JP2012130213A - Electric vehicle control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric vehicle control device that is capable of suitably achieving the life prolongation of a battery and improvement of charge efficiency.SOLUTION: The electric vehicle (1) mounts a power-driven motor (4) thereon by the charged power of the battery (11), and charges the battery by regeneratively driving the motor when traveling on a downward slope. The control device of the electric vehicle includes: a means (17) of acquiring slope information on a traveling road surface; a means (15) of detecting the charging amount of the battery (11); and a control means (26) which sets the regeneration amount of the motor (4) during traveling on the downward slope so that the charging amount of the battery reaches the upper limit thereof.

Description

  The present invention provides an electric vehicle that is equipped with an electric motor that functions as a power source for traveling by power running driving with electric power stored in a battery, and that recharges the electric motor during traveling on a downward slope. The present invention relates to the technical field of control devices.

  In recent years, in response to growing environmental awareness, in addition to conventional internal combustion engines such as gasoline engines and diesel engines, hybrid electric vehicles equipped with an electric motor that can be driven by battery charging power as a power source, or in place of internal combustion engines EV cars that run using such an electric motor as a power source have attracted attention. In this type of vehicle, for example, the kinetic energy of the vehicle that is gradually accelerating during downhill traveling is converted into electric energy by regenerative driving of the electric motor, thereby recovering the charge amount of the battery. As a result, the fuel efficiency is improved by reducing the fuel consumption of the internal combustion engine in the hybrid electric vehicle, and the travelable distance can be extended in the EV vehicle.

  Thus, in order to improve the fuel efficiency and the travelable distance in an electric vehicle such as a hybrid electric vehicle or an EV vehicle, it is important to improve the charging efficiency of the battery according to the traveling state. For example, in Patent Document 1, a navigation device mounted on a vehicle receives a GPS signal from a GPS communication satellite to acquire gradient information of a traveling road surface, and performs drive control of an electric motor according to a change in the gradient of the traveling road surface. Thus, a technique for improving the charging efficiency of the battery is disclosed.

JP 2000-217203 A

  When the charging current of the battery that flows during regenerative driving of the electric motor increases, the deterioration of the battery is promoted and the internal resistance increases. Then, there is a problem in that heat loss generated during charging increases, resulting in deterioration of charging efficiency. In the regeneration control of the electric motor in Patent Document 1, regeneration is performed with priority given to fully charging the battery early without considering the charging current value of the battery. For this reason, depending on the driving conditions, the charging current value of the battery may be larger than necessary, and there is a problem that the battery is deteriorated and as a result, the charging efficiency of the battery cannot be sufficiently improved. .

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a control device for an electric vehicle that can suitably realize improvement in battery charging efficiency and long life.

  In order to solve the above-described problems, an electric vehicle control apparatus according to the present invention is equipped with an electric motor that functions as a power source for driving by powering with electric power stored in a battery, and the electric motor is driven on a downward slope. A control device for an electric vehicle that recharges a battery by regenerative driving at times, and includes gradient information acquisition means for acquiring gradient information including an average gradient of the downward gradient and a gradient duration, and detects a charge amount of the battery Battery charge amount detection means, and when the electric vehicle reaches the lowest point of the downward slope, the regenerative amount of the electric motor is determined based on the gradient information so that the charge amount of the battery becomes the upper limit charge amount. And control means for setting.

  According to the present invention, when the electric vehicle reaches the lowest point of the downward slope, the regenerative drive of the electric motor is controlled based on the slope information so that the charge amount of the battery becomes the upper limit charge amount. Thereby, for example, while preventing the battery from being fully charged during traveling on a downward slope, the charging current of the battery can be kept small while ensuring the amount of charge so that the battery is fully charged. As a result, it is possible to improve the charging efficiency by reducing the loss that occurs during charging, and to extend the battery life.

  Preferably, the control means may be set so that the regeneration amount of the electric motor decreases as the gradient continuation distance increases. According to this aspect, when the gradient continuation distance is long, the charging current to the battery can be suppressed small so that the charging amount of the battery does not reach the upper limit charging amount during the downward gradient. On the other hand, when the gradient continuation distance is short, increase the charging current to the battery (increase the regeneration amount of the motor) so that the charging amount of the battery reaches the upper limit charging amount by the lowest point of the downward gradient Thus, the charging efficiency of the battery can be improved.

