JP2006280099A - Automobile and control method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automobile and a control method thereof wherein a shock due to acceleration/deceleration of a vehicle is suppressed. <P>SOLUTION: When the deviation ΔG between an inputted acceleration G and an averaging value Gpre obtained by averaging the previously inputted acceleration G is larger than a threshold value ΔGref (Step S150), it is determined that change in acceleration is great and such a shock that makes a driver uncomfortable. A variation in torque (ΔG×K) obtained by multiplying the deviation ΔG by a coefficient K is set as correction torque Tmrr (Step S160). The torque command Tm* for a motor is corrected using the set correction torque Tmrr (Step S180). Control is curried out so that the motor 42 is driven with the corrected torque command Tm* (Step S190). Thus, the torque so corrected that change in acceleration is suppressed is outputted from the motor 42, and the occurrence of a shock due to acceleration/deceleration can be suppressed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an automobile and a control method thereof, and more particularly, to an automobile including an electric motor capable of outputting driving power and a control method thereof.

Conventionally, this type of vehicle includes an engine that outputs power to a front shaft connected to front wheels via a transmission, and a motor that outputs power to a rear shaft connected to rear wheels. The thing which can drive and drive | work is proposed (refer especially patent document 1). In this automobile, when the total value of the driving force of the four wheels is smaller than the total value of the driving force of the four wheels before the start of the shift, the insufficient driving force is supplemented by the motor during the shift of the transmission. The transmission of power to the shaft is interrupted and the occurrence of shock due to deceleration is suppressed.
JP 2001-347846 A

  However, in the above-described automobile, consideration is given to suppressing a shock caused by deceleration during a shift of the transmission, but no consideration is given to a shock caused by acceleration / deceleration when overcoming road surface irregularities during traveling. There is a method to absorb the shock from the road surface using tires and suspensions as a method of suppressing the shock when getting over the unevenness of the road surface during traveling, but this method can sufficiently suppress the shock due to acceleration / deceleration of the vehicle. Absent.

  The object of the present invention is to suppress the occurrence of shock due to acceleration / deceleration.

  In order to achieve the above object, the automobile of the present invention and the control method thereof employ the following means.

The automobile of the present invention
An automobile equipped with an electric motor capable of outputting driving power,
Acceleration detecting means for detecting acceleration;
Control means for controlling the electric motor to output a suppression torque that suppresses the change in acceleration when the detected change in acceleration is equal to or greater than a predetermined change;
It is a summary to provide.

  In the automobile of the present invention, when the change in the acceleration of the vehicle is greater than or equal to a predetermined change, the electric motor is controlled so as to output a suppression torque that suppresses the change in acceleration. Since the change in the acceleration of the vehicle can be suppressed, the occurrence of a shock due to acceleration / deceleration can be suppressed.

  In the motor vehicle of the present invention, the control means outputs the suppression torque when the time differential value of the detected acceleration is equal to or greater than a predetermined value and the change in acceleration is equal to or greater than the predetermined change. It can also be a means for controlling. Since the electric motor is controlled so as to output the suppression torque when the time differential value of the acceleration of the vehicle is equal to or greater than a predetermined value, it is possible to suppress the occurrence of shock due to acceleration / deceleration.

  In the automobile of the present invention, the control means may be means for setting the suppression torque based on the time differential value of the detected acceleration. If it carries out like this, the suppression torque according to the time differential value of the acceleration of a vehicle can be output from an electric motor. In this case, the control means may be means for setting the suppression torque based on the weight of the automobile in addition to the time differential value of the detected acceleration. If it carries out like this, in addition to the time differential value of the acceleration of a vehicle, the suppression torque according to the weight of the motor vehicle can be output from an electric motor. As a result, the occurrence of shock due to acceleration / deceleration can be suppressed more appropriately.

  Further, in the automobile of the present invention, the control means estimates a change in acceleration based on the time differential value of the detected acceleration and sets the suppression torque based on the estimated change in acceleration, It may be a means for controlling the electric motor to output a set suppression torque. If it carries out like this, the suppression torque based on the change of the estimated acceleration can be output from an electric motor.

