Vehicle shift control method and device

Abstract

The present application relates to the technical field of vehicles, and discloses a vehicle gear shifting control method and device. The method comprises the following steps: obtaining a set of vehicle gear shifting control parameters to determine at least an engine torque state, a vehicle upshift gear shifting speed and an engine estimated speed; and performing a gear shifting control operation on the basis of a current gear of the vehicle when at least a throttle parameter, the engine torque state, the vehicle upshift gear shifting speed and the engine estimated speed simultaneously satisfy a gear update condition. The present application can at least prevent the engine from reaching a high idle speed maximum idle speed zone under a large resistance working condition, can adaptively identify an inflection point at which the engine torque starts to decrease or fluctuate when the engine torque is still close to the maximum engine torque and the vehicle is still accelerating, and can perform an upshift in advance, thereby improving the upshift success rate of the vehicle under the large resistance working condition, and being beneficial to improving the user vehicle experience, vehicle power performance and driving economy.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and in particular to a vehicle gear shifting control method and device. Background Technology

[0002] The existing AMT (Automated Manual Transmission) is developed from the MT (Manual Manual Transmission) by adding various sensors, transmission control unit, electronically controlled shift actuator, and clutch actuator. Compared with other automatic transmission solutions, it has the advantages of low cost and high transmission efficiency. Automatic transmissions can free drivers from frequent clutch and gear shifting operations, and can intelligently select the appropriate gear and driving mode according to road conditions and driver input, greatly reducing the driver's burden.

[0003] In recent years, with the development of industries such as logistics, the sales of tractor trucks equipped with AMT transmissions have shown a year-on-year growth trend. As AMT transmissions become more widespread, drivers' requirements for vehicle adaptability to various road conditions are constantly increasing, and their demands for power and comfort are also gradually rising. In particular, users in the Yunnan, Guizhou, and Sichuan regions have higher requirements for vehicles equipped with AMT transmissions when climbing mountain roads.

[0004] The mountainous regions of Yunnan, Guizhou, and Sichuan are characterized by numerous steep inclines, often exceeding 16%. Vehicles operating under these high-resistance conditions require automated manual transmissions (AMTs) to accurately select gears based on this resistance. However, when the incline is particularly steep, the upshift compensation RPM based on resistance is high. This means that when the driver depresses the accelerator to 100%, the actual upshift RPM reaches or is close to the engine's maximum idle speed. At this point, although the engine RPM is high, the engine torque becomes unstable and significantly lower than its maximum, resulting in insufficient power and noticeable vehicle deceleration. Consequently, shifting gears under high-resistance conditions causes a rapid decrease in vehicle speed, meaning the vehicle may not have enough time to increase torque after upshifting, and the RPM may fall below the downshift point, preventing the upshift from being completed. Summary of the Invention

[0005] The purpose of this invention is to provide a vehicle shift control method and device, which can at least prevent the engine from reaching the high idle speed range under high resistance conditions. When the engine torque is still close to the maximum engine torque and the vehicle is still accelerating, it can adaptively identify the inflection point of the engine torque drop or fluctuation and shift up in advance, thereby improving the success rate of upshifting under high resistance conditions and improving the user experience, vehicle power and driving economy.

[0006] To address the aforementioned technical problems, in a first aspect, the present invention provides a vehicle gear shifting control method, comprising at least:

[0007] S1. Obtain the vehicle shift control parameter set to at least determine the engine torque state, the vehicle upshift speed, and the estimated engine speed;

[0008] S2. At least when the throttle parameter, the engine torque state, the vehicle upshift speed and the estimated engine speed simultaneously meet the gear update conditions, perform a shift control operation based on the vehicle's current gear.

[0009] Optionally, the engine torque state includes at least an abnormal fluctuation state and a rapid decrease state;

[0010] The abnormal fluctuation state can be determined at least through the following methods:

[0011] At least the peak-to-peak value and / or standard deviation of the actual engine torque within any preset time period, as well as the average value, are calculated to determine whether the engine torque is abnormal and to obtain the abnormality judgment result.

[0012] The engine torque deviation should be calculated based at least on the current actual engine torque and the engine delayed torque at the preset time.

[0013] Based at least on the anomaly judgment result and the engine torque deviation, when the vehicle meets the abnormal fluctuation state judgment condition, it is determined that the engine torque state is in the abnormal fluctuation state.

[0014] Optionally, the abnormal fluctuation state determination conditions include at least:

[0015] The current clutch request for engine torque control is not in speed regulation mode;

[0016] Furthermore, the clutch control state is not the starting state;

[0017] Furthermore, the anomaly assessment result indicates that the engine torque is abnormal;

[0018] Furthermore, the transmission's torque control mode for the engine is in a non-intervention state;

[0019] Furthermore, the engine torque deviation is not less than the torque abnormal fluctuation judgment threshold;

[0020] Furthermore, the vehicle throttle opening is greater than a preset opening threshold and the absolute value of the throttle opening change rate is less than a preset absolute value threshold.

[0021] Furthermore, the vehicle's resistance torque is not less than the resistance torque threshold, or the estimated gradient is not less than the preset gradient threshold.

[0022] Furthermore, the vehicle is not currently in the process of shifting gears.

[0023] Optionally, if any of the following conditions are met, the engine torque state is determined to have exited the abnormal fluctuation state;

[0024] The clutch control state is the starting state;

[0025] The engine torque deviation is less than the torque abnormal fluctuation judgment threshold;

[0026] The vehicle throttle opening is not greater than a predetermined opening threshold, or the absolute value of the throttle opening change rate is not less than a predetermined absolute value threshold.

[0027] The vehicle's resistance torque is less than a predetermined torque threshold and the estimated gradient is less than a predetermined gradient threshold.

[0028] The vehicle is currently in the process of shifting gears.

