Vehicle speed regulation control method and related device

Abstract

The embodiment of the invention discloses a vehicle speed regulation control method which comprises the following steps: calculating an engine speed difference according to a first engine speed and a second engine speed; calculating an engine target rotating speed difference according to the first engine target rotating speed and the second engine target rotating speed; according to the engine rotating speed difference and the engine target rotating speed difference, the speed difference change rate of a first preset time period between the first moment and the second moment is calculated; calculating an error adjustment torque according to the speed difference change rate and the equivalent rotational inertia of the vehicle; and controlling an automatic transmission of the vehicle to operate according to the error adjusting torque. Therefore, error correction is carried out on the control torque of the automatic transmission according to the rotating speed difference of the clutch in one time period, the automatic transmission is controlled with the appropriate torque when the gear changes, gear shifting impact and pause caused by errors of the clutch are reduced, and the driving experience of a vehicle is improved.

Description

Technical Field

[0001] The present application relates to the technical field of vehicles, and in particular, to a vehicle speed control method and related device. Background Art

[0002] With the development of vehicle technology, automatic transmissions (ATs) are increasingly used in vehicles. Due to their advantages such as fast shift response, high transmission efficiency, small power loss, and good fuel economy, vehicles equipped with ATs are increasingly favored by the market.

[0003] For example, ATs such as dual-clutch automatic transmissions and mechanical hydraulic automatic transmissions belong to stepped automatic transmissions and have obvious gear positions. During vehicle driving, gear shifting is involved. To reduce the power loss during upshifting, a reconnection interaction method is generally used for power switching, that is, when the low-gear clutch is opened, the high-gear is engaged. After the torque interaction is completed, the engine speed is adjusted to be synchronized with the target gear speed, thereby completing the gear shift.

[0004] Due to the non-linear time-varying nature of the engine and the transmission, there is an error in the control accuracy of the transmission and the clutch, and the error changes with the use environment and time, resulting in error accumulation, making the traditional speed control algorithm unable to meet the performance indicators of different vehicles in different driving environments and the performance index requirements when the vehicle component states deteriorate. Summary of the Invention

[0005] To solve the above technical problems, the present application provides a vehicle speed control method and related device, which incorporates the real-time speed difference into the speed control method, enabling the method to achieve speed control for different-state transmissions and clutches.

[0006] The embodiments of the present application disclose the following technical solutions:

[0007] In a first aspect, the embodiments of the present application disclose a vehicle speed control method, the method comprising:

[0008] Obtain the first engine speed and the first engine target speed of the vehicle at a first moment;

[0009] Obtain the second engine speed and the second engine target speed of the vehicle at a second moment;

[0010] Calculate the engine speed difference according to the first engine speed and the second engine speed;

[0011] Calculate the engine target speed difference according to the first engine target speed and the second engine target speed;

[0012] Calculate the rate of change of speed difference within a first preset time period between the first moment and the second moment based on the engine speed difference and the target engine speed difference.

[0013] Calculate the error adjustment torque based on the rate of change of speed difference and the equivalent moment of inertia of the vehicle.

[0014] Control the operation of the automatic transmission of the vehicle according to the error adjustment torque.

[0015] Optionally, the method further includes:

[0016] Obtain the real-time engine speed of the vehicle.

[0017] Calculate the expected control torque of the vehicle based on a first preset control torque, a second preset control torque, and the real-time engine speed.

[0018] Determine the maximum value between the error adjustment torque and the expected control torque as the control torque of the vehicle.

[0019] The step of controlling the automatic transmission of the vehicle according to the error adjustment torque includes:

[0020] Control the operation of the automatic transmission of the vehicle according to the control torque.

[0021] Optionally, the method further includes:

[0022] In response to determining that the difference between the expected control torque and the error adjustment torque is less than a preset torque threshold, calculate the clutch speed difference within a second preset time period.

[0023] In response to determining that the clutch speed difference is greater than a preset slip threshold, based on the clutch speed difference and a first corresponding relationship between multiple clutch speed differences and multiple preset time values, determine the preset time value corresponding to the clutch speed difference.

[0024] Calculate the first clutch control torque of the clutch of the vehicle based on the clutch speed difference and the preset time value.

[0025] Control the clutch of the vehicle according to the first clutch control torque.

[0026] Optionally, the method further includes:

[0027] In response to determining that a third preset time is greater than the preset time value corresponding to the clutch speed difference, calculate the ratio between the third preset time and the preset time value.

[0028] Perform an equal-proportion reduction operation on the first clutch control torque according to the ratio to obtain a second clutch control torque.

[0029] Control the clutch of the vehicle according to the torque of the second clutch.

[0030] Optionally, the method further includes:

[0031] In response to determining that the clutch speed difference is greater than the clutch speed difference in the previous control cycle of the vehicle, calculate a rotational speed runaway speed difference according to the clutch speed difference and the clutch speed difference in the previous control cycle;

[0032] In response to determining that the rotational speed runaway speed difference is positive, calculate an inertial torque of the clutch of the vehicle according to the rotational speed runaway speed difference, a preset integral coefficient, and the moment of inertia of the clutch of the vehicle;

[0033] Control the clutch of the vehicle according to the inertial torque.

[0034] Optionally, the method further includes:

[0035] Obtain the clutch speed control time of the vehicle;

[0036] In response to determining that the clutch speed control time is greater than a preset speed control time, obtain the engine acceleration and the engine shaft speed difference of the vehicle;

[0037] According to the engine acceleration and the engine shaft speed difference, based on a second correspondence relationship between a plurality of engine accelerations, a plurality of engine shaft speed differences, and a plurality of clutch engagement rates, determine the clutch engagement rate at which the clutch of the vehicle engages;

[0038] Control the clutch of the vehicle to engage at the clutch engagement rate.

