JP2010030429A - Clutch control device for vehicle - Google Patents

Abstract

To provide a clutch control device for a vehicle capable of accurately estimating a transmission torque of a clutch interposed between a motor and a drive wheel while making it possible to create a torque estimation environment during traveling.
A drive system in which a second clutch CL2 is interposed between a motor generator MG, a left rear wheel RL, and a right rear wheel RR, and an AT controller 7 for controlling engagement / release of the second clutch CL2 are provided. It is a clutch control apparatus of FR hybrid vehicle. Motor torque value detection means for detecting the motor generator torque value _TMG is provided. Then, the AT controller 7 detects when the stabilization condition of the slip engagement state is satisfied, from the motor running in which the second clutch CL2 is engaged without slipping, gradually decreasing the clutch engagement force to the slip engagement state. based on the motor-generator torque value T _MG that is, having a learning value calculation block 72 for calculating the second clutch transmission torque estimation value T _CL2 of the second clutch CL2.
[Selection] Figure 4

Description

  The present invention is applied to a hybrid vehicle or an electric vehicle, and relates to a vehicle clutch control device including a drive system in which a clutch is set between a motor and drive wheels.

Conventionally, of the first and second clutches, a non-target clutch is maintained in an open state by a command from the first command means, and the motor is driven to rotate and the target clutch is engaged by a command from the second command means. When the rotation fluctuation is detected during the engagement operation of the target clutch, the engagement command value at this time is stored in the storage means as a learning value, and the stored learning value is corrected to decrease to the non-engagement side by a predetermined amount. A clutch control device for a hybrid vehicle that performs control when the target clutch is not engaged based on the reference command value is known (see, for example, Patent Document 1).
JP 2001-113971 A

  However, in the conventional hybrid vehicle clutch control device, since the motor rotation speed is constant and learning is performed when the clutch rotation fluctuation occurs while increasing the clutch hydraulic pressure, the motor rotation speed is constant when the vehicle stops. There is a problem that learning is possible only when the rotational speed is maintained, and it is difficult to learn while running.

  In other words, since the control is such that the clutch interposed between the motor and the driving wheel is once released and is engaged after the clutch is released (detection and correction of rotation fluctuation of the clutch), the motor torque to the driving wheel is controlled. Transmission is interrupted by opening the clutch.

  The present invention has been made paying attention to the above-mentioned problem, and accurately estimates the transmission torque of the clutch interposed between the motor and the drive wheel while making it possible to create a torque estimation environment during traveling. It is an object of the present invention to provide a vehicle clutch control device capable of performing

In order to achieve the above object, a clutch control apparatus for a vehicle according to the present invention includes a drive system in which a clutch is interposed between a motor and a drive wheel, and a clutch control means for controlling engagement / release of the clutch. .
Motor torque value detection means for detecting the torque value of the motor is provided.
The clutch control means is detected when the clutch engagement force is gradually reduced from the motor running to bring the clutch into a non-slip engagement state, and the slip engagement state is established. A clutch transmission torque estimated value calculation unit for calculating a clutch transmission torque estimated value of the clutch based on the motor torque value.

Therefore, in the vehicle clutch control device of the present invention, in the clutch transmission torque estimated value calculation unit, the clutch engagement force is gradually reduced to the slip engagement state from the motor running in which the clutch is in the engagement state without slipping, Based on the motor torque value detected when the slip engagement state stabilization condition is satisfied, a clutch transmission torque estimated value of the clutch is calculated.
That is, when calculating the clutch transmission torque estimated value, the clutch is simply shifted from the motor running state to the slip engagement state and the clutch running torque is used as the driving force. For this reason, it is possible to create an environment for calculating the clutch transmission torque estimated value while maintaining the vehicle running.
In addition, the motor torque value detected in the slip engagement state of the clutch that runs using only the motor as the power source and the clutch transmission torque as the driving force is a value corresponding to the clutch transmission torque if the influence of inertia, friction, etc. is ignored. Become.
As a result, it is possible to accurately estimate the transmission torque of the clutch interposed between the motor and the drive wheel while making it possible to create a torque estimation environment during traveling.

  Hereinafter, the best mode for realizing a clutch control device for a vehicle according to the present invention will be described based on a first embodiment 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 a vehicle) to which the clutch control device 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 MG (motor), and a second clutch CL2 (clutch). The automatic transmission AT, the propeller shaft PS, the differential DF, the left drive shaft DSL, the right drive shaft DSR, the left rear wheel RL (drive wheel), and the right rear wheel RR (drive wheel) . Note that FL is the left front wheel and FR is the right front wheel.

  The engine Eng is a gasoline engine or a diesel engine, and engine start control, engine stop control, and throttle valve opening control are performed based on an engine control command from the engine controller 1. 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. The first clutch control hydraulic pressure controls the engagement / release including slip engagement and slip release.

  The motor generator MG is a synchronous motor generator in which a permanent magnet is embedded in a rotor and a stator coil is wound around a stator, and a three-phase AC generated by an inverter 3 is applied based on a control command from the motor controller 2. It is controlled by doing. 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 state is referred to as “powering”), and the rotor receives rotational energy from the engine Eng or driving wheels. , The battery 4 can be charged by functioning as a generator that generates electromotive force at both ends of the stator coil (hereinafter, this operation state is referred to as “regeneration”). Note that the rotor of the motor generator MG is connected to the input shaft of the automatic transmission AT via a damper.

  The second clutch CL2 is a clutch interposed between the motor generator MG and the left and right rear wheels RL, RR, and is controlled by the second clutch hydraulic unit 8 based on a second clutch control command from the AT controller 7. The generated and controlled hydraulic pressure controls the fastening and opening including slip fastening and slip opening. 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 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 However, it is not newly added as a dedicated clutch, but the most suitable clutch or brake arranged in the torque transmission path is selected from a plurality of frictional engagement elements that are engaged at each gear stage of the automatic transmission AT. . 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.

