JPH10174213A - Control apparatus for electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a control apparatus which can obtain the same acceleration and deceleration feeling as an engine-driven vehicle when an electric vehicle is accelerated and decelerated. SOLUTION: When a vehicle is started, an accelerator operating amount Ac is at a prescribed judgment value Ac0 (e.g. about 90%) or higher, and a change speed ΔAc is at a prescribed judgment value ΔAc0 (e.g. about 300%/sec) or higher. Then, the torque instruction value T* of an electrically driven motor is increased to be a peak shape by a torque correction amount ΔTA which is decided in advance when the instruction value is increased. Even in a forward running operation or a regenerative control operation, the torque instruction value T* is changed to be a peak shape when a prescribed peak-control execution condition is satisfied.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an electric vehicle, and more particularly to peak control for temporarily increasing or decreasing the torque of an electric motor at the time of starting or the like.

[0002]

2. Description of the Related Art In recent years, electric vehicles that run using an electric motor as a power source have been proposed as measures against environmental problems caused by exhaust gas. Such an electric vehicle has torque control means for controlling the torque of the electric motor (including not only a positive power running torque but also a negative regenerative torque) according to an operating state such as an accelerator operation amount. In general, the torque of the electric motor is smoothly controlled in accordance with

[0003]

However, if the torque of the electric motor is smoothly controlled as described above, it may occur at the time of sudden acceleration at the time of starting or the like, or at the time of switching to regenerative braking (corresponding to the engine brake of an engine-driven vehicle). Unlike the engine-driven vehicles, which are often used today,
There is a possibility that the driver may feel uncomfortable. That is, in the case of an engine-driven automatic vehicle equipped with a torque converter, when the accelerator operation amount is suddenly increased, the drive torque is temporarily (peak-like) increased by the action of the torque converter. Since there is no torque increasing mechanism such as a torque converter, only the power running torque of the electric motor is generated, and even if the actual acceleration of the vehicle is substantially the same, the feeling of acceleration given to the driver may be insufficient. The same applies to deceleration by engine braking. When switching (at the start of engine braking), the braking torque temporarily (peak-like) increases due to the inertia of the engine, etc., whereas in electric vehicles, the regenerative torque of the electric motor is generated. Therefore, even if the actual decelerations are substantially the same, the driver may not have enough deceleration feeling.

[0004] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an acceleration / deceleration feeling similar to that of an engine-driven vehicle during acceleration / deceleration.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a control device for an electric vehicle running by using an electric motor as a power source, wherein the power running torque of the electric motor is temporarily reduced at a predetermined acceleration. Peak control means for temporarily increasing the regenerative torque of the electric motor at the time of predetermined deceleration. In addition,
In the present specification, the regenerative torque in the direction that prevents the rotation of the electric motor is regarded as negative, and temporarily reducing the regenerative torque means increasing the absolute value of the regenerative torque to obtain a larger vehicle braking force. Means to be able to

[0006]

In such a control device for an electric vehicle, the power running torque of the electric motor is temporarily increased at a predetermined acceleration, or the regenerative torque of the electric motor is temporarily reduced at a predetermined deceleration. Therefore, the same acceleration / deceleration feeling as that of the engine-driven vehicle can be obtained, and the sense of discomfort is eliminated.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Here, the present invention does not include a transmission having a plurality of speed stages having different speed ratios, and transmits power to drive wheels at a constant speed reduction ratio from an electric motor. It is suitably applied to a direct connection type electric vehicle. That is,
If the transmission is provided, if the transmission is downshifted during regenerative braking, the inertia of each part of the transmission temporarily increases the braking force, so the need for the peak control means of the present invention is somewhat reduced. It becomes.

The present invention can be applied not only to a pure electric vehicle that runs using only an electric motor as a power source, but also to a so-called hybrid vehicle equipped with an electric motor and an engine. Regarding the torque control of the electric motor, various physical quantities that can control the torque of the electric motor, such as a torque command value and a motor current value, can be controlled.

