Abstract: Disclosed are method and apparatus for controlling the blade elevation and blade slope angle of a dozer blade. Elevation and slope angle measurements are calculated from measurements received from a global navigation satellite system (GNSS) antenna and an inertial measurement unit mounted on the dozer blade. The inertial measurement unit includes three orthogonally placed accelerometers and three orthogonally placed rate gyros. The measurements are processed by algorithms to calculate estimates of the blade elevation, blade vertical velocity, blade slope angle, and blade slope angular velocity. These estimates are then provided as inputs to a control algorithm which provides control signals to control a dozer hydraulic system which controls the blade elevation and blade slope angle.

Abstract: A system and method for imaging a three-dimensional scene having one or more objects. The system includes a light source, a detector array, a timing circuit, an inertial guidance system and a processor connected to the timing circuit and the inertial guidance system. The light source generates an optical pulse and projects the optical pulse on an object so that it is reflected as a reflected pulse. The detector array includes a plurality of detectors, wherein the detectors are oriented to receive the reflected pulse. The timing circuit determines when the reflected pulse reached detectors on the detector array. The inertial guidance system measures angular velocity and acceleration. The processor forms a composite image of the three-dimensional scene as a function of camera position and range to objects in the three-dimensional scene.

Abstract: A method and apparatus for use with a satellite positioning system wherein the receive elements satellite positioning system receive antennas are maintained in an orientation with respect to the positioning system satellites in a way such that the strongest signals can be received from the greatest number of satellites. According to one embodiment, a housing of a positioning antenna is mounted in a gimbaled fashion onto a vehicle, such as an excavator. Such a gimbaled antenna maintains a horizontal orientation relative to a predetermined axis and, as a result, remains in a position to receive signals from positioning system satellites even during instances of high angular deflection of the antenna support, such as may occur during earth-moving operations.

Abstract: A graphical grade indicator for use in earth moving operations has an improved, variable resolution and a substantially unlimited range. This grade indicator results in a more accurate indication of the position of a cutting blade relative to the desired grade and, as a result, allows a machine operator to more accurately control grading operations. In one embodiment, a graphical grade indicator has a graphical scale with a substantially unlimited range and various indications indicating a desired grade level and at least a first undesirable grade level. When the cutting blade deviates from the desired grade level, a first indication is provided indicating, illustratively, the direction and magnitude of movement of the cutting blade repositioning necessary to achieve the desired grade. The resolution of the graphical scale can be changed in order to provide a desired degree of accuracy in grading operations.

Abstract: A virtual profilograph is disclosed that can provide measurements indicative of the ride quality of a roadway as the road is being constructed. As a result, a more timely, less costly indication of the ride quality of a roadway is obtained as compared to prior methods. In a first embodiment a Global Navigation Satellite System antenna is attached to a vehicle. When the vehicle travels over a roadway, measurements of the position of the antenna are recorded at different times. A profile of the roadway is created by measuring the elevation of the antenna as a function of the distance traveled from a starting point. In another embodiment, tilt sensors are used to measure the slope of the roadway and the tilt of the vehicle so that a precise orientation of the vehicle and, hence, the contours of the roadway, can be determined.

Abstract: A method and apparatus for using satellite positioning systems to more precisely locate the position of a portion of an attachment on an earthmoving machine is disclosed. More specifically, satellite positioning system antennas are mounted to an arm or other point relative to the arm of an illustrative excavator. A reference point relative to these antennas is used to determine the precise location of a portion of an attachment to the excavator, such as the prongs of a bucket. In one embodiment, an angle sensor or inclinometer is used to ascertain the position of the prongs when the bucket is scooped. In another embodiment, an angle sensor or inclinometer is used to measure the tilt of the body of the excavator, such as would occur when the excavator is resting on a sloped surface.

Abstract: Disclosed is a method and apparatus for processing signals in a satellite/laser positioning system capable of generating location coordinates from received satellite signals and a received laser signal. A height coordinate bias value is maintained by a filter processor during periods when the laser signal is available. The height coordinate bias value represents an estimated difference between a satellite signal derived height coordinate and a laser signal derived height coordinate. During periods when the laser signal is available, the laser signal derived height coordinate is output. During periods when the laser signal is not available, a corrected height coordinate value is generated by applying the height coordinate bias value to the satellite signal derived height coordinate.

Abstract: Disclosed are method and apparatus for controlling the blade elevation and blade slope angle of a dozer blade. Elevation and slope angle measurements are calculated from measurements received from a global navigation satellite system (GNSS) antenna and an inertial measurement unit mounted on the dozer blade. The inertial measurement unit includes three orthogonally placed accelerometers and three orthogonally placed rate gyros. The measurements are processed by algorithms to calculate estimates of the blade elevation, blade vertical velocity, blade slope angle, and blade slope angular velocity. These estimates are then provided as inputs to a control algorithm which provides control signals to control a dozer hydraulic system which controls the blade elevation and blade slope angle.

