JP2008279980A - Power supply control device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power supply control device for a vehicle capable of preventing the behavior of the vehicle from being unstable and the salability of the vehicle from being affected when the user parks the vehicle utilizing a parking support device. <P>SOLUTION: This power supply control device for a vehicle comprises: a power supply 2 for supplying a power to a load; a generator 3 driven by an engine for supplying a power to the power supply 2; a charged amount detection means 4a for detecting the charged amount of the power supply 2; a vehicle state detection means 4b for detecting the state of the vehicle; a parking support detection means 4c for detecting the parking support of the parking support device 5; a control means for variably controlling the generated voltage of the generator 3 according to the charged amount and the vehicle state; and a prohibiting means 4e for prohibiting the variable control of the control means 4d when the parking support detection means 4c detects the parking support of the parking support device 5. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a power supply control device for a vehicle suitable for application to automobiles such as passenger cars, trucks, and buses.

2. Description of the Related Art Conventionally, as a vehicle power supply control device used in a vehicle, for example, there is one described in Patent Document 1, and a power source such as a battery is charged by a generator such as an alternator driven by an engine. Has been done. In this case, when the vehicle is accelerating, the alternator power generation voltage is lowered, and when the vehicle is decelerating, the alternator power generation voltage is raised to reduce the engine load caused by the alternator power generation, thereby reducing the fuel consumption of the engine. So-called charging control for variably controlling the generated voltage is performed.
JP 2005-27389 A

  However, in such a vehicle power supply control device, the vehicle is equipped with a parking assist device (IPA: Intelligent Parking Assist), and when the parking assist device provides parking assistance, the above-described generated voltage can be varied. When so-called charging control is performed, the torque fluctuation of the alternator and, consequently, the engine load fluctuate, and the engine creep torque fluctuates accordingly, so the user can park using the parking assist function of the parking assist device. However, there is a problem that the vehicle behavior becomes unstable and may affect the merchantability of the vehicle.

  In view of the above problems, the present invention provides a vehicle power control that can prevent a vehicle behavior from becoming unstable and affecting the merchantability of a vehicle when a user parks using a parking assistance device. An object is to provide an apparatus.

In order to solve the above-described problems, a vehicle power supply control device according to the present invention includes:
A power source for supplying power to the load;
A generator driven by an engine to supply power to the load and the power source;
Charge amount detecting means for detecting a charge amount of the power source;
Vehicle state detection means for detecting the vehicle state;
Parking assistance detecting means for detecting parking assistance of the parking assistance device;
Control means for variably controlling the generated voltage of the generator based on the charge amount and the vehicle state;
Prohibiting means for prohibiting variable control of the control means when the parking assistance detecting means detects parking assistance of the parking assistance device,
It is characterized by providing.

  Here, the vehicle state includes, for example, whether the vehicle is in an acceleration state, a deceleration state, a constant speed state, whether the engine is in an idle state, whether a sensor and a switch are abnormal, Including whether or not it is time.

  According to this, the prohibiting means can prohibit the control of the power generation voltage of the generator by the control means when the parking support detecting means detects parking support of the parking support device. It is possible to prevent fluctuations in the torque of the generator and thus fluctuations in the engine load, and accordingly, fluctuations in the creep torque of the engine. Thereby, when a user parks using the parking assistance function of the parking assistance device, it is possible to prevent the vehicle behavior from becoming unstable and affecting the merchantability of the vehicle.

  ADVANTAGE OF THE INVENTION According to this invention, when a user parks using a parking assistance apparatus, the vehicle power supply control apparatus which can prevent that vehicle behavior becomes unstable and affects the merchantability of a vehicle is provided. can do.

  The best mode for carrying out the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a schematic diagram showing an embodiment of a vehicle power supply control device according to the present invention, and FIG. 2 is a schematic diagram showing a part of an embodiment of a vehicle power supply control device according to the present invention. .

  The vehicle power supply control device 1 of the present embodiment includes a battery 2, an alternator 3, an engine ECU (Electronic Control Unit) 4, an IPA (Intelligent Parking Assist) ECU 5, an EPS (Electric Power Steering) ECU 6, and an ABS (ABS). Anti-Lock Brake System) 7, EPS (Electric Power Steering: electric power steering device) 8, current sensor 9, and temperature sensor 10.

  The engine ECU 4, the IPA ECU 5, the EPS ECU 6, and the ABS 7 are connected to each other by a communication standard such as CAN (Controller Area Network).

