JPH09202157A - Vehicle drive controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve responsiveness with respect to control by calculating a target variation amount of traveling torque based on the deviation between a distance between cars and a target distance between cars, inputting an actuator manipulation amount and varying the speed. SOLUTION: A laser radar 10 detecting a steric hinderer through a reflected wave is provided. A controller unit 20 composed of a microprocesser finds a distance between cars from the output of the laser radar 10, detects the speed from the output of a speed sensor 12, and drives a throttle actuator 14. In order to control the distance between cars, throttle motor control amount is determined so that the deviation between the target distance between cars and the actual distance between cars may be zero. A target variation amount of the traveling torque is calculated on the basis of the deviation between the distance between cars and the target distance between cars and the manipulating amount is calculated on the basis of the target variation amount of the traveling torque and the self car speed. The actuator manipulation amount is calculated on the basis of the manipulation amount, inputted and the speed is varied. Thus responsiveness to variation of the distance between cars can be improved and acceleration and deceleration can be suitably controlled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle travel control device, and more particularly, to a vehicle travel control device for controlling a vehicle to follow a vehicle while maintaining a vehicle-to-vehicle distance at a predetermined value.
In the following description, the "inter-vehicle distance" is abbreviated as "inter-vehicle distance" for simplification.

[0002]

2. Description of the Related Art In inter-vehicle distance control, generally, a throttle opening is controlled by using a PID control law to control a vehicle speed to a target value. An example thereof is the technique described in Japanese Patent Laid-Open No. 5-213094. In this conventional technique, the target vehicle distance is calculated from the vehicle distance with the preceding vehicle and the own vehicle speed, the target vehicle speed after a predetermined time is predicted, and the acceleration gain is changed according to the vehicle distance to reach the target vehicle speed. The opening is being operated.

The technique described in Japanese Patent Laid-Open No. 4-283744 also proposes to set the control gain according to the target inter-vehicle distance and the actual inter-vehicle distance.

[0004]

However, in the above-mentioned prior art, since the acceleration gain is switched and reduced, there is a problem that an oscillatory behavior occurs near the switching of the gain. Further, if a means for smoothly changing the gain or reducing the overall gain is added to suppress the vibrational behavior, there is a problem that the responsiveness is lowered.

Therefore, a first object of the present invention is to provide a vehicular travel control device which solves the above-mentioned inconvenience and improves the control response.

In addition to this, when the target vehicle speed is calculated from the target vehicle distance and the throttle is controlled, for example, when a preceding vehicle is detected, the target vehicle speed is reduced to correct the vehicle distance. In order to improve the speed, as shown in FIG. 25, complicated control is required such as lowering the target vehicle speed more than necessary and returning the target vehicle speed to the original value after sufficiently decelerating.

To improve the responsiveness to the above problems without performing complicated control, it is conceivable to directly calculate the throttle control amount from the inter-vehicle distance without using the target vehicle speed. Since the relationship between the quantity and the torque (acceleration) is not linear, acceleration / deceleration control is difficult.

Therefore, a second object of the present invention is to provide a vehicular traveling control device capable of improving responsiveness to a change in vehicle distance and appropriately controlling acceleration / deceleration. And

Further, in the above-mentioned prior art, the operation amount is the throttle opening, but the control amount (engine output) may differ greatly even if the throttle opening has the same value. Therefore, if the throttle opening is the manipulated variable, it may not always be possible to obtain the intended control result.

Therefore, a third object of the present invention is to provide a vehicular travel control device which solves the above-mentioned drawbacks by making the operation amount a torque.

