JP2010149556A - Control device for hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device for a hybrid vehicle, allowing inexpensive detection of a fixed state of a second clutch provided between a motor/generator and drive wheels. <P>SOLUTION: An integrated control device 10 includes a slip decision means deciding whether the second clutch CL2 is in a slip state or in the fixed state when bringing the second clutch CL2 into the slip state including release. The slip decision means performs the decision based on a vibration waveform of input shaft rotation of the second clutch CL2 when driving the motor/generator MG. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a control device for a hybrid vehicle including an engine and a motor as drive sources, and more particularly to a control device provided with a second clutch between a motor and a drive wheel side.

  Conventionally, a hybrid vehicle including an engine and a motor / generator is known in which a second clutch is interposed between the motor / generator.

In such a hybrid vehicle, for example, Patent Document 1 discloses that the second clutch slips when the motor / generator is driven to start the engine.
JP 2001-88588 A

  In such a hybrid vehicle, the second clutch is released and the motor is driven to start the engine while the vehicle is stopped, or the motor is driven while the second clutch is slipped while the vehicle is stopped or at an extremely low speed. There is a case.

  However, in the conventional control device for a hybrid vehicle, the slip state of the second clutch is detected based on the rotational speed difference between the input side and the output side of the second clutch. When the rotation speed on the output side of the second clutch is performed by using a vehicle speed sensor provided on the drive wheel side, when the vehicle is stopped or at an extremely low speed, the rotation speed on the output shaft side of the second clutch is set. Since the rotational speed could not be detected with high accuracy, the slip state of the second clutch, in particular, the sticking could not be detected.

  Therefore, when the second clutch is fixed while giving a command to release the second clutch, when the motor is driven, the drive is transmitted to the driving wheels, and there is a possibility that the vehicle may be shocked.

  Also, by providing a pressure sensor in the second clutch, it becomes possible to detect whether or not the second clutch is fixed at the time of input to the second clutch. In this case, a dedicated pressure sensor is required. Incurs cost increase.

  The present invention has been made paying attention to the above-described problem, and an object thereof is to provide a control device for a hybrid vehicle that can detect a fixed state of a second clutch provided between a motor and a drive wheel at a low cost. To do.

  In order to achieve the above object, in the hybrid vehicle control device of the present invention, the slip determination means for determining the slip state of the second clutch provided between the motor and the drive wheels is the first when the motor is driven. The hybrid vehicle control device is characterized in that the slip state determination is performed based on the vibration waveform of the input shaft rotation speed of the two clutches.

  In the hybrid vehicle control device of the present invention, when the slip determination means determines the slip, the motor is driven and torque is input to the input side of the second clutch. Based on this, it is determined whether the second clutch is in a slipping state or a fixed state.

  That is, when the second clutch is in a slipping state, when the motor is driven, the motor rotation speed gradually increases.

  In contrast, the inventor of the present application has found that when the second clutch is in the fixed state, the motor rotational speed does not gradually increase and the secondary vibration system changes.

  Therefore, by detecting a state in which the motor rotation speed does not gradually increase, it is possible to detect the fixation of the second clutch at an early stage.

  Since this slip determination is performed based on the input rotation of the second clutch, it is possible to determine without adding a new pressure sensor or the like on the output side of the second clutch, which is advantageous in terms of cost.

    Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  In the hybrid vehicle control apparatus according to the embodiment of the present invention, an engine (Eng) and a motor / generator (MG) are directly connected or connected via a first clutch (CL1), and the motor / generator (MG) and drive wheels ( RL, RR) is interposed between the second clutch (CL2), and when the second clutch (CL2) is in a slipping state including release, the second clutch (CL2) is in a slipping state or a fixed state. The hybrid vehicle control apparatus includes a slip determination unit (105) that determines whether the second clutch (CL2) is driven when the motor / generator (MG) is driven. ), The determination is performed based on the vibration waveform of the input shaft rotational speed.

  Based on FIGS. 1-10, the control apparatus of the hybrid vehicle of Example 1 of the best embodiment of this invention is demonstrated.

