A vehicle control method and device for hill start, vehicle and storage medium

Abstract

The present application relates to the technical field of vehicle control, and discloses a vehicle hill shift control method, device, vehicle and storage medium, the method comprising: obtaining vehicle operation information; determining whether the vehicle has a risk of coasting downhill according to the vehicle operation information; if the speed of the gearbox output shaft meets a preset continuous downward trend under the condition of the risk of coasting downhill, downshifting is performed, and upshifting is prohibited at the same time. The present application uses the continuous change trend of the speed of the gearbox output shaft as a criterion, and short parameter fluctuations caused by road bumps and instantaneous wheel skidding do not trigger the shift action, so that the probability of unintended active downshifting can be effectively suppressed.

Description

Technical Field

[0001] This invention relates to the field of vehicle control technology, and specifically to a control method, device, vehicle, and storage medium for vehicle hill shifting. Background Technology

[0002] With the continuous development of electrification in commercial vehicles, electric AMT (Automated Manual Transmission) drive assemblies are constantly being upgraded in terms of electrification and intelligence. Commercial vehicles are also placing increasingly higher demands on the power and economy of AMT transmission assemblies. Heavy-duty commercial vehicles sometimes experience insufficient power after upshifting and then downshifting when going uphill on long inclines. Sometimes, the transmission fails to downshift in time when going uphill in a high gear, resulting in low overall vehicle operating efficiency and poor economy. Therefore, intelligent shifting on slopes is crucial. Related technologies, under the condition that the throttle and slope meet preset values, consider the vehicle's power insufficient if the acceleration is less than an acceleration threshold, which can easily trigger an accidental active downshift. Summary of the Invention

[0003] This invention provides a method, device, vehicle, and storage medium for controlling gear shifting on a slope, in order to solve the problem that slope gear control is prone to accidental triggering of active downshifting.

[0004] In a first aspect, the present invention provides a control method for vehicle hill shifting, the method comprising: acquiring vehicle operating information; determining whether the vehicle has a risk of rolling back on a hill based on the vehicle operating information; if, under the condition of having a risk of rolling back on a hill, the speed of the transmission output shaft meets a preset continuous downward trend, then downshifting is performed and upshifting is prohibited at the same time.

[0005] In some optional implementations, determining whether a vehicle has a risk of rolling back on a slope based on vehicle operation information includes: determining whether the throttle opening is greater than a preset throttle opening threshold within a first preset time; determining whether the current slope value is greater than a preset slope threshold; determining whether the current motor torque is greater than a preset torque threshold; determining whether the vehicle speed value is greater than a preset vehicle speed threshold; if all of the above conditions are met, then it is determined that there is a risk of rolling back on a slope.

[0006] In some alternative implementations, the preset speed threshold is determined based on the current gradient and the current gear, and is positively correlated with the current gradient and the current gear.

[0007] In some optional implementations, if the gearbox output shaft speed meets a preset continuous downward trend under conditions of potential runaway, then downshifting is performed and upshifting is prohibited at the same time. This includes: if the gearbox output shaft speed decreases by more than a preset threshold within a second preset time period under conditions of potential runaway, then downshifting is performed and upshifting is prohibited at the same time.

[0008] In some optional implementations, the method further includes: if, during the process of monitoring whether the output shaft speed of the transmission meets a preset continuous downward trend, it is determined that the vehicle does not currently have a risk of rolling back, then the current gear is maintained, and the step of determining whether the vehicle has a risk of rolling back based on the vehicle's operating information is continued.

[0009] In some alternative implementations, if the gearbox output shaft speed meets a preset continuous downward trend under conditions of potential slippage, and downshifting is performed while upshifting is prohibited, the method further includes: when the motor speed is greater than a preset speed threshold, or when the motor power is less than a preset power threshold, the upshift prohibition restriction is lifted.

[0010] In some alternative implementations, after lifting the restriction on upshifting, the method further includes: querying the shift map based on vehicle speed and throttle signal; if the shift map determines that the current vehicle speed and throttle signal meet the upshifting conditions, then upshifting is performed.

[0011] Secondly, the present invention provides a control device for vehicle hill shifting, the device comprising: an attribute acquisition module for acquiring vehicle operating information; a risk condition detection module for determining whether the vehicle has a risk of rolling back on a hill based on the vehicle operating information; and a downshift detection module for performing downshifting and simultaneously prohibiting upshifting if the gearbox output shaft speed meets a preset continuous downward trend under the condition of rolling back on a hill.

[0012] Thirdly, the present invention provides a vehicle comprising: a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, and the processor executing the computer instructions to perform the method described in the first aspect or any corresponding embodiment thereof.

