JP2016043916A - Control device of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly avoid an event in which, although an operator steps on a brake pedal, a motor applies a rotational driving force to an axle or a crank shaft of an internal combustion engine.SOLUTION: A control device of a vehicle controls a vehicle on which a motor that applies a rotational driving force to an axle or a crank shaft of an internal combustion engine is mounted. It determines whether or not a brake signal representing that an operator has stepped on a brake pedal is correctly received, and prohibits applying of the rotational driving force to the axle or the crank shaft by the motor thereafter when it is determined that the brake signal is not properly received.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a control device for controlling a vehicle on which an electric motor capable of giving a rotational driving force to a crankshaft or an axle of an internal combustion engine is mounted.

  There is known a vehicle equipped with an electric motor that can assist the internal combustion engine by applying rotational driving force to the crankshaft of the internal combustion engine, which is a drive source for driving the axle (and drive wheels) and auxiliary equipment (for example, (See the following patent document). This type of vehicle is sometimes referred to as a micro hybrid vehicle.

JP 2014-101847 A

  Usually, the application of rotational driving force to the crankshaft or axle of an internal combustion engine by an electric motor is not performed when the driver of the vehicle is stepping on a brake pedal. That is, an ECU (Electronic Control Unit) that controls the vehicle prohibits the assist of the internal combustion engine by the electric motor when receiving a brake signal indicating that the driver has stepped on the brake pedal.

  However, due to disconnection of the signal line and other factors, the ECU may not be able to receive the brake signal correctly even though the driver is stepping on the brake pedal. In this case, there is a concern that the assist by the electric motor is erroneously executed even though the vehicle is about to be braked. In this case, the engine speed may increase excessively against the driver's intention.

  The present invention, which was made by paying attention to the above problems for the first time, appropriately avoids an event in which the electric motor applies a rotational driving force to the crankshaft or axle of the internal combustion engine even though the driver steps on the brake pedal. Is the intended purpose.

  The present invention controls a vehicle equipped with an electric motor capable of applying a rotational driving force to a crankshaft or an axle of an internal combustion engine, and normally applies a brake signal indicating that the driver has stepped on a brake pedal. It is determined whether or not the vehicle can be received, and when it is determined that the brake signal cannot be normally received, the vehicle control device is configured to prohibit the subsequent application of the rotational driving force to the crankshaft or the axle by the electric motor.

  As a specific method for determining whether or not the brake signal can be normally received, for example, after the start of the internal combustion engine, the brake signal is received and the brake signal is not received after that. Is considered to be able to be received normally.

  Further, when the vehicle speed is decelerated from the first predetermined speed to the second predetermined speed lower than the first predetermined speed without receiving the brake signal, it is determined that the brake signal cannot be normally received. You can also.

  According to the present invention, it is possible to appropriately avoid an event in which the electric motor applies a rotational driving force to the crankshaft or the axle of the internal combustion engine even though the driver steps on the brake pedal.

The figure which shows schematic structure of the internal combustion engine in one Embodiment of this invention. The figure which shows typically the aspect of the connection of the internal combustion engine and ISG in the embodiment. The figure which shows the electric circuit for controlling the various electric loads mounted in the vehicle. The figure which shows the electric circuit of ISG in the embodiment. The figure which shows the structure of the drive system of the vehicle in the embodiment. The timing diagram which shows the content of the self-diagnosis which the control apparatus in the embodiment implements. The timing diagram which shows the content of the self-diagnosis which the control apparatus in the embodiment implements. The timing diagram which shows the content of the self-diagnosis which the control apparatus in the embodiment implements.

  An embodiment of the present invention will be described with reference to the drawings. A vehicle internal combustion engine 100 shown in FIG. 1 is a spark ignition type four-stroke engine and includes a plurality of cylinders 1 (one of which is shown in FIG. 1). In the vicinity of the intake port of each cylinder 1, an injector 11 for injecting fuel is provided. A spark plug 12 is attached to the ceiling of the combustion chamber of each cylinder 1. The spark plug 12 receives spark voltage generated by the ignition coil and causes spark discharge between the center electrode and the ground electrode.

  The intake passage 3 for supplying intake air takes in air from the outside and guides it to the intake port of each cylinder 1. On the intake passage 3, an air cleaner 31, an electronic throttle valve 32, a surge tank 33, and an intake manifold 34 are arranged in this order from the upstream.

