JP2017175739A - Electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a driver to recognize a state of control of a regenerative braking force according to a friction coefficient of a road surface.SOLUTION: A target regenerative braking force and an actual regenerative braking force are simultaneously displayed at a regenerative braking force display part of a combination meter device 21. When a difference of the regenerative braking force comes to be a preset difference or larger, for example, if a slip occurs on a drive wheel 2 and the actual regenerative braking force becomes lower, a driver is made to recognize that the actual regenerative braking force does not agree with the target regenerative braking force.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electric vehicle that transmits driving force to driving wheels by a traveling motor.

  In recent years, vehicles (EV) in which driving wheels are driven by a traveling motor, and hybrid vehicles in which a traveling motor and an engine are combined to obtain the driving force of the vehicle have been developed and put into practical use. As a hybrid vehicle, not only a vehicle (HEV) that charges a battery that generates electricity by driving a generator by an engine and supplies power to a traveling motor (HEEV), but also a vehicle (PHEV) that can be charged by an external commercial power source. Development and practical use are progressing.

  In such an electric vehicle, for example, when the vehicle is decelerating while the accelerator pedal is released or coasting, the driving motor rotates by receiving energy from the drive wheels, and generates electric energy to obtain a predetermined value. Braking force (regenerative braking force) can be obtained. And when driving | running | working on the road surface (low micro road) with a low friction coefficient, the regenerative braking force is made small and the slip of a driving wheel (wheel) is prevented (for example, patent document 1).

  In the technique of Patent Document 1, since the regenerative braking force is controlled according to the friction coefficient (road surface μ) of the road surface, the running stability can be improved without giving the driver a sense of incongruity. However, if the driver has set the target regenerative braking force, the driving stability can be improved by controlling the regenerative braking force according to the road surface μ condition, but the driver has set (expected ) The electric vehicle travels with a braking force different from the braking force (regenerative braking force), which may cause the driver to feel uncomfortable.

Japanese Patent No. 3951957

  The present invention has been made in view of the above situation, and provides an electric vehicle capable of allowing a driver to recognize the state of control of regenerative braking force according to the state of the friction coefficient (road surface μ) of the road surface. Objective.

  In order to achieve the above object, an electric vehicle according to a first aspect of the present invention is an electric vehicle provided with a traveling motor that is supplied with electric power from a battery and transmits a driving force to the driving wheels. Target regenerative brake force setting means for setting force, actual regenerative brake force deriving means for deriving the actual regenerative brake force of the drive wheel during traveling, and target regenerative brake force set by the target regenerative brake force setting means And display means for simultaneously displaying the actual regenerative braking force derived by the actual regenerative braking force deriving means.

  In the first aspect of the present invention, the target regenerative braking force set by the target regenerative braking force setting means and the actual regenerative braking force derived by the actual regenerative braking force deriving means are simultaneously displayed on the display means. Accordingly, when the actual regenerative braking force does not match the target regenerative braking force, the driver can visually recognize that they do not match.

  Therefore, it becomes possible to make the driver recognize the state of control of the regenerative braking force according to the state of the road surface friction coefficient (road surface μ).

  The electric vehicle of the present invention according to claim 2 is the electric vehicle according to claim 1, wherein the display means displays the magnitude display of the target regenerative braking force and the actual regenerative braking force in an overlapping manner, The difference display portion is displayed in different colors.

  According to the second aspect of the present invention, since the portion of the difference between the target regenerative braking force and the actual regenerative braking force is displayed in different colors, the target regenerative brake is displayed when the different color sizes are displayed. It can be confirmed at a glance that there is a difference between the force and the actual regenerative braking force. In this case, it is possible to blink portions of different colors or display a mark for calling attention.

  An electric vehicle according to a third aspect of the present invention is the electric vehicle according to the first or second aspect, further comprising wheel speed detecting means for detecting a wheel speed of the drive wheel, and the actual regenerative braking force derivation. The means is characterized in that the actual regenerative braking force is obtained from the rotational speed of the drive wheel detected by the wheel speed detecting means.

  In the present invention according to claim 3, the actual regenerative braking force can be obtained by detecting the rotational speed of the drive wheel by the wheel speed detecting means.

  An electric vehicle according to a fourth aspect of the present invention is the electric vehicle according to any one of the first to third aspects, wherein the target regenerative braking force set by the target regenerative braking force setting means, and A comparison means for comparing the actual regenerative braking force derived by the actual regenerative braking force deriving means, wherein the target regenerative braking force setting means sets a braking force of an arbitrary strength from a plurality of braking forces. A target regenerative braking force that is set on the basis of a difference between the target regenerative braking force and the actual regenerative braking force compared by the comparison unit. It is characterized by changing to force.

