JP4883925B2 - Vehicle travel control device - Google Patents

Description

  The present invention relates to a vehicular travel control device, and more particularly to a vehicular travel control device that controls a vehicle to travel following a preceding vehicle.

  In recent years, in order to reduce the operational burden on a driver who drives a vehicle, a vehicular travel control device has been developed that travels the vehicle following a preceding vehicle traveling ahead. In such a travel control device, for example, the acceleration of the host vehicle is controlled such that the inter-vehicle distance between the preceding vehicle and the host vehicle detected by a sensor such as a camera or a radar becomes the target inter-vehicle distance.

  As this type of travel control device, for example, there is a vehicle travel control device disclosed in Japanese Patent Application Laid-Open No. 2002-166747. When calculating the target acceleration, this travel control device calculates a plurality of target acceleration candidates using different control gains, and sets the minimum value among the calculated target accelerations as the target acceleration. Specifically, the following equations (1) and (2) are used in calculating the target acceleration candidate.

αa = K1ΔL−K2ΔLs (1)
αb = K3ΔL−K4ΔLs (2)
Where αa, αb: target acceleration
ΔL: Relative speed between the preceding vehicle and the host vehicle
ΔLs: Deviation between target inter-vehicle distance and actual inter-vehicle distance
K1 to K4: Control gain
JP 2002-166747 A

  In the travel control device disclosed in Patent Document 1, since only the control gain is different between the formula (1) and the formula (2), the formula (1) is substantially the same. Switching to (2) means switching of control gain. Here, in the travel control device disclosed in Patent Document 1, the smaller one of the target accelerations obtained from Equations (1) and (2) with different control gains, regardless of the traveling state of the vehicle. Is determined as the target acceleration.

  When looking at the target accelerations αa and αb respectively obtained from the equations (1) and (2), the control gain is (K1 / K3 = K2 / K4) in the embodiment in Patent Document 1. Therefore, the point where the control gain for obtaining both is changed is that the target acceleration is zero. The point at which the target acceleration is zero is when the vehicle is in a steady running state in which the vehicle runs stably. When the control gain is switched in such a steady running state, there is a problem that the driver may feel uncomfortable due to acceleration / deceleration of the vehicle.

  In order to eliminate such a sense of incongruity, for example, it is conceivable to make the difference in control gain between the equations (1) and (2) very small. However, when the difference in control gain is reduced in this way, priority is given to either acceleration / deceleration in the steady running state or deceleration in the specific running state where the preceding vehicle approaches and sudden deceleration is required. It is necessary to determine the control gain. In this case, if priority is given to acceleration / deceleration in the steady driving state, there is a risk that sufficient deceleration in the specific driving state may not be performed. Conversely, if priority is given to deceleration in the specific driving state, acceleration in the steady driving state may occur. There was a problem that the deceleration was sudden and the ride comfort for the passengers was reduced.

  Accordingly, an object of the present invention is to prevent the driver from feeling uncomfortable due to acceleration / deceleration of the vehicle while preventing a decrease in ride comfort for the occupant during a steady driving state while reliably driving the vehicle during a specific driving state. Another object of the present invention is to provide a vehicle travel control device.

The vehicle travel control apparatus according to the present invention that has solved the above-described problems is a braking / driving force so that the relative relationship relating to the travel state between the preceding vehicle detected by the preceding vehicle detection means and the host vehicle becomes a set target relative relationship. In the vehicle travel control apparatus for controlling the vehicle, a value obtained by multiplying the inter-vehicle distance deviation, which is a deviation between the target inter-vehicle distance and the inter-vehicle distance between the preceding vehicle and the host vehicle , by the first control gain for the steady traveling state, The first calculation means for calculating the first speed control amount by adding the value obtained by multiplying the relative speed between the vehicle and the host vehicle by the second control gain for the steady running state, and the side for increasing the inter-vehicle distance deviation The value obtained by multiplying the inter-vehicle distance deviation for the specific traveling state obtained by offsetting by the first control gain for the specific traveling state larger than the first control gain for the steady traveling state, and the relative speed between the preceding vehicle and the host vehicle In addition, And a value obtained by multiplying the second control gain for a specific running condition is greater than the second control gain for normal running state by adding a second calculating means for calculating a second speed control amount, comprising a first speed control The braking / driving force of the vehicle is controlled based on the minimum value of the amount and the second speed control amount.
The specific running state inter-vehicle distance deviation is a deviation between the specific traveling state target inter-vehicle distance and the inter-vehicle distance that is smaller than the target inter-vehicle distance between the preceding vehicle and the host vehicle.

