JP5621929B2 - Vehicle control apparatus and control method - Google Patents

Description

  The present invention relates to a vehicle control device and a control method, and more particularly to a technique for recommending a driver to change a control mode.

  In addition to the engine, a hybrid vehicle equipped with an electric motor, or an electric vehicle equipped with a cruising range extension function (range extender) is known. In such a vehicle, for example, the engine and the electric motor are connected via a planetary gear unit. The planetary gear unit and the electric motor constitute an electric continuously variable transmission. Therefore, it is possible to increase or decrease the engine speed without being influenced by the vehicle speed. In general, the engine speed is controlled so that the thermal efficiency of the engine is optimized.

  However, if the engine speed is determined regardless of the vehicle speed, the driver cannot manually select the ratio between the engine speed and the axle speed, that is, the gear ratio. However, even in a vehicle such as a hybrid vehicle, there is a need to give a driver an operation experience of selecting a gear ratio, as in a general vehicle equipped with only an engine as a drive source. In order to meet such needs, there is also a hybrid vehicle in which the gear ratio can be changed in a pseudo manner by increasing or decreasing the engine speed in accordance with the manual operation of the driver.

  On the other hand, if the driver can select a gear ratio, an inappropriate gear ratio may be maintained. As one of the solutions to such a problem, Japanese Patent Application Laid-Open No. 2008-13827 (Patent Document 1) discloses that a shift mode or a shift speed is determined when it is determined that manual shift operation is not appropriate. It is disclosed that the guidance of the switching operation is notified to the driver.

JP 2008-138827 A

  However, in a vehicle such as a hybrid vehicle, even if the speed ratio selected by the driver is not inappropriate, the fuel consumption deteriorates. For example, when the engine speed is increased so as to simulate a downshift during deceleration, the kinetic energy lost due to engine friction increases. Therefore, the kinetic energy that can be recovered by regeneration is reduced. As a result, overall energy efficiency is degraded. Therefore, it is required to prompt the driver to select a control mode with better fuel efficiency.

  In one embodiment, a control device for a vehicle equipped with an engine can change a shift range manually by an operation of a driver, and controls a rotation speed of the engine according to the selected shift range. Control that selects either one of the mode and the second mode for controlling the engine speed so that the fuel consumption is reduced as compared with the first mode in accordance with the operation of the driver A unit and a recommended unit that recommends the driver to change from the first mode to the second mode when the first mode is selected.

  According to this configuration, when the driver selects the first mode in which the shift range can be manually changed by the driver's operation, the driver of the vehicle equipped with the engine is compared with the first mode. A change to the second mode in which the amount of fuel consumption is reduced is prompted.

  In another embodiment, the vehicle further includes an electric motor coupled to the engine. When the first mode is selected, the control unit increases the engine speed during deceleration compared to when the second mode is selected.

  According to this configuration, in the first mode, for example, the engine speed is increased in accordance with the selected shift range in order to realize a downshift in a pseudo manner. When such a first mode is selected, a change from the first mode to the second mode is recommended to the driver.

  In yet another embodiment, the vehicle is further equipped with a braking device that decelerates the vehicle. The recommendation unit restricts recommendation to change from the first mode to the second mode when the braking device is abnormal.

  According to this configuration, when it is required to reduce the kinetic energy by the friction of the engine, that is, when engine braking is required, the change to the second mode in which the braking force by the engine braking is difficult to be obtained is not prompted.

  In yet another embodiment, the first mode is a manual transmission mode. The second mode is an automatic transmission mode.

  According to this configuration, a change from the manual shift mode to the automatic shift mode is prompted.

  According to an embodiment, the driver is prompted to change to the second mode, where the fuel consumption is reduced compared to the first mode.

It is a schematic block diagram which shows a hybrid vehicle. It is an alignment chart of a power split mechanism. It is a figure which shows a brake system. It is a figure which shows a shift lever and a shift position. It is a figure which shows the period which an engine drives, and the period which stops. It is a figure which shows the operating line of an engine. It is a figure which shows the engine speed NE at the time of deceleration in manual shift mode and the engine speed NE at the time of deceleration in automatic transmission mode. It is a figure which shows an indicator lamp. It is a flowchart which shows the process which ECU performs.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  Referring to FIG. 1, engine 100, first motor generator 110, second motor generator 120, power split mechanism 130, reduction gear 140, and battery 150 are mounted on the hybrid vehicle. In the following description, a hybrid vehicle not having a charging function from an external power source will be described as an example, but a plug-in hybrid vehicle having a charging function from an external power source may be used.

