Vehicle control device and recording medium

Abstract

To provide a vehicle control device and the like that can indirectly estimate a battery voltage value even when an abnormality occurs in a voltage sensor or a current sensor and it becomes impossible to directly measure the battery voltage value.SOLUTION: A vehicle control device according to an embodiment of the present disclosure, which estimates a voltage value of a battery mounted on a vehicle without using both a voltage sensor capable of measuring a voltage value of the battery and a current sensor capable of measuring a current value of the battery includes: a processor; and a memory capable of storing a program executed by the processor. The program includes instructions that cause the processor to perform operations including calculating an estimated amount of power and the current value required to drive the vehicle, and estimating a voltage value of the battery based on the calculated estimated amount of power and the current value.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a vehicle control device and a recording medium that are applied to an electrically-driven vehicle such as an electric car equipped with a battery. [Background technology]

[0002] An electric vehicle equipped with an electric motor that can be driven by power supplied from a battery has a controller that detects the state of the battery. In such an electric vehicle, the driving state of the electric motor, the inverter, etc. is controlled based on the state of the battery detected by the controller, thereby controlling the charging and discharging of the battery.

[0003] The on-board battery is an element that supplies the power required to drive an electric vehicle, and has a function of supplying the necessary current to an electric motor via an inverter, for example. In this way, it is necessary to supply an appropriate current from the battery to drive the electric motor, and Patent Document 1 proposes preventing excessive charging and discharging of the battery when the controller breaks down. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-205386 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, current technologies, including those described in the above-mentioned patent documents, cannot adequately meet market needs, and the following problems exist: In other words, assuming an electric vehicle that is put into practical use, some kind of abnormality may occur in the voltage sensor or current sensor for monitoring the battery voltage value due to aging or malfunction, which may cause the voltage sensor or current sensor to become inoperable.

[0006] Even if an abnormality occurs in the voltage sensor or current sensor and the device that directly measures the battery voltage value becomes unusable, it is desirable to have a means for indirectly estimating the battery voltage value as a backup measure to protect the battery and continue operating the electric vehicle as long as possible.

[0007] The present disclosure has been made in consideration of the above-mentioned problems as an example, and aims to provide a vehicle control device, etc. that can indirectly estimate a battery voltage value even when an abnormality occurs in a voltage sensor or current sensor making it impossible to directly measure the battery voltage value. [Means for solving the problem]

[0008] In order to solve the above problems, the vehicle control device of the present disclosure is a control device that estimates a voltage value of a battery mounted on a vehicle without using either a voltage sensor capable of measuring the voltage value of the battery or a current sensor capable of measuring the current value of the battery, and is equipped with a processor and a memory capable of storing a program executed by the processor, the program including instructions that cause the processor to perform operations including calculating an estimated amount of power and a current value required to drive the vehicle, and estimating the voltage value of the battery based on the calculated estimated amount of power and the estimated current value. Effect of the Invention

[0009] According to the present disclosure, even if an abnormality occurs in a voltage sensor or a current sensor and it becomes impossible to directly measure the voltage value of the battery, it is possible to indirectly estimate the voltage value of the battery. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic diagram showing a configuration example of an electric vehicle according to a first embodiment. [Diagram 2] FIG. 1 is a functional block diagram of an electric vehicle according to a first embodiment. [Diagram 3]1 is a functional block diagram showing a vehicle control device and its peripheral devices mounted on an electric vehicle in a first embodiment. [Figure 4] FIG. 1 is a schematic diagram showing a known battery model using an RC equivalent circuit. [Diagram 5] 4 is a flowchart showing a voltage estimation method in the first embodiment. [Figure 6] FIG. 11 is a functional block diagram of an electric vehicle according to a second embodiment. [Figure 7] 10 is a flowchart showing a voltage estimation method in the second embodiment. [Figure 8] FIG. 2 is a schematic diagram showing a first vehicle motion model (one-wheel model). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Next, preferred embodiments of the present disclosure will be described. In this specification and the drawings, components having substantially the same functional configurations are denoted by the same reference numerals, and duplicated explanations will be omitted. In addition, configurations other than those described in detail below may be implemented by appropriately supplementing elemental technologies and configurations related to publicly known electric vehicles, including those described in the above-mentioned patent documents.

