Gear calculation method for fork-mounted gear of double-clutch automatic transmission

Abstract

The present application relates to the field of automatic gear vehicle control, in particular to a kind of shift fork gear engaging gear position calculation method for double clutch automatic gearbox, by the different priority of various preset conditions, the expected gear and preselected gear obtained by TCU according to the driving state of current vehicle, vehicle speed, throttle opening, engine speed and other parameters, and road conditions and other factors are re-judged and calculated, to determine the final shift fork action target gear position most consistent with the current actual situation, and the shift fork gear engaging gear position calculation result is obtained to control the shift fork of double clutch automatic gearbox to engage gear (including neutral), ensure the power and economy of automatic gear vehicle, improve the vehicle NVH performance, and the comfort and satisfaction of driver and passenger.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of automatic gear vehicle control, and particularly relates to a shift fork gear hanging gear position calculation method for a dual clutch automatic gearbox. BACKGROUND

[0002] Compared with a manual gear vehicle, an automatic gear vehicle greatly reduces the frequency of manual operation and gear shifting actions of a driver, greatly reduces the working strength of the driver, and has the characteristics of simple operation and convenience. Therefore, the automatic gear vehicle has been more and more widely publicized and used. Since a dual clutch transmission (DCT) has high transmission efficiency and gear shifting quality, a dual clutch automatic gearbox is usually used for power transmission in the automatic gear vehicle. Therefore, research on the shift fork gear hanging process in the dual clutch automatic gearbox plays a crucial role in driving of the automatic gear vehicle.

[0003] In a long-term use and research process, it is found that the automatic gear vehicle often has the following two problems in automatic control of the shift fork due to gear diversity (i.e., having multiple forward gears) of the dual clutch automatic gearbox.

[0004] ① Problem of uncertain control object and control action:

[0005] Which shift fork of the dual clutch automatic gearbox is operated? The operation is a gear hanging operation or a gear emptying operation?

[0006] ② Problem of uncertain control time:

[0007] When is the operation performed? What operation is performed first, and what operation is performed second?

[0008] If the above problems are not accurately handled, the shift fork cannot be accurately automatically controlled, and the following phenomena are caused:

[0009] For example, a shift fork gear being used is suddenly automatically emptied, or the dual clutch automatic gearbox suddenly empties a shift fork gear to be used, or a shift fork is hung on gear A instead of gear B, or a shift fork gear is not hung in advance, and the like.

[0010] These problems are ultimately the problem of the shift fork gear engagement gear calculation of the dual clutch automatic transmission. The current shift fork gear engagement gear calculation technology usually only obtains the desired gear and the preselected gear according to the current driving state, the vehicle speed, the throttle opening, the engine speed and various parameters of the vehicle, the road conditions and other factors by the TCU, and does not consider the actual situation of the shift fork inside the transmission. If the shift fork gear engagement gear calculation result calculated by the dual clutch automatic transmission of the automatic gear vehicle during the driving does not conform to the actual situation inside the transmission, not only the expectation of the driver will be violated, but also the power response or the fuel economy of the vehicle will be affected, and even the function use will be hindered, resulting in accidents, threatening the personal and property safety of the passengers and the driver. Therefore, it is necessary to carry out in-depth and continuous research on the shift fork gear engagement gear calculation. SUMMARY

[0011] The purpose of the present application is to provide a shift fork gear engagement gear calculation method for a dual clutch automatic transmission, which rejudges and calculates the desired gear and the preselected gear obtained by the TCU according to various preset conditions with different priorities, determines the target gear of the final shift fork action most conforming to the current actual situation, and controls the shift fork of the dual clutch automatic transmission to engage the gear (including the neutral gear) by using the final corrected shift fork gear engagement gear result, so as to ensure the power and the economy of the automatic gear vehicle, improve the NVH performance of the vehicle, and improve the comfort and the satisfaction of the driver and the passenger.

[0012] The purpose of the present application is achieved by the following scheme: a shift fork gear engagement gear calculation method for a dual clutch automatic transmission, comprising the following steps:

[0013] 1) presetting a shift fork M return neutral condition, a shift fork R return neutral condition, a preselected gear engagement condition, a gear K gear engagement condition and a gear G gear engagement condition, and setting two storage units for storing a first gear calculation result and a second gear calculation result;

[0014] 2) calculating the first gear calculation result and the second gear calculation result according to the desired gear and the preselected gear calculated by the TCU of the dual clutch automatic transmission, the preset shift fork M return neutral condition, the shift fork R return neutral condition, the preselected gear engagement condition, the gear K gear engagement condition, the gear G gear engagement condition and the current state of the dual clutch automatic transmission;

[0015] 3) obtaining the shift fork gear engagement gear calculation result according to the relationship between the first and second gear calculation results and the non-requested gear in the following manner:

[0016] 3-1) first judging the relationship between the first gear calculation result and the non-requested gear:

[0017] If the first gear calculation result is not the unrequested gear, the first gear calculation result is taken as the shift fork gear calculation result;

[0018] If the first gear calculation result is the unrequested gear, the relationship between the second gear calculation result and the unrequested gear is judged:

[0019] 3-2) If the second gear calculation result is not equal to the unrequested gear, the second gear calculation result is taken as the shift fork gear calculation result;

[0020] 3-3) If the second gear calculation result is equal to the unrequested gear, the shift fork gear calculation result is the unrequested gear.

