Shifting fork gear engaging gear calculation method for double-clutch automatic gearbox

Abstract

The invention relates to the field of automatic transmission vehicle control, in particular to a shifting fork gear engaging gear calculation method for a double-clutch automatic gearbox, which comprises the following steps of: according to various preset conditions with different priorities, calculating a shifting fork gear engaging gear position of a TCU (Transmission Control Unit) according to various parameters such as a driving state, a vehicle speed, an accelerator opening degree and an engine rotating speed of a current vehicle; according to the method, the expected gear and the pre-selected gear are obtained according to the factors such as the gear shifting condition, the road condition and the like, re-judgment and calculation are carried out to determine the final shifting fork action target gear most conforming to the current actual condition, and the shifting fork of the double-clutch automatic gearbox is controlled to engage the gear (including the neutral gear) according to the obtained shifting fork gear engaging gear calculation result. The dynamic property and the economical efficiency of the automatic transmission vehicle are guaranteed, the NVH performance of the vehicle is improved, and the comfort and the satisfaction degree of a driver and passengers are improved.

Description

Technical Field

[0001] The invention relates to the field of automatic transmission vehicle control, and in particular to a method for calculating a shift fork gear position for a dual-clutch automatic transmission. Background Art

[0002] Compared with manual transmission vehicles, automatic transmission vehicles greatly reduce the frequency of manual operation and gear shifting by the driver, greatly reduce the driver's workload, and have the characteristics of simple operation, convenience and speed. Therefore, automatic transmission vehicles have been more and more widely promoted and used. Since dual clutch transmission (DCT) has high transmission efficiency and shifting quality, dual clutch automatic transmission is usually used for power transmission in automatic transmission vehicles. Therefore, studying the shift fork shifting process in dual clutch automatic transmission plays a vital role in the driving of such automatic transmission vehicles.

[0003] During long-term use and research, it was found that this type of automatic transmission vehicle often has the following two problems in the automatic control of the shift fork due to the gear diversity of the dual-clutch automatic transmission (i.e., multiple forward gears): ① Problems with uncertain control objects and control actions: Which gear position of the dual-clutch automatic transmission should be controlled by the shift fork? Is this operation to shift gears or to return to neutral? ② Problems with uncertain control time: When should the operation be performed? Which operation should be performed first and which operation should be performed later? If the above problems are not handled accurately, the fork cannot be automatically controlled accurately, resulting in the following phenomena: For example, the shift fork gear that is currently in use is suddenly automatically returned to neutral, or the shift fork gear that is about to be used in a dual-clutch automatic transmission is suddenly returned to neutral, or a certain shift fork should have been used in A gear but it was instead in B gear, and the shift fork gear was not engaged when it should have been engaged in advance, etc.

[0004] These problems ultimately come down to the difficulty of calculating the gear position of the dual-clutch automatic transmission's shift fork. The current shift fork gear position calculation technology usually only uses the TCU to obtain the expected gear position and pre-selected gear position based on multiple parameters such as the current vehicle's driving state, vehicle speed, throttle opening, engine speed, and road conditions, without taking into account the actual situation of the shift fork inside the transmission. If the shift fork gear position calculation result calculated by the dual-clutch automatic transmission used in the automatic vehicle during driving does not meet the actual situation inside the transmission, it will not only violate the driver's expectations, but also affect the vehicle's power response or fuel economy, and even bring obstacles to the use of functions, leading to accidents and threatening the personal and property safety of passengers and drivers. Therefore, it is necessary to conduct in-depth and continuous research on the calculation of the shift fork gear position. Summary of the invention

[0005] The purpose of the present invention is to provide a method for calculating the gear position of a shift fork for a dual-clutch automatic transmission in response to the corresponding deficiencies in the prior art. The method re-judges and calculates the expected gear position and the pre-selected gear position obtained by the TCU based on various preset conditions with different priorities, determines the target gear position of the final shift fork action that best meets the current actual situation, and uses the final corrected shift fork gear position result to control the shift fork of the dual-clutch automatic transmission to engage gears (including neutral gear), thereby ensuring the power and economy of the automatic transmission vehicle, improving the vehicle's NVH performance, and the comfort and satisfaction of the driver and passengers.

