Apparatus and method for controlling vehicle and vehicle system having same

Abstract

The present invention provides an apparatus and a method for controlling a vehicle and a vehicle system having same. According to an embodiment, the apparatus for controlling a vehicle comprises: a processor; and a storage medium storing instructions executable by the processor, wherein the processor is configured to execute the instructions to: determine a driving mode on the basis of traveling information of a vehicle; determine the shaft ratios of a plurality of motors included in the vehicle on the basis of the driving mode and a boundary speed; and drive the vehicle on the basis of the shaft ratios of the plurality of motors.

Description

Vehicle control device, method and vehicle system including the same

[0001] The present invention relates to a vehicle control device, method and vehicle system including the same.

[0002] To improve the fuel efficiency of electric vehicles, methods include increasing battery capacity or improving power-consuming components. Compared to the first-generation electric vehicles released in the early days, recent second-generation electric vehicles have significantly increased battery capacity, resulting in fuel efficiency of 350-600 km. However, this has the negative effect of reducing driving range due to increased battery weight, and significantly increasing the manufacturing cost of electric vehicles. Since battery prices account for 40-70% of the total manufacturing cost of an electric vehicle, continuously increasing battery capacity is cost-prohibitive.

[0003] Another way to improve fuel economy is to improve the operating efficiency of the electrified powertrain, which corresponds to the engine and transmission of an internal combustion engine vehicle.

[0004] An electrified powertrain consists of a drive motor, a control unit, and a reducer. The drive motor converts electrical energy from the battery into kinetic energy, which powers the vehicle. The control unit uses an inverter to convert the direct current (DC) stored in the battery into alternating current (AC), supplying the power needed to drive the motor. Furthermore, the reducer is a mechanical energy conversion device that reduces the motor's high rotational speed to the appropriate rotational speed required for vehicle operation, while simultaneously amplifying the motor's torque to provide the high power required for vehicle movement.

[0005] The maximum efficiency of the drive motors installed in recently released electric vehicles is approximately 95-98%. However, motor design technology has historically been at a level that makes further improvement difficult. Without innovative advancements in the materials that make up the drive motor, such as magnets, conductors (copper windings, aluminum windings), and cores (electrical steel), further improvements in motor efficiency have reached technological limits.

[0006] Therefore, it was necessary to develop a technology that could improve fuel efficiency by controlling the vehicle's drive system.

[0007] (Patent Document 1) KR 10-2018-0039158 A (2018.04.17)

[0008] The present invention aims to provide a vehicle control device, method and vehicle system including the same that can improve the fuel efficiency of an electric vehicle having a plurality of motors.

[0009] According to one embodiment of the present invention, a vehicle control device, method and vehicle system including the same can be provided, which can optimize the operating conditions of a powertrain by controlling the shaft ratio of a main drive motor and the shaft ratio of an auxiliary drive motor in a vehicle having a plurality of motors, and improve fuel efficiency by minimizing unnecessary power loss.

[0010] The objectives of the present invention are not limited to the above-described scope. Those skilled in the art will have no difficulty understanding the additional objectives of the present invention from the overall content of this specification.

[0011] In order to achieve the above-mentioned purpose, the present invention provides the following vehicle control device, method and vehicle system including the same.

[0012] In one embodiment, the present invention provides a vehicle control device including a processor and a storage medium storing instructions executable by the processor, wherein the processor executes the instructions to determine a driving mode based on driving information of a vehicle, determine an axis ratio of a plurality of motors included in the vehicle based on the driving mode and a boundary speed, and drive the vehicle based on the axis ratio of the plurality of motors, wherein the axis ratio of the plurality of motors includes a ratio of a rotational speed of a motor rotational shaft connected to one of the plurality of motors to a rotational speed of a wheel rotational shaft of the vehicle, and the boundary speed is set based on an operating efficiency distribution of at least one of the plurality of motors.

[0013] The present invention relates to a vehicle control device according to one embodiment, wherein the plurality of motors include a main drive motor and one or more auxiliary drive motors, and the processor determines one of a first drive mode in which only the main drive motor is operated based on driving information of the vehicle and a second drive mode in which the main drive motor and the one or more auxiliary drive motors are operated simultaneously.

[0014] The present invention relates to a vehicle control device according to one embodiment, wherein the main drive motor includes a first motor, the one or more auxiliary drive motors include a second motor, and the processor determines a shaft ratio of the first motor in the first drive mode, and determines a shaft ratio of the first motor and a shaft ratio of the second motor in the second drive mode, wherein the shaft ratio of the first motor is a ratio of a rotational speed of a first motor rotational shaft connected to the first motor to a rotational speed of a wheel rotational shaft of the vehicle, and the shaft ratio of the second motor is a ratio of a rotational speed of a second motor rotational shaft connected to the second motor to a rotational speed of a wheel rotational shaft of the vehicle.

[0015] In one embodiment of the present invention, the processor of a vehicle control device compares the speed of the vehicle with the magnitude of the boundary speed, and determines the shaft ratio of the first motor as the first shaft ratio when the speed of the vehicle has a value lower than the boundary speed, and determines the shaft ratio of the first motor as the second shaft ratio having a value smaller than the first shaft ratio when the speed of the vehicle has a value higher than the boundary speed.

[0016] In one embodiment of the present invention, the processor of the vehicle control device determines the shaft ratio of the second motor in the second driving mode as a third shaft ratio having a value greater than the first shaft ratio.

[0017] The present invention relates to a vehicle control device according to one embodiment, wherein the efficiency of the main drive motor is included in one of a first efficiency section set in advance and a second efficiency section having lower efficiency than the first efficiency section, and the processor determines the shaft ratio of the plurality of motors based on a ratio of a period during which the efficiency of the main drive motor is included in the first efficiency section while the vehicle is driving.

[0018] The present invention relates to a vehicle control device according to one embodiment, wherein the efficiency of the at least one auxiliary drive motor is included in one of a third efficiency section set in advance and a fourth efficiency section having a lower efficiency than the third efficiency section, and the processor determines the shaft ratio of the plurality of motors based further on a ratio of a period during which the efficiency of the at least one auxiliary drive motor is included in the third efficiency section while the vehicle is driving.

[0019] The boundary speed of the vehicle control device according to one embodiment of the present invention is 35 km / h or less.

[0020] The boundary speed of the vehicle control device according to one embodiment of the present invention has a value in the range of 20 to 30 km / h.

[0021] The present invention provides a vehicle control device according to one embodiment wherein the value of the first axis ratio is 38 or less, and the first axis ratio has a value that is 1.3 times or more greater than the second axis ratio.

[0022] The present invention provides a vehicle control device according to one embodiment wherein the value of the first axis ratio is 30 or less, and the first axis ratio has a value that is twice or more than the second axis ratio.

[0023] The present invention provides a vehicle control device according to one embodiment wherein the second axis ratio has a value greater than 6.5 and less than 11.

[0024] The present invention provides a vehicle control method, in one embodiment, which is performed in a computing device including a processor and a storage medium storing instructions executable by the processor, the method comprising the steps of: determining a driving mode based on driving information of a vehicle; determining an axis ratio of a plurality of motors included in the vehicle based on the driving mode and a boundary speed; and driving the vehicle based on the axis ratios of the plurality of motors, wherein the axis ratio of the plurality of motors includes a ratio of a rotational speed of a motor rotational shaft connected to any one of the plurality of motors to a rotational speed of a wheel rotational shaft of the vehicle, and the boundary speed is set based on an operating efficiency distribution of at least one of the plurality of motors.