  In the vehicular travel control apparatus according to the present invention, the first calculation means calculates the first speed control amount based on the deviation between the target relative positional relationship and the relative positional relationship and the first control gain. In the second calculation means, the speed control amount is offset to the side based on the deviation between the target relative positional relationship and the relative positional relationship and the second control control gain larger than the first control gain. The second speed control amount is calculated. For this reason, in the steady running state, the braking / driving force of the vehicle is controlled based on the first speed control amount calculated by the first calculating unit, and in the specific running state, the second speed control amount calculated by the second calculating unit is set. Based on this, the braking / driving force of the vehicle is controlled. This point will be further described. In the second calculation means, the second speed control amount corresponding to the specific travel state is offset to the side that increases the speed control amount. The first speed control amount becomes smaller. On the other hand, since the second control gain is larger than the first control gain, when the speed control amount decreases beyond the offset in the specific traveling state, the second calculation gain is calculated. The second speed control amount is smaller than the first speed control amount. Therefore, while the vehicle is surely traveling in the specific traveling state, it is possible to prevent the driver from feeling uncomfortable due to the acceleration / deceleration of the vehicle while preventing the ride comfort for the occupant from being lowered in the steady traveling state.

  The “speed control amount” as used in the present invention refers to an amount that can control the vehicle speed as a result of the control, such as an acceleration control amount and a driving force control amount, in addition to a speed control amount that directly controls the vehicle speed. Is included. In addition, the “target relative positional relationship” in the present invention is a target of a relative relationship between the target object and the host vehicle. Specifically, for example, when the target object is a preceding vehicle, the target Examples include inter-vehicle distance, target inter-vehicle time, target relative speed, and the like.

Here, the offset may be an aspect when the relative relation deviation for the specific traveling state is obtained by making the relative relation deviation larger by reducing the target relative relation . Furthermore, the deviation between the target relative relationship and the relative relationship may be a deviation between the target relative speed and the relative speed, or a deviation between the target distance and the distance.

On the other hand, the vehicular travel control apparatus according to the present invention that has solved the above-mentioned problems is for a vehicle that controls the braking / driving force so that the relative distance from the target object detected by the object detection means becomes the set target relative distance. In the travel control device, a relative speed acquisition means for acquiring a relative speed with respect to the target object, a relative distance deviation that is a deviation between the target relative distance and the relative distance, a first control gain that multiplies the relative distance deviation, and a relative speed. A first calculation means for calculating a first speed control amount based on a third control gain to be multiplied, a relative distance deviation for a specific running state obtained by offsetting to the side that increases the relative distance deviation, and a first control greater than the gain, calculating a second control gain to be multiplied by the relative distance deviation for a specific running condition, greater than the third control gain, and a fourth control gain to be multiplied by the relative speed, on the basis of the second speed control amount That a second calculating means comprises, it controls the braking and driving force of the vehicle based on the minimum value of the first speed control amount and the second speed control amount.

  According to the vehicle travel control device of the present invention, the vehicle is reliably traveled in the specific travel state, while the driver feels uncomfortable due to the acceleration / deceleration of the vehicle while preventing a decrease in the ride comfort for the occupant during the steady travel state. It is possible to prevent them from being remembered.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block configuration diagram of a vehicle travel control apparatus according to the present invention, and FIG. 2 is a block configuration diagram of a tracking target acceleration calculation unit.

