Vehicle control device

Abstract

To provide a control device for a vehicle having a continuously variable transmission which can easily suppress fore-and-aft vibration of a vehicle during running.SOLUTION: Filtering is applied to a hydraulic control command value Pindi, an amount of correction Pcrt is calculated based on a vibration component Pvib which is extracted by subtracting a filtered filtering value Pfilt and the hydraulic control command value Pindi, and the amount of correction Pcrt is subtracted from the hydraulic control command value Pindi, thereby calculating a corrected correction hydraulic command value Pindic. Consequently, fluctuation of the hydraulic control command value Pindi can be suppressed. Also, having a wide frequency band for filtering allows stable handling of a variable frequency based on a gear change ratio γcvt of a continuously variable transmission 18. Furthermore, when a sufficient vibration suppression effect cannot be achieved by directly extracting the vibration component Pvib, the amount of correction Pcrt is adjusted by a PI-controller 88 as appropriate.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a control device for a vehicle having a continuously variable transmission. [Background technology]

[0002] Patent Document 1 describes that in a vehicle having a continuously variable transmission, longitudinal vibration of the vehicle is generated by coupling torque fluctuations occurring in a predetermined frequency band with the gear shifting of the continuously variable transmission, and that longitudinal vibration of the vehicle is suppressed by performing phase lead compensation. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-52731 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in Patent Document 1, the compensation amount (gain) and the phase lead amount during compensation depend on the designed compensator. As a result, it becomes necessary to redesign the compensator when the characteristics are deviated, the compensation amount is insufficient, or the phase lead amount is too much or too little. This design becomes even more difficult in powertrains where the resonant frequency is variable depending on the gear ratio, such as continuously variable transmissions.

[0005] The present invention has been made against the background of the above circumstances, and its object is to provide a control device for a vehicle having a continuously variable transmission that can easily suppress front-to-rear vibrations of the vehicle while it is running. [Means for solving the problem]

[0006] The gist of the present invention is (a) a control device for a vehicle having a continuously variable transmission capable of continuously changing a gear ratio, (b) a filter processing unit that filters a hydraulic control command value of the continuously variable transmission, (c) a vibration component extraction unit that extracts a vibration component by subtracting a calculated value after the filter processing from the hydraulic control command value, and (d) a control unit that extracts a vibration component based on the vibration component. , so that the value becomes larger as the vibration damping effect of the vibration component becomes insufficient. The hydraulic control system is characterized by comprising: (a) a correction amount calculation unit that calculates a correction amount for the hydraulic control command value; and (e) a command value correction unit that calculates a corrected hydraulic control command value by subtracting the correction amount from the hydraulic control command value. [Effects of the Invention]

[0007] According to the present invention, a hydraulic control command value is filtered, and a calculation is performed based on a vibration component extracted by subtracting the filtered calculated value from the hydraulic control command value. , the hydraulic control command value is set to a larger value as the vibration damping effect of the vibration component is insufficient. By calculating a correction amount and subtracting the correction amount from the hydraulic control command value, the corrected hydraulic control command value is calculated, thereby suppressing fluctuations in the hydraulic control command value. Furthermore, by providing a wide frequency band for filter processing, it becomes possible to stably respond to variable frequencies based on the gear ratio of the continuously variable transmission. Furthermore, if extracting direct vibration components does not provide a sufficient vibration damping effect, an appropriate vibration damping effect can be achieved by adjusting the correction amount appropriately. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating a schematic configuration of a vehicle to which the present invention is applied, and is also a diagram illustrating control functions and main parts of a control system for various controls in the vehicle. [Figure 2] 4 is a flowchart showing a flow of calculation of a corrected hydraulic control command value from a hydraulic control command value. [Figure 3] FIG. 3 is a diagram showing a control state based on FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that in the following embodiments, the drawings are appropriately simplified or modified, and the dimensional ratios and shapes of the various parts are not necessarily drawn accurately. [Example]

[0010] Fig. 1 is a diagram illustrating the schematic configuration of a vehicle 10 to which the present invention is applied, and also illustrates the main parts of the control functions and control systems for various controls in the vehicle 10. In Fig. 1, the vehicle 10 is equipped with an engine 12 as a power source for traveling, a torque converter 14, a forward / reverse switching device 16, a belt-type continuously variable transmission 18 (hereinafter referred to as continuously variable transmission 18), a reduction gear device 20, a differential gear device 22, a pair of left and right front wheels 24L, 24R, etc.

[0011] The forward / reverse switching device 16 is mainly composed of a forward clutch C1, a reverse brake B1, and a double-pinion planetary gear set 16p. Because the forward / reverse switching device 16 is well known, detailed description of its structure and operation will be omitted.

