Control method of vehicle, vehicle, and storage medium

Abstract

The application discloses a control method of a vehicle, the vehicle and a storage medium, and belongs to the technical field of hybrid power. The method comprises the following steps: when the vehicle is switched from a series mode to a power split mode, the actual engine speed and a target speed range of the engine are obtained, the target speed range is calculated based on the maximum motor speed and the minimum motor speed of a first motor and is used to indicate the engine speed at which the vehicle can smoothly shift gears; in the case that the actual engine speed is not in the target speed range, the actual engine speed of the engine is adjusted to the target speed range; the actual engine speed after the adjustment is controlled to be unchanged, and the speed of the first motor is adjusted so that the sun gear speed of the planetary gear train reaches a target gear speed, and then the gear shifting operation of the target gear can be completed. In this way, the success rate of gear shifting in the process that the vehicle is switched from the series mode to the power split mode can be improved, and then the success rate that the vehicle is switched from the series mode to the power split mode can be improved.

Description

Technical Field

[0001] This application relates to the field of hybrid power technology, and in particular to a vehicle control method, a vehicle, and a storage medium. Background Technology

[0002] Currently, some hybrid vehicles use a planetary gear set power coupling mechanism, where the engine outputs power through the planetary gear set to achieve torque coupling and drive the vehicle. In this configuration, the power flow path is complex, with multiple components such as the engine, generator, sun gear, ring gear, and planet carrier interdependent. Furthermore, the speeds of the sun gear, planet carrier, and ring gear usually need to maintain a certain balance to ensure smooth power transmission.

[0003] During the switching from series mode to power-split mode, the gearbox is typically engaged by adjusting the speed of the gear ring, thus achieving the mode switch. However, if the gear ring speed cannot reach the target gear speed, the gear engagement cannot be completed, and therefore the switch to power-split mode cannot be successful. Summary of the Invention

[0004] This application provides a vehicle control method, a vehicle, and a storage medium. The method involves first adjusting the engine's actual speed to a range within which the vehicle can smoothly engage gears, and then adjusting the speed of the first motor to ensure the gear ring speed reaches the target gear speed, thereby enabling successful gear engagement and improving the gear engagement success rate. The technical solution includes the following:

[0005] In a first aspect, a vehicle control method is provided, applied to a hybrid vehicle, the vehicle comprising: an engine, a transmission, a first electric motor, and a planetary gear set, wherein the engine is connected to the planet carrier of the planetary gear set, the first electric motor is connected to the sun gear of the planetary gear set, and the input shaft of the transmission is connected to the ring gear of the planetary gear set, the method comprising: When the vehicle switches from series mode to power split mode, the actual speed and target speed range of the engine are obtained. The target speed range is calculated based on the highest and lowest motor speeds of the first motor and is used to indicate the engine speed at which the vehicle can smoothly engage gears. If the actual engine speed is not within the target speed range, adjust the actual engine speed to the target speed range; The actual speed of the engine remains unchanged after the control adjustment. The speed of the first motor is adjusted so that the speed of the planetary gear ring reaches the target gear speed and can complete the shifting of the target gear.

[0006] In this application, when a vehicle switches from series mode to power-split mode, the actual engine speed and the target engine speed range are first obtained. The target speed range is calculated based on the highest and lowest speeds of the first motor and includes the engine speed required for smooth gear engagement. In other words, the target speed range defines the engine speed within the first motor's capability range that allows for smooth gear engagement. This means that when the actual engine speed is within the target speed range, adjusting the first motor's speed will ensure that the ring gear speed reaches the target gear speed without exceeding the upper or lower speed limits. Therefore, by determining whether the actual engine speed is within the target speed range, if it is not, the engine speed can be adjusted to the target range. Then, the adjusted engine speed is kept constant, and the first motor speed is adjusted again, so that the ring gear speed of the planetary gear set can reach the target gear speed, thus completing the gear engagement operation. This improves the success rate of gear engagement during the switch from series mode to power-split mode, and consequently, the success rate of switching from series mode to power-split mode.

[0007] Optionally, the target speed range includes a minimum effective speed and a maximum effective speed, wherein the minimum effective speed is the minimum value of the target speed range, and the maximum effective speed is the maximum value of the target speed range. The step of determining the target speed range includes: The output shaft speed of the gearbox, the highest motor speed, and the lowest motor speed of the first motor are obtained. Based on the output shaft speed, the target transmission ratio, the gear ratio of the planetary gear set, the highest motor speed, and the lowest motor speed, the highest reference speed and the lowest reference speed of the engine are determined, and the target transmission ratio is the transmission ratio at the target gear. The minimum value between the engine's highest physical speed and the highest reference speed is determined as the highest effective speed, and the maximum value between the engine's lowest physical speed and the lowest reference speed is determined as the lowest effective speed; the target speed range is determined based on the lowest effective speed and the highest effective speed, where the highest physical speed is the highest speed the engine can reach and the lowest physical speed is the lowest speed the engine can reach.

[0008] In the above method, with the target gearbox being engaged in the desired gear as the objective, a maximum reference speed and a minimum reference speed are first calculated based on the upper and lower limits of the first motor's speed, the output shaft speed, and the target gear ratio. This yields the maximum and minimum speeds that the engine can reach within the first motor's speed adjustment capability, assuming successful gear engagement. Then, the minimum of the maximum physical speed and the maximum reference speed, and the maximum of the minimum physical speed and the minimum reference speed are taken. This ensures that the calculated maximum and minimum effective speeds are within the first motor's speed adjustment capability, and that the engine's maximum speed within its capability guarantees successful gear engagement. This avoids situations where the engine speed exceeds its capability range, leading to unsafe conditions or inability to engage gears.

[0009] Optionally, determining the engine's highest and lowest reference speeds based on the output shaft speed, the target transmission ratio, the planetary gear set ratio, the highest motor speed, and the lowest motor speed includes: The maximum reference speed is determined based on the output shaft speed, the target transmission ratio, the gear ratio of the planetary set, and the maximum motor speed, according to the speed balance relationship of the planetary set. The minimum reference speed is determined based on the output shaft speed, the target transmission ratio, the gear ratio of the planetary gear set, and the minimum motor speed, according to the speed balance relationship of the planetary gear set.

[0010] In the above method, by incorporating the highest and lowest motor speeds into the speed balance relationship of the planetary gear set, the speed adjustment process of the first motor can be simulated, thereby allowing for a faster and more convenient determination of the engine's expected speed limits.

[0011] Optionally, adjusting the actual speed of the engine to the target speed range includes: Based on the actual speed of the engine, a target engine speed is determined, and the target engine speed is within the target speed range; The first motor speed is determined based on the output shaft speed of the gearbox, the target transmission ratio, the gear ratio of the planetary gear set, and the target engine speed. The speed of the first motor is adjusted to the speed of the first motor so that the actual speed of the engine is adjusted to the target speed range.

[0012] In the above method, the engine speed to be adjusted is defined by the target engine speed, which is the engine speed that should be reached to successfully engage the target gear. Then, the speed of the first motor is calculated based on the output shaft speed of the gearbox, the target gear ratio, and the target engine speed. Subsequently, the speed of the first motor is controlled to achieve the target engine speed range. This is equivalent to providing a way to adjust the engine speed through the first motor, which can quickly adjust the actual engine speed to the target speed range.

[0013] Optionally, the target speed range includes a minimum effective speed and a maximum effective speed, wherein the minimum effective speed is the minimum value of the target speed range, and the maximum effective speed is the maximum value of the target speed range. Determining the target engine speed based on the actual engine speed includes: If the actual engine speed is greater than the maximum effective speed, the target engine speed is obtained by subtracting the first preset speed from the maximum effective speed. If the actual speed of the engine is less than the minimum effective speed, the minimum effective speed is added to the second preset speed to obtain the target engine speed.

[0014] In the above method, when the actual engine speed is greater than the maximum effective speed, the desired adjusted engine speed is obtained by subtracting a first preset speed from the maximum effective speed, ensuring that the actual engine speed is lower than the maximum effective speed by a certain margin. Conversely, when the actual engine speed is less than the minimum effective speed, the actual engine speed is increased by a second preset speed to ensure that it is higher than the minimum effective speed by a certain margin. Therefore, even if the engine speed fluctuates, the actual engine speed can be maintained within the target speed range, ensuring that the subsequent gear ring speed can reach the target gear speed, thus guaranteeing smooth engagement of the target gear.