[0013] Fourthly, the present invention provides a computer-readable storage medium storing computer instructions for causing a computer to perform the method described in the first aspect or any corresponding embodiment thereof.

[0014] Fifthly, the present invention provides a computer program product, including computer instructions for causing a computer to perform the method described in the first aspect or any corresponding embodiment thereof.

[0015] The technical solution provided by this invention has the following advantages: Instead of using instantaneous acceleration as a criterion for insufficient power, the continuous trend of the transmission output shaft speed is used. Brief fluctuations in parameters caused by road bumps or momentary wheel slippage will not trigger gear shifts, effectively suppressing the probability of unexpected active downshifts. A slope slip risk assessment is introduced upfront, constraining downshifting behavior within safe driving conditions and avoiding the safety hazard of vehicle backward slippage during AMT power interruptions, thus improving driving safety under heavy loads and uphill conditions. Once a downshift is triggered, upshift suppression is applied simultaneously, preventing gear shifting and allowing the motor to stably maintain a high torque output range. This ensures continuous power output for the vehicle during uphill climbs, reducing the frequency of power interruptions caused by gear shifts. This improves efficiency on mountain slopes and reduces component wear caused by frequent gear shifts in the electric drive transmission system. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a schematic flowchart of a first method for controlling vehicle gear shifting on a slope according to an embodiment of the present invention. Figure 2 This is a second flowchart illustrating a vehicle ramp shifting control method according to an embodiment of the present invention; Figure 3 This is a structural block diagram of a vehicle ramp shifting control device according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the hardware structure of an electronic device according to an embodiment of the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] It is understood that before using the technical solutions disclosed in the various embodiments of the present invention, users should be informed of the types, scope of use, and usage scenarios of the personal information involved in the present invention and their authorization should be obtained in accordance with relevant laws and regulations through appropriate means.

[0020] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0021] According to an embodiment of the present invention, a control method for vehicle ramp shifting is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0022] This embodiment provides a control method for vehicle gear shifting on a slope, which can be used in vehicles. Figure 1 This is a flowchart of a vehicle hill-start shifting control method according to an embodiment of the present invention, the process including the following steps: Step S101: Obtain vehicle operation information; Step S102: Determine whether the vehicle has a risk of slipping off the slope based on the vehicle operation information; In step S103, if the gearbox output shaft speed meets the preset continuous downward trend under the condition of risk of slippage, then downshifting is performed and upshifting is prohibited at the same time.

[0023] Specifically, during long-distance uphill driving of heavy-duty commercial vehicles, the shifting strategy based on instantaneous acceleration criteria is prone to unexpected downshifting. Furthermore, excessively low vehicle speed during downshifting can induce a rollback safety hazard. The slope shifting control scheme described in this embodiment is designed for uphill driving conditions of electric AMT commercial vehicles. It completes shifting decisions by combining multi-dimensional vehicle operating parameters with the trend of transmission output shaft speed changes.

[0024] The vehicle controller first collects vehicle operation information. This information consists of a set of real-time vehicle status parameters directly readable from the vehicle's CAN bus, including but not limited to physical quantities strongly correlated with hill-climbing driving, such as throttle opening, road gradient, motor output torque, gearbox output shaft speed, and vehicle speed. The gearbox output shaft speed characterizes the rotational rate of the gearbox output end; this physical quantity is positively correlated with vehicle speed and directly reflects the actual power output matching state of the vehicle, distinct from the vehicle acceleration signal which is easily affected by road bumps. Taking a fully loaded 49-ton heavy-duty electric tractor traveling uphill in a mountainous area as an example, the vehicle controller periodically reads bus messages, obtaining the current throttle opening of 85%, road gradient of 12%, motor output torque of 2100 N·m, gearbox output shaft speed of 1150 r / min, and current vehicle speed of 22 km / h. This completes the acquisition of all raw operating parameters, providing the initial input data source for subsequent risk assessment.

[0025] After obtaining all vehicle operating parameters, the system assesses the risk of rollback based on these parameters. Rollback risk here refers to the potential danger of the vehicle sliding backward during a brief power interruption when the AMT transmission downshifts. If the vehicle's driving force is insufficient to overcome the slope resistance during this time, the risk is mitigated. This step doesn't directly determine if there's insufficient power; instead, it performs a preliminary screening of the current driving conditions. Only when the vehicle enters a high-risk driving zone will the subsequent speed trend observation process begin. Continuing with the example of heavy-load hill climbing in mountainous areas, the system compares the collected throttle, gradient, motor torque, and vehicle speed with preset thresholds. If all parameters fall within the high-risk range, the current driving scenario is marked as having a rollback risk. If any parameter fails to meet the corresponding threshold, the subsequent observation process is terminated, and the transmission remains in its original gear.