[0011]

In order to achieve the above first object and the like, a traveling control device for a vehicle according to claim 1 is an inter-vehicle distance for detecting an inter-vehicle distance between a host vehicle and a preceding vehicle. Detecting means, target inter-vehicle distance setting means for setting the target inter-vehicle distance, obtaining the own vehicle speed, and multiplying it by the coefficient of the factor affecting the behavior of the vehicle to calculate the running torque currently output by the own vehicle Means, a running torque target change amount calculating means for calculating a target change amount of the running torque based on a deviation between the inter-vehicle distance and the target inter-vehicle distance, and operation based on the running torque, the target change amount of the running torque, and the own vehicle speed. An operation amount calculation means for calculating an amount, an actuator operation amount calculation means for calculating an actuator operation amount based on the operation amount, and an actuator for changing the vehicle speed by inputting the actuator operation amount. Yueta, it was constructed as consisting of.

[0012]

[Operation] While improving the responsiveness to changes in vehicle distance,
Acceleration / deceleration can be controlled appropriately.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a vehicle travel control device according to the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is an explanatory block diagram generally showing a vehicle travel control device according to the present invention.

As shown in the figure, this device is equipped with a laser radar 10 which is mounted in front of the own vehicle and detects a three-dimensional obstacle such as a preceding vehicle ahead of the own vehicle through reflected waves (FIG. 2).
Hereinafter, the laser radar is indicated by L / R). Further, a vehicle speed sensor 12 for detecting the traveling speed of the vehicle is provided at an appropriate position such as a drive shaft (not shown) of the vehicle, and a throttle actuator (throttle motor) formed of an electric motor is provided for the throttle valve (not shown). 14 is attached via a clutch (not shown).

A control unit (controller) 20 including a microprocessor obtains the inter-vehicle distance from the output of the laser radar 10 and detects the vehicle speed from the output of the vehicle speed sensor 12, and outputs a control command as described later. The throttle actuator 14 is driven.

Since the device according to the present invention relates to inter-vehicle distance control, it will be described below.

To control the following distance, as shown in FIG.
The throttle motor control amount (throttle change amount) may be determined so that the deviation between the target vehicle distance and the actual vehicle distance m becomes zero. Therefore, as shown in FIG. 3, the throttle operation d of the own vehicle is performed.
The behavior from θth to the inter-vehicle distance 1 [m] was modeled.

That is, the throttle opening θth is obtained by integrating the throttle change amount dθth (input),
converted to trq. The driving force f (axial torque) is obtained by dividing it by the tire radius. The surplus driving force is obtained by subtracting the air resistance (the product of the square value v ^{2 of the} vehicle speed, the air resistance coefficient Cd and the front surface area A) and the rolling resistance from the driving force f.

When the surplus driving force f is divided by the vehicle weight (including the equivalent inertial mass) and the gravity acceleration g is multiplied, the acceleration α [m / s ² ] that can be output on the horizontal road surface is obtained. The vehicle speed v is obtained by integrating it, and the moving distance (vehicle distance) 1 [m] is obtained by further integrating it.

There is a delay due to intake characteristics and combustion delay until the throttle operation is reflected in the torque trq.
It was considered as a second-order delay from the experimental value. Also, since the characteristic of the torque change with respect to the throttle is non-linear, this part was excluded and linearized.

This is shown in FIG. As shown in the figure, the air resistance value was replaced with a linear function centered around 100 km / h for linearization (the center speed is 100 k
The speed is not limited to m / h, and other speeds may be used).

As is clear from the control model shown in FIG. 2, the input of the vehicle is the inter-vehicle (relative distance), which is a relative system. Therefore, the output of the own vehicle model is also a relative distance from the preceding vehicle, and the input dtrq (torque change amount, FIG. 4) is also the relative torque to the preceding vehicle.

Therefore, when the own vehicle model of FIG. 4 is replaced with the linear state model as shown in FIG. 5 and a linear state equation of input = relative torque output = inter-vehicle distance (distance) is obtained from the own vehicle model, it is shown in Equation 1. (X: state variable, U: input, Y: output (scalar)).

[0025]

[Equation 1]

The state equation represented by a determinant except for the output Y is fitted as a coefficient between the respective orders by the constant vectors A, B, and C, as shown in Equation 2,
Determined uniquely.

