Gear shifting control method based on dog clutch and related device

Abstract

The invention discloses a forward gear control method based on a dog clutch and a related device, and the method comprises the steps: determining a first speed difference threshold value according to an obtained optimal combination speed difference, a first actual speed difference change rate and first hydraulic response time; a first current actual speed difference is obtained, the change rate of the first current actual speed difference is the same as the change rate of the first actual speed difference, and if the first current actual speed difference is reduced to the first speed difference threshold value, it is indicated that on the premise that the change rate of the first actual speed difference is not changed, after the first hydraulic response time, the first hydraulic response speed is reduced; when the actual speed difference of the dog clutch is predicted to reach the optimal combination speed difference, the control state of the dog clutch is controlled to be changed from the separation state to the gear advancing state at the moment, namely gear advancing operation is executed, and therefore the actual speed difference of the dog clutch is the optimal combination speed difference when combination of the dog clutch is completed; the situation that the actual speed difference of the dog clutch exceeds the hardware allowable limit of the dog clutch due to impact brought by the dog clutch at the moment of combination is avoided.

Description

Technical Field

[0001] The present invention relates to the field of vehicle control technology, and in particular to a gear shift control method based on a dog clutch and a related device. Background Art

[0002] Compared with other types of transmissions, automatic transmissions with dog clutches have a wider gear ratio range and have the advantages of comfortable driving, low emissions, and good fuel economy. In addition, compared with traditional wet clutches, the design of the dog clutch is smaller in size, simpler in mechanical structure, and has a shorter gear shift response time.

[0003] In the related art, the optimal engagement speed difference of the dog clutch is generally judged and calculated based on the gear position. When the actual speed difference of the dog clutch is lower than the optimal engagement speed difference, a shift operation is performed based on the dog clutch to control the control state of the dog clutch from a disengaged state to an engaged state, thereby realizing a shift control based on the dog clutch.

[0004] However, since there is a certain delay time in the movement of the dog tooth piston and the switching of the oil circuit, after the actual gear shifting operation, when the control state of the dog tooth clutch changes to the engaged state, the actual speed difference of the dog tooth clutch is not only lower than the optimal engagement speed difference, but may also exceed the hardware allowable limit of the dog tooth clutch. As a result, there is not only a risk of damage to the dog tooth clutch, but also noise will occur during the engagement process of the dog tooth piston, resulting in a poor user experience. Summary of the invention

[0005] In response to the above problems, the present application provides a gear shift control method and related devices based on a dog clutch, which are used to reduce the risk of damage to the dog clutch and the probability of noise, and improve the user experience.

[0006] Based on this, the embodiments of the present application disclose the following technical solutions:

[0007] On the one hand, an embodiment of the present application provides a gear shift control method based on a dog clutch, the method comprising:

[0008] Obtaining an optimal engagement speed difference, a first actual speed difference change rate, and a first hydraulic response time of the dog clutch;

[0009] determining a first speed difference threshold value according to the optimal combined speed difference, the first actual speed difference change rate, and the first hydraulic response time;

[0010] Acquire a first current actual speed difference, wherein a change rate of the first current actual speed difference is the same as a change rate of the first actual speed difference;

[0011] If the first current actual speed difference drops to the first speed difference threshold, the control state of the dog clutch is changed from a disengaged state to a shift-in state.

[0012] Optionally, determining a first speed difference threshold according to the optimal combined speed difference, the first actual speed difference change rate and the first hydraulic response time includes:

[0013] The first speed difference threshold is calculated according to the optimal combined speed difference, the first actual speed difference change rate and the first hydraulic response time, and the calculation formula is as follows:

[0014] Δω1≤Δω opt +α1×ΔT1;

[0015] Wherein, Δω1 represents the first speed difference threshold, Δω opt represents the optimal combined speed difference, α1 represents the first actual speed difference change rate, and ΔT1 represents the first hydraulic pressure response time.

[0016] Optionally, during the process in which the control state of the dog clutch is the shift-in state, the method further includes:

[0017] Obtaining a speed difference upper limit, a second actual speed difference change rate, and a second hydraulic response time of the dog clutch, wherein a change trend corresponding to the second actual speed difference change rate is opposite to a change trend corresponding to the first actual speed difference change rate;

[0018] determining a second speed difference threshold value according to the speed difference upper limit, the second actual speed difference change rate, and the second hydraulic pressure response time;

[0019] Get the second current actual speed difference;

[0020] If the second current actual speed difference exceeds the second speed difference threshold, the oil circuit of the dog clutch is closed.

[0021] Optionally, determining the second speed difference threshold according to the speed difference upper limit, the second actual speed difference change rate and the second hydraulic response time includes:

[0022] The second speed difference threshold is calculated according to the speed difference upper limit, the second actual speed difference change rate and the second hydraulic response time, and the calculation formula is as follows:

[0023] |Δω2+α2×ΔT2|≥Δω max ;

[0024] Wherein, Δω2 represents the second speed difference threshold, Δω max represents the speed difference upper limit, α2 represents the second actual speed difference change rate, and ΔT2 represents the second hydraulic pressure response time.

[0025] Optionally, the method further includes:

[0026] Controlling the actual speed difference of the dog clutch to decrease according to a third actual speed difference change rate, so that after the actual speed difference of the dog clutch decreases according to the third actual speed difference change rate for a first period of time, the actual speed difference of the dog clutch reaches a third speed difference threshold, the third speed difference threshold being determined based on an upper speed difference limit of the dog clutch, and the third actual speed difference change rate being greater than the first actual speed difference change rate;

[0027] The actual speed difference of the dog clutch is controlled to decrease according to the first actual speed difference change rate, so that after the actual speed difference of the dog clutch decreases according to the first actual speed difference change rate for a second time period, the actual speed difference of the dog clutch reaches the optimal engagement speed difference.

