JP2014125127A - Vehicle control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure reliable discharging, by using a discharge circuit, a charge stored in a power storage member when a vehicle is collided in a case where communication between a hybrid control part (HV_ECU) and a motor control part (MG_ECU) is cut off.SOLUTION: There is a possibility that a vehicle continues to travel in a case where communication between a hybrid control part (HV_ECU) and a motor control part (MG_ECU) is simply cut off. As a countermeasure, a vehicle collision is determined on the basis of a change in a vehicle speed V and the like (e.g., a motor rotation speed) at the time of communication cut-off when that occurs, to discharge, by using a discharge circuit, a charge stored in a smoothing capacitor, and therefore it is possible to discharge a charge reliably when the vehicle collides.

Description

  The present invention relates to a vehicle control device including an engine and an electric motor as a driving force source for traveling, and more particularly to a technique for coping with a vehicle collision.

  A vehicle that includes an engine and an electric motor and can travel using the engine and the electric motor as a driving force source is well known. In a vehicle including such an electric motor, for example, electric power is transferred between the electric motor and a power storage device (for example, a secondary battery or a battery) via an electric circuit (for example, an inverter unit). This inverter unit has a power storage member (for example, a capacitor), and the voltage of the power storage member is relatively high. Therefore, various techniques for discharging the electric charge of the power storage member have been proposed in order to improve safety when the vehicle collides or when the operation is stopped. For example, Patent Document 1 describes that when an electric motor is operated in a state where an inverter is controlled so that output torque is not generated in the event of a vehicle collision, the accumulated charge of the capacitor is discharged safely and reliably. . Patent Document 2 describes that a discharge circuit in which a discharge relay circuit and a discharge resistor are connected in series is provided in parallel with a capacitor, and the residual charge of the capacitor is discharged by energizing the discharge relay circuit. ing.

JP 2010-178595 A JP 2005-73399 A

  Incidentally, a vehicle including a hybrid control unit (HV_ECU) that controls the entire vehicle and an electric motor control unit (MG_ECU) that controls the electric motor based on communication with the HV_ECU is also well known. In such a vehicle, when the traveling is stopped when the communication between the HV_ECU and the MG_ECU is interrupted, the charge of the capacitor is quickly removed by using the discharge circuit described in Patent Document 2 described above when the communication is interrupted. Discharge can be performed. On the other hand, in the vehicle as described above, when the engine continues to run even if the communication is interrupted, if the discharge is performed using the discharge circuit at the time when the communication is simply interrupted instead of the vehicle collision or the like, the engine traveling is continued. Accordingly, the electric charge accumulated in the capacitor due to the electromotive force generated when the electric motor is driven to the driving wheel (or engine) cannot be discharged using the above discharge circuit at the time of an actual vehicle collision while the vehicle is running. there is a possibility. This is due to the fact that the discharge circuit that is activated in the event of a vehicle collision is not designed on the assumption that it is repeatedly used. In other words, in order to design the discharge circuit to withstand repeated use, for example, it is necessary to increase the size of the components to the extent that heat resistance performance can be ensured, which is disadvantageous in terms of vehicle mounting space. The above-described problem is not known, and even if the discharge circuit is not designed to be used repeatedly, the charge stored in the power storage member at the time of a vehicle collision can be obtained using the discharge circuit. It has not yet been proposed for reliable discharge.

  The present invention has been made in the background of the above circumstances, and the object of the present invention is to discharge the charge stored in the power storage member at the time of a vehicle collision when the communication between the HV_ECU and the MG_ECU is interrupted. It is providing the control apparatus of the vehicle which can discharge reliably using.

  The subject matter of the first invention for achieving the above object is (a) a hybrid that controls the entire vehicle including an engine, an electric motor, and a control that travels using the engine and the electric motor as a driving force source. An electric motor control unit that controls the electric motor based on communication between the control unit and the hybrid control unit, and an electric storage that controls the transfer of electric power related to the operation of the electric motor and temporarily stores the electric power An electric circuit having a member and a discharge circuit provided in parallel to the power storage member, and when the vehicle collision is detected by the hybrid control unit, the motor control unit is stored in the power storage member (B) the hybrid control unit drives the engine even when communication with the electric motor control unit is interrupted. (C) when the communication with the hybrid control unit is interrupted, the electric motor control unit determines a change in vehicle speed or a rotation speed related to the vehicle speed in advance. When the value is larger than the collision determination threshold value and toward zero, the charge stored in the power storage member is discharged using the discharge circuit.

