Trimble Ab

Trimble Navigation Limited

Magnus Westermark

Mikael Hertzman

Thomas Klang

Ulf Berg

Christian Grässer

Set Svanholm

Mikael Nordenfelt

Peter Cornelius Kistler

Gerard Scanlon

James Neil Greenberg

Georgios Gatsios

Robin Grieves

Rod Johnson

Staffan Palm

Embodiments provide for a geodetic assembly () for land surveying. The geodetic assembly () may include a first element () including a first magnetic unit () and a second element () including a second magnetic unit (). The second element may be part of a support structure () of the geodetic assembly and is adapted to mate with the first element for supporting a geodetic device (), the first element being attached to the geodetic device (or vice versa). The second magnetic unit is arranged to interact with the first magnetic unit for locking or unlocking the first element on the support structure. Each of the first magnetic unit and the second magnetic unit is divided in a plurality of regions (--) arranged in a circular manner such that two adjacent regions have magnetic poles of opposite polarities. The geodetic assembly may further comprise at least one magnetic shield () for shielding the geodetic device, or a magnetically sensitive device () arranged at the support structure, from the first magnetic unit and the second magnetic unit.

Geodetic assembly with magnetic attaching arrangement

The present disclosure provides a geodetic instrument () adapted to determine a direction and/or a distance to a target. The geodetic instrument includes an attachment device () for attaching the geodetic instrument to a holding arrangement (); a motorized position arrangement for aiming a line of sight (L) of the geodetic instrument via rotation and/or translation of at least a part of the motorized position arrangement relative to the holding arrangement, and a controller (). The controller is configured to, upon determining that a setting up of the geodetic instrument is required, provide a control sequence to the motorized positioning arrangement for causing a series of oscillatory rotational and/or translational movements of the at least a part of the motorized positioning arrangement. A method of setting up a geodetic instrument is also provided.

Geodetic instrument with reduced drift

Geodetic instrument

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.

Enhanced position measurement systems and methods

A method for a measuring instrument is disclosed, for separating the angular deviation of a rotational axis of an instrument body from a corresponding true rotational axis due to imperfections in at least one rolling-element bearing effectuating the rotational mounting of the instrument body into different parts corresponding to type of imperfection. The method comprises detecting rotary position of the at least one rolling-element bearing, and determining angular deviation of the rotational axis from the corresponding true rotational axis in a plurality of rotational positions of the instrument body, wherein the instrument body is rotated a plurality of successive full or partial revolutions about the rotational axis. There is also disclosed a measuring system and a measuring instrument to be used in such a measuring system.

Method for a measuring instrument

A winding for an n-phase electric motor is disclosed. The inventive winding comprises a number of consecutive winding groups of n individual windings, wherein at any point in time an individual winding of a first group exhibits one direction of current flow and wherein at the same point in time a corresponding individual winding of an adjacent group exhibits the opposite direction of current flow. There is also disclosed a method for preparing such winding. It is further disclosed a magnetic unit adapted for such winding, comprising permanent magnets being essentially triangular in cross-section. Further, there is disclosed electric motors using the inventive winding concept, as well as geodetic instruments taking advantage thereof. An electric motor according to the disclosed inventive concept is particularly well suited for direct drive.

Electric motor

A position-determining apparatus, such as measuring or surveying instruments, is disclosed. In at least one embodiment, the present invention relates to a tilt sensor for a measuring instrument including a movable housing that is controllably rotatable around a rotational axis, wherein the rotational axis may be positioned so that it deviates from a true vertical axis being parallel with a gravitational axis. In at least one embodiment, the tilt sensor includes a gravity sensitive gradient indicating element arranged such that a surface of the element is positioned orthogonally to the true vertical axis during movements of the measuring instrument, wherein the gravity sensitive gradient indicating element is arranged in connection to the non-rotating base; and a detecting device adapted to produce at least one detecting signal and to receive at least one response signal, wherein a deviation between the rotational axis and the true vertical axis is detectable using the at least one response signal.

Tilt sensor for a measuring instrument

A geodetic instrument is disclosed, wherein an image sensor is used for locating the instrument above a desired point on the ground. The positioning of the image sensor with respect to the instrument vertical rotation axis is determined, or calibrated, using a method where two images are captured at different horizontal rotational positions for the instrument, and where the center pixel of the image sensor is related to the vertical rotation axis by means of image processing. It is also disclosed how reflecting elements, such as prisms, may be used for providing stereoscopic vision that can be used for determining the instrument height above the ground.

Geodetic instrument and related method

In a position control arrangement for controlling the rotational position of a movable unit, especially for a surveying instrument, an electric motor is arranged to rotate the movable unit around an axis of rotation, and there are controllers for enabling the motor to stop the movable unit in a desired rotational position. The motor is a direct drive motor, the shaft of which forms the axis of rotation for the movable unit, and the motor is arranged to selectively operate in either a first, normal mode for rotating the movable unit to a desired position, or in a second, friction mode for providing resistance to a forced rotation of the movable unit from a predetermined position to a new position. A control unit detects the presence of a forced rotation and automatically changes the mode of operation in response thereto.

Position control arrangement, especially for a surveying instrument, and a surveying instrument

An absolute optical encoder apparatus for measuring an absolute position comprises an optical disk or scale element () having both incremental and absolute code tracks formed thereon. In the embodiment, a photoemitter light source () illuminates the tracks onto a CCD area array sensor () such that an image is formed from a pixel matrix having of rows and columns. Two detector line rows () of the pixel matrix are each read out from the portion of the matrix comprising the incremental and absolute code tracks respectively. Inaccurate mounting of the disk or scale element can cause fluctuations in the period of the code tracks resulting from the rotation of the disk or movement of the scale element. The mounting inaccuracies are compensated for either by matching the spatial frequency by dynamically changing row of detector line read from the incremental image of the code track or by altering the numerical value of the pattern period used in the Fourier phase algorithm. The absolute position is numerically calculated from the imaged code tracks.

Growing community of inventors

Ekerö, Sweden

Magnus Westermark