DE112013002892T5 - Coordinate measuring machines with removable accessories - Google Patents

Abstract

A portable articulated arm coordinate measuring machine is provided for measuring the coordinates of an object in space. The articulated arm CMM includes a base and an arm portion having opposite first and second ends. The arm portion includes a plurality of connected arm segments, each arm segment comprising at least one position measuring device for generating a position signal. An electronic circuit is provided which receives the position signal of the at least one position measuring device. A probe element is coupled to the first end. A non-contact measuring device is coupled to the probe element, the device comprising a transmitter of electromagnetic radiation and configured to determine a distance to an object based at least in part on the propagation time of the emitted and reflected light beams.

Description

background

The present disclosure relates to a coordinate measuring machine, and more particularly, to a portable articulated arm coordinate measuring machine having a connector on a probe element of the CMM that allows coupling of auxiliary devices that determine a distance based at least in part on the propagation time of the emitted and reflected light beams.

Portable articulated arm CMMs have found widespread use in the manufacture of parts where there is a need to increase the dimensions of the part during various steps in the fabrication (eg, machining) of the part Partly fast and accurate Verify. Portable articulated arm CMM's represent a significant improvement over known fixed, costly, and relatively difficult to use gauges, especially in terms of the time required to perform dimensional measurements of relatively complex parts. Normally, an operator of a portable articulated arm CMM simply inserts a probe along the surface of the part or object to be measured. The measurement data is then recorded and provided to the operator. In some cases, the data is provided to the operator in an optical form, such as in three-dimensional (3-D) form on a computer screen. In other cases, the data is provided to the operator in numerical form, for example, when measuring the diameter of a hole, the text "diameter = 1.0034" is displayed on a computer screen.

An example of a prior art portable articulated arm CMM will be described in U.S. Patent No. 5,348,054 U.S. Patent No. 5,402,582 ('582) of the same assignee. The '582 patent discloses a 3-D measuring system comprising a manually operated articulated arm CMM with a support base at one end and a probe at the other end. The U.S. Patent No. 5,611,147 ('147) of the same assignee discloses a similar articulated arm CMM. In the '147 patent, the articulated arm CMM includes several features including an additional pivot on the probe element providing a two-two-two or two-two-three axis configuration for one arm (the latter being a seven-axis arm). ,

Three-dimensional surfaces can also be measured by contactless methods. One type of non-contact device, sometimes referred to as a "laser line probe", emits laser light either at a point or along a line. An imaging device such as a charge-coupled device (CCD) is positioned adjacent to the laser to capture an image of the light reflected from the surface. The surface of the object to be measured causes a diffuse reflection. The image on the sensor changes as the distance between the sensor and the surface changes. If the relationship between the imaging sensor and the laser and the position of the laser image on the sensor is known, triangulation techniques can be used to measure points on the surface.

Although existing CMMs are suitable for their intended purposes, there is a need for a portable articulated arm CMM incorporating certain features of embodiments of the present invention.

Summary of the invention

According to one aspect of the invention, there is provided a portable articulated arm coordinate measuring machine (articulated arm CMM) for measuring three-dimensional coordinates of an object in space. The articulated arm CMM includes a pedestal. There is provided a manually positionable arm portion having opposite first and second ends rotatably coupled to the base. The arm portion includes a plurality of connected arm segments, each arm segment comprising at least one position measuring device for generating a position signal. An electronic circuit is provided which receives the position signal of the at least one position measuring device. A probe element is coupled to the first end. A contactless three-dimensional measuring device is coupled to the probe element, wherein the contactless three-dimensional measuring device has a transmitter configured for emitting at least one measuring beam of electromagnetic radiation and a receiver configured to receive at least one reflected beam. The non-contact measuring device has a mirror, which is arranged for reflecting both the at least one measuring beam and the at least one reflected beam. The contactless three-dimensional measuring device further comprises a control device configured to determine a distance to the object based at least in part on a combined propagation time of the at least one measurement beam and the at least one reflected beam and on the speed of light in air. A processor is electrically coupled to the electronic circuit, the processor configured to obtain the three-dimensional coordinates of a point on the object in response to receipt of position signals from the position encoders and in response to receipt, from the controller, of determining the measured distance.

According to one aspect of the invention, there is provided a method of operating a portable articulated arm coordinate measuring machine for measuring three-dimensional coordinates of an object in space. The method includes providing a manually positionable arm portion having opposite first and second ends, the arm portion including a plurality of connected arm segments, each arm segment comprising at least one position gauge for generating a position signal. The position signals are received at an electronic circuit from the position measuring devices. A three-dimensional measuring device is electrically coupled to the electronic circuit, wherein the three-dimensional measuring device comprises a transmitter of electromagnetic radiation, a sensor and a movable first mirror. The first mirror is moved. A measuring beam of electromagnetic radiation is allowed to reflect on the object with the first mirror. A reflected beam of electromagnetic radiation is collected by the first mirror and relayed to the sensor. A distance to the object from the reflected beam of electromagnetic radiation received by the sensor and based at least in part on a combined propagation time of the measurement beam and the reflected beam and on the speed of light in air is determined. The three-dimensional coordinates of a point on the object are determined based at least in part on the determined distance and the position signals.

According to another aspect of the invention, there is provided a portable articulated arm coordinate measuring machine (articulated arm CMM) for measuring three-dimensional coordinates of an object in space. The articulated arm CMM has a pedestal. A manually positionable arm portion having opposite first and second ends is rotatably coupled to the base. The arm portion includes a plurality of connected arm segments, each arm segment comprising at least one position measuring device for generating a position signal. An electronic circuit receives the position signal of the at least one position measuring device. A contactless three-dimensional measuring device is removably coupled to the arm portion, wherein the non-contact three-dimensional measuring device comprises a light source and an optical receiver; Further, a mirror is disposed so as to reflect a first light beam emitted from the light source and to reflect a second light beam reflected from the object. The contactless three-dimensional measuring device is configured to determine a distance to the object based at least in part on a combined propagation time of the first light beam and the second light beam and on the speed of light in air. A processor is electrically coupled to the electronic circuit, the processor configured to determine the three-dimensional coordinates of a point on the object in response to receiving the position signals of the position encoders and in response to receiving the measured distance.