[0015] Optionally, determining the first motor speed based on the output shaft speed of the gearbox, the target transmission ratio, the gear ratio of the planetary gear set, and the target engine speed includes: Multiply the output shaft speed by the target transmission ratio to obtain the target gear ring speed; Multiply the target gear ring speed by the gear ratio of the planetary gear set to obtain the first reference speed; A second reference speed is determined based on the target engine speed and the gear ratio of the planetary gear set; The first motor speed is obtained by subtracting the second reference speed from the first reference speed.

[0016] Optionally, the method further includes: The second motor speed is determined based on the adjusted actual speed of the engine, the output shaft speed of the gearbox, the target transmission ratio, and the gear ratio of the planetary gear set. And, the actual speed of the engine remains unchanged after the control adjustment, the speed of the first motor is adjusted so that the speed of the planetary gear ring gear reaches the target gear speed, and the target gear is engaged, including: The actual speed of the engine remains unchanged after the control adjustment. The speed of the first motor is adjusted to the speed of the second motor so that the speed of the gear ring reaches the target gear speed and can complete the shifting of the target gear.

[0017] In the above method, the speed of the second motor is the motor speed that enables the gear ring speed to reach the target gear speed. Therefore, by adjusting the speed of the first motor to the speed of the second motor, the gear ring speed can quickly reach the target gear speed. This is equivalent to giving a target speed for the first motor, so that by adjusting the speed of the first motor, the gear ring speed can quickly reach the target gear speed, thereby ensuring that the target gear can be engaged quickly, and thus improving the switching efficiency from series mode to power split mode.

[0018] Optionally, the method further includes: When the actual speed of the engine is within the target speed range, the speed of the third motor is determined directly based on the actual speed of the engine, the output shaft speed of the gearbox, the target transmission ratio, and the gear ratio of the planetary gear set. The actual speed of the engine is kept constant, and the speed of the first motor is adjusted to the speed of the third motor so that the speed of the gear ring reaches the target gear speed and the target gear can be engaged.

[0019] Secondly, a vehicle control device is provided for a hybrid vehicle, the vehicle comprising: an engine, a transmission, a first electric motor, and a planetary gear set, wherein the engine is connected to the planet carrier of the planetary gear set, the first electric motor is connected to the sun gear of the planetary gear set, and the input shaft of the transmission is connected to the ring gear of the planetary gear set, the device comprising: The acquisition module is used to acquire the actual speed and target speed range of the engine when the vehicle switches from series mode to power split mode. The target speed range is calculated based on the highest and lowest motor speed of the first motor and is used to indicate the engine speed at which the vehicle can smoothly engage gears. The first adjustment module is used to adjust the actual speed of the engine to the target speed range when the actual speed of the engine is not within the target speed range; The second adjustment module is used to control the actual speed of the engine after adjustment to remain unchanged, and to adjust the speed of the first motor so that the speed of the planetary gear ring reaches the target gear speed and can complete the shifting of the target gear.

[0020] Optionally, the target speed range includes a minimum effective speed and a maximum effective speed, wherein the minimum effective speed is the minimum value of the target speed range, and the maximum effective speed is the maximum value of the target speed range. The acquisition module is specifically used for: The output shaft speed of the gearbox, the highest motor speed, and the lowest motor speed of the first motor are obtained. Based on the output shaft speed, the target transmission ratio, the gear ratio of the planetary gear set, the highest motor speed, and the lowest motor speed, the highest reference speed and the lowest reference speed of the engine are determined, and the target transmission ratio is the transmission ratio at the target gear. The minimum value between the engine's highest physical speed and the highest reference speed is determined as the highest effective speed, and the maximum value between the engine's lowest physical speed and the lowest reference speed is determined as the lowest effective speed; the target speed range is determined based on the lowest effective speed and the highest effective speed, where the highest physical speed is the highest speed the engine can reach and the lowest physical speed is the lowest speed the engine can reach.

[0021] Optionally, the acquisition module is specifically used for: The maximum reference speed is determined based on the output shaft speed, the target transmission ratio, the gear ratio of the planetary set, and the maximum motor speed, according to the speed balance relationship of the planetary set. The minimum reference speed is determined based on the output shaft speed, the target transmission ratio, the gear ratio of the planetary gear set, and the minimum motor speed, according to the speed balance relationship of the planetary gear set.

[0022] Optionally, the first adjustment module is specifically used for: Based on the actual speed of the engine, a target engine speed is determined, and the target engine speed is within the target speed range; The first motor speed is determined based on the output shaft speed of the gearbox, the target transmission ratio, the gear ratio of the planetary gear set, and the target engine speed. The speed of the first motor is adjusted to the speed of the first motor so that the actual speed of the engine is adjusted to the target speed range.

[0023] Optionally, the target speed range includes a minimum effective speed and a maximum effective speed, wherein the minimum effective speed is the minimum value of the target speed range, and the maximum effective speed is the maximum value of the target speed range. The first adjustment module is specifically used for: If the actual engine speed is greater than the maximum effective speed, the target engine speed is obtained by subtracting the first preset speed from the maximum effective speed. If the actual speed of the engine is less than the minimum effective speed, the minimum effective speed is added to the second preset speed to obtain the target engine speed.

[0024] Optionally, the first adjustment module is specifically used for: Multiply the output shaft speed by the target transmission ratio to obtain the target gear ring speed; Multiply the target gear ring speed by the gear ratio of the planetary gear set to obtain the first reference speed; A second reference speed is determined based on the target engine speed and the gear ratio of the planetary gear set; The first motor speed is obtained by subtracting the second reference speed from the first reference speed.

[0025] Optionally, the device further includes: The determining module is used to determine the speed of the second motor based on the adjusted actual speed of the engine, the output shaft speed of the gearbox, the target transmission ratio, and the gear ratio of the planetary gear set; The second adjustment module is specifically used for: The actual speed of the engine remains unchanged after the control adjustment. The speed of the first motor is adjusted to the speed of the second motor so that the speed of the gear ring reaches the target gear speed and can complete the shifting of the target gear.

[0026] Optionally, the second adjustment module is further configured to: When the actual speed of the engine is within the target speed range, the speed of the third motor is determined directly based on the actual speed of the engine, the output shaft speed of the gearbox, the target transmission ratio, and the gear ratio of the planetary gear set. The actual speed of the engine is kept constant, and the speed of the first motor is adjusted to the speed of the third motor so that the speed of the gear ring reaches the target gear speed and the target gear can be engaged.

[0027] Thirdly, a vehicle is provided, the vehicle comprising: Memory, used to store executable program code; A processor is configured to call and run the executable program code from the memory, causing the vehicle to perform the aforementioned vehicle control method.

[0028] Fourthly, a computer-readable storage medium is provided, the computer-readable storage medium storing a computer program, which, when executed by a processor, implements the above-described vehicle control method.

[0029] Fifthly, a computer program product containing instructions is provided, which, when run on a computer, causes the computer to perform the steps of the vehicle control method described above.

[0030] It is understood that the beneficial effects of the second, third, fourth, and fifth aspects mentioned above can be found in the relevant descriptions in the first aspect above, and will not be repeated here. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is an architecture diagram of a power system for a hybrid vehicle provided in an embodiment of this application; Figure 2 This is a flowchart of a vehicle control method provided in an embodiment of this application; Figure 3 This is a comparison diagram of the rotation speed effect provided in an embodiment of this application; Figure 4 This is a flowchart of another vehicle control method provided in an embodiment of this application; Figure 5 This is a schematic diagram of the structure of a vehicle control device provided in an embodiment of this application; Figure 6 This is a schematic diagram of the structure of a vehicle provided in an embodiment of this application. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0034] It should be understood that "multiple" as mentioned in this application refers to two or more. In the description of this application, unless otherwise stated, " / " indicates "or," for example, A / B can mean A or B; "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist, for example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, to facilitate a clear description of the technical solutions of this application, the terms "first," "second," etc., are used to distinguish identical or similar items with essentially the same function and effect. Those skilled in the art will understand that the terms "first," "second," etc., do not limit the quantity or execution order, and that "first," "second," etc., do not necessarily imply differences.

[0035] Before describing the vehicle control method provided in the embodiments of this application, the power system architecture of the hybrid vehicle involved in the embodiments of this application will be described first.

[0036] For example, Figure 1 This is an architectural diagram of a power system for a hybrid vehicle provided in an embodiment of this application.

