JP2011031659A - Hybrid vehicle - Google Patents

Abstract

In start control of a 1-motor 2-clutch hybrid vehicle, if the HCM 10 is normal, the internal combustion engine 1 controls itself based on the target torque from the HCM 10, and the motor generator 3 controls the internal combustion engine 1. By absorbing this output, the second clutch 2 is slightly slipped to realize a start in consideration of durability. An object of the present application is to enable retreat travel while ensuring the durability of the second clutch even in the control at the time of vehicle start when CAN communication fails and the motor generator 3 is abnormal. To do.
When the ECM 11 is isolated from the HCM 10 due to CAN communication failure and the motor generator 3 is abnormal, the ECM 11 engages the second clutch 5 so that the vehicle can start while the second clutch 5 slightly slips. The internal combustion engine 1 is controlled according to the torque (vehicle speed). Thereby, the start which considered durability can be implement | achieved.
[Selection] Figure 1

Description

  The present invention relates to control of a hybrid vehicle including an internal combustion engine and an electric motor as power sources.

  A plurality of friction elements including an internal combustion engine, an electric motor and an automatic transmission arranged in series, a first clutch provided between the internal combustion engine and the electric motor, and a clutch and a brake used for changing the planetary gear in the automatic transmission Patent Document 1 discloses a hybrid system having a one-motor two-clutch structure that includes a second clutch that uses several friction elements as starting clutches.

  In Patent Document 1, an internal combustion engine, an electric motor, a first clutch, a second clutch, and an automatic transmission are controlled by dedicated controllers, and each dedicated controller is a CAN (Controller Area Network) that can exchange information with an integrated controller. ) Connected to each other via a communication line, and executes various controls based on command values from the integrated controller.

  When starting using the driving force of the internal combustion engine, slip control is executed to gradually engage the clutch in the automatic transmission while slipping the clutch in the state where the clutch between the internal combustion engine and the electric motor is engaged. Yes.

JP 2008-128346 A

  By the way, when communication between the integrated controller and the engine controller becomes impossible and the command value is not sent from the integrated controller to the engine controller, the engine controller sets the target torque according to the running state and the throttle opening associated therewith. It becomes impossible to perform degree control, fuel injection control, ignition timing control, and the like.

  In such a case, a traveling mode (hereinafter referred to as evacuation traveling) for arriving at a repair shop or the like is required. However, traveling with only the electric motor with the internal combustion engine stopped can travel only for the amount of battery charge. The distance is at most a few kilometers.

  On the other hand, if the internal combustion engine is operated using the fuel in the fuel tank, a longer travel distance can be realized. However, as described above, the engine controller cannot obtain a command value such as a target torque from the integrated controller. is there.

  If the electric motor can be used, the internal combustion engine is operated at a constant output torque regardless of the driver's request, and the electric motor is operated as a generator to absorb the output torque of the internal combustion engine. The slip amount of the clutch in the automatic transmission can be controlled.

  However, when the electric motor cannot be used, the output torque cannot be absorbed by the electric motor, so the heat load due to friction during slip control increases. Since the clutch in the automatic transmission is not considered for use in situations where the input / output torque difference is large, repeated start / stop causes a problem that the durability of the clutch in the automatic transmission is significantly reduced by the thermal load caused by friction. is there.

  Therefore, in the present invention, even if the CAN communication between the integrated controller and the engine controller becomes unstable and the electric motor becomes unusable, the engine is driven without reducing the durability of the clutch in the automatic transmission. It is an object of the present invention to provide a control device that enables all retreat travel.

  A control apparatus for a hybrid vehicle of the present invention includes an internal combustion engine, a motor generator that is interposed in a power transmission path from the internal combustion engine to drive wheels, and functions as a generator or a drive source, and is interposed between the internal combustion engine and the motor generator. And a second fastening means interposed between the motor generator and the drive wheel. And an internal combustion engine control means for controlling the internal combustion engine, a motor generator control means for controlling the operation of the motor generator, a fastening release control means for controlling the fastening and opening of the first fastening means and the second fastening means, and the internal combustion engine. A vehicle control unit that is connected to the control unit, the motor generator control unit, and the fastening release unit so as to be capable of two-way communication, and comprehensively controls each control unit according to the driving state. Further, when communication between the internal combustion engine control means and the vehicle control means becomes unsatisfactory and the motor generator cannot be used, the vehicle starts while slipping the second fastening means with the first fastening means fastened. The internal combustion engine control means controls the output of the internal combustion engine according to the fastening torque of the second fastening means.

  According to the present invention, even if the CAN communication becomes unsatisfactory, since the vehicle travels using the internal combustion engine, the retreat travel can be performed for a longer distance than when the retreat travel battery is used alone. Further, the internal combustion engine control means estimates these independently and controls the output according to the vehicle speed even if information such as the engagement state of the first engagement means is not supplied, so that the durability of the clutch in the automatic transmission is increased. Can be avoided.

1 is an overall system diagram showing a hybrid vehicle to which an embodiment of the present invention is applied. 7 is a flowchart for explaining a control routine executed by the ECM when CAN communication between the HCM and the ECM is disabled. It is a flowchart for demonstrating the control routine performed by step S30 of FIG. It is a table for motor generator regeneration possible torque calculation. It is a setting table of the minimum acceleration of a vehicle when CAN communication becomes impossible between HCM-ECM.

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

  FIG. 1 is an overall system diagram showing a hybrid vehicle to which this embodiment is applied. The drive system of the hybrid vehicle includes an internal combustion engine 1, a first clutch 2 as a first engagement means, a motor generator 3, an automatic transmission 4, a second clutch 5 as a second engagement means, and a differential 6. And a right rear wheel 7R and a left rear wheel 7L as drive wheels.