[0012] [First embodiment] <Electric vehicle 100> 1 and 2 are schematic diagrams showing configuration examples of an electric vehicle 100 according to this embodiment. Note that, as the electric vehicle 100 suitable for this embodiment, various known electric vehicles driven by an electric motor, such as an electric vehicle, a hybrid vehicle (HEV), and a plug-in hybrid vehicle (PHEV), which can be equipped with a battery 1 described later, can be used. Furthermore, as the battery 1 suitable for this embodiment, various known secondary batteries, such as a lithium ion secondary battery and a nickel metal hydride battery, can be used.

[0013] 1, an electric vehicle 100 is configured to be able to supply power from a battery 1 to an electric motor 50 via a known converter 20 under the control of a vehicle control device 10. The converter 20 in this embodiment may be configured to include a known AC / DC converter or DC / AC converter that appropriately converts between direct current and alternating current, as well as a known DC / DC converter that adjusts the voltage value of the direct current to a desired voltage value.

[0014] As shown in FIG. 2, the electric vehicle 100 is configured, as an example, as a four-wheel drive vehicle in which driving torque output from an electric motor 50 that generates driving torque for the vehicle is transmitted to a left front wheel 3LF, a right front wheel 3RF, a left rear wheel 3LR, and a right rear wheel 3RR (hereinafter collectively referred to as "driving wheels 3" unless a distinction is required).

[0015] There are no particular limitations on the electric motor 50 suitable for this embodiment, and any known electric motor as exemplified in the above-mentioned patent documents can be used. This electric motor 50 can output drive torque that is transmitted to the front drive shaft 2F and the rear drive shaft 2R via a known transmission 51, a front wheel differential mechanism 5F, and a rear wheel differential mechanism 5R, respectively.

[0016] In this embodiment, an example is shown in which a single electric motor 50 distributes drive torque to each wheel, but the electric motor 50 may be disposed on the front wheel side and one on the rear wheel side, or one electric motor 50 may be disposed on each drive wheel 3. In addition, the electric vehicle 100 of this embodiment is configured as a four-wheel drive vehicle as described above, but it may also be a two-wheel drive vehicle in which the electric motor described above drives either the front wheels or the rear wheels.

[0017] The electric motor 50 is electrically connected to the battery 1 via the converter 20. A vehicle control device 10, which will be described later, can execute control such as supplying electric power required to drive the electric motor 50 from the battery 1 via the converter 20, and charging the battery 1 with electric power generated by the electric motor 50 during regeneration via the converter 20.

[0018] The electric vehicle 100 of this embodiment is configured to include a publicly known electric steering device 8 and brake devices 4LF, 4RF, 4LR, 4RR (hereinafter, collectively referred to as "brake device 4" unless a distinction is required) as equipment used for driving control of the vehicle. In this embodiment, the front wheel drive shaft 2F is provided with the above-mentioned electric steering device 8. The electric steering device 8 includes a publicly known motor and gears (not shown) for driving the electric steering, and is controlled by a control ECU 11 to adjust the steering angles of the left front wheel 3LF and the right front wheel 3RF. Such a control ECU 11 may be, for example, one or more known electronic control devices (ECUs) that are installed in the vehicle and control the operation of the electric motor 50, the electric steering device 8, the steering wheel 9, and the brake device 4, respectively.

[0019] The vehicle control device 10 is configured as one of the above-mentioned electronic control devices (ECU), and may be configured to include one or more processors (CPU (Central Processing Unit)) and one or more memories communicatively connected to the one or more processors. The vehicle control device 10 may also be configured to be connectable to a known external network NT such as the Internet via various known communication devices CD such as a communication form involving a smartphone or an in-vehicle communication device, for example. Such a vehicle control device 10 is electrically connected to the above-mentioned communication device CD, sensors SR, storage devices MD such as known hard disks and SSDs, and notification devices PD including known speakers SP and displays DP, directly or via in-vehicle communication means such as CAN (Controller Area Network) and LIN (Local Inter Net).

