JP6020023B2 - Vehicle travel support device - Google Patents

Description

  The present invention relates to a vehicular travel support apparatus that reduces the effort related to an accelerator pedal operation by a driver, and more particularly to a vehicle even when constant speed travel control is started immediately after a transition from a flat road to an uphill or the like. Is able to continuously realize smooth running such as running on a flat road.

  As a conventional apparatus related to the present invention, for example, there is a constant speed traveling control apparatus described in Patent Document 1. That is, the constant speed traveling control device described in Patent Document 1 uses the vehicle speed at the time when the start command for constant speed traveling control is instructed as the target vehicle speed, and the actual vehicle speed is automatically set to the target vehicle speed during the constant speed traveling control. In the case of control to match, a dead zone is set in which the target vehicle speed is not changed even if the driver depresses the accelerator pedal, and the target vehicle speed is maintained while the amount of depression of the accelerator pedal is changing within the dead zone. When the accelerator pedal is depressed or the accelerator pedal is returned beyond the dead zone, the driver estimates that the driver intends to accelerate or decelerate, and changes the target vehicle speed according to the amount of depression of the accelerator pedal. The actual vehicle speed is increased or decreased.

  With such a configuration, the driver can perform constant speed control even with the foot on the accelerator pedal, so the driver intends to accelerate while preventing a delay in the depression of the brake pedal when performing a sudden stop. It was said that the difference from the operation during normal traveling can be reduced by appropriately dealing with cases.

Japanese Patent No. 4103814

However, the above-described conventional constant speed traveling control device simply performs control to make the actual vehicle speed coincide with the target vehicle speed. Therefore, the control is performed when the constant speed traveling control is shifted from being stopped to being in operation. The configuration starts suddenly. For this reason, there was an unsolved problem that the transition from the stop of the control to the operation cannot be performed smoothly.
The present invention has been made paying attention to such an unsolved problem in the conventional constant speed traveling control device. For example, the constant speed traveling control is started immediately after a transition from a flat road to a downhill or the like. An object of the present invention is to provide a vehicular travel support apparatus that can continuously realize smooth travel such that the vehicle travels on a flat road even in such a case.

  In order to solve the above problems, a vehicle travel support apparatus according to an aspect of the present invention calculates a target vehicle acceleration (reference acceleration) based on a driver's acceleration / deceleration request and a disturbance component that affects travel speed. A model to be calculated (standard vehicle model) is built, and the standard required by the standard vehicle model when the driver performs acceleration / deceleration by operating the accelerator and brakes (during constant speed control is stopped) While driving support control is performed so that the actual acceleration matches the acceleration, the disturbance component is made smaller during the constant speed driving control that automatically controls the vehicle speed regardless of the driver's operation than when the control is stopped. In the above, the driving support control is performed by obtaining the reference acceleration using the acceleration / deceleration request of the driver when the constant speed driving control is started.

  According to the present invention, the normative vehicle model that calculates the normative acceleration based on the acceleration / deceleration request of the driver and the disturbance component that affects the driving acceleration has the effect that the acceleration / deceleration request of the driver and the disturbance component affect the normative acceleration in parallel. Therefore, it is possible to make fine adjustments to achieve the desired vehicle behavior, and to smoothly shift to constant speed running control only by reducing the disturbance component (for example, to 0). There is.

It is a conceptual diagram which shows schematic structure of the motor vehicle 1 in 1st Embodiment. It is a block diagram which shows the whole structure of the system of 1st Embodiment. It is the block diagram which made the flow of the signal of 1st Embodiment visible. It is a block diagram which shows the structure of the normative vehicle model of 1st Embodiment. It is a wave form diagram which shows the time change of each value in 1st Embodiment. It is a flowchart which shows the outline | summary of the process of 1st Embodiment. It is a wave form diagram which shows an example of the effect at the time of applying to a real vehicle. It is a conceptual diagram which shows schematic structure of the motor vehicle 1 in 2nd Embodiment. It is a block diagram which shows the whole structure of the system of 2nd Embodiment. It is a wave form diagram which shows the time change of each value in 2nd Embodiment. It is a conceptual diagram which shows schematic structure of the motor vehicle 1 in 3rd Embodiment. It is a block diagram which shows the whole structure of the system of 3rd Embodiment. It is a block diagram which shows the structure of the normative vehicle model of 3rd Embodiment. It is explanatory drawing of a two-wheel model. It is a flowchart which shows the outline | summary of the process of 3rd Embodiment. It is a wave form diagram which shows the time change of each value in 3rd Embodiment.

Embodiments of the present invention will be described below.
(First embodiment)
(Constitution)
FIG. 1 is a diagram showing an overall configuration of a first embodiment of the present invention, and is a conceptual diagram showing a model of an automobile 1 to which a vehicular travel support apparatus according to the present invention is applied.

  The vehicle 1 in the present embodiment is an electric vehicle having an electric motor 2 as a drive source, and is connected to a transmission 3 to which a driving force output from the electric motor 2 is input and to an output side of the transmission 3. A drive shaft 4 extending in the width direction and left and right drive wheels 5 and 5 provided at both ends of the drive shaft 4 are provided, and the drive of the electric motor 2 transmitted to the drive shaft 4 via a transmission is provided. The force is transmitted to the drive wheels 5 and 5.

