JP6330648B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a technical field of a vehicle control device that controls a vehicle such as an automobile.

  This type of apparatus is disclosed in Patent Document 1. According to the vehicle control device disclosed in Patent Document 1, the output of the electric motor is substantially zero at the time of cruise control in which the vehicle speed is maintained at the target vehicle speed on condition that the vehicle speed is within the steady travel management range. Inertia is performed. Therefore, it is said that kinetic energy can be effectively used for vehicle travel, and fuel efficiency during cruise control can be improved.

JP 2011-239605 A

  From the viewpoint of improving the fuel consumption of the vehicle, it is preferable to increase the number of opportunities for coasting as much as possible. Therefore, it is considered that fuel efficiency can be further improved if coasting can be performed not only during the above-described automatic driving control but also during manual driving control. However, since the acceleration timing depends on the operation of the driver during manual driving, starting the coasting may cause the driver to feel uncomfortable. That is, even if the fuel efficiency can be improved by inertial driving, a technical problem that drivability is reduced due to a change in the vehicle speed not intended by the driver occurs.

  The present invention has been made in view of the above-described problems, for example, and an object of the present invention is to provide a vehicle control device capable of improving fuel efficiency without reducing drivability.

  In order to solve the above-described problem, a vehicle control device according to the present invention is a vehicle control device that controls a vehicle having an automatic driving control mode and a manual driving control mode, and the speed of the vehicle is equal to or lower than a predetermined speed. And when the target drive torque is within a predetermined range, the coasting operation control means for shutting down the internal combustion engine and the rotating electrical machine to perform the coasting operation, and in the case of the automatic operation control mode, the manual operation control mode Compared with the case, the adjusting means for increasing the predetermined speed or widening the predetermined range is provided.

  The vehicle according to the present invention is a hybrid vehicle including an internal combustion engine such as a gasoline engine as a power source and a rotating electric machine such as a motor generator, and includes an automatic operation control mode and a manual operation control mode as travel modes. Specifically, the vehicle according to the present invention has an automatic operation control mode in which the vehicle speed is automatically adjusted according to the vehicle speed of a preceding vehicle, for example, and a manual operation mode in which the vehicle speed is adjusted by the driver's operation. It is configured to be switchable.

  The vehicle control device according to the present invention is a device that controls the vehicle described above, and includes, for example, one or a plurality of CPUs (Central Processing Units), MPUs (Micro Processing Units), various processors or various controllers, or even ROM ( Various processing units such as a single or multiple ECUs (Electronic Controlled Units), various controllers or microcomputers, which can appropriately include various storage means such as read only memory (RAM), random access memory (RAM), buffer memory or flash memory. Various computer systems such as devices can be used.

  During operation of the vehicle control device according to the present invention, the coasting operation control means determines whether or not the vehicle speed is equal to or lower than a predetermined speed and whether or not the target drive torque is within a predetermined range. Here, the “predetermined speed” is a threshold value set in advance to determine that the speed of the vehicle is low enough to perform inertial driving, and the “predetermined range” is a target drive of the vehicle. This is a threshold that is set in advance to determine whether or not the torque is a value that enables inertial running. Specifically, the predetermined speed and the predetermined range indicate, for example, whether the fuel efficiency can be improved efficiently by carrying out inertial running, or whether there is no inconvenience by carrying out inertial running. It is set as a determinable value.

  The coasting operation control means shuts down the internal combustion engine and the rotating electrical machine and performs inertial traveling operation when the speed of the vehicle is equal to or lower than a predetermined speed and the target drive torque is within a predetermined range. Here, “shutdown” means to stop the fuel supply to the engine or to stop the operation of a power control device such as an inverter that electrically drives the rotating electrical machine. Therefore, by shutting down the engine and the rotating electrical machine, fuel consumption and power consumption of the vehicle can be reduced, and fuel consumption can be improved.

  Regarding the implementation of the inertia running described above, in the vehicle control device according to the present invention, in particular, at least one of the predetermined speed and the predetermined range is adjusted by the adjusting means. In other words, the adjusting means changes the conditions for coasting. Specifically, when the vehicle is in the automatic driving control mode, the adjusting means increases the predetermined speed or widens the predetermined range as compared with the case of the manual driving control mode. In other words, the adjusting means lowers the predetermined speed or narrows the predetermined range when the vehicle is in the manual operation control mode as compared with the automatic operation control mode. As a result, inertial traveling is easily performed in the automatic operation control mode, and inertial traveling is difficult to be performed in the manual operation control mode.

