JP2019055607A - Vehicle control device - Google Patents

Abstract

To provide a vehicle control device which can reduce execution frequency of forced charge control in a vehicle capable of controlling low state of charge (SOC).SOLUTION: A target charge rate adjustment unit acquires history information of the forced charge control in an execution period of the low SOC control and adjusts the target charge rate of a battery on the basis of the history information of the acquired forced charge control when a vehicle arrives at a point of predetermined distance short of destination. Thereby, it inhibits the low SOC control when the vehicle arrives at the point (step ST14) if the execution frequency of the forced charge control is high as the history (determination NO is provided at step ST9) and then maintains the target charge rate of the battery highly and can restrain fuel consumption rate from being deteriorated by lowering the execution frequency of the forced charge control.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a vehicle control device. In particular, the present invention relates to an improvement in control for adjusting a target charging rate of a secondary battery (battery) in a hybrid vehicle.

  2. Description of the Related Art Conventionally, for example, in a hybrid vehicle including an internal combustion engine (engine) and an electric motor as a driving power source, the electric motor generates driving power by receiving electric energy of a battery. Further, the engine not only generates the driving force for driving, but also converts the generated power into electric power as necessary (for example, according to the state of charge (SOC) of the battery) to charge the battery. It has become.

  In the hybrid vehicle, the warm-up operation of the engine is actively performed during cold start. Hereinafter, the engine running (running with driving of the engine) also serving as warm-up operation is referred to as “cold running”.

  In view of the fuel consumption rate, it is preferable that the power generated by the engine during cold running can be effectively converted into electric power so that the battery can be charged. That is, it is preferable to sufficiently enjoy the cold charging effect. However, in a situation where the SOC at the time of starting cold running is already sufficiently high, the cold charging effect will be limited.

  In view of this point, in Patent Document 1, the target charge rate of the battery is changed to a value lower than the normal target charge rate when the vehicle reaches a point a predetermined distance before the parking point (destination) of the vehicle. And it is disclosed that by setting the SOC at the time of the next cold running low, the cold charging effect at the time of the cold running can be fully enjoyed. Hereinafter, this control is referred to as low SOC control.

JP 2017-81416 A

  However, in the technique disclosed in Patent Document 1, a parking point from a point a predetermined distance before the parking point of the vehicle (a point where the target charging rate of the battery is changed to a value lower than the target charging rate at the normal time). Depending on the road environment (for example, a traffic jam situation) that affects the traveling state of the vehicle until then, the SOC may become too low. In this case, forced charging control for forcibly driving the engine to increase the SOC of the battery is performed by the time the vehicle reaches the parking spot, which may lead to deterioration of the fuel consumption rate. That is, there is a possibility that the control for improving the fuel consumption rate (the low SOC control) may be a factor that deteriorates the fuel consumption rate.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a vehicle control device capable of reducing the frequency (occurrence frequency) of forced charge control in a vehicle capable of low SOC control. Is to provide.

  In order to achieve the above object, the solution means of the present invention includes an internal combustion engine, an electric motor, and a secondary that is charged with electric power converted from power generated by the internal combustion engine and supplies electric power to the electric motor. A battery is provided, and the target charging rate of the secondary battery is set to a low value when the vehicle reaches a point a predetermined distance before the parking point where the parking time is predicted to be longer than a predetermined threshold in the vehicle travel route. It is assumed that the vehicle control device capable of low SOC control is changed to The vehicle control device acquires history information of forced charging control in which the internal combustion engine is forcibly driven to charge the secondary battery during execution of the low SOC control, and the acquired forced charging is performed. A target charging rate adjustment unit that adjusts a target charging rate of the secondary battery when a vehicle reaches a point a predetermined distance before the parking point based on control history information is provided. .

  By this specific matter, history information of forced charging control of the internal combustion engine (forced charging control in which the internal combustion engine is forcibly driven to charge the secondary battery) during execution of the low SOC control is acquired. Then, based on the acquired history information of forced charging control, the target charging rate of the secondary battery when the vehicle reaches a point a predetermined distance before the parking point is adjusted. For example, when the execution frequency of forced charging control is low as the history, the target charging rate of the secondary battery when the vehicle reaches the point is lowered, and the cold charging effect at the next cold running is sufficiently To improve the fuel consumption rate (by increasing the battery charging efficiency). On the other hand, when the execution frequency of the forced charging control is high as the history, the target charging rate of the secondary battery when the vehicle reaches the point is maintained high, and the forced charging is caused by the SOC becoming too low. The deterioration of the fuel consumption rate is suppressed by reducing the execution frequency of the charge control.

  In the present invention, history information of forced charging control during execution of low SOC control is acquired, and when the vehicle reaches a point a predetermined distance before the parking spot based on the acquired history information of forced charging control. The target charging rate of the secondary battery is adjusted. Thereby, when the execution frequency of forced charge control is high as the history, the target charge rate of the secondary battery when the vehicle reaches the point is maintained high, and the execution frequency of forced charge control is reduced. The deterioration of the fuel consumption rate can be suppressed.

