Vehicle control device and recording medium

Abstract

The invention provides a vehicle control device and a recording medium which can indirectly estimate the voltage value of a battery even if the voltage value of the battery cannot be directly measured due to an abnormality of a voltage sensor and a current sensor. A vehicle control device according to one embodiment of the present disclosure estimates the voltage value of a battery mounted in a vehicle without using both a voltage sensor capable of measuring the voltage value of the battery and a current sensor capable of measuring the current value of the battery. The vehicle control device includes a processor, and a memory capable of storing a program executed by the processor, the program including instructions that cause the processor to execute operations including: calculating a required amount of power and a current value estimated to be required for driving the vehicle; and estimating the voltage value of the battery on the basis of the calculated amount of required power and the estimated value of the current value.

Description

Technical Field

[0001] The present disclosure relates to a vehicle control device and a recording medium applied to an electric vehicle such as an electric car equipped with a battery. Background Art

[0002] An electric vehicle having an electric motor driven by electric power supplied from a battery has a controller for detecting the state of the battery. Such an electric vehicle controls the driving state of the electric motor, inverter, etc. based on the state of the battery detected by the controller to control the charge and discharge of the battery.

[0003] The on-board battery is an element that supplies the power required for driving the electric vehicle, and has a function of, for example, supplying the required current to the electric motor via the inverter to drive it. Thus, in order to drive the electric motor, it is necessary to supply an appropriate current from the battery, and therefore, Patent Document 1 proposes a solution for preventing excessive charging and discharging of the battery when a controller fails.

[0004] Prior art literature Patent Literature Patent Document 1: Japanese Patent Application Publication No. 2014-205386 Summary of the invention

[0005] Technical issues However, not limited to the above patent documents, the current technology cannot be said to have adequately met the market demand, and there are the following problems. That is, in the case of an electric vehicle that is assumed to be actually used, due to aging, poor conditions, etc., some abnormalities occur in the voltage sensor and current sensor for monitoring the voltage value of the battery, and thus the voltage sensor and current sensor may not operate.

[0006] Thus, even when a voltage sensor or current sensor fails and a device for directly measuring the battery voltage value cannot be used, it is desirable to have a unit for indirectly estimating the battery voltage value as a backup unit for protecting the battery and continuing to drive the electric vehicle as much as possible.

[0007] The present disclosure has been made in view of the above-mentioned problem as an example, and an object thereof is to provide a vehicle control device or the like that can indirectly estimate the battery voltage value even when a voltage sensor or a current sensor has an abnormality and cannot directly measure the battery voltage value.

[0008] Technical Solution In order to solve the above-mentioned problems, the vehicle control device in the present disclosure estimates the voltage value of the battery mounted on the vehicle without using both a voltage sensor capable of measuring the voltage value of the battery and a current sensor capable of measuring the current value of the battery. The vehicle control device has a processor and a memory capable of storing a program executed by the processor, the program including instructions, which cause the processor to perform the following operations, including: calculating the required power and current value estimated to be required for driving the vehicle; and estimating the voltage value of the battery based on the calculated required power and estimated value of the current value.

[0009] Technical Effects According to the present disclosure, even when a voltage sensor or a current sensor has an abnormality and cannot directly measure the voltage value of the battery, the voltage value of the battery can be indirectly estimated. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram showing a configuration example of an electric vehicle in the first embodiment.

[0011] Figure 2 This is a functional block diagram of the electric vehicle in the first embodiment.

[0012] Figure 3 This is a functional block diagram showing a vehicle control device and peripheral devices mounted on the electric vehicle according to the first embodiment.

[0013] Figure 4 It is a schematic diagram showing a known battery model using an RC equivalent circuit.

[0014] Figure 5 : is a flowchart showing the voltage estimation method in the first embodiment.

[0015] Figure 6 This is a functional block diagram of an electric vehicle in the second embodiment.

[0016] Figure 7 : is a flowchart showing the voltage estimation method in the second embodiment.