  Engine 100, first motor generator 110, second motor generator 120, and battery 150 are controlled by an ECU (Electronic Control Unit) 170. ECU 170 may be divided into a plurality of ECUs.

  This vehicle travels by driving force from at least one of engine 100 and second motor generator 120. That is, either one or both of engine 100 and second motor generator 120 is automatically selected as a drive source according to the operating state.

  For example, engine 100 and second motor generator 120 are controlled in accordance with the result of the driver operating the accelerator pedal. When the amount of operation of the accelerator pedal (accelerator opening) is small or the vehicle speed is low, the hybrid vehicle travels using only the second motor generator 120 as a drive source. In this case, engine 100 is stopped. However, the engine 100 may be driven for power generation or the like.

  Further, when the accelerator opening is large, the vehicle speed is high, or the remaining capacity (SOC: State Of Charge) of battery 150 is small, engine 100 is driven. In this case, the hybrid vehicle runs using only engine 100 or both engine 100 and second motor generator 120 as drive sources.

  The engine 100 is an internal combustion engine. As the fuel / air mixture burns in the combustion chamber, the crankshaft as the output shaft rotates. The exhaust gas discharged from the engine 100 is purified by the catalyst 102 and then discharged outside the vehicle. The catalyst 102 exhibits a purification action by being warmed up to a specific temperature. The catalyst 102 is warmed up by utilizing the heat of the exhaust gas. The catalyst 102 is, for example, a three-way catalyst.

  Engine 100, first motor generator 110, and second motor generator 120 are connected via power split mechanism 130. The power generated by the engine 100 is divided into two paths by the power split mechanism 130. One is a path for driving the front wheels 160 via the speed reducer 140. The other is a path for driving the first motor generator 110 to generate power.

  First motor generator 110 is a three-phase AC rotating electric machine including a U-phase coil, a V-phase coil, and a W-phase coil. First motor generator 110 generates power using the power of engine 100 divided by power split mechanism 130. The electric power generated by the first motor generator 110 is selectively used according to the running state of the vehicle and the remaining capacity of the battery 150. For example, during normal traveling, the electric power generated by first motor generator 110 becomes electric power for driving second motor generator 120 as it is. On the other hand, when the SOC of battery 150 is lower than a predetermined value, the electric power generated by first motor generator 110 is stored in battery 150.

  When first motor generator 110 is acting as a generator, first motor generator 110 generates negative torque. Here, the negative torque means a torque that becomes a load on engine 100. When first motor generator 110 is supplied with electric power and acts as a motor, first motor generator 110 generates positive torque. Here, the positive torque means a torque that does not become a load on the engine 100, that is, a torque that assists the rotation of the engine 100. The same applies to the second motor generator 120.

  Second motor generator 120 is a three-phase AC rotating electric machine including a U-phase coil, a V-phase coil, and a W-phase coil. Second motor generator 120 is driven by at least one of the electric power stored in battery 150 and the electric power generated by first motor generator 110.

  The driving force of the second motor generator 120 is transmitted to the front wheels 160 via the speed reducer 140. As a result, the second motor generator 120 assists the engine 100 or causes the vehicle to travel by the driving force from the second motor generator 120. The rear wheels may be driven instead of or in addition to the front wheels 160.

  During regenerative braking of the hybrid vehicle, the second motor generator 120 is driven by the front wheels 160 via the speed reducer 140, and the second motor generator 120 operates as a generator. Accordingly, second motor generator 120 operates as a regenerative brake that converts braking energy into electric power. The electric power generated by second motor generator 120 is stored in battery 150.

  Power split device 130 includes a planetary gear including a sun gear, a pinion gear, a carrier, and a ring gear. The pinion gear engages with the sun gear and the ring gear. The carrier supports the pinion gear so that it can rotate. The sun gear is connected to the rotation shaft of first motor generator 110. The carrier is connected to the crankshaft of engine 100. The ring gear is connected to the rotation shaft of second motor generator 120 and speed reducer 140.

  The engine 100, the first motor generator 110, and the second motor generator 120 are connected via a power split mechanism 130 that is a planetary gear, so that the rotational speeds of the engine 100, the first motor generator 110, and the second motor generator 120 are increased. As shown in FIG. 2, the relationship is connected by a straight line in the alignment chart.