[0029] Optionally, the rapid descent state is determined at least by the following means:

[0030] At least calculate the first delayed torque of the current engine actual torque at the first delayed time step, and the second delayed torque of the current engine actual torque at the second delayed time step;

[0031] The first torque change rate and the second torque change rate are calculated based at least on the current actual engine torque, the first delay time step, the first delay torque, the second delay time step, and the second delay torque;

[0032] Based at least on the current actual engine torque, the first torque change rate, and the second torque change rate, when the vehicle meets the rapid descent state determination conditions, the engine torque state is determined to be in the rapid descent state.

[0033] Optionally, the rapid descent state determination conditions include at least:

[0034] The clutch control is not in the starting state;

[0035] Furthermore, the actual torque of the current engine is greater than the minimum permissible torque threshold.

[0036] Furthermore, the transmission's torque control mode for the engine is in a non-intervention state;

[0037] Furthermore, the second torque change rate is less than the first torque change rate, the first torque change rate is less than 0, the second torque change rate is less than a preset change rate threshold, and the first torque change rate is greater than a set change rate threshold.

[0038] Furthermore, the vehicle throttle opening is greater than the set opening threshold and the absolute value of the throttle opening change rate is less than the set absolute value threshold.

[0039] Furthermore, the vehicle's resistance torque is not less than a set torque threshold, or the estimated gradient is not less than a set gradient threshold;

[0040] Furthermore, the vehicle is not currently in the process of shifting gears.

[0041] Optionally, if any of the following conditions are met, the engine torque state is determined to have exited the rapid decrease state;

[0042] The clutch control state is the starting state;

[0043] The second torque change rate is greater than the first torque change rate, or the first torque change rate is less than the first preset change rate threshold, or the second torque change rate is greater than the second preset change rate threshold.

[0044] The vehicle throttle opening is not greater than a preset opening threshold, or the absolute value of the throttle opening change rate is not less than a preset absolute value threshold.

[0045] The vehicle's resistance torque is less than a preset torque threshold and the estimated gradient is less than a preset gradient threshold.

[0046] Optionally, the upshift speed of the vehicle is determined at least by the following methods:

[0047] The first speed loss during the torque reduction process and the second speed loss during the speed adjustment process are calculated based on the vehicle shift control parameter set.

[0048] The vehicle's upshifting speed is determined at least based on the target speed after shifting, the gear ratio corresponding to the upshifted gear, the current gear ratio, the first lost speed, and the second lost speed.

[0049] The estimated engine speed is determined at least by the following means:

[0050] The estimated engine speed is determined based at least on the current gear ratio and the transmission output shaft speed.

[0051] Optionally, the throttle parameters include at least the current throttle, the throttle change rate, and the duration of the condition where the throttle change rate is less than a preset throttle change rate threshold.

[0052] The gear shift update conditions include at least the following:

[0053] The vehicle's upshift speed exceeds the set maximum shift speed threshold;

[0054] Furthermore, the current throttle is greater than the set throttle threshold, the throttle change rate is less than the preset throttle change rate threshold, and the duration of the operating condition reaches the set time threshold.

[0055] Furthermore, the engine torque state is either in an abnormal fluctuation state or a rapidly decreasing state;

[0056] Furthermore, the estimated engine speed is not lower than a preset estimated speed threshold;

[0057] If any of the above-mentioned gear update conditions are not met, the gear shift control operation will not be performed.

[0058] The shift control operation is at least to perform a shift up operation with a preset number of gears based on the current gear.

[0059] Based on the same concept, in a second aspect, the present invention also provides a vehicle shift control device for performing the vehicle shift control method described in any one of the first aspects;

[0060] The vehicle shift control device includes at least:

[0061] The acquisition and determination module is used to acquire the vehicle shift control parameter set to at least determine the engine torque state, the vehicle upshift speed, and the estimated engine speed;

[0062] The shift control module is used to perform shift control operations based on the current gear of the vehicle, at least when the throttle parameter, the engine torque state, the vehicle upshift speed and the estimated engine speed simultaneously meet the gear update conditions.

[0063] The technical solution provided by this invention obtains a set of vehicle shift control parameters to at least determine the engine torque state, the vehicle upshift speed, and the estimated engine speed. Furthermore, at least when the throttle parameters, engine torque state, vehicle upshift speed, and estimated engine speed simultaneously meet the gear update conditions, a shift control operation is performed based on the vehicle's current gear. Therefore, this invention can, at least under high resistance conditions, prevent the engine from reaching near its maximum idle speed range. When the engine torque is still close to its maximum torque and the vehicle is still accelerating, it can adaptively identify the inflection point where engine torque decreases or fluctuations begin, and perform upshifts in advance, improving the success rate of upshifts under high resistance conditions. This benefits the user experience, vehicle power, and driving economy. Attached Figure Description

[0064] Figure 1 This is a flowchart of a vehicle gear shifting control method provided in an embodiment of the present invention;

[0065] Figure 2 This is a schematic diagram of the structure of a vehicle gear shifting control device provided in an embodiment of the present invention;

[0066] Figure 3This is a schematic diagram illustrating the trend changes of engine speed and engine torque during a high-resistance adaptive shifting process, as provided in an embodiment of the invention. Detailed Implementation

[0067] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0068] It should be noted that any symbols and / or numbers present in the specification that are not marked in the accompanying drawings are not reference numerals.

[0069] Figure 1 This is a flowchart of a vehicle shift control method provided by an embodiment of the present invention. This embodiment is applicable to at least any vehicle equipped with an AMT transmission (which may include, but is not limited to, vehicles with drive forms such as gasoline engines, diesel engines, natural gas engines, hydrogen fuel cells, hybrid engines, and pure electric drives, matched with an AMT transmission) in adaptive shifting scenarios under high-resistance road conditions. The vehicle shift control method may be executed by, but is not limited to, the vehicle shift control device in this embodiment of the present invention as the execution subject, and this execution subject may be implemented in software and / or hardware. Figure 1 As shown, the vehicle shift control method includes at least the following steps:

[0070] S1. Obtain the vehicle shift control parameter set to at least determine the engine torque state, the vehicle upshift speed, and the estimated engine speed.

