Vehicle gear shifting control method and device, storage medium and vehicle

Abstract

The present disclosure relates to a vehicle gear shifting control method, device, storage medium and vehicle, the method comprising: when the gearbox downshifts, the hybrid controller HCU controls the motor in the speed control mode, if the HCU receives the shift-in request sent by the gearbox controller TCU, the HCU maintains the current operating state, and determines the jitter characteristic value according to the engine speed; if the jitter characteristic value is greater than the jitter threshold value, the HCU controls the motor in the torque control mode, and controls the motor torque to decrease; if the motor torque decreases to the motor torque threshold value, the TCU sends the HCU a shift-in completion message; in response to receiving the shift-in completion message, the HCU controls the vehicle torque to recover to the value before the gear shift. In this way, the time length of the HCU controlling the motor in the speed control mode can be prolonged, the vehicle gear shifting success rate can be improved; and when the vehicle jitters due to the motor being in the speed control mode for a long time, the speed control mode can be exited in time, and the jitter occurrence can be reduced.

Description

Technical Field

[0001] This disclosure relates to the field of vehicles, and more specifically, to a vehicle shift control method, apparatus, storage medium, and vehicle. Background Technology

[0002] Shifting gears is one of the most frequently used functions of a vehicle. Currently, the shifting process of an AMT transmission includes five steps: torque reduction, disengagement, speed adjustment, gear engagement, and torque reduction.

[0003] During the downshifting process, when the motor completes the "speed adjustment" phase and the vehicle enters the "upshifting" phase, the engine load is relatively large. If the HCU (Hybrid Control Unit) immediately switches the motor control mode, the engine dragging the motor speed will drop rapidly, which may cause the TCU (Transmission Control Unit) to fail to engage the gear. Summary of the Invention

[0004] The purpose of this disclosure is to provide a vehicle shift control method, apparatus, storage medium, and vehicle to improve the success rate of vehicle shifting and enhance the comfort of occupants.

[0005] To achieve the above objectives, the first aspect of this disclosure provides a vehicle gear shifting control method, comprising:

[0006] When the transmission downshifts and the hybrid control unit (HCU) controls the motor in speed control mode, if it receives a gear-up request from the transmission control unit (TCU), the HCU maintains its current operating state and determines the vibration characteristic value based on the engine speed.

[0007] If the jitter characteristic value is greater than the jitter threshold, the HCU controls the motor in torque control mode and reduces the motor torque.

[0008] If the motor torque decreases to the motor torque threshold, the TCU sends a gear shift completion message to the HCU;

[0009] In response to receiving the shift completion message, the HCU controls the vehicle torque to return to the value before the shift.

[0010] Optionally, before the TCU sends a file completion message to the HCU, the method further includes:

[0011] When the HCU controls the motor in torque control mode, the speed difference between the current cycle and the previous cycle of the gearbox input shaft is determined as the state difference.

[0012] If the state difference is greater than the state difference threshold, the HCU controls the motor to apply negative torque compensation.

[0013] If the state difference is less than the state difference threshold, the HCU controls the motor to apply positive torque compensation.

[0014] The positive torque compensation and the negative torque compensation are determined based on the state difference.

[0015] Optionally, the method further includes:

[0016] When the transmission downshifts and the hybrid control unit (HCU) controls the motor in speed control mode, the HCU controls the engine to inject fuel, determines the engine compensation torque, and controls the engine to increase the engine compensation torque.

[0017] Optionally, determining the engine compensation torque includes:

[0018] Based on vehicle status information, a correction factor is determined, wherein the vehicle status information includes motor speed, target speed, engine temperature, and battery SOC.

[0019] The engine compensation torque is determined based on the engine's friction torque and the correction factor.

[0020] Optionally, the method further includes:

[0021] When the transmission downshifts and the hybrid controller (HCU) controls the motor in speed control mode, if the motor speed reaches the target speed and the duration of reaching the target speed reaches a duration threshold, the TCU sends the upshift request to the HCU.

[0022] Optionally, the method further includes:

[0023] The TCU sends a shift request to the HCU, wherein the shift request is used to indicate the target gear;

[0024] If the shift request is received and the HCU controls the motor in torque control mode, the HCU controls the motor torque to decrease to the motor torque threshold.

[0025] If the motor torque decreases to the motor torque threshold, the TCU sends a target speed to the HCU, wherein the target speed is determined based on the target gear and the vehicle speed;

[0026] In response to receiving the target speed, the HCU begins to control the motor in speed control mode and controls the motor speed to reach the target speed.