  The control means may be set so that the regeneration amount of the electric motor increases as the detected charge amount of the battery decreases. According to this aspect, when the charge amount of the battery is small, the battery has a large margin for charging the regenerative energy obtained by regenerative driving of the electric motor. Charging efficiency can be improved.

  Moreover, it is preferable to further include a traveling speed detecting means for detecting the traveling speed of the electric vehicle, and the control means may be set so that the regeneration amount of the electric motor decreases as the detected traveling speed decreases. In this case, since the regeneration amount is set smaller as the traveling speed becomes lower, the safety of the vehicle at a low speed (such as when starting or stopping) can be ensured satisfactorily. That is, by suppressing the regenerative braking torque generated during regeneration of the electric motor to a low level, the vehicle can be accurately controlled by the driver's driving operation such as the depression of the brake pedal, and the safety during low-speed traveling can be improved.

  According to the present invention, when the electric vehicle reaches the lowest point of the downward slope, the regenerative drive of the electric motor is controlled based on the slope information so that the charge amount of the battery becomes the upper limit charge amount. As a result, for example, while avoiding the case where the battery is fully charged during traveling on a downward slope, the charging current to the battery is kept small while the charging amount is ensured so that the battery is fully charged. it can. Thereby, it is possible to improve the charging efficiency by reducing the loss generated at the time of charging, and to contribute to the extension of the battery life. On the other hand, for example, the charging current of the battery can be set to be large so that the battery is fully charged when traveling on a downward slope is completed, thereby improving the charging efficiency.

1 is a block diagram conceptually showing an overall configuration of a hybrid electric vehicle according to the present invention. It is a flowchart figure which shows the control content of the hybrid electric vehicle which concerns on this invention. It is a graph which shows the content of the map selected according to the case classification performed by step S106 to S109 of FIG. It is a graph which shows transition of the regeneration amount and charge amount in the hybrid electric vehicle which is drive | working the down grade with a long gradient continuation distance. It is a graph which shows transition of the regeneration amount and charge amount in the hybrid electric vehicle which is drive | working the downward slope with a short gradient continuation distance.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, but are merely illustrative examples. Not too much. In the present embodiment, as an example of an electric vehicle, a hybrid electric vehicle 1 that travels on a traveling road surface having a downward slope with power output from at least one of an internal combustion engine and a motor that is powered by using electric power stored in a battery as a power source. As will be described, the present invention can be similarly applied to an EV vehicle that travels using an electric motor as a power source instead of the internal combustion engine.

  First, an overall configuration of a hybrid electric vehicle 1 according to the present invention will be described with reference to FIG. FIG. 1 is a block diagram conceptually showing the overall configuration of the hybrid electric vehicle 1 according to the present invention.

  The hybrid electric vehicle 1 is a parallel hybrid electric vehicle, and an input shaft of a clutch 3 is connected to an output shaft of a diesel engine 2 (hereinafter referred to as “engine 2”), and a motor 4 is connected to an output shaft of the clutch 3. An input shaft of the transmission 5 is connected via a rotation shaft. Left and right drive wheels 9 are connected to the output shaft of the transmission 5 via a propeller shaft 6, a differential 7 and a drive shaft 8.

  The engine 2 is an internal combustion engine that functions as one of the power sources of the hybrid electric vehicle 1. The engine 2 is a diesel engine. For example, by reciprocating the air at high temperature and injecting fuel in the combustion chamber, the reciprocating motion of the piston caused by the explosive force by combustion using spontaneous ignition can be converted into the rotational motion of the output shaft. It is configured to be possible.

  The clutch 3 is provided between the output shaft of the engine 2 and the rotating shaft of the motor 4, and is a power transmission mechanism configured to be able to switch these mechanical connection states. When the clutch 3 is connected, since the output shaft of the engine 2 is mechanically connected to the rotation shaft of the motor 4, the drive wheel 9 is connected to both the output shaft of the engine 2 and the rotation shaft of the motor 4. It will be. On the other hand, when the clutch 3 is disengaged, the output shaft of the engine 2 is mechanically disconnected from the rotating shaft of the motor 4, so that only the rotating shaft of the motor 4 is connected to the drive wheel 9 via the transmission 5. Will be connected.

