JP2019507349A - Laser tracker system - Google Patents

Abstract

The three-dimensional coordinate measurement system includes a retro reflector (2810) and a laser tracker (2820). The laser tracker includes a first light source 47 configured to emit a first light beam from the laser tracker, a structure 15 rotatable about the first axis 18 and the second axis 20, and a first Two light sources 54, a first camera 52 proximate to the second light source, and a processor 800 responsive to executable instructions. When the executable instructions are executed by the processor, in the first stage, the operator 2805 determines that an operator following gesture made by the trolley reflector 2810 held by the operator is given by the operator 2805, and in response the structure The body is rotated so as to follow the movement of the worker, and in the second stage, it is determined that the lock-on gesture 2815B is given by the worker, and in response thereto, the first light beam is directed onto the retroreflector. To work. [Selection] Figure 29B

Description

[Cross-reference of related applications]
This PCT application is a divisional application of US Patent Application No. 13/803479 filed on March 14, 2013, which is a benefit of US Patent Application No. 14/180900 filed on February 14, 2014. No. 15/055699, filed Feb. 29, 2016, which is a continuation-in-part of U.S. Patent Application No. 14/53113, filed Nov. 3, 2014 Claiming priority. US Patent Application No. 13/803479 claims the benefit of US Provisional Patent Application No. 61/326294 filed on April 21, 2010, the entire contents of which are hereby incorporated by reference, 2011 This is a divisional application of US Patent Application No. 13/090889 filed on April 20th.

  The present disclosure relates to a coordinate measuring instrument. A set of coordinate measuring instruments belongs to the class of instruments that measure the three-dimensional (3D) coordinates of a point by sending a laser beam to the point intercepted by the retroreflector target. The instrument finds the coordinates of a point by measuring the distance to the target and two angles to the target. The distance is measured by a distance measuring device such as an absolute distance meter (ADM) or an interferometer. The angle is measured by an angle measuring device such as an angle encoder. A gimbal beam steering mechanism in the instrument directs the laser beam to the point of interest. An example of such a device is a laser tracker. Exemplary laser tracker systems are described in Brown et al. US Pat. No. 4,790,651 and Lau et al. US Pat. No. 4,714,339, which are hereby incorporated by reference.

  A coordinate measuring instrument closely related to the laser tracker is the total station. Total stations are most often used in surveying applications and can be used to measure the coordinates of diffuse scattering targets or retroreflective targets. In the following, the term laser tracker is used in a broad sense including total stations.

  Typically, a laser tracker sends a laser beam to a retro reflector target. A common type of retro-reflector target is a spherical retro-reflector (SMR), which includes a corner cube retro-reflector embedded in a metal sphere. The corner cube retroreflector includes three reflectors that are perpendicular to each other. The vertex of the corner cube is the common intersection of the three reflectors and is located at the center of the sphere. The general technique is to bring the SMR sphere into contact with the object to be measured and then move the SMR on the surface to be measured. Since the corner cube is thus arranged in the sphere, the vertical distance from the vertex of the corner cube to the surface of the object to be measured remains constant despite the rotation of the SMR. Thus, the 3D coordinates of the surface can be found by having the tracker follow the 3D coordinates of the SMR moving over the surface. A glass window can be placed on top of the SMR to prevent dust and dirt from contaminating the glass surface. An example of such a glass surface is shown in US Pat. No. 7,388,654 to Raab et al., Which is incorporated herein by reference.

  A gimbal mechanism in the laser tracker can be used to direct the laser beam from the tracker to the SMR. Part of the light retroreflected by the SMR enters the laser tracker and travels to the position detector. The position of the light impinging on the position detector is used by the tracker control system to adjust the rotation angle of the azimuth and zenith machine axes of the laser tracker to keep the laser beam at the center of the SMR. In this way, the tracker can follow (track) the SMR.

  Angle encoders attached to the tracker's azimuth and zenith machine axes can measure the azimuth and zenith angles of the laser beam (relative to the tracker's reference frame). One distance measurement and two angle measurements made by the laser tracker are sufficient to fully identify the three-dimensional position of the SMR.

  As described above, there are two types of distance meters, laser meters and interferometers and absolute distance meters (ADMs). In a laser tracker, the interferometer (if present) starts by counting the number of increments of a known length (usually half the wavelength of the laser beam) that the retroreflector target passes as it moves between the two points. The distance from the end point to the end point can be determined. If the beam is interrupted during the measurement, the count number cannot be known accurately and the distance information is lost. In contrast, the ADM in the laser tracker determines the absolute distance to the retro-reflector target and allows the target to be switched regardless of the beam block, so the ADM is “point-and-shot”. It is said that measurement is possible. Initially, absolute rangefinders could only measure stationary targets and were therefore always used with interferometers. However, some modern absolute rangefinders can make quick measurements, thus eliminating the need for interferometers. Such ADMs are described in US Pat. No. 7,352,446 to Bridges et al.

  In the tracking mode, the laser tracker automatically follows the movement of the SMR when the SMR is in the tracker's capture range. If the laser beam is interrupted, tracking stops. The beam can be interrupted by any of several means: (1) Obstacles between the instrument and the SMR, (2) Rapid movement of the SMR that the instrument cannot follow because it is too fast, or (3) The direction of the SMR bends beyond the acceptance angle of the SMR. By default, following beam interruption, the beam remains fixed at the beam interruption point or the last commanded position. In order to lock on the instrument to the SMR and continue tracking, an operator may need to visually search the tracking beam and place the SMR in the beam.

  Some laser trackers include one or more cameras. The camera axis may be coaxial with the measurement beam and may be offset from the measurement beam by a certain distance or angle. The camera can be used to provide a wide field of view for locating the retro reflector. A modulated light source placed near the optical axis of the camera can illuminate the retro-reflector, making it easier to identify the retro-reflector. In this case, the retroreflector flashes in phase with the irradiation, whereas the background object does not flash in phase with the irradiation. One application of such a camera is to detect multiple retro-reflectors in the field of view and measure each in an automated sequence. Exemplary systems are described in U.S. Pat. No. 6,166,809 to Pettersen et al. And U.S. Pat. No. 7,800,782 to Bridges et al.

Some laser trackers have a function that can be measured with six degrees of freedom (DOF), which can include three coordinates such as x, y, and z and three rotations such as pitch, roll, and yaw. Several systems based on laser trackers are available or proposed to measure 6 degrees of freedom. Exemplary systems include Bridges, U.S. Patent Application Publication No. 2010/0128259, Bridges et al., U.S. Pat. No. 7,800,758, Pettersen et al., U.S. Pat. No. 5,973,788, which are incorporated herein by reference. Lau in U.S. Pat. No. 7,230,689.
[User control of laser tracker function]

  Two common operating modes of the laser tracker are the tracking mode and the profiling mode. In tracking mode, the laser beam from the tracker follows the retro-reflector as the operator moves it around. In the profiling mode, the laser beam from the tracker travels in the direction given by the operator, either through computer commands or manual operation.

  In addition to these modes of operation that control the tracker's basic tracking and pointing behavior, there is also a special option mode that allows the tracker to respond as previously selected by the operator. The desired option mode is usually selected by software that controls the laser tracker. Such software may be on an external computer attached to the tracker (possibly via a network cable) or may be internal to the tracker itself. In the latter case, the software can be accessed via a console function built into the tracker.

  An example of an optional mode is an automatic reset mode where the laser beam is fired to a preset reference point whenever the laser beam is interrupted. One common reference point for the auto-reset option mode is the tracker home position, which is the position of the magnetic nest attached to the tracker body. An alternative mode of automatic reset is the no reset option mode. In this case, the laser beam continues to point in its original direction whenever the laser beam is interrupted. A description of the tracker home position is described in Cramer et al. US Pat. No. 7,327,446, which is incorporated herein by reference.

  Another example of a special option mode is PowerLock, a function that Leica Geosystems offers in its Leica Absolute Tracker ™. In the PowerLock option mode, the position of the retro reflector is found by the tracker whenever the tracker laser beam is interrupted. The camera immediately sends the retroreflector's angular coordinates to the tracker control system, thereby causing the tracker to redirect the laser beam to the retroreflector. Methods involving the automatic acquisition of retroreflectors are described in Dold et al., WO 2007/079961, and Kaneko, US Pat. No. 7,055,253.

  Some optional modes are somewhat complicated to operate. One example is the stability discrimination mode, which can be invoked whenever the SMR is stationary for a period of time. The operator can track and lower the SMR to the magnetic nest. If stability determination is active, the software begins to check the stability of the tracker's 3D coordinate reading. For example, the user may decide to determine that the SMR is stable if the peak-to-peak deviation of the SMR distance reading is less than 2 micrometers over a one second interval. After the stability discrimination is satisfied, the tracker measures 3D coordinates and the software records the data.

  More complex operating modes are possible with computer programs. For example, software is available that measures part surfaces and adapts them to geometric shapes. The software directs the operator to move the SMR over the surface and then lift the SMR from the surface of the object to finish the measurement when the data point collection is complete. Separating the SMR from the surface not only indicates that the measurement is complete, but also indicates the position of the SMR relative to the object surface. This position information is necessary for the application software to properly consider the offset caused by the SMR radius.

  A second example of complex computer control is tracker surveying. In surveying, the tracker is driven sequentially to each of several target positions according to a predetermined schedule. The operator can teach these positions before surveying by carrying the SMR to each of the desired positions.

  A third example of complex software control is tracker guidance measurement. The software guides the operator to move the SMR to the desired position. To do this, the software uses a graphic display to indicate the direction and distance to the desired location. When the operator is at the desired location, the color on the computer monitor can change, for example, from red to green.

An element common to all tracker operations described above is that the operator has limited ability to control the behavior of the tracker. On the other hand, the option mode selected by the software may allow the operator to pre-set a specific behavior of the tracker. However, when the option mode is selected by the user, the tracker behavior is established and cannot be changed unless the operator returns to the computer console. On the other hand, the computer program may guide the operator to perform complex operations that the software has analyzed in a sophisticated manner. In either case, workers are limited in their ability to control the tracker and the data collected by the tracker.
[Necessity of remote tracker command]

  Laser tracker operators perform two basic functions. The operator positions the SMR during measurement and sends commands to the tracker via the control computer. However, since a computer is usually far away from the measurement location, it is not easy for a single operator to perform both of these measurement functions. Various methods have been tried to overcome this limitation, but none are completely satisfactory.

  One method that is often used is for one operator to set the retro-reflector in place and return to the instrument control keyboard to execute the measurement commands. However, this is an inefficient use of operator and instrument time. If an operator has to hold a retro reflector for measurement, control by a single operator is only possible when the operator is in the immediate vicinity of the keyboard.

  The second method is to add a second worker. One worker waits near the computer and the second worker moves the SMR. This is clearly an expensive method, and verbal communication at long distances can be a problem.

  The third method is to equip the laser tracker with remote control. However, remote control has some limitations. Many facilities do not allow the use of remote control for safety or security reasons. Even if remote control is allowed, interference between radio channels can be a problem. Some remote control signals do not reach the full range of the laser tracker. Depending on the situation, such as working from a ladder, you may not be able to operate the remote control freely with your free hand. To use remote control, it is usually necessary to set up the computer and the remote control to work together, in which case only a small portion of the normal tracker command is always accessible. An example of a system based on this idea is described in Smith et al. US Pat. No. 7,233,316.

  The fourth method is to interface the mobile phone with a laser tracker. Commands are entered remotely by calling the instrument from a mobile phone and entering the number from the mobile phone keypad or by voice recognition. This method also has many drawbacks. Some facilities do not allow the use of mobile phones, and mobile phones may not be available in rural areas. Service requires a monthly service provider fee. The cell phone interface requires additional hardware to interface to a computer or laser tracker. Mobile phone technology is changing rapidly and may require upgrades. As with remote control, the computer and remote control must be set up to work together, and only a small portion of the normal tracker commands are always accessible.

