Shift control method, device, medium and vehicle

Abstract

The application relates to the technical field of vehicles and discloses a gear shifting control method and device, a medium and a vehicle. The method comprises the following steps: in the process of deceleration of the vehicle, according to the current running state of the vehicle, determining an estimated vehicle speed after a preset time length; according to the current running state and the throttle state of the vehicle, determining a target demand gear of the vehicle; according to the estimated vehicle speed and the gear speed ratio corresponding to the target demand gear, determining a target engine speed matched with the target demand gear; if the target engine speed is less than the allowable minimum speed of the engine, then according to the current actual gear of the vehicle, determining a target gear, wherein the time length required for the vehicle to shift from the actual gear to the target gear is less than the time length required for the vehicle to shift from the actual gear to the target demand gear; and the vehicle is controlled to shift to the target gear. The scheme can effectively solve the problem of engine stall in the process of deceleration of the vehicle.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicles, in particular, to a gear shifting control method and device, a medium and a vehicle. BACKGROUND

[0002] With the development of new energy vehicle technology, more and more users use new energy vehicles. The present inventors have found in practice that in the process of emergency braking or emergency braking of a vehicle, the engine of the vehicle may be turned off. SUMMARY

[0003] The present application aims to provide a gear shifting control method and device, a medium and a vehicle to solve the problem of engine turn-off of a vehicle in the process of emergency braking or emergency braking of the vehicle.

[0004] Other characteristics and advantages of the present application will become apparent from the following detailed description, or will be learned by practice of the present application.

[0005] According to an aspect of an embodiment of the present application, a gear shifting control method is provided, the method comprising: in the process of deceleration of a vehicle, determining an estimated vehicle speed after a preset time length according to a current operating state of the vehicle; determining a target required gear of the vehicle according to the current operating state and a throttle state of the vehicle; determining a target engine speed matched with the target required gear according to the estimated vehicle speed and a gear speed ratio corresponding to the target required gear; if the target engine speed is less than a minimum allowable engine speed, determining a target gear according to a current actual gear of the vehicle, wherein a time length required for the vehicle to shift from the actual gear to the target gear is less than a time length required for the vehicle to shift from the actual gear to the target required gear; and controlling the vehicle to shift to the target gear.

[0006] In some embodiments of the present application, based on the foregoing scheme, the current operating state of the vehicle indicates a current vehicle speed of the vehicle; the throttle state indicates a current throttle depth of the vehicle; the determination of the target required gear of the vehicle according to the current operating state and the throttle state comprises: obtaining a gear shifting law corresponding to the vehicle; the gear shifting law indicates a mapping relationship between vehicle speed and throttle depth in the case of switching between different gears; determining a gear corresponding to the current vehicle speed, the current throttle depth of the vehicle and the current actual gear of the vehicle according to the gear shifting law; and taking the gear corresponding to the current vehicle speed, the current throttle depth of the vehicle and the current actual gear of the vehicle as the target required gear.

[0007] In some embodiments of the present application, based on the foregoing scheme, the current operating state of the vehicle indicates the current vehicle speed and the current deceleration of the vehicle; and the determining, during the deceleration of the vehicle, of the estimated vehicle speed after the preset time length according to the current operating state of the vehicle comprises: obtaining, during the deceleration of the vehicle, state information of a brake pedal in the vehicle; determining a time length parameter corresponding to the state information of the brake pedal, taking the time length parameter corresponding to the state information of the brake pedal as the preset time length; and determining the estimated vehicle speed of the vehicle after the preset time length according to the current vehicle speed and the current deceleration of the vehicle.

[0008] In some embodiments of the present application, based on the foregoing scheme, the determining, according to the estimated vehicle speed and the gear speed ratio corresponding to the target demand gear, of the target engine speed matched with the target demand gear comprises: calculating the target engine speed matched with the target demand gear according to the estimated vehicle speed, the gear speed ratio corresponding to the target demand gear, the tire radius of the vehicle, and the main reduction ratio corresponding to the vehicle.

[0009] In some embodiments of the present application, based on the foregoing scheme, the determining, according to the current actual gear of the vehicle, of the target gear comprises: determining, according to a preset corresponding relationship between original gears and new gears, a new gear corresponding to the actual gear in the case that the actual gear is taken as an original gear; and taking the new gear corresponding to the actual gear as the target gear.

[0010] In some embodiments of the present application, based on the foregoing scheme, after the determining, according to the current operating state and the throttle state of the vehicle, of the target demand gear of the vehicle, the method further comprises: if the target demand gear is a gear in a preset gear set, controlling the vehicle to shift to the target demand gear.

[0011] In some embodiments of the present application, based on the foregoing scheme, after the determining, according to the estimated vehicle speed and the gear speed ratio corresponding to the target demand gear, of the target engine speed matched with the target demand gear, the method further comprises: if the target engine speed is within a preset safe speed range, controlling the vehicle to shift to the target demand gear.

[0012] According to another aspect of the embodiments of the present application, there is provided a shift control device, comprising: a predicted vehicle speed determination module configured to determine a predicted vehicle speed after a preset time period based on a current operating state of a vehicle during deceleration of the vehicle; a target demand gear determination module configured to determine a target demand gear of the vehicle based on the current operating state of the vehicle and a throttle state; a target engine speed determination module configured to determine a target engine speed matched with the target demand gear based on the predicted vehicle speed and a gear speed ratio corresponding to the target demand gear; a target gear determination module configured to determine a target gear based on a current actual gear of the vehicle if the target engine speed is less than a minimum allowable engine speed, wherein a time period required for the vehicle to shift from the actual gear to the target gear is less than a time period required for the vehicle to shift from the actual gear to the target demand gear; and a shift module configured to control the vehicle to shift to the target gear.

