JP4613124B2 - Navigation cooperative travel control device - Google Patents

Description

  The present invention relates to a control device (adaptive cruise control, hereinafter referred to as ACC) that is used in a vehicle such as an automobile and controls the traveling of the host vehicle so as to follow a preceding vehicle.

  Recently, an ACC device has been developed that controls the vehicle according to the distance between the vehicle and the preceding vehicle set by the driver, for example. Conventionally, the ACC device has been developed mainly on the premise that it is used on a highway, but development of a product that can be used on a general road with many changes in slope and curved roads is progressing.

  With regard to such an ACC device, a technique is known in which deceleration and the like are calculated based on the vehicle position information obtained from information such as vehicle speed and map information, etc., and the inter-vehicle distance control with the preceding vehicle is performed ( For example, Patent Document 1). This technology uses information such as the running resistance and deceleration of the own vehicle for follow-up control running with the preceding vehicle while the own vehicle is running on a flat road or a road with a slope.

JP-A-8-142717

  When the vehicle's running resistance is used for follow-up control after the vehicle actually reaches the slope point, there is a problem that the timing at which the brakes start to work is later than the timing at which the driver does not feel uncomfortable. In other words, when the preceding vehicle is steep, the preceding vehicle may decelerate and the inter-vehicle distance may suddenly become clogged. Further, when the preceding vehicle is going downhill, the inter-vehicle distance is widened due to the reverse phenomenon.

  Conventionally, in the ACC technology, in order to follow the preceding vehicle, follow-up control is performed by capturing changes in the inter-vehicle distance and relative speed with the preceding vehicle. However, usually, a predetermined confirmation time is required until the inter-vehicle distance and the relative speed information are determined. For this reason, in the above-described prior art, deceleration starts after the space between the vehicles is jammed, and the timing at which braking is applied tends to be slower than when the driver visually determines. Since the driver can visually recognize the slope in advance and can predict the deceleration of the preceding vehicle, the ACC device is required to respond promptly to deceleration and acceleration.

  In view of the above problems, an object of the present invention is to provide a travel control device capable of performing follow-up control while reducing the distance between the vehicles rapidly clogging or expanding and ensuring safe and comfortable travel. is there.

In order to achieve the above object, a travel control device according to the present invention provides a storage unit for storing a set inter-vehicle distance input by a driver and a vehicle so that the inter-vehicle distance between the host vehicle and a preceding vehicle becomes the set inter-vehicle distance. Estimated by the preceding vehicle information and terrain information estimation device from the inter-vehicle distance control unit that controls the actuator of the vehicle and the inter-vehicle distance sensor that detects at least one of the inter-vehicle distance and relative speed between the host vehicle and the preceding vehicle as preceding vehicle information based on the gradient information of the road that is, when the preceding vehicle and the gradient angle calculation unit that obtains a gradient angle difference of the vehicle, obtaining a result of the gradient angle calculation unit is a predetermined value or more, prior based on the gradient angle difference A gradient inter-vehicle time calculation unit that calculates the gradient inter-vehicle time to the vehicle, and the inter-vehicle distance control unit calculates the gradient inter-vehicle distance from the gradient inter-vehicle time and the own vehicle speed calculated by the gradient inter-vehicle time calculation unit, Calculated Gradient vehicle distance and calculates a target inter-vehicle distance from the set inter-vehicle distance, the structure of the travel control device for correction control of the engine output or motor torque of the vehicle so that the inter-vehicle distance becomes equal to the target inter-vehicle distance.
Further, the present invention stores the set inter-vehicle distance input by the driver, controls the actuator of the vehicle so that the inter-vehicle distance between the own vehicle and the preceding vehicle becomes the set inter-vehicle distance, and Based on the preceding vehicle information from the inter-vehicle distance sensor that detects at least one of the inter-vehicle distance and relative speed as the preceding vehicle information and the terrain information estimated by the terrain information estimation device, the gradient angle difference between the preceding vehicle and the host vehicle is calculated. When the calculation result of the gradient angle is equal to or greater than a predetermined value, the gradient inter-vehicle time to the preceding vehicle is calculated based on the gradient angle difference, and the gradient inter-vehicle distance is calculated from the calculated gradient inter-vehicle time and the own vehicle speed , A travel control method that calculates the target inter-vehicle distance from the calculated gradient inter-vehicle distance and the set inter-vehicle distance, and corrects and controls the vehicle engine output or the motor torque so that the inter-vehicle distance between the host vehicle and the preceding vehicle becomes the target inter-vehicle distance. And configuration.