[0025] The present invention relates to a vehicle control method according to one embodiment, wherein the plurality of motors include a main drive motor and one or more auxiliary drive motors, and the step of determining the drive mode determines one of a first drive mode that operates only the main drive motor based on driving information of the vehicle and a second drive mode that operates the main drive motor and one or more auxiliary drive motors simultaneously.

[0026] The present invention relates to a vehicle control method according to one embodiment, wherein the main drive motor includes a first motor, the one or more auxiliary drive motors include a second motor, and the step of determining shaft ratios of the plurality of motors includes determining the shaft ratio of the first motor in the first drive mode, and determining the shaft ratio of the first motor and the shaft ratio of the second motor in the second drive mode, wherein the shaft ratio of the first motor is a ratio of a rotational speed of a first motor rotational shaft connected to the first motor to a rotational speed of a wheel rotational shaft of the vehicle, and the shaft ratio of the second motor is a ratio of a rotational speed of a second motor rotational shaft connected to the second motor to a rotational speed of a wheel rotational shaft of the vehicle.

[0027] In one embodiment of the present invention, the step of determining the shaft ratio of the plurality of motors in the vehicle control method determines the shaft ratio of the first motor as the first shaft ratio when the speed of the vehicle has a value lower than or equal to the boundary speed, and determines the shaft ratio of the first motor as the second shaft ratio having a value smaller than the first shaft ratio when the speed of the vehicle has a value higher than the boundary speed.

[0028] In one embodiment of the present invention, the step of determining the shaft ratio of the plurality of motors in the vehicle control method determines the shaft ratio of the second motor in the second driving mode as a third shaft ratio having a value greater than the first shaft ratio.

[0029] The present invention provides a vehicle control method according to one embodiment, wherein the efficiency of the main drive motor is included in one of a first efficiency section set in advance and a second efficiency section having a lower efficiency than the first efficiency section, and the step of determining the shaft ratio of the plurality of motors determines the shaft ratio of the plurality of motors based on a ratio of a period during which the efficiency of the main drive motor is included in the first efficiency section while the vehicle is driving.

[0030] The present invention provides a vehicle control method according to one embodiment, wherein the efficiency of the at least one auxiliary drive motor is included in one of a third efficiency section set in advance and a fourth efficiency section having a lower efficiency than the third efficiency section, and the step of determining the shaft ratio of the plurality of motors further determines the shaft ratio of the plurality of motors based on a ratio of a period during which the efficiency of the at least one auxiliary drive motor is included in the third efficiency section while the vehicle is driving.

[0031] The boundary speed of the vehicle control method according to one embodiment of the present invention is 35 km / h or less.

[0032] The boundary speed of the vehicle control method according to one embodiment of the present invention has a value in the range of 20 to 30 km / h.

[0033] The present invention provides a vehicle control method according to one embodiment wherein the value of the first axis ratio is 38 or less, and the first axis ratio has a value that is 1.3 times or more greater than the second axis ratio.

[0034] The present invention provides a vehicle control method according to one embodiment wherein the value of the first axis ratio is 30 or less, and the first axis ratio has a value that is twice or more than the second axis ratio.

[0035] The present invention provides a vehicle control method according to one embodiment wherein the second axis ratio has a value greater than 6.5 and less than 11.

[0036] In one embodiment, the present invention provides a vehicle system including a driving unit including a first rotational axis and one or more driving wheels connected to the first rotational axis, a driving unit including a plurality of motors and a plurality of motor rotational shafts connected to the plurality of motors, a transmission unit for adjusting shaft ratios of the plurality of motors including a ratio of a rotational speed of one of the plurality of motor rotational shafts to a rotational speed of the first rotational axis, and a control unit for controlling the transmission unit, wherein the control unit determines shaft ratios of the plurality of motors based on driving modes and boundary speeds of the plurality of motors, and controls the transmission unit based on the determined shaft ratios of the plurality of motors, and the boundary speed is set based on an operating efficiency distribution of at least one of the plurality of motors.

[0037] The present invention provides a vehicle system according to one embodiment, which further includes a vehicle speed sensor for measuring a speed of the vehicle, wherein the plurality of motors include a main drive motor, and wherein the control unit receives a speed of the vehicle measured using the vehicle speed sensor, and determines an axis ratio of the main drive motor as one of a first axis ratio and a second axis ratio having a smaller value than the first axis ratio based on a result of comparing the speed of the vehicle with the magnitude of the boundary speed.

[0038] In one embodiment of the present invention, the control unit of the vehicle system determines the shaft ratio of the main drive motor as the first shaft ratio when the speed of the vehicle has a value lower than or equal to the boundary speed, and determines the shaft ratio of the main drive motor as the second shaft ratio when the speed of the vehicle has a value higher than the boundary speed.

[0039] The present invention relates to a vehicle system according to one embodiment, wherein the plurality of motors further include one or more auxiliary drive motors, and the control unit determines an axis ratio of the one or more auxiliary drive motors as a third axis ratio having a value greater than the first axis ratio in a driving mode that operates the main drive motor and the one or more auxiliary drive motors simultaneously.

[0040] The present invention relates to a vehicle system according to one embodiment, wherein the efficiency of the main drive motor is included in one of a first efficiency section set in advance and a second efficiency section lower in efficiency than the first efficiency section, the efficiency of the one or more auxiliary drive motors is included in one of a third efficiency section set in advance and a fourth efficiency section lower in efficiency than the third efficiency section, and the control unit determines shaft ratios of the plurality of motors based on a ratio of a period during which the efficiency of the main drive motor is included in the first efficiency section and a ratio of a period during which the efficiency of the one or more auxiliary drive motors is included in the third efficiency section while the vehicle is driving.

[0041] The boundary speed of the vehicle system according to one embodiment of the present invention is 35 km / h or less.

[0042] The boundary speed of the vehicle system according to one embodiment of the present invention has a value in the range of 20 to 30 km / h.

[0043] The present invention relates to a vehicle system according to one embodiment, wherein the value of the first axis ratio is 38 or less, and the first axis ratio has a value that is 1.3 times or more than the second axis ratio.

[0044] The present invention provides a vehicle system according to one embodiment wherein the value of the first axis ratio is 30 or less, and the first axis ratio has a value that is twice or more than the second axis ratio.

[0045] The present invention provides a vehicle system according to one embodiment wherein the second axis ratio has a value greater than 6.5 and less than 11.

[0046] The present invention can provide a vehicle control device, method and vehicle system including the same that can improve the fuel efficiency of an electric vehicle having a plurality of motors.

[0047] The present invention optimizes the operating conditions of a powertrain by controlling the shaft ratio of a main drive motor and the shaft ratio of an auxiliary drive motor in a vehicle equipped with a plurality of motors, and improves fuel efficiency by minimizing unnecessary power loss.

[0048] Figure 1 is an exemplary graph showing the efficiency of a drive motor according to the rotational speed of the drive motor rotational shaft and the torque of the drive motor.

[0049] Figure 2 is a block diagram of a vehicle system according to one embodiment of the present invention.

