to the speed control mode to achieve precise control of the speed of the first motor 103.

[0169] In this embodiment, after the motor controller receives the speed control request and switches to the speed control mode, it will activate the PI (proportional-integral) speed loop for the first motor 103 to control the current motor speed of the first motor 103 to follow the target motor speed in a closed-loop control manner.

[0170] In a specific implementation, a preset PI regulation strategy can be adopted to achieve closed-loop control of the motor speed. Specifically, the motor controller is internally provided with a proportional controller and an integral controller. The motor controller will first calculate the first speed difference between the target motor speed and the current motor speed, and then input the current motor speed and the first speed difference into the proportional controller, from which a proportional regulation value can be output; input the current motor speed and the first speed difference into the integral controller, from which an integral regulation value can be output; and then, based on the proportional regulation value and the integral regulation value, adjust the speed of the first motor 103.

[0171] In this embodiment, by comprehensively considering the current gear position of the first synchronizer 105 and the gear ratio between the first motor 103 and the engine 101, accurate calculation of the target motor speed can be achieved. At the same time, by performing closed-loop control on the motor speed, rapid and precise control of the current motor speed can be realized, thereby effectively balancing the speed difference at both ends of the first synchronizer 105 and ensuring that the first synchronizer 105 can be smoothly engaged into the target gear position.

[0172] In a feasible embodiment, the vehicle mode switching method may further include the following steps:

[0173] S601: Based on the current motor speed and the second gear ratio, determine the current ring gear speed of the ring gear.

[0174] In this embodiment, since the first motor 103 is connected to the sun gear 1042, based on the current motor speed and the second gear ratio between the ring gear 1041 and the sun gear 1042, the current ring gear speed of the ring gear 1041 can be calculated in real time.

[0175] S602: Based on the current engine torque, determine the current carrier speed of the carrier.

[0176] In this embodiment, since the engine 101 is connected to the carrier 1044, the current engine speed can be directly determined as the current carrier speed.

[0177] S603: When the speed difference between the current ring gear speed and the current carrier speed is less than the speed difference threshold, determine that the first synchronizer 105 meets the speed condition.

[0178] In this embodiment, since the first synchronizer 105 is arranged between the ring gear 1041 and the carrier 1044, by calculating the speed difference between the current ring gear speed and the current carrier speed, the speed difference at both ends of the first synchronizer 105 can be obtained in real time. Furthermore, when it is detected that the speed difference is less than the speed difference threshold, it indicates that the first synchronizer 105 meets the speed condition.

[0179] In this embodiment, by monitoring the rotational speed difference at both ends of the first synchronizer 105 in real time, the shifting safety of the first synchronizer 105 can be effectively ensured.

[0180] In a feasible embodiment, S203 may specifically include the following sub-steps:

[0181] S203-1: When the first synchronizer 105 meets the rotational speed condition, determine the sum of the first target torque and the preset shifting-in auxiliary torque as the second target torque.

[0182] In this embodiment, considering that when the first synchronizer 105 switches from the power split gear to the engaged gear, it needs to switch from the gear disengaged state to the locked state. Therefore, by superimposing the shifting-in auxiliary torque on the basis of the first target torque and controlling the first motor 103 to output the second target torque, the first motor 103 can assist the first synchronizer 105 to smoothly complete the shifting operation. Among them, the shifting-in auxiliary torque can be set to 2 N·m.

[0183] S203-1: Control the current motor torque of the first motor 103 to follow the second target torque to assist the first synchronizer 105 to switch from the power split gear to the engaged gear.

[0184] In specific implementation, the HCU sends a second motor torque adjustment request including the second target torque to the motor controller, so that the motor controller responds to the second motor torque adjustment request to adjust the torque of the first motor 103, so that the first motor 103 outputs the second target torque. When the first target torque is set to zero, the second target torque is the shifting-in auxiliary torque.

[0185] In this embodiment, by controlling the first motor 103 to further superimpose the shifting-in auxiliary torque on the basis of the first target torque, the first synchronizer 105 can effectively improve the shifting efficiency under the auxiliary drive of the first motor 103, and at the same time avoid the phenomenon of shifting failure of the first synchronizer 105.