  The motor 4 functions as one of the power sources of the hybrid electric vehicle 1 by driving power using the power stored in the battery 11 during power running, and generates power for charging the battery 11 during regeneration. It is an electric motor that functions as a machine.

  The transmission 5 is a transmission that converts power output from the engine 2 and the motor 4 and transmits the power to the left and right drive wheels 9 via the propeller shaft 6, the differential device 7, and the drive shaft 8. Note that the transmission ratio of the transmission 5 may be variable stepwise or continuously.

  The battery 11 is a rechargeable storage battery that functions as a power supply source for powering the motor 4. Direct current power is stored in the battery 11, and the direct current power is AC converted by the inverter 10 and then supplied to the motor 4. On the other hand, electric power generated during regeneration of the motor 4 is DC-converted by the inverter 10 and then charged by being supplied to the battery 11.

  When the clutch 3 is in the connected state, the output shaft of the engine 2 is mechanically connected to the rotating shaft of the motor 4, so that the drive wheel 9 is connected to both the output shaft of the engine 2 and the rotating shaft of the motor 4. . In this case, when the motor 4 is powered, both the output torque of the engine 2 and the output torque of the motor 4 are transmitted to the drive wheels 9 via the transmission 5. That is, a part of the torque for driving the drive wheels 9 is supplied from the engine 2 and the rest is supplied from the motor 4. Further, when the charge amount of the battery 11 decreases during traveling, the motor 4 is driven using the remaining output torque of the engine 2 while driving the drive wheels 9 using a part of the output torque of the engine 2. The battery 11 can be charged by regenerative driving. On the other hand, when the hybrid electric vehicle 1 is braked, the battery 4 can be charged by functioning as a generator by driving the motor 4 regeneratively.

  When the clutch is disengaged (that is, when the clutch is not connected), the output shaft of the engine 2 is mechanically disconnected from the rotating shaft of the motor 4 and only the rotating shaft of the motor 4 is shifted to the drive wheels 9. It is mechanically connected via the machine 5. In this case, when the motor 4 is powered, the output torque of the engine 2 is not transmitted to the drive wheels 9 and only the output torque of the motor 4 is transmitted. That is, the hybrid electric vehicle 1 travels exclusively by driving the motor 4 using the electric power stored in the battery 11. On the other hand, when the hybrid electric vehicle 1 is braked, the battery 4 can be charged by functioning as a generator by driving the motor 4 regeneratively.

  The battery charge amount detection means 15 includes, for example, a battery current sensor or a battery voltage sensor that monitors current and voltage applied to the battery 11, and can detect the charge amount of the battery 11 (hereinafter referred to as "SOC" as appropriate). It is a detection means. The vehicle speed sensor 16 is a travel speed detecting means that is a sensor for detecting the travel speed of the hybrid electric vehicle 1. The navigation device 17 is a gradient information acquisition unit for receiving position information of the hybrid electric vehicle and gradient information on the road surface (information including an average gradient and a gradient continuation distance) from the GPS communication satellite. The accelerator pedal 18 is configured to be able to control the output value of the engine 2 or the motor 4 when depressed by a driver.

  The vehicle ECU 26 performs the overall operation of the hybrid electric vehicle 1 based on various information obtained from the engine ECU 27, the inverter ECU 28, the battery ECU 29, the battery charge amount detection means 15, the vehicle speed sensor 16, the navigation device 17, the accelerator pedal 18, and the like. An electronic control unit configured to be controllable. Specifically, the vehicle ECU 26 transmits and receives control signals to and from the engine ECU 27, the inverter ECU 28, and the battery ECU 29, thereby configuring each hybrid electric vehicle 1 including the engine 2, the clutch 3, the motor 4, and the transmission 5. Control the operating state of the part.

  The engine ECU 27 is an electronic control unit for performing various controls necessary for the operation of the engine 2. For example, fuel injection in the engine 2 is performed so that torque to be output from the engine 2 set by the vehicle ECU 26 can be output. Control the amount and injection timing.

  The inverter ECU 28 is an electronic control unit for performing various controls necessary for the operation of the inverter 10. For example, the inverter ECU 28 controls the inverter 10 so that torque to be output from the motor 4 set by the vehicle ECU 26 can be output. Thus, the motor 4 is controlled to be powered or regeneratively driven.

  The battery ECU 29 obtains the information from the battery charge amount detection means 15 via the vehicle ECU 26 to obtain the charge amount of the battery 11 and transmits the obtained SOC to the vehicle ECU 26.

