Patents by Inventor Christian Grässer

Christian Grässer has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20190331486
    Abstract: The present disclosure provides a method for determining a direction to a geodetic target from a geodetic instrument. The method includes emitting an optical pulse from the geodetic target, capturing a first image and a second image of the geodetic target using a camera arranged at the geodetic instrument, obtaining a difference image between the first image and the second image, and determining a direction to the geodetic target from the geodetic instrument based on the position of the optical pulse in the difference image. The method further includes synchronizing the geodetic instrument and the geodetic target for emitting the optical pulse concurrently with the capturing of the first image and nonconcurrently with the capturing of the second image. The present disclosure also provides a geodetic instrument, a geodetic target and a geodetic surveying system.
    Type: Application
    Filed: July 8, 2019
    Publication date: October 31, 2019
    Inventors: Johan Carlén, Mikael Nordenfelt, Christian Grässer
  • Patent number: 10168153
    Abstract: Novel solutions for position measurement, including without limitation tools and techniques that can be used for land surveying and in similar applications. One such tool is a greatly enhanced position measurement system that takes the form of a surveying rod with substantial independent functionality, which can be used with or without a total station or similar device.
    Type: Grant
    Filed: September 30, 2013
    Date of Patent: January 1, 2019
    Assignee: Trimble Inc.
    Inventors: Christian Grässer, Peter Cornelius Kistler, James Greenberg, Rod Johnson
  • Patent number: 9936181
    Abstract: A system for projecting an image, including layout information, on a surface in a building under construction has a projector mounted on a moveable support for supporting a worker at a work position in the building. The projector projects an image on a surface above the moveable support in response to an image signal defining the image to be projected. The image indicates the location of connectors, anchors, and holes to be affixed to, or cut through, the surface. A system determines the two dimensional position of the projector in the building, and a distance measuring system for determines the distance from the projector to said surface. A processor, responsive to a memory having stored building plan images, provides an image signal to the projector adjusted for the two dimensional location of the projector and for the distance from the projector to the surface.
    Type: Grant
    Filed: July 23, 2015
    Date of Patent: April 3, 2018
    Assignee: Trimble Inc.
    Inventors: Kent Wayne Kahle, Jinwei Jiang, Christian Graesser, Andreas Winter, Ulrich Vollath
  • Patent number: 9879993
    Abstract: Novel tools and techniques that can be used to enhance the effectiveness of photogrammetric tools, such as bundle adjustment. One set of techniques can include a photo-observable backsight operation, in which a position of target point can be observed non-photographically, and this observed position can be used to constrain a pixel coordinate location of the same target point in a bundle adjustment operation. Using another technique, a photo-observable check shot operation, the observed position of another target point can be used to verify the validity of a bundle adjustment calculation. Such techniques can be used together or separately.
    Type: Grant
    Filed: September 30, 2013
    Date of Patent: January 30, 2018
    Assignee: Trimble Inc.
    Inventors: Chad McFadden, Amit Joshi, Christian Grässer, Troy L. Brown, Shaojun He
  • Patent number: 9874458
    Abstract: The present invention provides a method for calibrating a geodetic instrument, an instrument and a computer program product thereof. In the method and geodetic instrument of the present invention, a value of at least one parameter affecting the measurements made by the instrument is detected and compared with a predetermined threshold. On the basis of the comparison between the detected value and the predetermined threshold, the instrument aims at a reference target and a calibration is performed using the reference target. The present invention is advantageous in that the accuracy and reliability of the measurements performed by the instrument are increased. Further, the present invention is advantageous in that the requirements on mechanical stability are reduced.