[0186] Second, based on the same inventive concept, referring to Figure 3 , this application embodiment provides a vehicle mode switching device 300. The vehicle includes an engine 101, a clutch 102, a first motor 103, and a gearbox; the gearbox includes a power split mechanism 104, a first synchronizer 105, and a gearbox input shaft 107. The engine 101 is connected to the first input end of the power split mechanism 104 through the clutch 102, the first motor 103 is connected to the second input end of the power split mechanism 104, the output end of the power split mechanism 104 is connected to the gearbox input shaft 107, and the first synchronizer 105 is arranged between the first input end and the output end. The vehicle mode switching device 300 includes:

[0187] The torque adjustment module 301 is configured to keep the clutch 102 closed and adjust the torques of the engine 101 and the first motor 103 when the vehicle meets the mode switching condition for switching from the power split mode to the direct drive mode, so that the first synchronizer 105 meets the torque condition;

[0188] The speed adjustment module 302 is configured to adjust the speed of the first motor 103 when the first synchronizer 105 meets the torque condition, so that the first synchronizer 105 meets the speed condition;

[0189] The gear shifting module 303 is configured to control the first synchronizer 105 to shift from the power split gear to the engaged gear when the first synchronizer 105 meets the speed condition, so that the vehicle switches from the power split mode to the direct drive mode.

[0190] In an embodiment of the present application, the vehicle mode switching device 300 further includes:

[0191] The information acquisition sub-module is configured to acquire the current remaining power of the power battery and determine whether the driver has a strong power demand when the vehicle is in the power split mode;

[0192] The condition determination sub-module is configured to determine that the vehicle meets the mode switching condition for switching from the power split mode to the direct drive mode when it is determined that the driver has a strong power demand and the current remaining power is greater than the power threshold.

[0193] In an embodiment of the present application, the information acquisition sub-module includes:

[0194] The pedal information acquisition unit is configured to acquire the current throttle opening and the current throttle opening change rate of the throttle pedal;

[0195] The power demand determination unit is configured to determine that the driver has a strong power demand when the current throttle opening is greater than the opening threshold and the current throttle opening change rate is greater than the change rate threshold.

[0196] In an embodiment of the present application, the torque adjustment module 301 includes:

[0197] The torque adjustment sub-module is configured to control the current engine torque of the engine 101 and the current motor torque of the first motor 103 to follow a preset first target torque based on a preset torque adjustment gradient.

[0198] In an embodiment of the present application, the vehicle further includes a second motor, and the vehicle mode switching device 300 further includes:

[0199] The compensation torque determination module is configured to determine the compensation torque of the second motor based on the current engine torque and the current motor torque;

[0200] A driving torque determination module, configured to determine a target driving torque of the second motor based on a compensation torque and a current driving torque of the second motor;

[0201] A driving torque control module, configured to control the second motor to gradually increase from the current driving torque to the target driving torque based on a torque adjustment gradient during the process of adjusting the torques of the engine 101 and the first motor 103.

[0202] In an embodiment of the present application, the vehicle mode switching device 300 further includes:

[0203] A first timing module, configured to trigger timing for a first duration during which a first torque difference between a current engine torque and a first target torque is less than a first torque threshold;

[0204] A second timing module, configured to trigger timing for a second duration during which a second torque difference between a current motor torque and a first target torque is less than a second torque threshold;

[0205] A first condition determination module, configured to determine that the second synchronizer 106 satisfies a first gear shifting condition when the first duration is greater than a first duration threshold and the second duration is greater than a second duration threshold.

