Control device of vehicle

Abstract

To provide a control device of a vehicle which can suppress occurrence of abnormal vibration.SOLUTION: An electronic control device 90 of a vehicle 10 including a clutch K0 connecting and disconnecting power transmission between an engine 12 and an electric motor MG and a clutch WSC connecting and disconnecting power transmission between the electric motor MG and a pair of driving wheels 14 uses a method comprising the steps of: (a) learning, when a retardation between a crank shaft 30 of the clutch K0 at an engine 12 side and a rotor component MGrt at the electric motor MG side is Δφ in a case that the clutch K0 is in an engagement state and the clutch WSC is in a slip state, a retardation area Δφ_area where variation amount ΔNin of an input shaft 34 at the output side of the clutch WSC is less than a prescribed variation value ΔNin_jdg; and (b) executing, when changing the release state of the clutch K0 to the engagement state, an engagement control of the clutch K0 so that the retardation Δφ is to be within the retardation area Δφ_area.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a control device for a vehicle equipped with a first clutch that connects and disconnects the power transmission between an internal combustion engine and an electric motor, and a second clutch that connects and disconnects the power transmission between the electric motor and a pair of drive wheels. [Background technology]

[0002] In order to suppress the occurrence of abnormal vibrations (= judder) when the clutch is switched from a released state to an engaged state, a technique for reducing waviness on the surface of the friction material in the clutch is known. For example, one such technique is described in Patent Document 1. As described in Patent Document 1, if the surface of the friction material is smooth, the occurrence of abnormal vibrations is suppressed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 8-121516 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, in a vehicle equipped with a first clutch that connects and disconnects the power transmission between an internal combustion engine and an electric motor, and a second clutch that connects and disconnects the power transmission between the electric motor and a pair of drive wheels, even if the surface of the friction material of the second clutch is smooth, when the second clutch is in a slipping state, the friction material and the separator may come into contact at an angle, causing abnormal vibrations.

[0005] The present invention has been made in light of the above circumstances, and an object of the present invention is to provide a vehicle control device that can suppress the occurrence of abnormal vibrations. [Means for solving the problem]

[0006] The gist of the present invention is a control device for a vehicle equipped with a first clutch that connects and disconnects power transmission between an internal combustion engine and an electric motor, and a second clutch that connects and disconnects power transmission between the electric motor and a pair of drive wheels, which (a) learns a phase difference region for the phase difference between the internal combustion engine side rotating member and the electric motor side rotating member in the first clutch when the first clutch is engaged and the second clutch is in a slipping state, in which the rotational fluctuation amount of the output side rotating member of the second clutch is less than a predetermined fluctuation value, and (b) when the first clutch is switched from a released state to an engaged state, performs engagement control of the first clutch so that the phase difference is within the phase difference region. Effect of the Invention

[0007] According to the vehicle control device of the present invention, (a) when the first clutch is in an engaged state and the second clutch is in a slipping state, a phase difference region in which the rotation fluctuation amount of the output side rotating member of the second clutch is less than a predetermined fluctuation value is learned for the phase difference between the internal combustion engine side rotating member and the electric motor side rotating member in the first clutch, and (b) when the first clutch is switched from a released state to an engaged state, engagement control of the first clutch is executed so that the phase difference is within the phase difference region. This avoids abnormal vibration of the vehicle that occurs when the phase difference in the first clutch is outside the phase difference region. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic configuration diagram of a vehicle equipped with an electronic control device according to an embodiment of the present invention, and is also a functional block diagram showing essential parts of control functions for various controls in the vehicle. [Diagram 2] FIG. 11 is an explanatory diagram of the occurrence of abnormal vibrations using cross-sectional views of the clutch K0 and the clutch WSC, where (a) is an axial cross-sectional view of the clutch K0 and the clutch WSC, (b) is a schematic diagram explaining the occurrence of tilt of a rotor part, and (c) is an explanatory diagram of the slip state of the clutch WSC when tilt occurs in the rotor part. [Diagram 3]13 is an example of a learning result of the relationship between the phase difference in the clutch K0 and the amount of fluctuation in the input shaft. [Figure 4] 4 is an example of a flowchart illustrating a control operation of an electronic control device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[0010] FIG. 1 is a schematic diagram of a vehicle 10 equipped with an electronic control device 90 according to an embodiment of the present invention, and is also a functional block diagram showing the main parts of the control functions for various controls in the vehicle 10.

