JPH08182109A - Running controller for electric vehicle - Google Patents

Abstract

PURPOSE: To regenerate the kinetic energy more from a vehicle by eliminating loss of the kinetic energy caused by shifting a shift lever to N (neutral) range. CONSTITUTION: Even when a lever is shifted to N range (100) regenerative brake operation is enabled (126) on condition that a brake pedal is being stepped (122). When the brake pedal is not stepped (122), power supply to a motor system is interrupted (12O). If the regenerative brake operation is executed but a vehicle is not decelerating (126), a decision is made whether a hydraulic brake system is abnormal (130). If the hydraulic brake system is normal, a decision is made that the regenerative brake system is abnormal and power supply to the motor system is interrupted (120). When the hydraulic brake system is abnormal, brake operation is executed through the regenerative brake system (132) and when the regenerative brake system is also abnormal, power supply to the motor system is interrupted (120).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling control device mounted on an electric vehicle having a transmission between a motor for driving a vehicle and driving wheels and provided with means for controlling the transmission according to a shift position.

[0002]

2. Description of the Related Art An electric vehicle is a vehicle that drives a motor with electric power supplied from an on-vehicle battery and travels by using the output of the motor. Therefore, as the braking method, in addition to a braking method using an incompressible fluid such as hydraulic braking, regenerative braking in which braking energy is regenerated by a motor is possible. Regenerative braking is a braking method in which the kinetic energy of the vehicle is regenerated in the form of electric energy into a vehicle-mounted battery. Therefore, in order to improve the energy efficiency of the vehicle, more specifically, the frequency of battery charging operation is suppressed. It is effective in extending the mileage per charge.

Further, regenerative braking is normally performed when the position of the shift lever (shift position) is in a range such as D (drive), L (low), R (reverse), and N.
When it is in a range such as (neutral) or P (parking), regenerative braking is not performed (see Japanese Patent Laid-Open No. 6-70406). In other words, it is necessary to brake the vehicle when the vehicle is running, so as a general rule, regenerative braking should be allowed when the shift position indicates that the driver is driving the vehicle. It's enough.

[0004]

However, if the running control of the electric vehicle is executed in this way,
The maximum kinetic energy of the vehicle cannot be regenerated during braking. For example, when the brake pedal is depressed while the shift lever is in the D range or the like, regenerative braking is activated and the vehicle starts decelerating. After that, when the shift lever is put into the N range in a state where the vehicle has not yet stopped, the kinetic energy is not regenerated even when the brake pedal is depressed, although the kinetic energy that can be regenerated is still left. Further, when the shift position is switched from the D range or the like to the N range while the vehicle is traveling, the kinetic energy of the vehicle is not regenerated by the battery even if the brake pedal is depressed.

The present invention has been made to solve the above problems, and by permitting the regenerative braking under a predetermined condition when the shift position is in the neutral position (N), The purpose is to make it possible to regenerate more kinetic energy of the vehicle. Another object of the present invention is to reduce power consumption and control safety more securely by controlling power supply to a motor when the shift position is in neutral and regenerative braking is not required. To do.
An object of the present invention is to ensure the safety against the abnormality of the fluid pressure braking system by detecting the abnormality of the fluid pressure braking system (insufficient fluid pressure etc.) and controlling the regenerative braking force based on the result. And An object of the present invention is to ensure the safety against abnormality of regenerative braking force by detecting abnormality of regenerative braking force (insufficient regenerative ability etc.) and controlling power supply to the motor based on the result. And
An object of the present invention is to make it possible to regenerate more kinetic energy of a vehicle by prohibiting the shift position to be neutral when the vehicle is traveling. Another object of the present invention is to enable execution of an emergency evacuation operation that permits the shift position to be neutral when an abnormality in the braking system is detected.

[0006]

In order to achieve such an object, a first structure of the present invention is mounted on an electric vehicle having a transmission between a motor for driving a vehicle and driving wheels, and a shift function is provided. In a travel control device including means for controlling a transmission according to a position, when a shift position indicates any of forward, reverse, and neutral and a braking request is issued, the drive wheels are operated in response to the braking request. Regenerative braking is provided, and means for cutting off the power supply to the vehicle drive motor when the shift position is in the neutral position and the braking request is not issued.

