JP4617018B2 - Infrared image processing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement of an infrared image processing apparatus configured to be able to change the visual axis of an infrared camera according to a steering angle.
[0002]
[Prior art]
Various night vision systems using infrared cameras have been proposed in order to compensate for the lack of information under nighttime headlight illumination. In this type of night vision system, there is an infrared image display device in which an infrared camera is directed in the traveling direction of the vehicle in accordance with the rudder angle so that a pedestrian or the like can be quickly captured when traveling on a curve. And JP-A-9-315225.
[0003]
[Problems to be solved by the invention]
However, if you attempt to image a heating element (such as a pedestrian) at a long distance with high sensitivity, the imaging range (field angle) of the infrared camera becomes relatively narrow, so just change the direction of the infrared camera according to the steering angle. According to the conventional configuration of FIG. 5B, even if the infrared camera captures a pedestrian P1 or the like that is outside the turning circle while the vehicle A is traveling on a curve as shown in FIG. As shown in FIG. 3, the pedestrian P1 is suddenly out of the angle of view of the infrared camera, and a light image appears outside the display screen. Therefore, the driver may not be able to fully recognize the presence of the pedestrian P1. Concerned.
[0004]
The present invention has been devised to solve such problems of the prior art, and the main purpose of the present invention is improved so that the driver can accurately recognize the presence of a pedestrian or the like. Another object of the present invention is to provide an infrared image processing apparatus.
[0005]
[Means for Solving the Problems]
To achieve the above objects, the present onset Ming, the infrared camera (1), the imaging direction control means for performing the traveling direction imaging control for changing in accordance with the steering angle of the visual axis of the infrared camera (8) When the imaging direction control means detects the heating element within the angle of view of the infrared camera while the vehicle is turning, the heating element within the angle of view is substituted for the traveling direction imaging control. the performed for a predetermined time tracking control for controlling the viewing axis of the infrared camera to continue 捉 example, it was assumed, characterized in that subsequently returned to the traveling direction imaging control.
[0006]
In this way, when the infrared camera captures the heating element (pedestrian) while imaging the tip of the driver's line of sight by rotating the infrared camera in the turning direction of the vehicle, the visual axis of the infrared camera Is kept on the heating element for a predetermined time, so that the driver can easily recognize the pedestrian in the display screen.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
[0008]
1 and 2 show the overall configuration of an in-vehicle infrared image processing apparatus according to the present invention. The infrared image processing apparatus includes an infrared camera 1 attached to a front center portion of a vehicle body, an actuator 2 that swings the infrared camera 1 left and right on a horizontal plane (for example, an electric motor), and a steering wheel 3. A steering angle sensor 4 that detects the rotation angle φ, a vehicle speed sensor 6 that detects the vehicle speed V from the rotation speed of the rear wheel (driven wheel) 5, and a yaw rate that detects the yaw rate (yaw angular velocity) γ acting on the vehicle body that is turning. A sensor 7, a control unit 8 that controls the actuator 2 by processing the output signal of each sensor and the image output of the infrared camera 1, and a display 9 (such as a liquid crystal panel) that displays an image captured by the infrared camera 1. It is made up of.
[0009]
The control unit 8 includes first visual axis angle calculating means 11 for calculating a first swing angle θ1 from the output φ of the steering angle sensor 4 and the output V of the vehicle speed sensor 6, and the output V of the vehicle speed sensor 6 and the yaw rate sensor. The second visual axis angle calculating means 12 for calculating the second swing angle θ2 from the output γ of 7 and the first and second both swing angles θ1 · θ2 are compared, and the neck adapted to the running situation at that time The visual axis angle determining means 13 for determining the swing angle θ, the heating element determination means 14 for extracting a heating element such as a pedestrian that generates body heat from the image data of the infrared camera 1, and the heat generated by the heating element determination means 14 Select which of the follower 15 for outputting the target value of the swing angle so as to keep the body within the angle of view of the infrared camera 1, and the control signal for the visual axis angle determiner 13 and the follower 15 to be output. Control signal selection means 16 for , And it drives the oscillating actuator 2 by inputting a control signal selected to the driver 17.
[0010]
Next, the control flow of the apparatus of the present invention will be described with reference to FIGS.
[0011]
In the traveling direction imaging processing routine (step 1), the vehicle traveling direction is imaged while controlling the actuator 2. In the traveling direction imaging processing routine, first, the output φ of the steering angle sensor 4 and the output V of the vehicle speed sensor 6 Is input to the first visual axis angle calculating means 11, and the output V of the vehicle speed sensor 6 and the output γ of the yaw rate sensor 7 are input to the second visual axis angle calculating means 12 (step 11).
[0012]
The first visual axis angle calculation means calculates the first visual axis angle θ1 by the following equation (step 12).
[0013]
θ1 = K (V) · φ
[0014]