It is a figure which shows an example of the relationship between the driving | running | working position of a vehicle and SOC in the case of performing cold driving | running | working. It is a functional block diagram of a vehicle control system. It is a schematic diagram for demonstrating a route prediction method. It is a figure which shows frequency distribution of the parking time of the point B. FIG. It is a figure which shows frequency distribution of the parking time of the point C. FIG. It is a flowchart figure which shows the process sequence of the destination specific process in 1st Embodiment, and the process procedure of target charging rate adjustment control. FIG. 7A shows a change in the forced charge flag during vehicle travel, FIG. 7B shows a change in the forced charge probability, FIG. 7C shows an execution period of the low SOC control in the embodiment, and FIG. d) is a diagram showing an execution period of low SOC control in the prior art. It is a figure which shows an example of the execution frequency of forced charge control in each of a destination, a day of the week, and a time zone, and a forced charge probability. It is a flowchart figure which shows the process sequence of the target charging rate adjustment control in 2nd Embodiment. It is a flowchart figure which shows the process sequence of the target charging rate adjustment control in 3rd Embodiment. FIG. 11A is a diagram showing a change in the forced charging flag when the vehicle is traveling, and FIG. 11B is a diagram showing a transition of the SOC control center value.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. This embodiment demonstrates the case where this invention is applied to the hybrid vehicle provided with the internal combustion engine (engine) and the electric motor as driving | running | working driving force sources.

(First embodiment)
-Outline of low SOC control-
First, before describing the features of the present embodiment, an outline of control (low SOC control) premised on the present embodiment will be described.

  FIG. 1 is a diagram illustrating an example of a relationship between a traveling position of a vehicle and an SOC (battery charging rate) when performing cold traveling. The upper part of FIG. 1 shows the travel route of the vehicle 100. The lower part of FIG. 1 shows the change in SOC.

  As shown in FIG. 1, it is assumed that vehicle 100 leaves point S at time t0, reaches point P1 at time t1, reaches point P2 at time t2, and reaches point G at time t3. Point S is the departure point and point G is the destination. It is assumed that the point S to the point P1 is a cold travel section (hereinafter simply referred to as “cold section”).

  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 defined by the lower limit value CD and the upper limit value CU. The lower limit value CD is, for example, about 40%, and the upper limit value CU is, for example, about 80%.

  The target charging rate is set within this allowable range. Hereinafter, the target charge rate at the normal time is referred to as “basic target charge rate”. The basic target charging rate CM in this embodiment is about 65%.

Hereinafter, when the target charging rate is fixed to the basic target charging rate CM (conventional general method), and when the target charging rate is variable (method in low SOC control, which is the control premised in the present embodiment) ) Will be described in the cold running state.
(1) When the target charging rate is fixed When the target charging rate is fixed, the target charging rate is fixed to the basic target charging rate CM between the lower limit value CD and the upper limit value CU. It is SOC-P1 in FIG. 1 which shows the change of SOC in this system. In this case, charge / discharge control is performed so that SOC-P1 is maintained near the basic target charge rate CM. When the engine is cold-started and the vehicle 100 starts traveling from the point S, the vehicle 100 travels cold for a while, that is, travels with driving of the engine. At this time, the engine rotates not only the tire but also an electric motor (hereinafter sometimes simply referred to as a motor). Since the motor functions as a generator, cold charging can be performed. That is, if the SOC is lower than the target charging rate (basic target charging rate CM), cold charging is performed. In the case of FIG. 1, since SOC-P1 is in the vicinity of the basic target charging rate CM at time t0, the cold charging effect is hardly enjoyed.
(2) When the target charging rate is variable When the low SOC control is performed with the target charging rate being variable, at point S, the target charging rate is the basic target charging rate CM between the lower limit value CD and the upper limit value CU. The point set to is the same as in the case of (1). However, the point is that the SOC is lowered to near the lower limit CD at the point S. Details of the method of reducing the SOC at the point S will be described later. The SOC-P2 in FIG. 1 shows the change in SOC in this method. In this case, charge / discharge control is performed so that SOC-P2 is maintained near the basic target charge rate CM. When the engine is cold-started and the vehicle 100 starts traveling from the point S, the SOC-P2 rises until the basic target charging rate CM is reached by cold charging. Since the SOC at the start of cold running is sufficiently lower than the basic target charging rate CM, the cold charging effect can be fully enjoyed. Further, since the engine can be loaded by cold charging, there is an effect that warming up of the engine is promoted.