  FIG. 1 is an overall system diagram showing a rear-wheel drive FR hybrid vehicle (an example of a hybrid vehicle) to which the control device of 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, a second clutch CL2, and an automatic transmission AT. A propeller shaft PS, a differential DF, a left drive shaft DSL, a right drive shaft DSR, a left rear wheel RL (drive wheel), and a 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. Engagement / release is controlled by the first clutch control hydraulic pressure including the half clutch state. 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.

  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 based on a control command from the motor controller 2. It is controlled by applying. 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 rotates from the engine Eng or the driving wheel. When receiving energy, the battery 4 can be charged by functioning as a generator that generates electromotive force at both ends of the stator coil (this operation state is hereinafter referred to as “regeneration”). 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 in the automatic transmission AT, the input shaft side is connected to the motor / generator MG, and the output shaft side is connected to the left and right rear wheels RL and RR, and is interposed between the two. Clutch. The second clutch CL2 is controlled to be engaged and released including slip engagement and slip release 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 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 first clutch hydraulic unit 6 and the second clutch hydraulic unit 8 are incorporated 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 gears such as forward 7 speed / reverse 1 speed according to vehicle speed, accelerator opening, etc., and the second clutch CL2 includes: It is not newly added as a dedicated clutch, but an optimum 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, which is the output shaft side of the second clutch CL2, is connected to the left and right rear wheels RL, RR via a propeller shaft PS, a differential DF, a left drive shaft DSL, and a right drive shaft DSR. Yes.

  Thus, the second clutch CL2 uses an optimum engagement element according to the gear position in the automatic transmission AT. Therefore, the clutch inertia moment, the clutch damping coefficient, and the clutch spring coefficient of the second clutch CL2 Varies by stage.

  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 travel 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.

  The “HEV mode” is a mode in which the first clutch CL1 is engaged and the vehicle travels with the driving force of the engine Eng and the motor / generator MG. In the first embodiment, in the HEV mode, an engine travel mode, a motor assist travel mode, a travel power generation mode, and an HEV deceleration travel mode can be formed.

  The engine travel mode is a mode in which the torque of the motor / generator MG is 0 and the vehicle travels with the positive torque of the engine Eng.

  The motor assist travel mode is a mode in which the engine Eng torque and the motor / generator MG torque are both positive.

  The traveling power generation mode is a mode of traveling while generating power by the motor / generator MG as a regenerative operation state in which the torque of the engine Eng is positive while the torque of the motor / generator MG is negative.

  In contrast to the travel power generation mode, the HEV decelerating travel mode is a power running operation state in which the torque of the motor / generator MG is positive, while the torque of the engine Eng is a negative having a larger absolute value than the torque of the motor / generator MG due to friction. Is a mode in which the vehicle travels at a reduced speed.

  In the “WSC mode”, for example, when starting from the “EV mode” or starting from the “HEV mode”, the clutch transmission torque that causes the second clutch CL2 to be in the slip engagement state and the second clutch CL2 elapses is set. In this mode, the vehicle starts while controlling the clutch torque capacity so that the required driving torque is determined according to the vehicle state and the driver's operation. “WSC” is an abbreviation for “Wet Start clutch”.

  Next, the control system of the hybrid vehicle will be described.

  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, a first clutch hydraulic unit 6, an AT controller 7, The second clutch hydraulic unit 8, the brake controller 9, and the integrated controller 10 are included. 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 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 motor / generator MG is output to inverter 3. The motor controller 2 monitors the battery charge amount SOC representing the charge capacity of the battery 4, and this battery charge amount SOC information is used for control information of the motor / generator MG and is connected to the CAN communication line 11. To the integrated controller 10.

