JP2009296837A - Vehicle driving control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To equalize lifetime of batteries mounted on two or more vehicles. <P>SOLUTION: A management center 100 collects data of battery temperature and the like from each vehicle 1 which runs each run way. In an operation unit 108 of the management center 100 calculates the battery life for each run way based on the battery temperature, battery current, variation amount of SOC and the like, and directs each vehicle 1 by determining a running pattern where running days for each running way are established so that the battery life may be distributed. Two or more running patterns are established so that the battery life may be distributed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle operation control system, and more particularly to group control of a plurality of vehicles according to the life of a secondary battery.

  In a hybrid vehicle or the like using a secondary battery such as a nickel metal hydride battery or a lithium ion battery in which a plurality of battery modules made of one or a plurality of single batteries are connected in series, the degree of deterioration of the secondary battery Techniques for calculating are known. On the other hand, in a hybrid vehicle or the like, it is known that the degree of deterioration of the secondary battery varies depending on whether the main traveling area is a mountainous area or an urban area.

  In Patent Document 1 below, driving information relating to the running state of a vehicle powered by battery power and the operating state of the battery is calculated and processed, and the centralized management device via the communication means performs battery diagnosis based on the information on a plurality of vehicles. It is disclosed that a result of the measurement is sent to a vehicle. Specifically, the integrated management device is the lifetime elapsed time from the start of use of the secondary battery, lifetime travel distance, travel distance for each refueling, elapsed time, fuel consumption, fuel consumption, vehicle temperature history, engine speed history, The life of the secondary battery is simulated based on the battery history, the current battery characteristics, positioning in the whole life, and prediction of the life time are made, depending on whether the life time is in the initial, middle or end Thus, the lower limit and upper limit ranges of the voltage per cell of the secondary battery, the upper limit of the current, and the upper limit of the output and input are calculated.

JP 2003-264906 A

  However, the conventional technology does not take into consideration that the life of a plurality of vehicles is intentionally varied. In companies with multiple vehicles such as bus companies and freight companies, there is a problem from the viewpoint of maintenance work that the life of secondary batteries of multiple vehicles is almost at the same time and it is necessary to replace them at the same time. In some cases, it is convenient to appropriately distribute the life of the secondary battery. Conventionally, it is replaced only when the service life is reached, and there is no idea of intentionally performing group control of vehicles so that the service life of a plurality of vehicles is dispersed.

  An object of the present invention is to distribute the life of secondary batteries of a plurality of vehicles by group control.

  The present invention is a vehicle control system including a vehicle and a management center that transmits and receives data to and from the vehicle, the vehicle including a secondary battery, a motor driven by the power of the secondary battery, and the second Means for transmitting at least one of temperature data of the secondary battery, current value data, and one-trip SOC change amount data to the management center, and the management center receives the data transmitted from the vehicle. And an operation pattern in which the service life of the secondary battery is calculated for each travel route of the plurality of travel routes based on the received data, and the operation days for each travel route are set so that the life is distributed. And a plurality of calculating means.

  ADVANTAGE OF THE INVENTION According to this invention, it is controllable so that the lifetime of the secondary battery of a some vehicle is distributed systematically beforehand. Thereby, the maintenance of the secondary battery can be performed in a planned manner, and the work efficiency of the maintenance is improved. Cash flow can also be improved.

