JPH0215172B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an agricultural machine, more specifically, an ultrasonic sensor that emits ultrasonic waves toward the ground and receives the reflected waves, and covers the process from the transmission of ultrasonic waves of this ultrasonic sensor to the transmission of the ultrasonic waves. a microcomputer that detects the height of the working device above the ground by measuring the time of This article relates to an agricultural machine having:

Conventionally, it is necessary to detect the height of the working equipment from the ground so that the height of the working equipment above the ground can be automatically controlled and to prevent the working equipment from falling into a high place on the ground. Using a sonic sensor,
A means for non-contact detection of the height above the ground is employed by measuring the time interval from the transmission of ultrasonic waves to the reception thereof by this sensor. In recent years, microcomputers have been increasingly used as control devices that measure the height above the ground and control the elevation of the work equipment based on the measurement results.

When a control device is configured with a microcomputer in this way, it is basically possible to perform not only ground height control but also many other types of control by simply changing the software, that is, the program, using relatively small-scale hardware. This has the great advantage of increasing the degree of freedom of operation of the controlled device. On the other hand, however, due to its characteristics, it is not possible to perform many types of measurement control simultaneously, so if another measurement control is activated while one type of measurement control is being performed, malfunctions may occur. As a result, there is a drawback that the normal operation of the controlled device is no longer guaranteed.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to prevent the height measurement control of the working device from malfunctioning due to other control operations.

In order to achieve the above object, the agricultural machine according to the present invention provides that when the microcomputer starts measuring the time from the transmission of the ultrasonic waves to the reception of the ultrasonic waves while the microcomputer is performing measurement control other than ground height control, It is characterized by having a means to invalidate the measurement results.

Due to the above characteristic structure, the following excellent results were achieved.

In other words, even if the microcomputer as a control device starts measuring the height above the ground while other measurement control operations are in progress, there is a means to effectively invalidate the measurement result, so there will be no erroneous measurement. This has made it possible to reliably prevent work equipment from malfunctioning due to data.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a side view of a reaping section 1 as a working device provided at the front of a combine harvester as an agricultural working machine, and the reaping section 1 includes a pulling device 2, a reaping device 3,
It has a conveying device 4, and in front of the pulling device 2, a weeding tool 5... is provided. The lower end of the weeding tool 5 is fixed to a support frame 7 connected to the body frame 6. As shown in FIG. 2, a plate-shaped member 8 is provided with its front end fixed to the back of the weeding tool 5 and its lower end fixed to the upper part of the support frame 7, and the upper left and right sides of this member 8 have heights above the ground. A transmitter 10 and a receiver 11 of the ultrasonic sensor 9 are respectively attached to detect the ultrasonic wave.

The transmitter 10 of the ultrasonic sensor 9 emits ultrasonic waves towards the ground, and the receiver 11 receives the reflected waves, and measures the time from when the ultrasonic waves are emitted to when they are received. Accordingly, the height of the reaping section 1 above the ground is detected.
Then, the reaping section 1
is automatically raised and lowered, and the height above ground is automatically controlled.

Below, the transmission of ultrasonic waves from the ultrasonic sensor 9 will be explained.
The microcomputer 12 as a control device that controls reception time interval measurement will be explained.

As shown in Figure 3, the microcomputer 1
2 includes an input interface 13, an output interface 14, an arithmetic unit 15, and a storage device 16 as main parts, and generates a pulse signal T with a time width corresponding to the height above the ground based on the received signal from the ultrasonic sensor 9. Based on the measurement results of the signals from the pre-processing circuit 17 which generates _T1 and the rotational speed detection sensor 18 which generates the pulse signal _T2 corresponding to the rotational speed of the engine E which is the power source, the output interface 14 , are configured to generate control signals necessary for each controlled device.

Measurements of elements that involve time measurements that occur repeatedly at predetermined intervals, such as the measurement of the height above the ground and the rotation speed measurement of the engine E, are configured to be performed by so-called interrupt processing that is activated with the highest priority. There is.

That is, the preprocessing circuit 17 that converts the signal from the ultrasonic sensor 9 into a pulse signal and the pulse signal from the rotation speed detection sensor 18 are sent to the gate 19,
20 etc., the waveforms are converted and synthesized and input directly to the arithmetic unit 15 via the interrupt input port REQ. Time measurement is started by inputting a signal to this port REQ, and the input interface 13 It monitors changes in the pulse signal _T1 , which is the ground height data from the preprocessing circuit 17 _inputted via In this case, the time measurement data of the pulse signal _T1 is invalidated to prevent an erroneous height measurement result from occurring above the ground.

Incidentally, FIG. 4 A and B show the control device 12 explained above.
This is a flowchart showing the operation.

Incidentally, although reference numerals are written in the claims section for convenient comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of drawings]

The drawings show an embodiment of the agricultural machine according to the present invention,
Fig. 1 is a front side view of the combine, Fig. 2 is an enlarged perspective view of the main parts of the ultrasonic sensor, Fig. 3 is a block diagram of the control device, Fig. 4 is a flowchart showing the operation of the microcomputer, and , FIG. 3B is a flowchart showing the operation of the interrupt processing. 1... Working device, 9... Ultrasonic sensor, 12
...Microcomputer.

Claims (1)

[Claims] 1 Equipped with an ultrasonic sensor 9 that emits ultrasonic waves towards the ground and receives the reflected waves, and measures the time from the emission of ultrasonic waves of this ultrasonic sensor 9 to the emission, thereby determining the height above the ground of the working device 1. The agricultural machine has a microcomputer 12 that detects the height above the ground and automatically controls the height above the ground by automatically adjusting the height above the ground of the working device 1 based on the height detection result above the ground, 12 is characterized in that, when measurement of time from transmission to transmission of the ultrasonic waves is started during measurement control other than ground height control, means is provided to invalidate this time measurement result. Agricultural machinery.