  The fifth method is to equip the laser tracker with internet or wireless network capability and communicate the command to the laser tracker using a wireless portable computer or personal digital assistant (PDA). However, this method has the same limitations as mobile phones. This method is often used with a total station. Examples of systems using this method include U.S. Patent Application No. 2009/017618 to Kumagai et al., U.S. Pat. No. 6,034,722 to Viney et al., U.S. Pat. No. 7,423,742 to Gatios et al. U.S. Pat. No. 7,307,710, U.S. Pat. No. 7,552,539 to Piekutowski, and U.S. Pat. No. 6,133,998 to Monz et al. This method has also been used to control instruments according to the method described in Uchi et al. US Pat. No. 7,541,965.

  The sixth method is to use a pointer that points to the specific location where the measurement should be made. An example of this method is described in Ura et al. US Pat. No. 7,022,971. Although it may be possible to adapt this method to give commands to the laser tracker, it is usually not very easy to find a suitable surface on which to project the pointer beam pattern.

  The seventh method is to devise a complex target structure that houses at least the retro-reflector, transmitter and receiver. Such a system can be used with a total station to send accurate target information to an operator and to send global positioning system (GPS) information to the total station. An example of such a system is described in US Patent Application Publication No. 2008/0229592 to Hinderling et al. In this case, no method is provided for the operator to send a command to the measuring instrument (total station).

  The eighth method is to devise a complex target structure that contains at least a retroreflector, a transmitter and a receiver, the transmitter having the ability to transmit a modulated optical signal to the total station. A keypad can be used to transmit commands to the total station using modulated light. These commands are decoded by the total station. Examples of such systems are US Pat. No. 6,023,326 to Katayama et al., US Pat. No. 6,462,810 to Murakaka et al., US Pat. No. 6,295,174 to Ishinobe et al., And US Pat. It is described in the specification. This method is particularly suitable for surveying applications where complex targets and keypads are attached to large scales. Such a method is not suitable for use in laser trackers where it is advantageous to use a small target that is not connected to a large control pad. It is also desirable to have the ability to send commands even when the tracker is not locked on to the retroreflector target.

  A ninth method is to include both a wireless transmitter and a modulated light source on the target that transmits information to the total station. The wireless transmitter mainly transmits information about the angular orientation of the target so that the total station can point in the proper direction to send its laser beam to the target retroreflector. The modulated light source is placed near the retro-reflector so that it is picked up by a detector in the total station. In this way, the operator can be confident that the total station is oriented in the correct direction, thereby avoiding false reflections that did not come from the target retroreflector. An exemplary system based on this approach is described in US Pat. No. 5,313,409 to WIklund et al. This method does not provide a function for sending general-purpose commands to the laser tracker.

  The tenth method is to include a combination of a wireless transmitter, both target and total station compass assemblies, and a guided light transmitter. The target and total station compass assembly is used to allow alignment of the total station azimuth to the target. A guided light transmitter is a horizontal fan-like light that allows the target to pan vertically until a signal is received by a detector in the total station. When the guided light is collected at the center of the detector, the total station slightly adjusts its orientation to maximize the retroreflected signal. The wireless transmitter transmits information entered by the operator on the keypad located at the target. An exemplary system based on this method is described in US Pat. No. 7,304,729 to Wasutomi et al. This method does not provide a function for sending general-purpose commands to the laser tracker.

  The eleventh method is to modify the retroreflector to allow time modulation to be imposed on the retroreflected light, thereby transmitting the data. The retroreflector of the present invention includes a corner cube having a truncated face, an optical switch attached to the front surface of the corner cube, and an electronic circuit for transmitting and receiving data. An exemplary system of this type is described in Kennedy US Pat. No. 5,121,242. This type of retro reflector is complex and expensive. This type of retro-reflector reduces the quality of the retroreflected light due to the switch (which can be a ferroelectric photonic crystal material) and the truncation. Also, the light returned to the laser tracker has already been modulated for use in measuring the ADM beam, and switching the light on / off is not only for the ADM, but also for the tracker interferometer and position detector. Should be a problem.

  The twelfth method is to use a meter that includes a bi-directional transmitter for communicating with a target and an active retro-reflector that helps identify the retro-reflector. The bi-directional transmitter may be wireless or optical and is part of a complex target raid that includes a retro-reflector, transmitter, and control unit. An exemplary system of this type is described in US Pat. No. 5,828,057 to Hertzman et al. Such a method is not suitable for use in laser trackers where it is advantageous to use a small target that is not connected to a large control pad. Also, the method of identifying the retro reflector target of interest is complex and expensive.

  There is a need for a simple way for operators to communicate commands to the laser tracker from a distance. This method (1) can be used without a second operator, (2) can be used across the entire range of laser trackers, (3) can be used without additional hardware interfaces, and (4) works everywhere (5) No service provider fees, (6) No security restrictions, (7) Easy to use without additional setup or programming, (8) A wide range of simple tracker commands and complex It is desirable that a tracker command can be initiated, (9) can be used to call a tracker to a specific target among multiple targets, and (10) can be used with minimal additional equipment for the operator to carry.

  According to one embodiment of the present invention, a three-dimensional (3D) coordinate measurement system includes a retroreflector and a laser tracker, wherein the first light source is configured to emit a first light beam from the laser tracker. A structure rotatable about a first axis and a second axis; a second light source; a first camera proximate to the second light source; and a processor responsive to executable instructions, When executed by the processor, in a first stage, it is determined that an operator following gesture has been given by the operator, and in response thereto, the structure is rotated so as to follow the movement of the operator, and the second stage In response to an executable instruction that operates to direct a first light beam onto the retro-reflector in response to determining that a lock-on gesture has been provided by the operator That includes a processor, and includes a laser tracker, the.

  According to another embodiment of the present invention, a method for measuring three-dimensional (3D) coordinates comprises providing a retroreflector and a laser tracker, wherein the laser tracker emits a first light beam. A first light source configured as described above, a structure rotatable about the first axis and the second axis, a second light source, a first camera proximate to the second light source, and a processor A step of providing an operator following gesture in a first stage, and a processor executing an executable instruction in response to the operator following gesture in a first stage, Rotating the structure so as to follow, in a second stage, the operator giving a lock-on gesture, and responding to the lock-on gesture with the processor Run the executable instructions Te, comprising the steps of: directing a first light beam onto a retro-reflector, a.

  Reference is now made to the drawings. Like elements are numbered alike in some figures.

1 is a perspective view illustrating an exemplary laser tracker. FIG.

FIG. 3 shows computing and power supply elements attached to an exemplary laser tracker.

FIG. 6 illustrates how gesture information can be transmitted through a laser tracker tracking system and measurement system using a passive target. FIG. 6 illustrates how gesture information can be transmitted through a laser tracker tracking system and measurement system using a passive target. FIG. 6 illustrates how gesture information can be transmitted through a laser tracker tracking system and measurement system using a passive target. FIG. 6 illustrates how gesture information can be transmitted through a laser tracker tracking system and measurement system using a passive target. FIG. 6 illustrates how gesture information can be transmitted through a laser tracker tracking system and measurement system using a passive target.

FIG. 6 illustrates a method by which a passive target can be used to communicate gesture information via a laser tracker camera system. FIG. 6 illustrates a method by which a passive target can be used to communicate gesture information via a laser tracker camera system. FIG. 6 illustrates a method by which a passive target can be used to communicate gesture information via a laser tracker camera system.

FIG. 6 illustrates how gesture information can be communicated through a laser tracker camera system using an active target. FIG. 6 illustrates how gesture information can be communicated through a laser tracker camera system using an active target. FIG. 6 illustrates how gesture information can be communicated through a laser tracker camera system using an active target. FIG. 6 illustrates how gesture information can be communicated through a laser tracker camera system using an active target.

It is a flowchart which shows the step performed by a worker and a laser tracker when issuing and executing a gesture command.

It is a flowchart which shows the optional part and required part of a gesture command.

FIG. 4 shows selected laser tracker commands and corresponding gestures that can be used by an operator to communicate these commands to the laser tracker. FIG. 4 shows selected laser tracker commands and corresponding gestures that can be used by an operator to communicate these commands to the laser tracker. FIG. 4 shows selected laser tracker commands and corresponding gestures that can be used by an operator to communicate these commands to the laser tracker.

FIG. 6 shows an alternative type of gesture that may be used. FIG. 6 shows an alternative type of gesture that may be used. FIG. 6 shows an alternative type of gesture that may be used. FIG. 6 shows an alternative type of gesture that may be used. FIG. 6 shows an alternative type of gesture that may be used. FIG. 6 shows an alternative type of gesture that may be used.

FIG. 2 shows an exemplary command tablet for sending commands to a laser tracker by gestures.

FIG. 6 illustrates an exemplary method for setting a tracker reference point using a gesture.

FIG. 6 illustrates an example method for initializing an example command tablet using gestures.

FIG. 6 illustrates an exemplary method for measuring a circle using a gesture.

FIG. 6 illustrates an exemplary method for obtaining a retroreflector with a laser beam from a laser tracker using a gesture.

FIG. 2 illustrates an example electronic circuit and processing system associated with a laser tracker.

FIG. 4 illustrates an exemplary geometry that allows a camera located off the optical axis of a laser tracker to be used to find a target's three-dimensional coordinates.

FIG. 6 illustrates an exemplary method for communicating commands to a laser tracker by signaling with a retroreflector in a spatial pattern.

FIG. 6 illustrates an exemplary method for communicating a command to a laser tracker by indicating a position with a retro reflector.

FIG. 6 illustrates an exemplary method for communicating a command to a laser tracker by signaling with a retroreflector in a time pattern.

FIG. 6 illustrates an exemplary method for communicating commands to a laser tracker by measuring a change in posture of a 6-DOF target using a 6-DOF laser tracker.

An exemplary method for directing a laser beam from a laser tracker to a retro-reflector and transmitting a command to lock-on to the retro-reflector, where the transmission is based on a gesture with a spatial pattern generated using the retro-reflector. FIG. 3 is a diagram illustrating a method.

An exemplary method for transmitting a laser beam from a laser tracker to a retro-reflector and transmitting a command to lock on to the retro-reflector, the transmission being based on a gesture with a temporal pattern of optical power received by the laser tracker It is a figure which shows a method.

An exemplary method for directing a laser beam from a laser tracker to a retro-reflector and transmitting a command to lock-on to the retro-reflector, wherein the transmission is based on a gesture with a change in posture of a 6-DOF probe. It is a figure which shows a method.

1 is a perspective view of a 3D measurement system according to one embodiment. FIG.

FIG. 6 illustrates elements of a method for locking on a retro-reflector according to one embodiment.

It is a figure which shows the worker who gives the example worker following gesture based on the motion pattern of the retro reflector in space.

FIG. 28B is a front view of the exemplary retro-reflector shown in FIG. 28A. FIG. 28B is a perspective view of the exemplary retroreflector shown in FIG. 28A.

FIG. 5 is a diagram showing a laser tracker being rotated to follow an operator in response to receiving an operator follow command.

FIG. 5 shows an operator giving an exemplary lock-on gesture based on the motion pattern of retro reflectors in space.

FIG. 3 is a diagram showing a laser tracker that locks on a retro-reflector in response to receiving a lock-on gesture.

It is a figure which shows the operator who gives the alternative lock-on gesture based on the position of the operator's arm with respect to the operator's torso, and the laser tracker that locks on the retro-reflector in response.

  An exemplary laser tracker 10 is shown in FIG. The exemplary gimbal beam steering mechanism 12 of the laser tracker 10 includes a zenith carriage 14 that rotates about an azimuth axis 20 attached to an azimuth base 16. Payload 15 is attached to zenith carriage 14 and rotates about zenith axis 18. The zenith machine rotation axis 18 and the azimuth machine rotation axis 20 are orthogonal to each other inside the tracker 10 at a gimbal point 22, and the gimbal point 22 is usually an origin for distance measurement. The laser beam 46 is directed substantially through the gimbal point 22 and perpendicular to the zenith axis 18. In other words, the laser beam 46 is in a plane perpendicular to the zenith axis 18. Laser beam 46 is directed in a desired direction by a motor (not shown) in the tracker that causes payload 15 to rotate about zenith axis 18 and azimuth axis 20. A zenith angle encoder and an azimuth encoder (not shown) inside the tracker are attached to the zenith machine shaft 18 and the azimuth machine shaft 20 and indicate the rotation angle with high accuracy. Laser beam 46 travels to external retro-reflector 26, such as the spherical retro-reflector (SMR) described above. By measuring the radial distance between the gimbal point 22 and the retroreflector 26 and the rotation angle about the zenith axis 18 and the azimuth axis 20, the position of the retroreflector 26 is found in the tracker's spherical coordinate system. .

