JP5262938B2 - Vehicle travel control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle traveling controller for preliminarily suppressing the deterioration of driveability after the end of EV traveling. <P>SOLUTION: The vehicle traveling controller is loaded with a motor to be operated with power from a battery and a prescribed drive source different from the motor, and configured to control a hybrid car capable of EV-travel only by drive power of the motor, and provided with a first instruction means for instructing EV traveling by a driver; a second instruction means for instructing the driving of the vehicle with the drive power of a prescribed drive power source; and a determination means for determining whether to end the EV traveling on the basis of the charging state of the battery. In EV traveling based on an instruction to the first instruction means (S100-Y), even when the end of the EV traveling is determined by the determination means (S110-Y), and such conditions that drive power is required by the hybrid car based on at least either a traveling environment or a driving situation are established, and any instruction to the second instruction means is not detected (S120-Y), the EV traveling is continued until the lapse of a prescribed time (S140-Y). <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a vehicle travel control device, and more particularly to a vehicle travel control device that controls a hybrid vehicle capable of EV travel.

  Conventionally, in a hybrid vehicle equipped with a motor that operates with electric power supplied from a battery and a predetermined drive source different from the motor, means for determining whether or not to terminate EV traveling based on the state of charge of the battery What you have is known.

  For example, Patent Literature 1 includes at least one of a condition that a charge / discharge state (SOC) of a traveling battery is equal to or higher than a predetermined value and a condition that a vehicle speed is equal to or lower than a predetermined speed. When established, a vehicle control device is disclosed in which a hybrid vehicle is driven only by a motor.

JP 2007-185986 A

  Here, if it is determined whether or not to end EV traveling uniformly based on the state of charge of the battery, drivability may be reduced. For example, drivability may be reduced after EV travel ends. Conventionally, in the determination of whether or not to end EV travel, sufficient consideration has not been given to drivability after the end of EV travel.

  An object of the present invention is to suppress a reduction in drivability after the end of EV travel in a hybrid vehicle equipped with a motor and a predetermined drive source different from the motor and capable of EV travel traveling only with the power of the motor. It is providing the vehicle travel control apparatus which can do.

The vehicle travel control device of the present invention is equipped with a motor as a drive source that operates by electric power supplied from a battery and a predetermined drive source that is a drive source different from the motor, and travels only with the drive force of the motor. A vehicle travel control device for controlling a hybrid vehicle capable of EV travel, wherein a driver instructs the hybrid vehicle to perform the EV travel, and the hybrid vehicle is driven by a driving force of the predetermined drive source. Second instruction means for instructing the driver to do so, and determination means for determining whether or not to end the EV running based on the state of charge of the battery, wherein the predetermined drive source is the first drive source. in conjunction with the instructions for instructing means it is made is disconnected from the drive wheels, and the instruction to the second instruction means is connected to the drive wheel in conjunction with be made, the first finger Wherein during EV traveling based on the made the instruction to means, even if they are determined to end the EV running by the determination means, in the case a right turn at an intersection, and an instruction to said second instruction means is made If not, the EV travel is continued until a predetermined period of time elapses.

The vehicle travel control device according to the present invention includes a first instruction means for instructing the driver to perform EV traveling, and a second instruction means for instructing the driver to drive the hybrid vehicle with the driving force of a predetermined drive source. And determining means for determining whether or not to terminate EV traveling based on the state of charge of the battery, wherein the predetermined drive source is driven wheel in conjunction with an instruction to the first indicating means. And connected to the drive wheel in conjunction with an instruction to the second instruction means, and during the EV traveling based on the instruction made to the first instruction means, the determination means even if they are determined to end the EV traveling, in the case a right turn at an intersection, and, when an instruction to said second instruction means is not performed, the elapse of the predetermined time period a predetermined In continuing the EV traveling.

  As a result, when the hybrid vehicle requires driving force and the driver has not been instructed to drive the hybrid vehicle with the driving force of the predetermined driving source, EV driving is performed until a predetermined period elapses. Will continue. Therefore, when the hybrid vehicle requires driving force, the supply of electric power from the battery to the motor is continued, and the hybrid vehicle can be driven by the power of the motor. As a result, there is an effect that it is possible to suppress a decrease in drivability after the EV traveling is finished, as compared with a case where the EV traveling is ended with the determination result of the determining unit as it is.