[0006] The object of the present invention is to adopt the following scheme to achieve: a method for calculating the gear position of a shift fork engaged in a dual-clutch automatic transmission, comprising the following steps: 1) Preset the shift fork M return empty condition, the shift fork R return empty condition, the pre-selected gear condition, the gear K gear condition, and the gear G gear condition, and set two storage units for storing the first gear calculation result and the second gear calculation result; 2) According to the desired gear and pre-selected gear calculated by the dual-clutch automatic transmission TCU, as well as the preset shift fork M return condition, shift fork R return condition, pre-selected gear condition, gear K shift condition, gear G shift condition and the current state of the dual-clutch automatic transmission, the first gear calculation result and the second gear calculation result are calculated respectively; 3) According to the relationship between the calculation results of the first and second gears and the unrequested gear, the calculation result of the shift fork engaged gear is obtained in the following manner: 3-1) First determine the relationship between the first gear calculation result and the unrequested gear: If the first gear calculation result is not an unrequested gear, the first gear calculation result is used as the fork engaged gear calculation result; If the first gear calculation result is an unrequested gear, determine the relationship between the second gear calculation result and the unrequested gear: 3-2) If the second gear position calculation result is not equal to the unrequested gear position, the second gear position calculation result is used as the fork engaged gear position calculation result; 3-3) If the calculation result of the second gear is equal to the unrequested gear, the calculation result of the fork engaged gear is the unrequested gear.

[0007] Preferably, the first gear calculation result is calculated in the following manner: ① Determine whether the current state of the dual-clutch automatic transmission meets the shift fork M return condition: If the shift fork M return to empty condition is met, the calculation result of the first gear is shift fork M return to empty; ② If the shift fork M return condition is not met, continue to determine whether the current state of the dual-clutch automatic transmission meets the gear position K shift condition: If the gear engaging condition of gear position K is met, the calculation result of the first gear position is gear position K; If the gear engagement condition of gear K is not met, the first gear calculation result is an unrequested gear.

[0008] Preferably, the shift fork M return to empty condition is as follows: a) The gear position currently corresponding to the shift fork M is not neutral; b) The fork M can move; c) The PN gear allows the pre-gear calibration switch to be turned off, or the PN gear allows the pre-gear calibration switch to be turned on, but the pre-selected gear is not equal to the PN gear pre-gear corresponding to the shift fork M; d) The current state of the desired gear meets any one 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 the shift fork M, and the shift fork corresponding to the desired gear position is not the shift fork M.

[0009] Preferably, the gear engaging condition of gear position K is as follows: a) The desired gear is gear K; b) The current gear position of the shift fork where the gear position K is located is not the gear position K; c) The shift fork in gear position K can move.

[0010] Preferably, the second gear calculation result is calculated in the following manner: ① Determine whether the current state of the dual-clutch automatic transmission meets the conditions for the shift fork R to return to empty: If the shift fork R return to empty condition is met, the calculation result of the second gear is shift fork R return to empty; ② If the shift fork R return condition is not met, continue to determine whether the current state of the dual-clutch automatic transmission meets the pre-selected gear position condition: If the conditions for engaging the pre-selected gear are not met, the second gear calculation result is an unrequested gear; ③ If the pre-selected gear position conditions are met, continue to determine whether the current state of the dual-clutch automatic transmission meets the gear position G gear position conditions: If the gear position G gear engagement condition is met, the second gear position calculation result is gear position G; If the gear engagement condition for G is not met, the second gear calculation result is an unrequested gear.

[0011] Preferably, the shift fork R return to empty condition is as follows: a) The desired gear position is not coaxial with the gear position corresponding to the shift fork R; b) The first gear calculation result is an unrequested gear; c) The fork R can move; d) The shift fork R is not in neutral position; e) The current state of the pre-selected gear meets any one of the following two conditions: e-1) The pre-selected gear position is coaxial with the gear position corresponding to the shift fork R, and the shift fork corresponding to the pre-selected gear position is not the shift fork R.

[0012] e-2) The pre-selected gear is neutral.

[0013] Preferably, the conditions for engaging the pre-selected gear are as follows: a) The pre-selected gear is not neutral; b) The pre-selected gear is not coaxial with the desired gear; c) The first gear calculation result is an unrequested gear.

[0014] Preferably, the gear shifting condition of gear position G is as follows: a) The gear position of the shift fork corresponding to gear position G is not gear position G; b) The pre-selected gear is G; c) The shift fork corresponding to gear position G can move.