  Returning to FIG. 1, the battery 150 is an assembled battery configured by further connecting a plurality of battery modules in which a plurality of battery cells are integrated in series. The voltage of the battery 150 is about 200V, for example. A capacitor may be used instead of or in addition to the battery 150.

  With reference to FIG. 3, a brake system 300 for applying a braking force to the hybrid vehicle will be described. The brake pedal 302 is connected to the master cylinder 304. When the brake pedal 302 is operated, a hydraulic pressure corresponding to the brake operation amount is generated in the master cylinder 304.

  The hydraulic pressure generated in the master cylinder 304 is supplied to calipers 311 to 314 provided on each wheel via a brake actuator 306 controlled by the ECU 170. That is, when the brake pedal 302 is operated, the brake actuator 306 is controlled so that the hydraulic pressure generated in the master cylinder 304 is supplied to the calipers 311 to 314. When the hydraulic pressure is supplied to each of the calipers 311 to 314, the brake pad is pressed against the disc rotor. A braking force is applied to the vehicle by the frictional force between the brake pad and the disk rotor.

  The calipers 311 to 314 are supplied with the hydraulic pressure generated in the brake actuator 306 in addition to the hydraulic pressure corresponding to the operation amount of the brake pedal 302. The brake actuator 306 includes a solenoid valve and pumps 307 and 308.

  By controlling the opening and closing of the solenoid valve, the hydraulic pressure generated by the pumps 307 and 308 is supplied to the calipers 311 to 314, and the hydraulic pressure is discharged from the calipers 311 to 314. The braking force by 300 is controlled. The operation amount of each caliper 311 to 314 is an operation amount corresponding to the hydraulic pressure. A caliper that operates with electric power may be provided instead of the caliper that operates with hydraulic pressure. A drum brake may be used instead of the disc brake.

  The braking by the brake system 300 is controlled by the ECU 170 so as to cooperate with the regenerative braking by the second motor generator 120. As an example, the braking force of the second motor generator 120 and the braking force determined by the amount of depression of the brake pedal 302 are supplemented by the braking force of the braking system 300 to compensate for the insufficient braking force due to the regenerative braking. The braking force of the brake system 300 is coordinated. When the braking force required by the driver can be satisfied only by the braking force by regenerative braking, the braking force by the brake system 300 is made zero.

  A control mode of engine 100, first motor generator 110, and second motor generator 120 will be described with reference to FIG. In the present embodiment, the control mode of engine 100, first motor generator 110, and second motor generator 120 is selected in accordance with the driver's operation on shift lever 172. As shown in FIG. 4, the shift lever 172 moves along the shift gate. The control mode is selected according to the position PSH of the shift lever 172.

  The position PSH of the shift lever 172 is detected by the position sensor 174. The position sensor 174 detects the position PSH of the shift lever 172 by determining whether the contact provided at the position corresponding to the shift position is ON or OFF.

  When the position PSH of the shift lever 172 is the “parking (P)” position or the “N (neutral)” position, the engine 100, the first motor generator 110, and the second motor so that the vehicle has no driving force. The motor generator 120 is controlled. In this case, control of engine 100, first motor generator 110, and second motor generator 120 may be stopped.

  When the position PSH of the shift lever 172 is the “reverse (R)” position, the engine 100, the first motor generator 110, and the second motor generator are arranged so that the vehicle moves backward with a larger driving force as the amount of operation of the accelerator pedal increases. 120 is controlled. More specifically, the engine 100 is stopped, and the vehicle is controlled to move backward using only the second motor generator 120 as a drive source.

  When the position PSH of the shift lever 172 is the “drive (D)” position, the automatic transmission mode is selected. In the automatic transmission mode, the engine 100, the first motor generator 110, and the second motor generator 120 are controlled so that the vehicle advances with a larger driving force as the amount of operation of the accelerator pedal increases.

  More specifically, the engine 100 stops when the driver's request can be satisfied even when only the second motor generator 120 is used as a drive source, such as when the vehicle starts, at a low vehicle speed, or at a light load. The vehicle is controlled to move forward using only the second motor generator 120 as a drive source.

  In a traveling state where the efficiency of engine 100 is improved, engine 100 is started. In this case, the vehicle is controlled to move forward with engine 100 as the main drive source.

  During acceleration, the engine 100 is used as a drive source to secure the driving force of the vehicle, and the first motor generator 110 generates power using a part of the power of the engine 100. Further, the second motor generator 120 is driven using the electric power generated by the first motor generator 110 as a drive source, and the drive force of the second motor generator 120 is added to the drive force of the engine 100.

