JP6637827B2 - Combined scanner / tracker with focus adjustment mechanism - Google Patents

Description

  The present invention relates to an optical measurement device for measuring dimensional coordinates, and more particularly to a non-contact optical measurement device including a plurality of optical devices for measuring an object.

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a U.S. patent application Ser. No. 13/765, filed Feb. 12, 2013, entitled "Multi-Mode Optical Measurement Device and Method of Operation." No. 014, which is incorporated herein by reference in its entirety.

  Non-contact optical measurement equipment may be used to measure the coordinates of points on an object. One type of optical measurement instrument measures the three-dimensional (3D) coordinates of a point by sending a laser beam to that point. The laser beam may strike the point directly or may strike a retro-reflector target in contact with the point. In each case, the device determines the coordinates of the point by measuring the distance to the target and two angles. The distance is measured by a distance measuring device such as an absolute distance meter or an interferometer. The angle is measured by an angle measuring device such as an angle encoder. A gimbaled beam steering mechanism in the instrument directs the laser beam to a point of interest.

  A laser tracker is a specific type of coordinate measuring machine that tracks a retro-reflector target with one or more laser beams emitted by it. Optical measuring instruments closely related to the laser tracker are the laser scanner and the total station. Laser scanners step scan points on a surface with one or more laser beams. It picks up light scattered from the surface and specifies the distance from this light to each point and two angles. Total stations are most often used in the field of surveying and may be used to measure the coordinates of diffusely scattered (non-cooperative) or retroreflector-type (cooperative) targets.

  Laser trackers operate by sending a laser beam to a retro-reflector target, which is used to measure the coordinates of a particular point. A common type of retro-reflector target is a spherically mounted retroreflector (SMR), which includes a cube-corner retroreflector embedded within a metal sphere. The cube corner retroreflector includes three mutually perpendicular mirrors. The vertex, which is the common intersection of the three mirrors, is located at the center of the sphere. The mechanical relationship of the cube corner placement within the sphere to the measurement point is known (ie, the vertical distance from the apex to any surface on which the SMR rests remains constant as the SMR rotates). Therefore, the position of the measurement point can be specified. As a result, the laser tracker can measure the 3D coordinates of a surface by following its position as the SMR moves over the surface. In other words, a laser tracker can fully characterize the 3D coordinates of a surface if it measures only three degrees of freedom (one and two radial distances).

  One type of laser tracker includes only an interferometer (IFM) and does not have an absolute distance meter (ADM). If the object blocks the path of the laser beam from one of these trackers, the IFM loses its distance reference. The operator can then follow the retro-reflector to a known position and reset the reference distance before continuing the measurement. A workaround for this limitation is to include the ADM in the tracker. The ADM can measure the distance in a shooting manner.

  Since the tracker stays at a certain point, it is desirable to place constraints on the laser power and keep the desired classification within the IEC 60825-1 standard. Therefore, it is desired that the tracker operate at low laser power. In addition to clearly defining the measurement points, SMR returns most of the laser power. In contrast, laser scanners may be configured to move continuously, thereby achieving the desired IEC 60825-1 classification because the total energy deposited on a portion of the person in the operating area is small. it can. Thus, laser scanners operate at higher laser power levels and can operate with non-cooperative targets, but are generally less accurate and have a shorter distance than laser trackers.

  Laser scanners also direct a laser beam toward an object. Since the laser tracker interacts with the operator (via a retro-reflector target), it is desirable that the laser be visible. However, laser scanners may operate at other wavelengths, such as infrared or visible wavelengths, because the light beam may not be visible to the operator. Laser scanners receive light reflected from an object and determine, in part, the distance to a point on the object based on the time of flight before the light hits the object and returns to the scanner. Some laser scanners rotate continuously around the zenith axis while simultaneously rotating the laser beam around the azimuth axis to identify the coordinates of points in the area around the laser scanner. Still other laser scanners direct the light beam to a single point or in a predetermined pattern, for example, a raster pattern.

  It should be understood that a laser scanner can acquire coordinates of multiple points much faster than a laser tracker. However, laser trackers measure distance with greater accuracy. In addition, since the laser tracker stays at a particular point, the measurements are typically integrated in a fraction of a second to reduce the noise of electronic components and atmospheric turbulence. Because laser scanners typically measure points on the order of millions of seconds, measurements are typically made on the order of microseconds or fractions of a microsecond. Therefore, noise from electronic components and atmospheric turbulence can be much higher in a scanner.

US Patent No. 7,327,446 US Patent No. 7,701,559 US Patent Application Publication No. 2011/0032509

  Therefore, while existing non-contact optical measuring instruments are suitable for their intended purpose, they still need to be improved, especially optical measuring instruments that allow the operator to select one of several operating modes. Must be provided.

  According to one aspect of the present invention, the coordinate measuring device is a first absolute distance meter including an optical transmission system, a first light source, a first light detector, and a first electric circuit, The first light source is configured to send the first light to the retro-reflector target through the light transmission system, and the first light detector further includes a second light source responsive to the first light being reflected by the retro-reflector target. Generating a first electrical signal and transmitting the first electrical signal to a first electrical circuit, wherein the first electrical circuit includes a first distance from the coordinate measuring device to the retro-reflector target; A first absolute distance meter configured to determine based at least in part on the first electrical signal; a second light source; an adjustable focus adjustment mechanism; a second photodetector; A second absolute distance meter including an electrical circuit, The second light source is configured to send the second light to the object surface through the adjustable focusing mechanism light transmission system, and the second light detector is reflected by the object surface and passes through the light transmission system. The second light detector is further configured to receive the second light, the second light detector further generating a second electrical signal in response to the second light being reflected by the object surface, and generating the second electrical signal. Configured to transmit to a second electrical circuit, wherein the second electrical circuit determines a second distance from the coordinate measuring device to the object surface, at least in part, based on the second electrical signal. A second absolute distance meter as configured, a structure operatively connected to the optical transmission system and the first and second absolute distance meters, and rotating the structure about the first axis. A first motor configured to cause the first motor to be operatively coupled to the structure; A first angle transducer, wherein the first angle transducer is configured to measure a first rotational angle about the first axis, and the structure is rotated about the second axis. A second motor, the second axis of which is substantially perpendicular to the first axis, and a second angle operatively connected to the structure. A second angle transducer configured to measure a second rotation angle about the second axis, and a position detector, emitted by the coordinate measuring device, the retroreflector. A position detector configured to receive a portion of the radiation reflected by the target, and configured to generate a third electrical signal based at least in part on a location where the portion of the radiation strikes the position detector; , The processor, operating in the first mode and the second mode A first mode of tracking the retro-reflector target based at least in part on the third electrical signal, the first mode of the retro-reflector target. The three-dimensional coordinates are determined, at least in part, by a first rotation angle to the retro-reflector target at the first position, a second angle of the retro-reflector target at the first position, and a first angle of the retro-reflector target at the first position. Determining based on the distance of the second mode, directing a second light to the surface of the object, the second three-dimensional coordinates of a point on the surface of the object, at least in part, the surface of the object The first rotation angle to that point on the object, the second rotation angle of the point on the object surface, and the second distance of the point on the object surface Comprising the step of determining by Zui, second mode, further comprising the step of adjusting the adjustable focus adjustment mechanism.

  In the coordinate measuring device of the present invention, the optical transmission system has an inner optical path and an outer optical path, the outer optical path is coaxial with the inner optical path, and is outside the inner optical path, and the first photodetector is provided by a retroreflector target. The second light detector is configured to receive the first light reflected and passed through the inner light path of the light transmission system, and the second light detector is configured to receive the first light reflected by the object surface and passed through the outer light path of the light transmission system. Is also suitable.

  Further, in the coordinate measuring device of the present invention, it is preferable that the structure is rotated in one direction so that the second light is emitted along a spiral path, and the optical transmission system is reflected by the object surface. It is also suitable to further include an annular aperture positioned to receive a part of the second light.

  Further, in the coordinate measuring device of the present invention, it is preferable that the processor is configured to emit the first light when the second absolute distance meter emits the second light.

  In the coordinate measuring instrument of the present invention, the wavelength of the first light is preferably about 700 nm, and the wavelength of the second light is also preferably about 1550 nm. .

