JP2001187961A - Traveling control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a traveling control device for a vehicle capable of solving the inefficient feeling or uncomfortable feeling given to a driver at the starting of a vehicle to improve the drivability and reducing the development cost for product. SOLUTION: This device comprises an initial value arithmetic means for calculating the initial value of a target drive torque in the starting of the vehicle; a target speed arithmetic means for calculating the target speed of the vehicle; a vehicle speed measuring means for measuring the speed of the vehicle; a target drive torque arithmetic means for calculating the target drive torque of the vehicle on the basis of each output signal from the initial value arithmetic means, the target speed arithmetic means and the vehicle speed measuring means; and a target throttle opening arithmetic means for calculating a target throttle opening on the basis of the output signal from the target drive torque arithmetic means. The target drive torque arithmetic means calculates the target drive torque on the basis of the initial value, the target speed and the vehicle speed in the starting of the vehicle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a travel control device for a vehicle, and more particularly to a travel control device for a vehicle that reduces discomfort to a driver when the vehicle starts.

[0002]

2. Description of the Related Art In recent years, vehicles equipped with a following running function for automatically following a preceding vehicle have been developed. The follow-up traveling function is monotonous for the driver, such as when a long-time and constant-speed traveling is forced while maintaining the following distance,
This is a particularly effective function when a high degree of attention is required. At present, a vehicle is being developed which entrusts the following traveling function from the start to the stop of the vehicle.

[0003] It is known that a driving control device for a vehicle having the following function is improved in controllability by performing control based on a target driving torque for directly operating an internal variable of the own vehicle. As an example, there is a technology of a vehicle travel control device that controls a throttle valve, a transmission, a brake, and the like based on the target drive torque to accelerate the vehicle at the time of starting (for example, Japanese Patent Laid-Open No. 11-6).
No. 6499).

[0004] The technique described in Japanese Patent Application Laid-Open No. 11-66499 discloses that, when the inter-vehicle distance between the preceding vehicle and the own vehicle when the vehicle stops is shorter than the target inter-vehicle distance, the own vehicle starts moving from the preceding vehicle. In this case, the vehicle stops at the spot until the target inter-vehicle distance is reached, and the driver of the host vehicle gives a sense of backlash.

In other words, when the throttle valve is opened for starting from an idling state (a throttle valve fully closed state) when the vehicle is stopped, the target drive torque needs to be set to a value larger than a predetermined value. In order to obtain the predetermined value, the target drive torque Ttar 'is calculated by adding a feedforward term to the feedback term in addition to the feedback term. When starting, the target drive torque Tf by the feedforward term is set to the predetermined value. The self-vehicle is accelerated at the start based on the target drive torque Tf. That is, the target drive torque Ttar 'of the travel control device is calculated as in Equation 1.

[0006]

(Equation 1)

Here, the first to third terms of the equation (1) are P
This is a feedback term for performing ID control.
Denotes a proportional gain, Ev denotes a deviation between the target speed Vtar of the host vehicle and the host vehicle speed V, Ki in the second term denotes an integral gain, and Kd in the third term denotes a differential gain. The fourth term of the above equation 1 is a feedforward term that sets the target driving torque Ttar ′ to the target driving torque Tf at the time of starting, and is calculated as in equation 2.

[0008]

Tf = Tini × (1−V / V0) (2)

Here, Tini is the initial value of the target driving torque at time T0, and V and V0 are the own vehicle speed and the preset own vehicle speed, respectively. The feedforward term calculates the target drive torque Tf at the start based on parameters such as a preset target drive torque initial value Tini and a preset vehicle speed V0. V, that is, the vehicle speed V decreases as the vehicle speed V approaches the preset vehicle speed V0, becomes zero after a lapse of a predetermined time, acts when the vehicle speed V is low, and acts when the vehicle speed V is fast. It is not allowed to do so. After the elapse of the predetermined time, the target driving torque Ttar 'is calculated based on the deviation Ev between the target speed Vtar and the vehicle speed V by the feedback term,
The driving torque To of the own vehicle is changed to the target driving torque Tta.
The deviation Ev is controlled so as to follow r '.

Thus, even if the inter-vehicle distance is shorter than the target inter-vehicle distance, the self-vehicle which has determined that the preceding vehicle has started is immediately started via the feedforward term. To reduce the sloppy feeling given to the driver. Further, as another example of the travel control device based on the target drive torque, various technologies for controlling an engine, a brake, and the like during traveling of the own vehicle based on the target drive torque have been proposed (for example, see Japanese Patent Application Laid-Open No. Hei 6 (1994)). −064
460, JP-A-10-309959,
And JP-A-11-291789. In addition,
Various control devices have been proposed that compare the target drive torque with an initial value to reduce variations in engine torque and absorb variations due to machine differences and aging (for example, Japanese Patent Application Laid-Open No. 8-34266, JP-A-10-153
No. 256, etc.).

[0011]

The technique described in Japanese Patent Application Laid-Open No. H11-66499 is a travel control device that obtains a target drive torque at the time of starting from the feedforward term added to the feedback term. , The target drive torque Tf calculated from the added feedforward term is calculated based on the own vehicle speed V as in the above equation 2, and the target speed Vtar and the target speed Vtar are calculated.
Because it is not based on the deviation Ev between the vehicle speed V and the vehicle speed V, the vehicle speed may fluctuate without converging to the target speed Vtar.

That is, although the sloppy feeling at the time of starting can be reduced by the target driving torque Tf calculated from the feedforward term, the driving torque To of the own vehicle also changes with the fluctuation of the target driving torque Tf. Due to the fluctuation, the driver still feels uncomfortable due to the swing in the front-rear direction, and still has a problem of impairing drivability.

The self-vehicle using the target drive torque Tf calculated from the added feedforward term may cause the self-vehicle speed V to follow the target speed Vtar if the predetermined time has not elapsed from the start. When the predetermined time elapses, switching from the feedforward term to the feedback term is required, and there is a problem that smooth start and acceleration cannot be performed.

Further, as described above, the added feedforward term has two parameters of the preset initial value Tini of the target drive torque and the preset own vehicle speed V0. Since the control device is manufactured after tuning the two parameters in advance, there is a problem that the development time of the product cannot be reduced.

[0015] Furthermore, the other conventional technique described above is a travel control device or the like for controlling an engine and a brake while the own vehicle is running. No particular consideration is given to improving the drivability by eliminating the uncomfortable feeling given to the driver and the discomfort given to the driver by a certain time after the start.

The present invention has been made in view of such a problem, and an object of the present invention is to improve the drivability by eliminating the uncomfortable feeling and uncomfortable feeling given to the driver when the vehicle starts. It is another object of the present invention to provide a travel control device for a vehicle, which can reduce the development cost of a product.