    Type: Grant
    Filed: February 13, 2015
    Date of Patent: January 23, 2018
    Assignee: Trimble AB
    Inventor: Christian Grässer
  • Patent number: 9869549
    Abstract: A robotic laser-pointing apparatus has an instrument center, a first rotation axis, a second rotation axis, and a pointing axis, with the first rotation axis, the second rotation axis and the pointing axis in a known relationship to the instrument center. A laser source provides a pointing-laser beam along the pointing axis. A pointing drive system aims the laser beam by rotating the pointing axis about the instrument center in response to a pointing-direction control. Focusing optics having a focusing-optics drive serve to focus the pointing-laser beam in response to a focusing-optics control. A processor, responsive to target-position information, generates the pointing-direction control and the focusing-optics control. Some embodiments include an electronic-distance-measurement system having a measurement beam. Some embodiments provide for compensation of aiming errors of the pointing-laser beam and the measurement beam.
    Type: Grant
    Filed: May 27, 2015
    Date of Patent: January 16, 2018
    Assignee: Trimble AB
    Inventors: Christian Graesser, Robert Miller, Mikael Nordenfelt
  • Patent number: 9863782
    Abstract: The present invention provides a method for calibrating a geodetic instrument, an instrument and a computer program product thereof. In the method and geodetic instrument of the present invention, a value of at least one parameter affecting the measurements made by the instrument is detected and compared with a predetermined threshold. On the basis of the comparison between the detected value and the predetermined threshold, the instrument aims at a reference target and a calibration is performed using the reference target. The present invention is advantageous in that the accuracy and reliability of the measurements performed by the instrument are increased. Further, the present invention is advantageous in that the requirements on mechanical stability are reduced.
    Type: Grant
    Filed: February 4, 2015
    Date of Patent: January 9, 2018
    Assignee: TRIMBLE AB
    Inventor: Christian Grässer
  • Patent number: 9513120
    Abstract: A navigational apparatus includes a visual display, first and second imaging devices, and one or more processors. The first imaging device has an optical axis extending in a first direction and is configured to obtain first image data. The second imaging device has an optical axis extending in a second direction substantially perpendicular to the first direction and is configured to obtain second image data. When the visual display is displaying first image data, the one or more processors are configured to superimpose a first navigational graphic on the visual display overlaid on a portion of the first image data associated with the point of interest. When the visual display is displaying second image data, the one or more processors are configured to superimpose a second navigational graphic on the visual display overlaid on a portion of the second image data associated with the point of interest.
    Type: Grant
    Filed: March 11, 2013
    Date of Patent: December 6, 2016
    Assignee: Trimble Navigation Limited
    Inventors: Graham Briggs, Christian Graesser, James M. Janky
  • Patent number: 9482756
    Abstract: A tracker unit for a measuring instrument such as a total station is disclosed. The tracker unit comprises a first and at least a second optical radiation source arranged at different positions and each of which is noncoaxially arranged with respect to a tracker pointing axis and adapted to emit optical radiation towards the reflective target when activated. The first and the at least a second optical radiation source are arranged at such positions so that the tracker pointing axis and the position of the first optical radiation source define a first plane and the tracker pointing axis and the position of the at least a second optical radiation source define a second plane, such that the first optical radiation source is coaxial with respect to the tracker pointing axis in a plane perpendicular to the first plane and the at least a second optical radiation source is coaxial with respect to the tracker pointing axis in a plane perpendicular to the second plane.
    Type: Grant
    Filed: April 29, 2015
    Date of Patent: November 1, 2016
    Assignee: TRIMBLE AB
    Inventors: Christian Grässer, Suat Köker
  • Patent number: 9322652
    Abstract: A method for determining, in relation to a surveying instrument, target coordinates of a point of interest, or target, identified in two images captured by a camera in the surveying instrument. The method comprises determining coordinates of the surveying instrument, capturing a first image using the camera in the first camera position; identifying, in the first image, an object point associated with the target; measuring first image coordinates of the object point in the first image; rotating the surveying instrument around the horizontal axis and the vertical axis in order to position the camera in a second camera position; capturing a second image using the camera in the second camera position; identifying, in the second image, the object point identified in the first image; measuring second image coordinates of the object point in the second image; and determining the coordinates of the target in relation to the surveying instrument.