  The first clutch controller 5 receives the sensor information from the first clutch stroke sensor 15 that detects the stroke position of the piston 14a of the hydraulic actuator 14, the target first clutch torque command from the integrated controller 10, and other necessary information. input. Then, a command for controlling the 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 traveling with the D range selected, a control command for searching for the optimum gear position based on the position where the driving point determined by the accelerator pedal opening AP and the vehicle speed VSP exists on the shift map and obtaining the searched gear position is issued. Output to the AT hydraulic control valve unit CVU to control the engagement and release of each frictional engagement element (not shown). The shift map is a map in which an upshift line and a downshift line are written according to the accelerator opening AP and the vehicle speed VSP. In addition to the automatic shift control, the AT controller 7 receives a command for controlling the engagement / release of the second clutch CL2 in the AT hydraulic control valve unit CVU when the target second clutch torque command is input from the integrated controller 10. Second clutch control to be output to the two-clutch hydraulic unit 8 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 for the required braking force obtained from the brake stroke BS, the shortage is compensated by the mechanical braking force (hydraulic braking force or motor braking force) Perform regenerative cooperative brake control.

  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. Then, a target engine torque command to the engine controller 1, a target MG torque command and a target MG rotation speed command to the motor controller 2, a target first clutch torque command to the first clutch controller 5, a target second clutch torque command to the AT controller 7, A regenerative cooperative control command is output to the brake controller 9.

  FIG. 2 is a control block diagram showing, in particular, a portion for calculating the target MG torque in the arithmetic processing executed by the integrated controller 10 of the FR hybrid vehicle to which the 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 in the integrated controller 10 of the FR hybrid vehicle to which the control device of the first embodiment is applied. FIG. 4 is a diagram illustrating a target charge / discharge amount map used when battery charge control is performed by the integrated controller 10 of the FR hybrid vehicle to which the control device of 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 target drive torque calculation means 101, target power generation amount calculation means 102, torque distribution calculation means 103, estimated second clutch input rotation speed calculation means 104, second clutch slip determination means. (Slip determination means) 105, vehicle state management calculation means 106, and target MG torque calculation means 107 are provided. Then, a target MG torque command is output from the target MG torque calculation means 107 to the motor controller 2.

  The target drive torque calculation means 101 calculates the target MG torque of the motor / generator MG based on the accelerator opening AP and the vehicle speed VSP obtained from the accelerator opening sensor 16 and the vehicle speed sensor 17.

  The target power generation amount calculation means 102 includes a battery charge amount SOC obtained from the SOC detection means 201 included in the motor controller 2, an engine speed Em obtained from the engine speed sensor 12, and a motor speed obtained from the motor speed sensor 21. A target power generation amount is calculated based on Nm.

  Torque distribution calculating means 103 calculates torque distribution between the engine Eng and the motor / generator MG based on the target MG torque and the target power generation amount.

  The estimated second clutch input rotational speed calculation means 104 is based on the input torque (estimated MG torque) to the second clutch CL2 and is the estimated second clutch input rotational speed that is the estimated input rotational speed when the second clutch CL2 is fixed. Ask for.

  That is, the estimated second clutch input rotation speed calculation means 104 is included in the motor controller 2 and the gear position of the automatic transmission AT detected by the gear position detection means 202 included in the AT controller 7 and detects the gear position (shift stage). On the basis of the estimated MG torque obtained from the estimated MG torque detecting means 203 and the second clutch input rotational speed detected by the second clutch input rotational speed detecting means 204 when it is assumed that the second clutch CL2 is fixed. An estimated second clutch input rotational speed that is an estimated input rotational speed of the second clutch CL2 is obtained.

  Therefore, the estimated second clutch input rotation speed calculation means 104 calculates the estimated second clutch input rotation speed from the estimated motor torque based on the Laplace conversion equation shown in the following equation 1.

In the Laplace conversion equation, J is the second clutch inertia moment (input shaft conversion), C is the second clutch damping coefficient (input shaft conversion), K is the second clutch spring coefficient (input shaft conversion), and s is a variable. It is. In addition, since the second clutch moment of inertia, the second clutch damping coefficient, and the second clutch spring coefficient differ depending on the shift speed, the constants J, C, and K are set according to the shift speed.