A preferred embodiment of the present invention is a control device for an electric vehicle running by using an electric motor as a power source,
(a) temporarily increasing the powering torque of the electric motor at a predetermined acceleration, or determining whether peak control for temporarily reducing the regenerative torque of the electric motor at a predetermined deceleration is required, or not. It is characterized in that it has a judgment means for judging according to a peak control execution condition, and (b) peak control means for performing peak control when the judgment means judges that the peak control is necessary.

The peak control means may perform peak control of motor torque (powering torque or regenerative torque) at least during acceleration and deceleration.
For example, peak control may be performed only when the vehicle starts moving at a predetermined vehicle speed or lower. Further, a temporary increase or decrease in the powering torque or the regenerative torque means that the torque changes in a peak manner, and the control time (increase time or decrease time) thereof is extremely short, for example, several seconds (2 to 3 seconds). It is set to less than degree. The control time and the amount of change in torque (torque correction amount) may be changed depending on the speed of change of the accelerator operation amount, and the operating state such as acceleration or deceleration (during regenerative braking).

The conditions for executing the peak control during acceleration include a predetermined constant peak, which is relatively large, both of which are a driver's output demand such as an accelerator operation amount and a change speed of the output demand. It is set to execute peak control in the control area. The peak control may be performed when a peak request operation means such as a kick down switch that is turned on when the accelerator operation amount becomes substantially maximum is turned on by the driver. The timing at which the powering torque is temporarily increased is, for example, after a predetermined time elapses from the time point when the above-described peak control execution condition is satisfied, or when the increasing speed of the motor torque command value by the normal powering torque control starts to decrease. Is set.

The torque correction amount by the peak control is a constant value,
Alternatively, it may be a constant ratio to the powering torque by the normal powering torque control. However, according to a data map or an arithmetic expression using the output request amount and its change speed as parameters, the torque correction amount becomes larger as the output request amount and the change speed become larger. May be gradually increased. Other operating states, such as vehicle speed and motor torque, can be added as parameters for obtaining the torque correction amount. Further, for example, when the accelerator operation amount is the maximum, it is also possible to temporarily increase the torque value beyond the normal torque use area. The peak control of the present invention is only required to be able to give the driver an acceleration feeling. For example, about 1 second, and at most about a few seconds, is sufficient, and the motor torque is increased beyond the normal torque use area. No problem. In addition, the motor temperature and the inverter (motor drive control circuit) temperature are monitored in anticipation of the temperature rise due to the peak control, and a peak control prohibiting means for prohibiting the peak control when the temperature is higher than a predetermined value may be provided. desirable.

The peak control execution condition at the time of deceleration is set so that the peak control is always executed when the regenerative torque control is executed while satisfying, for example, a predetermined regenerative control condition for generating the regenerative torque. Regeneration selection means, such as a shift lever, that allows the driver to select and operate regenerative torque control, is ON
Only during operation, peak control is performed at the time of regenerative torque control performed based on the ON operation, and peak control is not performed at the time of regenerative torque control performed irrespective of operation of the regenerative selection means such as at the time of brake operation. You may do it. Furthermore, when the driver's output request amount such as the accelerator operation amount is 0 and the regenerative selection means is operated from OFF to ON to execute regenerative torque control, the driver wants the braking force by the regenerative torque control. Peak control may be performed only when it is clear that the When the magnitude of the regenerative torque can be switched in a stepwise manner, the peak control may be performed every time the regenerative torque is reduced (increased in absolute value).

The timing for temporarily reducing the regenerative torque is, for example, after a lapse of a predetermined time from the start of the regenerative torque control, or when the decreasing speed of the motor torque command value by the regenerative torque control is small (the inclination with respect to the time axis is gentle) It is set as appropriate, for example, when it starts to grow. Also, the torque correction amount (in this case, the down amount) by the peak control may be a constant value or a fixed ratio to the regenerative torque by the normal regenerative torque control. May be used as a parameter, for example, the larger the vehicle speed, the larger the torque correction amount.