[0017] Figure 8 is a schematic diagram showing a first vehicle motion model (single wheel model).

[0018] Explanation of symbols 100, 110: Electric vehicles 1: Battery 10: Vehicle control device 20: Converter 50: Electric motor DETAILED DESCRIPTION

[0019] Next, the preferred embodiment of the present disclosure is described. It should be noted that in this specification and the drawings, the same symbols are marked to omit repeated descriptions of components with substantially the same functional structure. In addition, with respect to structures other than those described in detail below, the element technologies and structures related to known electric vehicles including the above-mentioned patent documents can also be appropriately supplemented for implementation.

[0020] [First embodiment] <Electric Vehicle 100> Figure 1 and Figure 2 Schematic diagrams showing examples of the structure of the electric vehicle 100 of the present embodiment. It should be noted that various known electric vehicles driven by electric motors, such as electric vehicles, hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (PHEVs) that can be equipped with a battery 1 described later, can be applied as the electric vehicle 100 suitable for the present embodiment. In addition, various known secondary batteries such as lithium-ion secondary batteries and nickel-metal hydride batteries can be applied as the preferred battery 1 in the present embodiment.

[0021] like Figure 1 As shown, the electric vehicle 100 is configured to supply electric power from the battery 1 to the electric motor 50 via a known converter 20 under the control of the vehicle control device 10. The converter 20 of this embodiment may include a known DC / DC converter that adjusts the voltage value of the DC current to a desired voltage value in addition to a known AC / DC converter and a DC / AC converter that appropriately convert between a DC current and an AC current.

[0022] like Figure 2 As shown, as an example, the electric vehicle 100 is configured as a four-wheel drive vehicle that transmits the driving torque output from the electric motor 50 that generates the driving torque of the vehicle to the left front wheel 3LF, the right front wheel 3RF, the left rear wheel 3LR and the right rear wheel 3RR (hereinafter collectively referred to as "drive wheels 3" when no special distinction is required).

[0023] The electric motor 50 suitable for the present embodiment is not particularly limited, and a known electric motor such as that exemplified in the above-mentioned patent document can be applied. The electric motor 50 can output a driving torque transmitted to the front wheel drive shaft 2F and the rear wheel drive shaft 2R via a known transmission 51, a front wheel differential mechanism 5F, and a rear wheel differential mechanism 5R, respectively.

[0024] It should be noted that, in the present embodiment, an example is shown in which a single electric motor 50 distributes driving torque to each wheel, but an electric motor 50 may be provided on each of the front wheel side and the rear wheel side, or an electric motor 50 may be provided on each of the driving wheels 3. In addition, as described above, the electric vehicle 100 of the present embodiment is configured as a four-wheel drive vehicle, but it may also be a two-wheel drive vehicle in which the electric motor drives the front wheels or the rear wheels.

[0025] The electric motor 50 is electrically connected to the battery 1 via the converter 20. The vehicle control device 10 described later can control the supply of power required for driving the electric motor 50 from the battery 1 via the converter 20 or the charging of power generated by the electric motor 50 during regeneration into the battery 1 via the converter 20.

[0026] In addition, as equipment for driving control of the vehicle, the electric vehicle 100 of the present embodiment is configured to include a known electric steering device 8 and brake devices 4LF, 4RF, 4LR, 4RR (hereinafter, collectively referred to as "brake device 4" when no special distinction is required) and the like. In the present embodiment, the electric steering device 8 is provided on the front wheel drive shaft 2F. The electric steering device 8 includes a known motor and gears (not shown) for driving the electric steering device, and is controlled by the control ECU 11 to adjust the steering angles of the left front wheel 3LF and the right front wheel 3RF.

[0027] Such a control ECU 11 is mounted on the vehicle as a whole or divided into a plurality of ECUs, and may be one or a plurality of known electronic control units (ECUs) that respectively control the driving of the electric motor 50 , the electric steering device 8 , the steering wheel 9 , and the brake device 4 .

