JP5180888B2 - Control device for electric vehicle - Google Patents

Description

  The present invention relates to a control device for an electric vehicle that controls a line pressure that is a source pressure of an operating hydraulic pressure that fastens or releases a drive train frictional engagement element applied to the electric vehicle.

  Conventionally, the line pressure, which is the source pressure of the hydraulic pressure for engaging or releasing the clutch or brake of the automatic transmission, is as small as possible within the range in which the clutch or brake does not slip depending on the operating state of the automatic transmission. Is controlled. For this reason, it is known that when the slip occurs in the clutch, the line pressure is increased and corrected based on the slip amount (see, for example, Patent Document 1).

JP 2007-15679 A

  By the way, in the conventional control of the line pressure, since the line pressure is corrected to be increased after the slip has occurred in the clutch, the clutch that is increasing in rotation is suppressed to suppress the slip. Therefore, the burden of the clutch becomes large, and there is a possibility that the durability is lowered.

  Further, since the line pressure is increased and corrected based on the slip amount, the calculation of the correction amount of the line pressure becomes complicated, the accuracy of calculating an appropriate line pressure correction amount is poor, and while suppressing the occurrence of slipping of the clutch, an extra amount is required. It has been difficult to set an appropriate line pressure so that the minimum value has no margin.

  The present invention has been made paying attention to the above problem, and while suppressing the slip fastening of the frictional engagement element, it suppresses the decrease in the durability of the frictional engagement element, and increases the correction accuracy of the line pressure to set an excessive line pressure. An object of the present invention is to provide a control device for an electric vehicle that can be prevented.

In order to achieve the above object, the present invention controls an operating hydraulic pressure that is provided on a power transmission path between an electric motor as a traveling drive source and the electric motor and driving wheels, and uses a line pressure as a source pressure. In the control apparatus for an electric vehicle including line pressure setting means for setting the line pressure according to an operating state of the electric vehicle having a friction engagement element that switches between an engagement / release state, the line pressure setting means includes the friction pressure Slip detecting means for detecting the slip engagement state of the engagement element; and when the slip engagement state of the friction engagement element is detected, the rotational speed control of the electric motor is executed , and the input rotation speed to the friction engagement element is determined. Based on a slip suppression means that matches a target rotational speed, and an input torque change amount to the friction engagement element that occurs in association with the rotational speed control of the electric motor by the slip suppression means, Line pressure learning correction means for learning and correcting the line pressure.

  Therefore, in the control apparatus for an electric vehicle according to the present invention, when the slip engagement state of the frictional engagement element is detected by the slip detection means, the rotational speed control of the motor is executed by the slip suppression means and the slip engagement state is suppressed. At the same time, the line pressure is learned and corrected by the line pressure learning correction means based on the amount of change in the input torque to the frictional engagement element caused by the rotation speed control of the electric motor.

  That is, since slip suppression is controlled by controlling the number of revolutions of the electric motor, slip fastening can be suppressed without pressing the frictional engagement element, and a decrease in durability of the frictional engagement element can be suppressed. In addition, since the learning correction of the line pressure is made based on the amount of change in the input torque accompanying the rotation speed control of the motor, the line pressure is calculated by the hydraulic pressure conversion calculation method based on the torque conventionally used in ordinary automatic transmissions. The learning correction amount can be calculated.

  As a result, it is possible to suppress a decrease in durability of the frictional engagement element while suppressing slip engagement of the frictional engagement element, and it is possible to increase the correction accuracy of the line pressure and prevent excessive line pressure setting.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall system diagram showing an FR hybrid vehicle (an example of an electric vehicle) by rear wheel drive to which an electric vehicle control device of Embodiment 1 is applied. It is a control block diagram which shows the arithmetic processing performed with the integrated controller of FR hybrid vehicle to which the control apparatus of the electric vehicle of Example 1 was applied. It is a figure which shows the EV-HEV selection map used when performing the mode selection process in the integrated controller of FR hybrid vehicle to which the control apparatus of the electric vehicle of Example 1 is applied. It is a figure which shows the target charging / discharging amount map used when performing battery charge control with the integrated controller of FR hybrid vehicle to which the control apparatus of the electric vehicle of Example 1 was applied. 1 is a skeleton diagram showing an example of an automatic transmission AT mounted in an FR hybrid vehicle to which an electric vehicle control device of Embodiment 1 is applied. FIG. It is a fastening operation | movement table | surface which shows the fastening state of each friction fastening element for every gear stage in automatic transmission AT mounted in the FR hybrid vehicle to which the control apparatus of the electric vehicle of Example 1 was applied. It is a flowchart which shows the flow of the minimum line pressure setting process performed with the control apparatus of the electric vehicle of Example 1. FIG. It is a schematic diagram which shows the relationship between the change of working oil pressure learning correction amount, and the change of the difference of the target transmission torque and actual transmission torque accompanying working oil pressure learning correction. It is a map which shows the relationship between a clutch input torque correction amount and a line pressure correction amount. In the control apparatus for the electric vehicle according to the first embodiment, a line pressure characteristic diagram and a clutch input rotation speed / clutch input torque at the time of occurrence of idling of the travel drive source before the line pressure learning correction are shown. In the control apparatus of the electric vehicle of Example 1, it is the time chart which shows the line pressure characteristic figure after line pressure learning correction | amendment, and clutch input rotation speed and clutch input torque.

  Hereinafter, the best mode for realizing an electric vehicle control apparatus of the present invention will be described based on Example 1 shown in the drawings.