  According to another aspect of the invention, a coordinate measuring device includes a structure, a first motor configured to rotate the structure about a first axis, and a first motor operatively coupled to the structure. An angle transducer, wherein the first angle transducer is configured to measure a first rotation angle about a first axis, and the structure is configured to rotate the structure about a second axis. A second motor, wherein the second axis is substantially perpendicular to the first axis and the projection of the second axis intersects the projection of the first axis at a gimbal point. A second angle transducer operatively coupled to the second motor and the structure, the second angle transducer configured to measure a second rotation angle about the second axis. An optical transmission system operatively connected to the structure, and a first absolute distance meter operatively connected to the structure, wherein the first light source and the first A first light source includes a detector and a first electrical circuit, the first light source transmitting the first light through a first light transmission system along a portion of a first line extending from a gimbal point to a retroreflector target. Wherein the first line is perpendicular to the first axis and the first photodetector is configured to receive the first light reflected by the retro-reflector target and passing through the optical transmission system; The light detector is further configured to generate a first electrical signal in response to the first light being reflected by the retroreflector target, and to transmit the first electrical signal to the first electrical circuit. Wherein the first electrical circuit is configured to determine a first distance from the coordinate measuring device to the retro-reflector target based at least in part on the first electrical signal. And the structure An operably coupled second absolute distance meter, the second absolute light meter including a second light source, an adjustable focus adjustment mechanism, a second light detector, and a second electrical circuit, wherein the second light source is adjustable. Configured to send a second light through the focusing mechanism and the light transmission system along a portion of a second line extending from the gimbal point to the object surface, the second line being perpendicular to the first axis; The second line is different from the first line and the second light detector is configured to receive the second light reflected by the object surface and passing through the light transmission system, the second light detection The device is further configured to generate a second electrical signal in response to the second light being reflected by the object surface, and to transmit the second electrical signal to the second electrical circuit. The electrical circuit of at least partly measures the second distance from the coordinate measuring device to the surface of the object. A second absolute distance meter, such as configured to make a decision based on the signal, and a position detector for receiving a portion of the radiation emitted by the coordinate measuring instrument and reflected by the retroreflector target. A position detector configured to generate the third electrical signal based at least in part on a position at which a portion of the light radiation impinges on the position detector; and And a processor having a computer readable medium configured to operate in a second mode, wherein the first mode comprises a step of providing a retroreflector target based at least in part on a third electrical signal. Tracking and the first three-dimensional coordinates of the retro-reflector target at least in part at a first position of the retro-reflector target at the first location. Determining based on the rotation angle and a second rotation angle to the retro-reflector target at the first position and a first distance of the retro-reflector target at the first position, wherein the second mode comprises: Rotating about one axis, and converting the second three-dimensional coordinates of the point on the object surface, at least in part, to a first rotation angle to that point on the object surface and to that point on the object surface And the second mode further comprises adjusting the adjustable focus adjustment mechanism based on the second angle of rotation and the second distance of the point on the object surface.

  Also, in the coordinate measuring device of the present invention, the first line extends in the first radial direction, and the second line extends in the second radial direction, forming an angle between them, and an angle of 5 degrees or more. It is also preferable that the angle is 180 degrees, and that the angle is 90 degrees.

  According to another aspect of the present invention, the coordinate measuring device is a first absolute distance meter including an optical transmission system, a first light source, a first light detector, and a first electric circuit, One light source is configured to send the first light through the light transmission system to the retro-reflector target, and the first light detector reflects the first light reflected by the retro-reflector target and passing through the light transmission system. The first light detector is further configured to generate a first electrical signal in response to the first light being reflected by the retro-reflector target, and to generate the first electrical signal in the first light detector. The first electrical circuit is configured to determine a first distance from the coordinate measuring device to the retro-reflector target based at least in part on the first electrical signal. ing Such a first absolute distance meter, a second absolute distance meter including a second light source, an adjustable focus adjustment mechanism, a second photodetector and a second electric circuit, wherein the second light source, The second light detector is configured to send the second light to the object surface through the adjustable focus adjustment mechanism and the light transmission system, and the second light detector reflects the second light reflected by the object surface and passing through the light transmission system. The second light detector is further configured to generate a second electrical signal in response to the second light being reflected by the object surface, and to generate the second electrical signal in the second electrical detector. A second electrical circuit configured to transmit to the circuit, wherein the second electrical circuit is configured to determine a second distance from the coordinate measuring device to the object surface, based at least in part on the second electrical signal. Such as the second absolute distance meter, the optical transmission system and the first absolute distance meter A structure operatively connected to the absolute distance meter of claim 1, including a mirror mounted for rotation, wherein the mirror is positioned in an optical path of the first light and the second light. A first motor configured to rotate the structure about the first axis, and a first angle transducer operatively coupled to the structure, the first angle transducer being operatively connected to the structure. A first angle transducer configured to measure a rotation angle of the first motor and a second motor configured to rotate the mirror about a second axis, wherein the second axis is the first axis. A second motor substantially perpendicular to the axis of the second angle transducer operatively connected to the mirror for measuring a second angle of rotation about the second axis. And a position detector, wherein the retroreflector is emitted by a coordinate measuring device. A position detector configured to receive a portion of the radiation reflected by the target and configured to generate a third electrical signal based at least in part on a location where the portion of the radiation strikes a position detector. And a processor having a computer readable medium configured to operate in a first mode and a second mode, the first mode including at least a portion of the retro-reflector target. Tracking the first three-dimensional coordinates of the retro-reflector target based on the third electrical signal; and at least in part, a first rotation angle to the retro-reflector target at the first position and a first position. Based on a second rotation angle to the retro-reflector target at the first position and a first distance of the retro-reflector at the first position. Rotating the structure about a first axis and converting the second three-dimensional coordinates of a point on the object surface, at least in part, to its position on the object surface. Determining based on a first angle of rotation up to and a second angle of rotation to the position on the object surface and a second distance of the point on the object surface, wherein the second mode is adjustable The method further includes adjusting the focus adjustment mechanism.

  In the coordinate measuring device of the present invention, in the second mode, the first motor rotates the structure at the first speed, the second motor rotates the mirror at the second speed, and the second speed is It is also preferred that the speed is higher than the first speed, and that the second mode includes rotating the structure in one direction about the first axis.

  These and other advantages and features will become more apparent when the following description is read in conjunction with the drawings.

  The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The above and other features and advantages of the present invention will become apparent from the following detailed description when read in conjunction with the accompanying drawings.

  The present invention can provide an optical measuring device that allows an operator to select an operation mode from a plurality of operation modes.

1 is a perspective view of an optical measurement device according to an embodiment of the present invention. FIG. 2 is a partial perspective view of the optical measurement device of FIG. 1 showing the location of a tracker portion and a scanner portion including a sensor in the device. 2 is a block diagram of an electrical and computing system for the device of FIG. FIG. 2 is a schematic diagram of the apparatus of the payload portion of FIG. 1 including a block diagram of an optical measurement instrument according to an embodiment of the present invention. 2 is an absolute distance meter (ADM) for the laser track portion of the optical measuring instrument of FIG. FIG. 5 is a block diagram of the fiber network shown in FIG. 4. FIG. 5 is a block diagram of the fiber network shown in FIG. 4. FIG. 8 is a block diagram of the retroreflector shown in FIG. 7. FIG. 8 is another block diagram of the retroreflector shown in FIG. 7. FIG. 5 is another block diagram of the fiber network shown in FIG. 4. FIG. 2 is a schematic diagram of the apparatus of FIG. 1 showing an optical axis when light from a tracker and a scanner is projected. FIG. 2 is a perspective view of the apparatus of FIG. 1 showing another embodiment of a scanner portion and a tracker portion. FIG. 2 is a perspective view of the apparatus of FIG. 1 showing another embodiment of a scanner portion and a tracker portion. FIG. 2 is a perspective view of the apparatus of FIG. 1 showing another embodiment of a scanner portion and a tracker portion. 1 is a schematic diagram of an optical measurement device in a first operation mode according to an embodiment of the present invention. FIG. 4 is a schematic view of a first optical measurement device in a second operation mode. It is a flowchart which shows the step which operates an optical measuring instrument. It is a flowchart which shows the step which operates an optical measuring instrument. FIG. 4 illustrates an apparatus for emitting tracker light and scanner light in two different directions from a scanner-tracker according to an embodiment. FIG. 3 is a schematic diagram of a scanner-tracker device for directing a light beam from a tracker to a retro-reflector using a rotating mirror according to an embodiment of the present invention. FIG. 2 is a schematic diagram of the device payload portion of FIG. 1 including a block diagram of an optical measurement instrument according to an embodiment of the present invention. FIG. 2 is a schematic diagram of the apparatus of FIG. 1 showing the optical axis when light from the tracker portion and the scanner portion is projected. 1 is a schematic diagram of an optical measurement device in a first operation mode according to an embodiment of the present invention. FIG. 2 is a schematic diagram of the optical measurement device of FIG. 1 in a second operation mode. FIG. 4 illustrates an apparatus for emitting tracker light and scanner light in two different directions from a scanner-tracker according to an embodiment. FIG. 4 is a schematic diagram of an adjustable focus adjustment mechanism according to an embodiment.

  The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.

  Embodiments of the present invention provide an optical measurement device that can operate as both a laser tracker and a laser scanner. This has the advantage that both higher accuracy measurements are usually possible, using a cooperative target that the operator has in hand, and faster (usually) lower accuracy measurements, which are usually not actively supported by the operator. I will provide a. These two modes of operation are provided by a single integrated device.