  Returning to FIG. 2, the second clutch slip determination means 105 determines whether the second clutch CL <b> 2 is in a slip state or a fixed state. That is, the second clutch slip determining means 105 is configured to estimate the second clutch output rotational speed detected by the second clutch output rotational speed detecting means 205, the second clutch input rotational speed detected by the second clutch input rotational speed detecting means 204, and the estimation. Based on the estimated second clutch rotational speed obtained from the second clutch input rotational speed computing means 104, it is determined whether the second clutch CL2 is in a slip state or a fixed state. Details of this determination will be described later.

  In the first embodiment, the motor rotation speed sensor 21 is used as the second clutch input rotation speed detection means 204, and the rotation speed of the output shaft of the automatic transmission AT is determined as the second clutch output rotation speed detection means 205. A vehicle speed sensor 17 for detection is used.

  Further, the vehicle speed sensor 17 uses a sensor that outputs a change in magnetic force with the rotation of the propeller shaft PS and detects the rotation speed by counting the pulses. If it is less than that, the interval between pulses is increased, and a known structure that cannot detect the rotational speed with high accuracy is used.

  The vehicle state management calculation means 106 is a means for calculating which of the EV mode, the HEV mode, and the WSC mode to drive based on the accelerator opening AP, the vehicle speed VSP, the battery charge amount SOC, and the target MG torque. . That is, the vehicle state management calculation means 106 selects “EV mode” or “HEV mode” as the target travel mode from the accelerator opening AP and the vehicle speed VSP using the EV-HEV selection map shown in FIG. However, if the battery charge SOC is equal to or less than the predetermined value, the “HEV mode” is forcibly set as the target travel mode. Further, when starting from the “EV mode” or “HEV mode”, the “WSC mode” is selected as the target travel mode until the vehicle speed VSP reaches the first set vehicle speed VSP1.

  Target MG torque calculation means 107 calculates a target MG torque based on the vehicle state and the target drive torque. Furthermore, at the time of slip determination to be described later, as shown in FIG. 5, the slip determination is performed for slip determination at a time tb when a preset oil pressure decrease waiting delay time tw has elapsed from the engagement release time ta of the second clutch CL2. The process which outputs the MG torque for operation is performed. The slip determination MG torque is set for each shift stage of the automatic transmission AT according to the inertia moment, the damping coefficient, the spring coefficient, and the like of the shift stage.

  The integrated controller 10 calculates the target charge / discharge power tP from the battery charge amount SOC using the target charge / discharge amount map shown in FIG. Further, the integrated controller 10 calculates a target first clutch torque and a target second clutch torque based on the target engine torque, the target MG torque, and the target MG rotation speed, and generates a target first clutch torque command and a target second clutch. A torque command is output to each of the controllers 1, 2, 5, and 7 via the CAN communication line 11.

  Next, the flow of processing for calculating the target MG torque and outputting the target MG torque command to the motor controller 2 in the integrated controller 10 will be described based on the flowchart of FIG.

  In step S1, data is received from each of the controllers 1, 2, 5, 7, and 9, and the process proceeds to step S2.

  In step S2, the detection values of the sensors 16 to 22 and the detection means 201 to 205 are read, and the process proceeds to step S3.

  In step S3, the target drive torque calculation means 101 calculates the target drive torque, and the process proceeds to step S4.

  In step S4, the target power generation amount is calculated by the target power generation amount calculation means 102, and the process proceeds to step S5.

  In step S5, the torque distribution calculating means 103 calculates the torque distribution to the engine Eng and the motor / generator MG, and the process proceeds to step S6.

  In step S6, the estimated second clutch input rotational speed calculation means 104 calculates the estimated second clutch input rotational speed, and the process proceeds to step S7.

  In step S7, the second clutch slip determination means 105 performs the second clutch slip determination, and the process proceeds to step S8.

  In step S8, the vehicle state management calculation means 106 calculates which vehicle driving mode, ie, EV mode, HEV mode, or WSC mode is selected, and proceeds to step S9.

