Abstract: Systems and methods for controlling the cross slope of an asphalt paver screed. One system includes a tractor and an implement coupled to the tractor via a left tow arm and a right tow arm. The system also includes a left slope sensor mounted to the left tow arm and a right slope sensor mounted to the right tow arm. The system further includes one or more processors configured to perform operations including receiving left slope data and right slope data, calculating a measured cross slope of a virtual transverse beam extending between the left tow arm and the right tow arm based on the left slope data and the right slope data, obtaining a target cross slope, and causing movement of one or both of the left tow arm and the right tow arm based on a comparison between the measured cross slope and the target cross slope.

Abstract: A control and a method of control for a machine that applies a material to a subgrade at a work site and pulls a floating screed, having a screed plate, over the top surface of the material behind the machine is useful in paving with asphalt material. The floating screed is attached to the machine by a tow arm at a tow point on said tow arm. The vertical height of the tow point is controlled by an hydraulic cylinder on said machine in response to a valve control signal applied to an hydraulic valve by a valve control drive. The screed determines the thickness of the material on the subgrade and is manipulated by adjusting the height of the tow point. A first sensor is mounted on the floating screed for sensing three-dimensional position. A second sensor for senses the pitch of said screed. A processor circuit is responsive to the first and second sensors for determining the height of the trailing edge of the screed plate and the movement of the screed over the top surface of the material.

Abstract: A control and a method of control for a machine that applies a material to a subgrade at a work site and pulls a floating screed, having a screed plate, over the top surface of the material behind the machine is useful in paving with asphalt material. The floating screed is attached to the machine by a tow arm at a tow point on said tow arm. The vertical height of the tow point is controlled by an hydraulic cylinder on said machine in response to a valve control signal applied to an hydraulic valve by a valve control drive. The screed determines the thickness of the material on the subgrade and is manipulated by adjusting the height of the tow point. A first sensor is mounted on the floating screed for sensing three-dimensional position. A second sensor for senses the pitch of said screed. A processor circuit is responsive to the first and second sensors for determining the height of the trailing edge of the screed plate and the movement of the screed over the top surface of the material.