[0020] Among these, the sensors SR include 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 while traveling, and a known yaw rate sensor SR4 capable of detecting the yaw rate of the electric vehicle 100 while traveling. Note that the sensors SR of this embodiment may include known in-vehicle sensors such as a vehicle speed sensor, an imaging sensor, or a gyro sensor in addition to the above-mentioned sensors.

[0021] <Configuration of the vehicle control device 10> FIG. 3 shows an example of the configuration of the vehicle control device 10 and peripheral devices in this embodiment. As described above, the electric vehicle 100 is equipped with the voltage sensor SR1 and the current sensor SR2, and therefore the voltage value and the like of the battery 1 are detected via these voltage sensor SR1 and current sensor SR2 unless an abnormality such as a breakdown occurs. However, some abnormality may occur in these voltage sensor SR1 and current sensor SR2 due to aging deterioration or a malfunction, which may result in an abnormal situation in which the voltage value of the battery 1 cannot be detected via the voltage sensor or the current sensor.

[0022] Although there are some known examples of dealing with such abnormal situations by estimating the state of charge (SOC) of the battery 1, the conventional methods are limited to estimating the SOC. For this reason, the conventional methods may have difficulty accurately estimating the voltage of the battery, which dynamically changes with charging and discharging, for example. Therefore, it is more desirable to use a method that can more accurately estimate the battery voltage, which changes from moment to moment, by adding various models (a battery model and a vehicle motion model, which will be described later) as in this embodiment. In other words, the vehicle control device 10 is configured as a control device that estimates the voltage value of the battery 1 mounted on the vehicle without using either a voltage sensor SR1 capable of measuring the voltage value of the battery 1 or a current sensor SR2 capable of measuring the current value of the battery.

[0023] Such a vehicle control device 10 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 an estimated amount of power and a current value required to drive the vehicle, and estimating a voltage value of the battery based on the calculated estimated amount of power and the current value.

[0024] <Function blocks of the vehicle control device 10> As shown in FIG. 3, the vehicle control device 10 includes a voltage measurement 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.

[0025] (Voltage measurement unit 10a) The voltage measurement unit 10a is configured to have a function of measuring the voltage value of the battery 1 via the above-mentioned voltage sensor SR1. For example, the voltage measurement unit 10a can measure the voltage value of the battery 1 at a predetermined timing in order to drive the electric motor 50 while the electric vehicle 100 is traveling.

[0026] (Voltage sensor failure determination unit 10b) The voltage sensor failure determination unit 10b is configured to have a function of determining whether or not there is a failure in the voltage sensor SR1. More specifically, the voltage sensor failure determination unit 10b may determine whether or not there is a failure in the voltage sensor SR1 based on whether or not the voltage value of the battery 1 measured by the voltage measurement unit 10a described above falls within an abnormal range. The value of such an abnormal range can be determined in advance by experiment or simulation depending on the type and specifications of the battery 1 used. In addition to the above-described failure determination method, voltage sensor failure determination unit 10b may determine whether or not there is a failure in voltage sensor SR1 using a known voltage sensor failure detection method exemplified in International Publication WO2014 / 167644, for example.

[0027] (Motor output estimation unit 10c) The motor output estimating unit 10c acquires the required torque in the vehicle (i.e., the torque required of the electric motor 50 generated by the accelerator work of the driver) and estimates the motor output value based on the acquired required torque and the rotation speed of the electric motor 50 at that time. More specifically, the motor output estimating unit 10c is configured to have a function of estimating the motor output value by multiplying the required torque and the rotation speed of the electric motor 50 at that time.

[0028] The torque required for the electric motor 50 can be calculated by a known method based on the vehicle speed and the accelerator opening, for example. In addition to the above-mentioned method, the motor output estimator 10c may calculate the torque required for the electric motor 50 according to a known method disclosed in, for example, Japanese Patent Application Laid-Open No. 2016-096657 or Japanese Patent Application Laid-Open No. 2020-100360.