  In order to sufficiently reduce the SOC at the point S, a technique for predicting the start point of the next cold running, that is, the destination (point G) is required. Therefore, the vehicle 100 predicts the point G by a method described later, and lowers the target charging rate to the vicinity of the lower limit value CD at a point P2 that is a predetermined distance before the point G. The target charging rate at this time is referred to as “special target charging rate”. The point P2 is referred to as a “discharge point”.

  That is, the vehicle 100 predicts the point G during traveling, and sets the discharge point P2 before the predetermined distance. When the vehicle 100 reaches the discharge point P2, the target charging rate is reduced from the basic target charging rate CM to the special target charging rate (near the lower limit CD). After reaching the discharge point P2, since the electric energy is positively used as the driving force, the SOC-P2 rapidly decreases. As a result, when the vehicle 100 reaches the point G, the SOC-P2 is lowered to near the lower limit value CD. When the vehicle 100 restarts from the point G (restarts cold running), the target charging rate is returned to the basic target charging rate CM. At point G, SOC-P2 decreases to near the lower limit value CD, so that the cold charging effect can be fully enjoyed when restarting from point G. Easily enjoying the cold charging effect leads to an improvement in fuel consumption rate (fuel saving).

  The above is the outline of the low SOC control which is the control premised on the present embodiment.

  However, a road environment that affects the traveling state of the vehicle 100 between a point (discharge point P2) and a destination (point G) a predetermined distance before the destination (point G) of the vehicle 100 in this way (for example, The SOC may become too low depending on traffic conditions. In this case, forced charging control for forcibly driving the engine to increase the SOC of the battery is performed before the vehicle 100 reaches the destination (point G), leading to a deterioration in the fuel consumption rate. There is a fear.

  In view of this point, in this embodiment, in the vehicle capable of the low SOC control, it is possible to suppress the deterioration of the fuel consumption rate by reducing the execution frequency of the forced charging control. This will be specifically described below.

-Vehicle control system-
FIG. 2 is a functional block diagram of the vehicle control system 102 in the present embodiment.

  Each component of the vehicle control system 102 is centered on an arbitrary computer CPU, memory, a program for realizing 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.

  In the vehicle control system 102, the vehicle control device 104 and the management center 128 are connected via a communication network 138. The vehicle control device 104 is an electronic control device mounted on the vehicle 100. The management center 128 is a server that collects information from each vehicle control device 104 of each of the plurality of vehicles 100, analyzes the information, and sends instructions.

  The vehicle control device 104 is connected to the sensor unit 106, the car navigation system 108, the engine 110, the motor 112, the battery control unit 114, and the battery 116. The sensor unit 106 collects information related to the external environment and the traveling track of the vehicle 100. The sensor unit 106 may include a steering angle sensor, a yaw rate sensor, a wheel pulse sensor, a radar, a direction indicator, and the like.

  The battery 116 is a lithium ion secondary battery (storage battery). The battery control unit 114 controls the SOC of the battery 116 by controlling the engine 110 and the motor 112. The vehicle control device 104 instructs the target charge rate to the battery control unit 114. As described above, the normal target charging rate is set to the basic target charging rate CM, and is set to a lower special target charging rate (near the lower limit value CD) as necessary.

  Each functional block of the vehicle control device 104 in the present embodiment is configured by an ECU (Electronic Control Unit) and a software program executed thereon.

  The vehicle control device 104 includes a communication unit 118, a recording unit 120, a position detection unit 122, a prediction unit 124, and a target setting unit 126.

  The position detection unit 122 acquires various sensing information from the sensor unit 106 and current position information of the vehicle 100 from the car navigation system 108. The recording unit 120 appropriately records sensed information (hereinafter referred to as “primary information”) such as the current position, stop time, start time, and vehicle speed of the vehicle. The stop time is the time when the engine 110 is instructed to stop, and the start time is the time when the engine 110 is instructed to start. The recording unit 120 also records information on whether or not the timing at which the start of the engine 110 is instructed is during execution of the low SOC control. Specifically, when the engine 110 is started (forced charge control) during execution of the low SOC control, the recording unit 120 sets a forced charge flag, which will be described later, to “1”. The number of times that is set to “1” is accumulated and recorded. The communication unit 118 periodically transmits primary information including the vehicle ID to the management center 128. Vehicle ID should just be the information for identifying a vehicle uniquely.

  The prediction unit 124 predicts the travel route of the vehicle 100 from information such as the vehicle speed and steering angle from the sensor unit 106 and route setting information in the car navigation system 108. Further, the prediction unit 124 identifies the destination based on information sent from the management center 128. The target setting unit 126 adjusts the target charging rate of the battery 116. The purpose of the target setting unit 126 is to enhance the cold charging effect.

  The communication unit 118, the recording unit 120, and the position detection unit 122 constitute a DCM (Data Communication Module), the prediction unit 124 and the target setting unit 126 constitute an HV (Hybrid Vehicle) -ECU, Between these, CAN (Controller Area Network) communication is performed.