  The battery 2 is a power source composed of a well-known lead-acid battery, and is connected in parallel to the EPS 8 and other loads not shown here to supply electric power, and is charged by an alternator 3 driven by an engine (not shown). : State Of Charge) is controlled.

  The load supplied with power by the battery 2 includes a constant power load and a constant resistance load. The constant power load is a voltage such as a DC brushless motor used in the EPS 8 or a blower motor of an air conditioner. Regardless of the load, it means a load with constant power consumption.

  In addition, the constant resistance load is, for example, lamps other than HID (High Intensity Discharge Lamps), heat wire heaters such as a defogger, a seat heater, etc., and refers to a load whose resistance is constant regardless of voltage. In the constant resistance load, the power consumed is a value obtained by dividing the square of the voltage by the resistance, and the power consumed increases or decreases according to the voltage generated by the alternator 3.

  Along with this, the torque of the alternator 3 fluctuates in accordance with the generated voltage, causing engine load fluctuations, and accordingly, the engine creep torque also fluctuates. Therefore, when the user parks using the parking assistance of the IPA ECU 5 In addition, when the power generation voltage of the alternator 3 fluctuates, the vehicle behavior during reverse traveling becomes unstable.

  The alternator 3 is a generator that is driven by the engine and supplies power to the load and the battery 2, and the generated voltage is controlled by the engine ECU 4. More specifically, as shown in FIG. 2, the alternator 3 is PWM-controlled based on commands from a three-phase armature coil 11, a three-phase full-wave rectifier 12, a field coil 13, and an engine ECU 4. A transistor 14 for supplying an exciting current corresponding to the generated voltage determined by the ECU 4 to the field coil 13, and a flywheel diode 15 connected in parallel to the field coil 13 for supplying a commutation current when the transistor 14 is off; It is configured with.

  The engine ECU 4 includes, for example, a CPU, a ROM, a RAM, and a data bus that interconnects them, and performs each control described below according to a program stored in the ROM. Then, the engine control amount and the like are determined with reference to the accelerator map with reference to the target torque, and the transmission is controlled with reference to the shift map so as to achieve the target acceleration. Furthermore, the engine ECU 4 includes a charge amount detection unit 4a, a vehicle state detection unit 4b, a parking assistance detection unit 4c, a control unit 4d, and a prohibition unit 4e that execute the control described below.

  The IPA ECU 5 includes, for example, a CPU, a ROM, a RAM, and a data bus that interconnects them, and performs each control described below according to a program stored in the ROM.

  The IP AECU 5 determines the target parking position based on the image captured by a back monitor camera (not shown) attached to the rear of the vehicle, the steering angle of the EPS 8 acquired from the EPS ECU 6, and the vehicle speed acquired from the ABS 7 via the CAN. The parking trajectory is calculated, and the parking trajectory is displayed on a display (not shown), and the parking angle is controlled by controlling the steering angle of the EPS 8 via the EPS ECU 6 so that the parking trajectory is realized in the reverse traveling during the parking operation. The parking assistance apparatus which performs is comprised.

  The EPS ECU 6 includes, for example, a CPU, a ROM, a RAM, and a data bus that interconnects them, and performs each control described below in accordance with a program stored in the ROM. The EPS ECU 6 detects the driving force of the driver's steering wheel by a torque sensor such as a torsion bar provided on a steering shaft (not shown) inside the EPS 8, and an electric motor (not shown) of the EPS 8 is controlled according to the operating force. Driving to generate a steering force to steer the wheel and assist the driver's operating force.

  At the same time, the EPSECU 6 automatically controls the steering angle by the EPS 8 based on the command of the IPA ECU 5 so as to realize the parking path during the parking operation in a state where the IP AECU 5 supports parking.

  The ABS 7 is a device that prevents the wheel from being locked during braking, and obtains a vehicle speed to be used for the control from a wheel speed sensor (not shown), and the engine ECU 4 obtains the vehicle speed from the ABS 7 by transmission by CAN. ing.

  The charge amount detection means 4a of the engine ECU 4 integrates the current measured by the current sensor 9 provided on the downstream side of the battery 2 to detect the charge amount of the battery 2, that is, the SOC, and the temperature sensor 10 detects the temperature of the battery 2. Is detected.

  The vehicle state detection means 4b of the engine ECU 4 detects whether the vehicle is in an acceleration state, a deceleration state, or a constant speed state based on the vehicle speed acquired from the ABS 7 via the CAN, and the engine ECU 4 Whether the vehicle is in an idle state is detected based on the measured engine speed.