[0015] Preferably, a post-processing time threshold and several post-processing conditions are set. After the calculation result of the shift fork engaging gear position is obtained in step 3), a delay correction is performed on the calculation result of the shift fork engaging gear position according to the post-processing conditions in the following manner: Determine whether the current vehicle state meets the post-processing conditions. If not, the shift fork gear position calculation result does not need to be delayed corrected, and the shift fork gear position calculation result without delay correction is directly output; if it meets: 4-1) The post-processing timer starts counting and continuously determines whether the current reading of the post-processing timer reaches the post-processing time threshold: 4-2) If the current reading of the post-processing timer does not reach the post-processing time threshold, output that the gear is not requested and repeat step 4-1); 4-3) When the current reading of the post-processing timer is continuously determined to reach the post-processing time threshold, the shift fork gear position calculation result after delay correction processing is output.

[0016] Preferably, the post-processing condition is determined according to the accelerator pedal opening, brake pedal state, brake pressure, shift fork state, desired gear position, actual driving gear position, and shift fork engaged gear position calculation result.

[0017] The advantage of the present invention is that, by re-judging and calculating the expected gear and pre-selected gear obtained by the TCU according to various preset conditions with different priorities, the target gear of the final shift fork action that best meets the current actual situation is determined, and the final corrected shift fork shift position result is used to control the shift fork of the dual-clutch automatic transmission to shift gears (including neutral gear), thereby ensuring the power and economy of the automatic transmission vehicle, improving the vehicle's NVH performance, and the comfort and satisfaction of the driver and passengers. Glossary

[0018] Shift fork shifting: also called "shifting operation", means that 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 to make it engage or disengage with the corresponding gear shaft to achieve the switching of different gears, thereby transmitting power and driving the vehicle forward or backward. For example, when the shift fork is switched from the first gear to the second gear, the shift fork moves to separate the first gear gear that was originally engaged, and at the same time pushes the second gear gear to engage with the shaft to complete the gear change. It is worth noting that the "shift fork shifting" in the present invention refers to the "shifting operation" in a broad sense, that is, it is aimed at all gears of the gearbox, including neutral and reverse gear.

[0019] Return to neutral operation: When the shift fork switches from the current gear to the neutral gear, the power is cut off, causing the vehicle to slow down or stop.

[0020] Desired gear: In the present invention, it refers to the gear position that is expected to be responded to quickly, which is calculated by the shifting schedule module based on the driver's needs, road conditions, driving speed and other factors during the vehicle's driving process (non-stationary state). The TCU of the vehicle's transmission sends instructions to the execution component.

[0021] Pre-selected gear: In the present invention, it refers to a gear (a gear that may be switched and is predicted or prepared in advance) calculated by the gearbox shifting schedule module according to multiple parameters such as the current vehicle driving state, vehicle speed, throttle opening, engine speed, etc. during the vehicle driving process (non-stationary state). For example, when the vehicle accelerates, the gearbox may pre-select a higher gear, or when the vehicle decelerates, it may pre-select a lower gear, so that the gear shift can be completed quickly when the conditions are met.

[0022] Unrequested gear position: in the present invention, it means that the gearbox does not issue any instruction requesting a gear shift and does not perform any operation requesting a gear shift.

[0023] Target gear: is the gear calculation result in the present invention, that is, the target of the shift fork action, and the shift fork will eventually be engaged in this target gear.

[0024] PN gear pre-shifting: The purpose is the same as the pre-selected gear, which is to engage a certain fork gear in advance to save time. Both belong to pre-engaging a certain fork gear. The difference is that PN gear pre-shifting refers to the gear that the gearbox determines whether to pre-engage when the vehicle is stationary. For example, when the vehicle speed is zero and the shift handle is in P gear or N gear, the fork gear is pre-engaged. The pre-shifting corresponding to the PN gear is usually set when the gearbox leaves the factory, and it is fixed for the same gearbox. The desired gear and pre-selected gear are dynamically changeable during vehicle driving. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a flow chart of the present invention; Figure 2 is a flow chart of the post-processing process of the present invention; Figure 3 It is a schematic diagram of the overall process of an embodiment of the present invention; Figure 4 A schematic diagram of a flow chart for obtaining a calculation result of the first gear in an embodiment of the present invention; Figure 5 A schematic diagram of a flow chart for obtaining a calculation result of the second gear in an embodiment of the present invention; Figure 6 A schematic diagram of a flow chart for determining whether a DCT satisfies a shift fork M return-to-empty condition in an embodiment of the present invention; Figure 7 A schematic diagram of a flow chart for determining whether a DCT satisfies a gear shift condition of gear position K in an embodiment of the present invention; Figure 8 A schematic diagram of a flow chart for determining whether a DCT satisfies a shift fork R return-to-empty condition in an embodiment of the present invention; Fig. 9 A schematic diagram of a flow chart for determining whether a DCT satisfies a pre-selected gear position condition in an embodiment of the present invention; Fig.10 The figure is a flow chart of judging whether the DCT satisfies the gear shifting condition of the gear position G in the embodiment of the present invention. DETAILED DESCRIPTION