[0037] For example, such as Figure 1 As shown, the hybrid vehicle includes: an engine 101, a clutch (C1) 102, a first motor 103, a planetary gear set 104, a mold changer synchronizer (S1) 105, and a gearbox 106.

[0038] The engine 101 is one of the power sources of the vehicle, generating power by burning fuel (such as gasoline or diesel). The engine 101 is connected to the planetary gear set 104 via the clutch 102. The power generated by the engine 101 is transmitted to the planetary gear set 104 via the clutch 102, and then to the wheels of the vehicle via the gearbox 106, thus driving the vehicle.

[0039] Clutch (C1) 102 is disposed between engine 101 and planetary gear set 104, and is used to disconnect or connect the mechanical connection between engine 101 and planetary gear set 104. Specifically, when clutch 102 is in the closed state, engine 101 and planetary gear set 104 are mechanically connected, and engine 101 can output power to drive the vehicle. When clutch 102 is in the open state, engine 101 and planetary gear set 104 are disconnected, and engine 101 is decoupled from the transmission system.

[0040] The first motor 103, also called the TM motor (Traction Motor), is connected to the planetary gear set 104 and drives the vehicle by outputting power through the planetary gear set 104.

[0041] The planetary gear set 104 includes a planet carrier, a sun gear, and a ring gear. The engine 101 is specifically connected to the planet carrier of the planetary gear set 104, the first motor 103 is connected to the sun gear of the planetary gear set 104, and the ring gear of the planetary gear set 104 is connected to the input shaft of the gearbox 106.

[0042] In some embodiments, the power output by the engine 101 is partially transmitted to the ring gear via the planetary gear set 104, then to the wheel end via the gearbox 106 to drive the vehicle, and the other part is transmitted to the sun gear to drive the first motor 103 to generate electricity.

[0043] The mold-changing synchronizer 105 is connected to the planetary gear set 104 and is used to lock the planetary gear set 104. When the mold-changing synchronizer 105 is in neutral, the planetary gear set 104 is not locked. At this time, the power output by the engine 101 is partially transmitted to the ring gear through the planetary gear set 104 and then to the gearbox 106 to drive the vehicle, and partially transmitted to the sun gear to drive the first motor 103 to generate electricity. When the mold-changing synchronizer 105 is engaged (i.e., in gear), the planetary gear set 104 is locked. At this time, the engine 101 and the first motor 103 are mechanically connected, and the engine 101, the first motor 103, and the ring gear rotate at the same speed. All the power of the engine 101 is transmitted to the ring gear or the sun gear.

[0044] The gearbox 106 is used to change the speed and torque output by the engine 101 / first motor 103 to adapt to different driving conditions and different gears, ensuring efficient operation of the vehicle under different speeds and loads. Optionally, the number of gears in the gearbox may be multiple, such as 2, 3, 4, etc., and this application embodiment does not limit this.

[0045] like Figure 1 As shown, the gearbox 106 is equipped with synchronizer S2 and synchronizer S0. Each synchronizer can complete the shifting operation of two gears. The two synchronizers work together to achieve power switching of four forward gears. The gearbox 106 is a four-speed transmission mechanism.

[0046] Figure 1 The architecture shown can be set on one axle of the vehicle, and the other axle of the vehicle can also be equipped with a second motor to drive the wheels of the other axle of the vehicle, so as to realize four-wheel drive.

[0047] For example, Figure 1 The architecture shown can be installed on the front axle of the vehicle, in which case the first motor 103 can also be referred to as a front-drive motor, and both the engine 101 and the first motor 103 are used to drive the front wheels of the vehicle. Correspondingly, the second motor will be installed on the rear axle of the vehicle, and the second motor can also be referred to as a rear-drive motor, used to drive the rear wheels of the vehicle.

[0048] It should be understood that, in the above Figure 1Under the powertrain architecture shown, the vehicle can operate in pure electric mode, series mode, direct drive mode, and power split mode. The working process of these powertrain modes is explained below.

[0049] In pure electric mode, clutch 102 is open, engine 101 is not running, synchronizer 105 is in gear, planetary gear set 104 is locked, and first motor 103 rotates synchronously with ring gear. The power output of first motor 103 is directly transmitted to ring gear, and then enters gearbox 106 through the input shaft. Gearbox 106 is in gear (i.e., either synchronizer S2 or synchronizer S0 is engaged), and then the power output of ring gear is mechanically transmitted through the gear engaged in gearbox 106, finally transmitted to the wheels through the output shaft, realizing pure electric driving of the vehicle. It should be understood that the above working process applies to pure electric four-wheel drive mode / pure electric front-wheel drive mode.

[0050] In direct drive mode, clutch 102 is closed, engine 101 is running, mold change synchronizer 105 is in gear, planetary gear set 104 is locked, and gearbox 106 is in gear (i.e., either synchronizer S2 or synchronizer S0 is engaged). Engine 101 outputs power to ring gear through planetary gear set 104, which is then transmitted to gearbox 106. Finally, the power is transmitted to the wheels through the currently engaged gear in gearbox 106, thus driving the vehicle.

[0051] In series mode, clutch 102 is closed, engine 101 is running, synchronizer 105 is in gear, planetary gear set 104 is locked, engine 101, first motor 103 and ring gear rotate at the same speed, gearbox 106 is in neutral (i.e. synchronizer S2 and synchronizer S0 are in neutral). The engine drives the first motor 103 to generate electricity through planetary gear set 104. That is, the torque output by the engine is directly transmitted to the sun gear, which drives the first motor to rotate and generate electricity. At this time, although the ring gear rotates at the same speed as the engine and the first motor, the torque output by the first motor completely cancels the torque output by the engine. Therefore, the output torque of the ring gear is zero. Instead, the power battery supplies power to the second motor, and the second motor outputs power to drive the vehicle.

[0052] In power split mode, clutch 102 is closed, engine 101 is running, mold change synchronizer 105 is in neutral, planetary gear set 104 is not locked, and gearbox 106 is in gear (i.e., either synchronizer S2 or synchronizer S0 is engaged). The power output of engine 101 is transmitted through two paths: part is transmitted to the ring gear, and then mechanically transmitted to the wheel end through the currently engaged gear of gearbox 106 to drive the vehicle; the other part is transmitted to the sun gear, thereby driving the first motor 103 to generate electricity.

[0053] In addition, it should be understood that under the above power modes, the sun gear, planet carrier and ring gear all satisfy the following speed balance relationship as shown in formula (1).

[0054] (1) in, This refers to the rotational speed of the sun gear, which is also the rotational speed of the first motor. The rotational speed of the gear ring is... is the planetary carrier speed, which is also the engine speed, and k is the gear ratio of the planetary gear set, usually the number of teeth on the ring gear / the number of teeth on the sun gear.

[0055] It is worth noting that the embodiments in this application are based solely on the above description. Figure 1 The powertrain architecture described in the embodiments is used as an example for illustration. Any powertrain architecture that includes an engine, a front drive motor, a P4 motor (i.e., a rear drive motor located on the rear axle), and an AMT (Automated Manual Transmission), and that couples the engine, front drive motor, and AMT transmission through a planetary gear set, and that can realize both series mode and power split mode, falls within the protection scope of the embodiments of this application.

[0056] Researchers found that in the above Figure 1 In the powertrain architecture shown, during the transition from series mode to power-split mode, the transmission needs to engage a gear in power-split mode. Therefore, the transmission must shift from neutral to engaged, meaning synchronizer S2 or synchronizer S0 needs to engage a gear (such as the target gear). However, engaging the target gear requires the ring gear to reach the target gear's rotational speed. Only then can the gear speeds at both ends of the synchronizer corresponding to the target gear approach each other, allowing for a smooth gear engagement.

[0057] Since the sun gear, planet carrier, and ring gear satisfy the speed balance formula shown in Formula 1 above, to adjust the ring gear speed to reach the target gear speed, the engine speed can be kept constant, and then the speed of the first motor can be adjusted so that the ring gear speed can be changed under the constraint of the speed balance formula above.