  The exhaust passage 4 for discharging the exhaust guides the exhaust generated as a result of burning the fuel in the cylinder 1 from the exhaust port of each cylinder 1 to the outside. An exhaust manifold 42 and an exhaust purification three-way catalyst 41 are disposed on the exhaust passage 4.

  An external EGR (Exhaust Gas Recirculation) device 2 realizes a so-called high-pressure loop EGR. The EGR device 2 includes an external EGR passage 21 that communicates the upstream side of the catalyst 41 in the exhaust passage 4 and the downstream side of the throttle valve 32 in the intake passage 3, an EGR cooler 22 provided on the EGR passage 21, and an EGR passage 21. And an EGR valve 23 that controls the flow rate of the EGR gas flowing through the EGR passage 21. The inlet of the EGR passage 21 is connected to the exhaust manifold 42 in the exhaust passage 4 or a predetermined location downstream thereof. The outlet of the EGR passage 21 is connected to a predetermined location downstream of the throttle valve 32 in the intake passage 3, specifically to a surge tank 33.

  A brake booster 5 is attached to the vehicle of this embodiment. The brake booster 5 introduces intake negative pressure from a portion of the intake passage 3 downstream of the throttle valve 32, more specifically, from the surge tank 33, and uses this negative pressure to boost the pedaling force of the brake pedal. It is widely known in the field. The brake booster 5 has a constant pressure chamber for storing negative pressure and a variable pressure chamber for applying atmospheric pressure, and the constant pressure chamber is connected to the surge tank 33 via the negative pressure line 51. The negative pressure line 51 guides the intake negative pressure downstream of the throttle valve 32 to the constant pressure chamber. A check valve 52 is provided on the negative pressure line 51 to keep the negative pressure in the constant pressure chamber and prevent the positive pressure from being applied to the constant pressure chamber.

  When the brake pedal is not operated by the driver, the constant pressure chamber and the variable pressure chamber communicate with each other, and the variable pressure chamber is isolated from the atmospheric pressure. When the brake pedal is operated, the constant pressure chamber and the variable pressure chamber are interrupted, and the atmosphere is introduced into the variable pressure chamber. As a result, the pressure difference between the constant pressure chamber and the variable pressure chamber becomes a control pressure that boosts the depression force of the brake pedal. The brake pedal force amplified by the brake booster 5 is converted into hydraulic pressure in the master cylinder 6. The hydraulic fluid pressure output from the master cylinder 6 is transmitted to a brake device (not shown) such as a brake caliper or a wheel cylinder via a hydraulic circuit (not shown), and is used for braking the vehicle by the brake device.

  As shown in FIG. 2, the internal combustion engine 100 according to the present embodiment is accompanied by a starter motor (cell motor) 140, an ISG (Integrated Starter Generator), a compressor 130, and other auxiliary machines.

  The starter motor 140 is an electric motor dedicated to cranking that mainly drives the crankshaft 10 of the internal combustion engine 100 during cold start. The starter motor 140 has a pinion gear 141 on its output shaft, and the pinion gear 141 rotates on the crankshaft 10 by meshing with a ring gear 103 fixed to the crankshaft 10 that is the output shaft of the internal combustion engine 100. Transmits driving force. The pinion gear 141 is detached from the ring gear 103 except when the starter motor 140 is cranking the internal combustion engine 100.

  The ISG 110 has both a function as an electric motor that drives the crankshaft 10 and thus the vehicle axle (and drive wheels) 153, and a function as a generator that receives power from the crankshaft 10 and generates electric power. The ISG 110 is connected to one end side of the crankshaft 10 of the internal combustion engine 100 via the winding transmission mechanisms 112, 113, and 101.

  The ISG 110 is, for example, an inner-rotor type AC synchronous machine, and includes a rotor (rotor) having both permanent magnets and a rotor coil (excitation (field) winding) 116, and a three-phase AC facing the outer peripheral surface of the rotor. A stator (stator) including a stator coil (stator winding) 115 is used as an element. The rotor is fixed to the outer periphery of the rotor shaft 111. Pulleys (or sprockets) 112 and 101 are fixed to the rotor shaft 111 and the crankshaft 10, respectively, and the crankshaft 10 and the rotor shaft are secured by a belt (or chain) 113 wound around the pulleys 112 and 101. The rotational driving force is transmitted to and from 111 (bidirectionally).