Abstract: A valve switch unit has a detector configured to detect an input, such as current, from a machine controller. The valve switch unit also has a switching circuit configured to switch control of the one or more valves an automatic controller to the machine controller if the input from the machine controller exceeds a predetermined threshold. When the current detected exceeds the predetermined threshold, the circuit switches control from the automatic controller to the machine controller. In a similar fashion, when the current falls below the predetermined threshold, the circuit switches control back to the automatic controller.

Abstract: The position of an apparatus moving along a surface is determined by calculating a plurality of vertical angles between the apparatus and a known location, where the vertical angles vary only within a range having a largest expected maximum angle. A plurality of horizontal distances between the apparatus and the known location are determined, each of the horizontal distances associated with one of the vertical angles. The horizontal distances are computed to within a tolerance based at least in part on the largest expected maximum angle. A plurality of heights of the apparatus are then determined using the plurality of vertical angles and associated horizontal distances. In particular embodiments, the known location may be associated with a rotating laser used with a photodetector at the target to determine the vertical angle. Further, the target may comprise a GPS receiver for use in determining the horizontal distance measurements.

Abstract: An earthmoving machine including a control system is disclosed. The machine comprises first and second satellite navigation antennas mounted in a longitudinal direction on the earthmoving machine. A third satellite navigation antenna is mounted on a pole attached to an operational element of the earthmoving machine. In one embodiment, the earthmoving machine is a bulldozer and the operational element is a blade of the bulldozer. The machine further comprises a gravity reference sensor and a plurality of gyroscopes mounted on the machine. A computer processor generates control signals based on sensor data received from the various components. The disclosed system and method allows for dynamically stable operation of the earthmoving machine at relatively fast speeds without the development of unwanted oscillations.

Abstract: Disclosed are methods and apparatuses for generating the estimates of receiver's coordinates and/or time offset for a moment of time tn without large errors caused by short-term shading of a part of the observable global positioning satellites and also without large dynamic errors caused by the receiver movement. The receiver may be stationary or mobile (i.e., rovering). A set of snapshot-solution values for the position coordinates and time offset of the receiver at the time moment tn, and a set of predicted values for the position coordinates and time offset of the receiver at the time moment tn are generated. The accuracy of each of these sets are determined, and a set of refined estimates for the position and time offset of the receiver is generated based the snapshot solution values, the predicted position values, and the accuracies.

Abstract: Disclosed are methods for increasing the fail-safety characteristics of tracking systems for navigation receivers which receive signals from many satellites. In an exemplary embodiment of the present invention, an individual PLL circuit is used to track the phase of each satellite's carrier signal, and a vector common tracking loop is used to track the disturbances of the carrier phases which are caused by one or more common sources, such as the movement of the receiver's antenna(s) and/or the phase fluctuation of the receiver's main reference oscillator. The vector common tracking loop uses phase information from all of the satellites being tracked, and for this reason can be made more wide-band than each of the individual PLL circuits. The wider bandwidth of the vector common tracking loop provides higher dynamic properties and more safe tracking when faint and weakening satellite signals are present.

Abstract: Choke-ring ground planes are commonly used for multipath rejection in geodetic surveying systems. Such ground planes consist of a thick metal disc with deep grooves on one of the flat surfaces. An antenna is mounted in the center of the grooved surface. Known ground planes used in dual frequency communication systems (L1 and L2) could not be constructed to have good rejection of multipath signals in both L1 and L2 frequencies; instead, they are constructed for good rejection of multipath signals in L2 but not good for the rejection of multipath signals in L1. A first invention provides for equally good multipath rejection for both L1 and L2 frequencies by incorporating novel electromagnetic filter structures within the choke-ring grooves. The filter structures of the present invention enable the choke ring to provide multipath rejection in each frequency band which is as good as, or better than, the multipath rejection achieved in the L2 band with existing devices.

Abstract: Satellites of the GPS and GLONASS navigation systems broadcast code signals which are modulated onto respective carrier signals, and which are received by two receivers on Earth. The first receiver is situated at a point with known coordinates. The results of its measurements are transmitted to a user at a second receiver through a connection link, the user being interested in knowing his or her positioning. The second receiver is similar to the first receiver and it receives the signals of the same satellites. By processing data from the measurements of code delays and carrier phase shifts in the satellite signals received by two receivers, the methods and apparatuses of the inventions of the present application determine the location of the user with high precision and make the time indications of receiver clocks more accurate and exact.

Abstract: Method of suppression of narrow-band interferences attending at the receiver input added to the useful broadband signal and noise. There is a disclosed compensator rejecting narrow-band interferences by means of adjustment loops. Two general methods of construction of such loops are considered. The first general method is based on filtration of the in-phase and quadrature components of the error vector—difference of the interference vector and compensating vector. The second method is based on filtration of the amplitude and full phase of the interference signal. Automatic tuning of the compensator to the mean frequency and effective interference band is ensured.