Also, some drivers may not like the torque peak control as in the present invention.
It is desirable to provide a peak control selection switch that can arbitrarily select whether or not to execute peak control by a driver's operation.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram illustrating a control system of an electric vehicle to which the present invention is applied, and FIG. 2 is a skeleton diagram illustrating an example of an electric driving device 10. The electric drive device 10 includes an electric motor 12 and a speed reducer 16. The power output from an output shaft 14 of the electric motor 12 is reduced by a planetary gear type In the differential 18, the driving force is distributed to the left and right drive systems. One of the motive powers passes through the cylindrical output shaft 14, and the intermediate shaft 28 is disposed concentrically with the output shaft 14.
The power is transmitted to a left driving wheel 26L supported by a suspension device (not shown) via a first left constant velocity joint 20L, a left axle 22L, and a second left constant velocity joint 24L, and the other power is transmitted to the right first constant velocity joint 20R. Is transmitted to a right driving wheel 26R supported by a suspension device (not shown) via a right axle 22R and a second right constant velocity joint 24R. The drive wheels 26L and 26R constitute front wheels or rear wheels of an electric vehicle including four wheels.

The electric motor 12 comprises a cylindrical housing 30 and a first side housing 3 fitted at both ends thereof.
The output shaft 14 is housed in a housing including the second and second side housings 34 and the like, and is disposed in a posture parallel to the left and right direction of the vehicle. A stator 36 having a coil is fixed to the inner peripheral surface of the cylindrical housing 30, and a rotor 40 is fixed to the output shaft 14 concentrically with the stator 36. Such an electric motor 12
For example, various motors such as a permanent magnet type AC motor, an induction motor, a synchronous motor, and a DC motor can be used.

As is apparent from FIG.
A sun gear 4S rotatably supported by a sun gear 42S and a carrier 42C connected to the shaft end of the output shaft 14.
The planetary gear device includes a first planetary gear 42P meshing with the second planetary gear 2S, a second planetary gear 44P integral with the first planetary gear 42P, and a fixed ring gear 44R meshing with the second planetary gear 44P. 42
The rotation input to S is reduced according to a predetermined reduction ratio, and is output from the carrier 42C to the ring gear 46R of the planetary gear type differential 18 at the subsequent stage.

The differential device 18 is a double pinion type planetary gear device, and includes a sun gear 46S connected to the left end of the right first constant velocity joint 20R, a ring gear 46R connected to the carrier 42C, a sun gear 46S, and planetary gears 46P ₁ of one and the other with each mesh and a plurality of pairs of mutually meshing of the ring gear 46R, 46P _2, is the planetary gear 46P ₁ of the plurality pairs, the 46P ₂ rotatably supporting and connected to the right end of the intermediate shaft 28 Carrier 46
C is provided. As a result, the differential 18 distributes the power input to the ring gear 46R, and the carrier 46C operatively connected to the left driving wheel 26L and the sun gear 46S operatively connected to the right driving wheel 26R. Output to

Returning to FIG. 1, the electric motor 12 is driven to rotate in both forward and reverse directions by supplying drive power from a power source 50 such as a battery via a motor drive control circuit 52. The motor drive control circuit 52 is an inverter or the like, and controls the powering torque of the electric motor 12 by changing the frequency or current of the drive power in accordance with a command signal ST supplied from the motor control computer 54, The regenerative torque control for storing electric energy generated by the forced rotation of the power supply 12 in the power supply 50 is performed. The motor control computer 54 has a CPU
56, a RAM 58, a ROM 60, a clock signal source 62 such as a crystal oscillator, an A / D converter (not shown), an input / output interface circuit, etc., and a program stored in the ROM 60 in advance using the temporary storage function of the RAM 58. By performing signal processing according to the above, each function shown in FIG. 3 is executed.