The first structure of the present invention is further mounted on an electric vehicle having means for hydraulically braking the drive wheels in accordance with the required braking force, and while confirming that the braking force is acting, Means for applying one or both of the regenerative braking force and the fluid pressure braking force until the vehicle stops, a means for determining whether the fluid pressure braking force is acting when the braking force is not acting, and the above determination As a result, when it is determined that the fluid pressure braking force is not acting, it is considered that an abnormality has occurred in a member related to the fluid pressure braking, and a means for exerting the regenerative braking force is provided.

In the first structure of the present invention, when it is determined that the fluid pressure braking force is acting as a result of the above determination, it is considered that an abnormality has occurred in a member related to regenerative braking, and the vehicle running motor is instructed. It is characterized by comprising means for turning off the power supply and applying a fluid pressure braking force.

A second structure of the present invention is mounted on an electric vehicle having a transmission between a vehicle driving motor and driving wheels,
In a traveling control device including means for controlling a transmission according to a shift position, a means for determining whether or not the electric vehicle is traveling, and a transmission when the vehicle is determined to be traveling as a result of the determination. Means for prohibiting control to the neutral position, and means for regeneratively braking the drive wheels in response to the braking request when the shift position indicates either forward or backward and a braking request is issued. It is characterized by being provided.

In the second structure of the present invention, further, even when it is determined that the vehicle is traveling as a result of the above determination, the braking force is not applied even though the braking request is issued. Is provided with means for permitting control of the transmission to a neutral position.

[0011]

In the first structure of the present invention, braking is performed not only when the shift position indicates forward (D, L, etc.) or reverse (R), but also when the shift position indicates neutral (N). If the request is issued, regenerative braking control according to the braking request is executed. The braking request here is, for example, an operation of a brake pedal, and includes a braking request (engine braking in a gasoline engine vehicle) operation by a shift operation when the shift position indicates forward movement. Therefore, in the present configuration, the kinetic energy of the vehicle can be regenerated even when the shift position shows the neutral position, so that the energy efficiency of the vehicle is improved. Further, in this configuration, when the shift position is in the neutral position and the braking request is not issued, the power supply to the vehicle traveling motor is cut off. In other words, if the shift position shows neutral but regenerative braking is not necessary,
Power supply to the vehicle drive motor is cut off to reduce power consumption. In addition, if there is a possibility that an abnormality has occurred in the vehicle drive motor or various power components related to it, for example, the inverter for power conversion, simply supply the shift position to the neutral position to supply power to these components. Therefore, the fail-safe performance with respect to this type of abnormality is improved.

In the first configuration of the present invention, further,
Either or both of the regenerative braking force and the fluid pressure braking force are applied until the vehicle stops. At this time, if it is not recognized that the braking force is acting, it is first determined whether or not the fluid pressure braking force such as the hydraulic braking force is acting. As a result, if it is determined that the fluid pressure braking force is not acting, it is considered that an abnormality has occurred in a member related to the fluid pressure braking, for example, the hydraulic pipe or the valve, and the regenerative braking force is controlled. That is, when the fluid pressure braking force is abnormal, it is possible to perform control such that the regenerative braking force is increased more than usual, so that the fail-safe performance against abnormality of the fluid pressure braking system is improved.

In the first configuration of the present invention, when it is determined that the fluid pressure braking force is acting as a result of the determination,
It is considered that an abnormality has occurred in a member related to regenerative braking, such as a control circuit or signal wiring for regenerative braking control. In response to this, the power supply to the vehicle drive motor is cut off, and the braking is performed solely by the fluid pressure braking force. Therefore, in this configuration, the fail-safe performance with respect to the abnormality of the regenerative braking system is improved.

In the second structure of the present invention, even if the driver tries to shift the shift position to the neutral position while the vehicle is traveling, mechanical or electrical shift inhibition control is performed so that the transmission does not become neutral. To be executed. Therefore, loss of kinetic energy due to neutral shifting of the shift position while the vehicle is traveling can be avoided. Further, the kinetic energy corresponding to that amount can be regenerated only by applying the braking request by inputting the shift position to the forward or reverse direction, so that the energy efficiency of the vehicle is improved.