[0029] (Power Estimation Unit 10d) The power estimation unit 10d estimates the required amount of power (output amount) 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 described above and an 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 a function of estimating the required amount of power (output amount) to be supplied by the battery 1 described above by dividing the motor output value described above by the energy conversion efficiency coefficient in the electric motor 50 and the converter 20 (inverter in this example). The above-mentioned energy conversion efficiency coefficient may be obtained in advance, for example, by performing an experiment or a simulation, and then stored as coefficient information in the above-mentioned storage device MD, or may be downloaded from an external server via the communication device CD.

[0030] (Current estimation unit 10e) The current estimation unit 10e estimates the value of the current flowing through the battery 1 based on the required power amount (output amount) estimated by the power estimation unit 10d. More specifically, the current estimation unit 10e is configured to have a function of estimating the value of the current flowing through the battery 1 by dividing the required power amount (output amount) estimated by the power estimation unit 10d by the voltage value calculated at the previous calculation. As will be described later, the vehicle control device 10 can estimate the voltage value of the battery 1 at regular time intervals (for example, 1 ms to 10 ms), and therefore the voltage value of the battery 1 estimated Δt seconds (several milliseconds) ago can be used as the previous calculation.

[0031] (Voltage estimation unit 10f) The voltage estimation 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 estimation unit 10e described above into an equation of a known battery model. As the equation of such a battery model, the following voltage calculation equation based on a battery model using a known RC equivalent circuit as exemplified in FIG. 4 may be applied. Battery voltage formula: V(t k )=V OCV (SOC(t k ))-R0I(t k )-R1I R1 (t k )

[0032] That is, according to the above voltage calculation formula, at time t k The terminal voltage V(t k ) is the open circuit voltage V OCV From the above, the resistance R0 and current I(t k ) and the resistance R1 and current I(t k ) and the open circuit voltage V OCV It is preferable that the values ​​of the resistors R0 and R1 are determined in advance through experiments or simulations. The publicly known RC equivalent circuit shown in FIG. 4 is one example of a battery model, and the voltage estimation unit 10f may estimate the voltage value (terminal voltage) of the battery 1 by applying the current value estimated by the current estimation unit 10e to other publicly known battery models disclosed in, for example, JP 2014-74682 A and JP 2017-138128 A.

[0033] (Notification control unit 10g) The notification control unit 10g executes a process of notifying various information such as the presence or absence of a malfunction of the battery 1 and an estimated voltage value via the notification device PD including the above-mentioned speaker SP and display DP. The notification control unit 10g may present the above-mentioned various information to the occupant via the notification device PD mounted on the vehicle, or may control the notification by accessing an external terminal such as a smartphone carried by the occupant.

[0034] <Method for estimating the voltage of battery 1 without using a voltage sensor and a current sensor> Next, a battery voltage estimation method executable by the vehicle control device 10 in this embodiment will be described with reference to Fig. 5. As described above, the voltage estimation method of this example can be realized in the form of a program, and the program can be stored in a known recording medium.

[0035] 5, in step 1, the vehicle control device 10 determines whether or not an abnormality has occurred in the voltage sensor SR1 mounted on the vehicle. More specifically, the voltage sensor malfunction determination unit 10b of the vehicle control device 10 can determine whether or not there is a malfunction in the voltage sensor SR1 based on whether or not the voltage value of the battery 1 measured by the voltage measurement unit 10a has fallen into an abnormal range, for example.

[0036] If it is determined in step 1 that there is no abnormality in the voltage sensor SR1, then in step 2A, the vehicle control device 10 acquires a voltage value measured by the normally operating voltage sensor SR1. As a result, 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 yet turned off (No in step 6), returns to step 1 and repeats the process.

[0037] On the other hand, if it is determined in step 1 that an abnormality has occurred in the voltage sensor SR1 causing a failure, the vehicle control device 10 executes processing from the subsequent step 2B onwards to estimate the voltage value of the battery 1 without using the voltage sensor SR1 and the current sensor SR2. That is, the vehicle control device 10 first acquires information on the required torque of the electric motor 50 in step 2B. More specifically, the motor output estimator 10c of the vehicle control device 10 acquires the required torque in the vehicle (torque required by the electric motor 50) by the publicly known method described above.

[0038] Next, in step 3, the motor output estimating unit 10c of the vehicle control device 10 estimates a motor output value of the electric motor 50 based on the acquired required torque and the rotation speed of the electric motor 50 at that time.