  The automobile of the present invention may include an internal combustion engine that outputs power to the first axle, and the electric motor can output power to the second axle. If it carries out like this, the motive power from an internal combustion engine can be output to a 1st axle, and the suppression torque from an electric motor can be output to a 2nd axle.

The method for controlling an automobile of the present invention includes:
A method for controlling an automobile including an electric motor capable of outputting driving power,
Detect acceleration,
The gist is to control the electric motor so as to output a suppression torque for suppressing the change in acceleration when the detected change in acceleration is equal to or greater than a predetermined change.

  In the automobile control method of the present invention, when the change in the acceleration of the vehicle is equal to or greater than the predetermined change, the electric motor is controlled so as to output a suppression torque that suppresses the change in the acceleration. Since the change in the acceleration of the vehicle can be suppressed, the occurrence of a shock due to acceleration / deceleration can be suppressed.

  Next, the best mode for carrying out the present invention will be described using examples.

  FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 as an embodiment of the present invention. The hybrid vehicle 20 of the embodiment includes a torque converter 36 in which power from an engine 32 controlled by an engine electronic control unit (engine ECU in the figure) 33 is controlled by a CVT electronic control unit (CVTTEC in the figure) 38. And switching control of the switching element of the inverter 44 by the front wheel drive system 30 that outputs to the front wheels 22a and 22b via the CVT 37 as a continuously variable transmission and the motor electronic control unit (motor ECU in the figure) 43. A rear wheel drive system 40 that outputs power from the motor 42 to be controlled to the rear wheels 24a and 24b, and a hybrid electronic control unit 70 that controls the entire vehicle are provided.

  An alternator 52 is attached to the crankshaft 34 of the engine 32 of the front wheel drive system 30, and the generated electric power is supplied to the motor 42 via the high-voltage battery 46 and the inverter 44, or the low-voltage via the DC / DC converter 54. The battery 56 and a plurality of auxiliary machines 58a and 58b are supplied. The torque converter 36 of the front wheel drive system 30 is connected to the CVT 37 via the clutch C1. The clutch C1 can disconnect the engine 32 and the torque converter 36 from the front wheels 22a and 22b. Further, the engine electronic control unit 33 and the CVT electronic control unit 38 of the front wheel drive system 30 input the states of the engine 32 and the CVT 37 from various sensors (not shown) and based on commands from the hybrid electronic control unit 70 32, CVT 37, clutch C1, torque converter 36, and the like are controlled.

  The motor electronic control unit 43 of the rear wheel drive system 40 controls the motor 42 based on a signal input from a rotation position sensor 42 a attached to the motor 42 or a command from the hybrid electronic control unit 70.

  The hybrid electronic control unit 70 is configured as a microprocessor centered on the CPU 72, and in addition to the CPU 72, a ROM 74 for storing processing programs, a RAM 76 for temporarily storing data, an input / output port and communication not shown. And a port. The hybrid electronic control unit 70 includes a shift position SP from the shift position sensor 82 that detects the operation position of the shift lever 81, an accelerator opening Acc from the accelerator pedal position sensor 84 that detects the depression amount of the accelerator pedal 83, and a brake. The brake pedal position BP from the brake pedal position sensor 86 that detects the depression amount of the pedal 85, the vehicle speed V from the vehicle speed sensor 87 that detects the vehicle speed, the acceleration G from the acceleration sensor 88 that detects the acceleration, and the like via the input port. Have been entered. The hybrid electronic control unit 70 outputs a drive signal to the alternator 52, a control signal to the DC / DC converter 54, and the like via an output port. The hybrid electronic control unit 70 communicates with the engine electronic control unit 33, the CVT electronic control unit 38, and the motor electronic control unit 43, and exchanges various control signals and data. The hybrid electronic control unit 70 also manages the high voltage battery 46 and the low voltage battery 56, and is attached to signals necessary for managing the high voltage battery 46 and the low voltage battery 56, for example, output terminals of the respective batteries. A charge / discharge current from a current sensor (not shown), a battery temperature Tb from a temperature sensor (not shown) attached to each battery, and the like are input. The hybrid electronic control unit 70 also calculates the remaining capacity (SOC) of each battery based on the integrated value of the charge / discharge current detected by the current sensor in order to manage each battery.