  The management center 128 includes a weather information storage unit 130, an analysis unit 132, a communication unit 134, and a history information storage unit 136. The communication unit 134 periodically receives primary information from the vehicle control device 104. The analysis unit 132 processes the primary information to generate “secondary information” and records it in the history information storage unit 136. The secondary information includes information related to parking of the vehicle 100. That is, it is information indicating the parking date and time (time zone and day of the week), parking time, and parking spot of each vehicle 100. The history information storage unit 136 stores travel history information (secondary information) for each vehicle based on the vehicle ID. The weather information storage unit 130 stores weather information, in particular, weather information indicating expected temperatures in various places. The analysis unit 132 predicts the destination (parking point) of the vehicle 100 from the travel history information (secondary information) and weather information stored in the history information storage unit 136. Details of the destination prediction method will be described later. The communication unit 134 returns the destination to the vehicle control device 104.

-Destination prediction-
The vehicle 100 in the present embodiment predicts a destination in conjunction with the management center 128. In the present embodiment, “parking” refers to “a stopped state of the vehicle 100 in which the engine 110 is stopped”. Furthermore, “parking” is roughly divided into “short-term parking” in which the engine 110 does not cool so much, in other words, cold travel is unnecessary or not required and “long-term parking” in which sufficient cold travel is required. Is done. Specifically, it is classified as long-term parking when the parking time is longer than a threshold (hereinafter referred to as “parking threshold”), and short-term parking when short. It is assumed that the parking threshold in this embodiment is 6 hours. However, as will be described later, the parking threshold is variable according to the weather information. A point where short-term parking or a point where short-term parking is assumed is referred to as “via”, and a point where long-term parking or a point where long-term parking is assumed is referred to as “destination (parking point in the present invention)”. I will call it.

  FIG. 3 is a schematic diagram for explaining a route prediction method. The number given to each of the points A to F represents the number of times the vehicle 100 is parked during the predetermined period.

  The history information storage unit 136 stores travel history information (secondary information) for each vehicle 100. The travel history information includes the date and time when the vehicle is parked and the parking time. According to the travel history information shown in FIG. 3, the vehicle 100 has been parked at point A in the past 35 times. The 35 parkings include both short-term parking and long-term parking. The vehicle 100 that has departed from the point A goes to the point B 25 times out of 35 times, and goes to the point C 10 times. For this reason, when the vehicle 100 parks at the point A, the analysis unit 132 predicts that the next possibility is that the vehicle 100 is most likely to go to the point B.

  The vehicle 100 has been parked at the point B in the past 25 times, of which 20 have been directed to the point E and the remaining 5 have been directed to the point D. As predicted by such a method, when the vehicle 100 is parked at the point A, it is predicted that the vehicle 100 is parked at the points B, E, and F in order. As described above, the analysis unit 132 predicts a travel route (travel route) having the highest travel possibility based on the travel history information.

  Subsequently, the analysis unit 132 specifies whether the points B, E, and F are transit points for short-term parking or destinations for long-term parking.

  Hereinafter, the vehicle 100 will be described on the assumption that it departs from the point A at 13:30 on Tuesday. Assume that the analysis unit 132 predicts the arrival times of the points B, E, and F as 14:00, 15:00, and 16:00 based on the distances from the point A to the points B, E, and F, respectively.

  FIG. 4 is a diagram illustrating a frequency distribution of parking time at the point B. FIG.

  Specifically, the distribution of the parking time when the vehicle 100 is parked at the point B in the time zone around 14:00 on Tuesday, for example, from 13:30 to 14:30 is shown. For example, in the past, when parking in this time zone, the number of times the parking time was 3 hours (3 hours or more and less than 4 hours) is 5 times. According to the travel history information shown in FIG. 4, the mode value of the parking time when the vehicle 100 parks in the time zone around 14:00 on Tuesday is 4 hours (4 hours or more and less than 5 hours). That is, if the vehicle 100 departs from the point A at 13:30 on Tuesday, it is highly likely that the vehicle will park at the point B at 14:00, but the parking time predicted at that time is 4 hours and the parking threshold is 6 hours. It is predicted that parking will be short-term. Through the above process, the analysis unit 132 determines that the point B is not a destination but a waypoint. Since the parking is short-term at the point B, the engine 110 does not cool so much, and the cold section after the vehicle 100 departs from the point B is also shortened. Since sufficient cold charging cannot be expected, the process of reducing the target charging rate from the point before point B is not executed.

  FIG. 5 is a diagram showing the frequency distribution of the parking time at the point E. FIG.