[0050] FIG. 3 is a schematic diagram illustrating a vehicle system according to one embodiment of the present invention.

[0051] Figure 4 is a flowchart of a vehicle control method according to one embodiment of the present invention.

[0052] Figure 5 is a flowchart of a vehicle control method according to one embodiment of the present invention.

[0053] Figure 6 is a flowchart of a vehicle control method according to one embodiment of the present invention.

[0054] Figure 7a is a graph showing the efficiency distribution of the main drive motor when a vehicle is driven according to a conventional vehicle control method.

[0055] FIG. 7b is an exemplary graph showing the efficiency distribution of the main drive motor during driving of a vehicle controlled according to a vehicle control method according to one embodiment of the present invention.

[0056] Figure 8 is a flowchart of a vehicle control method according to another embodiment of the present invention.

[0057] FIG. 9 is a block diagram of a computing device that can fully or partially implement a vehicle control device according to one embodiment of the present invention.

[0058] Hereinafter, preferred embodiments of the present invention will be described with reference to the attached drawings. However, the embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below.

[0059] In addition, the embodiments of the present invention are provided to more completely explain the present invention to a person having average knowledge in the relevant technical field.

[0060] The shape and size of elements in the drawing may be exaggerated for clearer explanation.

[0061] In describing the embodiments of the present invention, if a detailed description of a known technology related to the present invention is judged to unnecessarily obscure the gist of the present invention, such detailed description will be omitted. In addition, the terms described below are terms defined in consideration of their functions in the present invention, and these may vary depending on the intention or custom of the user or operator. Therefore, the definitions should be made based on the contents throughout this specification. The terminology used in the detailed description is only for the purpose of describing the embodiments of the present invention and should in no way be limiting. Unless clearly defined otherwise, expressions in the singular form include plural meanings.

[0062] In this description, expressions such as "including" or "having" are intended to indicate certain features, numbers, steps, operations, elements, portions or combinations thereof, and should not be construed to exclude the presence or possibility of one or more other features, numbers, steps, operations, elements, portions or combinations thereof other than those described.

[0063] Unless otherwise specified in the specification of the present invention, the % unit means weight %.

[0064] In this specification, terms such as 'top', 'upper part', 'top surface', 'bottom', 'lower part', 'bottom', 'side', etc. are based on the drawings, and in reality, they may vary depending on the direction in which the elements or components are arranged.

[0065] Additionally, throughout the specification, when we say that a part is 'connected' to another part, this includes not only cases where it is 'directly connected', but also cases where it is 'indirectly connected' with other elements in between.

[0066] Below, the present invention will be described in detail through each embodiment or example of the present invention. It should be noted that each embodiment or example described in this specification is not limited to a single embodiment or example, but may be combined with other embodiments or examples. Therefore, the citation of a claim in the patent claims is only an example of an embodiment, and the technical concept of the present invention should not be interpreted solely as a combination with the cited claim, and combinations with various claims also fall within the scope of the technical concept of the present invention.

[0067] Figure 1 is an exemplary graph showing the efficiency of a drive motor according to the rotational speed of the drive motor rotational shaft and the torque of the drive motor. As shown in Figure 1, the efficiency of the drive motor includes the rotational speed of the drive motor rotational shaft and the torque of the drive motor as variables.

[0068] The efficiency of a drive motor can be derived as the ratio of mechanical output to electrical input. Here, the electrical input of the drive motor is the product of the voltage and current input to the drive motor and the power factor, and the mechanical output can be the product of the torque and rotational speed of the drive motor.

[0069] Referring to Fig. 1, in a region where the rotational speed of the drive motor shaft is within a low range of several tens to several hundred rpm and the torque of the drive motor is within a large range of several hundred Nm, the efficiency of the drive motor was found to be low, approximately 1 to 20%. In addition, as the rotational speed of the rotational shaft increases or the torque decreases, the efficiency of the drive motor was found to increase. In addition, as the rotational speed of the rotational shaft gradually increases, the efficiency of the drive motor improved, but in a region where the rotational speed of the rotational shaft is extremely high, the efficiency of the drive motor was found to deteriorate again rapidly.

[0070] The present invention relates to a method for optimizing the operating conditions of an electric powertrain, minimizing power loss, and improving fuel efficiency by changing the shaft ratios of a plurality of motors according to preset conditions while a vehicle equipped with a plurality of motors is driving, with respect to the efficiency of a drive motor having different values ​​depending on several variables as illustrated in FIG. 1, thereby minimizing power loss.

[0071] FIG. 2 illustrates a block diagram of a vehicle system according to one embodiment of the present invention, and FIG. 3 schematically illustrates a vehicle system according to one embodiment of the present invention.

[0072] The vehicle system (200) of the present invention may be an electric vehicle having a plurality of motors. The plurality of motors may include, for example, a main drive motor and one or more auxiliary drive motors.

[0073] In one embodiment, the vehicle system (200) may be a dual motor system having a main drive motor and one auxiliary drive motor.

[0074] In another embodiment, the vehicle system (200) may be a tri-motor system having a main drive motor and two auxiliary drive motors.

[0075] The vehicle system (200) may have two or more auxiliary drive motors.

[0076] Referring to FIGS. 2 and 3, the vehicle system (200) may include a vehicle control unit (210), a driving unit (220), a transmission unit (230), and a driving unit (240).

[0077] The vehicle control unit (210) can control various components necessary for controlling the starting, power, braking, steering, and shifting of the vehicle system (200). The vehicle control unit (210) can receive a control request signal from another component of the vehicle system (200) and generate a control signal for controlling the vehicle system (200).

[0078] For example, the vehicle control unit (210) can generate an acceleration control signal that controls the driving mechanism of the vehicle system (200) based on an acceleration request signal of an accelerator pedal position sensor input by the driver.

[0079] The vehicle control unit (210) may further include a storage unit and a communication unit. The storage unit may store various programs and data for implementing functions performed by the vehicle control unit (210). The communication unit may be used for the vehicle control unit (210) to transmit and receive data with other components of the vehicle system (200).

[0080] For example, the vehicle control unit (210) can transmit and receive a control request signal or a generated control signal to and from other components of the vehicle system (200) via a CAN (Controller Area Network) signal.

[0081] The vehicle system (200) may further include one or more sensors. The one or more sensors may include, for example, at least one of a wheel speed sensor, a vehicle speed sensor for detecting the speed of the vehicle, an accelerator pedal position sensor (APS) linked to the operation of an accelerator pedal, a brake pedal sensor linked to the operation of a brake pedal (BPS), a steering angle sensor (SAS) linked to the operation of a steering wheel, an external monitoring sensor for collecting information on the surroundings of the vehicle, a driver monitoring sensor for collecting information on the driver's status, and an internal monitoring sensor for collecting information on the internal environment of the vehicle.

[0082] The vehicle control unit (210) can receive information collected using one or more sensors via a CAN signal. For example, the vehicle control unit (210) can receive vehicle speed information measured using a vehicle speed sensor. Additionally, the vehicle control unit (210) can receive an acceleration request signal measured using an accelerator pedal position sensor.

[0083] The driving unit (220) may include a plurality of motors for generating driving force of the vehicle and a plurality of motor rotation shafts connected to the plurality of motors.