  In this way, there is a possibility that the vehicle may continue to run when communication is simply interrupted, whereas vehicle collisions based on changes in vehicle speed or the like (vehicle speed or rotational speed related to the vehicle speed) at the time of communication interruption. Therefore, since the electric charge stored in the power storage member is discharged using the discharge circuit, it is possible to reliably discharge at the time of a vehicle collision. Therefore, when communication between the HV_ECU and the MG_ECU is interrupted, the charge stored in the power storage member at the time of the vehicle collision can be reliably discharged using the discharge circuit.

  Here, according to a second aspect, in the vehicle control device according to the first aspect, the engine and the electric motor are connected, and the hybrid control unit communicates with the electric motor control unit. When the vehicle crashes without detecting the collision of the vehicle and continuing to run using the engine as a driving force source, the rotational speed of the engine is limited compared to when the communication is not interrupted. There is. In this way, if the vehicle continues to travel when communication is simply interrupted, it is possible to suppress the occurrence of electromotive force in the motor by reducing the engine rotation speed against the rotation of the motor with the rotation of the engine. The discharge time when discharging the charge stored in the power storage member at the time of a vehicle collision can be shortened.

  According to a third aspect of the present invention, in the vehicle control device according to the second aspect of the present invention, the hybrid control further includes an automatic transmission that constitutes a part of a power transmission path between the engine and the drive wheels. The part is to limit the rotational speed of the engine by setting the gear ratio of the automatic transmission to the high side. In this way, when the vehicle continues to travel when communication is simply interrupted, the engine speed can be appropriately reduced.

  According to a fourth aspect of the present invention, in the vehicle control device according to any one of the first to third aspects, the motor control unit is disconnected from the hybrid control unit. When the change in the vehicle speed or the rotational speed related to the vehicle speed is greater than a predetermined second collision determination threshold and increases, the charge stored in the power storage member is transferred to the discharge circuit. It is to discharge using. In this way, when the vehicle collides, the vehicle speed or the rotational speed related to the vehicle speed may overshoot due to the idling of the driving wheel, the shaft disconnection (disengagement) in the power transmission system, or the neutral state of the power transmission path due to the hydraulic pressure loss. In contrast to this, even when the change in the vehicle speed or the rotational speed related to the vehicle speed is larger than the collision determination threshold value and does not go to zero, it is possible to reliably discharge at the time of the vehicle collision.

  According to a fifth aspect of the present invention, in the vehicle control device according to any one of the first to fourth aspects, the discharge circuit includes a discharge element and a switching element connected in series. In other words, the electric charge stored in the power storage member is discharged by energizing the switching element by the motor control unit. If it does in this way, the electric charge stored in the electrical storage member using the discharge circuit can be discharged quickly.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure explaining the schematic structure of the vehicle to which this invention is applied, and is a figure explaining the principal part of the control system in a vehicle. It is a functional block diagram explaining the principal part of the control function of an electronic controller. The essential part of the control operation of the electronic control unit, that is, the electric charge stored in the smoothing capacitor at the time of a vehicle collision when communication between the hybrid control unit (HV_ECU) and the motor control unit (MG_ECU) is interrupted is ensured using a discharge circuit. It is a flowchart explaining the control action | operation for discharging to the inside.

  In the present invention, preferably, the automatic transmission is a single automatic transmission such as a stepped transmission or a continuously variable transmission, an automatic transmission having a fluid transmission, or an automatic transmission having a sub-transmission. Consists of.

  Preferably, the engine is an internal combustion engine such as a gasoline engine or a diesel engine that generates power by burning fuel. Further, a wet or dry engagement device (clutch) may be provided in a power transmission path between the engine and the electric motor.

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

  FIG. 1 is a diagram illustrating a schematic configuration of a vehicle 10 to which the present invention is applied, and a diagram illustrating a main part of a control system for various controls in the vehicle 10. In FIG. 1, a vehicle 10 is a hybrid vehicle including a power transmission device 12, an engine 14 that functions as a driving force source for traveling, and an electric motor MG. The power transmission device 12 includes an engine connection / disconnection clutch K0 (hereinafter referred to as connection / disconnection clutch K0), a torque converter 16, an automatic transmission 18 and the like in order from the engine 14 side in a transmission case 20 as a non-rotating member. It has. The power transmission device 12 is connected to a propeller shaft 26 connected to a transmission output shaft 24 that is an output rotating member of the automatic transmission 18, a differential gear 28 connected to the propeller shaft 26, and the differential gear 28. And a pair of axles 30 and the like. The power transmission device 12 configured in this manner is suitably used for, for example, an FR (front engine / rear drive) type vehicle 10. In the power transmission device 12, the power of the engine 14 (also synonymous with torque and force unless otherwise distinguished) connects the crankshaft of the engine 14 and the connection / disconnection clutch K0 when the connection / disconnection clutch K0 is engaged. It is transmitted from the engine connecting shaft 32 to the pair of drive wheels 34 via the connecting / disconnecting clutch K0, the torque converter 16, the automatic transmission 18, the propeller shaft 26, the differential gear 28, the pair of axles 30, and the like in order. The electric motor MG is connected to a power transmission path between the connection / disconnection clutch K0 and the torque converter 16 in the transmission case 20, and the power of the electric motor MG is sequentially passed through the torque converter 16, the automatic transmission 18 and the like. It is transmitted to the drive wheel 34. Thus, the power transmission device 12 constitutes a power transmission path from the engine 14 to the drive wheels 34.