  Laser beam 46 may include one or more laser wavelengths. For clarity and simplicity, the following discussion assumes a steering mechanism of the type shown in FIG. However, other types of steering mechanisms are possible. For example, it may be possible to reflect the laser beam from a reflector that rotates about the azimuth and zenith axes. An example of using such a reflector is described in US Pat. No. 4,714,339 to Lau et al. The techniques described herein are applicable regardless of the type of steering mechanism.

  In the exemplary laser tracker 10, the camera 52 and light source 54 are located on the payload 15. The light source 54 illuminates one or more retroreflector targets 26. The light source 54 may be an LED that is electrically excited to repeatedly emit pulsed light. Each camera 52 includes a photosensitive array and a lens disposed in front of the photosensitive array. The photosensitive array may be a CMOS or CCD array. The lens may have a relatively wide field of view, for example 30 degrees or 40 degrees. The purpose of the lens is to form an image of the object in the lens field of view on the photosensitive array. Each light source 54 is disposed near the camera 52 such that light from the light source 54 is reflected from each retroreflector target 26 onto the camera 52. In this way, retroreflector images are easily distinguished from the background on the photosensitive array because their image spots are brighter and pulsed than the background. Two cameras 52 and two light sources 54 can be arranged around the line of the laser beam 46. By using two cameras in this way, the triangulation principle can be used to find the 3D coordinates of any SMR within the camera's field of view. In addition, the three-dimensional coordinates of the SMR can be monitored as the SMR is moved from point to point. The use of two cameras for this purpose is described in US Patent Application Publication No. 2010/0128259 to Bridges.

  Other configurations of one or more cameras and light sources are possible. For example, the light source and camera can be coaxial or nearly coaxial with the laser beam emitted by the tracker. In this case, it may be necessary to avoid saturating the photosensitive array of the camera with a laser beam from the tracker using optical filtering or similar methods.

  Another possible configuration is to use a single camera located on the tracker payload or base. A single camera, when located off the laser tracker's optical axis, provides information about the two angles that define the direction to the retroreflector, but not the distance to the retroreflector. In many cases, this information is sufficient. If the 3D coordinates of the retroreflector are needed when using a single camera, one possible method is to rotate the tracker azimuthally 180 degrees and then turn the zenith axis to point again to the retroreflector It is to invert. In this way, the target can be viewed from two different directions and triangulation can be used to find the 3D position of the retroreflector.

A more common way to find the distance to the retro-reflector with a single camera is to rotate the laser tracker around either the azimuth axis or the zenith axis, with a camera located on the tracker for each of the two rotation angles. It is to observe a retro reflector. The retro reflector may be illuminated, for example, by an LED located near the camera. FIG. 18 shows how this procedure can be used to find the distance to the retroreflector. The test apparatus 900 includes a laser tracker 910, a first position camera 920, a second position camera 930, and a first position 940 and a second position 950 retroreflector. The camera is moved from the first position to the second position by rotating the laser tracker 910 about the tracker gimbal point 912 about the azimuth axis, the zenith axis, or both the azimuth and zenith axes. Camera 920 includes a lens system 922 and a photosensitive array 924. The lens system 922 has a projection center 926 through which the light beams from the retroreflectors 940 and 950 pass. Camera 930 is the same as camera 920 except that it is rotated to a different position. Distance from the surface of the laser tracker 910 to retroreflector 940 is _{L 1,} the distance from the surface of the laser tracker to retroreflector 950 is _{L 2.} A path from the gimbal point 912 to the projection center 926 of the lens 922 is drawn along line 914. A path from the gimbal point 912 to the projection center 936 of the lens 932 is drawn along line 916. The distances corresponding to lines 914 and 916 have the same numerical value. As can be seen from FIG. 18, the closer position 940 of the retro-reflector places the image spot 942 farther from the center of the photosensitive array than the image spot 952 corresponding to the photosensitive array 924 that is further away from the laser tracker. . This same pattern applies to the camera 930 located after rotation (see, for example, image spot 944 and image spot 954 on photosensitive array 934). As a result, the distance between the image points of the retro reflector 940 that are close before and after the rotation is greater than the distance between the image points of the retro reflector 950 that are far apart before and after the rotation. By rotating the laser tracker and noting the resulting change in the position of the image spot on the photosensitive array, the distance to the retroreflector can be found. A method for obtaining this distance can be easily found using trigonometry, as will be apparent to those skilled in the art.

  Another possible method is to switch between target measurement and imaging. An example of such a method is described in US Pat. No. 7,800,578 to Bridges et al. Other camera configurations are possible and can be used with the methods described herein.

  As shown in FIG. 2, the auxiliary unit 70 is usually a part of the laser tracker 10. The purpose of the auxiliary unit 70 is to supply power to the laser tracker body, and in some cases also to provide computing and clock control functions to the system. It is also possible to completely remove the auxiliary unit 70 by transferring the function of the auxiliary unit 70 to the tracker body. In most cases, the auxiliary unit 70 is attached to a general purpose computer 80. Application software loaded on the general-purpose computer 80 can provide application functions such as reverse engineering. It is also possible to eliminate the general-purpose computer 80 by directly incorporating the calculation capability of the general-purpose computer 80 into the laser tracker 10. In this case, a user interface, possibly providing keyboard and mouse functions, is incorporated into the laser tracker 10. The connection between the auxiliary unit 70 and the computer 80 may be wireless or via an electric cable. The computer 80 may be connected to a network, and the auxiliary unit 70 may also be connected to the network. A plurality of instruments, for example, a plurality of measurement instruments and actuators may be connected to each other via the computer 80 or the auxiliary unit 70.

  The laser tracker 10 may rotate on its side surface, may be turned upside down, and may be arranged in any direction. In these situations, the terms azimuth axis and zenith axis have the same direction as shown in FIG. 1 with respect to the laser tracker, regardless of the orientation of the laser tracker 10.

In another embodiment, payload 15 is replaced with a reflector that rotates about azimuth axis 20 and zenith axis 18. The laser beam is directed upward, hits the reflector, and is emitted from the reflector toward the retro-reflector 26.
[Send command to laser tracker from a distance]

  FIGS. 3A-3E, 4A-4C, and 5A-5D illustrate sensing means for transmitting a gesture pattern that an operator interprets and executes as a command by the exemplary laser tracker 10. FIG. 3A-3E illustrate sensing means for an operator to convey a gesture pattern that the exemplary laser tracker 10 interprets using its tracking and measurement systems. FIG. 3A shows a laser tracker 10 that emits a laser beam 46 that is blocked by a retroreflector target 26. When the target 26 is moved left and right, the laser beam from the tracker follows the movement. At the same time, the angle encoder in the tracker 10 measures the angular position of the target in the horizontal direction and the vertical direction. The angle encoder readings are recorded by the tracker as a function of time, forming a two-dimensional map of angles that can be analyzed to look for patterns of motion.

  FIG. 3B shows a laser beam 46 that tracks the retroreflector target 26. In this case, the distance from the tracker 10 to the target 26 is measured. The ADM or interferometer readings are recorded by the tracker 10 as a function of time to form a one-dimensional map of distance that can be analyzed to look for motion patterns. The combined operation of FIGS. 3A and 3B can also be evaluated by the laser tracker 10 to look for patterns in the three-dimensional space.

  Angles, distances, or variations in three-dimensional space can all be considered as examples of spatial patterns. Spatial patterns are constantly observed during normal laser tracker measurements. Within the possible range of observed patterns, some patterns may have an associated laser tracker command. There is one type of spatial pattern used today that can be considered a command. This pattern is a movement away from the surface of the object after measurement. For example, if an operator measures several points on an object with SMR to obtain the outer diameter of the object and then moves the SMR away from the surface of the object, it is clear that the outer diameter has been measured. . It is clear that the inner diameter was measured when the operator measured the inner diameter and then separated the SMR from the surface. Similarly, if the operator moves the SMR upward after measuring the plate, it is understood that the upper surface of the plate has been measured. It is important to know which side of the object is being measured. This is because it is necessary to remove the SMR offset, which is the distance from the center of the SMR to the outer surface. If this movement of the SMR away from the object is automatically interpreted by software associated with the laser tracker measurement, the SMR movement is considered a command to indicate “subtract the SMR offset from the direction of movement”. Can be. Thus, as described herein, there are multiple commands when this first command is included in addition to other commands based on the spatial pattern. In other words, there is a correspondence between a plurality of tracker commands and a plurality of spatial patterns.

  In all discussions in this application, it should be understood that the concept of commands for a laser tracker should be understood within the context of a particular measurement. For example, in the above situation where the retroreflector movement is said to indicate whether the retroreflector target was measuring the inner or outer diameter, this description measures an object with a circular contour. Should only be correct in the context of a tracker.

  FIG. 3C shows a laser beam 46 that tracks the retroreflector target 26. In this case, the retroreflector target 26 is fixed, and the tracker 10 measures three-dimensional coordinates. For example, a special meaning may be assigned to a specific position in the measurement volume, such as when a command tablet to be described later is located at a specific three-dimensional position.

  FIG. 3D shows the laser beam 46 being blocked from reaching the retro-reflector target 26. By alternately blocking and unblocking the laser beam 46, the pattern of optical power returned to the tracker 10 is confirmed by a tracker measurement system that includes a position detector and rangefinder. This returned pattern variation forms a pattern as a function of time that can be recorded by the tracker and analyzed to find the pattern.

  The pattern of optical power returned to the laser tracker is often confirmed during normal measurements. For example, it is common to prevent the laser beam from reaching the retroreflector and then recapture the laser beam with the retroreflector later, perhaps after moving the retroreflector to a new distance from the tracker . This action of blocking the laser beam and then recapturing the laser beam can be considered a simple type of user command that indicates that the retroreflector should be recaptured after being moved to a new position. . Thus, as described herein, there are multiple commands when including this first simple command in addition to other commands based on temporal variations in optical power. In other words, there is a correspondence between a plurality of tracker commands and a plurality of patterns based on variations in optical power received by a sensor placed on the laser tracker.

  The change in optical power is often confirmed during normal measurements where the laser beam is prevented from returning to the laser tracker. Such an operation can be interpreted as a command indicating “stop tracking” or “stop measurement”. Similarly, the retro reflector may be moved to block the laser beam. Such a simple operation can be interpreted as a command indicating “start tracking”. These simple commands are not of interest to this patent application. Thus, the commands discussed herein involve a change in optical power that includes at least an increase in optical power following a decrease in optical power.

  FIG. 3E shows a laser beam 46 that tracks a retroreflector 26 having a six degree of freedom (DOF) probe 110. Many types of six-degree-of-freedom probes are possible, and the six-degree-of-freedom probe 110 shown in FIG. 3E is merely representative and does not limit its design. The tracker 10 can find the angle of inclination of the probe. For example, the tracker may find and record the roll angle, pitch angle, and yaw angle of the probe 110 as a function of time. Analyzing a set of angles to find a pattern.

  4A-4C illustrate sensing means for an operator to convey gesture patterns that the exemplary laser tracker 10 interprets using its camera system. FIG. 4A shows a camera 52 that observes the motion of the retroreflector target 26. The camera 52 records the angular position of the target 26 as a function of time. These angles are later analyzed to look for patterns. While only one camera is required to follow the angular motion of the retroreflector target 26, the second camera allows the distance to the target to be calculated. An optional light source 54 illuminates the target 26, thereby facilitating identification at the center of the background image. In addition, the light source 54 may be pulsed to further simplify target identification.

  FIG. 4B shows a camera 52 that observes the motion of the retroreflector target 26. Camera 52 records the angular position of target 26 and uses triangulation to calculate the distance to target 26 as a function of time. These distances are later analyzed to look for patterns. An arbitrary light source 54 irradiates the target 26.

