Closed-loop proportional position control of an implement stabilizer wheel

An agricultural tillage implement having an implement frame supported above a ground surface by implement support wheels operatively connected to the frame by a depth control arrangement, further having an at least one remotely positionable stabilizer wheel arrangement attached to the frame, the at least one remotely positionable stabilizer wheel arrangement comprising:

• a stabilizer wheel adapted for engaging the ground surface;
• a stabilizer wheel positioning arrangement adapted for operatively connecting the stabilizer wheel to the frame;
• the stabilizer wheel positioning arrangement including a double-acting hydraulic cylinder, and being configured for adjusting engagement of the stabilizer wheel with the ground surface through action of the double-acting hydraulic cylinder;
• a position sensor operatively connected for indicating a present position of the stabilizer wheel with respect to the frame, and generating an electrical present position signal indicative of the present stabilizer wheel position with respect to the frame;
• the double-acting hydraulic cylinder of the stabilizer wheel positioning arrangement having an internal bore divided by a piston into a base end and a rod end of the internal bore, the double-acting hydraulic cylinder also having first and second ends thereof operatively attached within the stabilizer wheel positioning arrangement for extension and retraction of the stabilizer wheel positioning arrangement with respect to the frame by corresponding movement of the piston within the internal bore of the double-acting hydraulic cylinder to thereby position the stabilizer wheel with respect to the frame;
• an electro-hydraulic proportional flow control arrangement adapted for receiving a cylinder control electrical signal, and further adapted for operative connection in fluid communication with a source of pressurized hydraulic fluid for receiving a flow of pressurized hydraulic fluid from the source;
• the electro-hydraulic proportional flow control arrangement including a solenoid-operated proportional flow control valve operatively connected in fluid communication with both the base end and the rod end of the internal bore of the double-acting hydraulic cylinder and configured for simultaneously and cooperatively controlling the flow of hydraulic fluid to and from both the rod and base ends of the internal bore of the double-acting hydraulic cylinder, to thereby control extension and retraction of the double-acting hydraulic cylinder in accordance with the cylinder control signal;
• and
• an electrical controller adapted for receiving an input signal indicating a desired position of the stabilizer wheel with respect to the frame;
• the electrical controller being further adapted, operatively connected to the position sensor and the solenoid-operated proportional flow control valve, and configured for receiving the present position signal from the position sensor and for generating and providing the cylinder control signal to the solenoid-operated proportional flow control valve in response to the present position signal and the desired wheel position signal, to thereby cause the double-acting hydraulic cylinder to move the stabilizer wheel to and hold the stabilizer wheel at the desired stabilizer wheel position by simultaneously, cooperatively and proportionally controlling the flow of pressurized hydraulic fluid to and from both the rod and base ends of the internal bore of the double-acting hydraulic cylinder;
• wherein:
• the electrical controller and position sensor are operatively connected and configured to form a proportional negative feedback control arrangement for determining a present difference between the desired and present positions of the stabilizer wheel and adjusting the flow of hydraulic fluid to and from the rod and cylinder ends of the internal bore of the double-acting hydraulic cylinder in proportion to the determined present difference between the desired and present positions of the stabilizer wheel;
• the position sensor is further operatively connected for indicating a present position of the piston within the cylinder bore that corresponds to a present position of the stabilizer wheel with respect to the frame, the position sensor also being configured for generating an electrical signal indicative of the present position of the piston within the cylinder bore;
• the electrical controller is configured for determining a target position of the piston within the cylinder bore corresponding to the desired wheel position input signal, and for determining a present difference between the target and present positions of the piston within the cylinder bore and adjusting the flow of hydraulic fluid to and from the rod and cylinder ends of the internal bore of the double-acting hydraulic cylinder in proportion to the determined present difference between the target and present positions of the piston in the cylinder bore to move and hold the piston at the target position for the piston within the cylinder bore;
• and
• the electrical controller is configured to repetitively sample the present difference between the target and present positions of the piston within the internal bore of the double-acting hydraulic cylinder at a periodic rate, and to command a proportional control valve to simultaneously and cooperatively adjust the flow of pressurized hydraulic fluid to and from both the rod base ends of the internal bore of the double-acting hydraulic cylinder at the periodic rate.

A method for remotely positioning a stabilizer wheel of an agricultural tillage implement having an implement frame supported above a ground surface by implement support wheels operatively connected to the frame by a depth control arrangement, in accordance with a desired position of the stabilizer wheel with respect to the frame, the method comprising:

• operatively connecting the stabilizer wheel to the frame with a stabilizer wheel positioning arrangement including a double-acting hydraulic cylinder having an internal cylinder bore divided by a piston into a base end and a rod end of the internal bore, the double-acting hydraulic cylinder also having first and second ends thereof operatively attached within the stabilizer wheel positioning arrangement for extension and retraction of the stabilizer wheel positioning arrangement with respect to the frame by corresponding movement of the piston within the internal bore of the double-acting hydraulic cylinder to thereby position the stabilizer wheel with respect to the frame;
• determining a target position for the piston within the cylinder bore that corresponds to the desired position of the stabilizer wheel with respect to the frame;
• and
• simultaneously, cooperatively and proportionally controlling the flow of hydraulic fluid to and from both the rod and base ends of the internal bore of the double-acting hydraulic cylinder to thereby control extension and retraction of the double-acting hydraulic cylinder for moving the stabilizer wheel to, and holding the stabilizer wheel at, the desired stabilizer wheel position;
• determining a present position of the piston within the cylinder bore;
• determining a present difference between the target and present positions of the piston within the cylinder bore;
• and
• adjusting the flow of hydraulic fluid and to form the rod and cylinder ends of the internal bore of the double-acting hydraulic cylinder in proportion to the determined present difference between the target and present positions of the piston in the cylinder bore to move and hold the piston at the target position for the piston within the cylinder bore.