  As the first clutch CL1, for example, a dry single-plate clutch whose engagement / release is controlled by a hydraulic actuator 14 having a piston 14a is used. As the second clutch CL2, for example, a wet multi-plate clutch or a wet multi-plate brake capable of continuously controlling the oil flow rate and hydraulic pressure with a proportional solenoid is used. The hybrid drive system has two modes, an electric vehicle travel mode (hereinafter referred to as “EV mode”) and a hybrid vehicle travel mode (hereinafter referred to as “HEV mode”), depending on the engaged / released state of the first clutch CL1. Has two driving modes. The “EV mode” is a mode in which the first clutch CL1 is released and the vehicle runs only with the power of the motor generator MG. The “HEV mode” is a mode in which the first clutch CL1 is engaged and the vehicle is driven by the power of the engine Eng and the motor generator MG.

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, the target MG torque command and target MG rotation speed command from the integrated controller 10, and other necessary information. Then, a command for controlling the motor operating point (Nm, Tm) of motor generator MG is output to inverter 3. The motor controller 2 monitors the battery SOC indicating the state of charge of the battery 4, and the battery SOC information is used as control information for the motor generator MG and is also integrated via the CAN communication line 11. Supplied to.

  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 / disengagement 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 the accelerator opening sensor 16, the vehicle speed sensor 17, and the second clutch hydraulic pressure sensor 18. 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 engagement / release of the second clutch CL2 is output to the second clutch hydraulic unit 8 in the AT hydraulic control valve unit CVU. The second clutch control is performed.
Further, when a target shift speed command is input from the integrated controller 10 during travel mode switching control, etc., the shift control to the target shift speed and the target shift speed are maintained in preference to the shift command in the normal automatic shift control. Shift speed fixing control is performed.

  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 integrated controller 10 detects the motor rotation speed Nm, and the second clutch output rotation speed. Information from the second clutch output rotational speed sensor 22 and the like for detecting N2out and information via the CAN communication line 11 are input. Then, a target engine torque command is sent to the engine controller 1, a target MG torque command and a target MG speed command are sent to the motor controller 2, a target CL1 torque command is sent to the first clutch controller 5, a target CL2 torque command and a target gear speed command are sent to the AT controller 7. The regenerative cooperative control command is output to the brake controller 9.

  FIG. 2 is a control block diagram illustrating arithmetic processing executed by the integrated controller 10 of the FR hybrid vehicle to which the clutch control device of the first embodiment is applied. FIG. 3 is a diagram showing an EV-HEV selection map used when mode selection processing is performed by the integrated controller 10 of the FR hybrid vehicle. Hereinafter, based on FIG.2 and FIG.3, 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.

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

  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. , Target MG torque, target MG rotation speed, target CL1 torque, target CL2 torque, and target gear position are calculated. Then, the target engine torque command, the target MG torque command, the target MG rotational speed command, the target CL1 torque command, the target CL2 torque command, and the target shift speed command are sent to each of the controllers 1, 2, 5, 7 via the CAN communication line 11. Output to.

  FIG. 4 is a control block diagram illustrating arithmetic processing executed by the AT controller 7 to which the clutch control device of the first embodiment is applied.

  As shown in FIG. 4, the AT controller 7 (clutch control means) includes a learning permission determination block 71 (estimated value calculation permission determination unit), a learning value calculation block 72 (clutch transmission torque estimated value calculation unit), and a map. A learning correction block 73 (map learning correction unit), a CL2 torque-instruction oil pressure map setting block 74, a CL2 torque-instruction oil pressure conversion block 75, and an instruction oil pressure-instruction current conversion block 76 are provided.

  The learning permission determination block 71 includes mode information (extracting an engine start scene by switching from EV mode to HEV mode), engine speed information, target MG speed information, actual MG speed information, MG Torque value information, shift speed information, and CL2 differential rotation information are input. Then, based on these pieces of information, it is determined whether a plurality of learning permission determination conditions are satisfied after the engine start command is issued. When a plurality of learning permission determination conditions are satisfied, a learning permission flag is set.

The learning value calculation block 72 inputs the learning permission flag, the actual MG rotation speed information, the MG torque value information, and the gear position information from the learning permission determination block 71. In the first embodiment, the second clutch hydraulic pressure information from the second clutch hydraulic pressure sensor 18 (clutch hydraulic pressure detecting means) at the time when the learning permission flag is input is input. Then, the transmission torque of the second clutch CL2 is estimated and calculated based on the necessary calculation information, and the second clutch hydraulic pressure value P _CL2 and the second clutch transmission torque estimated value T _CL2 that are in this correspondence relationship are output as the clutch torque learning value. .

The map learning correction block 73 uses the second clutch oil pressure value P _CL2 and the second clutch transmission torque estimated value T _CL2 acquired by the learning value calculation block 72 as a clutch torque learning value, and the clutch torque learning value data is a predetermined amount. When accumulated, a learning correction command for correcting a change in inclination or offset of the characteristic of the CL2 torque-instructed oil pressure map set in the CL2 torque-instructed oil pressure map setting block 74 is output.

  The CL2 torque-instructed oil pressure map setting block 74 is set with a CL2 torque-instructed oil pressure map that characterizes the relationship between the second clutch torque (CL2 torque) and the instructed oil pressure to the second clutch CL2. When a learning correction command is input from the block 73, correction is added to the inclination change or offset of the CL2 torque-instruction hydraulic pressure map set at that time, and the corrected CL2 torque-instruction hydraulic pressure map is updated.