  It is possible to reduce a sudden increase or decrease in the inter-vehicle distance, and it is possible to ensure safe and comfortable travelability.

  The travel control device according to the present invention obtains a distance between the preceding vehicle and the own vehicle and a relative speed, a means for controlling the distance between the preceding vehicle, and a gradient of the positions of the preceding vehicle and the own vehicle. And means for calculating an inter-vehicle distance affected by the gradient from the obtained gradient, and when the preceding vehicle reaches the gradient point, the target inter-vehicle distance is changed and set according to the gradient.

  The travel control device according to the present invention preferably sets the target inter-vehicle distance when the preceding vehicle reaches the gradient point as a value obtained by adding the inter-vehicle distance affected by the gradient to the set inter-vehicle distance.

  Further, in another aspect of the present invention, the control for increasing the set inter-vehicle distance when the preceding vehicle reaches an ascending slope is started after detecting the start of deceleration of the preceding vehicle.

  In addition, the traveling control device starts the control for decreasing the set inter-vehicle distance when the preceding vehicle reaches a downward slope after detecting the acceleration start of the preceding vehicle.

  Hereinafter, the present invention will be described in detail according to specific examples.

  FIG. 1 is a block diagram of an ACC system in the first embodiment of the present invention.

  The inter-vehicle distance sensor 101 detects either the inter-vehicle distance and relative speed between the preceding vehicle and the host vehicle or the inter-vehicle distance and relative speed at a predetermined time interval and outputs them as preceding vehicle information. Specifically, it is configured by a radar or a stereo camera.

  The terrain information estimation device 102 estimates the terrain information around the vehicle position by collating (mapping) the vehicle position information from the outside with the map information stored in the memory at regular time intervals. Output information. Specifically, it is comprised by a navigation apparatus (henceforth, navigation). Further, the terrain information estimation device 102 acquires the preceding vehicle information from the above-mentioned inter-vehicle distance sensor 101, calculates the gradient at the traveling position of the preceding vehicle separated by the inter-vehicle distance, and outputs it as the gradient information of the preceding vehicle.

  The traveling control device (ACC device) 103 uses the preceding vehicle information from the inter-vehicle distance sensor 101, the terrain information of the own vehicle position information from the terrain information estimation device 102, and the gradient information of the preceding vehicle, and A signal for controlling the inter-vehicle distance is output.

The engine control device 105 performs acceleration and deceleration of the vehicle by controlling the fuel injection amount and the throttle valve opening based on the output signal from the travel control device 103. The engine control device 105 includes transmission control. The brake control device 104 decelerates the vehicle based on the output signal from the travel control device 103. The ACC system may include a motor as a vehicle drive source and a motor control device that controls the motor.

In the present embodiment, the travel control device 103 is provided as an independent device, but the number of parts can be reduced by incorporating the function of the travel control device 103 into the navigation device or the sensor.

  The travel control processing of this embodiment is realized by software processing, and a control program for this is stored in the travel control device and the navigation device.

  The interface unit 106 receives an input of the set vehicle speed or the set inter-vehicle distance by the driver, and displays the set vehicle speed or the inter-vehicle distance.

  The interface unit 106 is provided as a device independent of the navigation device or the ACC device, but the number of parts can be reduced by adding an interface function to the navigation device.