[0011] The vehicle 10 is a hybrid vehicle equipped with an engine 12 and an electric motor MG as power sources for traveling, and a power transmission device 16 provided on a power transmission path PT between the electric motor MG and a pair of drive wheels 14. The vehicle 10 also includes a hydraulic control circuit 60, an inverter 62, a battery 64, and an electronic control device 90.

[0012] The engine 12 is a well-known internal combustion engine and corresponds to the "internal combustion engine" in the present invention. The electric motor MG is, for example, a so-called motor generator, and is a three-phase synchronous motor. The electric motor MG is rotated and driven via an inverter 62 by electric power stored in a battery 64. The power transmission device 16 includes, in order from the engine 12 side in a case 18, a clutch K0, a rotor part MGrt including a rotor of the electric motor MG, a clutch WSC, an input shaft 34, an automatic transmission 22, and the like, as well as an output shaft 36, a differential 24, a pair of axles 38, and the like, which are well-known configurations. The clutch K0 is an engagement device capable of connecting and disconnecting the power transmission between the engine 12 and the electric motor MG, and is, for example, a wet-type multi-plate hydraulic friction engagement device. The rotor part MGrt is a component part disposed between the clutch K0 and the clutch WSC when both are in a released state, and includes a component part connected to the rotor of the electric motor MG. The engine 12 and the clutch K0 are connected by a crankshaft 30. The center line of rotation of the clutch K0, the rotor part MGrt, and the clutch WSC is the axis line CL. The clutch K0 and the clutch WSC correspond to the "first clutch" and the "second clutch" in the present invention, respectively.

[0013] The hydraulic control circuit 60 supplies the necessary hydraulic oil OIL to each part within the case 18 using the hydraulic pressure of the hydraulic oil OIL discharged from, for example, an oil pump (not shown) as a source pressure.

[0014] The vehicle 10 can select an engine driving mode in which the clutch K0 is in an engaged state and engine driving is enabled using at least the engine 12 as a power source for driving. In this specification, the term "engaged state" means a fully engaged state. For example, when the engine driving mode is selected, the clutch K0 is engaged and the clutch WSC is released when the vehicle is stopped. When the vehicle starts moving, the clutch WSC passes through a slip state and is engaged, so that the power of the engine 12 is transmitted to the pair of driving wheels 14. In this specification, unless otherwise specified, the terms torque, driving force, power, and force (power) are synonymous. In engine driving, a required driving torque Trdem [Nm] required by the driver for the pair of driving wheels 14 is calculated based on, for example, the accelerator opening θacc [%] and the vehicle speed V [km / h] operated by the driver.

[0015] FIG. 2 is an explanatory diagram of the occurrence of abnormal vibrations using cross-sectional views of the clutch K0 and the clutch WSC, where (a) is a cross-sectional view of the clutch K0 and the clutch WSC in the direction of the axis CL, (b) is a schematic diagram explaining the occurrence of tilt of the rotor part MGrt, and (c) is an explanatory diagram of the slip state of the clutch WSC when tilt occurs in the rotor part MGrt.

[0016] 2(a), the clutch WSC includes a separator 50 and a friction material 52. For example, the separator 50 is connected to the rotor component MGrt so as to be non-rotatable relative to the rotor component MGrt, and the friction material 52 is connected to the input shaft 34 so as not to be relatively rotatable relative to the rotor component MGrt.

[0017] As shown in FIG. 2(b), when the clutch K0 is in an engaged state, the rotor part MGrt may be tilted according to a phase difference Δφ (=φcrk-φrot) [rad], which is the difference between a rotation angle φcrk [rad] representing the rotation position of the crankshaft 30, which is a rotating member on the engine 12 side of the clutch K0, and a rotation angle φrot [rad] representing the rotation position of the rotor part MGrt, which is a rotating member on the electric motor MG side of the clutch K0. The tilt of the rotor part MGrt occurs due to an imbalance in weight of the rotor part MGrt of the electric motor MG, the clutch K0, and the crankshaft 30 as a whole when the clutch K0 is in an engaged state. The "tilt" here refers to the tilt of the axis CL with respect to a vertical plane. For example, when the phase difference Δφ is a value Δφ1, the tilt of the rotor part MGrt is the largest, and when the phase difference Δφ is a value Δφ2, the tilt of the rotor part MGrt is the smallest.

