Patent Description:
In automatic driving, it is necessary to continue grasping a surrounding situation. For this purpose, external recognition sensors such as a radar and a camera are used. If there is an abnormality in these sensors, there is a risk that a vehicle may be in a dangerous situation. Therefore, being able to detect an abnormality of the sensors is necessary.

Considering that a comparison object is required in order to know that a sensor installed in an own vehicle has an abnormal value, and the comparison object can also take an abnormal value, majority decision with three sensing results including itself is necessary. Conventionally, there are examples in which two sensors, such as a radar and a camera, are installed in an own vehicle (see, for example, <CIT>).

<CIT> discloses an inter-vehicle distance measuring apparatus and method for automotive. The inter-vehicle distance measuring apparatus equipped in a host vehicle receives inter-vehicle distance data measured by an external inter-vehicle distance measuring apparatus installed by a road through a road-to-vehicle communications unit, and corrects an error in the distance value measured by an inter-vehicle distance measuring unit equipped in the host vehicle as well as detects a trouble in the inter-vehicle distance measuring unit based on the received data.

However, installing three sensors with detection targets overlapping with each other on the own vehicle has a problem of being redundant for performing automatic driving and the like, and of increasing the cost.

Accordingly, it is an object of the present invention to provide a vehicle including a vehicle control device capable of performing abnormality determination of a sensor by majority decision without increasing the number of sensors in the vehicle.

The above-mentioned problem is solved by the subject-matter of claim <NUM>. The dependent claims describe preferred embodiments of the invention.

According to the present invention, it is possible to provide a vehicle control device capable of performing abnormality determination of a sensor by majority decision without increasing the number of sensors in a vehicle.

Hereinafter, a vehicle control device <NUM> according to an embodiment of the present invention will be described in detail with reference to the drawings.

<FIG> shows an overall configuration view of a vehicle <NUM> provided with the vehicle control device <NUM> according to the embodiment.

The vehicle <NUM> shown in <FIG> is a rear wheel drive vehicle having a general configuration and including, for example, a cylinder injection gasoline engine <NUM> as a power source for traveling, an automatic transmission <NUM> capable of contacting with and separating from the engine <NUM>, a propeller shaft <NUM>, a differential gear <NUM>, a drive shaft <NUM>, four wheels <NUM>, a hydraulic brake <NUM> provided with a wheel speed sensor, and an electric power steering system <NUM>. Further, the vehicle <NUM> includes an accelerator pedal <NUM>, a brake pedal <NUM>, and a steering wheel <NUM>.

The vehicle <NUM> further includes the vehicle control device <NUM> that is responsible for controlling devices, actuators, and equipment and the like that are installed and deployed. The vehicle control device <NUM>, and the devices including sensors, which will be described later, actuators, and equipment and the like are adapted to be able to exchange signals and data through LAN or CAN communication in the vehicle. The vehicle control device <NUM> obtains information on the outside of the own vehicle from sensors to be described later, and transmits command values for realizing control such as following a preceding vehicle, maintaining a center of white lines, and preventing deviation, to the engine <NUM>, the brake <NUM>, and the electric power steering system <NUM>.

The vehicle <NUM> further includes a camera <NUM>, a pair of front radars <NUM>, an own vehicle position measurement device <NUM>, and a communication device <NUM>. The camera <NUM> is a stereo camera or the like that is disposed in a front part of the vehicle <NUM> and provided with a solid-state imaging device or the like that captures an external environment in front of the vehicle <NUM> to acquire image information. The pair of front radars <NUM> is disposed in a front part of the vehicle <NUM>, and are laser radars, millimeter wave radars, or the like that receive reflected waves from a three-dimensional object that is present around the vehicle. A traveling state of a front obstacle and a front road environment are detected by the camera <NUM> and the front radar <NUM>, and the detected information is supplied to the vehicle control device <NUM>. Targets to be detected by the camera <NUM> and the front radar <NUM> are an inter-vehicle distance, a distance from a ground installation object, a presence of an object, a speed, an acceleration, and the like, and these correspond to the predetermined detection target.