In the second configuration of the present invention, further,
Even when the vehicle is running, if it is not recognized that the braking force is acting even though the braking request is issued, there is a possibility that an abnormality has occurred in the braking system. Is allowed to be controlled to a neutral position. That is, the emergency evacuation operation can be performed by setting the shift position to the neutral position.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the system configuration of an electric vehicle suitable for implementing the present invention. In the system of this figure, a three-phase AC motor is used as the vehicle drive motor 10. The drive power of the motor 10 is supplied from the vehicle-mounted main battery 14 via the inverter 12. That is, the discharge output of the main battery 14 is converted from DC to three-phase AC by the inverter 12, and the motor 10
Is supplied to. The motor 10 rotates according to the supply of this electric power. The output shaft of the motor 10 is connected to drive wheels (not shown) via the transmission 16. Therefore, when the operator operates the shift lever to put the transmission 16 in the D range, for example, the drive wheels are normally rotated by the output of the motor 10 and the vehicle is propelled forward.

The output of the motor 10 is controlled by the controller 18. The controller 18 causes the vehicle to perform power running when the vehicle operator depresses the accelerator pedal, and brakes when the vehicle pedal depresses the brake pedal. Further, the controller 18 turns on the contactor 20 provided between the main battery 14 and the inverter 12 when starting the vehicle or the like, and turns off the contactor 20 when cutting off the power supply to the inverter 12 or the like. .
The controller 18 further sets the regeneration mode according to the shift position. The controller 18 uses the oil pressure sensor 3
The hydraulic pressure of the wheel cylinder 36 (wheel cylinder pressure PW / C), which will be described later, is detected by 4 and used for determining whether or not there is an abnormality in the hydraulic braking system. When the controller 18 executes the control procedure according to the second embodiment described later,
A command is given to the shift interlock device 22 under a predetermined condition to prohibit the transmission 16 from entering the N range.

First, when the driver of the vehicle depresses the accelerator pedal, the controller 18 inputs the accelerator opening degree indicating the amount of depression of the accelerator pedal by the driver as information, and is attached to the motor 10. The rotation sensor 24 detects the rotation speed N of the motor 10 and determines a power running torque command based on these. The power running torque command is a command indicating the power running torque to be output from the motor 10. The controller 18 controls the power conversion operation by the inverter 12 so that this power running torque command is realized.

Next, when it is detected by the brake switch 28 attached to the brake pedal 26 that the driver depresses the brake pedal 26, the controller 18 causes the master cylinder pressure PM / C indicating the brake pedal depression force. To detect. That is, when the operator depresses the brake pedal 26, the brake switch 28 is turned on, and a hydraulic pressure (master cylinder pressure PM / C) corresponding to the brake pedal depressing force is generated in the master cylinder 30 and is detected by the hydraulic pressure sensor 32. The cylinder pressure PM / C is notified to the controller 18. The controller 18 determines a regenerative torque command based on the master cylinder pressure PM / C and the rotation speed N of the motor 10. The regenerative torque command is a command indicating the regenerative torque to be output from the motor 10.
The controller 18 controls the power conversion operation by the inverter 12 so that this regenerative torque command is realized.

The system shown in this figure is further provided with a hydraulic braking system. The hydraulic braking system is provided on the drive cylinder side and the driven wheel side wheel cylinders 36 and 38, hydraulic pipes connecting the master cylinder 30 and the wheel cylinders 36 and 38, and the hydraulic pipes in addition to the master cylinder 30 described above. It is composed of various valves. First,
When the brake pedal 26 is shallowly stepped on, the master cylinder pressure PM / C and the wheel cylinder pressure P reduced proportionally by the P & B (proportioning and bypass) valve 40.
Since the differential pressure that exceeds the opening pressure of the differential pressure valve 42 does not occur between the differential pressure valve 42 and W / C, the differential pressure valve 42 remains closed. When the brake pedal 26 is stepped on from this state, the differential pressure reaches the valve opening pressure of the differential pressure valve 42 at a certain point, and the differential pressure valve 42 opens. After that, while the brake pedal 26 is further depressed, the differential pressure is held by the differential pressure valve 42. When the brake pedal 26 is stepped back and the master cylinder pressure PM / C is lowered accordingly, the brake fluid is introduced from the wheel cylinders 36 and 38 side to the master cylinder 30 side by the check valve 44, and the above difference occurs. The pressure is released. Therefore, when such a hydraulic braking system is used, the hydraulic braking force does not act on the brake wheels 46 and 48 until the brake pedal 26 is depressed more than the opening value of the differential pressure regulating valve 42, and the brake pedal 26 is operated by the differential pressure regulating valve. A hydraulic braking characteristic is obtained in which the hydraulic braking force increases in accordance with the increase of the master cylinder pressure PM / C after the depression of the valve opening value of 42 or more is performed. Here, it is preferable that the characteristic of the braking force, which is the sum of the regenerative braking force and the hydraulic braking amount, is proportional to the master cylinder pressure PM / C, and thus to the brake pedal depression force.
The valve opening value of the differential pressure valve 42 is preferably set to correspond to the maximum value of the regenerative braking force, and further, the valve opening value of the differential pressure valve 42 is preferably controllable according to the regenerative ability of the main battery 14.