[0018] As shown in Fig. 2(c), for example, when the rotor part MGrt is tilted and the clutch WSC is in a slipping state when the vehicle starts moving, the separator 50 connected to the rotor part MGrt comes into contact with the friction material connected to the input shaft 34 in an inclined state. In Fig. 2(c), the separator 50 is shown by a solid line in a state in which it is inclined to the (+) side, but when the rotor part MGrt rotates, for example, the separator 50 comes into a state in which it is inclined to the (-) side as shown by a dashed line. When the clutch WSC is in a slipping state, the greater the inclination at which the separator 50 and the friction material 52 come into contact, the greater the abnormal vibration that occurs.

[0019] Returning to Fig. 1, the electronic control device 90 includes a so-called microcomputer equipped with, for example, a CPU, RAM, ROM, an input / output interface, etc., and the CPU executes various controls of the vehicle 10 by performing signal processing according to a program previously stored in the ROM while utilizing the temporary storage function of the RAM. The electronic control device 90 corresponds to the "control device" in the present invention. The electronic control device 90 receives various signals (such as an engine rotation speed Ne [rpm] that is the rotation speed of the engine 12, a rotation angle φcrk, an input shaft rotation speed Nin [rpm] that is the rotation speed of the input shaft 34, an output shaft rotation speed Nout [rpm] that is the rotation speed of the output shaft 36 corresponding to the vehicle speed V, an MG rotation speed Nmg [rpm] that is the rotation speed of the electric motor MG, a rotation angle φrot, an accelerator opening θacc that is the accelerator operation amount by the driver that indicates the magnitude of the driver's acceleration operation, and a state of charge value SOC of the battery 64) based on detection values ​​by various sensors (such as an engine rotation speed sensor 70, an input shaft rotation speed sensor 72, an output shaft rotation speed sensor 74, a MG rotation speed sensor 76, an accelerator opening sensor 78, a battery sensor 80, and the like) respectively. The engine rotation speed sensor 70 is, for example, a resolver that can detect the phase of the crankshaft 30, that is, the rotation direction and rotation speed of the engine 12. The MG rotation speed sensor 76 is, for example, a resolver capable of detecting the phase of the rotor part MGrt, i.e., the rotation direction and rotation speed of the electric motor MG. The state-of-charge value SOC is the ratio of the amount of charge actually stored to a predetermined full charge capacity. From the electronic control device 90, various command signals (for example, an engine control signal Se for controlling the engine 12, a shift control signal Sat for controlling the shifting of the automatic transmission 22, a K0 control signal Sk0 for controlling the engagement and disengagement of the clutch K0, a WSC control signal Swsc for controlling the engagement and disengagement of the clutch WSC, an MG control signal Smg for controlling the rotation of the electric motor MG via the inverter 62, etc.) are output to each device (for example, the engine 12, the hydraulic control circuit 60, the inverter 62, etc.) provided in the vehicle 10. The "engagement and disengagement control" refers to the control of the engagement and disengagement state (released state, slip state, engaged state) of the clutch K0 and the clutch WSC.