  When the target CL2 torque command is input from the integrated controller 10, the CL2 torque-instructed hydraulic pressure conversion block 75 searches the CL2 torque-instructed hydraulic pressure map set at that time, thereby corresponding to the target CL2 torque command. Convert to indicated oil pressure.

  The command hydraulic pressure-command current conversion block 76 receives the command hydraulic pressure from the CL2 torque-command hydraulic pressure conversion block 75 and converts it into a command current corresponding to the command hydraulic pressure. Then, a control command based on the command current obtained by this conversion is output to the second clutch hydraulic unit 8.

  FIG. 5 is a flowchart illustrating the flow of the second clutch learning correction control process executed by the learning permission determination block 71, the learning value calculation block 72, and the map learning correction block 73 of the AT controller 7 according to the first embodiment. Each step will be described. The second clutch learning correction control process is started during traveling in the “EV mode” in which the second clutch CL2 is in a completely engaged state without slipping.

  In step S101, it is determined whether or not an engine start command has been issued based on the determination of the travel mode switching from “EV mode” to “HEV mode”. If YES (engine start command is output), the process proceeds to step S102. If No (no engine start command output), the determination in step S101 is repeated.

  In step S102, following the determination that the engine start command is output in step S101, the clutch hydraulic pressure to the second clutch CL2 is gradually reduced, a minute slip is generated in the second clutch CL2, and the process proceeds to step S103. .

  In step S103, following the generation of the minute slip in step S102, the determination that the drive system learning permission condition is not satisfied in step S104, or the determination that the vehicle state learning permission condition is not satisfied in step S105, the second clutch CL2 Is slipping and whether or not the vehicle is running while maintaining the differential rotation of the second clutch CL2 by differential rotation feedback control by the motor generator MG. If YES (slip maintenance condition is satisfied) The process proceeds to step S104. If NO (slip maintenance condition is not satisfied), the process proceeds to the end.

  In step S104, following the determination that the slip maintenance condition is satisfied in step S103, the slip of the second clutch CL2 is stabilized, the differential rotation of the second clutch CL2 is within a specified range, and the driver or It is determined whether or not the change in the transient driving force by the system is within a certain range. If YES (driving system learning permission condition is satisfied), the process proceeds to step S105, and NO (driving system learning permission condition is not satisfied). In this case, the process returns to step S103.

  In step S105, following the determination in step S104 that the drive system learning permission condition is satisfied, the vehicle state (vehicle external environment, vehicle internal state, control state of each controller, fail state, etc.) is suitable for learning. It is determined whether or not the vehicle is in a state. If OK (vehicle state learning permission condition is satisfied), the process proceeds to step S106 while a learning permission flag is output. If NG (vehicle state learning permission condition is not satisfied), step S103 is performed. Return to.

In step S106, following the determination that the vehicle state learning permission condition is satisfied in step S105, a second clutch transmission torque estimated value T _CL2 and a second clutch hydraulic pressure value P _CL2 that are learning values are calculated, and step S107. Migrate to
Here, second clutch transmission torque estimated value T _CL2 is estimated and calculated based on the MG torque value of motor generator MG. The second clutch hydraulic pressure value P _CL2 is calculated based on the sensor value from the second clutch hydraulic pressure sensor 18.

In step S107, following the calculation of the learning value (T _CL2 , P _CL2 ) in step S106, a correction calculation that reflects the effects of inertia and motor friction on the second clutch transmission torque estimated value T _CL2 among the learning values. Then, the process proceeds to step S108.
A detailed calculation method of the second clutch transmission torque estimated value _TCL2 will be described later.

In step S108, following the correction calculation of the second clutch transmission torque estimated value T _CL2 in step S107, the learning values (T _CL2 , P _CL2 ) acquired every time the learning permission condition is satisfied are stored and learned. When the stored data amount of the values (T _CL2 , P _CL2 ) reaches a predetermined amount, learning correction is performed by reflecting the change in the slope or offset in the characteristics of the CL2 torque-indicated hydraulic pressure map, and the process returns to step S103.

Next, the operation will be described.
The effects of the FR vehicle clutch control apparatus according to the first embodiment are as follows: “About the clutch capacity learning correction of the second clutch CL2”, “State transition action of drive system components in the engine start scene”, “Learning permission determination action”, The explanation will be divided into “the calculation method of the second clutch transmission torque estimated value TCL2” and “learning correction control action”.

[Clutch capacity learning correction for the second clutch CL2]
FIG. 6 is a diagram showing an offset change and an inclination change due to deterioration of a relational characteristic between the command hydraulic pressure of the second clutch and the clutch transmission torque included in the drive system of the hybrid vehicle. FIG. 7 is a driving force characteristic diagram showing a driving force step when the driving force control traveling with the second clutch included in the driving system of the hybrid vehicle is slip-engaged to shift to driving force control traveling with complete engagement. FIG. 8 is a diagram showing relational characteristics including the allowable range of front and rear G and the variation range due to the clutch transmission torque of the second clutch and the driving force level difference in the drive system of the hybrid vehicle.

  First, when the transmission hydraulic fluid of the second clutch CL2 deteriorates (ATF deterioration) and when the spring characteristics of the second clutch CL2 deteriorate, as shown in FIG. 6, the relational characteristic between the indicated hydraulic pressure and the clutch transmission torque is obtained. Has an offset change in which the characteristic moves in the vertical slide direction without changing the tilt. It should be noted that the deterioration in the spring characteristics includes a change in absolute value of the hydraulic pressure caused by a solenoid valve or a solenoid spring caused by a valve spring, and deterioration of the clutch spring. Further, when the clutch friction coefficient μ of the second clutch CL2 deteriorates (μ deterioration of the friction material), as shown in FIG. 6, the relationship characteristic between the command hydraulic pressure and the clutch transmission torque changes not the offset change but the slope. .