Brief description of the drawings

Referring now to the drawings, exemplary embodiments are shown that are not to be construed as limiting the entire scope of the disclosure, and wherein the elements in several figures are numbered alike. Show it:

1 : including 1A and 1B perspective views of a portable articulated arm coordinate measuring machine (articulated arm CMM) having embodiments of various aspects of the present invention therein;

2 : including 2A - 2D taken together, a block diagram of the electronics used as part of the articulated arm CMM of 1 is used according to an embodiment;

3 : including 3A and 3B taken together, a block diagram showing the detailed features of the electronic data processing system of 2 according to one embodiment;

4 : an isometric view of the probe element of the articulated arm CMM of 1 ;

5 : a side view of the probe element of 4 with the handle coupled thereto;

6 : a side view of the probe element of 4 with the handle attached thereto;

7 FIG. 2: an enlarged partial side view of the connection point section of the probe element of FIG 6 ;

8th FIG. 4: another enlarged partial side view of the terminal portion of the probe element of FIG 5 ;

9 an isometric view, partially in cross section, of the handle of 4 ;

10 FIG. 2 is a schematic illustration of a contactless distance measuring device attached to the Probe element of the articulated arm CMM of 1 is attached;

11 FIG. 2: a side view of the contactless distance measuring device of FIG 10 according to an embodiment of the invention;

12 : A perspective view of the contactless distance measuring device of 11 ;

13 Another perspective view of the contactless distance measuring device of 11 ;

14 a schematic representation of a contactless distance measuring device with a Galvo mirror assembly according to an embodiment of the invention; and

15 : A schematic representation of a contactless distance measuring device with a mirror with microelectromechanical system (MEMS mirror) according to an embodiment of the invention.

Detailed description

Portable articulated arm CMMs are used in a variety of applications to obtain measurements of objects. Embodiments of the present invention provide advantages in allowing an operator to easily and quickly couple auxiliary devices to a probe element of the articulated arm CMM, which utilize projected light to provide contactless measurement of a three-dimensional object. Embodiments of the present invention provide further advantages by providing the communication of data representing a distance to an object measured by the attachment. Embodiments of the present invention provide still further benefits by providing power and data communication to a removable accessory without external connections or wiring.

1A and 1B illustrate in perspective an articulated arm CMM 100 according to various embodiments of the present invention, wherein an articulated arm is a type of coordinate measuring machine. 1A and 1B show that the exemplary articulated arm CMM 100 a joint measuring device with six or seven axes with a probe element 401 ( 4 ), which is a probe housing 102 comprising, at one end to an arm portion 104 the articulated arm CMM 100 is coupled. The arm section 104 includes a first arm segment 106 that through a first grouping of bearing inserts 110 (eg two bearing inserts) to a second arm segment 108 is coupled. A second grouping of bearing inserts 112 (eg two bearing inserts) couples the second arm segment 108 to the probe housing 102 , A third group of bearing inserts 114 (eg three bearing inserts) couples the first arm segment 106 to a pedestal 116 at the other end of the arm section 104 the articulated arm CMM 100 is arranged. Each grouping of bearing inserts 110 . 112 . 114 provides multiple axes of articulation. The probe element 401 can also be a probe housing 102 comprising the shaft of a pivot for the articulated arm CMM 100 includes (eg, an insert containing an encoder system that controls the movement of the measuring device, such as a probe 118 , in an axis of rotation for the articulated arm CMM 100 determined). The probe element 401 can rotate in this embodiment about an axis extending through the center of the probe housing 102 extends. The base 116 is when using the articulated arm CMM 100 usually attached to a work surface.

Each bearing insert in each bearing insert grouping 110 . 112 . 114 typically includes an encoder system (eg, an optical angle encoder system). The encoder system (ie, a position gauge) provides an indication of the position of the respective arm segments 106 . 108 and the corresponding warehouse operations groupings 110 . 112 . 114 ready, all together giving an indication of the position of the probe 118 in terms of the socket 116 (and thus the position of the through the articulated arm CMM 100 measured object in a given frame of reference, for example, a local or global frame of reference). The arm segments 106 . 108 may be made of a suitably rigid material, such as, but not limited to, a carbon fiber composite material. A portable articulated arm CMM 100 having six or seven axes of articulation (ie degrees of freedom) provides the benefits of allowing the operator to probe 118 at a desired location in a 360 ° area around the pedestal 116 to position, with an arm section 104 is provided, which can be easily handled by the operator. It is understood, however, that the representation of an arm section 104 with two arm segments 106 . 108 as an example and that the claimed invention should not be limited thereby. An articulated arm CMM 100 may comprise any number of arm segments coupled together by bearing inserts (and thus more or fewer than six or seven axes of articulation or degrees of freedom).

The probe 118 is removable on the probe housing 102 attached, which with the bearing insert grouping 112 connected is. A handle 126 is in relation to the probe housing 102 for example, removable by means of a quick connector connection point. As will be discussed in more detail below, the handle 126 be replaced by another device configured to provide contactless distance measurement of an object, thereby providing benefits by providing the operator with both contact measurements and non-contact measurements with the same articulated arm CMM 100 be enabled. The probe 118 In exemplary embodiments, a contact measuring device is removable. The probe 118 can be different tips 118 which physically contact the object to be measured and include, but are not limited to: ball-type probes, touch-sensitive, bent and elongated. In other embodiments, the measurement is performed, for example, by a non-contact device such as a laser scanner device. The handle 126 is replaced in one embodiment by the laser scanner device, wherein the quick connector connection point is used. Other types of measuring devices may have the removable handle 126 replace to provide additional functionality. The examples of such measuring devices include, but are not limited to, e.g. B. one or more illumination lamps, a temperature sensor, a thermal scanner, a bar code scanner, a projector, a paint spray gun, a camera or the like.

In 1A and 1B it can be seen that the articulated arm CMM 100 the removable handle 126 which provides the advantages that additional parts or functionalities can be replaced without the probe housing 102 from the warehouse operations grouping 112 Will get removed. As based on 2 can be discussed in more detail, the removable handle 126 Also include an electrical connector that allows electrical energy and data to be handled 126 and in the probe element 401 arranged to be replaced corresponding electronics.