  FIG. 4C shows a camera 52 that observes the position of the retroreflector target 26 that is fixed. The tracker 10 measures the three-dimensional coordinates of the target 26. For example, a special meaning may be assigned to a specific position in the measurement volume, such as when a command tablet to be described later is located at a specific three-dimensional position.

  5A-5D illustrate sensing means for an operator to convey a gesture pattern that the exemplary laser tracker 10 interprets using its camera system in combination with an active light source. FIG. 5A shows a camera 52 that observes the active retro-reflector target 120. The active retro-reflector target includes a retro-reflector target 126 with a light source 122 and a control button 124 that turns the light source 122 on and off. The operator turns on / off the control button 124 in a predetermined pattern, and turns on the light source 122 in a pattern confirmed by the camera 52 and analyzed by the tracker 10.

  Another mode of operation in FIG. 5A is to hold down the control button 124 only while the operator signals a command that can be given using, for example, left and right movements and up and down movements. By pressing the control button 124 only during this time, the analysis and analysis at the tracker 10 is simplified. There are several ways in which the tracker can obtain a pattern of movement, regardless of whether the control button 124 is pressed. (1) The camera 52 can follow the movement of the light source 122. (2) The camera 52 follows the movement of the retroreflector 126 that is optionally irradiated by the light source 54 (see, for example, FIGS. 4A to 4C). Or (3) the tracking system and measurement system of the laser tracker 10 can follow the movement of the retroreflector 126. In addition, while the tracker is following the retro-reflector 126 to collect measurement data, the operator simultaneously presses the control button 124 up and down to generate an LED emission time pattern that issues commands to the tracker. It is also possible to do.

  FIG. 5B shows the camera 52 that observes the light source 132 on the six-degree-of-freedom probe 130. The six degree of freedom probe 130 includes a retro reflector 136, a light source 132, and a control button 134. The operator turns on and off the control button 134 in a predetermined manner and turns on the light source 132 in a pattern confirmed by the camera 54 and analyzed by the tracker 10.

  An alternative mode of operation in FIG. 5B is to hold down the control button 134 only while the operator signals a command that can be given using, for example, left and right movement and up and down movement or rotation. By pressing the control button 134 only during this time, the analysis and analysis at the tracker 10 is simplified. In this case, there are several ways in which the tracker can get the pattern of movement. (1) The camera 52 can follow the movement of the light source 132. (2) The camera 52 can observe the movement of the retro-reflector 136 that is optionally illuminated by the light source 54 (see, eg, FIGS. 4A-4C). Or (3) the tracking system and measurement system of the laser tracker 10 can follow the movement or rotation of the six-degree-of-freedom target 130.

  5A and 5B can also be used to indicate a specific location. For example, a point on the sphere of the active retroreflector target 120 or a point on the sphere of the six-degree-of-freedom probe 130 can be held against an object that provides a position that can be determined by the camera 52. For example, a special meaning may be assigned to a specific position in the measurement volume, such as when the command tablet described with reference to FIG. 12 is located at a specific three-dimensional position.

  FIG. 5C shows the camera 52 observing the light source 142 on the wand 140. The wand 140 includes a light source 142 and a control button 144. The operator turns on and off the control button 144 in a predetermined manner and turns on the light source 142 in a time pattern confirmed by the camera 54 and analyzed by the tracker 10.

  FIG. 5D shows the camera 52 observing the light source 142 on the wand 140. The operator presses the control button 144 on the wand 140 to turn on the light source 142 continuously. As the operator moves the wand 140 in any direction, the camera 52 records the movement of the wand 140 and the pattern is analyzed by the tracker 10. A single camera 52 can be used if only the transverse (left and right, up and down) movement pattern is important and the radial movement is not important.

  As described above, the tracker 10 detects the spatial position and temporal pattern generated by the operator using the retroreflector target 26, the six degree of freedom target 110 or 130, the active retroreflector target 120, or the wand 140. Have the ability to These spatial patterns or temporal patterns are collectively called a gesture. The particular devices and sensing modes shown in FIGS. 3A-3E, 4A-4C, and 5A-5D are exemplary and should not be understood as limiting the scope of the present invention.

  FIG. 6 shows a flowchart 200 that describes the steps performed by the operator and the laser tracker 10 when issuing and executing gesture commands. At step 210, the laser tracker 10 constantly scans for commands. In other words, the tracker records the position, spatial pattern, and temporal pattern using one or more sensing modes shown in FIGS. 3A-3E, 4A-4C, and 5A-5D. In step 220, the operator sends a command. This means that the operator generates a gesture by performing an appropriate action on an object such as the retro-reflector target 26, the six-degree-of-freedom target 110 or 130, the active retro-reflector target 120, or the wand 140. means. Appropriate motion may involve movement to a specific absolute coordinate or movement that generates a specific spatial or temporal pattern.

  At step 230, the tracker 10 intercepts and analyzes the command just sent by the operator. The tracker 10 intercepts commands by sensing and recording spatial and temporal information from moving objects. The tracker 10 parses the command, possibly using computing power within the tracker, splits the data stream into appropriate subunits, and identifies the patterns formed by the subunits according to an algorithm. The types of algorithms that can be used are described below.

  At step 240, the tracker confirms that the command has been received. The confirmation may be, for example, in the form of flashing light located on the tracker. Confirmation can take several forms, depending on whether the command was clearly received, garbled, or incomplete, or impossible to perform for some reason. Signals for each of these different conditions can be provided in a wide variety of ways. For example, different colored lamps, different patterns or flashing durations may be possible. Audible sound can also be used as feedback.

  In step 250, the tracker 10 checks whether the command is garbled. In other words, are you sure of the meaning of the received command? It is. If the command is garbled, the flow returns to step 210 where the tracker 10 continues to scan the command. If not, the flow proceeds to step 260 where the tracker 10 checks to see if the command is incomplete. In other words, do you need more information to fully define the command? It is. If the command is incomplete, the flow returns to step 210 where the tracker 10 continues to scan for commands. Otherwise, the flow proceeds to step 270.

  In step 270, the tracker 10 performs the operation requested by the command. In some cases, the operation requires multiple steps on both the tracker side and the worker side. Examples of such cases are considered below. At step 280, the tracker 10 signals that the measurement is complete. The flow then returns to step 210 where the tracker continues to scan for commands.

  FIG. 7 shows that step 220 in which the operator sends a command includes three steps: step 222-prologue, step 224-command, and step 226-epilogue. The prologue step and epilogue step are optional. The command part of the command is the part of the command that conveys the command to be followed. The prolog part of the command tells the tracker that the command is starting and that a command will be given soon. The epilog portion of the command tells the tracker that the command has finished.

  FIGS. 8-10 show two example gesture sets (“Example 1 gesture” and “Example 2” gesture) corresponding to the example command set. An exemplary command set is shown in the leftmost column of FIGS. Some of these commands were taken from FARO CAM2 software. Other commands were taken from other software, such as SMX Insight software or utility software shipped with the FARO laser tracker. Beyond these examples, commands may be obtained from other software or simply generated for specific needs. Each second column of FIGS. 8-10 shows a software shortcut in the CAM2 software, if available. The operator can press this software shortcut on the keyboard to execute the corresponding command. The third and fourth columns of FIGS. 8-10 show some spatial patterns that can be used to represent a particular command. A two-dimensional spatial pattern can be sensed using, for example, the method shown in FIG. 3A, FIG. 4A or FIG. 5D.

  The start position is indicated by a small circle and the end position is indicated by an arrow for each of the gestures in the third row and the fourth row in FIGS. The gestures in the third column of FIGS. 8-10 are simple shapes, i.e., circles, triangles, or squares. The 28 shapes shown in this column are distinguished from each other by their orientation and starting position. In contrast, the shape of the fourth column in FIGS. 8 and 9 suggests the command to be executed. The main advantage of the shape of the third row is that they are easy to recognize and interpret as commands for the computer. This aspect is discussed in more detail below. The main advantage of the shape of the fourth row in FIGS. 8 and 9 is that they are easy for the operator.

  Figures 11A-11F illustrate some alternative spatial patterns that may be used in gestures. FIG. 11A shows a single stroke, FIG. 11B shows alphanumeric characters, FIG. 11C shows a simple shape, FIG. 11D shows a simple path where the path is reversed or repeated once, and FIG. A composite path formed from two or more simpler patterns is shown, and FIG. 11F shows a pattern formed from two or more characters.

  FIG. 12 shows an exemplary command tablet 300. The operator carries the command tablet 300 to a convenient location near the location where the measurement is being made. The command tablet 300 may be made of a rigid material having a size larger than that of notebook paper. The operator can place the command tablet 300 on the appropriate surface and use various means to hold the target in place. Such means may include tapes, magnets, thermal adhesives, scissors or velcro tapes. The operator establishes the position of the command tablet 300 in the reference system of the laser tracker 10 by touching the reference positions 310, 312 and 314 with the retroreflector 26. It would also be possible to use multiple command tablets in a given environment. An exemplary procedure for finding the command tablet location is discussed below.

  The command tablet 300 can be divided into several squares. In addition to the reference location squares 310, 312, and 314, there are the command squares of FIGS. 8-10 and other squares corresponding to the target type, nest type, direction, and number. The layout and content of the example command tablet 300 is merely suggestive, and the command tablet can be designed in a wide variety of ways in practice. Custom command tablets may be designed for specific tasks.

  In order to signal a command to the laser tracker 10, the operator touches a desired reflector on the command tablet 300 with a retro reflector. This operation by the operator corresponds to step 220 in FIG. Motion sensing can be performed, for example, by the method shown in FIG. 3C or FIG. 4C. When a sequence with a plurality of numbers (for example, a number of 3.50) is input, the square 3, the square point, the square 5, and the square 0 are touched in order. As described below, there are various ways to instruct the tracker that a square is read. One possible way is to wait for a preset time, eg at least 2 seconds. The tracker then gives a signal, which may be, for example, a flashing light, indicating that the tracker has read the square content. Once the entire number sequence is entered, the operator can end the sequence in a predetermined manner. For example, the agreed end may be touching one of the reference points.

  Command tablet 300 may be used with an articulated arm CMM instead of a laser tracker. The articulated arm CMM includes several joint segments attached to a fixed base at one end and a probe, scanner or sensor at the other end. Exemplary articulated arm CMMs are described in Raab et al. US Pat. No. 6,935,036 incorporated herein by reference and Raab et al. US Pat. No. 6,965,843 incorporated herein by reference. When the laser tracker is used, the probe tip is brought into contact with the square of the command tablet 300 in the same manner that the retroreflector target is brought into contact with the square of the command tablet 300. The articulated arm CMM typically takes measurements over a much smaller measurement volume than does a laser tracker. For this reason, when using the articulated arm CMM, it is usually easy to find a convenient place to attach the command tablet 300. The specific command contained in the command tablet 300 is adapted to a command suitable for the articulated arm CMM, which is different from the command of the laser tracker. The advantage of using the command tablet with the articulated arm CMM is that the command tablet places the probe from the operator, moves to the computer, and eliminates the inconvenience and loss time of entering commands before returning to the articulated arm CMM. is there.

  Next, FIGS. 13 to 16 show four examples of how gestures can be used. FIG. 13 shows the gestures used to set the reference point of the exemplary laser tracker 10. Recall from the previous discussion that automatic reset is a possible option mode for laser trackers. When the laser tracker is set to the automatic reset option, the laser beam is directed to the reference position whenever the beam path is interrupted. A common reference position is the tracker's home position, which corresponds to the position of the magnetic nest permanently attached to the body of the laser tracker. Alternatively, a reference point close to the working volume may be selected to eliminate the need for the operator to return to the tracker when the beam is interrupted. (Typically, this feature is most important when the tracker uses an interferometer instead of an ADM to make measurements).