[0058] However, in series mode, the engine is generally controlled to run at a lower speed. In this case, while keeping the engine speed constant at a low speed, the speed of the first motor is adjusted. According to the speed balance relationship shown in the above formula (1), if the gear ring speed is to reach a higher target gear speed, the negative speed of the first motor needs to be higher. However, the first motor generally has upper and lower speed limits, that is, there is a maximum positive speed in the positive direction (called the highest motor speed of the first motor) and a maximum negative speed in the negative direction (called the lowest motor speed of the first motor). If the speed of the first motor has been adjusted to the maximum negative speed in the negative direction, but the gear ring speed still cannot reach the target gear speed, then the gear shifting operation cannot be completed, and the vehicle cannot smoothly switch to the power split mode.

[0059] In addition, there are specific extreme operating conditions in the series mode. In this case, in order to protect the system or meet the high power demand, the engine speed may be increased, and the engine may run at a higher speed. In this case, while keeping the high speed of the engine constant, in the process of adjusting the speed of the first motor, according to the speed balance relationship shown in the above formula (1), if the speed of the gear ring is to reach a smaller target gear speed, the forward speed of the first motor needs to be higher. If the speed of the first motor has been adjusted to the maximum forward speed in the process of adjusting the speed of the first motor in the forward direction, but the speed of the gear ring still cannot reach the target gear speed, then the gear shifting operation cannot be completed in this case, and the vehicle cannot switch to the power split mode smoothly.

[0060] Therefore, this application provides a vehicle control method that can be applied to scenarios where the vehicle's power mode switches from series mode to power split mode.

[0061] Specifically, when the vehicle switches from series mode to power-split mode, a target engine speed range can be calculated based on the highest and lowest motor speeds of the first motor. This target speed range includes the engine speeds that allow the vehicle to smoothly engage gears. Then, it is determined whether the actual engine speed is within the target speed range. If the actual engine speed is not within the target speed range, the actual engine speed is first adjusted to the target speed range. Then, the adjusted actual engine speed is kept constant while the speed of the first motor is adjusted so that the gear ring speed reaches the target gear speed, thereby enabling the gear engagement operation.

[0062] In this scenario, the target speed range defines the engine speed within the capability of the first motor that allows the vehicle to smoothly engage gears. In other words, when the actual engine speed is within the target speed range, adjusting the first motor speed will ensure that the ring gear speed reaches the target gear speed without exceeding the upper or lower speed limits. Therefore, by first adjusting the engine speed to the target range when it is not yet within it, and then adjusting the first motor speed, the ring gear speed of the planetary gear set can reach the target gear speed, thus enabling the engagement of the target gear. This improves the success rate of gear engagement during the transition from series mode to power-split mode, and consequently, the success rate of switching from series mode to power-split mode.

[0063] The vehicle control method provided in the embodiments of this application will be explained in detail below.

[0064] Figure 2 This is a flowchart illustrating a vehicle control method provided in an embodiment of this application. This method can be applied to vehicles containing… Figure 1 The powertrain architecture of hybrid vehicles specifically applies to the hybrid control unit (HCU). See also Figure 2 The method includes the following steps 201-203.

[0065] Step 201: When the vehicle switches from series mode to power split mode, the actual speed and target speed range of the engine are obtained. The target speed range is calculated based on the highest and lowest motor speeds of the first motor and is used to indicate the engine speed at which the vehicle can smoothly engage gears.

[0066] The maximum motor speed refers to the highest speed that can be achieved within the first motor's capability range, while the minimum motor speed refers to the lowest speed that can be achieved within the first motor's capability range. Generally, the minimum motor speed is the maximum negative speed (i.e., the maximum speed of negative rotation). For example, the maximum motor speed can be 6600 rpm, and the minimum motor speed can be -6600 rpm.

[0067] The actual speed of the engine is the speed of the engine at the current moment.

[0068] The target speed range is calculated based on the highest and lowest motor speeds of the first motor, and it includes the engine speed that allows the vehicle to smoothly engage gears. In other words, the target speed range defines the engine speed within the capability range of the first motor that allows the vehicle to smoothly engage gears. That is to say, when the actual engine speed is within the target speed range, no matter how the speed of the first motor is adjusted, it can be guaranteed that the speed of the gear ring will reach the target gear speed without exceeding the upper and lower speed limits.

[0069] In this embodiment, the target speed range includes a minimum effective speed and a maximum effective speed. The minimum effective speed is the minimum value of the target speed range, and the maximum effective speed is the maximum value of the target speed range. In other words, the minimum effective speed is the lowest engine speed within the first motor's speed capability range that allows the vehicle to smoothly engage gears, and the maximum effective speed is the highest engine speed within the first motor's speed capability range that allows the vehicle to smoothly engage gears. In this case, after determining the minimum and maximum effective speeds, the target speed range is also determined. The process of determining the target speed range is explained below.

[0070] One possible approach is to obtain the output shaft speed of the gearbox, the maximum motor speed, and the minimum motor speed of the first motor; based on the output shaft speed of the gearbox, the target transmission ratio, the gear ratio of the planetary gear set, the maximum motor speed, and the maximum motor speed, determine the maximum reference speed and the minimum reference speed of the engine; determine the minimum value between the maximum physical speed and the maximum reference speed of the engine as the maximum effective speed, and determine the maximum value between the minimum physical speed and the minimum reference speed of the engine as the minimum effective speed; and determine the target speed range based on the minimum effective speed and the maximum effective speed.

[0071] The target gear ratio is the gear ratio of the transmission in the target gear, which is the gear ratio of the gear to be engaged.

[0072] The maximum reference speed is used to indicate the engine speed when the gearbox needs to engage the target gear under the maximum speed capability (maximum motor speed) of the first motor. It is also the highest speed that the engine can reach under this condition. If the engine exceeds this speed, the speed of the first motor will also exceed the speed capability range.

[0073] The minimum reference speed is used to indicate the engine speed at which the gearbox needs to engage the target gear under the minimum speed capability (minimum motor speed) of the first motor. It is also the lowest speed that the engine can reach under this condition. If the engine speed is lower than this speed, the speed of the first motor may exceed the speed capability range.

[0074] The maximum physical speed is the highest speed that the engine can reach, and the minimum physical speed is the lowest speed that the engine can reach. Both the maximum and minimum physical speeds are pre-calibrated based on the engine's capability characteristics and are used to represent the highest and lowest speeds within the engine's capability range. For example, the maximum physical speed is 5800 rpm and the minimum physical speed is 700 rpm.

[0075] Since the engine's physical capabilities are not considered when calculating the engine speed based on the highest and lowest motor speeds of the first motor and the output shaft speed of the gearbox, the highest and lowest reference speeds calculated in this way are likely to exceed the engine's capabilities. Therefore, the minimum value between the engine's highest physical speed and the highest reference speed should be determined as the highest effective speed, and the maximum value between the engine's lowest physical speed and the lowest reference speed should be determined as the lowest effective speed.

[0076] In the above method, with the target gearbox being engaged in the desired gear as the objective, a maximum reference speed and a minimum reference speed are first calculated based on the upper and lower limits of the first motor's speed, the output shaft speed, and the target gear ratio. This yields the maximum and minimum speeds that the engine can reach within the first motor's speed adjustment capability, assuming successful gear engagement. Then, the minimum of the maximum physical speed and the maximum reference speed, and the maximum of the minimum physical speed and the minimum reference speed are taken. This ensures that the calculated maximum and minimum effective speeds are within the first motor's speed adjustment capability, and that the engine's maximum speed within its capability guarantees successful gear engagement. This avoids situations where the engine speed exceeds its capability range, leading to unsafe conditions or inability to engage gears.

[0077] It should be understood that after obtaining the highest effective speed and the lowest effective speed, the lowest effective speed, the speed between the lowest effective speed and the highest effective speed, and the highest effective speed can be determined as multiple engine speeds within the target speed range, that is, the target speed range of [lowest effective speed, highest effective speed] can be obtained.

[0078] Specifically, the operation of determining the engine's maximum and minimum reference speeds based on the gearbox's output shaft speed, target transmission ratio, planetary gear set ratio, maximum motor speed, and maximum motor speed can be as follows: determine the maximum reference speed based on the gearbox's output shaft speed, target transmission ratio, planetary gear set ratio, and maximum motor speed, according to the planetary gear set's speed balance relationship; determine the minimum reference speed based on the output shaft speed, target transmission ratio, planetary gear set ratio, and minimum motor speed, according to the planetary gear set's speed balance relationship.

[0079] It should be understood that the rotational speed balance relationship of the planetary gear set is shown in the following formula (2).

[0080] (2) in, The output shaft speed of the gearbox. The target gear ratio is the gear ratio at the target gear position.

