Vehicle drive control device

Abstract

To provide a highly practical vehicle drive control device.SOLUTION: A vehicle drive control device determines a target longitudinal acceleration G* which is a desired longitudinal acceleration of a vehicle based on a vehicle speed and an accelerator opening δ, and controls a drive unit based on the target longitudinal acceleration G*. The vehicle control device determines the target longitudinal acceleration corresponding to any given accelerator opening through interpolation based on five pieces of data (each corresponding to the target longitudinal acceleration for a specific accelerator opening and allocated to positions marked with numbers in circles or triangles) stored for each vehicle speed. Thus, the vehicle drive control device can appropriately control the drive unit with a relatively small amount of stored data.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a vehicle drive control device that controls a drive device mounted on a vehicle. [Background technology]

[0002] The following patent document describes a technology for a vehicle drive control device that controls a drive unit that uses an engine or the like as a drive source. This technology determines the drive force to be generated for the vehicle based on the vehicle's traveling speed and accelerator pedal depression, and controls the drive unit based on the determined drive force. This technology uses a map set for each vehicle traveling speed, specifically a map showing the relationship between accelerator pedal depression and drive force, and determines the drive force based on the map. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-28903 Summary of the Invention [Problem to be solved by the invention]

[0004] In the technology described in the above patent application, the vehicle drive control device stores the above-mentioned map, but the amount of data related to the map is considerably large, imposing a heavy burden on the vehicle drive control device. Therefore, by reducing the amount of data to be stored, the practicality of the vehicle drive control device will be improved. The present invention has been made in consideration of such circumstances, and an object of the present invention is to provide a vehicle drive control device with high practicality. [Means for solving the problem]

[0005] In order to solve the above problems, the vehicle drive control device of the present invention comprises: A vehicle drive control device for controlling a drive device provided in a vehicle, A target driving index, which is the longitudinal acceleration of the vehicle to be realized or the driving force to be generated, is determined based on the traveling speed of the vehicle and the accelerator opening, and the driving device is controlled based on the target driving index, The vehicle drive control device, As data for determining the target driving index, only five or less values ​​of the target driving index corresponding to a specific accelerator opening degree or data for determining the value are stored for each vehicle traveling speed, The target drive index corresponding to any accelerator opening is determined by interpolation processing based on the five or fewer pieces of data. [Effects of the Invention]

[0006] According to the vehicle drive control device of the present invention, it is possible to appropriately control the drive device by simply storing a relatively small amount of data.

[0007] In the present invention, the "vehicle traveling speed (hereinafter sometimes abbreviated as "vehicle speed")" can be measured or estimated based on, for example, the rotational speed of the drive shaft. "Accelerator opening" is a concept that broadly includes the degree of operation of an accelerator operating member such as an accelerator pedal or joystick, such as the amount of operation, the operation speed, and the operation strength. In the following explanation, for convenience, the accelerator opening will be expressed as a percentage, with 100% being when the accelerator operating member is fully operated and 0% being when it is not operated at all. With regard to the "target driving index," if the target driving index is longitudinal acceleration, that longitudinal acceleration becomes deceleration when decelerating the vehicle, and if it is driving force, that driving force acts as a braking force when decelerating the vehicle.

[0008] The "drive device" in the present invention may be, for example, a device using a gasoline engine or the like as a drive source, an electric motor as a drive source, or both. That is, the vehicle in which the vehicle drive control device of the present invention is adopted may be a gasoline engine vehicle, or may be a so-called BEV or HEV. In the case of a gasoline engine vehicle, the vehicle drive control device may simply control the throttle opening, fuel injection amount, transmission, etc. based on the target drive index. In the case of a vehicle using an electric motor as a drive source, the vehicle drive control device may simply control the current supplied to the electric motor based on the target drive index.

[0009] In the present invention, "data for determining the value of the target driving index" broadly includes, for example, the gradient of the target driving index in a range that includes a specific accelerator opening. The above-mentioned "interpolation process" may be, for example, linear interpolation, or may be interpolation using some kind of quadratic or higher function with the accelerator opening as a parameter.