  The ISG 110 supplies power from the in-vehicle power storage device 61 mainly when the internal combustion engine 100 that has been idle-stopped is restarted or when the traveling drive force supplied to the axle 153 is increased (particularly during acceleration or climbing). In response, the crankshaft 10 is rotationally driven. Power storage device 61 includes a battery and / or a capacitor. In turn, when power is generated by being rotationally driven by the crankshaft 10, the power storage device 61 is charged with the generated power. When the vehicle decelerates, regenerative braking is performed by the ISG 110, and the kinetic energy of the vehicle can be recovered as electric energy.

  The compressor 130 for compressing the refrigerant of the air conditioner is also connected to one end side of the crankshaft 10 of the internal combustion engine 100 via the winding transmission mechanisms 102, 134, 133, similarly to the ISG 110. Pulleys (or sprockets) 133 and 102 are fixed to the input shaft 132 and the crankshaft 10 of the compressor 130, respectively, and the belt (or chain) 134 wound around the pulleys 133 and 102 causes the crankshaft 10 The rotational driving force is transmitted to the input shaft 132. The belt 134 may transmit driving force to a lubricating oil pump (not shown), a cooling water pump (not shown), or the like, which is an auxiliary machine other than the compressor 130. A magnet clutch 131 that can be connected and disconnected is provided between the main body of the compressor 130 and the input shaft 132, and the clutch 131 is disconnected when the air conditioner is not operated.

  The transmission 120 that connects the internal combustion engine 100 and the axle 153 is installed on the other end side of the crankshaft 10.

  Various electric loads are mounted on the vehicle. Specific examples of electrical loads include air conditioner blowers, rear glass defoggers, audio equipment, car navigation systems, lighting (headlamps, taillights, stoplights (brakelights), foglights, turn signals (turns) Signal lamp)), a radiator fan for cooling the cooling water of the internal combustion engine 100, an electric power steering device, and the like.

  FIG. 3 shows an electric circuit for controlling the electric load. As already described, the magnet clutch 131 is interposed between the crankshaft 10 of the internal combustion engine 100 and the refrigerant compression compressor 130. When operating the air conditioner, the magnet clutch 131 is energized to engage the clutch 131. When the air conditioner is not operated, the magnet clutch 131 is not energized and the clutch 131 is disconnected. Energization and disconnection of the magnet clutch 131 is performed by ON / OFF of the relay switch 62.

  The motor 63 that rotationally drives the blower for blowing and the heating wire heater 65 laid on the rear glass as a defogger operate by receiving power supply from the power storage device 61 (or ISG 110). The energization and interruption of the motor 63 and the heater 65 are performed by turning ON / OFF the relay switch 64 or starting / switching a semiconductor switching element (power device represented by a power transistor, power MOSFET, etc.). Do by arc extinguishing.

  The same applies to audio devices, car navigation systems, illumination lamps, motors that rotate the radiator fan, and other electrical loads.

  FIG. 4 shows an equivalent circuit of the ISG 110 that functions as a generator. When the ISG 110 is operated as a generator, a three-phase AC induced current is generated in the stator coil 115 which is a three-phase coil. This induced current is converted to a direct current by a rectifier 113 using a diode, and then supplied to the power storage device 61 and an electric load.

  The controller 114 attached to the ISG 110 receives a control signal n for instructing a target value of the output voltage of the ISG 110, which is issued from the ECU 0 that is the control device of the present embodiment. Then, in order to make the terminal voltage of the power storage device 61 (in other words, the power supply voltage supplied to the electrical system) follow the commanded target voltage, the exciting current applied to the rotor coil 116 by switching the semiconductor switching element 119 PWM (Pulse Width Modulation) control is performed to adjust the size of. The output voltage of the ISG 110, that is, the generated voltage induced in the stator coil 115, increases as the exciting current flowing through the rotor coil 116 increases.