  In the present invention according to claim 4, the reference vehicle speed value, which is the vehicle speed as the target regenerative braking force, is compared with the rotational speed value of the drive wheel, which is the actual regenerative braking force, and a difference of a predetermined value or more is generated. For example, when the rotational speed of the driving wheel is higher than the reference vehicle speed, it is determined that slip has occurred, and the target regenerative braking force (reference vehicle speed) and the actual regenerative braking force (rotating speed of the driving wheel) are determined. Are not matched, the target regenerative braking force is changed to a weaker braking force than the current braking force, and the control shifts to a control for causing the regenerative braking force to follow the weak regenerative braking target regenerative braking force. Thereby, traveling stability can be maintained irrespective of the friction coefficient of the road surface.

  The comparison means can compare the target regenerative braking force with the actual regenerative braking force by comparing the rate of deceleration using the rate of change of the rotational speed of the drive wheel, the rate of change of the reference vehicle speed, or information from the acceleration sensor. It is. Further, as the wheel speed detecting means, for example, a vehicle speed detecting means for detecting the rotational speed of the output shaft of the traveling motor and obtaining the vehicle speed can be applied. In addition, when there is a difference of more than a predetermined value between the vehicle speed value and the driving wheel rotation speed value, the actual friction coefficient of the road surface is grasped by means of measuring the friction coefficient of the road surface, and slipping has occurred. It is also possible to confirm.

  The electric vehicle of the present invention makes it possible for the driver to recognize the state of control of the regenerative braking force in accordance with the state of the friction coefficient (road surface μ) of the road surface.

1 is an overall schematic configuration diagram of an electric vehicle according to an embodiment of the present invention. 1 is an external view of a combination meter device for an electric vehicle according to an embodiment of the present invention. It is a block block diagram of the control apparatus of the electric vehicle which concerns on one Example of this invention. It is a control flowchart of the electric vehicle which concerns on one Example of this invention. It is explanatory drawing showing the specific example of a display of a display means.

  The configuration of the electric vehicle will be described with reference to FIGS. 1 and 2. FIG. 1 shows an overall schematic configuration of an electric vehicle according to an embodiment of the present invention, and FIG. 2 shows an example of a combination meter device for an electric vehicle according to an embodiment of the present invention.

  As shown in FIG. 1, the electric vehicle (vehicle) 1 is provided with a traveling motor 3 that transmits power to the drive wheels 2. Although two driving wheels 2 are shown in the figure, power can be similarly transmitted from the traveling motor 3 to a vehicle in which all four wheels are driving wheels. The driving force of the travel motor 3 is transmitted to the drive wheels 2 via a power transmission mechanism (not shown). A battery 4 is connected to the traveling motor 3 via an inverter or the like. Electric power corresponding to the operation of the accelerator pedal 5 of the occupant is supplied from the battery 4 to the traveling motor 3.

  A vehicle speed sensor 11 is provided on the output shaft of the traveling motor 3, and an accelerator switch 12 is provided on the accelerator pedal 5. Further, a wheel speed sensor 13 as a wheel speed detecting means for detecting the wheel speed of the drive wheel 2 is provided on the rotation shaft of the drive wheel 2. Further, the handle 14 is provided with a selection switch 15 for selecting a regenerative braking force having an arbitrary strength from a plurality of braking forces.

  The detection information of the vehicle speed sensor 11, the detection information of the accelerator switch 12, the detection information of the wheel speed sensor 13, and the request information for the strength of the regenerative braking force selected by the selection switch 15 are input to the control device 16.

  The control device 16 outputs an operation command (control command) to various devices based on the input information, and is controlled to a desired travel state by the travel motor 3 so that the vehicle 1 is powered. When the accelerator pedal 5 is released (accelerator switch 12 is turned off) and the vehicle is decelerating or coasting, the traveling motor 3 is rotated by receiving energy from the drive wheels 2, Electric energy is generated to obtain a predetermined braking force (regenerative braking force) (regenerative operation).

  The regenerative operation is performed, for example, when the accelerator switch 12 is detected to be off. In the control device 16, the target regenerative braking force is set based on the regenerative braking force with the strength selected by the selection switch 15 (target regenerative braking force setting means). Then, the rotational speed of the driving wheel 2 during traveling is detected by the wheel speed sensor 13, and the actual regenerative braking force (actual regenerative braking force) is calculated (derived) based on the detection information of the wheel speed sensor 13 (actual). Regenerative braking force deriving means). When the regenerative operation is performed, information on the target regenerative braking force is sent from the control device 16 to the combination meter device 21 (display unit).

