JP5245649B2 - Vehicle speed limit control device - Google Patents

Description

The present invention relates to a vehicle speed limit control device that limits the driving force so that the actual vehicle speed does not exceed the limit vehicle speed.
In particular, the present invention relates to a shock countermeasure when the actual vehicle speed substantially coincides with the limit vehicle speed and the limit of the driving force is finished.

The vehicle speed limit control device controls the driving force so that the actual vehicle speed does not exceed the arbitrarily set limit vehicle speed even when the driver depresses the accelerator pedal greatly.
This is very useful in that the driver can carry out observing the legal vehicle speed while keeping the vehicle speed below the limit vehicle speed without worrying about the accelerator pedal operation.

As such a vehicle speed limit control device, a device described in Patent Document 1, for example, is conventionally known.
This vehicle speed limit control device limits the maximum value of the engine operation demand load such as the accelerator opening and the throttle opening according to the vehicle speed deviation between the limit vehicle speed and the actual vehicle speed, and the actual vehicle speed exceeds the limit vehicle speed. It is to avoid.
JP 11-294215 A

  However, in the above-described conventional vehicle speed limit control device, there is a concern that a shock may occur for the following reason when the actual vehicle speed substantially coincides with the limit vehicle speed and the limit of the driving force is finished.

In other words, when the actual vehicle speed almost coincides with the limit vehicle speed and the limit of the driving force is finished, the driving force has been decreasing at a predetermined change rate according to the decrease in the vehicle speed deviation before that. Thereafter, the driving force is kept constant to maintain the limited vehicle speed.
Therefore, when the actual vehicle speed substantially coincides with the limit vehicle speed and the limit of the driving force is finished, the driving force is switched from a state of decreasing at a predetermined change rate to a state of holding a constant value, and the time series change characteristic of the driving force is “ The “horn” stands.

This time-series change of the driving force with the “angle” causes torsional vibration of the driving force transmission system, and when the actual vehicle speed substantially coincides with the limit vehicle speed and the limit of the driving force is finished, a vibration shock is applied. Cause it to occur.
By the way, recently, there is a tendency to make it possible to set the vehicle speed limit to a low vehicle speed of about 30 km / h. Especially when the vehicle speed limit is set in such a low vehicle speed range, the above-mentioned problem related to shock becomes prominent. Therefore, countermeasures were desired.

  An object of the present invention is to propose a vehicle speed limit control device that can reliably prevent the above-described shock problem even when a limited vehicle speed is set in a low vehicle speed range.

For this purpose, the vehicle speed limiting control device according to the present invention is configured as described in claim 1.
First, to explain the vehicle speed limit control device which is the premise of the present invention,
Vehicle speed detection means for detecting the actual vehicle speed;
Limit vehicle speed setting means for setting a limit vehicle speed as a vehicle speed upper limit value;
Driving force limit for limiting driving force so that the actual vehicle speed does not exceed the limit vehicle speed according to the actual vehicle speed detected by the vehicle speed detection means and the vehicle speed deviation between the limit vehicle speed set by the limit vehicle speed setting means Means ,
Comprising a driver requested driving force calculating means for calculating a driver requested driving force requested by the driver;
The driving force limiting means reduces a vehicle speed limiting target driving force for preventing the detected actual vehicle speed from exceeding the set limiting vehicle speed as the vehicle speed deviation decreases; and The smaller one of the vehicle speed limiting target driving force and the driver required driving force is selected as the final target driving force, and the driving force control is performed so that the final target driving force is achieved. Thus, the driving force for limiting the vehicle speed is limited .

The present invention is characterized in that the vehicle speed limit control device is provided with a driving force change speed limiting means for limiting the change speed of the driving force being limited as described below .
In other words, the driving force change speed limiting means performs a first-order lag process with respect to the decrease in the target driving force for limiting the vehicle speed, and the driver requested driving force increases under the condition that the vehicle speed deviation is less than a set value. Is started, the change rate restriction is applied to the increase in the driver required driving force, and the smaller one of the target driving force for limiting the vehicle speed after the first-order lag processing and the driver request driving force after the change rate restriction is set to the final value. By selecting the target driving force as the target driving force, the changing speed of the driving force being limited by the driving force limiting means is limited.

According to such a vehicle speed limit control device of the present invention, first-order lag processing is performed with respect to a decrease in the target drive force for limiting the vehicle speed, and the driver-requested drive force is obtained under a state where the vehicle speed deviation is less than a set value. When the vehicle starts to increase, the rate of change is limited with respect to the increase in the driver required driving force, and the smaller one of the target driving force for limiting the vehicle speed after the first-order lag processing and the driver required driving force after the rate of change is limited. In order to select it as the final target driving force , the following effect and effect are restricted with respect to the changing speed of the driving force that is being restricted by the driving force restricting means .
In other words, according to the limitation on the driving force change speed, when the actual vehicle speed substantially coincides with the limiting vehicle speed and the limitation of the driving force is finished, the time-series change characteristic of the driving force becomes “angular”. It can be prevented or at least mitigated, and torsional vibration of the driving force transmission system can be prevented or at least mitigated.
Therefore, even when the limited vehicle speed is set in the low vehicle speed range, it is possible to prevent or at least alleviate a shock when the actual vehicle speed substantially coincides with the limited vehicle speed and finishes limiting the driving force.