[0017]

In order to achieve the above object,
A traveling control device for a vehicle according to the present invention includes an initial value computing unit that computes an initial value of a target driving torque when the vehicle starts, a target speed computing unit that computes a target speed of the vehicle, and a speed of the vehicle. Own vehicle speed measuring means for measuring, the initial value calculating means, the target speed calculating means, and a target driving torque calculating means for calculating a target driving torque of the vehicle based on each output signal from the own vehicle speed measuring means And target throttle opening calculating means for calculating a target throttle opening based on an output signal from the target driving torque calculating means. The target driving torque calculating means is configured to output the target driving torque when the vehicle starts. Is calculated based on the initial value, the target speed, and the host vehicle speed. Specifically, the target drive torque calculating means calculates the target speed and the host vehicle speed. Performs PI control based on a deviation between degrees, to the PI control within is characterized by having a feed-forward term for calculating on the basis of the target driving torque and the initial value and the deviation.

The running control apparatus for a vehicle according to the present invention configured as described above is calculated from the initial value obtained by calculating the target driving torque at the time of starting, the target speed of the own vehicle, and the own vehicle speed. In the feedback term calculated from the deviation between the target speed and the vehicle speed, a feedforward term based on the initial value and the deviation is included. Acceleration and switching of acceleration after a lapse of a predetermined time can be performed smoothly, the target drive torque does not fluctuate, and the drivability is improved at the time of starting and the discomfort caused by the swing in the front-rear direction is improved. Can be achieved. Further, since the target drive torque at the time of starting is based on the calculated initial value and the deviation, it is not necessary to perform tuning in advance, and it is possible to shorten the product development time.

In a specific aspect of the vehicle travel control device according to the present invention, the initial value calculating means calculates a driving torque of the vehicle, and determines whether the vehicle starts or stops. Own-vehicle traveling determining means, torque error calculating means for calculating an error of the driving torque, and initial value correcting means for correcting the initial value, own-vehicle acceleration calculating means for calculating acceleration of the vehicle, The vehicle weight calculating means for calculating the weight of the vehicle, and the slope calculating means for calculating the slope of the road; and calculating the slope of the road based on the map information of the car navigation of the vehicle. Calculating the gradient of the road based on the driving torque of the vehicle, the speed and acceleration of the vehicle, or based on a map consisting of the weight of the vehicle and the gradient of the road. It is characterized by calculating the serial initial value.

Further, in another specific aspect of the vehicle travel control device according to the present invention, the target throttle opening calculating means includes an input of the transmission based on an engine speed and a turbine speed of the transmission. Torque ratio calculating means for calculating a torque ratio between a shaft and an output shaft; and target engine torque calculating means for calculating a target torque of the engine based on the torque ratio, the gear position of the transmission, and the target driving torque. And throttle opening search means for searching for a target throttle opening based on the target engine torque and the engine speed, or the engine speed, the turbine speed of the transmission. And an estimated driving torque calculating means for calculating an estimated driving torque based on the gear position, and an estimated driving torque based on a deviation between the estimated driving torque and the target driving torque. Control means (PID control means) for performing control (PID control), and calculating another target throttle opening degree by adding a calculation result of the control means to the target throttle opening degree; or The target drive torque calculating means clears the initial value when the vehicle starts moving.

Still another specific embodiment of the vehicle traveling control device according to the present invention is characterized in that the target speed calculating means automatically adjusts the inter-vehicle distance between a preceding vehicle traveling ahead and the preceding vehicle. Output signals from an inter-vehicle distance measuring means for measuring an inter-vehicle distance between the own vehicles and a relative speed measuring means for measuring a relative speed between the preceding vehicle and the own vehicle, and the start of the own vehicle from the start of the preceding vehicle The inter-vehicle distance setting means for setting the inter-vehicle distance until the start and the relative speed setting means for setting the relative speed from the start of the preceding vehicle to the start of the start of the own vehicle, based on each output signal, To start the own vehicle, or that each output signal from the inter-vehicle distance setting means and the relative speed setting means can be switched simultaneously, the inter-vehicle distance setting means and the relative speed setting means When the inter-vehicle distance is set to be long, the relative speed is set to be small, or when the inter-vehicle distance is set to be short, the relative speed is set to be large. It has a map consisting of the inter-vehicle distance between the own vehicle and the relative speed between the preceding vehicle and the own vehicle, and the preceding vehicle and the own vehicle are in an area surrounded by the inter-vehicle distance and the relative speed. In this case, the vehicle is stopped. Further, the travel control device for a vehicle includes a clutch between an engine and a transmission, and operates the clutch based on the initial value.

[0022]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram of an automobile 100 including a vehicle travel control device 10 according to each embodiment of the present invention.

The automobile 100 is provided with the traveling control device 10
, A transmission 70 for transmitting the output of the engine 60 to the axle via gears, and four wheels 54, 55 driven and driven by the output from the transmission 70.
56, 57, a brake pedal 51 for operating a brake for braking the wheels 54 and the like, a brake pedal force detecting means 52 for detecting a stepping force of the brake pedal 51 by a driver, an accelerator for detecting an accelerator pedal operation amount Input means 47, an inter-vehicle distance measuring device 80 for measuring an inter-vehicle distance Ds between a preceding vehicle (preceding vehicle) traveling in front and the vehicle (own vehicle) and a relative speed Vr thereof, and automatic following in accordance with the operation of the driver A switch input means 90 is provided for switching between an operation mode and a manual operation mode, setting an inter-vehicle distance Ds between the preceding vehicle and the own vehicle, a relative speed Vr thereof, and switching an input. The inter-vehicle distance measuring device 80 is constituted by, for example, a radar device such as a millimeter wave radar, a laser radar, and the like. The brake depressing force detecting means 52 includes a brake pedal 51 in addition to a sensor for detecting a depressing force. May be a sensor that detects the stroke amount of the vehicle, or a sensor that detects the brake fluid pressure.

The traveling control device 10 comprises a driving force management unit 1, a transmission control unit 2, an engine control unit 3, a throttle control unit 4, and a brake control unit 5. The driving force management unit 1 includes an inter-vehicle distance Ds between the preceding vehicle and the host vehicle measured by the inter-vehicle distance measuring device 80 and a relative speed Vs thereof.
r, an inter-vehicle distance Ds between the preceding vehicle and the host vehicle set by the driver's operation via the switch input means 90.
After calculating the target speed Vtar of the own vehicle based on the relative speed Vr and the relative speed Vr, a target drive torque Ttar for making the running speed V of the own vehicle equal to the target speed Vtar is calculated. Further, the driving force management unit 1
Sets the target drive torque Ttar to a predetermined value or more based on an initial value Tini of a target drive torque, which will be described later, calculated from the gradient of the road and the like when the vehicle starts moving.