  The ISG 110 that operates as a generator is a mechanical load when viewed from the internal combustion engine 100. When the output voltage of the ISG 110 exceeds the terminal voltage of the power storage device 61, the power storage device 61 is charged and power is supplied from the ISG 110 to the electric load. That is, the ISG 110 spends the energy of rotation of the crankshaft 10 to generate electrical energy. The amount of charge to the power storage device 61 and the amount of power supplied to the electrical load depend on the potential difference between the output voltage of the ISG 110 and the terminal voltage of the power storage device 61.

  Conversely, when the output voltage of ISG 110 is less than or close to the terminal voltage of power storage device 61, power storage device 61 is not charged, and no power is supplied from ISG 110 to the electrical load (power from power storage device 61 to the electrical load). May be supplied). In other words, the ISG 110 does not perform work that consumes the energy of rotation of the crankshaft 10, or the work is reduced.

  In short, when a high power generation voltage is commanded from the ECU 0 to the ISG 110, the mechanical load of the ISG 110 with respect to engine rotation increases, and when a low power generation voltage is commanded, the mechanical load of the ISG 110 with respect to engine rotation decreases.

  Incidentally, the controller 114 has a gradual excitation function that gradually increases the excitation current instead of increasing the excitation current stepwise when increasing the amount of power generated by the ISG 110 in accordance with an increase in the electrical load. This gradual excitation function avoids temporary concentration of the mechanical load on the internal combustion engine 100 and prevents a decrease in engine rotation in an idle operation or low load operation region.

  In addition, the controller 114 receives a control signal n that is issued from the ECU 0 and commands an upper limit value of the excitation current, detects the magnitude of the excitation current flowing through the rotor coil 116 via the sensor 117, and commands the excitation current. Regulated below the specified upper limit. The upper limit of the excitation current is intended to prevent the mechanical rotation on the internal combustion engine 100 from becoming excessive and the engine rotation from becoming unstable. Therefore, for example, when the refrigerant compression compressor 130 is operated and when it is not operated, the upper limit value of the excitation current is lower in the former case.

  Clipping to the upper limit value of the excitation current has priority over following the target voltage value of the generated voltage of the ISG 110. In other words, even if the terminal voltage of the power storage device 61 is still less than the target voltage commanded from the ECU 0, the controller 114, when the excitation current flowing through the rotor coil 116 has already reached the upper limit commanded from the ECU 0, The excitation current is not increased further.

  On the other hand, when the ISG 110 is operated as an electric motor for driving the crankshaft 10, a three-phase alternating current is passed through the inverter 118 using a semiconductor switching element to the stator coil 115 while energizing the rotor coil 116 with a required excitation current. Is applied to generate a rotating magnetic field around the rotor. The high side switch and the low side switch of each phase of the inverter 118 are fired / extinguished by the controller 114.

  FIG. 5 shows an example of a transmission 120 of a drive train provided in the vehicle. The transmission 120 includes a torque converter 7 and automatic transmissions 8 and 9. In particular, in the present embodiment, a forward / reverse switching device 8 using a planetary gear mechanism and a belt-type CVT (Continuously Variable Transmission) 9 which is a type of continuously variable transmission are adopted as components of the automatic transmissions 8 and 9. doing.

  The rotational torque output from the internal combustion engine 100 is input from the crankshaft of the internal combustion engine 100 to the pump impeller 71 on the input side of the torque converter 7 and transmitted to the turbine runner 72 on the output side. The rotation of the turbine runner 72 is transmitted to the drive shaft 94 of the CVT 9 via the forward / reverse switching device 8 and rotates the driven shaft 95 through a shift in the CVT 9. The rotation of the driven shaft 95 is transmitted to the output gear 151. The output gear 151 meshes with the ring gear 152 of the differential device, and rotates the axle 153 and the drive wheels (not shown) via the differential device.

  The torque converter 7 includes a lockup mechanism. The lock-up mechanism is known in this field, and a lock-up clutch 73 that fastens the input side and the output side of the torque converter 7 so as not to rotate relative to each other, and an operation for switching the connection of the lock-up clutch 73. A lock-up solenoid valve (not shown) for controlling the hydraulic pressure (hydraulic pressure) is used as an element. The lockup solenoid valve is a flow rate control valve that receives a control signal t and changes its opening degree.

