JP2001251706A - Electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent sense of speed change from decreasing, when switching the range by operating a shift lever. SOLUTION: The electric vehicle is provided with a vehicle speed detection means 12, an acceleration opening detection means 13, a range selection means, a shift sensor 14 for detecting the range, an output torque command calculation means 15a for calculating an output torque command from a vehicle speed and an acceleration opening, and an advance direction determining means 16 for determining advance direction. The output torque command value calculation means 15a sets an output command to zero, if the switching of a range where a drive direction is inverted in made, when the absolute value of the vehicle speed is equal to or more than a preset value. If the switching of a range, where the drive direction is inverted, is made when the absolute value of the vehicle speed is equal to or more than the preset value, the output torque command value is set to zero, thus preventing the drive direction of a motor 21 from being inverted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric vehicle.

[0002]

2. Description of the Related Art Conventionally, an electric vehicle generates an output torque by driving a motor, and transmits the rotation of the motor to driving wheels as it is or decelerates it by a transmission.
The power is transmitted to the driving wheels.

In such an electric vehicle, an output torque control device is provided, and a forward range, a reverse range, a neutral range, and the like can be selected by operating a shift lever, and when an accelerator pedal or the like is depressed, The output torque of the motor can be controlled.

In this case, a shift sensor is provided for detecting the position of the shift lever, that is, the range position, and a signal of the range position detected by the shift sensor is sent to the output torque control device, and the output torque control device is controlled. The apparatus determines the selected range. The shift sensor is a single independent contact type shift sensor.

FIG. 7 is a diagram for explaining the operation of a shift sensor used in a conventional electric vehicle. In the figure, (a)
Shows the contact of the shift sensor, and (b) shows the operation of the shift sensor.

In FIG. 1, reference numeral 1 denotes a slide contact connected to a shift lever (hereinafter, referred to as a "shift lever"), and reference numeral 2 denotes a shift sensor. In the shift sensor 2, the shift lever 1 is located at each of a parking range (P), a reverse range (R), a neutral range (N), a forward range (D), and a low range (L).

IG is a common contact, P _L is a parking contact connected to the common contact IG when the parking range is selected, and _RL is a reverse contact connected to the common contact IG when the reverse range is selected. Contact, N _L is a neutral contact connected to the common contact IG when the neutral range is selected, D _L is a forward contact connected to the common contact IG when the forward range is selected, and _LL is a low range This is a low contact that is connected to the common contact IG when the contact is made.

[0008] The parking contact P _L , the reverse contact R
_L , neutral contact N _L , forward contact D _L, and low contact L _L are all arranged on the same circumference, and are independently connected to a common contact IG. Turns on one-on-one.

[0009]

However, in the conventional electric vehicle, for example, when switching from the forward range to the reverse range (hereinafter referred to as "D → R shift"), the shift lever 1 is moved to the reverse contact R. _As soon as _L is reached, the driving direction of the motor is reversed.
In this case, an excessive engine braking state and an excessive regenerative state occur, so that not only the shift feeling but also the durability of the motor decreases.

The present invention solves the above-described problems of the conventional electric vehicle, and does not reduce the shift feeling and the durability of the motor when the shift lever is operated to switch the range. It is an object to provide an electric vehicle.

[0011]

For this purpose, in the electric vehicle according to the present invention, a vehicle speed detecting means for detecting a vehicle speed, an accelerator opening detecting means for detecting an accelerator opening, and a range selecting means for selecting a range. A shift sensor that detects a selected range, an output torque command value calculation unit that calculates an output torque command value from the detected vehicle speed and accelerator opening, and a traveling direction determination unit that determines the traveling direction of the electric vehicle. Have.

When the absolute value of the vehicle speed is equal to or greater than a predetermined value, the output torque command value calculating means outputs the output torque command value when the range in which the driving direction is reversed is changed. To 0.

In another electric vehicle according to the present invention, the output torque command value calculating means may further comprise: when the vehicle speed is negative, when the range is switched from the reverse range to the forward travel range. , The output torque command value is set to zero.