  The hybrid vehicle 20 configured as described above mainly travels by outputting the power from the engine 32 to the front wheels 22a and 22b in accordance with the accelerator operation of the operator, and if necessary, the power from the motor 42 is transmitted to the rear wheels 24a, It outputs to 24b and it drive | works by 4 wheel drive. Examples of traveling by four-wheel drive include sudden acceleration when the accelerator pedal 83 is greatly depressed, and when a wheel slips. Further, at the time of deceleration such as when the brake pedal 85 is depressed during traveling, the clutch 32 is disconnected and the engine 32 is stopped with the engine 32 disconnected from the CVT 38, and the motor 42 is regeneratively controlled to regenerate the rear wheel 24a. , 24 b is applied with a braking force and its kinetic energy is converted into electric power and collected in the high voltage battery 46.

  Next, the operation of the hybrid vehicle 20 of the embodiment configured as described above, particularly the operation when the acceleration changes during traveling will be described. FIG. 2 is a flowchart showing an example of a motor drive control routine executed by the hybrid electronic control unit 70. This routine is repeatedly executed every predetermined time (for example, every several msec).

  When the motor drive control routine is executed, the CPU 72 of the hybrid electronic control unit 70 first starts from the accelerator pedal position Acc from the accelerator pedal position sensor 84, the brake pedal position BP from the brake pedal position sensor 85, and the vehicle speed sensor 87. The vehicle speed V, the acceleration G from the acceleration sensor 88, the rotational speed Nm of the motor 42, the torque command Tm * of the motor 42, and other data necessary for control are input (step S100). Here, the rotational speed Nm of the motor 42 is calculated based on the rotational position of the rotor of the motor 42 detected by the rotational position detection sensor 42a and is input from the motor electronic control unit 43 by communication. . Further, the motor torque command Tm * is executed by the hybrid electronic control unit 70 separately from this routine when the power from the motor 42 is output to the rear wheels 24a and 24b and traveling by four-wheel drive. In the drive control routine, a torque command Tm * of the motor 42 set based on the accelerator opening Acc, the vehicle speed V, and the like is input. The torque command Tm * is determined based on the battery temperature of the high-voltage battery 46 detected by a temperature sensor (not shown) of the motor 42 and the remaining capacity (SOC) of the high-voltage battery 46. , Wout.

  When the data is input in this way, it is determined whether or not the input vehicle speed V is higher than a vehicle speed threshold value Vref that can be determined to be traveling at a low speed at which it is estimated that the vehicle is stopped (step S110). When the vehicle speed V is higher than the threshold value Vref, it is determined that the vehicle is not traveling at a low speed, and the brake pedal position BP is subsequently depressed by the driver so that the driver is requesting braking. It is determined whether it is smaller than the threshold BPref of the depression amount that can be determined as (step S120). When the brake pedal position BP is smaller than the threshold value BPref, it is determined that the driver does not request braking. Next, the time change rate ΔAcc of the accelerator opening Acc is suddenly depressed by the driver. Then, it is determined whether or not the change rate is smaller than a threshold ΔAcref at which it can be determined that the driver is requesting rapid acceleration (step S130). If the time change rate ΔAcc of the accelerator opening degree Acc is smaller than the threshold value ΔAccref, it is determined that the driver does not request rapid acceleration, and subsequently input when the routine is executed with the input acceleration G. The deviation from the smoothed value Gpre obtained by subjecting the acceleration G to the smoothed value is set as the deviation ΔG (step S140), and it is determined whether or not the absolute value of the set deviation ΔG is larger than the threshold value ΔGref. (Step S150). Here, the threshold value ΔGref is a time (for example, several msec) during which this routine is repeatedly executed on the absolute value of the time differential value of acceleration at which it is estimated that a shock that makes the driver feel uncomfortable is generated. It is set as a value multiplied by.

  When the absolute value of the deviation ΔG is larger than the threshold value ΔGref, it is determined that a shock that makes the driver feel uncomfortable is generated, and the torque change amount (ΔG · K) obtained by multiplying the deviation ΔG by the coefficient K Is set as the correction torque Tmrr (step S160). Here, the coefficient K is a conversion coefficient for converting the deviation ΔG as the acceleration deviation into a torque value, and is obtained from the vehicle weight, the tire diameter of the rear wheels 24a, 24b, and the like.

