Patent Publication Number: US-11045956-B2

Title: Programming of a robotic arm using a motion capture system

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application is a continuation of U.S. patent application Ser. No. 15/892,008 filed on Feb. 8, 2018, which is a continuation of U.S. patent application Ser. No. 15/242,875 filed on Aug. 22, 2016, which is a continuation of U.S. patent application Ser. No. 14/712,579 filed on May 14, 2015, which is a continuation of U.S. patent application Ser. No. 14/195,412 filed on Mar. 3, 2014, which claims priority to U.S. Provisional patent application Ser. No. 61/773,077 filed on Mar. 5, 2013, the entire contents of each of which are incorporated herein by reference, as if fully set forth in this description. 
    
    
     BACKGROUND 
     Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section. 
     Motion control is a type of automation, where the position of an object or objects is controlled using some type of device such as a robotic arm. In the production of videos, films, commercials, movies, and other such audiovisual works, the placement and movement of a camera and objects in a scene being captured by the camera is a major consideration and source of time and expense. In the film industry, motion control is used when a camera is mounted and controlled as part of the creation and recording of a video scene. This technique is commonly referred to as motion control photography. 
     SUMMARY 
     The present disclosure provides methods and apparatuses that allow for capturing motions of a demonstration tool and using the captured motions to cause a robotic device to replicate motions of the demonstration tool with a robot tool. A motion capture system may use one or more cameras to capture positions of the demonstration tool over time (e.g., as a user demonstrates some type of activity). A motion path for a robot tool (e.g., an end-effector-mounted tool on the robotic device) may be determined to replicate the motion path of the demonstration tool. The robotic device may then be controlled to move its robot tool along the motion path to replicate the motions of the demonstration tool. 
     In one example, a method is provided that includes receiving data from one or more cameras indicative of position of a demonstration tool. Based on the received data, the method may further include determining a motion path of the demonstration tool, where the motion path includes a sequence of positions of the demonstration tool. The method may also include determining a replication control path for a robotic device, where the replication control path includes one or more robot movements that cause the robotic device to move a robot tool through a motion path that corresponds to the motion path of the demonstration tool. The method may further include causing the robotic device to move the robot tool using the one or more robot movements within the replication control path. 
     In a further example, a system including a demonstration tool, a robotic device, at least one camera, and a control system is disclosed. The control system may be configured to receive data from the at least one camera indicative of position of the demonstration tool. Based on the received data, the control system may further be configured to determine a motion path of the demonstration tool, where the motion path includes a sequence of positions of the demonstration tool. The control system may also be configured to determine a replication control path for the robotic device, where the replication control path includes one or more robot movements that cause the robotic device to move a robot tool through a motion path that corresponds to the motion path of the demonstration tool. The control system may additionally be configured to cause the robotic device to move the robot tool using the one or more robot movements within the replication control path. 
     In another example, a non-transitory computer readable medium having stored therein instructions, that when executed by a computing system, cause the computing system to perform functions is disclosed. The functions may include receiving data from one or more cameras indicative of position of a demonstration tool. Based on the received data, the functions may further include determining a motion path of the demonstration tool, where the motion path includes a sequence of positions of the demonstration tool. The functions may also include determining a replication control path for a robotic device, where the replication control path includes one or more robot movements that cause the robotic device to move a robot tool through a motion path that corresponds to the motion path of the demonstration tool. The functions may further include causing the robotic device to move the robot tool using the one or more robot movements within the replication control path. 
     In yet another example, a system may include means for receiving information reports relating to driving conditions from a plurality of autonomous vehicles within a fleet of autonomous vehicles. The system may also include means for receiving data from one or more cameras indicative of position of a demonstration tool. Based on the received data, the system may further include means for determining a motion path of the demonstration tool, where the motion path includes a sequence of positions of the demonstration tool. The system may also include means for determining a replication control path for a robotic device, where the replication control path includes one or more robot movements that cause the robotic device to move a robot tool through a motion path that corresponds to the motion path of the demonstration tool. The system may further include means for causing the robotic device to move the robot tool using the one or more robot movements within the replication control path. 
     The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the figures and the following detailed description and the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a block diagram of a motion control photography system including a master scene control, according to an example embodiment. 
         FIG. 2  shows a perspective view of a robot for use with a motion control photography system, according to an example embodiment. 
         FIG. 3A  shows a view of a robot with 7 degrees of freedom, according to an example embodiment. 
         FIG. 3B  shows a view of a robot with an attached camera, according to an example embodiment. 
         FIG. 3C  shows a view of a robot with an attached lighting unit, according to an example embodiment. 
