Electronic bucket positioning and control system

A vehicle including:

• a support structure;
• boom assembly means pivotally mounted to the support structure;
• an attachment pivotally mounted to the boom assembly means;
• lift means for driving the boom assembly means with respect to the support structure;
• at least one hydraulic tilt cylinder for driving the attachment with respect to the boom assembly means;
• an electrically actuated hydraulic tilt valve responsive to tilt control signals for controlling the tilt cylinder;
• an operator actuated hydraulic tilt valve for controlling the hydraulic tilt cylinder and coupled to the tilt cylinder in a parallel hydraulic circuit with the electrically actuated hydraulic tilt valve;
• sensor means for providing position signals representative of the angular position of the attachement with respect to the support structure;
• memory means for storing data representative of a predetermined minimum rollout angle of the attachment with respect to the support structure;
• and
• control means coupled to the sensor means, electrically actuated hydraulic tilt valve, and memory means for providing anti-rollback tilt control signals preventing the attachment from being driven to a rollout angle with respect to the support structure which is less than the minimum rollout angle.

A vehicle including:

• a support structure;
• an attachment pivotally mounted with respect to the support structure;
• hydraulic tilt cylinder means having a piston which can be driven between first and second end positions within a cylinder housing, for driving the attachment with respect to the support structure;
• electrically actuated tilt valve means responsive to tilt cushion control signals for controlling the tilt cylinder means;
• tilt sensor means for providing tilt position signals representative of the position of the piston within the cylinder housing of the tilt cylinder means;
• memory means for storing data representative of a first cushion distance and a second cushion distance with respect to the first end position;
• and
• control means coupled to the electrically actuated tilt valve means, tilt sensor means and memory means for providing tilt cushion control signals causing the electrically actuated tilt valve means to be actuated in a manner causing speed of the piston to slow when the piston is being driven within the cylinder housing toward the first end position and is within the first cushion distance of the first end position, and to disable production of the tilt cushion control signals if the piston is moved from the first end position by a distance less than the second cushion distance immediately before being driven toward the first end position, whereby tilt cushion control signals are produced when the piston is within the first cushion distance only if the piston is being driven toward the first end position from a distance greater than the second cushion distance.

A vehicle including:

• a support structure;
• an attachment pivotally mounted with respect to the support structure;
• hydraulic tilt cylinder means having a piston which can be driven between first and second end positions within a cylinder housing, for driving the attachment with respect to the support structure;
• electrically actuated tilt valve means responsive to tilt cushion control signals for controlling the tilt cylinder means;
• tilt sensor means for providing tilt position signals representative of the position of the piston within the cylinder housing of the tilt cylinder means;
• memory means for storing data representative of a cushion distance;
• and
• control means coupled to the electrically actuated tilt valve means, tilt sensor means and memory means for providing tilt cushion control signals causing the electrically actuated tilt valve means to be actuated in a manner causing speed of the piston to slow when the piston is being driven within the cylinder housing toward the first end position from a distance greater than the cushion distance from the first end position and is within the cushion distance of the first end position, and to disable production of the tilt cushion control signals if the piston is moved from the first end position by a distance less than the cushion distance immediately before being driven toward the first end position.