[0028] Optionally, the method further includes:

[0029] The actual speed difference of the dog clutch is controlled to decrease according to a plurality of actual speed difference change rates, the plurality of actual speed difference change rates change from large to small, and the plurality of actual speed difference change rates include the first actual speed difference change rate.

[0030] Optionally, the method further includes:

[0031] The actual speed difference of the dog clutch is controlled to decrease according to the first actual speed difference change rate, and the first actual speed difference change rate is less than or equal to the speed difference change rate threshold.

[0032] On the other hand, the present application provides a gear-in control device based on a dog clutch, the device comprising: a first acquisition unit, a determination unit, a second acquisition unit and a control unit;

[0033] The first acquisition unit is used to acquire the optimal engagement speed difference, the first actual speed difference change rate and the first hydraulic response time of the dog clutch;

[0034] The determining unit is configured to determine a first speed difference threshold value according to the optimal combined speed difference, the first actual speed difference change rate, and the first hydraulic pressure response time;

[0035] The second acquisition unit is used to acquire a first current actual speed difference, wherein a change rate of the first current actual speed difference is the same as a change rate of the first actual speed difference;

[0036] The control unit is used to control the control state of the dog clutch to change from a disengaged state to a gear-in state if the first current actual speed difference drops to the first speed difference threshold.

[0037] Optionally, the determining unit is specifically configured to:

[0038] The first speed difference threshold is calculated according to the optimal combined speed difference, the first actual speed difference change rate and the first hydraulic response time, and the calculation formula is as follows:

[0039] Δω1≤Δω opt +α1×ΔT1;

[0040] Wherein, Δω1 represents the first speed difference threshold, Δω opt represents the optimal combined speed difference, α1 represents the first actual speed difference change rate, and ΔT1 represents the first hydraulic pressure response time.

[0041] Optionally, during the process in which the control state of the dog clutch is the shifting state, the first acquisition unit is used to acquire the speed difference upper limit, the second actual speed difference change rate, and the second hydraulic response time of the dog clutch, and the change trend corresponding to the second actual speed difference change rate is opposite to the change trend corresponding to the first speed difference actual change rate;

[0042] The determining unit is configured to determine a second speed difference threshold value according to the speed difference upper limit, the second actual speed difference change rate, and the second hydraulic pressure response time;

[0043] The second acquisition unit is used to acquire a second current actual speed difference;

[0044] The control unit is used to close the oil circuit of the dog clutch if the second current actual speed difference exceeds the second speed difference threshold.

[0045] Optionally, as a possible implementation manner, the determining unit 702 is specifically configured to:

[0046] The second speed difference threshold is calculated according to the speed difference upper limit, the second actual speed difference change rate and the second hydraulic response time, and the calculation formula is as follows:

[0047] |Δω2+α2×ΔT2|≥Δω max ;

[0048] Wherein, Δω2 represents the second speed difference threshold, Δω max represents the speed difference upper limit, α2 represents the second actual speed difference change rate, and ΔT2 represents the second hydraulic pressure response time.

[0049] Optionally, the control unit is specifically used to:

[0050] Controlling the actual speed difference of the dog clutch to decrease according to a third actual speed difference change rate, so that after the actual speed difference of the dog clutch decreases according to the third actual speed difference change rate for a first period of time, the actual speed difference of the dog clutch reaches a third speed difference threshold, the third speed difference threshold being determined based on an upper speed difference limit of the dog clutch, and the third actual speed difference change rate being greater than the first actual speed difference change rate;

[0051] The actual speed difference of the dog clutch is controlled to decrease according to the first actual speed difference change rate, so that after the actual speed difference of the dog clutch decreases according to the first actual speed difference change rate for a second time period, the actual speed difference of the dog clutch reaches the optimal engagement speed difference.

[0052] Optionally, the control unit is specifically used to:

[0053] The actual speed difference of the dog clutch is controlled to decrease according to a plurality of actual speed difference change rates, the plurality of actual speed difference change rates change from large to small, and the plurality of actual speed difference change rates include the first actual speed difference change rate.

[0054] Optionally, the control unit is specifically used to:

[0055] The actual speed difference of the dog clutch is controlled to decrease according to the first actual speed difference change rate, and the first actual speed difference change rate is less than or equal to the speed difference change rate threshold.

[0056] In another aspect, the present application provides a computer device, the device comprising a processor and a memory:

[0057] The memory is used to store program code and transmit the program code to the processor;

[0058] The processor is used to execute the method described in the above aspects according to the instructions in the program code.

[0059] On the other hand, the present application provides a computer-readable storage medium, wherein the computer-readable storage medium is used to store a computer program, and the computer program is used to execute the method described in the above aspects.

[0060] On the other hand, an embodiment of the present application provides a computer program product or a computer program, which includes computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the computer device executes the method described in the above aspects.

[0061] The advantages of the above technical solution of this application are:

[0062] The optimal engagement speed difference, the first actual speed difference change rate and the first hydraulic response time of the dog clutch are obtained, and the first speed difference threshold is determined according to the optimal engagement speed difference, the first actual speed difference change rate and the first hydraulic response time, that is, on the basis of the optimal engagement speed difference, a delay time applicable to the first actual speed difference change rate is added, or in other words, the first speed difference threshold is the speed difference corresponding to a period of time before the optimal engagement speed difference is reached under the premise that the first actual speed difference change rate remains unchanged. The first current actual speed difference is obtained, and the change rate of the first current actual speed difference is the same as the change rate of the first actual speed difference. If the first current actual speed difference drops to the first speed difference threshold, it means that under the premise that the first actual speed difference change rate remains unchanged, after the first hydraulic response time, it is predicted that the actual speed difference of the dog clutch will reach the optimal engagement speed difference. At this time, the control state of the dog clutch is controlled to change from the separation state to the shifting state, that is, the shifting operation is performed, so that the actual speed difference of the dog clutch is the optimal engagement speed difference when the dog clutch is completed, and the impact caused by the dog clutch at the moment of engagement is avoided so that the actual speed difference of the dog clutch exceeds the hardware allowable limit of the dog clutch.