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

  FIG. 1 shows an overall system diagram of a vehicle 1 in the present embodiment. The assembled battery 10 is configured by connecting a plurality of battery cells in series. The assembled battery 10 is, for example, a nickel metal hydride battery or a lithium ion battery, and 240 battery cells are connected in series to output a voltage of about 300V. The voltage of the assembled battery 10 is A / D converted by the voltage detection unit 40 in the battery monitoring device 32 and supplied to the battery state determination unit 42 in the battery monitoring device 32 as a digital value. The current of the assembled battery 10 is detected by the current sensor 11 and supplied to the current detection unit 36 in the battery monitoring device 32. The current sensor 11 detects, for example, a magnetic field generated by a current generated when the assembled battery 10 is charged or discharged, converts the magnetic field into a voltage signal, and supplies the voltage signal to the current detection unit 36. The current detection unit 36 A / D converts a voltage signal corresponding to the current supplied from the current sensor 11 and supplies the voltage signal to the battery state determination unit 42 as a digital value. Further, temperature sensors 13 that detect the temperature of the battery are provided in the vicinity of the assembled battery 10, and the battery temperature is detected and supplied to the temperature detection unit 38 in the battery monitoring device 32. The reason why the temperature sensors 13 are provided at a plurality of locations is that the assembled battery 10 is considerably large in size and a temperature difference occurs in the assembled battery 10. In particular, a temperature difference occurs in each block of the assembled battery 10 due to the arrangement of the cooling device and the flow rate of the refrigerant (cooling medium). Therefore, the battery state determination unit 42 performs block division so that blocks having relatively close temperatures are grouped in advance, and the temperature of the temperature sensor close to the temperature of the block is assigned in advance experiments or the like. Thereby, the influence of the battery voltage difference by a temperature difference can be removed. For example, a thermistor is used as the temperature sensor 13, and a resistance value that varies depending on the temperature is converted into a voltage and supplied to the temperature detection unit 38. The temperature detection unit 38 performs A / D conversion on the supplied voltage signal, and supplies the voltage signal to the battery state determination unit 42 as a digital value.

  The battery state determination unit 42 detects a state of charge (SOC) of the battery based on the supplied data, that is, data on the assembled battery voltage, battery current, and battery temperature, and controls the control unit 28 of the vehicle control unit 24. To supply. The output of the battery state determination unit 42 includes battery voltage, battery current, and battery temperature data in addition to the SOC.

  The vehicle control unit 24 uses the engine ECU 15 operation state data, the accelerator pedal 22 operation amount, the brake pedal 20 operation amount, the shift range set by the shift lever 18, the transmission shift position, and the like. Based on this, a torque command value is determined, and control is performed so that the output of the motor generator 17 matches the torque command value. The vehicle control unit 24 controls the switching of electric power from the assembled battery 10 to the motor generator by the inverter 12 and simultaneously supplies a signal for controlling the output of the engine 14 to the engine ECU 15. As a result, the output of the motor generator 17 is controlled to match the torque command value. The ignition switch 16 is a switch in which the driver controls the start and stop of the vehicle, and is supplied to the detection unit 26. Even when the ignition switch 16 is stopped, the battery monitoring device 32 and the vehicle control unit 24 operate, but the motor generator 17 and the engine 14 cannot be operated to travel.

  When the output of the engine 14 is larger than the output of the motor generator 17, the electric power from the inverter 12 is charged in the assembled battery 10. On the other hand, when the output of engine 14 is smaller than the output of motor generator 17, assembled battery 10 is discharged and electric power is supplied from inverter 12 to motor generator 17. Thus, the motor generator 17 operates as a power generation unit and an electric unit. For example, when a decrease in the SOC of the battery pack 10 is detected by the battery state determination unit 42, the motor generator 17 generates power using a part of the torque generated by the engine 14 and charges the battery pack 10. When the stored amount of the battery pack 10 increases, the output of the engine 14 is suppressed and the motor generator 17 is operated as an electric motor, and the generated torque is used for vehicle travel. When the vehicle brakes, the motor generator 17 is operated as a generator, and the assembled battery 10 is charged with the generated power. Since it is difficult to predict when the vehicle will be braked, it is desirable that the battery pack 10 can sufficiently accept the electric power generated by the braking. On the other hand, when the acceleration desired by the driver cannot be obtained only by the output of the engine, some SOC of the assembled battery 10 is necessary to operate the motor generator 17 as an electric motor. In order to satisfy this condition, the SOC of the battery pack 10 is controlled so as to be about the middle of the battery capacity. In the case of a hybrid vehicle that generates electric power from the output of the engine 14 and charges the battery, by appropriately managing the SOC of the assembled battery 10, the regenerative power during braking is sufficiently recovered and energy efficiency is improved. Acceleration can be achieved. Thus, it is important for a vehicle using a battery as a power source, such as a hybrid vehicle, to accurately detect and appropriately control the SOC of the battery pack 10.