         FIG. 4A  shows a view of wrist mount for use with a robotic arm, according to an example embodiment. 
         FIG. 4B  shows a view of a robot with an attached wrist mount, according to an example embodiment. 
         FIG. 5A  shows one potential embodiment of a master input for use with a motion control system, according to an example embodiment. 
         FIG. 5B  illustrates a global timeline coordinating device actor positions through a master control, according to an example embodiment. 
         FIG. 6  shows a block diagram of a motion control photography system including a master scene control, according to an example embodiment. 
         FIG. 7  shows one potential implementation of a computer or electronic device, according to an example embodiment. 
         FIG. 8  illustrates a potential user interface for a software control, according to an example embodiment. 
         FIG. 9  illustrates a potential user interface for a software control, according to an example embodiment. 
         FIG. 10  illustrates a method of control, according to an example embodiment. 
         FIG. 11  is a block diagram of a method, according to an example embodiment. 
         FIG. 12A  illustrates a motion capture system and a human actor with a demonstration tool, according to an example embodiment. 
         FIG. 12B  illustrates a motion path of a demonstration tool, according to an example embodiment. 
         FIG. 12C  illustrates a motion path of a demonstration tool and a corresponding motion path of a robot tool, according to an example embodiment. 
         FIG. 12D  illustrates a motion path of a robot tool, according to an example embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Example methods and systems are described herein. Any example embodiment or feature described herein is not necessarily to be construed as preferred or advantageous over other embodiments or features. The example embodiments described herein are not meant to be limiting. It will be readily understood that certain aspects of the disclosed systems and methods can be arranged and combined in a wide variety of different configurations, all of which are contemplated herein. 
     Furthermore, the particular arrangements shown in the Figures should not be viewed as limiting. It should be understood that other embodiments might include more or less of each element shown in a given Figure. Further, some of the illustrated elements may be combined or omitted. Yet further, an example embodiment may include elements that are not illustrated in the Figures. 
     Example embodiments may include or otherwise relate to a motion-capture system that may be used to record positions of a moving demonstration tool, and then use the recorded positions to program a robotic device. For example, an actor may demonstrate some type of activity using one of a number of possible different demonstration tools. A motion capture system may use one or more optical sensors to determine a motion path followed by the demonstration tool. The motion path of the demonstration tool may indicate the position of the tool (e.g., translation and orientation) over a series of timesteps. From the motion path of the demonstration tool, a motion path for a separate robot tool (e.g., an end-effector-mounted tool on a robotic device) may be derived. The robotic device may then be controlled in order to move its robot tool through the sequence of positions within the derived motion path. In some embodiments, by capturing the position of the demonstration tool precisely (e.g., 100 times a second or 1,000 times a second), a robotic device may be trained to move a tool in much the same manner as a human demonstrator. 
     Such a system may be useful for a wide variety of applications, and may be particularly useful in applications where it may be difficult to program a robot to move in the same nuanced manner as a human. For example, applications may exist in cinema (e.g., to control a camera), manufacturing (e.g., to control a welding tool), and/or design (e.g., to control a paint brush), among other possibilities. 
     In order to capture motion of the demonstration tool, one or more cameras may be directed toward an actor as the actor demonstrates how to use the tool. In some examples, precise motion capture may be achieved by attaching control markers onto the demonstration tool at one or more points. The control markers may be passive markers (e.g., colored points detectable by a camera when lighted) or active markers which generate their own signal (e.g., light emitting diodes). In further examples, some or all of the control markers may have one or more distinguishing characteristics that can be distinguished by a camera in order to determine which points on the demonstration tool are moving. A combination of different types of markers may also be used. 
     In additional examples, a user of the demonstration tool may be shown a display with a visual simulation of how the motion of the tool will be replicated by a robotic device. For example, the visual simulation may show a virtual robot actor that simulates robot movements that will be followed by the robotic device to use a robot tool based on the demonstration. In some examples, the visual simulation may also show one or more visual curves and/or numerical values corresponding to motion characteristics of the robotic device (e.g., joint angles, velocities, and/or accelerations). By watching the visual simulation, the user may be able to adjust movements of the demonstration tool on the fly to better train the robotic device. In additional examples, the demonstration tool may contain a button which controls when movements of the demonstration tool are recorded by the motion capture system. 
     In further examples, a warning signal may be provided to the user when the demonstrated movements are approaching or have exceeded one or more predefined constraints of the robotic device. Accordingly, the user may be able to adjust movements of the demonstration tool in order to stay within the feasible range of motion of the robotic device. In additional examples, the display for the visual simulation may be attached to or included within the demonstration tool (e.g., when the demonstration tool is a camera, a sub-window of a viewing screen of the camera may show the visual simulation). 