First, the configuration will be described.
FIG. 1 is an overall system diagram showing a rear-wheel drive FR hybrid vehicle (an example of an electric vehicle) to which the control apparatus for an electric vehicle according to the first embodiment is applied.

  As shown in FIG. 1, the drive system of the FR hybrid vehicle in the first embodiment includes an engine Eng, a flywheel FW, a first clutch CL1, a motor / generator (motor) MG, a second clutch CL2, and an automatic The transmission AT, the propeller shaft PS, the differential DF, the left drive shaft DSL, the right drive shaft DSR, the left rear wheel RL, and the right rear wheel RR are included. Note that FL is the left front wheel and FR is the right front wheel.

  The engine Eng is a travel drive source composed of a gasoline engine or a diesel engine. Based on an engine control command from the engine controller 1, engine start control, engine stop control, throttle valve opening control, fuel cut control, etc. Is done. The engine output shaft is provided with a flywheel FW.

  The first clutch CL1 is a clutch interposed between the engine Eng and the motor / generator MG, and is generated by the first clutch hydraulic unit 6 based on a first clutch control command from the first clutch controller 5. Engagement / slip engagement (half-clutch state) / release is controlled by the first clutch control oil pressure. As the first clutch CL1, for example, a normally closed dry type in which a complete engagement is maintained by an urging force of a diaphragm spring and a stroke control using a hydraulic actuator 14 having a piston 14a is controlled from a slip engagement to a complete release. A single plate clutch is used.

  The motor / generator MG is a traveling drive source composed of a synchronous motor / generator in which a permanent magnet is embedded in a rotor and a stator coil is wound around a stator, and is driven by an inverter 3 based on a control command from the motor controller 2. Controlled by applying the created three-phase alternating current. The motor / generator MG can operate as an electric motor that is driven to rotate by receiving power supplied from the battery 4 (hereinafter, this operation state is referred to as “powering”), and the rotor is driven from the engine Eng or the drive wheel. When receiving rotational energy, it functions as a generator that generates electromotive force at both ends of the stator coil, and can also charge the battery 4 (hereinafter, this operation state is referred to as “regeneration”). Note that the rotor of the motor / generator MG is connected to the transmission input shaft of the automatic transmission AT via a damper.

  The second clutch CL2 is provided on the power transmission path between the motor / generator MG and the left and right rear wheels RL, RR, and the engaged / released state is switched by controlling the operating hydraulic pressure using the line pressure as a source pressure. It is a friction fastening element. The control of the engagement / slip engagement / release state of the second clutch CL2 is performed by the control hydraulic pressure generated by the second clutch hydraulic unit 8 based on the second clutch control command from the AT controller 7. As the second clutch CL2, for example, a normally open wet multi-plate clutch or wet multi-plate brake capable of continuously controlling the oil flow rate and hydraulic pressure with a proportional solenoid is used. Here, each shift stage of the automatic transmission AT is used. Any of the plurality of frictional engagement elements that are fastened at the time corresponds to.

  The first clutch hydraulic unit 6 and the second clutch hydraulic unit 8 are built in an AT hydraulic control valve unit CVU attached to the automatic transmission AT.

  The AT hydraulic control valve unit CVU supplies hydraulic oil to the second clutch CL2 and the like, and controls the hydraulic pressure supplied from the hydraulic pressure (line pressure) supplied from an oil pump (not shown) as a source pressure. Here, the line pressure is regulated by controlling the solenoid valve 7 a by the AT controller 7.

  The automatic transmission AT is, for example, a stepped transmission that automatically switches stepped speeds such as forward 7 speed / reverse speed 1 according to vehicle speed, accelerator opening, etc., and the second clutch CL2 Is not newly added as a dedicated clutch, but selects the most suitable clutch or brake to be placed in the torque (power) transmission path among the multiple friction engagement elements that are engaged at each gear stage of the automatic transmission AT doing. The output shaft of the automatic transmission AT is connected to the left and right rear wheels RL and RR via a propeller shaft PS, a differential DF, a left drive shaft DSL, and a right drive shaft DSR.

  The hybrid drive system of the first embodiment includes an electric vehicle travel mode (hereinafter referred to as “EV mode”), a hybrid vehicle travel mode (hereinafter referred to as “HEV mode”), and a drive torque control travel mode (hereinafter referred to as “ It has a driving mode such as “WSC mode”.

  The “EV mode” is a mode in which the first clutch CL1 is disengaged and the vehicle travels only with the power of the motor / generator MG. That is, this is a mode in which only the motor / generator MG is used as a driving source. The “HEV mode” is a mode in which the first clutch CL1 is engaged and the vehicle travels in any of the motor assist travel mode, travel power generation mode, and engine travel mode. That is, this is a mode in which the travel drive source includes at least the engine Eng. The "WSC mode" is used to control the rotational speed of the motor / generator MG when P, N → D select starts from the "HEV mode" or when the D range starts from the "EV mode" or "HEV mode". This mode maintains the slip engagement state of the second clutch CL2 and starts while controlling the clutch torque capacity so that the transmission torque passing through the second clutch CL2 becomes the required drive torque determined according to the vehicle state and driver operation. It is. “WSC” is an abbreviation for “Wet Start clutch”.

Next, the control system of the hybrid vehicle will be described.
As shown in FIG. 1, the control system of the FR hybrid vehicle in the first embodiment includes an engine controller 1, a motor controller 2, an inverter 3, a battery 4, a first clutch controller 5, and a first clutch hydraulic unit 6. And an AT controller 7, a second clutch hydraulic unit 8, a brake controller 9, and an integrated controller 10. The engine controller 1, the motor controller 2, the first clutch controller 5, the AT controller 7, the brake controller 9, and the integrated controller 10 are connected via a CAN communication line 11 that can mutually exchange information. ing.