First Embodiment. FIG. 2 shows an example of the regenerative torque command determination map used in the first embodiment of the present invention. In this figure, the four solid lines are numbered I to IV, respectively. These solid lines are
Both are maps showing the characteristics of the regenerative torque command with respect to the motor rotation speed N, and are used in different regenerative modes represented by corresponding numbers. For example, when the regeneration mode is set to II, the map corresponding to the solid line with the number II is referred to by the motor rotation speed N, whereby the maximum regenerative torque that can be realized at that motor rotation speed N is obtained. The order is decided. Then, the value obtained by proposing this maximum regenerative torque command by the brake pedal force given as the master cylinder pressure PM / C (during normal braking) or the value of the maximum regenerative torque command (during engine braking equivalent braking), Used for control.

Two types of regenerative modes are prepared as shown in FIG. 2 in order to select different characteristics according to the shift position or the like to realize the required braking performance. For example, the regenerative mode II is a mode used in the D range which requires a standard regenerative braking force, and the regenerative mode III is a mode used in the L range which requires a regenerative braking force larger than the D range. The regenerative mode IV is a mode used in the R range in which the drive wheels are reversed. When trying to obtain the so-called engine braking equivalent regenerative braking force, the regenerative braking force is one rank smaller than usual, such as the regenerative mode I for the D range and the regenerative mode II for the L range. Select a mode. The regenerative modes II and III having a relatively large regenerative braking force are used for the regeneration in the N range and the regeneration in the abnormal hydraulic pressure, which are the features of this embodiment.

Since a plurality of types of regenerative modes are prepared in this manner, the characteristics of the master cylinder pressure PM / C versus the regenerative hydraulic total braking force are different for each regenerative mode. For example, when the valve opening value of the differential pressure valve 42 is set so that the master cylinder pressure PM / C versus the total regenerative hydraulic braking force is linear in the regenerative mode II, the characteristics in the regenerative modes I to III are respectively shown in FIGS. It becomes the characteristic shown in c). However, Trmax1 to Trmax3 in the figure are respectively regenerative modes I to I.
It is the maximum value of the maximum regenerative torque command in II. When a valve whose valve opening value is controllable is used as the differential pressure valve 42, the non-linearity shown in FIGS. 3A and 3C can be eliminated.

FIG. 4 shows the operation flow of the controller 18 in the first embodiment of the present invention. The operation shown in this figure is an operation that is repeatedly executed at a predetermined frequency after the motor 10 is started.

In this control procedure, first, the controller 18 determines the shift position (10).
0). When the result of this determination is that the shift position is in the D or L range, the controller 18 determines whether or not the accelerator is on (102, 104). While the accelerator is on, the controller 18 determines the power running torque command by the above-described procedure, and controls the power conversion operation by the inverter 12 based on the determined power running torque command (not shown). When the accelerator is turned off while the shift position is in the D or L range, the controller 18
Sets the regeneration mode to I (in the D range) or II (in the L range) so that the regenerative braking force equivalent to the engine brake can be generated (106, 108). That is, when the accelerator is turned off while the shift position is in the D or L range, the regenerative mode is I (for the D range) or II (for the L range) so that the regenerative braking force equivalent to the engine brake is generated. Is selected. Until the brake pedal 26 is depressed (110, 112),
This regeneration mode is continuously selected.

