GPS controlled guidance system for farm tractor/implement combination

Apparatus for controlling the position of an implement of the type which has an elongated transverse tool bar being drawn by a tractor relative to a desired path of movement while the tractor travels forwardly generally along the path, the tractor having a three point mounting hitch that is configured for limited lateral movement of about 10 inches relative to the tractor, said apparatus comprising:

• a guidance system hitch for attachment to the three point mounting hitch of the tractor and configured to have the implement mounted thereto, said guidance system hitch having hydraulic means to adjust the angular orientation of a connecting portion of said guidance system hitch relative to the mounting hitch by selectively retracting and extending both sides of said connecting portion of said guidance system hitch in a generally horizontal direction relative to the mounting hitch of the tractor wherein the extension or retraction of one side results in a corresponding retraction and extension of the other side;
• a global positioning system having a receiver and an antenna, said antenna being operatively connected to one of said guidance system hitch for detecting the position of the tool bar relative to the desired path as the tractor moves generally along the desired path and generating correction signals indicating deviation from the desired path;
• a control system responsive to said correction signals for operating said hydraulic means to selectively extend or retract each side of said connecting portion of said guidance system hitch to adjust the horizontal angular orientation of the tool bar.

Apparatus for controlling the position of a farm implement of the type which has an elongated transverse tool bar as the implement is drawn by a tractor so that the implement follows a desired path of movement as the tractor moves generally forwardly along the path, the tractor having a three point mounting hitch configured to permit lateral movement thereof at least about 10 inches relative to the tractor, said apparatus comprising:

• a guidance system hitch for attachment to the three point mounting hitch of the tractor and configured to have the implement mounted thereto, said guidance system hitch having hydraulic means to adjust the angular orientation of a connecting portion of said guidance system hitch relative to the mounting hitch by selectively retracting and extending both sides of a connecting portion of said guidance system hitch in a generally horizontal direction relative to the mounting hitch of the tractor, wherein the extension or retraction of one side results in a corresponding retraction and extension of the other side;
• first sensing means for sensing the horizontal angular orientation of said connecting portion of said guidance system hitch relative to the mounting hitch and generating a first signal indicative of said sensed orientation;
• a global positioning system having a receiver and an antenna wherein at least said antenna is mounted on said guidance system hitch or said implement and extends to a location that is at least forwardly of the tool bar including being coextensive with said guidance system hitch, said system being operable to detect the position of the antenna relative to the desired path as the tractor moves generally along the desired path and generate a second signal that is indicative of said lateral position;
• means for controlling said hydraulic means to adjust the angular orientation of said said connecting portion of said guidance system hitch so that the implement follows the desired path of movement in response to said second signals from said global positioning system.