  The engine controller 1 inputs engine speed information from the engine speed sensor 12, a target engine torque command from the integrated controller 10, and other necessary information. Then, a command for controlling the engine operating point (Ne, Te) is output to the throttle valve actuator or the like of the engine Eng.

  The motor controller 2 inputs information from the resolver 13 that detects the rotor rotational position of the motor / generator MG, a target MG torque command and a target MG rotational speed command from the integrated controller 10, and other necessary information. Then, a command for controlling the motor operating point (Nm, Tm) of the motor / generator MG is output to the inverter 3. The motor controller 2 monitors the battery SOC representing the charge capacity of the battery 4, and this battery SOC information is used as control information for the motor / generator MG and is integrated via the CAN communication line 11. 10 is supplied.

  The first clutch controller 5 inputs sensor information from the first clutch stroke sensor 15 that detects the stroke position of the piston 14a of the hydraulic actuator 14, a target CL1 torque command from the integrated controller 10, and other necessary information. . Then, a command for controlling engagement / slip engagement / release of the first clutch CL1 is output to the first clutch hydraulic unit 6 in the AT hydraulic control valve unit CVU.

  The AT controller 7 inputs information from an accelerator opening sensor 16, a vehicle speed sensor 17, and other sensors 18 (transmission input rotation speed sensor, inhibitor switch, etc.). Then, when driving with the D range selected, a control command for obtaining the searched gear position is searched for the optimum gear position based on the position where the operating point determined by the accelerator opening APO and the vehicle speed VSP exists on the shift map. Output to AT hydraulic control valve unit CVU. The shift map is a map in which an upshift line and a downshift line are written according to the accelerator opening and the vehicle speed. In addition to the above automatic shift control, when a target CL2 torque command is input from the integrated controller 10, a command for controlling slip engagement of the second clutch CL2 is output to the second clutch hydraulic unit 8 in the AT hydraulic control valve unit CVU. Second clutch control is performed. Further, when a shift control change command is output from the integrated controller 10, a shift control according to the shift control change command is performed instead of the normal shift control.

  The brake controller 9 inputs a wheel speed sensor 19 for detecting the wheel speeds of the four wheels, sensor information from the brake stroke sensor 20, a regenerative cooperative control command from the integrated controller 10, and other necessary information. And, for example, at the time of brake depression, if the regenerative braking force is insufficient with respect to the required braking force required from the brake stroke BS, the shortage is compensated with mechanical braking force (hydraulic braking force or motor braking force) Regenerative cooperative brake control is performed.

  The integrated controller 10 manages the energy consumption of the entire vehicle and has a function for running the vehicle with the highest efficiency. The motor rotation number sensor 21 for detecting the motor rotation number Nm and other sensors and switches 22 Necessary information and information via the CAN communication line 11 are input. The target engine torque command to the engine controller 1, the target MG torque command and the target MG speed command to the motor controller 2, the target CL1 torque command to the first clutch controller 5, the target CL2 torque command to the AT controller 7, and the brake controller 9 Regenerative cooperative control command is output.

  FIG. 2 is a control block diagram illustrating arithmetic processing executed by the integrated controller 10 of the FR hybrid vehicle to which the control device for the electric vehicle according to the first embodiment is applied. FIG. 3 is a diagram illustrating an EV-HEV selection map used when mode selection processing is performed in the integrated controller 10 of the FR hybrid vehicle to which the electric vehicle control apparatus according to the first embodiment is applied. FIG. 4 is a diagram illustrating a target charge / discharge amount map used when the battery charging control is performed by the integrated controller 10 of the FR hybrid vehicle to which the control device for the electric vehicle according to the first embodiment is applied. Hereinafter, based on FIGS. 2-4, the arithmetic processing performed in the integrated controller 10 of Example 1 is demonstrated.

  As shown in FIG. 2, the integrated controller 10 includes a target driving force calculation unit 100, a mode selection unit 200, a target charge / discharge calculation unit 300, and an operating point command unit 400.

  The target driving force calculation unit 100 calculates a target driving force tFoO from the accelerator opening APO and the vehicle speed VSP using the target driving force map.

  The mode selection unit 200 uses the EV-HEV selection map shown in FIG. 3 to select “EV mode” or “HEV mode” as the target travel mode from the accelerator opening APO and the vehicle speed VSP. However, if the battery SOC is equal to or lower than the predetermined value, the “HEV mode” is forcibly set as the target travel mode. Further, at the time of P, N → D selection start from the “HEV mode”, the “WSC mode” is selected as the target travel mode until the vehicle speed VSP reaches the first set vehicle speed VSP1.

  The target charge / discharge calculation unit 300 calculates the target charge / discharge power tP from the battery SOC using the target charge / discharge amount map shown in FIG.

  In the operating point command unit 400, based on input information such as the accelerator opening APO, the target driving force tFoO, the target travel mode, the vehicle speed VSP, the target charge / discharge power tP, etc., the target engine torque is set as the operating point reaching target. And target MG torque, target MG rotation speed, target CL1 torque, and target CL2 torque. Then, the target engine torque command, the target MG torque command, the target MG rotational speed command, the target CL1 torque command, and the target CL2 torque command are output to the controllers 1, 2, 5, and 7 via the CAN communication line 11.