[0026] like Figure 1 As shown, a method for calculating the gear position of a shift fork engaged in a dual-clutch automatic transmission comprises the following steps: 1) Preset the shift fork M return empty condition, the shift fork R return empty condition, the pre-selected gear condition, the gear K gear condition, and the gear G gear condition, and set two storage units for storing the first gear calculation result and the second gear calculation result; 2) According to the expected gear and pre-selected gear calculated by the dual-clutch automatic transmission TCU, as well as the preset shift fork M return condition, shift fork R return condition, pre-selected gear condition, gear K shift condition, gear G shift condition and the current state of the dual-clutch automatic transmission, the first gear calculation result and the second gear calculation result are calculated respectively: 2-1) The first gear calculation result is calculated in the following way: ① Determine whether the current state of the DCT satisfies the shift fork M return to empty condition, the shift fork M return to empty condition is as follows: a) The gear position currently corresponding to the shift fork M is not neutral; b) The fork M can move; c) The PN gear allows the pre-gear calibration switch to be turned off, or the PN gear allows the pre-gear calibration switch to be turned on, but the pre-selected gear is not equal to the PN gear pre-gear corresponding to the shift fork M; d) The current state of the desired gear meets any one 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 the shift fork M, and the shift fork corresponding to the desired gear position is not the shift fork M.

[0027] If the current state of DCT meets the shift fork M return to empty condition, the calculation result of the first gear is shift fork M return to empty; ② If the current state of the DCT does not meet the shift fork M return to neutral condition, then continue to determine whether the current state of the dual-clutch automatic transmission meets the gear position K shifting condition, and the gear position K shifting condition is as follows: a) The desired gear is gear K; b) The current gear position of the shift fork where the gear position K is located is not the gear position K; c) The shift fork in gear position K can move.

[0028] If the current state of the DCT satisfies the gear K engagement condition, the first gear calculation result is gear K; If the current state of the DCT does not meet the gear engagement condition of gear K, the first gear calculation result is an unrequested gear.

[0029] 2-2) The second gear calculation result is calculated in the following way: ① Determine whether the current state of the DCT satisfies the shift fork R return to empty condition, the shift fork R return to empty condition is as follows: a) The desired gear position is not coaxial with the gear position corresponding to the shift fork R; b) The first gear calculation result is an unrequested gear; c) The fork R can move; d) The shift fork R is not in neutral position; e) The current state of the pre-selected gear meets any one of the following two conditions: e-1) The pre-selected gear position is coaxial with the gear position corresponding to the shift fork R, and the shift fork corresponding to the pre-selected gear position is not the shift fork R.

[0030] e-2) The pre-selected gear is neutral.

[0031] If the current state of DCT meets the shift fork R return to empty condition, the calculation result of the second gear is shift fork R return to empty; ② If the current state of the DCT does not meet the shift fork R return to neutral condition, then continue to determine whether the current state of the dual-clutch automatic transmission meets the pre-selected gear position condition. The pre-selected gear position condition is as follows: a) The pre-selected gear is not neutral; b) The pre-selected gear is not coaxial with the desired gear, that is, they are not gears on the same output shaft. For example, if the pre-selected gear is on an odd-numbered shaft, then the desired gear can only be on an even-numbered shaft to meet this condition; c) The first gear calculation result is an unrequested gear.

[0032] If the current state of the DCT does not meet the conditions for engaging the pre-selected gear, the second gear calculation result is an unrequested gear; ③ If the current state of the DCT satisfies the pre-selected gear condition, then continue to determine whether the current state of the dual-clutch automatic transmission satisfies the gear position G gear condition, and the gear position G gear condition is as follows: a) The gear position of the shift fork corresponding to gear position G is not gear position G; b) The pre-selected gear is G; c) The shift fork corresponding to gear position G can move.