When the brake pedal 26 is depressed with the shift position in the D or L range (110, 11)
2) That is, when the brake switch 28 is turned on, the controller 18 selects II (for D range) or III (for L range) as the regeneration mode (114,
116). That is, depending on the motor speed N, the regeneration mode
The map relating to II or III is referred to, the obtained maximum regenerative torque command value is proportionally divided by the brake power given as the master cylinder pressure PM / C, and the regenerative torque command used for control is determined. The motor 18 controls the power conversion operation by the inverter 12 using the determined regenerative torque command. When an effective regenerative braking force is applied by this control, or when a sufficient hydraulic braking force is applied by opening the differential pressure valve 42, the vehicle starts decelerating and finally stops. The controller 18 determines whether or not the vehicle is decelerating based on the motor rotation speed N detected by the rotation sensor 24 and the vehicle speed detected by a vehicle speed sensor (not shown). The controller 18 detects that the vehicle has stopped as a result of deceleration based on the motor rotation speed N and the like (118), and accordingly turns off the power to the motor system (120). That is, by turning off the contactor 20, the main battery 14 is switched to the inverter 12
And the power supply to the motor 10 is cut off.

Further, when it is determined in step 100 that the shift position is in the N or R range, the controller 18 does not need to generate the regenerative braking force equivalent to the engine brake, and therefore executes the determination regarding the accelerator. Without doing so, it is immediately determined whether or not the brake pedal 26 has been depressed (122, 124). If the brake pedal 26 is not depressed, the controller 18 executes step 120 to prevent power consumption by the inverter 12 and the motor 10. When the brake pedal 26 is depressed, the controller 1
8 is II (for N range) or IV as the regeneration mode
(For R range) is selected (126, 128). That is, the controller 18 determines the regenerative torque command for control by referring to the map related to the regenerative mode II or IV with the motor rotation speed N, and further apportioning the result by the brake pedal force, and the power generated by the inverter 12 is determined. Control is performed based on the regenerative torque command that performs the conversion operation. Then, the operation of the controller 18 proceeds to step 118.

If it is determined in step 100 that the shift position is in the P range, the controller 18 immediately executes step 120.

As described above, according to this embodiment, even when the shift position is in the N range, the regenerative braking operation is executed if the brake pedal 26 is depressed. Therefore,
It becomes possible to regenerate more kinetic energy of the vehicle to the main battery 14 than in the conventional case, and the energy efficiency of the vehicle is improved. This is the main battery 14
This means that the operation of charging the battery does not have to be performed as frequently as in the conventional case, and that the travelable distance per charge of the main battery 14 is extended. Further, since the power supply to the motor system is cut off by putting the shift position into the N range without depressing the brake pedal 26, even if some abnormality occurs in the inverter 12, the motor 10, or the like, This can be effectively dealt with, and fail-safe performance similar to or better than the conventional one can be obtained.

In the control procedure shown in FIG. 4, it is also executed to determine whether the hydraulic braking system or the regenerative braking system is functioning normally. That is, when it is detected in step 116 that the vehicle is not decelerating, it can be considered that at least one of the regenerative braking system and the hydraulic braking system is abnormal. Therefore, the controller 18 determines whether or not an abnormality has occurred in the hydraulic braking system based on the wheel cylinder pressure PW / C detected by the hydraulic sensor 34 (130).
As a result, when it is detected that the hydraulic braking system is normal, it can be considered that an abnormality has occurred in the regenerative braking system, and thus step 120 is executed. The abnormality of the regenerative braking system mentioned here means, for example, the main battery 1
If the regenerative torque command determined by the controller 18 cannot be realized because the voltage of No. 4 rises and as a result the ability to receive regenerative energy decreases,
This is the case, for example, when an abnormality occurs in the wiring between the circuits that make up the circuit and the control procedure related to regenerative braking cannot be executed accurately. If such a situation is detected, the above step 120 is performed.
By executing the above, it is possible to prevent the behavior of the motor 10 and the inverter 12 from adversely affecting the vehicle, and the fail-safe performance is improved. When a valve whose open value is controllable is used as the differential pressure valve 42, the master cylinder pressure PM / C is controlled by controlling the open value to 0.
Can be transmitted to the wheel cylinder 36 or 38 as it is, so that the required braking force can be realized by the hydraulic braking system alone.