  FIG. 5 is a skeleton diagram illustrating an example of an automatic transmission AT mounted on an FR hybrid vehicle to which the control device for an electric vehicle according to the first embodiment is applied.

  The automatic transmission AT is a stepped automatic transmission with 7 forward speeds and 1 reverse speed, and driving force from at least one of the engine Eng and the motor generator MG is input from the transmission input shaft Input, The rotational speed is changed by the planetary gear and the seven frictional engagement elements, and is output from the transmission output shaft Output. Next, a transmission gear mechanism between the transmission input shaft Input and the transmission output shaft Output will be described.

  The first planetary gear set GS1, the third planetary gear G3, and the fourth planetary gear G4 by the first planetary gear G1 and the second planetary gear G2 are sequentially arranged on the shaft from the transmission input shaft Input side to the transmission output shaft Output side. The second planetary gear set GS2 by is arranged. Further, a first clutch C1, a second clutch C2, a third clutch C3, a first brake B1, a second brake B2, a third brake B3, and a fourth brake B4 are arranged as friction engagement elements. Further, a first one-way clutch F1 and a second one-way clutch F2 are arranged.

  The first planetary gear G1 is a single pinion planetary gear having a first sun gear S1, a first ring gear R1, and a first carrier PC1 that supports a first pinion P1 that meshes with both gears S1, R1. .

  The second planetary gear G2 is a single pinion type planetary gear having a second sun gear S2, a second ring gear R2, and a second carrier PC2 that supports a second pinion P2 meshing with both gears S2 and R2. .

  The third planetary gear G3 is a single pinion planetary gear having a third sun gear S3, a third ring gear R3, and a third carrier PC3 that supports a third pinion P3 that meshes with both gears S3 and R3. .

  The fourth planetary gear G4 is a single pinion planetary gear having a fourth sun gear S4, a fourth ring gear R4, and a fourth carrier PC4 that supports a fourth pinion P4 meshing with both the gears S4 and R4. .

  The transmission input shaft Input is connected to the second ring gear R2 and inputs rotational driving force from at least one of the engine Eng and the motor generator MG. The transmission output shaft Output is connected to the third carrier PC3 and transmits the output rotational driving force to the driving wheels (left and right rear wheels RL, RR) via a final gear or the like.

  The first ring gear R1, the second carrier PC2, and the fourth ring gear R4 are integrally connected by a first connecting member M1. The third ring gear R3 and the fourth carrier PC4 are integrally connected by a second connecting member M2. The first sun gear S1 and the second sun gear S2 are integrally connected by a third connecting member M3.

  The first planetary gear set GS1 includes four rotating elements by connecting the first planetary gear G1 and the second planetary gear G2 with the first connecting member M1 and the third connecting member M3. Is done. Further, the second planetary gear set GS2 is configured to have five rotating elements by connecting the third planetary gear G3 and the fourth planetary gear G4 by the second connecting member M2.

  In the first planetary gear set GS1, torque is input to the second ring gear R2 from the transmission input shaft Input, and the input torque is output to the second planetary gear set GS2 via the first connecting member M1. In the second planetary gear set GS2, torque is directly input to the second connecting member M2 from the transmission input shaft Input, and is also input to the fourth ring gear R4 via the first connecting member M1. Is output from the third carrier PC3 to the transmission output shaft Output.

  The first clutch C1 (input clutch I / C) is a clutch that selectively connects and disconnects the transmission input shaft Input and the second connecting member M2. The second clutch C2 (direct clutch D / C) is a clutch that selectively connects and disconnects the fourth sun gear S4 and the fourth carrier PC4. The third clutch C3 (H & LR clutch H & LR / C) is a clutch that selectively connects and disconnects the third sun gear S3 and the fourth sun gear S4.

  The second one-way clutch F2 is disposed between the third sun gear S3 and the fourth sun gear S4. Thereby, the third clutch C3 is released, and when the rotational speed of the fourth sun gear S4 is higher than that of the third sun gear S3, the third sun gear S3 and the fourth sun gear S4 generate independent rotational speeds. Therefore, the third planetary gear G3 and the fourth planetary gear G4 are connected via the second connecting member M2, and each planetary gear achieves an independent gear ratio.

  The first brake B1 (front brake Fr / B) is a brake that selectively stops the rotation of the first carrier PC1 with respect to the transmission case Case. The first one-way clutch F1 is disposed in parallel with the first brake B1. The second brake B2 (low brake LOW / B) is a brake that selectively stops the rotation of the third sun gear S3 with respect to the transmission case Case. The third brake B3 (2346 brake 2346 / B) is a brake that selectively stops the rotation of the third connecting member M3 that connects the first sun gear S1 and the second sun gear S2 with respect to the transmission case Case. The fourth brake B4 (reverse brake R / B) is a brake that selectively stops the rotation of the fourth carrier PC4 with respect to the transmission case Case.

  FIG. 6 is a fastening operation table showing a fastening state of each frictional engagement element for each shift stage in the automatic transmission AT mounted in the FR hybrid vehicle to which the control device for the electric vehicle according to the first embodiment is applied. In FIG. 6, ◯ indicates that the friction engagement element is in an engaged state, (◯) indicates that the friction engagement element is in an engagement state at least when the engine brake is operated, and no mark indicates the friction engagement. Indicates that the element is in a released state.

  Of each frictional engagement element provided in the transmission gear mechanism configured as described above, one of the frictional engagement elements that have been engaged is released, and one of the frictional engagement elements that have been released is engaged. By doing so, it is possible to realize a first reverse speed with seven forward speeds as described below.

