Trimble Ab

Thomas Klang

Mikael Hertzman

Magnus Westermark

Mikael Nordenfelt

Ulf Berg

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

The present invention relates to a measuring instrument and methods for such a measuring instrument for tracking a moving object, measuring a distance to an object. According to the invention, sets of target position data including at least horizontal (Ha) and vertical angle (Va) between the measuring instrument () and said at least one target () in consecutive measurements during a measurement session are obtained (); a model describing a path of and/or a distance to the target () is calculated; at least a present position of the target is estimated () using the model; and, the estimated position of the target () is used () when searching for the target ().

Methods and instruments for estimating target motion

There is disclosed methods and apparatus for compensated measurement of angular displacement within an instrument (), such as a total station. Improved and compensated measurement of angular displacement is obtained by using a combination of e.g. an angular resolver () and an inertial sensor (). A compensated angular position measurement is produced by combining at least portions of the output signals obtained from the angular resolver and the inertial sensor, respectively.

Compensated measurement of angular displacement

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

A surveying instrument and method determine a duration of a measuring period for obtaining readings of angle values of an angle measuring system in dependence of readings of an error signal produced by a tracking system. It is thus possible to determine a value of the angle represented by the readings of the angle signal with a desired accuracy in the presence of air turbulence wherein the measuring period is shorter at low degrees of air turbulence and longer at higher degrees of air turbulence.

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Sollentuna, Sweden

Thomas Klang