FIG. 1 is a flowchart showing the operation of the embodiment of the vehicle travel control device according to the present invention. FIG. 2 is a diagram showing a schematic configuration of a hybrid vehicle equipped with the device according to the embodiment of the vehicle travel control device of the present invention. FIG. 3 is a diagram showing a shift interface (shift pattern) of the transmission in the embodiment of the vehicle travel control device according to the present invention. FIG. 4 is a diagram for explaining a situation when the vehicle turns right at an intersection in the embodiment of the vehicle travel control device according to the present invention. FIG. 5 is a flowchart showing an operation of determining whether or not a decrease in drivability occurs in the embodiment of the vehicle travel control apparatus according to the present invention. FIG. 6 is a flowchart showing an operation of determining whether or not a predetermined period has ended in the embodiment of the vehicle travel control apparatus according to the present invention. FIG. 7 is a flowchart showing an operation for determining whether or not a predetermined period has ended in the first modified example of the embodiment of the vehicle travel control apparatus according to the present invention. FIG. 8 is a flowchart showing an operation of determining whether or not a predetermined period has ended in the second modification of the embodiment of the vehicle travel control apparatus according to the present invention.

  Hereinafter, an embodiment of a vehicle travel control device according to the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by this embodiment. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same.

(Embodiment)
The embodiment will be described with reference to FIGS. 1 to 6. The present embodiment relates to a vehicle travel control device that controls a hybrid vehicle capable of EV travel. FIG. 1 is a flowchart showing the operation of the embodiment of the vehicle travel control device according to the present invention, FIG. 2 is a diagram showing a schematic configuration of a hybrid vehicle equipped with the vehicle travel control device of the present embodiment, and FIG. FIG. 4 is a diagram illustrating a shift interface (shift pattern) of the transmission 2 in the present embodiment, and FIG. 4 is a diagram for explaining a situation when the vehicle turns right at an intersection.

  In the present embodiment, in a hybrid system of a stepped T / M + 1 motor having an EV gear, when the EV gear is selected and the EV travel is performed, the motor travel is determined not to be permitted due to a decrease in SOC. However, if a decrease in drivability due to the end of EV travel is predicted, EV travel is continued for a certain period (predetermined period). Here, the case where a decrease in drivability is predicted means that the condition that the hybrid vehicle requires driving force is established, and that the driver is instructed to drive the hybrid vehicle with the driving force of the engine (predetermined driving source). Is not done by. Specifically, when there is a vehicle traveling in the opposite lane at the time of a right turn and the vehicle is stopped in the intersection, if the shift position remains in the EV gear, it is determined that the drivability is deteriorated.

  When it is predicted that a decrease in drivability will occur, EV traveling is permitted for a certain period (for example, a certain time). Thus, it is possible to continue EV traveling until a state in which drivability deteriorates is resolved, for example, until a right turn is completed and the vehicle leaves the intersection. Therefore, according to the vehicle travel control device of the present embodiment, it is possible to suppress a decrease in drivability after the EV travel is finished.

  In FIG. 2, the code | symbol 100 shows the hybrid vehicle by which the vehicle travel control apparatus of this embodiment is mounted. Hybrid vehicle 100 includes an engine 1, a transmission 2, a motor generator 3, a battery 4, and an ECU 30.

  The engine 1 is a known internal combustion engine. An intake path (not shown), a throttle valve that adjusts the flow rate of intake air flowing through the intake path, a fuel injection device that injects fuel into the intake path, and an air-fuel mixture in a cylinder are ignited. An ignition device. The engine 1 burns an air-fuel mixture of air supplied via an intake passage and fuel supplied by a fuel injection device in a cylinder, and converts the generated combustion energy into rotational motion of the crankshaft 11 for output. Is. The engine 1 is not limited to a spark ignition type internal combustion engine, and may be a compression self-ignition type internal combustion engine or the like. Further, the predetermined drive source as a drive source different from the motor generator 3 is not limited to the internal combustion engine.

  The transmission 2 is a manual transmission (MT), and a gear shift is executed mechanically by a driver's operation (clutch operation and shift operation).

  The transmission 2 has an input shaft 2A, an output shaft 2B, and a clutch 2C. The input shaft 2A is arranged coaxially with the crankshaft 11. The rotation of the crankshaft 11 is transmitted to the input shaft 2A via the clutch 2C. The clutch 2C is engaged or released by a driver's operation on a clutch pedal (not shown). The clutch 2C is connected to a shift lever, and is released in conjunction with the driver operating the shift lever to an EV gear described later.