The transmission control unit 2 includes a transmission 70
The vehicle speed V is measured by detecting the number of revolutions of the output shaft of the vehicle, and the vehicle speed V is output to the driving force management unit 1 and the target driving torque Ttar calculated by the driving force management unit 1 is calculated. Transmission 70 based on
To output a control signal.

The engine control unit 3 calculates the fuel injection amount and ignition timing of the engine 60 based on the target driving torque Ttar calculated by the driving force management unit 1, and outputs a control signal thereof. The throttle control unit 4 calculates the opening of the throttle valve 48 based on the target driving torque Ttar calculated by the driving force management unit 101 or a signal from the accelerator input means 47, and outputs a control signal therefor.

When the target driving torque Ttar calculated by the driving force management unit 1 becomes negative, the brake control unit 5 outputs a driving signal to the brake actuator 53 according to the value in the negative direction. ,
The wheels 54, 55, 56, 57 are braked. The brake actuator 53 is different from the hydraulic cylinder (master cylinder) of the brake pedal 51, and generates a braking force by applying pressure to the brake fluid in the brake pipe.

FIG. 2 is a control block diagram of the traveling control device 10. As shown in FIG. The driving force management unit 1 of the traveling control device 10 includes an initial value calculating unit 1 that calculates an initial value Tini of a target driving torque when the vehicle starts moving.
1, target speed calculating means 12 for calculating the target speed Vtar of the own vehicle, and target drive torque calculating means 13 for calculating the target drive torque Ttar of the own vehicle.

The initial value calculating means 11 includes a driving torque calculating means for calculating the driving torque To of the host vehicle, a host vehicle acceleration calculating means for calculating acceleration, a host vehicle weight calculating means for calculating weight, and a road. A self-vehicle running determining means for calculating the initial value Tini based on each of the calculated values to determine whether the vehicle has started or stopped, and an error in the driving torque. And an initial value correcting means for correcting the initial value Tini.

When the throttle valve 48 is opened to start from an idling state (throttle valve fully closed) when the vehicle is stopped, the initial value calculating means 11 sets the target drive torque Ttar to a torque value larger than a predetermined value. In addition, the torque value is set to correspond to a change in the road gradient S and the weight m of the own vehicle, so that the stopped own vehicle can be started more smoothly. An initial value Tini of the target drive torque is calculated in consideration of the situation of the own vehicle.

The target speed calculating means 12 calculates the relative distance Dr between the preceding vehicle and the own vehicle by the following distance measuring means 81 of the following distance measuring device 80 and the relative distance between the preceding vehicle and the own vehicle by relative speed measuring means 82. The speed Vr and the inter-vehicle distance D from the start of the preceding vehicle to the start of start of the own vehicle by the inter-vehicle distance setting means 91 of the switch input means 90
a target speed Vtar is calculated based on each output signal of the relative speed Vs from the start of the preceding vehicle to the start of start of the host vehicle by the relative speed setting means 92 and the target drive torque calculating means 13 Output the signal.

The target driving torque calculating means 13 outputs the initial vehicle speed calculating means 11, the target speed calculating means 12, and the own vehicle speed V output signal from the own vehicle speed measuring means 21 of the transmission control unit 2 to each output signal. A target drive torque Ttar of the vehicle described later is calculated based on the target speed V
The deviation Ev between tar and the vehicle speed V is eliminated, and the signal of the target drive torque Ttar is output to the target throttle opening calculating means 41 of the throttle control unit 4. Then, the target throttle opening calculating means 41 calculates a target throttle opening Otar based on the target driving torque Ttar, and calculates the target throttle opening Otar.
8 is controlled.

FIG. 3 is an operation flowchart of the initial value calculating means 11 in the traveling control device 10 according to the first embodiment of the present invention. This routine is executed periodically, for example, every 10 (ms). In step 101, the driving torque calculating means calculates the rotational speed of the engine 60 and the transmission 70
The driving torque To of the host vehicle is calculated based on the turbine rotation speed and the final reduction ratio of the host vehicle. In step 102, the host vehicle acceleration calculating means differentiates the host vehicle speed V to obtain the host vehicle acceleration α. In step 103, the own vehicle weight calculating means calculates the weight m of the own vehicle as shown in Expression 3.

[0034]

M = (To1-To2) / ((α1-α2) × Rt) (3)

Here, To1 and α1 are the driving torque and acceleration of the vehicle calculated in the previous cycle, respectively, and To2 and α2 are the driving torque and the acceleration of the vehicle calculated in the current cycle, respectively. Acceleration. Also, R
t is a tire radius. In step 104, the gradient calculating means calculates the road gradient S based on the car navigation map information (node information), the vehicle speed V, and the like, which will be described later.
In step 105, the initial value Tin of the target drive torque required to start the vehicle smoothly
Compute i.

In step 106, the vehicle running determination means determines whether or not the vehicle is running. If the vehicle speed V is not 0 (m / s), that is, if YES, the routine proceeds to step 107. , The torque error calculating means,
An error Et between a target driving torque Ttar of a feedback term described later and the driving torque To during traveling is expressed by the following equation (4).
And proceeds to step 108.

[0037]

## EQU4 ## Et = Ttar / To (4)

On the other hand, at step 106, the vehicle speed V becomes zero.
Also at (m / s), the routine proceeds to step 108, where the own vehicle running determination means determines whether or not the own vehicle starts to start, and the own vehicle speed V is 0 (m / s). Target speed Vt
If ar is greater than 0 (m / s), that is, if YES, the process proceeds to step 109, where the initial value correction means calculates the correction value Th of the initial value on the basis of the error Et using the equation (5).
And the routine is terminated. In addition,
If the vehicle does not start moving at step 108, this routine is terminated.

[0039]

Th = Tini × Et (5)

From step 106 to step 1
09, the target driving torque T due to the aging of the engine 60, the transmission 70, etc., or the roughness of the road surface.
Even if there is a steady-state deviation between tar and the driving torque To, this can be absorbed.

FIG. 4 is an operation flowchart of the gradient calculating means in the initial value calculating means 11. In the present embodiment, the gradient S of the road is calculated based on the node information of car navigation and the like. Step 201
Then, the vehicle running determination means determines whether or not the vehicle is stopped. If the vehicle speed V is 0 (m / s), that is, if YES, the process proceeds to step 202,
From the car navigation map data, three-dimensional position information (X, Y,
Z) and the node information including the intersection number and the like are taken in. On the other hand, when the vehicle speed V is not 0 (m / s),
This routine ends. In step 203, the three-dimensional position information (X, Y, Z) in the node information is fetched, and the process proceeds to step 204, where the gradient calculating means calculates the gradient of the road on which the vehicle is present as shown in Expression 6. , And
This routine ends.