  Referring now to FIGS. 1-2, there is shown a coordinate measuring device 30 that provides multiple modes of operation. The device 30 has a housing 32, which includes a tracker portion 34 that supports a laser tracking function and a scanner portion 36 that supports a scanner function. The exemplary gimbaled beam steering mechanism 38 includes a Zenith carriage 42, which is mounted on an azimuth base 40 and rotates about an azimuth axis 44. The payload structure 46 is mounted on a zenith carriage 42 that rotates about a zenith axis 48. Zenith axis 48 and azimuth axis 44 intersect vertically at gimbal point 50 inside instrument 30. Gimbal point 50 is generally the origin of distance and angle measurements. One or more light beams 52 effectively pass through gimbal point 50. The emitted light beam is directed in a direction perpendicular to the zenith axis 48. In other words, the light beam 52 is in a plane substantially perpendicular to the zenith axis 48 and including the azimuth axis 44. The light beam 52 is directed in a desired direction by rotating the payload structure 46 about a zenith axis 48 and rotating the zenith carriage 42 about an azimuth axis 44.

  A zenith motor 51 and a zenith angle encoder 54 are located inside the housing 32 and are mounted on a zenith mechanical axis that is aligned with the zenith axis 48. An azimuth motor 55 and an azimuth angle encoder 56 are also located inside the instrument 30 and are mounted on an azimuth machine shaft that is aligned with the azimuth shaft 44. Zenith motor 51 and azimuth motor 55 operate to rotate payload structure 46 about axes 44 and 48 simultaneously. As will be described in more detail below, in the scanner mode, the zenith motor 51 and the azimuth motor 55 are each operated in a single direction, so that the scanner light follows a continuous path that does not reverse direction. Zenith and azimuth angle encoders 54 and 56 measure the zenith and azimuth rotation angles with relatively high accuracy.

  Light beam 52 travels to target 58, which reflects light beam 52 back to instrument 30. Target 58 may be a non-cooperative target, for example, object surface 58 '. Alternatively, the target 58 may be a retro-reflector, for example, a spherically mounted retroreflector (SMR). By measuring the radial distance between the gimbal point 50 and the target 58, the angle of rotation about the zenith axis 48, and the angle of rotation about the azimuth axis 44, the position of the target 58 is determined in the spherical coordinate system of the device 30. May be found at As described in more detail herein, device 30 includes one or more mirrors, lenses, or apertures that define an optical transmission system that directs and receives light.

  Light beam 52 may include one or more light wavelengths, such as visible and infrared wavelengths. It should be understood that although the embodiments herein are described with respect to a gimbaled beam steering mechanism 38, other types of steering mechanisms may be used. In other embodiments, for example, the mirror may be rotated about the azimuth and zenith axes 44,48. In another embodiment, the light may be guided using a galvo mirror. As with the exemplary embodiment, these other embodiments (eg, galvo mirrors) may be used to direct light in a single direction along a path that does not reverse direction, as described in more detail below. .

  In one embodiment, a magnetic nest 60 may be located on the azimuth base 40. The magnetic nest 60 resets the tracker to a "home position" such as a different sized SMR, such as a 1.5, 7/8, and 0.5 inch (38.1 mm, 22.225 mm, 12.7 mm) SMR. For use with the tracker portion 34. A retro-reflector on the device may then be used to reset tracker portion 34 to a reference distance. Further, a mirror (not shown) may be used with the retroreflector to allow for performing self-correction, which is described in US Pat.

  Referring now to FIG. 3, an exemplary controller 64 for controlling operation of the device 30 is shown. Controller 64 includes a distributed processing system 66, a temperature sensor 68, a processing system for a personal digital assistant 72, an external computer 74, and other network components 76, shown here as clouds. Exemplary embodiments of the distributed processing system 66 include a master processor 78, a payload function electronics unit 80, an azimuth encoder electronics 82, a Zenith encoder electronics 86, a display and user interface (UI) 88, a removable It includes storage hardware 90, radio frequency identification (RFID) radio electronics 92, and antenna 94. The payload function electronic component unit 80 includes, for example, a scanner electronic component 96, a camera electronic component 98 (for the color camera 168 in FIG. 11), an ADM electronic component 100, a position detector (PSD) electronic component 102, and a level electronic component 104. Includes many features. Some or all of the subordinate functions in the payload function electronics unit 80 have at least one processing unit, which may be, for example, a digital signal processor (DSP) or a field programmable gate array (FPGA).

  Many types of peripherals can be used, such as a temperature sensor 68 and a personal digital assistant 72. The portable information terminal 72 may be a cellular telecommunication device, for example, a smartphone. The device 30 may communicate with the peripheral device in various ways, such as by wireless communication through an antenna 94, by a video system such as a camera, and by reading the distance and angle from the laser tracker to the cooperative target. The peripheral device may include a processor. In general, where the term scanner electronics, laser tracker electronics, or measurement instrument processor is used, this shall include available external computers and cloud support.

  In some embodiments, another communication medium or bus extends from the master processor 78 to each of the payload functional electronics units 80, 82, 86, 88, 90, 92. Each communication medium may have, for example, three serial lines including a data line, a clock line, and a frame line. The frame line indicates whether the electronic component unit should pay attention to the clock line. If it indicates that attention should be paid, the electronics unit reads the current value of the data line at each clock signal. The clock signal may correspond to, for example, a rising edge of a clock pulse. In one embodiment, the information is transmitted on data lines in the form of packets. In another embodiment, each packet includes an address, a numerical value, a data message, and a checksum. The address indicates where in the electronic component unit the data message should be directed. The location may correspond to, for example, a processor subroutine in the electronic component unit. The numerical value indicates the length of the data message. The data message contains data or instructions to be executed by the electronic component unit. The checksum is a numerical value used to minimize the probability of occurrence of an error in data transmitted on a communication line.

  In one embodiment, the master processor 78 transmits the information packet to the payload function electronics unit 80 on the bus line 106, to the azimuth encoder electronics 82 on the bus line 108, to the Zenith encoder electronics 86 on the bus line 110, to the bus 112 To the display and UI electronics 88, to the removable storage hardware 90 on the bus 114, and to the RFID and wireless electronics 92 on the bus 116.

  In one embodiment, master processor 78 also sends a synchronization pulse on synch bus 118 to each of the electronics units simultaneously. The synch pulse provides a way to synchronize the numerical values collected by the measurement function of the device 30. For example, azimuth encoder electronics 82 within Zenith encoder electronics 86 latches the encoder value upon receipt of a synch pulse. Similarly, the payload function electronics unit 80 latches data collected by electronics housed within the payload structure. The ADM and position detector all latch data when a synch pulse is applied. In most embodiments, the camera and inclinometer acquire data at a slower synch pulse rate, but may latch data at multiples of the synch period.

  In one embodiment, azimuth encoder electronics 82 and Zenith encoder electronics 86 are separated from each other and from payload function electronics unit 80 by slip rings (not shown). If a slip ring is used, the bus lines 106, 108, 110 may be separate buses. Distributed processing system 66 may communicate with external computer 74 or may provide communication, display, and UI functions within device 30. The device 30 communicates with the external computer 74 over a communication link 120, for example, an Ethernet line or a wireless connection. Device 30 may also communicate over communication link 122 with other elements represented by cloud 76, including one or more electrical cables, such as an Ethernet cable, or one or more wireless connections. You may go out. Element 76 may be another three-dimensional test device, such as an articulated arm CMM, which may be moved by device 30. Communication link 124 between external computer 74 and element 76 may be wired or wireless. An operator sitting in front of the external computer 74 connects to the Internet, represented by the cloud 76, via an Ethernet or wireless link, which connects them to the master processor 78 over the Ethernet or wireless link. Connect with. In this way, a user can control the operation of a remote device, for example, a laser tracker.

  Referring now to FIG. 4, one embodiment of a payload structure 46 in a device 30 having a tracker portion 34 and a scanner portion 36 is shown. The tracker portion 34 and the scanner portion 36 are integrated to emit light from the tracker portion 34 and the scanner portion 36 on a substantially common inner optical path, which is illustrated in FIGS. It is shown. However, although the light emitted by the tracker portion 34 and the scanner portion 36 travels on substantially a common optical path, in some embodiments, the light beams from the tracker portion 34 and the scanner portion 36 are emitted at different times. In other embodiments, the beams are emitted simultaneously.

  The tracker section 34 includes a light source 126, an isolator 128, a fiber network 136, ADM electronics 140, a fiber launch system 130, a beam splitter 132, and a position detector 134. In some embodiments, light source 126 emits visible light. The light source may be, for example, a red or green diode laser or a vertical cavity surface emitting laser. The isolator may be a Faraday isolator, attenuator, or any other suitable device that can substantially reduce the amount of light returned to light source 126. Light from isolator 128 travels to fiber network 136. In one embodiment, fiber network 136 is the fiber network shown in FIG. 6, which is described in more detail below. Position detector 134 is arranged to receive a portion of the radiation emitted by light source 126 and reflected by target 58. Position detector 134 is configured to provide a signal to controller 64. The signal is used by the controller 64 to operate the motors 51, 55 to direct the light beam 52 to track the target 58.