[0206] In an embodiment of the present application, the power split mechanism 104 includes a ring gear, a sun gear, a plurality of planet gears meshing between the ring gear and the sun gear, and a planet carrier rotatably connected to the plurality of planet gears; the planet carrier 1044 serves as a first input end of the power split mechanism 104 and is connected to the engine 101, the sun gear 1042 serves as a second input end of the power split mechanism 104 and is connected to the first motor 103, the ring gear 1041 serves as an output end of the power split mechanism 104 and is connected to the transmission input shaft 107, and the first synchronizer 105 is disposed between the planet carrier 1044 and the ring gear 1041; the speed regulation module 302 includes:

[0207] A gear ratio determination sub-module, configured to determine that a gear ratio between the planet carrier and the ring gear is a first gear ratio when the current gear position of the first synchronizer 105 is a power split gear position;

[0208] A target ring gear speed determination sub-module, configured to determine a target ring gear speed of the ring gear based on a current engine speed of the engine 101 and the first gear ratio;

[0209] A motor speed determination sub-module, configured to determine a target motor speed of the first motor 103 based on the target ring gear speed and a second gear ratio between the ring gear and the sun gear;

[0210] The motor speed control sub-module is used to control the current motor speed of the first motor 103 to follow the target motor speed.

[0211] In an embodiment of the present application, the vehicle mode switching device 300 further includes:

[0212] The current ring gear speed determination module is used to determine the current ring gear speed of the ring gear based on the current motor speed and the second gear ratio;

[0213] The current carrier speed determination module is used to determine the current carrier speed of the carrier based on the current engine torque;

[0214] The second condition determination module is used to determine that the first synchronizer 105 meets the speed condition when the speed difference between the current ring gear speed and the current carrier speed is less than the speed difference threshold.

[0215] In an embodiment of the present application, the gear shift module 303 includes:

[0216] The target torque determination sub-module is used to determine the second target torque as the sum of the first target torque and the preset shift assist torque when the first synchronizer 105 meets the speed condition;

[0217] The gear shift sub-module is used to control the current motor torque of the first motor 103 to follow the second target torque to assist the first synchronizer 105 to switch from the power split gear to the engaged gear.

[0218] It should be noted that the specific implementation manner of the vehicle mode switching device 300 in the embodiment of the present application refers to the specific implementation manner of the vehicle mode switching method proposed in the first aspect of the embodiment of the present application, which will not be elaborated here.

[0219] In a third aspect, based on the same inventive concept, referring to Figure 4 , the embodiment of the present application provides a vehicle mode switching system 400. The vehicle includes an engine 101, a clutch 102, a first motor 103 and a transmission; the transmission includes a power split mechanism 104, a first synchronizer 105 and a transmission input shaft 107. The engine 101 is connected to the first input end of the power split mechanism 104 through the clutch 102, the first motor 103 is connected to the second input end of the power split mechanism 104, the output end of the power split mechanism 104 is connected to the transmission input shaft 107, and the first synchronizer 105 is arranged between the first input end and the output end; the vehicle mode switching system 400 includes a vehicle controller 401, a transmission controller 402, a motor controller 403 and an engine controller 404.

[0220] The vehicle controller 401 is configured to send a clutch state holding request to the transmission controller 402, an engine torque adjustment request to the engine controller 404, and a motor torque adjustment request to the motor controller 403 when the vehicle meets the mode switching condition for switching from the power split mode to the direct drive mode;

[0221] The transmission controller 402 is configured to keep the clutch 102 in a closed state in response to the clutch state holding request;

[0222] The engine controller 404 is configured to adjust the torque of the engine 101 in response to the engine torque adjustment request, and the motor controller 403 is configured to adjust the torque of the first motor 103 in response to the motor torque adjustment request so that the first synchronizer 105 meets the torque condition;

[0223] The vehicle controller 401 is further configured to send a speed adjustment request to the motor controller 403 when the first synchronizer 105 meets the torque condition;

[0224] The motor controller 403 is further configured to adjust the speed of the first motor 103 in response to the speed adjustment request so that the first synchronizer 105 meets the speed condition;

[0225] The vehicle controller 401 is further configured to send a gear shift request to the transmission controller 402 when the first synchronizer 105 meets the speed condition;

[0226] The transmission controller 402 is further configured to control the first synchronizer 105 to switch from the power split gear to the engaged gear in response to the gear shift request, so that the vehicle switches from the power split mode to the direct drive mode.