[0028] The vehicle control device 10 may also be configured as one of the above-mentioned electronic control units (ECUs), and may be configured to include one or more processors (CPUs (Central Processing Units)), and one or more memories connected to the one or more processors in a communicative manner. In addition, as an example, the vehicle control device 10 may also be configured to be connected to a known external network NT such as the Internet via various known communication devices CD such as a communication method via a smartphone or an on-board communication device. Such a vehicle control device 10 is electrically connected to the above-mentioned communication device CD, a sensor type SR, a known hard disk, a storage device MD such as an SSD, a notification device PD including a known speaker SP, a display DP, etc., directly or via an on-board communication unit such as a CAN (Controller Area Network) or a LIN (Local Inter Net).

[0029] The sensor type SR is composed of a known voltage sensor SR1 capable of detecting the voltage value of the battery 1, a known current sensor SR2 capable of detecting the current value of the battery 1, a known acceleration sensor SR3 capable of detecting the acceleration of the electric vehicle 100 during driving, and a known yaw rate sensor SR4 capable of detecting the yaw rate of the electric vehicle 100 during driving. It should be noted that the sensor type SR of this embodiment may include, in addition to the above-mentioned sensors, known vehicle-mounted sensors such as a vehicle speed sensor, a camera sensor, or a gyro sensor.

[0030] <Configuration of Vehicle Control Device 10 > Figure 3 A configuration example of the vehicle control device 10 and peripheral devices in the present embodiment is shown.

[0031] As described above, since the electric vehicle 100 is equipped with the voltage sensor SR1 and the current sensor SR2, the voltage value of the battery 1 is detected via the voltage sensor SR1 and the current sensor SR2 unless an abnormality such as a malfunction occurs. However, due to aging, malfunction, etc., some abnormality occurs in the voltage sensor SR1 and the current sensor SR2, and thus an abnormality may occur in which the voltage value of the battery 1 cannot be detected via the voltage sensor and the current sensor.

[0032] Although there are many known examples of dealing with such abnormal conditions by estimating the charge rate (SOC) of the battery 1, the conventional method is limited to the estimation of the SOC. Therefore, in the conventional method, for example, it may be difficult to accurately estimate the voltage of the battery that dynamically fluctuates with charging and discharging. Therefore, it can be said that a method that can more accurately estimate the voltage of the battery that changes all the time by considering various models (battery model and vehicle motion model described later) as in the present embodiment is more desirable.

[0033] That is, the vehicle control device 10 is configured as a control device that estimates the voltage value of the battery 1 without using both the voltage sensor SR1 capable of measuring the voltage value of the battery 1 mounted on the vehicle and the current sensor SR2 capable of measuring the current value of the battery.

[0034] Such a vehicle control device 10 includes a processor and a memory capable of storing a program executed by the processor. The program includes instructions. The instructions cause the processor to perform the following operations, including calculating a required power and a current value estimated to be required for driving the vehicle, and estimating the voltage value of the battery based on the calculated required power and the estimated value of the current value.

[0035] <Functional Block of Vehicle Control Device 10> like Figure 3 As shown, the vehicle control device 10 includes a voltage measuring unit 10a, a voltage sensor failure determination unit 10b, a motor output estimation unit 10c, a power estimation unit 10d, a current estimation unit 10e, a voltage estimation unit 10f, and a notification control unit 10g.

[0036] (Voltage measurement unit 10a) The voltage measuring unit 10a is configured to have a function of measuring the voltage value of the battery 1 via the voltage sensor SR1. The voltage measuring unit 10a can measure the voltage value of the battery 1 at a predetermined timing by driving the electric motor 50 while the electric vehicle 100 is traveling, for example.

[0037] (Voltage Sensor Failure Determination Unit 10 b ) The voltage sensor failure determination unit 10b is configured to have a function of determining whether the voltage sensor SR1 has a failure. More specifically, the voltage sensor failure determination unit 10b can determine whether the voltage sensor SR1 has a failure based on whether the voltage value of the battery 1 measured by the voltage measuring unit 10a is within an abnormal range. The value of such an abnormal range can be determined in advance by experiments or simulations according to the type and specifications of the battery 1 used.