In various embodiments, each grouping of bearing inserts 110 . 112 . 114 in that the arm section 104 the articulated arm CMM 100 is moved around several axes of rotation. As already mentioned, each storage unit grouping comprises 110 . 112 . 114 corresponding encoder systems such as optical angle encoders, each coaxial with the corresponding axis of rotation z. B. the arm segments 106 . 108 are arranged. The optical encoder system detects a rotational movement (pivotal movement) or transverse movement (joint movement) of, for example, each of the arm segments 106 . 108 about the corresponding axis and transmits a signal to an electronic data processing system in the articulated arm CMM 100 , as described in more detail below. Each single unprocessed encoder count is sent separately as a signal to the electronic data processing system where it is further processed into measurement data. It is not one of the articulated arm CMM 100 even separate position calculator (eg, a serial box) required in the U.S. Patent No. 5,402,582 ('582) of the same assignee.

The base 116 may be a fastening or mounting device 120 include. The mounting device 120 allows removable mounting of the articulated arm CMM 100 at a desired location such as an inspection table, a machining center, a wall or the floor. The base 116 in one embodiment comprises a handle portion 122 , which is a convenient location where the operator can access the pedestal 116 stops while the articulated arm CMM 100 is moved. In one embodiment, the socket comprises 116 Further, a movable cover portion 124 which is foldable to release a user interface such as a display screen.

According to one embodiment, the socket contains or accommodates 116 portable articulated arm CMM 100 an electronic circuit comprising an electronic data processing system comprising two main components: a basic processing system which stores the data of the various encoder systems in the articulated arm CMM 100 and processing data representing other arm parameters to support the three-dimensional (3-D) position calculations; and a user interface processing system that includes an integrated operating system, a touch-sensitive screen, and resident application software that facilitates the implementation of relatively complete metrology functions within the articulated arm CMM 100 without having to be connected to an external computer.

The electronic data processing system in the socket 116 Can with the encoder systems, sensors and other peripheral hardware, which are removed from the socket 116 is arranged (for example, a contactless distance measuring device, which on the removable handle 126 on the articulated arm CMM 100 can be mounted), communicate. The electronics that support these peripheral hardware devices or features can be found in any of the portable articulated arm CMMs 100 arranged camp use groupings 110 . 112 . 114 to be ordered.

2 FIG. 12 is a block diagram of the electronics that are configured in an articulated arm CMM according to one embodiment 100 is used. In the 2A illustrated Embodiment comprises an electronic data processing system 210 that is a base processor card 204 for implementing the base processing system, a user interface card 202 , a basic energy card 206 to provide energy, a Bluetooth module 232 and a base pitch card 208 includes. The user interface card 202 includes a computer processor for executing the application software to perform the user interface, the screen, and other functions described herein.

In 2A it can be seen that the electronic data processing system 210 over one or more Armbusse 218 communicates with the aforementioned plurality of encoder systems. Each encoder system generates at the in 2 B and 2C 1 and 2 illustrates an encoder-armature interface 214 , a digital encoder signal processor (DSP) 216 , an encoder readhead interface 234 and a temperature sensor 212 , Other devices, such as strain sensors, can attach to the arm 218 be connected.

In 2D is also the probe element electronics 230 shown with the arm 218 communicated. The probe element electronics 230 includes a probe element DSP 228 , a temperature sensor 212 , a handle / device interface bus 240 in one embodiment, via the quick connector interface with the handle 126 or with the contactless distance measuring device 242 connects, and a probe interface 226 , The quick connector interface allows access to the handle 126 on the data bus, the control lines, that of the contactless distance measuring device 242 used power bus and other accessories. The probe element electronics 230 is in one embodiment in the probe housing 102 on the articulated arm CMM 100 arranged. The handle 126 In one embodiment, it may be removed from the quick connector interface and the measurement may be made with the contactless distance measuring device 242 via the interface bus 240 with the probe element electronics 230 the articulated arm CMM 100 be communicated. In one embodiment, the electronic data processing system 210 in the pedestal 116 the articulated arm CMM 100 , the probe element electronics 230 in the probe housing 102 the articulated arm CMM 100 and the encoder systems in the bearing insert groupings 110 . 112 . 114 arranged. The probe interface 226 can be identified by any suitable communication protocol, the commercially available products from Maxim Integrated Products, Inc., as a 1-Wire ^® communication protocol 236 are formed, with the probe element DSP 228 get connected.

3A is a block diagram showing the detailed features of the electronic data processing system 210 the articulated arm CMM 100 describes according to an embodiment. The electronic data processing system 210 is in one embodiment in the socket 116 the articulated arm CMM 100 arranged and includes the base processor card 204 , the user interface card 202 , a basic energy card 206 , a Bluetooth module 232 and a base tilt module 208 ,

At an in 3A illustrated embodiment includes the base processor card 204 the various functional blocks presented herein. A basic processor function 302 For example, it is used to capture the measurement data of the articulated arm CMM 100 to support and receive over the arm 218 and a bus control module function 308 the unprocessed arm data (eg data of the encoder system). The memory function 304 stores programs and static arm configuration data. The base processor card 204 further includes a port function provided for an external hardware option 310 to interface with any external hardware devices or accessories such as a contactless distance measuring device 242 to communicate. A real-time clock (RTC) and a protocol 306 , a battery pack interface (IF; interface) 316 and a diagnostic port 318 are also in functionality in an embodiment of in 3 pictured base processor card 204 contain.

The base processor card 204 also conducts all the wired and wireless data communication to external (host computer) and internal (display processor 202 ) Devices. The base processor card 204 is able to have an ethernet function 320 with an Ethernet network [e.g. B. a clock synchronization standard such as IEEE (Institute of Electrical and Electronics Engineers) 1588 is used], via a LAN function 322 with a Wireless Local Area Network (WLAN) and a Parallel-to-Serial Communication (PSK) feature 314 with the Bluetooth module 232 to communicate. The base processor card 204 further includes a connection to a universal serial bus device (USB device) 312 ,

The base processor card 204 transmits and collects unprocessed measurement data (eg, encoder system counts, temperature measurements) for processing into measurement data, without the need for any pre-processing, such as disclosed in the serial box of the aforementioned '582 patent. The base processor 204 sends the processed data via an RS485 interface (IF) 326 to the display processor 328 on the user interface card 202 , at In one embodiment, the base processor sends 204 also the unprocessed measurement data to an external computer.

