JP2017124719A - Vehicle control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle control device capable of improving fuel efficiency in a hybrid vehicle.SOLUTION: A vehicle control device comprises: a congestion section detection part 114 for detecting a congestion section in a travel direction of an own vehicle; a target setting part 116 for setting a target charge ratio of a secondary battery 126 to a specific target charge ratio at a start point of the congestion section, and setting the target charge ratio to an ordinary basic target charge ratio after passing an end point of the congestion section; a sensor unit 108 for detecting an accelerator opening; and a charge ratio control part 124 for controlling an engine 120 and a motor 122 on the basis of the target charge ratio of the secondary battery 126. The charge ratio control part 124 drives the engine on the basis of the specific target charge ratio when the accelerator opening exceeds a first accelerator opening, in a section from the start point of the congestion section to the start point of the congestion section, and drives the engine 120 on the basis of the specific target charge ratio when the accelerator opening exceeds a second accelerator opening which is larger than an accelerator opening α, in a section from the start point of the congestion section to the end point of the congestion section.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a vehicle control device used for a hybrid vehicle.

  A hybrid vehicle has two types of drive sources, an engine and a motor. The motor converts the electric energy of the secondary battery (battery) into driving force. When the vehicle runs on a road surface that is inclined downward, the rotation of the axle is transmitted to the motor, and the secondary battery can be charged by the electromotive force of the motor. In addition to providing driving force, the engine can also charge the secondary battery.

  A large change in the state of charge (SOC) of the secondary battery deteriorates the secondary battery. For this reason, normally, a lower limit value and an upper limit value are set for the SOC, and charge / discharge control is performed so that the SOC falls within a range between the upper limit value and the lower limit value (hereinafter referred to as “allowable range”).

  In Patent Document 1, when there is a traffic jam section at the travel destination, the target charging rate of the secondary battery is increased from a certain point before the traffic jam section to the start point of the traffic jam section. Increasing the target charging rate and actively driving the engine and increasing the SOC before entering the charging section makes it difficult for the SOC to reach the lower limit in the traffic jam section and prevent forced charging from occurring.

JP 2014-15125 A

  In the technique described in Patent Document 1, when the vehicle enters a traffic jam section, the low-speed electric traveling is performed, so that the SOC gradually decreases. For this reason, it is considered that the SOC easily reaches the lower limit value in the traffic jam section. When the SOC reaches the lower limit value, it becomes necessary to drive the engine and perform forced charging.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a vehicle control device capable of improving fuel efficiency in a hybrid vehicle.

  In order to solve the above-described problems, a vehicle control apparatus according to an aspect of the present invention includes an engine, a motor, and a secondary battery that supplies power to the motor, and charges the secondary battery with an electromotive force generated by the engine. From a prediction unit that is mounted on a hybrid vehicle capable of predicting the travel route of the host vehicle, a traffic jam section detection unit that detects a traffic jam section in the traveling direction of the host vehicle, and a start point of the traffic jam section Also, the target charging rate of the secondary battery is set to a value higher than the target charging rate at the normal time at a point in front of the predetermined distance, and the target charging rate of the secondary battery is normally set at a point after the end point of the traffic jam section. A target setting unit for setting the target charging rate at the time, an accelerator opening detecting unit for detecting the accelerator opening, and controlling the engine and motor based on the target charging rate of the secondary battery And a, and a charge rate controller for controlling the charging rate of the secondary battery. When the accelerator opening exceeds the first accelerator opening between the point just before the predetermined distance from the start point of the traffic jam section and the start point of the traffic jam section, the charging rate control unit is higher than normal. The engine is driven based on the target charging rate set to, and the accelerator opening exceeds the second accelerator opening that is larger than the first accelerator opening between the start point of the congestion section and the end point of the congestion section. And the engine is driven based on a target charging rate set to a value higher than normal.

  According to this aspect, since the engine is actively driven in the traffic jam section in addition to the section before the traffic jam section, the SOC hardly reaches the lower limit value in the traffic jam section. Therefore, forced charging is less likely to occur in a traffic jam section. Further, in the traffic jam section, the accelerator opening condition for driving the engine to perform charging becomes stricter than in the section before the traffic jam section, so that the engine can be prevented from being driven more than necessary. That is, according to the above-described aspect, fuel efficiency can be improved.

  ADVANTAGE OF THE INVENTION According to this invention, the vehicle control apparatus which can improve a fuel consumption efficiency can be provided.

It is a schematic diagram for demonstrating the charging rate control method of a traffic congestion area. It is a functional block diagram of a vehicle control system. It is a flowchart which shows the process by a vehicle control apparatus. It is a flowchart which shows the charging process at the time of traffic jam.

