Excavator control system and method

Abstract

The system determines the orientation, r, of an excavator or other machine sitting on a sloped portion of-a construction or work site with respect to the direction across the site in which there is no slope. This direction across the site in which there is no slope is perpendicular to the direction of the fall line of the sloped portion. The system includes a first inclinometer for determining the pitch angle, Pitch, of the machine and providing a pitch angle output. The system includes a second inclinometer for determining the roll angle, Roll, of the machine and for providing a roll angle output. Finally, the system includes a processor, responsive to said pitch angle output and said roll angle output, with the processor determining the orientation, r, according to one of the following: r=sin−1 [Pitch / (Pitch2+Roll2)1 / 2]; or r=cos−1 [Roll / (Pitch2+Roll2)1 / 2]; or r=tan−1 [Pitch / Roll]. The first and second inclinometers may comprise a single, dual axis inclinometer, or they may comprise a pair of appropriately oriented inclinometers. The system may use only one of the three formulae continuously, or may select various ones of the formulae for use at various times, depending upon which formula is judged to provide the most accurate indication of orientation. For example, the formula may be selected based upon the quadrant in which the longitudinal axis of the machine is oriented.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]Not applicable.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT[0002]Not applicable.BACKGROUND OF THE INVENTION[0003]The present invention relates to excavators and similar types of machines and, more particularly, to a system and method for determining the orientation of the machine or a part of the machine without necessitating the use of additional sensors, detectors or receivers.[0004]Excavators are used for excavating at construction sites, quarries, agricultural sites, and similar environments. To control an excavator with precision, it is important to know the position and the orientation of the excavator, including its cab, its boom, its dipper stick, and its bucket. A number of different arrangements have been used to collect this information. For example, a GPS antenna and receiver provide information as to the location of the excavator in three dimensions. However, a single GPS receiver and antenna cannot provide...

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