When it is determined in step 130 that the hydraulic braking system is abnormal, the controller 18 selects II, III or IV as the regeneration mode (132). That is, if the regenerative mode used up to that point is II, select II or III, select III if it is III, and select IV if it is IV, and brake with only the regenerative braking system. To be able to. In particular, if the regenerative mode up to that point is II, if the regenerative mode III is selected in step 132, the regenerative braking force can be increased and a regenerative braking force close to the required braking force can be obtained. be able to. After execution of step 132, the process returns to step 118. By performing such an operation, it becomes possible to brake the vehicle even when there is an abnormality in the hydraulic braking system, such as a failure in the hydraulic piping or a failure in the valve.

However, if an abnormality occurs in the hydraulic braking system and the regenerative braking system at the same time, if it is determined in step 130 that there is an abnormality in the hydraulic braking system, step 132 is unconditionally executed. The power supply to the motor system will continue to be executed despite the occurrence of an abnormality in the regenerative braking system. In order to avoid such a problem, if the vehicle does not decelerate even after executing step 132 (116), it may be considered that the regenerative braking system is also abnormal. Therefore, in this embodiment, the flag is set when step 132 is executed (134), and step 132
If it is determined in step 116 that the vehicle is not decelerating (136), the motor system is powered off (120). By performing such a process, fail-safe is ensured.

Second embodiment. FIG. 5 shows a control flow of the controller 18 in the second embodiment of the present invention.

In this embodiment, the controller 18
First determines the shift position (200). At that time, if the shift position is in the range other than D or L such as N range, the controller 18 gives a command to the shift interlock device 22 to permit the transmission 16 to be put in neutral. (202).

After that, when the shift position is set to the D or L range (200), the controller 18 determines whether the vehicle is stopped or not based on the motor rotation speed N detected by the rotation sensor 24 and the like ( 204). If the vehicle is stopped, the controller 18 proceeds to step 202
To execute. If the vehicle is not stopped, the controller 18 gives a command to the shift interlock device 22 to prohibit the transmission 16 from being put into neutral (20).
6). Therefore, after this step 206 is executed,
The operator cannot put the shift lever into the N range. This state is maintained until the vehicle stops (20
4), or until an abnormality is detected in the braking system.

When the brake pedal 26 is depressed with the shift position in the D or L range (208), the hydraulic pressure reduced by the differential pressure valve 42 is applied to the wheel cylinder 36.
And 38, and the controller 18 controls the regenerative braking torque according to the brake pedal force (not shown). When such a braking operation is normally performed, the vehicle decelerates. The controller 18 detects that the vehicle is decelerating based on the motor rotation speed N and the like (21
0). When the vehicle is decelerating, the shift position is continuously maintained in the D or L range. On the other hand, when it is determined that the vehicle is not decelerating (210), the controller 18 considers that an abnormality has occurred in either the hydraulic braking system or the regenerative braking system, and sets the transmission 16 to neutral. Allow control. That is, a command is given to the shift interlock device 22 to permit the transmission 16 to be put into neutral (202).

As described above, according to the present embodiment, it is prohibited to shift the shift position to the N range while the vehicle is traveling. Therefore, the shift position is shifted to the N range while the vehicle is traveling. It is possible to suppress loss of kinetic energy and eventually decrease of braking energy regeneration efficiency. Therefore, as in the first embodiment described above, the frequency of charging the main battery 14 by the external power source can be suppressed, and the travelable distance per charge of the main battery 14 can be extended. Further, since it is possible to control the transmission 16 to be neutral when it is detected that the vehicle is not decelerating despite the depression of the brake pedal 26, when an abnormality occurs in the braking system, The pilot can put the shift lever into the N range and perform an emergency evacuation.

[0039]

As described above, according to the first configuration of the present invention, the braking request is satisfied not only when the shift position indicates forward or backward but also when the shift position indicates neutral. Since the regenerative braking is executed, the kinetic energy of the vehicle can be regenerated even when the shift position shows neutral, and the energy efficiency of the vehicle can be improved. Further, according to this configuration, when the shift position is in the neutral position and the braking request is not issued, the power supply to the vehicle traveling motor is cut off, so that the power consumption can be reduced and the vehicle traveling motor can be reduced. It is possible to improve the fail-safe performance against abnormalities of various power components related to the above.

According to the first aspect of the present invention, further, when the braking force is not recognized to be acting even though the vehicle is not stopped, first, the fluid pressure braking force such as the hydraulic braking force is first applied. If it is determined that the fluid pressure braking force is not acting, it is considered that an abnormality has occurred in the member related to the fluid pressure braking and the regenerative braking force is controlled. Since it is possible to control the regenerative braking force to increase, for example, more than usual when an abnormality occurs,
It is possible to improve fail-safe performance against abnormalities in the fluid pressure braking system.