[0020] The electronic control device 90 functionally includes a drive control unit 92 and a learning unit 94. The drive control unit 92 functionally includes an engine control unit 92a, an MG control unit 92b, a transmission control unit 92c, a K0 control unit 92d, a WSC control unit 92e, a release determination unit 92f, and a start determination unit 92g. To realize the required drive torque Trdem, the engine control unit 92a controls the output torque of the engine 12, the MG control unit 92b controls the output torque of the electric motor MG, and the transmission control unit 92c controls the gear ratio γat of the automatic transmission 22. The K0 control unit 92d controls the engagement and disengagement of the clutch K0. The WSC control unit 92e controls the engagement and disengagement of the clutch WSC. The learning unit 94 functionally includes an engagement determination unit 94a, a slip determination unit 94b, a phase difference acquisition unit 94c, a fluctuation amount acquisition unit 94d, and a region calculation unit 94e. The learning unit 94 learns a phase difference area Δφ_area, which will be described later, in which abnormal vibration falls within an allowable range when the drive control unit 92 engages the clutch K0 and puts the clutch WSC in a slip state. The engagement determination unit 94a determines whether the clutch K0 is engaged. The slip determination unit 94b determines whether the clutch WSC is in a slip state. When the clutch K0 is engaged, the phase difference acquisition unit 94c calculates and acquires the phase difference Δφ. Note that the "crankshaft 30" and the "rotor part MGrt" correspond to the "internal combustion engine side rotating member" and the "electric motor side rotating member" in the present invention, respectively. When the clutch K0 is engaged and the clutch WSC is in a slip state, the fluctuation amount acquisition unit 94d calculates and acquires the fluctuation amount ΔNin of the input shaft rotation speed Nin. The fluctuation amount ΔNin is the difference between the maximum value and the minimum value of the input shaft rotation speed Nin. The input shaft 34 corresponds to the "output side rotating member of the second clutch" in the present invention, and the fluctuation amount ΔNin corresponds to the "rotation fluctuation amount of the output side rotating member of the second clutch" in the present invention. For example, the input shaft rotation speed Nin is subjected to a successive fast Fourier transform, and further subjected to band pass filter processing to extract the first order component, thereby calculating the fluctuation amount ΔNin.When the phase difference Δφ and the fluctuation amount ΔNin are acquired, the area calculation unit 94e updates the learning map that indicates the correlation between the phase difference Δφ and the fluctuation amount ΔNin, and calculates, that is, learns, the phase difference area Δφ_area in which the fluctuation amount ΔNin is less than a predetermined fluctuation value ΔNin_jdg. The predetermined fluctuation value ΔNin_jdg is a judgment value that is determined in advance experimentally or by design so that the abnormal vibration is within an acceptable range.

[0021] 3 shows an example of a learned result of the relationship between the phase difference Δφ in the clutch K0 and the fluctuation amount ΔNin in the input shaft 34. For example, when the phase difference Δφ varies from 0 to 2π [rad], the magnitude of the fluctuation amount ΔNin varies periodically according to the phase difference Δφ. For example, when the fluctuation amount ΔNin is maximum, the phase difference Δφ has a value Δφ1, and when the fluctuation amount ΔNin is minimum, the phase difference Δφ has a value Δφ2.

[0022] Returning to Fig. 1, the drive control unit 92 executes engine start control, for example, by engaging the clutch K0 and starting the engine 12 with the output torque of the electric motor MG.

[0023] The release determination unit 92f determines whether the clutch K0 is in a released state. The start determination unit 92g determines whether the start of the engine 12 is requested. For example, it is determined that the start is requested when any of the following is true: (a) the required drive torque Trdem exceeds a range that can be covered only by the output torque of the electric motor MG, (b) the engine 12, etc. needs to be warmed up, and (c) the state of charge value SOC is less than a predetermined engine start threshold. The predetermined engine start threshold is a predetermined threshold for determining that the state of charge value SOC is at a level at which the engine 12 needs to be automatically started and the battery 64 needs to be charged.

[0024] When the start determination unit 92g determines that the start of the engine 12 is requested, the K0 control unit 92d executes engagement control to switch the clutch K0 from an engaged state to an engaged state via a slip state in order to transmit the cranking torque Tcr [Nm] from the electric motor MG side to the engine 12 side. The K0 control unit 92d controls the phase difference Δφ to be in the engaged state within the phase difference region Δφ_area. For example, when the clutch K0 is in the final stage of the slip state (=slightly before the engaged state), the phase difference Δφ changes relatively slowly, so that it is easy to make the phase difference Δφ in the engaged state within the phase difference region Δφ_area. For example, when the clutch K0 is engaged when the phase difference Δφ is outside the phase difference region Δφ_area, the hydraulic pressure supplied to the hydraulic actuator controlling the engagement / disengagement state of the clutch K0 is slightly lowered to cause the clutch K0 to slip again and the phase difference Δφ is gradually changed, and then the hydraulic pressure supplied to the hydraulic actuator is increased so that the phase difference Δφ is within the phase difference region Δφ_area and the clutch K0 is engaged again. Preferably, in order to suppress a decrease in drivability, when the required drive torque Trdem is equal to or less than a predetermined torque value Trdem_jdg, control is executed in which the clutch K0 is slipped again and then engaged again. The predetermined torque value Trdem_jdg is a judgment value that is experimentally or design-based and that allows the decrease in drivability to be within an allowable range.