[0084] The vehicle system (200) may include a driving unit (220) including a first motor (221a), a second motor (221b), a first motor rotation shaft (222a), and a second motor rotation shaft (222b), as in the example illustrated in FIG. 3.

[0085] For example, the first motor (221a) may be a main drive motor for mainly driving the vehicle, and the second motor (221b) may be an auxiliary drive motor for generating power to assist the first motor (221a).

[0086] The first motor (221a) and the first motor rotation shaft (222a) can be connected to each other, and the second motor (221b) and the second motor rotation shaft (222b) can be connected to each other.

[0087] The plurality of motors generate power to drive the vehicle and can transmit the power to the driving wheels of the vehicle through at least one of the plurality of motor rotation shafts.

[0088] The transmission (230) may include one or more reducers (231) capable of adjusting the shaft ratio of the plurality of motors. The shaft ratio of the plurality of motors may include a ratio of the rotational speed of a motor rotational shaft connected to any one of the plurality of motors to the rotational speed of a wheel rotational shaft (242) of the vehicle.

[0089] The transmission unit (230) may be configured to include, for example, a plurality of reducers, or to include one reducer and a transmission gear connected to the reducer.

[0090] The driving unit (240) may include one or more driving wheels (241) and a wheel rotation shaft (242) for driving the vehicle. The one or more driving wheels (241) and the wheel rotation shaft (242) may be connected to each other.

[0091] One or more driving wheels (241) can receive power through a wheel rotation shaft (242) and drive the vehicle. The one or more driving wheels (241) can include a front driving wheel positioned at the front of the vehicle and a rear driving wheel positioned at the rear of the vehicle.

[0092] The vehicle control unit (210) can determine the driving mode of multiple motors based on vehicle driving information. The vehicle driving information can include one or more of vehicle speed information, an acceleration request signal, a deceleration request signal, slope information of the road on which the vehicle is driving, and resistance information applied to the vehicle.

[0093] The vehicle control unit (210) can determine the driving mode as either a first driving mode or a second driving mode. The first driving mode may be a mode in which only the main driving motor is operated, and the second driving mode may be a mode in which the main driving motor and one or more auxiliary driving motors are operated simultaneously.

[0094] For example, the vehicle control unit (210) may determine the driving mode of the plurality of motors as the second driving mode when the required power of the vehicle is greater than a preset threshold based on vehicle driving information, and may determine the driving mode of the plurality of motors as the first driving mode when the required power of the vehicle is less than the threshold.

[0095] Additionally, the vehicle control unit (210) can control the transmission unit (230) to change the shaft ratios of the plurality of motors. For example, the vehicle control unit (210) can determine the shaft ratios of the plurality of motors based on the driving modes and boundary speeds of the plurality of motors, and control the transmission unit (230) according to the determined shaft ratios of the plurality of motors.

[0096] Here, the boundary speed is a speed that serves as a reference for determining the shaft ratio of multiple motors and may have a preset value. The boundary speed may be set based on the operating efficiency distribution of at least one of the multiple motors.

[0097] For example, in a vehicle system (200) equipped with multiple motors, the threshold speed may be 35 km / h or less. As another example, the threshold speed may have a value within the range of 20 to 30 km / h. When the threshold speed value exceeds 35 km / h, the proportion of the multiple motors operating in a section where the efficiency is 90% or less increases, which may result in a decrease in the vehicle's fuel efficiency.

[0098] The vehicle control unit (210) can determine the shaft ratio of the plurality of motors based on the driving mode and boundary speed of the plurality of motors. The plurality of motors can include a main driving motor and one or more auxiliary driving motors.

[0099] The vehicle control unit (210) can determine the shaft ratio of the main drive motor in the first drive mode, and can determine the shaft ratio of the main drive motor and the shaft ratio of one or more auxiliary drive motors in the second drive mode.

[0100] In the example illustrated in FIG. 3, when the main drive motor is the first motor (221a), the shaft ratio of the main drive motor may be the ratio of the rotational speed of the first motor rotational shaft (222a) connected to the first motor (221a) to the rotational speed of the wheel rotational shaft (242) of the vehicle. In addition, when the auxiliary drive motor is the second motor (221b), the shaft ratio of the auxiliary drive motor may be the ratio of the rotational speed of the second motor rotational shaft (222b) connected to the second motor (221b) to the rotational speed of the wheel rotational shaft (242) of the vehicle.

[0101] The vehicle control unit (210) can determine the shaft ratio of the main drive motor as one of the first shaft ratio and the second shaft ratio, which are preset. The second shaft ratio can have a smaller value than the first shaft ratio.

[0102] For example, the first shaft ratio may have a value that is 1.3 times greater than the second shaft ratio and less than or equal to 38. The second shaft ratio may have a value that is greater than 6.5 and less than 11. When the second shaft ratio is less than 6.5 or greater than 11, the proportion of the plurality of motors operating in a section where their efficiency is less than 90% increases, which may result in a decrease in the vehicle's fuel efficiency.

[0103] In another example, the first axis ratio can have a value that is at least twice the second axis ratio and less than 30. The second axis ratio can have a value that is greater than 8 and less than 11.

[0104] The vehicle control unit (210) can determine the shaft ratio of the main drive motor as either the first shaft ratio or the second shaft ratio based on the result of comparing the speed of the vehicle and the size of the boundary speed.

[0105] For example, the vehicle control unit (210) may determine the shaft ratio of the main drive motor as the first shaft ratio when the speed of the vehicle has a value lower than the boundary speed. In addition, the vehicle control unit (210) may determine the shaft ratio of the main drive motor as the second shaft ratio when the speed of the vehicle has a value higher than the boundary speed. The second shaft ratio may have a value lower than the first shaft ratio.

[0106] The vehicle control unit (210) can determine the shaft ratio of one or more auxiliary drive motors as a third shaft ratio. The third shaft ratio can have a value greater than the first shaft ratio.

[0107] Depending on the vehicle's moving speed and the power requirements required for traction, the driving states of the multiple motors may vary, and the efficiency of the driving motors may change accordingly.

[0108] The efficiency of the main drive motor can fall within either a first efficiency range that is preset or a second efficiency range that is lower in efficiency than the first efficiency range.

[0109] For example, the first efficiency range may be a range in which the efficiency of the main drive motor has a value of 90% or more, and the second efficiency range may be a range in which the efficiency of the main drive motor has a value of less than 90%.

[0110] The efficiency of the auxiliary drive motor may fall within either a third efficiency zone or a fourth efficiency zone that is less efficient than the third efficiency zone.

[0111] For example, the third efficiency section may be a section in which the efficiency of the auxiliary drive motor has a value of 90% or more, and the fourth efficiency section may be a section in which the efficiency of the auxiliary drive motor has a value of less than 90%.

[0112] The vehicle control unit (210) can determine the shaft ratio of the plurality of motors based on the vehicle speed and the preset boundary speed. This can include the ratio of the rotational speed of the motor rotational shaft connected to any one of the plurality of motors to the rotational speed of the wheel rotational shaft (242) of the vehicle.

[0113] For example, as shown in Fig. 3, the rotational speed of the first motor rotation shaft (222a) connected to the first motor (221a) is W mta , and the rotational speed of the wheel rotation axis (242) is W wh When the shaft ratio (R) of the first motor (221a) xla ) can be expressed as in mathematical expression 1.