  Specifically, the distribution of parking time when the vehicle 100 is parked at the point E in a time zone around 15:00 on Tuesday, for example, 14:30 to 15:30 is shown. In the past, the mode value of the parking time when the vehicle 100 parks in the time zone around 15:00 on Tuesday is 7 hours (7 hours or more and less than 8 hours). That is, if the vehicle 100 departs from the point A at 13:30 on Tuesday, it is highly likely that the vehicle will park at the point E at 15:00, but the parking time predicted at that time is 7 hours and the parking threshold is 6 hours. Longer than expected, long-term parking is expected. Through the above process, the analysis unit 132 determines that the point E is the destination. Since the point E is parked for a long time, the engine 110 is sufficiently cooled. Since the cold section after the vehicle 100 departs from the point E becomes longer, sufficient cold charging is expected. Accordingly, a discharge point is set at a point before point E. When the vehicle 100 actually reaches the discharge point, the target charging rate is lowered by the low SOC control.

  Thus, when the vehicle 100 is at the point A, the point E is specified as the destination from the travel history information, and a predetermined distance, for example, a point 5 kilometers before the point E is set as the discharge point on the travel route. The However, the above is only an expectation, and the vehicle 100 does not always run as expected. For example, when the vehicle 100 departs from the point A and goes to the point C instead of the point B, the travel route is predicted and changed to the points C, D, and A (see FIG. 3). In this case, the analysis unit 132 specifies the destination from the points C, D, and A by the same method as described above, and resets the discharge point.

-Target charge rate adjustment control-
In the present embodiment, the history information of forced charge control (forced charge control execution frequency) in which the engine 110 is forcibly driven to charge the battery 116 during execution of the low SOC control is acquired. Based on the acquired history information of forced charging control, the target charging rate of the battery 116 when the vehicle reaches a point (the discharge point) a predetermined distance before the destination (the long-term parking point) is adjusted. I am doing so.

  Specifically, when the execution frequency of the forced charging control recorded in the recording unit 120 (the number of times that the forced charging flag is set to “1”) is low as the history, The target charging rate of the battery 116 when the vehicle 100 reaches the discharge point is lowered (the low SOC control is executed) so that the cold charging effect during the next cold running can be fully enjoyed ( Improve fuel consumption rate by increasing battery charging efficiency. On the other hand, when the execution frequency of the forced charging control recorded in the recording unit 120 is high as the history, the target charging rate of the battery 116 when the vehicle 100 reaches the discharge point is maintained high, and the SOC The deterioration of the fuel consumption rate is suppressed by reducing the execution frequency of the forced charging control due to the fact that the fuel consumption becomes too low. The target charging rate adjustment control is executed by the target setting unit 126. For this reason, in the target setting unit 126, the functional part that performs the adjustment control of the target charging rate is the target charging rate adjusting unit (the internal combustion engine is forced to charge the secondary battery during the execution of the low SOC control). Information of forced charging control that is driven automatically, and based on the acquired history information of forced charging control, target charging of the secondary battery when the vehicle reaches a point a predetermined distance before the parking spot The target charging rate adjusting unit for adjusting the rate).

  FIG. 6 is a flowchart showing a destination specifying process and a target charge rate adjustment control process.

  The process shown in FIG. 6 is a loop process that is repeated at regular intervals, for example, every few minutes. The position detection unit 122 acquires the current position of the vehicle 100 from the sensor unit 106 and the car navigation system 108 (step ST1). At this time, the recording unit 120 also acquires the vehicle speed, and also acquires the time when there is a stop or start. The recording unit 120 records sensed information as primary information. The communication unit 118 adds the vehicle ID to the primary information and transmits it to the management center 128 (step ST2).

  When the communication unit 134 of the management center 128 receives the primary information, the analysis unit 132 updates the travel history information (secondary information) in the history information storage unit 136 (step ST3). For example, when information indicating the start time is newly received after receiving the information indicating the stop time, the analysis unit 132 specifies the time from the stop time to the start time as the parking time. As a result, the frequency distribution information as shown in FIGS. 4 and 5 is updated. Moreover, the analysis part 132 updates the driving | running | working frequency from the last parking spot to this parking spot, when parking is detected. As a result, the travel route prediction information shown in FIG. 3 is updated.

  The analysis unit 132 predicts a subsequent parking spot from the current location of the vehicle 100 and the travel route prediction information shown in FIG. 3 (specification of a candidate spot for a parking spot in step ST4). In this way, one or more parking spots are specified as candidate spots for the parking spot (destination). The analysis unit 132 predicts the arrival time of each candidate site (step ST5). The arrival time can be calculated by an algorithm similar to the algorithm performed by the car navigation system 108 or the like.