  The set vehicle speed and the set inter-vehicle distance input by the driver via the interface unit 106 are converted into ACC data and stored in the ACC device. The set inter-vehicle distance may be stored as the set inter-vehicle time in order to correspond to the own vehicle speed change.

  The communication cable 107 connects the above-described devices and control devices, and transmits data exchanged between the devices. Communication between apparatuses via the communication cable 107 may use a CAN (Controller Area Network).

FIG. 3 is an internal processing block configuration diagram of the ACC device 103. The ACC device 103
An ACC processing unit 301 and an ACC correction calculation unit 302 are included. The ACC processing unit 301 includes a target inter-vehicle distance calculation unit 303 and an inter-vehicle distance control unit 304, and controls the inter-vehicle distance and the relative speed in order to perform follow-up control.

  The ACC correction calculation unit 302 calculates the gradient inter-vehicle time from the gradient information of the host vehicle and the preceding vehicle transmitted from the terrain information estimation apparatus 102 and outputs data to the target inter-vehicle distance calculation unit 303. Here, the gradient inter-vehicle time means an inter-vehicle time in which the speed of the preceding vehicle increases or decreases due to the preceding vehicle approaching the gradient, and the inter-vehicle distance between the host vehicle and the preceding vehicle becomes longer or shorter. A method of calculating the gradient inter-vehicle time will be described later.

  Hereinafter, the flow of processing when the preceding vehicle is on a slope is shown in the order of data 305 to 309 shown in FIG.

The ACC correction calculation unit 302 acquires the inter-vehicle distance information with the preceding vehicle from the inter-vehicle distance sensor 101, and sends the inter-vehicle distance information to the terrain information estimation apparatus 102 via the communication cable 107 (305). This process is executed at regular time intervals.

Based on the map information stored in the memory, the terrain information estimation apparatus 102 calculates the gradient and gradient angle difference between the own vehicle position and the preceding vehicle position, and transmits the calculation result to the ACC apparatus via the CAN (306). Here, the gradient angle difference is a difference in gradient between the own vehicle position and the preceding vehicle position.

  Based on the gradient or gradient angle difference data, the ACC correction calculation unit 302 calculates the gradient inter-vehicle time assuming that the preceding vehicle decelerates while traveling in the gradient section, and transmits the calculation result to the target inter-vehicle distance calculation unit 303. (307).

  The target inter-vehicle distance calculation unit 303 calculates the target inter-vehicle distance based on the set inter-vehicle distance time and the gradient inter-vehicle time, and transmits the target inter-vehicle distance to the inter-vehicle distance control unit 304 (308). Here, the set inter-vehicle distance time is calculated from the set inter-vehicle distance and the set speed input by the driver to the interface unit 106, and is stored in the target inter-vehicle distance calculation unit 303. The inter-vehicle distance control unit 304 controls both the inter-vehicle distance and the relative speed so that the actual inter-vehicle distance becomes the target inter-vehicle distance and the relative speed converges to zero.

  Further, the ACC correction calculation unit 302 sets the gradient inter-vehicle time to 0 when the own vehicle advances by the inter-vehicle distance and reaches the gradient start point of the preceding vehicle, and sets the gradient inter-vehicle distance to 0 in the target inter-vehicle distance calculation unit. The data indicating that it has become is transmitted (309).

  Note that the above-mentioned inter-vehicle distance information may be directly transmitted from the inter-vehicle distance sensor 101 to the terrain information estimating apparatus 102 without passing through the ACC apparatus 103. By doing in this way, the calculation load in an ACC apparatus can be reduced.

  FIG. 2 is a schematic diagram showing a scene in which a preceding vehicle is on a climbing slope point.

  FIG. 2 (1) shows a scene in which a preceding vehicle that is separated by an inter-vehicle distance L0 has reached an ascending slope point. V0 is the vehicle speed at that time. T0 is the time it takes for the vehicle to reach a gradient start point at a speed V0 and a distance L0 between the vehicles.

