JP2010269712A - Control device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device enhancing fuel economy performance by securing an idling-stoppable time even if a vehicle abruptly encounters a traffic congestion road. <P>SOLUTION: The control device for the vehicle includes a power generation control means 4 for controlling a power generation amount of a generator 1 and a charging amount of a battery 2; and a traffic congestion prediction means 6 for predicting the existence of traffic congestion on an advancement route. The power generation control means 4 sets the charging amount of the battery higher as compared with the case that the traffic congestion is not predicted when the traffic congestion is predicted by the traffic congestion prediction means 6. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a power control apparatus for a vehicle, and more particularly to a power control apparatus for a vehicle that performs so-called idle stop.

  In a vehicle that recovers travel energy by applying regenerative braking by a motor generator during braking, a target charge amount during normal travel (hereinafter referred to as SOC (State Of Charge)) is set lower than a target SOC for engine start. Is disclosed in Patent Document 1. In this configuration, the electric power required for starting the engine is ensured while preventing overcharge of the battery due to regenerative braking by switching to the target SOC for starting the engine for a predetermined period before reaching the destination.

JP 2004-245190 A

  However, in the configuration described in Patent Document 1, if an unexpected traffic jam is encountered during traveling with the target SOC for normal traveling, idle stop may not be performed. In other words, when the idle stop is performed, the electric power necessary for the engine restart cannot be secured due to the discharge during the idle stop, and there is a possibility that the implementation of the idle stop may be limited.

  Therefore, an object of the present invention is to provide a control device that secures a time during which idle stop is possible and improves fuel efficiency even when a congested road is unexpectedly encountered.

  The vehicle control device of the present invention includes a generator, a battery for charging the power generated by the generator, a power generation control means for controlling the power generation amount of the generator and the charge amount of the battery, and congestion on the travel route. And a traffic jam prediction means for predicting presence or absence. Furthermore, the power generation control unit sets the battery charge amount higher when the traffic jam is predicted by the traffic jam prediction unit than when the traffic jam is not predicted.

  According to the present invention, when it is predicted that there is a traffic jam, the battery charge amount is increased. Therefore, it is possible to secure a time during which the vehicle can be idle stopped when the vehicle stops due to the traffic jam. As a result, fuel efficiency can be improved.

It is a system configuration figure of this embodiment. It is a flowchart explaining the control routine for target SOC determination which a power generation controller performs. It is an example of the map used in order to estimate the stop time in traffic jam stored in the electric power generation controller. It is an example of the time chart at the time of performing control of this embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a configuration diagram of a system according to this embodiment.

  The power generator 1 includes, for example, a generator that is driven by an engine and generates power, such as an alternator, and an inverter that converts AC generated power of the generator into DC power. In addition, in the power generation device 1, when the vehicle is decelerated, the inverter generates a regenerative braking force, and recovers traveling energy as electric power.

  The power generation amount of the power generation device 1 is determined by a power generation controller 4 as power generation control means. The electric power generated by the power generation device 1 is charged in the battery 2 or used to drive an electrical component 5 such as a starter motor.

  The power generation controller 4 receives detection signals from a temperature sensor 3 a that detects battery temperature and a current sensor 3 b that detects charge / discharge current of the battery 2.

  Since the electric power that can be discharged becomes small when the battery temperature is low, the battery temperature is detected for target SOC calculation control described later.

  The actual battery SOC can be calculated by integrating the charge / discharge current of the battery 2. In addition to this, for example, a method of estimating the battery SOC from the terminal voltage and the charge / discharge current by detecting the terminal voltage of the battery 2 or a method of estimating the battery SOC from only the terminal voltage may be used.

  In addition, information such as traffic jam information and predicted stop time (hereinafter referred to as navigation information) is sequentially input from the IT device 6 as a traffic jam prediction unit such as a car navigation system. And based on these input signals etc., the target SOC of the battery 2 is determined, and the electric power generation amount of the electric power generating apparatus 1 is determined. It is also determined whether or not idle stop is possible with the current battery SOC.

  The IT device 6 is connected to a mobile phone, an input device, a GPS receiver, a vehicle speed sensor, a storage device, and the like. The GPS receiver receives signal radio waves from GPS satellites to detect the current position of the vehicle, and obtains weather forecasts and traffic jam information through communication with an information center or vehicle-to-vehicle communication via a mobile phone. Further, a route to the destination set by the input device is searched using the road map stored in the storage device, and route guidance is performed.