[0027] Optionally, the vehicle torque includes engine torque and electric motor torque; the HCU controls the vehicle torque to return to its pre-shift value, including:

[0028] The HCU controls the increase of motor torque;

[0029] If the motor torque increases to the value of the vehicle torque before the gear shift, the HCU controls the engine torque to increase and the motor torque to decrease. During the process of controlling the engine torque to increase and the motor torque to decrease, the sum of the engine torque and the motor torque is equal to the value of the vehicle torque before the gear shift.

[0030] A second aspect of this disclosure provides a vehicle shift control device, comprising:

[0031] The hybrid controller (HCU) is used to maintain the current operating state when the transmission downshifts and the hybrid controller (HCU) controls the motor in speed control mode. If it receives an upshift request from the transmission controller (TCU), it determines the jitter characteristic value based on the engine speed. If the jitter characteristic value is greater than the jitter threshold, it controls the motor in torque control mode and controls the motor torque to decrease.

[0032] The transmission controller (TCU) is used to send a gear shift completion message to the transmission control unit (HCU) if the motor torque decreases to a motor torque threshold.

[0033] The HCU is also used to control the vehicle torque to return to the value before the shift when the shift completion message is received.

[0034] Optionally, before the TCU sends the advance completion message to the HCU, the HCU is further configured to:

[0035] When the HCU controls the motor in torque control mode, the speed difference between the current cycle and the previous cycle of the gearbox input shaft is determined as the state difference.

[0036] If the state difference is greater than the state difference threshold, then control the motor to apply negative torque compensation;

[0037] If the state difference is less than the state difference threshold, then control the motor to apply positive torque compensation;

[0038] The positive torque compensation and the negative torque compensation are determined based on the state difference.

[0039] Optionally, the HCU is also used for:

[0040] When the transmission downshifts and the hybrid controller (HCU) controls the motor in speed control mode, it controls the engine to inject fuel, determines the engine compensation torque, and controls the engine to increase the engine compensation torque.

[0041] Optionally, the HCU is also used to determine the engine compensation torque in the following ways:

[0042] Based on vehicle status information, a correction factor is determined, wherein the vehicle status information includes motor speed, target speed, engine temperature, and battery SOC.

[0043] The engine compensation torque is determined based on the engine's friction torque and the correction factor.

[0044] Optionally, the TCU is also used for:

[0045] When the transmission downshifts and the hybrid control unit (HCU) controls the motor in speed control mode, if the motor speed reaches the target speed and the duration of reaching the target speed reaches a duration threshold, the upshift request is sent to the HCU.

[0046] Optionally, the TCU is further configured to send a shift request to the HCU, wherein the shift request is used to indicate a target gear;

[0047] The HCU is also configured to, if it receives the shift request and the HCU controls the motor in torque control mode, reduce the motor torque to the motor torque threshold.

[0048] The TCU is also used to send a target speed to the HCU if the motor torque decreases to the motor torque threshold, wherein the target speed is determined based on the target gear and the vehicle speed;

[0049] The HCU is also used to respond to receiving the target speed, start controlling the motor in speed control mode, and control the motor speed to reach the target speed.

[0050] Optionally, the HCU is used to control the vehicle torque to return to the value before the gear shift by:

[0051] The HCU controls the increase of motor torque;

[0052] If the motor torque increases to the value of the vehicle torque before the gear shift, the HCU controls the engine torque to increase and the motor torque to decrease. During the process of controlling the engine torque to increase and the motor torque to decrease, the sum of the engine torque and the motor torque is equal to the value of the vehicle torque before the gear shift.

[0053] A third aspect of this disclosure provides a non-transitory computer-readable storage medium having a computer program stored thereon that, when executed by a processor, implements the steps of the method provided in the first aspect of this disclosure.

[0054] This disclosure provides a vehicle in a fourth aspect, the vehicle including an electric motor, an engine, a clutch, a gearbox, and a shift control device provided in the second aspect of this disclosure.