In still another electric vehicle according to the present invention, the output torque command value calculating means may further comprise: when the range is switched from the forward traveling range to the reverse range when the vehicle speed is positive. Then, the output torque command value is set to 0.

In still another electric vehicle according to the present invention, the output torque command value calculating means may further include a step of switching the range when the absolute value of the vehicle speed becomes smaller than a preset value. The output torque command value according to the range is output.

[0016]

According to the present invention, in the electric vehicle as described above, the vehicle speed detecting means for detecting the vehicle speed,
Accelerator opening detecting means for detecting the accelerator opening, range selecting means for selecting a range, a shift sensor for detecting the selected range, and an output for calculating an output torque command value from the detected vehicle speed and accelerator opening The vehicle includes a torque command value calculating unit and a traveling direction determining unit that determines a traveling direction of the electric vehicle.

The output torque command value calculating means, when the absolute value of the vehicle speed is equal to or greater than a predetermined value, changes the output torque command value when the range in which the driving direction is reversed is changed. To 0.

In this case, if the absolute value of the vehicle speed is equal to or higher than a preset value and the range of the driving direction is switched, the output torque command value is set to zero.

Therefore, since the driving direction of the motor cannot be reversed, it is possible to prevent an excessive engine braking state and an excessive regeneration state from occurring. as a result,
The shift feeling does not decrease, and the durability of the motor does not decrease.

[0020]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram of an electric vehicle according to an embodiment of the present invention, and FIG. 2 is an operation explanatory diagram of a shift sensor according to the embodiment of the present invention. In FIG. 2, (a) shows the contacts of the shift sensor, and (b) shows the operation of the shift sensor.

In FIG. 1, reference numeral 11 denotes a CP (not shown).
Output torque control device composed of U, RAM, ROM, etc., 1
2 is a vehicle speed detecting means including, for example, a motor speed sensor for detecting an absolute position of a rotating body in the motor 21;
Reference numeral 13 denotes an accelerator opening detecting means comprising an accelerator sensor or the like for detecting the accelerator opening based on the amount of depression of an accelerator pedal (not shown). Reference numeral 14 denotes a range selected by the driver operating a shift lever described later to change the range of the shift lever. This is a shift sensor that detects a position, that is, a range position.

Reference numeral 12a denotes a vehicle speed calculating means for calculating a vehicle speed based on a temporal change amount of the position detected by the vehicle speed detecting means 12, and 16 denotes a vehicle speed calculating means 12a.
Traveling direction determining means for determining the traveling direction of the electric vehicle based on whether the change in the position detected by the vehicle is positive or negative.

An accelerator opening calculating means 13a calculates an accelerator opening based on the signal sent from the accelerator opening detecting means 13, and a selector 14a selects the accelerator opening based on a range position signal from the shift sensor 14. This is a range determining means for determining the set range.

Reference numeral 15 denotes output torque command value / drive direction calculation means, which comprises output torque command value calculation means 15a and drive direction calculation means 15b. The output torque command value calculation means 15a receives the signal of the vehicle speed calculated by the vehicle speed calculation means 12a and the signal of the accelerator opening calculated by the accelerator opening calculation means 13a, and calculates an output torque command value. Further, the driving direction calculating means 15b
Is the vehicle speed signal, the range signal determined by the range position determining means 14a, and the traveling direction determining means 16
The driving direction of the motor 21 is calculated based on the signal of the traveling direction of the electric vehicle determined by the above.

Reference numeral 17 denotes output torque command value output means for outputting the output torque command value and drive direction calculated by the output torque command value / drive direction calculation means 15 to the motor 21. When the motor 21 receives the output torque command value and the driving direction from the output torque command value output means 17, the corresponding motor current is supplied and driven to generate the output torque.

Next, the shift sensor 14 will be described.

In FIG. 2, reference numeral 3 denotes a shift lever as range selection means for selecting a range, and reference numeral 14 denotes a double shift sensor having a gray code type output pattern and a one-to-one type output pattern. In the shift sensor 14, the shift lever 3 is located at each of a parking range (P), a reverse range (R), a neutral range (N), a forward range (D), and a low range (L).