[0021] Preferably, the first gear calculation result is calculated in the following manner:

[0022] ① The current state of the double clutch automatic transmission is judged to see if it meets the shift fork M return empty condition:

[0023] If the shift fork M return empty condition is met, the first gear calculation result is the shift fork M return empty;

[0024] ② If the shift fork M return empty condition is not met, the current state of the double clutch automatic transmission is continuously judged to see if it meets the gear K gear engagement condition:

[0025] If the gear K gear engagement condition is met, the first gear calculation result is the gear K;

[0026] If the gear K gear engagement condition is not met, the first gear calculation result is the unrequested gear.

[0027] Preferably, the shift fork M return empty condition is as follows:

[0028] a) The shift fork M currently corresponding gear is not the neutral gear;

[0029] b) The shift fork M can be moved;

[0030] c) The PN gear allows pre-gear engagement calibration switch is closed, or the PN gear allows pre-gear engagement calibration switch is open, but the preselected gear is not equal to the shift fork M corresponding PN gear pre-gear engagement;

[0031] d) The current state of the desired gear meets any one of the following two conditions:

[0032] d-1) The desired gear is the neutral gear;

[0033] d-2) The desired gear is coaxial with the shift fork M corresponding gear, and the shift fork corresponding to the desired gear is not the shift fork M.

[0034] Preferably, the gear K gear engagement condition is as follows:

[0035] a) the desired gear is gear K;

[0036] b) the current gear of the shift fork K is not gear K;

[0037] c) the shift fork K is movable.

[0038] Preferably, the second gear calculation result is calculated in the following way:

[0039] ① judge whether the current state of the double clutch automatic transmission satisfies the shift fork R return empty condition:

[0040] If the shift fork R return empty condition is satisfied, the second gear calculation result is shift fork R return empty;

[0041] ② If the shift fork R return empty condition is not satisfied, continue to judge whether the current state of the double clutch automatic transmission satisfies the preselected gear engagement condition:

[0042] If the preselected gear engagement condition is not satisfied, the second gear calculation result is no requested gear;

[0043] ③ If the preselected gear engagement condition is satisfied, continue to judge whether the current state of the double clutch automatic transmission satisfies the gear G engagement condition:

[0044] If the gear G engagement condition is satisfied, the second gear calculation result is gear G;

[0045] If the gear G engagement condition is not satisfied, the second gear calculation result is no requested gear.

[0046] Preferably, the shift fork R return empty condition is as follows:

[0047] a) the desired gear is different from the gear corresponding to the shift fork R;

[0048] b) the first gear calculation result is no requested gear;

[0049] c) the shift fork R is movable;

[0050] d) the shift fork R is not empty;

[0051] e) the current state of the preselected gear satisfies any one of the following two conditions:

[0052] e-1) the preselected gear is coaxial with the gear corresponding to the shift fork R, and the preselected gear corresponds to a shift fork other than the shift fork R.

[0053] e-2) the preselected gear is empty.

[0054] Preferably, the preselected gear engagement condition is as follows:

[0055] a) the preselected gear is not empty;

[0056] b) the preselected gear is different from the desired gear;

[0057] c) the first gear calculation result is an unrequested gear.

[0058] Preferably, the gear G engagement condition is as follows:

[0059] a) the gear corresponding to the gear G is not the gear G;

[0060] b) the preselected gear is the gear G;

[0061] c) the gear corresponding to the gear G can be moved.

[0062] Preferably, a post-processing time threshold value and a plurality of post-processing conditions are set, and after the gear engagement gear calculation result of the shift fork is obtained in step 3), the gear engagement gear calculation result of the shift fork is corrected in a delayed manner according to the post-processing conditions as follows:

[0063] It is determined whether the current vehicle state meets the post-processing condition, if not, the gear engagement gear calculation result of the shift fork does not need to be corrected in a delayed manner, and the gear engagement gear calculation result of the shift fork is directly output without being corrected in a delayed manner; if so:

[0064] 4-1) the post-processing timer is timed, and it is continuously determined whether the current reading of the post-processing timer reaches the post-processing time threshold value:

[0065] 4-2) if the current reading of the post-processing timer does not reach the post-processing time threshold value, an unrequested gear is output, and step 4-1) is repeated;

[0066] 4-3) when it is continuously determined that the current reading of the post-processing timer reaches the post-processing time threshold value, the gear engagement gear calculation result of the shift fork corrected in a delayed manner is output.