Referring now to the user interface card 202 in 3B , the angular and position data received from the base processor are displayed on the display processor 328 used applications to provide an autonomous metrological system in the articulated arm CMM 100 to provide. The applications can work on the display processor 328 to support, for example, the following, but not limited to functions: measurement of features, instructional and training graphics, remote diagnostics, temperature corrections, control of various operating characteristics, connection to various networks, and display of measured objects. The user interface card 202 includes along with the display processor 328 and an interface for a liquid crystal display (LCD screen) 338 (such as a touch-sensitive LCD screen) have multiple interface options, including a Secure Digital Card (SD Card) Interface 330 , a store 332 , a USB host interface 334 , a diagnostic port 336 , a camera port 340 , an audio / video editing section 342 , a dial-up / wireless modem 344 and a port 346 belong to the global positioning system (GPS).

This in 3A pictured electronic data processing system 210 also includes a basic energy card 206 with an environment recorder 362 for recording environmental data. The basic energy card 206 also provides energy for the electronic data processing system 210 ready, being an AC to DC converter 358 and a battery charger control 360 be used. The basic energy card 206 communicates via a serial single-ended bus 354 having an Inter-Integrated Circuit (I2C) and a serial peripheral interface including DMA (DSPI) 357 with the base processor card 204 , The basic energy card 206 is via an input / output extension function (I / O expansion function) 364 that are in the base energy card 206 is implemented, with a tilt sensor and a radio identification module (radio ID module) 208 connected.

Although illustrated as separate components, all or a subset of the components in other embodiments may be physically located at different locations and / or functions other than those described in U.S. Patent Nos. 4,648,774 3 be shown combined. For example, the base processor card 204 and the user interface card 202 combined in one embodiment in a physical map.

Now referring to 4 - 9 , Is there an exemplary embodiment of a probe element 401 This illustrates a probe housing 102 comprising a mechanical and electrical quick connector interface which facilitates coupling a removable and replaceable device 400 with the articulated arm CMM 100 allows. The device 400 includes an enclosure in the exemplary embodiment 402 holding a handle section 404 includes, which is sized and shaped so that it is held in one hand of the operator, so for example as a pistol grip. The enclosure 402 is a thin-walled structure with a cavity 406 ( 9 ). The cavity 406 is sized and configured to be a control device 408 receives. The control device 408 may be a digital circuit, for example, having a microprocessor, or an analog circuit. The control device 408 is in one embodiment in asynchronous bidirectional communication with the electronic data processing system 210 ( 2 and 3 ). The communication connection between the control device 408 and the electronic data processing system 210 can be wired (eg via a control device 420 ), a direct or indirect wireless connection (eg Bluetooth or IEEE 802.11) or a combination of wired and wireless connections. In the exemplary embodiment, the enclosure is 402 in two halves 410 . 412 formed, for example, from an injection-molded plastic material. The halves 410 . 412 can with fasteners such as screws 414 be attached to each other. The enclosing halves 410 . 412 For example, adhesives or ultrasonic welding may be secured together in other embodiments.

The grip section 404 also includes buttons or actuators 416 . 418 which the operator can turn on manually. The actors 416 . 418 are to the control device 408 coupled, which is a signal to a control device 420 in the probe housing 102 transfers. The actors 416 . 418 lead in the exemplary embodiments, the functions of actuators 422 . 424 through, on the probe housing 102 opposite the device 400 are arranged. It is understood that the device 400 may have additional switches, buttons or other actuators, which also to control the device 400 , the articulated arm CMM 100 or vice versa can be used. The device 400 may also include display devices such as light emitting diodes (LEDs), sound generators, meters, displays or testers. The device 400 can in one embodiment digital voice recorder, which allows the synchronization of voice comments with a measured point. In yet another embodiment, the device comprises 400 a microphone that allows the operator to transmit voice activated commands to the electronic data processing system 210 allowed.

The grip section 404 may be configured in one embodiment for use with one of the two hands of the operator or for a particular hand (eg, the left hand or the right hand). The grip section 404 may also be configured to facilitate the use of operators with disabilities (eg, operators with missing fingers or operators with arm prostheses). Furthermore, the handle portion 404 be removed and the probe housing 102 be used alone when the free space is limited. As discussed above, the probe element 401 also the shaft of an axis of rotation for the articulated arm CMM 100 include.

The probe element 401 includes a mechanical and electrical connection point 426 with a first connector 429 ( 8th ) on the device 400 that with a second connector 428 on the probe housing 102 interacts. The connectors 428 . 429 may include electrical and mechanical features that facilitate coupling of the device 400 to the probe housing 102 allow. The connection point 426 in one embodiment comprises a first surface 430 with a mechanical coupler 432 and an electrical connector 434 thereon. The enclosure 402 further comprises a second surface 436 that are adjacent to the first surface 430 positioned and offset therefrom. The second surface 436 In the exemplary embodiment, the surface area is approximately 12 mm from the first surface 430 is offset. This offset provides free space for the operator's fingers when a fastener such as a collar 438 tightened or loosened. The connection point 426 provides a relatively fast and secure electronic connection between the device 400 and the probe housing 102 available without the need to align connector pins and without the need for separate cables or connectors.

The electrical connector 434 extends from the first surface 430 and includes one or more connector pins 440 that, for example, via one or more Armbusse 218 , in asynchronous bidirectional communication electrically with the electronic data processing system 210 ( 2 and 3 ) are coupled. The bidirectional communication link may be wired (eg, via the arm 218 ), wireless (eg Bluetooth or IEEE 802.11) or a combination of wired and wireless connections. In one embodiment, the electrical connector 434 electrically to the control device 420 coupled. The control device 420 may be in asynchronous bidirectional communication with the electronic data processing system 210 stand, for example, over one or more Armbusse 218 , The electrical connector 434 is positioned to provide a relatively fast and secure electronic connection to an electrical connector 442 on the probe housing 102 provides. The electrical connectors 434 . 442 are connected together when the device 400 on the probe housing 102 is attached. The electrical connectors 434 . 442 For example, each may include a metal encapsulated connector housing that provides electromagnetic interference shielding that protects connector pins and alignment of the pins during the process of securing the device 400 on the probe housing 102 supported.