  The output shaft 2B is disposed in parallel with the input shaft 2A. The input shaft 2A and the output shaft 2B are opposed to each other in the radial direction, and power is transmitted between the input shaft 2A and the output shaft 2B via any of the gears described later. The transmission 2 can perform a five-speed shift from the first forward speed to the fifth speed. The transmission 2 includes a first gear 21, a second gear 22, a third gear 23, a fourth gear which are provided on the input shaft 2 </ b> A and the output shaft 2 </ b> B and mesh with each other and have different gear ratios. A gear 24 and a fifth speed gear 25 are provided. The first gear 21 has the largest gear ratio, and the gear ratio decreases in the order of the second gear 22, the third gear 23, the fourth gear 24, and the fifth gear 25. The transmission 2 is provided with a reverse gear 2R as a reverse gear.

  The transmission 2 includes a synchronizer provided in each gear, not shown. When a shift operation is performed by the driver, a gear synchronizer is operated in accordance with the shift position selected in conjunction with the shift operation. Thereby, the rotation of the engine 1 is transmitted from the input shaft 2A to the output shaft 2B at the selected gear ratio.

  The output shaft 2B is provided with an MG input gear 2M to which the power of the motor generator 3 is transmitted. The motor generator 3 has both a function (power running function) as an electric motor driven by the supply of electric power and a function (regeneration function) as a generator that converts mechanical energy into electric energy. As the motor generator 3, for example, an AC synchronous motor generator can be used. The hybrid vehicle 100 is equipped with a battery 4 as a power supply device that supplies power to the motor generator 3. The battery 4 is a chargeable / dischargeable secondary battery. Motor generator 3 is connected to battery 4 via an inverter (not shown). Instead of motor generator 3, another power source that converts electric energy supplied from battery 4 into driving force of hybrid vehicle 100 may be used.

  The battery 4 is provided with a battery current sensor (not shown). The battery current sensor is a charging / discharging current detecting means, and detects a charging / discharging current value Ix (A) that is a current value when the battery 4 is charged and a current value when the battery 4 is discharged. . The ECU 30 is connected to the battery current sensor, and calculates the charge rate of the battery 4 that is the state of charge of the battery 4, that is, the SOC value (%), based on the charge / discharge current value Ix detected by the battery current sensor. .

  The rotation shaft 31 of the motor generator 3 is provided with an MG gear 32 that rotates integrally with the rotation shaft 31. The MG gear 32 meshes with the MG input gear 2M, and the power of the motor generator 3 is transmitted to the output shaft 2B via the rotary shaft 31, the MG gear 32, and the MG input gear 2M. Output shaft 2B can function as a power combining mechanism in which the power of engine 1 and the power of motor generator 3 are combined. The power transmitted to the output shaft 2B is transmitted to the drive wheels 15 via the differential gear 13 and the drive shaft 14.

  The hybrid vehicle 100 is provided with a shift position sensor 12 that detects a shift position of a shift lever operated by a driver. A signal indicating the shift position detected by the shift position sensor 12 is input to the ECU 30. . FIG. 3 is a diagram illustrating an example of a shift interface (shift pattern) of the shift lever. The shift lever is provided with an R (reverse) range, an N (neutral) range, and an EV range in addition to the five ranges (shift positions) corresponding to the first to fifth gears. The EV range corresponds to first instruction means for instructing EV traveling. When the shift lever is operated to the EV range, the clutch 2C of the transmission 2 is released by a mechanism that operates in conjunction with the shift lever. Further, when the shift lever is removed from the EV range, the releasing operation for the clutch 2C by the mechanism is completed.

  When the shift position is operated in five ranges from 1st to 5th speed or R range, the power of the engine 1 is transmitted from the input shaft 2A to the output shaft 2B via the gear corresponding to the shift position. The At this time, the ECU 30 performs operation control of the engine 1 and operation control of the motor generator 30. As a result, when the motor generator 30 is subjected to power running control, the power of the engine 1 is combined with the power of the motor generator 30 and transmitted to the drive wheels 15. In other words, the five ranges from the first speed to the fifth speed of the shift position and the R range correspond to second instruction means for instructing to drive the hybrid vehicle with the driving force of the engine 1.