  In FIG. 13, the operations shown in flowchart 400 are performed to set a reference point using a gesture. In step 420, the worker moves the target in the pattern shown in “Set reference point” in FIG. 10. The target in this case may be, for example, a retro reflector 26 as shown in FIG. 3A. In step 430, the laser tracker 10 intercepts and analyzes the command to confirm that the command has been received. In this case, the form of confirmation is a double flashing of the red lamp on the front panel of the tracker. However, other feedback such as different colors and patterns, or audible sounds may be used. At step 440, the operator places the SMR 26 in a magnetic nest that defines a reference position. The laser tracker 10 constantly monitors the position data of the SMR 26 and recognizes when the SMR 26 is stationary. If the SMR is stationary for 5 seconds, the tracker 10 recognizes that the operator has intentionally placed the SMR in the nest and the tracker starts the measurement by step 450. While the measurement is taking place, for example, a red lamp on the tracker panel can be lit. When the measurement is complete, the red lamp will turn off.

  In FIG. 14, the operations shown in flowchart 500 are performed to establish the position of exemplary command tablet 300 in three-dimensional space. Recall from the previous discussion that the command tablet 300 has three reference positions 310, 312, and 314. By touching the retro reflector target at these three positions, the position of the command tablet 300 in the three-dimensional space can be found. In step 510, the worker moves the target in the pattern shown in “Initial setting of command tablet” in FIG. The target in this case may be, for example, a retro reflector 26 as shown in FIG. 3A. At step 520, the laser tracker 10 intercepts and analyzes the command and confirms that the command has been received by blinking the red lamp twice. At step 530, the operator holds the SMR 26 for one of the three reference points. The laser tracker 10 constantly monitors the position data of the SMR 26 and recognizes when the SMR is stationary. In step 540, if the SMR 26 is stationary for 5 seconds, the tracker 10 measures the position of the SMR 26. In step 550, the operator holds the SMR 26 for the second of the three reference points. In step 560, if the SMR 26 is stationary for 5 seconds, the tracker 10 measures the position of the SMR 26. At step 570, the operator holds the SMR 26 for the third of the three reference points. In step 580, if the SMR 26 is stationary for 5 seconds, the tracker 10 measures the position of the SMR 26. Here, the tracker 10 knows the three-dimensional position of each of the three reference points and can calculate the distance between the three point pairs from these three points. At step 590, the tracker 10 searches for errors by comparing the known distance between points to the calculated distance between points. If the difference is too large, at step 595, a signal error is indicated by an appropriate indication, which may be a flashing red lamp for 5 seconds.

  In FIG. 15, the operations shown in flowchart 600 are performed to measure a circle using a gesture. In step 610, the operator moves the target in the pattern shown in "Measure circle" in FIG. The target in this case may be, for example, a retro reflector 26 as shown in FIG. 3A. In step 620, the laser tracker 10 intercepts and analyzes the command and confirms that the command has been received by blinking the red lamp twice. In step 630, the operator holds the retro reflector 26 against the workpiece. For example, when an operator is measuring the inside of a circular hole, the operator applies the SMR to a portion inside the hole. The laser tracker 10 constantly monitors the position data of the retroreflector 26 and recognizes when the SMR is stationary. In step 640, after the retro-reflector 26 has been stationary for 5 seconds, the red lamp is lit and the tracker 10 begins a continuous measurement of the position of the retro-reflector 26. In step 650, the operator moves the retroreflector 10 along the circle of interest. In step 660, when enough points have been collected, the operator moves the retroreflector 26 away from the surface of the object being measured. The movement of the retro reflector 26 indicates that the measurement is complete. The motion of the retroreflector 26 also indicates whether the retroreflector target 26 is measuring the inner diameter or the outer diameter, allowing application software to remove the offset distance to account for the retroreflector 26 radius. To do. At step 670, the tracker 10 blinks the red lamp twice to indicate that the necessary measurement data has been collected.

  In FIG. 16, the operation shown in flowchart 700 is performed to acquire a retroreflector after the laser beam from laser tracker 10 is interrupted. In step 710, the worker moves the retro reflector in the pattern shown in “Obtain SMR” in FIG. 10. The target in this case may be, for example, a retro reflector 26 as shown in FIG. 4A. At the beginning of this procedure, the SMR has not obtained an SMR, so the modes shown in FIGS. 3A-3E cannot be used. Instead, the camera 52 and light source 54 are used to locate the retroreflector 26. At step 720, the laser tracker 10 intercepts and analyzes the command and confirms that the command has been received by blinking the red lamp twice. At the same time, the laser tracker 10 emits a laser beam 46 toward the center of the retro reflector 26. At step 730, the tracker 10 checks whether the laser beam has been captured by the retroreflector 26. In most cases, the laser beam is fired sufficiently close to the center of the retroreflector 26 to strike the active area of the position detector in the tracker. In this case, the tracker servo system fires the laser beam in a direction that directs the laser beam toward the center of the position detector, and this causes the laser beam to travel to the center of the retroreflector 26. Thereafter, normal tracking is performed. If the laser beam is not fired near the center of the retroreflector 26 enough to hit the position detector in the tracker, one possible method is to perform a helical search as shown in step 740. The laser tracker 10 performs a spiral search by directing the laser beam in the starting direction and then directing the beam into a continuously expanding spiral. Whether to perform a spiral search can be optionally set in the laser tracker or application software used with the laser tracker. Another option that may be appropriate for a rapidly moving target is to repeat step 720 repeatedly until the laser beam is captured by a retroreflector or a timeout occurs.

  As described above with reference to FIG. 7, an operator sends a command using three steps: an optional prologue, a command, and an optional epilogue. If the tracker 10 is constantly analyzing the data and can respond quickly when the desired pattern is generated, it is possible to use only commands without a prologue or epilogue. Similarly, if an operator touches a position on the command tablet 300, the command should be revealed to the tracker without requiring a prologue or epilogue. On the other hand, if the tracker cannot parse quickly enough to respond immediately to the pattern generated by the worker, or if the worker may unintentionally generate a command pattern, the prologue, It may be necessary to use an epilogue, or both.

  An example of a simple prologue or epilogue is simply a pause in target movement, which may be any of the targets shown in FIGS. 3A-3E, 4A-4C, and 5A-5D. . For example, the operator may rest for 1 or 2 seconds before the start of the pattern and 1 or 2 seconds at the end of the pattern. By pausing in this way, the start and end positions of each gesture, indicated by circles and arrows in FIGS. 8 to 10, respectively, and circles and squares in FIG. 11 respectively, are determined by the tracker or analysis software in the computer. It becomes easy to understand.

  Another example of a simple prologue or epilogue is the rapid interruption and release of the laser beam from the tracker. For example, the operator may spread his fingers so that a space is created between each of the four digits. Thereafter, by quickly moving the finger across the laser beam, the beam will be quickly blocked and unblocked four times in succession. Such a time pattern is sometimes referred to as “four finger salute” and is easily recognized by the laser tracker. A sensing mode based on the time variation of the returned laser power is shown in FIG. 3D for a passive target and in FIGS. 5A-5C for an active target.

  In addition to using a prologue or epilogue for gesture commands, some type of prologue may be required at the beginning of the action by the laser tracker. For example, in the examples of FIGS. 13 to 15, after a command is given, there is a waiting for 5 seconds before the tracker measurement is performed. The purpose of this waiting is to give the operator time to place the retro-reflector target in place before starting the measurement. Of course, the time of 5 seconds is arbitrary and can be set to any desired value. In addition, other indications may be used that indicate that a measurement should be initiated. For example, it may be possible to use a four-finger salute rather than a time delay to indicate that a measurement is ready.

  Active targets such as those shown in FIGS. 5A-5D are useful in applications such as jig setup and device assembly. A tool is a type of device created to support the manufacture of other devices. In fields such as automobile manufacturing and aerospace manufacturing, tools are built to strict specifications. Laser trackers are useful for both assembly and inspection of such tools. In many cases, it is necessary to align the components of the tool with respect to each other. A single retro-reflector target, such as retro-reflector 26, can be used to establish a coordinate system for properly aligning each element of the tool. However, for complex jigs, this can involve many repeated measurements. An alternative method is to attach multiple retro-reflector targets to the tool element and then measure all of these quickly and continuously. Such rapid measurements are now possible with modern tracker technologies such as absolute rangefinders and camera systems (components 52, 54, etc.). If multiple retro-reflectors are directly attached to the tool, it may be difficult or inefficient for an operator to generate gesture commands using one of these retro-reflectors. It may be more convenient to use a wand such as 140 shown in FIG. 5C or 5D. The operator can use the wand to give commands quickly without disturbing the retro-reflector attached to the tool. Such a wand may be attached to the end of a hammer or similar device to allow free assembly and adjustment with both hands of the operator. In some cases, a separate retro-reflector or 6-degree-of-freedom probe as shown in FIGS. 5A and 5B, respectively, may be required during tool set-up. By adding light sources and control buttons to a basic SMR or 6 DOF probe, the operator can issue commands in a very flexible manner.

  Active targets such as those shown in FIGS. 5A-5D are also useful in device assemblies. The latest trend is flexible assembly using a laser tracker rather than automated tool assembly. An important advantage of the tracker approach is that little advance preparation is required. One of the factors that has led to such assembly today is the availability of software that matches CAD software drawings with measurements made by a laser tracker. By placing a retro-reflector on each part to be assembled and measuring the retro-reflector sequentially with a laser tracker, red to indicate “far”, yellow to indicate “close”, and “close enough” A color such as green indicating can be used to indicate the proximity of the assembly on the computer display. Using an active target, an operator can be given a command to measure a selected target or group of targets in a way that optimizes the assembly process.

  Multiple retro-reflectors are often located within a single measurement volume. An example of tool setup and device assembly using multiple retroreflectors has been described above. These examples showed that active targets can be particularly useful. In other cases, the ability of the laser tracker to recognize the movement of multiple passive retro-reflectors can be useful. For example, it is assumed that a plurality of retro reflectors are arranged on a jig such as a sheet metal stamping press, and the operator wants to perform a target survey after each operation of the jig. In this survey, the coordinates of each target are sequentially measured in order to confirm the repeatability of the tool. A simple way for the operator to set up the initial survey coordinates is to lift each retroreflector sequentially from its nest and move the retroreflector around according to a predetermined gesture pattern. When the tracker recognizes the pattern, it measures the coordinates of the retroreflector within its nest. The function of the tracker camera is to recognize gesture patterns over a wide field of view that allows the operator to conveniently switch between retro reflectors.

  As previously mentioned, there are several different types of methods or algorithms that can be used to identify gesture patterns and interpret them as commands. Here we propose several methods, but also recognize that a wide variety of methods and algorithms can be used, and they should work equally well. As explained above, there are three main types of patterns of interest: (1) single point absolute position, (2) temporal pattern, and (3) motion pattern. Recognizing single point absolute position is almost certainly the simplest of these three categories. In this case, the tracker simply needs to compare the measured coordinates to see if they match within the specified tolerances for the coordinates on the surface of the command tablet 300.

  Time patterns can also be identified relatively easily. A particular pattern may consist of, for example, a particular number of on / off iterations, and additional constraints may be imposed on the number of allowed on / off cycles. In this case, the tracker 10 simply records the number of on / off times and periodically checks whether there is a match with a predetermined pattern. Of course, it is also possible to reduce the power level rather than completely extinguishing the lamp that sends the signal to the tracker. A reduction in the level of retroreflective laser power can be obtained by many means such as the use of ND filters, polarizers, stops.

  The motion pattern can be analyzed in one, two or three dimensions. The change in the radial distance is an example of a one-dimensional movement. The change in crossing (up and down, left and right) movement is an example of a two-dimensional measurement. The change in radial dimension and transverse dimension is an example of a three-dimensional measurement. Of course, the dimensions of interest are those currently monitored by the laser tracker system. One way to help simplify the parsing and recognition task is to require it to be done in time and space within a certain range. For example, the pattern may be in the range of 200 mm to 800 mm (8 inches to 32 inches) and may need to be completed in 1 to 3 seconds. For transverse movements, the tracker must recognize these movements as changes in angle and multiply these angles in radians by the distance to the target to get the size of the pattern. By limiting the allowed patterns to a time and space within a certain range, many movements can be excluded from further consideration as gesture commands. The remaining movement can be evaluated in various ways. For example, the data may be temporarily stored in a buffer that is periodically evaluated to see if there is a potential match with any of the recognized gesture patterns. A special case of a gesture movement pattern that is particularly easy to identify is when the command button 124 of FIG. 5A is pressed to turn on the lamp 122 that indicates that a gesture is being performed. The computer then simply has to record the pattern made when the lamp 122 is lit and then evaluate the pattern to see if a valid gesture has been generated. A similar approach can be taken when the operator presses the command button 134 to turn on the lamp 132 in FIG. 5B, or presses the command button 144 to turn on the lamp 142 in FIG. 5D.