[0039] Optionally, the method further includes:

[0040] Obtain the clutch speed control time and the clutch temperature of the vehicle;

[0041] In response to determining that the clutch speed control time is greater than a fourth preset time, control the clutch of the vehicle to engage;

[0042] In response to determining that the clutch temperature is greater than a preset temperature, control the clutch of the vehicle to engage.

[0043] In a second aspect, an embodiment of the present application discloses a vehicle speed control device, and the device includes:

[0044] A first acquisition unit, configured to acquire a first engine speed and a first engine target speed of a vehicle at a first moment;

[0045] A second acquisition unit, configured to acquire a second engine speed and a second engine target speed of the vehicle at a second moment;

[0046] A first calculation unit, configured to calculate an engine speed difference according to the first engine speed and the second engine speed;

[0047] A second calculation unit, configured to calculate an engine target speed difference according to the first engine target speed and the second engine target speed;

[0048] A third calculation unit, configured to calculate a speed difference change rate of a first preset time period between the first moment and the second moment according to the engine speed difference and the engine target speed difference;

[0049] A fourth calculation unit, configured to calculate an error adjustment torque according to the speed difference change rate and an equivalent moment of inertia of the vehicle;

[0050] A first control unit, configured to control the operation of an automatic transmission of the vehicle according to the error adjustment torque.

[0051] Optionally, the device further includes:

[0052] A third acquisition unit, configured to acquire a real-time engine speed of the vehicle;

[0053] A fifth calculation unit, configured to calculate an expected control torque of the vehicle according to a first preset control torque, a second preset control torque, and the real-time engine speed;

[0054] A first determination unit, configured to determine a maximum value between the error adjustment torque and the expected control torque as a control torque of the vehicle;

[0055] The first control unit is further configured to:

[0056] Control the operation of the automatic transmission of the vehicle according to the control torque.

[0057] Optionally, the device further includes:

[0058] A sixth calculation unit, configured to calculate a clutch speed difference of a second preset time period in response to determining that a difference between the expected control torque and the error adjustment torque is less than a preset torque threshold;

[0059] A second determination unit, configured to determine, in response to determining that the clutch speed difference is greater than a preset slip threshold, a preset time value corresponding to the clutch speed difference according to the clutch speed difference based on a first correspondence between a plurality of clutch speed differences and a plurality of preset time values;

[0060] A seventh calculation unit for calculating a first clutch control torque of the vehicle's clutch according to the clutch speed difference and the preset time value;

[0061] A second control unit for controlling the vehicle's clutch according to the first clutch control torque.

[0062] Optionally, the device further includes:

[0063] An eighth calculation unit for calculating a ratio between the third preset time and the preset time value in response to determining that the third preset time is greater than the preset time value corresponding to the clutch speed difference;

[0064] A fourth acquisition unit for performing an equal-proportion reduction operation on the first clutch control torque according to the ratio to obtain a second clutch control torque;

[0065] A third control unit for controlling the vehicle's clutch according to the second clutch control torque.

[0066] Optionally, the device further includes:

[0067] A ninth calculation unit for calculating a rotational speed runaway speed difference according to the clutch speed difference and the clutch speed difference of the previous control cycle of the vehicle in response to determining that the clutch speed difference is greater than the clutch speed difference of the previous control cycle of the vehicle;

[0068] A tenth calculation unit for calculating an inertia torque of the vehicle's clutch according to the rotational speed runaway speed difference, a preset integral coefficient, and the moment of inertia of the vehicle's clutch in response to determining that the rotational speed runaway speed difference is positive;

[0069] A fourth control unit for controlling the vehicle's clutch according to the inertia torque.

[0070] Optionally, the device further includes:

[0071] A fifth acquisition unit for acquiring the clutch speed control time of the vehicle;

[0072] A sixth acquisition unit for acquiring the engine acceleration and the engine shaft speed difference of the vehicle in response to determining that the clutch speed control time is greater than the preset speed control time;

[0073] A third determination unit for determining the clutch engagement rate of the vehicle's clutch based on a second correspondence relationship among multiple engine accelerations, multiple engine shaft speed differences, and multiple clutch engagement rates according to the engine acceleration and the engine shaft speed difference;

[0074] A fifth control unit for controlling the clutch of the vehicle to engage at the clutch engagement rate.

[0075] Optionally, the device further includes:

[0076] A seventh acquisition unit for acquiring the clutch speed regulation control time and the clutch temperature of the vehicle;

[0077] A sixth control unit for controlling the clutch of the vehicle to engage in response to determining that the clutch speed regulation control time is greater than a fourth preset time;

[0078] A seventh control unit for controlling the clutch of the vehicle to engage in response to determining that the clutch temperature is greater than a preset temperature.

[0079] In a third aspect, an embodiment of the present application discloses a computer device, which includes a processor and a memory:

[0080] The memory is used for storing program codes and transmitting the program codes to the processor;

[0081] The processor is used for executing the vehicle speed regulation control method as described in the first aspect and any optional item of the first aspect according to the instructions in the program codes.

[0082] In a fourth aspect, an embodiment of the present application discloses a computer-readable storage medium, which is used for storing a computer program, and the computer program is used for executing the vehicle speed regulation control method as described in the first aspect and any optional item of the first aspect when being executed by a processor.