[0063] Therefore, the shift operation is no longer performed when the first current actual speed difference reaches the optimal engagement speed difference, but when the first current actual speed difference drops to the first speed difference threshold, that is, when the first hydraulic response time before the optimal engagement speed difference is reached. Even if there is a delay in the movement of the dog tooth piston and the oil circuit switching, by performing the shift operation in advance, it is expected that when the dog tooth clutch is fully engaged, the actual speed difference of the dog tooth clutch can reach the optimal engagement speed difference, thereby avoiding the problem of the actual speed difference of the dog tooth clutch suddenly changing at the moment of engagement of the dog tooth clutch, and exceeding the hardware allowable limit of the dog tooth clutch, thereby reducing the risk of damage to the dog tooth clutch and the probability of noise, and improving the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0065] Figure 1 is a schematic diagram of a transmission chain of an automatic transmission;

[0066] Figure 2 A schematic diagram of the actual speed difference change of a dog clutch;

[0067] Figure 3A flowchart of a gear shift control method based on a dog clutch provided in an embodiment of the present application;

[0068] Figure 4 A schematic diagram of the actual speed difference change of a dog clutch provided in an embodiment of the present application;

[0069] Figure 5 A schematic diagram of a speed difference of a dog clutch provided in an embodiment of the present application;

[0070] Figure 6 A schematic diagram of actual speed difference change of a dog clutch provided in an embodiment of the present application;

[0071] Figure 7 A schematic diagram of a gear-entry control device based on a dog clutch provided in an embodiment of the present application;

[0072] Figure 8 A structural diagram of a computer device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0073] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0074] See also Figure 1 , this figure is a schematic diagram of the transmission chain of an automatic transmission. Both sides of the dog gear piston are filled with oil. When the dog gear clutch is ready to engage, the pressure value of the oil cylinder pressure on the engagement side increases, and the pressure value of the oil cylinder pressure on the separation side is zero, and the dog gear clutch begins to engage under the action of the combined force; conversely, when the dog gear clutch is ready to disengage, the pressure value of the oil cylinder pressure on the engagement side is zero, and the pressure value of the oil cylinder pressure on the separation side increases, and the dog gear clutch begins to disengage under the action of the combined force. Figure 1 In the embodiment, the two sides of the dog tooth piston of the dog tooth clutch are in a separated state. When the dog tooth clutch is involved in the shifting process, the locking clutch is engaged, and the auxiliary clutch 3 controls the speed difference at both ends of the dog tooth clutch. The speed at both ends of the dog tooth clutch can be obtained through the input shaft speed and the output shaft speed, and then the actual speed difference of the dog tooth clutch can be obtained.

[0075] In the related art, the optimal engagement speed difference of the dog clutch is generally judged and calculated based on the gear position. When the actual speed difference of the dog clutch is lower than the optimal engagement speed difference, a shift operation is performed based on the dog clutch to control the control state of the dog clutch from a disengaged state to an engaged state.

[0076] However, due to the delay in the movement of the dog gear piston and the oil circuit switching, after the actual shift operation, when the control state of the dog gear clutch changes to the engaged state, the actual speed difference of the dog gear clutch is not only lower than the optimal engagement speed difference, but may also exceed the hardware allowable limit of the dog gear clutch. Figure 2 Provide explanation.

[0077] See also Figure 2 , which is a schematic diagram of the actual speed difference change of a dog clutch. Figure 2 In the process, when the actual speed difference of the dog clutch drops to the optimal engagement speed difference, the control state of the dog clutch changes from a completely disengaged state to a gear-in state. Since there is a certain delay time in the movement of the dog piston and the oil circuit switching, the pressure value of the engagement side oil cylinder pressure starts to increase from 0 after a period of time after the control state of the dog clutch changes to the gear-in state, and the position of the dog piston included in the dog clutch changes from disengaged to engaged. At the moment of engagement of the dog clutch, the actual speed difference of the dog clutch changes suddenly, which will bring a certain impact to the dog clutch. Figure 2 In the process, due to the existing delay, the dog clutch starts to engage only after the actual speed difference of the dog clutch exceeds the hardware limit of the dog clutch. The actual speed difference of the dog clutch exceeds the hardware limit of the dog clutch before the mutation, which not only poses a risk of damage to the dog clutch, but also generates noise during the engagement of the dog piston, resulting in a poor user experience.

[0078] Based on this, the embodiment of the present application provides a gear-up control method and related device based on a dog-tooth clutch, which no longer performs the gear-up operation when the first current actual speed difference reaches the optimal engagement speed difference, but performs the gear-up operation when the first current actual speed difference drops to the first speed difference threshold, that is, when the first hydraulic response time before the optimal engagement speed difference is reached. Even if there is a delay in the movement of the dog-tooth piston and the oil circuit switching, by performing the gear-up operation in advance, it is expected that when the dog-tooth clutch is completed, the actual speed difference of the dog-tooth clutch can reach the optimal engagement speed difference, thereby avoiding the problem that the actual speed difference of the dog-tooth clutch suddenly changes at the moment of engagement of the dog-tooth clutch, and the problem that the hardware allowable limit of the dog-tooth clutch is exceeded, thereby reducing the risk of damage to the dog-tooth clutch and the probability of noise, and improving the user experience.

[0079] Combine the following Figure 3 , a gear shift control method based on a dog clutch provided in an embodiment of the present application is introduced. Figure 3 The method shown in the embodiment may be executed by an electronic control unit (ECU) included in a vehicle, for example. Figure 3, this figure is a flow chart of a gear shift control method based on a dog clutch provided in an embodiment of the present application, and the method may include S301-S304.

