Abstract: A transducer arrangement and method that generates control signals indicating relative positions of the ends of a hydraulically movable tool of a machine. The generated control signals of the present invention are used by a conventional control circuit of the machine to control the ends of the hydraulically movable tool having elevation receivers as an desired mode of operation or when reception by one of the elevational receivers of a elevational reference, which provides an absolute position of the ends of the tool, is interrupted. The conventional control circuit of the machine uses the generated signal of the transducer arrangement of the present invention to maintain a relative elevation position of one side of the tool to the absolute position of the other side of the tool as desired or until both receiver can reacquire the elevational reference.

Abstract: A transducer arrangement and method that generates control signals indicating relative positions of the ends of a hydraulically movable tool of a machine. The generated control signals of the present invention are used by a conventional control circuit of the machine to control the ends of the hydraulically movable tool having elevation receivers as an desired mode of operation or when reception by one of the elevational receivers of a elevational reference, which provides an absolute position of the ends of the tool, is interrupted. The conventional control circuit of the machine uses the generated signal of the transducer arrangement of the present invention to maintain a relative elevation position of one side of the tool to the absolute position of the other side of the tool as desired or until both receiver can reacquire the elevational reference.

Abstract: A control system controls movement of individual hydraulically moveable ends of a screed head carried by a boom of a machine so as to maintain a selected elevational position between each end of the screed head and a reference in a concrete paving application. One of a pair of elevation receivers is mounted at each end of the screed head, providing a first and second signals indicating the position of the first and second ends of the screed head in relation to the reference. A sensor, mounted on the screed head, senses the orientation of the screed head along its length from the first end to the second end and providing a third signal indicating such orientation.

Abstract: A method and apparatus are disclosed for controlling the cross slope angle cut by the blade of an articulated frame motorgrader being steered through a turn, operated in a straight frame mode, in a crabbed steering position and/or traveling in a non-horizontal plane. The blade angle is sensed and controlled such that the sensed blade angle is maintained substantially equal to a calculated blade angle. In a first embodiment, the blade angle calculation is performed using the equation: tan BS=(sin .tau.')(tan R)+(cos .tau.')(tan CS) where BS is the required blade slope angle of said blade relative to horizontal; .tau.' is a rotational angle of the blade with respect to the blade's direction of travel projected into horizontal; R is an angle between the blade's direction of travel and horizontal; and CS is the desired cross slope angle which is entered by an operator of the motorgrader. In a further embodiment, the blade angle calculation is performed using the equation: tan BS=(sin .tau.")(tan R')+(cos .tau.

Abstract: A method and apparatus are disclosed for controlling the cross slope angle cut by the blade of an articulated frame motorgrader operated in the crabbed steering mode wherein the articulation angle of the motorgrader frame is sensed and used to calculate the blade angle relative to horizontal required to maintain a desired cross slope angle. The blade angle is sensed and controlled such that the sensed blade angle is maintained substantially equal to the calculated blade angle.