[0013] According to another aspect of the embodiments of the present application, there is provided a computer readable storage medium having computer readable instructions stored therein, which, when executed by a processor, implement the shift control method as above.

[0014] According to another aspect of the embodiments of the present application, there is provided a vehicle comprising a processor and a memory having computer readable instructions stored therein, which, when executed by the processor, implement the shift control method as above.

[0015] According to another aspect of the embodiments of the present application, there is provided a computer program product or computer program comprising computer instructions stored in a computer readable storage medium, which, when executed by a processor, implement the shift control method as above.

[0016] In the scheme of the present application, during deceleration of a vehicle, a predicted vehicle speed after a preset time period is determined based on a current operating state of the vehicle, and a target demand gear of the vehicle is determined based on the current operating state of the vehicle and a throttle state, then a target engine speed matched with the target demand gear is determined based on the predicted vehicle speed and a gear speed ratio corresponding to the target demand gear, and in the case that the target engine speed is less than a minimum allowable engine speed, the vehicle is controlled to shift to a target gear, so as to ensure that a time required for the vehicle to switch from a current actual gear to the target gear is less than a time required for the vehicle to switch from the actual gear to the target demand gear.

[0017] In the present application, the preset time length is equivalent to the time length reserved for the vehicle to switch from the actual gear to the target demand gear, and then, the estimated vehicle speed after the preset time length is estimated, and the target engine speed of the engine under the target demand gear is calculated based on the estimated vehicle speed, which is equivalent to the estimated speed of the engine under the target demand gear when the vehicle normally shifts from the current actual gear. As described above, if the target engine speed is less than the minimum speed, it indicates that there is a gear that cannot be passed during the shifting from the actual gear to the target gear, so that the vehicle is stopped at a gear between the actual gear and the target demand gear, and then the engine speed and the wheel speed are not matched, causing the engine to stall. Therefore, in this case, the target gear is determined based on the actual gear of the vehicle, and the shifting to the target gear is controlled, so that the time required for the vehicle to switch from the current actual gear to the target gear is less than the time required for the vehicle to switch from the actual gear to the target demand gear, thereby ensuring that the vehicle speed is not zero when the vehicle shifts to the target gear, and then, it is ensured that the engine will not be reversed to cause the engine to stall, effectively solving the problem of engine stall in the prior art during the process of emergency braking or emergency deceleration of the vehicle.

[0018] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF DRAWINGS

[0019] The drawings incorporated into the specification and forming part of the specification, show embodiments consistent with the present application, and together with the specification, serve to explain the principles of the present application. It is obvious that the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained from these drawings without creative labor for those skilled in the art. In the drawings:

[0020] Figure 1 is a trend chart of the change of various parameters of the vehicle during the shifting and deceleration.

[0021] Figure 2 is a flowchart of the shifting control method according to an embodiment of the present application.

[0022] Figure 3 is Figure 2 The flowchart of step 210 in the corresponding embodiment in an embodiment.

[0023] Figure 4 is Figure 2 The flowchart of step 220 in the corresponding embodiment in an embodiment.

[0024] Figure 5 An exemplary schematic diagram of a shifting curve of a vehicle is shown.

[0025] Figure 6 is a flow chart of a gear shift control method according to an embodiment of the present application.

[0026] Figure 7 is a block diagram of a gear shift control device according to an embodiment of the present application. DETAILED DESCRIPTION

[0027] Example implementations will now be described more fully with reference to the accompanying drawings. Example implementations may, however, be implemented in many different forms and should not be construed as limited to the implementations set forth herein; rather, these implementations are provided so that this disclosure will be thorough and complete, and will fully convey the scope of example implementations to those skilled in the art.

[0028] Moreover, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments of the application. One skilled in the relevant art will recognize, however, that the

[0029] The block diagrams in the drawings show only the functionality of the embodiments and do not necessarily imply a physical or an architectural arrangement of the embodiments. That is, the functionality can be implemented in software, hardware, or a combination thereof. The embodiments can be implemented in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0030] The flow diagrams depicted in the drawings show the functionality of example embodiments and do not necessarily imply a sequential order of operations, or a necessity of combinations of elements in this order. That is, elements can occur in various orders and / or various elements can be combined or omitted.

[0031] It should be noted that the term "a plurality of" means two or more. The term "and / or" describes associated objects in association with the objects connected by the term. That is, A and / or B means that there are three cases: A alone, A and B together, and B alone. The character " / " generally means that the associated objects before and after the character are in an "or" relationship.

[0032] With the development of new energy automobile technology, more and more users use new energy automobiles. The inventors of the present application have found in practice that in the process of emergency braking or emergency braking of a vehicle, the engine of the vehicle may be extinguished. Based on this, the scheme of the present application is proposed.

[0033] The inventors of the present application found through research that the main reason for engine stall of a vehicle during emergency braking or emergency braking in the prior art is that each gear of the vehicle has a minimum speed requirement limit, and multiple gears can only be shifted in sequence, if at a certain moment, the engine speed is lower than the minimum speed, due to the gear of the transmission cannot be crossed, thus, the engine speed to wheel end speed ratio does not match, and further leads to the problem of engine stall.

[0034] The power system in a hybrid vehicle generally includes an engine and a motor, and through the engine or the motor, or a combination of the engine and the motor, torque is output at the wheel end to drive the vehicle. A synchronizer is provided in the transmission, and gear shifting can generally be achieved by changing the position of the synchronizer. Specifically, the position of the synchronizer is changed to synchronize the difference between the input shaft and the output shaft with the acceleration of the input and output torques of the synchronizer; when the difference between the two ends of the synchronizer is less than a certain threshold and synchronized with the acceleration of the output torque of the synchronizer, gear shifting can be performed. The switching timing of multiple gears is controlled by the VCU (Vehicle control unit, vehicle controller) and executed by the HTCU (Hybrid Transmission Control Unit, hybrid transmission control unit).