[0080] S301: Obtaining the optimal engagement speed difference, the first actual speed difference change rate and the first hydraulic response time of the dog clutch.

[0081] Among them, the optimal engagement speed difference of the dog clutch can be judged and calculated based on the gear position. The first actual speed difference change rate of the dog clutch can be calculated based on the actual speed difference of the dog clutch and the piston movement time. The first hydraulic response time refers to the hydraulic response time of the dog piston moving to the engagement side, which is affected by the cylinder parameters and the direction of piston movement. From the foregoing, it can be seen that there is a certain delay time in the movement of the dog piston and the oil circuit switching. The delay time can be the first hydraulic response time (there may be deviations, but the deviations are not large), which can be obtained based on bench testing. For example, a bench test is performed on the transmission, that is, a coupling side oil pressure command is given, and the time from the issuance of the command to the start of the piston movement is taken as the first hydraulic response time.

[0082] It can be understood that the first actual speed difference change rate refers to how fast the actual speed difference value changes within a period of time. It has no positive or negative concept and is the absolute value of the slope of the actual speed difference change curve.

[0083] S302: Determine a first speed difference threshold value according to the best combined speed difference, the first actual speed difference change rate and the first hydraulic response time.

[0084] As a possible implementation manner, the first speed difference threshold value can be determined according to the optimal combined speed difference, the first actual speed difference change rate and the first hydraulic response time, which can be expressed as formula (1).

[0085] Δω1≤Δω opt +α1×ΔT1 (1)

[0086] Among them, Δω1 represents the first speed difference threshold, Δω opt represents the optimal combined speed difference, α1 represents the first actual speed difference change rate, and ΔT1 represents the first hydraulic response time.

[0087] Therefore, the first speed difference threshold is determined according to the optimal engagement speed difference, the first actual speed difference change rate and the first hydraulic response time. The first speed difference threshold is the speed difference corresponding to a period of time before the optimal engagement speed difference is reached, under the premise that the first actual speed difference change rate remains unchanged. In other words, on the basis of the optimal engagement speed difference, a delay time applicable to the first actual speed difference change rate is added. The actual speed difference of the dog clutch is based on the process of reducing the first actual speed difference change rate. It is estimated that after the first hydraulic response time, the estimated actual speed difference of the dog clutch will reach the optimal engagement speed difference. Figure 4Provide explanation.

[0088] See also Figure 4 , which is a schematic diagram of the actual speed difference change of a dog clutch provided in an embodiment of the present application. Figure 4 In the embodiment, after the actual speed difference of the dog clutch decreases based on the first actual speed difference change rate, when the actual speed difference decreases to point A, it is estimated that after the first hydraulic response time, the actual speed difference estimated by the dog clutch will reach the optimal engagement speed difference.

[0089] S303: Obtain a first current actual speed difference.

[0090] Among them, the first current actual speed difference is the actual speed difference obtained after the actual speed difference of the dog clutch changes based on the first actual speed difference. Therefore, by obtaining the first current actual speed difference in real time, it is possible to monitor when the first current actual speed difference drops to the optimal engagement speed difference.

[0091] In addition, the change rate of the first current actual speed difference is the same as the first actual speed difference change rate, and it can be estimated how long it will take for the dog clutch to reach the optimal engagement speed difference based on the first actual speed difference change rate and the first current actual speed difference.

[0092] S304: If the first current actual speed difference drops to the first speed difference threshold, the control state of the dog clutch is changed from the disengaged state to the shifting state.

[0093] If the first current actual speed difference drops to the first speed difference threshold, it means that under the premise that the first actual speed difference change rate remains unchanged, after the first hydraulic response time, it is predicted that the actual speed difference of the dog clutch will reach the optimal engagement speed difference. At this time, the control state of the dog clutch is changed from the disengagement state to the gear shifting state, that is, the gear shifting operation is executed.

[0094] Continue to see Figure 4 , as the actual speed difference of the dog clutch continues to decrease, when the first current actual speed difference drops to the first speed difference threshold, that is, Figure 4 At the midpoint A, the dog clutch continues to decrease based on the first actual speed difference change rate. After the first hydraulic response time, it is expected that the actual speed difference of the dog clutch will be equal to the optimal engagement speed difference. At the optimal engagement speed difference, even if a sudden change occurs, the actual speed difference of the dog clutch will not exceed its hardware limit, such as Figure 4 As shown, after the mutation occurs, the actual speed difference of the dog clutch is still near the optimal engagement speed difference and does not exceed the optimal engagement speed difference.

[0095] Continue to see Figure 4As the actual speed difference of the dog clutch continues to decrease, when the first current actual speed difference drops to the first speed difference threshold, that is, the actual speed difference is at point A, the control state of the dog clutch is changed from the separation state (complete separation) to the shifting state, that is, the shifting operation is performed. After the shifting operation is performed, since there is a certain delay time in the movement of the dog piston and the oil circuit switching, the pressure value of the oil cylinder pressure on the engagement side of the dog clutch will not increase from 0, but after a period of time of performing the shifting operation, the pressure value of the oil cylinder pressure on the engagement side of the dog clutch will increase from 0. At the same time, after executing the shifting operation for a period of time, the actual speed difference of the dog clutch reaches the optimal engagement speed difference. At this time, the control state of the dog clutch changes from the shifting state to the engagement state, that is, the position of the dog piston changes from separation to engagement. Even if the engagement moment of the dog clutch causes a sudden change in the actual speed difference of the dog clutch, which will bring a certain impact to the dog clutch, at the moment of the dog clutch engagement, the actual speed difference of the dog clutch is the optimal engagement speed difference, and is still far from the upper or lower limit of the speed difference, that is, the problem of exceeding the hardware allowable limit of the dog clutch at the moment of the dog clutch engagement is avoided, thereby reducing the risk of damage to the dog clutch and the probability of noise, and improving the user experience.