    Type: Grant
    Filed: October 24, 2014
    Date of Patent: April 26, 2016
    Assignee: Trimble AB
    Inventors: Nick Mein, Set Svanholm, Christian Graesser, Michael Vogel
  • Publication number: 20150334362
    Abstract: A system for projecting an image, including layout information, on a surface in a building under construction has a projector mounted on a moveable support for supporting a worker at a work position in the building. The projector projects an image on a surface above the moveable support in response to an image signal defining the image to be projected. The image indicates the location of connectors, anchors, and holes to be affixed to, or cut through, the surface. A system determines the two dimensional position of the projector in the building, and a distance measuring system for determines the distance from the projector to said surface. A processor, responsive to a memory having stored building plan images, provides an image signal to the projector adjusted for the two dimensional location of the projector and for the distance from the projector to the surface.
    Type: Application
    Filed: July 23, 2015
    Publication date: November 19, 2015
    Inventors: Kent Wayne Kahle, Jinwei Jiang, Christian Graesser, Andreas Winter, Ulrich Vollath
  • Patent number: 9189858
    Abstract: A method is disclosed for determining coordinates of a target in relation to a surveying instrument wherein a first image is captured using a first camera in a first camera position and orientation, a target is selected by identifying at least one object point in the first image, and first image coordinates of the object point in the first image are measured. In at least one embodiment, a second image is captured using a second camera in a second camera position and orientation, the object point identified in the first image is identified in the second image, and second image coordinates of the object point in the second image are measured. Target coordinates of the target in relation to the rotation center of the surveying instrument are then determined based on the first camera position and orientation, the first image coordinates, the second camera position and orientation, the second image coordinates, and first and second camera calibration data.
    Type: Grant
    Filed: February 29, 2008
    Date of Patent: November 17, 2015
    Assignee: TRIMBLE AB
    Inventors: Set Svanholm, Michael Vogel, Christian Grässer
  • Patent number: 9182229
    Abstract: Novel solutions for position measurement, including without limitation tools and techniques that can be used for land surveying and in similar applications. One such tool is a greatly enhanced position measurement system that takes the form of a surveying rod with substantial independent functionality, which can be used with or without a total station or similar device.
    Type: Grant
    Filed: December 21, 2011
    Date of Patent: November 10, 2015
    Assignee: Trimble Navigation Limited
    Inventors: Christian Grässer, Peter Cornelius Kistler, James Greenberg, Rod Johnson, Magnus Westermark
  • Patent number: 9160140
    Abstract: It is disclosed a method for driving a laser diode such as to enable mitigation or elimination of so called spiking effects related to the number of injected carriers in the laser overshooting the equilibrium value at the beginning of the lasing process. In this manner, among other things, the efficiency of a master oscillator power amplifier that may be utilized in range finding applications will be improved. It is further disclosed an optical pulse transmitter comprising such a laser diode.
    Type: Grant
    Filed: May 27, 2014
    Date of Patent: October 13, 2015
    Assignee: TRIMBLE AB
    Inventors: Yuri P. Gusev, Mikael Hertzman, Evgeny Vanin, Christian Grässer
  • Publication number: 20150276401
    Abstract: A robotic laser-pointing apparatus has an instrument center, a first rotation axis, a second rotation axis, and a pointing axis, with the first rotation axis, the second rotation axis and the pointing axis in a known relationship to the instrument center. A laser source provides a pointing-laser beam along the pointing axis. A pointing drive system aims the laser beam by rotating the pointing axis about the instrument center in response to a pointing-direction control. Focusing optics having a focusing-optics drive serve to focus the pointing-laser beam in response to a focusing-optics control. A processor, responsive to target-position information, generates the pointing-direction control and the focusing-optics control. Some embodiments include an electronic-distance-measurement system having a measurement beam. Some embodiments provide for compensation of aiming errors of the pointing-laser beam and the measurement beam.