[0067] Preferably, the post-processing condition is determined according to the accelerator pedal opening degree, the brake pedal state, the brake pressure, the shift fork state, the desired gear, the actual driving gear, and the gear engagement gear calculation result of the shift fork.

[0068] The advantage of the present application is that by rejudging and calculating the desired gear and the preselected gear of the TCU according to various preset conditions with different priorities, the target gear of the final shift fork action most suitable for the current actual situation is determined, and the gear engagement gear result of the final shift fork corrected is used to control the shift fork of the dual-clutch automatic transmission to engage (including the neutral gear), so as to ensure the power and economy of the automatic transmission vehicle, improve the NVH performance of the vehicle, and improve the comfort and satisfaction of the driver and passengers.

[0069] Glossary

[0070] Shift fork hanging gear: also called "gear hanging operation", refers to when the shift fork moves from the current gear to the target gear, the shift fork will push the synchronizer or directly push the gear, so that it is combined or separated with the corresponding gear shaft, realizing the switching of different gears, so as to transmit power and drive the vehicle to move forward or backward. For example, when the shift fork is shifted from gear one to gear two, the shift fork separates the originally combined gear one gear by moving, and at the same time pushes the gear two gear to combine with the shaft, completing the gear change. It is worth noting that "shift fork hanging gear" in the present application refers to the "gear hanging operation" in a broad sense, that is, it is for all gears of the gearbox, including neutral and reverse gears.

[0071] Neutral operation: refers to when the shift fork is switched from the current gear to neutral, the power is cut off, so that the vehicle slows down or stops.

[0072] Desired gear: in the present application, it refers to during vehicle driving (non-stationary state), the TCU of the vehicle gearbox calculates the desired gear according to the driver's demand, road conditions, driving speed and other factors, and sends instructions to the execution component to express the gear that the execution component is expected to quickly respond to.

[0073] Preselected gear: in the present application, it refers to during vehicle driving (non-stationary state), the gearbox shift schedule module calculates a gear (previously predicted or prepared gear to be switched) according to various parameters such as the current vehicle driving state, vehicle speed, throttle opening, engine speed, etc. For example, when the vehicle accelerates, the gearbox may preselect a higher gear, or when the vehicle decelerates, it may preselect a lower gear, so as to quickly complete the gear shift when the conditions are met.

[0074] Unrequested gear: in the present application, it refers to the gearbox not sending any instruction to request gear shifting, and not performing any operation to request gear shifting.

[0075] Target gear: the gear calculation result in the present application, that is, the target of the shift fork action, the shift fork finally hangs on the target gear.

[0076] PN gear pre-hanging gear: like the purpose of preselected gear, both are to pre-hang a certain shift fork gear in order to save time, both belong to pre-hanging a certain shift fork gear. The difference is that PN gear pre-hanging gear refers to the vehicle in a stationary state judged by the gearbox whether to pre-hang a gear. For example, when the vehicle speed is zero, the shift lever is in P gear or N gear, and the pre-hung shift fork gear. The pre-hung gear corresponding to PN gear is usually set when the gearbox is factory-fitted, and is fixed for the same gearbox. The desired gear and the preselected gear are dynamically variable during vehicle driving. BRIEF DESCRIPTION OF DRAWINGS

[0077] Figure 1 Flow chart of the present application;

[0078] Figure 2 Flow chart of the post-processing process of the present application;

[0079] Figure 3 Overall flow chart of the embodiment of the present application;

[0080] Figure 4 Flow chart of obtaining the first gear calculation result in the embodiment of the present application;

[0081] Figure 5 Flow chart of obtaining the second gear calculation result in the embodiment of the present application;

[0082] Figure 6 Flow chart of judging whether the DCT meets the fork M return empty condition in the embodiment of the present application;

[0083] Figure 7 Flow chart of judging whether the DCT meets the gear K gear engagement condition in the embodiment of the present application;

[0084] Figure 8 Flow chart of judging whether the DCT meets the fork R return empty condition in the embodiment of the present application;

[0085] Figure 9 Flow chart of judging whether the DCT meets the preselected gear engagement condition in the embodiment of the present application;

[0086] Figure 10 Flow chart of judging whether the DCT meets the gear G gear engagement condition in the embodiment of the present application. DETAILED DESCRIPTION

[0087] As shown in the figure, a fork gear engagement gear calculation method for a dual clutch automatic transmission comprises the following steps: Figure 1 1) presetting a fork M return empty condition, a fork R return empty condition, a preselected gear engagement condition, a gear K gear engagement condition, and a gear G gear engagement condition, and setting two storage units for storing a first gear calculation result and a second gear calculation result;