  FIG. 2 (2) is a scene in which the host vehicle approaches a preceding vehicle that has decelerated due to a change in gradient. In FIG. 2 (1), when the preceding vehicle decelerates due to a change in gradient, the distance between the host vehicle and the preceding vehicle is reduced. The inter-vehicle distance L (t) and the inter-vehicle time S (t) after the elapse of time t can be obtained from Equation 1 and Equation 2. Here, g is gravitational acceleration, and the gradient angle difference is obtained by subtracting the gradient angle of the vehicle position from the gradient angle of the preceding vehicle position as described above.

Inter-vehicle distance L (t) = Inter-vehicle distance L0−0.5 × g × sin (gradient angle difference) × t × t
Inter-vehicle time S (t) = T0−0.5 × g × sin (gradient angle difference) × t × t / V0
FIG. 2 (3) shows a scene in which the host vehicle has advanced by an inter-vehicle distance (L0) and has reached a slope point. The inter-vehicle distance L (T0) and the inter-vehicle time S (T0) when the host vehicle reaches the gradient start point separated by the inter-vehicle distance L0 can be obtained from Equations 3 and 4.
Inter-vehicle distance L (T0) = Inter-vehicle distance L0−0.5 × g × sin (gradient angle difference) × T0 × T0
Inter-vehicle time S (T0) = T0−0.5 × g × sin (gradient angle difference) × T0 × T0 / V0.
Therefore, the gradient inter-vehicle distance and the gradient inter-vehicle time can be obtained from Equations 5 and 6.

Gradient distance between cars = 0.5 x g x sin (gradient angle difference) x T0 x T0 ... Formula 5
Gradient time between cars = 0.5 x g x sin (gradient angle difference) x T0 x T0 / V0
Next, correction of the inter-vehicle distance will be described. When the preceding vehicle reaches a target gradient (see FIG. 2 (1)), the target inter-vehicle distance and the target inter-vehicle time are calculated by Equations 7 and 8. Here, the fact that the preceding vehicle has reached the target gradient is based on the information from the terrain information estimation device 102, and the current vehicle position currently traveling is separated from the distance between the vehicles set by the ACC device. This can be detected by referring to the position gradient.

Target inter-vehicle distance = (set inter-vehicle distance) + (gradient inter-vehicle distance) × (constant 1)
Target inter-vehicle time = (set inter-vehicle distance time) + (gradient inter-vehicle time) x (constant 2) ... number 8
The default values of the constants 1 and 2 in Equations 7 and 8 are 1. However, the values can be set according to the feeling of each driver by the input operation of the interface unit described above. For example, by setting the constants 1 and 2 to be larger than the default values, a larger braking force is generated when the preceding vehicle approaches an ascending slope. On the other hand, by setting the constants 1 and 2 to be greater than the default values, a smaller braking force is generated when the preceding vehicle approaches the climbing slope.

  As shown in FIG. 2 (3), an increase in the inter-vehicle distance is set in consideration of the fact that the preceding vehicle is decelerated in advance from the speed and gradient of the host vehicle when the preceding vehicle approaches the gradient.

  Normally, the ACC control smoothly controls the acceleration of the vehicle so that the driver does not feel uncomfortable when the set inter-vehicle distance is changed by the driver. Therefore, even if the target value of the inter-vehicle distance is changed in a step shape as in this embodiment, speed control can be performed without causing the driver to feel uncomfortable. Such ACC control is well known and will not be described.

  The cancellation of the target inter-vehicle distance or the target inter-vehicle time is performed when the host vehicle reaches a slope start point separated by an inter-vehicle distance L0 as shown in FIG. 2 (3) as an example. This is to prevent the inter-vehicle distance of the preceding vehicle from unnecessarily increasing after the host vehicle reaches the slope start point. Furthermore, the method of returning the target inter-vehicle distance to the original is equivalent to the above-described known ACC control, and is smoothly controlled.