  In addition, the vehicle state detection means 4b of the engine ECU 4 includes a current sensor 9, a temperature sensor 10, the aforementioned wheel speed sensor, a throttle position sensor (not shown) inside the engine, a crank angle sensor, a stop lamp switch, a neutral position switch sensor, and Whether or not an abnormality has occurred in the switch is detected, and whether or not the engine is starting is detected based on the operation of an ignition key (not shown).

  Furthermore, the parking assistance detection means 4c of the engine ECU 4 acquires information from the IP AECU 5 via the CAN whether or not the IP AECU 5 is assisting parking. Further, the control means 4d of the engine ECU 4 is as follows when the SOC is within the control range, the temperature of the battery 2 is within the control range, no abnormality has occurred in the sensor and the switch, and the engine is not started. As will be described, charge control for variably controlling the power generation voltage of the alternator 3 is performed.

  Further, the prohibiting means 4e of the engine ECU 4 prohibits the charging control by the control means 4d and fixes the generated voltage to a standard value when the IPA ECU 5 provides parking assistance. Further, the prohibiting means 4e of the engine ECU 4 is any one of the case where the SOC is not within the control range, the temperature of the battery 2 is not within the control range, the sensor and the switch are abnormal, or the engine is being started. In some cases, the charging control by the control means 4d is stopped and the generated voltage is fixed to the standard value.

  That is, except for the case described above, when the vehicle state is the idle state, the control means 4d of the engine ECU 4 variably controls the power generation voltage of the alternator 3 so as to maintain the SOC, and the vehicle state is the acceleration state. In this case, the power generation voltage of the alternator 3 is variably controlled to the lower limit value. When the vehicle state is in the deceleration state, the power generation voltage of the alternator 3 is variably controlled to the upper limit value, and the vehicle state is in the other constant speed state. If so, the power generation voltage of the alternator 3 is variably controlled so as to maintain the SOC.

  Hereinafter, the control contents of the vehicle power supply control device 1 according to the present embodiment will be described with reference to flowcharts. FIG. 3 is a flowchart showing the control contents of the vehicle power supply control device 1 of this embodiment.

  In S1, the parking assist detection means 4c of the engine ECU 4 detects whether or not the IP AECU 5 supports parking from the IP AECU 5 via CAN. In S2, the prohibition means 4e of the engine ECU 4 determines whether or not the IP AECU 5 supports parking. If it is determined that parking assistance is being provided, the process proceeds to S17. If it is not determined that parking assistance is being provided, the process proceeds to S3.

  Furthermore, in S3, the vehicle state detection means 4b of the engine ECU 4 determines whether the vehicle is in an acceleration state, a deceleration state, or a constant speed state based on the vehicle speed acquired from the ABS 7 via the CAN. Based on the engine speed measured by the engine ECU 4 itself, it is detected whether the vehicle is in an idle state.

  In addition, the vehicle state detection means 4b has an abnormality in the current sensor 9, the temperature sensor 10, the wheel speed sensor described above, the throttle position sensor in the engine, the crank angle sensor, the stop lamp switch, the neutral position switch sensor and the switch. It is detected whether or not the engine is starting.

  Furthermore, in S4, the charge amount detection means 4a of the engine ECU 4 detects the charge amount of the battery 2, that is, the SOC by integrating the current measured by the current sensor 9 provided on the downstream side of the battery 2 over time. Subsequently, in S <b> 5, the charge amount detection unit 4 a of the engine ECU 4 detects the temperature of the battery 2 by the temperature sensor 10.

  In S6, the prohibiting means 4e of the engine ECU 4 determines whether or not the SOC is within the control range. If it is determined that the SOC is within the control range, the process proceeds to S7, and the SOC is within the control range. If not, the process proceeds to S17.

  In S7, the prohibiting means 4e of the engine ECU 4 determines whether or not the temperature of the battery 2 is within the control range. If it is determined that the temperature of the battery 2 is within the control range, the process proceeds to S8, and the battery If it is not determined that the temperature of 2 is within the control range, the process proceeds to S17.

  In S8, the prohibiting means 4e of the engine ECU 4 determines whether or not an abnormality has occurred in the wheel speed sensor, the throttle position sensor in the engine, the crank angle sensor, the stop lamp switch, the neutral position switch sensor, and the switch. If it is not determined that the problem has occurred, the process proceeds to S9. If it is determined that an abnormality has occurred, the process proceeds to S17.