[0026] After marking the risk of rollback, the vehicle continuously monitors the evolution of the transmission output shaft speed. Only when a rollback risk is determined will the change in output shaft speed be further evaluated. The preset continuous downward trend indicates that the speed is not a random drop at a single sampling point, but rather a continuous decrease in speed value over a continuous time window, representing that the actual output power of the vehicle is continuously unable to overcome the resistance of the slope. For example, if a rollback risk is determined, the system continuously tracks the output shaft speed. Within the set observation period, the speed gradually decreases from 1150 r / min to 920 r / min, forming a continuous downward change, satisfying the trend judgment condition. At this time, the vehicle controller issues a downshift execution command, controlling the transmission to complete the downshift. Simultaneously, an upshift suppression constraint is applied, disallowing the transmission from responding to upshift requests issued by the regular shift MAP, avoiding the repetitive shifting phenomenon of downshifting followed immediately upshifting during the climb.

[0027] Based on the aforementioned technical means, this embodiment of the invention abandons instantaneous acceleration as the criterion for judging insufficient power, and instead uses the continuous change trend of the transmission output shaft speed as the criterion. Brief parameter fluctuations caused by road bumps and momentary wheel slippage will not trigger gear shifting, effectively suppressing the probability of unexpected active downshifting. Secondly, a slope slip risk assessment is introduced before the process begins, constraining downshifting behavior within safe driving conditions, avoiding the safety hazard of the vehicle slipping backward during AMT power interruption, and improving driving safety under heavy-load uphill conditions. Once downshifting is triggered, upshift suppression constraints are applied simultaneously, preventing gear shifting and allowing the motor to stably maintain a high torque output range. The vehicle's uphill power output is continuous, reducing the frequency of power interruptions caused by gear shifting, thus improving the efficiency of mountain slopes and reducing component wear caused by frequent gear shifting in the electric drive transmission system.

[0028] In some optional implementations, step S102 above includes: Step a1: Determine whether the throttle opening is greater than the preset throttle opening threshold within the first preset time. Step a2: Determine whether the current slope value is greater than the preset slope threshold; Step a3: Determine whether the current motor torque is greater than the preset torque threshold; Step a4: Determine whether the vehicle speed value is greater than the preset vehicle speed threshold; Step a5: If all the above conditions are met, then the risk of landslide is determined.

[0029] Specifically, this embodiment of the invention is a multi-condition joint verification process for determining slope slip risk. First, a continuous verification of throttle opening is performed, which means constraining the driver's power request over time. The judgment condition is not determined simply by the throttle opening momentarily exceeding the threshold at the time of data collection; rather, it examines the continuous performance of the throttle opening within a first preset time window. The first preset time is obtained through actual vehicle calibration. For heavy-duty electric commercial vehicles, a typical calibration value can be 1.5 seconds (this is just an example and not a limitation). The preset throttle opening threshold (ACC) is also determined based on vehicle calibration, for example, set to 70% opening. The core of this verification is to identify the driver's driving state of having a continuous demand for high power output, eliminating misjudgments caused by short-term operations such as the driver momentarily pressing and releasing the accelerator pedal. For example, if a fully loaded 49-ton electric heavy truck is driving on a mountain slope, and the throttle pedal opening remains at 78% for 1.5 seconds, which is greater than the preset throttle opening threshold of 70%, then this verification passes. If there is only a brief 0.4s of heavy throttle input followed by a rapid drop in pedal opening, this condition will still not be met, even if the instantaneous opening exceeds the threshold.

[0030] Simultaneously, a road slope comparison and verification was also conducted, comparing the current slope value output by the vehicle's slope sensors with a preset slope threshold. The preset slope threshold represents the minimum gradient at which risk management needs to be activated; for heavy-duty commercial vehicles, this can be calibrated as 8%. The slope value directly reflects the slope resistance level. When the road slope is below this threshold, the slope resistance is limited, and even if the transmission downshifts, the possibility of the vehicle sliding backward during the power interruption phase is extremely low, and it does not need to be included in the rollback risk scenario. For example, if the vehicle is traveling on a long uphill road with a 12% slope, and the collected slope value is greater than the preset slope threshold of 8%, this verification is satisfied; if the vehicle is traveling on a gentle uphill road with a 3% slope, this condition is not met, and the rollback risk is directly excluded.