  Based on the signal from the battery state determination unit 42, the control unit 28 in the vehicle control unit 24 determines the charge / discharge power allowed for the assembled battery 10 from the three types of data of the assembled battery voltage, the battery current, and the current temperature, respectively. Calculated as a discharge allowable power value and a charge allowable power value. For example, when the SOC of the battery decreases, the SOC is induced higher as a result by reducing the discharge allowable power value. Further, in a situation where the SOC is high, the SOC is guided to the lower side by reducing the charge allowable power value. Further, the battery monitoring device 32 supplies the SOC value to the vehicle control unit 24, and the vehicle control unit 24 performs control so that the charge / discharge balance is adjusted so that this value is in the middle of the SOC, for example, near SOC = 60%. Do. The SOC is normally calculated and estimated from the battery temperature, the current applied to the battery, and the battery voltage, but is omitted because it is known. Further, since the internal resistance of the battery rises and the input / output is remarkably restricted in the low temperature range, the control unit 28 controls to reduce both the charge allowable power value and the discharge allowable power value. Also, when the battery voltage becomes low, the allowable discharge power value is reduced to prevent overdischarge of the battery, and when the battery voltage becomes high, the allowable charge power is used to suppress gas generation inside the battery. Decrease the value.

  The output shaft of the engine 14 is connected to the rotor of the motor generator 17 and is connected to the transmission via a clutch. The motor generator 17 functions as a three-phase AC generator or a three-phase AC motor. The clutch mechanism is constituted by a clutch cover, a clutch disk, and a flywheel, and controls to supply or shut off the torque of the output shaft of the engine 14 to the transmission by driving a solenoid by a signal from the vehicle control unit 24.

  In the transmission, the rotational speed of the engine output shaft is decelerated through an internal gear, and the drive force is connected to a drive shaft coupled with drive wheels (not shown) through a differential. With the above configuration, the output of the engine 14 or the motor generator 17 is transmitted to the drive wheels to drive the vehicle.

The engine ECU 15 obtains an output in accordance with the torque command of the control unit 28 determined by the operation amount of the accelerator pedal 22 and the operation state of the motor generator 17, so that the environmental conditions such as the cooling water temperature, the intake air temperature, the intake air flow rate, the crank Based on the operation data of the engine 14 by a sensor, knock sensor, O ₂ sensor or the like, output and rotation speed are controlled.

  The battery cooling fan 30 is arranged for air-cooling the assembled battery 10, and the intake air temperature sensor 50 is arranged for measuring the temperature of the refrigerant. When the battery temperature rises, the vehicle control unit 24 outputs a signal for changing the fan speed according to the intake air temperature TA, and controls the battery temperature to be in an appropriate temperature range by changing the fan speed. . Here, as the battery temperature, an average value, a maximum value, a minimum value, or the like of the battery temperature is selected and used according to the control content. The assembled battery 10 is disposed behind the rear seat of the vehicle and in the front part of the trunk room. The refrigerant that cools the assembled battery 10 is sucked from the passenger compartment and exhausted to the trunk room after the assembled battery is cooled.

The control unit 28 is configured such that the battery temperature (temperature average value of all blocks) TBave obtained by traveling on a predetermined traveling path, the SOC change amount ΔSOC of one trip (from turning on the ignition switch 16 to turning it off next), Each data of the time average I ² ave of the square of the battery current value and the vehicle speed SPEED is acquired and transmitted to the management center. The management center calculates the battery life for each travel path based on these data. In this embodiment, it is assumed that the traveling paths A, B, and C exist as different traveling paths, and one or a plurality of vehicles are traveled for each traveling path, and based on these data acquired for each traveling path, The battery life is calculated for each of the travel paths A, B, and C.

  FIG. 2 shows the overall configuration of the system in this embodiment. The system includes a vehicle 1 and a management center 100. The vehicle 1 and the management center 100 are connected via a base station 70. The base station may be a public line base station or a dedicated line base station. An example of a public line is a mobile phone line.

The vehicle 1 includes a control unit 28 and a transmission / reception unit (not shown), and TBave, ΔSOC, I ² ave, and SPEED obtained by traveling on a predetermined traveling path together with a vehicle ID that is data for specifying the vehicle. Are sent to the management center 100.

  The management center 100 includes an input unit 102, a communication unit 104, an output unit 106, a calculation unit 108, and a storage unit 110.