Next, when deterioration (offset change or inclination change) is left without performing clutch capacity learning correction of the second clutch CL2 in which the clutch capacity cannot be directly measured, as shown in FIG. When the driving force control running with the second clutch CL2 having slip engagement is shifted to the driving force control running with complete fastening, a driving force step is generated. The driving force control traveling in which the second clutch CL2 is slip-engaged and the driving force is controlled by the second clutch CL2 is referred to as WSC (abbreviation of Wet Start Clutch) traveling.
That is, as shown in FIG. 8, if the G characteristic due to the driving force step is present at the point A of the allowable range in the assembling stage, even if the deterioration is left unattended, it moves to the point B and moves to the allowable range. The driving force step is enlarged. Further, when the second clutch CL2 is in the limit region of the variation range (region between the allowable range and the variation range) at the assembly stage, it is already out of the allowable range.

  Thus, it is necessary to perform clutch capacity learning correction of the second clutch CL2 in order to suppress the driving force step. However, for example, when the number of measurable points is limited to a specific point as in the prior art, it is not possible to cope with the inclination change even if only the offset change can be dealt with. .

On the other hand, as shown in FIG. 6, the data acquisition range is from 40 Nm creep to 120 Nm, and by obtaining the measurement information at multiple points, the offset change and the slope correspond to the change “CL2 capacity due to μ slip. The purpose is to perform learning control.
In order to achieve this purpose, the following (μ slip), (μ slip CL2 capacity learning), (learning value correction location), (hardware to be corrected) were adopted. The learning permission condition will be described in “Learning permission determination action” below. The learning action will be described in “Learning correction control action” below.

・ Μ slip
With the aim of shortening the engine start time by absorbing jerky vibration during EV traveling and accelerating slip-in, the hydraulic pressure of the second clutch CL2 is gradually lowered during EV traveling to generate and maintain a minute slip.

・ Μ slip CL2 capacity learning When performing μ slip, the motor generator MG controls the torque, and the second clutch CL2 performs control to generate a minute slip. This control also has an effect of confirming an equilibrium point between the motor generator torque and the clutch transmission torque. Since the calculation in the AT controller 7 can be controlled by making the motor generator torque positive, learning that fills the difference between the motor generator torque and the clutch transmission torque during μ-slip and when the learning is permitted. Make corrections.

・ Learning value correction place As a learning value correction place, correction is performed on a highly reliable portion close to linearity. And in order to ensure robustness, it correct | amends with respect to the part which performs torque-hydraulic conversion.

Hardware to be corrected Hardware to be corrected is μ change of friction material, ATF deterioration, absolute value fluctuation of hydraulic pressure by solenoid valve (solenoid spring, valve spring), and clutch spring deterioration.

[Transition of drive system components in the engine start scene]
FIG. 9 shows mode selection characteristics, learning permission flag characteristics, Eng rotation characteristics, MG target rotation characteristics, MG rotation characteristics, MG torque characteristics, shift speed characteristics, and engine selection scenes in the FR vehicle clutch control apparatus according to the first embodiment. It is a time chart which shows an example of CL1 stroke characteristics (CL1 torque characteristics), CL2 torque characteristics, and CL2 differential rotation characteristics.

  In FIG. 9, t1 indicates a point in time when an engine start command is issued, t2 indicates an MG torque rising point, t3 indicates an Eng rotation rising point, t4 indicates an Eng rotation constant value point (before ignition), t5 Indicates the time when the HEV transition command was issued. Hereinafter, each state transition of the first clutch CL1, the second clutch CL2, the engine Eng, and the motor generator MG will be described.

(State transition of the first clutch CL1)
The first clutch CL1 is disengaged in the “EV mode” until time t1, is disengaged (during the stroke) from time t1 to t2, is intermediate capacity from time t2 to t3, is intermediate capacity from time t3 to t4, and is from time t4 to During t5, the intermediate capacity is reached, and after time t5, transition is made to complete fastening, and fastening is performed in “HEV mode”.

(Changes in the state of the second clutch CL2)
The second clutch CL2 is engaged in the “EV mode” until time t1, slip engagement between times t1 and t2, slip engagement between times t2 and t3, slip engagement between times t3 and t4, and between times t4 and t5. Slip engagement, after time t5, shifts to engagement and is engaged in “HEV mode”.

(Changes in engine Eng state)
The engine Eng is stopped in the “EV mode” until time t1, stopped between times t1 and t2, and stopped between times t2 and t3, but receiving torque from the first clutch CL1, and cranking between times t3 and t4. During the period from time t4 to t5, the operation is shifted, and after time t5, the operation state including the “HEV mode” is set.

(State transition of motor generator MG)
The motor generator MG performs torque control for obtaining a target torque in the “EV mode” until time t1, rotation speed control for obtaining a target rotation speed between times t1 and t2, rotation speed control between times t2 and t3, and times t3 to t4. Rotational speed control is performed during the period, rotational speed control is performed between times t4 and t5, and after time t5, the rotational speed control is shifted to torque control for obtaining target torque in the “HEV mode”.

  As described above, in the engine start scene where the driving mode is switched from “EV mode” to “HEV mode” during driving, the transition mode is changed from “EV mode” in which the engine Eng is stopped and the first clutch CL1 is released. After the “engine starting mode” has elapsed, the engine Eng is operated and the first clutch CL1 is engaged and the mode is switched to the “HEV mode”.

  In this engine starting scene, in the “engine starting mode”, the second clutch CL2 is in the slip engagement state, and the mode switching shock due to the transmission of the torque that fluctuates with the mode switching to the drive wheels is suppressed.