  As shown in FIG. 1, the vehicle travel control apparatus according to the present embodiment includes a target acceleration calculation unit 1. The target acceleration calculation unit 1 is provided with a recognition unit 2, a target acceleration candidate calculation unit 3, an arbitration unit 4, and a change rate limiting unit 5 that are relative relationship calculation means. In addition, a distance sensor 11, a CCD camera 12, a vehicle speed sensor 13, and an actuator selection unit 14 are connected to the target acceleration calculation unit 1. Further, the target acceleration candidate calculation unit 3 is provided with a follow-up target acceleration calculation unit 20, a constant speed target acceleration calculation unit 30, and a corner acceleration prohibition target acceleration calculation unit 40. The tracking target acceleration calculation unit 20 includes a target relative relationship storage unit 21, a steady running state target acceleration calculation unit 22 that is a first calculation unit, a specific running state target acceleration calculation unit 23 that is a second calculation unit, and A selection unit 24 is provided.

  The distance sensor 11 is composed of, for example, a millimeter wave radar sensor attached to the tip of the host vehicle, and detects the distance (actual vehicle distance) from the preceding vehicle that is the target object of the present invention located in front of the host vehicle. Yes. The distance sensor 11 transmits the detected actual inter-vehicle distance between the preceding vehicle and the host vehicle to the recognition unit 2 in the target acceleration calculation unit 1. The CCD camera 12 is provided in the vicinity of the windshield of the host vehicle, for example, and takes an image in front of the host vehicle. The CCD camera 12 transmits the captured image to the recognition unit 2 in the target acceleration calculation unit 1. The vehicle speed sensor 13 is attached to the body of the host vehicle, for example, and detects the vehicle speed of the host vehicle. The vehicle speed sensor 13 transmits the detected vehicle speed to the recognition unit 2.

  The recognizing unit 2 performs image processing on the image transmitted from the CCD camera 12, thereby recognizing a white line drawn on the road, an obstacle on the road, and a preceding vehicle serving as a target object. The recognizing unit 2 recognizes the preceding vehicle, thereby confirming that the actual inter-vehicle distance transmitted from the distance sensor 11 is the actual inter-vehicle distance with respect to the preceding vehicle and confirming the target acceleration for tracking in the target acceleration candidate calculating unit 3. This is transmitted to the steady running state target acceleration computing unit 22 and the specific running state target acceleration computing unit 23 of the computing unit 20, respectively. Further, the recognizing unit 2 transmits the vehicle speed transmitted from the vehicle speed sensor 13 to the steady travel state target acceleration calculation unit 22 and the specific travel state target acceleration calculation unit 23, respectively.

  The target relative relationship storage unit 21 in the tracking target acceleration calculation unit 20 includes steady running state control gains K11 and K21 used for calculating acceleration in the steady running state target acceleration calculation unit 22, and a specific running state target acceleration calculation unit. 23, the control gains K12 and K22 for specific running state used for calculating the acceleration are stored. Further, the target relative relationship storage unit 21 includes the target travel time target ht1 for use in calculating the target inter-vehicle distance in the steady travel state target acceleration calculation unit 22 and the target inter-vehicle distance in the specific travel state target acceleration calculation unit 23. The target inter-vehicle time ht2 for the specific traveling state used for calculating the vehicle travel time is stored.

  Among these, the first control gain K11 for steady running state is set smaller than the first control gain K12 for specific running state, and the second control gain K21 for steady running state is the second control gain for specific running state. It is set smaller than K22.

  In addition, the specific travel state target inter-vehicle time ht2 is smaller than the steady travel state target inter-vehicle time ht1, and is set such that the following equation (3) holds. This relationship is a relationship in which the target inter-vehicle time ht2 for the specific travel state is offset toward the side where the target inter-vehicle time ht1 for the steady travel state is decreased.

ht2 = 0.8 * ht1 (3)
The target relative relationship storage unit 21 transmits the stored steady state control gains K11 and K21 and the steady state target vehicle time ht1 to the steady state target acceleration calculation unit 22, respectively. Further, the target relative relationship storage unit 21 transmits the stored specific travel state control gains K12 and K22 and the specific travel state target inter-vehicle time ht2 to the specific travel state target acceleration calculation unit 23, respectively.

