JP3179585B2 - Electric vehicle - Google Patents

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,
By operating the shift lever, forward range, reverse range,
A neutral range or the like can be selected, and the output torque of the motor can be controlled by depressing an accelerator pedal or the like.

In this case, a shift sensor is provided to detect the position of the shift lever, that is, the range position.
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 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. (A) of the figure shows the contact of the shift sensor, and (b) shows the operation of the shift sensor. In the figure, reference numeral 1 denotes a slide contact connected to a shift lever (hereinafter, referred to as "shift lever"), and reference numeral 2 denotes a shift sensor. In the shift sensor 2, the shift lever 1
In the parking range (P), the reverse range (R), the neutral range (N), the forward range (D), and the 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 R _L 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.

[0006] The parking for the contact P _L, 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.

[0007]

However, in the conventional electric vehicle, since the shift sensor 2 is of a single-system independent contact type, when the shift lever 1 is operated, for example, from the forward range to the low range. When switching (hereinafter referred to as “D → L shift”), the shift lever 1 passes through the dead zone of the shift sensor 2 for a very short time. That is, in the middle of the forward contact point D _L and low contact points L _L shift lever 1 when the position sensor output becomes off.

In this case, in the output torque control device, since the sensor input from the shift sensor 2 becomes unstable, fail safe processing is performed to set the output torque command value to zero. During this time the time very short, when the shift lever 1 reaches the low contact points L _L, but the sensor output is turned on, the torque loss condition occurs during running, shift feeling is deteriorated.

Further, for example, when switching from the forward range to the reverse range (hereinafter referred to as “D → R shift”),
As soon as the shift lever 1 reaches the reverse contact _RL , 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 is reduced but also the durability of the motor is reduced.

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, and calculates an output torque command value from the detected vehicle speed and accelerator opening, and when the indefinite time of the sensor input from the shift sensor is shorter than a preset time. Has an output torque command value calculation means for maintaining the previous range and setting the output torque command value to 0 or a value almost close to 0 when a predetermined time or more is reached.

[0012]

[0013]

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 calculating an output torque command value from the detected vehicle speed and accelerator opening. When the indefinite time of the sensor input from the shift sensor is shorter than a preset time, the previous range is maintained, and when the preset time is exceeded, the output torque command value is set to 0 or a value close to almost 0. Output torque command value calculating means.

In this case, if the indefinite time of the sensor input from the shift sensor is shorter than the preset time, the previous range is maintained, and if it becomes longer than the preset time, the output torque command value becomes zero or almost zero. It is set to a value close to zero.

Therefore, when the range selection means passes through the dead zone of the shift sensor when selecting a range, even if the sensor output becomes temporarily unstable, the previous range is maintained and the vehicle is driven. No torque loss occurs during running, and the shift feeling does not decrease.

[0016]

[0017]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram of an output torque control device for an electric vehicle according to an embodiment of the present invention, and FIG. 2 is an operation explanatory diagram of a shift sensor used in the electric vehicle of the present invention. FIG. 2A shows the contacts of the shift sensor, and FIG. 2B shows the operation of the shift sensor.

In FIG. 1, reference numeral 11 denotes a CPU (not shown),
An output torque control device comprising a RAM, a ROM, etc., 12 is a vehicle speed detecting means for detecting the vehicle speed of the electric vehicle by, for example, a motor speed sensor (not shown) for detecting an absolute position of a rotating body inside the motor 21, and 13 Accelerator opening detecting means such as an accelerator sensor (not shown) that detects the accelerator opening based on the depression amount of an accelerator pedal (not shown), and a shift lever position, which is selected by a driver operating a shift lever described later, is described below. That is, it is a shift sensor that detects at the range position.

Reference numeral 12a denotes a vehicle speed calculating means for calculating a vehicle speed based on a temporal change amount of the absolute position of the rotating body from the vehicle speed detecting means 12, and 16 denotes a vehicle speed calculating means 12a.
Is a traveling direction determining unit that determines the traveling direction of the electric vehicle based on whether the absolute position change of the rotating body from the vehicle speed detecting unit 12 is positive or negative. 13a is an accelerator opening calculating means for calculating an accelerator opening based on a signal of an accelerator pedal depression amount from the accelerator opening detecting means 13, and 14a is selected by a range position signal from the shift sensor 14. Range determination means for determining the 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 calculation means 15b outputs the signal of the vehicle speed,
The driving direction of the motor 21 is calculated by receiving the signal of the range determined by the range position determining means 14a and the signal of the traveling direction determined by the traveling direction determining means 16.

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 unit 17, the motor 21 is driven by supplying the corresponding motor current and generates the output torque.

Next, a shift sensor 14 used in an electric vehicle according to an embodiment of the present invention will be described. In FIG. 2, reference numeral 3 denotes a shift lever, and reference numeral 14 denotes a double shift sensor having a gray code output pattern and a one-to-one output pattern. In the shift sensor 14, the shift lever 3 is moved to the parking range (P), the reverse range (R), the neutral range (N), and the forward range (D).
And the 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 BL connected to the common contact IG when the neutral range is selected.
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 form a one-to-one output pattern. 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 1.

A to C and PA are contacts for forming a gray code type output pattern, and operate as shown in FIG. 3B to turn 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 contact failure 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. Therefore, when the sensor input becomes unstable, the previous range is maintained for a fixed time.

Next, the operation of the electric vehicle according to the embodiment of the present invention will be described. 3 is a first flowchart illustrating the operation of the electric vehicle according to the embodiment of the present invention, FIG. 4 is a second flowchart illustrating the operation of the electric vehicle according to the embodiment of the present invention, and FIG. FIG. 6 is a diagram illustrating a vehicle output torque command value map, and FIG. 6 is a diagram illustrating a torque output rate map of the electric vehicle according to the embodiment of the present invention.