  First, the configuration of the drive system will be described.

  The internal combustion engine 1 may be either a gasoline engine or a diesel engine, and the output torque is controlled based on a command from an engine control module (hereinafter referred to as ECM) 11 as internal combustion engine control means. The ECM 11 will be described later.

  The motor generator 3 is a synchronous motor generator in which a permanent magnet is embedded in a rotor and a stator coil is wound around a stator. Based on a control command from a motor controller (hereinafter referred to as MC) 13 as motor generator control means, It is controlled by applying a three-phase alternating current generated by the inverter 8. The MC 13 will be described later.

  The motor generator 3 can also operate as an electric motor that is driven to rotate by receiving power supplied from the battery 9 (this state is referred to as “powering”), and when the rotor is rotated by an external force, The battery 9 can also 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”). Switching between power running and regeneration is performed based on a control command from a hybrid controller (hereinafter referred to as HCM) 10 as vehicle control means. The rotor of the motor generator 3 is connected to the input shaft of the automatic transmission 4. The HCM 10 will be described later.

  The output control of the battery 9 and the management of the state of charge (hereinafter referred to as battery SOC) are performed by a battery controller (hereinafter referred to as LBC) 12. The LBC 12 will be described later.

  The first clutch 2 and the second clutch 5 are controlled to be engaged or disengaged by controlling a solenoid based on a control command of an automatic transmission control unit (hereinafter referred to as ATCU) 14 serving as an engagement / release control means. It is a wet multi-plate clutch. The fastening and releasing are controlled by controlling the oil flow rate and hydraulic pressure with a solenoid. The ATCU 14 will be described later. The fastening state and the release state include a slip fastening state and a slip opening state, respectively.

  The first clutch 2 is interposed between the internal combustion engine 1 and the motor generator 3, and the second clutch 5 is interposed between the motor generator 3 and the differential 6.

  The second clutch 5 is not newly added as a dedicated clutch for connecting / disconnecting the driving force between the motor generator 3 and the differential 6, but includes a clutch and a brake used for changing the planetary gear in the automatic transmission 4. Among the plurality of friction elements, some friction elements are used as starting clutches.

  The automatic transmission 4 is a transmission that switches a stepped gear ratio such as forward 5 speed, reverse 1 speed, etc., depending on the vehicle speed, accelerator opening, or the like. The gear ratio switching control is performed based on a control command from the ATCU 14.

  The output shaft of the automatic transmission 4 is connected to the right rear wheel 7R and the left rear wheel 7L via a differential 6.

  The drive system of the hybrid vehicle has three travel modes according to the engaged / released state of the first clutch 2.

  The first travel mode is an electric vehicle travel mode (hereinafter, referred to as “EV travel mode”) as a motor use travel mode in which the first clutch 2 is disengaged and travels using only the power of the motor generator 3 as a power source. .

  The second travel mode is a travel mode using an internal combustion engine that travels while the first clutch 2 is engaged and includes the internal combustion engine 1 as a power source (hereinafter referred to as “HEV travel mode”).

  The third traveling mode is a slip traveling mode using an internal combustion engine (hereinafter referred to as “WSC (Wet (Wet)”), in which the second clutch 5 is slip-controlled while the first clutch 2 is engaged and the internal combustion engine 1 is included in the power source. This is referred to as “Start Clutch) driving mode”.

  The “WSC travel mode” is a travel mode that is always performed when the vehicle is stopped using the internal combustion engine 1 or the motor generator 3 from a vehicle stop state. The rotational speed on the input side and the rotational speed on the output side of the automatic transmission 4 are set. In this control, the difference in rotational speed is absorbed by gradually increasing the torque capacity of the second clutch 5.

  For example, when the SOC of the battery 9 is low, the internal combustion engine 1 is operating for charging and the first clutch 2 is engaged. At this time, when the vehicle is stopped, the input side of the automatic transmission 4, that is, the internal combustion engine 1 and the motor generator 3 side is rotating, whereas the output side of the automatic transmission 4, that is, the drive wheels 7R, Since the 7L side is stopped, there is a difference in rotational speed. Therefore, when the second clutch 5 is suddenly engaged, the torque is rapidly transmitted to the drive wheels 7R and 7L, and so-called torque shock is generated. Therefore, a WSC travel mode that absorbs this rotational speed difference is required.

  In the initial stage of starting, although the torque capacity of the second clutch 5 is small, the rotational speed difference between the input side and the output side described above is large, so that the durability of the second clutch 5 is reduced due to the thermal load generated by the slip. There is a risk. When the motor generator 3 can be operated normally, a part of the output torque of the internal combustion engine 1 is absorbed by setting the motor generator 3 in a regenerative state, and the rotational speed input to the automatic transmission 4 is controlled. An excessive slip can be suppressed and the thermal load of the second clutch 5 can be reduced. Details of the start control in the WSC travel mode will be described later.

  The “HEV travel mode” as the second travel mode has three travel modes of “internal combustion engine travel mode”, “motor assist travel mode”, and “travel power generation mode”.

  The “internal combustion engine travel mode” included in the “HEV travel mode” moves the drive wheels using only the internal combustion engine 1 as a power source.

  In the “motor assist travel mode” included in the “HEV travel mode”, the drive wheels are moved using two of the internal combustion engine 1 and the motor generator 3 as power sources.