[0083] It can be seen from the above technical solutions that by acquiring the first engine speed and the first engine target speed of the vehicle at a first moment; acquiring the second engine speed and the second engine target speed of the vehicle at a second moment; calculating the engine speed difference according to the first engine speed and the second engine speed; calculating the engine target speed difference according to the first engine target speed and the second engine target speed; calculating the speed difference change rate of a first preset time period between the first moment and the second moment according to the engine speed difference and the engine target speed difference; calculating the error adjustment torque according to the speed difference change rate and the equivalent moment of inertia of the vehicle; controlling the operation of the automatic transmission of the vehicle according to the error adjustment torque. Thus, the control torque of the automatic transmission is corrected for errors according to the clutch speed difference within a time period, so that the automatic transmission is controlled with a suitable torque during gear shifting, thereby reducing the shift shock and jerks caused by the errors of the clutch itself and improving the driving experience of the vehicle. Description of the Drawings

[0084] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can also be obtained based on these drawings.

[0085] Figure 1 It is a schematic diagram of the torque control process during the upshift of a stepped automatic transmission in the related art;

[0086] Figure 2 It is a flowchart of a vehicle speed control method provided by an embodiment of the present application;

[0087] Figure 3 It is a schematic diagram of a vehicle speed control method provided by an embodiment of the present application;

[0088] Figure 4 It is a structural block diagram of a vehicle speed control device provided by an embodiment of the present application;

[0089] Figure 5 It is a structural block diagram of a computer device for vehicle speed control provided by an embodiment of the present application. Detailed implementation manners

[0090] In order to enable those skilled in the art of the present technology to better understand the solutions of the present application, the following will clearly and completely describe the technical solutions in the embodiments of the present application in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all embodiments.

[0091] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that such terms can be interchanged under appropriate circumstances, which is only a way of distinguishing objects with the same attributes when describing the embodiments of the present application.

[0092] With the development of vehicle technology, automatic transmissions (ATs) are increasingly used in vehicles. Due to their advantages such as fast shift response, high transmission efficiency, small power loss, and good fuel economy, vehicles equipped with ATs are increasingly favored by the market.

[0093] For example, ATs such as dual-clutch automatic transmissions and mechanical hydraulic automatic transmissions belong to stepped automatic transmissions and have obvious gear positions. During vehicle driving, gear shifting is involved. To reduce the shift power loss during upshifting, a reconnection interaction method is generally used for power switching. Please refer toFigure 1 , Figure 1 is a schematic diagram of the torque control process during the upshift of a stepped automatic transmission in the related art. In Figure 1 , when the low gear clutch is opened, the high gear is engaged. After the torque interaction is completed, the engine speed is adjusted to be synchronized with the target gear speed, so that the clutch completes the process of reducing speed and increasing torque, and then the gear shift is completed.

[0094] Due to the non-linear time-varying nature of the engine and the transmission, there is an error in the control accuracy of the transmission and the clutch, and the error changes with the use environment and time, resulting in error accumulation, so that the traditional speed control algorithm cannot meet the performance indicators of different vehicles in different driving environments and the performance index requirements when the vehicle component states deteriorate.

[0095] To solve the above technical problems, the embodiments of the present application disclose a vehicle speed control method, which obtains the transmission speed difference within a certain period of time in real time, and then performs corresponding calculations according to the speed difference to incorporate the error into the control torque of the clutch, so as to eliminate the speed difference error during clutch shifting, reduce the shifting impact of the clutch, and improve the driving experience of the vehicle.

[0096] Next, the vehicle speed control method will be introduced in conjunction with the accompanying drawings. Among them, this control method can be directly applied to the electronic control unit (Electronic Control Unit, ECU) or electronic controller of the vehicle. Please refer to Figure 2 when referring to Figure 3 , Figure 3 is a schematic diagram of a vehicle speed control method provided by an embodiment of the present application. For convenience of description, the vehicle speed control method will be introduced in conjunction with the Figure 3 schematic diagram shown.

[0097] It can be understood that this method is also applicable to the speed control of a dual clutch transmission (DCT) or other hybrid transmissions.

[0098] Please refer to Figure 2 , Figure 2 is a flowchart of a vehicle speed control method provided by an embodiment of the present application. The method includes S201 - S207:

[0099] S201: Obtain the first engine speed and the first engine target speed of the vehicle at the first moment.

[0100] S202: Obtain the second engine speed and the second engine target speed of the vehicle at the second moment.

[0101] The inventors found that traditional vehicle speed regulation methods mostly regulate the vehicle speed through classical control algorithms such as the Proportion-Integral-Differential coefficient (PID) algorithm. However, this method has the defect of a large jump in the calculation of the rate of change. In the subsequent filtering process, if the filtering is severe, errors will occur due to filtering distortion, affecting the accuracy of speed regulation control; if the filtering is light, due to the large jump in the rate of change, the stability of vehicle speed regulation control is poor, thereby affecting the robustness of vehicle operation.

[0102] The inventors also found that for these possible errors or jumps, some control methods are adjusted through the Proportion-Integral coefficient (PI) algorithm. However, due to the inherent delay of the PI algorithm, the speed of vehicle speed adjustment is slow and cannot meet the real-time requirements of vehicle speed regulation control.

[0103] Based on the above findings, the present invention provides a vehicle speed regulation based on the concept of average acceleration error.

[0104] In some possible implementation manners, the engine speed can be obtained through a speed sensor. At this time, the first engine speed is recorded as N Act , the second engine speed is recorded as N ActFrz , the first engine target speed is recorded as N Tgt , and the second engine target speed is recorded as N TgtFrz .

[0105] S203: Calculate the engine speed difference according to the first engine speed and the second engine speed.

[0106] S204: Calculate the engine target speed difference according to the first engine target speed and the second engine target speed.