[0055] In the above technical solution, when the transmission downshifts and the hybrid control unit (HCU) controls the motor in speed control mode, if it receives an upshift request from the transmission controller (TCU), the HCU maintains its current operating state and determines the vibration characteristic value based on the engine speed. If the vibration characteristic value is greater than the vibration threshold, the HCU controls the motor in torque control mode and reduces the motor torque. If the motor torque decreases to the motor torque threshold, the TCU sends an upshift completion message to the HCU. In response to receiving the upshift completion message, the HCU controls the vehicle torque to return to the value before the shift. Thus, on the one hand, when the vibration characteristic value is greater than the vibration threshold, the HCU exits speed control mode and switches to torque control mode, extending the duration of speed control mode control and preventing the engine from dragging the motor speed down rapidly, thus improving the success rate of vehicle shifting. On the other hand, it can promptly exit speed control mode when vehicle vibration is caused by the motor being in speed control mode for an extended period, reducing vibration and improving the comfort of the occupants.

[0056] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0057] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings:

[0058] Figure 1 This is a schematic diagram of the mechanical structure of a vehicle provided in an exemplary embodiment of this disclosure.

[0059] Figure 2 This is a flowchart of a vehicle gear shifting control method provided in an exemplary embodiment of this disclosure.

[0060] Figure 3 This is a flowchart of a vehicle gear shifting control method provided in an exemplary embodiment of this disclosure.

[0061] Figure 4 This is an interaction diagram between the TCU and HCU in a vehicle shift control method provided by an exemplary embodiment of this disclosure.

[0062] Figure 5This is a block diagram of a vehicle shift control device provided in an exemplary embodiment of the present disclosure. Detailed Implementation

[0063] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0064] It should be noted that all actions involving the acquisition of signals, information, or data in this disclosure are carried out in compliance with the relevant data protection laws and policies of the country where the location is situated, and with authorization from the owner of the relevant device.

[0065] like Figure 1 As shown, the mechanical structure of the hybrid vehicle is such that the motor 13 is directly connected to the transmission 14, and the engine 11 is connected to the motor 13 via a clutch 12. Assuming the transmission 14 is an AMT transmission, the power transmission path of the entire vehicle includes:

[0066] (1) Pure electric path (EV mode): Motor 13 transmits power to the wheel end through gearbox 14 and main reducer 15;

[0067] (2) Parallel path (parallel mode): With clutch 12 closed, engine 11 transmits power to the wheel ends via clutch 12 and motor 13, through gearbox 14 and main reducer 15. This parallel path includes three modes: direct drive by engine 11, parallel drive, and hybrid drive.

[0068] The shifting process of an AMT transmission includes five stages: torque reduction, disengagement, speed adjustment, gear engagement, and torque reduction. When the vehicle is in parallel mode, during the "speed adjustment" stage, the motor 13 drives the engine 11 to adjust its speed according to the target gear. At this time, due to the heavy load on the engine 11, if the HCU immediately switches the control mode of the motor 13 when the transmission enters the "gear engagement" stage after the motor 13 has finished adjusting its speed, the speed of the motor 13 driven by the engine 11 will drop rapidly. This will cause the speed difference between the input and output shafts of the transmission to exceed the transmission's gear engagement speed threshold, resulting in gear engagement failure. When the vehicle is in pure electric mode, the speed of the motor 13 may also drop rapidly during the "gear engagement" process, leading to gear engagement failure.

[0069] To address the aforementioned problems, this disclosure provides a shift control method.

[0070] Figure 2 This is a flowchart of a vehicle shift control method provided in an exemplary embodiment of this disclosure. This method can be applied to hybrid vehicles with a P2 structure. Figure 2 As shown, the method may include S101 to S104.

[0071] S101, when the transmission downshifts and the hybrid controller HCU controls the motor in speed control mode, if it receives a gear-up request from the transmission controller TCU, the HCU will maintain the current operating state and determine the vibration characteristic value based on the engine speed.

[0072] For example, the TCU can automatically generate shift requests based on the vehicle's operating status to put the vehicle into a shifting state, allowing the transmission to upshift or downshift. When not shifting, the HCU controls the motor's operation in torque control mode. When the vehicle initially enters a shifting state, the HCU controls torque unloading (corresponding to the "torque reduction" stage above). When the motor torque is 0, the TCU can send a neutral command to the TCU to control the transmission to disengage, putting the transmission in neutral (corresponding to the "disengagement" stage above). Upon detecting that the transmission is in neutral, the TCU can send a target speed to the HCU, causing the HCU to begin controlling the motor's operation in speed control mode (corresponding to the "speed adjustment" stage above). When the motor speed reaches the target speed, the TCU can send an upshift request to the HCU, entering the "upshift" stage. Provided the transmission downshifts, the HCU can determine the motor's vibration characteristics to determine the appropriate time to end the "upshift" stage.