  That is, in the “first speed”, only the second brake B2 is engaged, and thereby the first one-way clutch F1 and the second one-way clutch F2 are engaged. In “second speed”, the second brake B2 and the third brake B3 are engaged, and the second one-way clutch F2 is engaged. In “third speed”, the second brake B2, the third brake B3, and the second clutch C2 are engaged, and the first one-way clutch F1 and the second one-way clutch F2 are not engaged. In “fourth speed”, the third brake B3, the second clutch C2, and the third clutch C3 are engaged. In "5th gear", the first clutch C1, the second clutch C2, and the third clutch C3 are engaged. In “6th speed”, the third brake B3, the first clutch C1, and the third clutch C3 are engaged. In “7th speed”, the first brake B1, the first clutch C1, and the third clutch C3 are engaged, and the first one-way clutch F1 is engaged. In “reverse speed”, the fourth brake B4, the first brake B1, and the third clutch C3 are engaged.

  Here, as the second clutch CL2 shown in FIG. 1, a friction engagement element that is engaged at each shift speed can be selected. For example, the second brake B2, “1st speed to 3rd speed”, “ The second clutch C2 is used at the "4th speed", the third clutch C3 is used at the "5th speed", and the first clutch C1 is used at the "6th and 7th speed".

FIG. 7 is a flowchart showing a flow of a minimum line pressure setting process executed by the control device for an electric vehicle according to the first embodiment ( line pressure setting means ). Hereinafter, each step of the flowchart shown in FIG. 7 will be described.

  In step S1, it is determined whether or not air blowing has occurred in the travel drive source (engine Eng or motor / generator MG). If YES (air blowing has occurred), the process proceeds to step S2, and NO (no air blowing has occurred). In step S1, step S1 is repeated. Here, the determination of the presence or absence of the occurrence of air blow is made based on whether or not the input rotational speed Nin to the second clutch CL2, that is, the rotational speed of the transmission input shaft input of the automatic transmission AT exceeds the target rotational speed. If the input rotational speed Nin exceeds the target rotational speed, it is determined that the drive source rotational speed has increased excessively and air blow occurs.

  When the input rotational speed Nin to the second clutch CL2 exceeds the target rotational speed, it can be determined that the input rotational speed Nin is higher than the output rotational speed Nout from the second clutch CL2, and the second clutch CL2 Then, differential rotation occurs and a so-called slip fastening state is established. Therefore, this step S1 corresponds to a slip detection means for detecting the slip engagement state of the friction engagement element.

  In the in-gear μ-slip control or WSC mode, when the second clutch CL2 slips more than a predetermined slip amount, that is, the input rotational speed Nin causes the second clutch CL2 to be in a predetermined slip state. When the set value is exceeded, it is determined that an air blow has occurred. Here, the μ slip control means that when the automatic transmission AT is in the first speed stage or the second speed stage in the EV mode, the slip engagement state of the second clutch CL2 is maintained by the rotational speed control of the motor / generator MG. In this control, the clutch torque capacity is controlled so that the transmission torque passing through the clutch CL2 becomes the required drive torque.

  Further, when the automatic transmission AT shifts, even when there is a divergence between the target transmission torque passing through the second clutch CL2 and the actual transmission torque, the rotational speed control of the motor / generator MG is executed in the inertia phase. The shift shock is mitigated by reducing the input torque to the second clutch CL2 and adjusting the input rotational speed Nin to the target rotational speed. For this reason, even when the automatic transmission AT shifts, if the second clutch CL2 slips more than a predetermined slip amount, that is, the input rotational speed Nin is set to bring the second clutch CL2 into a predetermined slip state. When the value is exceeded, it is determined that an air blow has occurred.

  In step S2, following the determination of the occurrence of air blow in step S1, air blow of the travel drive source is suppressed, and the process proceeds to step S3. Here, the idling suppression is performed by reducing the input torque (hereinafter referred to as clutch input torque) Tin to the second clutch CL2 so that the input rotational speed Nin of the second clutch CL2 matches the target rotational speed. . That is, in this step S2, the rotational speed control for adjusting the rotational speed of the motor / generator MG to the target rotational speed is executed, and the clutch input torque Tin input to the second clutch CL2 is reduced.

  Thus, in step S2, when the slip engagement state of the second clutch CL2 is detected (when it is determined YES in step S1), the rotational speed control of the motor / generator MG is executed to determine the slip engagement state. This corresponds to slip suppression means for suppressing Note that the clutch input torque correction amount ΔTin, which is a change amount of the clutch input torque Tin, is stored in a memory or the like included in the integrated controller 10.

  In step S3, the hydraulic pressure is learned and corrected so as to suppress the slip engagement state of the second clutch CL2 to reduce the difference (difference) between the target transmission torque passing through the second clutch CL2 and the actual transmission torque. The process proceeds to step S4. Here, is the idling of the travel drive source caused by so-called hardware variations such as variations in the pressure adjustment accuracy of the hydraulic pressure of the automatic transmission AT and the deviation between the command pressure of the hydraulic pressure and the actual pressure? Therefore, it cannot be determined whether it is caused by insufficient line pressure (insufficient source pressure). Therefore, it is necessary to correct the hard pressure variation by learning correction and then to correct the line pressure by learning. The hardware variation is corrected by correcting the hydraulic pressure amount of the working hydraulic pressure. That is, this step S3 corresponds to an operating oil pressure learning correction means for learning and correcting the operating oil pressure so as to suppress the slip engagement state when the slip engagement state of the second clutch CL2 is detected.