Hereinafter, embodiments of the present invention will be described in detail based on examples shown in the drawings.
FIG. 1 is a functional block diagram of a vehicle speed limit control device 1 according to an embodiment of the present invention.
2 denotes an engine as a power source, and 3 denotes an automatic transmission.
A vehicle having a power train composed of the engine 2 and the automatic transmission 3 can travel while the power from the engine 2 is transmitted to driving wheels (not shown) while being shifted by the automatic transmission 3.

  The vehicle speed limit control device 1 includes a vehicle speed limit operation determination unit 11, a vehicle speed limit target driving force calculation unit 12, a primary delay setting unit 13, a meter display signal generation unit 14, a driver request driving force calculation unit 15, The change rate limit setting unit 16, the driving force command selection unit 17, the throttle opening command calculation unit 18, and the kickdown determination unit 19 are configured.

The vehicle speed limit control device 1 includes a signal from a vehicle speed sensor 21 (vehicle speed detection means) that detects the actual vehicle speed VSP,
A signal from a vehicle speed limit control switch group 22a provided on the steering wheel 22,
A signal from an accelerator opening sensor 23a for detecting the depression amount (accelerator opening) APO of the accelerator pedal 23;
A signal from the engine rotation sensor 24 for detecting the engine speed Ne is input.

The vehicle speed limit control switch group 22a includes a "SET" switch, a "RES" switch, and a "CANCEL" switch.
In response to the “SET” signal, “RES” signal, and “CANCEL” signal from these switches, the vehicle speed limit operation determination unit 11 sets the limit vehicle speed LmtVSP as described below, The vehicle speed limit shall be lifted.

After the engine 2 ignition switch (not shown) is turned on and the vehicle speed limit has not been performed yet, and the driver desires vehicle speed limit control, the “SET” switch or “RES” Press the switch.
At this time, in response to the “SET” signal or the “RES” signal from the “SET” switch or the “RES” switch, the vehicle speed limit operation determining unit 11 sets the actual vehicle speed VSP at the time of the switch operation as the limited vehicle speed LmtVSP. ,
At the same time, a vehicle speed limit operation signal Sop is output to indicate that the vehicle speed limit control should be performed.

Thereafter, every time the driver presses the “SET” switch, the vehicle speed limit operation determination unit 11 increases the limit vehicle speed LmtVSP at a pitch = “1 Km / h” pitch in response to the “SET” signal from the switch,
Each time the driver presses the “RES” switch, the vehicle speed limit operation determination unit 11 decreases the limit vehicle speed LmtVSP at a pitch = “1 Km / h” pitch in response to the “RES” signal from the switch.

At this time, if the driver keeps pressing the “SET” switch for more than the set time, the vehicle speed limit operation determination unit 11 responds to the “SET” signal duration from the switch and increases the pitch of the limit vehicle speed LmtVSP. Switch the Pitch from the original “1Km / h” to “10Km / h” and increase the speed limit LmtVSP at a pitch of “10Km / h”
When the driver keeps pressing the “RES” switch for a set time or longer, the vehicle speed limit operation determination unit 11 initially sets the decrease pitch Pitch of the limit vehicle speed LmtVSP in response to the “RES” signal duration from the switch. From “1Km / h” to “10Km / h”, the speed limit LmtVSP is rapidly reduced at Pitch = “10Km / h” pitch.

Therefore, the "SET" switch and the "RES" switch of the vehicle speed limit control switch group 22a each serve to command the limit vehicle speed,
The vehicle speed limit operation determination unit 11 corresponds to a limit vehicle speed setting means in the present invention that sets a limit vehicle speed that is a vehicle speed upper limit value in response to the limit vehicle speed command.

The driver presses the “CANCEL” switch when he wants to end the vehicle speed limit control.
At this time, the vehicle speed limit operation determination unit 11 causes the vehicle speed limit operation signal Sop to disappear in response to the “CANCEL” signal from the switch.
Therefore, the limit vehicle speed LmtVSP is kept at the value at the time of disappearance of the vehicle speed limit operation signal Sop until the engine ignition switch is turned OFF for the next vehicle speed limit control.
Next, when the driver desires vehicle speed limit control and presses the “SET” switch or “RES” switch, the stored limit vehicle speed LmtVSP is used as an initial value.

Based on the accelerator opening APO, the kick-down determination unit 19 determines whether or not the accelerator pedal 23 is in a kick-down state in which the pedal is depressed to the maximum vicinity, and outputs a kick-down signal Skd when in the kick-down state. When not in the kick down state, the kick down signal Skd is not output.
As described above, the vehicle speed limit operation determining unit 11 eliminates the vehicle speed limit operation signal Sop in response to the “CANCEL” signal, and also when the vehicle is in the kickdown state in response to the kickdown signal Skd, Let Sop disappear.