  Some of the light incident on fiber network 136 is transmitted over optical fiber 138 to the reference channel of ADM electronics 140. Another portion of the light incident on fiber network 136 passes through fiber network 136 and beam splitter 132. The light reaches a dichroic beam splitter 142, which is configured to transmit light at the wavelength of the ADM light source. Light from tracker portion 34 exits from payload structure 46 through aperture 146 along optical path 144. Light from the tracker portion 34 travels along the optical path 144, is reflected by the target 58, returns along the optical path 144, and reenters the payload structure 46 through the aperture 146. This return light passes through the dichroic beam splitter 142 and returns to the tracker section 34. The first portion of the return light passes through beam splitter 132, enters fiber launch system 130, and enters fiber network 136. Some of the light passes into optical fiber 148 and enters the measurement channel of ADM electronics 140. A second portion of the return light is reflected by beam splitter 132 and enters position detector 134.

In one embodiment, ADM electronics 140 is that shown in FIG. The ADM electronics 140 includes a frequency reference 3302, a synthesizer 3304, a measurement detector 3306, a reference detector 3308, a measurement mixer 3310, a reference mixer 3312, conditioning electronics 3314, 3316, 3318, 3320, N It includes a frequency dividing prescaler 3324 and an analog-to-digital converter (ADC) 3322. The frequency reference may be, for example, a thermostated crystal oscillator, for example, sending a 10 MHz reference frequency f _REF to the synthesizer, which generates two electrical signals, one signal at frequency f _RF and two signals at frequency f _LO. Generate The signal at frequency f _RF enters light source 126. Two signals of frequency f _LO enter measurement mixer 3310 and reference mixer 3312. Light from optical fibers 138, 148 enters the reference and measurement channels, respectively. The reference detector 3308 and the measurement detector 3306 convert an optical signal into an electric signal. These signals are conditioned by conditioning electronics 3316, 3314, respectively, and transmitted to mixers 3312, 3310, respectively. The mixer generates a frequency f _IF of the signal equal to the absolute value f _LO -f _RF. The signal at frequency f _RF may have a relatively high frequency, eg, 2 GHz, while the signal at frequency f _IF may have a relatively low frequency, eg, 10 kHz.

The reference frequency f _REF is sent to a prescaler 3324, which divides the frequency by an integer. For example, a frequency of 10 MHz may be divided by 40 to obtain an output frequency of 250 kHz. In this example, the 10 kHz signal entering ADC 3322 is sampled at a rate of 20 kHz, which produces 25 samples per cycle. Signals from ADC 3322 are sent to a data processor 3400, eg, one or more digital signal processors.

  The method for extracting the distance is based on calculating the phase of the ADC signal for the reference and measurement channels. This method is described in detail in Bridges et al., US Pat. The calculation involves the use of equations (1)-(8) of US Pat. In addition, when the ADM first starts measuring the target, the frequency generated by the synthesizer is changed several times (eg, three times) and the possible ADM distance is calculated each time. By comparing the possible ADM distances for each of the selected frequencies, the ambiguity of the ADM measurement is eliminated. By combining the equations (1) to (8) of Patent Document 2 with the synchronization method and the Kalman filter method described in Patent Document 2, the ADM can measure a moving target. In other embodiments, other methods may be used to obtain absolute distance measurements, such as pulsed time-of-flight.

  One embodiment of the fiber network 136 of FIG. 4 is shown in FIG. 6 as fiber network 420A. This embodiment includes a first fiber optic coupler 430, a second fiber optic coupler 436, and low transmittance reflectors 435, 440. The first and second fiber optic couplers are 2 × 2 couplers, each having two input ports and two output ports. This type of coupler is typically made by placing two fiber cores in close proximity and then drawing the fiber. In this way, evanescent coupling between the fibers can separate the desired portion of light to adjacent fibers. The light travels through the first optical fiber coupler 430 and passes through two paths, namely, the first path through the optical fiber 433 to the second optical fiber coupler 436, the optical fiber 422, and the fiber length equalizing means 423. Divide into a second path through. The fiber length equalization means 423 leads to the optical fiber 138 of FIG. 4, which leads to the reference channel of the ADM electronics 140. The purpose of the fiber length equalization means 423 is to match the length of the optical fiber through which the light passes in the reference channel with the length of the optical fiber through which the light traverses in the measurement channel. Matching the fiber lengths in this way reduces ADM errors due to changes in ambient temperature. Such an error may occur because the effective optical path length of the optical fiber is equal to the average refractive index of the optical fiber times the length of the fiber. Since the refractive index of an optical fiber depends on the temperature of the fiber, changing the temperature of the optical fiber changes the effective optical path length of the measurement and reference channels. If the effective optical path length of the optical fiber in the measurement channel changes with respect to the effective optical path length of the optical fiber in the reference channel, the position of the target 58 will appear to have changed, even if the target 58 is left stationary. To avoid this problem, two steps are taken. First, the fiber length in the reference channel is matched as closely as possible to the fiber length in the measurement channel. Second, the measurement and reference fibers are placed as side-by-side as possible so that the optical fibers in the two channels are exposed to approximately the same temperature changes.

  The light travels through optical fiber 433 to a second fiber optic coupler 436, two paths: a first path to low reflection fiber terminator 440, and a second path to optical fiber 438 where it exits the fiber network. Divide into routes.

Another embodiment of the fiber network 136 is shown in FIG. In this embodiment, the fiber network 136 includes a first optical fiber coupler 457, a second optical fiber coupler 463, two low reflection terminators 462, 467, an optical switch 468, a retro reflector 472, and an optical switch 468. And an electrical input 469. There are several types of optical switches 468. A commercially available and relatively inexpensive type is the MEMS (micro-electro-mechanical system) type. This type may use, for example, a small mirror configured as part of a semiconductor structure. Alternatively, the switch can be a modulator, which can be used for very fast switching at a particular wavelength, and is slightly more expensive than a MEMS type switch. The switch may also consist of an optical attenuator, which may be responsive to an electrical signal and may be turned on and off by an electrical signal sent to the attenuator. A description of specifications that may be considered in selecting an optical fiber switch is described in Bridges, US Pat. Generally, the switch may be a fiber optic switch to achieve the desired performance and simplicity. It should be understood that the optical switch concept described above should perform equally well in a two-color based fiber network.

  The fiber network 136 includes an optical switch 468 and a retro-reflector 472. Typically, light exits fiber 465 through the upper port of optical switch 468 to optical fiber 470. However, from time to time, when the laser tracker is not measuring the target, the optical switch 468 diverts the optical signal from the optical fiber 465 to the optical fiber 471 and further to the retroreflector 472. The purpose of switching the light to the retroreflector 472 is to eliminate any thermal drift that may have occurred in the components of the ADM system. Such components include, for example, optoelectronic components such as photodetectors, optical fibers of ADM systems, conditioning electronics such as mixers, amplifiers, synthesizers, analog-to-digital converters, and optical components such as lenses and lens mounts. You may go out. For example, suppose initially that the path length of the measurement channel was found to be 20 mm longer than the reference channel having an optical switch 468 that splits light into the retro-reflector 472. Thereafter, it is assumed that the path length of the measurement channel is found to be 20.003 mm longer than the reference channel path length having the optical switch 468 for branching the light to the retro-reflector 472. The ADM data processor subtracts 0.003 mm from subsequent ADM readings. It should be understood that this procedure will be updated each time the tracker sets the ADM value to the home position of the laser tracker.

  In one embodiment, retroreflector 472 is fiber optic retroreflector 472A of FIG. This type of retro-reflector 472 is typically a ferrule, where the optical fiber is polished at the end of the ferrule and coated with a coating 473, which may be, for example, gold or a multi-layer dielectric thin film. In another embodiment, the retroreflector 472 is the free-space retroreflector 472B of FIG. 9, which includes a collimator 474 and a retroreflector 476, which may be, for example, a cube corner retroreflector slag.

  Another embodiment of the fiber network 136 is shown in FIG. In this embodiment, the fiber network 136 includes a first fiber optic coupler 1730, a second fiber optic coupler 1740, a third fiber coupler 1750, and three low reflection terminators 1738, 1748, 1758. Light from the optical fiber 1781 enters the fiber network 136 at the input port. Light travels through a first fiber optic coupler 1730. Some of the light passes through the optical fiber 138 and the fiber length compensator 423 before entering the reference channel of the ADM electronics 140. Some of the light passes through a second fiber optic coupler 1740 and a third fiber coupler 1750 before exiting the fiber network on optical fiber 1753. Light from optical fiber 1743 enters third fiber coupler 1750, where it is combined with light from a second light source (not shown) via optical fiber 1790 to form a composite light beam, which is Proceed over optical fiber 1753. Optical coupler 1750 is a dichroic coupler because it is designed to use two wavelengths. After the composite light beam carried in optical fiber 1753 exits the laser tracker and is reflected at target 58, it returns to fiber network 136. Light from the first light source passes through the third fiber coupler 1750, the second fiber optic coupler 1740, and enters the optical fiber 148, which reaches the measurement channel of the ADM electronics 140. Light from a second light source (not shown) returns to optical fiber 1790 and returns to a second light source (not shown).