[0027]

[Equation 2]

Here, as shown in FIG. 6, the state variable X is estimated by using a known observer, and as shown in FIG. 7, the estimated result is multiplied by the observer gain Ke to be fed back. That is, since the own vehicle model is a vehicle model, it is essentially necessary to input the throttle operation and output the inter-vehicle distance, but by using the observer, the throttle operation amount (torque) can be calculated from the inter-vehicle input. It can be rewritten to the model to be output.

Then, as shown in FIG. 8, a feedback system is provided in which the distance between vehicles is input to this own vehicle model and feedback is performed so that the difference from the detected value is converged to zero.

Further, in the control according to the above theory, since a linear control object can be controlled more easily, the input of the controller is the inter-vehicle output and the output is the relative torque (as an increase / decrease of the running torque currently output by the vehicle). Target value). However, as shown in FIG. 9, in order to input to the actual vehicle, it is necessary to convert the non-linear portion from the relative torque trq to the actual vehicle throttle opening θth. For that purpose, the equation of motion is back-calculated to calculate the own vehicle absolute torque (running torque currently output by the own vehicle) trqa, and based on the value obtained by adding both values (described later with reference to FIG. 22), as shown in FIG. From the characteristics, throttle opening θth
I tried to search.

On the other hand, the throttle opening .theta.tha is searched from the same characteristic based on the current absolute torque of the vehicle, and the difference between the two is found to find the throttle opening change amount d.theta.th. Thus, including the vehicle speed shown in FIG.
The throttle opening is searched by the torque value and the vehicle speed value from the dimension map.

When a shift change is carried out, FIG.
As shown in, the torque value is multiplied by the coefficient Kshift corresponding to the shift position to search the map. Then, the operation amount of the throttle motor (throttle actuator) 14 is determined and operated so that the searched throttle opening degree is obtained.

FIG. 11 shows the overall model determined as described above. A target vehicle distance (described later) is input, and the throttle opening is controlled so that it becomes that value. Although the control system is shown as a continuous system for the sake of convenience, this control is performed by a discrete system using digital inputs. It is shown in FIG.

In addition to the above, the apparatus according to the present invention also performs constant speed, so-called auto cruise control. FIG.
The configuration is shown in FIG. This is to control the vehicle speed of the own vehicle by driving the throttle motor 14 using a PID controller as much as possible to the vehicle speed set by the driver. It should be noted that, except for the point that the brake actuator is omitted for simplification, this is a known structure per se, and thus detailed description will be omitted.

Based on the above, the operation of the vehicle travel control device according to the present invention will be described with reference to the flow chart of FIG. The program shown in the figure is, for example, 100 m.
It is started every sec.

First, in S1, the vehicle distance is calculated from the laser data output, and in S2, the (target) relative torque (a target value or a target change amount as an increment / decrement of the running torque currently output by the vehicle) is calculated. . This is done using the technique described above with respect to FIG.

FIG. 15 is a subroutine flow chart showing the calculation (more specifically, calculation of the feedback gain kr).

Explaining below, first, in S10, it is judged whether or not the difference (absolute value) between the vehicle-interval value mn-1 calculated last time and the vehicle-interval value mn calculated this time exceeds 2 [m]. As shown in FIG. 16, n represents the sampling period in the discrete system.

When the result in S10 is NO, it is determined that the target (preceding vehicle) has not been changed, and the process proceeds to S12, in which it is determined whether or not there is an interruption of another vehicle per a predetermined unit time. Included count (target change count)
Count w. Here, "interruption" means an interruption of another vehicle in this way. Also, the predetermined unit time is a time that is sufficiently larger than this program start cycle, for example, 1
Set to 0 sec.