     In some examples, a replication control path consisting of robot movements of the robotic device may be determined that cause the robotic device to move the robot tool through captured positions of the demonstration tool. For instance, a sequence of joint angles of one or more joints of the robot may be determined that cause the robot to position an end-effector-mounted robot tool over a timeline. In some examples, a mapping between motion parameters of the robot (including joint angles, joint velocities, and/or joint accelerations) and corresponding positions of the robot tool may be determined in order to enable the robot to move an end-effector-mounted tool through a motion path that corresponds to the motion path of the demonstration tool. In further examples, the control path may sometimes be refined before it is used by the robotic device to replicate the movements of the demonstration tool. For example, motion curves within the control path may be smoothed (e.g., to avoid jerking movements by the robot). In another example, a visual simulation (e.g., animation of projected robot movements) may be displayed to the user through a graphical interface that allows the user to make adjustments to the robot movements within the control path during a review phase before the robotic device replicates the movements. 
     In other examples, multiple review and replication phases may be used in order to iteratively improve the motion paths of the robotic actor. Through an iterative cycle, a robotic actor may be quickly trained to perform complicated motion paths. In other examples, separate review and replication phases may not exist. For instance, a robotic device may be controlled to use a robot tool in much the same way that a human demonstrator uses a demonstration tool in real time or approximately real time. Real time control may be useful in situations where the robotic device is operating in an area that is unsafe for a human, for example. 
     In further examples, the control path may cause the robotic device to move the robot tool by applying a certain scaling factor to captured positions of the demonstration tool. Accordingly, a small demonstration tool may be used to control a larger robot tool or a large demonstration tool may be used to control a smaller robot tool. For instance, a microscopic tool for surgery may be used by a robotic device based on demonstrated movements of a larger tool that can be more easily manipulated by a human surgeon. 
     After determining (and possibly refining) a control path for the robotic device, the robotic device may then be used to replicate the motion of the demonstration tool with its own robot tool. In some examples, the robotic activity may then be repeated many times (e.g., a robot trained to use a glue gun with the deft of a skilled human actor may be used to repeat the process hundreds or thousands of times in manufacturing). In further examples, positions of the robot tool may also be captured using motion capture (e.g., using LED tags and a camera). These positions may be used to verify and/or refine the control path of the robot by comparing the actual resulting positions of the robot tool to the previously recorded positions of the demonstration tool. Multiple iterations of this process may also be used to further refine the robot control path as well. 
     In additional examples, the demonstration tool may be controlled by forces of nature instead of or in addition to a human demonstrator. For instance, a ball with LED tags may be dropped and allowed to bounce as positions of the ball are captured by a camera. A robot may then instructed to control a robot tool (e.g., a ball held by an end-effector of the robot) through a series of movements that replicate the bouncing ball. Accordingly, a control path of robot movements that simulate an object&#39;s changing position resulting from physical forces may be determined which may result in a more accurate simulation than trying to directly program the robot movements. 
     Example embodiments may involve use of a robotic control system to create automated programming of robotics arms using motion control.  FIG. 1  describes an example motion control system  100 . Motion control system  100  is part of a motion controlled set used to film a scene using motion control photography. Motion control system  100  comprises a master control  10 , input and feedback systems  20 , device actors  40 , and safety systems  90 . From the most basic perspective, motion control system  100  functions when an input system  20  provides instructions to a device actor  40  via master control  10 . 
     For the purposes of the present invention, a scene comprises a set of motions and actions by device actors  40  over a continuous period of time, such that a set of players in front of a camera is recorded in video, sound, or both. The players are people, stationary objects, or objects controlled or moved by one or more devices of device actors  40 . In one embodiment, the camera is mounted to a robot arm of device actors  40 . At a beginning of a scene, a camera and a plurality of players begin in a first position. Motion control of device actors  40  moves the camera and the players through a sequence of motions to the end of a scene, with players and sound from the scene recorded using the camera and potentially other audio and video recording equipment to capture the motion. 
     In one potential embodiment as part of a motion control system  100 , input and feedback systems  20  include a database  22 , a master input  24 , a software control  26 , and an independent manual control  28 . As part of the input and feedback systems  20 , database  22  operates to provide a set of timing and position data to direct all or a portion of device actors  40 . Alternatively, database  22  stores data being created by manual or individual movement or data input related to operation and function of device actors  40 . Database  22  also stores data created independently of device actors  40 , such as data created using software modeling features of a software control  26 . 