  Further, if the preceding vehicle approaches the slope, the preceding vehicle may be out of the detection range of the own vehicle's inter-vehicle distance sensor 101, and the inter-vehicle distance sensor 101 may not be able to detect the behavior of the preceding vehicle. The reason why the preceding vehicle cannot be detected as the preceding vehicle when the inter-vehicle distance sensor 101 reaches the starting point of the gradient of the preceding vehicle is that the preceding vehicle has accelerated or because the preceding vehicle has reached a new gradient. The case where it deviates from a detection range can be considered. Canceling the target inter-vehicle distance or the target inter-vehicle time when the preceding vehicle reaches the slope start point at a distance L0 between the vehicles in a scene where the preceding vehicle approaches a new gradient and deviates from the detection range of the inter-vehicle distance sensor 101 If the vehicle travels at the vehicle speed set by the interface unit 106, there is a possibility that the vehicle will find the preceding vehicle and suddenly decelerate when the vehicle approaches the new gradient. Therefore, if the preceding vehicle is out of the detection range of the inter-vehicle distance sensor 101, the cancellation of the target inter-vehicle distance or the target inter-vehicle time is set after traveling n times the inter-vehicle distance L0 from when the inter-vehicle distance increase setting is made, for example. The sudden deceleration from the set vehicle speed may be reduced.

  The scene where the preceding vehicle is climbing is not limited to the case where the vehicle is traveling on a flat ground as described above. Therefore, FIG. 2 (4) shows a case where the host vehicle is traveling on an upward slope, and FIG. 2 (5) shows a case where the host vehicle is traveling on a downward slope. Even in these cases, it is determined whether or not the above-described control should be performed by taking the difference in the gradient angle of the vehicle position from the gradient angle of the preceding vehicle position and evaluating the gradient angle difference. it can.

  FIG. 4 is a flowchart showing processing of the correction calculation unit 302 in the ACC apparatus. This process is executed at regular time intervals.

  In S401, it is determined whether or not the decrement timer is O, that is, whether or not the ACC correction control of this embodiment is being executed. When S401 is Yes, the inter-vehicle distance measured by the inter-vehicle distance sensor is transmitted to the navigation (S402). In S403, a gradient and a gradient angle difference between the own vehicle and the preceding vehicle position are obtained from the navigation. If it is determined in S404 that the preceding vehicle is at the climb slope point and the gradient angle difference from the own vehicle is larger than the threshold value, the process proceeds to S405. If the determination in S404 is No, the gradient inter-vehicle time is set to 0 in S411 so that this control is not operated.

  Next, in S405, when it is determined that the preceding vehicle is decelerating, the process proceeds to S406. Whether the preceding vehicle is accelerating or decelerating can be determined from a change in the signal from the inter-vehicle distance sensor 101. When S405 is No, the gradient inter-vehicle time is set to 0 in S411 so that this control is not operated. Next, in S406, the gradient inter-vehicle time that is expected to decrease by the time when the vehicle has advanced to the preceding vehicle position is obtained from (Equation 6). In S407, a decrement timer corresponding to the time T0 when the vehicle reaches the slope point is set. In step S408, the gradient inter-vehicle time is transferred and set in the memory.

  Next, when the determination process of S401 is executed again, since the decrement timer is set because the gradient inter-vehicle time has been transferred to the target inter-vehicle distance calculation processing unit, the determination is No, and the decrement timer subtraction of S409 is performed. Proceed to If it is determined in S410 that the decrement timer is not zero, the process directly returns. When the decrement timer is zero, it is determined that the vehicle has reached the gradient point, the gradient inter-vehicle time is set to 0 in the processing of S411, and the increase setting of the inter-vehicle distance is cancelled.

  FIG. 5 is a flowchart showing a target inter-vehicle distance calculation process of ACC. This process is executed by the target inter-vehicle distance calculation unit 303, and gives the target inter-vehicle distance as a target value to the ACC inter-vehicle control processing unit.