[0012] The continuously variable transmission 18 includes an input-side primary pulley 26 that serves as an input-side member and has a variable effective diameter, an output-side secondary pulley 28 that serves as an output-side member and has a variable effective diameter, and a power transmission belt 30 that is wound between the primary pulley 26 and the secondary pulley 28. The continuously variable transmission 18 transmits power via frictional forces between the primary pulley 26, the secondary pulley 28 and the power transmission belt 30.

[0013] The input side primary pulley 26 is equipped with a fixed sheave 26a as an input side fixed rotating body, a movable sheave 26b as an input side movable rotating body, and a hydraulic actuator (hydraulic cylinder) 26c that applies an input side thrust (primary thrust) Wpri (= primary pressure Ppri × pressure receiving area) to change the V-groove width between the fixed sheave 26a and the movable sheave 26b.

[0014] The output side secondary pulley 28 is equipped with a fixed sheave 28a as an output side fixed rotating body, a movable sheave 28b as an output side movable rotating body, and a hydraulic actuator 28c that applies a thrust (secondary thrust) Wsec (= secondary pressure Psec × pressure-receiving area) to change the V-groove width between the fixed sheave 28a and the movable sheave 28b.

[0015] In the continuously variable transmission 18, the primary pressure Ppri, which is the hydraulic pressure supplied to the hydraulic actuator 26c of the primary pulley 26, and the secondary pressure Psec, which is the hydraulic pressure supplied to the hydraulic actuator 28c of the secondary pulley 28, are each regulated and controlled by a hydraulic control circuit 40, thereby controlling the primary thrust Wpri and the secondary thrust Wsec. As a result, by changing the V-groove widths of the primary pulley 26 and the secondary pulley 28, the gear ratio γcvt of the continuously variable transmission 18 can be continuously changed.

[0016] The vehicle 10 is equipped with an electronic control device 50 for executing various controls, including shift control of the continuously variable transmission 18.

[0017] Various input signals based on detection values ​​detected by various sensors (52, 54, 56, 58, 60, 62, etc.) provided on the vehicle 10 are input to the electronic control device 50. For example, various signals representing the engine rotation speed Ne (rpm), turbine rotation speed Nt (rpm), input rotation speed Nin (rpm), output rotation speed Nout (rpm) corresponding to vehicle speed V (km / h), accelerator opening θacc (°), throttle valve opening θth (°), etc. are input.

[0018] The electronic control device 50 outputs, for example, a command signal Se for controlling the engine output of the engine 12, a CVT hydraulic control command signal Scvt for hydraulic control related to the shifting of the continuously variable transmission 18, and a hydraulic control command signal Sc for hydraulic control related to the engagement operation of the forward clutch C1 and the reverse brake B1.

[0019] The electronic control device 50 functionally comprises an engine control section for controlling the engine 12, a continuously variable transmission control section for controlling the continuously variable transmission 18, and the like.

[0020] In a vehicle 10 equipped with the above-described continuously variable transmission 18, when torque fluctuations occurring at the resonant frequency of the powertrain and hydraulic vibrations caused by vibrations in the primary pressure Ppri and secondary pressure Psec influence each other and overlap to generate coupled vibrations, vehicle longitudinal vibrations may occur. In response to this, the electronic control device 50 has a function of appropriately adjusting the command pressure for the primary pressure Ppri and the command pressure for the secondary pressure Psec to suppress the hydraulic vibrations and thereby suppress vehicle longitudinal vibrations. Note that, below, the command pressure for the primary pressure Ppri and the command pressure for the secondary pressure Psec of the continuously variable transmission 18 will be collectively described as the hydraulic control command value Pindi for the continuously variable transmission 18.

[0021] The electronic control unit 50 functionally comprises a filter processing unit 80, a vibration component extraction unit 82, a correction amount calculation unit 84, and a command value correction unit 86, which are executed to suppress vehicle longitudinal vibration.

[0022] The filter processing unit 80 filters the hydraulic control command value Pindi to remove vibration components in a predetermined frequency band. For example, a band elimination filter or a low-pass filter is applied to the hydraulic control command value Pindi to remove vibration components in the predetermined frequency band, and the hydraulic control command value Pindi becomes a smoothed filtered value Pfilt. Here, the predetermined frequency band is determined in advance by experiment or design, and is set to, for example, a band in which hydraulic vibration occurs (i.e., a resonance frequency band). Furthermore, in the continuously variable transmission 18, the resonance frequency changes depending on the gear ratio γcvt, so the frequency band is set to a wide band taking into consideration the gear ratio γcvt of the continuously variable transmission 18.