When the sensor input from the shift sensor 14 (FIG. 1) becomes unstable, the range judging means 14a notifies the output torque command value / driving direction calculating means 15 of it. The output torque command value / drive direction calculation means 15 measures an indefinite time after the sensor input becomes indefinite by the indefinite time measurement timer, and the indefinite time is, for example, 1 [s].
ec] or more, the output torque command value / drive direction calculation means 15 is notified of it.

On the other hand, 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 warns the driver with a lamp or the like. In addition, the indefinite time is 1 [se
c], the output torque command value / drive direction calculation means 15 outputs the previous shift position data M _OLD.
Is saved as the current shift position data M _NEW , and the range is not switched even though the shift lever 3 is operated.

If the sensor input from the shift sensor 14 is not uncertain, the timer is reset, the current shift position data M _NEW received as a range signal from the range determining means 14a is saved, and the shift lever 3 Switch the range according to the operation. By the way, when the range is switched during 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 regenerating state occur,
Not only does the shift feeling decrease, but also the durability of the motor 21 decreases. Therefore, the drive direction calculating means 15b of the output torque command value / drive direction calculating means 15
Is the motor 21 in the forward range or the reverse range.
Is not reversed immediately.

[0030] 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, the current shift position data M _NEW is canceled, the neutral range or parking range data is forcibly written into the current shift position data M _OLD , and the neutral range or the parking range is determined.

On the other hand, when the vehicle speed is higher than -5 [km / h],
In this case, it is determined that the driving direction of the motor 21 may be reversed.
And the previous shift position data M_OLDThis shift
Position data M_NEWCopy the forward range or
Determine the low range. Also, this shift position
Data M_NEWIf the reverse range is selected by
If the previous range is the reverse range, the previous shift position
Option data M _OLDThe current shift position data M
_NEWCopy This defines 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. Not to be inverted. Therefore, the current shift position data M _NEW is canceled, the neutral range or parking range data is forcibly written into the current shift position data M _OLD , and the neutral range or the 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.
This shift position data _MNEW is copied to the previous shift position data _MOLD , and the reverse range is determined. Next, the output torque command value calculating means 15a in the output torque command value / drive direction calculating means 15 outputs a forward map (not shown) when the range thus determined is the forward range or the low range, in the reverse range. In some cases, the output torque command value is calculated with reference to a reverse map (not shown). In the case of the neutral range or the parking range, the output torque command value is set to 0 and is output 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 of FIG.
An output torque command value corresponding to the current vehicle speed at 0% is calculated. Next, a torque output rate corresponding to the accelerator opening at that time is calculated with reference to the torque output rate map of FIG.

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. 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 uncertain, go to step S5.
If not, 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. 1
If it is equal to or longer than [sec], 1 [se
c], the process proceeds to step S7. Step S6: Perform fail-safe 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 forward range data and the low range data, the process proceeds to step S15. If it is the neutral range data and the parking range data, the process proceeds to step S14. Step S11 Previous shift position data M _OLD
Is the data of the reverse range. If the data is in the reverse range, the process proceeds to step S13; otherwise, the process proceeds to step S12. Step S12: It is determined whether or not the vehicle speed is 5 [km / h] or more. If it is 5 [km / h] or more, step S14 is performed. If it is lower than 5 [km / h], step S14 is performed.
Proceed to 13. Step S13: The shift position data M _{OLD is set} to the reverse range data. Step S14: The 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 S1 is performed.
Proceed to 6. Step S16: It is determined whether or not the vehicle speed is lower than -5 [km / h]. If it is lower than -5 [km / h], the operation proceeds to step S14, and if it is higher than -5 [km / h], the operation proceeds to step S17. Step S17 The shift position data M _{OLD is changed} to forward range data or low range data. Step S18: It is determined whether or not the range of the shift position data M _OLD is data. If the data is in the reverse range, the process proceeds to step S19. If the data is in the neutral range or the parking range, the process proceeds to step S20. If the data is in the forward range or the low range, 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: Set the output torque command value 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 the present embodiment, the forward traveling range is described as being constituted by the forward range and the low range, but it is also possible to include a second range and the like. It should be noted that the present invention is not limited to the above-described embodiments, 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 output torque control device for an electric vehicle according to an embodiment of the present invention.

FIG. 2 is an operation explanatory view of a shift sensor used in the electric vehicle according to 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 detecting means 14 shift sensor 15a output torque command value calculating means 15b driving direction calculating means 16 traveling direction determining means

──────────────────────────────────────────────────の Continued on the front page (72) Inventor Hiroyuki Kojima 10 Takane, Fujii-machi, Anjo, Aichi Prefecture Inside Aisin AW Co., Ltd. (72) Inventor Akira Suzuki 10 Takane, Fujii-cho, Anjo, Aichi Aisin・ AW Co., Ltd. (72) Inventor Toshiyuki Sekimori 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Co., Ltd. (72) Inventor Junwa Company 1 Toyota Town Toyota City, Aichi Prefecture Toyota Motor Stock In-house examiner Takayuki Chima (56) References JP-A-50-48613 (JP, A) JP-A-59-226601 (JP, A) JP-A-51-122212 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) B60L 1/00-15/42

Claims (1)

(57) [Claims] (A) vehicle speed detecting means for detecting a vehicle speed; (b) accelerator opening detecting means for detecting an accelerator opening; (c) range selecting means for selecting a range; And (e) calculating an output torque command value from the detected vehicle speed and accelerator opening, and when the indefinite time of the sensor input from the shift sensor is shorter than a preset time. Maintains the previous range, and when the time exceeds a preset time, sets the output torque command value to 0 or almost 0.
An output torque command value calculation means for setting the output torque command value to a value close to.