IG is a common contact, NS is a parking contact connected to the common contact IG when the parking range is selected, and a neutral contact is connected to the common contact IG when the neutral range is selected. B
L is a reverse contact which is connected to the common contact IG when the reverse range is selected. The parking contact, the neutral contact NS, and the reverse contact BL are one-to-one.
Form the output pattern of the expression. These are independently connected to the common contact IG, and are turned on one-to-one with respect to the position of the shift lever 3.

A to C and PA are contacts that form a gray code type output pattern, and operate as shown in FIG. 3B to be turned on corresponding to each range position.

As described above, since the double output pattern is formed concentrically on the shift sensor 14, the probability of erroneously determining the range position is reduced even if a poor contact or noise occurs.

When the shift lever 3 passes through the dead zone of the shift sensor 14, the output torque control device 11
The sensor input from the shift sensor 14 to (FIG. 1) becomes indefinite. In this case, if the fail-safe processing is performed and the output torque command value is set to 0, a torque loss state occurs, so that the shift feeling decreases.

Then, when the sensor input becomes unstable,
The previous range is maintained for a certain period of time.

Next, the operation of the electric vehicle will be described.

FIG. 3 is a first flowchart showing the operation of the electric vehicle according to the embodiment of the present invention, FIG. 4 is a second flowchart showing the operation of the electric vehicle according to the embodiment of the present invention, and FIG. FIG. 6 is a diagram showing an output torque command value map of the electric vehicle in the example, and FIG. 6 is a diagram showing a torque output rate map of the electric vehicle in the embodiment of the present invention. In FIG. 5, the horizontal axis represents the vehicle speed, the vertical axis represents the output torque command value, and the horizontal axis represents the accelerator opening, and the vertical axis represents the torque output rate.

When the sensor input from the shift sensor 14 (FIG. 1) becomes unstable, the range determining means 14a notifies the output torque command value / drive direction calculating means 15 of the uncertainty of the sensor input. The output torque command value / drive direction calculation means 15 measures an indefinite time after the sensor input becomes indefinite by a timer (not shown) for measuring indefinite time,
If the indefinite time is, for example, 1 [sec] or more, the output torque command value / drive direction calculation means 15 performs a fail-safe process, sets the output torque command value to 0 or a value close to 0, and operates using a lamp or the like. Warn the person.

If the indefinite time is less than 1 [sec], the output torque command value / drive direction calculation means 1
5 saves the previous shift position data M _OLD as the current shift position data M _NEW and does not switch the range even though the shift lever 3 is operated.

If the sensor input from the shift sensor 14 is not uncertain, the timer is reset and the current shift position data M _NEW received as a range signal from the range determining means 14a is saved. Switch the range according to the operation.

When the range is switched in the forward range or the reverse range, and the driving direction of the motor 21 is reversed, an excessive engine braking state and an excessive regenerative state occur, and only the shift feeling deteriorates. As a result, the durability of the motor 21 also decreases.
Therefore, the driving direction calculating means 15b prevents the direction of the motor 21 from being immediately reversed in the forward range or the reverse range.

[0040] That is, the current shift position data M _NEW by neutral range, that is, the neutral range or the parking range is selected, copies the current shift position data M _NEW to the previous shift position data M _OLD. As a result, the neutral range or the parking range is determined, and switching to the neutral range or the parking range is performed.

The current shift position data M
_{When the} forward traveling range, that is, the forward range or the low range is selected by _NEW , if the previous range is the forward range or the low range, the current shift position data _MNEW is copied to the previous shift position data _MOLD . Thus, the forward range or the low range is determined, and switching to the forward range or the low range is performed.

On the other hand, if the previous range is other than the forward range or the low range, and the vehicle speed is, for example, -5 [km]
/ H] or less (absolute value is 5 km / h or more)
The driving direction of the motor 21 is not reversed. Therefore, switching of the range between the forward range or the low range and the reverse range is prohibited, that is, the current shift position data M _NEW is canceled, and the data of the neutral range or the parking range is forcibly changed to the previous shift position. The data is written into the data _MOLD to determine the neutral range or the parking range.

On the other hand, if the vehicle speed is higher than -5 [km / h], it is determined that the driving direction of the motor 21 may be reversed, and the current shift position data M _NEW is _added to the previous shift position data M _OLD. The forward range or the low range after the copy and range switching are performed is determined.