  The vehicle ECU 26, the engine ECU 27, the inverter ECU 28, and the battery ECU 29 described above are electronic control units each including a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. In accordance with the control program stored in the program, various controls described later can be executed. The physical, mechanical and electrical configurations of these various controls are not limited to this.

  Next, a specific operation of the hybrid electric vehicle 1 configured as described above will be described. FIG. 2 is a flowchart showing the control contents of the hybrid electric vehicle 1 according to the present invention.

  First, the vehicle ECU 26 acquires various information necessary for this control, such as the travel speed V, the SOC of the battery 11, the depression amount F of the accelerator pedal 18, and the downward gradient information (average gradient, gradient continuation distance L) (step S101). . Here, the traveling speed V is detected from the speed sensor 16, the SOC is detected from the battery charge amount detection means 15, the depression amount F of the accelerator pedal 18 is detected from the accelerator pedal 18, and the downward gradient information (that is, average gradient and (Gradient continuation distance) is acquired from the GPS signal acquired by the navigation device 17 and road information.

  The vehicle ECU 26 determines whether the driver has turned off the accelerator pedal 18 from the depression amount F of the accelerator pedal 18 acquired in step 101 (step S102). When the accelerator pedal 18 is ON (step S102: NO), it is assumed that the driver has an intention to accelerate the vehicle, so that it is not necessary to perform regenerative driving of the motor 4 described below. End (END).

  On the other hand, when the accelerator pedal 18 is OFF (step S102: YES), the vehicle ECU 26 determines whether or not the traveling speed V acquired from the vehicle speed sensor 16 is higher than a predetermined traveling speed V1 defined in advance (step S103). . Then, according to the determination result, the vehicle ECU 26 determines whether or not the SOC acquired from the charge amount detection means 15 is larger than the predetermined charge amount SOC1 or SOC2 (steps S104 and S105). As will be described later with reference to FIG. 3, the regeneration amount of the motor 4 is set based on four types of maps prepared corresponding to the travel speed V and the charge amount SOC of the battery 11. In steps S103, S104, and S105, the four types of maps are selected depending on the travel speed V and the amount of charge SOC of the battery 11, respectively.

  First, when the running speed V is greater than V1 and the SOC is greater than SOC1 (step S103: YES & step S104: YES), based on the high-speed / high SOC correspondence map (see FIG. 3A), The regeneration amount of the motor 4 is set (step S106). Further, when the traveling speed V is higher than V1 and the SOC is SOC1 or lower (step S103: YES & step S104: NO), based on the high speed / low SOC correspondence map (see FIG. 3B). The regeneration amount of the motor 4 is set (step S107). Further, when the traveling speed V is equal to or lower than V1 and the SOC is higher than the SOC2 (step S103: NO & step S105: YES), based on the low speed / high SOC correspondence map (see FIG. 3C). The regeneration amount of the motor 4 is set (step S108). Further, when the traveling speed V is V1 or lower and the SOC is SOC2 or lower (step S103: NO & step S105: NO), based on the low speed / low SOC correspondence map (see FIG. 3D). Thus, the regeneration amount of the motor 4 is set (step S109).

  After the vehicle ECU 26 sets the regeneration amount of the motor 4 in accordance with the traveling condition as described above (step S110), the vehicle ECU 26 performs control so that the motor 4 is regeneratively driven with the set regeneration amount (step S111).

  Here, with reference to FIG. 3, the specific content of the map selected according to the case classification performed in steps S106 to S109 in FIG. 2 will be described. FIG. 3 is a graph showing the contents of the map selected according to the case classification performed in steps S106 to S109 in FIG. In FIG. 3, the horizontal axis indicates the average gradient of the downhill slope that the traveling road surface has, and the vertical axis indicates the gradient continuation distance, and the point at which the regeneration amount of the motor 4 becomes equal is indicated by a solid line.

  FIG. 3A shows the high-speed / high SOC correspondence map read in step S106. The regeneration amount of the motor 4 is set so as to increase as the average gradient of the traveling road surface increases (as the down gradient becomes tighter). When the average gradient is large, the acceleration of the vehicle on the downward gradient is assumed to gradually increase. Therefore, by setting the regeneration amount to a large value, the regenerative braking torque is transmitted to the drive wheels 9 to decelerate, and the regenerative energy is supplied to the battery 11. It can be recovered.

