Trimble Navigation Limited

Spectra Precision, Inc.

Caterpillar Trimble Control Technologies LLC

Frank Beard Douglas

Philip Lynn Detweiler

Francisco Roberto Green

James E Denney

Jonathan A Jackson

James Nelson Hayes

Nathan A Corey

Jonathon A Jackson

An earthmoving system including a bulldozer has a pair of GPS receivers mounted on the cutting blade of the bulldozer. The cutting blade is supported by a blade support extending from the frame. The blade support includes a pair of hydraulic cylinders for raising and lowering the blade in relation to the frame and a blade tilt cylinder for controlling the lateral tilt of the cutting blade. Sensors, including gyroscopic sensors and an accelerometer, sense rotation of the frame about three orthogonal axes and vertical movement of the bulldozer frame that would affect the position of the blade. A control is responsive to the pair of GPS receivers and to the gyroscopic sensors, for controlling the operation of the hydraulic cylinders and thereby the position of the cutting blade. The control monitors the position of the cutting blade with repeated calculations based on the outputs of the GPS receivers and with low-latency feed-forward correction of these repeated calculations, based on the outputs of the gyroscopic sensors and the accelerometer.

Grade control for an earthmoving system at higher machine speeds

A system and a method sense the inclination of a machine element, such as a platform, and eliminate tangential and radial acceleration errors. The platform defines orthogonal X and Y axes, and is rotatable about a Z axis. An inclinometer, mounted on the platform at a location spaced from the axis of rotation by a distance r, provides inclinometer outputs indicating acceleration in the X and Y directions, Iand I, respectively. A rate gyro on the platform senses the rotational speed w of the platform. The rate gyro output w is differentiated and multiplied by r to determined tangential acceleration at the inclinometer. A circuit resolves the tangential acceleration into X axis and Y axis components, which are used to correct the inclinometer outputs Iand Ifor errors that would otherwise result from tangential acceleration.

Inclinometer measurement system and method providing correction for movement induced acceleration errors

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.

Strobe light and laser beam detection for laser receiver having a comparison of variation in energy levels among photodetectors

A laser level with a sensorless DC motor controller having a feedback sampling circuit connected in parallel with the coil to sense back EMF. An integrator provides a feedback signal from the sensed back EMF, which the amplified difference from a reference level is used as a pulse width control signal. A pulse width modulation generator uses the control signal to generate variable 'on' time pulse widths for each motor drive pulse such that high resolution is provided to the DC motor, permitting accurate rotor position at low rotational speeds. It is emphasized that this abstract is provided to comply with the rules requiring an abstract to allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that is will not be used to interpret or limit the scope or meaning of the claims.

Electronic rotor pointing with high angular resolution

A laser beam receiver with non-interdigitated photosensors arranged in a repeating pattern of 'n' channels of photosensors in each of 'm' sectors is disclosed. The photocurrent from both the anode and cathode terminals of the photosensor is used to determine laser beam position. The repeating patterns connect one set of &#x201c;n&#x201d; channel amplifier channels with the corresponding set of &#x201c;m&#x201d; sector amplifier channels. The position of the laser beam is determined by its position relative to the sector and channel the laser beam impinges on. The laser beam position relative to sector boundaries is determined by the distribution of photosensor current into the &#x201c;n&#x201d; channels of amplifiers from the &#x201c;n&#x201d; photosensors within each sector. The sector of the photosensor the laser beam impinges on is determined by the distribution of photosensor current into the &#x201c;m&#x201d; channels of sector amplifiers from the &#x201c;m&#x201d; groups of &#x201c;n&#x201d; photosensors.

Receiver circuit with 'm' sectors each with 'n' channels

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.

Strobe light and laser beam detection for laser receiver

Field-deployable spatial positioning or measurement systems are provided for improved versatility, reliability and performance. The spatial positioning or measurement systems use rotating laser fans or beams for positioning and measuring and include a system integrated field-deployable length standard that uses a reelable tape with positional indents. The systems further include the use of labyrinth seals at interface volumes between rotating laser heads and transmitter assemblies to prevent ingress of contaminants and allow for elimination of the use of rotary seals. Further, new dynamic leveling techniques are provided to plumb positional laser transmitter systems. Still further, strobe beam configurations are provided for improved near/far performance and a vertical mode sensing scheme that allows switching to measuring tall structures when needed.