  In step S9, the target MG torque is calculated by the target MG torque calculating means 107, and the process proceeds to step S10.

  In step S <b> 10, the target MG torque is output to the motor controller 2. At the same time, each command value is output to each controller 1, 5, 7, 9.

  Next, the flow of the second clutch slip determination process in step S7 will be described based on the flowchart of FIG. This slip determination is executed, for example, when the engine Eng is started when shifting from the EV mode to the HEV mode. That is, when the engine Eng is started, if the slip amount of the second clutch CL2 exceeds a preset slip amount, the first clutch CL1 is engaged and the rotation of the motor / generator MG is transmitted to the engine Eng. The engine Eng is started.

  First, in step S81, it is determined whether or not the second clutch output rotation speed is greater than the resolution lower limit value of the second clutch output rotation speed detection means 205 (vehicle speed sensor 17). If the resolution is lower than the lower limit, the process proceeds to step S83.

  In step S82, the slip determination of the second clutch CL2 in the normal mode is performed. That is, in the normal mode, the slip determination of the second clutch CL2 is performed based on the difference between the second clutch input rotation speed and the second clutch output rotation speed.

  On the other hand, in step S83, the second clutch slip determination in the vehicle stop mode is performed. That is, as described above, the second clutch output rotation speed detection means 205 (vehicle speed sensor 17) cannot accurately detect the rotation speed of the propeller shaft PS below the resolution lower limit value. Therefore, as in step S82, the slip determination cannot be performed based on the difference between the second clutch input rotational speed and the second clutch output rotational speed.

  Therefore, in the first embodiment, the second clutch slip determination in the vehicle stop mode is based on the second clutch input rotational speed and the estimated second clutch input rotational speed obtained based on the estimated MG torque. Do.

  Here, the inventor of the present application has found that the second clutch input rotation speed is different between the slip state and the fixed state of the second clutch CL2.

  That is, as shown in FIG. 8, when the second clutch CL2 is in the slip state, the second clutch input rotational speed gradually increases from the rising point t1 of the estimated MG torque as indicated by the slip characteristic S1. On the other hand, when the second clutch CL2 is fixed, the second clutch input rotational speed shows the response of the secondary vibration system as indicated by the characteristic S2 at the time of fixation.

  Therefore, in the first embodiment, it is determined whether the state is a fixed state or a slip state based on the waveform of the secondary vibration system.

  Specifically, in the first embodiment, the actual second clutch input rotational speed detected by the second clutch input rotational speed detecting means 204 (motor rotational speed sensor 21) is compared with the estimated second clutch input rotational speed. When the actual second clutch input rotation speed exceeds the estimated second clutch input rotation speed, it is determined that the slip state is detected. Therefore, in the time chart shown in FIG. 8, the characteristic S2 at the time of fixation corresponds to the estimated second clutch input rotation speed, and the actual second clutch input rotation speed increases as the characteristic S1 at the time of slipping, and the characteristic at the time of fixation. When the time t2 exceeds S2, or when the difference between the two becomes equal to or greater than a preset value, it is determined that the slip state is present, and otherwise, it is determined that the belt is stuck.

  Next, in the target MG torque calculation process of step S9, the process flow when starting the engine from the EV mode will be described based on the flowchart of FIG.

  In step S101, it is determined whether or not the EV mode is set. If the EV mode is set, the process proceeds to step S102, and otherwise returns to the start.

  In step S102, it is determined whether there is an engine start request. If there is an engine start request, the process proceeds to step S103, and if there is no engine start request, the process returns to start.

  In step S103, while engaging 1st clutch CL1, the process which cancels | releases engagement of 2nd clutch CL2 is performed, and it progresses to step S104.

  In step S104, after waiting for the oil pressure decrease waiting delay time tw, the slip determination MG torque is output, and then the process proceeds to step S105. The slip determination MG torque is formed, for example, by adding an additional value MGK to the target drive torque as shown in FIG. This added value MGK is set for each gear position according to the second clutch moment of inertia, the second clutch damping coefficient, and the second clutch spring coefficient. Further, an upper limit value (this upper limit value is set to a value smaller than the torque required at the time of engine start) is set for the slip determination MG torque, and the additional value MGK is added to the target drive torque. If the value exceeds the upper limit value, the upper limit value is set.