  In addition to these three main patterns, it is also possible to generate patterns generated using passive objects or a combination of passive objects and retroreflectors. For example, a camera on a tracker may recognize that a specific command has been given whenever a specific size passive red square is brought within 1 inch of the SMR.

  It is also possible to combine two of the three main patterns. For example, the pattern type 2 and the pattern type 3 can be combined by combining the moving speed with a specific spatial pattern. As another example, an operator may send a specific command having a serrated pattern that includes a sudden lift and subsequent slow back movement. Similarly, acceleration may be used. For example, a flick motion may be used to “project” the laser beam around the object in a particular direction.

  Variations are possible within the pattern type. For example, within the category of spatial patterns, it is possible to distinguish between small squares (eg, 3 inches on each side) and large squares (eg, 24 inches (60.96 cm) on each side). .

  The algorithmic method described above is implemented by a processing system 800 shown in FIG. The processing system 800 includes a tracker processing unit 810 and optionally a computer 80. The processing unit 810 includes at least one processor (or processing circuit), which may be a microprocessor, digital signal processor (DSP), field programmable gate array (FPGA), or similar device. Processing power is provided to process the information and issue commands to the internal tracker processor. Such processors may include a position detector processor 812, an orientation encoder processor 814, a zenith encoder processor 816, an indicator light processor 818, an ADM processor 820, an interferometer (IFM) processor 822, and a camera processor 824. A gesture preprocessor 826 that assists in the evaluation or analysis of gesture patterns may be included. The auxiliary unit processor 870 optionally provides timing and microprocessor support for other processors in the tracker's processor unit 810. The auxiliary unit processor 870 can communicate with other processors via the device bus 830, which can transfer information across trackers via data packets, as is well known in the art. The computing power may be distributed throughout the tracker processing unit 810, and the DSP and FPGA perform intermediate calculations on the data collected by the tracker sensor. The results of these intermediate calculations are returned to the auxiliary unit processor 870. As previously described, the auxiliary unit 70 may be attached to the body of the laser tracker 10 via a long cable and the body of the laser tracker so that the tracker connects directly (or optionally) to the computer 80. You may be pulled in. Auxiliary unit 870 may be connected to computer 80 by connection 840, which may be, for example, an Ethernet cable or a wireless connection. Auxiliary unit 870 and computer 80 may be connected to the network via connections 842, 844, which may be, for example, an Ethernet cable or a wireless connection.

  Sensor data pre-processing may be evaluated for gesture content by any of the processors 812-824, although there may be a processor 826 specifically designated to perform gesture pre-processing. Gesture preprocessor 826 may be a microprocessor, DSP, FPGA, or similar device. Gesture preprocessor 826 may include a buffer that stores data to be evaluated for gesture content. The preprocessed data may be sent to the auxiliary unit for final evaluation, and a final evaluation of the gesture content may be performed by the gesture preprocessor 826. Alternatively, raw data or preprocessed data may be sent to computer 80 for analysis.

  While the use of gestures described above is largely focused on use with a single laser tracker, it is also beneficial to use gestures with a collection of laser trackers or with a combination of laser trackers and other instruments. . One possible way is to designate one laser tracker as the master sending commands to other instruments. For example, a set of four laser trackers can be used in a multilateration measurement where 3D coordinates are calculated using only the distance measured by each tracker. Commands can be given to a single tracker, which relays commands to other trackers. Another possible way is to allow multiple instruments to respond to gestures. For example, assume that a laser tracker was used to reposition the articulated arm CMM. An example of such a system is described in Raab US Pat. No. 7,804,602, which is incorporated herein by reference. In this case, the laser tracker can be designated as the master in the relocation procedure. The operator gives a gesture command to the tracker, and the tracker sends an appropriate command to the articulated arm CMM. After the relocation procedure is complete, the operator can give a gesture command to the articulated arm CMM using the command tablet as described above.

  FIG. 19 shows a step 1900 that is performed in providing a laser tracker with a gesture to convey a command in accordance with the discussion with reference to FIGS. 3A-3B, 4A-4B, and 5A. Step 1910 is to provide a correspondence rule between the command and the spatial pattern. Step 1920 is to select a command from the commands available to the user. Step 1930 is that the user moves the retro reflector in a spatial pattern corresponding to the desired command. The spatial pattern may be transverse or radial. Step 1940 is projecting light from the laser tracker to the retro-reflector. This light may be a light beam emitted along the optical axis of the laser tracker, or it may be light emitted by an LED near the camera located on the laser tracker. Step 1950 is to reflect light from the retroreflector to the laser tracker. Step 1960 is sensing the reflected light. Sensing can be performed by a photosensitive array in a camera placed on the tracker, by a position detector in the tracker, or by a distance meter in the tracker. Step 1970 is to determine a command based on the correspondence rule. Step 1980 is to execute a command.

  FIG. 20 shows step 2000 performed in giving a gesture to communicate a command to the laser tracker in accordance with the discussion with reference to FIGS. 3C, 4C, and 5A. Step 2010 is to provide a correspondence rule between the command and the three-dimensional position. Step 2020 is to select a command from the commands available to the user. Step 2030 is that the user moves the retroreflector to a position corresponding to the desired command, perhaps by contacting the retroreflector target with the command tablet. Step 2040 is to project light from the laser tracker to the retro reflector. This light may be a light beam emitted along the optical axis of the laser tracker, or it may be light emitted by an LED near the camera located on the laser tracker. Step 2050 is to reflect light from the retro-reflector to the laser tracker. Step 2060 is sensing the reflected light. Sensing can be performed by a photosensitive array in a camera placed on the tracker, by a position detector in the tracker, or by a distance meter in the tracker. Step 2070 is to determine the command based on the correspondence rule. Step 2080 is to execute the command.

  FIG. 21 shows the steps 2100 that are performed in giving the laser tracker a gesture to convey a command in accordance with the discussion with reference to FIGS. 3D and 5A. Step 2110 is to provide correspondence rules between commands and time patterns. Step 2120 is to select a command from the commands available to the user. Step 2130 is to project light from the laser tracker to the retro-reflector. This light may be a light beam emitted along the optical axis of the laser tracker, or it may be light emitted by an LED near the camera located on the laser tracker. Step 2140 is to reflect light from the retroreflector to the laser tracker. Step 2150 is sensing the reflected light. Sensing can be performed by a photosensitive array in a camera placed on the tracker, by a position detector in the tracker, or by a distance meter in the tracker. Step 2160 is that the user generates a time pattern of the optical power received by the sensor on the laser tracker. Such a time pattern is facilitated by blocking and unblocking the light beam, as discussed below. Step 2170 is to determine a command based on the correspondence rule. Step 2180 is to execute a command.

  FIG. 22 shows the steps 2200 performed in giving a gesture to convey a command to the 6-DOF laser tracker according to the discussion with reference to FIGS. 3E and 5B. Step 2210 is to provide a correspondence rule between the command and the 6 DOF target pose. Step 2220 is to select a command from the commands available to the user. Step 2230 is to measure at least one coordinate of a six degree of freedom target in a first posture using a six degree of freedom laser tracker. The posture includes three translation coordinates (x, y, z, etc.) and three posture angle coordinates (roll, pitch, yaw, etc.). Step 2240 is for the user to change at least one of the six dimensions of the six degree of freedom target pose. Step 2250 is to measure at least one coordinate of the second posture, which is the posture obtained after the user completes step 2240. Step 2260 is to determine a command based on the correspondence rule. Step 2270 is to execute a command.

  FIG. 23 shows step 2300 that is performed in giving the laser tracker a gesture that directs the laser beam from the laser tracker to the target and communicates a command to lock on the target. Step 2310 is to project light onto the retroreflector. This light may be light emitted by an LED near the camera located on the laser tracker. Step 2320 is for the user to move the retro reflector in a predetermined spatial pattern. Step 2330 is to reflect light from the retro reflector to the laser tracker. Step 2340 is sensing the reflected light. Sensing can be performed, for example, by a photosensitive array in a camera located on the tracker. Step 2350 is to determine a command based on the correspondence rule. Step 2360 is to direct the light beam from the tracker to the retro-reflector. Step 2370 is to lock on the retro reflector with the laser beam from the tracker.

  FIG. 24 shows step 2400 that is performed in giving the laser tracker a gesture that directs the laser beam from the laser tracker to the target and conveys a command to lock on the target. Step 2410 is to project light onto the retroreflector. This light may be light emitted by an LED near the camera located on the laser tracker. Step 2420 is to reflect light from the retroreflector to the laser tracker. Step 2430 is sensing the reflected light. Sensing can be performed, for example, by a photosensitive array in a camera located on the tracker. Step 2440 is to generate a predetermined time pattern as described above. Step 2450 is to determine a command based on the correspondence rule. Step 2460 is to direct the light beam from the tracker to the retro-reflector. Step 2470 is to lock on the retro-reflector with a laser beam from the tracker.

  FIG. 25 shows the steps 2500 performed in giving the laser tracker a gesture that directs the laser beam from the laser tracker to the target and conveys a command to lock on the target. Step 2510 is to project light onto the retroreflector. This light may be light emitted by an LED near the camera located on the laser tracker. Step 2520 is to measure at least one coordinate of the first orientation of the six degree of freedom target. As described above, this posture includes three translational degrees of freedom and three posture angle degrees of freedom. Step 2530 is to change at least one coordinate of the first posture. Step 2540 is measuring at least one coordinate of the second orientation, which is the orientation obtained after the at least one coordinate of the six degree of freedom probe is changed. Step 2550 is to determine that the correspondence rule has been satisfied. Step 2560 is to direct the light beam from the tracker to the retro-reflector. Step 2570 is to lock on the retro reflector with the laser beam from the tracker.

  26 shows a laser tracker 10B that is similar to the laser tracker 10 of FIG. 1, but the cameras 2610, 2620 of FIG. 26 are specified as having different fields of view. In one embodiment, the wide field of view (FOV) camera 2610 has a wider FOV than the narrow field of view camera 2620. Laser tracker 10B further includes a light source 2622 proximate to the entrance aperture of narrow field camera 2620. The light source 2622 is selected such that the narrow-field camera 2620 emits light in a sensitive wavelength range. In one embodiment, wide field camera 2610 is responsive to at least visible wavelengths and narrow field camera is responsive to at least infrared wavelengths. In other embodiments, the cameras 2610, 2620 are responsive to wavelengths of light in alternative spectral regions.

  The term FOV is used herein to mean the angular range visible from the camera. For example, if the diagonal length of the photosensitive array of the camera is x, for a camera lens having a focal length f, the angle of view can be defined as 2 arctan (x / 2f). Of course, other definitions of FOV may be used, and the general concept is that FOV represents the angular range of the scene captured by the camera's photosensitive array. In one embodiment, the wide field camera 2610 has an FOV in the range of 40 degrees to 90 degrees. In another embodiment, the camera 2610 is a fisheye lens having a wider FOV, eg, 100 degrees to 180 degrees. In one embodiment, the narrow field camera 2620 has a FOV of 0.5 degrees to 20 degrees. By noting that the small angle of the narrow-field camera 2620 is about 60 degrees for one radian, one can find the approximate linear transverse dimension visible from the camera. In that case, for the distance R from the tracker to the observation point, the transverse straight line dimension L observed by the camera is approximately L = R · FOV / 60, and the FOV is given in degrees. For example, if the narrow-field camera 2620 has a 4 degree FOV and the tracker is looking at an object point R = 15 meters away, the transverse linear distance seen by the narrow-field camera 2620's photosensitive array is about (15 m) ( 4) / 60 = 1 meter. If the narrow-field camera photosensitive array has 1000 pixels along a linear dimension, the resolution of the narrow-field camera is approximately 1 meter / 1000 = 1 mm. In contrast, for a wide-field camera with a 60 degree FOV, the FOV is found more accurately by the equation 2R · tan (60 ° / 2). For example, when the distance from the tracker to the observation point is 15 meters, the crossing length observed by the camera is (2) (15 m) (tan (60 ° / 2)) = 17.3 m. If this dimension is imaged by the photosensitive array of wide field camera 2610 over 1000 pixels, the resolution of the object point is approximately 17.3 m / 1000 = 17.3 mm.