The motor control computer 54 includes:
Accelerator operation amount sensor 64, motor rotation speed sensor 6
6, brake switch 68, shift position sensor 7
0, motor temperature sensor 74, inverter temperature sensor 7
6, an EB (engine brake) switch 78 and the like are connected, an accelerator operation amount signal SAc indicating an operation amount Ac of an accelerator pedal, which is a driver output required amount, and an electric motor 12.
, A motor rotation speed signal SNm indicating the rotation speed Nm, a brake signal SB indicating whether or not the brake pedal is depressed, a shift position signal SSh indicating an operation range Sh of the shift lever 72, and a temperature T of the electric motor 12.
m, a motor temperature control signal representing the motor temperature signal STm,
2, an inverter temperature signal STi representing the temperature Ti, and an EB signal SEB representing that the EB switch 78 has been turned ON.
Etc. are respectively supplied. Motor rotation speed sensor 66
Detects the rotation speed Nm by distinguishing between forward rotation of the vehicle moving forward and reverse rotation of the vehicle moving backward. For example, a pair of pulse signals having different phase shifts in forward and reverse rotations are output with the rotation of the motor. Is configured. Motor rotation speed N
m corresponds to the vehicle speed v. The shift lever 72 is disposed near the driver's seat and has a D (drive) range for moving the vehicle forward, an R (reverse) range for moving the vehicle backward, and a P for parking.
In addition to the (parking) range and the N (neutral) range allowing the electric motor 12 to rotate freely, the electric motor 1 applies a braking force similar to that of the engine brake of the engine-driven vehicle.
A selection operation is performed to a B (brake) range or the like generated by the regenerative (power generation) control 2. The EB switch 78 is a switch for generating a braking force smaller than that in the B range by regenerative (power generation) control of the electric motor 12 in the D range, and is disposed on a knob of the shift lever 72, for example.

In FIG. 3, a torque control block 80 functions as a torque control means, calculates a torque command value T ^* according to a torque command value map shown in FIG. 4, and outputs the command signal T ^* representing the torque command value T ^*. It includes a power running torque control unit 80a that outputs ST and drives the electric motor 12 to rotate, and a regenerative torque control unit 80b that controls regeneration (charging) of the electric motor 12. Power torque control section 80a is the accelerator operation amount Ac and the motor rotation speed Nm as a parameter, in normal running to calculate the torque command value T ^* in accordance with power torque command value map M _A in the area indicated by the solid line, uphill, etc. Under a predetermined condition requiring high torque, the torque command value T ^* is calculated by expanding the range shown by a dashed line only within a predetermined time set in advance, and calculating the torque command value T ^* . And outputs a command signal ST.

The regenerative torque control section 80b controls the regenerative control of the electric motor 12 to generate a braking force when a predetermined regenerative control condition is satisfied.
When the switch 78 is ON, the torque command value T ^* is calculated according to the first regenerative torque command value map M _B1 shown by a solid line when the accelerator operation amount Ac is 0, while when the accelerator operation amount Ac is 0, the accelerator operation amount Ac Is 0, the torque command value T is _calculated according to the second regenerative torque command value map M _B2 indicated by the one-dot chain line.
^{* And} outputs a command signal ST representing the torque command value T ^* . The EB switch 78 and the shift lever 72 correspond to regeneration selection means. Regenerative torque control unit 80
b, even when the EB switch 78 is OFF in the D range, when the brake signal SB is ON, a predetermined regenerative torque control is performed to generate a braking force and to charge the power supply 50.

The torque control block 80 basically changes the torque command value T ^* smoothly so as not to cause a shock due to a sudden change in driving force or braking force. The start-time peak control block 82, the running-time peak control block 84, and the regeneration-time peak control block 86 temporarily increase (decrease) the torque command value T ^* at a predetermined acceleration / deceleration, thereby providing the same as an engine-driven vehicle. This is for obtaining a good acceleration / deceleration feeling. Hereinafter, individual peak control blocks 8
2, 84 and 86 will be specifically described.

The start-time peak control block 82 is for temporarily (peak-like) increasing the powering torque at the time of sudden start, and performs signal processing according to the flowchart shown in FIG. Step SA1~SA3 in Figure 5 functions as a determination unit, whether or not the vehicle speed v corresponding to the motor rotation speed Nm respectively predetermined judgment value v ₀ or less, the accelerator operation amount Ac changing speed DerutaAc (time It is determined whether or not (the inclination with respect to the axis) is equal to or greater than a predetermined determination value ΔAc _{0 and} whether or not the accelerator operation amount Ac is equal to or greater than a predetermined determination value Ac ₀ . The determination value v ₀ is set to an extremely low speed of, for example, about 2 to 3 km / h so that it can be determined whether or not the vehicle is starting. The determination value ΔAc ₀ can determine the driver's intention to rapidly accelerate. As described above, a large value of, for example, about 300% / sec is set, and the determination value Ac ₀ is set to, for example, a value of about 90% so that it can be determined whether or not the accelerator pedal is almost completely depressed. These determination values v ₀ , ΔAc ₀ , and Ac ₀ are peak controls for determining whether or not peak control for temporarily increasing normal power running torque controlled by the torque control block 80 at the time of starting is necessary. It corresponds to the execution condition.