[0081] In the above steps, when calculating the maximum reference speed, the maximum motor speed is used as... Then, by substituting the output shaft speed of the gearbox, the target transmission ratio, the gear ratio of the planetary gear set, and the maximum motor speed into the above formula (2), an engine speed can be calculated. This engine speed is the maximum reference speed. Similarly, when calculating the minimum reference speed, the minimum motor speed is used as... Then, by substituting the output shaft speed of the gearbox, the target transmission ratio, the gear ratio of the planetary gear set, and the minimum motor speed into the above formula (2), an engine speed can be calculated, which is the minimum reference speed.

[0082] Since there is a speed balance relationship between the sun gear, planet carrier, and ring gear in the planetary gear set, the engine speed, the speed of the first motor, and the speed of the ring gear also have the above-mentioned speed balance relationship. Therefore, when the gearbox is engaged in the target gear, the speed that the ring gear should reach (i.e., the target gear speed) can be obtained based on the output shaft speed and the transmission ratio under the target gear. Then, the speed that the ring gear should reach is substituted into the above formula (2), and the highest motor speed and the lowest motor speed are substituted into the formula respectively. This is equivalent to simulating the upper and lower limits of the first motor during the speed adjustment process. In this case, the engine speed that allows the vehicle to smoothly engage gears within the capability range of the first motor can be obtained.

[0083] In the above method, by incorporating the highest and lowest motor speeds into the speed balance relationship of the planetary gear set, the speed adjustment process of the first motor can be simulated, thereby allowing for a faster and more convenient determination of the engine's expected speed limits.

[0084] Furthermore, after determining the target speed range, the actual engine speed can be compared with the target speed range to determine whether the actual engine speed is within the target speed range.

[0085] It should be understood that since the target speed range is within the engine speed range that the vehicle can smoothly engage gears within the speed adjustment capability of the first motor, when the actual engine speed is within the target speed range, it means that subsequent adjustments to the first motor will not exceed the speed capability range of the first motor, thus enabling the gear ring speed to reach the target gear speed. Therefore, by determining whether the actual engine speed is within the target speed range, it can be determined whether the vehicle can smoothly engage gears by directly adjusting the first motor at the current actual engine speed.

[0086] In some embodiments, when the actual engine speed is within the target speed range, the actual engine speed can be directly controlled to remain unchanged, and the speed of the first motor can be adjusted so that the speed of the gear ring reaches the target gear speed.

[0087] It should be understood that the target gear speed is the speed that the gear ring corresponding to the target gear should reach, which is determined by the gearbox output shaft and the target gear ratio.

[0088] If the actual engine speed is within the target speed range, it means that at the current actual engine speed, by directly adjusting the speed of the first motor, the gear ring speed can reach the target gear speed, so that the vehicle can smoothly engage gears. Therefore, in this case, the actual engine speed can be kept constant while adjusting the speed of the first motor.

[0089] Specifically, when the actual engine speed is within the target speed range, the speed of the third motor can be determined directly based on the actual engine speed, the output shaft speed of the gearbox, the target transmission ratio, and the gear ratio of the planetary gear set. Then, the actual engine speed is kept constant, and the speed of the first motor is adjusted to the speed of the third motor so that the speed of the gear ring reaches the target gear speed and the target gear can be engaged.

[0090] The specific operation for determining the speed of the third motor based on the actual engine speed, the output shaft speed of the gearbox, the target transmission ratio, and the gear ratio of the planetary gear set is as follows: substitute the actual engine speed, the output shaft speed of the gearbox, the target transmission ratio, and the gear ratio of the planetary gear set into the above formula (2) to calculate the speed of the first motor. Then the speed of the third motor can be obtained.

[0091] In the above steps, the goal is to engage the target gear in the transmission. The actual engine speed is fixed, and the speed of the first motor is adjusted with the speed of the third motor as the target. During the adjustment of the speed of the first motor, it is determined whether the speed of the gear ring reaches the target gear speed. If the speed of the gear ring reaches the target gear speed, the adjustment of the first motor is stopped, and the target gear can be engaged at this time.

[0092] It is also worth noting that when the vehicle is driving in series mode, the planetary gear set is locked, and the engine speed, the speed of the first motor, and the speed of the ring gear are the same. Before adjusting the speed of the first motor, it is necessary to control the mold change synchronizer to be in neutral so that the planetary gear set is not locked. This allows the actual speed of the engine to remain unchanged, while adjusting the speed of the first motor to make the speed of the ring gear reach the target gear speed.

[0093] Step 202: If the actual engine speed is not within the target speed range, adjust the actual engine speed to the target speed range.

[0094] If the actual engine speed is not within the target speed range, it means that at the current actual engine speed, directly adjusting the speed of the first motor may result in the first motor speed reaching its upper or lower limit, but the gear ring speed still cannot reach the target gear speed, thus preventing the vehicle from shifting gears smoothly. Therefore, in this case, the actual engine speed can be adjusted to the target speed range first.

[0095] In the above method, when the actual engine speed is not within the target speed range, the actual engine speed is first adjusted to the target speed range. This ensures that the actual engine speed after adjustment is within the capability range of the first motor, allowing the gear ring speed to reach the target gear speed, thereby improving the success rate of shifting to the target gear.

[0096] One possible approach is that the operation of step 202 may include the following steps (1)-(3).

[0097] (1) Determine the target engine speed based on the actual engine speed.

[0098] The target engine speed is the speed at which the engine is expected to reach after adjustment, and the target engine speed is within the target speed range. In other words, the target engine speed is the speed at which the engine should reach when the target gear is engaged.

[0099] In some embodiments, step (1) can be performed as follows: when the actual speed of the engine is greater than the maximum effective speed, the maximum effective speed is subtracted from the first preset speed to obtain the target engine speed; when the actual speed of the engine is less than the minimum effective speed, the minimum effective speed is added to the second preset speed to obtain the target engine speed.

[0100] Both the first preset speed and the second preset speed are used to indicate the safety margin that keeps the actual speed of the engine within the target speed range. In addition, the first preset speed and the second preset speed can be pre-calibrated by technicians. In some embodiments, the first preset speed and the second preset speed can be the same or different.

[0101] During the calibration process of the first preset speed, for a vehicle model, an initial calibration value is first set. Then, the actual speed of the engine is controlled to be greater than the maximum effective speed. The vehicle is then controlled at different speeds to determine whether the initial calibration value can keep the actual speed of the engine within the target speed range and maintain it for a certain period of time (preset duration) at different speeds. If the initial calibration value cannot keep the actual speed of the engine within the target speed range and maintain it for a certain period of time, the initial calibration value can be adjusted until the adjusted calibration value can keep the actual speed of the engine within the target speed range and maintain it for a certain period of time at different speeds. The adjusted calibration value can then be set as the first preset speed. Based on the same principle, in the calibration process of the second preset speed, for a vehicle model, an initial calibration value is first set. Then, the actual speed of the engine can be controlled to be lower than the minimum effective speed. Then, the vehicle is controlled at different speeds to determine whether the initial calibration value can keep the actual speed of the engine within the target speed range and maintain it for a certain period of time (preset duration) at different speeds. If the initial calibration value cannot keep the actual speed of the engine within the target speed range and maintain it for a certain period of time, the initial calibration value can be adjusted until the adjusted calibration value can keep the actual speed of the engine within the target speed range and maintain it for a certain period of time at different speeds. Then, the adjusted calibration value can be set as the second preset speed.

[0102] Because engine speed fluctuates and is not constant, if the actual engine speed is greater than the maximum effective speed, and the engine speed is only adjusted to the maximum effective speed, or if the actual engine speed is less than the minimum effective speed, and the engine speed is only adjusted to the minimum effective speed, that is, only the actual engine speed is adjusted to the boundary of the target speed range, then the engine speed may be outside the target speed range due to fluctuations. Therefore, adjusting the speed of the first motor may still not be able to make the gear ring speed reach the target gear speed.

[0103] In the above method, when the actual engine speed is greater than the maximum effective speed, the desired adjusted engine speed is obtained by subtracting a first preset speed from the maximum effective speed, ensuring that the actual engine speed is lower than the maximum effective speed by a certain margin. Conversely, when the actual engine speed is less than the minimum effective speed, the actual engine speed is increased by a second preset speed to ensure that it is higher than the minimum effective speed by a certain margin. Therefore, even if the engine speed fluctuates, the actual engine speed can be maintained within the target speed range, ensuring that the subsequent gear ring speed can reach the target gear speed, thus guaranteeing smooth engagement of the target gear.