[0107] Among them, the engine speed difference is recorded as N Act -N ActFrz , and the engine target speed difference is N Tgt -N TgtFrz .

[0108] S205: Calculate the speed difference change rate of the first preset time period between the first moment and the second moment according to the engine speed difference and the engine target speed difference.

[0109] At this time, if the change trends of the engine speed difference and the engine target speed difference are the same, it indicates that there is no engine speed control error, and the calculated speed difference change rate is 0.

[0110] If the change trends of the engine speed difference and the target engine speed difference are different, it indicates that there is an engine speed control error. At this time, the calculation of the speed difference change rate can be obtained by the following formula:

[0111]

[0112] In the formula, n is the speed difference change rate, and t 1 is the first preset time period between the first moment and the second time. In some possible implementation manners, t 1 is the time process from when the speed control algorithm enters the speed phase until it stops after passing the first preset time period.

[0113] S206: Calculate the error adjustment torque according to the speed difference change rate and the equivalent moment of inertia of the vehicle.

[0114] In some possible implementation manners, the equivalent moment of inertia of the vehicle may be the sum of the moment of inertia of the engine and the equivalent moment of inertia of the transmission equivalent to the engine end.

[0115] Among them, the error adjustment torque of the vehicle can be obtained by the following formula:

[0116] T 1Raw = n * J

[0117] In the formula, T 1Raw is the error adjustment torque, and J is the equivalent moment of inertia of the vehicle.

[0118] S207: Control the operation of the automatic transmission of the vehicle according to the error adjustment torque.

[0119] To reduce the fluctuation of the error adjustment torque control and improve the stability of the vehicle speed control, based on the above embodiments, further, the method further includes:

[0120] Obtain the real-time engine speed of the vehicle;

[0121] Calculate the expected control torque of the vehicle according to the first preset control torque, the second preset control torque and the real-time engine speed;

[0122] Determine the maximum value of the error adjustment torque and the expected control torque as the control torque of the vehicle;

[0123] Controlling the automatic transmission of the vehicle according to the error adjustment torque includes:

[0124] Control the operation of the automatic transmission of the vehicle according to the control torque.

[0125] Since there are inevitable errors in the engine speed obtained by the rotational speed sensor, there are also certain errors in the calculated engine speed difference, which in turn leads to corresponding errors in the obtained error adjustment torque, causing fluctuations in vehicle speed control.

[0126] Based on the above findings, it is necessary to limit the change rate of the clutch control torque, that is, its change rate cannot exceed a certain value. Taking a certain vehicle as an example, the change rate of the clutch control torque cannot exceed 200 Nm / s - 1000 Nm / s.

[0127] In some possible implementation manners, when the gear of the vehicle is relatively high, for example, when the vehicle is in the fourth or fifth gear, etc., the change rate of the clutch control torque can be allowed to be larger; when the vehicle is in a lower gear such as the first or second gear, the change rate of the clutch control torque is controlled to be smaller, and its specific value can be calibrated according to the vehicle configuration.

[0128] In some possible implementation manners, the clutch control torque can be obtained through the following formula:

[0129] T 1 =Max(T 1 +sign(T 1 -T 1Raw )*Rat, T 1Raw )

[0130] In the formula, T 1 is the expected control torque, sign() is the sign function. When T 1 >T 1Raw , that is, when T 1 -T 1Raw is a positive value, the sign function takes 1; and when T 1 <T 1Raw , that is, when T 1 -T 1Raw is a negative value, the sign function takes -1, and Rat is the engine speed.

[0131] To further eliminate the speed difference, based on the above embodiments, further, the method further includes:

[0132] In response to determining that the difference between the expected control torque and the error adjustment torque is less than a preset torque threshold, calculate the clutch speed difference for a second preset time period;

[0133] In response to determining that the clutch speed difference is greater than a preset slip threshold, based on the clutch speed difference and according to a first correspondence relationship between multiple clutch speed differences and multiple preset time values, determine the preset time value corresponding to the clutch speed difference;

[0134] Calculate the first clutch control torque of the vehicle's clutch based on the clutch speed difference and the preset time value;

[0135] Control the vehicle's clutch according to the first clutch control torque.

[0136] Due to the response delay in the system, for example, the response delay is 0.1 second, it is necessary to wait for 0.1 second before performing the corresponding speed adjustment control. At this time, when the difference between the expected control torque and the error adjustment torque is less than the preset torque threshold, perform speed difference elimination planning control to further eliminate the vehicle's speed difference.

[0137] Among them, the preset torque threshold can be calibrated. For example, this value can be calibrated to 5 Nm.

[0138] In some possible implementation manners, when the speed difference elimination planning control starts timing, the timing value is the preset time value t 2 , and at this time, start to record the speed difference as N ErrSpdFrz , and at the same time, find the maximum speed difference during the whole process of the preset time value t 2 , and record it as N MaxErrSpd .

[0139] Then, calculate the clutch speed difference within the t 2 time period. At this time, the clutch speed difference can be obtained by the following formula:

[0140] N ErrSpd = abs(N Tgt - N Act )

[0141] Among them, N ErrSpd is the calculated clutch speed difference, abs() is the absolute value function, ensuring that the difference between N Tgt and N Act is a positive value for convenient calculation.

[0142] During the whole process of the t 2 time period, at the initial moment, N MaxErrSpd can be defined as N ErrSpdFrz . If the calculated N ErrSpd is greater than N MaxErrSpd , then update N MaxErrSpd to N ErrSpd , otherwise maintain the original value.