  The “traveling power generation mode” included in the “HEV traveling mode” causes the motor generator 3 to function as a generator at the same time as the drive wheels 7R and 7L are moved using the internal combustion engine 1 as a power source. During constant speed operation or acceleration operation, the motor generator 3 is operated as a generator using the power of the internal combustion engine 1. Further, during deceleration operation, braking energy is regenerated and electric power is generated by the motor generator 3 and used for charging the battery 9.

  In addition to the first to third travel modes, as a further mode, there is a power generation mode in which the motor generator 3 is operated as a generator using the power of the internal combustion engine 1 when the vehicle is stopped.

  Next, the control system will be described.

  The HCM 10, the ECM 11, the LBC 12, the MC 13, and the ATCU 14 are connected to each other via a CAN communication line 15 that can exchange information.

  The ECM 11 receives the engine speed information from the engine speed sensor 31 and calculates a command for controlling the engine operating point (Ne, Te) according to the target engine torque command from the HCM 10. Output to a valve actuator (not shown). Further, in the ECM 11, an output torque estimation unit that estimates the output torque Te based on the fuel injection amount of the internal combustion engine 1, the throttle opening degree, and the like is provided. Information on the engine speed Ne and the estimated output torque Te is supplied to the HCM 10 via the CAN communication line 15.

  The LBC 12 monitors the battery SOC, and this battery SOC information is provided to the MC 13 via the CAN communication line 15 and used for the control information of the motor generator 3 and supplied to the HCM 10 via the CAN communication line 15. .

  The MC 13 receives input of information from the resolver 20 that detects the rotor rotational position of the motor generator 3, and the motor operating point of the motor generator 3 (in accordance with the target motor generator torque command, the target motor generator rotational speed command, etc. from the HCM 10). A command for controlling Nm, Tm) is calculated and output to the inverter 8. The MC 13 estimates a motor generator torque (hereinafter referred to as a motor torque Tm) based on the value of the current flowing through the motor generator 3 (the driving torque and the regenerative torque are distinguished from each other depending on whether the current value is positive or negative). Information on the estimated motor torque Tm is supplied to the HCM 10 via the CAN communication line 15.

  The ATCU 14 receives sensor information from the first clutch hydraulic pressure sensor 21 and the first clutch stroke sensor 22. The hydraulic pressure supplied to the first clutch 2 is controlled according to this and a command (first clutch control command) for engaging / disengaging the first clutch 2 determined by the HCM 10.

  Information on the stroke of the first clutch 2 is supplied to the HCM 10 via the CAN communication line 15. Further, sensor information from the accelerator opening sensor 23, the vehicle speed sensor 24, and the second clutch hydraulic pressure sensor 25 is received, and the engagement / release of the second clutch 5 is controlled in accordance with the second clutch control command from the HCM 10. The command is calculated and output to the hydraulic control unit of the second clutch 5 in the AT hydraulic control valve. Information on the accelerator opening and the vehicle speed is supplied to the HCM 10 via the CAN communication line 15.

  The HCM 10 manages the energy consumption of the entire vehicle and has the function of running the vehicle with higher efficiency. The HCM 10 includes a motor rotation speed sensor 26 that detects a motor generator rotation speed (hereinafter referred to as a motor rotation speed Nm), A second clutch output rotational speed sensor 27 that detects a two-clutch output rotational speed N2out, a second clutch engagement torque sensor 28 that detects an engagement torque TCL2 of the second clutch 5, a brake hydraulic pressure sensor 29, and a vehicle acceleration. The information from the acceleration sensor 30 and information obtained through the CAN communication line 15 are received. The second clutch output rotation speed N2out refers to the rotation speed of the output shaft on the drive wheel side of the second clutch 5.

  The HCM 10 also controls the operation of the internal combustion engine 1 based on the control command to the ECM 11, the operation control of the motor generator 3 based on the control command to the MC 13, and the engagement of the first clutch 2 and the second clutch 5 based on the control command to the ATCU 14.・ Open control is performed.

  Next, the control at the time of vehicle start-up while the internal combustion engine 1 is in operation and the first clutch 2 is engaged, that is, the start control in the WSC travel mode will be described.

  The HCM 10 calculates the target driving force tFo0 of the internal combustion engine 1 according to the driver's request by searching the map from the accelerator pedal opening and the vehicle speed. If the accelerator pedal is not depressed, the driving force equivalent to creep becomes the target value. Based on this, the target engagement torque TCL2 * of the second clutch 5 is calculated. The target engagement torque CL2 * of the second clutch 5 is a value that determines the starting torque at the time of starting the vehicle. For example, when the target driving force tFo0 of the internal combustion engine 1 according to the driver's request is large, The target fastening torque TCL2 * is set so as to increase instantaneously so as to satisfy the request.

  When the target engagement torque TCL2 * is thus set, the second clutch engagement torque control is executed so that the actual engagement torque TCL2 becomes the target engagement torque TCL2 *.

  The target engagement torque TCL2 * is set in consideration of the vehicle load. The higher the vehicle load, the higher the target engagement torque TCL2 *. For example, the vehicle load includes a weight load applied to the vehicle due to a road surface gradient.

  If the target driving force tFo0 on the internal combustion engine 1 side is larger than the target engagement torque CL2 * of the second clutch 5, the second clutch 5 may be overheated more than necessary. Therefore, simultaneously with the control of the internal combustion engine 1 and the second clutch 5, the feedback control of the motor rotational speed (slightly slipping) is made with the target value as a value that makes the input rotational speed N2in slightly higher than the output rotational speed N2out of the second clutch Control).

  As a result, even when the target driving force tFo0 is large, the motor generator 3 is greatly regenerated by feedback control of the motor rotation speed, and the second clutch 5 is maintained in a state of slightly slipping. The second clutch 5 can be prevented from being overheated more than necessary.