  The torque converter 16 is a fluid transmission device that outputs the power input to the pump impeller 16a through the fluid to output from the turbine impeller 16b. The pump impeller 16a is connected to the engine connecting shaft 32 via the connection / disconnection clutch K0 and is directly connected to the electric motor MG. The turbine impeller 16 b is directly connected to a transmission input shaft 36 that is an input rotation member of the automatic transmission 18. An oil pump 22 is connected to the pump impeller 16a. The oil pump 22 is rotationally driven by the engine 14 (and / or the electric motor MG) to generate hydraulic pressure for executing the shift control of the automatic transmission 18 and the engagement / release control of the connection / disconnection clutch K0. It is a mechanical oil pump.

  The automatic transmission 18 constitutes a part of a power transmission path between the engine 14 and the electric motor MG and the drive wheels 34, and the power from the driving power source for travel (the engine 14 and the electric motor MG) is directed to the drive wheels 34. A transmission for transmission. The automatic transmission 18 is a known planet in which a plurality of shift stages (gear stages) having different gear ratios (gear ratios) γ (= transmission input rotation speed Nin / transmission output rotation speed Nout) are selectively established. A gear type multi-stage transmission or a known continuously variable transmission whose gear ratio γ is continuously changed continuously. In the automatic transmission 18, for example, a hydraulic actuator is controlled by the hydraulic control circuit 40, whereby a predetermined gear stage (gear ratio) is established according to the accelerator operation of the driver, the vehicle speed V, and the like.

  The electric motor MG is a so-called motor generator having a function as a motor that generates mechanical power from electric energy and a function as a generator that generates electric energy from mechanical energy. The electric motor MG is connected to the battery unit 52 via a power control unit (PCU) 50. The electric motor MG functions as a driving force source for traveling that generates traveling power together with the engine 14 as an alternative to the engine 14 that is a power source. The electric motor MG generates electric energy by regeneration from the power generated by the engine 14 and the driven force input from the drive wheel 34 side, and stores the electric energy in the battery unit 52 via the power control unit 50. And so on. The electric motor MG is operatively connected to the pump impeller 16a, and power is transmitted between the electric motor MG and the pump impeller 16a. Therefore, the electric motor MG is connected to the transmission input shaft 36 of the automatic transmission 18 so as to be able to transmit power without the connection / disconnection clutch K0.

  The connection / disconnection clutch K0 is a wet multi-plate hydraulic friction engagement device in which, for example, a plurality of friction plates stacked on each other are pressed by a hydraulic actuator, and hydraulic control is performed using the hydraulic pressure generated by the oil pump 22 as a source pressure. Engagement release control is performed by the circuit 40. In the engagement release control, the torque capacity (hereinafter referred to as K0 torque) of the connection / disconnection clutch K0 is changed by adjusting the pressure of a linear solenoid valve or the like in the hydraulic control circuit 40, for example. In the engaged state of the connection / disconnection clutch K0, the pump impeller 16a and the engine 14 are integrally rotated via the engine connecting shaft 32. Therefore, the engine 14 and the electric motor MG are indirectly connected via the connection / disconnection clutch K0 without differential relative rotation. On the other hand, in the released state of the connection / disconnection clutch K0, power transmission between the engine 14 and the pump impeller 16a is interrupted. That is, the engine 14 and the drive wheel 34 are disconnected by releasing the connection / disconnection clutch K0. Since the electric motor MG is connected to the pump impeller 16a, the connection / disconnection clutch K0 is provided in a power transmission path between the engine 14 and the electric motor MG, and also functions as a clutch for connecting / disconnecting the power transmission path.