[0033] If the current state of the DCT satisfies the gear engagement condition of gear G, the second gear calculation result is gear G; If the current state of the DCT does not meet the gear engagement condition of gear G, the second gear calculation result is an unrequested gear.

[0034] 3) According to the relationship between the calculation results of the first and second gears and the unrequested gear, the calculation result of the shift fork engaged gear is obtained in the following manner: 3-1) First determine the relationship between the first gear calculation result and the unrequested gear: If the first gear calculation result is not an unrequested gear, the first gear calculation result is used as the fork engaged gear calculation result; If the first gear calculation result is an unrequested gear, determine the relationship between the second gear calculation result and the unrequested gear: 3-2) If the second gear position calculation result is not equal to the unrequested gear position, the second gear position calculation result is used as the fork engaged gear position calculation result; 3-3) If the calculation result of the second gear is equal to the unrequested gear, the calculation result of the fork engaged gear is the unrequested gear.

[0035] In actual applications, the TCU of the dual-clutch automatic transmission will simultaneously judge the status of all shift forks and gears of the dual-clutch automatic transmission according to the above method, that is, the value ranges of the shift fork M and the shift fork R are all the shift forks of the dual-clutch automatic transmission, and the value ranges of the gear K and the gear G are all the gears of the dual-clutch automatic transmission.

[0036] It is worth noting that in order to make the DCT gear shifting timing more accurate, the following settings can also be made: ① The value of the post-processing time threshold T is obtained by looking up a two-dimensional table according to the real-time oil temperature of the DCT. The two-dimensional table is formed by obtaining a number of data according to the performance parameters and driving status of the whole vehicle through the whole vehicle calibration test, and is used to express 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 within what range, what is the most appropriate value of the post-processing time threshold T, which can meet the pre-designed standards (power, fuel economy, NVH performance and other indicators).

[0037] ② According to the accelerator pedal opening, brake pedal status, brake pressure, shift fork status, desired gear, actual driving gear, and the shift fork gear calculation result calculated in step 3), set several post-processing conditions (such as brake pressure threshold and other indicators). Similarly, these post-processing conditions are also determined through vehicle calibration tests, giving priority to indicators such as power and fuel economy, and then considering the impact on vehicle NVH performance. The post-processing conditions of this embodiment include: a) The brake pressure is greater than the preset brake pressure threshold; b) The desired gear is equal to the preset gear (e.g. 2nd gear); c) The state of another shift fork on the same axis is the specified state, that is, the shift fork corresponding to the shift fork gear position calculation result calculated in step 3), and the state of another shift fork on the same axis is the preset shift fork control state, which includes open-loop control state, closed-loop control state, etc., and is also determined through vehicle calibration experiments; d) The shift fork gear position calculation result is that the other shift fork on the same axis returns to empty, that is, the shift fork corresponding to the shift fork gear position calculation result calculated in step 3) returns to empty on the same axis.

[0038] In this way, after the calculation result of the shift fork gear position is obtained in step 3), the calculation result of the shift fork gear position can be delayed and corrected according to the preset post-processing conditions and the post-processing time threshold T in the following manner to obtain the calculation result of the shift fork gear position that best conforms to the actual situation, such as Figure 2 As shown: Determine whether the current vehicle status meets the post-processing conditions: If it is not satisfied, the shift fork gear position calculation result does not need delay correction, and the shift fork gear position calculation result without delay correction is directly output; If satisfied: 4-1) The post-processing timer starts counting and continuously determines whether the current reading of the post-processing timer reaches the post-processing time threshold T: 4-2) If the current reading of the post-processing timer does not reach the post-processing time threshold T, output that the gear is not requested and repeat step 4-1); 4-3) When the current reading of the post-processing timer reaches the post-processing time threshold T, the calculation result of the shift fork gear position after delay correction is output.

[0039] In fact, the shift fork gear position calculation result without delay correction processing is the same as the shift fork gear position calculation result after delay correction processing. It is just to make the DCT gear shifting timing more accurate. Therefore, it is necessary to confirm a series of processing conditions through vehicle calibration experiments, and delay the output of the shift fork gear position calculation result to make the timing of outputting the shift fork gear position calculation result more accurate, while ensuring the vehicle's dynamics, fuel economy and other indicators, while improving its NVH performance.