  The vehicle 1 also detects a vehicle speed sensor 7 that detects a vehicle speed (actual vehicle speed) based on the number of rotations of the drive wheels 5, an accelerator pedal 8 that can be depressed by the driver, and a depression amount of the accelerator pedal 8. And an accelerator operation detecting device 9 for performing the operation. The controller 6 is supplied with a vehicle speed detection signal Vd output from the vehicle speed sensor 7 and an accelerator operation detection signal Ad output from the accelerator operation detection device 9.

  The controller 6 includes a CPU, a driver circuit, and the like (not shown). The controller 6 performs arithmetic processing to be described later on the electric motor 2 based on the supplied vehicle speed detection signal Vd and accelerator operation detection signal Ad. A command current Iout is output to control the rotation direction and driving force. In this embodiment, the electric motor 2 generates a driving force of the automobile 1 and also generates a braking force by regeneration. That is, although the electric motor 2 functions as a braking / driving actuator, a mechanical braking device that generates a braking force due to friction with respect to the driving wheel 5 and a driven wheel (not shown) separately from the braking force due to regeneration. A regenerative brake by the electric motor 2 and a mechanical brake device may be used in combination.

FIG. 2 is a block diagram showing an overall functional configuration of the first embodiment.
That is, as shown in FIG. 2, the controller 6 includes a driver acceleration / deceleration request estimation unit 6A, a command value calculation unit 6B, a servo compensator 6C, an adder 6D, and an actual acceleration detection unit 6E. Yes.

  The driver acceleration / deceleration request estimation unit 6A is configured to obtain an estimated value of acceleration requested by the driver of the automobile 1 based on the accelerator operation detection signal Ad supplied from the accelerator operation detection device 9. Specifically, the driver acceleration / deceleration request estimation unit 6A basically obtains an estimated value Ge of acceleration requested by the driver by multiplying the magnitude of the accelerator operation detection signal Ad by a predetermined gain. It has become. Further, the method of obtaining the estimated value Ge is not limited to this. For example, it can be obtained in proportion to the square of the accelerator operation detection signal Ad, or the absolute value of the accelerator operation detection signal Ad. And the amount of change (differential value) thereof. However, considering the driver who is accustomed to the driving characteristics of the vehicle using the internal combustion engine as the driving source, the estimated value Ge should be set to a characteristic that causes a slight delay with respect to the change in the accelerator operation detection signal Ad. In this embodiment, such a delay component is set.

  Further, when the driver is operating the accelerator pedal 8, the driver acceleration / deceleration request estimation unit 6A constantly updates the estimated value Ge corresponding to the accelerator operation detection signal Ad indicating the opening degree of the accelerator pedal 8 at that time. Output. On the other hand, the driver acceleration / deceleration request estimation unit 6A determines that the driver intends to start constant speed running control that automatically controls the vehicle speed regardless of his / her operation when the driver removes his / her foot from the accelerator pedal 8. In addition, the estimated value Ge set immediately before the separation is held. In the case of an automobile having a configuration in which the driver notifies the system side of the start of constant speed traveling control by operating a switch provided on the steering wheel, the driver is fixed when the switch is operated. It may be determined that the start of the high-speed driving control is intended, and the estimated value Ge at that time may be held.

The estimated value Ge obtained by the driver acceleration / deceleration request estimating unit 6A and the actual acceleration Gd calculated by the actual acceleration detecting unit 6E are supplied to the command value calculating unit 6B.
The command value calculation unit 6B executes a predetermined calculation process based on the supplied estimated value Ge to obtain the reference acceleration Gc that is the optimum acceleration as the acceleration of the current vehicle 1 and the current traveling speed of the vehicle 1. A reference vehicle speed Vc which is an optimum speed is obtained. Further, the command value calculation unit 6B calculates and outputs an acceleration command value Gdif based on an acceleration difference (Gd−Gc) that is a difference between the current acceleration (actual acceleration) Gd and the reference acceleration Gc. .

The servo compensator 6C generates and outputs an assist torque Gout, which is a control command value as acceleration, based on the acceleration command value Gdif supplied from the command value calculation unit 6B.
Then, the adder 6D adds the estimated value Ge and the assist torque Gout and outputs it as a command current Iout for the electric motor 2.
The actual acceleration detection unit 6E differentiates the current traveling speed Vd (actual speed) of the automobile 1 supplied from the vehicle speed sensor 7, and estimates the actual acceleration Gd that is the traveling acceleration in the front-rear direction of the automobile 1. The actual acceleration detector 6E supplies the estimated actual acceleration Gd to the command value calculator 6B.

In this embodiment, the vehicle speed detection signal Vd supplied from the vehicle speed sensor 7 is differentiated to estimate the actual acceleration Gd in the front-rear direction of the automobile 1. However, the present invention is not limited to this configuration. 1 may be configured to detect the actual acceleration Gd in the front-rear direction.
FIG. 3 is a block diagram representing the system configuration of the present embodiment so that the flow of each signal can be seen as a whole. The reference value calculation unit 6B calculates the reference acceleration Gc based on the estimated value Ge. The point is composed of the model 10 and a subtractor 11 that calculates the difference Gdif (Gd−Gc) between the actual acceleration Gd and the reference acceleration Gc.