[0071] The vehicle shift control parameter set can consist of various vehicle shift control parameters, such as the current actual engine torque, the engine delay torque at a preset time, the vehicle resistance torque, and the vehicle throttle opening. It is understood that these various vehicle shift control parameters can be obtained, but are not limited to, through various onboard sensors, the CAN bus, and the MCUs of various application domains within the vehicle.

[0072] In one specific implementation, the engine torque state may optionally include at least an abnormal fluctuation state and a rapid decrease state;

[0073] Abnormal fluctuations can be determined at least through the following methods:

[0074] At least the peak-to-peak value and / or standard deviation of the actual engine torque within any preset time period, as well as the average value, are calculated to determine whether the engine torque is abnormal and to obtain the abnormality judgment result.

[0075] The engine torque deviation should be calculated based at least on the current actual engine torque and the engine delayed torque at the preset time.

[0076] Based on at least the abnormal judgment results and the engine torque deviation, when the vehicle meets the abnormal fluctuation state judgment conditions, it is determined that the engine torque state is in an abnormal fluctuation state.

[0077] In another specific implementation, the abnormal fluctuation state determination criteria may optionally include at least:

[0078] The current clutch request for engine torque control is not in speed regulation mode;

[0079] Furthermore, the clutch control state is not the starting state;

[0080] Furthermore, the anomaly assessment result indicated an abnormality in engine torque;

[0081] Furthermore, the transmission's torque control mode for the engine is in a non-intervention state;

[0082] Furthermore, the engine torque deviation is not less than the threshold for judging abnormal torque fluctuations;

[0083] Furthermore, the vehicle throttle opening is greater than a preset opening threshold and the absolute value of the throttle opening change rate is less than a preset absolute value threshold.

[0084] Furthermore, the vehicle's resistance torque is not less than the resistance torque threshold, or the estimated gradient is not less than the preset gradient threshold.

[0085] Furthermore, the vehicle is not currently in the process of shifting gears.

[0086] In another specific implementation, optionally, the engine torque state is determined to have exited the abnormal fluctuation state if any of the following conditions are met.

[0087] The clutch control state is the starting state;

[0088] The engine torque deviation is less than the threshold for judging abnormal torque fluctuations;

[0089] The vehicle throttle opening is not greater than a predetermined opening threshold, or the absolute value of the throttle opening change rate is not less than a predetermined absolute value threshold.

[0090] The vehicle's resistance torque is less than the predetermined torque threshold and the estimated gradient is less than the predetermined gradient threshold.

[0091] The vehicle is currently in the process of shifting gears.

[0092] In yet another specific implementation, the rapid descent state may optionally be determined at least by the following means:

[0093] At least calculate the first delayed torque of the current engine actual torque under the first delayed time step, and the second delayed torque of the current engine actual torque under the second delayed time step;

[0094] The first torque change rate and the second torque change rate are calculated based at least on the current actual engine torque, the first delay time step, the first delay torque, the second delay time step, and the second delay torque.

[0095] Based at least on the current actual engine torque, the first torque change rate, and the second torque change rate, when the vehicle meets the conditions for determining the rapid torque decrease state, it is determined that the engine torque state is in a rapid torque decrease state.

[0096] In yet another specific implementation, the rapid descent state determination criteria may optionally include at least:

[0097] The clutch control is not in the starting state;

[0098] Furthermore, the actual torque of the engine is currently greater than the minimum permissible torque threshold.

[0099] Furthermore, the transmission's torque control mode for the engine is in a non-intervention state;

[0100] Furthermore, the second torque change rate is less than the first torque change rate, the first torque change rate is less than 0, the second torque change rate is less than a preset change rate threshold and the first torque change rate is greater than a set change rate threshold.

[0101] Furthermore, the vehicle throttle opening is greater than the set opening threshold and the absolute value of the throttle opening change rate is less than the set absolute value threshold.

[0102] Furthermore, the vehicle's resistance torque is not less than a set torque threshold, or the estimated gradient is not less than a set gradient threshold;

[0103] Furthermore, the vehicle is not currently in the process of shifting gears.

[0104] In yet another specific implementation, optionally, the engine torque state is determined to have exited the rapid decrease state if any of the following conditions are met.

[0105] The clutch control state is the starting state;

[0106] The second torque change rate is greater than the first torque change rate, or the first torque change rate is less than the first preset change rate threshold, or the second torque change rate is greater than the second preset change rate threshold.

[0107] The vehicle throttle opening is not greater than the preset opening threshold, or the absolute value of the throttle opening change rate is not less than the preset absolute value threshold.

[0108] The vehicle's resistance torque is less than the preset torque threshold and the estimated gradient is less than the preset gradient threshold.

[0109] In yet another specific implementation, the vehicle upshift speed may optionally be determined by at least the following means:

[0110] The first speed loss during the torque reduction process and the second speed loss during the speed adjustment process are calculated based on the vehicle shift control parameter set.

[0111] The vehicle's upshifting speed should be determined based at least on the target speed after shifting, the gear ratio corresponding to the upshifted gear, the current gear ratio, the first loss speed, and the second loss speed.

[0112] The estimated engine speed is determined at least by the following methods:

[0113] The estimated engine speed should be determined based at least on the current gear ratio and the transmission output shaft speed.