  In step S4, it is determined whether or not the difference ΔTc between the target transmission torque passing through the second clutch CL2 and the actual transmission torque is equal to or less than a threshold value ΔTc1, and if YES (less than the threshold value), the process proceeds to step S5 and NO ( If the threshold is exceeded, the process returns to step S1. Here, the difference ΔTc between the target transmission torque and the actual transmission torque has a correlation with the working oil pressure learning correction amount ΔPS, and if the difference ΔTc between the target transmission torque and the actual transmission torque is equal to or less than the threshold value ΔTc1. The hydraulic pressure learning correction amount ΔPS executed in step S3 becomes equal to or less than the predetermined value ΔPS1, and it can be determined that the hydraulic pressure learning correction has converged.

  FIG. 8 is a schematic diagram showing the relationship between the change in the working oil pressure learning correction amount ΔPS and the change in the difference ΔTc between the target transmission torque and the actual transmission torque associated with the working oil pressure learning correction. In FIG. 8, the working oil pressure learning correction amount ΔPS decreases with the passage of time and becomes equal to or less than the predetermined value ΔPS1 at time T1. On the other hand, the difference ΔTc between the target transmission torque and the actual transmission torque decreases with time and becomes equal to or less than the threshold value ΔTc1 at time T1. Therefore, at time T1 when the difference ΔTc between the target transmission torque and the actual transmission torque becomes equal to or less than the threshold value ΔTc1, it is determined that the hydraulic oil learning correction amount ΔPS becomes equal to or less than the predetermined value ΔPS1 and the hydraulic oil learning correction has converged. it can.

  In step S5, following the determination that the torque difference threshold value is equal to or smaller than that in step S4, a line pressure correction amount ΔPL is calculated, and the process proceeds to step S6. Here, the line pressure correction amount ΔPL is based on the clutch input torque correction amount⇔line pressure correction amount conversion map shown in FIG. 9 and the clutch input torque correction amount ΔTin stored in the memory or the like included in the integrated controller 10 in step S2. And calculated by searching.

  In step S6, it is determined whether or not learning correction is permitted. If YES (permitted), the process proceeds to step S7. If NO (prohibited), the process returns to step S1. In an excessive region such as when the accelerator is depressed, the torque / hydraulic response is affected. Therefore, it is difficult to determine whether the slip engagement of the second clutch CL2 is caused by a shortage of the hydraulic pressure command value from the AT controller 7 or a shortage of the line pressure. Therefore, the learning correction of the line pressure needs to be executed only in a region where the clutch input torque Tin is small or a region where the change rate of the clutch input torque Tin is small. Accordingly, the learning correction permission determination in step S6 is determined based on whether the clutch input torque Tin is less than a predetermined value or whether the rate of change of the clutch input torque Tin is less than a predetermined value. When the clutch input torque Tin is equal to or greater than a predetermined value, or when the rate of change of the clutch input torque Tin is equal to or greater than a predetermined value, the learning correction is prohibited and the line pressure learning correction is not executed.

  In step S7, following the determination that learning correction is permitted in step S6, the current line pressure PL is corrected by the line pressure correction amount ΔPL calculated in step S5, and the process proceeds to the end. Here, Steps S5 to S7 learn and correct the line pressure based on the clutch input torque correction amount (change amount) ΔTin to the second clutch CL2 that is generated in association with the rotation speed control of the motor / generator MG in Step S2. This corresponds to the line pressure learning correction means.

Next, the operation will be described.
The line pressure learning correction action in the control apparatus for an electric vehicle according to the first embodiment will be described.

[Line pressure learning control action]
FIG. 10 is a time chart showing a line pressure characteristic diagram and a clutch input rotation speed / clutch input torque when an air blow occurs in the travel drive source before the line pressure learning correction in the electric vehicle control apparatus according to the first embodiment. . FIG. 11 is a time chart showing the line pressure characteristic diagram after the line pressure learning correction and the clutch input rotation speed / clutch input torque in the electric vehicle control apparatus according to the first embodiment. In the figure, “clutch” means the second clutch CL2.

  As shown in FIG. 10, when the input rotational speed Nin to the second clutch CL2 exceeds the target rotational speed at time t1, the process proceeds from step S1 to step S2 to reduce the clutch input torque Tin and reduce the input rotational speed. The rise of the number Nin, that is, the idling of the travel drive source is suppressed. If the input rotational speed Nin matches the target rotational speed at time t2, the integrated controller calculates the difference between the clutch input torque at that time and the clutch input torque at time t1, that is, the clutch input torque correction amount ΔTin. Store it at 10 mag.

  On the other hand, the hardware variation in the second clutch CL2 is corrected by learning and correcting the hydraulic pressure of the second clutch CL2. At this time, as shown in FIG. 8, when the difference ΔTc between the target transmission torque and the actual transmission torque becomes equal to or less than the threshold value ΔTc1, a predetermined value by which the working oil pressure learning correction amount ΔPS can be determined to have converged. Reach ΔPS1. Accordingly, the process proceeds from step S3 to step S4, and if the difference ΔTc between the target transmission torque and the actual transmission torque is equal to or less than the threshold value ΔTc1, it is determined that the working hydraulic pressure learning correction has converged, and the process proceeds to step S5.

  Then, the process proceeds from step S5 to step S6 to step S7, and if it is determined that learning correction is possible, the line pressure correction amount ΔPL is calculated based on the clutch input torque correction amount ΔTin, and the learning correction is performed as shown in FIG. The line pressure is corrected by the line pressure correction amount ΔPL obtained in step S5 with respect to the previous line pressure (indicated by a broken line in FIG. 11), and a new line pressure map indicated by a solid line in FIG. 11 is set.