  On the other hand, in the engine starting scene, in the “engine starting mode”, the first clutch CL1 is changed from the released state to the half-clutch state maintaining the intermediate capacity, and the motor generator MG is switched from the torque control to the rotation speed control. Accordingly, the input shaft rotation of the automatic transmission AT is kept constant while starting the engine Eng by receiving torque from the motor generator MG via the first clutch CL1. That is, in the “engine starting mode”, the rotational speed control is performed so that the rotational speed matches the target rotational speed while increasing the torque of the motor generator MG.

Then, in the engine start scene where the “EV mode” is switched to the “HEV mode”, the engine Eng is stopped and the first clutch CL1 is released from the “EV mode” where the first clutch CL1 is left open. 2Slip the clutch CL2. Therefore, during the period from time t1 to time t2, based on the MG torque value, a suitable scene for calculating the second clutch transmission torque estimation value T _CL2 of the second clutch CL2 is slip-engaged.

[Learning permission judgment action]
In the flowchart of FIG. 5, the process does not proceed to step S106 unless the learning permission determination is OK in step S105. That is, unless the learning permission flag is output from the learning permission determination block 71 in FIG. 4, the learning value calculation block 72 does not calculate the second clutch transmission torque estimated value T _CL2 . Hereinafter, the learning permission determination operation in the learning permission determination block 71 will be described.

  In step S101, it is determined whether or not an engine start command has been issued. If an engine start command is output, the process proceeds to step S102. In step S102, the clutch hydraulic pressure to the second clutch CL2 is gradually reduced, and a minute slip is generated in the second clutch CL2. In step S103, the second clutch CL2 is slipping, and the slip maintenance is performed to determine whether or not the second clutch CL2 is traveling while maintaining the differential rotation of the second clutch CL2 by the differential rotation feedback control by the motor generator MG. If the condition is determined and the slip maintaining condition is satisfied, the process proceeds to step S104. In step S104, whether or not the slip of the second clutch CL2 is stabilized, the differential rotation of the second clutch CL2 is within a specified range, and the change of the transient driving force by the driver or the system is within a certain range. When the driving system learning permission condition is determined and the driving system learning permission condition is satisfied, the process proceeds to step S105. In step S105, the vehicle state learning permission condition is determined based on whether or not the vehicle state (vehicle external environment, vehicle internal state, control state of each controller, fail state, etc.) is a vehicle state suitable for learning. If the permission condition is satisfied, the process proceeds to step S106 while the learning permission flag is output.

In this way, from the time t1 when the engine start command is issued,
-The second clutch CL2 is slipping and traveling while maintaining the differential rotation of the second clutch CL2 (slip maintaining condition).
・ The slip of the second clutch CL2 is stabilized, the differential rotation of the second clutch CL2 is within a specified range (C in FIG. 9), and the change of the transient driving force by the driver or the system is within a certain range (FIG. 9). (D) of driving system learning permission condition).
・ Vehicle state (vehicle state learning permission condition) suitable for learning such as vehicle external environment, vehicle internal state, control state of each controller, and fail state.
In the flowchart of FIG. 5, the process proceeds from step S103 to step S104 to step S105. For example, at time t1 ′ in FIG. 9, the slip maintenance condition, the drive system learning permission condition, and the vehicle state learning permission are determined. When all of the conditions are met, a learning permission flag is set.
Here, the learning permission is not issued in the region where the slip maintenance condition is not satisfied. The driving force is controlled by the transmission torque of the second clutch CL2, and the WSC in which the motor generator torque _TMG and the second clutch transmission torque have an equilibrium relationship. This is because it is not running. The reason why the learning permission is not issued in the transition region where the drive system learning permission condition is not satisfied is that the measurement error is large.

[Calculation method of second clutch transmission torque estimated value TCL2]
In the flowchart of FIG. 5, when the learning permission flag is set in step S105, the process proceeds from step S106 to step S107, and the calculation of the second clutch transmission torque estimated value _TCL2 is executed. That is, when the learning permission flag is output from the learning permission determination block 71 of FIG. 4, the learning value calculation block 72 calculates the second clutch transmission torque estimated value T _CL2 . Hereinafter, a calculation method of the second clutch transmission torque estimated value T _{CL2 in} the learning value calculation block 72 will be described.

First, the equation of motion in the time domain from time t1 to t2 is
T _MG = T _CL2 + I ・ ω ' _MG + F _MG … (1)
However, T _MG : MG torque value, T _CL2 : Second clutch transmission torque estimated value, I: Inertia for each gear, ω ′ _MG : Rotational angular acceleration of motor generator MG, F _MG : Motor friction
Therefore, the above equation (1) is
T _CL2 ＝ T _MG −I ・ ω ′ _MG −F _MG … (1 ′)
It is expressed.
Since the motor friction is very small, if the (F _MG ) term is ignored, the above equation (1 ') is
T _CL2 = T _MG -I ・ ω ' _MG (1 ")
It is expressed.
Here, T _MG (MG torque value) is the MG torque obtained during the learning correction time from time t1 ′ to time t2, and the inertia I for each gear is known if the gear information is known. , Ω ′ _MG can be calculated from the rotation difference of the motor generator MG around the MG torque value.
By the way, the equation of motion in the time domain from time t2 to t4 is
T _MG = T _CL1 + T _CL2 + I ・ ω ' _MG + F _MG (2)
Unlike the time t1 to the time t2, it is necessary to obtain the first clutch transmission torque estimated value T _CL1 , which is an out-of-target region for CL2 capacity learning control.