[0073] Among them, the speed control mode is a control mode aimed at controlling the speed of the motor, and the torque control mode is a control mode aimed at controlling the torque of the motor.

[0074] The HCU maintains the current operating state by controlling the motor in speed control mode and maintaining the motor speed at the target speed. The jitter characteristic value can be determined using the following formula:

[0075]

[0076] Where j is the jitter characteristic value, K is a preset constant, n is the motor speed, and t is the duration.

[0077] S102, if the jitter characteristic value is greater than the jitter threshold, the HCU will control the motor in torque control mode and control the motor torque to decrease.

[0078] In this scenario, prolonged use of speed control mode by the HCU to control the motor may cause vehicle vibration. Upon receiving a shift request and entering the "shift" state, the HCU can determine whether to exit speed control mode and switch to torque control mode based on whether the vibration characteristic value exceeds a vibration threshold. The vibration characteristic value can be understood as a physical quantity describing the rate of acceleration change, also known as jerk, variable acceleration, or abrupt change, representing the sudden movement of the vehicle. Significant vehicle vibration occurs after the HCU has controlled the motor in speed control mode for a period of time. If the vibration characteristic value is too large, it will cause noticeable bumps to be felt by the occupants and may also damage the performance structure of the transmission. Therefore, when the vibration characteristic value exceeds the vibration threshold, the HCU can switch to torque control mode to control the motor. In this way, compared to directly switching the motor from speed control mode to torque mode when entering the "shift" phase, the duration of speed control mode can be extended, preventing the heavily loaded engine from dragging the motor speed down rapidly and improving the success rate of gear shifts. Furthermore, it can promptly exit the speed control mode when vehicle vibration occurs due to the motor being in speed control mode for an extended period, thereby reducing vibration and improving passenger comfort.

[0079] Downshifting increases engine speed, while upshifting decreases it. During upshifting, if the transmission receives an upshift request from the TCU, the HCU can immediately switch from speed control mode to torque control mode to control the motor, cutting off fuel to the engine and allowing the engine speed to drop naturally under heavy load. It's important to note that in parallel hybrid mode, the motor and engine shafts are connected, and the transmission input shaft is connected to the motor; therefore, the actual speeds of the motor, engine, and transmission input shafts are the same.

[0080] S103, if the motor torque decreases to the motor torque threshold, the TCU sends a gear shift completion message to the HCU.

[0081] S104, in response to receiving the shift completion message, the HCU controls the vehicle torque to be restored to the value before the shift.

[0082] For example, the motor torque threshold can be preset, such as to zero (zero torque is a calibrated value; actual torque close to zero is acceptable). The TCU can connect to a sensor capable of acquiring motor torque information to determine if the motor torque has decreased to the motor torque threshold. During the process of the motor torque decreasing to zero, engine torque can be controlled based on friction torque to maintain vehicle stability. If the motor torque decreases to the motor torque threshold, the TCU can determine that the "shifting" phase is complete and can enter the "torque recovery" phase. It can send a shift completion message to the HCU so that the HCU can control the vehicle torque to return to the value before the shift, completing the entire shifting process.

[0083] In the above technical solution, when the transmission downshifts and the hybrid control unit (HCU) controls the motor in speed control mode, if it receives an upshift request from the transmission controller (TCU), the HCU maintains its current operating state and determines the vibration characteristic value based on the engine speed. If the vibration characteristic value is greater than the vibration threshold, the HCU controls the motor in torque control mode and reduces the motor torque. If the motor torque decreases to the motor torque threshold, the TCU sends an upshift completion message to the HCU. In response to receiving the upshift completion message, the HCU controls the vehicle torque to return to the value before the shift. Thus, on the one hand, when the vibration characteristic value is greater than the vibration threshold, the HCU exits speed control mode and switches to torque control mode, extending the duration of speed control mode control and preventing the engine from dragging the motor speed down rapidly, thus improving the success rate of vehicle shifting. On the other hand, it can promptly exit speed control mode when vehicle vibration is caused by the motor being in speed control mode for an extended period, reducing vibration and improving the comfort of the occupants.

[0084] In an optional embodiment, before the TCU sends the shift completion message to the HCU, the shift control method provided in this disclosure further includes:

[0085] When the HCU controls the motor in torque control mode, the speed difference between the current cycle and the previous cycle of the gearbox input shaft is determined as the state difference.

[0086] If the state difference is greater than the state difference threshold, the HCU will control the motor to apply negative torque compensation.