[0031] Simultaneously, a threshold comparison of the motor output torque needs to be performed. The current motor torque here is taken from the actual output torque fed back by the electric drive system. The preset torque threshold Tq is a calibration parameter, which can be calibrated to 1600N based on the characteristics of the electric drive assembly. (m is just an example and not a limitation). Motor torque represents the driving capability output by the electric drive system. Only when the motor has already output a high level of driving torque and still faces a situation of difficulty climbing hills, is there a prerequisite for the possibility of rolling back after shifting gears. If the actual output torque of the motor is low, it means that the vehicle's driving demand itself is not high, and there is no characteristic of high-load hill climbing.

[0032] The existing active downshifting technology does not set a minimum speed at which downshifting is allowed. For example, when climbing a hill in second gear, insufficient power necessitates first gear to meet the power requirements, but the vehicle speed is only around 5 kph. If downshifting from second to first gear at this point, the power interruption during the AMT shift, coupled with a heavy load climbing the hill, could cause the vehicle to roll backward, which is extremely dangerous. The technical solution provided in this invention further determines the vehicle speed condition by comparing the current vehicle speed with a preset vehicle speed threshold V. Shifting tests are conducted under different gradients and different gear combinations, recording the critical speed at which the vehicle just avoids rolling backward during the shifting process. This critical speed is used as the threshold benchmark for the corresponding operating point. If the actual vehicle speed is higher than the preset speed threshold V, the vehicle speed condition verification is successful. If, due to climbing resistance, the vehicle speed drops below the safe speed threshold corresponding to that operating condition, even if the other three conditions are met, the vehicle speed condition cannot be achieved.

[0033] In some optional implementations, the preset speed threshold is determined based on the current gradient and the current gear, and is positively correlated with both. The greater the gradient and the higher the current gear, the higher the corresponding preset speed threshold V is, ensuring that downshifting is only triggered when the speed exceeds the critical safe speed. Taking a 12% gradient and the vehicle currently in 3rd gear as an example, the preset speed threshold V for this condition is 18 km / h, calibrated through real-vehicle testing. If the actual vehicle speed is 22 km / h, which is higher than 18 km / h, the speed condition verification passes. However, if the vehicle speed drops to 15 km / h due to climbing resistance, which is lower than the safe speed threshold for this condition, the speed condition cannot be met even if the other three conditions are met.

[0034] The above four checks are logical "AND" constraints. Only when the throttle opening continuity condition, slope condition, motor torque condition, and vehicle speed condition are all met will the system determine that the current driving scenario has a risk of rolling backwards, and then jump to the subsequent monitoring process of the transmission output shaft speed change trend. If any one of the four conditions is not met, it is determined that there is no risk of rolling backwards, the subsequent speed trend monitoring will not be initiated, and the vehicle will continue to operate in the current gear.

[0035] Based on the aforementioned technical methods, non-continuous power input from the driver is filtered by the duration of throttle input; and high-load uphill scenarios are screened by combining gradient and motor torque. Additionally, an adaptive speed threshold constrains gear shifting operations to a speed range that will not induce rollback. These four parameters mutually constrain each other, identifying operating conditions from multiple dimensions including driver operation, road conditions, drive system load, and overall vehicle driving status. This reduces unnecessary monitoring under non-target conditions, lowering the possibility of accidental gear shifts at the source. Especially when insufficient vehicle power is detected, a minimum vehicle speed condition is added to prevent rollback during downshifting, ensuring gear shifting safety.

[0036] In some optional implementations, step S103 above includes: Step b1: If, under conditions of risk of slippage, the speed of the gearbox output shaft decreases by more than a preset threshold within a second preset time period, then downshifting is performed and upshifting is prohibited at the same time.

[0037] Specifically, the output shaft speed of the gearbox is directly related to the wheel speed, and can objectively reflect the vehicle's driving characteristics. The dynamic equilibrium state of resistance results in stronger sampling stability of the output shaft speed signal compared to the vehicle acceleration signal, which is easily affected by road bumps and momentary wheel slippage. The second preset time is a pre-calibrated continuous observation duration, corresponding to the actual vehicle calibration parameter T2. The preset amplitude threshold represents the maximum allowable speed drop range within this observation window. This value needs to be calibrated by matching the transmission system speed ratio and the total vehicle weight. In the example, this amplitude threshold can be set to 180 r / min. The decrease can be limited to the complete observation period of the second preset time. The speed sampling sequence maintains a downward trend overall, and there is no phenomenon of speed rebound or increase within the observation interval, excluding occasional signals that recover quickly after brief fluctuations. Even if a rebound occurs, each rebound high point is lower than the previous high, and each pullback low point is lower than the previous low, thus serving as a standard for judging the overall trend of continuous decline.