[0035] During emergency braking, the vehicle speed decreases rapidly, for example, from the gear corresponding to the EV (Electron-Volt or Electric vehicle, electric vehicle) mode to the gear corresponding to the ECVT1 mode (engine driving-power generation mode), the speed near a synchronization ring (assuming that the synchronization ring in the synchronizer is located at S1R position) in the synchronizer decreases to near 0 rpm, and the target synchronization speed is Speed_S1R. In order to be able to engage the synchronizer S1R position, the motor will continue to adjust the speed, and further drag the engine, resulting in engine stall. Moreover, since the gears can only be shifted in sequence (i.e., cannot be skipped), the time for the emergency braking vehicle to make the vehicle speed 0 is extremely short, which may result in missing the opportunity to switch to the target gear.

[0036] Figure 1 is a trend chart of various parameters of the vehicle during gear shifting deceleration. Specifically, Figure 1 includes curve I, curve II, curve III, curve IV, and curve V. Curve I is a curve graph of the gear of the vehicle at different times, which is obtained by Figure 1As can be seen from curve I, the gear the vehicle is in at the time point corresponding to mark 1 is different from the gear the vehicle is in at the time point corresponding to mark 2, which means that the vehicle shifted gears during the process from the time point corresponding to mark 1 to the time point corresponding to mark 2.

[0037] exist Figure 1 In the diagram, curve II represents the feedback torque of the electric motor in the vehicle at different times; curve III represents the trend of engine speed variation in the vehicle at different times; curve IV represents the trend of target synchronous speed variation at different time points; and curve V represents the trend of vehicle speed variation at different time points. Figure 1 As can be seen, the vehicle decelerates from the time point corresponding to mark 1 to the time point corresponding to mark 2. At the time point corresponding to mark 1, the vehicle's engine speed is approximately 1253 r / min, which is within a safe speed range. The target synchronous speed calculated for the time point corresponding to mark 2 is approximately 301.98 r / min. To make the vehicle's engine speed approximately the same as the target synchronous speed, the engine speed is adjusted by the GCU (Generator Control Unit) to bring the engine speed closer to the target synchronous speed. In this case, if the target synchronous speed is too low, the engine will stall.

[0038] The positions of the synchronizers in the vehicle equipped with a specific multi-gear hybrid transmission are shown in Table 1 below. As shown in Table 1, the driving modes of the vehicle include: Start engine, Battery charging at standstill, Series, Internal Combustion Engine 1st (ICE 1st), ECVT (Engine-Charging) 1st, ICE 2nd, EV (Electric Drive Mode, or Electric Mode), ECVT 2nd, ICE 3rd, ECVT 2nd, ICE 4th. The multi-gear hybrid transmission includes two synchronizers (i.e. synchronizer S1 and synchronizer S2 in the table below), and the switching between different driving modes is achieved by switching the positions of the synchronizers. In Table 1, S1L means the engagement in synchronizer S1 moves to near the left synchronizing ring in synchronizer S1; S1R means the engagement in synchronizer S1 moves to near the right synchronizing ring in synchronizer S1; similarly, S2L means the engagement in synchronizer S2 moves to near the left synchronizing ring in synchronizer S2; S2R means the engagement in synchronizer S2 moves to near the right synchronizing ring in synchronizer S2. In the multi-gear hybrid transmission, the driving modes corresponding to each gear, and the positions of the synchronizers in each gear are shown in Table 1 below. For a synchronizer, the engagement can be selected from three positions: moving to the left synchronizing ring, being in the middle of the two synchronizing rings, and moving to the right synchronizing ring.

[0039] Table 1

[0040]

[0041] In the multi-gear hybrid transmission, the switching sequence of the gears is from gear 1 to gear 11, for example, if it is needed to switch from gear 1 to gear 2, the engagement in synchronizer S1 needs to be moved to S1R position; if it is needed to switch from gear 2 to gear 4, the position of synchronizer S2L needs to be removed (i.e. the engagement in synchronizer S2 is moved to the middle of the two synchronizing rings) first to reach gear 3, and then after waiting for the synchronization condition to be met, synchronizer S2 is engaged in S2R position.

[0042] In the case that switching from one gear to another gear needs to go through multiple intermediate gears, for example, switching from gear 4 to gear 8, which needs to go through gears 5-7 in the middle, the time length required for switching from gear 4 to gear 8 is relatively large. In the deceleration process of emergency braking of the vehicle, the deceleration of the vehicle is large, and there may be a case that the vehicle speed of the vehicle is reduced to 0 before the vehicle is switched to the target gear (for example, gear 8), at this time, if the gear needs to be engaged, it will directly cause the engine to stall. Therefore, the scheme of the present application is proposed to solve the problem.

[0043] The implementation details of the technical solutions of the embodiments of the present application are described in detail as follows:

[0044] Figure 2 is a flow chart of the gear shifting control method according to an embodiment of the present application. The gear shifting control method can be executed by a vehicle, more specifically, can be executed by a controller in the vehicle. As shown in Figure 2 , the method at least includes steps 210-250, which are described in detail as follows:

[0045] Step 210, during the deceleration process of the vehicle, determining an estimated vehicle speed after a preset time length according to the current running state of the vehicle.

[0046] The current running state of the vehicle can indicate the current vehicle speed of the vehicle, and further, the current running state of the vehicle can also indicate the current deceleration of the vehicle. The deceleration of the vehicle can also be referred to as negative acceleration. The vehicle speed can be collected by a speed sensor on the vehicle, and the current deceleration of the vehicle can be detected by an acceleration sensor provided on the vehicle, of course, the current deceleration of the vehicle can also be calculated by the vehicle speed in a short time.