[0087] If the state difference is less than the state difference threshold, the HCU will control the motor to apply positive torque compensation.

[0088] Among them, positive torque compensation and negative torque compensation are determined based on the state difference.

[0089] For example, the duration of the cycle can be preset. In this disclosure, the sampled data is discrete and the sampling frequency is constant, i.e., the cycle is fixed. The rotational speed of each cycle can be determined by the HCU, which is also used to determine the state difference. The HCU can also determine whether the input shaft of the gearbox has a tendency to rotate too fast or too slow when the input and output shafts are engaged, based on the relationship between the state difference and the state difference threshold. If the state difference is greater than the state difference threshold, it can be determined that the input shaft has a tendency to rotate too fast, which can be suppressed by negative torque compensation from the motor. If the state difference is less than the state difference threshold, it can be determined that the input shaft has a tendency to rotate too slow, which can be suppressed by positive torque compensation from the motor. In this way, the rotational speeds of the gearbox input and output shafts can be maintained in a relatively static state, improving the stability of vehicle operation during gear shifting and reducing the degree of damage to the gearbox.

[0090] It should be noted that the above methods for determining the negative torque compensation and positive torque compensation of the control motor can be applied not only before the transmission downshifts into "torque return" but also during the upshifting process of the vehicle, which will not be elaborated here.

[0091] The correspondence between the state difference and negative torque compensation can be preset through experimental results, and this correspondence can be represented, for example, by a function or mapping table. Similarly, the correspondence between the state difference and positive torque compensation can be preset through experimental results, and this correspondence can be represented, for example, by a function or mapping table. Thus, given the determination of the magnitude relationship between the state difference and its threshold, torque compensation can be determined based on this correspondence.

[0092] In an optional embodiment, the shift control method provided in this disclosure further includes:

[0093] When the gearbox downshifts and the HCU controls the motor in speed control mode, the HCU controls the engine to inject fuel, determines the engine compensation torque, and controls the engine to increase the engine compensation torque.

[0094] For example, during the downshifting or upshifting process of the vehicle's transmission, the HCU can control the engine to inject fuel to provide a small torque to the engine, reduce the pressure on the motor, and enable the speed to rise to the target speed more quickly, or maintain the speed at the target speed.

[0095] The engine compensation torque can be determined in the following ways:

[0096] Based on vehicle status information, a correction factor is determined, including motor speed, target speed, engine temperature, and battery SOC.

[0097] The engine compensation torque is determined based on the engine's friction torque and correction factor.

[0098] For example, the acquired vehicle state information can be input into a pre-trained PI controller, and the output value of the PI controller is the correction factor. The engine's friction torque can also be determined based on the vehicle state information. Specifically, the value of the friction torque can be determined using methods for determining engine friction torque in related technologies; no limitations are imposed here. For instance, the product of the friction torque and the correction factor can be determined as the engine compensation torque.

[0099] As mentioned above, the input shafts of the motor, engine, and transmission rotate at the same speed. Therefore, by controlling the engine to increase its compensation torque, in situations where the battery's SOC (State of Charge) is too low, preventing the motor from reaching its target speed, the engine can compensate for the torque, providing energy for speed control, increasing the likelihood of successful gear shifts, and ensuring the maintenance of the engine speed to guarantee smooth vehicle operation.

[0100] In an optional embodiment, the shift control method provided in this disclosure further includes:

[0101] When the gearbox downshifts and the HCU controls the motor in speed control mode, if the motor speed reaches the target speed and the duration of reaching the target speed reaches the duration threshold, the TCU sends an upshift request to the HCU.

[0102] For example, the target speed can be determined based on the target gear and vehicle speed. For instance, the correspondence between the base speed and gear can be pre-defined. When determining the target gear, the TCU can determine the base speed by looking up this correspondence and then correct the determined base speed based on the actual vehicle speed to determine a target speed that adapts to the actual operating state of the vehicle. Afterward, the TCU can send the target speed to the HCU; the HCU can control the motor speed in speed control mode to make the motor speed reach the target speed. It should be noted that the target speed can refer to a range. A duration threshold can be pre-set. If the duration for reaching the target speed reaches the duration threshold, it can be determined that the current motor operating state is relatively stable. At this time, the TCU can send a gear shift request to the HCU to smoothly enter the "gear shift" state.

[0103] In an alternative embodiment, such as Figure 3 As shown, prior to step S101, the shift control method provided in this disclosure further includes steps S105 to S108.