  In a vehicle equipped with CVT 9, when the vehicle speed is a predetermined value (for example, 10 km / h) or more, the torque converter 7 is almost always locked up. When the vehicle speed is equal to or lower than the predetermined value, the lockup of the torque converter 7 is released. During lockup, the lockup clutch 73 is pressed against the torque converter cover 74 and rotates together with the torque converter cover 74. The engine torque input to the input side (drive plate) of the torque converter 7 at the time of lock-up is output from the torque converter cover 74 via the lock-up clutch 73 and thus to the forward / reverse switching device 8. Communicated directly to. At the time of lockup, the speed ratio, which is the ratio of the output side rotational speed of the torque converter 7 to the input side rotational speed, is 1.

  In turn, the lock-up clutch 73 is separated from the torque converter cover 74 at the time of non-lock-up. At the time of non-lock-up, the engine torque input to the input side of the torque converter 7 is transmitted from the torque converter cover 74 to the pump impeller 71 and the turbine 72 and is transmitted to the forward / reverse switching device 8. At the time of non-lock-up, the speed ratio of the torque converter 7 becomes smaller or larger than 1 depending on the driving state.

  In the forward / reverse switching device 8, the sun gear 81 communicates with the turbine runner 72, and the ring gear 82 communicates with the drive shaft 94. Between the planetary carrier 83 that supports the planetary gear 831 and the transmission case, a forward brake 84 that is a hydraulic clutch that can be connected and disconnected is interposed. Further, a reverse clutch 85, which is a hydraulic clutch capable of switching connection / disconnection, is also interposed between the planetary carrier 83 and the sun gear 81 (or the output side of the torque converter 7).

  In the D range of the traveling range, the forward brake 84 is engaged and the reverse clutch 85 is disconnected. As a result, the rotation of the output shaft of the torque converter 7 is reversed and decelerated and transmitted to the drive shaft 94 for forward travel. In turn, in the R range, the reverse clutch 85 is engaged and the forward brake 84 is disconnected. As a result, the sun gear 81 and the planetary carrier 83 rotate integrally, and the output shaft of the torque converter 7 and the drive shaft 94 are directly connected to perform reverse travel. A solenoid valve (not shown) that controls the hydraulic pressure for driving the forward brake 84 or the reverse clutch 85 to connect / disconnect is a flow rate control valve that receives a control signal u and changes its opening.

  In the N range of the non-traveling range, both the forward brake 84 and the reverse clutch 85 are disconnected. In the P range, the axle 153 is mechanically locked so as not to move.

  The CVT 9 includes a driving pulley 91 and a driven pulley 92, and a belt 93 wound around the pulleys 91 and 92 as elements. The drive pulley 91 is disposed behind the movable sheave 912, a fixed sheave 911 fixed to the drive shaft 94, a movable sheave 912 supported on the drive shaft 91 via a roller spline so as to be displaceable in the axial direction. A hydraulic servo 913 is provided, and the gear ratio can be changed steplessly by operating the hydraulic servo 913 and displacing the movable sheave 912. The driven pulley 92 is disposed on the back of the movable sheave 922, a fixed sheave 921 fixed to the driven shaft 95, a movable sheave 922 supported on the driven shaft 95 via a roller spline so as to be displaceable in the axial direction. A hydraulic servo 923 is provided, and a belt thrust necessary for torque transmission is applied by operating the hydraulic servo 923 and displacing the movable sheave 922.

  The ECU 0 is a microcomputer system having a processor, a memory, an input interface, an output interface, and the like. The input interface includes a vehicle speed signal a output from a vehicle speed sensor that detects the actual vehicle speed of the vehicle, a crank angle signal b output from an engine rotation sensor that detects the rotation angle of the crankshaft 10 and the engine speed, and an accelerator pedal. From an accelerator opening signal c output from a sensor that detects the amount of depression of the engine or the opening of the throttle valve 32 as an accelerator opening (in other words, a required load), a sensor (shift position switch) for knowing the range of the shift lever An output shift range signal d, an intake air temperature / intake pressure signal e output from a sensor for detecting intake air temperature and intake air pressure in the intake passage 3 (particularly, the surge tank 33), a brake pedal being depressed, or A brake output from a sensor (brake switch, etc.) that detects the amount of brake pedal depression Signal (or stop lamp signal) f, master cylinder pressure signal g output from a hydraulic pressure sensor that detects the pressure of the hydraulic fluid discharged from the master cylinder 6, the terminal voltage and the terminal current of the power storage device 61 A voltage / current signal h output from a sensor for detecting (particularly battery voltage or battery current), an operation request signal m regarding whether or not each of the air conditioner and various electric loads should be operated, a controller of the ISG 110 A status signal s etc. provided from 114 is input.