  The power control unit 50 includes an inverter unit 54 that controls transmission / reception of electric power related to the operation of the electric motor MG, a boost converter unit 56 disposed between the battery unit 52 and the inverter unit 54, and a voltage on the battery unit 52 side. This is an electric circuit having a DC / DC converter 60 for charging the auxiliary battery 58 by stepping down the voltage and an input capacitor (or filter capacitor) Ci provided between the terminals on the battery unit 52 side of the boost converter unit 56. is there. The inverter unit 54 includes, for example, a known switching element, and in response to a command from an electronic control device 90 (particularly, MG_ECU), which will be described later, to obtain the output torque or regenerative torque required for the electric motor MG. The switching operation of the switching element is controlled. Boost converter unit 56 functions as a reactor L, an upper arm 62 (switching element Q1 and diode D1), a lower arm 64 (switching element Q2 and diode D2), and a power storage member that temporarily stores electric power related to the operation of electric motor MG. A smoothing capacitor Cs, a discharge circuit 66 provided in parallel with the smoothing capacitor Cs, and a discharge resistor Rd provided in parallel with the smoothing capacitor Cs are provided. , MG_ECU) is switched on / off by the switching elements Q1 and Q2, thereby boosting the voltage on the battery unit 52 side or lowering the voltage on the inverter unit 54 side. The discharge circuit 66 includes a rapid discharge resistor Rqd as a discharge element connected in series and a discharge relay DR as a switching element. The discharge relay DR is in response to a command from an electronic control device 90 (in particular, MG_ECU) described later. As a result, the electric charge stored in the smoothing capacitor Cs is quickly discharged. The discharge resistor Rd has a sufficiently large resistance value as compared with the rapid discharge resistor Rqd. For example, when the ignition is off, the electric charge stored in the smoothing capacitor Cs is slowly discharged.

  The battery unit 52 includes, for example, a battery unit 68 that is a chargeable / dischargeable secondary battery such as a lithium ion assembled battery or a nickel hydride assembled battery, and a power control unit according to a command from an electronic control device 90 (particularly, HV_ECU) described later. 50, system relays SR1 and SR2 that open and close an electrical path to and from the power control unit 50 (that is, connect and disconnect the battery unit 68 to and from the power control unit 50). The battery unit 68 may be, for example, a capacitor or a capacitor.

  The vehicle 10 is provided with an electronic control device 90 including a control device for the vehicle 10 related to control of the entire vehicle, for example. The electronic control unit 90 includes, for example, a so-called microcomputer having a CPU, a RAM, a ROM, an input / output interface, and the like. The CPU uses a temporary storage function of the RAM and follows a program stored in the ROM in advance. Various controls of the vehicle 10 are executed by performing signal processing. For example, the electronic control unit 90 performs output control of the engine 14, drive control of the motor MG including regeneration control of the motor MG, shift control of the automatic transmission 18, torque capacity control of the connection / disconnection clutch K0, and the like. The computer is divided into a hybrid control computer (HV_ECU), an electric motor control computer (MG_ECU), a shift control computer (AT_ECU), and the like that control the entire vehicle as necessary. The electronic control unit 90 includes various sensors (for example, an engine rotational speed sensor 70, a turbine rotational speed sensor 72, an output shaft rotational speed sensor 74, an electric motor rotational speed sensor 76, an accelerator opening sensor 78, an acceleration sensor 80, a battery sensor 82, etc. ) (For example, engine rotational speed Ne, which is the rotational speed of the engine 14, turbine rotational speed Nt, that is, transmission input rotational speed Nin, which is the rotational speed of the transmission input shaft 36), and shifts corresponding to the vehicle speed V. The transmission output rotational speed Nout, which is the rotational speed of the machine output shaft 24, the motor rotational speed Nmg, which is the rotational speed of the electric motor MG, the accelerator opening θacc corresponding to the amount of driving required for the vehicle 10 by the driver, and the acceleration acting on the vehicle 10 (Or deceleration) G, the charging state (charging capacity) SOC of the battery unit 68, etc. It is. From the electronic control unit 90, various command signals (for example, the engine control command signal Se, the engine 14, the inverter unit 54, the hydraulic control circuit 40, the battery unit 52, the discharge circuit 66, etc.) are provided to each device provided in the vehicle 10. An electric motor control command signal Sm, a hydraulic control command signal Sp, a power control command signal Sbat, a discharge signal Sdis, etc.) are supplied.

  FIG. 2 is a functional block diagram for explaining a main part of the control function by the electronic control unit 90. In FIG. 2, the hybrid control means included in the HV_ECU, that is, the hybrid control unit 92 includes a function for controlling the drive of the engine 14 and a function for instructing the operation of the electric motor MG, and the engine 14 and the electric motor MG are controlled by these control functions. And control of the entire vehicle 10 including hybrid drive control that travels using the power as a driving force source. For example, the hybrid control unit 92 calculates a required drive torque Touttgt as a drive request amount (that is, a driver request amount) for the vehicle 10 by the driver based on the accelerator opening θacc and the vehicle speed V, and transmission loss, auxiliary load, In consideration of the gear ratio γ of the automatic transmission 18, the charging capacity SOC of the battery unit 68, and the like, the output torque of the driving power source (engine 14 and electric motor MG) for obtaining the required driving torque Touttgt is calculated. The hybrid control unit 92 controls the throttle valve opening, the fuel injection amount (fuel supply amount), the ignition timing, and the like so that the calculated output torque (engine torque) Te of the engine 14 is obtained. Se is output. Further, the hybrid control unit 92 outputs a command signal for controlling the electric motor MG to the electric motor control unit 94 to be described later so that the calculated output torque (MG torque) Tmg of the electric motor MG is obtained. The required drive amount includes, in addition to the required drive torque Touttgt [Nm] in the drive wheel 34, the required drive force [N] in the drive wheel 34, the required drive power [W] in the drive wheel 34, and the transmission output shaft 24. The required transmission output torque, the required transmission input torque at the transmission input shaft 36, and the like can also be used. Further, the accelerator opening degree θacc [%], the throttle valve opening degree, the intake air amount, or the like can also be used as the required drive amount.