[0227] It should be noted that the specific implementation of the vehicle mode switching system 400 in the embodiments of the present application refers to the specific implementation of the vehicle mode switching method proposed in the first aspect of the present application, which will not be elaborated here.

[0228] Fourthly, based on the same inventive concept, referring to Figure 5 , the embodiments of the present application provide a vehicle 500, including the vehicle mode switching system 400 proposed in the third aspect of the present application.

[0229] It should be noted that the specific implementation of the vehicle 500 in the embodiments of the present application refers to the specific implementation of the vehicle mode switching system 400 proposed in the third aspect of the present application, which will not be elaborated here.

[0230] Those skilled in the art should understand that the embodiments of the present invention can be provided as methods, apparatuses, or computer program products. Therefore, the embodiments of the present invention can take the form of all-hardware embodiments, all-software embodiments, or embodiments combining software and hardware aspects. Moreover, the embodiments of the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0231] The embodiments of the present invention are described with reference to the flowcharts and / or block diagrams of methods, terminal devices (systems), and computer program products according to the embodiments of the present invention. It should be understood that each flow and / or block in the flowchart and / or block diagram, as well as the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing terminal devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing terminal devices generate means for implementing the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0232] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing terminal device to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured article including instruction means, and the instruction means implements the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0233] These computer program instructions can also be loaded onto a computer or other programmable data processing terminal device, so that a series of operation steps are executed on the computer or other programmable terminal device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable terminal device provide steps for implementing the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0234] Although the preferred embodiments of the embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications once they know the basic creative concepts. Therefore, the appended claims are intended to be construed as including the preferred embodiments and all changes and modifications falling within the scope of the embodiments of the present invention.

[0235] Finally, it should also be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or terminal device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or terminal device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or terminal device comprising the element.

[0236] The above has introduced in detail a vehicle mode switching method, system and vehicle provided by the present invention. Specific examples are used in this text to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A vehicle mode switching method, characterized in that, The vehicle includes an engine, a clutch, a first motor, and a transmission; the transmission includes a power split mechanism, a first synchronizer, and a transmission input shaft. The engine is connected to a first input end of the power split mechanism through the clutch, the first motor is connected to a second input end of the power split mechanism, an output end of the power split mechanism is connected to the transmission input shaft, and the first synchronizer is arranged between the first input end and the output end; the method includes: When the vehicle meets the mode switching condition for switching from the power split mode to the direct drive mode, keep the clutch in a closed state, and adjust the torques of the engine and the first motor so that the first synchronizer meets the torque condition; When the first synchronizer meets the torque condition, adjust the speed of the first motor so that the first synchronizer meets the speed condition; When the first synchronizer meets the speed condition, control the first synchronizer to switch from the power split gear to the engaged gear so that the vehicle switches from the power split mode to the direct drive mode.

2. The vehicle mode switching method according to claim 1, wherein The method further includes: When the vehicle is in the power split mode, obtain the current remaining power of the power battery and determine whether the driver has a strong power demand; When it is determined that the driver has the strong power demand and the current remaining power is greater than the power threshold, determine that the vehicle meets the mode switching condition for switching from the power split mode to the direct drive mode.

3. The vehicle mode switching method according to claim 2, wherein The step of determining whether the driver has a strong power demand includes: Obtain the current throttle opening and the current throttle opening change rate of the throttle pedal; When the current throttle opening is greater than the opening threshold and the current throttle opening change rate is greater than the change rate threshold, determine that the driver has a strong power demand.

4. The vehicle mode switching method according to claim 1, characterized in that, The step of adjusting the torques of the engine and the first motor includes: Based on a preset torque adjustment gradient, control the current engine torque of the engine and the current motor torque of the first motor to follow a preset first target torque.

5. The vehicle mode switching method according to claim 4, characterized in that, The vehicle further includes a second motor, and the method further includes: Based on the current engine torque and the current motor torque, determine the compensation torque of the second motor; Based on the compensation torque and the current drive torque of the second motor, determine the target drive torque of the second motor; During the process of adjusting the torques of the engine and the first motor, based on the torque adjustment gradient, control the second motor to gradually increase from the current drive torque to the target drive torque.