  The second clutch input rotational speed N2in refers to the rotational speed of the input shaft of the second clutch 5 on the motor generator 3 side.

  By the way, if communication between the HCM 10 and the ECM 11 becomes impossible due to, for example, disconnection of the CAN communication line 15, the ECM 11 is isolated from the CAN communication network, so information from the HCM 10 necessary for controlling the internal combustion engine 1, for example, target drive The force tFo0 cannot be received. In this case, it is necessary to switch to retreat travel. The following two patterns can be considered as the retreat travel.

  In the first retreat travel pattern, the internal combustion engine 1 is stopped and the motor generator 3 travels only.

  The second retreat travel pattern is a state in which, for example, the output of the internal combustion engine 1 is kept constant by fixing the internal combustion engine 1 to a default state, and the above-described WSC travel mode is executed only by the internal combustion engine 1 at the start. is there.

  Note that the default state is a state for generating the minimum output necessary for evacuation travel, in which the throttle opening is fixed at a predetermined opening, and the fuel injection amount, fuel injection timing, ignition according to this is fixed. It is in a timed state. Here, the predetermined opening of the throttle opening is an opening in a state where the throttle valve is returned by a return spring or the like when the energization to the throttle valve actuator is stopped. This opening degree is set to such an extent that a minimum output necessary for traveling of the vehicle is obtained.

  By the way, in the first retreat travel pattern, the travelable distance is determined by the battery SOC. In a battery for a general hybrid vehicle, the travelable distance is about several kilometers at the longest.

  On the other hand, in the second retreat travel pattern, it is possible to travel until the fuel runs out, and it is possible to secure a longer travelable distance than the first retreat travel pattern. Therefore, the second retreat travel pattern is more desirable.

  When the internal combustion engine 1 is set to a default state, which is a higher output state than during normal start, in the second retreat travel pattern, the output torque of the internal combustion engine 1 increases. In this case, if the motor generator 3 is functioning normally, the slip amount of the second clutch 5 at the start of the vehicle is the same as in the normal WSC traveling mode by feedback control of the motor rotation speed.

  However, if the motor generator 3 does not function normally, the large output torque of the internal combustion engine 1 set to the default state is applied to the second clutch 5 as it is, which is larger than the slip amount at the start in the normal WSC mode. Become.

  Therefore, if the motor generator 3 does not function normally, repeating the engagement control of the second clutch 5 each time the vehicle starts, it is originally a friction element for changing the planetary gear, and the durability against the heat load is dedicated to the start. The second clutch 5, which is lower than the clutch having the structure described above, may be deteriorated in durability due to a thermal load caused by slipping.

  As a method for solving this, the output of the internal combustion engine 1 is reduced, that is, the output control of the internal combustion engine 1 is performed so that the second clutch 5 slightly slips without fixing the internal combustion engine 1 to the default state. desirable. However, in this method, communication between the ECM 11 and the HCM 10 is interrupted, and it is necessary to control the output of the internal combustion engine 1 in a state where there is no signal from the HCM 10 as in normal driving.

  Therefore, in this embodiment, when the motor generator 3 cannot be used at the time of starting in a state where CAN communication is disabled between the HCM 10 and the ECM 11, the output of the internal combustion engine 1 is set to the vehicle speed as described below. The control of controlling in accordance with is executed.

  Since it is desirable to control the second clutch 5 to slightly slip when the vehicle starts, the output of the internal combustion engine 1 is set so that the rotational speed on the input shaft side is slightly higher than the rotational speed on the output shaft side of the second clutch 5. Give it. In the present embodiment, the vehicle speed is used as a means for grasping the rotational speed on the output shaft side of the second clutch 5.

  FIG. 2 is a flowchart for explaining a control routine executed by the ECM 11 when starting in a state where CAN communication is disabled between the HCM 10 and the ECM 11. This control routine is repeatedly executed at a short cycle of, for example, about 10 milliseconds. It is assumed that the CAN communication between the controller other than the ECM 11 and the HCM 10 is normal.

  In step S10, it is determined whether or not CAN communication is disabled. If CAN communication is not possible, the process proceeds to step S20. If CAN communication is possible, the process ends. As a determination method, a known CAN communication failure diagnosis can be used. Here, if the signal from the HCM 10 is interrupted for a certain time or more, it is determined that the CAN communication is disabled. For example, about 2 seconds is sufficient for the “certain time”.

  In step S20, first, the internal combustion engine 1 is temporarily set to a default state. This is because it is unknown to the ECM 11 that the motor generator 3 can be used in the initial state in which CAN communication is impossible. Therefore, it is determined whether the motor generator 3 can be used by the processing in step S30 described later. This is a necessary setting.

  Note that if step S20 is executed in the first routine after it is determined in step S10 that CAN communication is not possible, it is not necessary to execute it in the subsequent routine. This step is merely preparation for determining whether or not the motor generator 3 can be used, and it is sufficient to grasp this determination once when CAN communication is impossible. Of course, it may be determined whether the motor generator 3 can be used by setting a default for every predetermined period after it is determined that CAN communication is impossible.

  In step S30, it is determined whether or not the motor generator 3 is normal. FIG. 3 is a flowchart for explaining the control routine executed in step S30, based on whether the actual vehicle speed changes according to the running torque estimated when the internal combustion engine 1 is set to the default state. This is to determine whether the motor generator 3 is being used.

  In step S200, the engine output torque in the default state is estimated. Specifically, it is estimated by map search or the like based on the intake air amount detected by the air flow meter, the ignition timing, the engine speed, and the like.