  As shown in FIG. 2, the combination meter device 21 includes a meter display unit 22 that displays a discharge charge area and displays a vehicle speed. In addition, for example, a remaining amount display unit 23 that displays the remaining amount of the battery 4 (see FIG. 1) and a distance display unit 24 that displays a cruising distance are provided.

  The combination meter device 21 is provided with a regenerative brake force display unit 25 as display means for displaying the magnitude of the target regenerative brake force by increasing or decreasing the area as information on the target regenerative brake force. In the regenerative braking force display unit 25, the S position where the braking force is the strongest is set at the top, and the weakest W position is set at the bottom. And, for example, a scale of a region where the braking force gradually increases in the order of B1, B2, B3, B4, and B5 from the W position to the S position, and information on the actual regenerative braking force is provided. The position is indicated by the indicating needle 26.

  Since the display on the regenerative braking force display unit 25 indicates that the regenerative amount decreases from the upper side (S position) to the lower side (W position), the upper side (S position) to the lower side (W Toward the position), the width of the display region is gradually narrowed. As a result, the driver can visually check the regenerative braking force display unit 25 to check the width of the display together with the display that changes up and down, and that the regenerative force decreases toward the lower side. It can be clearly confirmed.

  The control device 16 compares the target regenerative braking force set by the target regenerative braking force setting unit with the actual regenerative braking force calculated by the actual regenerative braking force deriving unit (comparing unit). When the difference of the regenerative braking force compared by the comparison means is equal to or larger than a preset difference, for example, when the actual regenerative braking force is smaller than a preset difference with respect to the target regenerative braking force ( When the rotational speed of the drive wheel 2 becomes faster than the set difference with respect to the set vehicle speed), in addition to displaying the target regenerative braking force, the actual regenerative braking force is displayed. It is displayed on the display unit 25.

  For example, when the drive wheel 2 slips, the actual regenerative braking force becomes smaller than a preset difference, so that the regenerative braking force display is performed in a state where the target regenerative braking force and the actual regenerative braking force are different. Displayed on the unit 25. In this case, although details will be described later, the indicating needle 26 indicating the position of the actual regenerative braking force indicates the position on the side close to the W position (for example, B2). And the area | region between the position (for example, B5) of the magnitude | size of target regenerative braking force and the position which the indicator hand 26 is pointing (between B2 and B5) is displayed with a different color. .

  Therefore, the driver can recognize that the actual regenerative braking force does not match the target regenerative braking force by the difference in display color of the regenerative braking force display unit 25, and according to the friction coefficient of the road surface. Thus, the driver can be made aware of the state of control of the regenerative braking force.

  A functional configuration for performing the regenerative operation of the control device 16 will be described based on FIG. 3. FIG. 3 shows a block configuration of the control device 16.

  As shown in the figure, the selection information of the selection switch 15, the detection information of the wheel speed sensor 13, and the detection information of the vehicle speed sensor 11 are input to the control device 16. The control device 16 includes a target regenerative braking force setting unit 31 as a target regenerative braking force setting unit, and sets a target regenerative braking force based on selection information of the selection switch 15.

  On the other hand, the control device 16 is provided with an actual regenerative brake force calculating unit 32 as an actual regenerative brake force deriving unit, and the actual regenerative brake force is calculated based on detection information of the wheel speed sensor 13. Further, the control device 16 is provided with a slip determination unit 33 as a comparison means, and when the difference between the target regenerative braking force and the actual regenerative braking force is greater than or equal to a preset difference (the rotational speed of the drive wheel 2 is When the vehicle speed is higher than a preset difference with respect to the set vehicle speed), a slip occurs because the road surface μ is running on a low road surface (low μ road), and the regenerative braking force cannot be obtained sufficiently. Is determined.

  When the regenerative operation is instructed, the control device 16 outputs a control command to the traveling motor 3 (battery 4), and the regenerative operation is performed with the target regenerative braking force. Further, the control device 16 outputs information on the target regenerative braking force and the actual regenerative braking force to the combination meter device 21. In addition to the target regenerative braking force, the regenerative braking is performed. The force display unit 25 displays them simultaneously.

The processing flow of the control device 16 will be described based on FIG. In addition, the display state on the regenerative braking force display unit 25 will be described with reference to FIG.
FIG. 4 is a control flowchart for explaining the processing flow of the control device 16 in the electric vehicle according to the embodiment of the present invention. FIG. 5 is a specific display example on the regenerative braking force display unit 25 of the combination meter device 21. Is shown.