The own vehicle position measurement device <NUM> measures own vehicle position information (latitude and longitude) on the basis of information obtained from a GPS, and supplies the measurement result to the vehicle control device <NUM>.

The communication device <NUM> receives the detection result acquired by the device external to the own vehicle, through vehicle-to-vehicle communication/road-to-vehicle communication (C2X communication) and supplies the detection result to the vehicle control device <NUM>. The detection result is an inter-vehicle distance, a distance from a ground installation object, a presence of an object, a curvature of a road, a speed, an acceleration, and the like. The communication device <NUM> can also transmit an abnormality determination result determined by the vehicle control device <NUM>, to a device external to the own vehicle.

Note that the vehicle <NUM> in <FIG> is an example of a vehicle to which the present embodiment can be applied, and does not limit a configuration of a vehicle to which the present embodiment can be applied. For example, a vehicle employing a continuously variable transmission (CVT) instead of the automatic transmission <NUM> may be used. In addition, while the camera <NUM> and the radar <NUM> are used as two external recognition sensors, two sensors with an overlapping detection range are sufficient.

Next, with reference to <FIG>, a description will be given to a method for the vehicle control device <NUM> to acquire information on a predetermined detection target from a device external to the own vehicle in the comparative example.

<FIG> shows an explanatory view of a method for the vehicle control device <NUM> to acquire information on a predetermined detection target from a device external to the own vehicle in the comparative example.

In <FIG>, a method of acquiring an inter-vehicle distance from a road-to-vehicle communication device <NUM>, which is a device external to the own vehicle, will be described. In <FIG>, it is assumed that the vehicle (own vehicle) <NUM> is performing preceding vehicle follow-up for following a preceding vehicle <NUM>. An on-road camera <NUM> installed along a road captures the vehicle <NUM> and the preceding vehicle <NUM> as an image, and measures an inter-vehicle distance between the vehicle <NUM> and the preceding vehicle <NUM> in an image processing device <NUM>. Information on the measured inter-vehicle distance is transmitted by the road-to-vehicle communication device <NUM>, and the communication device <NUM> of the vehicle <NUM> receives the information. In this manner, the communication device <NUM> receives information on the inter-vehicle distance through road-to-vehicle communication with the road-to-vehicle communication device <NUM>, which is the device external to the own vehicle.

Next, a sensor abnormality determination process executed by the vehicle control device <NUM> according to the comparative example will be described with reference to <FIG>. In <FIG>, a description is given to a process of determining an abnormality of the camera <NUM> and the radar <NUM> on the basis of an inter-vehicle distance when the vehicle <NUM> is performing preceding vehicle follow-up. Note that the vehicle control device <NUM> corresponds to first acquisition means, second acquisition means, and abnormality determination means.

<FIG> shows a flowchart of the sensor abnormality determination process executed by the vehicle control device <NUM> in the comparative example.

The vehicle control device <NUM> receives inter-vehicle distances dCAM and dRAD between with the preceding vehicle <NUM> detected by the camera <NUM> and the radar <NUM> corresponding to the plurality of sensors (step S101). The vehicle control device <NUM> determines whether or not an absolute value of a difference between the two inter-vehicle distances dCAM and dRAD is larger than a predetermined threshold value K (step S102). When the absolute value is equal to or smaller than the threshold value K (step S102: NO), the vehicle control device <NUM> continues the preceding vehicle follow-up control by using the inter-vehicle distance dCAM (step S110). That is, it is regarded that there is no abnormality in the camera <NUM> and the radar <NUM>. Note that the threshold value K is a distance with which a difference between the inter-vehicle distances can be regarded to be a sufficiently small, and is set on the basis of a performance and the like of each sensor.

