JP6997963B2 - Vehicle control device - Google Patents

Description

The present invention relates to a vehicle control device that supports the traveling of a vehicle.

Conventionally, in a vehicle such as an automobile, a vehicle control device that supports the traveling of the vehicle so as to appropriately avoid a collision between the own vehicle and another vehicle has been used. For example, in Patent Document 1 (Japanese Unexamined Patent Publication No. 2006-218935), in a vehicle traveling support device that assists traveling so that a safe distance is secured between the own vehicle and the object, the orientation of the object is set. The invention is disclosed in which the safety distance is set accordingly.

Japanese Unexamined Patent Publication No. 2006-218935

As described above, in the vehicle control device, driving support is provided between the own vehicle and the target vehicle so as to secure a vehicle distance for avoiding a collision, and the safety of vehicle running is ensured. However, for the proper driving of the vehicle, the distance between the own vehicle and the target vehicle is not only the safety is ensured, but also the appropriate distance (the driver's normal distance) so that the vehicle can drive comfortably. It is necessary to control the safety / safety along the operation interval). Further, such control of the vehicle spacing needs to be finely executed according to the traveling environment of the own vehicle (for example, what kind of slope the traveling road surface has).

The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a vehicle control device that enables safe and comfortable driving according to the slope condition of the road surface on which the vehicle is traveling. The purpose is to provide.

In order to achieve the above object, the following solution is adopted in the present invention. That is, as described in claim 1,
Target vehicle detection means that detects the target vehicle around the own vehicle,
A speed upper limit distribution setting means for setting a speed upper limit distribution, which is a distribution of a plurality of upper limits of the relative speed between the own vehicle and the target vehicle, which is defined for each point in the peripheral region of the target vehicle.
The speed of the own vehicle traveling in the peripheral area of the target vehicle or / / And in a vehicle control device provided with a traveling control means for controlling steering.
The gradient detecting means for detecting the gradient of the road surface on which the own vehicle is traveling, and the gradient detecting means.
The speed upper limit value distribution changing means for changing the distribution of the plurality of upper limit values in the speed upper limit value distribution according to the slope of the road surface detected by the gradient detecting means is provided.

According to the above solution method, the speed upper limit distribution is appropriately set according to the change in the braking distance of the own vehicle in response to the change in the slope of the road surface on which the own vehicle is traveling, so that safe and comfortable driving is possible. Can be realized.

A preferred embodiment premised on the above-mentioned solution method is as described in claim 2 or less within the scope of claims. That is, the speed upper limit value distribution changing means is described so that when the slope of the road surface is an uphill slope, the upper limit value of the relative speed at each point in the distribution is larger than when the road surface is a flat road. Change the speed upper limit distribution (corresponding to claim 2). In this case, since the slope is an uphill slope, the braking distance is shorter than that on a flat road, and even if the vehicle travels around the target vehicle at a relatively high speed, braking can be performed quickly, whereas the relative speed is achieved. Since the upper limit value of is set large, it is possible to prevent the brake assist from being applied from an unnecessarily distant position, and it is possible to suppress the driver's discomfort.

The speed upper limit value distribution changing means is such that when the slope of the road surface is a downward slope, the upper limit value of the relative speed at each point in the distribution is smaller than when the road surface is a flat road. Change the value distribution (corresponding to claim 3). in this case,
Since the slope is a downward slope, the braking distance is longer than on a flat road, making it difficult to brake the own vehicle quickly, while the upper limit of the relative speed is set small, so the surroundings of the target vehicle. The speed of the own vehicle is limited to a low speed, and appropriate safety can be ensured.

The speed upper limit value distribution changing means increases the degree of change of the relative speed upper limit value as the absolute value of the slope of the road surface increases (corresponding to claim 4). In this case, it is possible to respond more precisely to the change in the braking distance due to the change in the gradient (the braking distance becomes longer as the absolute value of the gradient increases).