In addition, the vehicle speed limit operation determination unit 11 also eliminates the vehicle speed limit operation signal Sop even when the vehicle speed VSP is a low vehicle speed lower than the set vehicle speed that should not be limited.
Even when the vehicle speed limit operation signal Sop disappears in response to these kick-down states or low vehicle speeds, the vehicle speed limit operation signal Sop remains until the engine ignition switch is turned OFF for the next vehicle speed limit control. Keep the value at the time of disappearance of
Next, when the driver desires vehicle speed limit control and presses the “SET” switch or “RES” switch, the stored limit vehicle speed LmtVSP is used as an initial value.

The vehicle speed limiting target driving force calculation unit 12 receives the vehicle speed limiting operation signal Sop, the limiting vehicle speed LmtVSP, and the actual vehicle speed VSP, and between the limited vehicle speed LmtVSP and the actual vehicle speed VSP while the vehicle speed limiting operation signal Sop exists. In response to the vehicle speed deviation ΔVSP, the driving force is limited by a predetermined control gain G to calculate the vehicle speed limiting target driving force LmtTd so that the actual vehicle speed VSP does not exceed the limiting vehicle speed LmtVSP.
Therefore, the vehicle speed limiting target driving force calculator 12 corresponds to the driving force limiting means in the present invention.
Thus, while the vehicle speed limiting operation signal Sop is not present, the vehicle speed limiting target driving force calculation unit 12 fixes the vehicle speed limiting target driving force LmtTd to a maximum realizable value.

The primary delay setting unit 13 is input with the target driving force LmtTd for limiting the vehicle speed, the vehicle speed limiting operation signal Sop, the limiting vehicle speed LmtVSP, and the actual vehicle speed VSP,
While the vehicle speed limit operation signal Sop exists, if the vehicle speed deviation ΔVSP between the limited vehicle speed LmtVSP and the actual vehicle speed VSP is less than the set vehicle speed deviation ΔVSPs, a primary delay process is applied to the decrease in the target driving force LmtTd for limiting the vehicle speed. Then, the target driving force fLmtTd for primary speed processed vehicle speed restriction is obtained.
Therefore, the primary delay setting unit 13 constitutes a driving force change speed limiting means in the present invention.

Here, the set vehicle speed deviation ΔVSPs is made to correspond to the lower limit value of the vehicle speed deviation ΔVSP that does not cause a problem related to the vibration shock to be solved by the present invention.
Further, the first-order lag setting unit 13 obtains the first-delay processed vehicle speed limiting target driving force fLmtTd by filtering the decreasing vehicle speed limiting target driving force LmtTd,
When the actual vehicle speed VSP substantially coincides with the limit vehicle speed LmtVSP and the drive force limit is completed with the filter value (time constant), the drive force is always in a smooth and constant state with a time-series change without the aforementioned “angle”. As described above (so as not to cause the problem relating to the shock to be solved by the present invention), the smaller the vehicle speed deviation ΔVSP, the larger the filter value (time constant).

Therefore, even if the vehicle speed limit operation signal Sop exists, the first-order lag setting unit 13 may cause a problem related to the shock to be solved by the present invention if the vehicle speed deviation ΔVSP is equal to or greater than the set vehicle speed deviation ΔVSPs. Therefore, the vehicle speed limiting target driving force LmtTd is directly used as the first-order-delay processed vehicle speed limiting target driving force fLmtTd.
If the vehicle speed limiting operation signal Sop does not exist, the primary delay setting unit 13 naturally uses the vehicle speed limiting target driving force LmtTd as it is as the primary delay processed vehicle speed limiting target driving force fLmtTd.

When the vehicle speed limit operation signal Sop is present based on the limit vehicle speed LmtVSP and the vehicle speed limit operation signal Sop, the meter display signal generation unit 14 is as shown in the limit vehicle speed display unit 31a of the meter panel 31 in front of the driver seat. Generate a meter display signal to display the limit vehicle speed LmtVSP,
When the vehicle speed limit operation signal Sop does not exist, a meter display signal is generated so that the vehicle speed limit non-operation is displayed on the limit vehicle speed display unit 31a of the meter panel 31 instead of the limit vehicle speed LmtVSP.

The driver requested driving force calculation unit 15 is requested by the driver by operating the accelerator pedal based on the current engine speed Ne based on the planned driving force map from the accelerator opening APO and the engine speed Ne. The required driver driving force DrvTd is calculated.
Therefore, the driver required driving force calculating unit 15 corresponds to the driver required driving force calculating means in the present invention.

The change rate limit setting unit 16 is input with the driver requested driving force DrvTd, the vehicle speed limit operation signal Sop, the limit vehicle speed LmtVSP, and the actual vehicle speed VSP,
While the vehicle speed limit operation signal Sop exists, if the vehicle speed deviation ΔVSP between the limited vehicle speed LmtVSP and the actual vehicle speed VSP is less than the set vehicle speed deviation ΔVSPs, the rate of change restriction process is applied to the increase in the driver required driving force DrvTd. Then, the driver requested driving force kDrvTd whose rate of change is limited is obtained.
Therefore, the change rate limit setting unit 16 constitutes a driving force change speed limiting means in the present invention.