  The hybrid vehicle 100 is provided with an electronic control unit (ECU) 30 as control means for controlling a vehicle system including the engine 1, the transmission 2, and the motor generator 3. The ECU 30 is configured by a well-known microcomputer and performs traveling control of the hybrid vehicle 100. The vehicle travel control device of this embodiment is incorporated in the ECU 30. A shift position sensor 12, a vehicle speed sensor (not shown), an accelerator opening sensor, a battery current sensor, a steering angle sensor, and the like are connected to an input port (not shown) of the ECU 30, and signals indicating detection results of the sensors are respectively sent to the ECU 30. Entered. Further, the engine 1, the motor generator 3, the transmission 2, and the like are connected to an output port (not shown) of the ECU 30, and the engine 1, the motor generator 3, and the transmission 2 are controlled by the ECU 30, respectively.

  Specifically, the ECU 30 sets the injection signal, the ignition signal, the valve based on the required braking / driving force required for the hybrid vehicle 100 that is set based on the driver's intention or calculated in the travel control of the hybrid vehicle 100. An opening signal or the like is output to the engine 1. By these output signals, fuel injection control such as fuel supply amount and injection timing of fuel supplied to the engine 1 by the fuel injection device, ignition control of the ignition device, valve opening control of the throttle valve, and the like are performed.

  The ECU 30 executes a combination of drive control or fuel cut control in the engine 1 and power running control or regenerative control in the motor generator 3 according to the required drive force and the SOC value of the battery 4. For example, when the requested driving force is large, the ECU 30 assists the output of the engine 1 with the motor generator 3 by setting the engine 1 in a driving state and setting the motor generator 3 in a power running state. Further, at the time of deceleration, the engine 1 performs fuel cut and the motor generator 3 performs regenerative control so that the battery 4 is charged with the electric power generated by the motor generator 3.

  When the shift position is in the EV range and EV travel is possible, the ECU 30 executes EV travel control of the hybrid vehicle 100. ECU 30 determines whether or not to execute EV traveling (whether or not EV traveling is possible) based on a predetermined EV traveling execution condition. If it is determined that EV traveling is to be performed, motor generator 30 EV traveling is performed using only the power of the vehicle. Specifically, ECU 30 determines that the EV travel execution condition is satisfied when the SOC value of battery 4 exceeds a predetermined SOC lower limit value α. When the EV travel execution condition is satisfied, ECU 30 stops the operation of engine 1 and executes EV travel by power running control or regenerative control of motor generator 3. At this time, the clutch 2C of the transmission 2 is released, and the engine 1 and the input shaft 2A are disconnected. Note that the EV travel execution condition may include not only the SOC value but also other parameters.

  The ECU 30 controls the motor generator 3 based on the calculated required driving force. In the power running control, the ECU 30 drives the motor generator 3 by supplying power from the battery 4 and controls the output torque of the motor generator 3 so as to realize the required driving force. Further, at the time of deceleration, the ECU 30 performs regenerative control that causes the motor generator 3 to function as a generator and charges the generated power to the battery 4.

  Here, when the SOC value of the battery 4 decreases during EV travel, the EV travel execution condition is not satisfied, and EV travel is stopped. ECU 30 has a function of determining means for determining whether or not to end EV traveling based on the state of charge of battery 4, and determines that EV traveling is to be ended when the SOC value is equal to or lower than SOC lower limit value α. . The ECU 30 periodically detects the SOC value of the battery 4 during EV travel. ECU 30 urges the driver to shift from EV traveling to traveling using the driving force of engine 1 when the SOC value falls to a predetermined value that is larger than SOC lower limit value α. A driver who has been informed by the indicator lamp or the like that the SOC value needs to be shifted to travel by the driving force of the engine 1 needs to shift the shift lever from the EV range to the engine travel gear (for example, the first gear 21). ) The predetermined value is set to a value that can secure a sufficient time for the driver to perform a shift operation and shift to engine running.

  However, if an unexpected decrease in the SOC value occurs, the SOC value may decrease to the SOC lower limit value α before the driver performs a shift operation. For example, it is conceivable that the SOC value rapidly decreases due to an increase in the electric load of an electric power steering, the electric load of an air conditioner, or the like. At this time, if EV driving is terminated and the driving force of the vehicle is lost, drivability may be deteriorated as described below with reference to FIG.