  The operation request signal m is manually issued from an operation switch (or control panel) for each air conditioner or electric load, which is manually operated by a driver or passenger who desires to operate the air conditioner and various electric loads. It may be a control signal or an automatic control signal issued from an auto air conditioner ECU that controls the auto air conditioner system.

  The status signal s includes various information related to the ISG 110, such as the rotation speed and temperature, the magnitude of the excitation current flowing through the rotor coil 116, the current operation mode (that is, whether the power generation is being performed, the internal combustion engine 100 is being cranked, Information on whether the internal combustion engine 100 is motor-assisted or in a no-load state in which neither the generator nor the motor works.

  From the output interface of the ECU 0, an ignition signal i for the igniter of the spark plug 12, a fuel injection signal j for the injector 11, an opening operation signal k for the throttle valve 32, and an opening operation for the EGR valve 23. Signal l, control signal n for controlling the controller 114 of the ISG 110, clutch engagement signal o for the switch 62 on the electric circuit for energizing the magnet clutch 131, the motor 63, the heater 65 and other electric loads Switch ON signals p and q for the switches 64 and 66 on the electric circuit to be energized, the opening control signal t for the lockup solenoid valve for switching the connection and disconnection of the lockup clutch 73, the forward brake 84 or the reverse clutch 85. Opening control signal u for the solenoid valve for switching connection / disconnection of And outputs the transmission ratio control signal v such relative VT9.

  The control signal n is a signal for instructing the operation mode of the ISG 110 and for instructing a target value of the generated voltage to be output from the ISG 110 when operating as a generator, an upper limit value of the excitation current to be supplied to the rotor coil 116, and the like. .

  The processor of the ECU 0 interprets and executes a program stored in advance in the memory, calculates operation parameters, and controls the operation of the internal combustion engine 100. The ECU 0 acquires various information a, b, c, d, e, f, g, h, m, and s necessary for operation control of the internal combustion engine 100 via the input interface, and the required throttle valve 32 opening degree. , Required fuel injection amount, fuel injection timing (including the number of fuel injections for one combustion), fuel injection pressure, ignition timing, whether or not to lock up the torque converter 7, Various operation parameters such as a gear ratio, ON / OFF of an air conditioner compressor, ON / OFF of various electric loads, and a power generation amount or output of the ISG 110 are determined. The ECU 0 applies various control signals i, j, k, l, n, o, p, q, and s corresponding to the operation parameters via the output interface.

  In addition, the ECU 0 inputs the control signal r to the starter motor 140 when the internal combustion engine 100 is started, particularly during cold start, and engages the pinion gear 141 with the ring gear 103 to crank the internal combustion engine 100.

  The ECU 0 executes an idle stop that stops the idle rotation of the internal combustion engine 100 when a predetermined idle stop condition is satisfied. The ECU 0 has a brake pedal depression amount or a master cylinder pressure that is equal to or greater than a threshold value (the brake pedal is depressed), the cooling water temperature of the internal combustion engine 100 is higher than a predetermined value, and the terminal voltage of the power storage device 61 is higher than a predetermined value. The ISG 110 is not substantially generating electric power, the magnet clutch 131 is disconnected, the refrigerant compression compressor 130 is not operating, the shift range is the travel range, and the vehicle speeds up to a certain vehicle speed or higher after the end of the previous idle stop. And the current vehicle speed is below a certain vehicle speed (for example, the vehicle speed has dropped from 13.5 km / h to 13 km / h, or from 9.5 km / h to 7 km / h) It is determined that the idle stop condition is satisfied when all the above conditions are satisfied.