[0038] If the system has completed the pre-verification and confirmed that the current driving scenario has a risk of rolling back, it will then begin continuous monitoring of the transmission output shaft speed. Assuming the initial output shaft speed recorded at the start of the monitoring period is 1140 r / min, within a second preset time window of 1.2 seconds, the continuously sampled speeds are 1085 r / min, 1020 r / min, and 970 r / min, with the sampled values ​​continuously decreasing. The total drop in speed over the entire time interval reaches 170 r / min. This drop exceeds the preset threshold constraint of 180 r / min, so no downshift operation is triggered, and the transmission maintains its current gear. If, under the same operating condition, the speed continuously drops from 1160 r / min to 950 r / min within the monitoring window, with a total decrease of 210 r / min, exceeding the preset threshold of 180 r / min, then it is determined that the vehicle's power is insufficient to overcome the slope resistance. After satisfying the above constraints, the vehicle controller sends a control command to the electric AMT to execute a downshift operation, while simultaneously imposing constraints on upshift requests.

[0039] This invention uses a monotonically decreasing rotational speed and an excessive reduction in speed within a continuous time window as a joint criterion. This eliminates instantaneous speed disturbances caused by road bumps and momentary wheel slippage, preventing downshifting from being triggered by sudden changes in rotational speed at a single sampling moment, significantly reducing the probability of erroneous gear shifts. By limiting speed variation constraints to conditions where a rollback risk is confirmed, this judgment process is not activated in risk-free scenarios such as flat roads and gentle slopes, thus reasonably managing the computational overhead of the control algorithm. Simultaneously, upshift suppression is applied during downshifting to prevent gear shifting during uphill driving. This allows the motor to operate stably in the high torque output range, ensuring continuous drive power output, reducing power interruptions during gear shifts, improving the uphill driving ability of heavy-duty vehicles, and reducing mechanical shocks caused by frequent gear shifts in the transmission mechanism.

[0040] In some alternative implementations, the method further includes: Step c1: If, during the process of monitoring whether the output shaft speed of the transmission meets the preset continuous downward trend, it is determined that the vehicle does not currently have the risk of rolling back, then the current gear is maintained, and the step of determining whether the vehicle has the risk of rolling back based on the vehicle's operating information is continued.

[0041] Specifically, after the transmission output shaft speed change trend observation is started, the control process will not be locked in the monitoring stage in one direction, but will continue to refresh the vehicle operation information in parallel and repeatedly carry out the review and judgment of the slope risk conditions.

[0042] If, during the speed monitoring process, factors such as releasing the accelerator pedal, a decrease in road gradient, or a drop in vehicle speed cause all four risk assessment conditions to no longer be met, the system identifies that the vehicle no longer poses a risk of rolling backwards. The system directly maintains the current gear position of the transmission without changing it, does not output a downshift command, and simultaneously jumps back to the rolling backwards risk assessment step, continuously collecting vehicle operating parameters and re-verifying the risk conditions.

[0043] For example, if a heavy-duty truck is in the phase of observing a decreasing engine speed, and the driver releases the accelerator pedal, causing the throttle opening to drop below a threshold, the rollback risk assessment fails. In this situation, the system retains the current gear, does not downshift, and re-enters the risk assessment loop, waiting for all prerequisite conditions to be met again before activating speed monitoring. This logic enables dynamic tracking of operating conditions; once driving conditions leave the high-risk zone, downshifting is promptly stopped, preventing continuous invalid calculations by the algorithm and ensuring the vehicle can quickly respond to further changes in driving status.

[0044] In some alternative implementations, the method further includes: Step d1: When the motor speed is greater than the preset speed threshold, or the motor power is less than the preset power threshold, the restriction on prohibiting upshifting is lifted. Step d2: After lifting the restriction on upshifting, query the shift map based on vehicle speed and throttle signal; Step d3: If the shift MAP determines that the current vehicle speed and throttle signal meet the upshift conditions, then upshifting is performed.

[0045] Specifically, unlike related technologies that rely on slope changes as the basis for lifting the restriction, this invention selects two types of internal parameters of the electric drive system—motor speed and motor power—to determine the lifting of the restriction on upshifting. Motor speed and motor power are measured parameters directly output by the electric drive controller, requiring no complex filtering or calculations. They directly reflect the actual power output state of the vehicle, avoiding delays in slope signal filtering and distortions in slope estimation on bumpy roads that could lead to delayed lifting or misjudgment.