[0114] [Mathematical Formula 1]

[0115]

[0116] Additionally, the rotation speed of the second motor rotation shaft (222b) connected to the second motor (221b) is W mtb , and the rotational speed of the wheel rotation axis (242) is W wh When the shaft ratio (R) of the second motor (221b) xlb ) can be expressed as in mathematical formula 2.

[0117] [Equation 2]

[0118]

[0119] The vehicle control unit (210) can determine the shaft ratio of multiple motors based on the efficiency distribution of the multiple motors while the vehicle is driving.

[0120] Specifically, the vehicle control unit (210) may determine the shaft ratios of the plurality of motors so that, while the vehicle is driving, the efficiency of the main drive motor has a greater value in the ratio of the period of time included in the first efficiency section than in the ratio of the period of time included in the second efficiency section. In addition, the vehicle control unit (210) may determine the shaft ratios of the plurality of motors so that, while the vehicle is driving, the efficiency of the auxiliary drive motor has a greater value in the ratio of the period of time included in the third efficiency section than in the ratio of the period of time included in the fourth efficiency section.

[0121] For example, the vehicle control unit (210) can determine the shaft ratios of the plurality of motors so that the efficiency of the main drive motor is included in the first efficiency section at a rate of 70% or more while the vehicle is driving, and the efficiency of the auxiliary drive motor is included in the third efficiency section at a rate of 10% or more.

[0122] FIG. 4 is a flowchart of a vehicle control method according to one embodiment of the present invention. The vehicle control method (S400) illustrated in FIG. 4 may be performed in a vehicle system having multiple motors. The multiple motors may include a first drive motor included in a main drive motor and a second drive motor included in one or more auxiliary drive motors.

[0123] The vehicle control method (S400) may include a step (S410) of determining a driving mode based on vehicle driving information.

[0124] The vehicle driving information may include one or more of vehicle speed information, an acceleration request signal, a deceleration request signal, slope information of the road on which the vehicle is driving, and resistance information applied to the vehicle.

[0125] In the step of determining the driving mode (S410), the driving mode can be determined as one of a first driving mode that operates only the main driving motor and a second driving mode that operates the main driving motor and one or more auxiliary driving motors simultaneously.

[0126] If the mode is not one that drives multiple motors in step S420, the process may proceed to a step of operating the first motor, which is the main drive motor (S430), a step of determining the axis ratio of the first motor based on the speed and boundary speed of the vehicle (S440), and a step of driving the vehicle based on the axis ratio (S470).

[0127] In the step of determining the shaft ratio of the first motor (S440), the shaft ratio of the first motor may be a ratio of the rotational speed of the motor rotational shaft connected to the first motor to the rotational speed of the wheel rotational shaft of the vehicle. The shaft ratio may be adjusted using one or more reducers installed in the vehicle.

[0128] Figure 5 is a detailed flowchart of a step (S440) of determining the shaft ratio of the first motor included in the vehicle control method (S400).

[0129] Referring to FIG. 5, the step (S440) of determining the shaft ratio of the first motor may include a step (S441) of comparing the size of the vehicle speed and the boundary speed.

[0130] The boundary speed is a speed that serves as a reference for determining the shaft ratio of the first motor and may have a preset value. For example, the boundary speed may be 35 km / h or less. As another example, the boundary speed may have a value within the range of 20 to 30 km / h.

[0131] In step S442, if the speed of the vehicle has a value lower than or equal to the boundary speed, the process may proceed to step S443 of determining the shaft ratio of the first motor as the first shaft ratio.

[0132] Meanwhile, if the vehicle speed has a value exceeding the boundary speed in step S442, the process may proceed to step S444 of determining the shaft ratio of the first motor as the second shaft ratio. The second shaft ratio may have a value smaller than the first shaft ratio.

[0133] For example, the first shaft ratio may have a value that is 1.3 times greater than the second shaft ratio and less than or equal to 38. The second shaft ratio may have a value that is greater than 6.5 and less than 11. When the second shaft ratio is less than 6.5 or greater than 11, the proportion of the plurality of motors operating in a section where their efficiency is less than 90% increases, which may result in a decrease in the vehicle's fuel efficiency.

[0134] In another example, the first axis ratio can have a value that is at least twice the second axis ratio and less than 30. The second axis ratio can have a value that is greater than 8 and less than 11.

[0135] Meanwhile, referring back to FIG. 4, in the case of a mode in which multiple motors are driven in step S420, the process may proceed to a step of operating multiple motors (S450), a step of determining the axis ratio of the multiple motors based on the speed and boundary speed of the vehicle (S460), and a step of driving the vehicle based on the axis ratio (S470).

[0136] Fig. 6 is a detailed flowchart of a step (S460) of determining the shaft ratio of multiple motors included in a vehicle control method (S400).

[0137] Referring to FIG. 6, the step (S460) of determining the shaft ratio of multiple motors may include a step (S461) of comparing the size of the vehicle speed and the boundary speed.

[0138] In step S462, if the speed of the vehicle has a value lower than or equal to the boundary speed, the process may proceed to step S463 of determining the shaft ratio of the first motor, which is the main drive motor, as the first shaft ratio.

[0139] Meanwhile, if the vehicle speed has a value exceeding the boundary speed in step S462, the process may proceed to step S464 of determining the shaft ratio of the first motor as the second shaft ratio. The second shaft ratio may have a value smaller than the first shaft ratio.

[0140] The step (S460) of determining the shaft ratio of the plurality of motors may further include a step (S465) of determining the shaft ratio of the second motor, which is an auxiliary drive motor, as a third shaft ratio. The third shaft ratio may have a value greater than the first shaft ratio.

[0141] Referring again to FIG. 4, in the step of driving the vehicle based on the axle ratio (S470), the vehicle may be controlled to drive based on the axle ratio determined in the step of determining the axle ratio of the first motor (S440) or the step of determining the axle ratios of multiple motors (S460).

[0142] That is, the vehicle control method according to the present invention can control the shaft ratio of the drive motor to have a relatively large value when the vehicle speed is low, and can control the shaft ratio of the drive motor to have a relatively small value when the vehicle speed increases. In addition, the vehicle control method according to the present invention can control the shaft ratio of the auxiliary drive motor to have a larger value than the shaft ratio of the main drive motor in a drive mode in which multiple motors are driven.

[0143] The present invention can optimize the operating conditions of the powertrain of a vehicle by controlling the axle ratio of a vehicle equipped with multiple motors, and improve fuel efficiency by minimizing unnecessary power loss.

[0144] FIG. 7a is a graph showing the efficiency distribution of a main drive motor when a vehicle is driven while being controlled according to a conventional vehicle control method, and FIG. 7b is an exemplary graph showing the efficiency distribution of a main drive motor when a vehicle is driven while being controlled according to a vehicle control method according to an embodiment of the present invention.

[0145] Comparing Fig. 7a and Fig. 7b, in the efficiency distribution graph shown in Fig. 7a, the efficiency of the main drive motor is distributed relatively diversely in the range of 0 to 100%, but in the efficiency distribution graph shown in Fig. 7b, the efficiency of the main drive motor is shown to be more concentrated on the high side.