[0104] (2) Determine the speed of the first motor based on the output shaft speed of the gearbox, the target transmission ratio, the gear ratio of the planetary gear set and the target engine speed.

[0105] The purpose here is to adjust the engine speed using the first motor so that the engine speed reaches the speed it should reach when engaging the target gear (i.e., within the target speed range). According to the speed balance relationship, to reach the engine speed required for engaging the target gear, the speed the first motor should reach needs to be calculated based on the gear ring speed of the target gear. Only then can the engine speed be adjusted to achieve the target gear speed. Otherwise, if the current gear ring speed does not match the target gear speed, the calculated engine speed may be invalid, and the target gear cannot be engaged. Therefore, the first motor speed is determined based on the output shaft speed of the transmission, the target gear ratio, and the target engine speed.

[0106] One possible approach is to multiply the output shaft speed of the gearbox by the target transmission ratio to obtain the target ring gear speed; multiply the target ring gear speed by the planetary gear set ratio to obtain the first reference speed; determine the second reference speed based on the target engine speed and the planetary gear set ratio; and subtract the first reference speed from the second reference speed to obtain the first motor speed.

[0107] The target gear speed is also the target gear speed, which is the speed at which the gear ring should reach when the transmission is to engage the target gear.

[0108] It should be understood that the above method calculates the speed of the first motor based on the speed balance relationship between the sun gear, planet carrier, and ring gear. Therefore, the output shaft speed is multiplied by the target transmission ratio to obtain the target ring gear speed; the target ring gear speed is multiplied by the planetary gear ratio to obtain the first reference speed; based on the target engine speed and the planetary gear ratio, the second reference speed is determined; the operation of subtracting the first reference speed from the second reference speed to obtain the first motor speed is essentially substituting the output shaft speed into the following formula (3). Substitute the target transmission ratio into And substitute the target engine speed into The calculated motor speed is obtained through calculation. This is the speed of the first motor.

[0109] (3) in, The second reference speed, The first reference speed, The target gear ring speed.

[0110] It is worth noting that during the process of switching the vehicle from series mode to power split mode, the mold change synchronizer needs to be switched from the in-gear state to the neutral state. After the mold change synchronizer is switched to the neutral state, the planetary gear set is not locked. In this case, the speed of the first motor can be calculated by the above step (2).

[0111] In other embodiments, after obtaining the target engine speed, in addition to calculating the first motor speed through the operation of step (2) above, the target engine speed can also be directly determined as the first motor speed.

[0112] When the vehicle is running in series mode, the mode change synchronizer is in gear, the planetary gear set is locked, and the engine and the first motor are rigidly connected, meaning they rotate at the same speed. In this case, the target engine speed can be directly set as the first motor speed. After the speed of the first motor is adjusted to the first motor speed, the actual engine speed can also be within the target speed range.

[0113] (3) Control the speed of the first motor to adjust to the speed of the first motor so that the actual speed of the engine is adjusted to the target speed range.

[0114] Specifically, the operation in step (3) can be implemented in the following two cases.

[0115] In the first scenario, if the mold change synchronizer is switched to neutral and the planetary gear set is not locked, the speed of the gear ring can be kept constant while adjusting the actual speed of the engine through the first motor. This allows the speed of the first motor to be adjusted to the first motor speed, thereby adjusting the actual speed of the engine to the target engine speed, which means the actual speed of the engine can be adjusted to the target speed range.

[0116] In the second scenario, when the vehicle is driving in series mode, the mold-changing synchronizer is in gear. If the mold-changing synchronizer has not yet switched to neutral, the planetary gear set is still locked, and the engine and the first motor are rigidly connected, meaning they rotate at the same speed. Therefore, in this case, by directly adjusting the first motor to its speed, the actual speed of the engine will also change accordingly. This achieves the effect of adjusting the engine speed through the first motor, ensuring that the actual speed of the engine is within the target speed range.

[0117] In steps (1) to (3) above, the engine speed to be adjusted is defined by the target engine speed, which is the engine speed that should be reached to smoothly engage the target gear. Then, the first motor speed is calculated based on the output shaft speed and the target gear ratio, as well as the target engine speed. Subsequently, the engine speed is kept within the target speed range by controlling the speed of the first motor. This is equivalent to providing a way to adjust the engine speed through the first motor, which can quickly adjust the actual engine speed to the target speed range.

[0118] It should be understood that in the process of adjusting the speed of the first motor to the target speed range by controlling the speed of the first motor, the actual speed of the engine can be continuously acquired to determine whether the actual speed of the engine is within the target speed range, or whether the actual speed of the engine has reached the target engine speed. If the actual speed of the engine is within the target speed range, the adjustment of the speed of the first motor can be stopped, or if the actual speed of the engine has reached the target engine speed, the adjustment of the speed of the first motor can be stopped.

[0119] Furthermore, once the actual engine speed is within the target speed range, it indicates that adjusting the speed of the first motor will allow the gear ring speed to reach the target gear speed. Therefore, in this case, the mold change synchronizer can be switched to neutral or kept in neutral to prevent the planetary gear set from locking. Then, the actual engine speed is kept constant while adjusting the speed of the first motor to change the gear ring speed, which means that step 203 can be executed further.

[0120] Step 203: Keep the actual speed of the engine unchanged after adjustment, and adjust the speed of the first motor so that the speed of the planetary gear ring reaches the target gear speed and can complete the shifting of the target gear.

[0121] Since the speed of the first motor is calculated based on the target gear ring speed and the engine speed that should be reached when the target gear is engaged, if the engine has already reached the speed that should be reached when the target gear is engaged, by keeping the actual speed of the engine unchanged after adjustment and adjusting the speed of the first motor, the gear ring speed can be made to reach the target gear speed.

[0122] In some embodiments, when the engine speed is adjusted to the target speed range by the first motor and the target engine speed is reached, the engine speed can be directly controlled to remain at the target engine speed, and the first motor can be kept running at the first motor speed, so that the gear ring speed can reach the target gear ring speed, that is, the gear ring speed can reach the target gear speed.

[0123] Since the first motor speed is calculated based on the target gear ring speed (i.e., the target gear speed) and the target engine speed, when the engine speed has reached the target engine speed, the engine speed is kept constant, and the first motor is controlled to maintain its speed so that the gear ring speed can naturally reach the target gear speed.

[0124] In other embodiments, the engine speed is adjusted to the target speed range by the first motor, but not necessarily to the target engine speed. In this case, in order to make the gear ring speed quickly reach the target gear speed, the speed of the second motor can be determined first based on the actual speed of the adjusted engine, the output shaft speed of the gearbox, the target transmission ratio, and the gear ratio of the planetary gear set, and then the speed of the first motor can be adjusted based on the speed of the second motor.

[0125] The second motor speed is the speed that the first motor needs to reach in order for the gear ring speed to reach the target gear speed.

[0126] Specifically, the output shaft speed of the gearbox can be substituted into the above formula (3). Substituting the target transmission ratio into the above formula (3) Then, the actual engine speed after adjustment can be substituted into the above formula (3). To calculate the motor speed, the calculated motor speed is... Then it is the second motor speed, that is, when the actual speed of the engine has reached the engine speed that can smoothly engage the target gear, the motor speed that can make the gear ring speed reach the target gear speed is calculated by the speed balance relationship of the above formula (2).

[0127] In this case, step 203 can be performed as follows: keep the actual speed of the engine unchanged after adjustment, adjust the speed of the first motor to the speed of the second motor so that the speed of the gear ring reaches the target gear speed and can complete the shifting of the target gear.

[0128] In the above method, the speed of the second motor is the motor speed that enables the gear ring speed to reach the target gear speed. Therefore, by adjusting the speed of the first motor to the speed of the second motor, the gear ring speed can quickly reach the target gear speed. This is equivalent to giving a target speed for the first motor, so that by adjusting the speed of the first motor, the gear ring speed can quickly reach the target gear speed, thereby ensuring that the target gear can be engaged quickly, and thus improving the switching efficiency from series mode to power split mode.