  When the SOC of battery 150 decreases, engine 100 is used as a drive source to secure the driving force of the vehicle, and first motor generator 110 generates power using a part of the power of engine 100.

  As described above, when the D range is selected as the shift range, the engine 100 is intermittently operated by being driven or stopped according to the traveling state of the vehicle.

  With reference to FIG. 5, the control mode of engine 100 in the automatic transmission mode will be further described. As shown in FIG. 5, when the output power of the hybrid vehicle is smaller than the engine start threshold value, the hybrid vehicle travels using only the driving force of second motor generator 120.

  The output power is set as power used for running the hybrid vehicle. The output power is calculated by ECU 170 according to a map having, for example, the accelerator opening and the vehicle speed as parameters. The method for calculating the output power is not limited to this. Note that torque, acceleration, driving force, accelerator opening, and the like may be used instead of output power.

  When the output power of the hybrid vehicle exceeds the engine start threshold value, engine 100 is driven. Thus, the hybrid vehicle travels using the driving force of engine 100 in addition to or instead of the driving force of second motor generator 120. Further, the electric power generated by first motor generator 110 using the driving force of engine 100 is directly supplied to second motor generator 120.

  As shown in FIG. 6, the operating point of engine 100, that is, engine speed NE and output torque TE are determined by the intersection of the output power and the operating line.

  The output power is indicated by an isopower line. The operating line is predetermined by the developer based on the results of experiments and simulations. The operation line is set so that the engine 100 can be driven so that the fuel consumption becomes optimum (minimum). That is, when the engine 100 is driven along the operation line, optimal fuel consumption is realized.

  Returning to FIG. 4, when the position PSH of the shift lever 172 is the “sequential shift (S)” position, the manual transmission mode is selected. In the manual shift mode, the shift range can be manually changed within a range of 1 to 6, for example, by a shift operation for moving the shift lever 172 back and forth. In the manual shift mode, the engine speed is controlled in accordance with the selected shift range.

  In short, in the manual shift mode, sequential shift control is executed in which the driving force or braking force of the hybrid vehicle is controlled to change stepwise by moving the shift lever 172 back and forth.

  For example, when the position PSH of the shift lever 172 is the “S” position, when the driver operates the shift lever 172 toward the front of the vehicle, the engine speed NE is increased as in the case where the automatic transmission is upshifted. The engine 100, the first motor generator 110, and the second motor generator 120 are controlled so as to decrease. As an example, the higher the selected shift range, that is, the greater the number of upshifts, the lower the engine speed NE.

  Conversely, when the position PSH of the shift lever 172 is the “S” position and the driver operates the shift lever 172 toward the rear of the vehicle while the vehicle is decelerating, the automatic transmission is downshifted. Further, engine 100, first motor generator 110, and second motor generator 120 are controlled such that engine speed NE decreases. As an example, the lower the selected shift range, that is, the greater the number of downshifts, the higher the engine speed NE.

  More specifically, as indicated by a solid line in FIG. 7, assuming that the vehicle speed does not change, the engine speed NE is increased by increasing the speed of the first motor generator 110. On the other hand, as indicated by a broken line in FIG. 7, when the automatic transmission mode is selected, the engine speed NE is generally zero. That is, engine 100 is stopped. Therefore, when the manual transmission mode is selected, the engine speed NE at the time of deceleration is increased as compared with the case where the automatic transmission mode is selected.

  By the way, when the engine speed NE increases, the kinetic energy lost due to the friction of the engine 100 increases. Therefore, the kinetic energy that can be recovered by regeneration during deceleration is reduced. Therefore, the remaining capacity of the battery 150 is reduced more quickly. Therefore, it may take a long time to drive engine 100 for power generation. As a result, the fuel consumption of the engine 100 in the manual shift mode is larger than the fuel consumption of the engine 100 in the automatic shift mode. In other words, in the automatic transmission mode, the engine speed NE is controlled so that the fuel consumption is reduced compared to the manual transmission mode.