[0046] During the period when the upshift prohibition constraint remains in effect, the system continuously reads the real-time operating parameters of the motor and compares them with two lifting conditions. One criterion is a preset speed threshold, MotSpd, which is a higher value obtained from real-vehicle calibration. This threshold represents that the vehicle speed has increased to a level suitable for upshifting. For example, for the target electric drive assembly, MotSpd can be calibrated to 2800 r / min. When the motor speed exceeds this threshold, it indicates that the vehicle speed is sufficient, providing an objective basis for shifting upshifts. The other criterion is that the motor power is less than a preset power threshold P, which is also obtained from real-vehicle calibration. For uphill throttle release scenarios, a slope-related delay mechanism is added; the steeper the slope, the longer the delay time. This is to handle the driver's brief release of the accelerator followed by immediate re-pressing the pedal, preventing a sudden drop in power that could cause the upshift prohibition constraint to be incorrectly lifted. The two criteria are logically ORed; if either the motor speed is greater than the speed threshold or the motor power is less than the power threshold, the upshift prohibition constraint is lifted.

[0047] After the upshift restriction is lifted, the upshift action will not be executed immediately. The system retrieves the shift map, using real-time vehicle speed and throttle opening signal as lookup parameters. The shift map is a pre-calibrated shift data table stored inside the vehicle controller, containing pre-stored shift data for different vehicle speeds. The system defines the upshift and downshift boundaries corresponding to the throttle combination. It uses the currently collected vehicle speed and throttle signals to perform a lookup process, comparing the operating points. Only if the MAP table determines that the current operating point falls within the upshift range will the system issue a command to execute an upshift; if the lookup result does not meet the upshift boundaries, the current gear will remain unchanged.

[0048] For example, after the upshift restriction is lifted, if the current vehicle speed is 31 km / h and the throttle opening is 65%, the two sets of parameters are checked against the shift MAP. The result of the lookup table indicates that the upshift boundary has been reached, and the transmission performs the upshift action. If the vehicle speed is only 20 km / h, even if the upshift restriction has been lifted, the MAP determines that the upshift conditions are not met, and the vehicle continues to operate in the current gear.

[0049] Based on the aforementioned technical methods, motor speed and power are used as the unlocking criteria, eliminating reliance on slope signals. On mountain roads with frequently fluctuating slopes, this allows for unlocking timing that more closely reflects the actual power state, eliminating the time lag caused by slope filtering. A slope-related delay is introduced for the power criterion to suppress mis-unlocking caused by short-term driver pedal disturbances, improving control robustness under complex operations. After unlocking, the standard shift MAP is still used for final upshift confirmation. Unlocking only removes the constraint lock; it does not bypass the basic shift boundaries to directly force an upshift. This balances the special control logic for slopes with the vehicle's original shift calibration system, ensuring both driving power and transmission system safety.

[0050] like Figure 2 As shown, a complete application example is as follows: Taking the electric AMT heavy-duty tractor traveling on a long uphill mountain road as a practical application scenario, the vehicle controller periodically collects vehicle operation information from the vehicle CAN bus. The collected operation information includes accelerator pedal opening, road gradient, actual motor output torque, vehicle speed, gearbox output shaft speed, motor speed, and motor output power. All of the above measured parameters serve as the input basis for the entire control process.

[0051] After obtaining various vehicle operation information, the system performs four parallel slope slip risk checks. The first check observes the continuous state of the accelerator pedal opening within a first preset time T1, determining whether the accelerator pedal opening continuously exceeds a preset value ACC during this time window. The second check compares the collected road slope with a preset slope threshold Slop. The third check compares the actual output torque of the motor with a preset torque threshold Tq. The fourth check uses a table to obtain a preset vehicle speed V for the corresponding operating condition based on the current slope, comparing the real-time vehicle speed with the preset speed V obtained from the table. Only when all four check conditions are met is the current driving condition deemed to have a slope slip risk, and the transmission output shaft speed Spd1 at that moment is recorded simultaneously, serving as the starting reference for subsequent speed change observations. If any of the four check conditions are not met, the system does not enter the continuous speed change monitoring stage, the vehicle maintains its current gear, and returns to the vehicle operation information acquisition step to continuously cycle and detect changes in operating conditions.

[0052] After confirming the risk of rollback and recording the initial output shaft speed Spd1, the system opens an observation window with a second preset time T2 to continuously track the change in the transmission output shaft speed and identify whether the output shaft speed shows a continuous decreasing trend within this time range. Throughout the T2 observation window, the system continues to refresh vehicle operating information and repeatedly executes the four conditions for rollback risk verification. If all four conditions are no longer met simultaneously, the speed trend monitoring process is directly terminated, the current gear is kept unchanged, and the system jumps back to the condition risk judgment stage. If the transmission output shaft speed shows a continuous decrease within the T2 time window, it indicates that the vehicle's driving capability is insufficient to overcome the slope resistance, and the system determines that the vehicle's power is insufficient. It then triggers an active downshift action and simultaneously sets the upshift prohibition flag to block the upshift requests from the vehicle's original shift MAP output, avoiding the phenomenon of jumping back and forth between downshifts and upshifts during rollback.

