JP6091462B2 - Electric vehicle charging control device - Google Patents

Description

  The present invention travels using the power of an electric motor driven by electric power supplied from the power storage device, applies braking force by regenerative braking by the motor, and prohibits regenerative braking when the power storage device is in a predetermined state. The present invention relates to a charging control device for an electric vehicle, which applies a friction braking force when being applied.

  An electric vehicle using an electric motor as traveling power is known. For example, in Patent Document 1, since regenerative braking is limited when the battery of an electric vehicle is fully charged, a braking device for an electric vehicle that can switch from regenerative braking to friction braking and obtain a braking force without a sense of incongruity is provided. Proposed.

JP-A-10-271605

  By the way, for example, as shown in FIG. 4A, when the electric vehicle is fully charged every day in a parking lot such as a house located on a hill, a deceleration G dropout occurs immediately when going down a hill. For this reason, when the deceleration G escape is avoided by friction braking, there is a problem that the brake pad temperature rises and the deceleration force decreases, and the brake pad wear amount increases and the brake durability decreases. . In addition, it is conceivable to simply set a charging margin in SOC (State Of Charge), but in this case, there is a problem that the cruising distance becomes short.

  The present invention has been made in order to solve the above-described problems, and a first object of the present invention is to provide a charge control device for an electric vehicle that suppresses the amount of wear of the brake pads and prevents a decrease in brake durability. . It is a second object of the present invention to provide a charging control device for an electric vehicle that prevents a cruising distance from being shortened.

  The invention according to claim 1 travels using the power of an electric motor driven by electric power supplied from the power storage device, applies braking force by regenerative braking by the motor, and the power storage device is in a predetermined state. An electric vehicle charging control device that applies a friction braking force when the regenerative braking is prohibited, an acquisition unit that acquires distance information of a downhill road on which the electric vehicle travels, and the power storage device. Control means for controlling the charge amount of the vehicle, wherein the control means suppresses the charge amount according to the distance of the downhill road acquired by the acquisition means.

  According to a second aspect of the present invention, in the charging control device for an electric vehicle according to the first aspect, the acquisition unit acquires distance information of the downhill road from map information.

  According to a third aspect of the present invention, in the charging control device for an electric vehicle according to the first aspect, when the control means has a plurality of downhill roads acquired by the acquisition means, the distance of the downhill road is the shortest distance. The charge amount is suppressed according to the above.

  According to a fourth aspect of the present invention, in the charging control device for an electric vehicle according to the third aspect, the control means performs charging by the regenerative braking when the electric vehicle travels on a downhill road that is not the shortest downhill road. Control which suppresses quantity is performed.

  According to a fifth aspect of the present invention, in the charging control device for an electric vehicle according to the fourth aspect, when the control means travels in the shift position B range, the control means performs control to gradually approach the regenerative braking amount in the shift position D range. When traveling in the shift position D range, the regenerative braking amount is controlled to gradually approach zero.

  According to the present invention, it is possible to provide a charging control device for an electric vehicle that suppresses the wear amount of the brake pad to prevent a decrease in brake durability and prevents a cruising distance from being shortened.

It is a block diagram which shows the structure of embodiment of this invention. It is a flowchart which shows the operation | movement of FIG. It is the figure explaining an example of charge amount control with the graph. It is the figure which showed the driving | running route containing the slope near home.

  Embodiments of the present invention (hereinafter referred to as “this embodiment”) will be described below with reference to the accompanying drawings.

(Configuration of the embodiment)
FIG. 1 is a block diagram showing a configuration of a charging control device for an electric vehicle according to the present embodiment. The electric vehicle 10 of the present embodiment travels using the power of the electric motor 12 driven by the electric power supplied from the power storage device 22, applies braking force by regenerative braking by the electric motor 12, and the power storage device 22 Friction braking force is applied when regenerative braking is prohibited in a state. For this reason, the electric vehicle 10 includes an electric motor 12 that generates power, and the rotating shaft of the electric motor 12 is connected to the wheels 16 via the transmission 14 and the like. A friction brake 18 that applies a braking force is engaged with the wheel 16.

  The motor 12 is connected to an inverter 20 (power converter) via a three-phase connection, and the inverter 20 is connected to a power storage device 22, and a motor that controls the motor 12 by controlling the drive of the inverter 20. An ECU (Electronic Control Unit) 24 is connected.

  The power storage device 22 is energy storage, and a lithium ion secondary battery, a nickel hydride secondary battery, a capacitor, or the like can be used. The power storage device 22 includes a charge / discharge circuit 60 that controls or limits the charge / discharge current. The power storage device 22 includes a charge detection unit 261 that controls a charge / discharge current of the charge / discharge circuit 60 and detects a state of charge (SOC) that is a charge state of the power storage device 22, and a charge current (regeneration amount). ) Is connected to a battery ECU 26 having a charge amount control unit 262 for controlling.

