JPH10257603A - Electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform a preventive operation with margin, even when an abnormality is generated in a vehicle by a method wherein, on the basis of the detection result of an abnormality detecting means, the output torque of a motor is suppressed by being divided into at least two stages. SOLUTION: An abnormality detecting means 15 is composed of a motor- temperature sensor 11, of a battery-temperature detecting sensor 12, of a battery- voltage sensor 13 and of a vacuum-pressure sensor 14. When it is judged by a judgment means 7 on the basis of detection information from the respective sensors 11 to 14 that an abnormality has been generated in a vehicle, a computing means 8 gradually lowers a torque gain within a prescribed time. Then, simultaneously with the detection of the abnormality of the vehicle, a torque suppression and control operation is started. As a result, when the abnormality is detected, warning lights 10A to 10C corresponding to the causes are turned on, and lamps 30, 31 corresponding to running modes blink. As a result, the safety of the vehicle can be increased, the abnormality of the vehicle can be noticed at an early stage, and a drier can perform a preventive operation or the like with margin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric vehicle driven by a driving motor, and more particularly, to an electric vehicle capable of securing a sufficient motor torque even when an abnormality occurs in the vehicle.

[0002]

2. Description of the Related Art Conventionally, in an electric vehicle running by an electric motor (running motor or simply a motor), when an abnormality occurs in a device such as a motor or a battery, a torque generated by the motor is required to protect the device. Is suddenly limited to a predetermined value. Such an abnormality of the vehicle may be, for example, a case where the temperature of the motor or the battery becomes higher than a predetermined temperature. In such a case, the motor torque is rapidly limited to, for example, 50% of the normal output. It is done.

[0003] By limiting the output torque of the motor in this way, the running performance of the vehicle is suppressed, thereby reducing the load on devices such as the motor and the battery. Further, by suppressing the running performance of the vehicle in this way, the safety of the vehicle is ensured.

[0004]

However, if the above-described abnormality occurs in the vehicle while traveling on a high-speed lane (overtaking lane) on a highway, for example, the motor torque suddenly reaches a predetermined value in the prior art. Because it will decrease
This may make it difficult to avoid the vehicle on the low-speed lane (traveling lane) or the roadside zone (evacuation driving).

[0005] That is, when an abnormality occurs in a vehicle, when a driver tries to change the course from a high-speed lane to a low-speed lane or a roadside zone to avoid danger,
It is necessary to overtake depending on the road conditions. In this case, a relatively large motor torque is required. However, in the related art, there is a problem that the motor torque sharply decreases and a torque required for overtaking cannot be obtained.

It should be noted that JP-A-4-145802, JP-A-5-115106, and JP-A-7-111708.
Japanese Patent Application Laid-Open No. 8-70501 and Japanese Patent Application Laid-Open No. 8-70501 also disclose related techniques, but none of them solves the above-mentioned problems. The present invention has been made in view of such a problem, and even if an abnormality occurs in a vehicle,
An object of the present invention is to provide an electric vehicle capable of performing an avoidance operation with a margin.

[0007]

According to the present invention, there is provided an electric vehicle according to the first aspect of the present invention, which includes an abnormality detecting means for detecting an abnormality of a device mounted on the vehicle in an electric vehicle driven by driving an electric motor. And a torque suppressing means for suppressing the output torque of the electric motor in at least two stages based on the detection result of the abnormality detecting means.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, when an abnormality of the device is detected by the abnormality detecting means, the abnormality of the device is determined by the driver. Is provided on the vehicle. Further, the electric vehicle according to the present invention described in claim 3 is, in addition to the configuration described in claim 1 or 2,
When an abnormality of the device is detected by the abnormality detection unit, the torque suppression unit controls the ratio of the output torque to the output torque in the normal state so as to decrease in accordance with the elapsed time from the abnormality detection. Features.

At this time, the degree of decrease in the output torque may be changed a predetermined time after the abnormality is detected. For example, the output torque may be suppressed to a first suppression value after a first predetermined time from the abnormality detection, and the output torque may be suppressed to a final suppression value after a second predetermined time. .