[0143] At this time, control the control torque of the clutch to increase to the torque T Plan that can eliminate the error within a certain time (t 2 / 2). Among them, T 2 can be calculated by the following formula:

[0144]

[0145] In the formula, t Plan is the time for eliminating the current speed difference N in the speed difference elimination planning control MaxErrSpd in the planning.

[0146] Among them, t Plan can be determined according to the first correspondence. The first correspondence can be pre-stored in the vehicle's ECU in the form of a table or other data storage. When the N of the vehicle is obtained ErrSpd , query the t corresponding to this N value according to this table ErrSpd . Plan .

[0147] As a possible implementation, the correspondence table between t Plan and N ErrSpd is shown in Table 1 below:

[0148] Differential speed (r) 0 50 100 200 400 800 <![CDATA[t P lan(s)]]> 0.1 0.1 0.15 0.2 0.4 0.7

[0149] Table 1

[0150] Please refer to Figure 3 . In the "1" stage of this speed difference elimination planning control as shown in Figure 3 , since N ErrSpd is continuously rising, the calculated first clutch control torque also rises accordingly.

[0151] In order to reduce the jitter problem caused by the speed fluctuation and the clutch torque fluctuation, based on the above embodiment, further, the method further includes:

[0152] In response to determining that the third preset time is greater than the preset time value corresponding to the clutch speed difference, calculate the ratio between the third preset time and the preset time value;

[0153] Perform a proportional reduction operation on the first clutch control torque according to the ratio to obtain the second clutch control torque;

[0154] Control the clutch of the vehicle according to the second clutch control torque.

[0155] Please continue to refer to Figure 3 . In the "2" stage of Figure 3 , when t 2 >t Plan / 2, in this stage, the elimination error torque T of the clutch 2 decreases proportionally with the speed difference, and at the same time record the elimination error torque T at this time 2Max . Among them, T 2Max can be calculated by the following formula:

[0156]

[0157] At this time, record the minimum value of the speed difference change, and determine that the speed difference at this time is N MinErrSpd_1 .

[0158] Similar to the aforementioned control method, at the initial moment of control, let N MinErrSpd = N MinErrSpd_1 . If N ErrSpd is less than N MinErrSpd , then update N ErrSpd to N MinErrSpd , otherwise maintain the original value.

[0159] That is, within the entire speed regulation control time period, the update process for N MinErrSpd can be shown by the following recurrence formula:

[0160] N MinErrSpd_1 = N ErrSpd

[0161] N MinErrSpd2 = Min(N MinErrSp1 , N ErrSpd )

[0162] ……

[0163] N MinErrSpd_n = Min(N MinErrSp_n_1 , N ErrSpd )

[0164] At this time, the torque of the clutch is monotonically decreasing. In some possible implementation manners, if it is detected that N ErrSpd is greater than the speed difference N ErrSpd_n_1 of the previous cycle, then maintain the clutch torque of the previous cycle, that is, enter the Figure 3 control stage shown as "3" in.

[0165] When it is detected that N ErrSpd - N MinErrSpd > Offset, where Offset can be determined according to the calibration and debugging of the actual vehicle. For example, it can be defined between 60 - 120 r / min. At this time, enter the Figure 3 stage "4" in, and its specific algorithm is similar to the control algorithm for the "2" stage described above, which will not be elaborated here.

[0166] The difference from the control algorithm for the aforementioned "2" stage is that at this time, it is necessary to recalculate N MaxErrSpd , and according to the new N MaxErrSpd , calculate the torque of the clutch and the new planned time t Plan , and at the same time, start timing t 2 again.

[0167] When the new t 2 > tPlan / 2, then enter the Figure 3 "5"-stage speed regulation control in

[0168] Among them, the speed regulation control in the "5" stage is similar to those in the "2" and "4" stages. However, at this time, it is necessary to re-initialize N MinErrSpd for calculation, and use this as the judgment criterion for whether to re-enter the "1" stage control of the next speed regulation control cycle.

[0169] To reduce the system instability problem caused by excessive adjustment to avoid system response delay, based on the above embodiments, the further method further includes:

[0170] In response to determining that the clutch speed difference is greater than the clutch speed difference in the previous control cycle of the vehicle, calculate the rotational speed runaway speed difference according to the clutch speed difference and the clutch speed difference in the previous control cycle;

[0171] In response to determining that the rotational speed runaway speed difference is positive, calculate the inertial torque of the vehicle's clutch according to the rotational speed runaway speed difference, the preset integral coefficient, and the moment of inertia of the vehicle's clutch;

[0172] Control the vehicle's clutch according to the inertial torque.

[0173] Please combine Figure 3 In the ② and ③ stages in, after the speed difference elimination planning control starts, it is necessary to perform rotational speed runaway detection, that is, enter Figure 3 the ③ stage in

[0174] Due to system response delay, it is necessary to make corresponding adjustments to the system, but excessive adjustment will cause system instability problems. To solve this technical problem, please combine Figure 3 as shown in the "2" and "5" parts in, select to start monitoring in the second half after the speed difference elimination planning control starts, that is, when it is detected that N MaxErrSpd has a tendency to expand in two consecutive vehicle speed adjustment control cycles, that is, judge whether the following formula is satisfied:

[0175] N MaxErrSpd_n -N MaxErrSpd_n_1 >0 && N MaxErrSpd_n_1 -N MaxErrSpd_n_2

[0176] In the formula, n represents the current vehicle speed adjustment control cycle, n_1 represents the previous vehicle speed adjustment control cycle, and n_2 represents the vehicle speed adjustment control cycle before the previous one. When the above formula holds, it means that the current control cannot achieve the purpose of controlling the rotational speed, so it is necessary to activate the rotational speed runaway control.