  In step S501, the set inter-vehicle distance time calculated from the set inter-vehicle distance and the set speed input to the interface unit 106 by the driver is acquired. In S502, the set inter-vehicle distance time and the own vehicle speed are multiplied to obtain the inter-vehicle distance and set it as a target value. In step S503, a gradient inter-vehicle distance is obtained from the gradient inter-vehicle time and the own vehicle speed. In S504, the gradient inter-vehicle distance is added to the target inter-vehicle distance. Finally, in S505, the target inter-vehicle distance is stored in a memory in the target inter-vehicle distance calculation unit 303, and the target inter-vehicle distance is passed to the inter-vehicle distance control unit 304.

  FIG. 6 is a flowchart showing processing in the terrain information estimation apparatus 102. In S601, the inter-vehicle distance is acquired from the ACC device. In S602, the preceding vehicle position is obtained. In step S603, a gradient and a gradient angle difference between the own vehicle position and the preceding vehicle position are obtained. In step S <b> 604, the gradient and the gradient angle difference are transmitted to the ACC device 103 via the communication cable 107.

  FIG. 7 is a schematic diagram showing a scene in which the preceding vehicle is on a downward slope point.

  FIG. 7 (1) shows a scene in which the vehicle has advanced by an inter-vehicle distance and reached a slope point from a scene where the preceding vehicle is on the slope point.

  When the preceding vehicle is on a downward slope, the inter-vehicle distance increases. Based on this increased inter-vehicle distance, the target inter-vehicle distance is set short. As in the case of the above-described climbing gradient, the increased inter-vehicle distance and the increased inter-vehicle time are obtained from Equations 5 and 6 as the gradient inter-vehicle distance and the gradient inter-vehicle time. Here, the gradient angle difference takes a negative value.

  When the preceding vehicle reaches a target gradient, the target inter-vehicle distance and the target inter-vehicle time are calculated by Equations 7 and 8 in the same manner as described above.

  When the preceding vehicle is on a downward slope, the reduction of the inter-vehicle distance obtained from the calculation is performed in consideration of the acceleration of the preceding vehicle in advance. This is shown in FIG. Canceling the reduction setting of the inter-vehicle distance is performed in the same manner as described above when the host vehicle has advanced by the inter-vehicle distance and reached the slope point.

  In addition to the above-mentioned scenes, the following two cases are conceivable as scenes where the preceding vehicle is going downhill. FIG. 7 (2) shows the first case, which is a scene in which the preceding vehicle is on a downward slope point and the vehicle is traveling on a downward slope. Second, FIG. 7 (3) shows the second case, where the preceding vehicle is on a downhill slope and the vehicle is traveling on an uphill slope. In either case, the difference between the gradient angle of the preceding vehicle position and the gradient angle of the host vehicle position is calculated, the gradient angle difference is calculated, and it can be determined whether or not the gradient should be controlled in this embodiment. .

  In the present embodiment, even when the preceding vehicle travels uphill or downhill, it is possible to reduce the distance between the vehicles suddenly clogging or expanding, and it is possible to ensure safe and comfortable travelability.

  FIG. 8 is an internal processing block diagram of the ACC device in the second embodiment. The components denoted by the same reference numerals as those in FIG. 3 have the same functions as the corresponding components in the first embodiment, and thus description thereof is omitted here.

  The storage unit 801 acquires the set vehicle speed or the set inter-vehicle distance input by the driver from the interface unit 106 and stores it in the memory. The inter-vehicle distance control unit 304 controls the engine output of the vehicle or the torque of the motor based on the stored set vehicle speed or the set inter-vehicle distance.

  The determination unit 802 acquires the inter-vehicle distance between the preceding vehicle and the host vehicle (or the inter-vehicle distance calculated from the set vehicle speed) from the inter-vehicle distance sensor 101, and transmits this inter-vehicle distance to the terrain information estimation device 102. Here, the inter-vehicle distance information from the inter-vehicle distance sensor 101 may be directly transmitted to the terrain information estimation apparatus 102 without passing through the determination unit 802.