[0053] While the "No Upshift" indicator is in the set state, the controller continuously reads two measured parameters of the electric drive system: motor speed and motor output power. The motor speed is directly compared with the preset speed value MotSpd; the motor power is determined by looking up a table based on the motor temperature to obtain a corresponding preset power value P, which is then compared with the preset power value P output from the table. The two criteria are logically ORed: either the motor speed is greater than the preset speed value MotSpd, or the motor power is less than the preset power value P obtained from the table. If either condition is met, the "No Upshift" indicator is deactivated. For the power criterion, the system incorporates a delay control logic strongly correlated with road gradient. The greater the road gradient, the longer the configured delay time. This is to handle situations where the driver briefly releases the accelerator and then immediately presses the pedal again, preventing a sudden drop in power that could cause the "No Upshift" indicator to be incorrectly reset.

[0054] After the upshift prohibition flag is reset, the hardware execution action for upshifting will not be triggered directly. The vehicle controller retrieves the internal shift map and performs a lookup operation using the current vehicle speed and throttle opening signals as input parameters. Only when the shift map determines that the current vehicle speed and throttle opening combination falls within the upshift working range will the transmission perform an upshift operation; if the lookup result does not meet the upshift boundary conditions, the current gear will continue to be maintained, and the vehicle controller will continuously cycle through the entire hill shift control process.

[0055] This embodiment also provides a vehicle ramp shifting control device, which is used to implement the above embodiments and preferred embodiments, and will not be repeated as already described. As used below, the term "module" can be a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0056] This embodiment provides a control device for vehicle gear shifting on a slope, such as... Figure 3 As shown, it includes: Attribute acquisition module 301: Applications acquire vehicle operation information; The risk condition detection module 302 is used to determine whether a vehicle has the risk of slipping off a slope based on vehicle operation information. The downshift detection module 303 is used to downshift and simultaneously prohibit upshifting if the output shaft speed of the gearbox meets a preset continuous downward trend under conditions with the risk of slippage.

[0057] In some alternative implementations, the risk condition detection module 302 includes: The throttle opening determination unit is used to determine whether the throttle opening is greater than the preset throttle opening threshold within a first preset time. The slope value judgment unit is used to determine whether the current slope value is greater than the preset slope threshold. The motor torque determination unit is used to determine whether the current motor torque is greater than a preset torque threshold. The vehicle speed determination unit is used to determine whether the vehicle speed value is greater than a preset vehicle speed threshold. The comprehensive analysis unit is used to determine the risk of landslide if all the above conditions are met.

[0058] In some alternative embodiments, the apparatus further includes: The gear-holding module is used to maintain the current gear and continue executing the steps of determining whether the vehicle is at risk of rolling backwards based on the vehicle's operating information if it is determined that the vehicle does not currently have a risk of rolling backwards while monitoring whether the output shaft speed of the transmission meets the preset continuous downward trend.

[0059] The upshift restriction removal module is used to remove the upshift restriction when the motor speed is greater than a preset speed threshold or the motor power is less than a preset power threshold.

[0060] The MAP query module is used to query shift MAPs based on vehicle speed and throttle signal. The upshift control module is used to upshift if the current vehicle speed and throttle signal meet the upshift conditions as determined by the shift MAP.

[0061] The apparatus provided in this embodiment of the invention can execute the method provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects for executing the method. Further functional descriptions of the various modules and units described above are the same as those in the corresponding embodiments described above, and will not be repeated here.

[0062] Figure 4 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention.

[0063] The following is a detailed reference. Figure 4 This diagram illustrates a structural schematic suitable for implementing an electronic device according to embodiments of the present invention. The electronic device may include a processor (e.g., a central processing unit, graphics processor, etc.) 401, which can perform various appropriate actions and processes according to a program stored in read-only memory (ROM) 402 or a program loaded from memory 408 into random access memory (RAM) 403. The RAM 403 also stores various programs and data required for the operation of the electronic device. The processor 401, ROM 402, and RAM 403 are interconnected via a bus 404. An input / output (I / O) interface 405 is also connected to the bus 404.

[0064] Typically, the following devices can be connected to I / O interface 405: input devices 406 including, for example, touchscreens, touchpads, keyboards, mice, cameras, microphones, accelerometers, gyroscopes, etc.; output devices 407 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; memory devices 408 including, for example, magnetic tapes, hard disks, etc.; and communication devices 409. Communication device 409 allows electronic devices to communicate wirelessly or wiredly with other devices to exchange data. Although Figure 4 Electronic devices with various devices are shown, but it should be understood that it is not required to implement or have all of the devices shown, and more or fewer devices may be implemented or have instead.