  FIG. 4 is a diagram for explaining a situation when the vehicle turns right at an intersection. In FIG. 4, the code | symbol 101 shows an oncoming vehicle. FIG. 4 shows a state in which the hybrid vehicle (own vehicle) 100 is stopped in the intersection because there is an oncoming vehicle 101 traveling in the opposite lane when making a right turn. When the vehicle is turning right during EV traveling and the vehicle is stopped at the intersection in this way, drivability may decrease if the SOC decreases and EV traveling is not permitted. When EV traveling is not permitted and EV traveling is terminated, the output of motor generator 30 is cut. At this time, since the vehicle is traveling in EV, the clutch 2C is disengaged in the transmission 2, and the engine 1 is mechanically disconnected from the input shaft 2A of the transmission 2. That is, when the EV range is selected, the engine 1 is in a state where it is mechanically separated from the drive wheels 15 and cannot transmit power to the drive wheels 15.

  In order to start the hybrid vehicle 100, the driver needs to perform a shift operation for switching the shift lever from the EV range to the forward range (for example, first gear), which may lead to a decrease in drivability. In such a case, if the EV travel can be continued a little more and the shift to the manual shift by the power of the engine can be made after the right turn is completed, a decrease in drivability can be suppressed in advance.

  In the present embodiment, as described below, even if it is determined that the EV value is not to be executed due to a decrease in the SOC value, drivability is predicted to decrease when the EV drive is terminated on the spot. In this case, EV traveling is continued for a certain period. As a result, a decrease in drivability is suppressed in advance.

  The operation of this embodiment will be described with reference to FIG. The control flow in FIG. 1 is executed while the vehicle system of the hybrid vehicle 100 is in operation, and is repeatedly executed at predetermined intervals, for example.

  First, in step S100, the ECU 30 determines whether or not the EV gear (EV range) is selected. The ECU 30 performs the determination in step S100 based on the detection result of the shift position sensor 12. As a result of the determination, if it is determined that the EV gear is selected (step S100-Y), the process proceeds to step S110, and if not (step S100-N), the control flow ends.

  In step S110, the ECU 30 determines whether or not the SOC value of the battery 4 is equal to or lower than the SOC lower limit value α. When the SOC value is equal to or lower than the SOC lower limit value α, the EV travel execution condition is not satisfied. As a result of the determination in step S110, if it is determined that the SOC value is equal to or lower than the SOC lower limit value α (step S110-Y), the process proceeds to step S120, and if not, the process proceeds to step S160.

  In step S120, the ECU 30 determines whether or not a decrease in drivability occurs. A method for determining whether or not a decrease in drivability occurs will be described below with reference to FIG. FIG. 5 is a flowchart illustrating an operation for determining whether or not a decrease in drivability occurs. In the present embodiment, it is determined that drivability is reduced when it is determined that the vehicle is stopping in the intersection because there is an oncoming vehicle during a right turn during EV traveling.

  In step S121, the ECU 30 determines whether or not the lighting time (operation time) of the right direction indicator is equal to or longer than a predetermined t1 second. In step S121, it is determined whether or not the driver requests a right turn at an intersection or the like. As a result of the determination, if it is determined that the lighting time of the right direction indicator is t1 seconds or more (step S121-Y), the process proceeds to step S122. If not (step S121-N), the process proceeds to step S125. move on.

  In step S122, the ECU 30 determines whether or not the steering angle is equal to or greater than a predetermined angle θs1. In step S122, it is determined whether a right turn is actually started. In a situation where the steering is not turned off (step S122-N), it is determined that the vehicle is waiting for a signal or waiting for a vehicle ahead, and that the drivability is not deteriorated even if the EV traveling is finished. The ECU 30 performs the determination in step S122 based on the steering angle (steering angle) that is the rotation angle of the steering detected by the steering angle sensor. As a result of the determination, if it is determined that the steering angle is greater than or equal to the angle θs1 (step S122-Y), the process proceeds to step S123, and if not (step S122-N), the process proceeds to step S125.

  In step S123, the ECU 30 determines whether or not the vehicle is stopped. The ECU 30 performs the determination in step S123 based on the vehicle speed detected by the vehicle speed sensor. As a result of the determination, if it is determined that the vehicle is stopped (step S123-Y), the process proceeds to step S124, and if not (step S123-N), the process proceeds to step S125.