[0114] The following example further illustrates that step S1 can be specifically described as follows:

[0115] I. Obtain the vehicle shift control parameter set

[0116] Obtain the current actual engine torque T from the CAN bus. eact Obtain the current actual engine speed n from the CAN bus. eact The system obtains the clutch control status from the clutch control unit, the clutch request engine torque control status from the clutch control unit, the accelerator pedal opening (corresponding to the aforementioned vehicle accelerator opening) from the CAN bus, the vehicle acceleration from the acceleration calculation unit, the current gear from the gear update unit, the transmission output shaft speed from the transmission output shaft speed sensor, the transmission torque control mode for the engine from the transmission torque interface unit, and the current estimated resistance (corresponding to the aforementioned vehicle resistance torque) and estimated vehicle mass from the resistance calculation unit; and so on, without further details.

[0117] Second, identify torque changes, i.e., determine the engine torque status.

[0118] 1. Engine torque abnormal fluctuation identification (i.e., identification of abnormal fluctuation states)

[0119] 1) Calculation of abnormal fluctuations in engine torque

[0120] Calculate the current actual engine torque T eact Within the time interval tdly (i.e., the aforementioned preset time interval) after a certain number of time steps ndly, T eact The maximum value T max Minimum value T min and average value Tmean Calculate the peak-to-peak value T using the maximum and minimum values. pp =T max -T min If T pp >p×T mean If p is abnormal, it is considered that the engine torque is fluctuating abnormally (i.e., the abnormal judgment result is that the engine torque is abnormal); more specifically, p represents the average torque coefficient, which can be taken as 30%.

[0121] And / or, calculate T within the time period tdly eact Standard deviation T std Then calculate T within the time period tdly. eact Volatility CV=T std / T mean ×100%; if CV>f, then the engine torque is considered to have fluctuated abnormally; more specifically, f represents the volatility coefficient, for example, 15% for heavy commercial vehicles and 12% for medium-sized vehicles.

[0122] For example, for the aforementioned number of time steps ndly and time period tdly, if the current single step length of the software is 5ms, then the number of time steps ndly can be 500ms, and the time period tdly = 5 × 500 = 2500ms.

[0123] 2) Calculate the engine torque deviation, which can be achieved by measuring the current actual engine torque T. eact Subtract the delayed torque T before the tdly time period eactdly (Using tdly=2500ms as an example for explanation, the delay torque T) eactdly The engine torque deviation is obtained by referring to the actual engine torque at the moment 2500ms away from the current moment.

[0124] 3) Judgment of abnormal fluctuations in engine torque

[0125] If all of the following conditions are met and the confirmation time for each condition is continuously maintained, then the engine torque is determined to be fluctuating abnormally:

[0126] 3.1) The current clutch request for engine torque control is not in speed regulation mode (speed regulation mode can refer to a mode in which the current control request from the transmission to the engine is based on the target speed calculated by the transmission to control the engine torque).

[0127] 3.2) The clutch control state is not the starting state (the starting state can be the state where the vehicle starts automatically after the transmission is engaged and the accelerator is not pressed, and the engine speed and the input shaft speed are not synchronized; or the state where the vehicle starts to move after the transmission is engaged and the accelerator is pressed, and the engine speed and the input shaft speed are not synchronized).

[0128] 3.3) The calculation results of abnormal engine torque fluctuations meet the abnormal engine torque conditions (i.e., T) pp >p×T mean And / or CV>f; that is, the anomaly judgment result is that the engine torque is abnormal).

[0129] 3.4) The transmission's torque control mode for the engine is in a non-intervention state (a non-intervention state can mean that the current control request sent by the transmission to the engine is neither to request engine torque control according to the requested target speed nor to request engine torque control according to the requested target torque).

[0130] 3.5) The engine torque deviation is not less than the threshold for judging abnormal torque fluctuations;

[0131] 3.6) The driver's throttle opening (i.e., the vehicle's throttle opening) is greater than 90% (i.e., the preset opening threshold can be 90%), and the absolute value of the throttle opening change rate is less than a certain threshold, such as 5% / s (i.e., the preset absolute value threshold is 5% / s).

[0132] 3.7) The resistance torque (i.e., the aforementioned vehicle resistance torque) is not less than the set torque, for example, 20,000 Nm (i.e., the resistance torque threshold can be taken as 20,000 Nm); or the estimated slope is not less than a certain threshold, for example, 12% (i.e., the preset slope threshold can be taken as 12%).

[0133] 3.8) Not currently in the gear shifting process (i.e., the vehicle is not currently in the gear shifting process; the gear shifting process can refer to the process from the start of engine torque reduction to the end of engine torque recovery).

[0134] 4) Judgment that the abnormal fluctuation of engine torque is no longer met (i.e., the judgment condition that determines that the engine torque state has exited the abnormal fluctuation state).

[0135] If any of the following conditions are met, the abnormal fluctuation of engine torque will no longer be satisfied:

[0136] 4.1) The clutch control state is the starting state;

[0137] 4.2) The engine torque deviation is less than the threshold for judging abnormal torque fluctuations;

[0138] 4.3) The driver's throttle opening is not greater than 85% (i.e., the aforementioned predetermined opening threshold can be taken as 85%), or the absolute value of the throttle change rate (i.e., the aforementioned throttle opening change rate) is not less than a certain threshold, such as 7% / s (i.e., the aforementioned predetermined absolute value threshold can be taken as 7% / s).

[0139] 4.4) The resistance torque is less than the set torque, for example, 19000 Nm (i.e., the aforementioned predetermined torque threshold can be taken as 19000 Nm); and the estimated slope is less than a certain threshold, for example, 11% (i.e., the aforementioned predetermined slope threshold can be taken as 11%).

[0140] 4.5) Currently in the process of shifting gears (i.e., the aforementioned vehicle is currently in the process of shifting gears).