  Couplers 1730, 1740, and 1750 may be of a fused type. With this type of optical coupler, the two fiber core / cladding regions are brought closer together and fused. As a result, light between the cores is exchanged by evanescent coupling. For two different wavelengths, it is possible to design an evanescent coupling device that can completely transmit the first wavelength along the original fiber and completely couple the second wavelength on the same fiber. . Typically, light is not completely (100%) coupled to coupler 1750. However, fiber optic couplers that provide good coupling for two or more different wavelengths are commercially available at common wavelengths such as 980 nm, 1300 nm, and 1550 nm. In addition, optical fiber couplers can be purchased commercially for other wavelengths, such as visible wavelengths, and may be designed and manufactured for other wavelengths. For example, in FIG. 10, the optical fiber coupler 1750 can be configured such that the first light of the first wavelength travels from the optical fiber 1743 to the optical fiber 1753 to reduce the optical loss. At the same time, the device may be configured to couple the second light on optical fiber 1790 almost completely on optical fiber 1753. Therefore, it is possible to transmit the first light and the second light through the optical fiber coupler to the same fiber 1753 with a small loss. Optical couplers for coupling wavelengths having greatly different wavelengths are also commercially available. For example, couplers are commercially available that couple light at a wavelength of 1310 nm to light at a wavelength of 550 nm. Due to long distance propagation, which propagates both wavelengths in a single transverse mode while reducing the loss of optical power during propagation in an optical fiber, the two wavelengths must be relatively close to each other. Generally desirable. For example, the two selected wavelengths are 633 nm and 780 nm, which are relatively close to each other in wavelength values, can be transmitted over long distances, and without high loss, through a single mode optical fiber. An advantage of the dichroic fiber coupler 1750 in the fiber network 136 is that it is more compact than a free space beam splitter. In addition, the dichroic fiber coupler allows the first and second lights to be very well aligned, eliminating the need for special optical alignment procedures during production.

  Returning to FIG. 4, the scanner portion 36 may be embedded in a scanner, for example, as shown in FIG. 11 below. Light from the scanner portion 36, such as, for example, approximately 1550 nm infrared light, travels along the optical path 150 to the dichroic beam splitter 142. Dichroic beam splitter 142 is configured to reflect light from the scanner, while passing light from the laser tracker. Light from the scanner portion 36 travels to the target 58 and returns along the optical path 152 to the annular aperture 154. The return light passes through the annular aperture 154, is reflected by the dichroic beam splitter 142 along the outer optical path, and returns to the scanner section 36 along the optical path 156. In one embodiment, the outer light path (defined by the annular aperture 154) is coaxial with the inner light path (defined by the aperture 146). Returning the scanner light back through the annular opening 154 may have the advantage that unnecessary light from the opening 146 that may damage light reflected from the target 58 is avoided.

  In this exemplary embodiment, the opening 146 and the annular opening 154 are arranged concentrically. In this embodiment, the opening 146 has a diameter of about 15 mm, and the annular opening 154 has an inner diameter of 15 mm and an outer diameter of 3 mm.

  It should be understood that in this exemplary embodiment, dichroic beam splitter 142 is located at gimbal point 50. In this manner, light from both the scanner portion 36 and the tracker portion 34 may appear to be emanating from the same point within the device 30. In this exemplary embodiment, tracker portion emits visible laser light and scanner portion emits light in the near infrared spectrum. The wavelength of light from tracker portion 34 may be about 70 nm, and the wavelength of light from scanner portion 36 may be about 1550 nm.

  One embodiment of the scanner portion 36 is shown in FIG. In this embodiment, the scanner portion 36 includes a light emitter 160 that emits a light beam 162 through a collimator 165. Light emitter 160 may be a laser diode that emits light at a wavelength in the range of about 1550 nm. It should be understood, for example, that other electromagnetic waves having smaller or larger wavelengths may be used. The light beam 162 may be intensity or amplitude modulated, for example, by a sine or square waveform modulation signal. The light beam 162 is sent to a dichroic beam splitter 172, which reflects the light beam 162 toward the target 58 through the aperture 146. In this exemplary embodiment, light beam 162 is reflected by mirror 170 and dichroic beam splitter 172, and light beam 162 can travel along a desired optical path of light beams 52, 150. As will be described in more detail below, using a dichroic beam splitter 172 offers the advantage of allowing the incorporation of a color camera 168 that acquires images during operation. In another embodiment, the light emitter 160 is arranged to transmit light directly to the dichroic beam splitter 142 and need not first be reflected by the mirror 170 and the dichroic beam splitter 172.

  As shown in FIGS. 4 and 11, both the emitted light from the tracker portion 34 and the scanner portion 36 pass through the same aperture 146. Light from these tracker portion 34 and scanner portion 36 is substantially linear and travels along the optical path of light beam 52 of FIG. On the return path, light from the tracker portion 34 is reflected by the retro-reflector target, so that when it returns to the device 30, it is substantially straight. The return beam of tracker light returns through aperture 146, which is the same aperture as it exits instrument 30. In contrast, light from the scanner portion 36 typically hits the diffusely scattered object surface 58 'and spreads back over a wider angle. A small portion of the reflected light passes through an annular opening 154 positioned such that the inside diameter is the same (or concentric with) the outside diameter of the opening 146. The return light 163 is reflected by the dichroic beam splitter 172, passes through the lens 160 as a light beam 163, is reflected by the reflection surfaces 180, 178, and 176, passes through the lens group in the light receiver 182, and then passes through the photodetector. To reach. Return scanner light is directed through annular aperture 154 and does not include any light returning through inner aperture 146. This is advantageous because it is desirable that the optical power of the emitted light be much greater than that of the light returned by the object surface 58 ', and that reflections at the optical elements be returned along the path of the inner aperture 146. It is.

  In some embodiments, the optional color camera 168 receives a portion of the light reflected by the object surface 58 'through the dichroic beam splitter 172 and enters the color camera 168. The coating on the dichroic beam splitter 172 is selected to pass visible wavelengths picked up by the color camera, while reflecting light of the wavelength emitted by the light emitter 160. The color camera 168 may be coupled to the light receiving lens 160, for example, with an adhesive or in a recess. A color image can be acquired by the color camera 168, which is typically done by taking several discrete steps at some point after acquiring the data points with the rangefinder in the scanner.

  In some embodiments, the mask 174 is coaxially disposed on the optical axis behind the receiving lens 160. The mask 174 has a large area through which the return light beam 163 can pass without interruption. The mask 174 has a shielding area positioned radially outward from the optical axis, thereby making the intensity of the return light beam 163 more equal even if the intensity of the return light is different from the device 30 to the object surface 58 ′. To be reduced.

  In some embodiments, a rear mirror 176 is positioned on the optical axis behind the mask 174. The rear mirror 176 reflects the return light beam 163, which is refracted by the light receiving lens 166 and travels to the center mirror 178. The center mirror 178 is arranged on the optical axis at the center of the mask 174. In embodiments having a color camera 168, this area may be shadowed by the color camera 168. Central mirror 178 may be an aspheric mirror, which may be a negative lens (ie, extend the focal length) or a near-field correction lens (ie, shift the focus of return light beam 163 reflected by the target). ) Also works. In addition, reflection is provided only to the extent that the return light beam 163 passes through a mask 174 located above the central mirror 178. Central mirror 178 reflects the return light beam and passes through central aperture 180 of rear mirror 176.

  A light receiver 182 having an entrance stop, a collimator with filter, a condenser lens, and a photodetector is located near the rear mirror 176 and opposite the mask 174. In one embodiment, mirror 184 deflects return light beam 163 by 90 °.

  In one embodiment, the scanner portion 36 may include one or more processors 186, which may be the same as or complementary to the scanner electronics 96 of FIG. Processor 186 performs control and evaluation functions for scanner portion 36. Processor 186 is coupled to and in communication with light emitter 160 and light receiver 182. Processor 186 determines the distance between instrument 30 and target 58 for each measurement point based on the time of flight of emitted beam 162 and return light beam 163. In other embodiments, processor 186 and its functions may be incorporated into controller 64, which may correspond to scanner electronics 96, master processor 78, external computer 74, or network element 76 of FIG. .

  The optical rangefinder of the tracker portion 34 and the scanner portion 36 may determine the distance using the time-of-flight principle. It should be understood that the term time of flight is used herein to indicate any method of evaluating modulated light to determine the distance to a target. For example, light from the tracker portion 34 or the scanner portion 36 may have its optical power modulated using a sine wave (intensity modulation). The detected light is evaluated to determine the phase shift between the reference beam and the measurement beam and determine the distance to the target. In other embodiments, the optical power of the light may be modulated by a substantially rectangular pulsed light. In this case, the leading edge of the pulse may be measured on the way out of the device 30 and when returning to the device 30. In this case, the distance to the target is specified using the elapsed time. Another method involves changing the state of deflection of the light with respect to time by modulating an external modulator, and then recording the modulation frequency at which the return light disappears after passing through the polarizer. Many other methods for distance measurement are included in the general time-of-flight classification.

  Another common method for measuring distance is called coherent or interferometric. Unlike the above-described method in which the optical power of the light beam is evaluated, the coherent or interferometric method combines two mutually coherent light beams so that optical interference of the electric field occurs. Applying an electric field instead of optical power is the same as applying a voltage instead of electric power. One type of coherent distance meter varies the wavelength of light over time. For example, the wavelength may be changed in a sawtooth pattern (change linearly with periodic repetition). Equipment made in this manner is sometimes referred to as a frequency modulated coherent laser (FMCL) radar. Either the coherent type or the time-of-flight type can be used for the distance meter of the tracker portion 34 and the scanner portion 36.