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 to 6 show an electric vehicle as an embodiment of the present invention. Will be explained. FIG. 1 is a block diagram showing a main configuration of the electric vehicle. As shown in FIG.
The electric vehicle is provided with a traveling motor 2 for driving the drive wheels 1A and 1B. Here, it is described that one driving motor 2 drives the left and right driving wheels 1A and 1B. However, the driving motor 2 may be provided for each driving wheel. , The driving wheels 1A and 1B may be driven via a transmission.

The traveling motor 2 is connected to a battery 4 via a power conversion circuit 3, and the power conversion circuit 3 is controlled by a torque control means 5, which also has a function as a torque suppression means. In the powering mode, power is supplied from the battery 4 to the traveling motor 2 through the power conversion circuit 3, and in the regenerative mode, the wheels 1A,
The rotational force of 1B is converted into electric power by the traveling motor 2, and the converted electric power is sent to the battery 4 through the electric power conversion circuit 3 to charge the battery.

The mode selection between the powering mode and the regenerative mode is as follows.
Accelerator operation amount (accelerator opening) by torque control means 5
When the accelerator operation amount is equal to or more than a small predetermined value (that is, when a significant accelerator operation is performed), the power running mode is selected, and the accelerator operation is performed. When the amount is less than a minute predetermined value (that is, no significant accelerator operation is performed) and the motor rotation speed is larger than the predetermined value, the regeneration mode is selected.

The regenerative mode includes a weak regenerative brake mode corresponding to the engine brake and a strong regenerative brake mode stronger than the engine brake. When the brake pedal is depressed in the regenerative mode (for example, when the brake switch is turned on) ) Is set to the strong regenerative braking mode, otherwise (when the brake pedal is not depressed), the weak regenerative braking mode is set.

By the way, the torque control means 5 is used to store data such as maps and tables for control.
Storage means 6 including M, etc .; determination means 7 for making a determination for controlling the traveling motor 2; arithmetic means 8 for performing various calculations based on the determination results by the determination means 7; An instruction means 9 for giving various instructions based on the calculation results by the arithmetic means 8 and a display means 10 for notifying the driver of the state of the vehicle based on information from the instruction means 9 are provided.

Further, the electric vehicle is provided with abnormality detecting means 15 for detecting an abnormality of a device mounted on the vehicle. The abnormality detection means 15 mainly includes a motor temperature detection means (motor temperature sensor) 11, a battery temperature detection means (battery temperature detection sensor) 12, a battery voltage detection means (battery voltage sensor) 13, and a brake abnormality detection means (vacuum) Pressure sensor) 14 and the like.
Based on the detection information from the storage unit 14 and the information from the storage unit 6, a calculation for suppressing the motor torque is performed.

Here, the determination means 7 determines that an abnormality has occurred in the vehicle in the following cases. That is, when the motor temperature sensor 11 detects that the temperature of the motor 2 has exceeded a predetermined value, or when the battery temperature detection sensor 12 detects that the battery temperature has reached a predetermined value or more, or When the battery voltage sensor 13 detects that the battery voltage has become equal to or higher than a predetermined value, or when the vacuum pressure sensor 14 detects that the negative pressure acting on the brake booster has become equal to or lower than a predetermined value. It is. If at least one of these is detected, the determination means 7 determines that an abnormality has occurred in the vehicle.

The display means 10 is provided in an instrument panel (vehicle status display) 16 as shown in FIG. 5, and mainly includes a motor warning light 10A, a battery warning light 10B, a brake warning light 10C, Motor regeneration lamp 3
0, a motor powering ramp 31 and the like. Then, in a normal state (normal state), the motor powering lamp 31 is turned on in the powering mode, and the motor regenerative lamp 30 is turned on in the regenerative mode.