  The analysis unit 132 predicts the parking time of each candidate site by the method described in relation to FIGS. 4 and 5 (step ST6). In the present embodiment, the parking threshold for separating short-term parking and long-term parking is 6 hours, but the parking threshold is adjusted according to the outside air temperature. For example, in the winter season, the engine 110 is sufficiently cooled even if the parking time is 3 hours, for example, and therefore, it is necessary to travel sufficiently cold during the restart. Therefore, if the predicted temperature at the arrival time of each candidate site is less than a predetermined temperature threshold, for example, less than 5 degrees Celsius, the prediction unit 124 decreases the parking threshold from 6 hours to 2 hours. Thus, the analysis part 132 correct | amends a parking threshold value according to the estimated external temperature (step ST7). The weather information storage unit 130 stores the predicted temperature of each place as weather information. The weather information is acquired by the management center 128 from the Japan Meteorological Agency. The analysis unit 132 specifies the first candidate site predicted to park for a longer time than the parking threshold as the destination (step ST8).

  Thereafter, the process proceeds to step ST9, and it is determined whether or not the forced charging probability corresponding to the specified destination is equal to or less than a predetermined prohibition constant. The forced charging probability and the prohibition constant will be described later.

  If the forced charging probability is equal to or less than the prohibition constant, and YES is determined in step ST9, the communication unit 134 of the management center 128 notifies the vehicle control apparatus 104 of the predicted destination together with the waypoint (step). ST10). The prediction unit 124 predicts a travel route from the waypoint and the destination, and sets a discharge point at a point a predetermined distance before the destination (update of the discharge point in step ST11). In this case, after that, it is determined in step ST12 whether or not the vehicle 100 has reached the discharge point set a predetermined distance before the destination by traveling, and if the discharge point has not yet been reached, A NO determination is made in step ST12, and the process directly returns. On the other hand, when vehicle 100 reaches the discharge point and YES is determined in step ST12, the process proceeds to step ST13, and the low SOC control described above is started (target setting unit 126 performs target charging of battery 116). The rate is reduced from the basic target charge rate to the special target charge rate).

  On the other hand, if the forced charging probability exceeds the prohibition constant and NO is determined in step ST9, the process proceeds to step ST14, and the low SOC control described above is prohibited. In other words, the communication unit 134 of the management center 128 does not notify the vehicle control device 104 of the predicted destination, and also assumes that the vehicle 100 has reached a discharge point set a predetermined distance before the destination. In addition, the target setting unit 126 maintains the target charging rate at the basic target charging rate CM.

  The process shown in FIG. 6 is periodically executed. For this reason, before reaching the destination, the prediction of the destination or waypoint may change. When the destination or waypoint changes, the prediction unit 124 resets the discharge point as appropriate.

  Here, a specific example of the forced charging probability and the prohibition constant, and the determination process in step ST9 using the forced charging probability and the prohibition constant will be described.

  FIG. 7 shows an example of the traveling state of the vehicle 100 for a certain period (specifically, the period from November 1 to December 29), and FIG. FIG. 7B shows the transition of the forced charging probability, FIG. 7C shows the execution period of the low SOC control in this embodiment, and FIG. 7D shows the low SOC control in the prior art. The execution period of each is shown. The forced charge flag is a flag that is reset to “0” when the forced charge control is not executed, and is set to “1” when the forced charge control is executed. The forced charge probability indicates a ratio of the number of trips for which the forced charge control is executed to the number of trips within a predetermined period.

  As shown in FIG. 7, the forced charging probability increases as the frequency with which the forced charging flag is set to “1” increases. A forbidden constant X as a threshold is defined for the forced charging probability, a range in which the forced charging probability is equal to or smaller than the forbidden constant X is a low SOC control permission region, and a forced charging probability is the prohibition. The ranges exceeding the constant X are respectively defined as the low SOC control prohibited areas. The prohibition constant X is set to about 12%, for example. This value is not limited to this, and can be set arbitrarily.

  In the example shown in FIG. 7, in the period from November 8 to December 10, the low SOC control prohibited region where the forced charging probability exceeds the prohibition constant X. Therefore, in periods other than this period (the period from November 1 to November 7 and the period from December 11 to December 29; the period hatched in FIG. 7 (c)) The determination at step ST9 is YES, and the low SOC control is executed when the vehicle 100 reaches the discharge point set a predetermined distance before the destination. That is, the target charging rate of the battery 116 is lowered to the special target charging rate (near the lower limit value CD). On the other hand, in the period from November 8 to December 10 in which the forced charging probability exceeds the prohibition constant X, NO determination is made in the above-mentioned step ST9, and it is set a predetermined distance before the destination. Even if the vehicle 100 reaches the discharged point, the low SOC control is prohibited and the target charging rate is maintained at the basic target charging rate CM.

  On the other hand, in the prior art, as shown in FIG. 7 (d), regardless of the forced charging probability, when the vehicle reaches a discharge point set a predetermined distance before the destination, the low SOC control is performed. Was running. For this reason, forced charging control is performed by the time the vehicle reaches the destination, which may lead to a deterioration in the fuel consumption rate.