  Since inertial running has the effect of improving fuel efficiency as described above, it is preferable that there are as many opportunities as possible. Therefore, it is preferable that inertial running is appropriately performed both in the automatic operation control mode and in the manual operation control mode. However, when the vehicle is traveling in the manual operation control mode, the acceleration timing of the vehicle depends on the operation of the driver, so that the coasting may start, which may cause the driver to feel uncomfortable. There is. That is, drivability may be reduced due to a change in the vehicle speed not intended by the driver.

  However, in the present invention, as described above, inertial traveling is less likely to be performed in the manual operation control mode than in the automatic operation control mode. Therefore, it is possible to suppress a decrease in drivability due to the inertia running being performed in the manual operation control mode. Even in the manual operation control mode, coasting is performed when the vehicle speed is sufficiently low or the target drive torque is in an extremely appropriate range, so that a fuel efficiency improvement effect can be obtained accordingly. .

  On the other hand, in the automatic operation control mode, inertial traveling is more easily performed than in the manual operation control mode. Therefore, in the automatic driving control mode, the opportunity for coasting is increased, and as a result, fuel efficiency can be effectively improved.

  As described above, according to the vehicle control device of the present invention, since the execution condition of inertial traveling is changed according to the traveling mode, it is preferable while avoiding inconveniences that may occur when inertial traveling is performed. It is possible to improve fuel efficiency.

  Such an operation and other advantages of the present invention will become apparent from the embodiments described below.

1 is a schematic configuration diagram conceptually showing a configuration of a hybrid vehicle according to an embodiment. It is a schematic block diagram of the hybrid drive device concerning an embodiment. It is a flowchart which shows the process which determines whether to carry out inertial running. It is a flowchart which shows the process which changes the implementation condition of inertial running.

<Embodiment of the Invention>
Hereinafter, various embodiments of the present invention will be described with reference to the drawings.

<Configuration of Embodiment>
First, the configuration of the hybrid vehicle 1 according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic configuration diagram conceptually showing the configuration of the hybrid vehicle according to the embodiment.

  In FIG. 1, a hybrid vehicle 1 is an example of a “vehicle” according to the present invention that includes an ECU (Electronic Control Unit) 100, a PCU (Power Control Unit) 20, a battery 30, and a hybrid drive device 10. is there.

  The ECU 100 is an electronic control unit that includes a CPU, a ROM, a RAM, and the like and is configured so as to be able to control the operation of each part of the hybrid vehicle 1, and is an example of the “vehicle control device” according to the present invention. The ECU 100 can execute an “inertia travel execution determination process” and an “inertia travel execution condition change process” to be described later according to a control program stored in the ROM.

  The PCU 20 converts DC power extracted from the battery 30 into AC power and supplies it to a motor generator MG1 and a motor generator MG2, which will be described later, and converts AC power generated by the motor generator MG1 and the motor generator MG2 into DC power. Inverter 22 (not shown) configured to be able to be supplied to battery 30, the power input / output between battery 30 and each motor generator, or the power input / output between each motor generator (that is, in this case) The control unit is configured to be capable of controlling power transfer between the motor generators without using the battery 30. The PCU 20 is electrically connected to the ECU 100 and its operation is controlled by the ECU 100.

  The battery 30 is a rechargeable secondary battery unit that functions as a power supply source related to power for powering the motor generator MG1 and the motor generator MG2. The battery 30 has a configuration in which a plurality of unit battery cells such as lithium ion battery cells are connected in series.

  Although illustration is omitted, the hybrid vehicle 1 includes various sensors that detect various state quantities of the hybrid vehicle 1. For example, the various sensors include a vehicle speed sensor that detects the vehicle speed V of the hybrid vehicle 1, an accelerator opening sensor that detects an accelerator opening Ta that is an operation amount of an accelerator pedal, a brake pedal sensor that detects an operation amount of a brake pedal, It includes a battery temperature sensor that detects the temperature of the battery 12, an SOC sensor that detects the SOC of the battery 12, and the like. Each of these sensors is electrically connected to the ECU 100, and the detected various state quantities, control quantities, or physical quantities are appropriately referred to by the ECU 100.

