Hexagon Technology Center Gmbh

Leica Geosystems Ag

Tesa Sa

Bernhard Sprenger

Claudio Iseli

Knut Siercks

Bo Pettersson

Pascal Jordil

Benjamin Vullioud

Alberto Tarizzo

Silvan Meile

Julien Chardonnens

Paolo Mastrapasqua

A computer program product for numerically correcting an endpoint position of a Coordinate Measuring Machine (CMM) implemented on a computing unit, receiving as input temporally resolved information from a set of sensors attached to or integrated into the CMM, and to a method for numerically correcting an endpoint position of a CMM, wherein errors between a targeted endpoint position and an actual endpoint position reached during a measurement process are numerically compensated through the use of the computer program product.

Dynamical modeling of CMMs for numerically correcting measurement results

A method of compensating errors in a coordinate measuring machine adapted for determination of at least one spatial coordinate of a measurement point on an object to be measured. The method comprises measuring a distance from the first reference element to the first structural component, wherein the measured distance indicates a displacement or a deformation of the first structural component, defining a dynamic model with a first set of state variables, the state variables being related to a set of physical properties of the reference module and representing an actual state of the reference module, deriving the actual state of the reference module by a calculation based on the dynamic model, and deducing compensation parameters based on the actual state.

Error compensation for coordinate measuring machines using a reference module

Method for providing avoiding of excitations of oscillations of a measuring machine and/or for reducing or damping such oscillations by actively controlling a driving unit of the measuring machine or actively controlling an actuation of an additionally attached actuator. The method using information about an actual state of the measuring device, the actual state is derived based on a dynamic model and/or by use of a suitable sensor unit. A state controller, an actuator or a frequency-filtering element are used for counteracting or preventing oscillations.

Active damping of a measuring device

A hexapod CMM or hexapod-like CMM has a base structure and a movable structure connected to each other by at least three telescopically extendable legs via spherical joints. Each of the telescopically extendable legs comprises a linear first member and a linear second member having countersliding surfaces and are designed in such a way that allows a relative, linear movement of the first linear member and the second linear member. Further each of the telescopically extendable legs has an air cushioning mechanism, which comprises at least one air supply system connected to at least one source of compressed air and having at least one air escape. The air escape is arranged in such a way that compressed air escaping the air escape flows into a gap between the countersliding surfaces of the at least two linear members of the leg cushioning the two linear members against each other.

Non-cartesian hexapod or hexapod-like coordinate measuring machine

An inclinable measuring head for use in a coordinate measuring machine or in another measure system. The inclinable head has a support element and a probe holder rotatably linked to the support element by a spherical joint that is capable of being rotated about three independent axes. The measuring head further includes a position encoder providing relative orientation of the probe holder with respect to the support element, and an actuator arranged for orienting the probe holder relative to the support element.

Motorized orientable head for measuring system

A coordinate measuring machine (CMM) having a belt drive unit for an elongated axis element of the CMM, the belt drive unit comprising a belt, the ends of which are clamped on the elongated axis element, a pulley unit, comprising a drive pulley and two idler pulleys, wherein the belt entangles the drive pulley and the idle pulleys in an omega-shaped manner, and wherein the pulley unit is configured to cause a relative linear movement between the axis element and the pulley unit, wherein a damping layer is disposed adjacent to the belt.

Coordinate measuring machine with an improved belt drive

A method for providing static and dynamic position information of a designated point of a measuring device having a surface and a structure that includes the designated point and being arranged moveable relatively to the surface. The method includes defining a model for representing an actual position of the designated point relative to the surface and deriving the actual position of the designated point by a calculation based on the defined model. At least two cells are used to model the structure. The at least two cells are linearly arranged in a linear extension direction. At least one of the cells is a variable cell of a set of at least one variable cell and exhibits variable elongation as to the extension direction. An actual elongation of the at least one variable cell is set to model a positional change, particularly in linear extension direction, of the designated point.