Thus, the second clutch transmission torque estimated value T _CL2 is calculated using the above equation (1 ′) or (1 ″) using the MG torque value (T _MG ) and the inertia term (I · ω ′ _MG ). Can be sought.
That is, the motor torque value detected in the slip engagement state of the second clutch CL2 when the WSC travels using only the motor generator MG as a power source and the clutch transmission torque of the second clutch CL2 as a driving force is the inertia, friction, etc. If the influence is ignored, the value corresponds to the second clutch transmission torque.
Therefore, it is possible to create a torque estimation environment while maintaining WSC running. Since this is an estimation using the traveling region, the influence of inertia due to traveling is taken into account by using the above equation (1 ') or (1 ") that subtracts the loss due to inertia I from the MG torque value. The second clutch transmission torque estimated value TCL2 can be accurately estimated.

[Learning correction control action]
The current hybrid vehicle has a region (wet start clutch control region: WSC control region) that responds to the driver's accelerator operation by controlling the transmission driving torque of the second clutch. Due to the existence of this WSC control region, the vehicle drive modes include “electric vehicle travel mode using only motor generator”, “hybrid vehicle travel mode using engine and motor generator as driving force”, and “second clutch. There is a “WSC driving mode” where the driving force is controlled by the clutch while slipping. In order to make the responses from the drivers of the respective controls the same, it is necessary to unify the clutch transmission driving torque of the second clutch based on the motor torque in the usage region.

  The existing learning control does not consider the need for an accelerator response with the second clutch, and there is a problem in the learning correction accuracy in the regular region. In addition, there are few learning correction opportunities in the practical running area. Further, it is impossible to correct the clutch μ deterioration.

  In contrast, in the first embodiment, when the learning permission flag is set in step S105 in the flowchart of FIG. 5, the process proceeds from step S106 to step S107 to step S108. In step S108, the learning value is set to the CL2 torque-instruction. Learning correction is reflected in the hydraulic map.

That is, in step S108, the second clutch hydraulic pressure value P _CL2 and the second clutch transmission torque estimated value T _CL2 that are in a corresponding relationship are used as the clutch torque learning value, and the learning value ( T _CL2 , P _CL2 ) are stored, and when the stored data amount of the learning values (T _CL2 , P _CL2 ) reaches a predetermined amount, learning correction is performed by reflecting the change in slope and offset in the characteristics of the CL2 torque-indicated hydraulic pressure map. The Hereinafter, advantages of learning correction control according to the first embodiment will be described.

First, learning correction opportunities can be created in the practical driving range.
That is, when calculating the second clutch transmission torque estimated value T _CL2 , the second clutch CL 2 is brought into the slip engagement state from the motor running state in the electric vehicle running mode, and the WSC runs using the clutch transmission torque of the second clutch CL 2 as the driving force. It just shifts to the running state. For this reason, the “fixed number of revolutions” of the prior art is removed, and the second clutch transmission torque estimated value T _CL2 can be calculated and learned in many areas while maintaining vehicle travel. it can.

Secondly, in consideration of the necessity of making an accelerator response with the second clutch CL2, it is possible to obtain high learning correction accuracy in the normal range.
In other words, as described above, the environment can be created during driving, and by adding inertia correction, learning can be performed except in regions where the transient change in driving force is too large, greatly increasing learning opportunities. In addition, considering the use of the travel area, the accuracy of the learning result can be improved by subtracting the loss due to inertia from the correction value.

Thirdly, it is possible to correct the μ degradation of the second clutch CL2.
That is, the learning environment is a WSC traveling state in which traveling is performed using the clutch transmission torque of the second clutch CL2 in the slip engagement state as a driving force, and the measurable points are greatly expanded as shown in FIG. For this reason, from the measurement result, it is possible to add not only correction for offset change but also correction for inclination change to the linear characteristic of “CL2 torque → indicated hydraulic pressure map”, and correction to μ degradation of the second clutch CL2. Is also possible.

Next, the effect will be described.
In the clutch control device for the FR hybrid vehicle of the first embodiment, the effects listed below can be obtained.

(1) A drive system in which a clutch (second clutch CL2) is interposed between a motor (motor generator MG) and drive wheels (left rear wheel RL and right rear wheel RR), and a clutch for controlling engagement and release of the clutch And a clutch control device for a vehicle (FR hybrid vehicle) provided with a control means (AT controller 7), provided with a motor torque value detection means for detecting a torque value of the motor, wherein the clutch control means slips the clutch. The motor torque value (motor generator torque value T _MG ) detected when the clutch running force is gradually reduced to the slip-engaged state and the slip-engaged stabilization condition is satisfied. the basis, the clutch transmission torque estimation value of the clutch the clutch transmission torque estimation value calculation unit for calculating a (second clutch transmission torque estimation value T _CL2) Having a learning value calculation block 72). Therefore, it is possible to accurately estimate the clutch transmission torque (second clutch transmission torque estimated value TCL2) while making it possible to create a torque estimation environment during traveling.

(2) The clutch (second clutch CL2) includes a hydraulic actuator for performing engagement / disengagement control, and a clutch oil pressure detecting means (second clutch oil pressure sensor 18) for detecting clutch oil pressure in the engagement control hydraulic system of the clutch. The clutch transmission torque estimated value calculation unit (learning value calculation block 72) detects the motor torque value (motor generator torque value T _MG ) at the same time as the clutch hydraulic pressure value (second clutch hydraulic pressure value P). _CL2 ) is detected, and the clutch transmission torque estimated value (second clutch transmission torque estimated value T _CL2 ) is calculated in correspondence with the clutch hydraulic pressure value. Therefore, the clutch oil pressure value (second clutch oil pressure value P _CL2) and clutch transmission torque estimation value that associates (second clutch transmission torque estimation value T _CL2) is obtained by substituting the clutch oil pressure value in the clutch control system The clutch transmission torque can be controlled.