  The communication unit 104 receives data transmitted from the vehicle 1 via the base station 70.

  The calculation unit 108 stores the received data in the storage unit 110 and calculates the battery life for each travel path. And the operation pattern of each vehicle 1 is created so that the battery life of several vehicles 1 may be disperse | distributed, in other words, leveled. The created operation pattern is provided to each vehicle 1. The degree of dispersion is arbitrary, but an equal interval is an example.

  The storage unit 110 includes databases of vehicle information, travel route information, vehicle operation pattern information, and cash flow information.

  The vehicle information database includes the vehicle ID and data received from each vehicle 1.

  The travel path database has life parameters for each travel path. The life parameter for each travel route is created from data acquired in advance when the travel route is driven by a vehicle. Because these parameters are more accurate in predicting the life expectancy by taking into account fluctuations in traffic flow (traffic flow), temperature, atmospheric environment, etc., multiple vehicles, multiple times, multiple drivers, multiple rides It is desirable to change the conditions such as the number of people, change the departure time in order to take into account variations in traffic flow, and acquire data over a long period of time. However, it is also possible to acquire data in a short time in consideration of the time, labor, and economic burden required for data acquisition. For example, the route travel is performed by the number of samples of about 10 times on the same route, the life parameter of each route is acquired by estimating from the life variation factor of the secondary battery obtained in advance through experiments or the like. A description will be given of the battery temperature TBave as an example of estimation of environmental variation factors among the life parameters. The intake air of the secondary battery (that is, the refrigerant used for cooling the secondary battery) is assumed to use outside air. The battery temperature can be estimated by calculation from the intake air temperature, the heat capacity of the battery, the thermal resistance between the battery and the outside of the battery, the temperature difference between the outside of the battery, the Joule heating due to the battery current, etc. By measuring and comparing with the meteorological data of the government office on the day, and using the past meteorological data, the annual transition of the battery temperature TBave can be estimated.

  The vehicle operation pattern information database stores the number of operation days and the expected value of life for each vehicle operation pattern.

  The cash flow information database (or life leveling request value database) stores cash flow request values, that is, request values for leveling and replacing secondary batteries between 1000 days and 4500 days. The battery life interval may be set as the required value. Here, “leveling” means that the lifetime of the secondary battery is dispersed so that the lifetime of the secondary battery periodically visits the time axis.

FIG. 3 shows details of the travel route information database stored in the storage unit 110 of the management center 100. Various data are stored for each of the traveling paths A, B, and C. The battery temperature TBave is, for example, 20 (° C.) for the travel route A, 30 (° C.) for the travel route B, and 35 (° C.) for the travel route C. The travel time TimeTrip is the travel time for each travel path, and is set to 5 hours, for example. In terms of seconds, 5 hours = 18000 (seconds). ΔSOC is 10% on the road A, 15% on the road B, and 15% on the road C. I ² ave is 135 (A ² ) on the road A, 200 (A ² ) on the road B, and 300 (A ² ) on the road C. SPEED (average vehicle speed) is 20 (km / h) on the road A, 30 (km / h) on the road B, and 40 (km / h) on the road C. Further, the battery temperature and stop time during the stop are also stored. The stop time is 68 hours (seconds) when converted to 19 hours and seconds on all travel routes. fLifeon (TBave), fLife (ΔSOC), fLife (I ² ave), fLife (SPEED), and fLifeoff (TBave) are variables for calculating the battery life, and are actually stored in the storage device 110 as a lookup table. Remembered.