[0039] Then, after the motor output value is estimated in step 3, in the following step 4, the vehicle control device 10 estimates a current value from the battery 1 corresponding to the above-mentioned motor output value. As described above, the power estimation unit 10d of the vehicle control device 10 estimates the required amount of power (output amount) to be supplied by the battery 1 based on the above-mentioned motor output value and the above-mentioned 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 value of the current flowing to the battery 1 by the above-mentioned method based on the required amount of power (output amount) estimated above.

[0040] After the current value from the battery is estimated in step 4, in the following step 5, the vehicle control device 10 estimates a voltage value (terminal voltage) in the battery 1 based on the estimated current value flowing through the battery 1. More specifically, the voltage estimation unit 10f of the vehicle control device 10 estimates the voltage value (terminal voltage) in the battery 1 by substituting the current value of the battery 1 into the above-mentioned battery model equation.

[0041] By going through the above steps 2B to 5, the vehicle control device 10 is able to estimate the voltage value of the battery 1 with high accuracy without using the voltage sensor SR1 and the current sensor SR2 that have become unusable due to some abnormality or malfunction.

[0042] After estimating the voltage value of the battery 1 in step 5, the vehicle control device 10 returns to step 1 and repeats the above-mentioned process unless it is determined in step 6 that the system has been turned off. As an example, the vehicle control device 10 may estimate the voltage value by repeating the processes from step 1 to step 6 at a predetermined cycle (for example, several milliseconds to several tens of milliseconds).

[0043] <Recording Media> As described above, the above-described battery voltage estimation method can be implemented as a computer-readable voltage value estimation program. That is, the vehicle control device 10 may be configured to be able to read the battery voltage value estimation program. As will be described later, the battery voltage value estimation program may be stored in a known recording medium. Furthermore, the voltage value estimation program may be downloaded to the electric vehicle 100 from a known server such as a cloud.

[0044] Thus, a recording medium suitable for this embodiment is a non-transient tangible recording medium having recorded thereon a voltage value estimation program for estimating the voltage value of a battery mounted on a vehicle without using either a voltage sensor capable of measuring the voltage value of the battery or a current sensor capable of measuring the current value of the battery, the voltage value estimation program including instructions that cause a processor to perform operations including calculating an estimated amount of power and a current value required to drive the vehicle, and estimating the voltage value of the battery based on the calculated estimated amount of power and the estimated current value.

[0045] The recording medium for recording a computer program may be a magnetic medium such as a hard disk, a floppy disk, or a magnetic tape; an optical recording medium such as a CD-ROM (Compact Disk Read Only Memory), a DVD (Digital Versatile Disk), or a Blu-ray (registered trademark); a magnetic optical medium such as a floptical disk; a memory element such as a RAM or a ROM; a flash memory such as a USB (Universal Serial Bus) memory; an SSD (Solid State Drive); or any other medium capable of storing a program.

[0046] According to the vehicle control device 10 in the first embodiment described above and the electric vehicle 100 equipped with the vehicle control device 10, even if an abnormality occurs in the voltage sensor or current sensor making it impossible to directly measure the battery voltage value, the battery voltage value can be indirectly estimated based on the required torque to the electric motor.

[0047] [Second embodiment] Next, a method for estimating the voltage of the electrically powered vehicle 110 and the battery 1 according to the second embodiment will be described with reference to Figs. The vehicle control device 10 in the electric vehicle 110 of this 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 by utilizing the torque required for the motor, but the vehicle control device 10 of this embodiment is mainly characterized in that it estimates the motor output value of the electric motor 50 by mainly utilizing acceleration information of the vehicle traveling straight ahead.

[0048] Here, the vehicle control device 10 can determine whether the vehicle is traveling straight when, for example, the steering angle of the steering wheel 9 is within a predetermined angle. The method of determining whether the vehicle is traveling straight is not limited to the above, and other known methods such as detection using a gyro sensor may be applied. In addition, the vehicle control device 10 may detect the road conditions ahead of the vehicle based on, for example, map information from an on-board navigation device, and determine whether the vehicle is traveling straight based on the road conditions ahead.