According to the present invention, safe and comfortable driving can be realized according to the slope of the road surface on which the own vehicle is traveling.

The block block diagram which shows an example of the control system of this invention. Explanatory drawing for demonstrating the vehicle control of this invention. The figure which shows the setting of the speed upper limit value distribution when there is a preceding vehicle on a flat road. A graph showing an example of the relationship between the front-rear distance between the own vehicle and the preceding vehicle and the relative speed upper limit value. The figure which shows the setting of the speed upper limit value distribution when there is a preceding vehicle in the uphill. The figure which shows the setting of the speed upper limit value distribution when there is a preceding vehicle in the downhill. A graph showing an example of the relationship between the front-rear distance between the own vehicle and the preceding vehicle and the relative speed upper limit value on each of a flat road, an uphill slope, and a downhill slope. The graph which shows the setting method of the correction coefficient in the uphill. The graph which shows the setting supplement method of the correction coefficient in the downhill. The flowchart which shows the control procedure of an example of the vehicle control of this invention. A flowchart showing an example of speed upper limit distribution setting processing.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows an example of the control system (vehicle control system) of the present invention in a block configuration diagram. As shown in the figure, the control system is mounted on the own vehicle 1 (see FIG. 2), and includes an ECU 10, a plurality of information providing means (sensors), and a plurality of control systems. The information providing means includes, for example, an in-vehicle camera 21, a millimeter wave radar 22, a vehicle speed sensor 23, a positioning system 24, a navigation system 25, and a road-to-vehicle communication unit 26. Further, the control system includes an engine control system 31, a brake control system 32, and a steering control system 33.

The ECU 10 is composed of a computer equipped with a CPU, a memory for storing various programs, an input / output device, and the like, and can output a control signal to each of the control systems based on the signals received from the sensors. ..

The in-vehicle camera 21 captures an image of the surroundings of the vehicle 1 and outputs the captured image data. The ECU 10 identifies an object (for example, a vehicle existing in front of the own vehicle 1) based on image data. The millimeter wave radar 22 is a measuring device that measures the position and speed of an object, transmits radio waves (transmitted waves) toward the front of the own vehicle 1, and reflects reflected waves (received waves) by the object. By receiving the wave), the distance between the own vehicle 1 and the object (for example, the inter-vehicle distance) and the relative speed of the object with respect to the own vehicle 1 are measured based on the transmitted wave and the received wave. As the measuring device for measuring the position and speed of the object, any measuring device such as a laser radar or an ultrasonic sensor can be used instead of the millimeter wave radar 22.

The vehicle speed sensor 23 is a sensor that detects the absolute speed of the own vehicle 1. The positioning system 24 is a means for calculating the position of the own vehicle 1, and is composed of, for example, a GPS system or a gyro system. The navigation system 25 is a means for providing map information to the ECU 10.

The road-to-vehicle communication unit 26 is a communication means for acquiring various information by communicating with the road infrastructure, and is composed of a communication device for wireless communication and the like. In the present embodiment, the road-to-vehicle communication unit 26 acquires, in particular, the gradient information of the road surface on which the own vehicle 1 is traveling. The slope information of the road surface may be acquired by using another detection means such as a G sensor.

The engine control system 31 is a controller for controlling the brake device of the own vehicle 1. When it is necessary to accelerate or decelerate the own vehicle 1, the ECU 10 outputs a signal requesting a change in the engine output to the engine control system 31.

The brake control system 32 is a controller for controlling the brake device of the own vehicle 1. When it is necessary to decelerate the own vehicle 1, the ECU 10 outputs a signal requesting the generation of a braking force to the own vehicle 1 to the brake control system 32.

The steering control system 33 is a controller that controls the steering device of the own vehicle 1. When it is necessary to change the traveling direction of the own vehicle 1, the ECU 10 outputs a signal requesting the steering control system 33 to change the steering direction.