[0065] In particular, according to embodiments of the present invention, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of the present invention include a computer program product comprising a computer program carried on a non-transitory computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device 409, or installed from a memory 408, or installed from a ROM 402. When the computer program is executed by the processor 401, it performs the functions defined in the methods of the embodiments of the present invention.

[0066] Figure 4 The electronic device shown is merely an example and should not be construed as limiting the functionality and scope of the embodiments of the present invention.

[0067] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as computer code that can be recorded on a storage medium, or implemented as computer code downloaded via a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and then stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code, which, when accessed and executed by the computer, processor, or hardware, implements the methods shown in the above embodiments.

[0068] A portion of this invention can be applied as a computer program product, such as computer program instructions, which, when executed by a computer, can invoke or provide the methods and / or technical solutions according to the invention through the operation of the computer. Those skilled in the art will understand that the forms in which computer program instructions exist in a computer-readable medium include, but are not limited to, source files, executable files, installation package files, etc. Correspondingly, the ways in which computer program instructions are executed by a computer include, but are not limited to: the computer directly executing the instructions, or the computer compiling the instructions and then executing the corresponding compiled program, or the computer reading and executing the instructions, or the computer reading and installing the instructions and then executing the corresponding installed program. Here, the computer-readable medium can be any available computer-readable storage medium or communication medium accessible to a computer.

[0069] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A control method for vehicle gear shifting on a slope, characterized in that, The method includes: Obtain vehicle operation information; Determine whether the vehicle has a risk of slipping off the slope based on the vehicle operation information; If, under the aforementioned risk of slippage, the output shaft speed of the gearbox meets the preset continuous downward trend, then downshifting is executed, and upshifting is prohibited at the same time.

2. The method according to claim 1, characterized in that, The step of determining whether a vehicle has a risk of slipping off a slope based on the vehicle's operating information includes: Determine whether the throttle opening is greater than a preset throttle opening threshold within a first preset time period; Determine if the current slope value is greater than the preset slope threshold; Determine whether the current motor torque is greater than a preset torque threshold; Determine if the vehicle speed value is greater than a preset vehicle speed threshold; If all of the above conditions are met, then the slope risk is confirmed.

3. The method according to claim 2, characterized in that, The preset speed threshold is determined based on the current slope value and the current gear, and is positively correlated with the current slope value and the current gear.

4. The method according to claim 1, characterized in that, If, under the condition of the aforementioned risk of slippage, the output shaft speed of the transmission meets a preset continuous downward trend, then a downshift is executed, and upshifting is simultaneously prohibited, including: If, under the aforementioned risk of slippage, the speed of the gearbox output shaft decreases by more than a preset threshold within a second preset time period, then downshifting is executed, and upshifting is simultaneously prohibited.

5. The method according to claim 1, characterized in that, Also includes: If, during the process of monitoring whether the output shaft speed of the transmission meets the preset continuous downward trend, it is determined that the vehicle does not currently have the risk of rolling backwards, then the current gear is maintained, and the step of determining whether the vehicle has the risk of rolling backwards based on the vehicle's operating information is continued.

6. The method according to claim 1, characterized in that, After stating that if, under the condition of the aforementioned risk of slippage, the output shaft speed of the transmission meets a preset continuous decreasing trend, then downshifting is performed and upshifting is simultaneously prohibited, the method further includes: When the motor speed is greater than the preset speed threshold, or the motor power is less than the preset power threshold, the restriction on not being allowed to shift up gears is lifted.

7. The method according to claim 6, characterized in that, After lifting the restriction on upshifting, the methods also include: Query the shift map based on vehicle speed and throttle signal; If the shift map determines that the current vehicle speed and throttle signal meet the upshift conditions, then the upshift is performed.

8. A control device for vehicle hill-start shifting, characterized in that, The device includes: The attribute acquisition module allows the application to obtain vehicle operation information. The risk condition detection module is used to determine whether the vehicle has a risk of slipping off a slope based on the vehicle operation information. The downshift detection module is used to downshift and simultaneously prohibit upshifting if the output shaft speed of the gearbox meets a preset continuous downward trend under the condition of the risk of slippage.

9. A vehicle, characterized in that, include: A vehicle body, a memory, and a processor, wherein the memory and the processor are installed within the vehicle body and are communicatively connected to each other, the memory stores computer instructions, and the processor executes the computer instructions to perform the method of any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing the computer to perform the method of any one of claims 1 to 7.

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