  In the present embodiment, since the low SOC control is prohibited when the forced charging probability exceeds the prohibition constant X, the target charging rate of the battery 116 when the vehicle 100 reaches the discharge point is increased. Thus, the deterioration of the fuel consumption rate can be suppressed by reducing the execution frequency of the forced charging control due to the SOC becoming too low.

  Further, the control for prohibiting the low SOC control according to the forced charge probability can be individually determined according to the destination, day of the week, and time zone. FIG. 8 is a diagram illustrating an example of the number of executions of forced charging control and the forced charging probability for each destination, day of the week, and time period. In FIG. 8, the destination is classified into “company”, “home”, and “other (other than company and home)”, the day of the week is classified into “weekday” and “holiday”, and the time zone is “0”. -5 o'clock "," 5-11 o'clock "," 11-14 o'clock "," 14-20 o'clock ", and" 20-24 o'clock ". For each category, the number of times that forced charging is performed and the number of times that forced charging is not performed are integrated to determine the respective forced charging probabilities.

  In the example shown in FIG. 8, there are a total of 22 trips with “company” as the destination, and forced charge control is executed in 3 trips of “5-11 o'clock” on “weekdays”. The forced charge probability in the trip of “5-11 o'clock” on “weekdays” with “company” as the destination is “13.64%”. In other cases, the forced charging probability is “0%”. In this case, if the prohibition constant X is set to “12%”, for example, the forced charge probability is set to “5-11 o'clock” trip on “weekdays” with this “company” as the destination. Since the prohibition constant X is exceeded, a NO determination is made in step ST9 in the above-described flowchart (FIG. 6), and “5-11 o'clock” of “weekdays” with this “company” as the destination. In this trip, low SOC control is prohibited. Thereby, the execution frequency of the forced charging control due to the SOC of the battery 116 becoming too low becomes low, and it becomes possible to suppress the deterioration of the fuel consumption rate.

(Second Embodiment)
Next, a second embodiment will be described. In the present embodiment, the processing procedure of the target charging rate adjustment control is different from that in the previous embodiment. Accordingly, only the processing procedure of the target charging rate adjustment control will be described here.

  FIG. 9 is a flowchart showing a processing procedure of the target charging rate adjustment control in the present embodiment. First, when the ignition of the vehicle 100 is turned on, YES is determined in step ST21, and the process proceeds to step ST22. In step ST22, the destination is specified in the same manner as in steps ST3 to ST8 in the embodiment.

  Thereafter, the process proceeds to step ST23, where it is determined whether or not the vehicle 100 has reached a discharge point set a predetermined distance before the destination. If the discharge point has not yet been reached, a NO determination is made at step ST23 and the process returns. On the other hand, when vehicle 100 reaches the discharge point and YES is determined in step ST23, the process proceeds to step ST24, and the low SOC control described above is executed.

  With the low SOC control executed in this way, the process proceeds to step ST25, and whether or not the forced charge control is executed during the low SOC control in the current trip, that is, the engine is reduced due to the decrease in the SOC. It is determined whether 110 is driven.

  If the forced charge control is not executed and NO is determined in step ST25, the process proceeds to step ST26, and the SOC control center value is decreased by a predetermined amount. For example, decrease by 5%. Thereby, in the next trip, charge / discharge control is performed according to the SOC control center value lowered by a predetermined amount. As the SOC control center value is lowered in this way, the lower limit value of the allowable range in the SOC is also lowered, and the cold charging effect during cold running can be fully enjoyed.

  On the other hand, when the forced charging control is executed during the execution of the low SOC control, and YES is determined in step ST25, the process proceeds to step ST27, where the SOC control center value is set to the previous value (the SOC before the lowering in the previous trip) Return to the control center value. That is, the SOC control center value is increased by a predetermined amount. For example, increase by 5%. Thereafter, the process proceeds to step ST28, and this SOC control center value (current SOC control center value) is maintained. Thereby, in the next trip, charge / discharge control is performed according to the SOC control center value increased by a predetermined amount.

  As described above, according to the present embodiment, the SOC control center value is automatically learned according to whether or not the forced charging control is performed during the execution of the low SOC control. For this reason, as in the case of the above-described embodiment, it is possible to reduce the frequency of execution of forced charging control resulting from the SOC being too low, and to improve the fuel consumption rate.

(Third embodiment)
Next, a third embodiment will be described. Also in this embodiment, the processing procedure of the target charging rate adjustment control is different from that of the above embodiment. Accordingly, only the processing procedure of the target charging rate adjustment control will be described here.

  FIG. 10 is a flowchart showing a processing procedure for target charging rate adjustment control in the present embodiment. Here, steps that are the same as the steps in the flowchart shown in FIG. 9 in the second embodiment are given the same step numbers in FIG. 10, and detailed descriptions thereof are omitted.