9 to 13 show examples of these lookup tables. FIG. 9 is a look-up table of fLifeon (TBave), which is a battery life variable determined according to the battery temperature during travel, and is a function of TBave. The computing unit 108 determines the value of fLife (TBave) for each travel path by referring to this lookup table. The travel route A is determined as 1, the travel route B as 2, and the travel route C as 3. FIG. 10 is a look-up table of fLife (ΔSOC), which is a battery life variable determined according to ΔSOC, and is a function of ΔSOC. The calculation unit 108 determines the value of fLife (ΔSOC) of each travel path by referring to this lookup table. The travel path A is determined to be 0.75, the travel path B is determined to be 1, and the travel path C is determined to be 1. FIG. 11 is a look-up table of fLife (SPEED), which is a battery life variable determined according to the vehicle speed SPEED, and is a function of SPEED. By referring to this look-up table, it is determined that the travel route A is 1.05, the travel route B is 1, and the travel route C is 0.94. FIG. 12 is a look-up table of fLife (I ² ave), which is a battery life variable determined according to I ² ave, which is the time average of the square of the battery current value, and is a function of I ² ave. By referring to this lookup table, it is determined that the travel route A is 0.85, the travel route B is 1, and the travel route C is 1.3. FIG. 13 is a look-up table of fLifeoff (TBave), which is a battery life variable determined according to the battery temperature while the vehicle is stopped, and is a function of TBave. By referring to this lookup table, it is determined that the travel route A is 0.7, the travel route B is 0.7, and the travel route C is 0.7.

After calculating these variables by referring to the look-up table, the calculation unit 108 further calculates LifeStack, which is a stack of battery life variables, for each traveling path. Running LifeStack is
LifeStack = fLifeon (TBave) × TimeTrip × fLife (ΔSOC) × fLife (I ² ave) × fLife (SPEED)
Is calculated by Therefore, it is calculated as 12048.75 for the traveling route A, 36000 for the traveling route B, and 65988 for the traveling route C. Similarly, the LifeStack being stopped is LifeStack = fLifeoff (TBave) × TimeTrip × fLife (ΔSOC) × fLife (I ² ave) × fLife (SPEED)
Is calculated by Therefore, 47880 is calculated for the travel route A, 47880 is calculated for the travel route B, and 47880 is calculated for the travel route C. The LifeStackDay for one day is the sum of the LifeStack that is running and stopped, and is calculated as 59828.75 for the road A, 83880 for the road B, and 113868 for the road C. The travel distance may be data measured in advance or may be received from the vehicle 1.

  FIG. 4 shows details of the vehicle operation pattern information stored in the storage unit 110 of the management center 100. The calculation unit 108 performs leveling so that the battery life appears periodically with respect to the time axis based on the battery life for each travel path. Specifically, the expected value of the number of operating days until the end of the service life is leveled with a vehicle operating pattern in which the operating days of the traveling paths A, B, and C are changed using the traveling path information database. The vehicle operation patterns are assumed to be 5 patterns 1 to 5, and the operation days of the travel route A, the operation days of the travel route B, and the operation days of the travel route C are assigned to each pattern. In the operation pattern 1, the traveling route A travels for 400 days, the traveling route B does not travel, and the traveling route C travels for 1103 days. The operation pattern 2 is such that the travel route A travels 1000 days, the travel route B travels 411 days, and the travel route C travels 750 days. The Life variable is obtained by multiplying the LifeStackDay of each travel route by the operation days of each travel route and dividing by the operation seconds (battery usage time) of the entire travel, and is a variable representing the battery life. The figure also shows the expected operation days and the expected travel distance. Thus, by setting the operation pattern based on the LifeStackDay for each travel path, the battery life can be distributed and leveled (battery life periodically visits).

  FIG. 5 shows the life appearance rate when the Life variable = 1,2500 days and 300,000 km travel, and FIG. 6 shows the case where the same number of vehicles are assigned to patterns 1 to 5 in the operation pattern as shown in FIG. The life appearance rate is shown. Pattern 1 has the smallest operation days expectation value, followed by patterns 2, 3, 4 and 5 in order of the operation days expectation value, and the interval between the operation days expectation values is 658 days between patterns 1 and 2. 724 days between patterns 2 and 3, 661 days between patterns 3 and 4, and 625 days between patterns 4 and 5, so that the expected operating value varies approximately at regular intervals centered around 670 days. Set to When the operation pattern is set so that the battery life is leveled as described above, the arithmetic unit 108 instructs each vehicle 1 to operate along the set operation pattern. A specific level of leveling is given by cash flow information. The calculation unit 108 assigns the number of operating days for each traveling route so as to satisfy the request given by the cash flow information.