[0096] It can be seen from the above technical solution that the best engagement speed difference, the first actual speed difference change rate and the first hydraulic response time of the dog clutch are obtained, and the first speed difference threshold is determined according to the best engagement speed difference, the first actual speed difference change rate and the first hydraulic response time, that is, on the basis of the best engagement speed difference, a delay time applicable to the first actual speed difference change rate is added, or in other words, the first speed difference threshold is the speed difference corresponding to a period of time before the best engagement speed difference is reached under the premise that the first actual speed difference change rate remains unchanged. The first current actual speed difference is obtained, and the change rate of the first current actual speed difference is the same as the change rate of the first actual speed difference. If the first current actual speed difference drops to the first speed difference threshold, it means that under the premise that the first actual speed difference change rate remains unchanged, after the first hydraulic response time, it is predicted that the actual speed difference of the dog clutch will reach the best engagement speed difference. At this time, the control state of the dog clutch is controlled to change from the separation state to the shifting state, that is, the shifting operation is performed, so that the actual speed difference of the dog clutch is the best engagement speed difference when the dog clutch is completed, and the impact caused by the dog clutch at the moment of engagement is avoided so that the actual speed difference of the dog clutch exceeds the hardware allowable limit of the dog clutch.

[0097] Therefore, the shift operation is no longer performed when the first current actual speed difference reaches the optimal engagement speed difference, but when the first current actual speed difference drops to the first speed difference threshold, that is, when the first hydraulic response time before the optimal engagement speed difference is reached. Even if there is a delay in the movement of the dog tooth piston and the oil circuit switching, by performing the shift operation in advance, it is expected that when the dog tooth clutch is fully engaged, the actual speed difference of the dog tooth clutch can reach the optimal engagement speed difference, thereby avoiding the problem of the actual speed difference of the dog tooth clutch suddenly changing at the moment of engagement of the dog tooth clutch, and exceeding the hardware allowable limit of the dog tooth clutch, thereby reducing the risk of damage to the dog tooth clutch and the probability of noise, and improving the user experience.

[0098] In addition, in actual applications, the time required for the dog clutch to change from a disengaged state to an engaged state is relatively long, which affects the shifting performance. After research, it was found that in the relevant technology, the actual speed difference decreases linearly, such as Figure 5 In the original strategy speed difference shown, the actual speed difference changes linearly during the decline, and the required time is T1. Moreover, the rate of change of the linearly changing actual speed difference is small, which leads to a longer time for the actual speed difference to decrease to the optimal engagement speed difference, and a longer time for the dog clutch to change from the disengaged state to the engaged state, which affects the shifting performance.

[0099] Based on this, the embodiment of the present application controls the actual speed difference to decrease rapidly based on a larger rate. Specifically, the actual speed difference of the dog clutch is controlled to decrease according to the first actual speed difference change rate, wherein the first actual speed difference change rate is less than or equal to the speed difference change rate threshold, such as Figure 5 In the new strategy speed difference form (1) shown, the first actual speed difference change rate is smaller than the change rate in the related art, and the required time is shortened from T1 to T2. Therefore, the actual speed difference can be controlled to drop rapidly based on the larger actual speed difference change rate, shortening the time required for the dog clutch to change from a disengaged state to a coupled state, thereby avoiding affecting the shifting performance. Among them, the speed difference change rate threshold can be set by technicians skilled in the art according to actual needs, as long as the first actual speed difference change rate is greater than the change rate in the related art.

[0100] However, in the process of using the above method, since the actual speed difference decreases quickly, and there is a delay in the movement of the dog gear piston and the oil circuit switching, the time for controlling the dog gear clutch to change from the disengaged state to the engaged state is short, or the control window time of the dog gear clutch is short, and it is not easy to control the actual speed difference of the dog gear clutch to reach the optimal engagement speed difference, so that the dog gear clutch is engaged. Based on this, the embodiment of the present application provides a two-stage rate control method. The following is a detailed description.

[0101] The actual speed difference of the dog clutch is controlled to decrease according to the third actual speed difference change rate, so that after the actual speed difference of the dog clutch decreases according to the third actual speed difference change rate for a first period of time, the actual speed difference of the dog clutch reaches the third speed difference threshold. After the actual speed difference of the dog clutch reaches the third speed difference threshold, the actual speed difference of the dog clutch is controlled to decrease according to the first actual speed difference change rate, so that after the actual speed difference of the dog clutch decreases according to the first actual speed difference change rate for a second period of time, the actual speed difference of the dog clutch reaches the optimal engagement speed difference. Figure 5 The new strategy speed difference form shown is (2). The third speed difference threshold is determined based on the speed difference upper limit of the dog clutch, and the third actual speed difference change rate is greater than the first actual speed difference change rate.

[0102] Continue to see Figure 4 The actual speed difference of the dog clutch first drops rapidly to near the speed difference upper limit (i.e., the third speed difference threshold) at the third actual speed difference change rate within a short period of time (i.e., within the first time period), and then continues to drop to the optimal engagement speed difference at the first actual speed difference change rate.

[0103] Therefore, the actual speed difference of the dog clutch can quickly drop to near the upper limit of the speed difference based on the larger third actual speed difference change rate, and then continue to drop to the optimal engagement speed difference at the first actual speed difference change rate. Since the first actual speed difference change rate is smaller than the third actual speed difference change rate, the control window of the dog clutch can be increased, so that the dog clutch can be better controlled from a disengaged state to an engaged state, which is simple and convenient.

[0104] As a possible implementation method, the actual speed difference of the dog clutch can also be controlled to decrease according to multiple actual speed difference change rates, and the multiple actual speed difference change rates change from large to small, such as Figure 5 The new strategy speed difference shape shown in (3) makes the change of the actual speed difference appear as a concave arc, wherein the multiple actual speed difference change rates include the first actual speed difference change rate.