[0104] S105, the TCU sends a shift request to the HCU, wherein the shift request is used to indicate the target gear.

[0105] For example, when the target gear is determined, the gear shift can be determined by combining the current gear, whether the transmission should downshift or upshift.

[0106] S106, if a shift request is received and the HCU controls the motor in torque control mode, the HCU controls the motor torque to decrease to the motor torque threshold.

[0107] S107, if the motor torque decreases to the motor torque threshold, the TCU sends the target speed to the HCU, where the target speed is determined based on the target gear and vehicle speed.

[0108] For example, upon receiving a shift request and with the HCU controlling the motor in torque control mode, the HCU can control the motor torque to decrease to a motor torque threshold via the motor controller (MCU). Simultaneously, the HCU can also control the engine torque to decrease to an engine torque threshold via the engine controller (EMS), where the engine torque threshold can be zero. In other words, upon receiving a shift request and with the HCU controlling the motor in torque control mode, it can control the vehicle torque to decrease to zero. The TCU can send the target speed to the HCU once the vehicle torque unloading is complete (i.e., reduced to zero).

[0109] Although the motor torque has been adjusted to zero in S106, the motor torque will increase when the motor speed is adjusted in step S108. Therefore, the motor torque needs to be adjusted again in step S102 to make the motor torque zero again so that the TCU can control the gearbox to switch to the target gear. After that, the TCU can send a gear shift completion message to the HCU to execute step S104.

[0110] S108, in response to receiving the target speed, the HCU starts controlling the motor in speed control mode and controls the motor speed to reach the target speed.

[0111] For example, the HCU can control the change of motor speed through the motor controller (MCU).

[0112] In an optional embodiment, the vehicle torque may include engine torque and electric motor torque; in S104, the HCU controls the vehicle torque to return to its value before the gear shift, which may include:

[0113] HCU controls the increase of motor torque;

[0114] If the motor torque increases to the value of the vehicle torque before the gear shift, the HCU controls the engine torque to increase and the motor torque to decrease. During the process of controlling the engine torque to increase and the motor torque to decrease, the sum of the engine torque and the motor torque is equal to the value of the vehicle torque before the gear shift.

[0115] For example, during the downshifting process of the transmission, when entering the "torque recovery" phase (i.e., when controlling torque restoration), the torque restoration here is an increase in torque. Since the engine torque response is relatively slow, the HCU can prioritize increasing the electric motor torque to first meet the driver's torque needs. As the engine torque response increases, the electric motor torque can be gradually reduced. During this process of controlling the increase in engine torque and the decrease in electric motor torque, the sum of the engine torque and the electric motor torque equals the vehicle's torque value before the shift, meaning the torque is in a balanced state. This allows for rapid torque response and improves the user experience.

[0116] Figure 4 This is an interaction diagram between the TCU and HCU in a vehicle shift control method provided by an exemplary embodiment of this disclosure. Through this... Figure 4 This allows for a clearer understanding of the implementation process of the vehicle shift control method provided in this disclosure. For example... Figure 4 As shown, the method may include S201 to S209. Figure 4 The specific methods for performing each step have been described in detail in the embodiments of the method, and will not be elaborated here.

[0117] S201, the TCU sends a gear shift request to the HCU.

[0118] S202, HCU controls the motor torque to decrease to the motor torque threshold.

[0119] S203, the TCU sends the target rotational speed to the HCU.

[0120] S204, the HCU switches from controlling the motor in torque control mode to controlling the motor in speed control mode, and controls the motor speed to reach the target speed.

[0121] S205, the TCU sends a file advance request to the HCU.

[0122] S206, HCU maintains the current operating state and determines the jitter characteristic value.

[0123] S207 If the jitter characteristic value is greater than the jitter threshold, the HCU will start to control the motor in torque control mode and control the motor torque to decrease to the motor torque threshold.

[0124] S208, the TCU sends a file advance completion message to the HCU.

[0125] S209, HCU controls the vehicle's torque to return to the value before the gear shift.

[0126] In this way, the likelihood of successful gear shifting can be increased, while smooth gear shifting can be achieved, thus improving the user experience.

[0127] Based on the same inventive concept, this disclosure also provides a vehicle shift control device. Figure 5 This is a block diagram of a vehicle shift control device 300 provided in an exemplary embodiment of this disclosure. (Refer to...) Figure 5 The vehicle shift control device 300 may include:

[0128] The hybrid controller HCU 301 is used to maintain the current operating state when the transmission downshifts and the hybrid controller HCU 301 controls the motor in speed control mode. If it receives a gear shift request from the transmission controller TCU 302, it determines the jitter characteristic value based on the engine speed. If the jitter characteristic value is greater than the jitter threshold, it controls the motor in torque control mode and controls the motor torque to decrease.