When the judging means 7 judges that the vehicle is abnormal, a torque suppression control which will be described later is performed, and the warning lights 10A to 10C corresponding to the abnormal parts of the vehicle according to the command signal from the instruction means 9. Lights up, and
The lamps 30 and 31 according to the traveling mode blink. In addition, in FIG. 5, 22 is a speedometer, 2
4 is a shift indicator, 25 is a trip meter, 26
Is an odometer, 28 is a seat belt wearing warning light or a door opening / closing warning light, 29 is a motor operation lamp, and 33 is a battery remaining amount lamp.

On the other hand, the storage means 6 stores maps as shown in FIGS. The map shown in FIG. 2 shows the basic characteristics of the change in the torque gain (this torque gain will be described later) when the vehicle is abnormal. When the abnormality detecting means 15 detects the abnormality of the vehicle, the map shown in FIG. The output torque of the motor 2 is suppressed in two stages. In other words, the torque gain is suppressed to 80% after time T1 (first predetermined time) and the final torque gain is Y% after time T2 (second predetermined time) based on the time of abnormality detection. It is set to.

The map shown in FIG. 3 stores the values of the parameters T1, T2, and Y, and the parameters T1, T2, and Y are stored in accordance with various causes of the vehicle abnormality detected by the abnormality detecting means 15. By changing the values of T1, T2, and Y, the motor torque suppression characteristics are changed. Then, the calculating means 8 calculates a motor torque suppression value from such a map, and outputs the calculation result to the instruction means 9. Instructing means 9
Then, the output torque suppression signal of the motor 2 is output to the power conversion circuit 3 based on the calculation result from the calculation means 8 and the operation signals to the warning lights 10A to 10C and the lamps 30 and 31 are output to the display means 10. Is supposed to.

Here, the torque suppression control in the event of a vehicle abnormality will be described in more detail.
The torque command value to the motor 2 is calculated by the following equation. Torque command value = Torque gain × Accelerator pedal proportional torque command value When a vehicle abnormality occurs, the torque gain is changed according to the cause of the abnormality.
It is always set to 100%. Therefore, at normal times, the torque command value and the accelerator pedal proportional torque command value match.

The accelerator pedal proportional torque command value is a torque command value proportional to the accelerator opening. That is, an accelerator position sensor is provided near the accelerator pedal, and a voltage corresponding to the opening of the accelerator pedal is output from the accelerator position sensor. A command value proportional to this voltage is stored in the storage means 6 in advance, and this command value is output as the accelerator pedal proportional torque command value.

The accelerator pedal proportional torque command value is set to a characteristic as shown in FIG. 4, for example. That is,
In a region where the accelerator opening is small, the torque command value is set to 0% irrespective of the accelerator opening, and when the accelerator opening is within a predetermined range, the torque command value has a linear characteristic according to the accelerator opening. Is set between 0 and 100%,
When the accelerator opening is larger than a certain opening, the torque command value is set to 100% regardless of the accelerator opening.

When the determining means 7 determines that an abnormality has occurred in the vehicle based on the detection information from the sensors 11 to 14 (that is, the abnormality detecting means 15), the calculating means 8 executes, for example, FIG. In this case, the predetermined times T1, T2 and the final suppression value Y% of the torque gain are set in advance according to the cause of the abnormality as described above. Have been.

Here, the setting of the parameters T1, T2, and Y for the cause of the vehicle abnormality will be described with reference to FIG. 3. First, when the temperature of the motor 2 rises and the abnormality of the motor 2 is detected, The setting is divided into two stages of “low” and “high” according to the overheat level of the motor 2.
Here, when the overheating level of the motor 2 is “low”, although the temperature of the motor 2 has reached a higher temperature than that of the case where the motor 2 is overheated by normal running, serious damage to the motor 2 and other devices is immediately caused. Is not high enough to cause

However, in this case, if the driver does not take any evasive action, the possibility that the overheating level of the motor 2 shifts to “high” is extremely high. In addition, when the overheating level of the motor 2 becomes “high”, if the running is not stopped immediately, serious damage such as melting of the coil of the motor 2 due to high heat may occur. Therefore, when the overheating level of the motor 2 is "low", for example, as shown in the map shown in FIG. 3, T1, T2, and Y are set to 30 seconds, 60 seconds, and 25%, respectively. 3 from abnormality detection
Until 0 seconds, gradually increase the torque gain from 100% to 80.
%.