[0010] The above-mentioned "five or less pieces of data" can include, for example, the following: By adopting one or more of the following pieces of data, it is possible to appropriately reflect the driver's intentions and driving characteristics based on the design concept in the control of the drive unit. (1) Target driving index value at 0% accelerator opening (2) The accelerator opening when the value of the target driving index becomes 0, for example, when the vehicle is neither accelerating nor decelerating. (3) The gradient of increase of the target driving index with respect to the accelerator opening in a steady state region (a range in which the accelerator opening is relatively small) including a specific accelerator opening. (4) The value of the target driving index at the upper limit of the normal high acceleration range (the range of relatively large accelerator openings under normal driving conditions) (5) Target driving index value when accelerator opening is 100% [Brief explanation of the drawings]

[0011] [Figure 1]1 is a schematic diagram showing the configuration of a vehicle equipped with a vehicle drive control device according to an embodiment; [Figure 2] 4 is a graph showing the relationship between a target longitudinal acceleration determined in the vehicle drive control device of the embodiment and an accelerator opening degree. [Figure 3] 4 is a flowchart of a vehicle drive program executed in the vehicle drive control device. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, a vehicle drive control device according to an embodiment of the present invention will be described in detail with reference to the drawings. In addition to the following embodiment, the present invention can be embodied in various forms including those described in the above section "Modes of the Invention" and various modifications and improvements based on the knowledge of those skilled in the art. [Example]

[0013] [A] Configuration of a vehicle equipped with a vehicle drive control device 1, a vehicle equipped with a vehicle drive control device of the embodiment includes a pair of left and right wheels ("front wheels") 10, and a drive unit 12 that drives the vehicle by rotating the wheels 10. The drive unit 12 uses a drive motor 14, which is an electric motor, as a drive source, and the rotation of the drive motor 14 is transmitted to the two wheels 10 via a reducer 16, a differential 18, and drive shafts 20 and 22.

[0014] The vehicle is equipped with a drive electronic control unit (hereinafter sometimes referred to as "drive ECU") 24 as a vehicle drive control device that controls the drive of the vehicle by controlling the drive device 12. The drive ECU 24 has a computer 26 that manages control and a driver (drive circuit) 28 that is controlled and operated by the computer 26. The driver 28 has the function of supplying current from the battery 30 to the drive motor 14 while controlling it, and when the drive motor 14 is a three-phase brushless DC motor, it is mainly composed of an inverter. Although a detailed explanation will be omitted, the drive device 12 is also capable of applying braking force to the vehicle by using the electromotive force of the drive motor 14 to regenerate the current generated by the drive motor 14.

[0015] Because a driving force corresponding to the magnitude of the current supplied to the drive motor 14 is imparted to the vehicle, the computer 26 controls the driver 28 so that a current corresponding to the required driving force is supplied to the drive motor 14. The control will be described in detail later, but in order to obtain the parameters required for the control, the vehicle is provided with an accelerator position sensor 34 that detects the amount of operation of an accelerator pedal 32, which is an accelerator operating member, i.e., an accelerator position δ, and a motor rotation speed sensor 36 that detects a motor rotation speed θ, which is the rotation speed of the drive motor 14. The accelerator position δ and motor rotation speed θ detected by these sensors 34, 36 are input as signals to the computer 26.

[0016] [B] Control of the drive unit by the vehicle drive control device i) Overview The drive ECU 24, which is a vehicle drive control device, controls the operation of the drive unit 12, more specifically, the drive motor 14, thereby controlling the drive of the vehicle. A computer 26 of the drive ECU 24 determines a target drive index as a target drive index, which is a guideline for the drive of the vehicle, and controls the drive unit 12 via a driver 28 based on the target drive index. The target drive index may be the drive force that the drive unit 12 should generate, but in this vehicle, the target drive index is set to a target longitudinal acceleration G, which is the longitudinal acceleration G that should be realized in the vehicle. * will be adopted.

[0017] The computer 26 of the drive ECU 24 calculates the actual longitudinal acceleration G, which is the actual longitudinal acceleration at the current time, as the target longitudinal acceleration G. * Although detailed explanation will be omitted, for example, the actual longitudinal acceleration G is controlled to approach the target longitudinal acceleration G * Based on the deviation from the target longitudinal acceleration G, the current to be supplied to the drive motor 14 is determined in accordance with the PID feedback control law, and a command is given to the driver 28 to supply that current. The actual longitudinal acceleration G is determined based on the motor rotation speed θ detected by the motor rotation speed sensor 36. * When the actual longitudinal acceleration G is greater than the actual longitudinal acceleration G, a negative driving force, that is, a braking force is applied to the vehicle by the regenerative current from the drive motor 14.