The current shift position data M
_NEWIf the reverse range is selected by
If the current position is in reverse, the previous shift position
Data M _OLDThe current shift position data M_NEWThe
To This determines the reverse range,
Maintain the reverse range.

On the other hand, when the previous range is other than the reverse range and the vehicle speed is, for example, 5 km / h or more (the absolute value is 5 km / h or more), the driving direction of the motor 21 is changed. Should not be inverted. For this purpose, the current shift position data M _NEW is canceled, the neutral range or parking range data is forcibly written to the previous shift position data M _OLD , and the neutral range or parking range is determined.

On the other hand, when the vehicle speed is lower than 5 [km / h], it is determined that the driving direction of the motor 21 may be reversed.
The current shift position data _MNEW is copied to the previous shift position data _MOLD, and the reverse range after the range switching is performed is determined.

Next, the output torque command value calculating means 15a
Calculates the output torque command value with reference to a forward map (not shown) if the range thus determined is the forward range or the low range, and to a reverse map (not shown) if the range is the reverse range. In the case of the neutral range or the parking range, the output torque command value is set to 0. Then, the output torque command value / drive direction calculation means 15 outputs the output torque command value to the motor 21.

When calculating the output torque command value in the output torque command value calculation means 15a, first, referring to the output torque command value map shown in FIG. 5, the output torque command value when the accelerator opening is 100% is used. An output torque command value corresponding to the vehicle speed at the time is calculated. Next, referring to the torque output rate map shown in FIG. 6, a torque output rate corresponding to the accelerator opening at that time is calculated.

The accelerator opening is 100%.
The output torque command value can be calculated by multiplying the output torque command value at time by the torque output rate. In this case, different output torque command value maps and different torque output rate maps are set for the forward range and the reverse range.

As described above, when the absolute value of the vehicle speed is equal to or greater than the preset value, switching of the forward range or the range between the low range and the reverse range is prohibited, and the neutral range is determined. Cannot be reversed.

Therefore, since the excessive engine braking state and the excessive regenerative state do not occur, the shift feeling does not decrease and the durability of the motor 21 does not decrease.

Next, the flowchart will be described. Step S1 The accelerator opening calculating means 13a calculates the accelerator opening from the signal of the accelerator pedal depression amount. Step S2 The vehicle speed calculation means 12a calculates the vehicle speed from the temporal change of the absolute position of the rotating body, and the traveling direction determination means 16 determines the traveling direction. Step S3: A sensor input from the shift sensor 14 is made to the range determining means 14a. Step S4 Output torque command value / drive direction calculation means 1
5 determines whether the sensor input from the shift sensor 14 is indeterminate. If the sensor input is indeterminate, the process proceeds to step S5; otherwise, the process proceeds to step S8. Step S5: It is determined whether or not the indefinite time measured by the indefinite time measurement timer is 1 [sec] or more. If the indefinite time is 1 [sec] or more, step S6
If it is less than 1 [sec], the process proceeds to step S7. Step S6: Perform fail-safe processing and end the processing. Step S7 The current shift position data _MNEW is copied to the previous shift position data _MOLD , and the process proceeds to step S10. Step S8: The timer for measuring the indefinite time is reset. Step S9 The current shift position data M _NEW is saved. Step S10 Current shift position data M _NEW
Is in which range. If it is the reverse range data, the process proceeds to step S11. If it is the neutral range data and the parking range data, the process proceeds to step S14. If it is the forward range data and the low range data, the process proceeds to step S15. Step S11 Previous shift position data M _OLD
Is determined to be in the reverse range. If the previous shift position data M _OLD is data in the reverse range, the process proceeds to step S13, and if not, the process proceeds to step S12. Step S12: It is determined whether the vehicle speed is 5 [km / h] or more. When the vehicle speed is 5 [km / h] or more, the process proceeds to step S14, and when the vehicle speed is lower than 5 [km / h], the process proceeds to step S13. Step S13 Previous shift position data M _OLD
To the reverse range data. Step S14 Previous shift position data M _OLD
Is set to neutral range data or parking range data. Step S15 Previous shift position data M _OLD
Is the data of the forward range or the data of the low range. If the data is forward range data or low range data, step S17 is performed. If it is not forward range data or low range data, step S17 is performed.
Proceed to 16. Step S16: It is determined whether or not the vehicle speed is -5 [km / h] or less. When the vehicle speed is lower than -5 [km / h], the process proceeds to step S14, and when the vehicle speed is higher than -5 [km / h], the process proceeds to step S17. Step S17 Previous shift position data M _OLD
Into forward range data or low range data. Step S18 Previous shift position data M _OLD
Is in which range. If the previous shift position data M _OLD is data in the reverse range, the flow proceeds to step S19. If the data is data in the neutral range or parking range, the flow proceeds to step S19.
If the data is forward range data or low range data, the process proceeds to step S21. Step S19 The output torque command value calculation means 15a of the output torque command value / drive direction calculation means 15 calculates the output torque command value with reference to the reverse map. Step S20 The output torque command value is set to 0. Step S21 The output torque command value calculation means 15a of the output torque command value / drive direction calculation means 15 calculates the output torque command value with reference to the forward map. Step S22: The output torque command value and the driving direction are output to the motor 21.