  In step S105, the slip determination result in step S7 described above is read, and it is determined whether or not the slip determination result is in the fixed state. If the determination is fixed, the process proceeds to step S106. If the slip determination is determined, the process proceeds to step S108.

  In step S106, it is determined whether or not the target MG torque is less than the low drive torque threshold tqs set for each gear position. If the target MG torque is less than the low drive torque threshold tqs, the process proceeds to step S107, and the low drive torque threshold tqs or more. In this case, the process proceeds to step S108.

  Note that the low drive torque threshold tqs is based on the characteristics of the second clutch CL2, and even if the second clutch CL2 is fixed, this fixed state is canceled and the second clutch CL2 is shifted to the slip state. This corresponds to the MG torque that can be generated. Further, what is engaged as the second clutch CL2 may be different depending on the gear position, and the inertia moment, the damping coefficient, and the spring coefficient of the second clutch CL2 are different depending on the gear position as described above. The threshold value tqs is also set for each gear position.

  In step S107, the target MG torque (added target MG torque) is calculated by adding the added value calculated based on the difference from the low drive torque threshold tqs so that the target MG torque exceeds the low drive torque threshold tqs. To do.

  Therefore, at the time of slip determination, the target MG torque is output to the motor controller 2 as it is. Even when the sticking is determined, if the target MG torque exceeds the low drive torque threshold tqs, the target MG torque is output to the motor controller 2 as it is.

  On the other hand, if the target MG torque is less than the low drive torque threshold tqs at the time of sticking determination, the target MG torque obtained by adding the added value to the target MG torque (added target MG torque) is output to the motor controller 2. The added value uses a value that can make the target MG torque larger than the low drive torque threshold value tqs, and is set based on the difference between the target MG torque and the low drive torque threshold value tqs, for example. . Further, a different value is used for each shift stage according to the characteristics of the second clutch CL2.

  Next, the operation for starting the engine Eng while the vehicle is stopped in the EV mode will be described with reference to the time chart of FIG.

  When the engine start request is made (t11), the second clutch CL2 is switched from the engaged state to the released state, and the second clutch torque command value is reduced from the maximum (MAX) to a value corresponding to the released drive state. (Based on the process flow of steps S101 → S102 → S103).

  Then, in the second clutch CL2, taking into account the hydraulic response, at the time (t12) when the hydraulic pressure decrease waiting delay time tw, which is the time required for releasing the engagement, has passed, the slip determination MG torque is applied. The target MG torque is commanded (step S104).

  At this time, the estimated second clutch input speed calculating means 104 calculates the estimated second clutch input speed based on the estimated MG torque, and the second clutch slip determining means 105 further calculates the actual second clutch input speed. Slip determination is performed based on the difference between the (motor rotation speed) and the estimated second clutch input rotation speed.

  That is, when the estimated MG rotation speed gradually increases as shown in the slip characteristic, the actual second clutch input rotation speed exceeds the estimated second clutch input rotation speed (at time t12), and is determined to be a slip. On the other hand, when the second clutch CL2 is fixed, the drive wheels RL and RR remain stopped, and the actual second clutch input rotational speed does not increase and does not exceed the estimated second clutch input rotational speed. Therefore, a sticking determination is made.

  Thereafter, the target MG torque necessary for starting the engine Eng is output as the target MG torque at time t14 when the time required for the second clutch CL2 to normally shift to the slip state has elapsed.

  When the sticking determination is made at the time t13, if the target MG torque is less than the low drive torque threshold tqs, an addition value is added and a target MG torque (addition target MG) larger than the low drive torque threshold tqs is added. (Torque) is calculated (based on the processing of steps S105 → S106 → S107).

