Abstract: Terrain-based machines are provided comprising a translational chassis movement indicator, a terrain-based implement, an implement inclinometer, and an implement state estimator. The translational chassis movement indicator provides a measurement indicative of movement of the machine chassis in one or more translational degrees of freedom. The implement inclinometer comprises (i) an implement accelerometer, which provides a measurement indicative of acceleration of the terrain-based implement in one or more translational or rotational degrees of freedom and (ii) an implement angular rate sensor, which provides a measurement of a rate at which the terrain-based implement is rotating in one or more degrees of rotational freedom.

Abstract: Terrain-based machines are provided comprising a translational chassis movement indicator, a terrain-based implement, an implement inclinometer, and an implement state estimator. The translational chassis movement indicator provides a measurement indicative of movement of the machine chassis in one or more translational degrees of freedom. The implement inclinometer comprises (i) an implement accelerometer, which provides a measurement indicative of acceleration of the terrain-based implement in one or more translational or rotational degrees of freedom and (ii) an implement angular rate sensor, which provides a measurement of a rate at which the terrain-based implement is rotating in one or more degrees of rotational freedom.

Abstract: Earthmoving machines are provided comprising a translational chassis movement indicator, an earthmoving implement inclinometer, and an implement state estimator. The translational chassis movement indicator provides a measurement indicative of movement of the machine chassis in one or more translational degrees of freedom. The implement inclinometer comprises (i) an implement accelerometer, which provides a measurement indicative of acceleration of the earthmoving implement in one or more translational or rotational degrees of freedom and (ii) an implement angular rate sensor, which provides a measurement of a rate at which the earthmoving implement is rotating in one or more degrees of rotational freedom.

Abstract: A method of calibrating an electrically actuated hydraulic valve in a system that controls the flow of hydraulic fluid to a hydraulic cylinder connected to a machine element operates automatically. The system includes an ultrasonic sensor providing an indication of the position of the machine element. The calibration method includes the step of automatically applying a command signal to the hydraulic valve while monitoring the ultrasonic sensor to determine the level of the command signal required to cause the hydraulic cylinder to begin to move. The calibration method includes the additional step of automatically applying in succession a plurality of command signals of increasing level to the hydraulic valve while monitoring the ultrasonic sensor to determine the speed of movement of the hydraulic cylinder resulting from each of the command signals.

Abstract: A method of calibrating an electrically actuated hydraulic valve in a system that controls the flow of hydraulic fluid to a hydraulic cylinder connected to a machine element operates automatically. The system includes an ultrasonic sensor providing an indication of the position of the machine element. The calibration method includes the step of automatically applying a command signal to the hydraulic valve while monitoring the ultrasonic sensor to determine the level of the command signal required to cause the hydraulic cylinder to begin to move. The calibration method includes the additional step of automatically applying in succession a plurality of command signals of increasing level to the hydraulic valve while monitoring the ultrasonic sensor to determine the speed of movement of the hydraulic cylinder resulting from each of the command signals.

Abstract: A device and method detect a moving, relatively thin beam of laser light, and distinguishing between illumination of photodetectors by the beam, and illumination of the photodetectors by an omnidirectional pulse of light. A plurality of photodetector arrays are arranged in a generally vertical row, with each array having a generally vertical row of photodetector elements. Weighting circuits associated with the arrays provide first and second reference signals for each array related to the elements illuminated in the array. The ratio of sum of the reference signals to the difference between the largest and smallest of the reference signals is determined and interpreted as indicating illumination by a relatively thin beam of laser light when the ratio is less than a predetermined level, and as indicating illumination by an omnidirectional pulse of light when the ration is greater than the predetermined level.

Abstract: The system determines the orientation, r, of an excavator or other machine sitting on a sloped portion of-a construction or work site with respect to the direction across the site in which there is no slope. This direction across the site in which there is no slope is perpendicular to the direction of the fall line of the sloped portion. The system includes a first inclinometer for determining the pitch angle, Pitch, of the machine and providing a pitch angle output. The system includes a second inclinometer for determining the roll angle, Roll, of the machine and for providing a roll angle output. Finally, the system includes a processor, responsive to said pitch angle output and said roll angle output, with the processor determining the orientation, r, according to one of the following: r=sin?1 [Pitch/(Pitch2+Roll2)1/2]; or r=cos?1 [Roll/(Pitch2+Roll2)1/2]; or r=tan?1 [Pitch/Roll].

Abstract: A device and method detect a moving, relatively thin beam of laser light, and distinguishing between illumination of photodetectors by the beam, and illumination of the photodetectors by an omnidirectional pulse of light. A plurality of photodetector arrays are arranged in a generally vertical row, with each array having a generally vertical row of photodetector elements. Weighting circuits associated with the arrays provide first and second reference signals for each array related to the elements illuminated in the array. The ratio of sum of the reference signals to the difference between the largest and smallest of the reference signals is determined and interpreted as indicating illumination by a relatively thin beam of laser light when the ratio is less than a predetermined level, and as indicating illumination by an omnidirectional pulse of light when the ratio is greater than the predetermined level.