According to the first aspect of the present invention, when it is determined that the fluid pressure braking force is acting as a result of the determination, it is considered that an abnormality has occurred in a member relating to regenerative braking, and power is supplied to the vehicle running motor. Since the supply is cut off and the braking is performed only by the fluid pressure braking force, the fail-safe performance against the abnormal regenerative braking force can be improved.

According to the second configuration of the present invention, even if the driver tries to shift the shift position to neutral while the vehicle is traveling, the shift inhibition control is executed so that the transmission does not become neutral. It is possible to avoid the loss of kinetic energy caused by turning the shift position to neutral while running, and to regenerate it by giving the shift position forward or backward and applying a braking request, so that the energy efficiency of the vehicle is improved.

According to the second configuration of the present invention, further, even when the vehicle is traveling, when it is not recognized that the braking force is acting even though the braking request is issued,
Since the transmission is allowed to be controlled to the neutral position, it is possible to perform the emergency evacuation operation in which the shift position is set to the neutral position even though the shift prohibition control is executed while the vehicle is traveling.

[Brief description of drawings]

FIG. 1 is a block diagram showing a system configuration of an electric vehicle suitable for implementing the present invention.

FIG. 2 is a motor rotation speed vs. torque map showing each regenerative mode used in the first embodiment of the present invention.

FIG. 3 is a diagram showing characteristics of a master cylinder pressure versus a total braking force for each regeneration mode, in which (a) shows a regeneration mode I;
(B) shows regeneration mode II, (c) shows regeneration mode III,
It is a figure which respectively shows.

FIG. 4 is a flowchart showing a flow of control operation executed by a controller in the first embodiment of the present invention.

FIG. 5 is a flowchart showing a control operation executed by a controller in the second embodiment of the present invention.

[Explanation of symbols]

10 motor, 12 inverter, 14 main battery,
16 gearbox, 18 controller, 20 contactor,
22 shift interlock device, 24 rotation sensor, 2
6 Brake pedal, 28 Brake switch, 30
Master cylinder, 32, 34 Oil pressure sensor, 36, 38
Wheel cylinder.

Claims (5)

[Claims] 1. A traveling control device, which is mounted on an electric vehicle having a transmission between a vehicle traveling motor and drive wheels, and has means for controlling the transmission according to the shift position, wherein the shift position is forward or backward. And neutral, and when a braking request is issued, means for regeneratively braking the drive wheels in response to the braking request, and when the shift position is neutral and the braking request is not issued. And a means for cutting off the power supply to the vehicle driving motor. 2. The traveling control device according to claim 1, which is mounted on an electric vehicle having means for hydraulically braking the drive wheels in accordance with the required braking force, while confirming that the braking force is acting. Means for applying one or both of the regenerative braking force and the fluid pressure braking force until the electric vehicle stops, means for determining whether or not the fluid pressure braking force is acting when the braking force is not acting, A traveling control device comprising: a unit that, when it is determined that the fluid pressure braking force is not acting, determines that an abnormality has occurred in a member related to the fluid pressure braking and applies the regenerative braking force to the member. 3. The traveling control device according to claim 2, wherein when a fluid pressure braking force is acting as a result of the determination, it is considered that an abnormality has occurred in a member relating to regenerative braking, and the vehicle traveling motor is instructed. And a means for applying a fluid pressure braking force by cutting off the power supply of the vehicle. 4. A travel control device, which is mounted on an electric vehicle having a transmission between a motor for driving a vehicle and a drive wheel and has means for controlling the transmission according to a shift position, wherein the electric vehicle is driven. Means for determining whether or not the vehicle is running, means for prohibiting control of the transmission to the neutral position if the vehicle is traveling as a result of the above determination, and the shift position indicates either forward or backward. And a braking request is issued, a travel control device comprising: means for regeneratively braking the drive wheels in response to the braking request. 5. The traveling control device according to claim 4, wherein even when it is determined that the vehicle is traveling as a result of the determination,
A travel control device comprising means for permitting control of the transmission to a neutral position when the braking force is not acting despite the braking request being issued.