  When a predetermined idle stop end condition is satisfied after the idle stop condition is satisfied, the internal combustion engine 100 is restarted. The ECU 0 determines that the brake pedal depression amount or the master cylinder pressure is 0 or less than a threshold value close to 0 (the brake pedal is no longer depressed), and conversely, the brake pedal depression amount or the master cylinder pressure further increases (brake The idle stop termination condition is met when the pedal is depressed more), the accelerator opening is increased (the accelerator pedal is depressed), or the predetermined time (3 minutes) has elapsed in the idle stop state. Judge that it was done. In principle, when restarting after an idle stop, the internal combustion engine 100 is cranked by operating the ISG 110 as an electric motor.

  In the vehicle according to the present embodiment, motor assist is performed in which the ISG 110 is operated as an electric motor, and the rotational driving force output from the ISG 110 is input to the crankshaft 10 of the internal combustion engine 100 and supplied to auxiliary machines such as the axle 153 and the compressor 130. Can be implemented.

  This motor assist is not performed when the driver of the vehicle is stepping on the brake pedal. That is, the ECU 0 prohibits motor assistance by the ISG 110 when receiving a brake signal f indicating that the driver has stepped on the brake pedal.

  However, there is no possibility that the ECU 0 cannot correctly receive the brake signal f even though the driver is stepping on the brake pedal due to disconnection of the signal line or other factors. Therefore, the ECU 0 of this embodiment performs self-diagnosis (diagnosis) on whether or not the driver can normally receive the brake signal f indicating that the driver has stepped on the brake pedal, and diagnoses that the brake signal f cannot be received normally. Thereafter, the motor assist by the ISC 110 will not be performed.

  There are several possible methods for diagnosing whether the brake signal f can be received normally. Typically, as shown in FIGS. 6 and 7, the brake signal f is normally set on condition that the brake signal f is received after the internal combustion engine 100 is started and the brake signal f is not received after that. Judge that it can be received.

  In particular, as shown in FIG. 6, after the start of the internal combustion engine 100, the brake signal f is changed until the condition that the brake signal f is not received after the brake signal f is received is satisfied. It shall be in the situation where it cannot receive normally. That is, at the beginning of the internal combustion engine 100, the brake signal reception self-diagnosis flag is set to a value meaning "abnormal". As long as the value of the flag is “abnormal”, the ECU 0 does not perform motor assist by the ISG 110.

  Thus, as indicated by a chain line in FIG. 6, the ECU 0 can normally receive the brake signal f when detecting a change that the brake signal f is not received after the brake signal f is received. The brake signal reception self-diagnosis flag is set to a value meaning “normal” by judging that the situation is present. Then, based on the value of the flag, the motor assist by the ISG 110 is lifted (of course, the motor assist is executed only when the brake pedal is not depressed).

  Alternatively, as shown in FIG. 7, the brake signal f is received before the shift range is switched from the non-travel range to the travel range, and the brake signal f is not received after the shift range is switched. It is also possible to determine that the brake signal f cannot be normally received when the condition that the condition is met is not satisfied.

  After the internal combustion engine 100 is started, the driver always steps on the brake pedal when the driver switches the shift range from the P range, which is the non-traveling range, to the traveling range, for example, the D range. This is because a known safety mechanism is incorporated in the vehicle so that the shift range cannot be changed from the P range to the D range or the like unless the brake pedal is depressed. Then, after the shift range is switched to the D range or the like, when starting the vehicle, the driver removes his foot from the brake pedal. Therefore, as indicated by a chain line in FIG. 7, if the ECU 0 can normally receive the brake signal f, the brake signal f is always turned ON before the shift range is switched from the P range, and the shift range is P. The brake signal f should be OFF after switching from the range. Nevertheless, as indicated by the solid line in FIG. 7, when such ON / OFF of the brake signal f cannot be detected, the ECU 0 determines that the brake signal f cannot be normally received. The subsequent motor assist is prohibited.

  Although this is not the case in FIG. 7, the brake signal reception self-diagnosis flag at the start of the internal combustion engine 100 is set to “abnormal” in the same way as in FIG. The flag may be set to “normal” when the OFF of the brake signal f in the D range or the like is detected. In any case, the ECU 0 does not accept motor assist by the ISG 110 unless the condition that the brake signal f is received after the internal combustion engine 100 is started and the brake signal f is not received thereafter is satisfied.