[0105] As a possible implementation method, when the dog clutch is in the gear-in state, there may be a risk of hardware damage to the dog clutch due to the actual speed difference being too high. For example, if the vehicle accelerates first and then starts to decelerate, the actual speed difference first decreases and then increases, and the increased actual speed difference may exceed the risk of hardware damage to the dog clutch.

[0106] Based on this, the speed difference upper limit, the second actual speed difference change rate and the second hydraulic response time of the dog clutch can be obtained, and the second speed difference threshold is determined according to the speed difference upper limit, the second actual speed difference change rate and the second hydraulic response time. The second current actual speed difference is obtained, and if the second current actual speed difference exceeds the second speed difference threshold, the oil circuit of the dog clutch is closed.

[0107] Among them, the upper limit of the speed difference of the dog clutch can be determined based on the type of the dog clutch. The second actual speed difference change rate of the dog clutch can be calculated based on the actual speed difference of the dog clutch and the piston movement time. The second hydraulic response time refers to the hydraulic response time of the dog piston moving to the separation side, which is affected by the cylinder parameters and the direction of piston movement. From the above, it can be seen that there is a certain delay time in the movement of the dog piston and the oil circuit switching. The delay time can be the second hydraulic response time (there may be deviations, but the deviations are not large), which can be obtained based on bench testing. For example, the transmission is bench tested, that is, a separation side oil pressure command is given, and the time from the issuance of the command to the start of the piston movement is observed as the second hydraulic response time.

[0108] It should be noted that, due to differences in parameters such as the volume of the separation side oil chamber and the combined oil measurement chamber, the first hydraulic response time and the second hydraulic response time may be different.

[0109] It can be understood that the second actual speed difference change rate refers to the speed at which the actual speed difference value changes within a period of time. It has no positive or negative concept and is the absolute value of the slope of the actual speed difference change curve. The change trend of the second actual speed difference change rate is opposite to the change trend of the first speed difference actual change rate. For example, the change trend corresponding to the first actual speed difference change rate is a decrease (such as vehicle acceleration), and the change trend corresponding to the second actual speed difference change rate is an increase (such as vehicle deceleration).

[0110] The second current actual speed difference is the actual speed difference obtained after the actual speed difference of the dog clutch changes based on the second actual speed difference. Therefore, by obtaining the second current actual speed difference in real time, it is possible to monitor when the second current actual speed difference exceeds the second speed difference threshold.

[0111] The second speed difference threshold is not specifically limited in this field, and those skilled in the art may set it according to actual needs, such as setting it based on the speed difference upper limit to avoid the second current actual speed difference exceeding the speed difference upper limit too much.

[0112] As a possible implementation, the second speed difference threshold is calculated according to the speed difference upper limit, the second actual speed difference change rate and the second hydraulic response time. The calculation formula is as follows:

[0113] |Δω2+α2×ΔT2|≥Δω max (2)

[0114] Wherein, Δω2 represents the second speed difference threshold, Δω max represents the speed difference upper limit, α2 represents the second actual speed difference change rate, and ΔT2 represents the second hydraulic response time.

[0115] Therefore, the second speed difference threshold is determined based on the speed difference upper limit, the second actual speed difference change rate, and the second hydraulic response time. The second speed difference threshold is the speed difference corresponding to a period of time before the speed difference upper limit is reached, under the premise that the second actual speed difference change rate remains unchanged. In other words, on the basis of the speed difference upper limit, a delay time applicable to the second actual speed difference change rate is added. The actual speed difference of the dog clutch is based on the process of the second actual speed difference change rate rising. After the second hydraulic response time, the estimated actual speed difference of the dog clutch may exceed the speed difference upper limit or exceed the speed difference upper limit by a threshold. The following is combined with Figure 6 Provide explanation.

[0116] See also Figure 6 , which is a schematic diagram of the actual speed difference change of a dog clutch provided in an embodiment of the present application. After the actual speed difference of the dog clutch decreases based on the first actual speed difference change rate, the vehicle starts to decelerate, and the actual speed difference of the dog clutch starts to increase. In other words, the actual speed difference of the dog clutch changes from the first actual speed difference change rate to the second actual speed difference change rate.

[0117] In the process of changing based on the second actual speed difference change rate, it is expected that the actual speed difference of the dog clutch will exceed the speed difference upper limit by a lot, so the second speed difference threshold is calculated based on the above formula (2). The actual speed difference of the dog clutch is monitored in real time, that is, the second current actual speed difference is obtained. If the second current actual speed difference exceeds the second speed difference threshold, it means that the second actual speed difference change rate continues to change and may exceed the speed difference upper limit of the dog clutch by a lot. For example, if the second current actual speed difference is Figure 6 At point B, it is estimated that after the second hydraulic response time, the actual speed difference of the dog clutch may exceed the speed difference upper limit of the dog clutch by a lot. At this time, the oil circuit of the dog clutch is closed so that the state of the dog clutch can change from the retarded state to the fully disengaged state. Due to the delay, after a period of time, the actual speed difference no longer increases, and the Figure 6 It can be seen that the actual speed difference controlled based on the above method only exceeds the upper limit of the dog clutch speed difference by a little bit, which reduces the risk of damage to the dog clutch caused by excessive actual speed difference.

[0118] Therefore, when the control state of the dog clutch is the said shift-in state, it will continue to monitor whether the second current actual speed difference exceeds the speed difference upper limit of the dog clutch. Moreover, the shift-down operation is no longer performed when the second current actual speed difference exceeds the speed difference upper limit, but the shift-in operation is performed when the second current actual speed difference exceeds the second speed difference threshold. Even if there is a delay in the movement of the dog piston and the oil circuit switching, by performing the shift-down operation in advance, it is expected that when the dog clutch is completely separated, the actual speed difference of the dog clutch will not exceed the speed difference upper limit by a lot, thereby avoiding the problem of the hardware allowable limit of the dog clutch, and further reducing the risk of damage to the dog clutch.