(3) The clutch control means (AT controller 7) sets a torque-instruction oil pressure map (CL2 torque-instruction oil pressure map) that characterizes the relationship between the clutch torque of the clutch (second clutch CL2) and the instruction oil pressure. together, and the clutch transmission torque estimation value calculation unit (learned value calculation block 72) learned value acquired information by (a second clutch oil pressure value P _CL2 second clutch transmission torque estimation value T _CL2), the torque - instruction A torque-instructed oil pressure map learning correction unit (map learning correction block 73) to be reflected in the oil pressure map is provided. Therefore, learning correction at many points determined by the torque (CL2 torque) and the command oil pressure causes a change in the slope of the torque-command oil pressure characteristics due to the μ deterioration of the clutch (second clutch CL2). Correction can be achieved.

(4) The clutch transmission torque estimated value calculation unit (learning value calculation block 72) subtracts the loss due to inertia (I · ω ′ _MG ) from the detected motor torque value (T _MG ), and the clutch ( A clutch transmission torque estimated value (second clutch transmission torque estimated value T _CL2 ) of the second clutch _CL2 ) is calculated. For this reason, the calculation of the clutch transmission torque estimated value during traveling with rotational inertia in the drive system is considered, and the clutch transmission torque estimated value (second clutch transmission torque estimated value T _CL2 ) can be calculated with high accuracy. it can.

(5) The clutch control means (AT controller 7) is capable of differential rotation stabilization in which the input / output differential rotation of the clutch is converged and stabilized in a constant width rotation region in addition to the slip stabilization condition in which the slip engagement state is stabilized. If both the condition and the transient driving force stability condition that the change of the transient driving force by the driver or the system is within a certain range are satisfied (YES in step S104), the clutch transmission torque estimated value calculation unit (learning value calculation block 72) _Has an estimated value calculation permission determination unit (learning permission determination block 71) that permits calculation of a clutch transmission torque estimated value (second clutch transmission torque estimated value T _CL2 ). For this reason, an unstable region of differential rotation and an unstable region of transient driving force of the clutch (second clutch CL2) in which an estimation error of the clutch transmission torque becomes large are eliminated, and a clutch transmission torque estimated value (second clutch transmission torque estimation) The value T _CL2 ) can be calculated with high accuracy.

(6) The vehicle has a first clutch CL1 interposed between the engine Eng and the motor (motor generator MG), and a second clutch between the motor and the drive wheels (left rear wheel RL and right rear wheel RR). A hybrid vehicle having a drive system including CL2 and having, as travel modes, an “electric vehicle travel mode” in which the first clutch CL1 is released and a “hybrid vehicle travel mode” in which the first clutch CL1 is engaged ( FR hybrid vehicle), and the estimated value calculation permission determination unit (learning permission determination block 71) is in a transition period from the electric vehicle traveling mode to the hybrid vehicle traveling mode and releases the first clutch CL1. And the clutch transmission torque estimated value calculation unit when the second clutch CL2 is slip-engaged and a start command is output to the stopped engine Eng. The calculation permission judgment of the clutch transmission torque estimated value (second clutch transmission torque estimated value T _CL2 ) by the (learning value calculation block 72) is performed. Therefore, without intentionally applying slip engagement control of the second clutch CL2 to perform learning correction, the switch from the electric vehicle traveling mode to the hybrid vehicle traveling mode experienced during traveling in the hybrid vehicle is effectively used. In addition, the learned values (second clutch hydraulic pressure value P _CL2 and second clutch transmission torque estimated value T _CL2 ) can be acquired with high frequency.

  As mentioned above, although the clutch control apparatus of the 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, the clutch transmission torque estimated value is calculated in association with the clutch hydraulic pressure value. However, instead of the clutch hydraulic pressure value, the estimated clutch transmission torque value may be calculated in association with other elements (for example, clutch stroke amount, clutch engagement command, etc.) that have a corresponding relationship with the clutch transmission torque.

In the first embodiment, an example in which the inertia term (I · ω ′ _MG ) is subtracted in consideration of the influence of inertia when calculating the second clutch transmission torque estimated value T _CL2 . However, when the change in the rotational speed of the drive system is small, an example in which the inertia term is ignored and the second clutch transmission torque estimated value T _CL2 is calculated only by the motor generator torque value T _MG is also possible.