  In step S124, the ECU 30 determines that the drivability is reduced due to the end of EV travel. The situation where the vehicle is stopped at the intersection because there is an oncoming vehicle when making a right turn is a situation where the hybrid vehicle 100 requires driving force, in other words, a situation where the vehicle must travel as it is when the accelerator is depressed. At this time, if the shift position remains in the EV range even though the EV travel execution condition is not satisfied, it is determined that the drivability is lowered due to the end of the EV travel. When step S124 is executed, this control flow is ended, and the process returns to step S120 in FIG.

  In step S125, the ECU 30 determines that a decrease in drivability is avoided (not a state in which a decrease in drivability occurs) even if the EV traveling is terminated. When step S125 is executed, this control flow is terminated, and the process returns to step S120 in FIG.

  Returning to step S120 of FIG. 1, if it is determined that a decrease in drivability occurs (step S120-Y), the process proceeds to step S130, and if not (step S120-N), the process proceeds to step S150.

  In step S130, the ECU 30 executes EV traveling for a certain period. The ECU 30 gives priority to avoiding a state in which a decrease in drivability occurs, and continues the EV travel (exceptionally) until a predetermined time period ends.

  In step S140, the ECU 30 determines whether or not the fixed period of step S130 has ended. A method for determining whether or not a certain period has ended will be described below with reference to FIG. FIG. 6 is a flowchart showing an operation for determining whether or not a predetermined period has ended. In the present embodiment, it is determined whether or not the certain period has ended based on the elapsed time.

  In step S141, the ECU 30 determines whether or not the EV traveling time after the certain period starts is equal to or longer than a predetermined time t2. This time t2 is determined from the viewpoint of suppressing a decrease in drivability in advance, and is set as an EV travel time necessary to avoid a situation in which a decrease in drivability occurs. The time t2 can be set based on, for example, a matching experiment. The ECU 30 measures the elapsed time since the start of EV travel for avoiding the situation in which drivability deterioration occurs, and determines whether or not the elapsed time has reached t2. As a result of the determination, if it is determined that the EV traveling time after the start of the certain period is t2 or more (step S141-Y), the process proceeds to step S142, and otherwise (step S141-N). The process proceeds to step S143.

  In step S142, the ECU 30 determines that the certain period has ended. When step S142 is executed, this control flow is ended, and the process returns to step S140 in FIG.

  In step S143, the ECU 30 permits EV travel. When step S143 is executed, the control flow is ended, and the process returns to step S140 in FIG.

  Returning to step S140, if it is determined that the predetermined period has ended (step S140-Y), the process proceeds to step S150. If EV traveling is permitted (step S140-N), the process proceeds to step S130. Continue running.

  In step S150, the output of the motor generator 3 is cut by the ECU 30. At the time when the EV traveling is finished, the hybrid vehicle 100 has finished the right turn at the intersection and has left the intersection, so that the traveling from the EV traveling to the engine traveling is continued without lowering the drivability. Can do. Moreover, EV driving | running | working is complete | finished and the battery 4 is protected by the further fall of the SOC value of the battery 4 being suppressed. When step S150 is executed, the control flow ends.

  When a negative determination is made in step S110 and the process proceeds to step S160, the EV travel is executed by the ECU 30 in step S160. Since the SOC value exceeds the SOC lower limit value α, the EV travel execution condition is satisfied, and normal EV travel is performed. When step S160 is executed, the control flow ends.

  The hybrid vehicle 100 may be provided with an indicator lamp or the like that is turned on when EV traveling for suppressing a decrease in drivability is continued (step S130). By notifying the driver that the exceptional EV traveling for suppressing the decrease in drivability is being executed, the driver is promptly shifted to traveling by the driving force of the engine 1 and the decrease in the SOC value is suppressed. It becomes possible.

  In the present embodiment, the case where the transmission 2 is an MT that mechanically engages / releases the clutch and switches the gear in conjunction with the driver's shift operation has been described. However, the present invention is not limited to this. The transmission 2 may be an automatic transmission that automatically shifts to a selected shift speed. For example, this embodiment is applied to a hybrid vehicle that includes an actuator that engages / releases a clutch and an actuator that performs a gear switching operation, and includes an automatic transmission that is controlled by ECU 30 in response to an operation on a shift lever. Form control may be applied.