FIG. 2 is a diagram illustrating a scene in which control is performed in order to explain vehicle control according to the present embodiment. As shown in the figure, the own vehicle 1 provided with the vehicle control device of the present invention is traveling on the travel path 2, and will overtake the object 3 existing in front of the own vehicle 1 (in the direction of travel). It is supposed to be. In this example, the object 3 is a stopped vehicle parked on the side of the road of the traveling road 2.

The vehicle control device sets a speed upper limit value distribution 40 in a predetermined region around the object 3. The speed upper limit value distribution 40 is a two-dimensional distribution that defines an allowable upper limit value of the relative speed between the own vehicle 1 and the object 3, and each point of the speed upper limit value distribution 40 has an allowable relative speed. The upper limit V _lim is set. In FIG. 2, for convenience of understanding, the velocity upper limit value distribution 40 is shown by contour lines a, b, c, and d connecting points where the same upper limit value V _lim is set. In this example, the contour line d indicates the outer edge of the region where the velocity upper limit value distribution 40 is set.

In the vehicle control device, when the own vehicle 1 travels around the object 3 (within the speed upper limit distribution 40), the relative speed V between the own vehicle 1 and the object 3 is the speed at the traveling point of the own vehicle 1. The speed and / or steering (traveling route) of the own vehicle 1 is controlled so as not to exceed the upper limit value V _lim . FIG. 2 shows, as an example of the travel route of the own vehicle 1, a travel route R1 that maintains the straight detour of the own vehicle 1 and limits the speed V to the speed upper limit value V _lim or less, and the speed of the own vehicle 1 is not limited. The traveling route R2 that detours outside the speed upper limit distribution 40 and the traveling route R3 (a route that detours the object 3 while limiting the speed to some extent) between the traveling route R1 and the traveling route R2 are broken lines. Indicated by.

The speed upper limit value distribution 40 is set so that the speed upper limit value V _lim becomes smaller as the lateral distance and the vertical distance from the object 3 become smaller (closer to the object). In FIG. 2, the upper speed limit value V _lim increases in the order of contour lines a, b, c, and d. As a result, when the own vehicle 1 passes the object 3 (passes the stopped vehicle), the speed of the own vehicle 1 is limited as the distance D between the own vehicle 1 and the object 3 in the front-rear direction becomes smaller, and the running safety is reduced. Is to be secured. This also enables the driver of the own vehicle 1 to travel at a speed that matches the normal driving interval.

The speed upper limit distribution 40 does not necessarily have to be set over the entire circumference of the object 3, and may be provided only on the side where the own vehicle 1 of the object 3 exists (on the right side in the figure). .. Further, the speed upper limit value distribution 40 may be set only on the travel path 2.

The driving control may be executed by automatic driving by the vehicle control device, or by the vehicle control device while allowing the driving operation (accelerator, brake, steering operation) by the driver of the own vehicle 1. Driving assistance may be provided.

When the driving operation by the driver is not performed (in the case of automatic driving), the vehicle control device controls the vehicle speed and / or steering of the own vehicle 1 according to a preset mode. The mode is selected from, for example, three types of modes: (A) linear priority mode, (B) intermediate mode, and (C) speed priority mode.

In the straight line priority mode, the control is performed to prioritize the maintenance of the straight running of the own vehicle 1, and the own vehicle 1 travels along the traveling route R1. In the speed priority mode, control is performed to prioritize the maintenance of the vehicle speed of the own vehicle 1, and the own vehicle 1 travels along, for example, the traveling route R2. In the intermediate mode, control that balances the maintenance of straight running and the maintenance of the vehicle speed of the own vehicle 1 (for example, the control that minimizes both the change in the vehicle speed and the steering) is performed, and the own vehicle 1 is, for example, the travel route R3. Will run along.