  Therefore, starting of the engine Eng is started by the output torque of the motor / generator MG, and the second clutch CL2 is released from being locked, so that the torque of the motor / generator MG can be prevented from being transmitted to the drive wheel side. .

  As described above, in the first embodiment, the effects listed below can be obtained.

  a) The second clutch slip determining means 105 determines whether the slip state or the fixed state is determined based on the vibration waveform of the estimated second clutch input shaft rotational speed when a release command is given to the second clutch CL2. To do.

  Therefore, in the insensitive region of the second clutch output rotational speed detection means 205, even if the slip determination cannot be performed based on the input / output rotational speed difference of the second clutch CL2, the second clutch CL2 is in the slip state or the fixed state. It became possible to judge.

  Since this slip determination is performed based on the motor rotation speed and the estimated MG torque, it is possible to determine without adding a dedicated sensor for detecting the state of the second clutch CL2, such as a hydraulic sensor or a stroke sensor. This is advantageous in terms of cost.

  b) The estimated second clutch input rotational speed calculation means 104 sets a second clutch moment of inertia, a second clutch damping coefficient, and a second clutch spring coefficient for each gear position when calculating the estimated second clutch rotational speed. did.

  Therefore, it is possible to estimate the second clutch input rotation speed with high accuracy as compared with those using constant values as these values. Thereby, the slip determination of the second clutch CL2 can also be performed with high accuracy.

  c) Since the slip determination MG torque is output at the time t12 before the engine start start time (at time t14 in FIG. 7), the second time at the time before the start of the engine Eng starts. The slip determination of the clutch CL2 can be performed.

  Therefore, early slip determination is possible.

  In addition, since the slip determination MG torque is input to the second clutch CL2 before the engine is started, there is a possibility that the lock may be released by this torque input and the start of the engine start. This makes it possible to release the sticking at an early stage. Therefore, it is possible to suppress the occurrence of a shock due to torque transmission to the drive wheels RL and RR as compared with the case where the slip determination MG torque is not input.

  d) The slip determination MG torque was set according to the second clutch moment of inertia, the second clutch damping coefficient, and the second clutch spring coefficient for each gear position. Therefore, it is possible to further suppress the uncomfortable feeling given to the occupant as compared with those not set for each gear position.

  e) The slip determination MG torque is output after the delay time tw of waiting time for lowering the hydraulic pressure of the second clutch CL2 in consideration of the response of the second clutch CL2. Therefore, it is possible to suppress the occurrence of a shock in the vehicle by outputting the slip determination MG torque in a state where the hydraulic pressure remains in the second clutch CL2 and transmitting it to the drive wheels RL and RR. Therefore, it can suppress giving a sense of incongruity to a passenger | crew by shocking in a vehicle.

  f) The slip determination MG torque is given by adding the added value MGK to the target drive torque, and an upper limit value lower than the target MG torque required at the time of starting the engine is set and does not exceed the upper limit value. Value.

  Therefore, in a situation where the target MG torque of the motor / generator MG is not generated, the motor / generator MG can be driven to input the torque to the second clutch CL2, and the second torque CL can be suppressed by keeping the torque low. Even if the clutch CL2 is fixed, it is possible to suppress the uncomfortable feeling given to the passenger.

  g) When the target MG torque is lower than the low drive torque threshold value tqs, the target MG torque (added target MG torque) to which a preset added value is added is output, so that the second clutch CL2 is released from being locked. It is executed even earlier than the one without the addition value.

  The hybrid vehicle control device of the present invention has been described based on the embodiment and the first embodiment, but the specific configuration is not limited to the first embodiment and the first embodiment. Design changes and additions are permitted without departing from the spirit of the invention according to each claim of the scope.

  In the first embodiment, an example in which the second clutch CL2 is provided as a fastening element of the automatic transmission AT is shown. However, the present invention is not limited to this, and the motor / generator and the drive wheel are independently used. You may provide between. Further, although the automatic transmission AT is interposed between the motor / generator MG and the driving wheels RR and RL, the output side of the second clutch CL2 is used as the driving wheel without providing the automatic transmission AT. It may be directly connected.