Next, in S14, it is determined whether or not the counter value has exceeded 0 times, in other words, whether or not another vehicle has interrupted even once per unit time. When the result in S14 is affirmative, that is, when it is determined that the other vehicle has interrupted even once within the predetermined unit time, the predetermined unit time is set to be sufficiently long, so the difference compared in S10 is This is the difference from the interrupting vehicle, and therefore the control is performed as described above, so that the program is terminated as it is. Note that the target vehicle distance in this case is, as shown in FIG. 17, the vehicle head distance (distance that the vehicle travels in 1 second) × proportional constant Kn, and the regulator gain Kr is preset according to the actual vehicle distance at that time. Replace with a value.

On the other hand, when it is determined in S14 that there has been no interruption of another vehicle within the unit time, the process proceeds to S16,
The vehicle speed change dv of the preceding vehicle per unit time is calculated, and S1
In step 8, it is determined whether the calculated vehicle speed change dv is less than 5 km / h. When the result in S18 is negative, the program is ended while continuing the conventional control, and when the result in S18 is affirmative, the traveling of the preceding vehicle is stable, specifically, the vehicle distance is stable. It is determined that the road is vacant, the process proceeds to S20 and stable convergence control is executed to reduce the variable gain.

FIG. 18 is a subroutine flow chart showing the work.

This will be described. In this device, as described above, the feedback control is performed, and the product obtained by multiplying the input of the own vehicle model by the feedback gain (regulator gain) Kr is output as the relative torque. As shown, the variable gain Kout is further multiplied by the regulator gain Kr, and the variable gain Kout is asymptotically reduced when the inter-vehicle distance is stable.

This is partly because the driver's fatigue level increases when the preceding vehicle is robustly followed when the road is empty as described above. Secondly, since the absolute value of the input vehicle-to-vehicle value decreases when the vehicle-to-vehicle distance is stable, it is a countermeasure against a relatively large proportion of noise detected by the laser radar 12. Specifically, when it is determined that the vehicle distance is stable, the value of the variable gain Kout is reduced with time from 1 (initial value) to about 0.63.

Explaining with reference to the flow chart of FIG. 18, it is judged in S100 whether the count value c is less than 100, and if affirmative, the routine proceeds to S102, increments the count value and proceeds to S104, and count value The variable gain Kout is reduced and corrected by subtracting the product obtained by multiplying c by the coefficient k (about 0.0037) from 1.0.

Since the program shown in FIG. 18 is looped every time the program shown in FIG. 15 is started, the variable gain is gradually reduced every time the program shown in FIG. 15 is looped. Is also reduced. When the result in S100 is negative, the process proceeds to S106 and the count value is fixed at 100.

Returning to the flow chart of FIG.
If it is determined that the difference between the previous value and the current value between the vehicles exceeds 2 [m] in absolute value, it is estimated that the preceding vehicle (target) has changed lanes, etc. The difference between the current value mn and the previous value mn-1 is obtained, and it is determined whether the difference is greater than 0, in other words, whether the vehicle has left or approached the preceding vehicle.

When the result in S22 is affirmative, it is determined that the preceding vehicle has changed lanes in consideration of the determination in S10, the process proceeds to S24, and it is determined whether or not the inter-vehicle current value mn is less than 100 [m], and the result is negative. If so, it is determined that there is no preceding vehicle, and the routine proceeds to S26 to perform constant speed control, so-called auto cruise control.
This is done using the controller previously described with respect to FIG.

That is, in this device, as shown in FIG. 17, when the distance from the preceding vehicle is less than 100 [m], the following distance control is performed, and when it is 100 [m] or more, the constant speed control is performed. I chose

On the other hand, S in the flow chart of FIG.
If it is determined at 24 that the current value mn between the vehicles is less than 100 [m], the process proceeds to S28 to make a target change determination. This is because the value of the preceding vehicle was changed because the preceding vehicle was changed,
This is to prevent the old preceding vehicle from being erroneously recognized as the position and speed of the new preceding vehicle instantaneously in terms of control, and to properly follow the new preceding vehicle.