  Referring now to FIGS. 12-14, one embodiment of the instrument is shown, the front cover has been removed, and some optics and conditioning electronics have been omitted for clarity. In this embodiment, instrument 30 includes a gimbal assembly 3610, which includes a zenith shaft 3630 and an optics bench assembly 3620 having a coupling tube 3622. The zenith shaft includes a shaft 3634 and a coupling sleeve 3632. Zenith shaft 3630 may be manufactured from a single piece of metal, which increases stiffness and temperature stability. FIG. 14 illustrates one embodiment of an optics bench assembly 3720 and a zenith shaft 3630. The optics bench assembly 3720 includes a main optics assembly 3650 and a secondary optics assembly 3740. The housing of the main optics assembly 3650 may be manufactured from a single piece of metal, which increases stiffness and temperature stability and includes a coupling tube 3622. In some embodiments, the central axis of the coupling tube 3622 coincides with the central axis of the coupling sleeve 3632. In one embodiment, four fasteners 3664 attach secondary optics assembly 3740 to primary optics assembly 3650. The coupling tube 3622 is inserted into the coupling sleeve 3632 and is held in place by three screws 3662. In one embodiment, the coupling tube 3622 is aligned with the coupling sleeve 3632 by two pins at one end of the coupling tube 3622 and the pins are fitted into holes 3666.

  The gimbal assembly 3610 is designed to hold the optics bench assembly 3620, but other types of equipment, such as cameras, laser engravers, video trackers, laser pointers, and angle measurers, as well as Light A Detection and Ranging (LIDAR) system can also be installed on the Zenith shaft 3630. The registration provided by the coupling sleeve 3632 allows such equipment to be easily and accurately attached to the gimbal assembly 3610. In this exemplary embodiment, tracker portion 34 is located within primary optics assembly 3650 and scanner portion 36 is located within secondary optics assembly 3740. The dichroic beam splitter 142 is located in the main optics assembly 3650, as shown in FIG.

  In operation, device 30 has two modes of operation, as shown in FIGS. 15 and 16, depending on the level of accuracy desired. The first mode (FIG. 15) uses the tracker portion 34 with a cooperative target 58 such as a retroreflector target, which may be, for example, a spherically mounted retroreflector (SMR). In this first mode, instrument 30 emits a light beam 52, which in effect passes through gimbal point 50, dichroic beam splitter 142, and aperture 146 toward target 58. Light 52 strikes target 58 and a portion of the light returns along aperture 146 and dichroic beam splitter 142 along the same optical axis to tracker portion 34. The device 30 then determines the distance from the device 30 to the target 58 as described above with respect to FIGS. In some embodiments, during this first mode of operation, the scanner portion 36 does not operate.

  In the second mode of operation, shown in FIG. 16, the scanner portion 36 emits a light beam 162, which is reflected by a dichroic beam splitter 142 and emitted through an aperture 146 toward a target 58. It should be understood that the scanner portion 36 may measure a distance to a non-cooperative target and does not require a target such as a retro-reflector to obtain the measurement. The light is reflected (scattered) by the target 58 and a portion 163 of the light returns through the annular aperture 154. As discussed above, it is desirable for the return light 163 to pass through the annular aperture 154 because it provides the advantage of reducing back reflections from the optics that can corrupt the return light signal. . Return light 163 is reflected by dichroic beam splitter 142 and returns to scanner portion 36, where the distance from device 30 to target 58 is determined as described above with respect to FIG. The scanner portion 36 operates continuously with the payload structure 46 being rotated about the azimuth axis 44 and the zenith axis 48 simultaneously. In this exemplary embodiment, the path followed by light beam 162 travels in a single direction (eg, does not reverse) while payload structure 46 rotates about axes 44,48. This path may be realized by continuously rotating each of the Zenith and azimuth motors in a single direction. In other words, in the second mode, the beam is directed to the object surface 58 ', while the zenith and azimuth angles change continuously and monotonically. Note that the beam may be guided at a high speed around one axis (zenith or azimuth axis), while at the same time being guided at a relatively low speed around the other axis. In one embodiment, movement of the payload structure 46 causes the light beam to follow a spiral path.

  It should be understood that operating scanner portion 36 such that the path of light beam 162 does not have to be reversed offers several advantages over a scanner that follows a raster or random pattern. First, since no direction reversal is required, a large amount of data can be efficiently collected. As a result, the scanner portion 36 can effectively scan a large area while acquiring data at a high sampling rate, such as over one million three-dimensional points per second. Second, by traveling continuously in one direction, when the light beam intersects a person, the total energy that falls on a certain area of the person can be small. Thereby, a more desirable laser classification based on IEC 60825-1 can be realized.

  In one embodiment, tracker portion 34 emits a light beam 52 in the visible light spectrum. In this embodiment, tracker portion 34 may emit light beam 52 while scanner portion 36 emits light 162. This is advantageous because the visible light 52 from the tracker portion 34 is a visible reference for the operator.

  Here, referring to FIGS. 17 and 18, a method of operating the device 30 is shown. Method 190 begins at block 192 with selecting an operating mode of tracker portion 34. The method then proceeds to block 194 where the tracker portion 34 is activated. At block 196, the gimbal mechanism is then moved about the zenith and azimuth axes to direct the light beam toward the target 58. At block 198, light is reflected from the cooperative target 58 and returns to the device 30 through the aperture 146. At block 200, device 30 then calculates the distance from device 30 to target 58. At block 202, the azimuth and zenith angles are determined, and the three-dimensional coordinates (distance and two angles) of the measurement point are determined. This process can be repeated until all desired measurement points have been identified.

  Referring now to FIG. 18, a method 203 is illustrated in which a scanner portion 36 is selected at block 204. The method 203 then proceeds to block 206 where the scanner portion 36 is activated. If it is desired to provide a visible reference light, block 208 activates light from the tracker portion 34. Light is transmitted from scanner portion 36 through aperture 146 to target 58. In this exemplary embodiment, as shown in block 209, light from the scanner portion 36 is emitted along a path in one direction (eg, spirally) and the direction is not reversed. The light is reflected from the target 58 and returns to the device 30. At block 210, return light is received through the annular aperture 154. At block 212, the distance from the device 30 to the target 58 is determined. In block 214, the azimuth and zenith angles are specified, and the coordinates (distance and two angles) to the measurement point on the target 58 are specified.

  The method of directing the light beam from the scanner portion 36 to the object surface 58 'may be performed other than as described above. In a first embodiment, light from scanner portion 36 is directed at gimbal assembly 3610 facing in the same direction. In this mode of operation, the beam is directed to any desired point. In a second embodiment, light from the scanner portion 36 is directed at a gimbal assembly 3610 that pivots at a relatively fast constant speed about an axis, which may be either the azimuth axis or the zenith axis. The other axis is also moved, but at a relatively slow speed. In this way, the beam is directed in a slow spiral. In the second embodiment, a complete scan of a large volume can be performed quickly. Another advantage of the second embodiment is that the time during which the constantly moving beam intersects the pupil of the human eye during its continuous movement is shorter. Thus, the desired IEC 60825-1 classification can be provided while using stronger laser power.

  Referring now to FIG. 19, another embodiment of the device 30 is shown, which includes a first absolute distance meter in the tracker portion 34 and a second absolute distance meter in the scanner portion 36. And a tracker portion 34 and a scanner portion 36 are coupled to a payload structure 46. In this embodiment, tracker portion 34 and scanner portion 36 do not emit light on a common optical path. Tracker portion 34 is arranged to direct light beam 52 in a first radial direction, while scanner portion 36 is arranged to direct light beam 162 in a second radial direction toward object surface 58 '. Is done. The first radial direction and the second radial direction form an angle θ therebetween. In the exemplary embodiment, angle θ is 90 °. In another embodiment, the angle θ is between 5 degrees and 180 degrees. However, any suitable angle can be used, provided that the tracker portion 34 and the scanner portion 36 can be positioned within the payload structure 46. It should be understood that as the payload structure 46 is rotated about the azimuth axis 44, the tracker portion 34 and the scanner portion 36 are oriented at the same azimuth angle.

  Referring now to FIG. 20, another embodiment of the device 30 is shown, which has a tracker portion 34 and a scanner portion 36. In this embodiment, tracker portion 34 is oriented parallel to scanner portion 36 and reflects light 52 toward dichroic beam splitter 142 using mirror 216. In this embodiment, dichroic beam splitter 142 is configured to reflect light 52 while transmitting light 162 from scanner portion 36.