  In the present embodiment, it is determined that the hybrid vehicle 100 needs the driving force when it is “stopped in the intersection because there is a vehicle traveling in the opposite lane when turning right”, but the hybrid vehicle 100 is driven. The method for determining (guessing) whether or not force is required is not limited to this. Whether or not the hybrid vehicle 100 requires driving force may be determined based on at least one of the traveling environment and the driving situation. The condition that the hybrid vehicle 100 requires driving force is set as a traveling environment or driving situation in which the output of the motor generator 3 should not be cut, or a driving environment or driving situation in which the vehicle must travel as it is with the accelerator ON. For example, it may be determined that the hybrid vehicle 100 needs a driving force when it is “temporarily stopped before the crossing”. In this case, for example, the determination can be performed using information of the navigation system.

  The navigation system has a basic function of guiding the host vehicle to a predetermined destination and stores information necessary for driving the vehicle (such as maps, straight roads, curves, uphills, and highways). It includes a storage medium, an information detection device that detects the current position of the host vehicle and road conditions by self-contained navigation and radio wave navigation using GPS. When it is determined that the host vehicle is located before the crossing based on the information of the navigation system and the host vehicle is determined to be stopped based on the vehicle speed information, Can be determined. In addition, the hybrid vehicle 100 may determine whether or not the hybrid vehicle 100 requires driving force based on the position of the host vehicle when the hybrid vehicle 100 is stopped, not limited to the temporary stop before the crossing.

  Whether hybrid vehicle 100 requires a driving force may be determined based on the detection result of the accelerator opening sensor. For example, when the driver performs an accelerator operation that requests a large driving force of a certain level or more with respect to the hybrid vehicle 100 at the time of stopping, it is considered that there is some reason for requesting a large driving force. In such a case, it is possible to suppress a decrease in drivability by continuing EV traveling.

(First Modification of Embodiment)
A first modification of the embodiment will be described. FIG. 7 is a flowchart showing an operation of determining whether or not a certain period has ended in the present modification.

  In the above embodiment, it is determined whether or not the fixed period has ended based on the elapsed time of EV travel (see steps S141 to S143 in FIG. 6). Based on the SOC value, the end of a certain period is determined.

  Specifically, when the SOC value is equal to or less than a predetermined threshold value β, it is determined that the certain period has ended. The threshold value β is set to a value smaller than the SOC lower limit value α. The threshold value β is determined from the viewpoint of suppressing a decrease in drivability, and is set based on an EV travel time or an EV travel distance necessary to avoid a situation in which a decrease in drivability occurs. . In other words, the threshold value β is set to a value that can avoid a situation in which drivability is reduced by performing EV traveling until the SOC value decreases to the threshold value β. The threshold value β can be set, for example, by a fitting experiment.

  With reference to FIG. 7, the determination method of the completion | finish of a fixed period in this modification is demonstrated. Note that operations other than the operations shown in FIG. 7 can be the same as the operations described with reference to FIGS. 1 and 5 in the above embodiment.

  First, in step S241, the ECU 30 determines whether or not the SOC of the battery 4 is equal to or less than the threshold value β. As a result of the determination, if it is determined that the SOC is equal to or less than the threshold value β (step S241-Y), the process proceeds to step S242. If not (step S241-N), the process proceeds to step S243.

  In step S242, the ECU 30 determines that the certain period has ended. When step S242 is executed, the control flow ends.

  In step S243, the ECU 30 permits EV travel. When step S243 is executed, the control flow ends.

  According to the determination method of the end of the fixed period in the present modification, EV traveling is ended when the SOC value decreases to the threshold value β. Therefore, an excessive decrease in the SOC value can be suppressed while avoiding a situation in which a decrease in drivability occurs.

(Second Modification of Embodiment)
A second modification of the embodiment will be described. FIG. 8 is a flowchart showing an operation of determining whether or not a certain period has ended in the present modification.

  In the above embodiment, it is determined whether or not the fixed period has ended based on the elapsed time of EV travel (see steps S141 to S143 in FIG. 6). An end determination for a certain period is made based on whether or not a situation in which a decrease occurs is avoided.

  With reference to FIG. 8, the determination method of the completion | finish of a fixed period in this modification is demonstrated. Note that operations other than the operations shown in FIG. 8 can be the same as the operations described with reference to FIGS. 1 and 5 in the above embodiment.