FIG. 3 shows a speed upper limit value distribution 41 set around the preceding vehicle 5 when the preceding vehicle 5 is an object for the own vehicle 1 traveling on a flat road surface 4. In the illustrated state, the own vehicle 1 is outside the region where the speed upper limit distribution 41 is set (outside the contour line d), but the own vehicle 1 catches up with the preceding vehicle 5, and the own vehicle 1 and the preceding vehicle As the front-rear distance D (the vehicle distance in the traveling direction of the own vehicle 1 and the distance from the rear end of the preceding vehicle 5 to the front end of the own vehicle 1) between 5 becomes narrower, the own vehicle 1 eventually becomes the contour line d. The speed is controlled so that the relative speed of the own vehicle 1 with respect to the preceding vehicle 5 does not exceed the speed upper limit value set by the speed upper limit value distribution 41, and the danger of collision with the preceding vehicle 5 is appropriately avoided. Will be done.

FIG. 4 is a graph (map) showing an example of setting the speed upper limit value V _lim in the speed upper limit value distribution 41 when there is a preceding vehicle 5 with respect to the own vehicle 1 as shown in FIG. This graph shows the relationship between the speed upper limit value V _lim (the allowable upper limit value of the relative speed of the own vehicle 1 with respect to the preceding vehicle 5) with respect to the front-rear direction distance D between the own vehicle 1 and the preceding vehicle 5.

As shown, when the anteroposterior distance D (m) is less than the safe distance D ₀ (m), the speed upper limit V _lim (km / h) is set to 0 (km / h) (contour line). Corresponds to the case where the own vehicle 1 invades the area inside a). That is, in the region where the front-rear distance D is the safe distance D ₀ or less, the traveling of the own vehicle 1 is prohibited. The safety distance D ₀ is set to, for example, 2 m.

On the other hand, when the distance D in the front-rear direction is equal to or greater than the safety distance D ₀ , the upper speed limit value V _lim is a quadratic function as the distance D in the front-rear direction increases, as shown in the following equation (1). Set to increase.
V _lim = αK × (DD ₀ ) ² / Vs… (1)
Here, Vs (km / h) is the current vehicle speed of the own vehicle 1. Further, K is a gain coefficient which is a constant, and α is a correction coefficient. As will be described in detail later, the correction coefficient α is changed according to the slope of the road surface on which the own vehicle is traveling, and when the own vehicle 1 is traveling on a flat road as shown in FIG. 3, α = 1 is set. By setting the speed upper limit value V _lim in this way, the speed limit of the own vehicle 1 becomes stricter as the distance D in the front-rear direction from the preceding vehicle 5 becomes shorter.

Next, with reference to FIGS. 5 and 6, the control characteristic of the present invention, that is, the control when the own vehicle 1 travels on a sloped road surface will be described. In this control, the vehicle control device (ECU 10) acquires information on the slope of the road surface on which the own vehicle 1 is traveling from, for example, the road-to-vehicle communication system 26, and appropriately adjusts the speed upper limit value distribution according to the slope of the road surface. Change to. That is, since the braking distance of the own vehicle 1 changes depending on the slope of the traveling road surface, the speed upper limit distribution is corrected so as to appropriately reflect the change in the braking distance.

As shown in FIG. 5, when the road surface 4A on which the own vehicle 1 is traveling has an uphill slope, the braking distance of the own vehicle 1 is shorter than that of a flat road, so that the vehicle is closer to the preceding vehicle 5 than the flat road. It becomes easier to avoid a rear-end collision. Therefore, the speed upper limit distribution is compared with the speed upper limit distribution 41 on a flat road (shown by a broken line in FIG. 5), and the speed upper limit value V _lim at the same point in the distribution is a larger value. Change to distribution 42 (shown by a solid line in FIG. 5).