[0040] In practical applications, the post-processing timer can also be replaced by a post-processing counter, and the corresponding post-processing time threshold T must be replaced by a post-processing delay cycle number threshold, which is also determined based on the vehicle calibration experiment.

[0041] According to the above method, the shift fork M return to empty condition, the shift fork R return to empty condition, the pre-selected gear condition, the gear K gear condition, the gear G gear condition, and the value of the post-processing time threshold T and several post-processing conditions are set. Figures 3 to 10 The logical steps are coded and stored in the TCU of DCT (or other hardware and software units with computing functions of DCT): like Figure 3 As shown: S1, if the calculation result of the first gear is not equal to the unrequested gear, execute S2; otherwise, execute S3; S2, outputting the first gear position calculation result as the fork gear position calculation result, and then executing S7; S3, if the calculation result of the second gear is not equal to the unrequested gear, execute S4; otherwise, execute S5; S4, outputting the second gear position calculation result as the fork gear position calculation result, and then executing S7; S5, the calculation result of the shift fork gear position is that the gear position is not requested, and then S7 is executed; S6, storing the shift fork gear position calculation result without delay correction processing; S7, judging whether the calculation result of the shift fork gear position needs to be delayed and corrected (i.e., whether the post-processing condition is met) according to the calculation result of the shift fork gear position and the vehicle state, if the post-processing condition is met, executing S8; otherwise, executing S9; S8, post-process the timer reading + 10ms, then execute S10; S9, directly output the calculation result of the shift fork engaged gear position without delay correction processing, and then end.

[0042] S10, if the post-processing timer reading is equal to the post-processing time threshold T, execute S12; otherwise, execute S11; S11, outputting that the gear position is not requested, and then jumping to step S8 to continue execution; S12, outputting the fork engagement gear position calculation result after the delay correction processing as the gear position calculation result, and then ending.

[0043] The post-processing conditions of this embodiment are as follows: a) The brake pressure is greater than the brake pressure threshold; b) The desired gear is equal to 2nd gear; c) The state of another shift fork on the same axis is the specified state; d) The calculation result of the shift fork shifting gear position is that the other shift fork on the same axis returns to empty.

[0044] The calculation result of the first gear in this embodiment is obtained in the following manner: S100, if the current state of the DCT satisfies the shift fork M return to empty condition, then execute S101; otherwise, execute S102; S101, taking "shift fork M returns to neutral" as the calculation result of the first gear position, and then ending.

[0045] S102, if the current state of the DCT satisfies the gear K engagement condition, execute S103; otherwise, execute S104; S103, the calculation result of the first gear is gear K, and then, the process ends.

[0046] S104: The calculation result of the first gear is an unrequested gear, and then the process ends.

[0047] The value range of the shift fork M is all the shift forks of the dual-clutch automatic transmission, and the value range of the gear position K is all the gear positions of the dual-clutch automatic transmission.

[0048] The calculation result of the second gear in this embodiment is obtained in the following manner: S300, if the current state of the DCT satisfies the shift fork R return to empty condition, then execute S301; otherwise, execute S302; S301, taking "shift fork R returns to neutral" as the calculation result of the second gear, and then ending.

[0049] S302, if the current state of the DCT does not meet the pre-selected gear condition, execute S303; otherwise, execute S304; S303: The calculation result of the second gear is an unrequested gear, and then the process ends.

[0050] S304, if the current state of the DCT satisfies the gear engagement condition of the gear position G, then execute S305; otherwise, execute S306; S305, the calculation result of the second gear is gear G, and then, end.

[0051] S306: The calculation result of the second gear is an unrequested gear, and then the process ends.

[0052] The value range of the shift fork R is all the shift forks of the dual-clutch automatic transmission, and the value range of the gear position G is all the gear positions of the dual-clutch automatic transmission.

[0053] In this embodiment, the method for judging whether the current state of the DCT satisfies the shift fork M return to empty condition is as follows: S10000: If the shift fork M is not in neutral, execute S10001; otherwise, execute S10008; S10001, if the movement of the shift fork M is allowed, execute S10002; otherwise, execute S10008; S10002: If the PN gear pre-gear calibration switch is turned on, execute S10003; otherwise, execute S10004 or S10005; S10003, if the pre-selected gear is not equal to the PN gear pre-engaged gear on the shift fork M, execute S10004 or S10005; otherwise, execute S10008; S10004, if the desired gear is neutral, execute S10007; otherwise, execute S10008; S10005, if the desired gear position is coaxial with the gear position on the shift fork M, execute S10006; otherwise, execute S10008; S10006, if the shift fork corresponding to the desired gear position is not the shift fork M, execute S10007; otherwise, execute S10008; S10007, the judgment result of the shift fork M return to empty condition is "the shift fork M return to empty condition is met", and then end.