The light beams 52, 162 pass through the aperture 146 and are directed along the optical axis A toward an oblique rotating mirror 218 arranged to rotate about a horizontal axis 48. Light 52,162 outward is reflected by the center C ₁₀ of the mirror, where it so toward the target 58 is reflected (in the case of tracker portion 34) or the object surface 58 '(when the scanner portion 36) Is deflected to Center C ₁₀ defines the origin of the reference system. Light reflected by target 58 or object surface 58 ′ is reflected from rotating mirror 218 and returned toward aperture 146. Light 52 is reflected at center C ₁₀ of rotating mirror 218 and returned through aperture 146. Light 52 is reflected by dichroic beam splitter 142 and mirror 216 before returning to tracker portion 34. Return light 163 is reflected by rotating mirror 218 and passes through annular aperture 154 before returning to scanner portion 36.

  The directions of the emitted light 52, 162 and the reflected light are determined by the angular position of the rotating mirror 218 about the horizontal axis 48 and the vertical axis 44. The angular position is measured by encoders 54 and 56, respectively. It should be understood that in one mode of operation, measurements by the tracker portion 34 and the scanner portion 36 are performed by a fast rotation of the rotating mirror 218 and a slow rotation of the payload structure 46. Therefore, the entire space is measured step by step as the instrument advances in a circle.

  In some embodiments, the light beam from the scanner is adjustably focused without collimation. In geometric optics, a focused light beam is a point, but in reality, the light beam is a beam waist near the calculated focal position. At the beam waist position, the width of the beam is minimized as the beam propagates.

  One advantage of sending a focused light beam from a scanner is that smaller beams allow more accurate 3D coordinate determination at the edges. For example, a smaller focused beam can more accurately identify the hole diameter or feature size. Another advantage of sending the focused light beam from the scanner is that the focused beam simply finds the position of maximum reflection of light from the touring ball retro-reflector, which is a shiny / highly reflective metal sphere. It is a point that can be guided. Such a method of directing the light beam from the scanner to the tooling ball allows the distance and angle to the tooling ball to be accurately measured. Therefore, a touring ball can be used as a target. An instrument that integrates the functions of a scanner and a tracker allows the use of two types of targets, SMR and tooling ball, as described herein. With the use of two types of targets, the tracker portion 34 and the scanner portion 36 can be easily placed in the same reference frame, which keeps both the SMR and the tooling ball in the same magnetic nest distributed in the environment. Because you can.

  In some embodiments, an adjustable focus adjustment mechanism 39 is added to other elements of the scanner section 36. Such an additional adjustable focus adjustment mechanism is shown in FIGS. FIG. 21 is similar to FIG. 4 except that the scanner portion 36 is shown having two internal components, a scanner component 37 and an adjustable focus adjustment mechanism 39. FIG. 22 is similar to FIG. 11, except that an adjustable focus adjustment mechanism 39 is included in the scanner portion 36. FIGS. 23 and 24 are similar to FIGS. 15 and 16 except that the scanner portion 36 is shown having a scanner element 37 and an adjustable focus adjustment mechanism 39. FIG. 25 is similar to FIG. 19, except that the scanner portion 36 is shown to include a scanner element 37 and an adjustable focus adjustment mechanism 39.

  In certain embodiments, the adjustable focus adjustment mechanism 39 includes a number of basic lens elements, which may include optional elements 2604, 2606, as shown in FIG. In addition, the adjustable focus adjustment mechanism 39 includes a lens element 2602 that is mounted on a motorized adjustable stage 2610 configured to move the lens 2602 back and forth and adjust as desired. In one embodiment, the scanner electronics 96 of FIG. 3 electrically controls the motorized adjustable stage 2610.

  Various lens assemblies and methods of adjustment are known in the art to provide an adjustable focus within the lens assembly. One skilled in the art will appreciate that any of the methods described herein may be used to provide an adjustable focus within the present invention.

  Although the invention has been described in detail with reference to only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the present invention can be modified to incorporate any number of variations, alternatives, permutations, or equivalent arrangements not described above but equivalent to the spirit and scope of the present invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be considered as limited by the foregoing description, but is only limited by the appended claims. Further, use of the terms first, second, etc., does not imply any order or importance, and the terms first, second, etc., are used to distinguish one element from another. Used in Further, use of terms such as articles (a, an) does not imply a limitation on the quantity, but implies that there is at least one item referred to.

  30 coordinate measuring equipment, 32 housing, 34 tracker part, 36 scanner part, 37 scanner element, 38 gimbal type beam steering mechanism, 39 adjustable focus adjustment mechanism, 40 azimuth base, 42 zenith carriage, 44 azimuth axis, 46 payload structure 48 Zenith axis, 50 gimbal points, 51 Zenith motor, 52, 162, 163 light beam, 54 Zenith angle encoder, 55 azimuth motor, 56 Azimuth angle encoder, 58 target (retro reflector target), 58 'object surface, 60 magnetic nest , 64 controllers, 66 distributed processing systems, 68 temperature sensors, 72 personal digital assistants, 74 external computers, 76 network components, 78 master processors, 80 payload function electronics Product unit, 82 azimuth encoder electronics, 86 Zenith encoder electronics, 88 display and UI electronics, 90 removable storage hardware, 92 wireless electronics, 94 antenna, 96 scanner electronics, 98 camera electronics, 100, 102, 104 electronic components, 106, 108, 110 bus lines, 112, 114, 116, 118 buses, 120, 122, 124 communication links, 126 light sources, 128 isolators, 130 fiber launch systems, 132 beam splitters, 134 position detectors, 136 Fiber network, 138, 148, 422, 433, 438, 465, 470, 471, 1743, 1753, 1781, 1790 Optical fiber, 140 electronic components, 142, 172 Croik beam splitter, 144, 150, 152, 156 Optical path, 146 Inner aperture, 154 Ring aperture, 160 light emitter, 165 Collimator, 166 Light receiving lens, 168 Color camera, 170, 184, 216 Mirror, 174 Mask, 176 Rear mirror 178 central mirror, 180 reflecting surface, 180 central aperture, 182 receiver, 186 processor, 218 rotating mirror, 420A fiber network, 423 fiber length equalization means (fiber length correction means), 430, 1740, 1750 optical fiber coupler, 435 low transmittance reflector, 436, 457, 463, 1730 optical fiber coupler, 440 low reflection fiber terminator, 462, 1738 low reflection terminator, 468 optical switch, 469 electrical input, 72,476 Retroreflector, 472A Fiber Optic Retroreflector, 472B Free Space Retroreflector, 473 Coating, 474 Collimator, 2602, 2604, 2606 Lens Element, 2610 Motorized Adjustable Stage, 3302 Frequency Reference, 3304 Synthesizer, 3306 Measurement and Detection , 3308 reference detector, 3310 measurement mixer, 3312 reference mixer, 3314, 3316 conditioning electronics, 3324 divide prescaler, 3400 data processor, 3610 gimbal assembly, 3620, 3720 optics bench assembly, 3622 coupling tube, 3630 Zenith shaft 3632 coupling sleeve, 3634 shaft, 3650 primary optics assembly, 36 4 fastener, 3666 hole, 3740 secondary optics assembly.

Claims (22)