[0042]

(Equation 6)

Here, X1, Y1, Z1, X2, Y2,
Z2 is three-dimensional position information of two points before and after the vehicle. As described above, the gradient S can be measured with high accuracy by using the node information of the car navigation.

FIG. 5 is an operation flowchart for calculating the initial value Tini in the initial value calculating means 11, and based on the own vehicle weight m and the gradient S, the initial value T of the target drive torque.
ini. In step 401, the own-vehicle traveling determining means determines whether or not the own-vehicle has started to start, and if the own-vehicle speed V is 0 (m / s) and the target speed Vta
If r is greater than 0 (m / s), that is, if YES, the routine proceeds to step 402, where the own vehicle running determination means calculates a correction value Ta of the own vehicle weight m as shown in equation 7. On the other hand, if the vehicle is not starting to start, this routine ends.

[0045]

## EQU7 ## Ta = Ka × m (7)

Here, Ka is a gain. Step 4
03, a correction value T of the road gradient S by the gradient calculating means.
b is calculated as shown in Expression 8.

[0047]

Tb = Kb × S (8)

Here, Kb is a gain. Step 4
In step 04, an initial value Tini of the target driving torque is calculated as shown in Expression 9 based on the correction value Ta of the vehicle weight m, the correction value Tb of the road gradient S, and the like, and this routine ends.

[0049]

(9) Tini = Ta + Tb + Tc (9)

Here, Tc is a driving torque required for starting on a flat road when only one driver gets on the vehicle, and is set in advance. FIG. 6 is an operation flowchart of the target speed Vtar calculation in the target speed calculation means 12, and this routine is periodically executed, for example, every 10 (ms).

In step 701, it is determined whether or not the own vehicle is stopped. If the own vehicle speed V is 0 (m / s), that is, if the answer is YES, the process proceeds to step 711, and the process proceeds to step 711. The speed Vpre is calculated as shown in Expression 10.

[0052]

Vpre = V + Vr (10)

Here, Vr is the relative speed measuring means 8
2 is the relative speed measured. In step 704,
It is determined whether or not the preceding vehicle is stopped. If the speed of the preceding vehicle is 0 (m / s), that is, if YES, the process proceeds to step 710, where the target speed Vt of the host vehicle is determined.
ar is set as shown in Expression 11, and this routine ends.

[0054]

Vtar = 0 (11)

On the other hand, when the preceding vehicle is not stopped at step 704, the process proceeds to step 705, where the setting results of the inter-vehicle distance setting means 91 and the relative speed setting means 92 are compared with the inter-vehicle distance measuring means 81 and the relative speed. The measurement result of the speed measurement means 82 is retrieved from a start map described later, and the process proceeds to step 706 to determine whether or not to start the own vehicle.

When the own vehicle is started in step 706, that is, when the answer is YES, the process proceeds to step 707, where the target inter-vehicle distance for causing the own vehicle to safely follow the preceding vehicle is calculated, and the process proceeds to step 708. In step 708, the target speed Vtar of the own vehicle is calculated by Expression 12 so as to eliminate the deviation Ed between the calculated target vehicle distance and the vehicle distance measured by the vehicle distance measuring means 81, This routine ends.

[0057]

(Equation 12)

Here, Kp, Ki, and Kd are a proportional gain, an integral gain, and a differential gain, respectively. On the other hand, when the self-vehicle is not started in step 706, the process proceeds to step 709, and the target speed Vtar of the self-vehicle is calculated by the following equation (11).
In the same manner as described above, the process is terminated with 0.

If it is determined in step 701 that the host vehicle is not stopped, the process proceeds to step 702, where a target inter-vehicle distance for causing the host vehicle to safely follow the preceding vehicle is calculated, and the process proceeds to step 703. Then, the step 70
3, the target speed Vt of the host vehicle is calculated in the same manner as in the equation (12).
ar is calculated, and this routine ends.

FIG. 7 shows the starting map of the step 705. The start map has an inter-vehicle distance on the horizontal axis and a relative speed on the vertical axis. The inter-vehicle distance Ds is set parallel to the vertical axis by the inter-vehicle distance setting means 91, and the relative speed Vs is set by the relative speed setting means 92. Are set in parallel with the horizontal axis, and a stop area 1901 is provided. The stop area 19
01 is to secure the safety by increasing the relative speed Vs when the inter-vehicle distance Ds is short. Then, when the relationship between the preceding vehicle and the own vehicle is inside the stop area 1901 and both the preceding vehicle and the own vehicle are stopped (indicated by a point A in the figure), The traveling control device 1
0 instructs the own vehicle to stop.

When the preceding vehicle is moving but is inside the stop area 1901 (indicated by the point B in the figure), the vehicle is instructed to stop. Then, when the preceding vehicle continues to run further and the relationship between the preceding vehicle and the own vehicle is outside the stop area 1901 (indicated by a point C in the figure), the vehicle starts moving to the own vehicle. Instruct and start.

The stop area 1901 is determined by the inter-vehicle distance Ds and the relative speed Vs by the switch input means 90.
At the same time, the stop area 190 is changed.
2, or the stop area 1903 can be changed. When the inter-vehicle distance Ds is long, the stop area 1903 is an area where safety is ensured even if the relative speed Vs is reduced.

FIGS. 8 and 9 show the calculation of the target drive torque Ttar by the target drive torque calculation means 13, and FIG. 8 is an operation flowchart of the target drive torque Ttar calculation. In step 601, the target vehicle speed Vtar of the host vehicle calculated by the target speed calculating means 12 is fetched, and the flow proceeds to step 602. In step 602, the own vehicle running determination means determines whether or not the own vehicle has started. If the own vehicle speed V is 0 (m / s), that is, if YES, the process proceeds to step 603. ,
As shown in Expression 13, the feedforward term Ev1 is set so that the target driving torque at the time of starting becomes the initial value Tini, and the target driving torque at the time of starting (initial value Tini) is calculated at step 604.

[0064]

(Equation 13)

On the other hand, if the vehicle speed V is not 0 (m / s) at step 602, the flow proceeds to step 604, and as shown in equation 14, the deviation is determined by PI control described later. Ev and the target drive torque T
Calculate tar and end this routine.

[0066]

[Equation 14]

Here, Kp and Ki are a proportional gain and an integral gain, respectively, based on a feedback term.
Is the deviation between the target speed Vtar and the vehicle speed V, Ev1
Is the feedforward term in Equation 13 above. This P
In the I control, as shown in FIG. 9, a value obtained by multiplying the deviation Ev by a proportional gain Kp and the deviation Ev are represented by a0, a1, b
The target drive torque Ttar is calculated by adding a value obtained by multiplying the integral gain Ki to a value integrated based on the value 1 and Z ^-1 or Ev1. FIG. 10 is a control block diagram of the target throttle opening calculating means 41.