[0177] At this time, the new rotational speed runaway speed difference is calculated as shown in the following formula:

[0178] NNewErrSpd =(N MaxErrSpd_n -N MaxErrSpdn1 )-(N MaxErrSpd_n_1 -N MaxErrSpd_n_2 )

[0179] If N NewErrSpd >0, then calculate the current inertia torque as shown in the following formula:

[0180]

[0181] where K i is the integration coefficient.

[0182] In some possible implementation manners, when N NewErrSpd ≤0, let T 31 =0.

[0183] The calculation of the clutch I-phase torque for the final speed runaway control is as shown in the following formula:

[0184] T 3 =∫T 31

[0185] As Figure 2 shown, it is the overshoot control scheme for the speed runaway control.

[0186] In some other possible implementation manners, if the actual speed drops faster than the target speed, then the sign problem of T 2 and T 3 needs to be considered, that is, calculate sign(N Act -N Tgt ):

[0187] At this time: if the signs of T 2 and T 3 are positive, that is, sign(N Act -N Tgt ) is 1, then the clutch needs to increase the torque;

[0188] If the speed drops, that is, sign(N Act -N Tgt ) is -1, then the calculated values of T 2 and T 3 need to be changed to negative values, and at this time the clutch needs to reduce the torque.

[0189] In some possible implementation manners, the method further includes:

[0190] Obtain the clutch speed regulation control time of the vehicle;

[0191] In response to determining that the clutch speed regulation control time is greater than the preset speed regulation control time, obtain the engine acceleration and engine shaft speed difference of the vehicle;

[0192] Based on the engine acceleration and the engine shaft speed difference, and based on a second corresponding relationship among a plurality of engine accelerations, a plurality of engine shaft speed differences, and a plurality of clutch engagement rates, determine the clutch engagement rate at which the vehicle's clutch engages;

[0193] Control the vehicle's clutch to engage at the clutch engagement rate.

[0194] Among them, the preset speed regulation control time can be calibrated in advance. In some possible implementation manners, the preset speed regulation control time can be calibrated to be twice the normal vehicle speed regulation control time.

[0195] Among them, the normal vehicle speed regulation control time can be calibrated through actual vehicle testing according to the vehicle's gear and torque. For example, it can be calibrated to be between 0.5 s and 0.8 s.

[0196] In order to reduce the impact caused by speed synchronization during clutch engagement, the clutch engagement rate for timeout engagement needs to consider the engine acceleration and the shaft speed difference. Among them, the engine shaft speed difference is the difference between the engine speed and the input shaft speed of the clutch when the vehicle is adjusted to the target gear.

[0197] Among them, the second corresponding relationship can be stored in the form of a table, such as shown in Table 2. Among them, the first row of Table 2 represents the engine speed change rate, the first column represents the engine shaft speed difference, with the unit of Nm / s, and the other values are the corresponding clutch engagement rates under their corresponding engine speed change rates and engine shaft speed differences.

[0198] -3000 -1500 -500 -250 0 500 1000 0 50 100 150 150 200 250 500 250 100 100 150 150 200 250 500 500 150 200 200 250 300 400 500 1000 200 300 400 500 600 700 700 2000 200 400 500 600 700 800 1000

[0199] Table 2

[0200] To reduce the probability of clutch damage and improve the service life of the clutch, based on the above embodiments, further, the method further includes:

[0201] Obtain the clutch speed regulation control time and the clutch temperature of the vehicle;

[0202] In response to determining that the clutch speed regulation control time is greater than a fourth preset time, control the vehicle's clutch to engage;

[0203] In response to determining that the clutch temperature is greater than a preset temperature, control the vehicle's clutch to engage.

[0204] When the speed regulation time for shifting exceeds the fourth preset time T 2 , to protect the clutch hardware, the vehicle's clutch can be controlled to quickly and forcibly engage regardless of other control conditions.

[0205] Among them, T 2The specific value can be determined by looking up a table according to different gears. In some possible implementation manners, for low gears below the third gear, T 2 is generally set to not exceed 3 s, and for high gears above the fourth gear, T 2 is generally set to not exceed 2 s.

[0206] When the clutch temperature during gear shifting is greater than the preset temperature, to protect the clutch hardware, the vehicle's clutch can be controlled to quickly and forcibly engage regardless of other control conditions, thereby protecting the clutch hardware at the slight cost of slightly sacrificing the vehicle driving comfort and preventing the clutch from being damaged due to overheating.

[0207] Of course, the preset temperature can also be calibrated in advance. For example, it can be determined according to the characteristics of the clutch friction plate material and is generally set between 200 °C and 300 °C.

[0208] Please refer to Figure 4 , Figure 4 which is a structural block diagram of a vehicle speed control device provided by an embodiment of the present application. The device includes:

[0209] A first acquisition unit 410, configured to acquire a first engine speed and a first engine target speed of the vehicle at a first moment;

[0210] A second acquisition unit 420, configured to acquire a second engine speed and a second engine target speed of the vehicle at a second moment;

[0211] A first calculation unit 430, configured to calculate an engine speed difference according to the first engine speed and the second engine speed;

[0212] A second calculation unit 440, configured to calculate an engine target speed difference according to the first engine target speed and the second engine target speed;

[0213] A third calculation unit 450, configured to calculate a speed difference change rate of a first preset time period between the first moment and the second moment according to the engine speed difference and the engine target speed difference;

[0214] A fourth calculation unit 460, configured to calculate an error adjustment torque according to the speed difference change rate and the equivalent moment of inertia of the vehicle;

[0215] A first control unit 470, configured to control the operation of the automatic transmission of the vehicle according to the error adjustment torque.