  In addition, when the vehicle speed decreases more than a certain degree while the vehicle is running, the driver often steps on the brake pedal to perform braking by the brake device. If the vehicle speed has been decelerated many times, at least one of them will be stepping on the brake pedal. Accordingly, as indicated by a chain line in FIG. 8, if the ECU 0 can normally receive the brake signal f, the vehicle speed is changed from the first predetermined speed (for example, 30 km / h) to the second predetermined speed (for example, for example). When decelerating to 3 km / h), the brake signal f should be turned on. Nevertheless, as indicated by the solid line in FIG. 8, the brake signal f is turned on once while the deceleration from the first predetermined speed to the second predetermined speed is repeated a predetermined number of times (for example, ten times). If it is not sensed that the braking signal f is detected, the ECU 0 determines that the brake signal f cannot be normally received, and prohibits subsequent motor assist.

  The ECU 0 counts the number of times that the deceleration from the first predetermined speed to the second predetermined speed is continuously performed while the brake signal f remains OFF, and when the number reaches the predetermined number of times, It is determined that the signal f cannot be received normally. On the other hand, if it is detected that the brake signal f is turned on before the number reaches the predetermined number, the counted number of decelerations is reset to zero. Even if the counted number of decelerations reaches the predetermined number of times, if the master cylinder pressure increases or exceeds a predetermined value while the brake signal f remains OFF, the driver It may be determined that the brake signal f cannot be normally received because the brake signal f is not turned ON while the braking is performed.

  As a result of the self-diagnosis, the ECU 0 that has determined that the brake signal f cannot be received normally writes information (diagnosis code) indicating that in the memory and stores it. This information will help determine the cause of the anomaly in the subsequent inspection and repair work, and identify the repair location. In addition, the failure detected by self-diagnosis (and the type of failure) may be reported in a manner that appeals to the driver's vision or hearing. For example, a warning light (engine check lamp) installed in a cockpit of a vehicle is turned on, displayed on a display, or a warning sound is output from a buzzer or a speaker.

  In the present embodiment, the vehicle is equipped with an electric motor 110 capable of applying a rotational driving force to the crankshaft 10 or the axle 153 of the internal combustion engine 100, and indicates that the driver has stepped on the brake pedal. A vehicle that determines whether or not the brake signal f can be normally received, and prohibits subsequent application of rotational driving force to the crankshaft 10 or the axle 153 by the electric motor 110 when it is determined that the brake signal f cannot be normally received. The control device 0 was configured.

  According to the present embodiment, in the situation where the driver cannot correctly receive the brake signal f even though the driver is stepping on the brake pedal, the assist by the electric motor 110 is erroneously executed even though the vehicle is about to be braked. The event can be appropriately avoided, and the engine speed can be prevented from excessively increasing against the driver's intention.

  In particular, immediately after the internal combustion engine 100 is started, the brake signal reception self-diagnosis flag is set to “abnormal”, and only when it is determined that the brake signal f can be correctly received, the flag is set to “normal”. Since a transition is made to a state that allows execution, high safety can be ensured.

  The present invention is not limited to the embodiment described in detail above. Various modifications can be made to the specific configuration of each part, processing procedure, and the like without departing from the spirit of the present invention.

  The present invention can be applied to control of a vehicle equipped with an electric motor capable of giving a rotational driving force to a crankshaft or an axle of an internal combustion engine.

0 ... Control unit (ECU)
DESCRIPTION OF SYMBOLS 100 ... Internal combustion engine 10 ... Crankshaft 110 ... Generator, electric motor (ISG)
153 ... Axle f ... Brake signal g ... Master cylinder pressure signal

Claims (3)

Controlling a vehicle equipped with an electric motor capable of applying a rotational driving force to a crankshaft or an axle of an internal combustion engine,
It is determined whether the driver can normally receive a brake signal indicating that the driver has stepped on the brake pedal, and when it is determined that the brake signal cannot be received normally, the subsequent rotational driving force to the crankshaft or axle by the electric motor Vehicle control device that prohibits the application of The vehicle control device according to claim 1, wherein after starting the internal combustion engine, it is determined that the brake signal can be normally received on condition that a brake signal is received and no brake signal is received thereafter. 2. The brake signal is judged not to be normally received when the vehicle speed is decelerated from the first predetermined speed to the second predetermined speed lower than the first predetermined speed for a predetermined number of times without receiving the brake signal. Or the control apparatus of the vehicle of 2.

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