The mechanical coupler 432 provides a relatively rigid mechanical coupling between the device 400 and the probe housing 102 ready to hold relatively accurate applications where the position of the device 400 at the end of the arm section 104 the articulated arm CMM 100 preferably not moved or moved. Any such movement may typically result in undesirable degradation in the accuracy of the measurement result. These desired results are achieved with various structural features of the mechanical fastening configuration section of the mechanical and electronic quick connector interface of one embodiment of the present invention.

The mechanical coupler 432 in one embodiment comprises a first projection 444 that on one end 448 (The leading edge or the "front" of the device 400 ) is arranged. The first advantage 444 may include a grooved, notched, or bevelled junction that includes a lip 446 forms, extending from the first projection 444 extends out. The lip 446 is sized to fit in a slot 450 is absorbed by a projection 452 is defined, extending from the probe housing 102 out extends ( 8th ). It is understood that the first projection 444 and the slot 450 together with the federal government 438 form a coupler arrangement such that when the lip 446 in the slot 450 is positioned, the slot 450 can be used to both the longitudinal and the lateral movement of the device 400 restrict it when on the probe housing 102 is attached. As will be discussed in more detail below, one can see the rotation of the collar 438 for fixing the lip 446 in the slot 450 use.

Opposite the first lead 444 can the mechanical coupler 432 a second projection 454 include. The second projection 454 can have a grooved, a notched lip, or a beveled pad surface 456 include ( 5 ). The second projection 454 is arranged such that it is a the probe housing 102 associated fastener, such as the federal government 438 , engages. As will be discussed in more detail below, the mechanical coupler includes 432 one above the surface 430 protruding raised surface that connects to the electrical connector 434 adjacent or around the electrical connector 434 is arranged, which is a pivot point for the connection point 426 forms ( 7 and 8th ). This serves as the third of three points of mechanical contact between the device 400 and the probe housing 102 when the device 400 attached to it.

The probe housing 102 includes a fret 438 which is mounted coaxially on one end. The Bund 438 includes a threaded portion that is movable between a first position (FIG. 5 ) and a second position ( 7 ) can be moved. The Bund 438 can by its rotation for attaching or removing the device 400 can be used without the need for external tools. The rotation of the waistband 438 move it along a cylinder 474 with a relatively coarse flat thread. The use of such a relatively large flat thread and such contoured surfaces allows for significant clamping force with minimal torque. The rough pitch of the threads of the cylinder 474 also allows tightening or loosening of the collar 438 with minimal rotation.

For coupling the device 400 to the probe housing 102 becomes the lip 446 in the slot 450 introduced and the device pivoted to the second projection 454 to a surface 458 turn around as indicated by the arrow 464 is displayed ( 5 ). The Bund 438 is turned, which causes him in the direction indicated by the arrow 462 indicated direction in engagement with the surface 456 is moved or moved. The movement of the covenant 438 against the angled surface 456 leads the mechanical coupler 432 against the raised surface 460 , This helps to overcome potential problems in warping the interface or, in the case of foreign objects on the surface of the interface, the rigid seat of the device 400 on the probe housing 102 could affect. The exercise of power by the federal government 438 on the second lead 454 causes the mechanical coupler 432 is moved forward, taking the lip 446 into a seat on the probe housing 102 suppressed. While the federal government 438 is further tightened, the second projection 454 applying pressure to a pivot point up to the probe housing 102 pressed down. This provides a rocking arrangement that puts pressure on the second projection 454 , the lip 446 and applying the center pivot point to move or rock the device 400 to reduce or eliminate. The pivot point presses directly against the underside of the probe housing 102 while the lip 446 a downward force on the end of the probe housing 102 exercises. 5 contains arrows 462 . 464 to the direction of movement of the device 400 and the federal government 438 display. 7 contains arrows 466 . 468 . 470 to the direction of the applied pressure in the junction 426 display when the fret 438 is tightened. It is understood that the dislocation distance of the surface 436 the device 400 a gap 472 between the covenant 438 and the surface 436 forms ( 6 ). The gap 472 allows the operator to tie the waistband 438 tighter, while reducing the risk that his fingers during the rotation of the collar 438 be trapped. The probe housing 102 in one embodiment has sufficient rigidity to warp when tightening the collar 438 to reduce or prevent.

Embodiments of the connection point 426 allow the correct alignment of the mechanical coupler 432 and the electrical connector 434 and also protect the electronic interface from applied stresses that would otherwise be due to the clamping action of the collar 438 , the lip 446 and the surface 456 can arise. This provides advantages in reducing or eliminating damage to a printed circuit board caused by stress 476 on which the electrical connectors 432 . 442 are attached, which may have soldered connections. Further, the embodiments offer advantages over known approaches in that a user does not need tools to manipulate the device 400 with the probe housing 102 to connect or disconnect from it. This gives the operator the ability to relatively easily use the device 400 manually with the probe housing 102 to connect or disconnect from it.

Because of the relatively large number of shielded electrical connections connected to the junction 426 are possible, one can have a relatively large number of functions between the articulated arm CMM 100 and the device 400 split. For example, switches, knobs, or other actuators that work on the articulated arm CMM 100 are arranged to control the device 400 be used or vice versa. Furthermore, commands and data from the electronic data processing system 210 to the device 400 be transmitted. The device 400 is at one Embodiment of a video camera that transmits data of a captured image stored in a memory on the base processor 204 to save or on the display device 328 is to be displayed. In another embodiment, the device 400 an image projector that retrieves data from the electronic data processing system 210 receives. In addition, temperature sensors can be used in either the articulated arm CMM 100 or in the device 400 are arranged to be shared among themselves. It should be understood that embodiments of the present invention provide advantages in providing a flexible connection that facilitates the quick, easy and reliable coupling of a wide variety of accessories 400 to the articulated arm CMM 100 allowed. Furthermore, the ability to share functions between the articulated arm CMM 100 and the device 400 a reduction in the size, energy consumption and complexity of the articulated arm CMM 100 by preventing a duplicate deployment.

The control device 408 In one embodiment, the operation or the functionality of the probe element 401 the articulated arm CMM 100 to change. The control device 408 can, for example, indicator lights on the probe housing 102 to change that, when the device 400 is fixed, emit either a different colored light or a different light intensity or turn on / off at other times than when using the probe housing alone 102 , In one embodiment, the device comprises 400 a rangefinder sensor (not shown) that measures the distance to an object. The control device 408 In this embodiment, the indicator lights on the probe housing 102 to indicate to the operator how far the object is from the probe tip 118 is removed. In another embodiment, the control device 408 change the color of the indicator lights based on the quality of the image captured by a laser scanner device. This offers advantages in simplifying the requirements of the control device 420 and allows for improved or higher functionality through the addition of additional devices.