In this embodiment, the forward traveling range is described as being constituted by the forward range and the low range. However, the forward traveling range may also include a second range and the like.

The present invention is not limited to the above-described embodiment, but can be variously modified based on the gist of the present invention, and they are not excluded from the scope of the present invention.

[Brief description of the drawings]

FIG. 1 is a block diagram of an electric vehicle according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an operation of the shift sensor according to the embodiment of the present invention.

FIG. 3 is a first flowchart illustrating an operation of the electric vehicle according to the embodiment of the present invention.

FIG. 4 is a second flowchart showing the operation of the electric vehicle according to the embodiment of the present invention.

FIG. 5 is a diagram showing an output torque command value map of the electric vehicle according to the embodiment of the present invention.

FIG. 6 is a diagram showing a torque output rate map of the electric vehicle according to the embodiment of the present invention.

FIG. 7 is an operation explanatory diagram of a shift sensor used in a conventional electric vehicle.

[Explanation of symbols]

 Reference Signs List 3 shift lever 12 vehicle speed detecting means 13 accelerator opening degree detecting means 14 shift sensor 15a output torque command value calculating means 16 traveling direction judging means

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Yukihiro Minesawa 10 Takane, Fujii-machi, Anjo, Aichi Prefecture Inside Aisin AW Co., Ltd. (72) Inventor Hiroyuki Kojima 10 Takane, Fujii-machi, Anjo, Aichi Prefecture Aishi Inside AW Co., Ltd. (72) Inventor Akira Suzuki 10 Takane, Fujiicho, Anjo-shi, Aichi Prefecture Inside Aisin-AW Co., Ltd. (72) Toshiyuki Sekimori 1st Toyota Town, Toyota City, Aichi Prefecture Toyota (72) Inventor Junwa Shamoto 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation

Claims (4)

[Claims] 1. A vehicle speed detecting means for detecting a vehicle speed; an accelerator opening detecting means for detecting an accelerator opening; a range selecting means for selecting a range; a shift sensor for detecting a selected range; Output torque command value calculating means for calculating an output torque command value from the vehicle speed and accelerator opening, and a traveling direction determining means for determining the traveling direction of the electric vehicle, the output torque command value calculating means,
An electric vehicle wherein the output torque command value is set to 0 when the range in which the driving direction is reversed is changed when the absolute value of the vehicle speed is equal to or greater than a preset value. 2. The output torque command value calculation means sets the output torque command value to 0 when the range is switched from a reverse range to a forward travel range when the vehicle speed is negative. Item 2. The electric vehicle according to item 1. 3. The output torque command value calculating means sets the output torque command value to 0 when the range is switched from a forward traveling range to a reverse range when the vehicle speed is positive. Item 2. The electric vehicle according to item 1. 4. The output torque command value calculating means outputs an output torque command value according to the range after the range has been switched when the absolute value of the vehicle speed becomes smaller than a preset value. The electric vehicle according to claim 1.