The reason why the torque gain is gradually reduced within the predetermined time is to notify the driver of a vehicle abnormality. That is, if the output torque of the motor 2 gradually decreases, the vehicle speed will decrease even if the accelerator opening is constant, and the driver can experience the decrease in output. Then, the abnormality of the vehicle is noticed by such a decrease in the output.

The reason why the torque gain is temporarily reduced to 80% without being reduced immediately after the abnormality is detected is to prevent the running performance of the vehicle from suddenly lowering.
For example, if the vehicle is traveling on a highway on a highway, the driver may try to change to a low-speed lane or a roadside zone as an avoidance operation. This is because it is necessary to secure the torque required for overtaking.

The time T1 (30 in this case)
The second) is set to a time during which the driver can notice the abnormality of the vehicle due to the decrease in the motor torque and move the vehicle to the roadside zone or the like with a margin. Further, after a time T2 (60 seconds in this case) from the abnormality detection, the torque gain is suppressed to the final suppression value Y%. The torque gain final suppression value Y% is such a torque gain that the overheating level of the motor 2 does not shift from “low” to “high” even if the vehicle continues to run, and the cause of the abnormality is the overheating level of the motor 2. Is "low", the final suppression value Y is set to 25%.

When it is determined that the overheating level of the motor 2 is "high", the vehicle must be stopped immediately. In this case, T1, T2, and Y are all set to 0. . That is, the torque gain is set to 0% simultaneously with the detection of overheating of the motor 2. As described above, the torque gain is set to 0 at the same time when the overheat level
Although the setting of% seems to be coarse in control, in actuality, before the overheating level of the motor 2 becomes "high", the motor 2 must have gone through the state of the overheating level "low". It is unlikely that the overheating level will be "high" due to the torque suppression when the overheating level is "low".

However, if the overheating level of the motor 2 reaches "high" for some reason, the first consideration is to ensure the safety of the vehicle, and the torque gain is immediately reduced to zero.
%. In this case, the vehicle is in the coasting state (coasting state) until the vehicle stops.
Thus, the running torque gain is maintained at 0% and the running of the vehicle is prohibited until the vehicle becomes normal.

On the other hand, the temperature of the battery 4 is also shown in FIG.
As shown in the map of FIG.
As in the case of the above, the setting is divided into two stages of "low" and "high". When the overheating level of the battery 4 is "low", each of the parameters T1, T2 and Y is set to 30 seconds. ,
It is set to 30% for 60 seconds. When the overheating level of the battery 4 is "high", the parameters T1, T2,
Y is all assumed to be 0.

The parameters T 1, T 2, T 2, T 2, T 2, T 3, T 2, T 3, T 4, T 4, T 4, T 4, T 4, T 4, T 4, T 4, T 4, T 4, T 5, T 4, T 5, T 4 Y
Is set to 0. The case where the battery 4 is in an overvoltage state may be a case where regenerative braking is frequently performed. Further, as the abnormality of the brake, a decrease in the negative pressure of the booster can be considered. Therefore, in the present embodiment, the vacuum pressure sensor 14 is used as the brake abnormality detecting means. However, a brake oil pressure sensor may be provided. .

When various abnormalities occur as described above, warning lights 10A to 10C provided on the instrument panel 16 are turned on at the same time as the abnormality is detected, so as to notify the driver of the occurrence of the abnormality. Has become.
Here, the warning light is turned on according to the cause of the abnormality.
When A is the overheating and overvoltage of the battery 4, the battery warning light 10B is turned on, and when the brake is abnormal, the brake warning light 10C is turned on.