  Here, the regeneration amount of the motor 4 is set to decrease as the gradient continuation distance increases. In the prior art, if the regeneration amount (that is, the charging current value) is set to be large when the gradient continuation distance is long, the charge amount of the battery 11 reaches the upper limit charge amount during traveling on the downward slope, and more It may become impossible to charge. In the map of FIG. 3A, the regeneration amount of the motor 4 is set to be small when the gradient continuation distance is long so that the charge amount of the battery 11 becomes the upper limit charge amount when the lowest point of the downward slope is reached. By doing so, the charging current value of the battery 11 is suppressed so as not to become unnecessarily large. As a result, the charging current value can be kept small while charging the battery 11 with sufficient power, and the charging efficiency to the battery 11 is improved by suppressing the loss that occurs during charging, and the life of the battery 11 is extended. Can be achieved.

  Next, FIG. 3B shows a high speed / low SOC correspondence map read in step S107. The increasing / decreasing tendency of the regeneration amount of the motor 4 in FIG. 3B is basically the same as in the case of FIG. However, in FIG.3 (b), it sets so that the regeneration amount of the motor 4 may increase compared with Fig.3 (a) with high SOC. This is because, when the charge amount of the battery 11 is small, there remains a lot of room for charging the regenerative energy obtained by driving the motor 4 regeneratively. It is because it is improving.

  Next, FIG. 3C shows a low speed / high SOC correspondence map read in step S108. The increasing / decreasing tendency of the regeneration amount of the motor 4 in FIG. 3 (c) is basically the same as in FIGS. 3 (a) and 3 (b). However, in FIG.3 (c), compared with Fig.3 (a) with high traveling speed V, it sets so that the regeneration amount of the motor 4 may become small. In this case, since the regeneration amount of the motor 4 is set to be smaller as the traveling speed V becomes smaller, it is possible to satisfactorily ensure the safety of the vehicle at a low speed (when starting or stopping). That is, by suppressing the regenerative braking torque generated during the regeneration of the motor 4, it is possible to control the vehicle with high accuracy by the driver's driving operation such as a depression operation of a brake pedal (not shown), and to ensure safety. it can.

  Next, FIG. 3D shows a low speed / high SOC correspondence map read in step S108. The increasing / decreasing tendency of the regeneration amount of the motor 4 in FIG. 3 (d) is basically the same as in FIGS. 3 (a) and 3 (c). However, in FIG.3 (d), it sets so that the regeneration amount of the motor 4 may become large compared with FIG.3 (c) with high SOC. This is because, when the charge amount of the battery 11 is small, there is a large margin for charging the regenerative energy obtained by driving the motor 4 regeneratively, so that the regenerative amount of the motor 4 is increased to improve the charging efficiency of the battery 11. This is because.

  Next, with reference to FIG. 4 and FIG. 5, transition of the regeneration amount and the charge amount during the downhill traveling of the hybrid electric vehicle according to the present invention will be described. FIG. 4 is a graph showing the transition of the regeneration amount (generated current) and the charge amount (SOC) of the battery 11 in a hybrid electric vehicle traveling on a downward slope having a long gradient duration, and FIG. 5 is a short gradient duration. It is a graph which shows transition of the regeneration amount (generated electric current) and the charge amount (SOC) of the battery 11 in the hybrid electric vehicle which is drive | working a downward slope.

  First, as shown in FIG. 4A, it is assumed that the traveling road surface of the vehicle has a long downward slope from the distance R1 to R2. In this case, the regeneration amount (charging current) of the motor 4 is maintained at the value of K1 from the distance R1 at which the downward gradient starts, as shown by the solid line in FIG. As a result, as shown in FIG. 4 (c), the charge amount SOC of the battery 11 continuously increases while the vehicle is traveling on the downward slope, and the SOC of the battery 11 reaches the upper limit when the downward slope ends. Controlled to reach charge.