Versatile transmitter and receiver for position measurement

Receiver circuit with 'M' sectors each with 'N' channels

A device and method for detecting the relative position of reference light includes a plurality of photodetector arrays arranged in a generally vertical row. Each array includes a plurality of photodetector elements arranged in a generally vertical array row. The photodetector elements in the arrays are arranged in a generally vertically oriented, extended row. Each of the photodetector elements provides an electrical output when illuminated with the light. A plurality of weighting circuits is provided, each weighting circuit being associated with a respective one of the plurality of photodetector arrays. Each weighting circuit provides a portion of the electrical output of the illuminated photodetector element in the array as a first reference signal related to the spacing of the illuminated photodetector element from a first end of the array row, and provides a portion of the electrical output of the illuminated photodetector element as a second reference signal related to the spacing of the illuminated photodetector element from the second end of the array row. The weighting circuit associated with each array row is connected to the weighting circuits associated with adjacent array rows. A plurality of output circuits are provided, with each output circuit associated with, and responsive to, the reference signals from connected weighting circuits. The output circuits determine the relative levels of the reference signals from the weighting circuits such that the position of the reference plane of light may be determined with respect to the detector device.

Laser receiver using multiple arrays of photodetector elements

A device for detecting the relative position of a generally horizontal reference plane of light includes a plurality of photodetector elements, a weighting circuit, and an output circuit. The photodetector elements are positioned on the device in a generally vertically oriented row. The weighting circuit provides a portion of the electrical output of each photodetector element as a first reference signal related to the spacing of the photodetector element from a first end of said row, and a portion of the electrical output of each photodetector element as a second reference signal related to the spacing of the photodetector element from the second end of said row. The output circuit is responsive to the weighting circuit for determining the relative levels of the first and second reference signals and the position of said reference plane of light with respect to the detector device.

Laser receiver using pin diode photodetector elements

A laser level with a sensorless DC motor controller having a feedback sampling circuit connected in parallel with the coil to sense back EMF. An integrator provides a feedback signal from the sensed back EMF, which the amplified difference from a reference level is used as a pulse width control signal. A pulse width modulation generator uses the control signal to generate variable &ldquo;on&rdquo; time pulse widths for each motor drive pulse such that high resolution is provided to the DC motor, permitting accurate rotor position at low rotational speeds. It is emphasized that this abstract is provided to comply with the rules requiring an abstract to allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that is will not be used to interpret or limit the scope or meaning of the claims.

Receiver circuits are provided for detecting a target light source such as a swept laser beam. The circuits include a photodetector adapted to produce a first detector output signal and a second detector output signal where the relative amplitudes of the first and second detector output signals are related to the position of a swept laser beam impinging thereon. A first log signal is determined, which is based upon a logarithmic and optionally scaled calculation utilizing the first detector output signal. Correspondingly, a second log signal is determined, which is based upon a logarithmic and optionally scaled calculation utilizing the second detector output signal. The position of the beam is then computed based upon a subtraction of the second log output signal from the first log output signal.

Position detecting laser receiver

A laser transmitter is provided including a specialized compensator assembly damping mechanism. In accordance with one embodiment of the present invention, a compensator assembly position detector is arranged to detect a position X of the compensator assembly with respect to the X-axis, and a position Y of the compensator assembly with respect to the Y-axis. The compensator assembly damping mechanism includes an X-axis magnetic damping mechanism, a Y-axis magnetic damping mechanism, and a rotational damping mechanism. The active feedback circuit is arranged to (i) drive the X-axis magnetic damping mechanism so as to increase a damping force generated by the X-axis magnetic damping mechanism as a rate of change of the signal indicative of the position x increases, and (ii) drive the Y-axis magnetic damping mechanism so as to increase a damping force generated by the Y-axis magnetic damping mechanism as a rate of change of the signal indicative of the position y increases.

Growing community of inventors

Tipp City, OH, United States of America

Frank Beard Douglas