[0129] The transmission controller TCU 302 is used to send a gear shift completion message to the HCU 301 if the motor torque decreases to a motor torque threshold.

[0130] The HCU 301 is also used to control the vehicle torque to return to the value before the shift in response to receiving the shift completion message.

[0131] In the above technical solution, when the transmission downshifts and the hybrid controller HCU 301 controls the motor in speed control mode, if it receives a gear shift request from the transmission controller TCU 302, HCU 301 maintains its current operating state and determines the jitter characteristic value based on the engine speed. If the jitter characteristic value is greater than the jitter threshold, HCU 301 controls the motor in torque control mode and controls the motor torque to decrease. If the motor torque decreases to the motor torque threshold, TCU 302 sends a gear shift completion message to HCU 301. In response to receiving the gear shift completion message, HCU 301 controls the vehicle torque to return to the value before the gear shift. In this way, on the one hand, when the vibration characteristic value is greater than the vibration threshold, the HCU 301 exits the speed control mode to control the motor and switches to the torque control mode. This can extend the duration of the HCU 301 controlling the motor in speed control mode, avoid the engine dragging the motor speed down rapidly, and improve the success rate of vehicle gear shifting. On the other hand, it can promptly exit the speed control mode when the vehicle vibrates due to the motor being in speed control mode for a long time, reduce the occurrence of vibration, and improve the comfort of the passengers.

[0132] Optionally, before the TCU sends the advance completion message to the HCU, the HCU 301 is further configured to:

[0133] When the HCU controls the motor in torque control mode, the speed difference between the current cycle and the previous cycle of the gearbox input shaft is determined as the state difference.

[0134] If the state difference is greater than the state difference threshold, then control the motor to apply negative torque compensation;

[0135] If the state difference is less than the state difference threshold, then control the motor to apply positive torque compensation;

[0136] The positive torque compensation and the negative torque compensation are determined based on the state difference.

[0137] Optionally, the HCU 301 is further used for:

[0138] When the transmission downshifts and the hybrid controller HCU 301 controls the motor in speed control mode, it controls the engine to inject fuel, determines the engine compensation torque, and controls the engine to increase the engine compensation torque.

[0139] Optionally, the HCU 301 is also used to determine the engine compensation torque in the following manner:

[0140] Based on vehicle status information, a correction factor is determined, wherein the vehicle status information includes motor speed, target speed, engine temperature, and battery SOC.

[0141] The engine compensation torque is determined based on the engine's friction torque and the correction factor.

[0142] Optionally, the TCU 302 is further configured to:

[0143] When the transmission downshifts and the hybrid controller HCU 301 controls the motor in speed control mode, if the motor speed reaches the target speed and the duration of reaching the target speed reaches a duration threshold, then the upshift request is sent to the HCU 301.

[0144] Optionally, the TCU 302 is further configured to send a shift request to the HCU 301, wherein the shift request is used to indicate a target gear;

[0145] The HCU 301 is also configured to, if it receives the shift request and the HCU 301 controls the motor in torque control mode, reduce the motor torque to the motor torque threshold.

[0146] The TCU 302 is also used to send a target speed to the HCU 301 if the motor torque decreases to the motor torque threshold, wherein the target speed is determined based on the target gear and the vehicle speed;

[0147] The HCU 301 is also configured to, in response to receiving the target speed, start controlling the motor in speed control mode and control the motor speed to reach the target speed.

[0148] Optionally, the HCU 301 is used to control the vehicle torque to return to the value before the gear shift by:

[0149] The HCU 301 controls the increase of motor torque;

[0150] If the motor torque increases to the value of the vehicle torque before the gear shift, the HCU 301 controls the engine torque to increase and controls the motor torque to decrease. During the process of controlling the engine torque to increase and the motor torque to decrease, the sum of the engine torque and the motor torque is equal to the value of the vehicle torque before the gear shift.

[0151] Regarding the apparatus in the above embodiments, the specific manner in which each module performs its operation has been described in detail in the embodiments related to the method, and will not be elaborated upon here.

[0152] This disclosure also provides a vehicle including an electric motor, an engine, a clutch, a gearbox, and a vehicle shift control device 300 provided in this disclosure.