The target throttle opening calculating means 41 calculates the torque ratio between the input shaft and the output shaft of the transmission 70 based on the rotation speed of the engine 60 and the turbine rotation speed of the transmission 70 in the driving torque calculation means. Calculating torque ratio calculating means 4
2, the torque ratio, the gear position of the transmission 70, and the target drive torque Ttar of the target drive torque calculation means 13.
Engine torque calculating means 43 for calculating a target torque of the engine 60 based on the engine speed, and throttle opening degree searching means 44 for searching for a target throttle opening degree Otar based on the target engine torque and the rotation speed of the engine 60. The opening of the throttle valve 48 is controlled.

FIGS. 11 and 12 show a cruise control device according to a second embodiment of the present invention, except for the configuration of the initial value calculation means 11 and the configuration of the target throttle opening degree calculation means 41. Since the configuration is the same as that of the first embodiment, the configuration of the initial value calculation unit 11 and the configuration of the target throttle opening calculation unit 41 will be described in detail.

The traveling control device 10 of the present embodiment comprises a driving force management unit 1, a transmission control unit 2, an engine control unit 3, a throttle control unit 4, and a brake control unit 5, and the driving force management unit 1 An initial value calculating means 11 for calculating an initial value Tini of a target driving torque at the time of starting of the own vehicle, a target speed calculating means 12 for calculating a target speed Vtar of the own vehicle, and a target driving torque Ttar of the own vehicle.
And target drive torque calculating means 13 for calculating Then, based on the target driving torque Ttar by the target driving torque calculating means 13, the throttle opening searching means searches the target throttle opening Otar (first target throttle opening Otar).
tar1), the target throttle opening calculating means 41 of the throttle control unit 4 is provided with an estimated driving torque calculating means and a PID control means, which will be described later, and the target driving torque Ttar and the estimated driving torque by the estimated driving torque calculating means are provided. The target throttle opening Otar (second target throttle opening Otar2) is calculated based on the first target throttle opening Otar1 so as to eliminate the deviation from the torque Te.
8 is controlled.

The initial value calculating means 11 calculates a driving torque To of the own vehicle, a driving torque determining means for determining whether the initial value Tini is required, and an error of the driving torque. And an initial value correcting means for correcting the initial value Tini.

FIG. 11 is a flowchart showing the operation of the initial value calculating means 11.
s) is executed periodically. In step 801, in the calculation of the target driving torque Ttar and the feedforward term Ev1 for setting the target driving torque to the initial value Tini in the expressions 13 and 14, the initial value of the target driving torque Tini for the own vehicle is set to 0. Perform a value operation,
Proceed to step 802. Regarding the calculation of the initial value in the step 801, when a deviation between an estimated drive torque Te and a target drive torque Ttar, which will be described later, is generated, the target throttle opening calculation means 41 calculates the target throttle opening corresponding to the deviation. The degree Otar (the second target throttle opening degree Otar2) is immediately calculated, and the second target throttle opening degree Otar2 is not affected by changes in the vehicle weight m and the gradient S.
The initial value Tini in 3 and 14 is set to zero.

In step 802, the driving torque To of the host vehicle is calculated, and the flow advances to step 803.
In step 03, the vehicle running determination means determines whether or not the vehicle is running. If the vehicle speed V is not 0 (m / s), the process proceeds to step 804. An error Et between the target driving torque Ttar of the feedback term described later and the driving torque To is calculated by the above equation (4).

On the other hand, at step 803, the vehicle speed V becomes zero.
In the case of (m / s), the process proceeds to step 805, where the own vehicle running determination means determines whether or not the own vehicle starts to start, and if the own vehicle speed V is 0 (m / s) and the target Speed Vt
If ar is greater than 0 (m / s), step 806
Then, the correction value Th of the initial value Tini is calculated by the initial value correction means based on the error Et as shown in the above equation 5, and this routine is terminated. Step 8
This routine is also ended when the host vehicle does not start taking at 05. Steps 802 and 803
Steps 806 to 806 correspond to Step 1 in the first embodiment.
01, the same as steps 106 to 109.

FIG. 12 is a control block diagram of the target throttle opening calculating means 41 in the travel control device 10. The target throttle opening degree calculating means 41 calculates a torque ratio between an input shaft and an output shaft of the transmission 70 based on the rotation speed of the engine 60 and the turbine rotation speed of the transmission 70 by the driving torque calculation means. Ratio calculation means 42
A target engine torque calculator 43 for calculating a target torque of the engine 60 based on the torque ratio, the gear position of the transmission 70, and a target drive torque Ttar of the target drive torque calculator 13; Throttle opening search means 44 for searching for a target throttle opening (first target throttle opening Otar1) based on the torque and the rotation speed of the engine 60, as well as the rotation speed of the engine 60 and the transmission 70. Drive torque Te based on the turbine speed and the gear position
And a PI for performing PID control based on a deviation between the estimated drive torque Te and the target drive torque Ttar of the target drive torque calculator 13.
A D controller 46 is added to the first target throttle opening Otar1 to add the calculation result of the PID controller 46 to calculate another target throttle opening (second target throttle opening Otar2). The opening of the throttle valve 48 is controlled.

As described above, the traveling control device 1 of the present embodiment
In the case of 0, the deviation between the target drive torque Ttar and the estimated drive torque Te is absorbed by the target throttle opening calculating means 41, and is made to correspond to aging of the engine 60, the transmission 70 and the like. As described above, each of the embodiments of the present invention has the following functions due to the above configuration.

The traveling control device 10 of the first embodiment
Makes your vehicle automatically follow the preceding vehicle traveling ahead,
Initial value Ti of the target drive torque at the time of start of the vehicle
ni, an initial value calculating means 11 for calculating the target speed Vtar of the host vehicle, a host vehicle speed measuring means 21 for measuring the speed of the host vehicle, and the initial value calculating means 11 A target drive torque calculating means 13 for calculating a target drive torque Ttar of the host vehicle based on each output signal from the target speed calculating means 12 and the host vehicle speed measuring means 21;
And a target throttle opening calculating means 41 for calculating a target throttle opening based on an output signal from the vehicle. The target driving torque calculating means 13 calculates a target throttle opening based on a deviation Ev between the target speed Vtar and the host vehicle speed V. In the PI control, the target drive torque has a feedforward term based on the deviation Ev when the own vehicle starts, and the initial value Tini is calculated. Compared to the case of adding the forward term, the acceleration at the start and the switching of the acceleration after the lapse of a predetermined time are smoothly performed, and in addition to the feeling of sloppyness at the start,
Discomfort caused by swinging in the front-rear direction can be eliminated and drivability can be improved. Furthermore, since the target drive torque at the time of starting is based on the initial value and the deviation calculated from the road gradient S and the weight m of the vehicle, there is no need to perform tuning in advance, and the product development time is reduced. Can be achieved.