[0088] 2) calculating a first gear calculation result and a second gear calculation result according to an expected gear calculated by a TCU of the dual clutch automatic transmission, a preselected gear, and the preset fork M return empty condition, the fork R return empty condition, the preselected gear engagement condition, the gear K gear engagement condition, the gear G gear engagement condition, and a current state of the dual clutch automatic transmission:

[0089] 2-1) the first gear calculation result is calculated in the following manner:

[0090] ​

[0091] 1) determining whether the current state of the DCT satisfies the shift fork M return-to-neutral condition, which is as follows:

[0092] a) the shift fork M currently corresponds to a gear other than neutral;

[0093] b) the shift fork M is movable;

[0094] c) the PN gear pre-engagement permission switch is off, or the PN gear pre-engagement permission switch is on but the preselected gear is not equal to the PN gear pre-engagement gear corresponding to the shift fork M;

[0095] d) the current state of the desired gear satisfies any one of the following two conditions:

[0096] d-1) the desired gear is neutral;

[0097] d-2) the desired gear is coaxial with the gear corresponding to the shift fork M, and the shift fork corresponding to the desired gear is not the shift fork M.

[0098] If the current state of the DCT satisfies the shift fork M return-to-neutral condition, the first gear calculation result is that the shift fork M returns to neutral;

[0099] 2) if the current state of the DCT does not satisfy the shift fork M return-to-neutral condition, determining whether the current state of the DCT satisfies the gear K engagement condition, which is as follows:

[0100] a) the desired gear is gear K;

[0101] b) the gear corresponding to the shift fork where gear K is located is not gear K;

[0102] c) the shift fork where gear K is located is movable.

[0103] If the current state of the DCT satisfies the gear K engagement condition, the first gear calculation result is gear K;

[0104] If the current state of the DCT does not satisfy the gear K engagement condition, the first gear calculation result is the unrequested gear.

[0105] 2-2) the second gear calculation result is calculated as follows:

[0106] 1) determining whether the current state of the DCT satisfies the shift fork R return-to-neutral condition, which is as follows:

[0107] a) the desired gear is not coaxial with the gear corresponding to the shift fork R;

[0108] b) the first gear calculation result is the unrequested gear;

[0109] c) the shift fork R is movable;

[0110] d) the shift fork R is not in neutral;

[0111] e) the current state of the preselected gear satisfies any one of the following two conditions:

[0112] e-1) the preselected gear is coaxial with the gear corresponding to the shift fork R, and the shift fork corresponding to the preselected gear is not the shift fork R.

[0113] e-2) the preselected gear is neutral.

[0114] if the current state of the DCT satisfies the shift fork R return neutral condition, the second gear calculation result is that the shift fork R returns to neutral;

[0115] 2) if the current state of the DCT does not satisfy the shift fork R return neutral condition, it is determined whether the current state of the double clutch automatic transmission satisfies the preselected gear mounting condition, and the preselected gear mounting condition is as follows:

[0116] a) the preselected gear is not neutral;

[0117] b) the preselected gear is not coaxial with the desired gear, i.e., it is not a gear on the same output shaft. For example, if the preselected gear is on the odd shaft, then the desired gear can only be on the even shaft to satisfy this condition;

[0118] c) the first gear calculation result is the non-requested gear.

[0119] if the current state of the DCT does not satisfy the preselected gear mounting condition, the second gear calculation result is the non-requested gear;

[0120] 3) if the current state of the DCT satisfies the preselected gear mounting condition, it is determined whether the current state of the double clutch automatic transmission satisfies the gear G mounting condition, and the gear G mounting condition is as follows:

[0121] a) the gear corresponding to the shift fork G is not in gear G;

[0122] b) the preselected gear is gear G;

[0123] c) the shift fork corresponding to gear G can be moved.

[0124] if the current state of the DCT satisfies the gear G mounting condition, the second gear calculation result is gear G;

[0125] if the current state of the DCT does not satisfy the gear G mounting condition, the second gear calculation result is the non-requested gear.

[0126] 3) according to the relationship between the first, second gear calculation results and the non-requested gear, and in the following manner, the shift fork mounting gear calculation result is obtained:

[0127] 3-1) First, determine the relationship between the first gear calculation result and the non-requested gear:

[0128] If the first gear calculation result is not the non-requested gear, then the first gear calculation result is the fork-mounted gear calculation result;

[0129] If the first gear calculation result is the non-requested gear, then determine the relationship between the second gear calculation result and the non-requested gear:

[0130] 3-2) If the second gear calculation result is not equal to the non-requested gear, then the second gear calculation result is the fork-mounted gear calculation result;

[0131] 3-3) If the second gear calculation result is equal to the non-requested gear, then the fork-mounted gear calculation result is the non-requested gear.