When the absolute value of the difference between the inter-vehicle distances dCAM and dRAD is larger than the threshold value K (step S102: YES), the vehicle control device <NUM> acquires an inter-vehicle distance dV2I between the vehicle <NUM> and the preceding vehicle <NUM> calculated by the on-road camera <NUM> and the image processing device <NUM>, through road-to-vehicle communication via the road-to-vehicle communication device <NUM> and the communication device <NUM> (step S103). That is, it is regarded that there is an abnormality in either one of the camera <NUM> and the radar <NUM>, and the inter-vehicle distance detected by the device external to the own vehicle is acquired in order to determine the abnormality of the sensor.

The vehicle control device <NUM> determines whether or not an absolute value of a difference between the inter-vehicle distances dCAM and dV2I is smaller than an absolute value of a difference between the inter-vehicle distances dRAD and dV2I (step S104). When the absolute value of the difference between the inter-vehicle distances dCAM and dV2I is smaller (step S104: YES), the vehicle control device <NUM> further determines whether or not the absolute value of the difference between the inter-vehicle distances dCAM and dV2I is smaller than the absolute value of the difference between the inter-vehicle distances dCAM and dRAD (step S105).

When the absolute value of the difference between the inter-vehicle distances dCAM and dV2I is smaller than the absolute value of the difference between the inter-vehicle distances dCAM and dRAD (step S105: YES), the vehicle control device <NUM> adopts the inter-vehicle distance dCAM as the inter-vehicle distance of preceding vehicle follow-up, and continues the preceding vehicle follow-up (step S107). That is, since the inter-vehicle distance dRAD is the farthest value from the other inter-vehicle distances dCAM and dV2I as a result of the determination in steps S104 and S105, it is regarded that the inter-vehicle distance dRAD indicates an abnormal value and there is an abnormality in the radar <NUM>.

Whereas, when the absolute value of the difference between the inter-vehicle distances dCAM and dV2I is equal to or larger than the absolute value of the difference between the inter-vehicle distances dRAD and dV2I (step S104: NO), the vehicle control device <NUM> determines whether or not the absolute value of the difference between the inter-vehicle distances dRAD and dV2I is smaller than the absolute value of the difference between the inter-vehicle distances dCAM and dRAD (step S106).

When the absolute value of the difference between the inter-vehicle distances dRAD and dV2I is smaller than the absolute value of the difference between the inter-vehicle distances dCAM and dRAD (step S106: YES), the vehicle control device <NUM> adopts the inter-vehicle distance dRAD as the inter-vehicle distance of preceding vehicle follow-up, and continues the preceding vehicle follow-up (step S109). That is, since the inter-vehicle distance dCAM is the farthest value from the other inter-vehicle distances dRAD and dV2I as a result of the determination in steps S104 and S106, it is regarded that the inter-vehicle distance dCAM indicates an abnormal value and there is an abnormality in the camera <NUM>.

In step S105 or step S106, when it is determined that the absolute value of the difference between the inter-vehicle distances dV2I and dCAM or the absolute value of the difference between the inter-vehicle distances dV2I and dRAD is equal to or larger than the absolute value of the difference between the inter-vehicle distances dCAM and dRAD, the inter-vehicle distance dV2I is regarded as an abnormal value, and in this case, the preceding vehicle follow-up control is stopped since it is not possible to specify which of the camera <NUM> and the radar <NUM> has an abnormality, and it is also not possible to specify an accurate inter-vehicle distance (step S108).

According to the vehicle control device <NUM> as described above, it is determined whether or not there is an abnormality in the camera <NUM> and the radar <NUM>, on the basis of the inter-vehicle distance between with the preceding vehicle <NUM> detected by the camera <NUM> and the radar <NUM>, and the inter-vehicle distance between the vehicle <NUM> and the preceding vehicle <NUM> calculated by the on-road camera <NUM> and the image processing device <NUM>, which are devices external to the own vehicle.