In the present embodiment, the reference vehicle model 10 for calculating the reference acceleration Gc is configured as shown in FIG.
That is, the reference vehicle model 10 includes a rolling resistance component storage unit 10a that stores a rolling resistance component R1 that is a predetermined constant value, and an air resistance component setting unit 10b that sets the air resistance component R2 based on the reference vehicle speed Vc. And.

The air resistance component setting unit 10b calculates an air resistance component R2 that increases in accordance with the vehicle speed by multiplying the square value (Vc ² ) of the reference vehicle speed Vc by a fixed gain K.
Since both the rolling resistance component R1 and the air resistance component R2 are disturbance components that act in the direction of reducing the traveling speed of the vehicle, their signs are negative opposite to the estimated value Ge.

The rolling resistance component R1 and the air resistance component R2 are supplied to the selection units 10c and 10d, respectively.
On the other hand, “0” is supplied to each of the selection units 10c and 10d in addition to the rolling resistance component R1 and the air resistance component R2. Further, the flag Fa is supplied from the accelerator OFF flag setting unit 10e to each of the selection units 10c and 10d. Here, the flag Fa is a flag that is set when the accelerator pedal 8 corresponding to the accelerator operation unit is not operated in the present embodiment. Further, the flag Fa is a flag that is not set when the accelerator pedal 8 is operated.

  Each of the selection units 10c and 10d outputs a rolling resistance component R1 and an air resistance component R2 when the flag Fa is in a non-set state, and outputs “0” when the flag Fa is in a set state. ing. That is, when the flag Fa is not set, the selection units 10c and 10d output the rolling resistance component R1 and the air resistance component R2 supplied from the rolling resistance component storage unit 10a and the air resistance component setting unit 10b as they are. On the other hand, the selection units 10c and 10d are related to the values of the rolling resistance component R1 and the air resistance component R2 supplied from the rolling resistance component storage unit 10a and the air resistance component setting unit 10b after the flag Fa is set. Rather, the rolling resistance component R1 and the air resistance component R2 are forcibly reset to “0” and then output.

The outputs of the selectors 10c and 10d are supplied to the adder 10f together with the estimated value Ge.
That is, the adder 10f adds the estimated value Ge and the outputs of the selection units 10c and 10d. However, when the rolling resistance component R1 and the air resistance component R2 are output from the selection units 10c and 10d, the signs of the rolling resistance component R1 and the air resistance component R2 are negative. For this reason, the calculation in the adder 10f is Ge− (R1 + R2) in consideration of the sign, so the adder 10f substantially functions as a subtractor. Note that when the flag Fa is in the set state, the selection units 10c and 10d output “0”, and therefore the output of the adder 10f is the estimated value Ge itself.

The reference vehicle model 10 further includes a divider 10g and an integrator 10h. The divider 10g calculates the reference acceleration Gc as the target acceleration by dividing the output value of the adder 10f by the mass M of the automobile 1. The integrator 10h calculates the reference vehicle speed Vc by integrating the reference acceleration Gc supplied from the divider 10g.
Then, the reference acceleration output from the divider 10g is supplied to the subtractor 11 of FIG. 3 as the output of the reference vehicle model 10, and the reference vehicle speed Vc output from the integrator 10h is used as the air resistance component setting unit 10b. To be supplied.

FIG. 5 is a waveform diagram showing an example of a time change of each value, and shows an accelerator operation detection signal Ad, an estimated value Ge, a flag Fa, a rolling resistance component R1, an air resistance component R2, and a reference acceleration Gc. . Note that the rolling resistance component R1 and the air resistance component R2 have negative signs, but are shown as absolute values in FIG.
In FIG. 5, the amount of depression of the accelerator pedal 8 by the driver is substantially constant from time t0 to time t1, and the amount of depression of the accelerator pedal 8 is gradually reduced from around time t1, and the accelerator is depressed at time t2. A state where the foot is completely removed from the pedal 8 is shown.

In this case, after the time t1 is exceeded, the estimated value Ge decreases with a tendency to be slightly delayed with respect to the change in the accelerator operation detection signal Ad. However, when the driver completely removes the foot from the accelerator pedal 8 at time t2. The estimated value Ge is also 0.
The driver acceleration / deceleration request estimation unit 6A determines that the driver intended to start constant speed traveling control at time t2, and uses the estimated value Ge immediately before time t2 (for example, time t1) as the constant speed after time t2. It is stored as an estimated value Ge ′ for travel control.

The flag Fa is in a non-set state until time t2, and is set when time t2 is reached.
The rolling resistance component R1 has a constant value stored in the rolling resistance component storage unit 10a until time t2, but becomes 0 after reaching time t2.
Similarly, the air resistance component R2 has a value proportional to the square of the reference vehicle speed Vc until time t2, but becomes 0 after time t2.