  First, in step S341, the ECU 30 determines whether or not a decrease in drivability is avoided. The ECU 30 determines whether or not the state predicted to cause a decrease in drivability when the EV traveling is finished is removed. The ECU 30 makes an affirmative determination in step S341 when a condition that the hybrid vehicle 100 requires a driving force (such as a traveling environment or a driving situation) is resolved.

  For example, if it is determined that the drivability is lowered due to the end of EV traveling because it is determined that “the vehicle is on the right side because it is on the right side when turning right” (see step S124 in FIG. 5), If it is determined that the right turn of the vehicle has been completed, it can be determined that the state in which the drivability is degraded is removed. In this case, the ECU 30 determines “whether or not the right turn at the intersection has been completed” based on the same parameter as that used when determining that “the vehicle is on the right side and is stopped at the intersection”. can do. For example, when any of the condition that the direction indicator is not lit, the condition that the steering angle is less than a predetermined angle, or the condition that the vehicle speed is equal to or higher than a predetermined vehicle speed is satisfied, Alternatively, it can be determined that the right turn is completed when a plurality of these conditions are satisfied at the same time.

  Note that the method for determining whether or not the state that causes the decrease in drivability has been resolved is not limited to this. For example, when the hybrid vehicle 100 is equipped with a navigation system that detects the current position of the host vehicle, the state where the drivability is degraded is resolved based on the position of the host vehicle detected by the navigation system. It is possible to determine whether or not it has been done. For example, when the position of the host vehicle is not within an intersection and the traveling direction of the host vehicle is a direction away from the intersection, it can be determined that the state where drivability is reduced has been eliminated.

  As a result of the determination in step S341, if it is determined that a decrease in drivability is avoided (step S341-Y), the process proceeds to step S342. If not (step S341-N), the process proceeds to step S344.

  In step S342, the ECU 30 determines whether or not the vehicle has traveled for a certain period of time or a certain distance after it is determined that a decrease in drivability has been avoided. The certain time and certain distance are set from the viewpoint of providing a margin. By continuing the EV travel until it is determined that the decrease in drivability is avoided and the vehicle travels for a certain time or a certain distance, it is possible to more reliably suppress the decrease in drivability. As a result of the determination in step S342, if it is determined that the vehicle has traveled for a certain period of time or a certain distance after it is determined that the decrease in drivability has been avoided (step S342-Y), the process proceeds to step S343. In S342-N), the process proceeds to step S344.

  In step S343, the ECU 30 determines that the certain period has ended. When step S343 is executed, the control flow ends.

  In step S344, EV traveling is permitted by the ECU 30. When step S344 is executed, the control flow ends.

  According to the method for determining the end of the fixed period of the present modification, the end time of EV travel is determined at the timing when it is confirmed that the situation in which the decrease in drivability occurs is confirmed. Therefore, a decrease in drivability can be suppressed more reliably. Moreover, compared with the case where the fixed period which performs EV driving | running | working is set uniformly, it can suppress that a fixed period becomes long too much and can reduce the fall of SOC of the battery 4. FIG.

DESCRIPTION OF SYMBOLS 1 Engine 2 Transmission 2A Input shaft 2B Output shaft 2C Clutch 3 Motor generator 4 Battery 12 Shift position sensor 15 Drive wheel 30 ECU
100 hybrid vehicle

Claims (1)

A hybrid vehicle that is equipped with a motor as a drive source that operates by electric power supplied from a battery and a predetermined drive source that is a drive source different from the motor and that is capable of EV traveling that travels only by the driving force of the motor is controlled. A vehicle travel control device,
First instruction means for a driver to instruct to perform the EV traveling;
Second instruction means for instructing the driver to drive the hybrid vehicle with the driving force of the predetermined drive source;
Determination means for determining whether or not to end the EV running based on the state of charge of the battery;
The predetermined drive source is disconnected from the drive wheel in conjunction with an instruction to the first instruction means, and connected to the drive wheel in conjunction with an instruction to the second instruction means,
Even when it is determined by the determining means that the EV traveling is to be terminated during the EV traveling based on the instruction given to the first instruction means, the second instruction means is a case where a right turn is made at an intersection. The vehicle travel control device is characterized in that the EV travel is continued until a predetermined period of time elapses when no instruction is given.

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