According to this configuration, in addition to the inter-vehicle distance detected by the camera <NUM> and the radar <NUM>, the inter-vehicle distance detected by the device external to the own vehicle is acquired, and the abnormality of the camera <NUM> and the radar <NUM> is determined. Therefore, it is possible to determine the abnormality of the camera <NUM> and the radar <NUM> by majority decision with the three inter-vehicle distances, without increasing the number of sensors in the vehicle <NUM>, which is the own vehicle. Accordingly, abnormality determination of the camera <NUM> and the radar <NUM> becomes possible without increasing the cost.

Further, since the vehicle control device <NUM> performs the abnormality determination process by using the inter-vehicle distance acquired through road-to-vehicle communication, it is possible to easily acquire the inter-vehicle distance from the device external to the own vehicle without increasing the cost, and it is possible to perform the abnormality determination process by majority decision.

Further, since the detection target of the camera <NUM> and the radar <NUM> is the inter-vehicle distance, it is possible to easily acquire from data detected by the camera <NUM> and the radar <NUM>, and abnormality determination of the camera <NUM> and the radar <NUM> can be performed.

Further, when a difference of inter-vehicle distances between with the preceding vehicle <NUM> detected by the camera <NUM> and the radar <NUM> is equal to or smaller than a predetermined threshold value, the vehicle control device <NUM> determines that there is no abnormality in the camera <NUM> and the radar <NUM>. Whereas, when the difference is larger than the predetermined threshold value, the vehicle control device <NUM> determines the abnormality of the camera <NUM> and the radar <NUM> on the basis of the inter-vehicle distances detected by the camera <NUM> and the radar <NUM> and the inter-vehicle distance detected by the device external to the own vehicle. As described above, when the difference between the inter-vehicle distances detected by the camera <NUM> and the radar <NUM> is equal to or less than a predetermined threshold value, it is determined that there is no abnormality in the camera <NUM> and the radar <NUM>. Therefore, the abnormality determination process can be terminated at an early stage, and preceding vehicle follow-up can be performed by a normal sensor.

Further, when the vehicle <NUM> is performing preceding vehicle follow-up on the preceding vehicle <NUM>, the vehicle control device <NUM> determines whether or not there is an abnormality in a plurality of sensors. Therefore, it is possible to detect an abnormality in the sensor in performing preceding vehicle follow-up, and prevent preceding vehicle follow-up in an abnormal state of the sensor.

Next, a vehicle control device <NUM> according to an embodiment of the present invention will be described with reference to <FIG> and <FIG>.

First, with reference to <FIG>, a description will be given to a method for the vehicle control device <NUM> to acquire information on a predetermined detection target from a device external to an own vehicle in the present embodiment.

<FIG> shows an explanatory view of a method for the vehicle control device <NUM> to acquire information on a predetermined detection target from the device external to the own vehicle in the present embodiment.

In <FIG>, a method of acquiring an inter-vehicle distance from a preceding vehicle <NUM>, which is the device external to the own vehicle, will be described. In <FIG>, it is assumed that a vehicle (own vehicle) <NUM> is performing preceding vehicle follow-up for following the preceding vehicle <NUM>. The preceding vehicle <NUM> includes an own vehicle position measurement device <NUM> similar to an own vehicle position measurement device <NUM> of the vehicle <NUM>, and a communication device <NUM> similar to a communication device <NUM> of the vehicle <NUM>. The preceding vehicle <NUM> transmits own vehicle position information (latitude and longitude) measured by the own vehicle position measurement device <NUM>, to the vehicle <NUM> by the communication device <NUM>. The communication device <NUM> of the vehicle <NUM> receives the own vehicle position information from the communication device <NUM> of the preceding vehicle <NUM>, and transmits to the vehicle control device <NUM>. In this manner, the communication device <NUM> receives information on the inter-vehicle distance through vehicle-to-vehicle communication with the communication device <NUM> of the preceding vehicle <NUM>, which is the device external to the own vehicle. Then, the vehicle control device <NUM> calculates an inter-vehicle distance dV2V on the basis of the own vehicle position information of the preceding vehicle <NUM> and own vehicle position information of the vehicle <NUM>.

