Abstract: A hydraulic system has a source, a plurality of fluid actuators, and a controller. The controller is configured to receive an input indicative of which of the plurality of fluid actuators are a first and a second type of fluid actuator, to receive an input indicative of a desired flow rate for the plurality of fluid actuators, and to determine a current flow rate of the source. The controller is further configured to demand the desired flow rate for the first type of fluid actuator and to demand a scaled down desired flow rate for the second type of fluid actuator when a total desired flow rate exceeds the current flow rate of the source, and to demand a scaled down desired flow rate for all of the plurality of fluid actuators when the desired flow rate for the first type of fluid actuator exceeds the current flow rate of the source.

Abstract: A communications system and method for fleets of earthworking machines. The system and method includes a global communications level for communicating over long range distances, at least one site communications level for communicating over medium range distances, and at least one theater communications level for communicating over short range distances. The system and method also includes at least one local communications level for communicating between earthworking machines, and a fleet manager for coordinating communications of the earthworking machines as a function of at least one of the global communications level, the site communications level, the theater communications level, and the local communications level.

Abstract: An apparatus for controlling an electrohydraulic system of a work machine having an engine that drives a variable displacement pump is disclosed. A pump displacement setting device produces a pump command signal indicative of a desired displacement of the variable displacement pump. An engine speed setting device produces an engine command signal indicative of a desired rotational speed of the engine. A power manager receives the pump and engine command signals, determines an efficient engine speed and pump displacement, and produces an engine control signal that decreases the engine speed to the efficient engine speed and a pump control signal that increases the pump displacement to an efficient pump displacement, while maintaining a substantially constant pump flow rate.

Abstract: A system and method for controlling the navigation of surface based vehicle uses a route that is obtained by manually driving the vehicle over the route to collect data defining the absolute position of the vehicle at various positions along the route. The collected data is smoothed to provide a consistent route to be followed. The smoothed data is subsequently used to automatically guide the vehicle over the route.

Abstract: A system (400) for positioning and navigating an autonomous vehicle (310) allows the vehicle (310) to travel between locations. Position information (432) is derived from global positioning system satellites (200, 202, 204, and 206) or other sources (624) when the satellites (200, 202, 204, and 206) are not in the view of the vehicle (310). Navigation of the vehicle (310) is obtained using the position information (432), route information (414), obstacle detection and avoidance data (416), and on board vehicle data (908 and 910).

Abstract: A system and method for enabling an autonomous vehicle to track a desired path plans a continuous path to return to the desired path when the vehicle deviates from the desired path. The continuous path is determined based on the vehicle's position, the desired path, and a lookahead distance. The lookahead distance is the distance on the desired path within which the continuous path and the desired path converge. The lookahead distance may vary as a function of vehicle speed. In one embodiment of the present invention, the continuous path is determined as a quintic polynomial.

Abstract: A system (400) for positioning and navigating an autonomous vehicle (310) allows the vehicle (310) to travel between locations. Position information (432) is derived from global positioning system satellites (200, 202, 204, and 206) or other sources (624) when the satellites (200, 202, 204, and 206) are not in the view of the vehicle (310). Navigation of the vehicle (310) is obtained using the position information (432), route information (414), obstacle detection and avoidance data (416), and on board vehicle data (908 and 910).

Abstract: A system and method detects obstacles in a road being traveled by a vehicle. Edge points of the road are calculated from known road data. A series of scan lines are made of the road ahead of the vehicle to obtain an image plane of the road ahead of the vehicle. The calculated edge points are projected into the image plane to determine the left and right edge points of each scan line in the image plane. Each scan line is processed to locate any discontinuities between the left and right edge points, where the discontinuities correspond to objects in the road.

Abstract: A system and method for causing an autonomous vehicle to track a desired path uses reference postures to define the desired path. Actual vehicle postures are determined using sensors aboard the autonomous vehicle. An expected vehicle posture at the end of a next time interval is determined on the actual vehicle posture. A desired vehicle posture at the end of the next time interval is determined based on the reference postures. A steering angle for the next time interval for the autonomous vehicle is determined based on the difference between the reference posture and the desired vehicle posture at the end of the next time interval.

Abstract: A system for generating a path allows a vehicle to traverse a predetermined route. The system stores route data for the predetermined route. The route data identifies a series of contiguous path segments that form the predetermined route. The route data also identifies a series of nodes located at the beginning and the end of the predetermined route and between adjacent path segments. Each path segment represents a series of postures along the predetermined route. Each posture identifies a position, a heading, and a curvature for the vehicle at a particular point along the predetermined route. The system stores the path segments and nodes as compressed path data. In one embodiment, the compressed path data is a function that is continuous in posture, i.e., continuous in position, heading and curvature. The system retrieves the compressed path data and generates a series of postures from the retrieved compressed path data to allow the vehicle to traverse the predetermined route.