[0132] In actual application, the TCU of the dual-clutch automatic transmission will simultaneously determine the state of all forks and gears of the dual-clutch automatic transmission according to the above method, that is, the value range of the forks M and R is all the forks of the dual-clutch automatic transmission, and the value range of the gears K and G is all the gears of the dual-clutch automatic transmission.

[0133] It is worth noting that, in order to make the gear mounting timing of the DCT more accurate, the following settings can also be made:

[0134] ① Obtain the value of the post-processing time threshold T according to the real-time oil temperature of the DCT, and the two-dimensional table is formed by obtaining a number of data according to the performance parameters and driving states of the vehicle through vehicle calibration test, which is used to describe the relationship between the post-processing time threshold and the real-time oil temperature of the DCT, that is, when the real-time oil temperature of the DCT is in what interval range, what value of the post-processing time threshold T is most appropriate, which can meet the pre-designed standards (power performance, fuel economy, NVH performance, etc.).

[0135] ② Set a number of post-processing conditions (such as brake pressure threshold) according to the accelerator pedal opening, brake pedal state, brake pressure, fork state, desired gear, actual driving gear, and fork-mounted gear calculation result calculated in step 3). Similarly, these post-processing conditions are also determined through vehicle calibration test, and the power performance and fuel economy are given priority, and then the influence on the vehicle NVH performance is considered. The post-processing conditions of the present embodiment include:

[0136] a) The brake pressure is greater than the preset brake pressure threshold;

[0137] b) The desired gear is equal to the preset gear (for example, 2nd gear);

[0138] c) the state of the other shifter on the same shaft is the specified state, i.e. the state of the other shifter on the same shaft corresponding to the shifter gear engagement position calculated in step 3 is the preset shifter control state, which includes open-loop control state, closed-loop control state, etc., and is determined through vehicle calibration experiments;

[0139] d) the shifter gear engagement position calculated in step 3 is the state of the other shifter on the same shaft, i.e. the state of the other shifter on the same shaft corresponding to the shifter gear engagement position calculated in step 3 is empty.

[0140] In this way, after the shifter gear engagement position calculated in step 3, the shifter gear engagement position can be corrected according to the preset post-processing condition and post-processing time threshold T, as shown in the following formula: Figure 2

[0141] determine whether the current vehicle state meets the post-processing condition:

[0142] If not, the shifter gear engagement position does not need to be corrected, and the shifter gear engagement position calculated without correction is directly outputted.

[0143] If so:

[0144] 4-1) the post-processing timer is started, and it is continuously determined whether the current reading of the post-processing timer reaches the post-processing time threshold T:

[0145] 4-2) if the current reading of the post-processing timer does not reach the post-processing time threshold T, the gear position is outputted without request, and step 4-1 is repeated.

[0146] 4-3) when the current reading of the post-processing timer reaches the post-processing time threshold T, the shifter gear engagement position calculated after correction is outputted.

[0147] In fact, the shifter gear engagement position calculated without correction is the same as the shifter gear engagement position calculated after correction, but in order to make the DCT gear engagement more accurate, a series of processing conditions are determined through vehicle calibration experiments to delay the output of the shifter gear engagement position, so that the timing of the output shifter gear engagement position is more accurate, which ensures the vehicle power, fuel economy and other indicators, and improves the NVH performance.

[0148] ​In practical application, the post-processing timer can also be replaced by a post-processing counter, and the corresponding post-processing time threshold T is replaced by a post-processing delay cycle number threshold. The post-processing delay cycle number threshold is also determined according to the whole vehicle calibration experiment.

[0149] According to the above method, after the fork M back empty condition, the fork R back empty condition, the preselected gear condition, the gear K gear engagement condition, the gear G gear engagement condition, the post-processing time threshold T value and the post-processing condition are set, the following logic step code is coded and stored in the TCU of the DCT (or other software and hardware units with operation function of the DCT): Figures 3 to 10

[0150] As shown in Figure 3 S1, if the first gear calculation result is not equal to the non-requested gear, S2 is executed; otherwise, S3 is executed.

[0151] S2, output the first gear calculation result as the fork gear engagement gear calculation result, and then execute S7.

[0152] S3, if the second gear calculation result is not equal to the non-requested gear, S4 is executed; otherwise, S5 is executed.

[0153] S4, output the second gear calculation result as the fork gear engagement gear calculation result, and then execute S7.

[0154] S5, the fork gear engagement gear calculation result is the non-requested gear, and then execute S7.

[0155] S6, store the fork gear engagement gear calculation result without delay correction processing.

[0156] S7, according to the fork gear engagement gear calculation result and the whole vehicle state, judge whether the fork gear engagement gear calculation result needs delay correction (i.e. whether the post-processing condition is met), if the post-processing condition is met, execute S8; otherwise, execute S9.