[0047] In some embodiments, as shown in Figure 3 , step 210 includes:

[0048] Step 310, during the deceleration process of the vehicle, obtaining the state information of the brake pedal in the vehicle.

[0049] The state information of the brake pedal is used to indicate the state of the brake pedal, wherein the state of the brake pedal can be that the brake pedal is stepped down, or that the brake pedal is not stepped down.

[0050] Step 320, determining a time length parameter corresponding to the state information of the brake pedal, and taking the time length parameter corresponding to the state information of the brake pedal as the preset time length.

[0051] In specific embodiments, the time length parameter corresponding to the state of the brake pedal being stepped on can be preset, and the time length parameter corresponding to the state of the brake pedal not being stepped on can be set, and on this basis, the time length parameter corresponding to the state indicated by the state information of the brake pedal is determined as the preset time length according to the state indicated by the state information of the brake pedal.

[0052] In a specific embodiment, the time length parameter corresponding to the state of the brake pedal being stepped on can be preset as 1s, and the time length parameter corresponding to the state of the brake pedal not being stepped on can be set as 0.3s. The time length parameters corresponding to the two states set are not limited to this, and can be set according to actual needs.

[0053] Step 330, determining the estimated vehicle speed of the vehicle after the preset time length according to the current speed of the vehicle and the current deceleration of the vehicle.

[0054] The estimated speed refers to the speed of the vehicle after the preset time length based on the current speed of the vehicle and the current deceleration of the vehicle. Specifically, the estimated speed can be calculated according to the following formula:

[0055] V1 = V0 + a0-t; (Formula 1)

[0056] Wherein, V1 is the estimated speed, V0 is the current speed of the vehicle; a0 is the current deceleration of the vehicle; t is the preset time length.

[0057] In other embodiments, the time length parameter corresponding to the state of the brake pedal being stepped on and the time length parameter corresponding to the state of the brake pedal not being stepped on can also be the same, for example, the time length parameter corresponding to the state of the brake pedal not being stepped on is set as the preset time length.

[0058] Please continue to refer to Figure 2 , step 220, determining the target demand gear of the vehicle according to the current running state and the throttle state of the vehicle.

[0059] Wherein, the throttle state is used to indicate the current throttle depth of the vehicle. Specifically, as Figure 4 shown, step 220 includes:

[0060] Step 410, obtaining the gear shift rule corresponding to the vehicle; the gear shift rule indicates the mapping relationship between the vehicle speed and the throttle depth in the case of switching between different gears.

[0061] In specific embodiments, the gear shift rule corresponding to the vehicle can be embodied by a gear shift curve. Figure 5 An exemplary schematic diagram of a gear shift curve of a vehicle is shown. Figure 5 An exemplary gear shift curve from gear 2 to gear 1, from gear 3 to gear 2, and from gear 4 to gear 3 is shown in

[0062] Step 420, according to the shift schedule, determine the gear corresponding to the current vehicle speed, the current vehicle throttle depth and the current actual gear of the vehicle.

[0063] Step 430, the gear corresponding to the current vehicle speed, the current vehicle throttle depth and the current actual gear of the vehicle is taken as the target demand gear.

[0064] The shift schedule indicates the mapping relationship between the vehicle speed and the throttle depth in the case of switching between different gears, that is, the shift schedule indicates the corresponding relationship between the gear before switching, the gear after switching, the vehicle speed and the throttle depth. Specifically, in this application, the current actual gear of the vehicle is taken as the gear before switching, and then the gear after switching corresponding to the current vehicle speed, the current vehicle throttle depth and the current actual gear of the vehicle can be determined, which is the gear corresponding to the current vehicle speed, the current vehicle throttle depth and the current actual gear of the vehicle, that is, the target demand gear.

[0065] For example, assuming that the current vehicle speed is V0, the current vehicle throttle depth is T0, and the current actual gear of the vehicle is gear 3, combined with the shift curve shown in Figure 5 , based on the vehicle speed V0, the throttle depth T0 and the actual gear 3, it can be determined that the shift curve used under the current working condition of the vehicle is the shift curve from gear 3 to gear 2, and under the shift curve from gear 3 to gear 2, gear 2 is the gear after switching, and then it can be determined that gear 2 is the target demand gear.

[0066] Please continue to refer to Figure 2 , step 230, according to the estimated vehicle speed, the gear ratio corresponding to the target demand gear, determine the target engine speed matched with the target demand gear. The target engine speed refers to the speed of the engine matched with the target demand gear.

[0067] Specifically, step 230 includes: obtaining the gear ratio corresponding to the target demand gear, the main reduction ratio corresponding to the vehicle, and the tire diameter of the vehicle; according to the estimated vehicle speed, the gear ratio corresponding to the target demand gear, the tire radius of the vehicle and the main reduction ratio corresponding to the vehicle, the target engine speed matched with the target demand gear is calculated.

[0068] In specific embodiments, the target engine speed corresponding to the target demand gear can be calculated according to the following formula:

[0069]

[0070] Wherein, n1 is the target engine speed; V1 is the estimated vehicle speed; s1 is the gear ratio corresponding to the target demand gear; s2 is the main reduction ratio corresponding to the vehicle; R is the tire radius of the vehicle.

[0071] If the unit of the vehicle speed is km / h, the unit of n1 is r / s, and the unit of R is m, the above formula 2 can be further converted as:

[0072]

[0073] In step 240, if the target engine speed is less than the allowable minimum engine speed, the target gear is determined according to the current actual gear of the vehicle, wherein the time required for the vehicle to shift from the actual gear to the target gear is less than the time required for the vehicle to shift from the actual gear to the target demand gear.