[0146] That is, it can be confirmed that the operating points included in the efficiency range where the efficiency of the main drive motor is 90% or higher appear more frequently in the efficiency distribution graph illustrated in Fig. 7b than in the efficiency distribution graph illustrated in Fig. 7a. Through this, it can be confirmed that when controlling a vehicle according to the vehicle control method according to the present invention, the power consumption of the drive motor is reduced and the fuel efficiency is improved compared to the conventional vehicle control method.

[0147] Fig. 8 is a flowchart of a vehicle control method according to another embodiment of the present invention. The vehicle control method illustrated in Fig. 8 may be performed in whole or in part by the vehicle control unit (210) included in the vehicle system (200) illustrated in Fig. 2.

[0148] Referring to Fig. 8, steps S810 to S870 included in the vehicle control method (S800) may be performed in the same or similar manner as the steps included in the vehicle control method (S400) described above with reference to Figs. 2 to 6. Compared to the vehicle control method (S400), the vehicle control method (S800) may further include steps S880 and S890.

[0149] In the step of detecting a change in the speed of the vehicle (S880), after the vehicle is controlled to drive based on the axle ratio in step S870, it can be detected whether a change in the speed of the vehicle occurs.

[0150] In the step of detecting a change in the speed of the vehicle (S880), the speed of the vehicle can be measured using a wheel speed sensor or a vehicle speed sensor.

[0151] If a change in the vehicle speed is detected in the step of detecting a change in the vehicle speed (S880), the process can proceed to the step of detecting the power status of the vehicle (S890).

[0152] In the step (S890) of detecting the vehicle power status, if the vehicle power is turned on, the process may proceed to the step (S810) of determining the driving mode based on vehicle driving information. That is, if a change in vehicle speed is detected and the vehicle power is turned on, the vehicle driving mode may be re-determined.

[0153] Meanwhile, if the vehicle power is OFF in the step of detecting the vehicle power status (S890), the vehicle control method (S800) may be terminated.

[0154] The vehicle control method of the present invention can drive the vehicle under optimal efficiency conditions in response to changes in the vehicle's speed by readjusting the vehicle's driving mode and the motor's shaft ratio while the vehicle is driving.

[0155] FIG. 9 is a block diagram of a computing device (900) that can fully or partially implement a vehicle control device according to one embodiment of the present invention, which may be a vehicle control unit (210) included in the vehicle system (200) illustrated in FIG. 2.

[0156] As illustrated in FIG. 9, the computing device (900) includes at least one processor (901), a computer-readable storage medium (902), and a communication bus (903).

[0157] The processor (901) may cause the computing device (900) to operate according to the exemplary embodiments described above. For example, the processor (901) may execute one or more programs stored in a computer-readable storage medium (902). The one or more programs may include one or more computer-executable instructions, which, when executed by the processor (901), may be configured to cause the computing device (900) to perform operations according to the exemplary embodiments.

[0158] The computer-readable storage medium (902) is configured to store computer-executable instructions or program code, program data, and / or other suitable forms of information. A program (902a) stored in the computer-readable storage medium (902) includes a set of instructions executable by the processor (901). In one embodiment, the computer-readable storage medium (902) may be a memory (volatile memory such as random access memory, non-volatile memory, or a suitable combination thereof), one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, any other form of storage medium that can be accessed by the computing device (900) and capable of storing desired information, or a suitable combination thereof.

[0159] A communication bus (903) interconnects various other components of the computing device (900), including the processor (901) and computer-readable storage medium (902).

[0160] The computing device (900) may also include one or more input / output interfaces (905) that provide interfaces for one or more input / output devices (904) and one or more network communication interfaces (906). The input / output interfaces (905) and the network communication interfaces (906) are connected to a communication bus (903).

[0161] The network communication interface (906) may be an interface for in-vehicle communication or an interface for communication between the vehicle and other devices outside the vehicle, and may include, for example, a Controller Area Network (CAN), a Media Oriented Systems Transport (MOST) network, a Local Interconnect Network (LIN), and / or X-by-Wire (Flexray), Wi-Fi, Bluetooth, NFC, RFID, etc. The network may be a cellular network, such as a Global System for Mobile Communications (GSM), an Enhanced Data Rates for GSM Evolution (EDGE), a General Packet Radio Service (GPRS), a Code Division Multiple Access (CDMA), a Time Division-CDMA (TD-CDMA), a Universal Mobile Telecommunications System (UMTS), a Long Term Evolution (LTE), or any other cellular network.

[0162] The input / output device (904) may be connected to other components of the computing device (900) via an input / output interface (905). Exemplary input / output devices (904) may include input devices such as a pointing device (such as a mouse or a trackpad), a keyboard, a touch input device (such as a touchpad or a touchscreen), a voice or sound input device, various types of sensor devices and / or photographing devices, and / or output devices such as a display device, a printer, a speaker, and / or a network card. The exemplary input / output device (904) may be included within the computing device (900) as a component constituting the computing device (900), or may be connected to the computing device (900) as a separate device distinct from the computing device (900).

[0163] Below are the results of a comparative evaluation of vehicle control methods. During the evaluation, a 200kW interior permanent magnet motor (IPM) was used as the first motor, and a 150kW induction motor was used as the second motor. In addition, the vehicle's curb weight at the time of evaluation was 2215kg, and a battery with a capacity of 75kWh was installed. The highest efficiency when the first motor was in operation was 97.8%, and the highest efficiency of the second motor was 97%. The fuel efficiency was evaluated using an official cycle evaluation method that includes a combined driving cycle, and when the 2nd grade condition of 5.4 (km / kWh) was applied based on the combined energy consumption efficiency (km / kWh) of electric vehicles announced by the Ministry of Trade, Industry and Energy, it was evaluated as failing if the driving distance did not meet 405km or more.

[0164] Table 1 shows the results of evaluating the driving distance (fuel consumption) of a vehicle when a fixed shaft ratio is applied to the first and second motors and the vehicle is controlled to drive.

[0165]

[0166] Experimental examples 1 to 5 and 10 in Table 1 are cases where the shaft ratio of the first motor and the shaft ratio of the second motor are set to the same value. When the shaft ratio of the first motor and the shaft ratio of the second motor are the same, the driving distance increases as the value of the shaft ratio increases and then decreases again.

[0167] Comparing Experimental Examples 3, 6, and 7 in Table 1, the shaft ratio of the first motor is 9 and the value of the shaft ratio of the second motor was changed. R xl3 / R xl1 If this is less than 1, the driving distance has been reduced, and R xl3 / R xl1 When this is greater than 1, the driving distance appears to increase.

[0168] Comparing Experimental Example 3 and Experimental Example 8, it was found that the driving distance was drastically reduced when the shaft ratio of the second motor was 9, but the shaft ratio of the first motor was 12 (Experimental Example 8). This is because the shaft ratio of the first motor exceeded 11. xl3 / R xl1 It was confirmed that the driving distance was reduced by something less than 1.

[0169] Comparing Experimental Example 4 and Experimental Example 9, the shaft ratio of the first motor is the same at 11, but the shaft ratio of the second motor is 14 and R xl3 / R xl1 We were able to confirm that the driving distance increased when this 1.27 had a value greater than 1.

[0170] In addition, it was confirmed through Experimental Examples 10 and 11 that the driving distance was reduced when the shaft ratio of the first motor exceeded 11.