[0129] For example, Figure 3 This is a comparison diagram of the rotational speed effect provided in an embodiment of this application, such as... Figure 3 As shown, before applying the vehicle control method provided in this application embodiment, during the adjustment of the first motor, if the actual engine speed is lower than the minimum effective speed, the first motor speed has already reached the lower speed limit, and the gear ring speed is still lower than the target gear speed, thus preventing the target gear from being engaged. However, after applying the vehicle control method provided in this application embodiment, the actual engine speed is first controlled to be higher than the minimum effective speed. Therefore, during the adjustment of the first motor speed, the first motor speed will not exceed the lower speed limit, and in this case, the gear ring speed can successfully reach the target gear speed. It is evident that during the switch from series mode to power-split mode, by applying the vehicle control method provided in this application embodiment, the gear ring speed can reach the target gear speed by adjusting the first motor speed, thus ensuring successful engagement of the target gear and a smooth switch from series mode to power-split mode.

[0130] To facilitate understanding, we will now combine... Figure 4 The overall process of the vehicle control method provided in the embodiments of this application is described.

[0131] Figure 4 This is a flowchart of another vehicle control method provided in an embodiment of this application. See also... Figure 4 , Figure 4 The process includes the following steps 401-409.

[0132] Step 401: When the vehicle switches from series mode to power split mode, obtain the output shaft speed of the transmission, the target transmission ratio, the actual speed of the engine, and the highest and lowest motor speeds of the first motor.

[0133] Step 402: Determine the maximum reference speed and minimum reference speed based on the output shaft speed of the gearbox, the target transmission ratio, the gear ratio of the planetary gear set, the maximum motor speed, and the minimum motor speed.

[0134] Step 403: Determine the minimum value between the highest physical speed and the highest reference speed as the highest effective speed, and determine the maximum value between the lowest physical speed and the lowest reference speed as the lowest effective speed. Then, determine the target speed range based on the highest effective speed and the lowest effective speed.

[0135] Step 404: Determine whether the actual engine speed is within the target speed range. If the actual engine speed is not within the target speed range, continue to execute step 405 or step 406. If the actual engine speed is within the target speed range, directly execute step 409.

[0136] Step 405: If the actual engine speed is greater than the maximum effective speed, subtract the first preset speed from the maximum effective speed to obtain the target engine speed.

[0137] Step 406: If the actual engine speed is less than the minimum effective speed, add the minimum effective speed to the second preset speed to obtain the target engine speed.

[0138] Step 407: Determine the speed of the first motor based on the output shaft speed of the gearbox, the target transmission ratio, the gear ratio of the planetary gear set, and the target engine speed.

[0139] Step 408: Control the speed of the first motor to adjust to the speed of the first motor, so that the actual speed of the engine is adjusted to the target speed range.

[0140] Step 409: Keep the actual speed of the engine constant and adjust the speed of the first motor so that the speed of the gear ring reaches the target gear speed and can complete the shifting of the target gear.

[0141] In this embodiment, when the vehicle switches from series mode to power-split mode, the HCU first obtains the actual engine speed and the target engine speed range. The target speed range is calculated based on the highest and lowest speeds of the first motor and includes the engine speed required for smooth gear engagement. In other words, the target speed range defines the engine speed within the first motor's capability range that allows for smooth gear engagement. This means that when the actual engine speed is within the target speed range, regardless of adjustments to the first motor speed, the gear ring speed can reach the target gear speed without exceeding the upper or lower speed limits. Therefore, by determining whether the actual engine speed is within the target speed range, if it is not, the engine speed can be adjusted to the target range. Then, the adjusted engine speed is kept constant, and the first motor speed is adjusted again, so that the gear ring speed of the planetary gear set can reach the target gear speed, thus completing the gear engagement operation. This improves the success rate of gear engagement during the switch from series mode to power-split mode, and consequently, the success rate of switching from series mode to power-split mode.

[0142] Figure 5 This is a schematic diagram of a vehicle control device provided in an embodiment of this application. The vehicle control device can be implemented as part or all of the vehicle by software, hardware, or a combination of both. The vehicle can be described below. Figure 6 The vehicle shown. See also Figure 5 The device includes: an acquisition module 501, a first adjustment module 502, and a second adjustment module 503.

[0143] The acquisition module 501 is used to acquire the actual speed and target speed range of the engine when the vehicle switches from series mode to power split mode. The target speed range is calculated based on the highest and lowest motor speed of the first motor and is used to indicate the engine speed at which the vehicle can smoothly engage gears. The first adjustment module 502 is used to adjust the actual speed of the engine to the target speed range when the actual speed of the engine is not within the target speed range. The second adjustment module 503 is used to control the actual speed of the engine after adjustment to remain unchanged, and to adjust the speed of the first motor so that the speed of the planetary gear ring gear reaches the target gear speed and can complete the shifting of the target gear.

[0144] Optionally, the target speed range includes a minimum effective speed and a maximum effective speed, where the minimum effective speed is the minimum value of the target speed range and the maximum effective speed is the maximum value of the target speed range. The acquisition module 501 is specifically used for: Obtain the output shaft speed of the gearbox, the maximum motor speed of the first motor, and the minimum motor speed; Based on the output shaft speed, target transmission ratio, planetary gear ratio, maximum motor speed, and minimum motor speed, determine the engine's maximum reference speed and minimum reference speed. The target transmission ratio is the transmission ratio at the target gear. The minimum of the engine's highest physical speed and the highest reference speed is determined as the highest effective speed, and the maximum of the engine's lowest physical speed and the lowest reference speed is determined as the lowest effective speed. The target speed range is determined based on the lowest effective speed and the highest effective speed. The highest physical speed is the highest speed that the engine can reach, and the lowest physical speed is the lowest speed that the engine can reach.

[0145] Optionally, the acquisition module 501 is specifically used for: Based on the output shaft speed, target transmission ratio, planetary gear ratio, and maximum motor speed, the maximum reference speed is determined according to the speed balance relationship of the planetary gear set; The minimum reference speed is determined based on the output shaft speed, target transmission ratio, planetary gear ratio, and minimum motor speed, according to the speed balance relationship of the planetary gear set.

[0146] Optionally, the first adjustment module 502 is specifically used for: Based on the actual engine speed, determine the target engine speed, which must be within the target speed range; The speed of the first motor is determined based on the output shaft speed of the gearbox, the target transmission ratio, the gear ratio of the planetary gear set, and the target engine speed. The speed of the first motor is adjusted to the speed of the first motor so that the actual speed of the engine is adjusted to the target speed range.

[0147] Optionally, the target speed range includes a minimum effective speed and a maximum effective speed, where the minimum effective speed is the minimum value of the target speed range and the maximum effective speed is the maximum value of the target speed range. The first adjustment module 502 is specifically used for: If the actual engine speed is greater than the maximum effective speed, the target engine speed is obtained by subtracting the first preset speed from the maximum effective speed. If the actual engine speed is less than the minimum effective speed, the minimum effective speed is added to the second preset speed to obtain the target engine speed.

[0148] Optionally, the first adjustment module 502 is specifically used for: Multiply the output shaft speed by the target transmission ratio to obtain the target gear ring speed; Multiply the target gear ring speed by the planetary gear set ratio to obtain the first reference speed; The second reference speed is determined based on the target engine speed and the gear ratio of the planetary gear set; Subtracting the first reference speed from the second reference speed yields the first motor speed.

[0149] Optionally, the device further includes: The determination module is used to determine the speed of the second motor based on the actual speed of the adjusted engine, the output shaft speed of the gearbox, the target transmission ratio, and the gear ratio of the planetary gear set. The second adjustment module 503 is specifically used for: The actual speed of the engine remains unchanged after the control adjustment. The speed of the first motor is adjusted to the speed of the second motor so that the speed of the gear ring reaches the target gear speed and can complete the shifting of the target gear.

[0150] Optionally, the second adjustment module 503 is also used for: When the actual engine speed is within the target speed range, the speed of the third motor is determined directly based on the actual engine speed, the output shaft speed of the gearbox, the target transmission ratio, and the gear ratio of the planetary gear set. The actual speed of the engine is kept constant, and the speed of the first motor is adjusted to the speed of the third motor so that the speed of the gear ring reaches the target gear speed and can complete the shifting of the target gear.