[0119] In addition to the gear-in control method based on the dog-tooth clutch provided in the embodiment of the present application, a gear-in control device based on the dog-tooth clutch is also provided. Figure 7 As shown, it includes: a first acquisition unit 701, a determination unit 702, a second acquisition unit 703 and a control unit 704;

[0120] The first acquisition unit 701 is used to acquire the optimal engagement speed difference, the first actual speed difference change rate and the first hydraulic response time of the dog clutch;

[0121] The determining unit 702 is used to determine a first speed difference threshold according to the optimal combined speed difference, the first actual speed difference change rate and the first hydraulic response time;

[0122] The second acquisition unit 703 is used to acquire a first current actual speed difference, wherein a change rate of the first current actual speed difference is the same as a change rate of the first actual speed difference;

[0123] The control unit 704 is configured to control the dog clutch to change its control state from a disengaged state to a shifting state if the first current actual speed difference drops to the first speed difference threshold.

[0124] It can be seen from the above technical solution that the best engagement speed difference, the first actual speed difference change rate and the first hydraulic response time of the dog clutch are obtained, and the first speed difference threshold is determined according to the best engagement speed difference, the first actual speed difference change rate and the first hydraulic response time, that is, on the basis of the best engagement speed difference, a delay time applicable to the first actual speed difference change rate is added, or in other words, the first speed difference threshold is the speed difference corresponding to a period of time before the best engagement speed difference is reached under the premise that the first actual speed difference change rate remains unchanged. The first current actual speed difference is obtained, and the change rate of the first current actual speed difference is the same as the change rate of the first actual speed difference. If the first current actual speed difference drops to the first speed difference threshold, it means that under the premise that the first actual speed difference change rate remains unchanged, after the first hydraulic response time, it is predicted that the actual speed difference of the dog clutch will reach the best engagement speed difference. At this time, the control state of the dog clutch is controlled to change from the separation state to the shifting state, that is, the shifting operation is performed, so that the actual speed difference of the dog clutch is the best engagement speed difference when the dog clutch is completed, and the impact caused by the dog clutch at the moment of engagement is avoided so that the actual speed difference of the dog clutch exceeds the hardware allowable limit of the dog clutch.

[0125] Therefore, the shift operation is no longer performed when the first current actual speed difference reaches the optimal engagement speed difference, but when the first current actual speed difference drops to the first speed difference threshold, that is, when the first hydraulic response time before the optimal engagement speed difference is reached. Even if there is a delay in the movement of the dog tooth piston and the oil circuit switching, by performing the shift operation in advance, it is expected that when the dog tooth clutch is fully engaged, the actual speed difference of the dog tooth clutch can reach the optimal engagement speed difference, thereby avoiding the problem of the actual speed difference of the dog tooth clutch suddenly changing at the moment of engagement of the dog tooth clutch, and exceeding the hardware allowable limit of the dog tooth clutch, thereby reducing the risk of damage to the dog tooth clutch and the probability of noise, and improving the user experience.

[0126] As a possible implementation manner, the determining unit 702 is specifically configured to:

[0127] The first speed difference threshold is calculated according to the optimal combined speed difference, the first actual speed difference change rate and the first hydraulic response time, and the calculation formula is as follows:

[0128] Δω1≤Δω opt +α1×ΔT1;

[0129] Wherein, Δω1 represents the first speed difference threshold, Δω opt represents the optimal combined speed difference, α1 represents the first actual speed difference change rate, and ΔT1 represents the first hydraulic pressure response time.

[0130] As a possible implementation, during the process in which the control state of the dog clutch is the shifting state, the first acquisition unit 701 is used to acquire the speed difference upper limit, the second actual speed difference change rate, and the second hydraulic response time of the dog clutch, wherein the change trend corresponding to the second actual speed difference change rate is opposite to the change trend corresponding to the first speed difference actual change rate;

[0131] The determining unit 702 is used to determine a second speed difference threshold according to the speed difference upper limit, the second actual speed difference change rate and the second hydraulic response time;

[0132] The second acquisition unit 703 is used to acquire a second current actual speed difference;

[0133] The control unit 704 is configured to close the oil circuit of the dog clutch if the second current actual speed difference exceeds the second speed difference threshold.

[0134] As a possible implementation manner, as a possible implementation manner, the determining unit 702 is specifically configured to:

[0135] The second speed difference threshold is calculated according to the speed difference upper limit, the second actual speed difference change rate and the second hydraulic response time, and the calculation formula is as follows:

[0136] |Δω2+α2×ΔT2|≥Δω max ;

[0137] Wherein, Δω2 represents the second speed difference threshold, Δω max represents the speed difference upper limit, α2 represents the second actual speed difference change rate, and ΔT2 represents the second hydraulic pressure response time.

[0138] As a possible implementation manner, the control unit 704 is specifically configured to:

[0139] Controlling the actual speed difference of the dog clutch to decrease according to a third actual speed difference change rate, so that after the actual speed difference of the dog clutch decreases according to the third actual speed difference change rate for a first period of time, the actual speed difference of the dog clutch reaches a third speed difference threshold, the third speed difference threshold being determined based on an upper speed difference limit of the dog clutch, and the third actual speed difference change rate being greater than the first actual speed difference change rate;

[0140] The actual speed difference of the dog clutch is controlled to decrease according to the first actual speed difference change rate, so that after the actual speed difference of the dog clutch decreases according to the first actual speed difference change rate for a second time period, the actual speed difference of the dog clutch reaches the optimal engagement speed difference.

[0141] As a possible implementation manner, the control unit 704 is specifically configured to:

[0142] The actual speed difference of the dog clutch is controlled to decrease according to a plurality of actual speed difference change rates, the plurality of actual speed difference change rates change from large to small, and the plurality of actual speed difference change rates include the first actual speed difference change rate.