Then, the determinations in steps SA1 to SA3 are all YES, that is, v ≦ v ₀ , ΔAc ≧ ΔA
If c ₀ and Ac ≧ Ac ₀ , steps SA4 and thereafter are executed. Step SA4 functions as a peak control prohibiting means, in which the motor temperature Tm and the inverter temperature Ti are set to predetermined determination values Tm ₀ , Ti, respectively.
₀ or less, and Tm ≦ Tm ₀ and Ti
Only when ≦ Ti ₀ , the torque peak control of step SA5 is executed. The determination values Tm ₀ and Ti ₀ are set to predetermined values in advance at temperatures obtained by subtracting the temperature rise due to the torque peak control in step SA5 from the allowable maximum temperatures of the electric motor 12 and the motor drive control circuit 52, respectively. Thus, a failure due to overheating of the electric motor 12 and the motor drive control circuit 52 is avoided.

At Step SA5, the torque of the electric motor 12 is
Function as a peak control means to temporarily increase the
And the torque controlled by the powering torque control unit 80a.
Command value T^*Is temporarily increased. Specifically, power running
Torque command value T controlled by torque control unit 80a^*The
And the torque command value T^*Ascending speed (on the time axis
When the angle of inclination starts to decrease,
Constant torque correction amount ΔT_AOnly increase. The increase time is
In a very short time of about 1 second or less, the torque correction amount ΔT _AFigure 4
Is larger than the range indicated by the dashed line as indicated by the dotted line.
In normal torque control by the powering torque control unit 80a,
Temporarily generates a large powering torque that cannot be obtained.
Note that also in step SA5, the torque command value T
^*Motor temperature until peak control (increase control) of
Tm and the inverter temperature Ti are monitored,
Tm₀, Ti₀Torque peak system
It is designed to stop your control.

FIG. 6 is a time chart showing an example of such a torque peak control at the time of starting. The torque command value T ^* shown by a solid line indicates a case where the normal power running torque control by the power running torque control section 80a is performed. in, the torque correction amount [Delta] T _a indicated by a broken line is due to the torque peak control in step SA5. Time t ₁ is the time the accelerator pedal is started depression, the time t ₂ at the time the determination of step SA1~SA4 becomes all YES, the torque peak control in step SA5 in the time t ₂ after it is executed, The torque command value T ^* controlled by the powering torque control unit 80a is monitored. Time t ₃ is a time when the torque command value T ^* starts to increase by the torque peak control, and time t ₄ is a time when the torque peak control ends.

As described above, in the electric vehicle of the present embodiment, when the predetermined peak control execution condition is satisfied at the time of starting, that is, when all the determinations in steps SA1 to SA3 are YES, step SA4 is YES. The torque peak control of step SA5 is executed on condition that
In order to temporarily generate a large powering torque that cannot be obtained by normal torque control by the powering torque control unit 80a,
An acceleration feeling similar to that of an engine-driven vehicle equipped with a torque converter can be obtained, and the sense of discomfort is eliminated.

Further, even if satisfying the above steps SA1 to SA3, because the determination in step SA4 is NO, the torque peak control in step SA5 it is prohibited in the case of Tm> Tm ₀ or Ti> Ti _0, electric Failure due to overheating of the motor 12 and the motor drive control circuit 52 is avoided.

The running peak control block 84
Power when the driver wants rapid acceleration
For temporarily (peak-like) increase of line torque
Then, signal processing is performed according to the flowchart shown in FIG.
U. In step SB1 of FIG. 7, the vehicle speed v is determined in advance.
Boundary value v₁It is determined whether or not v ≦ v at a relatively low vehicle speed.
₁In step SB2, the torque correction amount ΔT is calculated in step SB2.
On the other hand, relatively high vehicle speed v> v₁If step SB
In step 3, the torque correction amount ΔT is calculated. These steps S
B1 to SB3 function as determination means.