(Embodiment)
An outline of the vehicle control device according to the embodiment will be described.
FIG. 1 is a schematic diagram for explaining a charging rate control method in a traffic jam section by the vehicle control device. The upper part of FIG. 1 shows a traffic jam section on a travel route planned by the vehicle 100. The vehicle control device acquires traffic jam information from the car navigation system. In the car navigation system, the travel route is divided and managed into a plurality of sections (section 0 to section 7 in FIG. 1). Assume that vehicle 100 is traveling in section 0. Assume that sections 3 to 6 are traffic jam sections. The lower part of FIG. 1 shows a change in SOC (charge rate of the secondary battery). The SOC has a minimum value of 0% and a maximum value of 100%. An allowable range is set for the SOC. The allowable range is a range from the lower limit value CD to the upper limit value CU. Specifically, the lower limit value CD = 40% and the upper limit value CU = 60% are assumed. The target charging rate is set within this allowable range. Usually, the target charging rate is set to an average value CM of the lower limit value CD and the upper limit value CU, generally about 50%. Hereinafter, the target charging rate at the normal time is referred to as “basic target charging rate”.

  In the traffic jam section, the vehicle 100 runs at a low speed. For this reason, electric travel is usually prioritized and the SOC is likely to decrease. On the other hand, at the beginning, the target charging rate is initially fixed at the basic target charging rate, and a point (a boundary point between the section 2 and the section 3 in the case of FIG. 1) a point before a predetermined distance (in FIG. 1) In the case of FIG. 1, the target charge rate is raised to the upper limit value CU at the boundary point between the zone 0 and the zone 1 (hereinafter, the target charge rate temporarily raised to the upper limit value CU is referred to as “special eye standard power rate”). A charging rate control method for returning the target charging rate to the basic target charging rate at the start point of the traffic jam section has been proposed. SOC-P1 indicates a change in SOC at this time. In this control method, the engine is actively driven before entering the traffic jam section, and the SOC-P1 is raised before entering the traffic jam section. However, when the vehicle enters the section 3 (congested section), the SOC-P1 gradually decreases because of low-speed electric traveling. For this reason, SOC-P1 easily reaches the lower limit value CD in the traffic jam section. When SOC-P1 reaches the lower limit value CD, it is necessary to drive the engine and perform forced charging.

  On the other hand, in the present embodiment, the target charging rate remains at the special target charging rate without returning the target charging rate to the basic target charging rate at the starting point of the charging interval, and the end point of the congestion interval (see FIG. 1). In this case, the target charging rate is returned to the basic target charging rate at a boundary point between the section 6 and the section 7) or at a point immediately after that. SOC-P2 indicates a change in the SOC at this time. In this control method, since the engine is actively driven even after entering the charging section, it is possible to suppress the decrease in SOC-P2 to the extent that the lower limit value CD is not reached, that is, to the extent that forced charging does not occur. Hereinafter, a section in which the target charging rate is set to the special target charging rate, specifically, a section from a point a predetermined distance before the start point of the traffic jam section to the end point of the traffic jam section (section 1 in the case of FIG. 1). ~ 6) is called "traffic control section". In addition, actively driving the engine in a traffic jam control section is called “charge processing during traffic jam”.

  Here, in the traffic jam section, it is sufficient that the SOC-P2 does not reach the lower limit CD, and it is not necessary to raise the SOC-P2. If the engine is driven more than necessary in a traffic jam section, fuel efficiency will be reduced. Therefore, in this embodiment, in the traffic jam control section after entering the traffic jam section (sections 3 to 6 in the case of FIG. 1), the traffic jam control section before entering the traffic jam section (sections 1 to 2 in the case of FIG. 1). ), The condition regarding the accelerator opening, which is a condition for driving the engine to execute charging, is made stricter. This will be specifically described below.

  FIG. 2 is a functional block diagram of the vehicle control system 106. Each component of the vehicle control system 106 is centered on an arbitrary computer CPU, memory, a program that realizes the components shown in the figure loaded in the memory, a storage unit such as a hard disk for storing the program, and a network connection interface. It is realized by any combination of hardware and software. It will be understood by those skilled in the art that there are various modifications to the implementation method and apparatus.

  The vehicle control system 106 includes a vehicle control device 128, a sensor unit 108, a car navigation system 110, an engine 120, a motor 122, and a secondary battery 126. The sensor unit 108 detects information related to the external environment and the traveling track of the host vehicle. The sensor unit 108 includes an accelerator opening sensor, a steering angle sensor, and a vehicle speed sensor. The sensor unit 108 transmits the detected information to the vehicle control device 128.