[0074] In the case where the target engine speed is less than the allowable minimum engine speed, if the vehicle is still shifted to the target gear, it may cause the engine to be turned off before reaching the target gear. Therefore, in order to avoid this problem, it is necessary to determine the target demand gear for the vehicle again, that is, to determine the target gear as the target demand gear again. Since the time required for the vehicle to shift from the actual gear to the target gear is less than the time required for the vehicle to shift from the actual gear to the target demand gear, it can be ensured that the vehicle speed does not decrease to 0 when the vehicle shifts from the actual gear to the target gear during deceleration, thereby avoiding the problem of engine stall caused by reverse dragging of the engine.

[0075] In some embodiments of the present application, step 240 comprises: determining the new gear corresponding to the actual gear as the original gear according to the preset correspondence between the original gear and the new gear; and determining the new gear corresponding to the actual gear as the target gear.

[0076] In some embodiments, the gear adjacent to the current actual gear of the vehicle can be determined as the target gear based on the preset gear switching order. Since the gear adjacent to the current actual gear is determined as the target gear, the time required for the vehicle to shift from the current actual gear to the target gear is less, and the shifting is also the most convenient, thereby effectively avoiding the problem that the vehicle speed decreases to 0 before shifting to the target demand gear during deceleration due to the long shifting time, resulting in reverse dragging of the engine, and further causing the engine to stall.

[0077] In specific embodiments, the target gear is determined based on a gear shift sequence consistent with a current gear shift direction and a current actual gear of the vehicle. The current gear shift direction refers to a gear shift direction from the current actual gear to the target demand gear, wherein the gear shift direction includes an upshift direction and a downshift direction, and the gear shift sequence consistent with the gear shift direction includes a gear upshift sequence corresponding to the upshift direction and a gear downshift sequence corresponding to the downshift direction. For example, if the gear shift direction from the actual gear to the target demand gear is the upshift direction, the next gear adjacent to the actual gear in the gear upshift sequence corresponding to the upshift direction is taken as the target gear.

[0078] At step 250, the vehicle is controlled to shift gears to the target gear.

[0079] In the scheme of the present application, during the process of deceleration of the vehicle, the estimated vehicle speed after a preset time length is determined based on the current operating state of the vehicle, and the target demand gear of the vehicle is determined based on the current operating state and the throttle state of the vehicle, and then the target engine speed corresponding to the target demand gear is determined according to the estimated vehicle speed and the gear speed ratio corresponding to the target demand gear, and in the case that the target engine speed is less than the allowable minimum engine speed, the vehicle is controlled to shift gears to the target gear, so as to ensure that the time required for the vehicle to shift from the current actual gear to the target gear is less than the time required for the vehicle to shift from the actual gear to the target demand gear.

[0080] In the present application, the preset time length is equivalent to the time length reserved for the vehicle to shift from the actual gear to the target demand gear, and then the estimated vehicle speed after the preset time length is estimated, and the target engine speed of the engine at the target demand gear is calculated based on the estimated vehicle speed, which is equivalent to the estimated engine speed of the engine at the target demand gear if the vehicle normally shifts from the current actual gear to the target demand gear. As described above, if the target engine speed is less than the minimum speed, it indicates that there may be a gear that cannot be passed during the process of shifting from the actual gear to the target gear, so that the vehicle is stranded between the actual gear and the target demand gear, and then the engine speed does not match the wheel speed, resulting in engine stall. Therefore, in this case, the target gear is determined based on the actual gear of the vehicle, and the vehicle is controlled to shift gears to the target gear, so as to ensure that the time required for the vehicle to shift from the current actual gear to the target gear is less than the time required for the vehicle to shift from the actual gear to the target demand gear, and then ensure that the vehicle speed is not zero when the vehicle shifts gears to the target gear, and then ensure that the engine will not be reversed to cause engine stall, thereby effectively solving the problem of engine stall in the prior art during the process of emergency braking or emergency deceleration of the vehicle.

[0081] In some embodiments of the present application, after step 240, the method further comprises: if the target demand gear is a gear in the preset gear set, controlling the vehicle to shift gears to the target demand gear.

[0082] The gears in the preset gear set can be gears that do not reverse-drag the engine. For a hybrid vehicle, the gears in the preset gear set can be gears corresponding to the electric drive mode, gears corresponding to the series mode, the neutral gear, and gears corresponding to the ECVT mode. For example, for a vehicle equipped with the multi-gear hybrid transmission described above, the gears in the preset gear set can be gears corresponding to the EV mode (gears 6 and 11 in Table 1), gears corresponding to the ECVT mode (gears 3, 5, 7, and 9 in Table 1), a gear corresponding to the series mode (gear 1 in Table 1), and the neutral gear.

[0083] Since the gears in the preset gear set are gears that do not reverse-drag the engine, in this case, the problem of engine stall caused by reverse-dragging of the engine does not occur during control of the vehicle to shift to the target demand gear, thereby ensuring that the vehicle can move continuously and stably.

[0084] In some embodiments of the present application, after step 230, the method further includes: if the target engine speed is within a preset safe speed range, controlling the vehicle to shift to the target demand gear.

[0085] The preset safe speed range can be a speed range from the lowest engine speed allowed to the highest engine speed allowed. Of course, in other embodiments, the safe speed range can also be a sub-speed range in the speed range from the lowest engine speed allowed to the highest engine speed allowed.

[0086] If the target engine speed is within the preset safe speed range, it indicates that the target engine speed is higher than the lowest engine speed allowed, and thus the problem of engine stall caused by reverse-dragging of the engine does not occur during shifting to the target demand gear.

[0087] Figure 6 is a flowchart of a shift control method according to an embodiment of the present application. As shown in Figure 6 The shift control method includes a shift validity verification step 610, an engine speed estimation step 620, and a gear decision step 630. Figure 6 The shift control method shown in FIG. 6 can be applied to a vehicle equipped with the multi-gear hybrid transmission corresponding to Table 1.