[0141] 2. Rapid decrease in engine torque identification

[0142] 1) Calculate the rate of change of torque

[0143] 1.1) Calculate the current actual engine torque T eact The delayed torque T after the delay time step t1dly (i.e., the aforementioned first delay time step) eact1dly (i.e., the aforementioned first delayed torque); calculate the current actual engine torque T. eact The delayed torque T after the delay time step t2dly (i.e., the aforementioned second delay time step) eact2dly (i.e., the aforementioned second delayed torque). It is understandable that T eact1dly Update to T after delaying t1dly time. eact T eact2dly Update to T after delaying t2dly time. eact The t1dly and t2dly times cannot be too long, because if the two delay times are too long, it will cause the torque change rate to be distorted. For example, they can be 100ms-200ms, and t2dly>t1dly.

[0144] 1.2) Calculate the segmented torque variation rate

[0145] Segment 1 (i.e., the aforementioned first torque change rate): dtq1=(-T eact2dly +T eact1dly ) / (t2dly-t1dly);

[0146] Segment 2 (i.e., the aforementioned second rate of torque change): dtq2=(-T eact1dly +T eact ) / t1dly;

[0147] 2) If all of the following conditions are met and the confirmation time for the conditions is continuously set, then the engine torque will decrease rapidly (i.e., the vehicle meets the conditions for determining the rapid decrease state, and it can be determined that the engine torque is in a state of rapid decrease):

[0148] 2.1) The clutch control state is not in the starting state;

[0149] 2.2) The current actual engine torque is greater than the minimum permissible torque threshold;

[0150] 2.3) The torque control mode of the transmission for the engine is a non-intervention state;

[0151] 2.4) dtq2<dtq1<0; and dtq1 is greater than a certain threshold, for example -500Nm / s (that is, the preset change rate threshold can be -500Nm / s); and dtq2 is less than a certain threshold, for example -1500Nm / s (that is, the set change rate threshold can be -1500Nm / s);

[0152] 2.5) The driver's accelerator opening is greater than 90% (that is, the set opening threshold can be 90%), and the absolute value of the accelerator opening change rate is less than a certain threshold, for example 5% / s (that is, the set absolute value threshold can be 5% / s);

[0153] 2.6) The drag torque is not less than the set torque, for example 20000Nm (that is, the set torque threshold can be 20000Nm); or the estimated gradient is not less than a certain threshold, for example 12% (that is, the set gradient threshold can be 12%);

[0154] 2.7) It is not currently in the shifting process.

[0155] 3) The engine torque drops rapidly and no longer satisfies the judgment (that is, determining the judgment condition for the engine torque state to exit the rapid drop state)

[0156] If any of the following conditions is satisfied, the rapid drop of engine torque no longer meets the requirement:

[0157] 3.1) The clutch control state is the starting state;

[0158] 3.2) dtq2>dtq1; or dtq1 is less than a certain threshold, for example -1000Nm / s (that is, the first preset change rate threshold can be -1000Nm / s); or dtq2 is greater than a certain threshold, for example -1000Nm / s (that is, the second preset change rate threshold can be -1000Nm / s);

[0159] 3.3) The driver's accelerator opening is not greater than 85% (that is, the preset opening threshold can be 85%), or the absolute value of the accelerator change rate is not less than a certain threshold, for example 7% / s (that is, the preset absolute value threshold can be 7% / s);

[0160] 3.4) The drag torque is less than the set torque, for example 19000Nm (that is, the preset torque threshold can be 19000Nm); and the estimated gradient is less than a certain threshold, for example 11% (that is, the preset gradient threshold can be 11%).

[0161] III. Data preparation before gear position update judgment

[0162] 1. Calculate the rotational speed loss n during torque reduction loss1That is, the aforementioned first loss speed

[0163] First, the torque reduction time t can be calculated and confirmed based on the current gear and current engine torque. jn Furthermore, calculate the current engine torque T. eact Current gear ratio i0 and rear axle ratio i g The product (which can be called the first product); further, calculate the first product minus twice the current estimated drag torque T. rest The difference is obtained; further, the difference and the torque reduction time t are calculated. jn Current gear ratio i g Rear axle speed ratio i1 and transmission inertia J trans The product (which can be called the second product); further, calculate the second product and divide it by the estimated vehicle mass M. veh The obtained quotient; further, calculate the engine's current speed change rate dn. e With shift start delay time threshold t stdly The product of the first product and the third product (which can be called the third product) is the first loss speed. Finally, the sum of the quotient and the third product is the first loss speed.

[0164] It is understandable that the shift start delay time threshold can refer to the system response time for shift execution; in addition, the torque reduction time calculated and confirmed based on the current gear and the current engine torque can be obtained by looking up a table or by polynomial calculation.

[0165] 2. Calculate the speed loss n during gear shifting and speed adjustment. loss2 That is, the aforementioned second loss speed

[0166] First, the shift time t can be calculated and confirmed based on the current gear and the estimated resistance torque. spdph Furthermore, the output shaft speed reduction rate dn can be calculated and confirmed based on the current gear and the current resistance torque. js Furthermore, determine the gear ratio i corresponding to the gear after shifting up one gear from the current gear position. nxg Finally, calculate the shift time t. spdph Output shaft speed reduction rate dn js The gear ratio i corresponding to the gear after shifting up one gear from the current gear number. nxg The product of these is the second loss speed.

[0167] It is understandable that the shifting and speed adjustment time t is calculated and confirmed based on the current gear and the current estimated resistance torque. spdph And the output shaft speed reduction rate dn calculated and confirmed based on the current gear and the current resistance torque. js All of these can be achieved through table lookup or polynomial calculation.

[0168] 3. Calculate the shift points for upshifting.

[0169] First, calculate the current gear ratio i0 and the target speed n after the gear shift. tgt The product of; further, calculate the product and the gear ratio i corresponding to the gear after shifting up one gear from the current gear number. nxg The quotient is calculated; finally, the sum of the quotient, the first loss speed, and the second loss speed is calculated, which is the upshift speed.

[0170] It is understandable that the target speed after shifting gears can be determined by the resistance and the current gear. The greater the resistance and the higher the gear, the higher the target speed after shifting gears.

