Articulated arm CMM

Patent metadata

Field	Value
Publication number	US-9541371-B2
Application number	US-201314406718-A
Country	US
Kind code	B2
Filing date	Jun 20, 2013
Priority date	Jun 22, 2012
Publication date	Jan 10, 2017
Grant date	Jan 10, 2017

Abstract

The invention relates to an articulated arm CMM, which is constructed in a modular way, and a modular assembling kit for constructing such an articulated arm CMM, comprising an articulated arm having a first end and a second end, wherein the second end is configured to support a tool. The articulated arm comprises at least two arm sections, connected to one another by pivot joints with integrated angle encoders. The arm sections are configured as modules having a PCB unit, said PCB unit comprises an elongated PCB section element and at least one PCB encoder element. The PCB encoder elements are configured to build an angle encoder and the PCB section elements comprise electronic transmission means for transmitting the encoder signals from the PCB encoder elements toward a circuit deriving the relative position between the arm sections.

First claim

What is claimed is:

1. An articulated arm comprising:
a first end and a second end, the second end configured to support a tool;
at least two longitudinal extending arm sections between the first end and the second end, wherein each pair of adjacent arm sections is connected with each other by a pivot joint having an integrated angle encoder generating encoder signals indicating the relative position of the arm sections; and
electronic transmission means for transmitting encoder signals from the angle encoders towards a circuit configured to derive at least the relative position between the adjacent arm sections from the encoder signals and to a reference point or reference coordinate system;
wherein the articulated arm coordinate measuring machine is a modular construction, wherein the arm sections are configured as arm section modules having a printed circuit board unit, said printed circuit board unit elongated printed circuit board section element printed circuit board encoder element end of the elongated printed circuit board section comprises an and at least one connected to one element;
wherein the printed circuit board encoder elements of adjacent arm sections are arranged face to face and pivotable against each other around a common axis, so that they form an angle encoder; and
wherein the printed circuit board section elements comprise the electronic transmission means for transmitting the encoder signals from the printed circuit board encoder elements toward the circuit.

2. The articulated arm according to claim 1 , further comprising sensor systems and electronic equipment, wherein the sensor systems is integrated in angle encoders and/or linear position encoders to measure eccentricity, wobbling, lateral and/or radial displacements.

3. The articulated arm according to claim 1 , wherein the elongated printed circuit board elements comprising a first end provided with a sending unit and an opposite second end provided with a corresponding receiving unit, wherein transmission of the encoder signals from one printed circuit board unit to an adjacent printed circuit board unit is achieved from the sending unit to the adjacent receiving unit by wires or by radio means or optical means or by inductive or capacitive coupling.

4. The articulated arm according to claim 1 ,
wherein the printed circuit board units comprise a first printed circuit board encoder element connected to one end of the elongated printed circuit board section element and provided with a pattern and/or a second printed circuit board encoder element connected to an opposite end of the elongated printed circuit board section element and provided with corresponding pattern recognition means;
wherein an angle encoder comprises a first printed circuit board encoder element arranged face to face with a second printed circuit board encoder element; and
wherein the angle encoder is configured as a capacitive system.

5. The articulated arm according to claim 1 , further comprising arm section modules, wherein the printed circuit board section element and the at least one printed circuit board encoder element of a printed circuit board unit have the same deformation characteristic, wherein the printed circuit board section element and the printed circuit board encoder element are preferably formed as a one piece printed circuit board unit.

6. The articulated arm according to claim 1 , further comprising arm section modules, wherein at least one printed circuit board encoder element is connected to the elongated printed circuit board section element by means of a flexible printed circuit board connecting element, said printed circuit board connecting element having a higher deformability than the connected printed circuit board elements.

7. The articulated arm according to claim 1 , wherein the elongated printed circuit board section elements of the printed circuit board units are configured stiff enough to support the tool and to build self-supporting arm sections and/or the printed circuit board encoder elements are built stiff enough to build pivot joints, wherein the stiffness is achieved by a reinforcement structure.

8. The articulated arm according to claim 7 , wherein the reinforcement structure comprising at least one element of the group comprising: carbon fibers, layers of carbon fiber reinforced plastics, layers of aluminum and/or aluminum-alloys and laminates of those layers.

9. The articulated arm according to claim 1 , further comprising arm section modules having an inner supporting structure, wherein the inner supporting structure comprising longitudinal extending frame elements supporting the elongated printed circuit board section elements of the printed circuit board units and/or disk like carrier elements supporting the printed circuit board encoder elements of the printed circuit board units.

10. The articulated arm according to claim 9 , wherein the longitudinal extending frame elements are longitudinal extending bodies or longitudinal extending hollow bodies or hollow tubes and the carrier elements are shaped as circles or annuli.

11. The articulated arm according to claim 9 , wherein the supporting structure are formed from at least one of the materials out of the group of: aluminum or light metal alloys, honeycomb structured metals or metal alloys, honeycomb structured plastics, plastic foams, carbon fiber, fiber reinforced plastics, honeycomb structured fiber reinforced plastics, fiber reinforced plastic foams, fiber reinforced metals and metal alloys.

12. The articulated arm according to claim 9 , wherein the printed circuit board units, printed circuit board section elements and/or printed circuit board encoder elements are fixed onto their supporting structure by gluing or welding, wherein the printed circuit board units, printed circuit board section elements and/or printed circuit board encoder elements have a deformation characteristic that allows them to clone the shape of their supporting structure when they are fixed on it.

13. The articulated arm according to claim 9 , wherein it comprises arm sections built by arm section modules comprising a first frame element supporting a printed circuit board unit and a second frame element supporting a printed circuit board unit, which second inner frame element is formed as a hollow body adopted to accommodate the first frame element, and wherein the two frame elements are supported relative to each other by cage bearings or roller bearings in a way that they can be moved relative to one another in a telescopic way and wherein the telescopic lateral movement is detected by a printed circuit board linear position encoder.

14. The articulated arm according to claim 9 , wherein a first frame element is configured in form of an elongated cylinder or a tube with an outer diameter and a second frame element formed as a tube with an inner diameter, said inner diameter of the second frame element is larger than the outer diameter of the first frame element and the first frame element is inserted into the second frame element, wherein the two frame elements are supported laterally movable against each other and/or rotative movable against each other by ball bearings.

15. The articulated arm according to claim 1 , wherein the printed circuit board elements include electronics configured to perform at least one of the following tasks:
generation of the excitation signals for the integrated angle encoders;
decoding of the received signals of the integrated angle encoders;
storage of calibration information of the encoders;
transmission of the trigger signal for the synchronization of the pos

Assignees

• Hexagon Technology Ct Gmbh

Inventors

• Pettersson Bo
• Jordil Pascal

Classifications

• G01B5/008

  using coordinate measuring machines · CPC title

• G01B7/008 Primary

  using coordinate measuring machines · CPC title

• G01D5/241 Primary

  by relative movement of capacitor electrodes · CPC title

• B25J18/00

  Arms · CPC title

• G01B21/045

  Correction of measurements (G01B9/02055 takes precedence) · CPC title