[0054] S10008, the judgment result of the shift fork M return to empty condition is "the shift fork M return to empty condition is not satisfied", and then, end.

[0055] Among them, the PN gear pre-gear on the shift fork M is generally 1st gear, 2nd gear, or reverse gear.

[0056] In this embodiment, the method for judging whether the current state of the DCT satisfies the gear engaging condition of the gear position K is as follows: S10200, if the desired gear position is gear position K, execute S10201; otherwise, execute S10204; S10201, if the gear position on the shift fork where the gear position K is located is not the gear position K, execute S10202; otherwise, execute S10204; S10202, if the shift fork where the gear position K is located is allowed to move, execute S10203; otherwise, execute S10204; S10203, the judgment result of the gear shifting condition of gear position K is "the gear shifting condition of gear position K is met", and then, the process ends.

[0057] S10204, the result of judging the gear shifting condition of gear position K is "the gear shifting condition of gear position K is not satisfied", and then, the process ends.

[0058] In this embodiment, the method for judging whether the current state satisfies the shift fork R return to empty condition is as follows: S30000: If the desired gear position is not coaxial with the gear position corresponding to the shift fork R, execute S30001; otherwise, execute S30008; S30001, if the calculation result of the first gear is that the gear is not requested, execute S30002; otherwise, execute S30008; S30002: If the movement of the shift fork R is allowed, execute S30003; otherwise, execute S30008; S30003, if the gear position corresponding to the shift fork R is not neutral, execute S30004 or S30006; otherwise, execute S30008; S30004: If the pre-selected gear is coaxial with the gear corresponding to the shift fork R, execute S30005; otherwise, execute S30008; S30005: If the shift fork corresponding to the pre-selected gear is not shift fork R, execute S30007; otherwise, execute S30008; S30006, if the pre-selected gear is neutral, execute S30007; otherwise, execute S30008; S30007, the judgment result of the shift fork R returning to empty condition is "the condition for the shift fork R returning to empty is met", and then the process ends.

[0059] S30008, the judgment result of the condition of the shift fork R returning to empty is "the shift fork R returning to empty condition is not satisfied", and then, the process ends.

[0060] In this embodiment, the method for determining whether the current state meets the condition for engaging the pre-selected gear is as follows: S30200, if the pre-selected gear is not neutral, execute S30201; otherwise, execute S30204; S30201, if the pre-selected gear position is not coaxial with the desired gear position, execute S30202; otherwise, execute S30204; S30202, if the calculation result of the first gear is that the gear is not requested, execute S30203; otherwise, execute S30204; S30203, the judgment result of the condition for engaging the pre-selected gear is "the condition for engaging the pre-selected gear is met", and then the process ends.

[0061] S30204, the judgment result of the condition for engaging the pre-selected gear is "the condition for engaging the pre-selected gear is not met", and then end.

[0062] In this embodiment, the method for judging whether the current state satisfies the gear shifting condition of gear position G is as follows: S30400, if the gear position currently corresponding to the shift fork where the gear position G is located is not the gear position G, execute S30401; otherwise, execute S30404; S30401, if the pre-selected gear is gear G, execute S30402; otherwise, execute S30404; S30402, if the shift fork where the gear position G is located is allowed to move, execute S30403; otherwise, execute S30404; S30403, the result of judging the gear shifting condition of gear position G is "the gear shifting condition of gear position G is met", and then, the process ends.

[0063] S30404, the result of judging the gear shifting condition of gear position G is "the gear shifting condition of gear position G is not satisfied", and then, the process ends.

[0064] Experiments have proved that controlling the shift fork of a dual-clutch automatic transmission to shift gears according to the shift fork shift position calculation result obtained in the present invention can determine the target gear position that best suits the actual situation, laying a solid foundation for subsequent shift fork shifting (including return operation), ensuring the power and economy of the automatic transmission vehicle, and improving the comfort and satisfaction of the driver and passengers.