  In S9, the prohibiting means 4e of the engine ECU 4 determines whether or not the engine is starting. If it is not determined that the engine is starting, the process proceeds to S10, and if it is determined that the engine is starting. Proceed to S17.

  In S10, the control means 4d of the engine ECU 4 determines whether or not the vehicle state is an idle state. If it is determined that the vehicle is in the idle state, the process proceeds to S11, and if it is not determined that the vehicle is in the idle state. Proceed to S12. In S11, the control means 4d of the engine ECU 4 variably controls the generated voltage of the alternator 3 in accordance with the increase / decrease of the load current so as to maintain the SOC.

  In S12, the control means 4d of the engine ECU 4 determines whether or not the vehicle state is the acceleration state. If it is determined that the vehicle is in the acceleration state, the process proceeds to S13, and if it is not determined that the vehicle is in the acceleration state. , Proceed to S14. In S13, the control means 4d of the engine ECU 4 variably controls the generated voltage of the alternator 3 to the lower limit value.

  In S14, the control means 4d of the engine ECU 4 determines whether or not the vehicle state is a deceleration state. If it is determined that the vehicle is in a deceleration state, the process proceeds to S15, and if it is not determined that the vehicle is in a deceleration state. , Proceed to S16. In S15, the control means 4d of the engine ECU 4 variably controls the generated voltage of the alternator 3 to the upper limit value.

  In S16, since the vehicle state is a constant speed state, the control means 4d of the engine ECU 4 variably controls the generated voltage of the alternator 3 in accordance with the increase or decrease of the load current so as to maintain the SOC.

  If it is determined in S2 that the IPA ECU 5 is assisting parking, if it is not determined in S6 that the SOC is within the control range, if it is not determined in S7 that the temperature of the battery 2 is within the control range, S8 In step S9, if it is determined that a sensor or switch abnormality has occurred, if it is determined in S9 that the engine is being started, the process proceeds to step S17, and the control unit 4d of the engine ECU 4 generates power from the alternator 3. The voltage is controlled to be fixed at a standard value.

  In the flowchart shown in FIG. 3 described above, the processing shown in S10 to S16 corresponds to charge control for variably controlling the power generation voltage of the alternator 3 according to the SOC and the vehicle state. When the vehicle is in an accelerating state, the power generation voltage of the alternator 3 is set to a lower limit value, and the load torque of the alternator 3 is reduced to reduce the load on the engine. When the vehicle is in a deceleration state, the power generation voltage of the alternator 3 is set to an upper limit value. The power generation voltage of the alternator 3 is increased.

  That is, in a traveling pattern in which an acceleration state, a constant speed state, and a deceleration state are repeated, the power generation capacity of the alternator 3 is suppressed as a lower limit value in the acceleration state, and the power generation capacity of the alternator 3 is suppressed to an upper limit value in the deceleration state. As a result, the power generation capacity is drawn out to the maximum extent so that the power balance of the battery 2 is positive in the total travel pattern, and the total fuel efficiency of the engine is reduced.

  In S6, when it is not determined that the SOC is within the control range, the charge control is stopped when the battery 2 is overcharged when the SOC is above the upper limit value of the control range. This is because the battery 2 is protected by preventing charging by the upper limit value of the generated voltage of the charging control in the deceleration state.

  Further, in S6, when the SOC is lower than the lower limit value of the control range, the battery 2 is overdischarged, so that charging according to the reference value of the generated voltage is performed to prevent a decrease in capacity of the battery 2. It is.

  The SOC control range of the battery 2 is a preferable range in terms of the control of the SOC of the battery 2, and the acceleration of deterioration of the battery 2 can be suppressed as long as it is at least the lower limit value and within the upper limit value.

  Similarly, in S7, when it is not determined that the temperature of the battery 2 is within the control range, the charge control is stopped when the temperature of the battery 2 is higher than the upper limit of the control range. This is to prevent the battery 2 from being charged by the upper limit value in the state.

  Further, in S7, when the SOC is below the control range adjustment, charging is performed with the standard value to prevent the capacity of the battery 2 from being reduced.

  The control range of the temperature of the battery 2 is a preferable range for controlling the temperature of the battery 2, and the deterioration of the battery 2 can be prevented from being accelerated if it is not less than the lower limit value and within the upper limit value.