[0038] In addition to the above-described failure determination method, the voltage sensor failure determination unit 10 b may determine whether the voltage sensor SR1 has a failure by using a known voltage sensor failure detection method as exemplified in International Publication WO2014 / 167644, for example.

[0039] (Motor Output Estimation Unit 10c) The motor output estimating unit 10c acquires the requested torque in the vehicle (i.e., the torque requested by the electric motor 50 generated in accordance with the accelerator operation of the driver), and estimates the motor output value based on the acquired requested torque and the current rotation speed of the electric motor 50. More specifically, the motor output estimating unit 10c is configured to have a function of estimating the motor output value by multiplying the requested torque by the current rotation speed of the electric motor 50.

[0040] It should be noted that, as an example, the requested torque for the electric motor 50 can be calculated by a known method based on the vehicle speed and the accelerator opening. In addition to the above method, the motor output estimating unit 10c can also calculate the requested torque for the electric motor 50 according to a known method disclosed in, for example, Japanese Patent Application Publication No. 2016-096657, Japanese Patent Application Publication No. 2020-100360, etc.

[0041] (Power Estimation Unit 10d) The power estimation unit 10d estimates the required power (output) to be supplied by the battery 1 based on the motor output value of the electric motor 50 estimated (calculated) by the motor output estimation unit 10c and the energy conversion efficiency coefficient in the power transmission path from the battery 1 to the electric motor 50. More specifically, the power estimation unit 10d is configured to have the following function: by dividing the motor output value by the energy conversion efficiency coefficient in the electric motor 50 and the converter 20 (inverter in this example), the required power (output) to be supplied by the battery 1 is estimated.

[0042] The energy conversion efficiency coefficient may be obtained in advance by performing experiments or simulations, for example, and then stored in the storage device MD as coefficient information, or may be downloaded from an external server or the like via the communication device CD.

[0043] (Current Estimation Unit 10e) The current estimating unit 10e estimates the current value flowing through the battery 1 based on the required power (output) estimated by the power estimating unit 10d. More specifically, the current estimating unit 10e is configured to have a function of estimating the current value flowing through the battery 1 by dividing the required power (output) estimated by the power estimating unit 10d by the voltage value calculated in the previous calculation. As described later, since the vehicle control device 10 can estimate the voltage value of the battery 1 at regular intervals (for example, 1 ms to 10 ms), the voltage value of the battery 1 estimated Δt seconds (several m seconds) ago can be used as the voltage value calculated in the previous calculation.

[0044] (Voltage Estimation Unit 10f) The voltage estimating unit 10f estimates the voltage value (terminal voltage) of the battery 1 by substituting the current value of the battery 1 estimated by the current estimating unit 10e into a known battery model formula. Such a battery model formula can be expressed as follows: Figure 4 As exemplified above, the following voltage calculation formula based on a battery model using a well-known RC equivalent circuit is applied.

[0045] Battery voltage formula: V (t k )=V OCV (SOC(t k ))-R0I(t k )-R1I R1 (t k ) That is, according to the above voltage calculation formula, it is possible to calculate the voltage from the open circuit voltage V OCV Subtract the resistance R0 representing the solution resistance of the battery and the current I (t k ) and the product of the resistance R1 representing the charge transfer resistance and the current I (tk ) to calculate the time t k The terminal voltage V of battery 1 (t k It should be noted that it is preferred to obtain the above open circuit voltage V in advance through experiments or simulations. OCV , the values ​​of resistor R0 and resistor R1.

[0046] It should be explained that Figure 4 The well-known RC equivalent circuit shown is an example of a battery model, and the voltage estimation unit 10f can also estimate the voltage value (terminal voltage) in the battery 1 by applying the above-mentioned current value estimated by the current estimation unit 10e to other well-known battery models disclosed in, for example, Japanese Patent Publication No. 2014-74682 and Japanese Patent Publication No. 2017-138128.