  When the hybrid controller 92 performs motor traveling (EV traveling) using only the electric motor MG as a driving force source for traveling, the power between the engine 14 and the torque converter 16 is released by releasing the connection / disconnection clutch K0. The transmission path is cut off, and an MG torque Tmg necessary for EV traveling is output from the electric motor MG by an electric motor control unit 94 described later. On the other hand, the hybrid control unit 92 engages the connecting / disconnecting clutch K0 and engages the torque with the engine 14 when performing engine traveling that travels at least using the engine 14 as a driving power source for traveling, that is, hybrid traveling (EHV traveling). The power transmission path to the converter 16 is connected, and the engine control unit 94 outputs the MG torque Tmg as the assist torque from the motor MG as needed by the motor control unit 94 while outputting the engine torque Te necessary for EHV traveling to the engine 14. .

  The motor control means, that is, the motor control unit 94 included in the MG_ECU can obtain the necessary MG torque Tmg based on a command signal from the hybrid control unit 92 (that is, based on communication with the hybrid control unit 92). Thus, the motor control command signal Sm for controlling the inverter unit 54 and the like is output, and the operation of the motor MG as a driving force source or a generator is controlled.

  The shift control means included in the AT_ECU, that is, the shift control unit 96 is calculated by the vehicle state (for example, the actual vehicle speed V and the hybrid control unit 92) from a predetermined known relationship (shift diagram, shift map; not shown), for example. Based on the required drive amount), it is determined whether or not the automatic transmission 18 should be shifted, and a hydraulic control command signal Sp (for example, a shift command value) for obtaining the determined gear stage (gear ratio). Is output to the hydraulic control circuit 40, and automatic transmission control of the automatic transmission 18 is executed.

  Here, for example, when the ignition switch is turned off, the hybrid control unit 92 outputs a power supply control command signal Sbat for opening (turning off) the system relays SR1 and SR2 to the power control unit 50. The battery unit 52 (battery unit 68) is shut off. As a result, no further charge is stored in the smoothing capacitor Cs of the power control unit 50. Therefore, the charge accumulated in the smoothing capacitor Cs that has been set to a high voltage up to this point is provided in parallel with the smoothing capacitor Cs, for example. It is discharged by the discharged resistance Rd. Alternatively, the motor control unit 94 performs a discharge operation by the inverter unit 54 based on a command signal from the hybrid control unit 92, and discharges the charge remaining in the smoothing capacitor Cs more quickly than the discharge by the discharge resistor Rd. You may do it. In this discharge operation, for example, the switching operation of the switching element in the inverter unit 54 is controlled so that the electric motor MG is operated at a field angle of the electric motor MG such that electric power is consumed without generating torque in the electric motor MG. The

  Further, when detecting a collision of the vehicle 10, the hybrid control unit 92 outputs a power supply control command signal Sbat for turning off the system relays SR1 and SR2, similarly to the case where the ignition switch is turned off. In addition, when the engine 14 is in the driving state, the hybrid control unit 92 stops the fuel supply to the engine 14 and turns off the ignition signal to turn off the engine control command signal Se for executing the fuel cut of the engine 14. Is output to an engine output control device such as a fuel injection device or an ignition device. Furthermore, the hybrid control unit 92 outputs a command signal for performing discharge control by the discharge circuit 66 (or a collision detection signal that a collision of the vehicle 10 has been detected) to the electric motor control unit 94. The motor control unit 94 outputs a discharge signal Sdis for energizing the discharge relay DR based on the command signal (or collision detection signal) from the hybrid control unit 92, and discharges the electric charge stored in the smoothing capacitor Cs. The circuit 66 is used for discharging. Thereby, at the time of a vehicle collision, the voltage of the battery unit 68 is not applied to the electric path outside the battery unit 52, and the electric charge remaining in the smoothing capacitor Cs is quickly discharged.