[0171] Table 2 shows that under the same conditions as Table 1, when the speed of the vehicle has a value lower than the boundary speed according to the vehicle control method of the present invention, the shaft ratio of the first motor is the first shaft ratio (R xl1 ) and, if the speed of the vehicle has a value exceeding the boundary speed, the shaft ratio of the first motor is controlled to be the second shaft ratio (R xl2 ) shows the results of evaluating the vehicle's driving distance (fuel consumption) when controlled to be 406.87 km or more. In Table 2, if the driving distance in Table 1 is not satisfied by 0.2%, it is evaluated as failed.

[0172]

[0173] Experimental examples 12 to 14 in Table 2 fixed the first motor shaft ratio at 27 and increased the boundary speed value. According to this, as the boundary speed increased, the driving distance increased and then decreased again, and Experimental example 14, in which the boundary speed was 40 km / h, failed to meet the driving distance requirement.

[0174] According to Experimental Examples 12 and 13, while the vehicle was running, the operating rate of the first motor with an efficiency of 90% or more was 73% or more, and the operating rate of the second motor with an efficiency of 90% or more was 12% or more. On the other hand, according to Experimental Example 14, while the vehicle was running, the operating rate of the first motor with an efficiency of 90% or more was 64.7%, and the operating rate of the second motor with an efficiency of 90% or more was 9.5%.

[0175] Comparing Experimental Examples 15 and 16, R xl1 / R xl2 It was found that the driving distance increased when this was greater than 1.3.

[0176] According to Experimental Example 15, while the vehicle was running, the operating rate of the first motor with an efficiency of 90% or more was 68.7%, and the operating rate of the second motor with an efficiency of 90% or more was 9.9%.

[0177] Comparing Experimental Examples 16 and 17, it was confirmed that the driving distance did not continue to increase as the boundary speed increased.

[0178] According to Experimental Examples 16 and 17, while the vehicle was running, the operating rate of the first motor with an efficiency of 90% or more was 72% or more, and the operating rate of the second motor with an efficiency of 90% or more was 11% or more.

[0179] Experimental examples 13, 16, 18, 19 and 22 were evaluated while changing the shaft ratio of the first motor when the boundary speed was 30 km / h. It was found that as the value of the first shaft ratio increased, the driving distance increased and then decreased again.

[0180] Comparing Experimental Examples 20 and 21, the driving distance was found to be unsatisfactory when the boundary speed exceeded 35 km / h. In addition, Experimental Examples 22 and 23 were found to be unsatisfactory when the first axle ratio exceeded 38 and the boundary speed was 35 km / h or less.

[0181] According to Experimental Examples 21 to 23, while the vehicle was driving, the operating rate of the first motor with an efficiency of 90% or more was less than 69%, and the operating rate of the second motor with an efficiency of 90% or more was less than 9.7%.

[0182] Through the above-described Tables 1 and 2, it was confirmed that the power efficiency was improved when controlling the shaft ratio of multiple motors according to the present invention.

[0183] Meanwhile, embodiments of the present invention may include a program for performing the methods described herein on a computer, and a computer-readable recording medium including the program. The computer-readable recording medium may include program commands, local data files, local data structures, etc., alone or in combination. The medium may be specially designed and configured for the present invention, or may be one commonly used in the field of computer software. Examples of the computer-readable recording medium include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical recording media such as CD-ROMs and DVDs, and hardware devices specially configured to store and execute program commands such as ROMs, RAMs, and flash memories. Examples of the program may include not only machine language codes such as those generated by a compiler, but also high-level language codes that can be executed by a computer using an interpreter, etc.

[0184] While representative embodiments of the present invention have been described in detail above, those skilled in the art will appreciate that various modifications to the above-described embodiments are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the claims set forth below but also by equivalents thereof.

[0185] (Explanation of symbols)

[0186] 200: Vehicle System

[0187] 210: Vehicle control unit

[0188] 220: Drive unit

[0189] 221a: First motor

[0190] 221b: Second motor

[0191] 222a: First motor rotation shaft

[0192] 222b: Second motor rotation axis

[0193] 230: Transmission

[0194] 231: Reducer

[0195] 240: Driving section

[0196] 241: Driving wheel

[0197] 242: Wheel rotation axis

[0198] 900: Computing Device

[0199] 901: Processor

[0200] 902: Computer-readable storage medium

[0201] 902a: Program

[0202] 903: Communication bus

[0203] 904: Input / output device

[0204] 905: Input / Output Interface

[0205] 906: Network Communication Interface

Claims

1. Processor; and A storage medium storing instructions executable by the processor, The above processor executes the above instruction, Determine the driving mode based on the vehicle's driving information, Determine the shaft ratio of a plurality of motors included in the vehicle based on the above driving mode and boundary speed, Drive the vehicle based on the shaft ratio of the plurality of motors, The shaft ratio of the plurality of motors includes a ratio of the rotational speed of a motor rotational shaft connected to any one of the plurality of motors to the rotational speed of a wheel rotational shaft of the vehicle, A vehicle control device, wherein the above boundary speed is set based on the operating efficiency distribution of at least one of the plurality of motors.

2. In paragraph 1, The above plurality of motors include a main drive motor and one or more auxiliary drive motors, The above processor, A vehicle control device that determines one of a first driving mode that operates only the main driving motor and a second driving mode that operates the main driving motor and one or more auxiliary driving motors simultaneously based on driving information of the vehicle.

3. In paragraph 2, The above main drive motor includes a first motor, wherein said one or more auxiliary drive motors include a second motor, The above processor, In the first driving mode, the shaft ratio of the first motor is determined, and in the second driving mode, the shaft ratio of the first motor and the shaft ratio of the second motor are determined, The shaft ratio of the first motor is the ratio of the rotational speed of the first motor rotational shaft connected to the first motor to the rotational speed of the wheel rotational shaft of the vehicle, A vehicle control device, wherein the shaft ratio of the second motor is a ratio of the rotational speed of the second motor rotational shaft connected to the second motor to the rotational speed of the wheel rotational shaft of the vehicle.

4. In paragraph 3, The above processor, Compare the speed of the above vehicle with the size of the above boundary speed, When the speed of the vehicle has a value less than or equal to the boundary speed, the shaft ratio of the first motor is determined as the first shaft ratio, A vehicle control device that determines the shaft ratio of the first motor as a second shaft ratio having a value smaller than the first shaft ratio when the speed of the vehicle has a value exceeding the boundary speed.

5. In paragraph 4, The above processor, A vehicle control device that determines the shaft ratio of the second motor in the second driving mode as a third shaft ratio having a value greater than the first shaft ratio.

6. In paragraph 2, The efficiency of the above main drive motor is included in either a first efficiency section set in advance or a second efficiency section having lower efficiency than the first efficiency section, The above processor, A vehicle control device that determines the shaft ratio of the plurality of motors based on the ratio of the period during which the efficiency of the main drive motor is included in the first efficiency section while the vehicle is driving.

7. In paragraph 6, The efficiency of the one or more auxiliary drive motors is included in either a third efficiency range set in advance or a fourth efficiency range having lower efficiency than the third efficiency range, The above processor, A vehicle control device that determines the shaft ratio of the plurality of motors based on a ratio of a period during which the efficiency of the one or more auxiliary drive motors is included in the third efficiency section while the vehicle is driving.