  The hybrid drive device 10 is a power train of the hybrid vehicle 1. Here, the detailed configuration of the hybrid drive apparatus 10 will be described with reference to FIG. FIG. 2 is a schematic configuration diagram conceptually showing the configuration of the hybrid drive apparatus 10. In the figure, the same reference numerals are given to the same portions as those in FIG. 1, and the description thereof will be omitted as appropriate.

  The hybrid drive device 10 includes an engine 200, a power split mechanism 300, an input shaft 400, a drive shaft 500, a speed reduction mechanism 600, a motor generator MG1 (hereinafter referred to as “MG1” where appropriate), a motor generator MG2 (hereinafter referred to as “MG2” as appropriate). For short).

  The engine 200 is a gasoline engine that functions as a main power source of the hybrid vehicle 1 and is an example of the “internal combustion engine” according to the present invention.

  The engine 200 includes a piston that reciprocates inside the cylinder in response to an explosive force generated when the air-fuel mixture burns in a combustion chamber formed inside the cylinder. The reciprocating motion of the piston is converted into the rotational motion of the crankshaft via the connecting rod, and is taken out from the input shaft 400 connected to the crankshaft. Note that the detailed configuration of the engine 200 is omitted here because it has a low relationship with the present invention. Although the engine 200 is a gasoline engine here, there are a wide variety of practical aspects that can be taken by the “internal combustion engine” according to the present invention. For example, the “internal combustion engine” according to the present invention is free in fuel type, cylinder arrangement, number of cylinders, fuel supply mode, valve system configuration, intake / exhaust system configuration, and the like.

  Motor generator MG1 is a motor generator having a power running function that converts electrical energy into kinetic energy and a regeneration function that converts kinetic energy into electrical energy.

  Motor generator MG2 is a motor generator having a larger physique than motor generator MG1, and, like motor generator MG1, has a power running function that converts electrical energy into kinetic energy and a regeneration function that converts kinetic energy into electrical energy. I have.

  The motor generators MG1 and MG2 are configured as synchronous motor generators and include, for example, a rotor having a plurality of permanent magnets on the outer peripheral surface and a stator wound with a three-phase coil that forms a rotating magnetic field. You may have the structure of.

  Motor generators MG1 and MG2 are examples of the “rotary electric machine” according to the present invention.

  The power split mechanism 300 is a known planetary gear mechanism that includes a plurality of rotating elements that have a differential action with respect to each other.

  The power split mechanism 300 is disposed between the sun gear S1 provided at the center, the ring gear R1 provided concentrically on the outer periphery of the sun gear S1, and the sun gear S1 and the ring gear R1. A plurality of pinion gears (not shown) that revolve while rotating, and a carrier C1 that supports the rotation shaft of each pinion gear.

  Sun gear S1 is a reaction force element for bearing reaction torque against engine torque Te, which is output torque of engine 200, and is fixed to an output rotation shaft to which the rotor of motor generator MG1 is fixed. Therefore, the rotational speed of sun gear S1 is equivalent to MG1 rotational speed Nmg1, which is the rotational speed of motor generator MG1.

  The ring gear R1 is an output element of the power split mechanism 300, and is connected to a drive shaft 500, which is a power output shaft of the power split mechanism 300, in a manner sharing its rotational axis. The drive shaft 500 is indirectly connected to the drive wheels DW of the hybrid vehicle 1 through a differential or the like.

  The carrier C1 is connected to the input shaft 400 connected to the crankshaft of the engine 200 via the torsion damper TDP so as to share the rotation shaft, and the rotation speed is equal to the engine speed NE of the engine 200. Is equivalent.

  In the power split mechanism 300, the engine torque Te supplied from the engine 200 to the input shaft 400 is transferred to the sun gear S1 and the ring gear R1 by the carrier C1 with the predetermined ratio (the gear ratio between the gears). It is possible to divide the power of the engine 200 into two systems.

  At this time, in order to make the operation of the power split mechanism 300 easy to understand, when the gear ratio ρ as the number of teeth of the sun gear S1 with respect to the number of teeth of the ring gear R1 is defined, the engine torque Te is applied from the engine 200 to the carrier C1. In this case, the torque Tes acting on the sun gear S1 is expressed by the following equation (1), and the direct torque Ter appearing on the drive shaft 500 is expressed by the following equation (2).

Tes = −Te × ρ / (1 + ρ) (1)
Ter = Te × 1 / (1 + ρ) (2)
Deceleration mechanism 600 is a planetary gear mechanism that includes rotation elements of sun gear S2, ring gear R2, pinion gear (not shown), and carrier C2 interposed between drive shaft 500 and motor generator MG2.