[0088] Specifically, in the shift validity verification step 610, the target demand gear is determined according to the current vehicle speed and the current throttle depth. Details of determining the target demand gear are described above and will not be repeated here.

[0089] If the target demand gear is a gear in the preset gear set and the current actual engine speed is in the preset safe speed range, the first signal A1 is set to 1, otherwise, the first signal A1 is set to 0. Specifically, the preset gear set includes a gear corresponding to the EV mode, a gear corresponding to the ECVT mode, a gear corresponding to the series mode and a neutral gear. If the first signal A1 is 1, the second signal A2 is set to 1. If the first signal A1 is not 1, the third signal A3 is determined in combination with the target engine speed determined in the engine speed estimation step 620.

[0090] Specifically, in the engine speed estimation step 620, the target engine speed is determined according to the current speed of the vehicle, the state signal of the brake pedal and the current deceleration of the vehicle. For details of the implementation of determining the target engine speed, please refer to the description above, which will not be repeated here.

[0091] The shift effectiveness verification step 610 further includes determining whether the target engine speed is in the preset safe speed range according to the target engine speed, the allowable minimum speed of the engine and the allowable maximum speed of the engine. If the target engine speed is in the preset safe speed range, the third signal A3 is set to 1, otherwise, the third signal A3 is set to 0.

[0092] Further, in the engine speed estimation step 620, it can be first determined whether the deceleration of the vehicle is less than a first threshold. If it is determined that the current deceleration of the vehicle is less than the first threshold, it is determined that the subsequent processes of estimating the speed and determining the target engine speed do not need to be performed, and the value of the third signal A3 is determined directly according to the value of the first signal determined in the shift effectiveness verification step 610. Otherwise, if it is determined that the current deceleration of the vehicle is in the range of the first threshold to a second threshold, it is determined that the subsequent processes of estimating the speed and determining the target engine speed need to be performed. The first threshold is a negative number, and the second threshold is greater than the second threshold. It can be understood that in the case that the current deceleration of the vehicle is less than the first threshold, it indicates that the absolute value of the deceleration is large at this time, and the rate of the current deceleration of the vehicle is very fast.

[0093] In the gear decision step 630, the value of the second signal A2 is ANDed with the value of the fourth signal A4, and the result of the AND operation is taken as the value of the fifth signal A5. The value of the fourth signal A4 is determined according to the comparison between the current actual gear of the vehicle and the target demand gear of the vehicle. If the current actual gear of the vehicle is the same as the target demand gear, the value of the fourth signal is determined to be 1, otherwise, if the current actual gear of the vehicle is different from the target demand gear, the target demand gear needs to be determined again based on the current actual gear of the vehicle.

[0094] By Figure 6It can be seen that when the value of the fifth signal A5 is 1, the vehicle is controlled to shift to the target gear determined based on the vehicle's current speed and throttle position. Specifically, when the value of the second signal A2 is 1 (the target gear is a gear in the preset gear set, or the target engine speed is within the preset safe speed range) and the value of the fourth signal is 1 (the target gear is the same as the actual gear), the value of the fifth signal A5 is 1.

[0095] Conversely, if the value of the fifth signal A5 is not 1, the target gear is re-determined based on the vehicle's current actual gear and the preset correspondence between the original gear and the new gear. The re-determined target gear is the target gear mentioned above. Then, the corresponding control shifts to the re-determined target gear (i.e., the target gear).

[0096] like Figure 6 As shown in Table 1, in the vehicles equipped with multi-speed hybrid transmissions, if the current actual gear of the vehicle is the gear corresponding to the internal combustion engine 1st gear (ICE 1st) (i.e., gear 2 in Table 1), then the gear corresponding to the series mode (i.e., gear 1 in Table 1) is redefined as the target gear; if the current actual gear of the vehicle is the gear corresponding to the internal combustion engine 2nd gear (ICE 2st) (i.e., gear 4 in Table 1) or any other gear besides the gears corresponding to the internal combustion engine 1st and 2nd gears, then the gear corresponding to the ECVT mode is redefined as the target gear. If the vehicle's current actual gear is ICE2nd / 3rd / 4th, then the gear corresponding to the ECVT mode will be redefined as the target gear. Specifically, if the vehicle's current actual gear is ICE2nd, the gear corresponding to ECVT1-1 in the ECVT mode will be redefined as the target gear; if the vehicle's current actual gear is ICE3rd, the gear corresponding to ECVT2_1 in the ECVT mode will be redefined as the target gear; and if the vehicle's current actual gear is ICE4th, the gear corresponding to ECVT2_2 in the ECVT mode will be redefined as the target gear.

[0097] In a specific embodiment, the system can further determine whether the current direct-drive gear is valid based on the estimated engine speed, i.e., the target engine speed that matches the target gear based on the estimated vehicle speed and the gear ratio corresponding to the target gear. If the target engine speed is within a reasonable range, the current direct-drive gear is determined to be valid; otherwise, if the target engine speed is not within a reasonable range, the current direct-drive gear is determined to be invalid. If the current direct-drive gear is valid, the system controls the gear shift to the target gear based on the throttle and vehicle speed. If the current direct-drive gear is invalid, the system needs to determine the gear to stay in based on the actual gear of the vehicle.

[0098] In specific embodiments, in the process of re-determining the target demand gear, the switching order of gears in the vehicle can also be referenced to determine, for example, as shown in Table 1, it is most convenient to shift from the gear corresponding to the 2nd gear of the internal combustion engine (i.e., gear 4) to gear 5, and thus, if the actual gear is gear 4 in Table 1, gear 5 in Table 1 can be taken as the target gear. That is, in the process of re-determining the target demand gear, the gear adjacent to the current actual gear of the vehicle in the preset shifting order is re-determined as the target demand gear, and it can be understood that the re-determined target demand gear also causes the vehicle speed to decrease.