  FIG. 2 is a flowchart for explaining a control routine for determining the target SOC, which is executed by the power generation controller 4. The power generation controller 4 executes this routine at regular intervals while the engine is operating. The fixed interval is, for example, 10 milliseconds.

  In step S <b> 1, it is determined based on the navigation information whether there is a traffic jam on a route to be taken (hereinafter referred to as a travel route). If there is no traffic jam, the process proceeds to step S2. If there is a traffic jam, the process proceeds to step S4, where a target SOC for normal driving is set. The target SOC for normal travel refers to an SOC that can secure driving force during travel by the power generation device 1 and charge the power generated by regenerative braking during braking. For example, it is within a range of about 30 to 80%.

  In step S2, it is determined whether there is a vehicle that is traveling along the traveling route and can communicate with the host vehicle. If the vehicle is present, the process proceeds to step S3, and if not, the process proceeds to step S5.

  In step S3, low vehicle time information is received from the vehicle. In step S5, information such as a traffic jam distance and a time required to pass through the traffic jam (hereinafter referred to as a traffic jam time) is received from the VICS information.

  When information is received in step S3 or step S5, the process proceeds to step S6, a target SOC at the time of traffic jam prediction is set based on the received information, and the process is terminated. The target SOC at the time of traffic jam prediction means an SOC that can be reliably started by a starter motor even in a low temperature environment at the next engine start. For example, when the outside air temperature is zero degrees, it is about 95%.

  FIG. 3 is an example of a map used for predicting a stop time during a traffic jam. On the vertical and horizontal axes, the traffic distance and the time required to pass the traffic (hereinafter referred to as traffic time) obtained from inter-vehicle communication or VICS information, respectively, were assigned statistically estimated stoppage times. Is.

  If the traffic distance is the same, the longer the traffic time, the longer the stop time is predicted. If the traffic time is the same, the shorter the traffic distance, the longer the stop time is predicted.

  Note that the estimated stoppage time in the map of FIG. 3 is merely an example. Actually, for each window in FIG. 3, the past performance in the traffic jam is statistically processed, and set to, for example, an average value + 1σ . However, there is a similar tendency with respect to the relationship between the above-described traffic distance and traffic time and the length of the predicted time.

  If the estimated stoppage time during a traffic jam is predicted based on the map, the required charging amount is calculated by the following equation (1) based on the predicted stoppage time. The target SOC at the time of traffic jam prediction is obtained by adding the required amount of charge to the target SOC during normal driving.

    Charge required amount [As] = Predicted stop time [s] × Battery discharge amount during idle stop [A] (1)

  Here, as the battery discharge amount during idle stop, the discharge current value measured by the current sensor 3b at the previous idle stop is used.

  That is, the amount of charge required is a predicted value of power consumed by a vehicle auxiliary machine such as an air conditioner or a car navigation system during an idle stop. In addition to the driving power for the starter motor, if the required charging amount is charged before the idle stop, the engine can be reliably started after the idle stop is released.

  The power generation controller 4 starts charging so that the required charging amount determined as described above is obtained. In general, charging is performed at a timing when the power generation efficiency of the power generator 1 is good, such as during deceleration. If the vehicle is traveling normally without traffic jams, the required amount of charge can be covered even with such charging, but the amount of power generation may be insufficient with respect to the required amount of charge during traffic jams.

  Therefore, when a traffic jam is predicted and a necessary amount of charging occurs, the power generation controller 4 does not depend on the power generation efficiency of the power generation apparatus 1, that is, the power generation efficiency of the power generation apparatus 1 during acceleration or constant speed travel. Even when the battery power is low, the power generation voltage of the power generation device 1 is increased in order to maintain or increase the battery SOC.

  FIG. 4 is an example of a time chart when control is performed when a traffic jam is predicted and a necessary amount of charging occurs. Here, the target battery SOC is set so as to secure the power necessary for starting the engine even during normal operation, the engine is started at t0, accelerates until t1, decelerates at t1-t2, and then t2-t3 is constant. It shows a case where the vehicle travels at a high speed, decelerates at t3 to t4, and stops at t4 due to traffic congestion.