[0018] ii) Determining the target longitudinal acceleration Determined target longitudinal acceleration G * has characteristics as shown in the graph of FIG. 2, for example, with respect to the accelerator opening δ. This graph shows a specific line at a specific vehicle traveling speed (hereinafter sometimes abbreviated as "vehicle speed") v. The accelerator opening δ is expressed as a percentage, with 0% (fully closed accelerator) when the accelerator pedal 32 is not depressed and 100% (fully open accelerator) when it is depressed to the maximum. Also, when the accelerator opening δ is small, the target longitudinal acceleration G * is a negative value, and in that case, the drive unit 12 is controlled to achieve deceleration.

[0019] As can be seen from the graph, for the sake of convenience, four regions are set for this vehicle according to the accelerator opening δ. The four regions are, in order of decreasing accelerator opening δ, the "pre-steady state region," the "steady state region," the "normal high acceleration region," and the "post-high acceleration region." Specifically, the pre-steady state region is the region from the accelerator fully closed to an accelerator opening a1 (e.g., 20-25%), and the steady state region is the region from the accelerator opening a1 to an accelerator opening a2 (e.g., 35-40%), i.e., the region where the accelerator is most frequently operated during normal driving. The normal high acceleration region is the region from the accelerator opening a2 to an accelerator opening a3 (e.g., 50-55%), i.e., the region where relatively high acceleration is desired during normal driving, and the post-high acceleration region is the region from the accelerator opening a3 to the fully open accelerator, i.e., the region where the accelerator is operated for fairly high acceleration.

[0020] In this vehicle, the computer 28 calculates the target longitudinal acceleration G at a specific vehicle speed v. * The data for determining the target longitudinal acceleration G (hereinafter referred to as "target longitudinal acceleration determination dependent data" or simply "dependent data") are stored as data for determining the target longitudinal acceleration G (hereinafter referred to as "target longitudinal acceleration determination dependent data" or simply "dependent data"). In other words, only these data are stored. * The data is a set of data for the value of v or data for determining that value. In other words, for one vehicle speed v, only five sets of data are stored.

[0021] Specifically, data 1 is the target longitudinal acceleration G when the accelerator is fully closed. * Data 2 is the target longitudinal acceleration G *The data is about the accelerator opening δ0 for maintaining vehicle speed, which is the accelerator opening δ when the current vehicle speed v is maintained. Data 3 is about the steady-state acceleration gradient [G / δ]0, which is the gradient of increase in longitudinal acceleration in the steady-state region above the accelerator opening δ0 for maintaining vehicle speed. In other words, data 3 is about the target longitudinal acceleration G at the accelerator opening a2, which is the end of the steady-state region (the beginning of the normal high acceleration region). * Data 4 can be considered as data for determining the target longitudinal acceleration G at the accelerator opening a3, which is the end of the normal high acceleration range. * This is data for the normal upper limit acceleration G1. Data 5 is the target longitudinal acceleration G when the accelerator is fully open. * The data is about the acceleration G2 when the throttle is fully opened. Note that the acceleration G2 when the throttle is fully opened is limited by the capacity of the drive unit 12.

[0022] In this vehicle, only the above five data are stored for one vehicle speed v, so the computer 26 of the drive ECU 24 calculates the target longitudinal acceleration G corresponding to an arbitrary accelerator opening δ. * In detail, when the accelerator opening degree δ to be determined is midway between two specific accelerator opening degrees δ corresponding to the stored data, the two target longitudinal acceleration G * The intermediate value of the target longitudinal acceleration G corresponding to the accelerator opening δ is used for determination. * The interpolation process may be a so-called linear interpolation, or may be performed based on some function set with the accelerator opening δ as a parameter. * can be determined based on the steady-state acceleration gradient [G / δ]0 described above. Note that, since it is desirable to have a small amount of data in order to reduce the burden on the computer 26, it is not necessary to use any of the data <1> to <5>. Furthermore, other data can be used in place of any of the above data <1> to <5>, as long as the number of data does not exceed five.