  In step S210, a friction torque that is a torque due to engine friction is estimated. Specifically, it is estimated by a table search or the like based on the coolant temperature and the engine speed.

  In step S220, the running resistance is converted into the shaft torque of the internal combustion engine 1. Specifically, the running resistance is calculated by a table search using the vehicle speed, the gear ratio of the automatic transmission 4, the gear ratio of the differential 6, the outer diameters of the drive wheels 7R and 7L, and conversion constants. And convert to torque. The gear ratio of the differential 6 and the outer diameters of the drive wheels 7R and 7L are stored in advance in the ECM 11 based on the vehicle specifications, and the gear ratio of the automatic transmission 4 is calculated based on the vehicle speed and the throttle opening. The vehicle speed information may be provided directly from the ATCU 14 to the ECM 11, or provided separately from the CAN shown in FIG. 1, a CAN communication line (Vehicle CAN) for controlling a speedometer, a tachometer, etc. May be provided.

  In step S230, the running torque, which is the torque used for actual running, is calculated by subtracting the friction torque and the running resistance torque from the engine output torque in the default state. If the engine output torque is greater than the sum of the friction torque and the torque due to the running resistance, the running torque will be a positive value. Therefore, the vehicle will accelerate without considering the power running or regeneration of the motor generator 3. On the contrary, if the sum of the friction torque and the torque due to the running resistance is larger than the engine output torque, the running torque becomes a negative value, so the vehicle decelerates.

  In step S240, it is determined whether or not the vehicle is changing the vehicle speed according to the running torque calculated in step S230. A vehicle speed corresponding to the running torque is calculated based on the running torque, vehicle weight, gear ratio, and the like, and the calculated value is compared with the vehicle speed.

  If the calculated value and the detected value are equal, it is determined that the vehicle speed has changed according to the running torque, and the process proceeds to step S250. If the calculated value and the detected value are equal, the motor generator 3 is neither powering nor regenerating, so in step S250 it is determined that the motor generator 3 is disabled.

  On the other hand, if the calculated value and the detected value are not equal, it is determined that the vehicle speed has not changed according to the running torque, and the process proceeds to step S260. As a case where the calculated value and the detected value are not equal, for example, the motor generator 3 is performing regeneration even though the running torque is a positive value, and the vehicle is decelerated due to the consumption of torque for regeneration. On the contrary, since the motor generator 3 performs power running, the traveling torque may be a negative value but accelerated, or the vehicle speed may be higher than the vehicle speed corresponding to the traveling torque. Therefore, in step S260, it is determined that motor generator 3 can be used.

  In addition, also when the 1st clutch 2 is open | released, it progresses to step S260. This is because if the first clutch 2 is released, the output torque of the internal combustion engine 1 is not transmitted to the drive wheels 7R and 7L, and therefore the vehicle speed does not change according to the running torque.

  As described above, when it is determined whether the motor generator 3 can be used or not according to the flowchart of FIG. 3, the process returns to the flowchart of FIG. 2. If the motor generator 3 is usable, the process proceeds to step S40. .

  In step S40, it is estimated whether or not the first clutch 2 is released by the ECM 11 itself without depending on the information from the HCM 10. If the engine speed corresponding to the intake air amount at the throttle opening in the default state is maintained for a certain time set as the determination time or more, it is estimated that the engine is open, otherwise it is engaged. . For example, the determination time may be about 2 to 3 seconds.

  The reason for the estimation is as follows. In the open state, the so-called internal combustion engine 1 rotates in a no-load state, so that a constant rotational speed is maintained. On the other hand, in the engaged state, the engine rotational speed should change due to the action of the running resistance, the rotational resistance of the motor generator 3, and the like.

  By this determination, the ECM 11 can grasp the state of the first clutch 2 even if the first clutch 2 is connected / disconnected according to the SOC of the battery 9 and the information is not sent from the ECM 11 to the ECM 11.

  Note that the engagement / release operation of the first clutch 2 which is a premise of this determination is as follows. First, the HCM 10 reads the SOC of the battery 9 from the LBC 12, and if the SOC exceeds a preset threshold value for preventing overcharge, the HCM 10 is opened.

  When it is estimated that the first clutch 2 is released, the process proceeds to step S50, and when it is estimated that the first clutch 2 is engaged, the process proceeds to step S60.

  In step S50, feedback control is executed so that the engine rotation speed is maintained at a preset idle rotation speed. This is because the first clutch 2 is disengaged and the output of the internal combustion engine 1 is not used for traveling, so it is sufficient to maintain the idle rotation speed.

  The fact that the first clutch 2 is released means that the battery 9 is prevented from being overcharged, that is, the amount of charge of the battery 9 is sufficient, so that the vehicle runs on EV.

  By the way, if the charge amount of the battery 9 is sufficient and the vehicle performs EV traveling, it is not necessary to operate the internal combustion engine 1. This is because if the CAN communication is normal, the internal combustion engine 1 is controlled to be restarted according to the charge amount of the battery 9 or an acceleration request. However, in a state where CAN communication between the HCM 10 and the ECM 11 is disabled, the ECM 11 cannot know whether there is a restart request for the internal combustion engine 1. For this reason, when the internal combustion engine 1 is stopped in this step, it is necessary to add a control logic for restarting the internal combustion engine 1 only when CAN communication is impossible. Therefore, in the present embodiment, the internal combustion engine 1 is not stopped in order to avoid the addition of control logic. Further, in order to reduce the fuel consumption due to the operation of the internal combustion engine 1, the idling rotational speed is maintained.

  In step S60, since the ECM 11 is independent of the CAN communication network, the retreat traveling control of the internal combustion engine 1 is performed.