6. The vehicle mode switching method according to claim 4, characterized in that, The method further includes: When a first torque difference between the current engine torque and the first target torque is less than a first torque threshold, trigger timing for a first duration during which the first torque difference is less than the first torque threshold; When a second torque difference between the current motor torque and the first target torque is less than a second torque threshold, trigger timing for a second duration during which the second torque difference is less than the second torque threshold; When the first duration is greater than the first duration threshold and the second duration is greater than the second duration threshold, it is determined that the first synchronizer meets the torque condition.

7. The vehicle mode switching method according to claim 1, characterized in that The power split mechanism includes a ring gear, a sun gear, a plurality of planet gears meshing between the ring gear and the sun gear, and a planet carrier rotatably connected to the plurality of planet gears; the planet carrier is connected to the engine as the first input end, the sun gear is connected to the first motor as the second input end, the ring gear is connected to the transmission input shaft as the output end, and the first synchronizer is arranged between the planet carrier and the ring gear; The step of adjusting the speed of the first motor includes: When the current gear position of the first synchronizer is the power split gear position, determining that the transmission ratio between the planet carrier and the ring gear is the first transmission ratio; Based on the current engine speed of the engine and the first transmission ratio, determining the target ring gear speed of the ring gear; Based on the target ring gear speed and the second transmission ratio between the ring gear and the sun gear, determining the target motor speed of the first motor; Controlling the current motor speed of the first motor to follow the target motor speed.

8. The vehicle mode switching method according to claim 7, wherein The method further includes: Based on the current motor speed and the second transmission ratio, determining the current ring gear speed of the ring gear; Based on the current engine torque, determining the current planet carrier speed of the planet carrier; When the speed difference between the current ring gear speed and the current planet carrier speed is less than the speed difference threshold, it is determined that the first synchronizer meets the speed condition.

9. The vehicle mode switching method according to claim 4, wherein When the first synchronizer meets the speed condition, the step of controlling the first synchronizer to switch from the power split gear position to the engaged gear position includes: When the first synchronizer meets the speed condition, determining the sum of the first target torque and the preset shift assist torque as the second target torque; Controlling the current motor torque of the first motor to follow the second target torque to assist the first synchronizer to switch from the power split gear position to the engaged gear position.

10. A vehicle mode switching system, characterized in that, The vehicle includes an engine, a clutch, a first motor, and a transmission; the transmission includes a power split mechanism, a first synchronizer, and a transmission input shaft. The engine is connected to the first input end of the power split mechanism through the clutch, the first motor is connected to the second input end of the power split mechanism, the output end of the power split mechanism is connected to the transmission input shaft, and the first synchronizer is arranged between the first input end and the output end; the system includes a vehicle controller, a transmission controller, a motor controller, and an engine controller; wherein, The vehicle controller is configured to send a clutch state holding request to the transmission controller, an engine torque adjustment request to the engine controller, and a motor torque adjustment request to the motor controller when the vehicle meets the mode switching condition for switching from the power split mode to the direct drive mode; The transmission controller is configured to keep the clutch in a closed state in response to the clutch state holding request; The engine controller is configured to adjust the torque of the engine in response to the engine torque adjustment request, and the motor controller is configured to adjust the torque of the first motor in response to the motor torque adjustment request so that the first synchronizer meets the torque condition; The vehicle controller is further configured to send a speed adjustment request to the motor controller when the first synchronizer meets the torque condition; The motor controller is further configured to adjust the speed of the first motor in response to the speed adjustment request so that the first synchronizer meets the speed condition; The vehicle controller is further configured to send a gear shift request to the transmission controller when the first synchronizer meets the speed condition; The transmission controller is further configured to control the first synchronizer to switch from the power split gear to the engaged gear in response to the gear shift request, so that the vehicle switches from the power split mode to the direct drive mode.

11. A vehicle, characterized in that, It includes the vehicle mode switching system as described in claim 10.

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