Abstract: A device for spatial positioning systems includes a programmable measurement filter that is dynamically tuned by the device signal processing unit. The signal processing unit analyzes available data including the measurement signal to determine the likelihood that a detected measurement comprises true device movement and adjusts the measurement filter bandwidth accordingly.

Abstract: A device for spatial positioning systems includes a programmable measurement filter that is dynamically tuned by the device signal processing unit. The signal processing unit analyzes available data including the measurement signal to determine the likelihood that a detected measurement comprises true device movement and adjusts the measurement filter bandwidth accordingly.

Abstract: A transducer arrangement and method that generates control signals indicating relative positions of the ends of a hydraulically movable screed head. The generated control signals of the present invention are used by a conventional control circuit controlling the hydraulically movable screed head with laser receivers in a column block situation, which interrupts the reception of a laser beam from a laser transmitter by one of the laser receivers, to provide an estimated absolute position of the interrupted receiver side of the screed head until the column block situation clears. Normally, absolute measurements are available on both sides of the screed head via the laser receivers receiving the laser beam.

Abstract: A transducer arrangement and method that generates control signals indicating relative positions of the ends of a hydraulically movable screed head. The generated control signals of the present invention are used by a conventional control circuit controlling the hydraulically movable screed head with laser receivers in a column block situation, which interrupts the reception of a laser beam from a laser transmitter by one of the laser receivers, to provide an estimated absolute position of the interrupted receiver side of the screed head until the column block situation clears. Normally, absolute measurements are available on both sides of the screed head via the laser receivers receiving the laser beam.

Abstract: A laser beam transmitting system is provided comprising at least one target, a laser detection module, an optical system, a rotary encoder, a dither zone memory, and a controller. The optical system is arranged to generate a reference laser beam selectively in one of a search mode and a target dither mode and to direct a laser beam reflected from the target to the laser detection module. The search mode is characterized by movement of the reference beam through a rotational arc defined about a central rotational axis and the target dither mode is characterized by movement of the reference beam through a selected discrete portion of the rotational arc. The rotary encoder is arranged to produce a rotary signal indicative of a rotary position of the reference beam relative to the rotational arc.

Abstract: A laser transmitter and a method of transmitting a reference laser beam are provided comprising an auto scan dither mode. According to one aspect of the present invention, a laser transmitter is provided comprising a laser detection module, an optical system, and a controller. The laser detection module is operative to produce a reflected laser beam signal. The optical system is arranged to generate a reference laser beam selectively in one of a search mode and a target dither mode and to direct a reflected laser beam to the laser detection module. The optical system defines a rotational axis and the reference beam projects radially from the rotational axis. The search mode is characterized by movement of the reference beam through a rotational arc defined about the rotational axis and the target dither mode is characterized by movement of the reference beam through a dither zone occupying a portion of the rotational arc.

Abstract: A laser beam transmitting system is provided comprising at least one target, a laser detection module, an optical system, a rotary encoder, a dither zone memory, and a controller. The optical system is arranged to generate a reference laser beam selectively in one of a search mode and a target dither mode and to direct a laser beam reflected from the target to the laser detection module. The search mode is characterized by movement of the reference beam through a rotational arc defined about a central rotational axis and the target dither mode is characterized by movement of the reference beam through a selected discrete portion of the rotational arc. The rotary encoder is arranged to produce a rotary signal indicative of a rotary position of the reference beam relative to the rotational arc.

Abstract: A system for distinguishing real target reflections from ghost target reflections for use in adjusting the orientation of a plane defined by a rotating laser beam from a laser transmitter is provided. One or more retroreflective targets are positioned in desired locations along a rotational arc to define the desired plane through which the laser beam is rotated. The laser beam rotates back and forth scanning for targets positioned along the rotational arc. The laser beam is reflected from the targets to the laser transmitter for processing. A plurality of detection zones are established within the rotational arc. The detection zones are associated with a direction of rotation of the laser beam so that the laser beam traverses a target prior to traversing a potential shiny surface which could cause a ghost target reflection. As the laser beam scans a target prior to a shiny surface, reflections received after a target reflection are ignored as being potentially invalid reflections.

Abstract: An autofocusing system for a laser transmitter is provided. A laser beam is swept across a target having a plurality of sections. The target includes a first reflective section and a second reflective section with a non-reflective section positioned therebetween. A photodetector detects a signal representative of the laser beam reflected from the target. The laser beam is focused by adjusting the focusing lens until a ratio of the duration of the non-reflective portion of the signal to the sum of the durations of the reflective portions of the signal is maximized.

Abstract: A system for adjusting the orientation of a plane defined by a rotating laser beam from a laser transmitter is provided. The laser beam is swept across one or more targets having a plurality of sections. The targets each include a first reflective section and a second reflective section with a non-reflective section positioned therebetween. The non-reflective section includes a portion which slopes across the reflective sections. A photodetector detects a signal representative of the laser beam reflected from each of the targets. The orientation of the laser beam is adjusted until the laser beam traverses the center of the target at which point the width of the first reflective section equals the width of the second reflective section. A processor calculates the distance or angle in which to adjust the laser transmitter so that the laser beam traverses the center of the target once the laser beam traverses the portion of the target including the sloped non-reflective section.