     A master input  24  is any device that functions to operate all of the device actors  40  associated with a particular scene being created with motion control system  100 . Master input  24  functions by sending input control signals to master control  10 . Master control  10  then adapts the signal from master input  24  to send individual control signals to a plurality of actors operating as device actors  40  for the particular scene. In one potential embodiment, every individual device of device actors  40  is provided a control signal from master control  10  when a signal is received from master input  24 , including a signal to maintain a status quo or non-action to devices that are not operating as device actors  40  for a particular scene. In an alternative embodiment, a portion of the device actors connected as part of motion control system  100  are not sent any signal from master control  10  as part of the operation of motion control system  100  for a particular scene. 
     Software control  26  acts as a replacement for master input  24  in sending control signals to the plurality of actors via the master control  10 . Alternately, software control  26  controls individual devices from among device actors  40  to alternate, change, or experiment with motions of the individual device. In other potential embodiments, software control  26  functions to model the behavior of individual devices of device actors  40  within a virtual environment. In such an embodiment, software control  26  contains a software model for an individual device, which allows control signals to be created for the device without actually sending the control signals to the device. The control signals are then be stored in the software control  26 , in database  22 , within a computer memory component that is part of master control  10 , or within computer memory that is part of the device of device actors  40  for which the controls are being created. After the control signal is created by software control  26  and propagated to the appropriate storage location, a master control signal from software control  26  or from master input  24  activates the control signal for the individual device to act in conjunction with other device actors  40 . 
     Certain devices of device actors  40  additionally have an independent manual control  28 . As described above with respect to software control  26 , control signals for an individual device are created in software modeling. Similarly, a device may have independent manual control  28  that is used to operate a device of device actors  40 . For example, in one potential embodiment, a device that is one of device actors  40  is a follow focus that controls the focus of a camera. The follow focus may have a control device that is designed to control the focus of the camera that may operate as an independent manual control. When a set of instructions is being created for the entire scene, the independent manual control  28  is given input commands over time that are recorded to database  22  or a memory device of master control  10 . During creation of a set of instructions using independent manual control  28 , the independent manual control  28  may communicate directly with the associated device of device actors  40 . Alternatively, the independent manual control  28  may send the control signal to master control  10 , which then conveys the signal to the associated device of device actors  40 . The control signal may then be created either from the signal of the independent manual control  28 , of from a measured feedback reading created by the operation of the associated device. Additionally, although in many situations it is preferable to have the independent manual control  28  actually control the associated device during control signal creation in order to view the results, control signals is created without controlling the device. For example, if expected input signals are expected for certain time marks, an independent manual control  28  is operated independent of the related device, and the control operation recorded. These function as ways in which instructions for individual device actors of device actors  40  is integrated into a motion controlled scene as part of motion control system  100 . 
     The result of the integration described above is considered as a global timeline for a motion controlled scene.  FIG. 5B , described in more detail below, provides an illustrated example, where the actions of multiple motion controlled actors are integrated into a global timeline using a master control. In  FIG. 5B , various actors such as camera and lighting robots move at certain points during a scene. The actors may receive control signals during the entire scene from time a to time f, or may only receive controls when they actually move or act. Certain other actors, such as 1 st  and 2 nd  special effects (fx) actors only receive single commands to act at one specific time, such as 1 st  fx actor acting at time b in the global timeline of  FIG. 5B . Such an integration into a global timeline allows simplified user control of complex actions impacting an entire scene that may save significant amounts of time in modifying a particular scene with a given timeline. This allows scrubbing through time forward and backwards as well as seeking to specific frame number or timecode for all actors in a particular scene, and slowing down or speeding up the performance of the entire set (system) in real time via a hardware device. 
     Although embodiments will be illustrated with reference to specific implementations, a person of ordinary skill in the art will understand that these implementations describe innovations which may have broad use other than the specifically described implementations. As described below, enhanced control may comprise systems and methods for a variety of functions, including safety systems, playback speed control, forward and reverse position scrubbing, and integrated detection systems, among others. 
     Such a system includes advantages over systems currently known in the art by providing accessible and highly sophisticated robotic controls in an art environment dominated by custom toolsets without simple or malleable integration toolsets. Such a use of highly accurate control systems with cameras is considered, in certain embodiments, to be “cinematic automation” or “3D projection automation” which allows the ambitions of visual story tellers to be matched through the application of automation systems. For example, improved control systems can coordinate sub-millimeter position of a camera in space with the position of the light, an actress, a robotic actor comprising a 3D projection surface, and special effects (pyrotechnics, video playback, sound cues, etc.). This allows execution of highly complex shots that would previously have required the coordination of several film departments with manual human positioning. Such control systems remove inaccuracy and introduced the repeatability of robotics, through highly accurate computer synchronization of events. In addition to developing a faster, more rigid, safer, and easier to program robotic arm system, embodiments of the present innovations include interfaces that allow a creative director to make very quick on-set adjustments. In the high pressure environment of feature films and commercial productions, it is critical that a director or visual effects supervisor is able to make very quick creative or technical calls, and the systems described herein enable this in a way not known in the previous art. 