  When the charge amount control unit 262 acquires distance information of a downhill road on which the electric vehicle 10 travels from a navigation ECU 42 described later, the charge amount control unit 262 performs control to suppress the charge amount according to the distance of the downhill road. In addition, when there are a plurality of downhill roads, the charge amount control unit 262 suppresses the charge amount according to the distance with the shortest downhill road distance. In addition, the charge amount control unit 262 performs control to suppress the charge amount due to regenerative braking when the electric vehicle 10 travels on a downhill road that is not the shortest downhill road.

  Motor ECU 24 includes a fully charged state determination unit 241 and a braking amount control unit 242. Fully charged state determination unit 241 controls movement amount control unit 242 by detecting whether or not the charged state SOC of power storage device 22 is in a fully charged state during traveling downhill. The movement amount control unit 242 performs control to gradually approach the regenerative braking amount of the D range when traveling in the B range, and performs control to gradually approach the regenerative braking amount to 0 when traveling in the D range.

  The motor ECU 24 includes an accelerator opening degree θ in which the operation amount of the accelerator pedal 28 is detected by the operation amount sensor 30, a brake operation amount B in which the operation amount of the brake pedal 32 is detected by the operation amount sensor 34, and a shift lever 36. The vehicle position detected by the vehicle speed sensor 40 and each shift position of the parking position P (P position), the reverse position R (R position), or the progressive position D (D position) detected by the shift position sensor 38. Vs, a motor rotation speed Nm detected by a rotation speed sensor such as a resolver constituting the electric motor 12, a motor rotation direction (forward direction, stop, reverse direction) Md, and the like are supplied.

  The motor ECU 24 is also connected to a navigation ECU (hereinafter simply referred to as a navigation ECU 42), and is supplied with information such as the position on the map and the altitude of the host vehicle from the navigation ECU 42, and travels on a slope (uphill / downhill). Presence / absence and distance information thereof are calculated.

  A brake ECU 50 is further connected to the motor ECU 24. The brake ECU 50 is supplied with a brake operation amount B from the operation amount sensor 34 of the brake pedal 32 and applies a friction braking force to the wheels 16 via the hydraulic pressure modulator 52.

  On the other hand, the motor ECU 24 applies a braking force for braking the wheels 16 by regenerative braking of the motor 12 by causing the power storage device 22 to collect the regenerative power of the motor 12 through the inverter 20. The motor ECU 24, the brake ECU 50, and the battery ECU 26 perform coordinated control of the braking force due to regenerative braking and the braking force due to friction braking.

  Note that the battery ECU 26, the motor ECU 24, and the brake ECU 50 are communicably connected, for example, using data mutually through a communication line (not shown) related to a communication network such as a CAN (Control Area Network: in-vehicle LAN).

  Accordingly, the navigation ECU 42 functions as “acquisition means for acquiring distance information of a downhill road on which the electric vehicle travels”, and the battery ECU 26 (charge amount control unit 262) and the motor ECU 24 (braking amount control unit 242) cooperate. By operating and operating, it functions as “a control means for controlling the amount of charge to the power storage device 22”. For example, when there are a plurality of downhill roads acquired by the navigation ECU 42, the charging amount is suppressed according to the distance of the shortest downhill road, and when traveling on the downhill road that is not the shortest downhill road, charging by regenerative braking is performed. Control to suppress the amount.

  Further, the motor ECU 24 (braking amount control unit 242) performs control to gradually approach the regenerative braking amount of the D range when traveling in the B range, and gradually decreases the regenerative braking amount to 0 when traveling in the D range. It also functions as a control means that performs a control to approach.

(Operation of the embodiment)
Hereinafter, the operation of the charging control apparatus for an electric vehicle according to the present embodiment will be described in detail with reference to the flowchart of FIG.

  Here, as shown in FIG. 4B, it is assumed that the electric vehicle 10 is fully charged every day in a parking lot such as a home located on a hill and goes down a hill. First, when the charge detection unit 261 of the battery ECU 26 detects the start of charging (step S101 “YES”), the charge amount control unit 262 receives the altitude of the current location from the navigation ECU 42 via the motor ECU 24 with reference to the built-in map information. The travel route information is acquired and the optimum SOC is calculated (step S102). Here, a charging margin is provided so that the battery is fully charged under the route B.

  That is, the charge amount control unit 262 travels on the route B (the travel distance is short) where the charge amount due to regeneration is small in the travel route including the downhill road shown in FIG. Calculate the SOC (eg 95%) so that it is fully charged at the location. Then, until the calculated value becomes equal to the SOC (“YES” at step S104), the charge amount is controlled by continuing the charge by regenerative braking (step S103). The unit 261 can detect the fully charged state.