  The car navigation system 110 identifies a section during traveling or a destination by comparing map information in a database and position information obtained from GPS (Global Positioning System). In addition, the car navigation system 110 acquires traffic jam information from VICS (Vehicle Information and Communication System) (registered trademark) or the like.

  The secondary battery 126 is a lithium ion secondary battery (storage battery). The vehicle control device 128 controls the SOC of the secondary battery 126 by controlling the engine 120 and the motor 122.

  The vehicle control device 128 includes a prediction unit 112, a traffic jam section detection unit 114, a target setting unit 116, a condition setting unit 118, and a charging rate control unit 124. Each functional block of the vehicle control device 128 in the present embodiment is configured by an ECU (Electronic Control Unit) and a software program executed thereon.

  The prediction unit 112 predicts the travel route of the vehicle 100 from information such as the vehicle speed and the steering angle from the sensor unit 108 and route setting information in the car navigation system 110. The traffic jam section detection unit 114 periodically acquires (pre-reads) information on not only the section being traveled but also the section on which travel is predicted from the car navigation system 110. The traffic jam section detection unit 114 detects information such as the presence / absence of a traffic jam section and its length. The target setting unit 116 sets a target charging rate according to the presence or absence of a traffic jam section. The target setting unit 116 sets the basic target charging rate as the target charging rate at the normal time, and sets the special target charging rate (upper limit value UD) as the target charging rate in the traffic jam control section.

  The condition setting unit 118 sets an accelerator opening condition for driving the engine 120 to charge the secondary battery. The condition setting unit 118 sets the accelerator opening α in the accelerator opening condition in the traffic jam control section before entering the traffic jam section, and opens a relatively high accelerator opening condition in the traffic jam control section after entering the traffic jam section. The degree β (> accelerator opening α) is set. That is, in the traffic jam control section after entering the traffic jam section, the accelerator opening condition for executing charging is made stricter than in the traffic jam control section before entering the traffic jam section.

  The charging rate control unit 124 controls the SOC of the secondary battery 126 by controlling the engine 120 and the motor 122 based on the target charging rate set by the target setting unit 116 and the accelerator opening condition set by the condition setting unit 118. Control. Specifically, the charging rate control unit 124 normally controls the engine 120 and the motor 122 so that the SOC approaches the basic target charging rate, and in the traffic jam control section, the engine 120 causes the SOC to approach the special target charging rate. And controls the motor 122. The charge rate control unit 124 drives the engine 120 when the accelerator opening of the vehicle 100 exceeds the accelerator opening α, particularly in the traffic control section before entering the traffic section (sections 1 and 2 in the case of FIG. 1). When the accelerator opening of the vehicle 100 exceeds the accelerator opening β in the traffic congestion control section (section 3 to 6 in the case of FIG. 2) after providing the driving force and charging the secondary battery and entering the traffic congestion section. The engine 120 is driven to provide a driving force and control to charge the secondary battery.

  FIG. 3 is a flowchart showing processing by the vehicle control device 128. The process shown in FIG. 3 is a loop process that is repeatedly executed at regular intervals, for example, every several milliseconds.

  The traffic jam section detection unit 114 determines whether or not a traffic jam section having a certain length (for example, 500 m) or longer exists on the travel route on the travel route predicted by the prediction unit 112 (S10). When such a traffic jam section does not exist (N in S10), the following processing is not executed and the next execution timing is awaited. When there is a traffic jam section (Y in S10), the target setting unit 116 determines the start point of the traffic jam control section (that is, a spot a predetermined distance before the start point of the traffic jam section) (S12). The target setting unit 116 may determine the start point of the traffic jam control section so that the SOC increases to the special target charging rate when the vehicle 100 travels from the start point of the traffic jam control section to the start point of the traffic jam section. FIG. 1 shows a case where the boundary point between the section 2 and the section 3 is determined as the start point of the congestion control section.

  If the vehicle 100 has not reached the start point of the traffic jam control section (N in S14), the process waits in S14. When the vehicle 100 reaches the start point of the traffic jam control section (Y in S14), the vehicle control device 128 executes a traffic jam charging process (S16). The charging process at the time of traffic jam in S16 will be described later with reference to FIG.