    Type: Application
    Filed: May 27, 2015
    Publication date: October 1, 2015
    Inventors: Christian Graesser, Robert Miller, Mikael Nordenfelt
  • Publication number: 20150276402
    Abstract: Novel solutions for position measurement, including without limitation tools and techniques that can be used for land surveying and in similar applications. One such tool is a greatly enhanced position measurement system that takes the form of a surveying rod with substantial independent functionality, which can be used with or without a total station or similar device.
    Type: Application
    Filed: September 30, 2013
    Publication date: October 1, 2015
    Inventors: Christian Grässer, Peter Cornelius Kistler, James Greenberg, Rod Johnson
  • Publication number: 20150268347
    Abstract: A tracker unit for a measuring instrument such as a total station is disclosed. The tracker unit comprises a first and at least a second optical radiation source arranged at different positions and each of which is noncoaxially arranged with respect to a tracker pointing axis and adapted to emit optical radiation towards the reflective target when activated. The first and the at least a second optical radiation source are arranged at such positions so that the tracker pointing axis and the position of the first optical radiation source define a first plane and the tracker pointing axis and the position of the at least a second optical radiation source define a second plane, such that the first optical radiation source is coaxial with respect to the tracker pointing axis in a plane perpendicular to the first plane and the at least a second optical radiation source is coaxial with respect to the tracker pointing axis in a plane perpendicular to the second plane.
    Type: Application
    Filed: April 29, 2015
    Publication date: September 24, 2015
    Inventors: Christian Grässer, Suat Köker
  • Publication number: 20150268043
    Abstract: Novel tools and techniques that can be used to enhance the effectiveness of photogrammetric tools, such as bundle adjustment. One set of techniques can include a photo-observable backsight operation, in which a position of target point can be observed non-photographically, and this observed position can be used to constrain a pixel coordinate location of the same target point in a bundle adjustment operation. Using another technique, a photo-observable check shot operation, the observed position of another target point can be used to verify the validity of a bundle adjustment calculation. Such techniques can be used together or separately.
    Type: Application
    Filed: September 30, 2013
    Publication date: September 24, 2015
    Inventors: Chad McFadden, Amit Joshi, Christian Grässer, Troy L. Brown, Shaojun He
  • Patent number: 9134127
    Abstract: A method of determining a tilt angle and a tilt direction of a survey instrument. The survey instrument has an imaging device that captures first images at a first location. The first images include features from an environment around the survey instrument. The imaging device also captures second images at a second location. The second images include a portion of the features. A pose of the imaging device is determined at the second location using observed changes in location of a common portion of the features between the first images and the second images. The tilt angle and the tilt direction of the survey instrument at the second location are determined using the pose of the imaging device.
    Type: Grant
    Filed: February 4, 2014
    Date of Patent: September 15, 2015
    Assignee: Trimble Navigation Limited
    Inventors: Omar Pierre Soubra, James M. Janky, Christian Graesser, Shawn D. Weisenburger
  • Patent number: 9121692
    Abstract: A system for projecting an image, including layout information, on a surface in a building under construction has a projector mounted on a moveable support for supporting a worker at a work position in the building. The projector projects an image on a surface above the moveable support in response to an image signal defining the image to be projected. The image indicates the location of connectors, anchors, and holes to be affixed to, or cut through, the surface. A system determines the two dimensional position of the projector in the building, and a distance measuring system for determines the distance from the projector to said surface. A processor, responsive to a memory having stored building plan images, provides an image signal to the projector adjusted for the two dimensional location of the projector and for the distance from the projector to the surface.
    Type: Grant
    Filed: March 13, 2013
    Date of Patent: September 1, 2015
    Assignee: Trimble Navigation Limited
    Inventors: Kent Wayne Kahle, Jinwei Jiang, Christian Graesser, Andreas Winter, Ulrich Vollath