[0157] S8, the reading of the post-processing timer + 10ms, and then execute S10.

[0158] S9, directly output the fork gear engagement gear calculation result without delay correction processing, and then end.

[0159] S10, if the reading of the post-processing timer is equal to the post-processing time threshold T, execute S12; otherwise, execute S11.

[0160] S11, output the non-requested gear, and then jump to step S8 for continuous execution.

[0161] ​S12, the fork gear shift gear position calculation result after the delay correction processing is output as the gear position calculation result, and then the process ends.

[0162] The post-processing conditions of this embodiment are as follows:

[0163] a) brake pressure is greater than brake pressure threshold value;

[0164] b) the desired gear position is equal to 2nd gear;

[0165] c) the state of the other fork on the same shaft is a specified state;

[0166] d) the fork gear shift gear position calculation result is the other fork on the same shaft back to empty.

[0167] The first gear position calculation result of this embodiment is obtained in the following manner:

[0168] S100, if the current state of the DCT meets the fork M back to empty condition, execute S101; otherwise, execute S102;

[0169] S101, "fork M back to empty" is taken as the first gear position calculation result, and then the process ends.

[0170] S102, if the current state of the DCT meets the gear K gear shift condition, execute S103; otherwise, execute S104;

[0171] S103, the first gear position calculation result is gear K, and then the process ends.

[0172] S104, the first gear position calculation result is the requested gear position, and then the process ends.

[0173] Wherein, the value range of fork M is all forks of the dual-clutch automatic transmission, and the value range of gear K is all gears of the dual-clutch automatic transmission.

[0174] The second gear position calculation result of this embodiment is obtained in the following manner:

[0175] S300, if the current state of the DCT meets the fork R back to empty condition, execute S301; otherwise, execute S302;

[0176] S301, "fork R back to empty" is taken as the second gear position calculation result, and then the process ends.

[0177] S302, if the current state of the DCT does not meet the preselected gear shift gear position condition, execute S303; otherwise, execute S304;

[0178] S303, the second gear position calculation result is the requested gear position, and then the process ends.

[0179] S304, if the current state of the DCT satisfies the gear G engagement condition, S305 is performed; otherwise, S306 is performed.

[0180] S305, the second gear calculation result is the gear G, and then the process ends.

[0181] S306, the second gear calculation result is the non-requested gear, and then the process ends.

[0182] wherein the value range of the shift fork R is all shift forks of the dual-clutch automatic transmission, and the value range of the gear G is all gears of the dual-clutch automatic transmission.

[0183] In this embodiment, the way of judging whether the current state of the DCT satisfies the shift fork M empty condition is as follows:

[0184] S10000, if the shift fork M is not empty, S10001 is performed; otherwise, S10008 is performed.

[0185] S10001, if the shift fork M is allowed to move, S10002 is performed; otherwise, S10008 is performed.

[0186] S10002, if the PN gear pre-engagement flag is open, S10003 is performed; otherwise, S10004 or S10005 is performed.

[0187] S10003, if the pre-selected gear is not equal to the PN gear pre-engagement on the shift fork M, S10004 or S10005 is performed; otherwise, S10008 is performed.

[0188] S10004, if the desired gear is empty, S10007 is performed; otherwise, S10008 is performed.

[0189] S10005, if the desired gear is coaxial with the gear on the shift fork M, S10006 is performed; otherwise, S10008 is performed.

[0190] S10006, if the desired gear corresponds to a shift fork other than the shift fork M, S10007 is performed; otherwise, S10008 is performed.

[0191] S10007, the judgment result of the shift fork M empty condition is "satisfies the shift fork M empty condition", and then the process ends.

[0192] S10008, the judgment result of the shift fork M empty condition is "does not satisfy the shift fork M empty condition", and then the process ends.

[0193] wherein the PN gear pre-engagement on the shift fork M is generally 1st gear, or 2nd gear, or reverse gear.

[0194] The manner of judging whether the current state of the DCT satisfies the gear K engagement condition in this embodiment is as follows:

[0195] S10200, if the desired gear is gear K, S10201 is executed; otherwise, S10204 is executed.

[0196] S10201, if the gear on the shift fork where gear K is located is not gear K, S10202 is executed; otherwise, S10204 is executed.

[0197] S10202, if the shift fork where gear K is located is allowed to move, S10203 is executed; otherwise, S10204 is executed.

[0198] S10203, the result of the judgment of the gear K engagement condition is "satisfying the gear K engagement condition", and then the process ends.

[0199] S10204, the result of the judgment of the gear K engagement condition is "not satisfying the gear K engagement condition", and then the process ends.