Abstract: An apparatus and method for navigating a vehicle along a predetermined route use route data and path data to define the predetermined route. The route data represents one or more contiguous path segments between adjacent nodes along the predetermined route. The path data includes postures of the vehicle along each of the path segments. The postures define the desired position, heading, curvature and speed of vehicle at various locations along the path segments. The apparatus and method use the posture information to generate and track a path thereby allowing the vehicle to navigate along the predetermined route.

Abstract: A system (400) for positioning and navigating an autonomous vehicle (310) allows the vehicle (310) to travel between locations. Position information (432) is derived from global positioning system satellites (200, 202, 204, and 206) or other sources (624) when the satellites (200, 202, 204, and 206) are not in the view of the vehicle (310). Navigation of the vehicle (310) is obtained using the position information (432), route information (414), obstacle detection and avoidance data (416), and on board vehicle data (908 and 910).

Abstract: A system (400) for positioning and navigating an autonomous vehicle (310) allows the vehicle (310) to travel between locations. Position information (432) is derived from global positioning system satellites (200, 202, 204, and 206) or other sources (624) when the satellites (200, 202, 204, and 206) are not in the view of the vehicle (310). Navigation of the vehicle (310) is obtained using the position information (432), route information (414), obstacle detection and avoidance data (416), and on board vehicle data (908 and 910).

Abstract: A control system is provided for a hydraulic circuit having first and second hydraulic valves, a valve spool position sensor, and first and second input devices for producing first and second operation signals. A controller receives a signal from the valve spool position sensor and the second operation signal and responsively modifies the value of the second operation signal in response to the valve spool position signal.

Abstract: A system (400) for positioning and navigating an autonomous vehicle (310) allows the vehicle (310) to travel between locations. Position information (432) is derived from global positioning system satellites (200, 202, 204, and 206) or other sources (624) when the satellites (200, 202, 204, and 206) are not in the view of the vehicle (310). Navigation of the vehicle (310) is obtained using the position information (432), route information (414), obstacle detection and avoidance data (416), and on board vehicle data (908 and 910).

Abstract: According to one aspect of the present invention, a control system for automatically controlling a work implement of an excavating machine through an excavation work cycle is provided. The work implement includes a boom, stick and bucket, each being controllably actuated by at least one respective hydraulic cylinder, the hydraulic cylinders containing pressurized hydraulic fluid. The control system includes an operator control element adapted to produce an operator control signal indicative of a desired velocity of one of the hydraulic cylinders. An electrohydraulic valve actuates predetermined ones of the hydraulic cylinders to perform an excavation work cycle in response to the control signal. A sensor produces signals indicative of the forces associated with at least one of the hydraulic cylinders.

Abstract: A method and apparatus for positioning a housing of an excavator housing. A motor receives pressurized fluid to cause rotation of the excavator housing. A motor position sensor determines the rotational position of the housing and responsively produces a housing position signal. A pressure sensor determines the fluid pressure supplied to the motor and responsively produces a pressure signal. A microprocessor produces a signal indicative of a desired rotational position of the housing. The microprocessor receives the position and pressure signals, and responsively controls fluid to the motor in order to rotate the housing to the desired position.

Abstract: An apparatus is provided for use in a vehicle having a source of pressurized fluid and a pair of hydraulic drive motors connected to the pressurized fluid source and powered thereby. First and second ground engaging devices are connected to and driven by the first and second motors, respectively. The apparatus includes first and second control members, each being positionable at a plurality of locations for indicating a desired speed and direction for a respective drive motor. First and second actuators are adapted to sense the position of the first and second control members, respectively, and responsively control the direction and rate of fluid flow to the first and second drive motors. A set switch is movable between first and second positions and is adapted to produce a set speed signal in the second position.

Abstract: An apparatus for controllably actuating a hydraulic actuator is provided. The apparatus is connected between a source of pressurized hydraulic fluid and the hydraulic actuator. The apparatus controllably provides pressurized hydraulic fluid to the hydraulic actuator. The apparatus includes a controller for receiving an operating signal and a load pressure signal and responsively actuating the hydraulic actuator.

Abstract: A control system is provided for use with a hydraulic system which includes a source of pressurized fluid, a plurality of flow regulator means, and a plurality of fluidly powered components. Each flow regulator means is adapted to receive the pressurized fluid and is responsive to a respective control signal for regulating the flow of pressurized fluid to respective fluidly powered components. The control system includes a plurality of control members, each being movable to a plurality of locations for indicating a desired fluid output for a respective flow regulator means. A plurality of sensors are provided for sensing the position of respective control members and responsively producing respective position signals. A primary controller is adapted to receive the position signals, process the received signals to responsively produce the control signals, and deliver the control signals to the flow regulator means.