[0171] 4. Calculate the estimated engine speed

[0172] The estimated engine speed can be obtained by multiplying the current gear ratio by the transmission output shaft speed.

[0173] S2. At least when the throttle parameters, engine torque status, vehicle upshift speed and estimated engine speed simultaneously meet the gear update conditions, perform a shift control operation based on the vehicle's current gear.

[0174] The gear update conditions can be adapted to the actual vehicle conditions, and this invention does not impose any restrictions on this.

[0175] In another specific implementation, optionally, the throttle parameters include at least the current throttle, the throttle change rate, and the duration of the condition where the throttle change rate is less than a preset throttle change rate threshold.

[0176] The conditions for gear shifting must include at least:

[0177] The vehicle's upshift speed exceeds the set maximum shift speed threshold.

[0178] Furthermore, the current throttle is greater than the set throttle threshold, the throttle change rate is less than the preset throttle change rate threshold, and the duration of the condition reaches the set time threshold.

[0179] Furthermore, the engine torque is exhibiting abnormal fluctuations or a rapid decrease.

[0180] Furthermore, the estimated engine speed is not lower than the preset estimated speed threshold;

[0181] If any of the above gear update conditions are not met, the gear shift control operation will not be performed;

[0182] The shift control operation is at least to perform a shift up to a preset number of gears based on the current gear.

[0183] For example, the shift control operation can specifically refer to performing a shift up one gear based on the current gear.

[0184] More specifically, when all of the following conditions are met, immediately shift to the target upshift gear by one gear from the current gear:

[0185] 1) The upshift speed exceeds the set maximum shift speed threshold, for example, 2000 rpm.

[0186] 2) The current throttle is greater than the set throttle threshold, for example, 90%; and the throttle opening change rate (i.e., the aforementioned throttle change rate) is less than a certain value, for example, 6% / s (i.e., the preset throttle change rate threshold can be 6% / s); and the time during which the throttle opening change rate is less than 6% / s (i.e., the aforementioned operating condition duration) reaches the set time threshold, for example, 10s.

[0187] 3) Abnormal fluctuations in engine torque or a rapid decrease in engine torque are detected (i.e., the aforementioned engine torque status is in an abnormal fluctuation state or a rapid decrease state).

[0188] 4) The estimated engine speed is not less than 1600 rpm (i.e., the aforementioned preset estimated speed threshold can be taken as 1600 rpm).

[0189] Understandably, if any of the above conditions are not met, the gear update will not be performed.

[0190] Furthermore, Figure 3 This is a schematic diagram illustrating the trend changes of engine speed and engine torque during high-resistance adaptive shifting, as provided in an embodiment of the present invention. (See attached diagram.) Figure 3 n highidle The maximum idle speed is ne, the engine speed is Te, the engine torque is t1-t2, the engine torque drops rapidly, and the engine torque fluctuates abnormally in the t3-t4 stage.

[0191] The technical solution provided in this embodiment obtains a set of vehicle shift control parameters to at least determine the engine torque state, the vehicle upshift speed, and the estimated engine speed. Furthermore, at least when the throttle parameters, engine torque state, vehicle upshift speed, and estimated engine speed simultaneously meet the gear update conditions, a shift control operation is performed based on the vehicle's current gear. Therefore, this embodiment can, at least under high resistance conditions, prevent the engine from reaching near its maximum idle speed range. When the engine torque is still close to its maximum torque and the vehicle is still accelerating, it can adaptively identify the inflection point where engine torque decreases or fluctuations begin, and perform upshifts in advance, improving the success rate of upshifts under high resistance conditions. This benefits the user experience, vehicle power, and driving economy.

[0192] It should be noted that the threshold values ​​given in the aforementioned technical solutions are all illustrative examples and can be adapted to actual vehicle conditions, and do not constitute a limitation on the present invention. The present invention aims to solve the problem that in mountainous road conditions with high resistance, the AMT transmission experiences a decrease in engine torque and insufficient vehicle power, leading to an inability to maintain the gear position after upshifting due to the high compensation speed at high resistance. By improving the rationality of gear selection timing under high resistance conditions, the vehicle's power and fuel economy can be improved.

[0193] Figure 2 This is a schematic diagram of a vehicle shift control device provided in an embodiment of the present invention. This embodiment is at least applicable to adaptive shifting scenarios under high-resistance road conditions in any vehicle equipped with an AMT transmission. The vehicle shift control device can be implemented using software and / or hardware. Figure 2 As shown, the vehicle shift control device includes at least:

[0194] The acquisition and determination module 110 is used to acquire the vehicle shift control parameter set to at least determine the engine torque state, the vehicle upshift speed and the estimated engine speed;

[0195] The shift control module 120 is used to perform shift control operations based on the current gear of the vehicle, at least when the throttle parameters, engine torque status, vehicle upshift speed and engine estimated speed simultaneously meet the gear update conditions.

[0196] Optionally, the engine torque status includes at least abnormal fluctuation status and rapid decrease status;

[0197] Abnormal fluctuations can be determined at least through the following methods:

[0198] At least the peak-to-peak value and / or standard deviation of the actual engine torque within any preset time period, as well as the average value, are calculated to determine whether the engine torque is abnormal and to obtain the abnormality judgment result.

[0199] The engine torque deviation should be calculated based at least on the current actual engine torque and the engine delayed torque at the preset time.

[0200] Based on at least the abnormal judgment results and the engine torque deviation, when the vehicle meets the abnormal fluctuation state judgment conditions, it is determined that the engine torque state is in an abnormal fluctuation state.