[0047] (Notification control unit 10g) The notification control unit 10g performs processing to notify various information such as whether the battery 1 has a fault, the estimated voltage value, etc. through the notification device PD including the above-mentioned speaker SP and display DP. It should be noted that the notification control unit 10g can present the above-mentioned various information to the occupants through the on-board notification device PD, or can perform the following control: access an external terminal such as a smartphone held by the occupants to make notifications.

[0048] <Method for estimating voltage of battery 1 without using voltage sensor and current sensor> Next, in reference Figure 5 At the same time, a battery voltage estimation method that can be executed by the vehicle control device 10 in this embodiment will be described. As described above, the voltage estimation method of this example can be implemented in the form of a program, and the program can be stored in a well-known recording medium.

[0049] like Figure 5 As shown, in step 1, the vehicle control device 10 determines whether the vehicle-mounted voltage sensor SR1 is abnormal. More specifically, as an example, the voltage sensor failure determination unit 10b of the vehicle control device 10 can determine whether the voltage sensor SR1 is faulty based on whether the voltage value of the battery 1 measured by the voltage measuring unit 10a is within the abnormal range.

[0050] If it is determined in step 1 that the voltage sensor SR1 is not abnormal, in the next step 2A, the vehicle control device 10 obtains the voltage value measured by the voltage sensor SR1 that is operating normally. Thus, the vehicle control device 10 holds the value measured by the voltage sensor SR1 as the voltage value of the battery 1, and if the system is not shut down (No in step 6), returns to step 1 and repeats the process.

[0051] On the other hand, when it is determined in step 1 that the voltage sensor SR1 is abnormal and has failed, the vehicle control device 10 performs the process of estimating the voltage value of the battery 1 without using the voltage sensor SR1 and the current sensor SR2 through the subsequent process of step 2B and thereafter. That is, the vehicle control device 10 first obtains information related to the requested torque of the electric motor 50 in step 2B. More specifically, the motor output estimation unit 10c of the vehicle control device 10 obtains the requested torque in the vehicle (the torque requested by the electric motor 50) by the above-mentioned well-known method.

[0052] Next, in step 3 , the motor output estimating unit 10 c of the vehicle control device 10 estimates the motor output value of the electric motor 50 based on the acquired requested torque and the rotation speed of the electric motor 50 at that time.

[0053] Then, after the motor output value is estimated in step 3, in the next step 4, the vehicle control device 10 estimates the current value from the battery 1 corresponding to the motor output value. As described above, the power estimation unit 10d of the vehicle control device 10 estimates the required power (output) to be supplied by the battery 1 based on the motor output value and the energy conversion efficiency coefficient from the battery 1 to the electric motor 50. Then, the current estimation unit 10e of the vehicle control device 10 estimates the current value flowing in the battery 1 by the above method based on the estimated required power (output).

[0054] After estimating the current value from the battery in step 4, in the next step 5, the vehicle control device 10 estimates the voltage value (terminal voltage) of the battery 1 based on the estimated current value flowing in the battery 1. More specifically, the voltage estimating unit 10f of the vehicle control device 10 estimates the voltage value (terminal voltage) of the battery 1 by substituting the current value of the battery 1 into the formula of the battery model.

[0055] By going through the above steps 2B to 5 , the vehicle control device 10 can estimate the voltage value of the battery 1 with high accuracy without using the voltage sensor SR1 and the current sensor SR2 which cannot be used due to some abnormality or failure.

[0056] In addition, after the vehicle control device 10 estimates the voltage value of the battery 1 in step 5, it returns to step 1 and repeats the above process unless it is determined that the system is off in step 6. As an example, the vehicle control device 10 can estimate the voltage value by repeatedly performing the processes of steps 1 to 6 at a predetermined cycle (for example, several milliseconds to tens of milliseconds).