Here, the set vehicle speed deviation ΔVSPs has the same purpose as described above with respect to the first-order delay setting unit 13, and the lower limit value of the vehicle speed deviation ΔVSP that does not cause the problem related to the vibration shock to be solved by the present invention. To correspond to.
The rate-of-change restriction setting unit 16 limits the rate of change (increase speed) of the driver-requested driving force DrvTd that is rising so that the torsional vibration of the drive system does not occur, and the driver-requested driving force kDrvTd that is rate-limited. And
This rate of change (climbing speed) limit is set to a larger rate of change (climbing speed) limit as the vehicle speed deviation ΔVSP is smaller so that the intended purpose is achieved.
As the vehicle speed deviation ΔVSP is larger, the actual vehicle speed VSP is made to follow the limit vehicle speed LmtVSP more quickly, so that the deficiency in driving force is eased.

Therefore, even if the vehicle speed limiting operation signal Sop exists, the change rate limit setting unit 16 determines that the primary delay setting unit 13 applies the vehicle speed limiting target driving force LmtTd to the vehicle speed limiting target driving force LmtTd if the vehicle speed deviation ΔVSP is equal to or greater than the set vehicle speed deviation ΔVSPs. Since the first-order lag processing is not performed, the driver request driving force DrvTd is directly used as the change rate limited driver request driving force kDrvTd.
If the vehicle speed limit operation signal Sop does not exist, the change rate limit setting unit 16 naturally sets the driver request driving force DrvTd as it is as the change rate limited driver request drive force kDrvTd.

The driving force command selection unit 17 uses the smaller Min (kDrvTd, fLmtTd) as the final driving force command tTd among the change rate limited driver requested driving force kDrvTd and the primary delay processed vehicle speed limiting target driving force fLmtTd. select.
Accordingly, the driving force command selection unit 17 together with the vehicle speed limiting target driving force calculation unit 12 constitutes a driving force limiting means in the present invention.
The throttle opening degree command calculation unit 18 obtains a throttle opening degree instruction tTVO for realizing the above-described final driving force instruction tTd = Min (kDrvTd, fLmtTd).

The engine 2 includes an electronically controlled throttle valve 32, and the output is adjusted by electronically controlling the opening degree of the throttle valve 32 by a motor 33.
The throttle opening command tTVO obtained by the throttle opening command calculation unit 18 is commanded to the motor 33, and the throttle valve 32 is electronically controlled via the motor 33 so that the opening coincides with the throttle opening command tTVO.

The vehicle speed limit control based on the output control of the engine 2 through the opening control of the electronically controlled throttle valve 32 will be described in detail below.
During the vehicle speed limiting control in which the vehicle speed limiting operation signal Sop is output, the vehicle speed limiting target driving force LmtTd obtained by the vehicle speed limiting target driving force calculation unit 12 becomes VSP (actual vehicle speed)> LmtVSP (restricted vehicle speed). It is a value that prevents it from happening.

  Therefore, when the driver depresses the accelerator pedal 23 greatly and the driver required driving force DrvTd is larger than the vehicle speed limiting target driving force LmtTd, the change rate limited driver required driving force kDrvTd from the change rate limit setting unit 16 (Described in detail later) is larger than the primary delay processed vehicle speed limiting target driving force fLmtTd (described in detail later) from the primary delay setting unit 13.

Therefore, the selection unit 17 finally determines the smaller one of the change rate-restricted driver required driving force kDrvTd and the primary delay processed vehicle speed limiting target driving force fLmtTd, that is, the primary delay processed vehicle speed limiting target driving force fLmtTd. Selected as the correct driving force command tTd.
The calculation unit 18 obtains a throttle opening command tTVO for realizing the final driving force command tTd, and contributes to the opening control of the electronically controlled throttle valve 32.
For this reason, even if the driver depresses the accelerator pedal 23 greatly, the output of the engine 2 is limited so that the actual vehicle speed VSP does not exceed the limit vehicle speed LmtVSP, and the vehicle speed limit control can be performed.

Even during the vehicle speed limiting control in which the vehicle speed limiting operation signal Sop is output, the amount of depression of the accelerator pedal 23 (accelerator opening APO) by the driver is small, and the driver required driving force DrvTd is the target driving force for limiting the vehicle speed. If less than LmtTd,
The change rate-restricted driver requested driving force kDrvTd (described in detail later) from the change rate limit setting unit 16 is a primary delay processed vehicle speed limiting target driving force fLmtTd (described in detail later) from the primary delay setting unit 13. Smaller than).

Therefore, the selection unit 17 finally determines the smaller one of the change rate limited driver required driving force kDrvTd and the primary delay processed vehicle speed limiting target driving force fLmtTd, that is, the change rate limited driver required driving force kDrvTd. Select as driving force command tTd.
The calculation unit 18 obtains a throttle opening command tTVO for realizing the final driving force command tTd, and contributes to the opening control of the electronically controlled throttle valve 32.
From the above, since the driver does not depress the accelerator pedal 23 greatly, during the driving in which the actual vehicle speed VSP does not exceed the limit vehicle speed LmtVSP, the engine 2 is driven with the change rate limited driver's required driving force kDrvTd (final Can be output-controlled to realize the driver-requested driving force (DrvTd), so that it is possible to avoid troubles in normal driving.