[0023] At a specific vehicle speed v, if the above five data are changed, the target longitudinal acceleration G * The characteristics of the vehicle, that is, the driving characteristics of the vehicle, change. Simply put, if the acceleration G0 at full closure in data <1> is increased (if the deceleration is decreased, if it is brought closer to 0), so-called coasting braking will be improved, and if it is decreased (if the deceleration is increased, if it is brought farther away from 0), the feeling of being caught in a corner will increase. If the accelerator opening degree δ0 to maintain vehicle speed in data <2> is increased, a relatively smooth (settled) driving of the vehicle will be realized, and conversely, if it is decreased, a brisk (good response) driving of the vehicle will be realized. If the steady-state acceleration gradient [G / δ]0 in data <3> is increased, the feeling of contact with the ground when the accelerator operation is finished (when the foot is taken off the accelerator pedal 32) can be improved, and if it is decreased, good coasting performance can be ensured. Target longitudinal acceleration G in the normal high acceleration range * Depending on the relationship with the increasing gradient of the acceleration, if the normal upper limit acceleration G1 of data 《4》 is lowered, the target longitudinal acceleration G * The change characteristics of the target longitudinal acceleration G are good, and if it is increased, * A change in the steady state will lead to a change in the steady state.

[0024] The computer 26 of the drive ECU 24 calculates the target longitudinal acceleration G at an arbitrary vehicle speed v. * The above five data for each vehicle v are stored for each vehicle speed v (for example, for each 5 to 10 km / h) in order to determine the target longitudinal acceleration G *The following settings are made taking into consideration the characteristics of the vehicle. Simply put, the full-close acceleration G0 is generally set lower as the vehicle speed v increases, and the vehicle speed maintenance accelerator opening δ0 is set larger as the vehicle speed v increases. In addition, the steady-state acceleration gradient [G / δ]0 is generally set smaller as the vehicle speed v increases, and the normal upper limit acceleration G1 is set lower as the vehicle speed v increases. Note that there is a limit to the driving capability of the vehicle, and the higher the vehicle speed v, the more driving force is required to maintain that vehicle speed v. Therefore, the full-open acceleration G2 is necessarily set lower as the vehicle speed v increases.

[0025] The computer 26 determines the current vehicle speed v based on the motor rotation speed θ detected by the motor rotation speed sensor 36, and then calculates the target longitudinal acceleration G corresponding to the current arbitrary accelerator opening δ by referring to data on vehicle speeds v close to the current vehicle speed v. * Determine.

[0026] According to the present drive ECU 24, it is possible to appropriately control the drive device 12, that is, the drive of the vehicle, by simply storing a relatively small amount of data.

[0027] [C] Vehicle drive control flow The above target longitudinal acceleration G * The control of the drive unit 12, including the determination of the above, is performed by the computer 26 repeatedly executing a vehicle drive program, the flowchart of which is shown in Figure 3, at relatively short intervals (for example, every few tens of milliseconds). Below, the flow of the vehicle drive control will be briefly explained with reference to the flowchart.

[0028] In the processing according to the above program, first, in step 1 (hereinafter abbreviated as "S1", the same applies to the other steps), the current vehicle speed v is determined based on the motor rotation speed θ detected by the motor rotation speed sensor 36. In the following step S2, a set of the above-mentioned reference data to be referenced is selected based on the vehicle speed v. In the next step S3, the current accelerator opening δ is determined based on the signal from the accelerator opening sensor 34, and in step S4, the above-mentioned interpolation processing is performed based on the accelerator opening δ to determine the target longitudinal acceleration G * In simple terms, the accelerator opening δ is determined to which region it belongs, and the target longitudinal acceleration G is calculated using the set function. * Then, in S5, the target longitudinal acceleration G * The current to be supplied to the drive motor 14 is determined based on the deviation of the actual longitudinal acceleration G at the current time from the target value. This current is supplied to the drive motor 14 via the driver 28. [Explanation of symbols]

[0029] 10: Front wheels 12: Drive unit 14: Drive motor 24: Drive electronic control unit (drive ECU) [vehicle drive control device] 32: Accelerator pedal δ: Accelerator opening (a1, a2, a3) v: Vehicle running speed (vehicle speed) G * :Target longitudinal acceleration

Claims

[Claim 1] A vehicle drive control device for controlling a drive device provided in a vehicle, A target driving index, which is the longitudinal acceleration of the vehicle to be realized or the driving force to be generated, is determined based on the traveling speed of the vehicle and the accelerator opening, and the driving device is controlled based on the target driving index, As data for determining the target driving index, the system stores five or less target driving index values ​​corresponding to specific accelerator openings for each vehicle traveling speed, or data for determining such values, The vehicle drive control device is characterized in that a target drive index corresponding to an arbitrary accelerator opening is determined by interpolation processing based on the five or fewer pieces of data.

Images