  The steady running state target acceleration calculation unit 22 calculates a base tracking target acceleration that is a base for determining the tracking target acceleration. The target acceleration calculated by the steady running state target acceleration calculation unit 22 is a target acceleration that is a base for calculating the optimum acceleration for following the preceding vehicle. The steady running state target acceleration calculation unit 22 calculates a steady state target acceleration at1 that is a target acceleration when the host vehicle is running in a steady state. For this purpose, first, the steady state target inter-vehicle distance based on the following equation (4), based on the vehicle speed V transmitted from the recognition unit 2 and the target inter-vehicle time ht1 for steady running state transmitted from the target relative relationship storage unit 21. AL1 is calculated.

AL1 = ht1 * V (4)
The steady running state target acceleration calculation unit 22 calculates the steady state target inter-vehicle distance AL1, the inter-vehicle distance L and the relative speed VR transmitted from the recognition unit 2, and the steady state transmitted from the target relative relationship storage unit 21. The steady state target acceleration at1 is calculated based on the following equation (5) using the running state control gains K11 and K21.

at1 = K11 (L-AL1) + K21 * VR (5)
The steady running state target acceleration calculation unit 22 transmits the steady state target acceleration at1 calculated based on the equation (5) to the selection unit 24.

  The specific running state target acceleration calculation unit 23 is a target acceleration when the host vehicle is suddenly decelerated when the distance between the preceding vehicle and the host vehicle is abruptly reduced due to sudden braking of the preceding vehicle. A specific state target acceleration at2 is calculated. Therefore, first, the specific state target inter-vehicle distance based on the following equation (6) based on the vehicle speed V transmitted from the recognizing unit 2 and the specific travel state target inter-vehicle time ht2 transmitted from the target relative relationship storage unit 21. AL2 is calculated.

AL2 = ht2 * V (6)
The specific running state target acceleration calculation unit 23 calculates the specific state target inter-vehicle distance AL2, the inter-vehicle distance L and relative speed VR transmitted from the recognition unit 2, and the specific relative relationship storage unit 21. The specific state target acceleration at2 is calculated based on the following equation (7) using the running state control gains K12 and K22.

at2 = K12 (L-AL2) + K22 * VR (7)
When comparing the term (L-AL1) and the term (L-AL2) in the above formulas (5) and (7), AL1> AL2, and the inter-vehicle distance L and the specific state target inter-vehicle distance in formula (7) The deviation from the distance AL2 is obtained by offsetting the deviation between the inter-vehicle distance L and the steady state target inter-vehicle distance AL1 in the equation (5) to the side where the target acceleration is increased. The specific running state target acceleration calculation unit 23 transmits the specific state target acceleration at2 calculated based on the above equation (7) to the selection unit 24.

  The selection unit 24 compares the steady state target acceleration at1 transmitted from the steady traveling state target acceleration calculation unit 22 with the specific state target acceleration at2 transmitted from the specific traveling state target acceleration calculation unit 23. Then, the smaller one of the steady state target acceleration at 1 and the specific state target acceleration at 2 is selected as the target acceleration for tracking and is transmitted to the arbitration unit 4.

  The constant speed target acceleration calculation unit 30 calculates a target acceleration for traveling at the set vehicle speed, and transmits the calculated target acceleration to the arbitration unit 4. Further, the corner acceleration prohibition target acceleration calculation unit 40 calculates the target acceleration of the host vehicle when the host vehicle is on a curve, and transmits the calculated target acceleration to the arbitration unit 4.

  The arbitration unit 4 performs arbitration among the three target accelerations transmitted from the following target acceleration calculation unit 20, the constant speed target acceleration calculation unit 30, and the corner acceleration prohibition target acceleration calculation unit 40, and finally To determine the target acceleration. The target acceleration determined in this way is transmitted to the change rate limiting unit 5.