The driver presses the `` CANCEL '' switch in the switch group 22a, the driver enters a kick-down state where the accelerator pedal 23 is depressed to the maximum vicinity, the vehicle speed VSP becomes extremely low, and the vehicle speed limit operation signal Sop is While vehicle speed limit control is not being executed after it no longer exists,
The vehicle speed limiting target driving force calculation unit 12 fixes the vehicle speed limiting target driving force LmtTd to the maximum feasible value.
Therefore, no matter how much the driver depresses the accelerator pedal 23, the driver required driving force DrvTd does not become larger than the vehicle speed limiting target driving force LmtTd, and the change rate restricted driver from the change rate restriction setting unit 16 The required driving force kDrvTd (described in detail later) does not become larger than the primary delay processed vehicle speed limiting target driving force fLmtTd (described in detail later) from the primary delay setting unit 13.

For this reason, the selection unit 17 always selects the smaller change rate-restricted driver-requested driving force kDrvTd as the final driving force command tTd.
The calculation unit 18 obtains a throttle opening command tTVO for realizing the final driving force command tTd, and contributes to the opening control of the electronically controlled throttle valve 32.
Therefore, when vehicle speed limit control is not being executed, the engine 2 can constantly be output controlled to achieve the driver-required drive force kDrvTd (change driver-required drive force DrvTd) with a limited rate of change. Driving can be performed.

Next, the automatic transmission 3 will be described. The automatic transmission 3 is assumed to be a forward seven-speed multistage automatic transmission, and its transmission control is performed by the transmission controller 34.
For this reason, the actual vehicle speed VSP detected by the sensor 21 and the throttle opening degree command tTVO obtained by the calculation unit 18 are input to the transmission controller 34.
From the actual vehicle speed VSP and the throttle opening command tTVO, the transmission controller 34 obtains the optimum gear position for the current operating state based on the planned shift pattern,
The automatic transmission 3 is automatically shifted from the currently selected shift speed to the optimum shift speed.

  Here, the primary delay is set based on the vehicle speed limiting target driving force LmtTd calculated by the vehicle speed limiting target driving force calculation unit 12 and the driver required driving force DrvTd calculated by the driver required driving force calculation unit 15. The manner in which the unit 13, the change rate limit setting unit 16, and the driving force command selection unit 17 obtain the final driving force command tTd will be described below with reference to FIG.

Prior to this description, the reason why the driving force command tTd needs to be obtained in the manner shown in FIG. 2 will be described with reference to FIG.
In FIG. 3, the limit vehicle speed LmtVSP is set as shown in the figure, the actual vehicle speed VSP is lower than the limit vehicle speed LmtVSP, and the vehicle speed deviation ΔVSP between the two is less than the set vehicle speed deviation ΔVSPs. 6 is a time chart when the accelerator pedal 23 is depressed and the driver's required driving force DrvTd increases stepwise as shown in the figure.

  When the actual vehicle speed VSP increases as shown in the engine output increase control (throttle opening increase control) in response to the increase in the driver required driving force DrvTd, the vehicle speed deviation ΔVSP between the actual vehicle speed VSP and the limit vehicle speed LmtVSP is illustrated. As the vehicle speed deviation ΔVSP decreases, the vehicle speed limiting target driving force LmtTd also decreases as shown in the figure.

As shown in FIG. 1, the first-order lag setting unit 13 and the change rate limit setting unit 16 in this embodiment are not provided, and the vehicle speed limiting target driving force LmtTd and the driver-requested driving force DrvTd are directly input to the driving force command selecting unit 17. if you did this,
The driving force command selection unit 17 selects the smaller one of the vehicle speed limiting target driving force LmtTd and the driver required driving force DrvTd as the driving force command tTd, and the driving force command tTd is as shown by a thick broken line α in FIG. Things and things.

In this case, the driving force command tTd rapidly increases to a large value immediately after the acceleration instant t1, and then decreases rapidly shortly thereafter.
Thus, when the driving force command tTd suddenly rises and falls within a short time, it causes torsional vibration of the driving force transmission system, and as is clear from the time series change indicated by the broken line of the vehicle longitudinal acceleration Gx, This causes a vibrational shock due to resonance vibration.

Also, at the end of the driving force limit when the actual vehicle speed VSP substantially matches the limited vehicle speed LmtVSP, the driving force command tTd is switched from the reduced state at the predetermined change rate to the constant state as shown in β, and when the driving force command tTd The series change characteristic becomes “horny”.
The time-series change of the driving force command tTd with such an "angular" also causes torsional vibration of the driving force transmission system, resulting in a vibration shock as is apparent from the time-series change indicated by the broken line of the vehicle longitudinal acceleration Gx. Let
By the way, recently, there is a tendency that the limit vehicle speed LmtVSP can be set to a low vehicle speed of about 30 km / h. Especially when the limit vehicle speed LmtVSP is set in such a low vehicle speed range, the above-mentioned problems related to both shocks are particularly problematic. Become prominent.