  In one embodiment, the 3D measurement system includes a laser tracker 10B, a retroreflector 26, and a communication device 2630. Although the retroreflector 26 is shown in the form of an SMR, the retroreflector can be any type of retroreflective target, such as a stand-alone corner cube retroreflector or cat eye retroreflector, or a retro embedded in a six degree of freedom target. It should be understood that it may be a reflector. In one embodiment, the communication device 2630 includes an operator control unit 2631 configured to control the light emission 2634 from the light source 2632. The light source 2632 may be a generally visible light source, for example, a “flash light” illuminator or remote control unit light found on many smartphones.

  In one embodiment, light source 2632 is activated when an operator depresses actuator 2636, which may be a touch screen selection icon on a user interface 2638 of a smart device (such as communication device 2630). A smart device is an electronic device that operates interactively and autonomously to some extent. In most cases, smart devices are Bluetooth®, Near Field Communication (NFC), Wi-Fi (IEEE 802.11 standard), cellular communication schemes (eg, 3G and LTE), or various other communication protocols. It can also be connected to other devices via a protocol such as Examples of smart devices include smart mobile phones, smart tablets, smart laptops, smart wearables, and the like.

  In an alternative embodiment, the communication device 2630 is a remote control device. The operator control unit (such as 2631) of the remote control may include a plurality of tactile keys (such as actuator 2636) that are activated when pressed by the user. These keys serve as actuators 2636 of the operator control unit 2631. Communication device 2630 further includes a light source 2632 that is activated by pressing one of the tactile keys. In one embodiment, the light source 2632 may be a white light LED or any other type of light source that illuminates in response to actuation of the actuator 2636 by an operator.

  An electrical component that may include a processor in worker control unit 2631 sends a signal to light source 2632 in response to actuation of actuator 2636 by the worker. The light source 2632 is turned on in response to the operation of the actuator 2636. The light emission 2634 is associated with the selected actuator in various patterns, for example, (1) while the operator is pressing the actuator icon, (2) for a predetermined fixed length of time, (3). The light emitted from the light source 2622 on the tracker 10B is reflected by the retro-reflector 26 and received by the narrow-field camera 2620.

  In one embodiment, the communication device 2630 is further configured to communicate with the laser tracker 10B in a wireless signal, whether it is a smart device or a remote control device. In one embodiment, the communication device 2630 further includes a battery 2633, which may be a rechargeable battery.

  The tracker lock-in command is a command for starting steering of the light beam 46 from the light source (generally indicated by reference numeral 47) in the tracker 10B. Light 46B newly directed by movement 2640 strikes retro-reflector 26. The light hitting the retro-reflector 26 is reflected and returns to the tracker 10B. A part of the reflected light travels to the position detector 13 in the tracker 10B, and another part travels to the distance meter 17. The position detector 13 provides a signal indicating the position where the reflected light hits the surface area of the position detector 13. After the signal is received by the position detector 13, the tracker control system 23 keeps the light beam 46B locked on to the retro-reflector 26, even when the retro-reflector 26 is moved. The operation of the tracker motor that holds the light beam 46B on the retroreflector 26 is based at least in part on the signal provided by the position detector 13.

  In one embodiment, when an operator presses a designated actuator 2636, a light 2634 is emitted from the communication device 2630, which is executed by the processor 800 to a processor (such as the processing system 800 shown in FIG. 17). It is determined whether a lock-in command has been issued via a possible command, and if so, the light beam 46 from the tracker 10B is manipulated to be directed to the retro-reflector 26, as represented by the light beam 46B. Let the retro reflector perform a series of steps to lock on.

  Light 2634 emitted from the light source 2632 by the communication device 2630 can provide a bright signal to the wide field camera 2610. The high level of light that can be provided can be easily ascertained by observing light 2634 from a typical flashlight function of a smartphone (such as communication device 2630). In most cases, such light is brighter than the surrounding objects, facilitating localization with the wide field camera 2610. In some cases, it may be advantageous to turn the light source 2632 on and off at a constant repetition frequency so that the tracker 10B can locate the light source 2632 from blinking. In some cases, the wide field camera 2610 may include an optical bandpass filter to more clearly show flashing light. In other cases, as will be discussed further below, the wide field camera 2610 may be a color camera having additional functions in addition to the function of initiating a lock-in sequence. In this case, the option is to select the illumination from among the sub-pixels of a specific color. For example, if the light source 2632 emits a red wavelength, the signal level of the red sub-pixel can be evaluated to determine the position of the strongest red emission.

  A processor in the tracker 10B (such as processing system 800) applies a digital image formed on a photosensitive array of a wide-field camera 2610 (also referred to herein as the first camera) that points to a light source 2632 that is lit. It is determined that a lock-in command has been given based at least in part. As shown in FIG. 17, the processor 800 may be an external computer, an interface box attached to the tracker, or one or more internal processors in the tracker, and may be a microprocessor, digital signal processor (DSP). , A field programmable gate array (FPGA), or any other type of computing device. A computing device typically has a certain amount of associated memory to use.

  In one embodiment, the processor 800 turns on the light source 2622 on the tracker 10B in response to being given a lock-in signal. Light from the light source 2622 irradiates the retroreflector 26 and is reflected toward the narrow-field camera 2620 (also referred to as a second camera in this specification). If the reflected light is within the FOV of the narrow field camera 2620, the processor 800 directs the tracker 10B motor to fire the light beam 46 to obstruct the retroreflector 26 as represented by the light beam 46B.

  If the reflected light from the light source 2622 on the tracker 10B is not within the FOV of the narrow field camera 2620, the processor 800 can provide information provided by the digital image of the wide field camera 2610 in response to the light 2634 from the communication device 2630. In use, the light beam 46 is directed from the tracker to the retro-reflector as a redirected light beam 46B while the light source 2622 on the tracker 10B continues to be turned on simultaneously. When the reflected light from the light source 2622 on the tracker 10B is confirmed by the narrow field camera 2620, the processor 800 determines that the steering is based primarily or completely on the digital image picked up on the second narrow field camera 2620. To do.

  In one embodiment, light 2634 from light source 2632 of communication device 2630 continues to be emitted in some pattern until reflected light from light source 2622 on tracker 10B is picked up by narrow-field camera 2620. By continuing to illuminate the light source 2632, for example, in a blinking pattern, the processor 800 can more accurately direct the light beam 46 toward the retroreflector 26 as represented by the light beam 46B. In one embodiment, the tracker 10B transmits a radio signal from the radio transceiver 2650 of the laser tracker 10B to the radio transceiver 2639 of the communication device 2630, which is transmitted from the light source 2622 on the tracker 10B by the narrow-field camera 2620. Indicates whether the reflected light has been picked up. In one embodiment, the wireless signal is an electromagnetic signal provided in the radio frequency (RF), microwave, or millimeter wave region of the electromagnetic spectrum.

  When the light beam 46B hits the retroreflector 26, the reflected light from the light source 2622 on the tracker 10B is on a line determined by the distance from the tracker 10B to the retroreflector 26 somewhere along the line on the photosensitive array. Hit the position of. This line on the photosensitive array may be determined at the factory and included in the memory of the processor 800 to speed up the acquisition of the retroreflector 26 when the beam 46 is directed.

  In some cases, the operator wants to carry the retroreflector 26 to a location and direct the light beam 46 to the retroreflector 26 without returning to the tracker 10B or computer console (such as the computer 80 shown in FIG. 2). Sometimes. In one embodiment, an operator pushes an actuator 2636 that causes light source 2632 to emit light 2634, leading to an event sequence directed by the processor described above. This method of directing the light beam 46 to the retroreflector 26 is particularly useful when an operator has to carry the SMR 26 to a difficult location, for example, by climbing a ladder.

  In some cases, the operator can lock on the light beam 46 to the SMR 26 at a location where the SMR 26 is held by the magnetic nest. The operator wants to carry the second SMR 26 to a second location, possibly climbing a ladder, causing the tracker's light beam 46 to be found and locked onto the second SMR 26. In one embodiment, the communication device 2630 has an actuator 2636 that corresponds to two different types of lock-in commands. In the first lock-in command, the light beam 46B locks on to the SMR 26 closest to the light source 2632. In the second lock-in command, the light beam 46B locks on to the nearest SMR 26 of the closest position as long as the closest position is within the FOV of the narrow field camera 2620.

  In one embodiment, the communication device 2630 includes an additional actuator 2636 that corresponds to an additional tracker command. In one embodiment, one of the tracker commands is a measurement command that causes the tracker to determine the 3D coordinates of the retroreflector 26 based at least in part on the distance and two angles measured by the tracker 10B. The distance can be measured by the distance meter 17, and the first angle and the second angle can be measured by the first angle encoder 21 and the second angle encoder 19, respectively.

  In one embodiment, the processor 800 is configured to show an image from the wide field camera 2610 on a display, such as on a smart device (such as a communication device 2630) held by an operator or on a computer monitor. Display (such as user interface 2638). For example, by selecting a position on the display with a mouse or other selection device, the operator may initiate a click-to-drive command in which the tracker 10B is directed to advance to the indicated position. The click to drive command can be set to automatically lock in further to the retro reflector 26 closest to the click to drive position (if a retro reflector is present).

  In one embodiment, the laser tracker 10B may send a wireless message from its wireless transceiver 2650 to the wireless transceiver 2639 of the communication device 2630 when the beam 46 is no longer locked on to the retro-reflector 26. In response, the communication device 2630 can provide a warning message, such as a flashing light or warning sound, to the operator. In response to the warning message, the operator can press the actuator 2636 corresponding to the lock-in command. Alternatively, the operator configures the communication device 2630 to automatically activate a lock-in sequence starting from the blinking light 2632 when the communication device 2630 receives a wireless “lock is lost” message from the laser tracker 10B. May be. In another embodiment, in response to receiving a wireless lock is lost message from laser tracker 10B, the wireless device (such as communication device 2630) returns a “lock in narrow” command to tracker 10B. Can be set as follows. This command does not cause the processor 800 to activate the light source 2632 to emit light 2634, but instead determines whether the narrow field camera 2620 can see the reflected light from the light source 2622 on the tracker 10B. If the narrow field camera 2620 can see the reflected light, the processor 800 directs the light beam 46 to lock on the retro-reflector 26 as represented by the light beam 46B.

  FIG. 27 illustrates elements of a method 2700 for locking on a retroreflector 26 with a laser tracker 10B according to one embodiment. Element 2705 includes providing communication device 2630, retro-reflector 26, and laser tracker 10B. The communication device 2630 includes a first light source 2632 and an operator control unit 2631 that controls emission of the first light 2634 from the first light source 2632. The retro reflector 26 is different from the communication device 2630. The laser tracker 10B includes a structure (eg, an orientation base 16), a distance meter 17, a first angle encoder 21, a second angle encoder 19, a first camera (wide-field camera) 2610, and a second Camera (narrow-field camera) 2620, second light source 2622, position detector 13, processor 800, and third light source 47. The structure 16 rotates about the first axis 20 and the second axis 18. The second camera 2620 is close to the second light source 2622 and has a narrower field of view than the first camera 2610. The first and second cameras 2610 and 2620 are attached to the outer portion of the structure 16. The position detector is inside the tracker 10B.

  Element 2710 includes emitting first light 2634 from communication device 2630. Element 2715 includes capturing first light 2634 with a first camera (wide field camera) 2610 to generate a first digital image (generally represented by reference numeral 2610 ′). Element 2720 determines that the processor 800 has been given a lock-in command based at least in part on the first digital image 2610 ′ and in response, a second light source (close to the narrow-field camera 2620). Actuating 2622 to generate second light.

  Element 2725 includes reflecting a portion of the second light from retroreflector 26 as a second reflected light. Element 2730 includes capturing second reflected light with a second camera 2620 to generate a second digital image (generally represented by reference numeral 2620 ′).