  As shown in FIG. 4, the system is activated in step S1, and information on the accelerator switch 12, the wheel speed sensor 13, and the selection switch 15 is read in step S2. Information on the vehicle speed sensor 11 is also read if necessary. In step S3, it is determined whether or not there is an instruction for regenerative operation. For example, when the regenerative braking force of arbitrary strength is selected by the selection switch 15 and the accelerator switch 12 is detected to be off, the regenerative braking force is obtained when the vehicle is decelerating or coasting. (It is determined that there was an instruction for regenerative operation).

  If it is determined in step S3 that there is no instruction for regenerative operation, the process returns and the process ends. If it is determined in step S3 that the regenerative operation has been instructed, the regenerative operation is performed with the target regenerative braking force in step S4. In step S4, the regenerative operation is performed with the target regenerative braking force, and the target regenerative braking force and the actual regenerative braking force are displayed simultaneously.

  When the regenerative operation is performed with the target regenerative braking force, the target regenerative braking force is compared with the actual regenerative braking force in step S5. That is, it is determined whether or not the difference between the target regenerative braking force and the actual regenerative braking force is greater than or equal to a preset difference. For example, in step S5, the absolute value of the difference between the rotational speed of the drive wheel 2 (see FIG. 1) detected by the wheel speed sensor 13 and the set vehicle speed, which is the vehicle speed based on the target regenerative braking force, is set in advance. It is determined whether or not a predetermined value (for example, X km / h) or more.

  When it is determined in step S5 that the absolute value of the difference is less than the predetermined value, it is determined that the actual regenerative braking force is substantially equal to the target regenerative braking force (the difference is less than a preset difference), and the drive wheels 2 (See FIG. 1), it is determined that no slip occurs, that is, the road surface μ is not low. If it is determined in step S5 that the absolute value of the difference is less than the predetermined value, a return is returned.

  In this case, the magnitude of the target regenerative braking force is displayed on the regenerative braking force display unit 25 (see FIG. 2), and at the same time, the indicator needle 26 (see FIG. 2) is shown at the same position as the target regenerative braking. It is. That is, as shown in FIG. 5A, for example, when the driver selects the braking force with the target regenerative braking force B5, the region up to B5 (shown by the mesh in the figure) is displayed. . Then, the position of the indicating needle 26 which becomes the mark of the actual regenerative braking force is set to the position B5.

  Returning to FIG. 4, when it is determined in step S5 that the absolute value of the difference is equal to or greater than the predetermined value, it is determined that the rotational speed of the drive wheels 2 is high (speed equal to or greater than the set difference with respect to the set vehicle speed). The actual regenerative braking force is determined to be smaller than the target regenerative braking force. That is, it is determined that the road surface μ is low and slipping occurs. When it is determined in step S5 that the absolute value of the difference is equal to or greater than the predetermined value, the regenerative braking force display unit 25 (see FIG. 2) displays the target regenerative braking force and the actual regenerative braking force.

  That is, as shown in FIG. 5B, for example, when the driver selects the braking force with the target regenerative braking force B5 and the actual regenerative braking force is in the state B2, the region up to B2 (see FIG. 5B). A medium mesh (for example, blue) is displayed as the magnitude of the actual regenerative braking force, and the position of the indicator hand 26 is set to the position B2. Then, the region from the position (B2) of the actual regenerative braking force level to B5, which is the target regenerative braking force level, is displayed as a different color area (shown by hatching in the drawing: for example, red). .

  For this reason, when the actual regenerative braking force becomes smaller than the target regenerative braking force (when the rotational speed of the drive wheel 2 becomes faster than the set vehicle speed), the display of the magnitude of the target regenerative braking force (up to B5) In addition, the display of the actual regenerative braking force (display up to B2) is displayed on the regenerative braking force display unit 25 in an overlapping manner. As a result, it is possible for the driver to recognize that there is a difference between the target regenerative braking force and the actual regenerative braking force by the difference in color. That is, it is possible to make the driver recognize that slip has occurred in the drive wheels 2 (see FIG. 1) by displaying the regenerative braking force display unit 25.

  In addition to changing the color in the area from the position (B2) of the actual regenerative braking force level to B5, which is the target regenerative braking force level, flashing the parts of different colors or calling attention It is possible to display a mark to do.