[0200] The manner of judging whether the current state satisfies the shift fork R return condition in this embodiment is as follows:

[0201] S30000, if the desired gear is different from the gear corresponding to the shift fork R, S30001 is executed; otherwise, S30008 is executed.

[0202] S30001, if the first gear calculation result is the gear not requested, S30002 is executed; otherwise, S30008 is executed.

[0203] S30002, if the shift fork R is allowed to move, S30003 is executed; otherwise, S30008 is executed.

[0204] S30003, if the gear corresponding to the shift fork R is not the neutral gear, S30004 or S30006 is executed; otherwise, S30008 is executed.

[0205] S30004, if the preselected gear is coaxial with the gear corresponding to the shift fork R, S30005 is executed; otherwise, S30008 is executed.

[0206] S30005, if the shift fork corresponding to the preselected gear is not the shift fork R, S30007 is executed; otherwise, S30008 is executed.

[0207] S30006, if the preselected gear is the neutral gear, S30007 is executed; otherwise, S30008 is executed.

[0208] S30007, the result of the judgment of the shift fork R return condition is "satisfying the shift fork R return condition", and then the process ends.

[0209] S30008, the result of the determination of the condition of the fork R returning to empty is that the fork R returning to empty condition is not satisfied, and then the process is ended.

[0210] The way of determining whether the current state satisfies the preselected gear engaging condition in the embodiment is as follows:

[0211] S30200, if the preselected gear is not empty, S30201 is executed; otherwise, S30204 is executed.

[0212] S30201, if the preselected gear is different from the expected gear, S30202 is executed; otherwise, S30204 is executed.

[0213] S30202, if the first gear calculation result is the gear not requested, S30203 is executed; otherwise, S30204 is executed.

[0214] S30203, the result of the determination of the preselected gear engaging condition is that the preselected gear engaging condition is satisfied, and then the process is ended.

[0215] S30204, the result of the determination of the preselected gear engaging condition is that the preselected gear engaging condition is not satisfied, and then the process is ended.

[0216] The way of determining whether the current state satisfies the gear G engaging condition in the embodiment is as follows:

[0217] S30400, if the gear G is not in the gear corresponding to the fork currently, S30401 is executed; otherwise, S30404 is executed.

[0218] S30401, if the preselected gear is the gear G, S30402 is executed; otherwise, S30404 is executed.

[0219] S30402, if the fork movement of the gear G is allowed, S30403 is executed; otherwise, S30404 is executed.

[0220] S30403, the result of the determination of the gear G engaging condition is that the gear G engaging condition is satisfied, and then the process is ended.

[0221] S30404, the result of the determination of the gear G engaging condition is that the gear G engaging condition is not satisfied, and then the process is ended.

[0222] Experiments prove that the fork engaging gear calculation result obtained according to the application can control the fork of the double-clutch automatic gearbox to engage, can determine the target gear most suitable for the actual situation, lays a solid foundation for subsequent fork engaging (including returning to empty operation), guarantees the power and economy of the automatic gear vehicle, and improves the comfort and satisfaction of the driver and passenger.

[0223] The above merely illustrates the preferred embodiments of the present application, and is not used to limit the present application, and any modification made by those skilled in the art without departing from the spirit of the present application shall fall into the protection scope of the present application.

Claims

1. A method for calculating the shift fork gear position in a dual-clutch automatic transmission, characterized in that, Includes the following steps: 1) Preset the conditions for shift fork M to return to neutral, shift fork R to return to neutral, pre-selected gear, gear K to engage, and gear G to engage, and set up two storage units to store the calculation results of the first gear and the calculation results of the second gear; 2) Based on the desired gear and pre-selected gear calculated by the TCU of the dual-clutch automatic transmission, as well as the preset conditions for shift fork M to return to neutral, shift fork R to return to neutral, pre-selected gear engagement, gear K engagement, gear G engagement, and the current state of the dual-clutch automatic transmission, calculate the calculation results for the first gear and the second gear respectively. 3) Based on the relationship between the calculation results of the first and second gears and the unrequested gears, the shift fork gear calculation results are obtained in the following manner: 3-1) First, determine the relationship between the calculated result of the first gear and the gear not requested: If the first gear calculation result is not an unrequested gear, then the first gear calculation result will be used as the shift fork engagement gear calculation result; If the first gear calculation result is "no gear requested", then determine the relationship between the second gear calculation result and the "no gear requested" result: 3-2) If the second gear calculation result is not equal to the unrequested gear, then the second gear calculation result shall be used as the shift fork engagement gear calculation result; 3-3) If the second gear calculation result is equal to the unrequested gear, then the shift fork gear calculation result is the unrequested gear.