  In reduction mechanism 600, sun gear S2 is fixed to an output rotation shaft fixed to the rotor of motor generator MG2. The carrier C2 is fixed to the outer case of the hybrid drive device 10 so as not to rotate. Further, the ring gear R <b> 2 is connected to the drive shaft 500. In such a configuration, the speed reduction mechanism 600 can transmit the rotational speed Nmg2 of the motor generator MG2 to the drive shaft 500 while reducing the speed according to the speed ratio determined according to the gear ratio of each rotation element (gear).

  It should be noted that the configuration of speed reduction mechanism 600 is merely one form that can be adopted by a mechanism that decelerates the rotation of motor generator MG2, and this type of speed reduction mechanism can have various forms in practice. Further, this type of reduction mechanism is not necessarily provided in the hybrid drive device. That is, motor generator MG2 may be directly connected to drive shaft 500.

<Driving mode of hybrid vehicle>
The hybrid vehicle 1 according to the present embodiment described above includes an automatic operation control mode and a manual operation control mode as travel modes.

  In the automatic driving control mode, for example, the speed of the hybrid vehicle 1 is automatically adjusted (that is, regardless of the driver's operation) based on the distance between the vehicle traveling ahead and other vehicle peripheral information. Is done. Specifically, when the inter-vehicle distance with the preceding vehicle increases, the hybrid vehicle 1 is automatically accelerated and the inter-vehicle distance with the preceding vehicle is reduced. On the other hand, when the inter-vehicle distance with the preceding vehicle decreases, the hybrid vehicle 1 is automatically decelerated and the inter-vehicle distance with the preceding vehicle is increased. Further, when a vehicle traveling on another lane, a pedestrian, another obstacle, or the like is detected, deceleration for avoiding a collision may be performed.

  The hybrid vehicle 1 according to the present embodiment includes, for example, an in-vehicle camera, a millimeter wave radar, a communication device, and the like (all not shown) in order to realize the above-described automatic driving control mode.

  In the manual operation control mode, the speed of the hybrid vehicle 1 changes according to the driver's operation as usual. Specifically, acceleration / deceleration of the hybrid vehicle 1 is realized based on the operation amount of the accelerator pedal and the brake pedal by the driver. Even in the manual operation control mode, automatic speed adjustment that does not depend on the driver's operation may be performed.

  The automatic operation control mode and the manual operation control mode are switched to each other by, for example, an on / off operation of a switch by the driver. However, the automatic operation control mode and the manual operation control mode may be automatically switched based on the traveling state of the hybrid vehicle 1 or the like.

  Further, the hybrid vehicle 1 according to the present embodiment can perform inertial traveling while traveling in the automatic operation control mode and the manual operation control mode. Inertia traveling is realized by shutting down engine 200 and motor generators MG1 and MG2. During inertial running, fuel supply to engine 200 is stopped, and operation of a power control device such as an inverter that electrically drives motor generators MG1 and MG2 is stopped. For this reason, by performing inertial running, fuel consumption and power consumption of the hybrid vehicle 1 can be reduced, and fuel consumption can be improved.

<Inertia travel execution determination process>
Below, with reference to FIG. 3, the inertia running execution determination process (namely, the process which determines whether to perform inertia driving) by the vehicle control apparatus which concerns on this embodiment is demonstrated. FIG. 3 is a flowchart showing a process for determining whether or not to carry out inertial running.

  In FIG. 3, when the hybrid vehicle 1 travels, the vehicle speed is detected by a vehicle speed sensor or the like and input to the ECU 100 (step S101). The ECU 100 calculates the target drive torque based on the detected vehicle speed and the driver's accelerator pedal operation amount or the target vehicle speed range in the automatic driving control (step S102).

  Subsequently, the ECU 100 determines whether or not the vehicle speed is equal to or less than a predetermined threshold value (step S103). If it is determined that the vehicle speed is equal to or lower than the predetermined threshold (step S103: YES), it is determined whether or not the target drive torque is within a predetermined range (step S104). If it is determined that the vehicle speed is not less than or equal to the predetermined threshold (step S103: NO), or if it is determined that the target drive torque is not within the predetermined range (step S104: NO), the subsequent processing is omitted.