  Depending on the type of the vehicle 1, there may be a case where an upper limit or a lower limit of the operating days of each traveling route per year is determined in advance. For example, it is assumed that the minimum number of days and the maximum number of days are limited for each of the traveling paths A, B, and C as shown in FIG. The minimum and maximum operating days are determined by the number of operating routes and the number of vehicles. If the number of days determined by each vehicle operation pattern is less than the minimum number of days, it can be supplemented by a vehicle that is not an electric vehicle, for example. In FIG. 8, the value which converted the operation days of each driving | running route of the operation pattern of FIG. 4 per year is shown. It may be determined whether or not this value satisfies the condition of FIG.

  It is also possible to store a real-time Life variable for each vehicle in the storage device 110 of the management center 100, and appropriately modify the operation pattern once set according to the Life variable. The real-time Life variable for each vehicle is accumulated by preparing a lookup table such as fLife (TBave) for each vehicle, calculating a Life coefficient for each vehicle, and transmitting it to the management center 100. The management center 100 determines whether or not the Life variable as originally predicted is obtained from the accumulated real-time Life variable, and if it is greatly deviated from the initial expected value, the vehicle is changed to another pattern. Make modifications such as allocating to.

  In this embodiment, in order to level the battery life, the number of operating days is assigned to each of the traveling routes A, B, and C. However, the operating days may be assigned to each traveling region instead of each traveling route, You may allocate for every time slot | zone. If attention is paid to a certain travel route, the degree of congestion, temperature, and vehicle speed may change depending on the travel time zone. Therefore, since the Life variable can vary greatly for each traveling time zone, it is also preferable to set the operation pattern in consideration of the traveling time zone. Referring to the travel route database in FIG. 3, each travel route is further divided into three time zones, morning, daytime, and night time, to obtain battery temperature, current value, and vehicle speed data from the vehicle 1. LifeStackDay is calculated for each time period. And in the operation pattern information of FIG. 4, what is necessary is just to allocate the frequency | count of operation for every time slot | zone of each driving path.

  In this embodiment, the control unit 28 transmits temperature data, current value data, and one-trip SOC change amount data of the secondary battery to the management center, and the management center calculates the battery life based on these data. However, the control unit 28 may transmit at least one of secondary battery temperature data, current value data, and one-trip SOC change amount data to the management center. For example, only the temperature data of the secondary battery may be transmitted. In this case, the management center calculates the battery life using predetermined data (statistically calculated fixed data) for the current value data and the SOC change amount data. Moreover, the control part 28 may transmit only the temperature data and current value data of a secondary battery. In this case, the management center calculates the battery life using predetermined data (statistical data) for the SOC change amount data. Only the SOC change amount may be transmitted to the management center. In this case, the management center calculates battery life using predetermined data (statistical data) for other data.

It is a lineblock diagram of vehicles of an embodiment. It is a system configuration figure of an embodiment. It is explanatory drawing of a travel route database. It is vehicle operation pattern information explanatory drawing. It is explanatory drawing of the lifetime appearance probability in the case of Life variable 1. It is a lifetime appearance probability explanatory drawing at the time of assigning to five operation patterns. It is condition explanatory drawing for every traveling path. It is an operation pattern explanatory view at the time of making it a year unit. It is explanatory drawing of fLifeon (TBave). It is explanatory drawing of fLife ((DELTA) SOC). It is explanatory drawing of fLife (SPEED). It is an illustration of fLife (I ² ave). It is explanatory drawing of fLifeoff (TBave).

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Vehicle, 28 control part, 100 management center, 102 input part, 104 communication part, 106 output part, 108 calculating part, 110 memory | storage part.

Claims (2)

A vehicle,
A management center for sending and receiving data to and from the vehicle;
A vehicle control system comprising:
The vehicle is
A secondary battery,
A motor driven by the power of the secondary battery;
Means for transmitting at least one of temperature data, current value data, and one-trip SOC change amount data of the secondary battery to a management center;
Have
The management center
Means for receiving data transmitted from the vehicle;
Based on the received data, the life of the secondary battery is calculated for each travel path of a plurality of travel paths, and a plurality of operation patterns are set in which the operation days for each travel path are set so that the life is distributed. Computing means;
A vehicle control system comprising: The system of claim 1, wherein
The calculation means calculates the life of the secondary battery for each travel route of each of the plurality of travel routes based on the received data, and for each travel route so that the life is distributed. A vehicle control system that sets a plurality of operation patterns in which operation days and the number of operations for each time period are set.

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