Then, since the estimated value Ge is constant from time t0 to time t1, the reference acceleration Gc is substantially constant accordingly.
On the other hand, from time t1 to time t2, the driver gradually decreases the amount of depression of the accelerator pedal 8, so that the reference acceleration Gc also decreases with a slight delay as the estimated value Ge decreases. Then, at time t2, the driver completely removes his / her foot from the accelerator pedal 8, so the estimated value Ge becomes zero. In addition, since the flag Fa is set at the time t2, both the rolling resistance component R1 and the air resistance component R2 become zero. As a result, the normative acceleration Gc is also zero.

(Operation)
Next, the operation will be described.
FIG. 6 is a flowchart showing an outline of processing in this embodiment.
That is, when the vehicle 1 is powered on, the controller 6 is supplied with the accelerator operation detection signal Ad and the vehicle speed detection signal Vd, and the processing shown in FIG. 6 is synchronized with a predetermined sampling clock based on these values. Repeatedly.

  In step 100 of FIG. 6, the driver acceleration / deceleration request estimation unit 6A obtains an estimated value Ge of the driver acceleration / deceleration request based on the accelerator operation detection signal Ad. Next, the process proceeds to step 110, and in the reference vehicle model 10, the reference acceleration Gc and the reference vehicle speed Vc are obtained based on the estimated value Ge. Next, the routine proceeds to step 120 where the subtractor 11 calculates the acceleration command value Gdif based on the reference acceleration Gc and the actual acceleration Gd. Then, the acceleration command value Gdif is output as the assist torque Gout through the servo compensator 6C, and finally, the command current Iout is output to the electric motor 2.

Therefore, the electric motor 2 is a command current obtained by adding the estimated value Ge representing the acceleration / deceleration request by the driver and the acceleration command value Gdif necessary for making the actual acceleration Gd of the automobile 1 coincide with the reference acceleration Gc. It is driven to rotate by Iout.
The processing shown in FIG. 6 is to repeatedly execute the above contents. However, if a driver who intends to start constant speed traveling control releases his / her foot from the accelerator pedal 8, the flag Fa is set thereafter. Thus, the rolling resistance component R1 and the air resistance component R2 become zero. However, the content of the calculation process is the same before and after the start of the constant speed traveling control, simply because the resistance components R1 and R2 that affect the vehicle speed have become zero.

In particular, as shown in FIG. 4, the reference vehicle model 10 has a configuration in which the reference acceleration Gc is continuously obtained before the start of the constant speed running control. Therefore, the constant speed running control is started as shown in FIG. 5. The reference acceleration Gc does not change suddenly at the time t2. Therefore, the command current Iout does not change stepwise from the time t2.
For this reason, the constant speed travel control is smoothly started, unlike the case where the calculation process for the constant speed travel control is newly started at the start of the constant speed travel control.

  FIG. 7 is a waveform diagram showing temporal changes in the reference acceleration Gc, the actual acceleration Gd, and the assist torque Gout when the configuration of the present embodiment is realized with an actual vehicle, and the accelerator pedal 8 is depressed on a flat road at time t10. Then, the vehicle 1 starts, and the constant speed traveling control is started by releasing the accelerator pedal 8 when the vehicle 1 starts moving from the flat road to the downhill at time t20.

A relatively large acceleration-side assist torque Gout is generated immediately after time t10, and a relatively large acceleration-side assist torque Gout is generated thereafter. A relatively large deceleration assist torque Gout is generated.
However, the difference between the actual acceleration Gd and the reference acceleration Gc is not particularly large immediately after starting and immediately after the start of constant speed running control.

  Here, in the conventional constant speed traveling control device, when the constant speed traveling control is started immediately after the transition from the flat road to the uphill, the actual vehicle speed greatly deviates in a direction lower than the target vehicle speed immediately after the control is started. After that, acceleration control is performed so as to match the target vehicle speed. Conversely, if constant speed control is started immediately after shifting from a flat road to a downhill, the actual vehicle speed deviates greatly in the direction higher than the target vehicle speed immediately after the start of control, and then deceleration control is performed. Will be done. For this reason, in the conventional constant speed traveling control device, acceleration / deceleration of the vehicle is likely to occur immediately after the start of the control, and the ride comfort is deteriorated accordingly. In order to prevent this, there is a countermeasure to increase the gain of differential control, for example, in feedback control so that acceleration / deceleration is quickly performed with respect to the deviation between the target vehicle speed and the actual vehicle speed. However, if the influence of the differential control increases, acceleration / deceleration is frequently performed, and the riding comfort is deteriorated when the constant speed traveling control is performed during traveling on a flat road.

  In contrast, in the present embodiment, the reference acceleration Gc is always calculated using the reference vehicle model 10, and the actual acceleration Gd matches the reference acceleration Gc both during and after the constant speed traveling control is stopped. The control is continued. Therefore, when the constant speed running control is started immediately after the transition from the flat road to the uphill, or as shown in FIG. 7, the constant speed running control is started immediately after the transition from the flat road to the downhill. Even in this case, the difference between the actual acceleration Gd and the reference acceleration Gc can be made relatively small, so that the constant speed traveling control can be started smoothly.