The present embodiment is provided with a first-order lag setting unit 13 and a change rate limit setting unit 16 as shown in FIG.
Based on the vehicle speed limiting target driving force LmtTd calculated by the vehicle speed limiting target driving force calculation unit 12 and the driver required driving force DrvTd calculated by the driver required driving force calculation unit 15, a primary delay setting unit 13, It is assumed that the change rate limit setting unit 16 and the driving force command selecting unit 17 execute the control program shown in FIG. 2 and obtain the final driving force command tTd as follows.

Step S11 in FIG. 2 corresponds to the vehicle speed limiting target driving force calculation unit 12 and the driver required driving force calculation unit 15 in FIG. 1, and the vehicle speed is calculated by the same calculation processing as that performed by these calculation units 12 and 15. The limiting target driving force LmtTd and the driver required driving force DrvTd are obtained.
In the next step S12, the same determination as that performed by the primary delay setting unit 13 and the change rate limit setting unit 16 in FIG. 1, that is, the vehicle speed deviation ΔVSP between the limit vehicle speed LmtVSP and the actual vehicle speed VSP is less than the set vehicle speed deviation ΔVSPs. It is determined whether or not there is a small vehicle speed deviation region that causes a shock due to the “angle” of the driving force change characteristic as in β of FIG.

If ΔVSP ≧ ΔVSPs, that is, if the “angle” β of the driving force change characteristic does not occur and a large vehicle speed deviation region does not cause a shock due to this, the control proceeds to step S13.
In this step S13, the same process as that of the driving force command selection unit 17 in FIG. 1 is performed, and the smaller Min of the change rate limited driver required driving force kDrvTd and the primary delay processed vehicle speed limiting target driving force fLmtTd. (KDrvTd, fLmtTd) is selected as the final driving force command tTd,
Now, ΔVSP ≧ ΔVSPs, and as described above, the change rate limit setting unit 16 directly changes the driver required driving force DrvTd to the change rate limited driver required driving force kDrvTd, and the primary delay setting unit 13 sets the target drive for vehicle speed limitation. In order to use the force LmtTd as it is as the target driving force fLmtTd for first-order lag processed vehicle speed limitation,
As a result, step S13 selects the smaller Min (DrvTd, LmtTd) of the driver required driving force DrvTd and the vehicle speed limiting target driving force LmtTd as the final driving force command tTd, and this is used for throttle opening control. (Engine output control)

If it is determined in step S12 that ΔVSP <ΔVSPs, that is, if the “angle” β of the driving force change characteristic is generated and a small vehicle speed deviation region causing a shock due to this occurs, control is performed in steps S14 to S17, and It progresses to step S18-step S21.
In the former step S14 to step S17, the same processing as the first-order lag setting unit 13 in FIG. 1 is performed to obtain the first-order lag processed target speed driving target fLmtTd as follows.

First, in step S14, it is checked whether or not the vehicle speed limiting target driving force LmtTd is decreased depending on whether or not the vehicle speed limiting target driving force LmtTd is smaller than LmtTd (previous value).
If the vehicle speed limiting target driving force LmtTd has not decreased, the vehicle speed limiting target driving force LmtTd is directly used as the primary delay processed vehicle speed limiting target driving force fLmtTd in step S15, and the primary delay processed vehicle speed is determined in the next step S17. Update the limiting target driving force fLmtTd.

If the vehicle speed limiting target driving force LmtTd has decreased, the vehicle speed limiting target driving force LmtTd is subjected to the first-order lag processing as follows to obtain the first-delay processed vehicle speed limiting target driving force fLmtTd in step S16.
fLmtTd = (fLmtTd × filter value) + {fLmtTd (previous value) × (1−filter value)}
The above filter value represents the time constant of the first-order lag processing. When the actual vehicle speed VSP substantially coincides with the limit vehicle speed LmtVSP and the drive force limit is completed, the drive force always has a time-series change without the above-mentioned “angle” β. The smaller the vehicle speed deviation ΔVSP is, the larger the filter value (time constant) is set so that the state becomes smooth and constant.

  In the next step S17, the primary delay processed vehicle speed limiting target driving force fLmtTd is updated with the primary delay processed vehicle speed limiting target driving force obtained in step S16 as described above.

  In the latter step S18 to step S21, processing similar to that performed by the rate-of-change restriction setting unit 16 in FIG.

First, in step S18, it is checked whether or not the driver required driving force DrvTd is increased depending on whether or not the driver required driving force DrvTd is larger than DrvTd (previous value).
If the driver required driving force DrvTd has not increased, the driver required driving force DrvTd is directly used as the change rate limited driver required driving force kDrvTd in step S19, and the change rate limited driver required driving is determined in the next step S21. Update the force kDrvTd.

If the driver required driving force DrvTd has increased, the driver requested driving force DrvTd is subjected to the change rate limiting process as follows in step S20 to obtain the change rate restricted driver required driving force kDrvTd.
kDrvTd = kDrvTd (previous value) + ΔDrvTd
The above ΔDrvTd represents the amount of increase in the driver required driving force DrvTd per control cycle, and regulates the increase change rate related to the driver required driving force DrvTd.
Immediately after the acceleration instant t1 in FIG. 3, the change rate (increase speed) of the driver-requested driving force DrvTd is set to a value so that the torsional vibration of the driving system does not occur.

