JPH07108124B2 - Line sensor for mobile agricultural machinery - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a line sensor for a mobile agricultural machine or the like, and detects the boundary line between an unworked area and an already-worked area by the line sensor to determine the work traveling direction of the mobile agricultural machine or the like. It is controlled and can be used for combine and tractor work.

Conventional technology and problems to be solved by the invention A line image sensor that detects a boundary line is a boundary line between an unworked area and an already-worked area detected on a screen, which is an optical bright and dark information from a sensor camera. Is electronically processed and determined, and the steering device of the mobile agricultural machine is steering-controlled so that the detected boundary line is located within a certain area of the sensor screen. Therefore,
If the boundary position of the image entering the sensor screen from the sensor camera is a short local portion in the traveling direction of the airframe, the steering by the image sensor is severely controlled, and the traveling direction is likely to cause hunting to the left and right.

Means for Solving the Problems The present invention is directed to a line image sensor that controls the steering while detecting a boundary line between an unworked area and an already-worked area, etc., and advances from a large number of image information detected on one sensor screen. The maximum value position of the frequency distribution distributed along the vertical line
A line sensor is configured by providing a boundary determination device that determines a boundary for each moving screen that is continuously detected for movement.

Action of the Invention A line image sensor is attached to a mobile agricultural machine in the traveling direction to detect a boundary portion between a front unworked area and an already worked area. A large amount of image information is input to one screen of the line image sensor over a certain length in the vertical line direction along the traveling direction and a certain width in the horizontal line direction orthogonal to the vertical line direction. This horizontal line is continuously moved on the sensor screen as the aircraft travels. The boundary position between the unworked area and the already-worked area is detected for each moving horizontal line. The boundary determination device totalizes the boundary positions detected on the one sensor screen for each vertical line and calculates the maximum value position of the frequency distribution. In this way, the maximum value position is calculated from the frequency distribution of the boundary position continuously at a constant interval from the moving sensor screen,
The position of the maximum value of movement is continued to determine the boundary line between the unworked area and the already worked area. In this way, steering control is performed based on the boundary line that is continuously determined, and the aircraft travels along the boundary line.

As described above, the boundary line between the unworked area and the already-worked area is locally determined in order to continuously determine the moving maximum value position of the frequency distribution from the image information detected on the sensor screen. It is possible to improve the boundary line detection accuracy and perform stable steering control without being affected by noise or the like due to image information or ambient light.

Example In the illustrated example, the line image sensor (1) is
It consists of an electronic camera, and the horizontal and vertical lines (X1), (X2), ... (Xn) are formed by arranging image elements of a certain section vertically and horizontally.
Along the left and right lateral directions orthogonal to the forward direction of travel (a) of the machine, and move the vertical line position from one end of the left and right sides to the other side (K1), (K2), ... (Km ).

The range switching device (2) is a line image sensor (1).
The output is adjusted according to the brightness and the like of the outside world at the time of detection, and when the state of insufficient output or excessive output continues for a certain time or longer, this output range is automatically switched.

The comparator (3) binarizes the input signal coming from the line image sensor (1) and inputs it to a boundary line judging unit composed of a microcomputer (CPU), and (4) is a binarization level output device, which is a gain The level of binarization of the comparator (3) is adjusted based on the correlation with the range switching by adjustment or the like.

With such a configuration, each boundary point (K) that determines the image information detected by the line image sensor (1) becomes a boundary line (L) for controlling the steering output is determined.

When the line image sensor (1) moves forward (a) with the boundary between the unworked area and the already worked area as the field of view, the image information on the field at this boundary is detected, and the image information over a certain distance in the front-rear direction is detected. Are simultaneously projected on the same screen (A), and the boundary information (P) which is this image information is detected for each horizontal line (X1), (X2), ... (Xn). The frequency distribution (B) of each horizontal line (X1) to (Xn) at this time is
Each vertical line (K1), (K2), ... (Km) is divided and stored in the memory (M) of the microcomputer (CPU) (5). From this frequency distribution (B), the vertical line (K4) of the division having the maximum frequency of the boundary information (P) is obtained as the boundary point (K) (6).

As a moving condition of the boundary point (K) | maximum frequency of previous boundary information (P) -maximum frequency of current boundary information (P) |> α, the boundary point (K) is the previous position (Ki) → current time Position (K
It is assumed that you have moved to j). Therefore, the absolute value is obtained (7), and when this absolute value is larger than α, the position (Kj) is taken as the current boundary point (K) (8) and stored in the memory (9). If the amount of change is less than or equal to α even if the frequency distribution changes, the boundary point (K) is assumed to remain unchanged, and the same position as the previous position (Ki) is held as the current boundary (1
0).

Thus, every time each horizontal line moves one pitch on the one sensor screen (A) as the aircraft advances, the boundary point that is the maximum value position of the frequency distribution from the image boundary information (P) on each horizontal line. (K) is determined. As a result of this determination, the boundary line (L) where this boundary point (K) is continuous serves as a reference for the steering control direction of the working machine, and the solenoid valves on the left and right of the steering control valve in the steering system including the steering clutch and the like. Output (11). (12) and (13) are output interfaces.

[Brief description of drawings]

1 is a block diagram, FIG. 2 is a control chart, FIG. 3 is a frequency distribution graph, and FIG. 4 is a flow chart. In the figure, reference numeral (1) is a line image sensor, (3) is a comparator, (11) is a solenoid valve, (CPU) is a microcomputer, (M) is a memory, (A) is a sensor screen, and (B) is a frequency. Distribution, (X1) to (Xn) are horizontal lines,
(K1) to (Km) are vertical lines, (K) is a boundary point, (Ki) is the previous position, (Kj) is the current position, (L) is the boundary line, and (P).
Indicates boundary information.

Claims (1)

[Claims] 1. A line image sensor for controlling steering while detecting a boundary line between an unworked area and an already-worked area, etc., in a vertical line direction along a traveling direction from a large number of image information detected on one sensor screen. The maximum value position of the distributed frequency distribution is
A line sensor provided with a boundary line determination device that determines a boundary line for each moving screen that is continuously detected for movement.