FIG. 20 is a subroutine flow chart showing the work.

Explaining below, the time counter value t is incremented in S200. Fig. 16 shows the time counter value.
Shown at the bottom.

Next, in S202, it is determined whether the counter value is less than 4. In the first loop, of course, the affirmative is affirmed, and the process proceeds to S204, S206, S208, and the switch SW.
Turn off 1, 2, 3 and proceed to S210 where the counter value is 4
The process returns to S200 until it is confirmed that the value exceeds.

This will be described with reference to FIGS. 16 and 18. Although it is determined in S22 in FIG. 15 that the preceding vehicle has changed lanes, the distance between the preceding vehicle and the preceding vehicle is 100 [m] in S24. When it is determined that the number of vehicles is less than the above, it is estimated that the target has been changed to a new preceding vehicle, for example. Therefore,
The control is switched so as to follow the new preceding vehicle during the control switching time shown in the timing chart of FIG.

That is, in the block diagram of FIG. 19, the operation amount is determined based on the relative torque input to the vehicle model while the switch SW1 is turned on, but during the control switching time, SW1 is turned off to zero. I tried to enter. Therefore, during that time, the throttle opening until then is maintained.

Similarly, in the own vehicle model, the switch S
W2 is turned off and zero is input (initialization). SW3 is for inputting an inter-vehicle distance and an average vehicle speed (described later), and this switch is originally set to be off (in that sense, the operation of S208 is a confirmation operation).

In the flow chart of FIG. 20, S20
If it is determined in 2 that the counter value is not less than 4, that is, if it is determined that it has reached 4, the process proceeds to S212, in which it is determined whether the counter value is less than 5. When the process proceeds to S212 for the first time, the result is naturally affirmative and the process proceeds to S214 and S216 to turn on the switches SW2 and SW3.

Next, the routine proceeds to S210, where it is judged if the counter value is greater than 4, and here it is denied and S200
Then, the counter value is incremented to 5 and becomes 5.
Therefore, the determinations in S202 and S212 are both denied, and the process proceeds to S218, where the average value of four cycles (counter value 4) of the vehicle speed (the first-floor difference value between the vehicles) is obtained, and S216 is performed first.
Since SW3 is turned on in, the data is input together with the vehicle distance.

Next, in S220, SW1 is turned on and the calculated relative torque value is output, and in S222, SW3 is turned off, and then the counter value is reset via S210 and S224 to finish.

As described above, by eliminating the influence of the preceding preceding vehicle and replacing the data with the new preceding vehicle, the inter-vehicle distance and the vehicle speed can be smoothly changed according to the new preceding vehicle. In other words, since the replaced new preceding vehicle is correctly followed, overshoot or undershoot does not occur, stable control can be realized, and drivability is improved.

Although the accuracy of the numerical value is improved by obtaining the average value of four vehicle speeds, the number of times of averaging may be reduced to shorten the time required to determine the vehicle speed of the preceding vehicle.

Returning to the flow chart of FIG. 15, S22.
If the difference between the inter-vehicle current value and the previous value is not positive, that is, if it is determined that the vehicle is approaching, the process proceeds to S30 and the interrupt number counter value w is incremented as if another vehicle interrupted. In S32, it is determined whether or not the inter-vehicle time value is smaller than the dangerous inter-vehicle distance. As shown in Fig. 17, the distance between dangerous vehicles is
It is calculated by multiplying the headway distance by the proportional gain KD.

When it is determined in S32 that the inter-vehicle current value is smaller than the dangerous inter-vehicle distance, the process proceeds to S34, and the clutch of the throttle motor 14 is released because it is too close to the preceding vehicle, and the process proceeds to S36 to apply the engine brake. Shift down intentionally. Next, in S38, the model is changed. That is, the value substituted into the state equation described by these constant vectors is changed. This is done by substituting a value corresponding to the downshifted position.