  Here, in the present embodiment, the driver acceleration / deceleration request estimation unit 6A corresponds to the acceleration / deceleration request estimation unit. The rolling resistance component storage unit 10a and the air resistance component setting unit 10b correspond to a disturbance component setting unit. The adder 10f and the divider 10g correspond to a target acceleration calculation unit. The actual acceleration detector 6E corresponds to the actual acceleration detector. The integrator 10h corresponds to the target vehicle speed calculation unit. The vehicle speed sensor 7 corresponds to the actual vehicle speed detection unit. The subtractor 11, servo compensator 6C, and adder 6D correspond to the acceleration / deceleration control unit. The accelerator pedal 8 corresponds to the accelerator operation unit.

(Effect of 1st Embodiment)
(1) The reference acceleration Gc is calculated using the reference vehicle model 10 while the constant speed traveling control is stopped and in operation, and the assist torque Gout is added to the driver so that the actual acceleration Gd of the automobile 1 matches the reference acceleration Gc. Since the control of adding to the deceleration request is executed, the constant speed traveling control is smoothly started, and there is an effect that the possibility that the vehicle riding comfort is deteriorated is low. Further, since the driving speed of the automobile 1 is controlled by using the servo compensator 6C with the acceleration as a controlled variable, the servo performance is improved in a scene where the slope of the road surface changes suddenly, and the constant speed driving control is performed. There is an effect that the driver can experience a smooth start.

(2) The constant speed running control is being performed after the rolling resistance component R1 and the air resistance component R2 that have been values larger than 0 are forcibly set to 0 when the flag Fa is set. Since the reference acceleration Gc is calculated, the configuration is simple and the constant speed traveling control can be easily started.
(3) The estimated value Ge is updated while the constant speed traveling control is stopped, and the estimated value Ge when the driver intends to start the constant speed traveling control is held during the operation of the constant speed traveling control. Even with the configuration using the reference vehicle model 10, the driving situation intended by the driver can be realized during constant speed driving, as in the conventional constant speed driving control.

(4) Since the rolling resistance component R1 and the air resistance component R2 are used as disturbance components in the reference vehicle model 10, the reference acceleration Gc is obtained with high accuracy by taking into account the disturbance components acting on the actual vehicle. Can do.
(5) A predetermined constant value is stored as the rolling resistance component R1, and when the flag Fa is in a non-set state, the reference acceleration Gc is obtained using the rolling resistance component R1 of the constant value. The reference acceleration Gc can be obtained in consideration of the rolling resistance component at.

(6) Since the reference vehicle speed Vc is obtained from the reference acceleration Gc using the reference vehicle model 10, and the air resistance component R2 is obtained by multiplying the square value (Vc2) of the reference vehicle speed Vc by a fixed gain K, The air resistance component that increases in proportion to the square of the actual vehicle speed can be obtained with high accuracy.
(7) Since the configuration is such that the flag Fa is set and the disturbance component is forcibly set to 0 in conjunction with the operation of releasing the accelerator pedal 8 to start constant speed running control. Compared to the constant speed running control system, the driver's operation does not increase.

(Second Embodiment)
FIGS. 8 to 10 are diagrams showing a second embodiment of the present invention, and FIG. 8 is a conceptual diagram showing a model of the automobile 1 in the second embodiment. In addition, the same code | symbol is attached | subjected to the structure similar to the said 1st Embodiment, and the overlapping description is abbreviate | omitted.
That is, in this embodiment, in addition to the accelerator pedal 8, a brake pedal 20 that can be operated by the driver and a brake operation detection device 21 that detects the amount of depression of the brake pedal 20 are provided. A brake operation detection signal Bd detected by the brake operation detection device 21 is supplied to the controller 6 together with a vehicle speed detection signal Vd output from the vehicle speed sensor 7 and an accelerator operation detection signal Ad output from the accelerator operation detection device 9. It has become so.

As shown in FIG. 9, an accelerator operation detection signal Ad and a brake operation detection signal Bd are supplied to the driver acceleration / deceleration request estimation unit 6A of the controller 6. The driver acceleration / deceleration request estimation unit 6A calculates an estimated value Ge based on the accelerator operation detection signal Ad and the brake operation detection signal Bd.
That is, in the first embodiment, the description is made on the assumption that the driver controls both acceleration and deceleration using only the accelerator pedal 8, but in the second embodiment, the deceleration operation can be performed by depressing the brake pedal 20. Can be done.

  FIG. 10 is a waveform diagram similar to FIG. Also in the waveform diagram shown in FIG. 10, the accelerator operation detection signal Ad gradually decreases from time t1 and becomes 0 at time t2. On the other hand, the brake operation detection signal Bd maintains 0 until time t3, but the driver starts stepping on the brake pedal 20 at time t3, and then the amount of depression gradually increases, and at time t4. The maximum amount of depression is reached, and the state is maintained thereafter. Since the brake operation detection signal Bd is a signal for a deceleration operation, the sign of the brake operation detection signal Ad is originally opposite to that of the accelerator operation detection signal Ad, but is shown as an absolute value in FIG. The reference acceleration Gc also has the same sign value as Bd corresponding to the magnitude of Bd after time t3, as in the case of the brake operation detection signal Bd, but is expressed as an absolute value in FIG.