[0099] The device embodiments of the present application are described below, which can be used to execute the gear shifting control method in the above-mentioned embodiments of the present application. For details not disclosed in the device embodiments of the present application, please refer to the above-mentioned embodiments of the gear shifting control method.

[0100] Figure 7 is a block diagram of a gear shifting control device according to an embodiment of the present application. The gear shifting control device can be deployed in a vehicle. As shown in Figure 7 The gear shifting control device includes: a predicted vehicle speed determination module 710, configured to determine a predicted vehicle speed after a preset time length according to a current running state of the vehicle during deceleration of the vehicle; a target demand gear determination module 720, configured to determine a target demand gear of the vehicle according to the current running state of the vehicle and a throttle state; a target engine speed determination module 730, configured to determine a target engine speed matched with the target demand gear according to the predicted vehicle speed and a gear speed ratio corresponding to the target demand gear; a target gear determination module 740, configured to determine a target gear according to a current actual gear of the vehicle if the target engine speed is less than a minimum allowable engine speed, wherein a time length required for the vehicle to shift from the actual gear to the target gear is less than a time length required for the vehicle to shift from the actual gear to the target demand gear; and a gear shifting module 750, configured to control the vehicle to shift to the target gear.

[0101] In some embodiments of the present application, the current running state of the vehicle indicates a current vehicle speed of the vehicle, and the throttle state indicates a current throttle depth of the vehicle. In this embodiment, the target gear determination module 740 includes: a gear shifting law acquisition unit, configured to acquire a gear shifting law corresponding to the vehicle; the gear shifting law indicates a mapping relationship between the vehicle speed and the throttle depth in the case of switching between different gears; a gear determination unit, configured to determine a gear corresponding to the current vehicle speed, the current throttle depth of the vehicle and the current actual gear of the vehicle according to the gear shifting law; and a target demand gear determination unit, configured to take the gear corresponding to the current vehicle speed, the current throttle depth of the vehicle and the current actual gear of the vehicle as the target demand gear.

[0102] In some embodiments of the present application, the current operating state of the vehicle indicates a current vehicle speed and a current deceleration of the vehicle; in this embodiment, the estimated vehicle speed determination module 710 comprises: a pedal state information acquisition unit configured to acquire state information of a brake pedal in the vehicle during deceleration of the vehicle; a preset time length determination unit configured to determine a time length parameter corresponding to the state information of the brake pedal, and take the time length parameter corresponding to the state information of the brake pedal as a preset time length; and an estimated vehicle speed determination unit configured to determine an estimated vehicle speed of the vehicle after the preset time length according to the current vehicle speed and the current deceleration of the vehicle.

[0103] In some embodiments of the present application, the target engine speed determination module 730 is further configured to calculate a target engine speed matching the target demand gear according to the estimated vehicle speed, a gear speed ratio corresponding to the target demand gear, a tire radius of the vehicle, and a main reduction ratio corresponding to the vehicle.

[0104] In some embodiments of the present application, the target gear determination module 740 is further configured to determine a new gear corresponding to the actual gear in a case where the actual gear is taken as an original gear according to a preset correspondence between the original gear and the new gear, and take the new gear corresponding to the actual gear as the target gear.

[0105] In some embodiments of the present application, the gear shifting control device further comprises a first control module configured to control the vehicle to shift to the target demand gear if the target demand gear is a gear in the preset gear set.

[0106] In some embodiments of the present application, the gear shifting control device further comprises a second control module configured to control the vehicle to shift to the target demand gear if the target engine speed is within a preset safe speed range.

[0107] The present application also provides a vehicle comprising a processor and a memory, wherein the memory stores computer readable instructions, and the computer readable instructions, when executed by the processor, implement the gear shifting control method in any of the above embodiments.

[0108] The present application also provides a vehicle-mounted device comprising a processor and a memory, wherein the memory stores computer readable instructions, and the computer readable instructions, when executed by the processor, implement the gear shifting control method in any of the above embodiments.

[0109] The present application also provides a computer readable storage medium, wherein the computer readable storage medium stores computer readable instructions, and the computer readable instructions, when executed by a processor, implement the gear shifting control method in any of the above embodiments.

[0110] The application also provides a computer program product or computer program comprising computer instructions stored in a computer readable storage medium. When the computer instructions are executed by a processor, the shift control method in any of the above embodiments is implemented.

[0111] A computer program product for implementing the above method according to the embodiments of the application can take a portable compact disc read-only memory (CD-ROM) and include program codes, and can be run on an electronic device, such as a vehicle. However, the computer program product of the application is not limited thereto, and in this document, the readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus or device.

[0112] The computer program product can take any combination of one or more readable media. The readable medium can be a readable signal medium or a readable storage medium. The readable storage medium may, for example, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus or device, or any combination thereof. More specific examples (non-exhaustive list) of readable storage media include an electrical connection having one or more wires, a portable disc, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof.

[0113] The computer readable signal medium can include a data signal propagated in a baseband or as part of a carrier wave, in which readable program codes are carried. Such a propagated data signal can take various forms, including but not limited to an electromagnetic signal, an optical signal or any suitable combination thereof. The readable signal medium can also be any readable medium other than the readable storage medium, which can send, propagate or transmit programs for use by or in conjunction with an instruction execution system, apparatus or device.

[0114] The program codes contained on the readable medium can be transmitted by any suitable medium, including but not limited to wireless, wired, optical cable, RF, etc., or any suitable combination thereof.