  The determination unit 802 obtains the gradient information or the gradient angle difference between the preceding vehicle and the own vehicle from the terrain information estimation device 102, the inter-vehicle distance between the own vehicle and the preceding vehicle, and the set inter-vehicle distance stored in the storage unit 801 described above. Compare with. If it is determined that the absolute value of the difference or the variation from the set vehicle speed is greater than or equal to a predetermined value, whether or not the variation greater than the predetermined value is due to the terrain shape based on the gradient information from the terrain information estimation device 102 Determine. This determination method will be described in detail with reference to FIG.

  FIG. 9 is a schematic view of the inter-vehicle distance variation due to the terrain shape. FIG. 9A shows a scene in which the ACC device is activated and the vehicle travels without changing the inter-vehicle distance (for example, 30 m) set by the driver from the A point to the F point. FIG. 9B shows changes in the gradient angle difference between the own vehicle and the preceding vehicle at each point of the own vehicle. This gradient angle difference may be acquired directly from the terrain information estimation apparatus 102 or may be obtained by calculation from the gradient angle acquired from the terrain information estimation apparatus 102. FIG. 9C shows a change in the inter-vehicle distance information acquired from the inter-vehicle distance sensor 101.

  First, the case where the vehicle as shown in FIG. 9A is controlled by a conventional ACC device will be described.

  When the host vehicle reaches point A, the preceding vehicle approaches the climb slope. That is, the own vehicle travels on a flat road and the preceding vehicle is traveling on an ascending slope, so that a difference in the gradient angle between the own vehicle and the preceding vehicle occurs (FIG. 9B). Further, since the preceding vehicle is traveling on an uphill, the vehicle is decelerated and the inter-vehicle distance is shortened (solid line in FIG. 9C).

  When the vehicle reaches point B, that is, when it reaches the climb gradient, the gradient angle difference between the vehicle and the preceding vehicle becomes almost zero. Here, the inter-vehicle distance returns to the set inter-vehicle distance before the host vehicle reaches the point B. This is because the inter-vehicle distance control unit 304 of the ACC device performs follow-up control with the preceding vehicle.

  When the host vehicle reaches point C, the preceding vehicle approaches the descending slope from the ascending slope. That is, the own vehicle travels on an ascending slope, and the preceding vehicle is traveling on a descending slope, so that a difference in the gradient angle between the own vehicle and the preceding vehicle occurs (FIG. 9B). Further, since the preceding vehicle is traveling on a downward slope, the vehicle accelerates and the inter-vehicle distance increases (solid line in FIG. 9C). When the vehicle reaches point D, that is, when it reaches a downward gradient, the gradient angle difference between the vehicle and the preceding vehicle becomes substantially zero. When the own vehicle reaches the E point and the F point, it is the same as above.

  Here, in this embodiment, for example, as shown in FIG. 9C, a threshold value of the inter-vehicle distance variation Δm is set, and for example, as shown in FIG. 9B, a threshold value of the gradient angle difference ΔΘ is set. To do. FIG. 10 shows a flowchart of correction control of the ACC device in the second embodiment using these threshold values. Processing using the same reference numerals as those in FIG. 4 is the same as that in FIG.

If it is determined in S401 that the decrement timer is 0, it is determined whether the inter-vehicle distance variation is greater than Δm (S1001). When S1001 is Yes, it is determined in S1002 whether the inter-vehicle distance variation Δm or more continues for a predetermined time (T) or longer. If S1002 is Yes, in S1003, it is determined whether the preceding vehicle is greater than or equal to the gradient angle difference ΔΘ on an ascending or descending gradient. When S1001, S1002, and S1003 are No, all move to S411. Since S401 and subsequent processes are the same as those in the first embodiment, a description thereof will be omitted.