  Corresponding to such changes in the accelerator operation detection signal Ad and the brake operation detection signal Bd, the flag Fa is once set at time t2, and then returned to the non-set state again at time t3. Similarly, after the rolling resistance component R1 and the air resistance component R2 are forcibly set to 0 at time t2, at time t3, the rolling resistance component R1 returns to a value before time t2, and the air resistance component R2 is The value is based on the reference vehicle speed Vc at that time.

  The reference acceleration Gc is fixed to 0 in response to the shift to the constant speed traveling control after the time t2. Then, the constant speed traveling control itself stops in response to the depression of the brake pedal 20 at time t3, and after time t3, the estimated value Ge corresponding to the brake operation detection signal Bd at that time is updated and the reference vehicle model is updated. 10 is supplied. Further, as described above, the rolling resistance component R1 and the air resistance component R2 also have values larger than zero. Therefore, the reference acceleration Gc becomes a value corresponding to the magnitudes of the brake operation detection signal Bd, the rolling resistance component R1, and the air resistance component R2 after time t3.

(Operation)
Next, the operation will be described.
That is, in the second embodiment, the constant speed traveling control is stopped by the depression of the brake pedal 20 during the constant speed traveling control operation, and the state is shifted to the normal traveling state. When the brake pedal 20 is depressed, the brake operation detection signal Bd increases in the minus direction, so that the estimated value Ge becomes a large value in the minus direction. The command value calculation unit 6B calculates a reference acceleration Gc based on the estimated value Ge that is a negative value. The subtractor 11 calculates an acceleration command value Gdif based on the reference acceleration Gc and the actual acceleration Gd from the actual acceleration detector 6E. The acceleration command value Gdif becomes the assist torque Gout through the servo compensator 6C, and the assist torque Gout is output to the electric motor 2 as the command current Iout through the adder 6D. As a result, the electric motor 2 substantially functions as a generator, and regenerative braking occurs.

In the present embodiment, when shifting from the constant speed traveling control to the normal traveling, the control for continuously matching the actual acceleration Gd with the normative acceleration Gc obtained based on the normative vehicle model 10 is continuously performed. is there. Therefore, as shown in FIG. 10, the reference acceleration Gc does not change suddenly at the time t3 when the constant speed traveling control is stopped. Therefore, the command current Iout does not change stepwise from the time t3 due to the influence of the reference acceleration Gc. For this reason, unlike the case where the constant speed traveling control is suddenly stopped when the constant speed traveling control is stopped, the constant speed traveling control can be smoothly shifted to the normal traveling.
Here, in this embodiment, the accelerator pedal 8 corresponds to an accelerator operation unit, and the brake pedal 20 corresponds to a brake operation unit.

(Effect of 2nd Embodiment)
(1) The actual acceleration is equal to the reference acceleration Gc determined based on the reference vehicle model 10 when shifting from the normal driving state to the constant speed driving control and when shifting from the constant speed driving control to the normal driving state. Since the control for matching the Gd is continuously performed, the switching between the constant speed traveling control state and the normal traveling state is smoothly performed, and there is an effect that the possibility of deteriorating the vehicle riding comfort is further reduced. is there.
(2) Since the brake pedal 20 is provided in addition to the accelerator pedal 8 and the brake pedal 20 is operated, the deceleration operation can be performed. Therefore, it is possible to drive with the same operation feeling as a general gasoline vehicle.

(Third embodiment)
FIGS. 11 to 16 are views showing a third embodiment of the present invention, and FIG. 11 is a conceptual diagram showing a model of the automobile 1 in the third embodiment. In addition, the same code | symbol is attached | subjected to the structure similar to the said 1st Embodiment and 2nd Embodiment, and the overlapping description is abbreviate | omitted.
That is, in the present embodiment, a steering wheel operation detection device 31 provided on the steering column 30 is provided, and the steering wheel operation detection device 31 is a rotation angle (steering angle δ) of the steering column 30 generated when the driver steers the steering wheel 30a. ) Is supplied to the controller 6. As shown in FIG. 12, the steering angle detection signal δd supplied from the steering operation detection device 31 is supplied to the command value calculation unit 6B.

The steering angle detection signal δd supplied to the command value calculation unit 6B is supplied to the reference vehicle model 10 as shown in FIG. The reference vehicle model 10 of the present embodiment includes a turning assist torque calculating unit 32 that calculates a turning assist torque Trq, and the steering angle detection signal δd is supplied to the turning assist torque calculating unit 32 together with the vehicle speed detection signal Vd. Has been.
That is, the turning assist torque calculation unit 32 calculates the turning assist torque Trq according to the calculation process described later. The turning assist torque is the reference acceleration Gc in the reference vehicle model 10 so that the actual vehicle speed does not exceed the target vehicle speed during turning calculated from the lateral acceleration and the target yaw rate obtained from the steering angle. Is the torque acting in the direction of decreasing Therefore, the sign of the turning assist torque Trq is negative with respect to the estimated value Ge.