  On the other hand, the alternate long and short dash line in the graph indicates the amount of regeneration (generated current) and the amount of charge (SOC) of the battery 11 when the electric vehicle according to the related art such as Patent Document 1 is traveling downhill under similar traveling conditions. It shows the transition. In the conventional regeneration control of the motor 4, an emphasis is placed on quickly recovering the charge amount of the battery by setting a large regeneration amount simultaneously with the start of the downward gradient. Therefore, the SOC of the battery 11 reaches the upper limit charge amount at a stage where the downward gradient does not end, and subsequent regeneration cannot be performed. In this case, since a large charging current temporarily flows in the battery 11, there is a problem that the charging efficiency of the battery 11 is deteriorated and the deterioration of the battery is advanced.

  In the present invention, the regenerative amount of the motor 4 is set so that the charge amount of the battery 11 becomes the upper limit charge amount when the downward slope is finished (when the lowest point of the downward slope is reached). The current value does not increase unnecessarily. That is, since the regeneration amount of the motor 4 is set based on the gradient information of the traveling road surface, the charging current value can be kept small while charging the battery 11 with a sufficient amount. Thereby, while suppressing the loss which arises at the time of charge, while improving the charging efficiency to the battery 11, the lifetime of the battery 11 can be extended.

  Subsequently, as shown in FIG. 5A, it is assumed that the traveling road surface of the vehicle has a short downward slope from a distance R3 to R4. In this case, as shown in FIG. 5B, the regeneration amount of the motor 4 is maintained at a value of K2 from the distance R3 at which the downward gradient starts. As a result, as shown in FIG. 5C, the charge amount SOC of the battery 11 continuously increases while the vehicle is traveling on the downward slope, and when the downward slope ends (the lowest point of the downward slope). ), The SOC of the battery 11 is controlled to reach the upper limit charge amount.

  On the other hand, as indicated by the alternate long and short dash line in the graph, with the regeneration amount set in the regeneration control of the conventional motor 4, the charge amount of the battery 11 cannot reach the upper limit charge amount during traveling on a downward slope. On the other hand, in the present invention, the charging efficiency of the battery can be improved by setting the regeneration amount larger than in the conventional case so that the SOC of the battery 11 reaches the upper limit charging amount when the downward slope is finished. .

  As described above, according to the present embodiment, the regenerative drive of the motor 4 is controlled so that the charge amount of the battery 11 becomes the upper limit charge amount when the hybrid electric vehicle 1 reaches the lowest point of the downward slope. Is done. Accordingly, for example, while avoiding the case where the battery 11 is fully charged during traveling on a downward slope, the charging current to the battery 11 is reduced while ensuring the charge amount so that the battery 11 is fully charged. Can be suppressed. Thereby, while reducing the loss which arises at the time of charge, while aiming at the improvement of charging efficiency, it can also contribute to the lifetime extension of the battery 11. FIG.

  The present invention provides an electric vehicle that is equipped with an electric motor that functions as a power source for traveling by power running driving with electric power stored in a battery, and that recharges the electric motor during traveling on a downward slope. It can be used for the control device.

DESCRIPTION OF SYMBOLS 1 Hybrid electric vehicle 2 Engine 3 Clutch 4 Motor 5 Transmission 9 Drive wheel 11 Battery 15 Charge amount detection means 16 Vehicle speed sensor 17 Navigation device 18 Accelerator pedal 26 Vehicle ECU
27 Engine ECU
28 Inverter ECU
29 Battery ECU

Claims (4)

A control apparatus for an electric vehicle, which is equipped with an electric motor that functions as a power source for traveling by powering driving with electric power stored in a battery, and charging the battery by driving the motor regeneratively during downhill traveling. ,
Gradient information acquisition means for acquiring gradient information including the average gradient of the downward gradient and the gradient continuation distance;
Battery charge amount detecting means for detecting the charge amount of the battery;
Control means for setting the regeneration amount of the electric motor based on the gradient information so that the charge amount of the battery becomes an upper limit charge amount when the electric vehicle reaches the lowest point of the downward gradient. A control apparatus for an electric vehicle.   2. The electric vehicle control device according to claim 1, wherein the control unit sets the regeneration amount of the electric motor to decrease as the gradient continuation distance increases. 3.   3. The electric vehicle control device according to claim 1, wherein the control unit sets the amount of regeneration of the electric motor to increase as the amount of charge of the detected battery decreases. 4. A travel speed detecting means for detecting a travel speed of the electric vehicle;
The control of the electric vehicle according to any one of claims 1 to 3, wherein the control means sets the amount of regeneration of the electric motor to decrease as the detected traveling speed decreases. apparatus.

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