  Element 2735 includes emitting a third light beam 46 from a third light source 47 and manipulating the structure 16 to direct the third light beam 46 toward the retroreflector 26, the manipulation comprising a second digital beam. At least partly based on one of the readings of the image and the position detector 13.

  Element 2740 includes reflecting a portion of third light beam 47 as third reflected light. Element 2745 includes capturing a first portion of the third reflected light with position detector 13. Element 2750 includes capturing a second portion of the third reflected light with distance meter 17.

  Element 2755 includes determining at a processor a first distance to the retroreflector 26 based at least in part on the second portion of the third reflected light. Step 2760 includes measuring a first rotation angle about 20 about the first axis with the first angle encoder 21. Step 2765 includes measuring a second rotation angle about the second axis 18 with the second angle encoder 19. Step 2760 includes determining at processor 800 three-dimensional (3D) coordinates of retroreflector 26 based at least in part on the first distance, the first rotation angle, and the second rotation angle. Step 2765 includes storing 3D coordinates.

  As described above, it is often desirable to lock on the retro-reflector after the retro-reflector has moved a relatively large angular distance from the direction indicated by the laser tracker. In some cases, an operator may attempt to place a retro-reflector in his pocket before moving to a new position, for example, before climbing a ladder. In other cases, an operator may have to pass behind an obstacle such as a pillar before resuming the desired path. In yet another case, an operator may simply be relieved to keep the retro-reflector pointing in the direction of the tracker's laser beam while moving from one location to another.

  Next, in the embodiment described with reference to FIGS. 28A-28C, 29A-29C, and 30, the gesture method is not performed while the operator is locked on the retro-reflector from the first position. It is possible to move to the second position. FIG. 28A shows an operator 2805 holding the SMR 2810 shown in the front view of FIG. 28B and the perspective view of FIG. 28C. In one embodiment, the worker moves the retro-reflector in a spatial pattern specified by a predefined correspondence rule that represents a “worker follow” command. In one example, the operator follow-up command is indicated by the upper and lower patterns 2815. If the light beam from the laser tracker is locked on to the retro-reflector 2810 when a gesture is made, the motion pattern (in this case up and down) can be detected by the laser tracker angle measurement system. Regardless of whether the light beam is locked on to the retro-reflector 2810, the retro-reflector is illuminated by the light beam from the light source 54 on the laser tracker 10 and the illuminated retro-reflector is illuminated by one or more cameras 52. It is captured. The spatial pattern (up and down in this example) is identified using either method, and the gesture command can be determined based on the spatial pattern. Alternatively, the worker may use any of the methods described above for generating worker tracking commands to generate a time pattern that results in a temporal change in the return light from the retroreflector.

  In one embodiment, the operator tracking command generated by the gesture command of FIG. 28A causes the laser tracker to rotate its structure, including the payload and zenith carriage, to work along path 2825A as shown in FIG. 29A. Face 2805A. In some cases, direction 2825A may correspond to a path traveled by visible light, eg, a red laser beam, emitted by a laser tracker. In another case, direction 2825A may follow worker 2805A without emitting a light beam. In some cases, the laser tracker 2820 of FIG. 29A may provide an indication that such tracking is performed, for example, by blinking colored light on the tracker in a predetermined pattern that can be recognized by an operator.

  In one embodiment, the structure of the tracker 2820 allows the operator movement 2830 from the first worker position 2805A to the second worker position 2805B, even if the worker passes behind the obstacle 2840. Keep following. An operator can be identified to a tracker in several different ways. Such identification is important because it allows the tracker structure to continue to point towards the operator even though the operator position 2805B has changed relatively significantly compared to the operator position 2805A. In many cases, the worker may be identified based on the worker's movement, and the worker's movement may be perceived as different from the background environment fixed by the image processing system. In many cases, the worker can be identified by the movement of the worker perceived as different from the fixed background. Such recognition may be performed, for example, by image processing software associated with one or more cameras 52 of tracker 10 or similar cameras for tracker 2820. In addition, the worker may be identified based on the worker's general size and shape using image processing methods known in the art.

  When the operator reaches the desired position 2805B where the laser tracker is to be locked on again to the retro-reflector 2810, as shown in FIGS. 29B and 29C, the operator gives a lock-on command, and the lock-on command is In the form, it is a space movement gesture 2815B as shown in FIG. 29B. In response, laser tracker 2820 directs the light beam from the tracker to lock on to retroreflector 2810 along direction 2825C, as shown in FIG. 29C.

  In an alternative embodiment, a system including a laser tracker monitors the worker's relative posture to obtain a gesture lock-on command. In the embodiment shown in FIG. 30, the gesture is provided by the operator holding the arm 2815C directly to the side of the torso. In one embodiment, such worker posture determination may be based on representing the worker as a bar chart with limb and torso elements modeled as lines. In one embodiment, the gesture preprocessor 826, when executed by the gesture preprocessor 826, is executable to analyze an image of the worker 2805 and execute an image analysis algorithm that evaluates or analyzes the gesture pattern performed by the worker 2805. Respond to commands.

  If the tracker determines that a lock-on gesture has been given, the tracker can turn on one or more lights, such as light 54, to obtain an illumination spot on one or more cameras 52. As described above, the position of the illumination spot on one or more cameras 52 provides information that allows the tracker to lock on to the retro-reflector 2810. Alternatively, in the case of the gesture method of FIG. 30, the lock-on position of the retro reflector is defined as being at the end of the operator's arm 2815C.

  From all of the above, one embodiment of the present invention includes a 3D coordinate measurement system including a retro-reflector 2810 and a laser tracker 2820 and a method for measuring 3D coordinates, wherein the laser tracker 2820 includes a first A first light source 47 (see laser tracker 10 in FIG. 1) configured to emit a light beam 2825A; a structure 15 rotatable about the first axis 18 and the second axis 20; Two light sources 54, a first camera 52 proximate to the second light source 54, and a processor 800 responsive to executable instructions, the executable instructions being executed by the processor 800, the first In the stage, it is determined that the worker following gesture 2815 is given by the worker 2805, and the worker following gesture is performed. In one embodiment, 2815 is performed with the retro-reflector 2810 held in the hand of the worker 2805, and in response, the structure 15 is rotated to 2825B following the movement 2830 of the worker 2805, In step 2, it is determined that the lock-on gesture 2815B is given by the worker 2805, and the lock-on gesture 2815B is performed in a state where the retro reflector 2810 is held in the hand of the worker 2805, and It will be appreciated that in response, it operates to direct 2825C the first light beam 2825B onto the retro-reflector 2810. In one embodiment, the operator tracking gesture 2815 may be a movement of the retro reflector 2810 in space, as shown in FIG. 28A, and as described above, is a temporal change in the return light from the retro reflector 2810. May be. Similarly, the lock-on gesture 2815B may be a movement of the retro reflector 2810 in space or a temporal change in the return light from the retro reflector 2810.

  In one embodiment, the laser tracker 2820 illuminates the retro-reflector 2810 with the second light source 54 during the operator tracking gesture 2815 and displays the image of the retro-reflector 2810 illuminated in response to the one or more cameras 52. In one embodiment, the second light source 54 illuminates the retro-reflector 2810 during the lock-on gesture 2815B and in response, the image of the retro-reflector 2810 illuminated in response to one or more cameras. 52 is configured to be captured.

  In one embodiment, worker follow-up gesture 2815, lock-on gesture 2815B, or both are based on the position of worker 2805's arm relative to worker 2805's torso.

  In one embodiment, the processor 800, when executed by the processor 800, tracks the movement of the retro-reflector 2810 with the first light beam 2825C following the lock-on gesture 2815B in a second stage, and the retro-reflector 2810. In response to executable instructions that operate to determine the 3D coordinates of

  While the preferred embodiments have been illustrated and described, various modifications and substitutions can be made to these embodiments without departing from the spirit and scope of the invention. Accordingly, it should be understood that the present invention has been described by way of illustration and not limitation.

  Accordingly, the embodiments of the present disclosure are illustrative in all respects rather than limiting, and the scope of the present invention is indicated by the appended claims rather than the foregoing description, and thus All changes that come within the meaning and range of equivalency are intended to be embraced by this invention.

Claims (20)

A three-dimensional (3D) coordinate measurement system,
With retro reflectors,
Including a laser tracker,
The laser tracker is
A first light source configured to emit a first light beam from the laser tracker;
A structure rotatable about a first axis and a second axis;
A second light source;
A first camera proximate to the second light source;
A processor responsive to executable instructions,
When the executable instructions are executed by the processor,
In the first stage, it is determined that an operator following gesture has been given by the operator, and in response thereto, the structure is rotated so as to follow the movement of the operator,
In a second stage, determining that a lock-on gesture has been given by the operator and operating in response to directing the first light beam onto the retro-reflector.   The system according to claim 1, wherein the worker following gesture is selected from the group consisting of a movement of the retroreflector in space and a temporal change in return light from the retroreflector.   The laser tracker is further configured to illuminate the retro-reflector with the second light source during the operator tracking gesture and to capture an image of the illuminated retro-reflector in response. Or the system of 2.   The system according to any one of claims 1 to 3, wherein the worker following gesture is performed in a state where the retro reflector is held in a hand of the worker.   The system according to claim 1, wherein the lock-on gesture is selected from the group consisting of movement of the retroreflector in space and temporal change of return light from the retroreflector.   The laser tracker is further configured to illuminate the retro-reflector with the second light source during the lock-on gesture and to capture an image of the illuminated retro-reflector in response. 6. The system according to any one of 5.   The system according to claim 1, wherein the lock-on gesture is performed in a state where the retro-reflector is held in the operator's hand.   The system according to claim 1, wherein at least one of the operator following gesture and the lock-on gesture is based on a position of the operator's arm with respect to the operator's torso.   When executed by the processor, the processor further includes executable instructions that, in the second stage, operate to track movement of the retroreflector with the first light beam following the lock-on gesture. The system according to any of claims 1 to 8, which responds.   The processor, when executed by the processor, further responds to executable instructions that, in the second stage, operate to determine a 3D coordinate of the retroreflector following the lock-on gesture. The system in any one of -9. A method for measuring three-dimensional (3D) coordinates, comprising:
Providing a retroreflector and a laser tracker, wherein the laser tracker rotates about a first axis and a second axis, a first light source configured to emit a first light beam; The providing step comprising: a possible structure; a second light source; a first camera proximate to the second light source; and a processor;
In the first stage,
A step in which an operator gives a worker following gesture;
In the processor, executing an executable instruction in response to the worker following gesture to rotate the structure to follow the movement of the worker;
In the second stage,
The operator giving a lock-on gesture;
Directing the first light beam on the retro-reflector with the processor executing an executable instruction in response to the lock-on gesture.   12. In the step of providing the worker following gesture, the worker following gesture is selected from the group consisting of a movement of the retroreflector in space and a temporal change in return light from the retroreflector. The method described in 1.   13. The method according to claim 11 or 12, wherein the laser tracker illuminates the retro-reflector with the second light source during the operator tracking gesture and captures an image of the illuminated retro-reflector in response. .   The method according to claim 11, wherein the worker following gesture is performed in a state where the retro reflector is held in the hand of the worker.   The step of giving the operator a lock-on gesture, wherein the lock-on gesture is selected from the group consisting of a movement of the retro-reflector in space and a temporal change in return light from the retro-reflector. The method according to any one of 11 to 14.   The laser tracker irradiates the retroreflector with the second light source during the lock-on gesture, and captures an image of the irradiated retroreflector in response thereto. The method described in 1.   The method according to any one of claims 11 to 16, wherein, in the second stage, the lock-on gesture is performed in a state where the retro reflector is held in a hand of the operator.   The method according to claim 11, wherein at least one of the operator following gesture and the lock-on gesture is based on a position of the operator's arm with respect to the operator's torso.   19. The method according to any of claims 11 to 18, wherein the laser tracker tracks the movement of the retro-reflector with the first light beam following the second stage.   20. A method according to any of claims 11 to 19, wherein the laser tracker determines 3D coordinates of the retroreflector following the second stage.