More specifically, considering a two-wheel model 1A as shown in FIG. 14, the lateral acceleration Yg, actual vehicle speed ν, steering angle δ, yaw rate φ acting on the two-wheel model 1A during turning, and the turning radius R at that time From other vehicle specifications (stability factor A, steering gear ratio N, wheelbase L), the target yaw rate φ * is
φ * = ν / (1 + Aν2) · δ / NL (1)
Can be obtained as

On the other hand, the estimated lateral acceleration Yg * acting on the two-wheel model 1A is
Yg * = ν × φ * (2)
It becomes.
The target vehicle speed during turning ν * can be considered as the upper limit value of the vehicle speed at which stable traveling becomes difficult if the two-wheel model 1A at the time of turning exceeds that.
ν * = Yg * / φ * (3)
It becomes.

Therefore, when the turning assist torque Trq is set so that the actual vehicle speed ν does not exceed the turning target vehicle speed ν * that can be obtained in this way, the following is obtained.
Trq = K (ν−ν *) (4)
However, when the actual vehicle speed ν is equal to or lower than the target vehicle speed ν * during turning, the sign is reversed when the turning assist torque Trq is obtained by the above equation (4). However, in such a situation, the turning assist torque Trq is unnecessary. It is. Therefore, in the present embodiment, when the lateral acceleration estimated value Yg * is equal to or less than the threshold value Th, the turning assist torque Trq is forcibly set to 0.

  Then, the turning assist torque calculator 32 shown in FIG. 13 supplies the turning assist torque Trq set according to the above equation (4) to the adder 10f. Therefore, the reference acceleration Gc and the reference vehicle speed Vc are reduced by the turn assist torque Trq while the automobile 1 is turning.

(Operation)
Next, the operation will be described.
FIG. 15 is a flowchart showing an outline of processing in the present embodiment. As shown in FIG. 15, first, at step 300, the steering angle detection signal δd supplied from the steering operation detection device 31 and the vehicle speed detection signal Vd supplied from the vehicle speed sensor 7 are read. Then, the actual operation amount of the handle 30a, that is, the steering angle δ is acquired based on the steering angle detection signal δd, and the actual vehicle speed ν is acquired based on the vehicle speed detection signal Vd.

Next, the process proceeds to step 310, where the lateral acceleration estimated value Yg * is estimated according to the vehicle specifications based on the above equations (1) and (2).
Then, the process proceeds to step 320, where it is determined whether or not the absolute value of the lateral acceleration estimated value Yg * exceeds the threshold value Th.
Here, when the vehicle is traveling straight or when the steering angle δ is small, the lateral acceleration estimated value Yg * is also a small value, so the determination in step 320 is “NO” and the process proceeds to step 330. . In step 330, the turning assist torque Trq = 0.

On the other hand, when the determination in step 320 is “YES”, the process proceeds to step 340, and the turning assist torque Trq is calculated according to the above equation (4).
Then, the process proceeds from step 330 or 340 to step 350, where the rolling resistance component R1, the air resistance component R2, and the turning assist torque Trq are subtracted from the estimated value Ge, and the subtraction result is divided by the mass M of the automobile 1. The reference acceleration Gc is calculated. Further, the reference vehicle speed Vc is calculated by integrating the reference acceleration Gc. Next, the process proceeds to step 360, and the command current Iout is output to the electric motor 2 via the servo compensator 6C, as in step 120 of the first embodiment.

FIG. 16 is a waveform diagram showing an example of the operation of the present embodiment. The automobile 1 that was in a straight traveling state at time t30 gradually shifts to turning as the driver operates the handle 30a, and at time t31. This shows a state where the estimated lateral acceleration value Yg * exceeds a threshold value Th.
In this example, until the time t31, the turning target vehicle speed ν * decreases from an infinite value, but is larger than the actual vehicle speed ν. Therefore, no turning assist torque Trq is generated.

However, as the turning state progresses, the actual vehicle speed ν also gradually decreases. Therefore, after time t31, the determination at step 320 becomes “YES”, and the processing at step 340 is executed to calculate the turning assist torque Trq. . Then, the reference acceleration Gc is set to be lower by the amount corresponding to the turning assist torque Trq, and the actual vehicle speed ν is also reduced.
As a result, as shown in FIG. 16, when the turning assist torque Trq is not used in the reference vehicle model 10, the actual vehicle speed ν tends to gradually decrease as shown by a broken line, whereas the present embodiment In the form, at the time t31, the actual vehicle speed ν coincides with the turning target vehicle speed ν *.

  Here, in the present embodiment, the steering operation detection device 31 corresponds to the steering angle detection unit, and the processing for calculating the target yaw rate φ * according to the above equation (1) in the turning assist torque calculation unit 32 is performed in the target yaw rate calculation unit. Correspondingly, the process of calculating the lateral acceleration estimated value Yg * in accordance with the above equation (2) in the turning assist torque calculating unit 32 corresponds to the lateral acceleration detecting unit, and in the turning assist torque calculating unit 32 according to the above equation (3). The processing for calculating the target vehicle speed ν * during turning corresponds to the target vehicle speed calculating unit during turning, and the processing for calculating the turning assist torque Trq according to the above equation (4) in the turning assist torque calculating unit 32 is performed in the turning assist torque calculating unit. Correspond.