  First, after the ignition of the vehicle 100 is turned on (step ST21) and the destination is specified (step ST22), it is determined whether or not the vehicle 100 has reached a discharge point set a predetermined distance before the destination. Determination is made (step ST23).

  If the discharge point has not yet been reached, a NO determination is made at step ST23 and the process returns. On the other hand, when vehicle 100 reaches the discharge point and YES is determined in step ST23, the process proceeds to step ST31, and the low SOC control is executed at the target charging rate at the previous trip.

  With the low SOC control executed in this way, the process proceeds to step ST25, and whether or not the forced charge control is executed during the low SOC control in the current trip, that is, the engine is reduced due to the decrease in the SOC. It is determined whether 110 is driven.

  If the forced charge control is not executed and NO is determined in step ST25, the process proceeds to step ST32, and it is determined whether or not a predetermined period (for example, 60 days) has elapsed since the previous determination of the target charge rate. If this predetermined period has not elapsed, NO is determined in step ST32, and the process returns as it is. On the other hand, if the predetermined period has elapsed, YES is determined in step ST32, and the process proceeds to step ST26, where the SOC control center value is decreased by a predetermined amount. For example, decrease by 5%. Thereby, in the next trip, charge / discharge control is performed according to the SOC control center value lowered by a predetermined amount.

  On the other hand, when the forced charging control is executed during the execution of the low SOC control, and YES is determined in step ST25, the process proceeds to step ST33, and the SOC control center value is increased by a predetermined amount. For example, increase by 5%. Then, it moves to step ST34 and determines again whether forced charge control was performed.

  If forced charge control is executed, a YES determination is made in step ST34, and the process returns to step ST33 to further increase the SOC control center value by a predetermined amount. For example, further increase by 5%. Such an operation is repeated each time forced charging control is executed (until forced charging control is not executed).

  If the forced charge control is not executed and NO is determined in step ST34, the process proceeds to step ST28, and this SOC control center value (current SOC control center value) is maintained. Thereby, in the next trip, charge / discharge control is performed according to the SOC control center value increased by a predetermined amount.

  As described above, according to the present embodiment, the SOC control center value is automatically learned according to whether or not the forced charging control is executed during the execution of the low SOC control. For this reason, as in the case of the above-described embodiment, it is possible to reduce the frequency of execution of forced charging control resulting from the SOC being too low, and to improve the fuel consumption rate.

  FIG. 11 shows an example of the traveling state of the vehicle 100 for a certain period (specifically, the period from November 1 to December 29), and FIG. FIG. 11B shows changes in the forced charge flag, and FIG. 11B shows changes in the SOC control center value.

  As shown in FIG. 11, after the elapse of the period T1 (destination learning period), in the period T2, the SOC control center value is not obtained because the forced charge control is not performed during the execution of the low SOC control. It is gradually decreasing. In the period T3, the SOC control center value is maintained without being lowered because the forced charge control is performed during the low SOC control, and then the SOC control center value is increased and the forced charge control is performed. If the situation is not performed, the current SOC control center value is maintained.

-Other embodiments-
The present invention is not limited to the above-described embodiments, and all modifications and applications encompassed within the scope of the claims and the scope equivalent thereto are possible.

  For example, in each of the above-described embodiments, the vehicle control device 104 receives information such as the destination from the management center 128 and information on the frequency of execution of forced charging control, and sets discharge points based on the information to perform low SOC control. I was trying to judge whether there was any prohibition. The present invention is not limited to this, and the vehicle control device 104 may determine the destination, the execution frequency of forced charging control, and the like, and may determine whether or not to prohibit the low SOC control.

  The present invention relates to a vehicle control device capable of low SOC control that changes a target charging rate of a battery to a value lower than a target charging rate at a normal time when the vehicle reaches a point a predetermined distance before the destination of the vehicle. It is applicable to.

DESCRIPTION OF SYMBOLS 100 Vehicle 102 Vehicle control system 104 Vehicle control apparatus 110 Engine (internal combustion engine)
112 Electric motor 116 Battery (secondary battery)
120 Recording Unit 122 Position Detection Unit 124 Prediction Unit 126 Target Setting Unit (Target Charging Rate Adjustment Unit)

Claims (1)

An internal combustion engine, an electric motor, and a secondary battery that is charged with electric power converted from the power generated by the internal combustion engine and supplies electric power to the electric motor, and in a vehicle travel route, a parking time is a predetermined threshold value In the vehicle control device capable of low SOC control to change the target charging rate of the secondary battery to a low value when the vehicle reaches a point a predetermined distance before the parking point predicted to be longer than
Acquires history information of forced charging control in which the internal combustion engine is forcibly driven for charging the secondary battery during the execution of the low SOC control, and based on the acquired history information of forced charging control, A vehicle control apparatus comprising: a target charging rate adjustment unit that adjusts a target charging rate of the secondary battery when the vehicle reaches a point a predetermined distance before the parking point.

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