[0057] <Recording Medium> As described above, as a computer-readable voltage value estimation program, the above-mentioned battery voltage estimation method can be implemented. That is, the vehicle control device 10 can also be configured to be able to read the battery voltage value estimation program. In addition, as described later, the battery voltage value estimation program can also be stored in a known recording medium. In addition, the voltage value estimation program can also be downloaded to the electric vehicle 100 from a known server such as a cloud.

[0058] In this way, a recording medium suitable for the present embodiment is implemented as a non-temporary tangible recording medium, which is a non-temporary tangible recording medium recording a voltage value estimation program, wherein the voltage value estimation program estimates the voltage value of the battery without using both a voltage sensor capable of measuring the voltage value of the battery mounted on the vehicle and a current sensor capable of measuring the current value of the battery, and the voltage value estimation program includes instructions that cause the processor to perform the following operations, including calculating the required power and current value estimated to be required for driving the vehicle, and estimating the voltage value of the battery based on the calculated required power and estimated value of the current value.

[0059] It should be noted that the recording medium for recording the computer program may be magnetic media such as a hard disk, a floppy disk, and a magnetic tape, optical recording media such as a CD-ROM (Compact Disk Read Only Memory), a DVD (Digital Versatile Disk), and Blu-ray (registered trademark), magneto-optical media such as an optical magnetic disk, storage elements such as a RAM and a ROM, flash memories such as a USB (Universal Serial Bus) memory, an SSD (Solid State Drive), or other media capable of storing a program.

[0060] According to the vehicle control device 10 and the electric vehicle 100 equipped with the vehicle control device 10 in the first embodiment described above, even when the voltage sensor and the current sensor are abnormal and the battery voltage value cannot be directly measured, the battery voltage value can be indirectly estimated based on the requested torque for the electric motor.

[0061] [Second embodiment] Next, use Figure 6~Figure 8 Next, a method for estimating the voltage of the electric vehicle 110 and the battery 1 according to the second embodiment will be described.

[0062] The vehicle control device 10 in the electric vehicle 110 of the present embodiment is configured to further include an acceleration acquisition unit 10h compared to the first embodiment described above. That is, in the first embodiment, the vehicle control device 10 estimates the motor output value of the electric motor 50 using the torque requested to the motor, but the vehicle control device 10 of the present embodiment is mainly characterized in that the motor output value of the electric motor 50 is estimated mainly using the acceleration information of the vehicle traveling straight.

[0063] Here, regarding the determination of whether the vehicle is traveling straight, the vehicle control device 10 can, for example, determine that the vehicle is traveling straight when the steering angle of the steering wheel 9 is within a predetermined angle. It should be noted that the method for determining whether the vehicle is traveling straight is not limited to the above method, and for example, other well-known methods such as detection using a gyro sensor can also be applied. In addition, the vehicle control device 10 can also detect the road conditions ahead of the vehicle based on the map information of the vehicle-mounted navigation device, and determine whether the vehicle is traveling straight based on the road conditions ahead.

[0064] (Acceleration acquisition unit 10h) The acceleration acquisition unit 10h is configured to have a function of acquiring acceleration information of the vehicle during travel via the acceleration sensor SR3 mounted on the electric vehicle 110. It should be noted that the acceleration acquisition unit 10h of the present embodiment obtains the acceleration of the vehicle from the acceleration sensor SR3, but is not limited to this method, and may also be a method of calculating the acceleration by performing differential processing using the values ​​of a known vehicle speed sensor or position information sensor mounted on the vehicle.

[0065] <Method for estimating voltage of battery 1 without using voltage sensor and current sensor> Next, in reference Figure 7 and Figure 8 At the same time, a battery voltage estimation method that can be executed by the vehicle control device 10 in the second embodiment will be described. It should be noted that in the voltage estimation method described below, the description of the same structure as that of the first embodiment is appropriately omitted.