  In S8, it is determined whether or not an abnormality has occurred in the wheel speed sensor, the throttle position sensor in the engine, the crank angle sensor, the stop lamp switch, the neutral position switch sensor, and the switch. When the determination is made, the reason why the charging control is stopped is that the charging control is stopped when the sensor and the switch system are out of order to prevent a decrease in the capacity of the battery 2.

  In S9, it is determined whether or not the engine is being started. If the engine is being started, the charging control is stopped because the battery 2 is discharged by a dark current before the engine is started. This is because it is preferable to perform charging with the standard value to prevent the capacity of the battery 2 from being reduced.

  According to the vehicle power supply control device 1 of the present embodiment described above, the following operational effects can be obtained.

  That is, since the prohibiting means 4e of the engine ECU 4 can prohibit the variable control of the generated voltage of the alternator 3 by the control means 4d of the engine ECU 4 when the parking support detecting means 4b detects the parking support of the IPACECU 5, the vehicle There are two types of loads: constant resistance load and constant power load, which prevents the torque fluctuation of the alternator 3 when the generated voltage becomes variable mainly by the former, and thus prevents the engine load fluctuation. Accordingly, fluctuations in the engine creep torque can be prevented.

  As a result, when the user parks using the parking assistance of the IPA ECU 5, the vehicle behavior becomes unstable and the merchantability of the vehicle is affected when the vehicle is driven backward mainly using creep torque. It can prevent giving.

  Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions are made to the above-described embodiments without departing from the scope of the present invention. be able to.

  For example, in the above-described embodiment, the control means 4d of the engine ECU 4 performs charge control for variably controlling the power generation voltage of the alternator 3. In addition to the presence / absence of parking assistance of the IPA ECU 5 according to the present invention, the SOC is within the control range. , Whether or not the temperature of the battery 2 is within the control range, whether or not the sensor and switch are abnormal, and whether or not the engine is starting, It is also possible to cancel.

  For example, when the charging control is continuously performed for 2 hours, the charging control is temporarily stopped using the current sensor 9 to correct the SOC integration error, and the battery 2 is connected with the power generation voltage of the alternator 3 as a standard value. By charging, the capacity reduction of the battery 2 can be prevented.

  Alternatively, when the cumulative operation time exceeds 20 hours, the charging control is stopped, and the battery 2 is periodically charged with the power generation voltage of the alternator 3 as a standard value. As a result, it is also possible to prevent life deterioration.

  Furthermore, in the embodiment described above, the alternator 3 is controlled by the engine ECU 4, but a dedicated alternator control ECU separate from the engine ECU 4 is provided, and the alternator control ECU and the engine ECU 4 are controlled by the CAN. It is good also as a structure to connect.

  The present invention relates to a vehicle power supply control device applied to an automobile. When a user performs parking using a parking support device by adding a relatively minor device and changing a control content, the vehicle behavior is described. It is possible to prevent the vehicle from becoming unstable and affecting the merchantability of the vehicle, so that it can be applied to various vehicles such as passenger cars, trucks, buses and the like.

It is a mimetic diagram showing one embodiment of a power supply control device for vehicles concerning the present invention. It is a schematic diagram which shows a part of one Embodiment of the vehicle power supply control apparatus concerning this invention. It is a flowchart which shows the control content of one Embodiment of the vehicle power supply control apparatus concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power supply control apparatus for vehicles 2 Battery 3 Alternator 4 Engine ECU
5 IPAECU
6 EPSECU
7 ABS
8 EPS
9 Current sensor 10 Temperature sensor 11 Three-phase armature coil 12 Three-phase full-wave rectifier 13 Field coil 14 Transistor 15 Flywheel diode

Claims (2)

  A power source that supplies power to a load, a generator that is driven by an engine to supply power to the load and the power source, a charge amount detection means that detects a charge amount of the power source, and a vehicle state detection that detects a vehicle state Means for detecting parking assistance of the parking assistance device, control means for variably controlling the power generation voltage of the generator based on the charge amount and the vehicle state, and the parking assistance detection means A vehicle power supply control device comprising: prohibiting means for prohibiting variable control of the control means when detecting parking assistance of the support device.   The vehicle state includes whether the vehicle is in an acceleration state, a deceleration state, a constant speed state, whether the engine is in an idle state, whether an abnormality has occurred in sensors and switches, and whether the engine is being started. The vehicle power supply control device according to claim 1, comprising:

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