[0023] The vibration component extracting unit 82 subtracts the filtered value Pfilt from the hydraulic control command value Pindi to extract the vibration component Pvib (=Pindi-Pfilt).

[0024] The correction amount calculation unit 84 calculates the correction amount Pcrt based on PI control by applying a PI controller 88 to the vibration component Pvib. In PI control, FB control is executed to appropriately adjust the correction amount Pcrt based on the vibration component Pvib, so that, for example, if the vibration damping effect is insufficient, the correction amount Pcrt is increased by PI control via the PI controller 88. In this way, the correction amount Pcrt is adjusted appropriately, thereby improving the vibration damping effect.

[0025] The command value corrector 86 calculates a corrected hydraulic control command value Pindic after correction by subtracting the correction amount Pcrt from the hydraulic control command value Pindi. This corrected hydraulic control command value Pindic is set as the new hydraulic control command value Pindi. By correcting the hydraulic control command value Pindi in this manner, hydraulic vibrations in the primary pressure Ppri and the secondary pressure Psec are suppressed, and fluctuations in the command values ​​of the primary pressure Ppri and the secondary pressure Psec are suppressed. As a result, vehicle longitudinal vibrations caused by hydraulic vibrations are suppressed. Furthermore, in the continuously variable transmission 18, the resonance frequency changes depending on the gear ratio γcvt, but by setting a wide frequency band for filtering, it is possible to stably respond to variable resonance frequencies.

[0026] Fig. 2 is a flow chart showing the flow from the hydraulic control command value Pindi to the calculation of the corrected hydraulic control command value Pindic Fig. 3 is a diagram showing the control state based on Fig. 2.

[0027] In FIG. 2, first, when the hydraulic control command value Pindi is given, filtering is performed. For example, as shown in FIG. 2, filtering is performed such that the gain G is reduced in a predetermined frequency band, thereby removing vibration components in the predetermined frequency band and calculating a filtered value Pfilt. This state corresponds to the states in FIGS. 3(a) to 3(c). Next, the filtered value Pfilt is subtracted from the hydraulic control command value Pindi to extract the vibration component Pvib, and PI control is performed on the vibration component Pvib by the PI controller 88 to calculate a correction amount Pcrt after PI control. Next, the correction amount Pcrt is subtracted from the hydraulic control command value Pindi to calculate a corrected hydraulic control command value Pindic after correction. This state corresponds to the states in FIGS. 3(d) to 3(f). In FIG. 3(f), the dashed line corresponds to the corrected hydraulic control command value Pindic. As shown by the dashed line in Figure 3(f), for example, by providing a command value in the opposite phase to the hydraulic control command value Pindi in Figure 3(a), hydraulic vibrations in the primary pressure Ppri and the secondary pressure Psec are suppressed, thereby suppressing vehicle longitudinal vibrations.

[0028] As described above, according to this embodiment, the hydraulic control command value Pindi is filtered, the correction amount Pcrt is calculated based on the vibration component Pvib extracted by subtracting the filtered value Pfilt (calculated value) from the hydraulic control command value Pindi, and the corrected hydraulic control command value Pindic is calculated by subtracting the correction amount Pcrt from the hydraulic control command value Pindi, thereby suppressing fluctuations in the hydraulic control command value Pindi. Furthermore, by providing a wide frequency band for filtering, it is possible to stably respond to variable frequencies based on the gear ratio γcvt of the continuously variable transmission 18. Furthermore, if extracting the direct vibration component Pvib does not provide a sufficient vibration damping effect, the PI controller 88 appropriately adjusts the correction amount Pcrt, thereby improving the vibration damping effect.

[0029] It should be noted that the above is merely one embodiment, and the present invention can be implemented in various forms with various modifications and improvements based on the knowledge of those skilled in the art. [Explanation of symbols]

[0030] 18: Continuously variable transmission 50: Electronic control unit (control unit) 80: Filter processing unit 82: Vibration component extraction unit 84: Correction amount calculation unit 86: Command value correction unit

Claims

[Claim 1] A control device for a vehicle having a continuously variable transmission capable of continuously changing a gear ratio, a filter processing unit that filters a hydraulic control command value of the continuously variable transmission; a vibration component extraction unit that extracts a vibration component by subtracting the calculated value after the filter processing from the hydraulic control command value; a correction amount calculation unit that calculates a correction amount of the hydraulic control command value based on the vibration component so that the correction amount becomes larger as the vibration damping effect of the vibration component becomes insufficient; a command value correcting unit that calculates a corrected hydraulic control command value by subtracting the correction amount from the hydraulic control command value. A vehicle control device comprising:

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