  The first embodiment shows an application example to an FR hybrid vehicle having a drive system that is a friction engagement element built in the automatic transmission AT as a clutch (second clutch CL2) that is an object of transmission torque calculation and learning correction. It was. However, it can of course be applied to FF hybrid vehicles. Further, an FR hybrid vehicle or FF hybrid vehicle (FIG. 10) having a drive system in which a clutch 2 is added between a motor and a speed change mechanism (AT, CVT, etc.), and between a speed change mechanism (AT, CVT, etc.) and drive wheels. The present invention can also be applied to an FR hybrid vehicle or an FF hybrid vehicle (FIG. 11) having a drive system in which a clutch 2 is added to the vehicle. Further, since this torque estimation and learning correction is established by the relationship between the motor and the clutch, the applicable range is expanded, for example, an electric system having a drive system using a motor and a clutch (including an independent type and a built-in transmission mechanism type). The present invention can also be applied to automobiles and fuel cell vehicles (FIG. 12). In short, the present invention can be applied to any vehicle clutch control device including a drive system in which a clutch is interposed between a motor and a drive wheel.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall system diagram showing a rear-wheel drive FR hybrid vehicle (an example of a hybrid vehicle) to which a clutch control device according to a first embodiment is applied. It is a control block diagram which shows the arithmetic processing performed in the integrated controller 10 of FR hybrid vehicle to which the clutch control apparatus 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 10 of FR hybrid vehicle. It is a control block diagram which shows the arithmetic processing performed with AT controller 7 to which the clutch control apparatus of Example 1 was applied. 7 is a flowchart showing a flow of a second clutch learning correction control process executed by a learning permission determination block 71, a learning value calculation block 72, and a torque-instruction hydraulic pressure map learning correction block 73 of the AT controller 7 according to the first embodiment. It is a figure which shows the offset change and inclination change by deterioration of the relationship characteristic of the instruction | indication oil_pressure | hydraulic of a 2nd clutch and clutch transmission torque which it has in the drive system of a hybrid vehicle. FIG. 5 is a driving force characteristic diagram showing a driving force step when the driving force control traveling with the second clutch included in the driving system of the hybrid vehicle being slip-engaged is shifted to driving force control traveling with complete engagement. It is a figure which shows the relationship characteristic including the tolerance | permissible_range of the front-back G by the clutch transmission torque of the 2nd clutch which has in the drive system of a hybrid vehicle, and a driving force level | step difference, and the variation range. In the FR hybrid vehicle clutch control device of the first embodiment, mode selection characteristics, learning permission flag characteristics, Eng rotation characteristics, MG target rotation characteristics, MG rotation characteristics, MG torque characteristics, shift speed characteristics, CL1 stroke characteristics in the engine start scene It is a time chart which shows an example of (CL1 torque characteristic) * CL2 torque characteristic * CL2 differential rotation characteristic. It is the schematic which shows the hybrid vehicle which has the drive system which added the clutch 2 between the motor which can apply the clutch control apparatus of this invention, and a transmission mechanism (AT, CVT, etc.). It is the schematic which shows the hybrid vehicle with the drive system which added the clutch 2 between the transmission mechanism (AT, CVT, etc.) which can apply the clutch control apparatus of this invention, and a driving wheel. 1 is a schematic view showing an electric vehicle and a fuel cell vehicle having a drive system using a motor and a clutch (including an independent type and a built-in transmission mechanism type) to which the clutch control device of the present invention can be applied.

Explanation of symbols

Eng engine
FW flywheel
CL1 1st clutch
MG motor generator
CL2 Second clutch (clutch)
AT automatic transmission
PS propeller shaft
DF differential
DSL left drive shaft
DSR right drive shaft
RL left rear wheel
RR right rear wheel
FL Left front wheel
FR Right front wheel 7 AT controller (clutch control means)
71 Learning permission determination block (estimated value calculation permission determination unit)
72 Learning value calculation block (clutch transmission torque estimated value calculation unit)
73 Map learning correction block (torque-instructed hydraulic map learning correction unit)
18 Second clutch oil pressure sensor (clutch oil pressure detecting means)
P _CL2 2nd clutch oil pressure value (clutch oil pressure value)
T _CL2 Second clutch transmission torque estimate (clutch transmission torque estimate)

Claims (6)

In a vehicle clutch control device comprising: a drive system having a clutch interposed between a motor and a drive wheel; and clutch control means for controlling engagement and release of the clutch.
Motor torque value detecting means for detecting the torque value of the motor is provided;
The clutch control means detects a motor detected when a slip engagement state is established by gradually lowering the clutch engagement force from a motor running in which the clutch is in an engagement state without slipping. A clutch control device for a vehicle, comprising: a clutch transmission torque estimated value calculation unit that calculates a clutch transmission torque estimated value of the clutch based on a torque value. In the vehicle clutch control device according to claim 1,
The clutch includes a hydraulic actuator that performs engagement / release control,
The clutch engagement control hydraulic system is provided with clutch hydraulic pressure detection means for detecting clutch hydraulic pressure,
The clutch transmission torque estimated value calculation unit detects the clutch hydraulic pressure value at the same timing when detecting the motor torque value, and calculates the clutch transmission torque estimated value in association with the clutch hydraulic pressure value. Clutch control device. The vehicle clutch control device according to claim 2,
The clutch control means sets a torque-instructed oil pressure map that characterizes the relationship between the clutch torque of the clutch and the instructed oil pressure, uses the information acquired by the clutch transmission torque estimated value calculation unit as a learning value, and sets the torque A torque control device that reflects a torque to be indicated in the indicated hydraulic map, and a clutch control device for a vehicle having a learning hydraulic map learning correction unit. In the vehicle clutch control device according to claim 3,
The clutch control device for a vehicle according to claim 1, wherein the clutch transmission torque estimated value calculation unit calculates a clutch transmission torque estimated value of the clutch by subtracting a loss due to inertia from the detected motor torque value. In the vehicle clutch control device according to claim 4,
In addition to the slip stabilization condition in which the slip engagement state is stabilized, the clutch control means includes a differential rotation stabilization condition in which the input / output differential rotation of the clutch is converged and stabilized in a constant width rotation range, and a transient by a driver or system. And having an estimated value calculation permission determination unit that permits calculation of the clutch transmission torque estimated value by the clutch transmission torque estimated value calculation unit when a transient driving force stabilization condition that the change of the driving force is within a certain range is satisfied. A vehicle clutch control device. The vehicle clutch control device according to claim 5,
The vehicle has a drive system in which a first clutch is interposed between an engine and a motor, and a second clutch is interposed between the motor and a drive wheel, and the first clutch is released as a travel mode. A hybrid vehicle having an electric vehicle traveling mode and a hybrid vehicle traveling mode in which the first clutch is engaged;
The estimated value calculation permission determination unit is in a transitional period from the electric vehicle travel mode to the hybrid vehicle travel mode, releases the first clutch, slips the second clutch, A clutch control apparatus for a vehicle, characterized in that, in an engine start mode in which a start command is output to an engine, the clutch transmission torque estimated value calculation permission determination is performed by the clutch transmission torque estimated value calculation unit.

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