  In this embodiment, the target acceleration calculation unit 20 for tracking, the target acceleration calculation unit 30 for constant speed, and the target acceleration calculation unit 40 for corner acceleration prohibition always calculate the target acceleration, and the arbitration unit 4 Of the plurality of target accelerations, the minimum value is determined as the target acceleration. However, the present invention is not limited to this, and the arbitration unit 4 selects one of a plurality of calculated target accelerations as the target acceleration based on the relationship between the preceding vehicle and the host vehicle, The acceleration may be determined, or a value obtained by taking a weighted average of each acceleration may be determined as the target acceleration.

  The change rate limiting unit 5 stores a predetermined limit value for the acceleration change rate of the host vehicle. The change rate limiting unit 5 compares the target acceleration transmitted from the arbitration unit 4 with the stored limit value, and when the change rate of acceleration does not exceed the limit value, the target rate transmitted from the arbitration unit 4 The acceleration is adopted as the target acceleration as it is. When the target acceleration transmitted from the arbitration unit 4 exceeds the limit value, the limit value is adopted as the target acceleration.

  The change rate limiting unit 5 transmits the adopted target acceleration to the actuator selection unit 14. The actuator selection unit 14 is connected to an engine control device and a brake control device (not shown). When the adopted target acceleration is positive, the actuator selection unit 14 transmits the target acceleration to the engine control device. The target acceleration is transmitted to the control device. The engine control device and the brake control device respectively control the engine and the brake so as to achieve the transmitted target acceleration.

  Next, a procedure for traveling control by the traveling control apparatus according to the present embodiment will be described. FIG. 3 is a flowchart showing a procedure of travel control according to the present embodiment. Here, a control procedure in the target acceleration calculation unit 20 for tracking, which is a characteristic part of the present embodiment, will be described.

  As shown in FIG. 3, in the traveling control according to the present embodiment, first, the steady state target acceleration at1 is calculated in the steady state target acceleration calculation unit 22 (S1). The steady state target acceleration at1 is calculated based on the above equation (5). The steady running state target acceleration calculation unit 22 transmits the calculated steady state target acceleration at1 to the selection unit 24. Next, the specific running state target acceleration calculating unit 23 calculates the specific state target acceleration at2 (S2). The specific state target acceleration at2 is calculated based on the above equation (7). The specific running state target acceleration calculation unit 23 transmits the calculated specific state target acceleration at2 to the selection unit 24.

  Thus, when the steady state target acceleration at1 and the specific state target acceleration at2 are calculated and transmitted to the selection unit 24, the selection unit 24 determines whether the steady state target acceleration at1 is equal to or less than the specific state target acceleration at2. (S3). As a result, when it is determined that the steady state target acceleration at1 is equal to or less than the specific state target acceleration at2, the steady state target acceleration at1 is selected as the target acceleration (S4). On the other hand, when it is determined that the steady state target acceleration at1 exceeds the specific state target acceleration at2 and is not equal to or less than the specific state target acceleration at2, the specific state target acceleration at2 is selected as the target acceleration (S5). The selection unit 24 determines the selected target acceleration (S6) and transmits it to the arbitration unit 4.

  Here, the steady running state target inter-vehicle time ht1 for calculating the steady state target inter-vehicle distance AL1 is set larger than the specific traveling state target inter-vehicle time ht2 for calculating the specific state target inter-vehicle distance AL2. . Further, the target inter-vehicle distances AL1 and AL2 are calculated by the above equations (4) and (6), respectively. Therefore, when comparing the steady state target inter-vehicle distance AL1 and the specific state target inter-vehicle distance AL2, the steady state target inter-vehicle distance AL1 is larger than the specific state target inter-vehicle distance AL2. On the other hand, the control gains K11 and K22 for calculating the steady state target acceleration at1 are set smaller than the control gains K12 and K22 for calculating the specific state target acceleration at2.

By setting the target inter-vehicle distance and the control gain as described above, the change in the target acceleration when shifting from steady travel to specific travel is as shown in FIG. 4, for example. The example shown in FIG. 4 shows an example in which the preceding vehicle suddenly decelerates and shifts to a specific traveling state at the time t1 from the state in which the preceding vehicle traveling at a substantially constant speed follows the steady state. Yes. In FIG. 4A, the time-dependent change of the steady state target acceleration at1 is shown by a broken line , the specific state target acceleration at2 is shown by a solid line , and FIG. 4B shows the time of the target acceleration at selected by the selection unit. It shows a change.