Next, a sensor abnormality determination process executed by the vehicle control device <NUM> according to the present embodiment will be described with reference to <FIG>. In <FIG>, a description is given to a process of determining an abnormality of a camera <NUM> and a radar <NUM> on the basis of an inter-vehicle distance when the vehicle <NUM> is performing preceding vehicle follow-up.

<FIG> shows a flowchart of the sensor abnormality determination process executed by the vehicle control device <NUM> in the present embodiment.

The vehicle control device <NUM> receives inter-vehicle distances dCAM and dRAD between with the preceding vehicle <NUM>, detected by the camera <NUM> and the radar <NUM> corresponding to the plurality of sensors (step S201). The vehicle control device <NUM> determines whether or not an absolute value of a difference between the two inter-vehicle distances dCAM and dRAD is larger than a predetermined threshold value K1 (step S202). When the absolute value is equal to or smaller than the threshold value K1 (step S202: NO), the vehicle control device <NUM> continues the preceding vehicle follow-up control by using the inter-vehicle distance dCAM (step S210). That is, it is regarded that there is no abnormality in the camera <NUM> and the radar <NUM>. Note that the threshold value K is a distance with which a difference between the inter-vehicle distances can be regarded to be a sufficiently small, and is set on the basis of a performance and the like of each sensor.

When the absolute value of the difference between the inter-vehicle distances dCAM and dRAD is larger than the threshold value K1 (step S202: YES), the vehicle control device <NUM> receives own vehicle position information of the preceding vehicle <NUM> by the communication device <NUM> through vehicle-to-vehicle communication, measures the inter-vehicle distance dV2V between the vehicle <NUM> and the preceding vehicle <NUM>, and acquires the inter-vehicle distance dV2V (step S203). That is, it is regarded that there is an abnormality in either one of the camera <NUM> and the radar <NUM>, and the inter-vehicle distance is acquired on the basis of information detected by the device external to the own vehicle in order to determine the abnormality of the sensor.

The vehicle control device <NUM> determines whether or not an absolute value of a difference between the inter-vehicle distance dCAM and dV2V is smaller than an absolute value of a difference between the inter-vehicle distance dRAD and dV2V (step S204). When the absolute value of the difference between the inter-vehicle distances dCAM and dV2V is smaller (step S204: YES), the vehicle control device <NUM> further determines whether or not the absolute value of the difference between the inter-vehicle distances dCAM and dV2V is smaller than the absolute value of the difference between the inter-vehicle distances dCAM and dRAD (step S205).

When the absolute value of the difference between the inter-vehicle distances dCAM and dV2V is smaller than the absolute value of the difference between the inter-vehicle distances dCAM and dRAD (step S205: YES), the vehicle control device <NUM> adopts the inter-vehicle distance dCAM as the inter-vehicle distance of preceding vehicle follow-up, and continues the preceding vehicle follow-up (step S207). That is, since the inter-vehicle distance dRAD is the farthest value from the other inter-vehicle distances dCAM and dV2V as a result of the determination in steps S204 and S205, it is regarded that the inter-vehicle distance dRAD indicates an abnormal value and there is an abnormality in the radar <NUM>.

Whereas, when the absolute value of the difference between the inter-vehicle distances dCAM and dV2V is equal to or larger than the absolute value of the difference between the inter-vehicle distances dRAD and dV2V (step S204: NO), the vehicle control device <NUM> determines whether or not the absolute value of the difference between the inter-vehicle distances dRAD and dV2V is smaller than the absolute value of the difference between the inter-vehicle distances dCAM and dRAD (step S206).