  Thereby, since the line pressure PL is sufficiently secured, as shown in FIG. 11, the input rotational speed Nin of the second clutch CL2 does not exceed the target rotational speed, and the running drive source is not blown. . Further, since the running drive source is not blown, it is not necessary to reduce the input torque Tin to the second clutch CL2, and the input torque Tin can be kept constant.

  Thus, when the slip engagement state of the second clutch CL2 is detected in step S1, the rotational speed control of the motor / generator MG is executed by reducing the input torque Tin to the second clutch CL2 in step S2, The slip engagement state of the second clutch CL2 is suppressed. In step S5, the line pressure is determined based on the input torque change amount (clutch input torque correction amount ΔTin) to the second clutch CL2 generated in association with the rotational speed control of the motor / generator MG in step S2 and the map shown in FIG. The correction amount ΔPL is calculated, and the line pressure is corrected by the line pressure correction amount ΔPL in step S7.

  Thereby, slip fastening can be suppressed without pressing down the second clutch CL2, and a decrease in durability of the second clutch CL2 can be suppressed. Further, since the learning correction of the line pressure is performed based on the clutch input torque correction amount ΔTin accompanying the rotation speed control of the motor / generator MG, the hydraulic pressure conversion based on the torque conventionally used in the normal automatic transmission AT. An appropriate line pressure correction amount ΔPL can be calculated by this calculation method (here, a search from the map shown in FIG. 9). As a result, it is possible to suppress the deterioration of the durability of the second clutch CL2 while suppressing the slip engagement of the second clutch CL2, and to increase the correction accuracy of the line pressure to prevent excessive line pressure setting.

  Furthermore, in the control apparatus for the electric vehicle according to the first embodiment, the hydraulic pressure learning correction is executed in step S3 to reduce the difference ΔTc between the target transmission torque and the actual transmission torque, and in step S4, the difference ΔTc is less than the threshold value ΔTc1. By determining whether it is present, the learning correction of the line pressure is not executed until the working oil pressure learning correction converges.

  As a result, after learning and correcting the hard variation, the amount that cannot be corrected by correcting the hard variation can be corrected to an appropriate state by the learning correction of the line pressure. Then, it is possible to prevent the line pressure from being increased and corrected at the time of occurrence of slip fastening that is not caused by insufficient line pressure, and to prevent the line pressure from being increased excessively.

  In step S6, the control apparatus for an electric vehicle according to the first embodiment determines whether the clutch input torque Tin is less than a predetermined value or whether the rate of change of the clutch input torque Tin is less than a predetermined value. The learning correction permission judgment is executed, and when the clutch input torque Tin is equal to or higher than a predetermined value, or when the rate of change of the clutch input torque Tin is equal to or higher than a predetermined value, the learning correction of the line pressure is not performed.

  Therefore, when it is difficult to determine whether slip engagement of the second clutch CL2 has occurred due to insufficient line pressure in an excessive region such as when the accelerator is depressed, the line pressure learning correction is not executed. Thereby, it is possible to prevent the line pressure from being increased and corrected.

  The control device for an electric vehicle according to the first embodiment is applied to a hybrid vehicle having an engine Eng and a motor / generator MG as a travel drive source. When the engine Eng and the motor / generator MG are activated in step S1. In the WSC mode in which the second clutch CL2 is slip-engaged and the μ slip control, it is determined that the slip engagement of the second clutch CL2 is greater than or equal to a predetermined value.

  Thereby, it is possible to prevent a decrease in durability of the second clutch CL2 by suppressing a slip amount more than necessary while securing a necessary slip engagement state. That is, in a vehicle with many scenes where the second clutch CL2 is slip-engaged, such as a hybrid vehicle, the effect of the present invention that suppresses the slip amount more than necessary and prevents the durability of the second clutch CL2 from being reduced is further exhibited. be able to.

Next, the effect will be described.
In the control apparatus for an electric vehicle according to the first embodiment, the following effects can be obtained.

(1) An electric motor (motor / generator) MG as a travel drive source, and a power transmission path between the electric motor MG and the drive wheels (left and right rear wheels) RL, RR, with line pressure as the original pressure Line pressure setting means (FIG. 7) is provided for setting the line pressure in accordance with the operating state of the electric vehicle having a friction engagement element (second clutch) CL2 whose engagement / release state is switched by controlling the hydraulic pressure . In the control apparatus for an electric vehicle, the line pressure setting means (FIG. 7) includes a slip detection means (step S1) for detecting a slip engagement state of the friction engagement element CL2, and a slip engagement state of the friction engagement element CL2. when it is detected, by executing the rotational speed control of the motor MG, the frictional engagement slip suppression means to match the target rotational speed of the input rotational speed of the element CL2 (step S2), and the slip suppressing means (stearyl Line pressure learning correction means for learning and correcting the line pressure on the basis of an input torque change amount (clutch input torque correction amount) ΔTin to the frictional engagement element CL2 generated in accordance with the rotational speed control of the electric motor MG in step S2). Step S5 to step S7). For this reason, while suppressing slip fastening of the frictional engagement element CL2, it is possible to suppress a decrease in the durability of the frictional engagement element CL2, and to increase the correction accuracy of the line pressure to prevent excessive line pressure setting.