In steps SB2 and SB3, the torque correction amount ΔT is calculated in accordance with the preset torque correction amount maps I and II using the accelerator operation amount Ac and its change speed ΔAc as parameters. Map I is the torque correction amount map on the higher vehicle speed side II
The torque correction amount ΔT is set to be larger than that. The torque correction amount ΔT is determined based on the torque command value T ^* by the powering torque control unit 80a as an increase rate (%) with respect to the torque command value T ^* , and the accelerator operation amount Ac and the change speed ΔAc are determined. In a peak control region (a region above ΔT = 0% in Steps SB2 and SB3) which is equal to or larger than a predetermined value, the torque correction amount ΔT is set to increase as they increase. Outside the peak control region, the torque correction amount ΔT = 0 (%). The boundary value v ₁ and the torque correction amount maps I and II are used to determine whether peak control for temporarily increasing the normal powering torque controlled by the torque control block 80 during running is necessary. This corresponds to a control execution condition.

When the torque correction amount ΔT is set in step SB2 or SB3, ΔT = 0 in step SB4.
(%), And if ΔT = 0 (%), the process is terminated as it is. If ΔT ≠ 0 (%), step SB
Step 5 is executed. Step SB5 is intended to function as a peak control prohibiting means, wherein the motor temperature as in step SA4 Tm and inverter temperature Ti is determined whether the determination value Tm _0, Ti ₀ or less, and at Tm ≦ Tm ₀ Ti If ≦ Ti ₀ , the torque peak control in step SB6 is executed. The determination values Tm ₀ and Ti ₀ may be set to predetermined values based on the allowable maximum temperatures of the electric motor 12 and the motor drive control circuit 52, respectively. However, these values may be set due to the torque peak control in step SB6. It is preferable that the temperature is set by an arithmetic expression or the like according to the torque correction amount ΔT so that the allowable maximum temperature is not exceeded. Step SB6 functions as a peak control means for temporarily increasing the torque of the electric motor 12, and changes the torque command value T ^* controlled by the powering torque control unit 80a, for example, at a predetermined timing. It is temporarily increased by the torque correction amount ΔT. The increase time is set to a very short time, for example, about 1 second or less.

As described above, in the electric vehicle of the present embodiment, when the accelerator operation amount Ac and the change speed ΔAc satisfy the predetermined peak control execution condition during forward running, that is, ΔT is 0 in the torque correction amount map I or II. %, The torque converter is provided to execute the torque peak control in step SB6 on condition that step SB5 is YES and to temporarily increase the normal powering torque by the powering torque control unit 80a. An acceleration feeling similar to that of an engine-driven vehicle can be obtained, and discomfort is eliminated. In particular, in the present embodiment, the torque correction amount ΔT is changed according to the magnitude of the accelerator operation amount Ac and the change speed ΔAc, so that an acceleration feeling closer to that of an engine-driven vehicle can be obtained.

Even if the accelerator operation amount Ac and the change speed ΔAc satisfy predetermined peak control execution conditions, Tm
> Tm ₀ or Ti> Ti ₀ if step SB5
Is NO, and the torque peak control in step SB6 is prohibited, so that a failure or the like due to overheating of the electric motor 12 or the motor drive control circuit 52 is avoided.

FIG. 8 shows a case where the torque correction amount ΔT when the vehicle speed v> v ₁ is set as a parameter with the current torque command value T ^* as compared with the case of FIG. torque command value in SB3-1 T ^* is determined whether the first boundary value T ^* ₀ or less, the torque correction amount in the case of T ^* ≦ T ^* ₀ according to the torque correction amount map II-1 in step SB3-2 Calculate ΔT. If T ^* > T ^* ₀ , it is determined in step SB3-3 whether the torque command value T ^* is equal to or less than the second boundary value T ^* _{1, and} if T ^* ≦ T ^* ₁ , it is determined in step SB3-4. The torque correction amount ΔT is calculated according to the torque correction amount map II-2. If T ^* > T ^* ₁ , the torque correction amount ΔT is set to 0 (%) in step SB3-5. The torque correction amount ΔT is set to be larger in the high torque side torque correction amount map II-2 than in the low torque side torque correction amount map II-1. T ^* ₁ is set at a compatible point between the hardware limit of the electric motor 12 and the acceleration feeling. Steps SB3-1 to SB3-4 function as determination means, and the first boundary value T ^* ₀ , the second boundary value T ^* ₁ , the torque correction amount maps II-1 and II-2 are used for controlling the torque during traveling. This corresponds to a peak control execution condition for determining whether or not peak control for temporarily increasing the normal powering torque controlled by the block 80 is necessary.