In the travel control device 10 according to the second embodiment, the target throttle opening degree calculating means 41 determines the target throttle opening degree based on the rotation speed of the engine 60, the turbine rotation speed of the transmission 70, and the gear position. An estimated drive torque calculating means for calculating an estimated drive torque Te; and a PID control means for performing PID control based on a deviation between the estimated drive torque Te and the target drive torque Ttar. Since the calculation result of the PID control means 46 is added to the opening degree Otar1 to calculate the second target throttle opening degree Otar2, the engine 60,
It is possible to cope with aging of the transmission 70 and the like. As described above, the deviation between the estimated driving torque Te and the target driving torque Ttar is absorbed, and the second target throttle opening Otar2 is not affected by changes in the vehicle weight m and the gradient S. The target drive torque calculating means 13 clears the initial value when the vehicle starts moving.

FIGS. 13 to 20 are timing charts of the traveling control device 10 of the first embodiment and the traveling control device of the prior art (Japanese Patent Laid-Open No. 11-66499) at the start. 13 to 16
Shows a timing chart when the vehicle starts on a flat road. FIG. 13 shows a case of the travel control device 10 of the first embodiment, in which the own vehicle stops the wheels 54 and the like by applying the brake until time T0, and the target speed Vtar of the own vehicle is 0 (m / s) at time T0, and 0.2 (m / s ² ) from time T0 to time T1.
, And after time T1, the target speed V
It is kept constant at tar.

When the travel control device 10 determines that the start of the vehicle starts at time T 0, the target drive torque calculating means 13 uses the target drive torque Tini (1800 (Nm)) based on the calculation result of the initial value calculation means 11. ) Is calculated. When the brake is released, the driving torque To rises immediately following the target driving torque Tini.

After the time T 1, the target drive torque calculating means 13 calculates the target driving torque based on the deviation Ev between the target speed Vtar obtained by the target speed calculating means 12 and the own vehicle speed V obtained by the own vehicle speed measuring means 21. The driving torque Ttar is calculated.
Then, a control signal of the drive torque To corresponding to the target drive torque Ttar is transmitted to the throttle valve 48 and the transmission 70.
And the deviation Ev between the vehicle speed V and the target speed Vtar
Has been followed to eliminate. On the other hand, FIG. 14 shows the case of the conventional traveling control device, and the target speed Vtar of the own vehicle is changed in the same manner as in FIG.

When the travel control device determines that the start of the own vehicle starts at time T0, the calculation result of the initial value Tini in the feedforward term of the equation (2) and the own vehicle speed V to a predetermined speed V0 determined in advance. , The target drive torque Tf (1800 (Nm)) is calculated, and the brake is released. Until time T3, the target drive torque Ttar is calculated from the feedforward term added to the PID control as in Equation 1, so that the target drive torque Ttar fluctuates, and accordingly, the drive torque To and the host vehicle It can be seen that the speed V also fluctuates, giving the driver discomfort in the front-rear direction. In addition, after the time T3, the target drive torque Ttar gradually eliminates the deviation Ev between the target speed Vtar and the host vehicle speed V.

In the conventional traveling control device, the feedforward term is calculated based on the own vehicle speed V, and the target speed Vtar and the target speed Vtar are calculated.
There are two parameters that are not based on the deviation Ev between the target driving torque Ttar and the own vehicle speed V. FIGS. 15 and 16 show the results of an attempt to eliminate the fluctuation of the target driving torque Ttar by changing the values of these parameters. The target speed Vtar in FIGS. 15 and 16 is the same as that in FIG. 13, and FIG. 15 shows that the initial value Tini of the target drive torque is set to 1500 (N
m), and FIG. 16 shows a case where the initial value Tini is set to a relatively large value of 2100 (Nm).

As shown in FIG. 15, the vehicle speed V runs in creep from time T0 to time T2. The target drive torque Ttar does not fluctuate until time T2.
Since the initial value Tini is small, the throttle is not opened, and the driving torque To cannot be transmitted to the road surface. Therefore,
Until the time T2, the own vehicle speed V is equal to the target speed Vt.
It can be seen that the deviation Ev increases without being able to follow ar, and as a result, the driver is given a feeling of backlash.

On the other hand, in FIG. 16, the target drive torque Tta
It can be seen that the fluctuation of r is large, and the vehicle speed V is too large than the target speed Vtar. This puts the vehicle at risk when performing the follow-up control in a traffic jam. Therefore, it is understood that the conventional traveling control device needs to adjust the parameters in advance, and cannot shorten the product development time. Next, FIGS. 17 and 18 show timing charts when the vehicle starts on an uphill road.

FIG. 17 shows the case of the travel control device 10 according to the first embodiment, wherein the own vehicle has a gradient S = 5 (%).
(0.05), the target speed Vtar becomes
13. Similar to FIG. 13, the initial value Tini of the target drive torque
Is 3000 (Nm).

The own vehicle speed V of the traveling control device 10 can follow the target speed Vtar similarly to the flat road. On the other hand, as shown in FIG. 18, the own vehicle speed V of the above-described conventional vehicle traveling control device is such that the target drive torque Ttar temporarily drops at time T4, and accordingly, the drive torque To
It can be seen that the target speed Vtar cannot be followed until the time T3 affected by the feedforward term. Further, FIGS. 19 and 20
Shows a timing chart when the vehicle starts on a downhill road.

FIG. 19 shows the case of the travel control device 10 according to the first embodiment, in which the own vehicle has a gradient S = −5.
(%) (-0.05) starting on the downhill, and the target speed Vt
ar is the same as in FIG. 13, and the initial value Tini of the target drive torque is -800 (Nm).

The own vehicle speed V of the travel control device 10 can be increased without increasing the output of the engine 60 under the influence of the own vehicle weight m.
Can be made to follow the target speed Vtar so as to eliminate the deviation Ev from the target speed Vtar. On the other hand, as shown in FIG.
Indicates that the target drive torque does not fluctuate as described above,
Since the target drive torque is large, it can be seen that the target speed is higher than the target speed Vtar until the time T3 affected by the feedforward term.

FIG. 21 shows the traveling control device 10 according to the present invention.
And the flat road in the prior art traveling control device,
The variation amount of the target drive torque Ttar due to the difference in the gradient S is shown. FIG. 21 shows the initial value Tin of the target drive torque.
The difference between the maximum value and the minimum value of the target drive torque Ttar from the time T0 when i is calculated to the time T1 when the target speed Vtar becomes constant is plotted.