  As can be seen from FIG. 4A, while the preceding vehicle is traveling at substantially constant speed, the steady state target acceleration at1 with a small control gain is smaller than the specific state target acceleration at2 with a large control gain. ing. For this reason, as shown in FIG. 4A, since the steady state target acceleration at1 is selected as the target acceleration, it is possible to prevent the ride comfort for the occupant from being lowered.

  On the other hand, at time t1, when the preceding vehicle starts sudden deceleration, each of the steady state target acceleration at1 and the specific state target acceleration at2 starts to decrease. Then, the steady state target acceleration at1 and the specific state target acceleration at2 intersect at the time t2, and thereafter, the specific state target acceleration at2 becomes smaller than the steady state target acceleration at1. For this reason, as shown in FIG.4 (b), since the specific state target acceleration at2 is selected as a target acceleration in the specific state when the preceding vehicle decelerates suddenly, the host vehicle can be greatly decelerated.

  At the time t1, when the target acceleration is switched from the steady state target acceleration at1 to the specific state target acceleration at2, both the steady state target acceleration at1 and the specific state target acceleration at2 are in a state of decreasing. For this reason, since the fluctuation | variation of the deceleration of the vehicle when a steady state target acceleration at1 and specific state target acceleration at2 cross | intersect and a control gain changes can be made small, the discomfort given to a driver can be made small.

  Furthermore, when control as a specific running state is necessary due to the relationship between the target relative position and the relative position, the selected target acceleration is replaced, that is, the control gain is replaced. The running state can be clearly distinguished. Therefore, since it is not necessary to set the control gain for the steady travel state in consideration of the specific travel state, the design freedom of the steady travel state control gains K11 and K21 can be increased. Similarly, since it is not necessary to set the control gain for the specific travel state in consideration of the steady travel state, the degree of freedom in designing the specific travel state control gains 12, K22 can be increased.

  Next, a modified example of the present invention will be described. This modification mainly differs from the above-described embodiment in the configuration of the tracking target acceleration calculation unit 20. FIG. 5 is a block diagram of a tracking target acceleration calculation unit according to the present modification.

  As shown in FIG. 5, the target acceleration calculation unit 20 for tracking according to the present modification includes a target relative relationship storage unit 21, a steady running state target acceleration calculation unit 22, and a specific running state target acceleration calculation similar to those in the above embodiment. A unit 23 and a selection unit 24 are provided. Furthermore, the target acceleration calculation unit 20 for follow-up according to the present modification includes a target acceleration calculation unit 25 for stop, a slow deceleration determination unit 26 for distant low speed vehicle, a catch-up acceleration limiting unit 27, and a target acceleration calculation unit for stop holding 28. Is provided.

  The target acceleration calculation unit for stop 25 calculates a target acceleration for stopping the host vehicle while preventing a decrease in ride comfort of the occupant when the preceding vehicle stops. The far low-speed vehicle presence deceleration determination unit 26 and the catch-up acceleration limiting unit 27 calculate a target acceleration when the preceding vehicle travels at a low speed or stops at a position far from the host vehicle. The stop-holding target acceleration calculation unit 28 calculates the target acceleration so as to continue the stop state when the vehicle is stopped with the actual inter-vehicle distance being larger than the target inter-vehicle distance.

  The stop target acceleration calculation unit 25, the far low speed vehicle timed deceleration determination unit 26, the catch-up acceleration limiting unit 27, and the stop holding target acceleration calculation unit 28 transmit the calculated target accelerations to the selection unit 24, respectively. In the selection unit 24, the steady running state target acceleration calculation unit 22, the specific running state target acceleration calculation unit 23, the stop target acceleration calculation unit 25, the far low speed vehicle presence deceleration determination unit 26, the catch-up acceleration limit unit 27, and the stop hold The target accelerations transmitted from the target acceleration calculation unit 28 are compared, and the smallest target acceleration is selected. Then, the selected target acceleration is transmitted to the arbitration unit 4.