Here, K (V) is a correction coefficient proportional to the vehicle speed. Thus, an appropriate first visual axis angle θ1 corresponding to the steering angle φ and the vehicle speed V is obtained.
[0015]
On the other hand, in the second visual axis angle calculation means 12, first, since the yaw rate γ acting on the vehicle body corresponds to the turning angular velocity of the vehicle, the turning radius R of the vehicle is obtained from the vehicle speed V and the yaw rate γ by the following equation (step 13). ).
[0016]
R = V / γ
[0017]
Next, assuming that the circumference of the road shoulder is part of a perfect circle, the distance from the vehicle body center to the road shoulder is x, and the visual axis of the infrared camera 1 is directed to the tangent line of the road shoulder circumference as follows. A second visual axis angle θ2 is obtained (step 14).
[0018]
θ2 = cos ⁻¹ {(R−x) / R}
[0019]
The first and second visual axis angles θ1 and θ2 obtained in this way are input to the visual axis angle determining means 13 that determines the visual axis angle θ of the infrared camera 1.
[0020]
The visual axis angle θ is determined by determining whether or not the signs of the first and second visual axis angles θ1 and θ2 match, that is, whether the target swinging direction is the same direction (step 15). The absolute values of the angles are compared (step 16). As a result, when the first and second visual axis angles θ1 and θ2 swing in the same direction and the first visual axis angle θ1 is larger, the first visual axis angle θ1 is changed to the target visual axis angle θ of the infrared camera 1. (Step 17), when the directions of the first and second visual axis angles θ1 and θ2 are different from each other, or when the second visual axis angle θ2 is larger, the second visual axis angle θ2 is set as the target of the infrared camera 1. The visual axis angle θ is set (step 18). The actuator 2 is controlled based on the target visual axis angle θ thus obtained (step 19).
[0021]
The above processing is to prevent the direction of the infrared camera 1 from changing excessively with respect to the behavior of the vehicle so as to prevent the driver from feeling uncomfortable.
[0022]
On the other hand, since the infrared image of the subject that generates body heat is captured as a high-luminance portion, when the light image is extracted and the entire high-luminance portion in the image output of the infrared camera 1 falls within the angle of view, If the area is equal to or larger than a predetermined value, it is determined as a follow-up control object such as a pedestrian (step 2).
[0023]
If the presence of the tracking control object, that is, the pedestrian is recognized, the tracking control is selected, the center of gravity of the high-luminance portion is obtained, and the actuator 2 is set so that the visual axis of the infrared camera 1 follows the moving speed of the center of gravity. Control (step 3) (see the shaded area in FIG. 5B). Unless the heating element is caught, the normal traveling direction photographing control is continued. As a result, the driver can surely recognize the presence of the pedestrian, and thus can take early avoidance action so as to take a safe distance from the pedestrian.
[0024]
After this follow-up control is continued for a predetermined time (1 to 2 seconds), the normal traveling direction imaging control is returned (step 4) to prepare for the next pedestrian detection (see P2 in FIG. 5-c).
[0025]
When there are a plurality of pedestrians ahead, prioritize the pedestrians ahead of the appropriate distance (for example, 30 meters) in order of closeness, and set the time to capture each pedestrian to about 1 to 2 seconds. After the elapse, it is preferable to return to normal control and prepare for the next pedestrian detection.
[0026]
【The invention's effect】
As described above in detail, according to the present invention, when the presence of a heating element such as a pedestrian is not detected while traveling on a curve, the screen flows according to the progress of the vehicle. Since the infrared camera changes the direction of the visual axis so as to fix the heating element in the screen, the flow of the screen stops and the driver can easily recognize the presence of a pedestrian or the like. In addition, since the vehicle is moving, the angle of view is fixed, so that the line of sight is fixed to the object, and the positional relationship with the surroundings can be easily grasped. Therefore, according to the present invention, a great effect can be achieved in improving the usability of the infrared image display device in which the camera is directed in the traveling direction of the vehicle in accordance with the steering angle.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of a vehicle to which the present invention is applied. FIG. 2 is a block diagram showing the configuration of the present invention. FIG. 3 is a flowchart of the present invention. Explanatory diagram showing how the angle of view changes [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Infrared camera 2 Actuator 8 Control unit 9 Display 11 1st visual axis angle calculation means 12 2nd current zone angle calculation means 13 Visual axis angle determination means 14 Heating element determination means 15 Follow-up means 16 Control signal selection means 17 Driver

Claims (1)

An infrared image processing apparatus having an infrared camera and imaging direction control means for performing imaging control in a traveling direction for changing a visual axis of the infrared camera according to a steering angle,
The imaging direction control means, the vehicle upon detecting a heating element in the angle of view of the infrared camera during turning, the said heating element to said angle of view in place of the traveling direction the imaging control to continue 捉 e An infrared image processing apparatus that performs follow-up control for controlling a visual axis of an infrared camera for a predetermined time and then returns to the traveling direction imaging control .

Images