  Since the ECM 11 does not include an acceleration request from the driver, it is difficult to control the output of the internal combustion engine 1 according to the driver's request. However, the motor generator 3 is connected to the driver by CAN communication from the HCM 10. It is possible to implement control that reflects the requirements of Therefore, as will be described later, the ECM 11 operates the internal combustion engine 1 at a torque that can maintain the current vehicle speed, and the motor generator 3 takes charge of the driver's acceleration / deceleration requests based on communication from the HCM 10, thereby It corresponds to reflect the driver's request even in the event of a failure.

  Next, the above control will be specifically described.

  The “torque capable of maintaining the vehicle speed” generated in the internal combustion engine 1 is a minimum necessary torque for maintaining the vehicle speed constant against the running resistance torque. The running resistance torque is determined according to the vehicle speed, and is obtained as described in step S230 of FIG.

  If a torque capable of maintaining the vehicle speed is determined, the ECM 11 controls the throttle opening so that the torque is obtained.

  The HCM 10 controls the output torque and power generation amount of the motor generator 3 according to the driver's acceleration request and the like. For example, when there is an acceleration request, the difference between the torque required for the acceleration according to the request and the output torque currently generated by the internal combustion engine 1 is covered by powering the motor generator 3, and the acceleration request is met. Achieve acceleration. On the other hand, when there is a request for deceleration, the output torque of the internal combustion engine 1 is absorbed by increasing the regeneration amount of the motor generator 3.

  By the way, in a low speed region such as when the vehicle starts, the output torque corresponding to the vehicle speed becomes small, so that the rotational speed of the internal combustion engine 1 becomes low and may stall. Therefore, in the low speed region including when the vehicle starts, the motor generator 3 may absorb the output torque that is excessive with respect to the vehicle speed while preventing the stall by fixing the internal combustion engine 1 to the default state.

  It should be noted that the output torque of the internal combustion engine 1 is set larger than the torque capable of maintaining the vehicle speed by a predetermined amount, and when there is no acceleration request, the predetermined amount of torque is regenerated by the motor generator 3 to charge the battery 9. You may do it.

  Next, step S70 and subsequent steps that proceed when the motor generator 3 cannot be used will be described. After step S70, since the motor generator 3 cannot be used, the output of the internal combustion engine 1 cannot be absorbed with the motor generator 3 in the regenerative state. Therefore, the output torque of the internal combustion engine 1 itself must be controlled to a magnitude according to the vehicle running state.

  In step S70, the operation of the vehicle speed sensor is confirmed, that is, it is determined whether or not the vehicle speed is normally input. If not normally input, the process proceeds to step S110 and the internal combustion engine 1 is stopped. If it is normally input, the process proceeds to step S80.

  In step S80, it is determined whether or not the vehicle speed is equal to or less than a specified value. The specified value is the upper limit of the vehicle speed at which the slip control of the second clutch 5 can be performed in the WSC travel mode, and is set to about 10 km / h, for example. As a result of the determination, if the vehicle speed is equal to or less than the specified value, that is, if slip control at the time of starting the vehicle is included, the process proceeds to step S90, and if greater than the specified value, the process proceeds to step S100.

  In step S90, the engine speed is feedback controlled to a value that causes the second clutch 5 to slip slightly. The engine rotational speed is controlled because the motor generator 3 cannot be used here, so that the excess torque cannot be absorbed by the motor generator 3 while maintaining the internal combustion engine 1 at a constant rotational speed as in step S60. .

  This feedback control is the same control as so-called idle speed control, and the engine rotational speed is adjusted by controlling the throttle opening.

  Next, the control contents of this step will be described.

  The fastening force of the second clutch 5 increases as the engine rotational speed increases, that is, as the vehicle speed increases. Therefore, the engine rotational speed at which the second clutch 5 slightly slips also has a value corresponding to the vehicle speed. Therefore, the target value of the feedback control is set according to the vehicle speed.

  Thereby, even when the vehicle speed changes, it is possible to realize an engine rotation speed at which the second clutch 5 slightly slips, thereby preventing the slip amount from becoming excessive and protecting the second clutch 5. be able to.

  However, since the output torque required to slip the second clutch 5 is small when the vehicle starts and after the start, the internal combustion engine 1 maintains autonomous operation when the engine speed is controlled according to the vehicle speed. There is a risk that the engine speed will be too low. Therefore, in the feedback control, the rotational speed at which the internal combustion engine 1 can operate autonomously is set as the lower limit value.

  In step S100, engine speed feedback control is executed in the default state. As a result, the output torque is increased as compared with step S90. However, slip control is not executed in this vehicle speed range, so the second clutch 5 is not deteriorated by a thermal load due to friction.

  In the above description, the output of the internal combustion engine 1 is controlled by the throttle opening. However, the present invention is not limited to this, and other methods may be used as long as the intake torque can be adjusted to control the output torque. .

  As described above, the following effects can be obtained in the present embodiment.

  (1) In a 1-motor 2-clutch hybrid system, when the communication between the ECM 11 and the HCM 10 is unsatisfactory and the motor generator 3 cannot be used, and the WSC running mode is executed, the ECM 11 The output of the internal combustion engine 1 is controlled according to the fastening torque 5. For this reason, it can prevent that the 2nd clutch 5 deteriorates by the heat load by the friction at the time of a slip, and durability falls.

  (2) When the internal combustion engine 1 is incapable of autonomous operation at the engine rotation speed for generating the output torque set according to the engagement torque of the second clutch 5, the ECM 11 Target engine speed control is performed with the lower limit as the target value. Thereby, it is possible to avoid the internal combustion engine 1 from stalling while preventing the durability of the second clutch 5 from decreasing.