While the torque suppression control is being executed, the motor powering lamp 31 blinks in the powering mode, and the motor regenerative lamp 30 blinks in the regenerative mode. In the present embodiment, since the torque suppression control is started simultaneously with the detection of the abnormality of the vehicle, the warning lamps 10A to 10C corresponding to the cause are turned on and the lamps 30 and 31 corresponding to the traveling mode blink at the time of detection of the abnormality. is there.

When a plurality of abnormalities occur at the same time, the torque suppression control is performed using the smaller one of the torque gains obtained from the maps shown in FIGS. . Thus, even when a plurality of abnormalities occur, the torque suppression control according to the more urgent abnormality cause is executed.

When the abnormality is no longer detected, the above-described torque suppression control is released.
For example, even if the overheat level “low” of the motor 2 is detected,
Thereafter, when the temperature of the motor 2 drops below a predetermined value and no abnormality is detected, the torque gain becomes a normal value (= 10
0%) so that the vehicle can travel normally.

Since the electric vehicle according to one embodiment of the present invention is configured as described above, the torque suppression control is executed according to, for example, a flowchart shown in FIG. First, in step S1, the abnormality detecting means 1
5 is used to determine whether an abnormality has been detected. If an abnormality is detected, the process proceeds to step S2. And step S
In step 2, the torque gain Gn is calculated according to the type of the cause of the abnormality and the elapsed time since the abnormality was detected. At this time, the torque gain Gn is calculated using the characteristics of the map shown in FIG. 2 and the values stored in the map shown in FIG.
In step S2, the warning lights 10A to 10C corresponding to the cause of the abnormality are turned on, and the lamps 30 and 31 corresponding to the traveling mode are blinked.

Thereafter, the process proceeds to step S3, where a minimum value Gmin of the torque gains Gn calculated for each cause of the abnormality is calculated. This is to ensure the safety of the vehicle by selecting the smallest torque gain Gmin when a plurality of abnormalities occur simultaneously. And step S
Then, the torque command value is calculated by the following equation using the torque gain Gmin calculated in step S3 and the accelerator pedal proportional torque command value obtained from the map shown in FIG.

Torque command value = Torque gain Gmin × Accelerator pedal proportional torque command value By executing such torque control,
There are the following effects or advantages. That is, even if an abnormality occurs in the vehicle while traveling on a high-speed lane or the like, the torque of the motor 2 is gradually suppressed while securing sufficient torque for overtaking, so that the vehicle can safely travel to the low-speed lane or roadside zone. Can be changed.

Further, since the torque is gradually suppressed, the driver can experience the torque suppression control by lowering the vehicle speed. In this case, since the driver often looks at the instrument panel 16, the driver can know the cause of the occurrence of the abnormality by turning on the warning lights 10A to 10C corresponding to the abnormal part of the vehicle. Further, at the time of the torque suppression control, the driver can know that the torque suppression control is being performed by blinking either the motor powering lamp 31 or the motor regenerative lamp 30 according to the traveling mode, so that the driver has a margin. There is an advantage that it is possible to take an avoidance action with.

When the degree of urgency is high, such as when the motor overheat level is "high", the torque gain is immediately set to 0.
, The safety of the vehicle can be sufficiently ensured. In the above-described embodiment, when the abnormality detecting means 15 detects the abnormality of the vehicle, the output torque of the motor 2 is changed to the first torque after the first predetermined time from the abnormality detection.
, And after a second predetermined time, the output torque is suppressed to the final suppression value. However, the present invention is not limited to such an embodiment. Instead, the torque may be suppressed in three or more stages. Alternatively, when the abnormality detection unit 15 detects an abnormality in the vehicle, the output torque of the motor 2 may be linearly suppressed to the final suppression value.

In the above embodiment, the electric vehicle is described as an electric vehicle that converts the electric power stored in the battery 4 into the rotational force of the motor 2 and drives the driving wheels 1A and 1B. The electric vehicle of the present invention is not limited to such an embodiment. For example, the present invention is also applied to a so-called hybrid electric vehicle in which a generator is driven by a driving force of an engine to supply power to the motor. In addition to the above, the present invention can be widely applied to various electric vehicles running by the driving force of a motor.