[0025] Fig. 4 is an example of a flowchart illustrating the control operation of the electronic control unit 90. The flowchart in Fig. 4 is repeatedly executed.

[0026] First, in step (hereinafter, step will be omitted) S10, it is determined whether the clutch K0 is in an engaged state. If the determination in S10 is YES, the phase difference Δφ is acquired in S20, and it is determined whether the clutch WSC is in a slipping state in S30. If the determination in S30 is YES, the fluctuation amount ΔNin is acquired in S40, and the phase difference area Δφ_area is calculated in S50. If the determination in S10 is NO, it is determined in S60 whether a start of the engine 12 has been requested. If the determination in S60 is YES, engagement control of the clutch K0 is executed in S70 so that the phase difference Δφ is in an engaged state within the phase difference area Δφ_area. If the determination in S30 is NO, after the execution of S50, if the determination in S60 is NO, and after the execution of S70, the process returns.

[0027] According to this embodiment, (a) when the clutch K0 is in an engaged state and the clutch WSC is in a slipping state, a phase difference region Δφ_area in which the fluctuation amount ΔNin is less than a predetermined fluctuation value ΔNin_jdg is learned, and (b) when the clutch K0 is switched from a released state to an engaged state, engagement control of the clutch K0 is executed so that the phase difference Δφ is within the phase difference region Δφ_area. This avoids abnormal vibration of the vehicle 10 that occurs when the phase difference Δφ in the clutch K0 is outside the phase difference region Δφ_area.

[0028] It should be noted that the above is an embodiment of the present invention, and the present invention can be embodied in various forms with various modifications and improvements based on the knowledge of those skilled in the art without departing from the spirit of the present invention.

[0029] In the above embodiment, the fluctuation amount ΔNin of the input shaft 34 is acquired based on the input shaft rotation speed Nin. However, for example, the acceleration Acc [m / sec] of the vehicle 10 in the longitudinal direction, which changes depending on the fluctuation amount ΔNin, may be acquired based on the input shaft rotation speed Nin. 2 ] is equivalent to the fluctuation amount ΔNin.

[0030] In the above-described embodiment, the vehicle 10 is a two-wheel drive vehicle. However, for example, if the vehicle is a four-wheel drive vehicle, a pair of wheels other than the pair of drive wheels 14 may be driven by another electric motor other than the electric motor MG so as to realize the required drive torque Trdem when the engagement control of the clutch K0 is executed. [Explanation of symbols]

[0031] 10: vehicle, 12: engine (internal combustion engine), 14: pair of drive wheels, 30: crankshaft (internal combustion engine side rotating member), 34: input shaft (output side rotating member of second clutch), 90: electronic control device (control device), K0: clutch (first clutch), MG: electric motor, MGrt: rotor part (electric motor side rotating member), WSC: clutch (second clutch), ΔNin: fluctuation amount (rotation fluctuation amount of output side rotating member of second clutch), ΔNin_jdg: predetermined fluctuation value, Δφ: phase difference, Δφ_area: phase difference area

Claims

[Claim 1] A control device for a vehicle including a first clutch that connects and disconnects power transmission between an internal combustion engine and an electric motor, and a second clutch that connects and disconnects power transmission between the electric motor and a pair of drive wheels, when the first clutch is in an engaged state and the second clutch is in a slip state, a phase difference region in which a rotation fluctuation amount of an output side rotating member of the second clutch is less than a predetermined fluctuation value is learned for a phase difference between the internal combustion engine side rotating member and the electric motor side rotating member in the first clutch, When the first clutch is switched from a released state to an engaged state, engagement control of the first clutch is executed so that the phase difference is within the phase difference region. A vehicle control device comprising:

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