Therefore, the above-mentioned ΔDrvTd has a small vehicle speed deviation ΔVSP so that the rate of change (rising speed) of the driver-required driving force kDrvTd with the rate-of-change limited can be achieved. Decide to be moderate.
However, when the vehicle speed deviation ΔVSP is large, the actual vehicle speed VSP quickly follows the limited vehicle speed LmtVSP to alleviate the lack of driving force. The ΔDrvTd is determined to be larger as the vehicle speed deviation ΔVSP is larger to meet this purpose.

  In the next step S21, the change rate limited driver required driving force kDrvTd is updated with the change rate limited driver required driving force obtained in step S20 as described above.

The target driving force fLmtTd for the first-order lag processed vehicle speed restriction is obtained in step S14 to step S17, and is selected after the change rate restricted driver demanded driving force kDrvTd is obtained in step S18 to step S21 as described above. In steps S22 to S24,
The same processing as that of the driving force command selection unit 17 in FIG. 1 is performed, and the smaller Min (kDrvTd, fLmtTd) of the change rate-restricted driver requested driving force kDrvTd and the first-order delayed processed vehicle speed limiting target driving force fLmtTd Is selected as the final driving force command tTd.

That is, first, in step S22, it is checked whether or not the change rate limited driver required driving force kDrvTd is smaller than the primary delay processed vehicle speed limiting target driving force fLmtTd.
If kDrvTd <fLmtTd, in step S23, the smaller one of them (change rate limited driver-requested driving force kDrvTd) is selected as the final driving force command tTd,
If kDrvTd ≧ fLmtTd, in step S24, the smaller one (first-order delayed processed vehicle speed limiting target driving force fLmtTd) is selected as the final driving force command tTd.
The final driving force command tTd determined as described above in step S23 or step S24 is used for throttle opening control (engine output control).

The driving force command tTd determined as described above with reference to FIG. 2 is considered below with respect to FIG.
The driver required driving force DrvTd indicated by a thin broken line is limited in its rate of change (rising speed) to the gradient determined by the above-described ΔDrvTd, and the driver required driving force kDrvTd which is moderately changed as indicated by a two-dot chain line (Step S20).
On the other hand, the target driving force LmtTd for limiting the vehicle speed indicated by the thin solid line is subjected to the first-order lag processing described above, and becomes the target driving force for limiting the vehicle speed fLmtTd after the first-order lag processing indicated by the one-dot chain line (step S16).

  Then, in step S22 to step S24, the smaller Min (kDrvTd, fLmtTd) of the change rate-restricted driver required driving force kDrvTd and the first-delay processed vehicle speed limiting target driving force fLmtTd is used as the final driving force command tTd. Therefore, the final driving force command tTd is as shown by a thick solid line in FIG.

The driving force command tTd according to this embodiment is an acceleration moment t1 during the vehicle speed limiting control, as is clear from the comparison with the driving force command characteristic α indicated by the thick broken line when the countermeasure as in this embodiment is not taken. The rate of change (rising speed) immediately after is moderate, limited by ΔDrvTd, and its maximum value is small,
As a result, the driving force command tTd is not greatly increased or decreased in a short time, and the torsional vibration of the driving force transmission system is not generated. As a result, the time series indicated by the solid line of the vehicle longitudinal acceleration Gx As is apparent from the change, it is possible to avoid the occurrence of a vibrational front-rear shock.

Therefore, the above ΔDrvTd is the vehicle speed deviation in order to ensure that the change rate (rising speed) ΔDrvTd of the driver requested drive force kDrvTd with the change rate restricted is the desired purpose (preventing torsional vibration of the drive system). Decrease so that ΔVSP is smaller as it is smaller.
However, when the vehicle speed deviation ΔVSP is large, the actual vehicle speed VSP needs to be quickly followed by the limit vehicle speed LmtVSP to alleviate the lack of driving force. Speed) ΔDrvTd is determined to be larger as the vehicle speed deviation ΔVSP is larger.

Further, since the driving force command tTd according to the present embodiment is decreasing and decreases in accordance with the primary delay processed vehicle speed limiting target driving force fLmtTd, the actual vehicle speed VSP (in FIG. As shown in the time series change of the driving force command tTd at γ at the end of the vehicle speed limit when only the actual vehicle speed without the countermeasures in the example is shown) is the same as the limit vehicle speed LmtVSP Switch smoothly.
Therefore, the “angle” β generated in the time series change characteristic α of the driving force command when the countermeasure of the present embodiment is not taken is not generated by the time series change of the driving force command tTd in the present embodiment. .

By the way, the time-series change of the driving force command tTd where the “angle” β stands causes torsional vibration of the driving force transmission system when the actual vehicle speed VSP substantially coincides with the limit vehicle speed LmtVSP and the limit of the driving force is finished. This causes a vibration shock,
This problem is particularly noticeable when the vehicle speed limit LmtVSP is set to a low vehicle speed of about 30 km / h.