In this case, when the vehicle speed v> v ₁ , the torque at that time, that is, the torque command value T ^*, and the accelerator operation amount A
c, since the torque correction amount ΔT is set in relation to the change speed ΔAc, the acceleration feeling can be further improved.

In the examples shown in FIGS. 7 and 8, the torque correction amount map is set with a downwardly convex curve. However, as shown in FIG. 9, a straight line, a broken line, or an upwardly convex curve is shown. It can also be set with such as. Instead of using such a data map, the torque correction amount ΔT may be calculated in accordance with an arithmetic expression using the accelerator operation amount Ac and its change speed ΔAc as parameters, for example, as shown in the following equation (1). . The coefficients k ₁ and k ₂ are set respectively corresponding to the torque correction amount maps I and II, for example. ΔT = f (Ac, ΔAc) = f (k ₁ · Ac + k ₂ · ΔAc) (1)

When the regenerative torque control is performed by the regenerative torque control unit 80b, the regenerative peak control block 86 operates under a predetermined condition, that is, when the driver intentionally desires the regenerative braking, This is for temporarily decreasing (increasing in absolute value) the torque.
Signal processing is performed according to the flowchart shown in FIG. FIG.
In step SC1 of 0, it is determined whether or not the accelerator operation amount Ac ≒ 0. If Ac ≒ 0, in step SC2, the operation range of the shift lever 72 is in the “D” range and the EB switch 78 is turned from OFF to ON. It is determined whether the switching has been performed. When the EB switch 78 is switched from OFF to ON with the accelerator operation amount Ac 量 0, the torque peak control in step SC3 is executed. Steps SC1 and SC2 function as determination means, and the EB switch 78 is operated when the accelerator operation amount AcＡ0.
Is switched from OFF to ON to determine whether peak control for temporarily reducing the normal regenerative torque controlled by the torque control block 80 at the start of the regenerative torque control is necessary. It corresponds to the execution condition.

Here, when the EB switch 78 is switched from OFF to ON with the accelerator operation amount Ac ≒ 0, the regenerative torque control unit 80b controls the first EB switch 78 shown by a solid line in FIG.
Is regenerative torque control is started in accordance with the regenerative torque command value map M _B1, the torque command value T ^*, as indicated by the solid line in time t ₁ after the time chart of FIG. 11, for example 0
Is smoothly lowered by a predetermined torque. The torque peak control in step SC3 functions as peak control means for temporarily reducing (increasing in absolute value) the regenerative torque of the electric motor 12, and the torque command value T controlled by the regenerative torque control unit 80b. ^* Reduce temporarily. Specifically, the torque command value T ^* controlled by the regenerative torque control unit 80b is monitored, and when the descending speed of the torque command value T ^* starts to decrease (gradient with respect to the time axis), Set torque correction amount ΔT
Decrease by _B1 . The torque correction amount ΔT _B1 is previously set to a constant value as shown by a dotted line in FIG. 4, and the control time is an extremely short time of about several seconds (2 to 3 seconds) or less.

If the determination in step SC2 is NO,
That is, the EB switch 78 remains OFF or
If the gear ratio remains N, it is determined in step SC4 whether or not the operation range of the shift lever 72 has been switched from the D range to the B range. Execute control.
Step SC4 functions as a judgment means together with step SC1. When the shift lever 72 is shifted from D to B with the accelerator operation amount Ac ≒ 0, the normal regenerative torque controlled by the torque control block 80 is temporarily reduced. This corresponds to a peak control execution condition for determining whether or not the peak control for reducing the peak is necessary.