The 10 - 15 refer to distance measuring devices operatively coupled to an articulated arm CMM wherein the distance to a point on an object is determined based at least in part on the speed of light in air through which the electromagnetic radiation propagates from the device to the object point. The speed of light in air depends on the properties of the air such as the air temperature, the atmospheric pressure, the relative humidity and the carbon dioxide concentration. Such air properties affect the refractive index n of the air. The speed of light in air is equal to the speed of light in vacuum c divided by the refractive index. This means: c _air = c / n. A distance measuring device of the type discussed herein is based on the transit time of the light in the air (the round trip time the light takes to travel from the device to the object and back to the device). A method of measuring the distance based on the transit time of light (or any type of electromagnetic radiation) depends on the speed of light in air, and thus readily differs from methods of measuring a distance based on triangulation. Triangulation-based methods require projecting the light from a light source along a particular direction and then capturing the light on a camera pixel along a particular direction. If the distance between the camera and the projector is known and if a projected angle matches a capture angle, the triangulation method allows the distance to the object to be determined using a known side length and two known angles of a triangle. The triangulation method therefore does not depend directly on the speed of light in air.

Referring to 10 - 13 , there is a device 500 shown, which allows a non-contact three-dimensional measurement of an object with a laser scanner. In one embodiment, the device 500 removable via a coupler mechanism and the connection point 426 to the probe element 401 coupled. The device 500 can be configured to be independent of the probe element 401 is operated. In another embodiment, the device 500 integral with the probe element 401 connected.

The device 500 includes a body 502 with a handle 504 which offers the operator the possibility of orientation of the device 500 to hold and operate. The connection point 426 is adjacent to the handle 504 for the mechanical and electrical coupling of the device 500 to the articulated arm CMM 100 arranged. On one side extends a scanning head 506 , The scanning head 506 has a first housing section 508 for a light transmitter 510 , an optical receiver 512 and a control device 514 , The light transmitter 510 is a suitable light source radiator electromagnetic radiation such as a coherent laser light. The laser light may have a wavelength in the visible or invisible spectrum. The device 500 In one embodiment, a device for distance measurement by means of a laser beam (LIDAR, light detection and ranging). The control device 514 is in asynchronous bidirectional communication with the electronic Data processing system 210 , In one embodiment, the control device comprises 514 an evaluation and control unit 515 and a field programmable array of field gateable gate array (FPGA) devices 517 , The evaluation and control unit 515 is a computer processor-based controller that is bidirectional with the FPGA 517 communicated. The FPGA 517 controls the light transmitter 510 such that it generates a modulated measuring beam Ls. The beam Ls is from the mirror 522 reflected in the direction of the object. The evaluation and control unit 515 receives a signal from the receiver 512 to determine the distance "d" and the light intensity of the reflected light beam Lr. In the exemplary embodiment, the distance is determined by means of the propagation time of the emitted light in the forward and reverse to the destination and back. In other words, the distance is determined on the basis of the combined propagation time of a measurement beam Ls and a reflected beam Lr. In 10 the outgoing light Ls is shown as a dotted line. The outgoing light is a collimated light beam, which means that the light rays moving out to the test object are approximately parallel. The goal can be a cooperative or non-cooperative goal. A cooperative target is a target designed to repulse a large portion of the light that strikes it. A common example of a cooperative goal is a retroreflector target such as a cube-corner retroreflector with a vertex centered in a metallic sphere. A non-cooperative target is one that is not specifically designed to reject a large portion of the beam energy. An example of a non-cooperating target is a surface of a test object, such as a test object. B. a surface of metal or plastic. For example, in the case of a non-cooperative target that scatters light, the light returns in a relatively wide angular spread and fills the mirror 522 out. This expansion aspect of the beam Lr is in 10 not shown, but in 14 as discussed below. At the in 10 As shown, the light is shown as being from a central light source 510 is emitted and through an outer portion of an optical receiver 512 returns. The outer portion of the optical receiver 512 For example, could be the outer portion of a lens. In the case of a cooperative target, such as a retroreflector, the reflected light is collimated.

Adjacent to the first housing section 508 is a second housing section 516 for a drive 518 and a rotor 520 arranged. A mirror 522 is on one end of the rotos 520 opposite the light transmitter 510 in one through the first housing 508 and the second housing 516 defined gap 527 arranged. In the exemplary embodiment, the mirror is 522 at a 45-degree angle relative to the light emitter 510 and the receiver 512 arranged. The drive 518 is arranged such that it, as indicated by the arrow 526 displayed, the rotor 520 around an axis 524 rotates. The axis 524 in one embodiment is parallel or collinear with that of the light emitter 510 emitted measuring beam. In one embodiment, a pair of angled surfaces 523 . 525 on one side of the gap 527 arranged to allow the scanner a wider field of view.

The device 500 switches the light transmitter during operation 510 in response to an operator action such as pressing the actuator 416 one. The measuring beam Ls leaves the first housing 508 over an opening 509 and is from the mirror 522 reflected. Because the drive 518 the mirror 522 the measuring beam Ls is emitted "fan-shaped" in such a way that it can illuminate almost all object points in an approximately flat area in a single rotation of the mirror. By the rotation of the mirror during the movement of the device 500 by the operator, a wide spatial area can be measured with the device. To correlate the distance and intensity information with the individual measurement points is the drive 518 with an angle measuring device such as an angle encoder 528 Mistake. The control device 514 can determine the coordinate data for each measured point from the distance and encoder data. It is understood that, because the device 500 to the probe element 401 the articulated arm CMM 100 coupled, the electronic data processing system 210 the position and orientation of the device 500 from the data of the encoder 214 can determine. In one embodiment, the control device transmits 514 the coordinate and intensity data over the bus 240 to the probe element 401 that sends the coordinate and intensity data to the electronic data processing system 210 transfers. In one embodiment, the electronic data processing system may include the x, y, z coordinate data (relative to the articulated arm CMM 100 ) for each measured object point by combining the arm encoder data with the distance data.