Explaining this, downshifting means that the rate of change between vehicles is different with respect to the change in throttle opening. Actually, the above-mentioned own vehicle model is not actually affected by the shift down except for the equivalent inertial mass, but since the delay system is inserted in replacing the relative torque with the torque control, the delay is reduced. This is because it is possible to obtain the same effect as if the torque was increased by downshifting.

Therefore, the constant vector is set separately for each shift position, and selected and substituted according to the shift position (gear position) of the destination stage. The constant vector is changed, and the observer gain Ke and the regulator gain Kr are also changed.

Further, the ratio of the torque axis in the map of FIG. 10 is changed according to the shift position, and the model is changed according to the own vehicle speed as shown in FIG. 21 to correct the linearization error of the air resistance. To do.

Next, in S40, the target change judgment similar to S28 is executed. This is because the target is the same in that it is changed. When the result in S32 is negative, the process immediately skips to S40.

In this embodiment, as described above, the own vehicle model is feedback-controlled, and the feedback gain is used to input to the actual vehicle.

The following is a general description of a method for obtaining the (target) running torque trq. trq = Fc (m-mt) x (1 / Dc) x (m-mt) where Fc: smoothing filter that suppresses noise in inverse calculation, Dc: time from torque generation to distance change of own vehicle Transfer function expressing delay, mt: target vehicle distance.

Returning to the explanation of the flow chart of FIG.
Next, in S3, the vehicle speed of the own vehicle is calculated from the output of the vehicle speed sensor, and in S4, the running torque (above-described absolute torque of the own vehicle or the running torque trqa currently output by the own vehicle) is calculated. This is as described above with respect to FIG.
This is obtained by back-calculating the equation of motion.

Next, in S5, the throttle opening, or more accurately, the throttle change amount dθth, is calculated as shown in FIG. This has already been mentioned. Next, in S6, the throttle actuator (throttle motor)
The manipulated variable TH of 14 is calculated.

FIG. 23 is a subroutine flow chart showing the calculation.

That is, for the throttle change amount dθth, S
At 300, the value of the inverse transfer function of the transfer function Dth (t) that represents the response time delay of the throttle actuator is calculated, and the value of the filter Fth (t) that suppresses noise is calculated for the value, and the value of the filter Fth (t) is calculated. Go to and gain map TH
Search for (TH) (characteristics not shown) to determine the actuator operation amount.

Specifically, the actuator operation amount TH = TH (TH) (Fth (dθth) /
It is calculated by Dth (dθth).

Next, in S7, the operation of the actuator is controlled based on the obtained value.

In this embodiment, as described above, the own vehicle model is feedback-controlled, and the feedback gain is used to input to the actual vehicle.

That is, in the conventional feedback control using the PID control law, the control is made so that the deviation is first canceled and then eliminated, but in this embodiment, it will be in the future. Since the vehicle distance, relative vehicle speed, relative acceleration, relative torque, and behavior delay can be used for control,
The control deviation is remarkably reduced, and the control response can be improved.

Further, the torque and the throttle opening have a non-linear relationship, but since they are placed outside the control model system, linear inter-vehicle distance control can be realized. Further, the absolute running torque of the host vehicle is estimated from the vehicle speed, the current throttle opening of the host vehicle is estimated according to the torque, the throttle opening is also determined from the target relative torque, and the difference between them is calculated. Therefore, the throttle opening is not finally obtained as an absolute value.

As described above, the absolute value is first obtained, but the relative deviation is finally obtained, so that the absolute value is not stored as the internal variable value. Further, in FIG. 9, since neither the uphill slope nor the uphill slope torque is performed, the output value of each difference does not have an error in the positive / negative directionality (throttle opening / closing direction) even on the uphill slope and the required throttle change amount. Can be corrected by feedback.