As shown in FIG. 21, the traveling control device of the prior art employs a deviation E between the target speed Vtar and the own vehicle speed V.
Since the target drive torque Ttar is calculated using a variable irrelevant to v, the travel control device 10 is susceptible to the gradient S.
Since the target drive torque Ttar is calculated from the deviation Ev from the above, it is understood that the target drive torque Ttar is hardly affected by the gradient S.

FIG. 22 shows that the traveling control device 10 automatically operates a dry single-plate clutch between the engine 60 and the transmission 70 based on the initial value Tini and the like. 5 is a timing chart when the vehicle is started. The dry single-plate clutch is commonly used in manual transmissions. Note that the target speed V
tar is changed in the same manner as in FIG.

As shown in FIG. 22, the traveling control device 1
If the start is determined at time T0, the target drive torque Ttar becomes 0 (Nm) because the clutch is disengaged and the drive torque To is not transmitted to the road surface at this time.
Here, in order to prevent the engine 60 from being stopped even when the clutch 60 is operated to connect the engine 60 and the transmission 70, it is necessary to open the throttle valve 48 to increase the engine torque. Valve 4
8 is calculated from the target engine torque and the number of revolutions of the engine 60 as described above, and the opening of the throttle valve 48 is set using the initial value Tini of the target drive torque as the target engine torque. When the clutch is engaged, the engine torque that does not stop the engine 60 is quickly started.

Then, the clutch is operated to operate at time T5.
When the vehicle is in the half-clutch state, the driving torque To is generated, the vehicle starts moving, and the vehicle is controlled based on the target driving torque Ttar calculated from the equation (13). Further, until time T6 when the clutch is completely engaged,
After time 6 when the clutch is gradually operated and the clutch is completely engaged, the vehicle speed V follows the target speed Vtar, and the traveling control device 10 automatically switches the dry single-plate clutch. The self-vehicle can be started by operating.

Although the embodiment of the present invention has been described in detail, the present invention is not limited to the embodiment, and various designs may be made without departing from the spirit of the invention described in the claims. Can be changed. For example, the vehicle travel control device 10 of each of the above embodiments
Is shown as a traveling control device for a vehicle (own vehicle) that automatically follows a preceding vehicle traveling ahead, but the present invention is not limited to the traveling control device and has a following function. Even if the present invention is used for another travel control device that does not perform the control, it is possible to reduce the discomfort given to the driver when the vehicle starts.

Further, the traveling control device 1 of the first embodiment
In step 104 of the initial value calculation means 11 at 0,
Although the gradient calculating means calculates the road gradient S based on the node information of the car navigation, the vehicle speed V, and the like, an existing sensor may be used.

FIG. 23 is a flowchart showing the operation of the gradient calculating means for calculating the road gradient S using the sensor. In step 301, the host vehicle running determination means determines whether the host vehicle is stopped or not.
If not (m / s), that is, if YES, the routine proceeds to step 302, where a flat-land running resistance torque Trl is calculated based on the vehicle speed V. On the other hand, if the vehicle speed V is 0 (m /
If not s), this routine ends. In step 303, the acceleration resistance torque Tα is calculated based on the host vehicle acceleration α, and in step 304, the gradient resistance torque Ts is calculated as shown in Expression 15.

[0098]

Ts = To− (Trl + Tα) (15)

In step 305, the gradient S is calculated based on the gradient resistance torque Ts as shown in Expression 16, and this routine is terminated.

[0100]

S = tan (sin ⁻¹ (Ts / (m × Rt))) (16)

As described above, the gradient S can be obtained by using the existing sensor in the same manner as in the case of using the car navigation. Step 10 of the initial value calculation means 11 in the travel control device 10 of the first embodiment.
In 5, the initial value Tini of the target drive torque is calculated based on the correction values of the vehicle weight m and the gradient S, but a map of the initial values prepared in advance may be used.

FIG. 24 is an operation flowchart for calculating the initial value Tini in the initial value calculating means 11 using the map. In step 501, the own vehicle running determination means determines whether or not the own vehicle has started to start, and the own vehicle speed V is 0 (m / s) and the target speed Vtar is 0.
If it is larger than (m / s), that is, if YES, the process proceeds to step 502, and a map search of initial values based on the prepared vehicle weight m and the gradient S is performed (for example, see FIG. 25).

FIG. 25 is a map of initial values in the map search. The initial value map has a gradient S on the horizontal axis,
The vehicle weight m is plotted on the vertical axis. For example, when the vehicle starts on an uphill slope with a vehicle weight m of 2050 (kg) and a slope S of 0.05, the map search is performed in the vicinity of the vehicle weight m.
Two rows of 00 (kg) and 2100 (kg) are selected, and two columns of 0.04 and 0.06 near the gradient S are selected, and four initial values at which the two rows and two columns intersect are selected. Data Tini1 to Tini4 are selected as candidates for the initial value Tini. In step 503, the selected initial value data is interpolated to calculate an initial value Tini, and this routine ends. Step 501
This routine is also terminated when the start is not started.

Further, step 70 of the target speed calculating means 12 in the travel control device 10 of the first embodiment.
In 5, the inter-vehicle distance is set parallel to the vertical axis by the inter-vehicle distance setting means 91, and the relative speed is set parallel to the horizontal axis by the relative speed setting means 92, as shown in FIG. The relative speed Vs1 at 0 (m) and the inter-vehicle distance Ds1 when the relative speed is 0 (m / s), and the stopping distance 2001 linearly decreases as the inter-vehicle distance increases. It may be. Also in the stop area 2001, the change of the inter-vehicle distance Ds and the relative speed Vs by the switch input means 90 causes the stop area 2002 or the stop area 200 to change.
3, the switching intended by the driver can be easily performed.

[0105]

As can be understood from the above description, the traveling control device of the present invention can smoothly switch between acceleration when the vehicle starts moving and acceleration after a predetermined time has elapsed, and provides It is possible to improve the drivability by eliminating the uncomfortable feeling at the time of starting and the uncomfortable feeling due to the swinging in the front-rear direction. Further, the target drive torque at the time of starting can be calculated based on the deviation between the target speed of the own vehicle and the own vehicle speed, and the product development time can be reduced.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an automobile including a vehicle travel control device according to each embodiment of the present invention.

FIG. 2 is a control block diagram of the traveling control device.

FIG. 3 is an operation flowchart of an initial value calculating means in the vehicle travel control device according to the first embodiment of the present invention.