[0066] First, in step 1, the vehicle control device 10 determines whether the voltage sensor SR1 is faulty in the same manner as in the first embodiment. Then, if the voltage sensor SR1 is not abnormal in step 1, the vehicle control device 10 stores the value measured by the voltage sensor SR1 as the voltage value of the battery 1 in the next step 2A. On the other hand, if the voltage sensor SR1 is abnormal in step 1, the voltage value of the battery 1 is estimated mainly using information obtained from the acceleration sensor SR3 in steps 2C and thereafter.

[0067] That is, in step 2C, the acceleration acquisition unit 10h of the vehicle control device 10 acquires acceleration information of the traveling electric vehicle 110 via the acceleration sensor.

[0068] After acquiring the acceleration information of the electric vehicle 110 , the motor output estimating unit 10 c of the vehicle control device 10 estimates the driving force generated in the driving wheels 3 of the electric vehicle 110 in the following method in the next step 2E.

[0069] That is, in this example, it is assumed that the electric vehicle 110 is accelerated at an acceleration α at a certain time t, and the current value flowing from the battery 1 at this time is estimated using a known vehicle motion model. Figure 8 As shown, in this example, a first vehicle motion model (single-wheel model) is applied, but it can also be applied to well-known multi-wheel models such as a two-wheel model. The first vehicle motion model is a model in which the electric vehicle 110 has only a single-wheel tire without considering the center of gravity movement, yaw motion, etc.

[0070] In this case, the estimated value of the driving force F generated by the electric vehicle on the driving wheels 3 to obtain the acceleration α among the resistances (in this example, limited to air resistance, rolling resistance, and slope resistance) applied to the vehicle is obtained by the following calculation formula.

[0071] Driving force F generated between driving wheel 3 and road surface = vehicle weight × acceleration α Here, the "vehicle weight" in the above calculation formula can be obtained in advance through experiments and simulations. It should be noted that, for the "vehicle weight" in the above calculation formula, it is also possible to use a known tire force sensor disclosed in Japanese Patent Publication No. 2006-349440 or other known wheel hub sensors to perform detection in a timely manner instead of the above experiments.

[0072] Therefore, in step 2E, the motor output estimating unit 10 c of the vehicle control device 10 estimates the driving force generated in the driving wheels 3 of the electric vehicle 110 based on the acceleration obtained in step 2C and the vehicle weight information stored in advance.

[0073] In the next step 2F, the motor output estimation unit 10c of the vehicle control device 10 estimates the torque generated by the electric motor 50 by the method shown below. That is, as described above, the resistance (the above-mentioned air resistance, rolling resistance, slope resistance, etc.) to the vehicle can be calculated in advance by experiments and simulations, so the torque T required by the electric motor 50 is obtained by the following calculation formula.

[0074] Torque T output by the motor = (driving force F generated between the driving wheel 3 and the road surface + resistance to the vehicle) × tire radius / gear ratio It should be noted that the air resistance of the above-mentioned vehicle can be calculated by a known method disclosed in, for example, Japanese Patent Publication No. 2014-080128 and Japanese Patent Publication No. 2023-036347. In addition, the rolling resistance of the vehicle can be calculated by a known method disclosed in, for example, Japanese Patent Publication No. 2009-045957 and Japanese Patent Publication No. 2014-080128. In addition, the slope resistance of the vehicle can be calculated by “body weight×sinθ” based on the inclination (slope angle θ) of the vehicle front-to-back direction relative to the horizontal plane using, for example, a gyro sensor mounted on the vehicle, or by a known method disclosed in, for example, Japanese Patent Publication No. 2020-010454.

[0075] Therefore, in step 2F, the motor output estimating unit 10c of the vehicle control device 10 estimates the torque T output by the electric motor 50 using the above calculation formula based on the driving force F estimated in step 2E and the previously stored information on the vehicle resistance, tire radius, and gear ratio.

[0076] After estimating the torque T output by the electric motor 50 in step 2F, the motor output estimating unit 10 c of the vehicle control device 10 estimates a motor output value by multiplying the torque T output by the electric motor 50 by the rotation speed of the electric motor 50 at that time in the next step 3 .