  Returning to FIG. 4, when it is determined in step S5 that the actual regenerative braking force is smaller than the target regenerative braking force in a state where the rotational speed of the drive wheel 2 is high (a speed greater than the set difference with respect to the set vehicle speed) In step S6, the target regenerative braking force is changed (for example, the strength of the regenerative braking force is changed from B5 to B2), and the process returns. That is, the driver is made to recognize that slip has occurred in the drive wheel 2 (see FIG. 1), the target regenerative braking force is changed to a weak regenerative braking force according to the state of the road surface μ, and the slip occurs. Control is performed so that the regenerative operation can be carried out in the absence of this.

  In addition, the degree of deceleration is compared using the rate of change of the rotational speed of the drive wheel 2 (see FIG. 1), the rate of change of the reference vehicle speed, or the information of the acceleration sensor, and the target regenerative braking force is compared with the actual regenerative braking force. It is also possible to do this. Moreover, it is possible to apply the detection information of the vehicle speed sensor 11 as a wheel speed detection means. Further, when the difference between the reference vehicle speed value and the rotational speed value of the drive wheels 2 (see FIG. 1) exceeds a predetermined value, the actual road surface friction coefficient is grasped by means for measuring the road surface friction coefficient. It is also possible to confirm that slip has occurred.

  In the above-described electric vehicle, when the difference in the regenerative braking force is greater than or equal to a predetermined difference set in advance, for example, when it is determined that the actual regenerative braking force is low due to slippage in the drive wheels 2, the combination meter The target regenerative braking force and the actual regenerative braking force are displayed simultaneously on the regenerative braking force display unit 25 of the device 21. Accordingly, the driver can recognize that the actual regenerative braking force does not match the target regenerative braking force. Then, the target regenerative braking force and the actual regenerative braking force are compared, and if there is a difference, the target regenerative braking force is changed to a weak regenerative braking force according to the condition of the road surface μ so that no slip occurs. Is done.

  At this time, the driver can recognize that the drive wheel 2 is slipping while traveling on a road surface with a low road surface μ (low μ road). In other words, the driver can recognize the road surface μ while traveling without using a sensor or the like that detects the friction coefficient.

  Therefore, it becomes possible to make the driver recognize the state of control of the regenerative braking force according to the state of the road surface μ. For this reason, when the driver has set the target regenerative braking force, even if the electric vehicle travels with a regenerative braking force different from the set regenerative braking force, the discomfort given to the driver can be greatly reduced. Can do.

  The present invention can be used in the industrial field of electric vehicles.

1 Electric vehicle (vehicle)
DESCRIPTION OF SYMBOLS 2 Drive wheel 3 Driving motor 4 Battery 5 Accelerator pedal 11 Vehicle speed sensor 12 Accelerator switch 13 Wheel speed sensor 14 Handle 15 Selection switch 16 Control device 21 Combination meter device 22 Meter display part 23 Remaining capacity display part 24 Distance display part 25 Regenerative brake Force display unit 26 Pointer 31 Target regenerative braking force setting unit 32 Actual regenerative braking force calculation unit 33 Slip determination unit

Claims (4)

In an electric vehicle equipped with a traveling motor that is supplied with electric power from a battery and transmits driving force to driving wheels,
Target regenerative braking force setting means for setting a target regenerative braking force of the drive wheel;
An actual regenerative braking force deriving means for deriving an actual regenerative braking force of the drive wheel during traveling;
An electric vehicle comprising: a target regenerative braking force set by the target regenerative braking force setting means; and a display means for simultaneously displaying the actual regenerative braking force derived by the actual regenerative braking force deriving means. . The electric vehicle according to claim 1,
The display means includes
An electric vehicle characterized in that the magnitude display of the target regenerative braking force and the actual regenerative braking force is displayed in an overlapping manner, and the difference portion between the magnitude indications is displayed in different colors. In the electric vehicle according to claim 1 or claim 2,
Wheel speed detecting means for detecting the wheel speed of the drive wheel,
The actual regenerative braking force deriving means is
An electric vehicle characterized in that it is means for obtaining an actual regenerative braking force from the rotational speed of the drive wheel detected by the wheel speed detection means. In the electric vehicle according to any one of claims 1 to 3,
Comparing means for comparing the target regenerative braking force set by the target regenerative braking force setting means and the actual regenerative braking force derived by the actual regenerative braking force deriving means,
The target regenerative braking force setting means is
A means for setting a braking force of an arbitrary strength from a plurality of braking forces,
According to the difference between the target regenerative braking force and the actual regenerative braking force compared by the comparison means, the set target regenerative braking force is changed to a braking force on the side weaker than the current braking force. A featured electric vehicle.

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