Therefore, it is not necessary to consider the accumulation of accumulated errors, no correction means is required, and the sensor does not need to be highly accurate. In this way, the operation amount is determined by the relative system, and since the operation amount is not determined from the actual measurement value,
Less affected by disturbances such as climbing and descending slopes.

Further, since the operation amount is configured to be the torque, the intended control result can be obtained. That is,
When the operation amount is determined by the throttle opening as seen in the prior art, the output torque may be different even with the same opening, but there is no such inconvenience.

Further, since the throttle operation amount can be smoothly changed by the above-mentioned structure, it can be controlled by the target relative torque, and the followability to the acceleration / deceleration of the preceding vehicle is improved. That is, the controllability can be improved as shown in FIG. 24 as compared with the conventional control shown in FIG.

FIG. 26 is a view similar to FIG. 19, showing a second embodiment of the present invention. In this embodiment, the variable gain Kout is placed on the input side of the own vehicle, and Kr ×
I tried to input Kout to my vehicle. Therefore, a value obtained by multiplying only the regulator gain is input to the model. As a result, the same effect as that of the first embodiment can be obtained.

In the vehicle travel control device according to the present invention, as described above, the inter-vehicle distance detecting means (laser radar 10) for detecting the inter-vehicle distance between the own vehicle and the preceding vehicle, and the target inter-vehicle distance are set. Target inter-vehicle distance setting means (Fig. 11, etc.),
Running torque calculating means (S4 in FIG. 14 and FIG. 11 etc.) for calculating the running speed of the running vehicle, which is obtained by obtaining the running speed of the running vehicle and multiplying it by a coefficient of a factor affecting the behavior of the running vehicle. And a target vehicle-to-vehicle distance based on the deviation of the target running torque, a running torque target change amount calculating means (S2 in FIG. 14, FIG. 11, and the like), the running torque, the target change amount in the running torque, and the vehicle speed. The operation amount calculating means for calculating the operation amount based on (S5, S in FIG. 14)
6 and FIG. 23), an actuator operation amount calculating means (FIG. 23) for calculating an actuator operation amount based on the operation amount, and an actuator (throttle actuator 14) for inputting the actuator operation amount and changing the vehicle speed. Configured as

Further, the factors that influence the behavior of the vehicle are at least the equivalent inertial mass, rolling resistance and air resistance (FIG. 9, etc.).

Furthermore, when a shift change is made,
The calculation is performed by multiplying the coefficient Kshift according to the shift position (FIG. 10).

Although the value substituted into the state equation is changed when downshifting is performed in the above-mentioned embodiment, the torque-throttle opening characteristic shown in FIG. 10 can be changed to the gear position without changing the state equation. It may be determined for each (shift position), and the throttle opening may be determined by selecting the characteristic corresponding to the destination stage.

Further, the torque-throttle opening characteristic shown in FIG. 10 is set for any gear position (shift position), and for other gear positions, an appropriate coefficient is added to the value obtained by searching the characteristic. You may correct by multiplying.

Further, as shown in FIG. 10, when the torque-throttle opening characteristic is searched after the shift change, the torque value is multiplied by the coefficient Kshift according to the shift position, but the present invention is not limited to this. You may multiply by the torque amplification coefficient according to the slip ratio of a torque converter.

Incidentally, in the above embodiment, a known control law such as PID control law or fuzzy control law may be used for calculating the target torque.

Further, the laser radar is used as the means for detecting the distance between the vehicle and the preceding vehicle, but the invention is not limited to this, and visual detection means or the like may be used.

Further, although only the throttle actuator is used, a brake actuator may be used together. The actuator is not limited to the electric type, but may be a negative pressure type.

[0093]

As described above, the responsiveness to the change in the vehicle distance can be improved and the acceleration / deceleration can be properly controlled.

[Brief description of drawings]

FIG. 1 is an explanatory block diagram generally showing a vehicle travel control device according to the present invention.

2 is an explanatory block diagram of a control model used by the device of FIG. 1. FIG.