[0077] After the motor output value is estimated in step 3, the vehicle control device 10 estimates the current value from the battery 1 corresponding to the motor output value in the next step 4. That is, the power estimation unit 10d of the vehicle control device 10 estimates the required power (output) to be supplied by the battery 1 based on the motor output value and the energy conversion efficiency coefficient from the battery 1 to the electric motor 50. Then, the current estimation unit 10e of the vehicle control device 10 estimates the current value flowing in the battery 1 based on the estimated required power (output) by the method described in the first embodiment.

[0078] In this way, based on the first embodiment and the second embodiment, the vehicle control device 10 in the present disclosure can calculate the above-mentioned required electric power based on at least one of the acceleration acquired from the vehicle and the requested torque in the vehicle.

[0079] It should be noted that since the processing after step 5 is the same as that of the above-mentioned first embodiment, the description thereof will be omitted.

[0080] According to the vehicle control device 10 and the electric vehicle 110 in the second embodiment described above, even if a voltage sensor or a current sensor fails to directly measure the battery voltage value, especially in a vehicle traveling straight, the battery voltage value can be indirectly estimated via the acceleration sensor.

[0081] <Modification> In the second embodiment, the motor output value of the electric motor 50 is estimated mainly by using the acceleration information of the vehicle traveling in a straight line, but the motor output value of the electric motor 50 when the vehicle turns may be estimated as follows. That is, when the vehicle turns on a curve, lateral force is generated on the tires due to the turning.

[0082] Therefore, during the above-mentioned turn, the lateral force is applied as "resistance applied to the vehicle", and therefore, the resistance caused by the lateral force may be added to the "resistance applied to the vehicle" in the above-mentioned formula of the torque T. As a method for calculating the resistance caused by such a lateral force, it may be calculated in advance by experiments or simulations, or a known estimation method disclosed in, for example, Japanese Patent Application Laid-Open No. 2007-331659 may be applied.

[0083] The vehicle control device 10 may detect the road condition ahead of the vehicle based on map information from a vehicle-mounted navigation device, for example, and estimate the motor output value of the electric motor 50 after determining whether the vehicle is turning based on the road condition ahead.

[0084] The preferred embodiments of the present disclosure are described in detail with reference to the accompanying drawings, but the present disclosure is not limited to this example. A person having ordinary knowledge in the technical field to which the present disclosure belongs will know that it is obvious to attempt to make further modifications to these embodiments and variations within the scope of the technical ideas described in the claims, and will understand that these also belong to the technical scope of the present disclosure.

Claims

1. A vehicle control device, characterized in that: The voltage value of the battery is estimated without using both a voltage sensor capable of measuring the voltage value of the battery mounted on the vehicle and a current sensor capable of measuring the current value of the battery. The vehicle control device includes a processor and a memory capable of storing a program executed by the processor. The program includes instructions, The instructions cause the processor to perform the following operations, which include: calculating a required amount of electricity and a current value estimated to be required for driving the vehicle; and A voltage value of the battery is estimated based on the calculated required power amount and the estimated value of the current value.

2. The vehicle control device according to claim 1, characterized in that: The required amount of power is calculated based on at least one of an acceleration acquired from the vehicle and a requested torque in the vehicle.

3. The vehicle control device according to claim 2, characterized in that: The instruction also includes determining the road condition ahead of the vehicle. When estimating the voltage of the battery, the voltage value of the battery is estimated based on acceleration information of the vehicle according to the road condition ahead.

4. A non-transitory tangible recording medium, characterized in that A voltage value estimation program is recorded, wherein the voltage value estimation program estimates the voltage value of a battery without using both a voltage sensor capable of measuring the voltage value of the battery mounted on a vehicle and a current sensor capable of measuring the current value of the battery, The voltage value estimation program includes instructions, The instructions cause the processor to perform the following operations, including: calculating a required amount of electricity and a current value estimated to be required for driving the vehicle; and A voltage value of the battery is estimated based on the calculated required power amount and the estimated value of the current value.

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