[0216] As a possible implementation manner, the device further includes:

[0217] A third acquisition unit, configured to acquire the real-time engine speed of the vehicle;

[0218] A fifth calculation unit, configured to calculate an expected control torque of the vehicle according to a first preset control torque, a second preset control torque, and the real-time engine speed;

[0219] A first determination unit, configured to determine the maximum value of the error adjustment torque and the expected control torque as the control torque of the vehicle;

[0220] The first control unit is further configured to:

[0221] Control the operation of an automatic transmission of the vehicle according to the control torque.

[0222] As a possible implementation manner, the device further includes:

[0223] A sixth calculation unit, configured to calculate a clutch speed difference for a second preset time period in response to determining that a difference between the expected control torque and the error adjustment torque is less than a preset torque threshold;

[0224] A second determination unit, configured to determine a preset time value corresponding to the clutch speed difference according to the clutch speed difference based on a first correspondence relationship between a plurality of clutch speed differences and a plurality of preset time values in response to determining that the clutch speed difference is greater than a preset slip threshold;

[0225] A seventh calculation unit, configured to calculate a first clutch control torque of a clutch of the vehicle according to the clutch speed difference and the preset time value;

[0226] A second control unit, configured to control the clutch of the vehicle according to the first clutch control torque.

[0227] As a possible implementation manner, the device further includes:

[0228] An eighth calculation unit, configured to calculate a ratio between the third preset time and the preset time value in response to determining that the third preset time is greater than the preset time value corresponding to the clutch speed difference;

[0229] A fourth acquisition unit, configured to perform a proportional reduction operation on the first clutch control torque according to the ratio to obtain a second clutch control torque;

[0230] A third control unit, configured to control the clutch of the vehicle according to the second clutch control torque.

[0231] As a possible implementation manner, the device further includes:

[0232] A ninth calculation unit, configured to calculate a rotational speed runaway speed difference according to the clutch speed difference and the clutch speed difference in the previous control cycle of the vehicle in response to determining that the clutch speed difference is greater than the clutch speed difference in the previous control cycle of the vehicle;

[0233] A tenth calculation unit, configured to calculate an inertial torque of the clutch of the vehicle according to the rotational speed runaway speed difference, a preset integration coefficient, and the moment of inertia of the clutch of the vehicle in response to determining that the rotational speed runaway speed difference is positive;

[0234] A fourth control unit, configured to control the clutch of the vehicle according to the inertial torque.

[0235] As a possible implementation manner, the device further includes:

[0236] A fifth acquisition unit, configured to acquire the clutch speed regulation control time of the vehicle;

[0237] A sixth acquisition unit, configured to acquire the engine acceleration and the engine shaft speed difference of the vehicle in response to determining that the clutch speed regulation control time is greater than a preset speed regulation control time;

[0238] A third determination unit, configured to determine the clutch engagement rate of the clutch engagement of the vehicle based on a second correspondence relationship among a plurality of engine accelerations, a plurality of engine shaft speed differences, and a plurality of clutch engagement rates according to the engine acceleration and the engine shaft speed difference;

[0239] A fifth control unit, configured to control the clutch of the vehicle to engage at the clutch engagement rate.

[0240] As a possible implementation manner, the device further includes:

[0241] A seventh acquisition unit, configured to acquire the clutch speed regulation control time and the clutch temperature of the vehicle;

[0242] A sixth control unit, configured to control the clutch of the vehicle to engage in response to determining that the clutch speed regulation control time is greater than a fourth preset time;

[0243] A seventh control unit, configured to control the clutch of the vehicle to engage in response to determining that the clutch temperature is greater than a preset temperature.

[0244] As can be seen from the above technical solutions, the first engine speed and the first engine target speed of the vehicle at the first moment are obtained; the second engine speed and the second engine target speed of the vehicle at the second moment are obtained; the engine speed difference is calculated according to the first engine speed and the second engine speed; the engine target speed difference is calculated according to the first engine target speed and the second engine target speed; the speed difference change rate of the first preset time period between the first moment and the second moment is calculated according to the engine speed difference and the engine target speed difference; the error adjustment torque is calculated according to the speed difference change rate and the equivalent moment of inertia of the vehicle; and the automatic transmission of the vehicle is controlled according to the error adjustment torque. Thus, the control torque of the automatic transmission is corrected for errors based on the clutch speed difference within a time period, so that the automatic transmission is controlled with an appropriate torque during gear shifting, thereby reducing the shifting impact and jerks caused by the errors of the clutch itself and improving the driving experience of the vehicle.

[0245] Please refer to Figure 5 , Figure 5 which is a structural block diagram of a computer device for vehicle speed control provided by an embodiment of the present application. The computer device includes a processor 510 and a memory 520:

[0246] The memory 520 is used to store program codes and transmit the program codes to the processor 510;

[0247] The processor 510 is used to execute the vehicle speed control method described in any one of the above embodiments according to the instructions in the program codes.

[0248] In a fourth aspect, an embodiment of the present application discloses a computer-readable storage medium, which is used to store a computer program. The computer program is used to execute the vehicle speed control method described in any one of the above embodiments when being executed by a processor.

[0249] It can be understood that this method can be applied to a processing device, which is a processing device capable of performing motion control. For example, it can be a terminal device or a server with motion control functions. This method can be independently executed by the terminal device or the server, or can be applied to a network scenario where the terminal device and the server communicate, and is executed in cooperation with the terminal device and the server. Among them, the terminal device can be a device such as a computer or a mobile phone. The server can be understood as an application server or a Web server. In actual deployment, the server can be an independent server or a cluster server.