(2) The line pressure setting means (FIG. 7) learns the hydraulic pressure so that the actual transmission torque in the frictional engagement element CL2 becomes the target transmission torque when the input torque to the frictional engagement element CL2 changes. The hydraulic pressure learning correction means (step S3) for correcting is provided, and the line pressure learning correction means (step S5 to step S7) is configured to perform the friction correction by learning correction of the hydraulic pressure by the hydraulic pressure learning correction means (step S3). The learning correction of the line pressure is not executed until the difference between the actual transmission torque and the target transmission torque in the fastening element CL2 becomes equal to or less than a threshold value . For this reason, it is possible to prevent the line pressure from being set excessively high when slip fastening that does not result from insufficient line pressure occurs.

(3) The line pressure learning correction means (steps S5 to S7) is configured such that when the input torque Tin to the frictional engagement element CL2 immediately before the slip engagement state of the frictional engagement element CL2 is detected is a set value or more, Alternatively, when the rate of change of the input torque to the frictional engagement element CL2 immediately before the slip engagement state of the frictional engagement element CL2 is detected is equal to or higher than a set value, the line pressure learning correction is not executed. For this reason, when it is difficult to determine whether slip engagement of the frictional engagement element CL2 is caused by insufficient command pressure or line pressure, it is possible to prohibit learning correction of the line pressure. It is possible to prevent the pressure from being corrected to increase.

(4) The electric vehicle is a hybrid vehicle having an engine Eng as a travel drive source in addition to the electric motor MG, and the slip detection means (step S1) is activated when the electric motor MG and the engine Eng are operated. if the slip amount when is engaged with the frictional engagement element CL2 is equal to or greater than the predetermined value, the frictional engagement element CL2 is configured to determine that the slip engagement state. For this reason, even in a hybrid vehicle where there are many slip engagement scenes of the friction engagement element CL2, it is possible to prevent excessive slip engagement and prevent a decrease in the durability of the friction engagement element CL2 while securing the necessary slip amount. it can.

  As mentioned above, although the control apparatus of the electric vehicle of this invention has been demonstrated based on Example 1, it is not restricted to this Example 1 about a concrete structure, The invention which concerns on each claim of a claim Design changes and additions are permitted without departing from the gist of the present invention.

  In the first embodiment, among the plurality of friction engagement elements in the automatic transmission AT, the one that is engaged at each shift stage corresponds to the second clutch CL2, and this second clutch CL2 is used as the friction engagement element. However, an independent clutch may be provided at a position between the motor / generator MG and the automatic transmission AT, and this may be used as a friction engagement element, or an independent clutch set between the automatic transmission AT and the left and right rear wheels RL and RR. The clutch may be a frictional engagement element.

  Further, in the first embodiment, an example of an automatic transmission of 7 forward speeds and 1 reverse speed as an automatic transmission AT is shown, but the present invention is not limited to this, and is an example of a continuously variable transmission that obtains a continuously variable gear stage. Also good.

  In the first embodiment, an example in which the control device for an electric vehicle according to the present invention is applied to an FR hybrid vehicle has been shown. However, the present invention is applicable not only to an FF hybrid vehicle but also to an electric vehicle having only an electric motor as a travel drive source. can do.

Eng engine
MG motor / generator (travel drive source)
CL2 2nd clutch (friction engagement element)
AT automatic transmission
LR Left rear wheel (drive wheel)
RR Right rear wheel (drive wheel)

Claims (4)

An electric motor as a travel drive source, and a frictional engagement element that is provided on a power transmission path between the electric motor and the drive wheel and that switches the engagement / disengagement state by controlling the operating hydraulic pressure using the line pressure as a source pressure. In the control apparatus for an electric vehicle comprising line pressure setting means for setting the line pressure according to the operating state of the electric vehicle having,
The line pressure setting means includes slip detection means for detecting a slip engagement state of the friction engagement element;
Slip detecting means for executing the rotational speed control of the electric motor when the slip engagement state of the friction engagement element is detected, and matching the input rotation speed to the friction engagement element with a target rotation speed ;
Line pressure learning correction means for learning and correcting the line pressure based on an amount of change in input torque to the frictional engagement element that is generated when the rotational speed of the motor is controlled by the slip suppression means. Control device for electric vehicle. In the control device of the electric vehicle according to claim 1,
The line pressure setting means includes working oil pressure learning correction means for learning and correcting the working oil pressure so that an actual transmission torque in the friction engagement element becomes a target transmission torque when an input torque to the friction engagement element changes. ,
The line pressure learning correction means learns the line pressure until the difference between the actual transmission torque and the target transmission torque in the frictional engagement element becomes equal to or less than a threshold by the learning correction of the hydraulic pressure by the hydraulic pressure learning correction means. A control device for an electric vehicle, characterized in that no correction is performed. In the control apparatus for the electric vehicle according to claim 1 or 2,
The line pressure learning correction means, when the input torque to the friction engagement element just before the slip engagement state of the frictional engagement element is detected is equal to or higher than a set value, or slip engagement state of the frictional engagement element is detected The control device for an electric vehicle, wherein the learning correction of the line pressure is not executed when the rate of change in input torque to the immediately preceding frictional engagement element is equal to or greater than a set value. In the control apparatus of the electric vehicle as described in any one of Claims 1-3,
The electric vehicle is a hybrid vehicle having an engine in addition to the electric motor as a travel drive source,
Said slip detecting means determines that when said said motor engine is activated, if the slip amount when is engaged with the frictional engagement element is a predetermined value or more, the frictional engagement element is in slip engagement state A control device for an electric vehicle.

Images