  The hybrid control unit 92 is determined in advance as a change in the deceleration G such that the deceleration G detected by the acceleration sensor 80 (deceleration in the front-rear direction and deceleration in the side direction) can be determined as a collision of the vehicle 10, for example. Based on the fact that the collision determination value has been reached, a collision of the vehicle 10 is detected. Alternatively, the hybrid control unit 92 is configured to detect the collision of the vehicle 10 based on the deceleration G or the like by a vehicle collision detection unit such as a computer for airbag control, that is, the vehicle collision detection unit, or the collision of the vehicle 10. A collision of the vehicle 10 may be detected when an activation signal for activating an airbag or the like is received along with the detection of the vehicle.

  By the way, it is conceivable that the communication between the hybrid control unit 92 and the motor control unit 94 is interrupted for some reason. Depending on the cause of the communication interruption (for example, when the communication interruption is not caused by a vehicle collision or the like), the hybrid control unit 92 is able to operate the engine even if communication with the motor control unit 94 is interrupted. It can be made to drive by using 14 as a driving force source. Further, when the communication interruption is caused by a vehicle collision or the like, the hybrid control unit 92 can detect the collision of the vehicle 10 even if the communication with the motor control unit 94 is interrupted. . On the other hand, when the communication with the hybrid control unit 92 is interrupted, the electric motor control unit 94 cannot perform drive control of the electric motor MG, and performs discharge control by the discharge circuit 66 from the hybrid control unit 92. The command signal (or collision detection signal) cannot be received. Considering the above, it is not preferable to determine that the communication interruption between the hybrid control unit 92 and the motor control unit 94 is a vehicle collision.

  Therefore, when the communication with the motor control unit 94 is interrupted, the hybrid control unit 92 supplies a power control command signal for turning off the system relays SR1 and SR2 in the same manner as when the ignition switch is turned off. Sbat is output. When the communication with the hybrid control unit 92 is interrupted, the motor control unit 94 determines that the vehicle speed V or a change in the rotation speed related to the vehicle speed V is a change in the rotation speed that can determine the collision of the vehicle 10. When it is larger than a predetermined collision determination threshold value and toward zero, the electric charge stored in the smoothing capacitor Cs is discharged using the discharge circuit 66. That is, when communication is interrupted, the motor control unit 94 determines a vehicle collision using signals directly input among various signals based on detection values from various sensors, and performs discharge using the discharge circuit 66. Since the motor rotation speed Nmg as the rotation speed related to the vehicle speed V is directly input to the motor control section 94, the motor control section 94 determines that a change in the motor rotation speed Nmg is a collision when communication is interrupted. When it is larger than the threshold value and toward zero, the electric charge of the smoothing capacitor Cs is discharged using the discharge circuit 66.

  However, in the event of a vehicle collision, a neutral state occurs due to the shaft such as the propeller shaft 26 being removed or the hydraulic pressure inside the automatic transmission 18 being lost, and the power transmission path between the drive wheel 34 and the motor MG is interrupted, or the drive wheel 34 is It is conceivable that the motor rotates idly and the change in the motor rotation speed Nmg is larger than the collision determination threshold and does not go to zero. In such a case, when the engine is running, the engine 14 that is directly connected to the electric motor MG does not immediately decrease even if the fuel cut is performed, and may overshoot (blow up). is there. Therefore, when the communication with the hybrid control unit 92 is interrupted, the motor control unit 94 causes the vehicle speed V or a change in the rotation speed related to the vehicle speed V (for example, the motor rotation speed Nmg) to cause the collision of the vehicle 10. When the rotational speed change that can be determined is larger than the predetermined second collision determination threshold and increases, the charge stored in the smoothing capacitor Cs is discharged using the discharge circuit 66. In other words, when the communication is interrupted, for example, in addition to a sudden decrease in the motor rotation speed Nmg, it is considered that a vehicle collision has occurred even in a state where the motor rotation speed Nmg overshoots.

  When communication is interrupted and no vehicle collision has actually occurred and the engine continues to run, it is better to suppress the generation of electromotive force by the driven motor MG. Therefore, it can be expected that the electric charge stored in the smoothing capacitor Cs is suppressed when a vehicle collision actually occurs, and the discharge time using the discharge circuit 66 can be shortened. Therefore, when the communication with the electric motor control unit 94 is interrupted, the hybrid control unit 92 does not detect the collision of the vehicle 10 and continues to run the engine when the communication is not interrupted. Compared with the engine speed Ne. That is, by lowering the engine rotation speed Ne while the engine is running (maintaining at a low rotation), the motor rotation speed Nmg is substantially reduced and the generation of electromotive force by the motor MG is suppressed. For example, the hybrid control unit 92 outputs a command signal for making the gear ratio of the automatic transmission 18 higher than the gear ratio determined based on the actual vehicle state from the shift map to the shift control unit 96 to automatically shift. The engine speed Ne is limited by setting the gear ratio of the machine 18 to the high side (high vehicle speed side). Alternatively, the hybrid control unit 92 may limit the engine rotational speed Ne by limiting the engine torque Te and decreasing the vehicle speed V.