[0250] Those of ordinary skill in the art will understand that all or part of the steps of implementing the above method embodiments can be completed by hardware related to program instructions. The foregoing program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps including those of the above method embodiments; and the foregoing storage medium can be at least one of the following media: read-only memory (ROM), RAM, magnetic disk, or optical disc, etc., various media that can store program codes.

[0251] It should be noted that the embodiments in this specification are all described in a progressive manner. For the same or similar parts among the embodiments, reference can be made to each other. Each embodiment focuses on the differences from other embodiments. In particular, for the device and system embodiments, since they are basically similar to the method embodiments, the description is relatively simple. For the relevant parts, reference can be made to the partial description of the method embodiments. The device and system embodiments described above are only illustrative. The units described as separate components may or may not be physically separated. The components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art can understand and implement it without creative efforts.

[0252] The above is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A vehicle speed control method, characterized in that, the method includes: Obtain the first engine speed and the first engine target speed of the vehicle at the first moment; Obtain the second engine speed and the second engine target speed of the vehicle at the second moment; Calculate the engine speed difference according to the first engine speed and the second engine speed; Calculate the engine target speed difference according to the first engine target speed and the second engine target speed; Calculate the speed difference change rate of the first preset time period between the first moment and the second moment according to the engine speed difference and the engine target speed difference; Calculate the error adjustment torque according to the speed difference change rate and the equivalent moment of inertia of the vehicle; Control the operation of the automatic transmission of the vehicle according to the error adjustment torque.

2. The method according to claim 1, characterized in that, the method further includes: Obtain the real-time engine speed of the vehicle; Calculate the expected control torque of the vehicle according to the first preset control torque, the second preset control torque and the real-time engine speed; Determine the maximum value of the error adjustment torque and the expected control torque as the control torque of the vehicle; The controlling the automatic transmission of the vehicle according to the error adjustment torque includes: Control the operation of the automatic transmission of the vehicle according to the control torque.

3. The method according to claim 1, characterized in that, the method further includes: In response to determining that the difference between the expected control torque and the error adjustment torque is less than a preset torque threshold, calculate the clutch speed difference in the second preset time period; In response to determining that the clutch speed difference is greater than a preset slip threshold, based on the clutch speed difference and a first correspondence between a plurality of clutch speed differences and a plurality of preset time values, determine the preset time value corresponding to the clutch speed difference; Calculate the first clutch control torque of the clutch of the vehicle according to the clutch speed difference and the preset time value; Control the clutch of the vehicle according to the first clutch control torque.

4. The method according to claim 3, characterized in that, the method further includes: In response to determining that a third preset time is greater than the preset time value corresponding to the clutch speed difference, calculate the ratio between the third preset time and the preset time value; Perform an equal-proportion reduction operation on the first clutch control torque according to the ratio to obtain a second clutch control torque; Control the clutch of the vehicle according to the second clutch control torque.

5. The method according to claim 4, characterized in that, the method further includes: In response to determining that the clutch speed difference is greater than the clutch speed difference of the previous control cycle of the vehicle, calculate the runaway speed difference according to the clutch speed difference and the clutch speed difference of the previous control cycle; In response to determining that the runaway speed difference is positive, calculate the inertial torque of the clutch of the vehicle according to the runaway speed difference, a preset integral coefficient and the moment of inertia of the clutch of the vehicle; Control the clutch of the vehicle according to the inertial torque.

6. The method according to claim 1, characterized in that, The method further includes: Obtaining the clutch speed regulation control time of the vehicle; In response to determining that the clutch speed regulation control time is greater than a preset speed regulation control time, obtaining the engine acceleration and the engine shaft speed difference of the vehicle; Based on the engine acceleration and the engine shaft speed difference, and based on a second correspondence relationship among a plurality of engine accelerations, a plurality of engine shaft speed differences, and a plurality of clutch engagement rates, determining the clutch engagement rate at which the clutch of the vehicle engages; Controlling the clutch of the vehicle to engage at the clutch engagement rate.

7. The method according to claim 1, wherein, the method further includes: Obtaining the clutch speed regulation control time and the clutch temperature of the vehicle; In response to determining that the clutch speed regulation control time is greater than a fourth preset time, controlling the clutch of the vehicle to engage; In response to determining that the clutch temperature is greater than a preset temperature, controlling the clutch of the vehicle to engage.

8. A vehicle speed regulation control device, wherein, the device includes: A first obtaining unit, configured to obtain a first engine speed and a first engine target speed of the vehicle at a first moment; A second obtaining unit, configured to obtain a second engine speed and a second engine target speed of the vehicle at a second moment; A first calculating unit, configured to calculate an engine speed difference according to the first engine speed and the second engine speed; A second calculating unit, configured to calculate an engine target speed difference according to the first engine target speed and the second engine target speed; A third calculating unit, configured to calculate a speed difference change rate of a first preset time period between the first moment and the second moment according to the engine speed difference and the engine target speed difference; A fourth calculating unit, configured to calculate an error adjustment torque according to the speed difference change rate and the equivalent rotational inertia of the vehicle; A first control unit, configured to control the operation of the automatic transmission of the vehicle according to the error adjustment torque.

9. A computer device, wherein, the computer device includes a processor and a memory: The memory is configured to store program code and transmit the program code to the processor; The processor is configured to execute the vehicle speed regulation control method according to any one of claims 1-7 according to the instructions in the program code.

10. A computer-readable storage medium, wherein, the computer-readable storage medium is configured to store a computer program, and the computer program is configured to execute the vehicle speed regulation control method according to any one of claims 1-7 when being executed by a processor.

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