When the absolute value of the difference between the inter-vehicle distances dRAD and dV2V is smaller than the absolute value of the difference between the inter-vehicle distances dCAM and dRAD (step S106: YES), the vehicle control device <NUM> adopts the inter-vehicle distance dRAD as the inter-vehicle distance of preceding vehicle follow-up, and continues the preceding vehicle follow-up (step S209). That is, since the inter-vehicle distance dCAM is the farthest value from the other inter-vehicle distances dRAD and dV2V as a result of the determination in steps S204 and S206, it is regarded that the inter-vehicle distance dCAM indicates an abnormal value and there is an abnormality in the camera <NUM>.

In step S205 or step S206, when it is determined that the absolute value of the difference between the inter-vehicle distances dV2V and dCAM or the absolute value of the difference between the inter-vehicle distances dV2V and dRAD is equal to or larger than the absolute value of the difference between the inter-vehicle distances dCAM and dRAD, the inter-vehicle distance dV2V is regarded as an abnormal value, and in this case, the preceding vehicle follow-up control is stopped since it is not possible to specify which of the camera <NUM> and the radar <NUM> has an abnormality, and it is also not possible to specify an accurate inter-vehicle distance (step S208).

The vehicle control device <NUM> according to the present embodiment can also achieve effects similar to those of the vehicle control device <NUM> according to the comparative example.

It should be noted that the present invention is not limited to the above-described embodiments. Those skilled in the art can make various additions and modifications within the scope of the present invention.

For example, in the above embodiments, the detection target is an inter-vehicle distance between with the preceding vehicle, but a distance between the vehicle <NUM> and a ground installation object (for example, a road sign), a presence of an object, a curvature of a road, a speed of the vehicle <NUM>, an acceleration of the vehicle <NUM>, or a car width of the preceding vehicle <NUM> may be used. In a case where the detection target is a distance between the vehicle <NUM> and a ground installation object, the information on the predetermined detection target received by the vehicle <NUM> from the device external to the own vehicle is the distance between the preceding vehicle <NUM> and the ground installation object and own vehicle position information of the preceding vehicle <NUM>. In a case where the detection target is a presence of an object, whether there is an object or not is detected by the camera <NUM> and the radar <NUM>. A case where the detection target is a curvature of a road is a case where two cameras are installed in front of the vehicle <NUM>.

Claim 1:
A vehicle including a plurality of sensors (<NUM>, <NUM>) configured to detect a predetermined detection target; communication means (<NUM>) configured to communicate with outside, an own vehicle position measurement device (<NUM>), and a vehicle control device (<NUM>), the vehicle control device (<NUM>) comprising:
first acquisition means configured to acquire information on the predetermined detection target from each of the plurality of sensors (<NUM>, <NUM>);
second acquisition means configured to acquire information on the predetermined detection target, the information being detected by a device external to the own vehicle (<NUM>) and received by the communication means (<NUM>); and
abnormality determination means configured to determine whether or not there is an abnormality in the plurality of sensors (<NUM>, <NUM>), based on information from the plurality of sensors (<NUM>, <NUM>) acquired by the first acquisition means and information from the device external to the own vehicle (<NUM>) acquired by the second acquisition means,
characterized in that the own vehicle position measurement device (<NUM>) is configured to measure own vehicle position information on the basis of information obtained from a GPS, and to supply the measurement result to the vehicle control device (<NUM>),
wherein the communication means (<NUM>) obtains information from the device external to the own vehicle through vehicle-to-vehicle communication,
wherein the abnormality determination means determines that there is no abnormality in the plurality of sensors (<NUM>, <NUM>) when a difference of a detection result of the predetermined detection target is equal to or less than a predetermined threshold value, based on information from the plurality of sensors (<NUM>, <NUM>) acquired by the first acquisition means, and the abnormality determination means determines whether or not there is an abnormality in the plurality of sensors (<NUM>, <NUM>) based on a detection result of the predetermined detection target detected by the plurality of sensors (<NUM>, <NUM>), and based on a detection result of the predetermined detection target based on information detected by the device external to the own vehicle (<NUM>) and acquired by the second acquisition means, when a difference of a detection result of the predetermined detection target detected by the plurality of sensors (<NUM>, <NUM>) is larger than the predetermined threshold value.