  FIG. 3 shows that the main part of the control operation of the electronic control unit 90, that is, the smoothing capacitor Cs is charged at the time of a vehicle collision when communication between the hybrid control unit 92 (HV_ECU) and the motor control unit 94 (MG_ECU) is interrupted. 5 is a flowchart for explaining a control operation for surely discharging electric charges using the discharge circuit 66, and is repeatedly executed with an extremely short cycle time of about several milliseconds to several tens of milliseconds, for example.

  In FIG. 3, first, in a step (hereinafter, step is omitted) S10 corresponding to the hybrid control unit 92 and the motor control unit 94, for example, between the hybrid control unit 92 (HV_ECU) and the motor control unit 94 (MG_ECU). It is determined whether or not communication has been interrupted. If the determination in S10 is negative, the present routine is terminated. If the determination is positive, in S20 corresponding to the motor control unit 94, for example, the vehicle speed V or the rotation speed related to the vehicle speed V (for example, the motor rotation speed Nmg). It is determined whether or not the change is larger than a predetermined collision determination threshold value and toward zero. In S20, for example, whether or not the change in the motor rotation speed Nmg is larger than a predetermined collision determination threshold value and toward zero, or is larger than a predetermined second collision determination threshold value and increased. May be determined. If the determination at S20 is negative, this routine is terminated. Alternatively, when the engine running is performed when the determination of S20 is denied, even when the engine speed Ne is limited, compared to when the engine is running when the S10 is denied. good. If the determination in S20 is affirmative, in S30 corresponding to the motor control unit 94, for example, so-called PCU discharge is performed in which the electric charge stored in the smoothing capacitor Cs is discharged using the discharge circuit 66.

  As described above, according to the present embodiment, the vehicle 10 may continue traveling when the communication between the hybrid control unit 92 (HV_ECU) and the electric motor control unit 94 (MG_ECU) is simply interrupted. Since the vehicle collision is judged based on the change in the vehicle speed V or the like (for example, the motor rotation speed Nmg) at the time of the communication interruption, and the electric charge stored in the smoothing capacitor Cs is discharged using the discharge circuit 66, the vehicle collision Sometimes it can be reliably discharged. Therefore, when communication between the HV_ECU and the MG_ECU is interrupted, the electric charge stored in the smoothing capacitor Cs can be reliably discharged using the discharge circuit 66 when the vehicle collides.

  Further, according to the present embodiment, when the communication with the motor control unit 94 is interrupted, the hybrid control unit 92 does not detect the collision of the vehicle 10 and continues the engine running. Since the engine speed Ne is limited as compared with when communication is not interrupted, if the vehicle 10 continues to travel when communication is simply interrupted, the engine speed is compared with the rotation of the motor MG with the motor MG. By reducing Ne, generation of electromotive force in the electric motor MG can be suppressed, and the discharge time when the electric charge stored in the smoothing capacitor Cs is discharged using the discharge circuit 66 at the time of a vehicle collision can be shortened.

  Further, according to the present embodiment, the hybrid control unit 92 limits the engine rotation speed Ne by setting the gear ratio of the automatic transmission 18 to the high side, so that the vehicle 10 continues to travel when communication is simply interrupted. In this case, the engine speed Ne can be appropriately reduced.

  Further, according to the present embodiment, when the communication with the hybrid control unit 92 is interrupted, the motor control unit 94 has a predetermined change in the vehicle speed V or the like (for example, the motor rotation speed Nmg). 2 is larger than the collision determination threshold value of 2, and the electric charge stored in the smoothing capacitor Cs is discharged using the discharge circuit 66. Therefore, at the time of the vehicle collision, the vehicle speed V or the like (for example, the motor rotation speed Nmg) Even if the change is larger than a predetermined collision determination threshold and does not go to zero, it is possible to reliably discharge at the time of a vehicle collision.

  In addition, according to the present embodiment, the discharge circuit 66 includes a rapid discharge resistor Rqd and a discharge relay DR connected in series, and the smoothing capacitor is energized when the discharge relay DR is energized by the motor control unit 94 (MG_ECU). Since the charge stored in Cs is discharged, the charge stored in the smoothing capacitor Cs can be quickly discharged using the discharge circuit 66.

  As mentioned above, although the Example of this invention was described in detail based on drawing, this invention is applied also in another aspect.

  For example, in the above-described embodiment, the motor control unit 94 determines a vehicle collision using the motor rotation speed Nmg, but the present invention is not limited to this. For example, a deceleration G or the like may be used as a change in rotational speed related to the vehicle speed V. In short, a vehicle collision may be determined using a sensor value that is directly input to the motor control unit 94 (MG_ECU).