8. In paragraph 1, A vehicle control device having a speed limit of 35 km / h or less.

9. In paragraph 8, A vehicle control device, wherein the above boundary speed has a value within the range of 20 to 30 km / h.

10. In paragraph 4, The value of the above first axis ratio is 38 or less, A vehicle control device, wherein the first axis ratio has a value that is 1.3 times or more greater than the second axis ratio.

11. In paragraph 10, The value of the above first axis ratio is 30 or less, A vehicle control device, wherein the first axis ratio has a value that is more than twice the second axis ratio.

12. In paragraph 11, A vehicle control device, wherein the second axis ratio has a value greater than 6.5 and less than 11.

13. Processor; and A method performed in a computing device including a storage medium storing instructions executable by the processor, A step of determining a driving mode based on the driving information of the vehicle; A step of determining the shaft ratio of a plurality of motors included in the vehicle based on the driving mode and boundary speed; and A step of driving the vehicle based on the shaft ratio of the plurality of motors. Including, The shaft ratio of the plurality of motors includes a ratio of the rotational speed of a motor rotational shaft connected to any one of the plurality of motors to the rotational speed of a wheel rotational shaft of the vehicle, A vehicle control method, wherein the above boundary speed is set based on the operating efficiency distribution of at least one of the plurality of motors.

14. In paragraph 13, The above plurality of motors include a main drive motor and one or more auxiliary drive motors, The step of determining the above driving mode is: A vehicle control method, which determines one of a first driving mode in which only the main driving motor is operated based on driving information of the vehicle and a second driving mode in which the main driving motor and one or more auxiliary driving motors are operated simultaneously.

15. In paragraph 14, The above main drive motor includes a first motor, wherein said one or more auxiliary drive motors include a second motor, The step of determining the shaft ratio of the above plurality of motors is: In the first driving mode, the shaft ratio of the first motor is determined, and in the second driving mode, the shaft ratio of the first motor and the shaft ratio of the second motor are determined, The shaft ratio of the first motor is the ratio of the rotational speed of the first motor rotational shaft connected to the first motor to the rotational speed of the wheel rotational shaft of the vehicle, A vehicle control method, wherein the shaft ratio of the second motor is a ratio of the rotational speed of the second motor rotational shaft connected to the second motor to the rotational speed of the wheel rotational shaft of the vehicle.

16. In paragraph 15, The step of determining the shaft ratio of the above plurality of motors is: A vehicle control method, wherein the shaft ratio of the first motor is determined as the first shaft ratio when the speed of the vehicle has a value lower than the boundary speed, and the shaft ratio of the first motor is determined as the second shaft ratio when the speed of the vehicle has a value higher than the boundary speed.

17. In paragraph 16, The step of determining the shaft ratio of the above plurality of motors is: A vehicle control method, wherein the shaft ratio of the second motor in the second driving mode is determined as a third shaft ratio having a value greater than the first shaft ratio.

18. In paragraph 14, The efficiency of the above main drive motor is included in either a first efficiency section set in advance or a second efficiency section having lower efficiency than the first efficiency section, The step of determining the shaft ratio of the above plurality of motors is: A vehicle control method, wherein the shaft ratio of the plurality of motors is determined based on the ratio of the period during which the efficiency of the main drive motor is included in the first efficiency section while the vehicle is driving.

19. In paragraph 18, The efficiency of the one or more auxiliary drive motors is included in either a third efficiency range set in advance or a fourth efficiency range having lower efficiency than the third efficiency range, The step of determining the shaft ratio of the above plurality of motors is: A vehicle control method, wherein the shaft ratio of the plurality of motors is determined based on a ratio of a period during which the efficiency of the one or more auxiliary drive motors is included in the third efficiency section while the vehicle is driving.

20. In paragraph 13, A vehicle control method wherein the above boundary speed is 35 km / h or less.

21. In paragraph 20, A vehicle control method wherein the above boundary speed has a value within the range of 20 to 30 km / h.

22. In paragraph 16, The value of the above first axis ratio is 38 or less, A vehicle control method, wherein the first axis ratio has a value that is 1.3 times or more greater than the second axis ratio.

23. In paragraph 22, The value of the above first axis ratio is 30 or less, A vehicle control method, wherein the first axis ratio has a value that is more than twice the second axis ratio.

24. In paragraph 23, A vehicle control method, wherein the second axis ratio has a value greater than 6.5 and less than 11.

25. A driving part including a first rotation axis and one or more driving wheels connected to the first rotation axis; A driving unit including a plurality of motors and a plurality of motor rotation shafts connected to the plurality of motors; A transmission unit that adjusts the shaft ratio of the plurality of motors, including the ratio of the rotation speed of one of the plurality of motor rotation shafts to the rotation speed of the first rotation shaft; and Control unit that controls the above gearbox Including, The control unit determines the shaft ratio of the plurality of motors based on the driving mode and boundary speed of the plurality of motors, and controls the transmission unit based on the determined shaft ratio of the plurality of motors. A vehicle system wherein the above boundary speed is set based on the operating efficiency distribution of at least one of the plurality of motors.

26. In paragraph 25, Further comprising a vehicle speed sensor for measuring the speed of the vehicle, The above plurality of motors include a main drive motor, A vehicle system in which the control unit receives the speed of the vehicle measured using the vehicle speed sensor, and determines the shaft ratio of the main drive motor as one of a first shaft ratio and a second shaft ratio having a value smaller than the first shaft ratio based on a result of comparing the speed of the vehicle with the magnitude of the boundary speed.

27. In paragraph 26, The control unit determines the shaft ratio of the main drive motor as the first shaft ratio when the speed of the vehicle has a value lower than or equal to the boundary speed, A vehicle system that determines the shaft ratio of the main drive motor as the second shaft ratio when the speed of the vehicle has a value exceeding the boundary speed.

28. In paragraph 27, The above plurality of motors further include one or more auxiliary drive motors, A vehicle system, wherein the control unit determines the shaft ratio of the one or more auxiliary drive motors as a third shaft ratio having a value greater than the first shaft ratio in a drive mode that operates the main drive motor and the one or more auxiliary drive motors simultaneously.

29. In paragraph 28, The efficiency of the above main drive motor is included in either a first efficiency section set in advance or a second efficiency section having lower efficiency than the first efficiency section, The efficiency of the one or more auxiliary drive motors is included in either a third efficiency range set in advance or a fourth efficiency range having lower efficiency than the third efficiency range, A vehicle system, wherein the control unit determines the shaft ratio of the plurality of motors based on a ratio of a period during which the efficiency of the main drive motor is included in the first efficiency section and a ratio of a period during which the efficiency of the one or more auxiliary drive motors is included in the third efficiency section while the vehicle is driving.

30. In paragraph 25, The above boundary speed is 35 km / h or less, vehicle system.

31. In paragraph 30, A vehicle system wherein the above boundary speed has a value in the range of 20 to 30 km / h.

32. In paragraph 26, The value of the above first axis ratio is 38 or less, A vehicle system wherein the first axis ratio has a value that is 1.3 times or more greater than the second axis ratio.

33. In paragraph 32, The value of the above first axis ratio is 30 or less, A vehicle system wherein the first axis ratio has a value that is more than twice the second axis ratio.

34. In paragraph 33, A vehicle system wherein the second axis ratio has a value greater than 6.5 and less than 11.

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