Variable modelling of a measuring device

Embodiments of the invention include a method for compensating a force at a probe element of a probing unit. The probing unit being attached to and moved along a defined moving path with a number of moving points by a coordinate measuring machine for approaching a measuring point at an object. The probing unit comprises an actuator which is arranged and designed in such manner that a force is applicable to the probe element with respect to at least one actuating direction in variable and defined manner, the force depending on an applied actuating signal. Movement information about an expected movement of the probing unit is received, the movement information provides information about an expected displacement behaviour of the probe element relative to the probing unit due to induced forces emerging by moving the probing unit.

Method of actively counteracting displacement forces with a probing unit

A method for providing dynamic state information for a coordinate measuring machine that includes a base, a probe head, a machine structure linking the probe head to the base and a drive mechanism that moves the probe head. A dynamic model with first state variables represents an actual state of physical properties of the coordinate measuring machine. The first state variables are provided in a database and the actual state of the coordinate measuring machine is determined using the dynamic model. The state variables are monitored and, based thereon, the change of the state variables is determined. Updated, second state variables are set regarding the determined change of the first state variables. The dynamic model is updated using the second state variables in place of the first state variables, wherein the actual state of the coordinate measuring machine is calculated based on the second state variables.

Dynamical monitoring and modelling of a coordinate measuring machine

A method for providing dynamic state information for a coordinate measuring machine that includes a base, a probe head, a machine structure with structural components linking the probe head to the base and a drive mechanism that moves the probe head relative to the base. A dynamic model is defined with actual state variables related to physical properties representing an actual state of the coordinate measuring machine. The actual state is derived by a calculation based on the dynamic model. A filtering process using the dynamic model includes deriving prediction variables based on the state variables that describe an expected proximate state of the coordinate measuring machine, measuring at least one of the state variables and determining observables, deriving successive state variables by comparing the prediction variables with the observables and updating the dynamic model using the successive state variables as the actual state variables.

Dynamical monitoring of a coordinate measuring machine using recursive filtering

A laser scanner measures a surface of spaces and/or objects and produces a point cloud representing the surface. The laser scanner includes a laser source for producing laser light, a detector for receiving the laser light, and a platform that pivots relative to a stationary base of the laser scanner. The laser light is directed to a particular point on the surface through an outlet point. Laser light scattered at the particular point is received through an inlet point on the platform. A distance to the particular point is determined using laser light scattered and received by the detector. A direction to the particular point is detected using, for example, one or more sensors for determining a pivot position of the platform relative to the base. A parallel kinematic drive pivots the platform relative to the base to scan the laser beam over points of the surface.

Laser scanner having means for capturing a spatial direction to the point on a surface

A coordinate measurement machine with a first frame element, a second frame element, a linear drive unit with a motor for moving the second frame element relative to the first frame element and a position measurement instrument, for determining a drive position of the second frame element relative to the first frame element. The drive unit has limited stiffness and dynamic deflections on movement. The machine comprises a mechanical coupler from the drive unit to the second frame element, which coupler comprises a first part fixed to the drive unit and a second part fixed to the second frame element, which parts are movable relative to each other by an active compensation actuator. The active compensation actuator is built in such a way to shift the second frame element against the drive unit to introduce a counter-displacement in such a way that the dynamic deflections are at least partially compensated.

Coordinate measuring machine

To determine the positions of a code on a movable support, said support can be moved in a displacement direction relative to a sensor element comprising at least one sensor array in the vicinity of said array. The sensor array or arrays determine(s) the position of imaged code elements that can be differentiated from radiation in the vicinity of the sensor elements, the recorded values being read out in at least one read-out direction and positional values being determined from said values. The array or arrays is or are read out twice from opposite read-out directions, or one sensor pair consisting of two sensor arrays, is read out as a pair from opposite directions. Positional values are derived from the positions of the differentiated code elements and said values are averaged to provide a position with an improved accuracy. The accuracy can thus be increased by simple means.

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Widnau, Switzerland

Bernhard Sprenger