  As long as the vehicle 100 has not reached the end point of the traffic jam control section (that is, the end point of the traffic jam section) (N in S18), the charging process during the traffic jam continues. When the vehicle 100 reaches the end point of the traffic congestion section (Y in S18), the charging process at the time of traffic congestion is completed, and once the processing is completed, it waits until the next execution timing. Note that when the vehicle 100 reaches the destination, the charge control function is turned off, or the power is turned off, the loop process of FIG. 3 ends.

  FIG. 4 is a flowchart showing a charging process in a traffic jam. FIG. 4 corresponds to S16 of FIG. The target setting unit 116 sets the target charging rate to a special target charging rate (upper limit UD) that is higher than the basic target charging rate (S20). If the vehicle 100 has not reached the start point of the traffic jam section (N in S22), the condition setting unit 118 sets the accelerator opening α to the accelerator opening condition (S24). When the vehicle 100 reaches the start point of the traffic jam section (Y in S22), the condition setting unit 118 sets the accelerator opening β (> accelerator opening α) as the accelerator opening condition (S26). In the present embodiment, condition setting unit 118 determines whether or not the traffic congestion section has been reached based on the traffic congestion information of the traveling section acquired from car navigation system 110. The charging rate control unit 124 controls the engine 120 and the motor 122 based on the special target charging rate and the accelerator opening condition.

  According to the vehicle control device 128 according to the present embodiment described above, the special target charging rate is set as the target charging rate even in a traffic jam section. That is, even in a traffic jam section, the engine can be actively driven to suppress the decrease in SOC. This makes it difficult for forced charging to occur in a traffic jam section. In a traffic jam section, conditions for executing charging are set to be relatively strict, so that driving the engine more than necessary can be suppressed. That is, according to the vehicle control device 128 according to the present embodiment, fuel efficiency can be improved.

  In the above, this invention was demonstrated based on the Example. The embodiments are merely examples, and it will be understood by those skilled in the art that various modifications can be made to the combination of each component and each processing process, and such modifications are within the scope of the present invention.

(Modification)
In the embodiment, the case has been described in which the vehicle control device 128 determines whether or not the vehicle has reached the traffic jam section based on the traffic jam information of the running segment acquired from the car navigation system 110. In this case, the vehicle control device 128 determines that the vehicle is not traveling in the traffic congestion section while traveling in a relatively short non-congestion section sandwiched between the traffic congestion sections. On the other hand, in this modification, when the length of the non-congested section sandwiched between the congested sections is a predetermined length (for example, 200 m) or less, that is, when the non-congested section sandwiched between the congested sections is relatively short, A non-congested section and a congested section sandwiching the non-congested section may be handled as a group of congested sections. For example, according to the traffic jam information acquired from the car navigation system 110, if the zones 3, 4, and 6 are traffic jam zones and the zone 5 is a non-jamm traffic zone, if the length of the zone 5 is 200 m or less, the zones 3 to 6 Treat as a congested section of traffic. In this case, when the vehicle 100 is traveling in the section 5, the vehicle control device 128 determines that the vehicle 100 is traveling in the traffic jam section.

DESCRIPTION OF SYMBOLS 100 ... Vehicle, 106 ... Vehicle control system, 108 ... Sensor unit, 110 ... Car navigation system, 112 ... Prediction part, 114 ... Congestion area detection part, 116 ... Target setting part, 118 ... Condition setting part, 120 ... Engine, 122 ... Motor, 124 ... Charge rate control unit, 126 ... Secondary battery, 128 ... Vehicle control device.

Claims (1)

An engine, a motor, and a secondary battery for supplying electric power to the motor; and mounted on a hybrid vehicle capable of charging the secondary battery by an electromotive force generated by the engine;
A prediction unit for predicting the traveling route of the host vehicle;
In the predicted travel route, a traffic jam section detection unit that detects a traffic jam section in the traveling direction of the host vehicle,
The target charge rate of the secondary battery is set to a value higher than the target charge rate at the normal time at a point a predetermined distance before the start point of the traffic jam section, and the secondary battery at a point after the end point of the traffic jam section A target setting unit that sets the target charging rate of to the normal target charging rate,
An accelerator position detector for detecting the accelerator position;
A charge rate control unit that controls the charge rate of the secondary battery by controlling the engine and the motor based on the target charge rate of the secondary battery, and
When the accelerator opening exceeds the first accelerator opening between the point before the predetermined distance from the start point of the traffic jam section and the start point of the traffic jam section, the charge rate control unit is higher than normal. The engine is driven based on the target charging rate set to, and the accelerator opening exceeds the second accelerator opening that is larger than the first accelerator opening between the start point of the congestion section and the end point of the congestion section. And a vehicle control device that drives the engine based on a target charging rate set to a value higher than normal.

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