In coordinate measuring equipment,
An optical transmission system,
A first absolute distance meter including a first light source, a first photodetector, and a first electrical circuit, wherein the first light source transmits the first light to the retro-reflector target through an optical transmission system. The first light detector is further configured to generate a first electrical signal in response to the first light being reflected by the retro-reflector target, and to generate the first electrical signal in a first electrical circuit. Wherein the first electrical circuit is configured to determine a first distance from the coordinate measuring device to the retroreflector target based at least in part on the first electrical signal. The first absolute distance meter,
A second absolute distance meter including a second light source, an adjustable focus adjustment mechanism, a second photodetector, and a second electrical circuit, wherein the second light source is through the adjustable focus adjustment mechanism and the optical transmission system. A second light detector configured to send the second light to the object surface, the second light detector configured to receive a portion of the second light reflected by the object surface and passing through the optical transmission system; The second photodetector further generates a second electrical signal in response to receiving a portion of the second light reflected by the object surface, and transfers the second electrical signal to a second electrical circuit. A second electrical circuit configured to transmit, the second electrical circuit being configured to determine a second distance from the coordinate measuring device to the object surface based at least in part on the second electrical signal. Two absolute distance meters,
A structure operatively connected to the optical transmission system, the first absolute distance meter, and the second absolute distance meter;
A first motor configured to rotate the structure about the first axis;
A first angle transducer operatively coupled to the structure, the first angle transducer configured to measure a first rotation angle about the first axis; and
A second motor configured to rotate the structure about a second axis, the second motor being substantially perpendicular to the first axis;
A second angle transducer operatively coupled to the structure, the second angle transducer configured to measure a second rotation angle about the second axis;
A position detector, configured to receive a portion of the radiation emitted by the coordinate measuring instrument and reflected by the retroreflector target, at least in part based on a position at which a portion of the radiation strikes the position detector. A position detector configured to generate three electrical signals;
A processor having a computer readable medium configured to operate in a first mode and a second mode;
Including
A first mode comprises: tracking a retroreflector target based at least in part on a third electrical signal; and providing a first three-dimensional coordinate of the retroreflector target at least partially to a retroreflector at a first location. Determining based on a first rotation angle to the target and a second angle of the retro-reflector target at the first position and a first distance of the retro-reflector target at the first position;
The second mode is a step of directing a second light toward the object surface, and converting a second three-dimensional coordinate of a point on the object surface into a first rotation angle at least partially to the point on the object surface. Determining based on a second rotation angle of the point on the object surface and a second distance of the point on the object surface, wherein the second mode comprises adjusting the adjustable focus adjustment mechanism. A coordinate measuring device further comprising: The coordinate measuring device according to claim 1,
The optical transmission system has an inner optical path and an outer optical path, wherein the outer optical path is coaxial with the inner optical path and outside the inner optical path;
A first light detector configured to receive the first light reflected by the retro-reflector target and passing through the inner light path of the light transmission system;
A coordinate measuring device, wherein the second photodetector is configured to receive second light reflected by the object surface and passing through an outer optical path of the optical transmission system. The coordinate measuring device according to claim 1,
A coordinate measuring device that emits second light along a spiral path by rotating the structure in one direction. The coordinate measuring device according to claim 1,
The coordinate measuring device, wherein the optical transmission system further comprises an annular aperture positioned to receive a portion of the second light reflected by the object surface. The coordinate measuring device according to claim 4,
A coordinate measuring device, wherein the processor is configured to emit the first light when the second absolute distance meter is emitting the second light. The coordinate measuring device according to claim 1,
A coordinate measuring instrument wherein the wavelength of the first light is about 700 nanometers. The coordinate measuring device according to claim 6,
A coordinate measuring device wherein the wavelength of the second light is about 1550 nanometers. In coordinate measuring equipment,
Structure and
A first motor configured to rotate the structure about the first axis;
A first angle transducer operatively coupled to the structure, the first angle transducer configured to measure a first rotation angle about the first axis; and
A second motor configured to rotate the structure about a second axis, wherein the second axis is substantially perpendicular to the first axis, and wherein the projection of the second axis is A second motor that intersects the projection of the first axis at the gimbal point,
A second angle transducer operatively coupled to the structure, the second angle transducer configured to measure a second rotation angle about the second axis;
An optical transmission system operatively connected to the structure;
A first absolute distance meter operatively connected to the structure, the first absolute distance meter including a first light source, a first photodetector, and a first electrical circuit, wherein the first light source passes through a first light transmission system. Configured to send a first light along a portion of a first line extending from the gimbal point to the retroreflector target, wherein the first line is perpendicular to the first axis and the first light detector Is configured to receive the first light reflected by the retro-reflector target and passing through the optical transmission system, the first photodetector further responsive to the first light reflected by the retro-reflector target. Generating a first electrical signal and transmitting the first electrical signal to a first electrical circuit, the first electrical circuit comprising a first distance from the coordinate measuring device to the retro-reflector target, First electricity at least partially A first absolute distance meter as configured to determine, based on the item,
A second absolute distance meter operatively connected to the structure, the second absolute distance meter including a second light source, an adjustable focusing mechanism, a second photodetector, and a second electrical circuit, wherein the second light source comprises: Configured to send a second light through the adjustable focusing mechanism and the light transmission system along a portion of a second line extending from the gimbal point to the object surface, the second line being perpendicular to the first axis. Wherein the second line is different from the first line and the second light detector is configured to receive a portion of the second light reflected by the object surface and passing through the light transmission system; The second photodetector further generates a second electrical signal in response to receiving a portion of the second light reflected by the object surface, and converts the second electrical signal to a second electrical circuit. The second electrical circuit is configured to transmit a second distance from the coordinate measuring device to the object surface, An absolute distance meter second as being configured to determine on the basis of the second electrical signal to a portion of even without,
A position detector, configured to receive a portion of the radiation emitted by the coordinate measuring instrument and reflected by the retroreflector target, the third electrical signal comprising at least a portion of the light radiation; A position detector configured to generate based on a position hitting the detector;
A processor having a computer readable medium configured to operate in a first mode and a second mode;
Including
The first mode includes: tracking a retro-reflector target based at least in part on a third electrical signal; and relocating a first three-dimensional coordinate of the retro-reflector target at least partially to a retro-position at a first location. Determining based on a first rotation angle of the reflector target and a second rotation angle to the retro-reflector target at the first position and a first distance of the retro-reflector target at the first position;
A second mode includes rotating the structure about a first axis and converting a second three-dimensional coordinate of a point on the object surface to at least in part a first rotation to that point on the object surface. Determining based on the angle and a second rotation angle to the point on the object surface and a second distance to the point on the object surface, the second mode adjusting the adjustable focus adjustment mechanism A coordinate measuring device, further comprising a step. The coordinate measuring device according to claim 8,
A first line extending in a first radial direction and a second line extending in a second radial direction, forming an angle therebetween, wherein the angle is between 5 degrees and 180 degrees. measuring equipment. The coordinate measuring device according to claim 9,
A coordinate measuring device having an angle of 90 degrees. The coordinate measuring device according to claim 8,
A coordinate measuring instrument wherein the wavelength of the first light is about 700 nanometers. The coordinate measuring device according to claim 9,
A coordinate measuring device wherein the wavelength of the second light is about 1550 nanometers. The coordinate measuring device according to claim 8,
The coordinate measuring device, wherein the optical transmission system further comprises an annular aperture positioned to receive a portion of the second light reflected by the object surface. The coordinate measuring device according to claim 8,
A coordinate measuring device, wherein the processor is configured to emit the first light when the second absolute distance meter is emitting the second light. In coordinate measuring equipment,
An optical transmission system,
A first absolute distance meter including a first light source, a first light detector, and a first electrical circuit, wherein the first light source sends the first light to a retro-reflector target through an optical transmission system. Wherein the first photodetector is configured to receive the first light reflected by the retro-reflector target and passing through the optical transmission system, the first photodetector further comprising: Generating a first electrical signal in response to being reflected by the retro-reflector target and transmitting the first electrical signal to a first electrical circuit, the first electrical circuit comprising a coordinate measuring device; A first absolute distance meter configured to determine a first distance from the retroreflector target based at least in part on the first electrical signal;
A second absolute distance meter including a second light source, an adjustable focus adjustment mechanism, a second photodetector, and a second electrical circuit, wherein the second light source includes an adjustable focus adjustment mechanism and an optical transmission system. A second light detector configured to receive a portion of the second light reflected by the object surface and passing through the light transmission system; The second photodetector further generates a second electrical signal in response to receiving a portion of the second light reflected by the object surface, and converts the second electrical signal to a second electrical circuit. The second electrical circuit is configured to determine a second distance from the coordinate measuring device to the object surface, at least in part, based on the second electrical signal. A second absolute distance meter,
A structure operatively coupled to the optical transmission system, the first absolute distance meter, and the second absolute distance meter, the mirror including a mirror mounted for rotation, the mirror comprising a first light and a second light; A structure arranged in the optical path of light,
A first motor configured to rotate the structure about the first axis;
A first angle transducer operatively coupled to the structure, the first angle transducer configured to measure a first rotation angle about the first axis; and
A second motor configured to rotate the mirror about a second axis, the second axis being substantially perpendicular to the first axis;
A second angle transducer operatively connected to the mirror, wherein the second angle transducer is configured to measure a second rotation angle about the second axis;
A position detector configured to receive a portion of the radiation emitted by the coordinate measuring instrument and reflected by the retro-reflector target, wherein the third electrical signal is at least partially localized. A position detector configured to generate based on the position of the device;
A processor having a computer readable medium configured to operate in a first mode and a second mode;
Including
The first mode includes: tracking a retro-reflector target based at least in part on a third electrical signal; and relocating a first three-dimensional coordinate of the retro-reflector target at least partially to a retro-position at a first location. Determining based on a first rotation angle to the reflector target and a second rotation angle to the retro-reflector target at the first position, and a first distance of the retro-reflector target at the first position;
A second mode includes rotating the structure about a first axis and converting a second three-dimensional coordinate of a point on the object surface to a first position at least partially to that position on the object surface. Determining based on the rotation angle and a second rotation angle to the position on the object surface and a second distance of the point on the object surface, the second mode adjusting the adjustable focus adjustment mechanism A coordinate measuring device, further comprising the step of: The coordinate measuring device according to claim 15,
In a second mode, the first motor rotates the structure at a first speed, the second motor rotates the mirror at a second speed, and the second speed is faster than the first speed. Coordinate measuring equipment. The coordinate measuring device according to claim 16,
The second mode comprises rotating the structure in one direction about a first axis. The coordinate measuring device according to claim 17,
A coordinate measuring device, wherein rotation of the first axis in one direction emits second light along a spiral path. The coordinate measuring device according to claim 15,
A coordinate measuring instrument wherein the wavelength of the first light is about 700 nanometers. The coordinate measuring device according to claim 19,
A coordinate measuring device wherein the wavelength of the second light is about 1550 nanometers. The coordinate measuring device according to claim 15,
The coordinate measuring device, wherein the optical transmission system further comprises an annular aperture positioned to receive a portion of the second light reflected by the object surface. The coordinate measuring device according to claim 15,
A coordinate measuring device, wherein the processor is configured to emit the first light when the second absolute distance meter is emitting the second light.

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