  On the other hand, when traveling on route A, which has a longer travel distance than route B, the braking amount control unit 242 of the motor ECU 24 suppresses the regenerative braking amount based on the road gradient and distance, and when the vehicle finishes on the hill. The full charge state determination unit 241 performs control so that the full charge state can be detected. FIG. 3 shows a specific braking amount suppression control method for that purpose.

  FIG. 3 is a braking characteristic diagram when the accelerator pedal and the brake pedal are not depressed, and a braking characteristic diagram in which the vehicle speed is plotted on the horizontal axis and the vehicle body G is plotted on the vertical axis is shown. According to FIG. 3, the quadrant above the horizontal axis is the power running side, and the lower quadrant is the friction side. As shown in FIG. 3, when the vehicle travels at a B shift position where the deceleration is higher than D in the forward range, the braking amount control unit 242 performs control to gradually approach the regenerative braking amount in the D range, as indicated by an arrow a. When the vehicle travels in the D range, control is performed so that the regenerative braking amount gradually approaches 0 as shown by an arrow b.

  In this way, the amount of brake operation can be reduced by suppressing the regenerative amount in accordance with the distance and the gradient, and extreme deceleration G omission and the use of a friction brake are avoided.

(Effect of embodiment)
As described above, according to the charging control device for an electric vehicle according to the present embodiment, for example, the distance information of the downhill road is acquired from the map information by suppressing the charge amount according to the acquired distance of the downhill road. When there are multiple downhill roads, the amount of charge can be controlled according to the distance of the shortest downhill road, so that extreme G slippage can be avoided, driving without discomfort, and reducing friction braking opportunities as much as possible. Therefore, it is possible to avoid a decrease in brake durability.

  In addition, when the electric vehicle 10 travels on a downhill road that is not the shortest downhill road, the normal deceleration G is generated by regenerative braking by controlling the amount of charge by regenerative braking, and the middle of the downhill road Thus, even if the fully charged state is avoided and the deceleration G missing due to the friction brake is avoided, the amount of brake operation can be reduced. Furthermore, in order to suppress the regenerative braking amount, when traveling in the B range, control is performed to gradually approach the regenerative braking amount in the D range, and when traveling in the D range, control is performed to gradually bring the regenerative braking amount closer to zero. By suppressing the regenerative braking amount based on the distance and the gradient, it is possible to avoid an extreme G loss and to operate without a sense of incongruity, and to reduce the friction braking opportunity as much as possible, thereby avoiding a decrease in brake durability.

  In addition, according to the charging control apparatus for an electric vehicle according to the present embodiment, the configuration in which the braking amount control unit 242 is mounted on the motor ECU 24 and the charging amount control unit 262 is mounted on the battery ECU 26 has been described. Alternatively, either of them is mounted on either one of the battery ECUs 26, or a new ECU that integrates the motor ECU 24 and the battery ECU 26 is designed, and the braking amount control unit 242 and the charge amount control unit 262 are mounted therein. Also good. In this case, since communication between ECUs becomes unnecessary, communication traffic is reduced, and the processing speed is improved accordingly. In addition to the navigation ECU 42, altitude information may be obtained from an atmospheric pressure sensor capable of detecting altitude.

  The present invention is not limited to the above-described exemplary embodiments, and those skilled in the art will be able to easily modify the above-described exemplary embodiments to the extent included in the claims. .

  DESCRIPTION OF SYMBOLS 10 ... Electric vehicle, 12 electric motor, 22 ... Power storage device, 24 ... Motor ECU, 26 ... Battery ECU, 42 ... Navigation ECU, 241 ... Fully charged state determination part, 242 ... Braking amount control part, 261 ... Charge detection part, 262 ... Charge amount control unit

Claims (4)

The vehicle travels using the power of an electric motor driven by the electric power supplied from the power storage device, applies a braking force by regenerative braking by the motor, and the power storage device is in a predetermined state and the regenerative braking is prohibited. A charging control device for an electric vehicle that applies friction braking force when
Obtaining means for obtaining distance information of a downhill road on which the electric vehicle travels;
Control means for controlling the amount of charge to the power storage device,
The control means includes
When there are a plurality of downhill roads acquired by the acquisition unit when the charging amount is suppressed according to the downhill road distance acquired by the acquisition unit, the downhill road distance is the shortest distance. A charge control device for an electric vehicle, wherein the charge amount is suppressed . The acquisition means includes
The charging control device for an electric vehicle according to claim 1, wherein distance information of the downhill road is acquired from map information. The control means includes
3. The charging control device for an electric vehicle according to claim 1, wherein when the electric vehicle travels on a downhill road that is not the shortest downhill road, a control for suppressing a charge amount by the regenerative braking is performed. The control means includes
When traveling in the shift position B range, control to gradually approach the regenerative braking amount in the shift position D range is performed. When traveling in the shift position D range, control to gradually bring the regenerative braking amount to 0 is performed. The charging control device for an electric vehicle according to claim 3 , wherein the charging control device is an electric vehicle.

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