As shown in the figure, the speed upper limit distribution 42 on the uphill has contour lines b1, c1, d1 indicating the same speed upper limit V _lim as the contour lines b, c, d in the speed upper limit distribution 41 on the flat road, respectively. It narrows to the preceding vehicle 5 side from the contour lines b, c, and d. As a result, the own vehicle 1 is allowed to travel at a relatively high speed up to a position close to the preceding vehicle 5 (a position where the distance D in the front-rear direction is short), and brake assist may be applied from an unnecessarily distant position. Since it is prevented, the discomfort caused by the brake assist to the driver is suppressed, and comfortable driving becomes possible.

On the other hand, as shown in FIG. 6, when the road surface 4B on which the own vehicle 1 is traveling has a downward slope, the braking distance of the own vehicle 1 is longer than that on a flat road, so that collision with the preceding vehicle 5 is avoided. Therefore, it is necessary to tighten the relative speed limit more than on a flat road. Therefore, the speed upper limit distribution is compared with the speed upper limit distribution 41 on a flat road (shown by a broken line in FIG. 6), and the speed upper limit value V _lim at the same point in the distribution is a smaller value. Change to distribution 43 (shown by a solid line in FIG. 6).

As shown in the figure, the speed upper limit distribution 43 on the downhill has contour lines b2, c2, d2 indicating the same speed upper limit V _lim as the contour lines b, c, d in the speed upper limit distribution 41 on the flat road, respectively. It spreads to the own vehicle 1 side rather than the contour lines b, c, and d. As a result, the own vehicle 1 is severely speed-limited even at a position far from the preceding vehicle 5 (a position where the distance D in the front-rear direction is long), and high safety is ensured.

Next, using FIGS. 7 to 9, an example of changing the speed upper limit value V _lim according to the slope of the traveling road surface of the own vehicle 1 will be shown. In this example, the speed upper limit value V _lim is set with respect to the front-rear distance D from the preceding vehicle 5 by using the above equation (1) also on the uphill and downhill slopes. In this case, the appropriate speed upper limit value V _lim is set by setting the correction coefficient α in the equation (1) to a value larger than 1 on the uphill slope and a value larger than 1 on the downhill slope. To.

FIG. 7 shows how the relationship of the speed upper limit value V _lim with respect to the front-rear direction distance D of the vehicle 1 and the preceding vehicle 5 changes when the slope of the traveling road surface of the own vehicle 1 changes. As shown in the figure, the characteristic curve A2 on an uphill slope has a larger inclination than the characteristic curve A1 on a flat road, and even when the distance D in the front-rear direction is short, the vehicle travels at a higher speed than on a flat road. Is acceptable. On the other hand, the characteristic curve A3 on a downhill slope has a gentler slope than the characteristic curve A1 on a flat road, and even if the distance D in the front-rear direction is long, the speed is severely limited as compared with the case of a flat road. You can see that.

As shown in FIGS. 8 and 9, the correction coefficient α in the equation (1) may be finely changed according to the magnitude of the gradient. In this example, as shown in FIG. 7, the correction coefficient α in the case of an upslope increases from 1 to 1.5 as the gradient increases in a linear relationship with the gradient. Further, as shown in FIG. 8, the correction coefficient α in the case of a downward gradient decreases from 1 to 0.5 in a linear relationship with respect to the gradient as the gradient (absolute value) increases. As a result, the correction coefficient α can be set so as to be more finely adapted to the change in the braking force of the own vehicle 1 due to the change in the gradient, and a more appropriate speed upper limit value distribution can be set.

Next, the vehicle control of the present invention will be described according to the flowchart of FIG.

In the control, first, in step S1, the ECU 10 of the own vehicle 1 acquires various data from a plurality of sensors. In the following step S2, the ECU 10 detects an object (target vehicle) based on the data acquired from various sensors.

In step S3, the velocity upper limit value distribution is set for each detected object. In step S4, the vehicle speed at each of the travel route and the travel route of the own vehicle 1 is calculated according to the preset mode so as to match the set speed upper limit value distribution. In step S5, vehicle travel control (acceleration / deceleration control and / or steering control) is executed based on the travel route and vehicle speed calculated in step S4.