  In the first embodiment, the application example to the FR hybrid vehicle in which the first clutch is interposed between the engine and the motor / generator is shown. However, the first clutch is omitted and the engine and the motor / generator are directly connected. It can also be applied to FR hybrid vehicles, FF hybrid vehicles, and four-wheel drive vehicles. Further, not only a motor / generator, but also a motor capable of only power running may be used.

1 is an overall system diagram showing an FR hybrid vehicle (an example of a hybrid vehicle) by rear wheel drive to which a hybrid vehicle control device of Embodiment 1 is applied. It is a control block diagram which shows the part which calculates target MG torque among the calculation processes performed in the integrated controller 10 of FR hybrid vehicle to which the 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 with the integrated controller 10 of the FR hybrid vehicle to which the control apparatus of Example 1 is applied. It is a figure which shows the target charging / discharging amount map used when performing battery charging / discharging process with the integrated controller 10 of the FR hybrid vehicle to which the control apparatus of Example 1 was applied. It is a time chart when the process which outputs the MG torque for slip determination at the time of the slip determination performed in the integrated controller 10 in Example 1 is performed. 4 is a flowchart showing a flow of processing for calculating a target MG torque by the control device according to the first embodiment and outputting a target MG torque command to the motor controller 2; It is a flowchart which shows the flow of a process of the 2nd clutch slip determination by the control apparatus of Example 1. FIG. It is a time chart which shows a 2nd clutch input rotation speed by the slip state of the 2nd clutch CL2 in Example 1, and the adhering state. 6 is a flowchart showing a flow of processing when starting the engine from the EV mode in target MG torque calculation processing in the control device of Embodiment 1; It is a time chart which shows an example of operation in the case of starting engine Eng while stopping in EV mode by the control device of Example 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Integrated controller 104 Estimated 2nd clutch input rotation speed calculating means 105 2nd clutch slip determination means (slip determination means)
AT automatic transmission (transmission)
CL1 First clutch CL2 Second clutch MG Motor / generator PS Propeller shaft RL Left rear wheel (drive wheel)
RR Right rear wheel (drive wheel)
SOC Battery charge tw Delay time

Claims (7)

The engine and the motor are directly connected or connected via a first clutch, and a second clutch is interposed between the motor and the drive wheel,
A control device for a hybrid vehicle, comprising: slip determination means for determining whether the second clutch is in a slipping state or a fixed state when the second clutch is in a slipping state including disengagement,
The control apparatus for a hybrid vehicle, wherein the slip determination means performs the determination based on a vibration waveform of an input shaft rotation speed of the second clutch when the motor is driven. An estimated second clutch input rotational speed calculation means for estimating an input rotational speed of the second clutch from an estimated motor torque of the motor;
The slip determination means performs the determination based on the rotation speed of the motor and the estimated second clutch input rotation speed corresponding to the time when the second clutch is fixed, calculated by the estimated second clutch input rotation speed calculation means. The control apparatus of the hybrid vehicle of Claim 1 characterized by these. A transmission is interposed between the motor and the drive wheel,
3. The control apparatus for a hybrid vehicle according to claim 2, wherein the estimated second clutch input rotation speed calculation means changes a value used for calculation in accordance with a gear position.   4. The hybrid vehicle according to claim 1, wherein the slip determination unit executes a determination output process for causing the motor to output a determination torque when the slip determination is performed. 5. Control device. A transmission is interposed between the motor and the drive wheel,
The hybrid vehicle control device according to claim 4, wherein the determination torque is set in accordance with a gear position of the transmission.   3. The slip determination means executes the output of the determination torque after a delay time considering a preset response delay time has elapsed from the engagement release command of the second clutch. Or the control apparatus of the hybrid vehicle of Claim 5.   The determination torque is set by adding an addition value corresponding to the shift speed to the target motor torque, and an upper limit value is set in advance. The hybrid vehicle control device according to claim 1.

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