2. The method for calculating the shift fork gear position in a dual-clutch automatic transmission according to claim 1, characterized in that, The first gear calculation result is calculated in the following manner: ① Determine whether the current state of the dual-clutch automatic transmission satisfies the shift fork M return-to-neutral condition: If the condition for the shift fork M to return to neutral is met, then the calculation result for the first gear is the shift fork M returning to neutral. ② If the condition for the shift fork to return to neutral (M) is not met, then continue to determine whether the current state of the dual-clutch automatic transmission meets the condition for engaging gear (K): If the conditions for engaging gear K are met, then the first gear will be calculated as gear K. If the conditions for engaging gear K are not met, the result of the first gear calculation is "gear not requested".

3. The method for calculating the shift fork gear position in a dual-clutch automatic transmission according to claim 2, characterized in that, The return-to-neutral condition for the shift fork M is as follows: a) The gear currently corresponding to shift fork M is not neutral; b) The shift fork M can move; c) The PN gear pre-engagement calibration switch is closed, or the PN gear pre-engagement calibration switch is open, but the pre-selected gear is not equal to the PN gear pre-engagement corresponding to shift fork M; d) The current state of the desired gear position satisfies either of the following two conditions: d-1) The desired gear is neutral; d-2) The desired gear position is coaxial with the gear position corresponding to shift fork M, and the shift fork corresponding to the desired gear position is not shift fork M.

4. The method for calculating the shift fork gear position in a dual-clutch automatic transmission according to claim 2, characterized in that, The conditions for engaging gear K are as follows: a) The desired gear is gear K; b) The shift fork containing gear K is not currently in gear K; c) The shift fork in gear K can move.

5. The method for calculating the shift fork gear position in a dual-clutch automatic transmission according to claim 1, characterized in that, The second gear calculation result is calculated in the following manner: ① Determine whether the current state of the dual-clutch automatic transmission satisfies the shift fork R return-to-neutral condition: If the condition for the shift fork to return to neutral is met, then the calculation result for the second gear is the shift fork to return to neutral. ② If the condition for the shift fork to return to neutral is not met, then continue to determine whether the current state of the dual-clutch automatic transmission meets the condition for engaging the pre-selected gear: If the conditions for engaging a pre-selected gear are not met, the result for the second gear will be "gear not requested". ③ If the conditions for engaging the pre-selected gear are met, then continue to determine whether the current state of the dual-clutch automatic transmission meets the conditions for engaging gear G: If the conditions for engaging gear G are met, then the calculated result for the second gear is gear G; If the conditions for engaging gear G are not met, the result of the second gear calculation will be "gear not requested".

6. The method for calculating the shift fork gear position in a dual-clutch automatic transmission according to claim 5, characterized in that, The return-to-neutral condition for the shift fork R is as follows: a) The desired gear position is not on the same axis as the gear position corresponding to shift fork R; b) The first gear calculation result is "gear not requested"; c) The shift fork R can move; d) The shift fork R is not in neutral; e) The current state of the pre-selected gear satisfies either of the following two conditions: e-1) The pre-selected gear is coaxial with the gear corresponding to shift fork R, and whether the shift fork corresponding to the pre-selected gear is not shift fork R; e-2) The pre-selected gear is neutral.

7. The method for calculating the shift fork gear position in a dual-clutch automatic transmission according to claim 5, characterized in that, The conditions for engaging the pre-selected gear are as follows: a) The selected gear is not neutral; b) The pre-selected gear and the desired gear are not on the same axis; c) The first gear calculation result is "gear not requested".

8. The method for calculating the shift fork gear position in a dual-clutch automatic transmission according to claim 5, characterized in that, The conditions for engaging gear G are as follows: a) The shift fork corresponding to gear G is not currently in gear G; b) The pre-selected gear is gear G; c) The shift fork corresponding to gear G can move.

9. The method for calculating the shift fork gear position in a dual-clutch automatic transmission according to claim 1, characterized in that, After setting a post-processing time threshold and several post-processing conditions, and obtaining the shift fork gear position calculation result in step 3), the shift fork gear position calculation result is delayed and corrected according to the post-processing conditions in the following manner: Determine if the current vehicle status meets the post-processing conditions. If not, the shift fork gear position calculation result does not require delay correction and is directly output without delay correction. If it meets the conditions: 4-1) The post-processing timer keeps running and continuously checks whether the current reading of the post-processing timer has reached the post-processing time threshold: 4-2) The current reading of the post-processing timer has not reached the post-processing time threshold, so the output "No gear requested" is displayed, and step 4-1 is repeated. 4-3) After continuously judging that the current reading of the post-processing timer has reached the post-processing time threshold, the shift fork gear position calculation result after delay correction is output.

10. The method for calculating the shift fork gear position in a dual-clutch automatic transmission according to claim 9, characterized in that, The post-processing conditions are determined based on the accelerator pedal opening, brake pedal status, brake pressure, shift fork status, desired gear, actual driving gear, and the shift fork gear engagement calculation results.

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