  On the other hand, when it is determined that the target drive torque is not within the predetermined range (step S104: YES), inertial running is performed. That is, inertial running is performed when the vehicle speed of the hybrid vehicle 1 is equal to or lower than a predetermined value and the target drive torque is within a predetermined range. Thus, if inertial running is performed based on a predetermined condition, the fuel consumption of the hybrid vehicle 1 can be improved efficiently.

<Problems of coasting>
Since inertial running has the effect of improving fuel efficiency as described above, it is preferable that there are as many opportunities as possible. Here, in the automatic driving control mode, since the acceleration / deceleration of the hybrid vehicle 1 is automatically executed, even if coasting is performed, the driver feels little or no sense of incongruity. However, in the manual operation control mode, since the acceleration / deceleration timing of the hybrid vehicle 1 depends on the operation of the driver, the driver may feel uncomfortable depending on the timing at which inertial traveling is started. . That is, drivability may be reduced due to a change in the vehicle speed not intended by the driver.

  In order to solve such a problem, the vehicle control device according to the present embodiment changes the conditions for carrying out inertial running according to the running mode.

<Inertia running condition change process>
Below, with reference to FIG. 4, the inertia running condition changing process (namely, the process which changes the inertia driving condition) by the vehicle control apparatus which concerns on this embodiment is demonstrated. FIG. 4 is a flowchart showing the process of changing the coasting condition.

  In FIG. 4, when the inertia running condition changing process is started, it is first determined whether or not the running mode of the hybrid vehicle 1 is the automatic driving control mode (step S201). That is, it is determined whether the travel mode is the automatic operation control mode or the manual operation control mode.

  If it is determined that the travel mode is the automatic operation control mode (step S201: YES), a predetermined threshold value that is an inertia travel execution condition for the vehicle speed is set high (step S202), and the inertia travel execution condition for the target drive torque is set. The predetermined range is set wide (step S203). On the other hand, when it is determined that the travel mode is the manual operation control mode (step S201: NO), a predetermined threshold value that is an inertial travel execution condition with respect to the vehicle speed is set low (step S204), and inertial travel is performed with respect to the target drive torque. The predetermined range as a condition is set narrow (step S205).

  Typically, the predetermined threshold in the automatic operation control mode is A, the lower limit of the predetermined range is B, the upper limit is C, the predetermined threshold in the manual operation control mode is D, the lower limit of the predetermined range is E, and the upper limit Assuming that the value is F, each value is set so that the relationship of A> D and B <E <F <C is established.

  By the condition change described above, inertial traveling is more easily performed in the automatic operation control mode than in the manual operation control mode. In other words, coasting is less likely to be performed in the manual operation control mode than in the automatic operation control mode. Therefore, it is possible to suppress a decrease in drivability due to the inertia running being performed in the manual operation control mode. Even in the manual operation control mode, coasting is performed when the vehicle speed is sufficiently low or the target drive torque is within an extremely appropriate range, so that a fuel efficiency improvement effect can be obtained accordingly. Moreover, in the automatic driving control mode, the chance of coasting is increased, and as a result, fuel efficiency can be effectively improved.

  In addition, in order to enhance the effect of the above-described change in the running condition of inertia traveling, the predetermined threshold value and the predetermined range in each traveling mode may be set as more appropriate values. Specifically, for example, a value that maximizes the fuel efficiency improvement or a value that can most suppress the decrease in drivability may be obtained and set by, for example, prior simulation.

  As described above, according to the vehicle control device according to the present embodiment, the conditions for coasting are changed according to the travel mode. Therefore, it is possible to suitably improve fuel efficiency while avoiding inconvenience that may occur when coasting is performed.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification. A vehicle control apparatus that includes such a change is also applicable. Moreover, it is included in the technical scope of the present invention.

1 Hybrid vehicle 10 Hybrid drive unit 20 PCU
30 battery 100 ECU
200 Engine 300 Power split mechanism 400 Input shaft 500 Drive shaft 600 Deceleration mechanism DW Drive wheel MG1, MG2 Motor generator TDP Torsion damper

Claims (1)

A vehicle control device for controlling a vehicle having an automatic operation control mode and a manual operation control mode,
Coasting operation control means for shutting down the internal combustion engine and the rotating electrical machine and performing coasting driving operation when the speed of the vehicle is equal to or lower than a predetermined speed and the target drive torque is within a predetermined range;
In the case of the automatic driving control mode, the vehicle control device further comprises adjusting means for increasing the predetermined speed or widening the predetermined range as compared with the case of the manual driving control mode.

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