  Further, in the above-described embodiment, when the engine travel is continued when communication is interrupted, the generation of electromotive force by the electric motor MG is suppressed by limiting the engine rotation speed Ne. At this time, the voltage on the inverter unit 54 side is stepped down by the step-up converter unit 56 to charge the auxiliary battery 58 via the DC / DC converter, or the power consumption by the vehicle auxiliary devices connected to the auxiliary battery 58 May be increased. Further, the system relays SR1 and SR2 may be turned on until the charge capacity SOC of the battery unit 68 is fully charged, and the reduced power may be supplied to the battery unit 68. This further shortens the discharge time using the discharge circuit 66 when a vehicle collision actually occurs. Note that the discharge resistor Rd is not necessarily provided as long as the discharge can be performed by other than the discharge resistor Rd.

  Further, in the above-described embodiment, the engine 14 and the electric motor MG are indirectly connected via the connection / disconnection clutch K0, but the connection state thereof is not limited to this mode. For example, the vehicle 10 may not include the connection / disconnection clutch K0, and the engine 14 and the electric motor MG may be directly connected.

  In the above-described embodiment, the discharge circuit 66 includes the rapid discharge resistor Rqd as a discharge element and the discharge relay DR as a switching element, but is not limited thereto. The discharge circuit 66 may be any circuit that is operated by the motor control unit 94 and can quickly remove the charge from the smoothing capacitor Cs.

  In the above-described embodiment, when discharging the electric charge stored in the smoothing capacitor Cs using the discharge circuit 66, in addition to using the discharge circuit 66, a discharge operation by the inverter unit 54 may be performed. .

  In the above-described embodiment, the torque converter 16 is used as the fluid transmission device. However, other fluid transmission devices such as a fluid coupling having no torque amplification action may be used. Further, this fluid transmission device is not necessarily provided.

  In the above-described embodiment, the vehicle 10 is provided with the automatic transmission 18, but the automatic transmission 18 is configured except that the gear ratio γ of the automatic transmission 18 is set to a high gear when communication is interrupted. It does not necessarily have to be provided.

  The above description is only an embodiment, and the present invention can be implemented in variously modified and improved forms based on the knowledge of those skilled in the art.

10: Vehicle 14: Engine 18: Automatic transmission 34: Drive wheel 50: Electric power control unit (electric circuit)
66: Discharge circuit 90: Electronic control device (control device)
92: Hybrid control unit 94: Electric motor control unit Cs: Smoothing capacitor (power storage member)
DR: Discharge relay (switching element)
MG: Electric motor Rqd: Rapid discharge resistance (discharge element)

Claims (5)

Control of the electric motor based on communication between the engine, an electric motor, a hybrid control unit that controls the entire vehicle including control that travels using the engine and the electric motor as a driving force source, and the hybrid control unit An electric circuit comprising: an electric motor control unit that controls the transfer of electric power related to the operation of the electric motor; and an electric storage member that temporarily stores the electric power; and a discharge circuit provided in parallel to the electric storage member When the collision of the vehicle is detected by the hybrid control unit, the motor control unit discharges the electric charge stored in the power storage member using the discharge circuit,
The hybrid control unit can run the engine as a driving force source even if communication with the electric motor control unit is interrupted,
When the communication with the hybrid control unit is interrupted, the motor control unit has a change in vehicle speed or a rotational speed related to the vehicle speed larger than a predetermined collision determination threshold value and heading toward zero. In the vehicle control apparatus, the electric charge stored in the power storage member is discharged using the discharge circuit. The engine and the electric motor are connected,
When the communication with the electric motor control unit is interrupted, the hybrid control unit does not detect the collision of the vehicle and continues to travel using the engine as a driving force source. The vehicle control device according to claim 1, wherein the rotation speed of the engine is limited as compared with a case where the engine is not interrupted. An automatic transmission that constitutes a part of a power transmission path between the engine and the drive wheels;
The vehicle control device according to claim 2, wherein the hybrid control unit limits a rotational speed of the engine by setting a gear ratio of the automatic transmission to a high side.   When the communication with the hybrid control unit is interrupted, the electric motor control unit increases and increases a change in the vehicle speed or a rotation speed related to the vehicle speed above a predetermined second collision determination threshold. 4. The vehicle control device according to claim 1, wherein the electric charge stored in the power storage member is discharged using the discharge circuit. 5.   The discharge circuit includes a discharge element and a switching element connected in series, and the electric charge stored in the power storage member is discharged when the switching element is energized by the electric motor control unit. Item 5. The vehicle control device according to any one of Items 1 to 4.

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