[0201] Optionally, the criteria for determining abnormal fluctuation states include at least the following:

[0202] The current clutch request for engine torque control is not in speed regulation mode;

[0203] Furthermore, the clutch control state is not the starting state;

[0204] Furthermore, the anomaly assessment result indicated an abnormality in engine torque;

[0205] Furthermore, the transmission's torque control mode for the engine is in a non-intervention state;

[0206] Furthermore, the engine torque deviation is not less than the threshold for judging abnormal torque fluctuations;

[0207] Furthermore, the vehicle throttle opening is greater than a preset opening threshold and the absolute value of the throttle opening change rate is less than a preset absolute value threshold.

[0208] Furthermore, the vehicle's resistance torque is not less than the resistance torque threshold, or the estimated gradient is not less than the preset gradient threshold.

[0209] Furthermore, the vehicle is not currently in the process of shifting gears.

[0210] Optionally, if any of the following conditions are met, the engine torque state is determined to have exited the abnormal fluctuation state.

[0211] The clutch control state is the starting state;

[0212] The engine torque deviation is less than the threshold for judging abnormal torque fluctuations;

[0213] The vehicle throttle opening is not greater than a predetermined opening threshold, or the absolute value of the throttle opening change rate is not less than a predetermined absolute value threshold.

[0214] The vehicle's resistance torque is less than the predetermined torque threshold and the estimated gradient is less than the predetermined gradient threshold.

[0215] The vehicle is currently in the process of shifting gears.

[0216] Optionally, the rapid descent state is determined at least by the following means:

[0217] At least calculate the first delayed torque of the current engine actual torque under the first delayed time step, and the second delayed torque of the current engine actual torque under the second delayed time step;

[0218] The first torque change rate and the second torque change rate are calculated based at least on the current actual engine torque, the first delay time step, the first delay torque, the second delay time step, and the second delay torque.

[0219] Based at least on the current actual engine torque, the first torque change rate, and the second torque change rate, when the vehicle meets the conditions for determining the rapid torque decrease state, it is determined that the engine torque state is in a rapid torque decrease state.

[0220] Optionally, the conditions for determining a rapid descent state include at least the following:

[0221] The clutch control is not in the starting state;

[0222] Furthermore, the actual torque of the engine is currently greater than the minimum permissible torque threshold.

[0223] Furthermore, the transmission's torque control mode for the engine is in a non-intervention state;

[0224] Furthermore, the second torque change rate is less than the first torque change rate, the first torque change rate is less than 0, the second torque change rate is less than a preset change rate threshold and the first torque change rate is greater than a set change rate threshold.

[0225] Furthermore, the vehicle throttle opening is greater than the set opening threshold and the absolute value of the throttle opening change rate is less than the set absolute value threshold.

[0226] Furthermore, the vehicle's resistance torque is not less than a set torque threshold, or the estimated gradient is not less than a set gradient threshold;

[0227] Furthermore, the vehicle is not currently in the process of shifting gears.

[0228] Optionally, if any of the following conditions are met, the engine torque state is determined to have exited the rapid decrease state;

[0229] The clutch control state is the starting state;

[0230] The second torque change rate is greater than the first torque change rate, or the first torque change rate is less than the first preset change rate threshold, or the second torque change rate is greater than the second preset change rate threshold.

[0231] The vehicle throttle opening is not greater than the preset opening threshold, or the absolute value of the throttle opening change rate is not less than the preset absolute value threshold.

[0232] The vehicle's resistance torque is less than the preset torque threshold and the estimated gradient is less than the preset gradient threshold.

[0233] Alternatively, the vehicle's upshift speed can be determined at least by the following methods:

[0234] The first speed loss during the torque reduction process and the second speed loss during the speed adjustment process are calculated based on the vehicle shift control parameter set.

[0235] The vehicle's upshifting speed should be determined based at least on the target speed after shifting, the gear ratio corresponding to the upshifted gear, the current gear ratio, the first loss speed, and the second loss speed.

[0236] The estimated engine speed is determined at least by the following methods:

[0237] The estimated engine speed should be determined based at least on the current gear ratio and the transmission output shaft speed.

[0238] Optionally, the throttle parameters include at least the current throttle, the throttle change rate, and the duration of the condition where the throttle change rate is less than a preset throttle change rate threshold.

[0239] The conditions for gear shifting must include at least:

[0240] The vehicle's upshift speed exceeds the set maximum shift speed threshold.

[0241] Furthermore, the current throttle is greater than the set throttle threshold, the throttle change rate is less than the preset throttle change rate threshold, and the duration of the condition reaches the set time threshold.

[0242] Furthermore, the engine torque is exhibiting abnormal fluctuations or a rapid decrease.

[0243] Furthermore, the estimated engine speed is not lower than the preset estimated speed threshold;

[0244] If any of the above gear update conditions are not met, the gear shift control operation will not be performed;

[0245] The shift control operation is at least to perform a shift up to a preset number of gears based on the current gear.

[0246] The technical solution provided in this embodiment obtains a set of vehicle shift control parameters through an acquisition and determination module to at least determine the engine torque state, the vehicle upshift speed, and the estimated engine speed. Furthermore, the shift control module performs a shift control operation based on the vehicle's current gear, at least when the throttle parameters, engine torque state, vehicle upshift speed, and estimated engine speed simultaneously meet the gear update conditions. Therefore, this embodiment can, at least under high resistance conditions, prevent the engine from reaching near its maximum idle speed range. When the engine torque is still close to its maximum torque and the vehicle is still accelerating, it can adaptively identify the inflection point where engine torque decreases or fluctuations begin, and shift up earlier, improving the success rate of upshifting under high resistance conditions. This benefits the user experience, vehicle power, and driving economy.

[0247] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A vehicle gear shifting control method, characterized in that, At least including: S1. Obtain the vehicle shift control parameter set to at least determine the engine torque state, the vehicle upshift speed, and the estimated engine speed; S2. At least when the throttle parameter, the engine torque state, the vehicle upshift speed and the estimated engine speed simultaneously meet the gear update conditions, perform a shift control operation based on the vehicle's current gear.