  From t0 to t1, the power generation efficiency of the power generation apparatus 1 is relatively low because of accelerated traveling. Therefore, the generated voltage is increased to such an extent that the current battery SOC can be maintained. The engine start here may be an engine start by releasing the idle stop or a normal engine start.

  Between t1 and t2, the power generation efficiency of the power generator 1 is relatively high due to the deceleration state. Therefore, the power generation voltage of the power generator 1 is increased to the extent that the battery SOC is increased.

  Since the power generation efficiency is relatively low during the period from t2 to t3 as in the period from t0 to t1, the power generation voltage is set so as to hold the battery SOC. Since the power generation efficiency is relatively high during the period from t3 to t4 as in the period from t1 to t2, the power generation voltage of the power generation apparatus 1 is increased to the extent that the battery SOC is increased. As a result, the battery SOC gradually increases without decreasing from the engine start to the idle stop.

  As described above, the power generation efficiency of the power generator 1 is controlled so that the battery SOC increases when the power generation efficiency is high, and the battery SOC is maintained when the power generation efficiency is low. As a result, even if discharging continues during idling stop, electric power necessary for engine restart can be secured until t6.

  On the other hand, for example, when the power generation voltage is not increased while the power generation efficiency between t2 and t3 is relatively low, the battery SOC is between t2 and t3 as indicated by a broken line in FIG. It will decline. For this reason, even if the power generation voltage is increased again between t3 and t4 where the power generation efficiency is relatively high, the battery SOC at the time t4 through the idle stop is lower than in this embodiment. If the discharge amount during the idle stop is the same, the battery SOC required for restarting the engine is reduced at a time t5 earlier than t6. That is, the idle stop can be continued only until t5. That is, according to the present embodiment, the idle stop can be performed for a long time by t5 to t6.

  As described above, according to the present embodiment, the following effects can be obtained.

  (1) When traffic congestion is predicted, the power generation controller 4 sets the target value of the battery SOC higher than that during normal operation. Therefore, the power generation controller 4 ensures a longer idle stop possible time when the vehicle is low due to traffic congestion. be able to. As a result, the fuel efficiency can be improved.

  (2) Since the power generation controller 4 sets the target value of the battery SOC when the traffic jam is predicted according to the stop time during the traffic jam acquired by the IT device 6, it is possible to avoid overcharging and insufficient charging. it can.

  (3) Since the IT device 6 obtains the stop time in a traffic jam through inter-vehicle communication with other vehicles traveling on the traveling route, it can obtain a more accurate stop time and the accuracy of the required amount of charge Rise.

  (4) The power generation controller 4 sets the target value of the battery SOC when the traffic jam is predicted according to the stop time during the traffic jam predicted based on the information acquired from the IT device 6, the traffic jam distance and the traffic jam time. Therefore, the amount of charge required can be calculated.

  (5) Since the power generation controller 4 sets the target value of the battery SOC higher as the predicted stoppage time in the traffic jam is longer, the idling stop possible time can be secured longer.

  The present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made within the scope of the technical idea described in the claims.

DESCRIPTION OF SYMBOLS 1 Power generator 2 Battery 3a Temperature sensor 3b Current sensor 4 Power generation controller 5 Electrical component 6 IT apparatus

Claims (6)

Power generation control means for controlling the power generation amount of the generator and the charge amount of the battery;
A traffic jam forecasting means for forecasting the presence or absence of traffic jam on the route,
In a vehicle control device comprising:
The power generation control unit sets the battery charge amount higher when the traffic jam is predicted by the traffic jam prediction unit than when the traffic jam is not predicted.   2. The vehicle control according to claim 1, wherein the power generation control unit sets a battery charge amount when the traffic jam is predicted according to a stop time during the traffic jam acquired by the traffic jam prediction unit. apparatus.   The vehicle control device according to claim 2, wherein the traffic jam prediction means acquires the stop time during the traffic jam by inter-vehicle communication with another vehicle traveling on a traveling route.   The power generation control unit sets the battery charge amount when the traffic jam is predicted according to a stop time during the traffic jam predicted based on information acquired from the traffic jam prediction unit. The vehicle control device described in 1.   The vehicle control device according to claim 4, wherein the information acquired from the traffic jam prediction unit is a traffic jam distance and a time required to pass the traffic jam.   6. The vehicle control device according to claim 2, wherein the power generation control unit sets the battery charge amount to be higher as the predicted stoppage time in the traffic jam is longer.

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