  As described above, the target acceleration is calculated not only in the steady running state target acceleration calculating unit 22 and the specific running state target acceleration calculating unit 23 but also in other modes, and the calculated target accelerations are calculated. It is also possible to select a minimum target acceleration from among the above.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment. For example, in the above embodiment, the speed control amount is set from the calculated target acceleration. However, for example, the target speed can be directly calculated or set from the target driving force control amount.

In the above embodiment, the target inter-vehicle distance is used as the target relative position relationship with the target object, but the target inter-vehicle time can also be used.

Furthermore, in the above embodiment, in calculating the target acceleration, the specific travel state target acceleration calculation unit 23 calculates the deviation (L-AL1) between the target inter-vehicle distance and the inter-vehicle distance in the steady travel state target acceleration calculation unit 22. The deviation (L-AL2) offset to the side of increasing the target acceleration (where AL2 = 0.8 * AL1) is used, but it can be offset in other manners .

1 is a block configuration diagram of a vehicle travel control device according to the present invention. FIG. It is a block block diagram of the target acceleration calculating part for tracking. It is a flowchart which shows the procedure of traveling control. (A) is a graph which shows a time-dependent change of normal state target acceleration and a specific state target acceleration, (b) is a graph which shows a time-dependent change of target acceleration. It is a block block diagram of the target acceleration calculating part for tracking which concerns on a modification.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Target acceleration calculating part, 2 ... Recognition part, 3 ... Target acceleration candidate calculating part, 4 ... Arbitration part, 5 ... Change rate limiting part, 11 ... Distance sensor, 12 ... CCD camera, 13 ... Vehicle speed sensor, 14 ... Actuator Selection unit, 20 ... tracking target acceleration calculation unit, 21 ... target relative relationship storage unit, 22 ... steady running state target acceleration calculation unit, 23 ... specific running state target acceleration calculation unit, 24 ... selection unit, 30 ... for constant speed Target acceleration calculation unit, 40 ... Corner acceleration prohibition target acceleration calculation unit, AL1 ... Steady state target inter-vehicle distance, AL2 ... Specific state target inter-vehicle distance, at ... Target acceleration, at1 ... Steady state target acceleration, at2 ... Specific state target acceleration , Ht1 ... target inter-vehicle time for steady running state, ht2 ... target inter-vehicle time for specific running state, K11, K21 ... control gain for steady running state, K12, K22 ... for specific running state Your gain.

Claims (2)

In the vehicle travel control device for controlling the braking / driving force so that the relative relationship regarding the travel state between the preceding vehicle and the host vehicle detected by the preceding vehicle detection means becomes the set target relative relationship,
A value obtained by multiplying the inter-vehicle distance deviation, which is the deviation between the target inter-vehicle distance and the inter-vehicle distance between the preceding vehicle and the host vehicle, by the first control gain for steady running state, and between the preceding vehicle and the host vehicle. A first calculation means for calculating a first speed control amount by adding a value obtained by multiplying the relative speed in step 2 by a second control gain for steady running state ;
A value obtained by multiplying the inter-vehicle distance deviation for specific running state obtained by offsetting the inter-vehicle distance deviation to the larger side, and a first control gain for specific running state larger than the first control gain for steady running state, and By adding a value obtained by multiplying the relative speed between the preceding vehicle and the host vehicle by the second control gain for the specific traveling state larger than the second control gain for the steady traveling state, the second speed control amount is obtained. Second calculating means for calculating,
A vehicle travel control device that controls braking / driving force of a vehicle based on a minimum value of the first speed control amount and the second speed control amount. The vehicle according to claim 1, wherein the inter-vehicle distance deviation for the specific traveling state is a deviation between the target inter-vehicle distance for the specific traveling state and the inter-vehicle distance that is smaller than the target inter-vehicle distance between the preceding vehicle and the host vehicle. Travel control device.

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