  (3) When the vehicle speed exceeds a predetermined vehicle speed at which slip control is not performed, the ECM 11 fixes the internal combustion engine 1 to a default state. Thereby, it is possible to simplify the calculation in the region where there is no fear of a decrease in durability due to the thermal load of the second clutch 5.

  (4) When the motor generator 3 can be used, the ECM 11 controls the output torque of the internal combustion engine 1 to a magnitude necessary to maintain the current vehicle speed, and the HCM 10 performs the motor according to the driver's acceleration request. The operation state of the generator 3 is determined, and the MC 13 controls the operation of the motor generator 3 based on the determination of the HCM 10. That is, the internal combustion engine 1 generates an output torque necessary for maintaining the vehicle speed, and a torque necessary for acceleration is generated by the motor generator 3. Thereby, output control according to a driver | operator's request | requirement is attained, simplifying control of the internal combustion engine 1 and the motor generator 3. FIG.

  (5) If the motor generator 3 can be used and the first clutch 2 is in an open state, the ECM 11 controls the engine rotation speed of the internal combustion engine 1 to be maintained at an idle rotation speed. Thereby, it is not necessary to add control logic for restarting the engine from idle stop when CAN communication is disabled, and the fuel consumption of the internal combustion engine 1 can be suppressed.

  (6) The ECM 11 sets the internal combustion engine 1 to a default state when CAN communication is disabled, and the motor generator 3 cannot be used when the vehicle speed changes to a value corresponding to the output torque in the default state. Otherwise, the motor generator 3 can be used. Judge. Thereby, even when CAN communication is impossible, the ECM 11 itself can determine whether or not the motor generator 3 can be used.

  (7) The ECM 11 sets the internal combustion engine 1 to a default state when CAN communication is disabled, and the first clutch 2 is in an open state when the engine rotation speed in the default state is maintained for a predetermined time or more. 2 is determined to be in a fastening state. Thereby, even when CAN communication is impossible, the ECM 11 itself can determine the engaged state of the first clutch 2.

  A second embodiment will be described.

  In the present embodiment, the system configuration and basic control are the same as those in the first embodiment, but the control contents of steps corresponding to step S60 in FIG. 2 are different.

  Here, the control content of the step corresponding to step S60 will be described.

  In this step, the output control of the internal combustion engine 1 for retreat traveling is performed by the ECM 11 alone. Here, the output torque generated in the internal combustion engine 1 is the sum of the regenerative torque of the motor generator 3, the output torque necessary for the minimum acceleration of the vehicle, and the running resistance torque, or the output torque in the default state. The larger one.

  When the output torque in the default state is larger, the engine torque in the default state is selected because the engine rotation speed in the default state generates the minimum output torque necessary for vehicle travel. It is.

  That is, in a low speed range such as when the vehicle starts, the sum of the torques is small, and the engine speed for generating the torque is also low. For this reason, there is a possibility that the internal combustion engine 1 cannot stall autonomously at the engine rotation speed and stalls. Therefore, the output torque in the default state is set as the lower limit value.

  With this setting, when the default state is selected, an output torque larger than the output torque necessary for starting is generated. However, since the surplus torque can be absorbed by the motor generator 3 as described above, the second torque The durability of the clutch 5 does not decrease.

  Note that the output torque necessary for the minimum acceleration of the vehicle is an output torque necessary for realizing the minimum acceleration when it is assumed that there is no running resistance, rotational resistance of the motor generator 3, and the like.

  The regenerative torque of the motor generator 3 is the torque shown by the HCM 10 as shown in FIG. In this range, it is arbitrarily determined based on the table. In FIG. 4, the horizontal axis represents the rotation speed of the motor generator 3, and the vertical axis represents the output of the motor generator 3. However, when the first clutch 2 is engaged, the engine rotation speed and the rotation speed of the motor generator 3 are substantially the same. Therefore, if the table of FIG. The regenerative torque can be obtained by searching the table 4.

  The torque Tamin required for the minimum acceleration of the vehicle is expressed as in equation (1).

    Tamin = A (v) × m × r / (Rf × Rg) (1)

  A (v) is the minimum acceleration of the vehicle, m is the vehicle weight, r is the driving wheel radius, Rf is the gear ratio of the differential 6 (so-called final gear ratio), and Rg is the gear ratio of the automatic transmission 4.

  The minimum acceleration A (v) of the vehicle is set according to the vehicle speed as shown in FIG. In FIG. 5, the horizontal axis represents the vehicle speed and the vertical axis represents the minimum acceleration. The minimum acceleration A0 in the figure is an acceleration that does not cause the driver to feel a pop-out feeling or the like, and is set based on sensory evaluation or the like. The vehicle speed Vb in the figure is set in advance as the maximum vehicle speed during retreat travel. The vehicle speed Va in the figure is the vehicle speed when the acceleration starts to decrease at a rate that does not give the driver a sense of incongruity when the acceleration is decreased to converge the vehicle speed to Vb. The acceleration here refers to the acceleration applied to the vehicle when the driver releases the accelerator pedal. In other words, in retreat travel at the time of throttle failure in a vehicle using only a general internal combustion engine as a power source, the torque when the throttle opening is equivalent to the default position is slightly accelerated to about 40 km / h. Decelerate by the amount of engine friction when fuel is cut. In the situation of the present embodiment, since the HCM 10 can issue a command according to the driver's intention to accelerate to the motor generator 3, the motor generator 3 provides the torque necessary for driving, and the engine is released when the driver releases the accelerator pedal. You may make it decelerate according to the amount of friction. In addition, since it is a failure mode in which the throttle opening can be operated, the acceleration may be such that fine acceleration is continued until the speed becomes higher than the default state.