[0115] The program code, when executed, can implement the techniques for the present application. The program code can be written in any combination of one or more programming languages, including an object oriented programming language such as Java, C++, or the like, and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code can execute entirely on the user's computing device, partly on the user's computing device, as a stand-alone software package, partly on the user's computing device and partly on a remote computing device or entirely on the remote computing device or server. In the latter scenario, the remote computing device can be connected to the user's computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection can be made to an external computing device, such as through the Internet using an Internet Service Provider.

[0116] Those skilled in the art will understand that the various aspects of the application can be implemented as a system, method or program product. Therefore, aspects of the application can take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, microcode, etc.) or an embodiment combining software and hardware aspects that can all generally be referred to herein as a "circuit," "module" or "system." Furthermore, aspects of the application can take the form of a program product embodied in one or more computer readable medium(s) having computer readable program code embodied thereon.

[0117] Those skilled in the art will understand that the various aspects of the application can be implemented as a system, method or program product. Therefore, aspects of the application can take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, microcode, etc.) or an embodiment combining software and hardware aspects that can all generally be referred to herein as a "circuit," "module" or "system." Furthermore, aspects of the application can take the form of a program product embodied in one or more computer readable medium(s) having computer readable program code embodied thereon.

[0118] In addition, the above-mentioned figures are only schematic illustrations of the processes included in the method according to the exemplary embodiments of the present application, and are not intended to be limiting. It is readily understood that the processes shown in the above-mentioned figures do not indicate or limit the time sequence of the processes. In addition, it is readily understood that the processes can be executed synchronously or asynchronously, for example, in a plurality of modules.

[0119] It is to be understood that the application is not limited to the precise construction described above and shown in the attached figures, and that various modifications and changes can be made without departing from the scope thereof. The scope of the application is limited only by the claims appended hereto.

Claims

1. A gear shifting control method, characterized in that, The method includes: During the vehicle deceleration process, the estimated vehicle speed after a preset time is determined based on the current operating state of the vehicle. Based on the vehicle's current operating status and throttle status, determine the target gear required for the vehicle; the vehicle's current operating status indicates the vehicle's current speed and / or the vehicle's current deceleration. Based on the estimated vehicle speed and the gear ratio corresponding to the target gear, determine the target engine speed that matches the target gear. If the target engine speed is less than the minimum allowable engine speed, then the target gear is determined according to the current actual gear of the vehicle, wherein the time required for the vehicle to shift from the actual gear to the target gear is less than the time required for the vehicle to shift from the actual gear to the target gear. Control the vehicle to shift to the target gear.

2. The method according to claim 1, characterized in that, The throttle status indicates the current throttle depth of the vehicle; Determining the target gear required for the vehicle based on its current operating status and throttle position includes: Obtain the shifting pattern corresponding to the vehicle; the shifting pattern indicates the mapping relationship between vehicle speed and throttle depth when switching between different gears; Based on the shifting pattern, determine the gear corresponding to the vehicle's current speed, current throttle position, and current actual gear position. The gear corresponding to the vehicle's current speed, the vehicle's current throttle position, and the vehicle's current actual gear position is taken as the target required gear.

3. The method according to claim 1, characterized in that, During vehicle deceleration, determining the estimated vehicle speed after a preset time period based on the vehicle's current operating state includes: During vehicle deceleration, the status information of the brake pedal in the vehicle is acquired; Determine the duration parameter corresponding to the state information of the brake pedal, and use the duration parameter corresponding to the state information of the brake pedal as the preset duration; Based on the vehicle's current speed and current deceleration, determine the estimated speed of the vehicle after a preset time.

4. The method according to claim 1, characterized in that, The step of determining the target engine speed that matches the target gear based on the estimated vehicle speed and the gear ratio corresponding to the target gear includes: Based on the estimated vehicle speed, the gear ratio corresponding to the target gear, the tire radius of the vehicle, and the final drive ratio of the vehicle, the target engine speed that matches the target gear is calculated.

5. The method according to claim 1, characterized in that, Determining the target gear based on the vehicle's current actual gear position includes: Based on the preset correspondence between the original gear and the new gear, determine the new gear corresponding to the actual gear when the actual gear is taken as the original gear; and take the new gear corresponding to the actual gear as the target gear.

6. The method according to claim 1, characterized in that, After determining the target gear required by the vehicle based on its current operating state and throttle position, the method further includes: If the target gear is a gear in a preset gear set, then control the vehicle to shift to the target gear.

7. The method according to claim 1, characterized in that, After determining the target engine speed that matches the target gear based on the estimated vehicle speed and the gear ratio corresponding to the target gear, the method further includes: If the target engine speed is within the preset safe speed range, then control the vehicle to shift to the target gear.

8. A gear shifting control device, characterized in that, The device includes: The estimated vehicle speed determination module is used to determine the estimated vehicle speed after a preset time period based on the current operating state of the vehicle during the vehicle deceleration process. The target gear requirement determination module is used to determine the target gear requirement of the vehicle based on the vehicle's current operating state and throttle state; the vehicle's current operating state indicates the vehicle's current speed and / or the vehicle's current deceleration. The target engine speed determination module is used to determine the target engine speed that matches the target gear based on the estimated vehicle speed and the gear ratio corresponding to the target gear. The target gear determination module is used to determine the target gear based on the current actual gear of the vehicle if the target engine speed is less than the minimum allowable speed of the engine. The time required for the vehicle to shift from the actual gear to the target gear is less than the time required for the vehicle to shift from the actual gear to the target gear. The gear shifting module is used to control the vehicle to shift to the target gear.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-readable instructions that, when executed by a processor, implement the method as described in any one of claims 1 to 7.

10. A vehicle, characterized in that, The method includes a processor and a memory, the memory storing computer-readable instructions that, when executed by the processor, implement the method as claimed in any one of claims 1 to 7.

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