[0065] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification made to the present invention by those skilled in the art without departing from the spirit of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for calculating the gear position of a shift fork for a dual-clutch automatic transmission, characterized in that: The following steps are involved: 1) Preset the shift fork M return empty condition, the shift fork R return empty condition, the pre-selected gear condition, the gear K gear condition, and the gear G gear condition, and set two storage units for storing the first gear calculation result and the second gear calculation result; 2) According to the desired gear and pre-selected gear calculated by the dual-clutch automatic transmission TCU, as well as the preset shift fork M return condition, shift fork R return condition, pre-selected gear condition, gear K shift condition, gear G shift condition and the current state of the dual-clutch automatic transmission, the first gear calculation result and the second gear calculation result are calculated respectively; 3) According to the relationship between the calculation results of the first and second gears and the unrequested gear, the calculation result of the shift fork engaged gear is obtained in the following manner: 3-1) First determine the relationship between the first gear calculation result and the unrequested gear: If the first gear calculation result is not an unrequested gear, the first gear calculation result is used as the fork engaged gear calculation result; If the first gear calculation result is an unrequested gear, determine the relationship between the second gear calculation result and the unrequested gear: 3-2) If the second gear position calculation result is not equal to the unrequested gear position, the second gear position calculation result is used as the fork engaged gear position calculation result; 3-3) If the calculation result of the second gear is equal to the unrequested gear, the calculation result of the fork engaged gear is the unrequested gear.

2. The method for calculating the gear position of a shift fork for 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 meets the shift fork M return condition: If the shift fork M return to empty condition is met, the calculation result of the first gear is shift fork M return to empty; ② If the shift fork M return condition is not met, continue to determine whether the current state of the dual-clutch automatic transmission meets the gear position K shift condition: If the gear engaging condition of gear position K is met, the calculation result of the first gear position is gear position K; If the gear engagement condition of gear K is not met, the first gear calculation result is an unrequested gear.

3. The method for calculating the shift fork gear position of a dual-clutch automatic transmission according to claim 2, characterized in that: The return condition of the shift fork M is as follows: a) The gear position currently corresponding to the shift fork M is not neutral; b) The fork M can move; c) The PN gear allows the pre-gear calibration switch to be turned off, or the PN gear allows the pre-gear calibration switch to be turned on, but the pre-selected gear is not equal to the PN gear pre-gear corresponding to the shift fork M; d) The current state of the desired gear meets any one 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 the shift fork M, and the shift fork corresponding to the desired gear position is not the shift fork M.

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

5. The method for calculating the shift fork gear position of 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 meets the conditions for the shift fork R to return to empty: If the shift fork R return to empty condition is met, the calculation result of the second gear is shift fork R return to empty; ② If the shift fork R return condition is not met, continue to determine whether the current state of the dual-clutch automatic transmission meets the pre-selected gear position condition: If the conditions for engaging the pre-selected gear are not met, the second gear calculation result is an unrequested gear; ③ If the pre-selected gear position conditions are met, continue to determine whether the current state of the dual-clutch automatic transmission meets the gear position G gear position conditions: If the gear position G gear engagement condition is met, the second gear position calculation result is gear position G; If the gear engagement condition for G is not met, the second gear calculation result is an unrequested gear.

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

7. The method for calculating the gear position of a shift fork for 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 pre-selected gear is not neutral; b) The pre-selected gear is not coaxial with the desired gear; c) The first gear calculation result is an unrequested gear.

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

9. The method for calculating the gear position of a shift fork for a dual-clutch automatic transmission according to claim 1, characterized in that: The post-processing time threshold and several post-processing conditions are set. After the calculation result of the shift fork gear position is obtained in step 3), the delay correction of the calculation result of the shift fork gear position is performed according to the post-processing conditions in the following manner: Determine whether the current vehicle state meets the post-processing conditions. If not, the shift fork gear position calculation result does not need to be delayed corrected, and the shift fork gear position calculation result without delay correction is directly output; if it meets: 4-1) The post-processing timer starts counting and continuously determines whether the current reading of the post-processing timer reaches the post-processing time threshold: 4-2) The current reading of the post-processing timer does not reach the post-processing time threshold, outputs "not requested gear", and repeats step 4-1); 4-3) When the current reading of the post-processing timer is continuously determined to reach the post-processing time threshold, the shift fork gear position calculation result after delay correction processing is output.

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

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