  By executing such a determination, it is possible to determine whether or not the preceding vehicle is accelerating or decelerating due to the terrain shape, and it is possible to ensure safer and more comfortable traveling.

  In addition, the techniques described in the first and second embodiments can improve safety or drivability particularly when a plurality of vehicles equipped with the ACC device are running in series.

  The present invention can be applied to a vehicle that performs inter-vehicle distance control with a preceding vehicle.

It is a block block diagram of an ACC system. It is the schematic which shows the scene where a preceding vehicle starts on a climb slope point. It is an internal process block block diagram of an ACC apparatus. It is a flowchart which shows the process of the correction | amendment calculating part in an ACC apparatus. It is a flowchart which shows the target inter-vehicle distance calculation process of ACC. It is a flowchart which shows the process in a terrain information estimation apparatus. It is the schematic which shows the scene where a preceding vehicle starts on a downward slope point. It is an internal process block block diagram of the ACC apparatus in 2nd Example. The schematic of the inter-vehicle distance fluctuation of the preceding vehicle and the own vehicle by the topographic shape is shown. It is a flowchart of the correction | amendment calculating part in the ACC apparatus in 2nd Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 ... Inter-vehicle distance sensor, 102 ... Terrain information estimation apparatus (navigation), 103 ... Traveling control apparatus (ACC apparatus), 104 ... Brake control apparatus, 105 ... Engine control apparatus, 106 ... Interface part, 107 ... Communication cable, 301 ... ACC processing unit 302... ACC correction calculation unit 303 303 target inter-vehicle distance calculation unit 304 304 inter-vehicle distance control unit

Claims (2)

A storage unit for storing the set inter-vehicle distance input by the driver;
An inter-vehicle distance control unit that controls an actuator of the vehicle so that the inter-vehicle distance between the host vehicle and the preceding vehicle becomes the set inter-vehicle distance;
Based on the preceding vehicle information from the inter-vehicle distance sensor that detects at least one of the inter-vehicle distance and relative speed between the host vehicle and the preceding vehicle as preceding vehicle information and road gradient information estimated by the terrain information estimation device, A gradient angle calculation unit for obtaining a gradient angle difference between the vehicle and the own vehicle;
A gradient inter-vehicle time calculation unit that calculates a gradient inter-vehicle time to a preceding vehicle based on the gradient angle difference when an acquisition result of the gradient angle calculation unit is a predetermined value or more;
The inter-vehicle distance control unit calculates a gradient inter-vehicle distance from the gradient inter-vehicle time and the vehicle speed calculated by the gradient inter-vehicle time calculation unit, and calculates a target inter-vehicle distance from the calculated inter-gradient vehicle distance and the set inter-vehicle distance. A travel control device that calculates and corrects an engine output of a vehicle or a torque of a motor so that the inter-vehicle distance becomes the target inter-vehicle distance. Memorize the set inter-vehicle distance input by the driver,
Controlling the actuator of the vehicle so that the distance between the vehicle and the preceding vehicle is the set distance between the vehicles,
Based on the preceding vehicle information from the inter-vehicle distance sensor that detects at least one of the inter-vehicle distance and relative speed between the host vehicle and the preceding vehicle as preceding vehicle information and the terrain information estimated by the terrain information estimating device, Calculate the gradient angle difference of your vehicle,
When the gradient angle difference is equal to or greater than a predetermined value, the gradient inter-vehicle time to the preceding vehicle is calculated based on the gradient angle difference ,
A gradient inter-vehicle distance is calculated from the calculated gradient inter-vehicle time and host vehicle speed, a target inter-vehicle distance is calculated from the calculated gradient inter-vehicle distance and the set inter-vehicle distance, and the inter-vehicle distance between the host vehicle and the preceding vehicle is A travel control method for correcting and controlling a vehicle engine output or a motor torque so as to achieve a target inter-vehicle distance.

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