In one embodiment, the device 500 independent of the probe element 401 operate. The device 500 can in this embodiment, further one or more positioning devices 530 include. The positioning device 530 may include one or more navigation inertial sensors, such as a gyro sensor, Global Positioning System (GPS) sensor, compass sensors, or accelerometers. Such sensors can be electrically connected to the control device 514 be coupled. Gyro and acceleration sensors can be uniaxial or multi-axis devices. The positioning device 530 is configured to the control device 514 to allow the measurement or maintenance of the orientation of the device, if the latter of the articulated arm CMM 100 is removed. A spinning top in the position device 530 may be a microelectromechanical system (MEMS) gyroscope, a semiconductor ring laser device, a fiber optic device, or another type of inertial device.

When the device 500 from the articulated arm CMM 100 is decreased, a method of combining images obtained by multiple scans is needed. A method for combining several of the device 704 captured images is to ensure that there is at least some overlap between adjacent images such that point cloud features can be matched. This matching function can be supported by the navigation inertial devices described above.

Another procedure that helps to ensure the accurate registration of the device 500 captured images is the use of reference marks. In one embodiment, the reference marks are small adhesive markings with an adhesive or adhesive backing layer, ie, for example, circular markings which are arranged on one or more objects to be measured. Even a small number of such tags may be useful in registering multiple images, especially if the measured object has a relatively small number of registry usable features. In one embodiment, the reference markers can be projected as points of light onto the test object (s). For example, you can arrange a small portable projector that can emit a variety of small dots in front of the or objects to be measured. An advantage of the projected points over glued points is that the dots do not have to be attached and later removed.

In one embodiment, the control device comprises 514 when the device 500 from the articulated arm CMM 100 is removed, a storage device (not shown) for storing data during operation. These stored data are then sent to the electronic data processing system 210 transferred when the device 500 back to the probe element 401 is coupled. In another embodiment, the device comprises a communication device, that of the device 500 the wireless transmission of distance and intensity data to the articulated arm CMM 100 or another computing device.

In 14 is another embodiment of the contactless measuring device 500 shown. In this embodiment, the mirror 522 through a galvanometer mirror system 532 replaced. A galvanometer, commonly called a "galvo" 534A . 534B is a device that moves in response to an electric current. By having a first galvo 534A orthogonal to a second galvo 534B The Galvos 534A . 534B mirror 536A . 536B around two axes 538 respectively. 540 move. The axes 538 . 540 in one embodiment are orthogonal to each other and the mirrors 536A . 536B are orthogonal to each other. As a result, the measurement beam Ls can be directed to point over an area 541 illuminated on the object instead of in a radially fanned line. The Galvos 534A . 534B are electrically connected to the control device in one embodiment 514 coupled. In order for the distance and intensity information to be related to the individual measurement points, in one embodiment each galvo includes an angle measurement device such as an angle encoder 542 to the position of the assigned galvo 534 to eat. In another embodiment, the angle is determined based on the current applied to each galvo. Although the goal 541 may be a cooperative or non-cooperative target type 14 the beam spread that occurs in the case where the target is a non-cooperative target with a target point 541 is, who scatters the light. Such a scattering would occur, for example, in a diffusely scattering surface. The light in this case is spread on the return path and enters an outer portion of the receiver 512 one.

The control device 514 determined in one embodiment, the distance to an object point and sets this with the data of the encoder 542 in relation to the three-dimensional coordinate data (for example, x, y, z) of the device 500 to investigate. This coordinate data is combined with the intensity data over the bus 240 to the probe element 401 transfer. In one embodiment, the electronic data processing system may include the x, y, z coordinate data (relative to the articulated arm CMM 100 ) of each measured object point by combining the arm encoder data with the distance data and the angle data of the galvo's.

In one embodiment, a single galvo 534A without the galvo 534B used so that the light beam is moved along a single dimension instead of along two dimensions. In this case, the movement of the contactless measuring device takes place 500 by the operator to obtain three-dimensional coordinates along both dimensions.

As discussed above, the device may 500 a positioning device 530 such as a navigation inertial device to facilitate the acquisition of coordinate data with the device 500 which was removed and independent of the probe element 401 is operated.

In 15 is a further embodiment of the contactless measuring device 500 shown. In this embodiment, the mirror is a device 544 with microelectromechanical system (MEMS). The MEMS device 544 in one embodiment comprises one on a semiconductor device 548 attached mirror 546 , In one embodiment, the MEMS system 544 a dual-axis scanning mirror mounted on a 24-pin chip from Mirrorcle Technologies, Inc. A MEMS system 544 uses a large voltage potential across capacitive plates to the mirror 546 around two orthogonal axes 550 . 552 to move. In the exemplary embodiment, the MEMS system may be the mirror 546 turn each axis at scanning angles of -10 ° to + 10 °. Similar to the galvo mirror system discussed above, the MEMS system allows 544 the illuminations of measured points over an area 541 instead of a line.

The orientation of the mirror 546 is directly proportional to the applied voltage in the exemplary embodiment. This offers advantages in that the encoder can be eliminated because the control device 514 based on the applied voltage, the distance and intensity data with the angle of the mirror 546 in order to determine the coordinate data (x, y, z) of the measured object points. This coordinate data is combined with the intensity data over the bus 240 to the probe element 401 transfer. In one embodiment, the electronic data processing system may include the x, y, z coordinate data (relative to the articulated arm CMM 100 ) for each measured object point by combining the arm encoder data with the distance and intensity data.

In another embodiment, the MEMS device includes 546 an array of small mirror elements that can be rotated in a desired direction.

As discussed above, the device may 500 a positioning device 530 such as a navigation inertial device to facilitate the acquisition of coordinate data with the device 500 which was removed and independent of the probe element 401 is operated.

It is understood that although embodiments herein are the device 500 illustrate how it emits the measuring beam perpendicular to its longitudinal axis, for illustrative purposes only, and that the claimed invention should not be so limited. In other embodiments, the measuring beam is from one end of the device 500 emitted (eg parallel to their length). In still further embodiments, the measuring beam is at an angle relative to the longitudinal axis of the device 500 emitted.