Here, when the shift lever 72 is shifted from D to B with the accelerator operation amount Ac ≒ 0, the regenerative torque control unit 80b follows the second regenerative torque command value map M _B2 shown by a dashed line in FIG. regenerative torque control is started, the torque command value T ^*, is caused to smoothly lowered by a predetermined torque, as shown by the solid line in time t ₂ after the time chart of FIG. 11, for example. The torque peak control in step SC5 functions as peak control means for temporarily reducing (increasing in absolute value) the regenerative torque of the electric motor 12, and the torque command value T controlled by the regenerative torque control unit 80b. ^* Reduce temporarily. Specifically, the torque command value T ^* controlled by the regenerative torque control unit 80b is monitored, and when the rate of decrease (inclination with respect to the time axis) of the torque command value T ^* starts to decrease, a preset value is set. It is decreased by the torque correction amount ΔT _B2 . The torque correction amount ΔT _B2 is set to a constant value in advance as shown by a dotted line in FIG. 4, and the control time is an extremely short time of about several seconds (2 to 3 seconds) or less.

As described above, the electric vehicle according to the present embodiment is designed so that when the regeneration (charging) control is performed, the predetermined peak control execution condition is satisfied, that is, the driver obtains the braking force by the regenerative torque control. When the EB switch 78 is turned on or the shift lever 72 is switched from the D range to the B range, the torque peak control of steps SC3 and SC5 is executed, and when the regenerative torque control by the regenerative torque control unit 80b starts. In the event of a decrease (or an increase in absolute value), the regenerative torque is temporarily (peak-like) decreased, so that a relatively large deceleration feeling similar to the engine brake accompanying a downshift of an automatic transmission in an engine-driven vehicle is generated. Can be obtained, and discomfort is eliminated.

The time chart of FIG.
"D" accelerator operation amount EB switch 78 is OFF in the range Ac = 0 becomes, EB switch 7 at time t ₁
8 is switched from OFF to ON, and the shift lever 72 is switched from the “D” range to the “B” range at time t ₂ .

Also in the torque peak control during regeneration, the motor temperature Tm and the inverter temperature Ti may be monitored, and the torque peak control may be stopped if necessary.

Although the embodiments of the present invention have been described in detail with reference to the drawings, this is merely an embodiment, and
For example, the present invention can be applied to a vertical electric vehicle in which the electric motor 12 and the speed reducer 16 are arranged along the front-rear direction of the vehicle, an electric vehicle having a transmission capable of changing the gear ratio, and the like. The invention can be embodied in modes with various changes and improvements based on the knowledge of those skilled in the art.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a control system of an electric vehicle including a control device according to an embodiment of the present invention.

FIG. 2 is a skeleton view illustrating an electric drive device of the electric vehicle of FIG. 1;

FIG. 3 is a block diagram illustrating functions provided in a motor control computer of the electric vehicle in FIG. 1;

FIG. 4 is a diagram illustrating a torque command value map of the electric vehicle of FIG. 1;

FIG. 5 is a flowchart illustrating a specific processing content of a start peak control block in FIG. 3;

FIG. 6 is a time chart illustrating an example of a case where torque peak control is performed at the time of starting according to the flowchart of FIG. 5;

FIG. 7 is a flowchart illustrating specific processing contents of a peak control block during traveling in FIG. 3;

FIG. 8 is a flowchart illustrating another embodiment of step SB3 in FIG. 7;

FIG. 9 is a diagram for explaining another mode of the torque correction amount map in FIGS. 7 and 8;

FIG. 10 is a flowchart illustrating specific processing contents of a regeneration peak control block in FIG. 3;

FIG. 11 is a time chart illustrating an example of a case where torque peak control is performed during regenerative torque control according to the flowchart of FIG. 10;

[Explanation of symbols]

12: Electric motor 54: Motor control computer 82: Starting peak control block 84: Running peak control block 86: Regeneration peak control block Steps SA5, SB6, SC3, SC5: Peak control means

Claims (1)

[Claims] 1. A control device for an electric vehicle that runs by using an electric motor as a power source, wherein a power running torque of the electric motor is temporarily increased at a predetermined acceleration, or a regenerative torque of the electric motor at a predetermined deceleration. A control device for an electric vehicle, comprising: a peak control means for temporarily reducing the power consumption.