FIG. 3 is a further explanatory block diagram of a control model used by the apparatus of FIG.

4 is an explanatory block diagram showing a linearized version of the configuration of FIG. 3 in a control model used by the apparatus of FIG.

5 is an explanatory block diagram of a control model (linear state model) used by the apparatus of FIG.

FIG. 6 is a further explanatory block diagram of a control model (linear state model) used by the apparatus of FIG.

7 is still another explanatory block diagram of a control model (linear state model) used by the device of FIG. 1. FIG.

8 is an explanatory block diagram showing an overall model in a state in which an observer is incorporated, which is used by the device of FIG.

9 is an explanatory block diagram of an overall model used by the apparatus of FIG.

FIG. 10 is an explanatory diagram showing characteristics of a torque-throttle opening conversion map in FIG. 9.

11 is another explanatory block diagram of an overall model similar to FIG. 9 used by the apparatus in FIG.

FIG. 12 is an explanatory block diagram in which the continuous control system shown in FIG. 11 is rewritten as a discrete system.

FIG. 13 is an explanatory block diagram of a configuration used by the device in FIG. 1 for constant speed traveling control.

FIG. 14 is a main flow chart showing the operation of the apparatus shown in FIG.

FIG. 15 is a subroutine flow chart showing the target relative torque calculation work of the flow chart of FIG.

16 is a timing chart for explaining the processing of the flow chart of FIG.

FIG. 17 is an explanatory diagram illustrating a dangerous distance between vehicles in the flowchart of FIG. 15;

18 is a subroutine flow chart showing a stable convergence control process in the flow chart of FIG.

FIG. 19 is a block diagram illustrating processing of the flow chart of FIG.

FIG. 20 is a subroutine flow chart showing target change determination processing in the flow chart of FIG.

FIG. 21 is an explanatory graph diagram of model change characteristics associated with shift change in the flow chart of FIG. 15;

22 is a subroutine flow chart showing a throttle opening calculation operation in the flow chart of FIG.

FIG. 23 is a subroutine flow chart showing the throttle actuator control amount calculation work in the flow chart of FIG. 14;

24 is an explanatory timing chart showing a control result of the control device of FIG. 1. FIG.

FIG. 25 is an explanatory timing chart showing a control result of the conventional control device.

FIG. 26 shows a second embodiment of the present invention, FIG.
It is a block diagram similar to.

[Explanation of symbols]

10 Laser Radar (Vehicle Distance Detection Means) 12 Vehicle Speed Sensor 14 Throttle Actuator (Throttle Motor) 20 Controller

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tetsuya Komi 1-4-1 Chuo, Wako-shi, Saitama Stock Research Institute, Honda R & D Co., Ltd.

Claims (3)

[Claims] 1. A. Inter-vehicle distance detecting means for detecting the inter-vehicle distance between the own vehicle and the preceding vehicle, b. Target inter-vehicle distance setting means for setting the target inter-vehicle distance, c. A traveling torque calculating means for obtaining the own vehicle speed and multiplying it by a coefficient of a factor affecting the behavior of the vehicle to calculate the traveling torque currently output by the own vehicle, d. Running torque target change amount calculating means for calculating a target change amount of the running torque based on a deviation between the inter-vehicle distance and the target inter-vehicle distance, e. An operation amount calculation means for calculating an operation amount based on the traveling torque, a target variation amount of the traveling torque, and the own vehicle speed, f. Actuator operation amount calculation means for calculating an actuator operation amount based on the operation amount; and g. A travel control device for a vehicle, comprising: an actuator that receives the actuator operation amount and changes a vehicle speed. 2. Factors that affect the behavior of the vehicle include:
2. The vehicle travel control device according to claim 1, wherein at least an equivalent inertial mass, rolling resistance and air resistance. 3. The vehicle travel control device according to claim 1, wherein the operation amount calculation means calculates when a shift change is made by multiplying by a coefficient corresponding to a shift position.