[0049] (Acceleration acquisition part 10h) The acceleration acquisition unit 10h is configured to have a function of acquiring acceleration information of the vehicle during traveling via the acceleration sensor SR3 mounted on the electric vehicle 110. Note that the acceleration acquisition unit 10h of this embodiment acquires the acceleration of the vehicle from the acceleration sensor SR3, but is not limited to this form, and may be configured to calculate the acceleration by performing differentiation processing using values ​​from a known vehicle speed sensor or position information sensor mounted on the vehicle.

[0050] <Method for estimating the voltage of battery 1 without using a voltage sensor and a current sensor> Next, a battery voltage estimation method executable by the vehicle control device 10 in the second embodiment will be described with reference to Figures 7 and 8. Note that in the voltage estimation method described below, the description of the same configuration as in the first embodiment will be omitted as appropriate.

[0051] First, in step 1, the vehicle control device 10 determines whether or not there is a malfunction in the voltage sensor SR1 in the same manner as in the first embodiment. If there is no abnormality in the voltage sensor SR1 in step 1, the vehicle control device 10 holds the value measured by the voltage sensor SR1 in the following step 2A as the voltage value of the battery 1. On the other hand, if an abnormality occurs in the voltage sensor SR1 in step 1, the voltage value of the battery 1 is estimated from step 2C onwards mainly using information obtained from the acceleration sensor SR3.

[0052] 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 above-mentioned acceleration sensor. After acquiring the acceleration information of the electric vehicle 110, the motor output estimator 10c of the vehicle control device 10 estimates the driving force generated at the driving wheels 3 of the electric vehicle 110 in the following step 2E.

[0053] That is, in this example, assuming that the electric vehicle 110 accelerates at an acceleration α at a certain time t, a known vehicle motion model is used to estimate the value of the current flowing from the battery 1 at this time. Note that, as shown in Fig. 8, in this example, a first vehicle motion model (one-wheel model) that is simplified by assuming that the electric vehicle 110 has only one tire without considering the movement of the center of gravity or yaw motion is applied, but it is also possible to apply known multi-wheel models such as a two-wheel model.

[0054] In this case, among the resistance forces that the vehicle is subjected to (which in this example are simplified and limited to air resistance, rolling resistance, and gradient resistance), an estimated value of the driving force F generated at the driving wheels 3 in order for the electric vehicle to obtain this acceleration α is calculated using the following formula. Driving force F generated between the drive wheel 3 and the road surface = vehicle weight x acceleration α

[0055] Here, the "vehicle weight" in the above calculation formula may be obtained in advance by experiment or simulation. Note that the "vehicle weight" in the above calculation formula may be detected at appropriate times using a known tire force sensor such as that disclosed in JP 2006-349440 A or other known hub sensor, instead of the above experiment. Therefore, in step 2E, the motor output estimating unit 10c of the vehicle control device 10 estimates the driving force generated at the driving wheels 3 of the electric vehicle 110 from the acceleration obtained in step 2C and the vehicle weight information stored in advance.

[0056] In the next step 2F, the motor output estimator 10c of the vehicle control device 10 estimates the torque generated by the electric motor 50 by the following method. That is, since the resistance forces (air resistance, rolling resistance, gradient resistance, etc.) that the vehicle experiences can be calculated in advance by experiments and simulations as described above, the torque T required by the electric motor 50 can be calculated by the following formula. Torque T output by the motor = (driving force F generated between the drive wheel 3 and the road surface + resistance force received by the vehicle) x tire radius / gear ratio The air resistance experienced by the vehicle may be calculated by a known method such as that disclosed in Japanese Patent Application Publication No. 2014-080128 or Japanese Patent Application Publication No. 2023-036347. The rolling resistance experienced by the vehicle may be calculated by a known method such as that disclosed in Japanese Patent Application Publication No. 2009-045957 or Japanese Patent Application Publication No. 2014-080128. The gradient resistance experienced by the vehicle may be calculated by "vehicle weight x sinθ" based on the inclination (gradient angle θ) of the vehicle in the fore-and-aft direction from the horizontal plane using a gyro sensor mounted on the vehicle, or may be calculated by a known method such as that disclosed in Japanese Patent Application Publication No. 2020-010454.