  Therefore, in view of fuel consumption, the automatic transmission mode is preferable to the manual transmission mode. Therefore, in the present embodiment, when the manual transmission mode is selected, as shown in FIG. 8, the indicator lamp 404 is lit or blinks in the meter 402 provided on the instrument panel 400 in front of the driver's seat. To do. In the present embodiment, indicator lamp 404 includes an arrow and characters “S” and “D”. “S” is written near the start point of the arrow, and “D” is written near the end point. It is recommended to the driver to move the shift lever 172 from the “S” position to the “D” position by turning on or blinking the indicator lamp 404. Therefore, when the manual shift mode is selected, a change from the manual shift mode to the automatic shift mode is recommended to the driver.

  The indicator lamp 404 is not limited to that shown in FIG. The indicator lamp 404 may be anything as long as it is recommended to the driver to change from the manual shift mode to the automatic shift mode. The driver may be recommended to change from the manual shift mode to the automatic shift mode by means of text, voice, warning sound, or the like.

  With reference to FIG. 9, a process executed by ECU 170 in the present embodiment will be described. The processing described below may be realized by software, may be realized by hardware, or may be realized by cooperation of software and hardware.

  In step (hereinafter, step is abbreviated as S) 100, the control mode is selected according to the position PSH of the shift lever 172. As described above, the automatic transmission mode is selected when the position PSH of the shift lever 172 is the “D” position. When the position PSH of the shift lever 172 is the “S” position, the manual transmission mode is selected.

  In S102, it is determined whether or not the manual transmission mode is selected. As described above, when the manual shift mode is selected, the engine speed NE during deceleration is increased as compared with the case where the automatic shift mode is selected.

  When manual transmission mode is selected (YES in S102), it is determined in S104 whether brake system 300 is abnormal. Whether or not the brake system 300 is abnormal may be determined by using a known general technique, and thus detailed description thereof will not be repeated here.

  If there is no abnormality in brake system 300 (NO in S104), the driver is recommended to change from the manual shift mode to the automatic shift mode by turning on or blinking indicator lamp 404 in S106.

  On the other hand, if there is an abnormality in brake system 300 (YES in S104), it is desirable to increase the braking force by engine braking by increasing engine speed NE during deceleration. Therefore, the indicator lamp 404 is turned off at S108. Therefore, the recommendation for changing from the manual shift mode to the automatic shift mode is limited.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  100 Engine, 110 First motor generator, 120 Second motor generator, 130 Power split mechanism, 170 ECU, 172 Shift lever, 174 Position sensor, 300 Brake system, 302 Brake pedal, 304 Master cylinder, 306 Brake actuator, 307, 308 Pump, 311, 312, 313, 314 caliper, 400 instrument panel, 402 meters, 404 indicator lamp.

Claims (5)

And engine, a control apparatus of a vehicle equipped with an electric motor coupled to the engine,
The shift range can be manually changed by a driver's operation, and the fuel consumption is compared with the first mode in which the engine speed is controlled in accordance with the selected shift range, compared to the first mode. When one of the second mode for controlling the engine speed so as to reduce the amount is selected according to the operation of the driver, and the first mode is selected, A control unit for increasing the number of revolutions of the engine during deceleration compared to when the second mode is selected;
A vehicle control device comprising: a recommendation unit that recommends a driver to change from the first mode to the second mode when the first mode is selected. The vehicle is further equipped with a braking device for decelerating the vehicle,
2. The vehicle control device according to claim 1, wherein the recommendation unit restricts a recommendation to change from the first mode to the second mode when the braking device is abnormal. 3. The first mode is a manual transmission mode,
The vehicle control device according to claim 1, wherein the second mode is an automatic transmission mode. And engine, a control method of a vehicle equipped with an electric motor coupled to the engine,
The shift range can be manually changed by a driver's operation, and the fuel consumption is compared with the first mode in which the engine speed is controlled in accordance with the selected shift range, compared to the first mode. Selecting either one of the second mode for controlling the engine speed so that the amount is reduced according to the operation of the driver;
Increasing the engine speed during deceleration when the first mode is selected as compared to when the second mode is selected;
And a step of recommending to the driver a change from the first mode to the second mode when the first mode is selected. And engine, a control apparatus of a vehicle equipped with an electric motor coupled to the engine,
The shift range can be manually changed by a driver's operation, and the fuel consumption is compared with the first mode in which the engine speed is controlled in accordance with the selected shift range, compared to the first mode. Selection means for selecting one of the second mode for controlling the engine speed so that the amount is reduced in accordance with the operation of the driver;
Means for increasing the engine speed during deceleration when the first mode is selected as compared to when the second mode is selected;
A vehicle control device comprising: a recommendation unit for recommending a driver to change from the first mode to the second mode when the first mode is selected.

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