However, in the present embodiment, as described above, since the “angle” as shown by β does not stand in the time series change of the driving force command tTd, even when the limited vehicle speed LmtVSP is set to a low vehicle speed,
When the actual vehicle speed VSP substantially coincides with the limit vehicle speed LmtVSP and the drive force limit is finished, the drive force transmission system does not cause torsional vibration, and the drive force transmission system torsional vibration generates a vibrational shock. The above-mentioned problem can be avoided reliably.

As in this embodiment, when the first-order lag processing filter value (time constant) is set to a larger filter value (time constant) as the vehicle speed deviation ΔVSP is smaller, the first-order lag effect is increased. It can be achieved more reliably.
Further, when the filter value (time constant) of the first-order lag process is set as in this embodiment, the greater the vehicle speed deviation ΔVSP, the greater the filter value (time constant) and the effect of the first-order lag is reduced. And
When the vehicle speed deviation ΔVSP is large, the driving force command tTd can be quickly reduced, and as a result, an overshoot in which the actual vehicle speed VSP greatly exceeds the limit vehicle speed LmtVSP can be avoided.

Here, the reason why the rate-of-change restriction is applied instead of the first-order lag process when restricting the rising speed of the driver-requested driving force DrvTd will be described below.
As is well known, the first-order lag process has a large process response delay, and when the driver requested drive force DrvTd is subjected to the first-order lag process to limit its rising speed, the driver requested drive force after the increase speed limit is If the response delay time has not elapsed since t1 (see FIG. 3), the vehicle will not start to rise, and the rising of the driving force will be delayed from the acceleration instant t1, giving the driver a sense of incongruity.

On the other hand, as in this embodiment, when limiting the rising speed of the driver required driving force DrvTd, the rate of change (rising speed) of the driver required driving force DrvTd is limited to ΔDrvTd by limiting the change rate. If you want to
As is clear from the rising response of the driver requested driving force kDrvTd with the rate of change limited from the acceleration instant t1 shown in Fig. 3, the driver requested driving without causing the driver to feel the rising response delay of the uncomfortable driving force. The above-mentioned effect can be achieved by limiting the rising speed of the force DrvTd.

It is a block diagram according to function which shows the vehicle speed restriction | limiting control apparatus which becomes one Example of this invention. 2 is a flowchart showing a control program for obtaining a driving force command used by the vehicle speed limit control device in FIG. 1 for limiting the vehicle speed. FIG. 3 is an operation time chart showing a calculation procedure of a driving force command by the control program of FIG.

Explanation of symbols

1 Vehicle speed limit control device
2 Engine
3 Automatic transmission
11 Vehicle speed limit operation determination section (Limited vehicle speed setting means)
12 Target driving force calculation unit for limiting vehicle speed (driving force limiting means)
13 Primary delay setting section (Driving force change speed limiting means)
14 Meter display signal generator
15 Driver required driving force calculator
16 Change rate limit setting section (Driving force change speed limiting means)
17 Driving force command selector (driving force limiting means)
18 Throttle opening calculator
19 Kickdown judgment part
21 Vehicle speed sensor (vehicle speed detection means)
22 Steering wheel
22a Speed limit control switch group
23 Accelerator pedal
23a Accelerator position sensor
24 Engine rotation sensor
31 Meter panel
31a Speed limit display
32 Electronically controlled throttle valve
33 Motor
34 Transmission controller

Claims (3)

Vehicle speed detection means for detecting the actual vehicle speed;
Limit vehicle speed setting means for setting a limit vehicle speed as a vehicle speed upper limit value;
Driving force limit for limiting driving force so that the actual vehicle speed does not exceed the limit vehicle speed according to the actual vehicle speed detected by the vehicle speed detection means and the vehicle speed deviation between the limit vehicle speed set by the limit vehicle speed setting means Means ,
A driver required driving force calculating means for calculating a driver required driving force requested by the driver,
The driving force limiting means reduces a vehicle speed limiting target driving force for preventing the detected actual vehicle speed from exceeding the set limiting vehicle speed as the vehicle speed deviation decreases; and The smaller one of the vehicle speed limiting target driving force and the driver required driving force is selected as the final target driving force, and the driving force control is performed so that the final target driving force is achieved. In the vehicle speed limit control device for limiting the driving force for limiting the vehicle speed,
A first-order lag process is performed with respect to a decrease in the target driving force for limiting the vehicle speed, and when the driver-requested driving force starts to increase under a state where the vehicle speed deviation is less than a set value, the driver-requested driving By applying a rate of change limitation to the increase in force, and selecting the smaller one of the target driving force for limiting the vehicle speed after the first-order lag processing and the driver request driving force for which the rate of change has been limited, as the final target driving force. A vehicle speed limiting control device comprising driving force change speed limiting means for limiting the speed of change of the driving force being limited by the driving force limiting means . In the vehicle speed limit control device according to claim 1 ,
The first-order lag process for the decrease in the target driving force for limiting the vehicle speed is a first-order lag process with a larger time constant as the vehicle speed deviation is smaller. In the vehicle speed limit control device according to claim 1 or 2 ,
The vehicle speed limit control device according to claim 1, wherein the change rate limit for the increase in the driver-requested driving force is a change rate limit that decreases as the vehicle speed deviation increases.

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