FIG. 4 is an operation flowchart of a gradient calculating means in the initial value calculating means of FIG. 3;

FIG. 5 is an operation flowchart of an initial value calculation in the initial value calculation means of FIG. 3;

FIG. 6 is an operation flowchart of a target speed calculation by a target speed calculation means in FIG. 3;

FIG. 7 is a start map of FIG. 6;

FIG. 8 is an operation flowchart of a target drive torque calculation in a target drive torque calculation means of FIG. 3;

FIG. 9 is a control block diagram of a target drive torque calculating means of FIG. 3;

FIG. 10 is a control block diagram of a target throttle opening calculating means of FIG. 3;

FIG. 11 is an operation flowchart of an initial value calculating means of the vehicle travel control device according to the second embodiment of the present invention.

FIG. 12 is a control block diagram of a target throttle opening calculating means in the traveling control device of FIG. 11;

FIG. 13 is a timing chart in the case of starting on a flat road in the traveling control device of FIG. 3;

FIG. 14 is a timing chart in the case where the vehicle travels on a flat road in the conventional vehicle travel control device.

FIG. 15 is a timing chart in the case of starting on a flat road in a conventional vehicle travel control device.

FIG. 16 is a timing chart in the case of starting on a flat road in a vehicle traveling control device according to a conventional technique.

FIG. 17 is a timing chart in the case of starting on an upward slope in the traveling control device of FIG. 3;

FIG. 18 is a timing chart in the case of starting on an upward slope in a vehicle traveling control device according to a conventional technique.

FIG. 19 is a timing chart in the case of starting on a down slope in the traveling control device of FIG. 3;

FIG. 20 is a timing chart in the case where the vehicle travels on a down slope in the vehicle traveling control device according to the related art.

FIG. 21 is a diagram showing a variation amount of a target drive torque due to a difference between a flat road and a gradient between the travel control device of FIG. 3 and the travel control device of the related art.

FIG. 22 is a timing chart in the case where the self-vehicle is started by automatically operating a dry single-plate clutch in the travel control device of FIG. 3;

FIG. 23 is an operation flowchart of another gradient calculating means in the traveling control device of FIG. 3;

FIG. 24 is an operation flowchart of an initial value calculation of an initial value calculation means using a map in the traveling control device of FIG. 3;

FIG. 25 is an initial value map for the map search of FIG. 24;

FIG. 26 is another start map of FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Vehicle running control apparatus 11 Initial value calculating means 12 Target speed calculating means 13 Target drive torque calculating means 21 Own vehicle speed measuring means 41 Target throttle opening calculating means 42 Torque ratio calculating means 43 Target engine torque calculating means 44 Throttle opening Searching means 45 Estimated driving torque calculating means 46 PID control means 60 Engine 70 Transmission 81 Inter-vehicle distance measuring means 82 Relative speed measuring means 91 Inter-vehicle distance setting means 92 Relative speed setting means 90 Switch input means

Claims (14)

[Claims] 1. An initial value calculating means for calculating an initial value of a target driving torque when a vehicle starts moving, a target speed calculating means for calculating a target speed of the vehicle, and a self-vehicle speed measurement for measuring a speed of the vehicle. Means, a target driving torque calculating means for calculating a target driving torque of the vehicle based on each output signal from the initial value calculating means, the target speed calculating means, and the own vehicle speed measuring means, and the target driving torque. Target throttle opening calculating means for calculating a target throttle opening based on an output signal from the calculating means, wherein the target driving torque calculating means sets the target driving torque to the initial value when the vehicle starts. A travel control apparatus for a vehicle, wherein the travel speed is calculated based on the target speed and the own vehicle speed. 2. The initial value calculating means calculates a driving torque of the vehicle, a driving torque determining means for determining whether the vehicle starts or stops, and an error of the driving torque. 2. The vehicle travel control device according to claim 1, comprising a torque error calculating means and an initial value correcting means for correcting the initial value. 3. The self-vehicle acceleration calculation means for calculating the acceleration of the vehicle, the self-vehicle weight calculation means for calculating the weight of the vehicle, and the slope calculation means for calculating the slope of the road. The travel control device for a vehicle according to claim 2, comprising: 4. The vehicle running control device according to claim 3, wherein the initial value calculating means calculates the gradient of the road based on map information of car navigation of the vehicle. 5. The vehicle running control device according to claim 3, wherein said initial value calculating means calculates the gradient of the road based on a driving torque of the vehicle, a speed and an acceleration of the vehicle. 6. The apparatus according to claim 3, wherein the initial value calculating means calculates the initial value based on a map including a weight of the vehicle and a gradient of the road. A travel control device for a vehicle according to any one of the preceding claims. 7. The target throttle opening calculating means calculates a target torque of the engine based on an engine speed, a turbine speed of a transmission, a gear position of the transmission, and the target drive torque. 7. A target engine torque calculating means for calculating a target throttle opening degree based on the target engine torque and the number of revolutions of the engine. The travel control device for a vehicle according to any one of the preceding claims. 8. The estimated drive torque calculation means for calculating an estimated drive torque based on the engine speed, the turbine speed of the transmission, and the gear position, and the estimated drive torque calculation means; Control means for performing control based on a deviation between the torque and the target drive torque, and calculating another target throttle opening degree by adding a calculation result of the control means to the target throttle opening degree. The travel control device for a vehicle according to claim 7, wherein: 9. The vehicle travel control device according to claim 8, wherein the target drive torque calculation means clears the initial value when the vehicle starts moving. 10. The inter-vehicle distance measurement means for measuring an inter-vehicle distance between a preceding vehicle traveling ahead and the own vehicle for automatically adjusting the inter-vehicle distance between the preceding vehicle and the target vehicle. Output signals from relative speed measuring means for measuring the relative speed between the own vehicle, and inter-vehicle distance setting means for setting an inter-vehicle distance from the start of the preceding vehicle to the start of start of the own vehicle, and The self-vehicle is started based on each output signal from relative speed setting means for setting a relative speed from a start to a start of the start of the self-vehicle. A travel control device for a vehicle according to claim 1. 11. The vehicle travel control device according to claim 10, wherein each output signal from said inter-vehicle distance setting means and said relative speed setting means can be switched simultaneously. 12. The inter-vehicle distance setting unit and the relative speed setting unit may set the relative speed to be small when the inter-vehicle distance is set long, or the relative speed to be set when the inter-vehicle distance is set short. The travel control device for a vehicle according to claim 10 or 11, wherein is set larger. 13. The target speed calculating means has a map including an inter-vehicle distance between the preceding vehicle and the own vehicle, and a relative speed between the preceding vehicle and the own vehicle. The vehicle travel control device according to any one of claims 10 to 12, wherein the vehicle is stopped when the vehicle is in an area surrounded by the inter-vehicle distance and the relative speed. 14. The traveling control device according to claim 1, wherein a clutch is provided between an engine and a transmission, and the clutch is operated based on the initial value. A travel control device for a vehicle according to claim 1.