(Effect of the third embodiment)
(1) In the reference vehicle model 10, in addition to executing the processing of the first embodiment, the turning assist torque Trq is obtained so as not to exceed the target vehicle speed ν * during turning which is the upper limit value of the vehicle speed at the time of turning. Since the reference acceleration Gc is decreased by the amount of the turning assist torque Trq, it is possible to adopt a configuration in which control for stabilizing traveling during turning is added to the constant speed traveling control.

(Modification)
In each of the above embodiments, the case where the vehicular driving support apparatus and the vehicle according to the present invention are applied to a so-called electric vehicle using the electric motor 2 as a power source is described, but the present invention is not limited thereto. The present invention can be applied even to an automobile using an internal combustion engine as a power source or a hybrid vehicle including an internal combustion engine and an electric motor.
In the above embodiments, the rolling resistance component R1 and the air resistance component R2 are set to 0 when the flag Fa is set. However, the present invention is not limited to this. Control that sets a slightly large value may be used.

In the third embodiment, the lateral acceleration estimated value is obtained by calculation. However, the present invention is not limited to this. A lateral acceleration sensor that directly detects the lateral acceleration is provided, and the output is obtained as the lateral acceleration. You may make it use for calculation as a detected value.
In each of the above embodiments, the actual acceleration of the vehicle is obtained by calculation based on the actual vehicle speed. However, the present invention is not limited to this, and an acceleration sensor that directly detects the longitudinal acceleration of the vehicle is provided. The output may be used as the actual acceleration detection value for the calculation.

DESCRIPTION OF SYMBOLS 1 Car 2 Electric motor 3 Transmission 4 Drive shaft 5 Drive wheel 6 Controller 6A Driver acceleration / deceleration request estimation part 6B Command value calculation part 6C Servo compensator 6D Adder 6E Actual acceleration detection part 7 Vehicle speed sensor 8 Accelerator pedal 9 Accelerator operation detection Device 10 Reference vehicle model 10a Rolling resistance component storage unit 10b Air resistance component setting unit 10c Selection unit 10d Setting unit 10e Flag setting unit 10f Adder 10g Divider 10h Integrator 11 Subtractor 20 Brake pedal 21 Brake operation detection device 30 Steering column 30a Handle 31 Handle operation detection device 32 Turning assist torque calculator

Claims (6)

An acceleration / deceleration request estimation unit for obtaining an estimated value of the acceleration / deceleration request of the driver;
A disturbance component setting unit for setting a disturbance component that affects the traveling speed of the vehicle;
A target acceleration calculation unit for obtaining a target acceleration based on a value obtained by subtracting the disturbance component from the estimated value estimated by the acceleration / deceleration request estimation unit;
An actual acceleration detector for estimating or detecting the actual acceleration of the vehicle;
An acceleration / deceleration control unit that performs acceleration / deceleration control on the vehicle so that the actual acceleration coincides with the target acceleration during the stop and operation of constant speed traveling control that automatically controls the vehicle speed regardless of the operation of the driver ;
With
The disturbance component setting unit, said of stopped cruise control to a value greater than 0 as the disturbance component, wherein during operation of cruise control is characterized by a 0 the disturbance component A vehicle travel support device. An actual vehicle speed detection unit for detecting the actual vehicle speed of the vehicle;
A steering angle detector for detecting the steering angle of the vehicle;
A target yaw rate calculator that calculates a target yaw rate of the vehicle based on the steering angle;
A lateral acceleration detector that estimates or detects lateral acceleration of the vehicle;
A target vehicle speed calculation unit during turning that calculates a target vehicle speed during turning based on the lateral acceleration and the target yaw rate;
A turning assist torque calculating unit that calculates a turning assist torque so that the actual vehicle speed is equal to or lower than the target vehicle speed during turning when the actual vehicle speed detected by the actual vehicle speed detection unit exceeds the target vehicle speed during turning;
With
2. The target acceleration calculation unit is configured to obtain the target acceleration based on a value obtained by subtracting the disturbance component and the turning assist torque from the estimated value estimated by the acceleration / deceleration request estimation unit. The vehicle travel support apparatus according to claim 1. The disturbance component setting unit, as the disturbance component, and the rolling resistance components, vehicular driving support apparatus according to claim 1 or 2 to set the air resistance component. The vehicular travel support apparatus according to claim 3 , wherein the disturbance component setting unit stores a predetermined constant value as the rolling resistance component. A target vehicle speed calculation unit for obtaining a target vehicle speed based on the target acceleration;
The vehicle travel support apparatus according to claim 3 or 4 , wherein the disturbance component setting unit sets a value proportional to a square value of the target vehicle speed as the air resistance component. The disturbance component setting unit determines that the constant speed traveling control is stopped when any of the accelerator operation unit and the brake operation unit is in an operating state, and determines which of the accelerator operation unit and the brake operation unit The vehicular travel support apparatus according to any one of claims 1 to 5 , wherein when the gear is in a non-operating state, it is determined that the constant speed travel control is in operation.

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