2. The vehicle shift control method according to claim 1, characterized in that, The engine torque status includes at least abnormal fluctuation status and rapid decrease status; The abnormal fluctuation state can be determined at least through the following methods: At least the peak-to-peak value and / or standard deviation of the actual engine torque within any preset time period, as well as the average value, are calculated to determine whether the engine torque is abnormal and to obtain the abnormality judgment result. The engine torque deviation should be calculated based at least on the current actual engine torque and the engine delayed torque at the preset time. Based at least on the anomaly judgment result and the engine torque deviation, when the vehicle meets the abnormal fluctuation state judgment condition, it is determined that the engine torque state is in the abnormal fluctuation state.

3. The vehicle shift control method according to claim 2, characterized in that, The conditions for determining abnormal fluctuation states include at least the following: The current clutch request for engine torque control is not in speed regulation mode; Furthermore, the clutch control state is not the starting state; Furthermore, the anomaly assessment result indicates that the engine torque is abnormal; Furthermore, the transmission's torque control mode for the engine is in a non-intervention state; Furthermore, the engine torque deviation is not less than the torque abnormal fluctuation judgment threshold; Furthermore, the vehicle throttle opening is greater than a preset opening threshold and the absolute value of the throttle opening change rate is less than a preset absolute value threshold. Furthermore, the vehicle's resistance torque is not less than the resistance torque threshold, or the estimated gradient is not less than the preset gradient threshold. Furthermore, the vehicle is not currently in the process of shifting gears.

4. The vehicle shift control method according to claim 3, characterized in that, If any of the following conditions are met, the engine torque state is determined to have exited the abnormal fluctuation state; The clutch control state is the starting state; The engine torque deviation is less than the torque abnormal fluctuation judgment threshold; The vehicle throttle opening is not greater than a predetermined opening threshold, or the absolute value of the throttle opening change rate is not less than a predetermined absolute value threshold. The vehicle's resistance torque is less than a predetermined torque threshold and the estimated gradient is less than a predetermined gradient threshold. The vehicle is currently in the process of shifting gears.

5. The vehicle shift control method according to claim 2, characterized in that, The rapid descent state is determined at least by the following means: At least calculate the first delayed torque of the current engine actual torque at the first delayed time step, and the second delayed torque of the current engine actual torque at the second delayed time step; The first torque change rate and the second torque change rate are calculated based at least on the current actual engine torque, the first delay time step, the first delay torque, the second delay time step, and the second delay torque; Based at least on the current actual engine torque, the first torque change rate, and the second torque change rate, when the vehicle meets the rapid descent state determination conditions, the engine torque state is determined to be in the rapid descent state.

6. The vehicle shift control method according to claim 5, characterized in that, The conditions for determining the rapid descent state include at least the following: The clutch control is not in the starting state; Furthermore, the actual torque of the current engine is greater than the minimum permissible torque threshold. Furthermore, the transmission's torque control mode for the engine is in a non-intervention state; Furthermore, the second torque change rate is less than the first torque change rate, the first torque change rate is less than 0, the second torque change rate is less than a preset change rate threshold, and the first torque change rate is greater than a set change rate threshold. Furthermore, the vehicle throttle opening is greater than the set opening threshold and the absolute value of the throttle opening change rate is less than the set absolute value threshold. Furthermore, the vehicle's resistance torque is not less than a set torque threshold, or the estimated gradient is not less than a set gradient threshold; Furthermore, the vehicle is not currently in the process of shifting gears.

7. The vehicle shift control method according to claim 6, characterized in that, If any of the following conditions are met, the engine torque state is determined to have exited the rapid decrease state; The clutch control state is the starting state; The second torque change rate is greater than the first torque change rate, or the first torque change rate is less than the first preset change rate threshold, or the second torque change rate is greater than the second preset change rate threshold. The vehicle throttle opening is not greater than a preset opening threshold, or the absolute value of the throttle opening change rate is not less than a preset absolute value threshold. The vehicle's resistance torque is less than a preset torque threshold and the estimated gradient is less than a preset gradient threshold.

8. The vehicle shift control method according to claim 1, characterized in that, The vehicle's upshift speed is determined at least by the following methods: The first speed loss during the torque reduction process and the second speed loss during the speed adjustment process are calculated based on the vehicle shift control parameter set. The vehicle's upshifting speed is determined at least based on the target speed after shifting, the gear ratio corresponding to the upshifted gear, the current gear ratio, the first lost speed, and the second lost speed. The estimated engine speed is determined at least by the following means: The estimated engine speed is determined based at least on the current gear ratio and the transmission output shaft speed.

9. The vehicle shift control method according to claim 1, characterized in that, The throttle parameters include at least the current throttle, the throttle change rate, and the duration of the condition where the throttle change rate is less than a preset throttle change rate threshold. The gear shift update conditions include at least the following: The vehicle's upshift speed exceeds the set maximum shift speed threshold; Furthermore, the current throttle is greater than the set throttle threshold, the throttle change rate is less than the preset throttle change rate threshold, and the duration of the operating condition reaches the set time threshold. Furthermore, the engine torque state is either in an abnormal fluctuation state or a rapidly decreasing state; Furthermore, the estimated engine speed is not lower than a preset estimated speed threshold; If any of the above-mentioned gear update conditions are not met, the gear shift control operation will not be performed. The shift control operation is at least to perform a shift up operation with a preset number of gears based on the current gear.

10. A vehicle gear shifting control device, characterized in that, Used to perform the vehicle shift control method according to any one of claims 1-9; The vehicle shift control device includes at least: The acquisition and determination module is used to acquire the vehicle shift control parameter set to at least determine the engine torque state, the vehicle upshift speed, and the estimated engine speed; The shift control module is used to perform shift control operations based on the current gear of the vehicle, at least when the throttle parameter, the engine torque state, the vehicle upshift speed, and the estimated engine speed simultaneously meet the gear update conditions.

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