  Even during retreat travel, only the CAN communication between the HCM 10 and the ECM 11 is interrupted here, and the internal combustion engine 1 itself is normal. Accordingly, the vehicle speed can be increased as the throttle opening is increased. However, since a high vehicle speed is not necessary during retreat, the maximum vehicle speed Vb is set as described above.

  The running resistance torque is a function corresponding to the vehicle speed and is obtained as described above.

  The ECM 11 controls the throttle opening so that the output torque is as described above. At this time, communication between the ECM 11 and the HCM 10 is interrupted, but the HCM 10 is executing regenerative / power running control of the motor generator 3.

  For example, when the second clutch 5 is gradually engaged, such as when the vehicle starts, if the input torque to the second clutch 5 is large enough to cause the slip amount of the second clutch 5 to be excessive, the HCM 10 3 is controlled to increase the regenerative torque. That is, a part of the output torque of the internal combustion engine 1 is consumed by the regeneration of the motor generator 3, and the slip amount of the second clutch 5 is suppressed. Thereby, it can prevent that the 2nd clutch 5 deteriorates by the thermal load by friction at the time of vehicle start. At this time, the magnitude of the input torque to the second clutch 5 can be detected by the MC 13.

  When the vehicle speed is unknown, the output torque of the internal combustion engine 1 is obtained by adding the regenerative torque of the motor generator 3 to the torque in the default state. If the engine speed is unknown, the internal combustion engine 1 is stopped and switched to traveling by the motor generator 3 alone.

  Also in this embodiment, the same effect as the first embodiment can be obtained.

  The present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made within the scope of the technical idea described in the claims.

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 1st clutch 3 Motor generator 4 Automatic transmission 5 2nd clutch 6 Differential 7R Right drive wheel 7L Left drive wheel 8 Inverter 9 Battery 10 Hybrid controller (HCM)
11 Engine controller (ECM)
12 Battery controller (LBC)
13 Motor controller (MC)
14 Automatic transmission control unit (ATCU)
DESCRIPTION OF SYMBOLS 15 CAN communication line 20 Resolver 21 1st clutch oil pressure sensor 22 1st clutch stroke sensor 23 Accelerator opening sensor 24 Vehicle speed sensor 25 2nd clutch oil pressure sensor 26 Motor rotational speed sensor 27 2nd clutch output rotational speed sensor 28 2nd clutch fastening Torque sensor 29 Brake hydraulic pressure sensor 30 Acceleration sensor 31 Engine rotation speed sensor

Claims (7)

An internal combustion engine;
A motor generator intervening in the power transmission path from the internal combustion engine to the drive wheels and functioning as a generator or a drive source;
First fastening means interposed between the internal combustion engine and the motor generator;
Second fastening means interposed between the motor generator and the drive wheel;
A control device for a hybrid vehicle comprising:
Internal combustion engine control means for controlling the internal combustion engine;
Motor generator control means for controlling the operation of the motor generator;
A fastening release control means for controlling fastening and release of the first fastening means and the second fastening means;
Vehicle control means connected to the internal combustion engine control means, the motor generator control means, and the fastening release means so as to be capable of two-way communication, and comprehensively controlling the respective control means according to an operating state;
Have
When the communication between the internal combustion engine control means and the vehicle control means is unsatisfactory and the motor generator cannot be used, the vehicle starts while slipping the second fastening means with the first fastening means fastened. In this case, the internal combustion engine control means controls the output of the internal combustion engine in accordance with the fastening torque of the second fastening means.   The internal combustion engine control means, when the engine rotational speed for generating the output of the internal combustion engine set according to the fastening torque of the second fastening means is an engine rotational speed at which the internal combustion engine cannot be autonomously operated. 2. The hybrid vehicle control device according to claim 1, wherein target engine rotation speed control is performed with a lower limit value of an engine rotation speed capable of autonomous operation as a target value.   3. The internal combustion engine control means fixes the internal combustion engine to a default state in which a preset output is generated when the vehicle speed exceeds a predetermined value after starting the vehicle. The control apparatus of the hybrid vehicle described in 2.   If the motor generator can be used, the internal combustion engine control means controls the output of the internal combustion engine to an output necessary to maintain the current vehicle speed, and the vehicle control means 4. The operation state of the motor generator is determined according to the control signal, and the motor generator control unit controls the operation of the motor generator based on the determination of the vehicle control unit. 5. The control apparatus of the hybrid vehicle as described in one.   When the motor generator is usable and the first fastening means is in an open state, the internal combustion engine control means controls to maintain the engine rotational speed of the internal combustion engine at an idle rotational speed. The hybrid vehicle control device according to any one of claims 1 to 4.   The internal combustion engine control means controls the internal combustion engine to generate a predetermined torque set in advance when communication with the vehicle control means fails, and the vehicle speed changes to a value corresponding to the predetermined torque. 6. The hybrid vehicle according to claim 1, wherein the motor generator is determined to be unusable when the motor generator is used, and is determined to be usable when the motor generator does not change to a value corresponding to the predetermined torque. Control device.   The internal combustion engine control means controls the internal combustion engine to generate a predetermined torque set in advance when communication with the vehicle control means becomes unsuccessful, and the predetermined time exceeds a predetermined time set as a determination time. 7. The method according to claim 1, wherein when the engine speed that generates torque is maintained, it is determined that the first fastening means is in an open state, and when the engine speed is not maintained, it is determined that the first fastening means is in a fastening state. The control apparatus of the hybrid vehicle as described in any one.

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