[0151] In this embodiment, when the vehicle switches from series mode to power-split mode, the actual engine speed and the target engine speed range are first obtained. The target speed range is calculated based on the highest and lowest motor speeds of the first motor, and includes the engine speed that allows the vehicle to smoothly engage gears. In other words, the target speed range defines the engine speed within the capability range of the first motor that allows the vehicle to smoothly engage gears. That is, when the actual engine speed is within the target speed range, regardless of the adjustment of the first motor speed, the gear ring speed can be guaranteed to reach the target gear speed without exceeding the upper or lower speed limits. Therefore, by determining whether the actual engine speed is within the target speed range, if the actual engine speed is not within the target speed range, the actual engine speed can be adjusted to the target speed range. Then, the adjusted actual engine speed is kept unchanged, and the speed of the first motor is adjusted again, so that the gear ring speed of the planetary gear set can reach the target gear speed, thereby completing the gear engagement operation. This improves the success rate of gear engagement during the vehicle's switch from series mode to power-split mode, and further improves the success rate of switching from series mode to power-split mode.

[0152] It should be noted that the vehicle control device provided in the above embodiments is only illustrated by the division of the above functional modules when the vehicle switches from series mode to power split mode. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0153] The functional units and modules in the above embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of the embodiments of this application.

[0154] The vehicle control device and vehicle control method embodiments provided in the above embodiments belong to the same concept. The specific working process and technical effects of the units and modules in the above embodiments can be found in the method embodiment section, and will not be repeated here.

[0155] Figure 6 This is a schematic diagram of the structure of a vehicle provided in an embodiment of this application.

[0156] For example, such as Figure 6 As shown, the vehicle 600 includes a memory 61 and a processor 60, wherein the memory 61 stores executable program code 62, and the processor 60 is used to call and execute the executable program code 62 to perform the above-described vehicle control method.

[0157] This embodiment can divide the vehicle into functional modules according to the above method example. For example, each function can be assigned to a separate module, or two or more functions can be integrated into one processing module. The integrated module can be implemented in hardware. It should be noted that the module division in this embodiment is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods.

[0158] When each functional module is divided according to its corresponding function, the vehicle may include: an acquisition module, a first adjustment module, and a second adjustment module. It should be noted that all relevant content regarding the steps involved in the above method embodiments can be referenced from the functional descriptions of the corresponding functional modules, and will not be repeated here.

[0159] The vehicle provided in this embodiment is used to execute the vehicle control method described above, and therefore can achieve the same effect as the above implementation method.

[0160] When using integrated units, the vehicle may include a processing module and a storage module. The processing module is used to control and manage the vehicle's actions. The storage module is used to support the vehicle in executing corresponding program code and data.

[0161] The processing module may be a processor or a controller, which can implement or execute various exemplary logic blocks, modules, and circuits shown in conjunction with the disclosure of this application. The processor may also be a combination of functions that implement computing capabilities, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and a microprocessor, etc., and the storage module may be a memory.

[0162] This embodiment also provides a computer-readable storage medium storing computer program code. When the computer program code is run on a computer, the computer executes the aforementioned related method steps to implement the vehicle control method described in the above embodiment.

[0163] This embodiment also provides a computer program product that, when run on a computer, causes the computer to perform the aforementioned steps to implement the vehicle control method described in the above embodiment.

[0164] In this embodiment, the vehicle, computer-readable storage medium, computer program product, or chip are all used to execute the method described above. Therefore, the beneficial effects that can be achieved can be referred to the beneficial effects of the method described above, and will not be repeated here.

[0165] Through the above description of the embodiments, those skilled in the art will understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0166] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are illustrative; for instance, the division of modules or units is merely a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another device, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0167] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for controlling a vehicle, characterized in that, A hybrid vehicle, the vehicle comprising: an engine, a transmission, a first electric motor, and a planetary gear set, wherein the engine is connected to the planet carrier of the planetary gear set, the first electric motor is connected to the sun gear of the planetary gear set, and the input shaft of the transmission is connected to the ring gear of the planetary gear set; the method comprising: When the vehicle switches from series mode to power split mode, the actual speed and target speed range of the engine are obtained. The target speed range is calculated based on the highest and lowest motor speeds of the first motor and is used to indicate the engine speed at which the vehicle can smoothly engage gears. If the actual engine speed is not within the target speed range, adjust the actual engine speed to the target speed range; The actual speed of the engine remains unchanged after the control adjustment. The speed of the first motor is adjusted so that the speed of the planetary gear ring reaches the target gear speed and can complete the shifting of the target gear.

2. The method according to claim 1, characterized in that, The target speed range includes a minimum effective speed and a maximum effective speed, wherein the minimum effective speed is the minimum value of the target speed range, and the maximum effective speed is the maximum value of the target speed range. The steps for determining the target speed range include: The output shaft speed of the gearbox, the highest motor speed, and the lowest motor speed of the first motor are obtained. Based on the output shaft speed, the target transmission ratio, the gear ratio of the planetary gear set, the highest motor speed, and the lowest motor speed, the highest reference speed and the lowest reference speed of the engine are determined, and the target transmission ratio is the transmission ratio at the target gear. The minimum value between the engine's highest physical speed and the highest reference speed is determined as the highest effective speed, and the maximum value between the engine's lowest physical speed and the lowest reference speed is determined as the lowest effective speed; the target speed range is determined based on the lowest effective speed and the highest effective speed, where the highest physical speed is the highest speed the engine can reach and the lowest physical speed is the lowest speed the engine can reach.

3. The method according to claim 2, characterized in that, The determination of the engine's maximum and minimum reference speeds based on the output shaft speed, target transmission ratio, planetary gear ratio, maximum motor speed, and minimum motor speed includes: The maximum reference speed is determined based on the output shaft speed, the target transmission ratio, the gear ratio of the planetary set, and the maximum motor speed, according to the speed balance relationship of the planetary set. The minimum reference speed is determined based on the output shaft speed, the target transmission ratio, the gear ratio of the planetary gear set, and the minimum motor speed, according to the speed balance relationship of the planetary gear set.

4. The method according to claim 1, characterized in that, Adjusting the actual speed of the engine to the target speed range includes: Based on the actual speed of the engine, a target engine speed is determined, and the target engine speed is within the target speed range; The first motor speed is determined based on the output shaft speed of the gearbox, the target transmission ratio, the gear ratio of the planetary gear set, and the target engine speed. The speed of the first motor is adjusted to the speed of the first motor so that the actual speed of the engine is adjusted to the target speed range.

5. The method according to claim 4, characterized in that, The target speed range includes a minimum effective speed and a maximum effective speed, wherein the minimum effective speed is the minimum value of the target speed range, and the maximum effective speed is the maximum value of the target speed range. Determining the target engine speed based on the actual engine speed includes: If the actual speed of the engine is greater than the maximum effective speed, the target engine speed is obtained by subtracting the first preset speed from the maximum effective speed. If the actual speed of the engine is less than the minimum effective speed, the minimum effective speed is added to the second preset speed to obtain the target engine speed.

6. The method according to claim 4, characterized in that, The determination of the first motor speed based on the output shaft speed of the gearbox, the target transmission ratio, the gear ratio of the planetary gear set, and the target engine speed includes: Multiply the output shaft speed by the target transmission ratio to obtain the target gear ring speed; Multiply the target gear ring speed by the gear ratio of the planetary gear set to obtain the first reference speed; A second reference speed is determined based on the target engine speed and the gear ratio of the planetary gear set; The first motor speed is obtained by subtracting the second reference speed from the first reference speed.

7. The method according to any one of claims 1-6, characterized in that, The method further includes: The second motor speed is determined based on the adjusted actual speed of the engine, the output shaft speed of the gearbox, the target transmission ratio, and the gear ratio of the planetary gear set. And, the actual speed of the engine remains unchanged after the control adjustment, the speed of the first motor is adjusted so that the speed of the planetary gear ring gear reaches the target gear speed, and the target gear is engaged, including: The actual speed of the engine remains unchanged after the control adjustment. The speed of the first motor is adjusted to the speed of the second motor so that the speed of the gear ring reaches the target gear speed and can complete the shifting of the target gear.

8. The method according to claim 1, characterized in that, The method further includes: When the actual speed of the engine is within the target speed range, the speed of the third motor is determined directly based on the actual speed of the engine, the output shaft speed of the gearbox, the target transmission ratio, and the gear ratio of the planetary gear set. The actual speed of the engine is kept constant, and the speed of the first motor is adjusted to the speed of the third motor so that the speed of the gear ring reaches the target gear speed and the target gear can be engaged.

9. A vehicle, characterized in that, The vehicles include: Memory, used to store executable program code; A processor for calling and running the executable program code from the memory, causing the vehicle to perform the method according to any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the method according to any one of claims 1 to 8.

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