FIG. 11 is a flowchart showing a processing procedure for setting a speed upper limit value distribution (corresponding to the processing in step S3 of FIG. 10) according to the slope of the road surface on which the own vehicle 1 is traveling. In setting the speed upper limit value distribution, first, in step S11, the gradient information of the road surface on which the own vehicle 1 is traveling is acquired. In the following step S12, it is determined whether or not the traveling road surface has an uphill slope. If the road surface has an uphill slope, the process proceeds to step S13, and the speed upper limit distribution for the uphill slope is set (in the equation (1)). The correction coefficient α is set to a value larger than 1), and the round process is completed.

On the other hand, in step S12, when it is determined that the slope is not uphill, the process proceeds to step S14 to determine whether or not the traveling road surface is downhill, and when the road surface is downhill, the process proceeds to step S15 and downhill. The speed upper limit distribution for the gradient is set (the correction coefficient α in the equation (1) is set to a value smaller than 1), and the round process is completed.

On the other hand, if it is determined in step S14 that the slope is not downward, the traveling road surface is a flat road. Therefore, in step S16, the speed upper limit distribution for the flat road is set (Equation (1). The correction coefficient α in is set to 1), and the round process is completed.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and appropriate modifications can be made within the scope described in the claims. For example, the setting of the speed upper limit value distribution in the above embodiment is an example, and various settings can be adopted according to the conditions required for control.

INDUSTRIAL APPLICABILITY The present invention can be used as a vehicle control device for supporting safe and comfortable driving in a vehicle such as an automobile.

1 Own vehicle 2 Travel path 3 Object (stopped vehicle)
4 Flat road surface 4A Uphill road surface 4B Downhill road surface 5 Leading vehicle 10 ECU
21 In-vehicle camera 22 Millimeter wave radar 23 Vehicle speed sensor 24 Positioning system 25 Navigation system 26 Road-to-vehicle communication unit 31 Engine control system 32 Brake control system 33 Steering control system 40 Speed upper limit distribution 41 Speed upper limit set for the preceding vehicle on a flat road Value distribution 42 Speed upper limit value distribution set for the preceding vehicle on the uphill 43 Speed upper limit value distribution set for the preceding vehicle on the downhill D Distance between the own vehicle and the preceding vehicle in the front-rear direction

Claims (4)

Target vehicle detection means that detects the target vehicle around the own vehicle,
A speed upper limit distribution setting means for setting a speed upper limit distribution, which is a distribution of a plurality of upper limits of the relative speed between the own vehicle and the target vehicle, which is defined for each point in the peripheral region of the target vehicle.
The speed of the own vehicle traveling in the peripheral area of the target vehicle or / / And in a vehicle control device provided with a traveling control means for controlling steering.
The gradient detecting means for detecting the gradient of the road surface on which the own vehicle is traveling, and the gradient detecting means.
A vehicle control device including a speed upper limit value distribution changing means for changing the distribution of the plurality of upper limit values in the speed upper limit value distribution according to the slope of the road surface detected by the gradient detecting means. In the vehicle control device according to claim 1,
The speed upper limit value distribution changing means is used so that when the slope of the road surface is an uphill slope, the upper limit value of the relative speed at each point in the distribution is larger than when the road surface is a flat road. A vehicle control device that changes the value distribution. In the vehicle control device according to claim 1 or 2.
The speed upper limit value distribution changing means is such that when the slope of the road surface is a downward slope, the upper limit value of the relative speed at each point in the distribution is smaller than when the road surface is a flat road. A vehicle control device that changes the value distribution. In the vehicle control device according to claim 2 or claim 3.
The speed upper limit value distribution changing means is a vehicle control device that increases the degree of change in the relative speed upper limit value as the absolute value of the slope of the road surface increases.

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