In the above-described embodiment, both the suppression of the motor torque and the operation of the display means 10 are performed simultaneously with the detection of the abnormality. Display means 1 simultaneously with abnormality detection
0 may be operated, and then the control for suppressing the motor torque may be performed.

[0045]

As described above in detail, according to the electric vehicle of the present invention, the output torque of the electric motor is suppressed in at least two stages based on the detection result of the abnormality detecting means. There is an advantage that the safety of the vehicle can be improved. In addition, since the driver can experience the torque suppression, there is an advantage that the driver can notice the abnormality of the vehicle at an early stage. Thus, there is an advantage that the driver can perform the avoidance operation or the like with a margin, and also can enhance the safety of the vehicle.

Further, according to the electric vehicle of the present invention, when the abnormality detecting means detects abnormality of the equipment of the vehicle, the display means is activated, so that the driver can know the cause of the occurrence of the abnormality. In addition to this, there is an advantage that it is possible to know that the torque suppression control is being performed, and it is possible to take an avoidance action with a margin.

According to the third aspect of the present invention, when the abnormality is detected by the abnormality detecting means, the ratio of the output torque to the normal output torque is detected by the torque suppressing means. Since it is controlled so as to decrease in accordance with the elapsed time from the time, for example, even if an abnormality occurs in the vehicle when the vehicle is traveling on a high-speed lane or the like, the torque of the motor is secured while ensuring sufficient torque for overtaking. , And there is an advantage that the course can be safely changed to a low-speed lane or a roadside zone. This also has the advantage that the safety of the vehicle can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram illustrating a main configuration of an electric vehicle according to an embodiment of the invention.

FIG. 2 is a map for explaining characteristics of torque suppression control in an electric vehicle as one embodiment of the present invention.

FIG. 3 is a map for explaining characteristics of torque suppression control according to an abnormality occurrence cause in an electric vehicle as one embodiment of the present invention.

FIG. 4 is a map showing characteristics of an accelerator pedal proportional torque command value in the electric vehicle as one embodiment of the present invention.

FIG. 5 is a schematic diagram showing an instrument panel in an electric vehicle as one embodiment of the present invention.

FIG. 6 is a flowchart illustrating an operation of torque suppression control in the electric vehicle as one embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 1A, 1B drive wheel 2 traveling motor (motor) 3 power conversion circuit 4 battery 5 torque suppression means (torque control means) 6 storage means 7 determination means 8 calculation means 9 indication means 10 display means 10A motor warning light 10B battery warning light 10C Brake warning light 11 Motor temperature detecting means (motor temperature sensor) 12 Battery temperature detecting means (battery temperature detecting sensor) 13 Battery voltage detecting means (battery voltage sensor) 14 Brake abnormality detecting means (vacuum pressure sensor) 15 Abnormality detecting means 16 Instrument panel (vehicle status display) 22 Speedometer 24 Shift indicator 25 Trip meter 26 Odometer 28 Warning light 29 Motor operation lamp 30 Motor regeneration lamp 31 Motor power running lamp 33 Battery remaining lamp

Claims (3)

[Claims] 1. An electric vehicle that runs by driving an electric motor, comprising: abnormality detection means for detecting an abnormality of a device mounted on the vehicle; and an output torque of the electric motor based on a detection result of the abnormality detection means. An electric vehicle, comprising: a torque suppressing unit that suppresses the power in stages. 2. The vehicle is provided with display means for notifying a driver of an abnormality of the equipment, and the display means is activated when the abnormality detection means detects an abnormality of the equipment. The electric vehicle according to claim 1, wherein: 3. When the abnormality is detected by the abnormality detecting means, the ratio of the output torque to the output torque in the normal state is reduced by the torque suppressing means in accordance with the elapsed time from the time of detecting the abnormality. The electric vehicle according to claim 1, wherein the electric vehicle is controlled.