[0153] In another exemplary embodiment, a computer program product is also provided, the computer program product comprising a computer program executable by a programmable device, the computer program having a code portion for performing the above-described vehicle shift control method when executed by the programmable device.

[0154] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0155] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0156] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A vehicle gear shifting control method, characterized in that, include: The transmission controller (TCU) sends a shift request to the hybrid controller (HCU), wherein the shift request is used to indicate the target gear. If the shift request is received and the HCU controls the motor in torque control mode, the HCU controls the motor torque to decrease to the motor torque threshold. If the motor torque decreases to the motor torque threshold, the TCU sends a target speed to the HCU, wherein the target speed is determined based on the target gear and the vehicle speed; In response to receiving the target speed, the HCU begins to control the motor in speed control mode and controls the motor speed to reach the target speed; When the gearbox downshifts and the HCU controls the motor in speed control mode, the HCU controls the engine to inject fuel, determines the engine compensation torque, and controls the engine to increase the engine compensation torque. When the transmission downshifts and the HCU controls the motor in speed control mode, if it receives a gear shifting request from the TCU, the HCU maintains its current operating state and determines the vibration characteristic value based on the engine speed. If the jitter characteristic value is greater than the jitter threshold, the HCU controls the motor in torque control mode and reduces the motor torque. If the motor torque decreases to the motor torque threshold, the TCU sends a gear shift completion message to the HCU; In response to receiving the shift completion message, the HCU controls the vehicle torque to return to the value before the shift.

2. The method according to claim 1, characterized in that, Before the TCU sends the advance completion message to the HCU, the method further includes: When the HCU controls the motor in torque control mode, the speed difference between the current cycle and the previous cycle of the gearbox input shaft is determined as the state difference. If the state difference is greater than the state difference threshold, the HCU controls the motor to apply negative torque compensation. If the state difference is less than the state difference threshold, the HCU controls the motor to apply positive torque compensation. The positive torque compensation and the negative torque compensation are determined based on the state difference.

3. The method according to claim 1, characterized in that, Determining the engine compensation torque includes: Based on vehicle status information, a correction factor is determined, wherein the vehicle status information includes motor speed, target speed, engine temperature, and battery SOC; The engine compensation torque is determined based on the engine's friction torque and the correction factor.

4. The method according to claim 1, characterized in that, The method further includes: When the gearbox downshifts and the HCU controls the motor in speed control mode, if the motor speed reaches the target speed and the duration of reaching the target speed reaches a duration threshold, the TCU sends the upshift request to the HCU.

5. The method according to claim 1, characterized in that, The vehicle torque includes engine torque and electric motor torque; the HCU controls the vehicle torque to return to its pre-shift value, including: The HCU controls the increase of motor torque; If the motor torque increases to the value of the vehicle torque before the gear shift, the HCU controls the engine torque to increase and the motor torque to decrease. During the process of controlling the engine torque to increase and the motor torque to decrease, the sum of the engine torque and the motor torque is equal to the value of the vehicle torque before the gear shift.

6. A vehicle gear shifting control device, characterized in that, include: The transmission controller (TCU) is used to send a shift request to the hybrid controller (HCU), wherein the shift request is used to indicate the target gear. The HCU is configured to, if it receives the shift request and controls the motor in torque control mode, reduce the motor torque to a motor torque threshold. The TCU is also used to send a target speed to the HCU if the motor torque decreases to the motor torque threshold, wherein the target speed is determined based on the target gear and the vehicle speed; The HCU is also configured to, in response to receiving the target speed, start controlling the motor in a speed control mode and control the motor speed to reach the target speed. The HCU is also used to control engine fuel injection, determine engine compensation torque, and control the engine to increase the engine compensation torque when the gearbox downshifts and the HCU controls the motor in speed control mode. The HCU is also used to maintain the current operating state and determine the jitter characteristic value based on the engine speed when the transmission downshifts and the HCU controls the motor in speed control mode; if it receives an upshift request from the transmission controller TCU, it controls the motor in torque control mode and controls the motor torque to decrease. The TCU is also used to send a gear shift completion message to the HCU if the motor torque decreases to the motor torque threshold. The HCU is also used to control the vehicle torque to return to the value before the shift when the shift completion message is received.

7. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the program implements the steps of the method described in any one of claims 1-5.

8. A vehicle, characterized in that, The vehicle includes a motor, an engine, a clutch, a gearbox, and a shift control device as described in claim 6.

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