[0143] As a possible implementation manner, the control unit 704 is specifically configured to:

[0144] The actual speed difference of the dog clutch is controlled to decrease according to the first actual speed difference change rate, and the first actual speed difference change rate is less than or equal to the speed difference change rate threshold.

[0145] The present application also provides a computer device, see Figure 8 , which shows a structural diagram of a computer device provided in an embodiment of the present application, such as Figure 8 As shown, the device includes a memory 810 and a processor 820:

[0146] The memory 810 is used to store program codes and transmit the program codes to the processor;

[0147] The processor 820 is used to execute any one of the dog clutch-based gear shift control methods provided in the above embodiments according to the instructions in the program code.

[0148] An embodiment of the present application provides a computer-readable storage medium, which is used to store a computer program. The computer program is used to execute any one of the dog clutch-based gear shift control methods provided in the above embodiments.

[0149] The embodiment of the present application also provides a computer program product or a computer program, which includes a computer instruction stored in a computer-readable storage medium. The processor of the computer device reads the computer instruction from the computer-readable storage medium, and the processor executes the computer instruction, so that the computer device executes the dog clutch-based gear shift control method provided in various optional implementations of the above aspects.

[0150] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referred to each other. For the system or device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description.

[0151] It should be understood that in the present application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0152] It should also be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0153] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0154] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A gear shift control method based on a dog clutch, characterized in that: The method comprises: Obtaining an optimal engagement speed difference, a first actual speed difference change rate, and a first hydraulic response time of the dog clutch; determining a first speed difference threshold value according to the optimal combined speed difference, the first actual speed difference change rate, and the first hydraulic response time; Acquire a first current actual speed difference, wherein a change rate of the first current actual speed difference is the same as a change rate of the first actual speed difference; If the first current actual speed difference drops to the first speed difference threshold, the control state of the dog clutch is changed from a disengaged state to a shift-in state.

2. The method according to claim 1, characterized in that The determining the first speed difference threshold according to the optimal combined speed difference, the first actual speed difference change rate and the first hydraulic pressure response time includes: The first speed difference threshold is calculated according to the optimal combined speed difference, the first actual speed difference change rate and the first hydraulic response time, and the calculation formula is as follows: Δω1≤Δω opt +a1×ΔT1; Wherein, Δω1 represents the first speed difference threshold, Δω opt represents the optimal combined speed difference, α1 represents the first actual speed difference change rate, and ΔT1 represents the first hydraulic pressure response time.

3. The method according to claim 1, characterized in that When the control state of the dog clutch is the gear-in state, the method further includes: Obtaining a speed difference upper limit, a second actual speed difference change rate, and a second hydraulic response time of the dog clutch, wherein a change trend corresponding to the second actual speed difference change rate is opposite to a change trend corresponding to the first actual speed difference change rate; determining a second speed difference threshold value according to the speed difference upper limit, the second actual speed difference change rate, and the second hydraulic pressure response time; Get the second current actual speed difference; If the second current actual speed difference exceeds the second speed difference threshold, the oil circuit of the dog clutch is closed.

4. The method according to claim 3, characterized in that The determining the second speed difference threshold according to the speed difference upper limit, the second actual speed difference change rate and the second hydraulic response time includes: The second speed difference threshold is calculated according to the speed difference upper limit, the second actual speed difference change rate and the second hydraulic response time, and the calculation formula is as follows: |Δω2+α2×ΔT2|≥Δω max ; Wherein, Δω2 represents the second speed difference threshold, Δω max represents the speed difference upper limit, α2 represents the second actual speed difference change rate, and ΔT2 represents the second hydraulic pressure response time.

5. The method according to claim 1, characterized in that The method further comprises: Controlling the actual speed difference of the dog clutch to decrease according to a third actual speed difference change rate, so that after the actual speed difference of the dog clutch decreases according to the third actual speed difference change rate for a first period of time, the actual speed difference of the dog clutch reaches a third speed difference threshold, the third speed difference threshold being determined based on an upper speed difference limit of the dog clutch, and the third actual speed difference change rate being greater than the first actual speed difference change rate; The actual speed difference of the dog clutch is controlled to decrease according to the first actual speed difference change rate, so that after the actual speed difference of the dog clutch decreases according to the first actual speed difference change rate for a second time period, the actual speed difference of the dog clutch reaches the optimal engagement speed difference.

6. The method according to claim 1, characterized in that The method further comprises: The actual speed difference of the dog clutch is controlled to decrease according to a plurality of actual speed difference change rates, the plurality of actual speed difference change rates change from large to small, and the plurality of actual speed difference change rates include the first actual speed difference change rate.

7. The method according to claim 1, characterized in that The method further comprises: The actual speed difference of the dog clutch is controlled to decrease according to the first actual speed difference change rate, and the first actual speed difference change rate is less than or equal to the speed difference change rate threshold.

8. A gear-advancing control device based on a dog clutch, characterized in that: The device comprises: a first acquisition unit, a determination unit, a second acquisition unit and a control unit; The first acquisition unit is used to acquire the optimal engagement speed difference, the first actual speed difference change rate and the first hydraulic response time of the dog clutch; The determining unit is configured to determine a first speed difference threshold value according to the optimal combined speed difference, the first actual speed difference change rate, and the first hydraulic pressure response time; The second acquisition unit is used to acquire a first current actual speed difference, wherein a change rate of the first current actual speed difference is the same as a change rate of the first actual speed difference; The control unit is used to control the control state of the dog clutch to change from a disengaged state to a gear-in state if the first current actual speed difference drops to the first speed difference threshold.

9. A computer device, characterized in that: The device comprises a processor and a memory: The memory is used to store program codes and transmit the program codes to the processor; The processor is used to execute the method according to any one of claims 1 to 7 according to the instructions in the program code.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium is used to store a computer program, and the computer program is used to execute the method according to any one of claims 1 to 7.

Images