  When the correction torque Tmrr is set in this way, a value obtained by subtracting the correction torque Tmrr from the motor torque command Tm * input in the process of step S100 is set as the torque command Tm * of the motor 42 (step S180). By setting the torque command Tm * of the motor 42 in this way, the torque output from the motor 42 can be set as a torque corrected by the correction torque Tmrr, that is, a torque that suppresses a change in acceleration.

  When the torque command Tm * is set, the torque command Tm * for the motor 42 is transmitted to the motor electronic control unit 43 (step S190), and the motor drive control routine is terminated. The motor electronic control unit 43 that has received the torque command Tm * performs switching control of the switching element of the inverter 41 so that the motor 42 is driven by the torque command Tm *.

  FIG. 3 is an explanatory diagram illustrating an example of a temporal change in acceleration of the vehicle. In the figure, a solid line A indicates a time change in acceleration when the torque command Tm * input in the process of step S100 is corrected with the correction torque Tmrr, and a broken line B indicates the torque command Tm * input in the process of step S100. The time change of the acceleration when not correcting with the correction torque Tmrr is shown. If the vehicle is traveling at a constant acceleration and overcame the unevenness of the road surface at time t0 and returns to the traveling state before time t0 at time t1, the motor is directly corrected without correcting the torque command Tm * with the correction torque Tmrr. When output from 42, as indicated by a broken line B, the acceleration of the vehicle greatly increases or decreases between time t0 and time t1. On the other hand, when the torque corrected by the correction torque Tmrr is output from the motor 42, as indicated by the solid line A, it is determined that the absolute value of the deviation ΔG is greater than the threshold value ΔGref at time t0, that is, the change in acceleration is large. Since the motor 42 outputs a torque that suppresses the change in acceleration, increase / decrease in the acceleration of the vehicle from time t0 to time t1 is alleviated. As described above, when the change in the acceleration is large, the increase or decrease in the acceleration of the vehicle can be suppressed by outputting the torque obtained by correcting the torque command Tm * input from the motor 42 in the process of step S100 with the correction torque Tmrr. it can. By so doing, it is possible to suppress the occurrence of shock due to acceleration / deceleration of the vehicle. If the torque command Tm * of the motor 42 is corrected in this way, the input / output limits Win and Wout of the high voltage battery 46 may be exceeded, but even if exceeded, the high voltage battery 46 will be damaged because it is instantaneous. There is no.

  On the other hand, when the absolute value of the deviation ΔG is equal to or less than the threshold value ΔGref, even if a change in acceleration is small and a shock is generated, the driver does not feel uncomfortable about riding. If it is determined that there is no, this routine is terminated.

  When the input vehicle speed V is lower than the vehicle speed threshold value Vref (step S110), the brake pedal position BP is larger than the threshold value BPref (step S120), or the time change rate ΔAcc of the accelerator opening degree Acc is larger than the threshold value ΔAcref. (Step S130), it is determined that it is not appropriate to perform control to suppress increase / decrease in acceleration because there is a possibility that the vehicle stops or the driver requests braking or rapid acceleration. Exit.

  According to the hybrid vehicle 20 of the embodiment described above, when the change in acceleration is large, the motor 42 outputs the torque corrected so as to suppress the change in acceleration, so that the change in the acceleration of the vehicle can be suppressed. As a result, the occurrence of shock due to acceleration / deceleration can be suppressed.

  In the hybrid vehicle 20 according to the embodiment, the deviation ΔG is set by using the smoothed value Gpre as a value obtained by performing the smoothing process on the acceleration G input when the routine is executed last time in the process of step S140. However, the deviation ΔG may be set using the acceleration G input when the routine was executed last time as it is.

  In the hybrid vehicle 20 of the embodiment, in the process of step S150, this routine is repeatedly executed on the absolute value of the acceleration deviation ΔG and the time differential value of acceleration at which a shock that causes the driver to feel uncomfortable is generated. The threshold value ΔGref as a value multiplied by time (for example, several msec) is compared. However, the time differential value obtained by dividing the acceleration deviation ΔG by the time (for example, several msec) when this routine is repeatedly executed It is good also as what compares with the time differential value of the acceleration which a shock generate | occur | produces that a driver | operator feels bad riding comfort.