[0057] Therefore, in step 2F, the motor output estimation 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 resistance force, tire radius, and gear ratio acting on the vehicle.

[0058] After estimating the torque T output by the electric motor 50 in step 2F, the motor output estimation unit 10c of the vehicle control device 10 estimates a motor output value in the following step 3 by multiplying the torque T output by the electric motor 50 by the rotation speed of the electric motor 50 at that time.

[0059] After the motor output value is estimated in step 3, in the following step 4, the vehicle control device 10 estimates a current value from the battery 1 corresponding to the above-mentioned motor output value. That is, the power estimation unit 10d of the vehicle control device 10 estimates the required amount of power (output amount) to be supplied by the battery 1 based on the above-mentioned motor output value and the above-mentioned 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 value of the current flowing to the battery 1 by the method already described in the first embodiment based on the required amount of power (output amount) estimated above.

[0060] Considering the first and second embodiments, the vehicle control device 10 in the present disclosure can calculate the required amount of power based on at least one of the acceleration obtained from the vehicle and the required torque in the vehicle. The processing from step 5 onwards is similar to that in the first embodiment described above, and therefore a description thereof will be omitted.

[0061] According to the vehicle control device 10 and the electric vehicle 110 in the second embodiment described above, even if an abnormality occurs in the voltage sensor or the current sensor and it becomes impossible to directly measure the battery voltage value, particularly in a vehicle traveling in a straight line, the battery voltage value can be indirectly estimated via the acceleration sensor.

[0062] <Modification> In the second embodiment described above, the motor output value of the electric motor 50 is estimated mainly 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 is turning may also be estimated as follows. That is, when the vehicle turns around a curve, a lateral force is generated in the tires due to the turn.

[0063] Therefore, since this lateral force is added as "resistance received by the vehicle" during the above-mentioned turning, this resistance caused by the lateral force may be incorporated into "resistance received by the vehicle" in the above-mentioned formula for torque T. Such a resistance caused by the lateral force may be calculated in advance by experiment or simulation, or a known estimation method such as that disclosed in JP 2007-331659 A may be applied. Furthermore, the vehicle control device 10 may detect road conditions ahead of the vehicle based on, for example, map information from an on-board navigation device, and may estimate the motor output value of the electric motor 50 described above after determining whether the vehicle is turning based on the road conditions ahead.

[0064] Although the preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings, the present disclosure is not limited to such examples. It is clear that a person having ordinary knowledge in the technical field to which the present disclosure belongs may attempt to further modify these embodiments and modifications within the scope of the technical ideas described in the claims, and it is understood that these also naturally belong to the technical scope of the present disclosure. [Explanation of symbols]

[0065] 100, 110 Electric vehicles 1 Battery 10 Vehicle control device 20 Converter 50 Electric motor

Claims

1. A control device that estimates a voltage value of a battery mounted on a vehicle without using either a voltage sensor capable of measuring a voltage value of the battery or a current sensor capable of measuring a current value of the battery, A processor and a memory capable of storing a program executed by the processor, The program includes instructions: The instructions cause the processor to: Calculating an estimated required amount of power and a current value required to drive the vehicle; and estimating a voltage value of the battery based on the calculated required power amount and the estimated current value. Vehicle control device.

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

3. The instructions further include determining road conditions ahead of the traveling vehicle; When estimating the voltage of the battery, a voltage value of the battery is estimated based on acceleration information of the vehicle in accordance with the road conditions ahead. The vehicle control device according to claim 2.

4. A non-transitory tangible recording medium having a voltage value estimation program recorded thereon, the voltage value estimation program being for estimating a voltage value of a battery mounted on a vehicle without using either a voltage sensor capable of measuring a voltage value of the battery or a current sensor capable of measuring a current value of the battery, The voltage value estimation program includes instructions: The instructions cause a processor to: Calculating an estimated required amount of power and a current value required to drive the vehicle; and estimating a voltage value of the battery based on the calculated required power amount and the estimated current value. Non-transitory tangible recording media.

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