Although the invention has been described by way of example embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for features thereof without departing from the scope of the invention. Furthermore, numerous modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Accordingly, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode of practicing this invention, but that the invention will include all aspects within the scope of the appended claims. Further, the use of the terms "first," "second," etc. does not mean any order or significance, but the terms "first," "second," and so forth are used to distinguish one feature from another. In addition, the use of the terms "a," "an," etc. does not mean a limitation on the amount, but rather the presence of at least one of the object referred to.

Claims (26)

A portable articulated arm coordinate measuring machine (articulated arm CMM) for measuring three-dimensional coordinates of an object in space, comprising: a pedestal; a manually positionable arm portion having opposite first and second ends, the arm portion being rotatably coupled to the base, the arm portion including a plurality of connected arm segments, each arm segment including at least one position gauge for generating a position signal; an electronic circuit which receives the position signal of the at least one position measuring device; a probe element coupled to the first end; a contactless measuring device coupled to the probe element, wherein the non-contact measuring device comprises a transmitter configured for emitting at least one measuring beam of electromagnetic radiation and a receiver configured to receive at least one reflected beam, wherein the non-contact measuring device comprises a mirror which is suitable for reflecting both the at least one measuring beam as well as the at least one reflected beam, wherein the contactless three-dimensional measuring device further comprises a control device configured to distance the object based at least in part on a combined propagation time of the at least one measuring beam and the at least one reflected beam and to determine at a speed of light in air; and a processor electrically coupled to the electronic circuit, wherein the processor is configured to receive a set of three-dimensional coordinates of a point on the object in response to receiving the position signals of the position encoders and in response to receiving, from the controller, the measured distance determine. Articulated arm CMM according to claim 1, wherein the contactless three-dimensional measuring device is configured for: to transmit a plurality of measurement beams over a period of time; receive a plurality of reflected rays over the time period; and determine a plurality of sets of three-dimensional coordinates in response to the transmission of the plurality of measurement beams and the reception of the plurality of reflected beams. Articulated arm CMM according to claim 1, wherein the mirror is movable about an axis. Articulated arm CMM according to claim 3, wherein the non-contact measuring device further comprises a rotor coupled to the mirror and a drive, wherein the drive is configured to rotate the rotor about the axis. Articulated arm CMM according to claim 3, wherein the mirror is a galvanometer mirror. Articulated arm CMM according to claim 5, wherein the galvanometer mirror comprises a first galvo device and a second galvo device, wherein the first galvo device and the second galvo device are in an orthogonal arrangement to move the mirror about two axes. Articulated arm CMM according to claim 3, wherein the mirror is a microelectromechanical system (MEMS) mirror. The articulated arm CMM of claim 1, wherein the MEMS mirror is configured to move about two orthogonal axes. Articulated arm CMM according to claim 1, wherein the transmitter of electromagnetic radiation is a laser. Articulated arm CMM according to claim 1, further comprising a contact measuring device coupled to the probe element. Articulated arm CMM according to claim 10, wherein the processor is arranged in the contactless measuring device. Articulated arm CMM according to claim 1, wherein the non-contact measuring device is removably coupled to the probe element. A method of operating a portable articulated arm coordinate measuring machine for measuring three-dimensional coordinates of an object in space, comprising: Providing a manually positionable arm portion having opposite first and second ends, the arm portion including a plurality of connected arm segments, each arm segment including at least one position gauge for generating a position signal; Receiving the position signals of the position measuring devices on an electronic circuit; Providing a contactless device electrically coupled to the electronic circuit, the non-contact measuring device comprising a transmitter of electromagnetic radiation, a sensor and a movable first mirror; Moving the first mirror; Reflecting a measurement beam of electromagnetic radiation with the first mirror onto the object; Collecting a reflected beam of electromagnetic radiation with the first mirror and passing the reflected beam of electromagnetic radiation to the sensor; Determining a distance to the object from the reflected beam of electromagnetic radiation received from the sensor and based at least in part on a combined propagation time of the measurement beam and the reflected beam and on a speed of light in air; and Determining three-dimensional coordinates of a point on the object based at least in part on the determined distance and the position signals. The method of claim 13, wherein the step of moving the first mirror comprises rotating the first mirror about a first axis. The method of claim 14, further comprising the step of moving the first mirror about a second axis. The method of claim 14, further comprising the steps of: Providing a movable second mirror; Rotating the second mirror about a second axis; Reflecting the measuring beam of electromagnetic radiation with the second mirror onto the first mirror; and Intercepting the reflected beam with the first mirror and transmitting the same to the second mirror. The method of claim 14, further comprising rotating the first mirror with a galvo device. The method of claim 13, wherein the mirror is a MEMS mirror. The method of claim 13, further comprising the steps of: Providing a contact measuring device coupled to the first end; and Measuring three-dimensional coordinates of a second point on the object with the contact measuring device. The method of claim 13, wherein in the step of providing a transmitter of electromagnetic radiation, the transmitter of electromagnetic radiation is a laser device. The method of claim 13, further comprising decoupling the non-contact measuring device from the manually positionable arm section prior to reflecting a measurement beam. Portable articulated arm coordinate measuring machine (articulated arm CMM) for measuring three-dimensional coordinates of an object in space, comprising: a pedestal; a manually positionable arm portion having opposite first and second ends, the arm portion being rotatably coupled to the base, the arm portion including a plurality of connected arm segments, each arm segment including at least one position gauge for generating a position signal; an electronic circuit which receives the position signal of the at least one position measuring device; a contactless measuring device removably coupled to the arm portion, the non-contact measuring device having a light source and an optical receiver, and a mirror arranged to reflect a first light beam emitted from the light source and to reflect a second light beam reflected from the object, the non-contact one Measuring device configured to determine a distance to the object based at least partially on a combined propagation time of the first light beam and the second light beam and on a speed of light in air; and a processor electrically coupled to the electronic circuit, the processor configured to determine the three-dimensional coordinates of a spot on the object in response to receiving the position signals of the position gauges and in response to receiving the measured distance. The articulated arm CMM of claim 22, wherein the mirror is disposed at a 45 degree angle relative to the light source and rotates about an axis that is substantially collinear with the first light beam. The articulated arm CMM of claim 22, wherein the mirror rotates about two orthogonal axes. The articulated arm CMM of claim 22, wherein the mirror is a galvanometer mirror. The articulated arm CMM of claim 22, wherein the mirror is a MEMS mirror.

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