  In the hybrid vehicle 20 of the embodiment, the motor torque command of the motor 42 is corrected using the deviation ΔG set based on the acceleration G input in step S160. The relationship between the motor 42 and the motor 42 is preliminarily determined by experiment, the time change of the acceleration is predicted from the deviation ΔG, and the motor torque command of the motor 42 is corrected with a torque that suppresses the increase and decrease of the acceleration based on the predicted change of the acceleration It is good also as what to do.

  The hybrid vehicle 20 of the embodiment includes a front wheel drive system 30 that drives the front wheels 22a and 22b with power from the engine 32, and a rear wheel drive system that drives the rear wheels 24a and 24b with power from the motor 42. Although it is assumed that the vehicle travels with the front wheel drive system, the configuration of the front wheel drive system and the configuration of the rear wheel drive system may be interchanged to travel mainly with the rear wheel drive system.

  In the hybrid vehicle 20 of the embodiment, the engine 32 of the front wheel drive system 30 and the motor 42 of the rear wheel drive system 40 are provided as power sources that output the power for traveling, but the power that outputs the power for traveling. Only the motor may be provided as a source, or another power source (for example, a motor) may be provided instead of the engine 32 of the front wheel drive system 30.

  The best mode for carrying out the present invention has been described above by using the embodiments. However, the present invention is not limited to these embodiments, and can of course be implemented in various forms.

  The present invention is applicable to the automobile industry and the like.

It is a block diagram which shows the outline of a structure of the hybrid vehicle 20 of an Example. 5 is a flowchart showing an example of a motor drive control routine executed by a hybrid electronic control unit 70. It is explanatory drawing which shows an example of the time change of the acceleration of a vehicle.

Explanation of symbols

20 hybrid vehicle, 22a, 22b front wheel, 24a, 24b rear wheel, 30 front wheel drive system, 32 engine, 33 engine electronic control unit, 34 crankshaft, 36 torque converter, 37 CVT, 38 CVT electronic control unit, 40 rear Wheel drive system, 42 motor, 42a rotational position sensor, 43 motor electronic control unit, 44 inverter, 46 high voltage battery, 52 alternator, 54 DC / DC converter, 56 low voltage battery, 58a, 58b auxiliary machine, 70 electronic control for hybrid Unit, 72 CPU, 74 ROM, 76 RAM, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 accelerator pedal position sensor, 85 brake pedal, 86 brake pedal position sensor, 87 vehicle speed Sensor, 88 acceleration sensor, C1 clutch.

Claims (7)

An automobile equipped with an electric motor capable of outputting driving power,
Acceleration detecting means for detecting acceleration;
Control means for controlling the electric motor to output a suppression torque that suppresses the change in acceleration when the detected change in acceleration is equal to or greater than a predetermined change;
Automobile equipped with.   The control means is a means for controlling the electric motor so as to output the suppression torque when a time differential value of the detected acceleration is not less than a predetermined value and a change in the acceleration is not less than a predetermined change. The automobile according to claim 1.   The automobile according to claim 1 or 2, wherein the control means is means for setting the suppression torque based on a time differential value of the detected acceleration.   4. The automobile according to claim 3, wherein the control means is means for setting the suppression torque based on the weight of the automobile in addition to the time differential value of the detected acceleration.   The control means estimates a change in acceleration based on the time differential value of the detected acceleration, sets the suppression torque based on the estimated change in acceleration, and outputs the set suppression torque The automobile according to claim 1 or 2, which is means for controlling the electric motor. The automobile according to any one of claims 1 to 5,
An internal combustion engine that outputs power to the first axle;
The electric motor can output power to a second axle. A method for controlling an automobile including an electric motor capable of outputting driving power,
Detect acceleration,
A method for controlling an automobile, wherein the motor is controlled to output a suppression torque that suppresses the change in acceleration when the detected change in acceleration is equal to or greater than a predetermined change.

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