     As a further example, if a system implementation of the innovations is being used in presentation of a scene in a live play, the system might be synchronizing a large robotic arm, a custom robotic rig to move the arm, video playback of a wall of LED&#39;s that serve as the light source, and the motion of a piece of background, and an animatronic actor with facial features animated from a projector attached to an animation computer with arm and leg movement animated by robotics. This is a highly technical, pre-programmed scene that has been pre-visualized in a computer, and the interplay of all the elements have been choreographed using the system. Real time during the play, if the actors are delivering their lines at a slower than normal rate, or there is a need to pause for extra applause, a play director may compensate real time by pausing the entire set or by simply turning a knob at the right moment to accommodate the actors. The robot slows down, the robotic rig complies, and the entire scene of the play decelerates. All of this happens in synchronicity. Plus the system can provide integrated enhanced safety to prevent the actors from being injured. 
     Referring now to  FIGS. 2-4 , several non-limiting examples of device actors  40  will be described. Although these figures focus on the use of robotic arms, device actors is other types of devices that is stationary, such as sensors, stationary lights, and signal sources, as will be described later. 
       FIG. 2  describes device actor  242 . Device actor  242  comprises robotic arm  246 , mounting point  248 , and rail  244 . Device actor  242  is described in  FIG. 2  with no specific functionality attached at any mounting point such as mounting point  248 . Mounting point  248  is configured to hold a camera, a light, a player that will be filmed by a camera, or any other relevant device or object. In certain embodiments, instructions is given to position mounting point  248  at a specific location, and the positions of the axis of robotic arm  246  and of rail  244  is calculated by a process of the related motion control system. In alternative embodiments, each axis of robotic arm  246  and the position of rail  244  require separate, individual settings and control commands. 
       FIG. 3A  describes device actor  342 , comprising a robotic arm with axis A 1 -A 6 , with axis A 0  associated with a rail which is not shown that allows side to side movement of the other eight axes.  FIG. 3B  describes device actor  342  with a camera mount  352  placed at a mounting point, and camera  350  attached to camera mount  352 .  FIG. 3C  describes device actor  342  with light  360  placed at a mounting point. 
       FIGS. 4A and 4B  describe an embodiment where a device actor  442  comprises a robotic arm  444  with a wrist mount  410  and a wrist mount interface  412 . Wrist mount  410  and wrist mount interface  412  enables multiple device actors to be mounted to robotic arm  444  in addition to standard mounts such as a camera or lighting fixture. In certain embodiments, the wrist mount interface enables temperature sensors, laser range detectors, microphones, speakers, fans, or other mechanical activated or special effects devices. 
       FIG. 5A  describes master input  524  which is one potential implementation of a master input such as master input  24  of  FIG. 1 . Master input  524  comprises a display interface  510 , and engage control  540 , a mode select  530 , and an analog interface  520 . The function of master input  524  will be described in conjunction with the global timeline of  FIG. 5B . 
       FIG. 5B  illustrates a global timeline associated with one potential embodiment of a motion controlled scene implemented in a motion control system such as motion control system  100  of  FIG. 1 .  FIG. 5B  includes a number of actors, as defined above, which operate during a scene with a nominal or standard running time from time a to time f. The global timeline is nominal and not referring to real clock time because, as will be detailed further below, master input controls alters the rate at which actors progress through motions from the beginning of a scene to the end of a scene. The global timeline may therefore alternately be thought of as a coordinated position chart for actors. During the scene running time, an actor may act or move during the entire scene, during a portion of the scene, or only for one instant of a scene. Each actor, though, will have a predetermined point for each nominal time from the beginning to the end of the scene. The predetermined points for each actor are associated with predetermined points for each other actor. 
     In one potential embodiment, individual control signals for specific device actors are coordinated into a single file within a memory of a master control with a common base time provided by a master clock within the master control. During operation, master control extracts control signals for each device actor and provides individual control signals to each device actor at the appropriate intervals. In an alternative embodiment, a master control maintains separate individual control signal files and timing data for different device actors, and synchronizes the different control signals separately from the individual control files. 
     In another alternative embodiment, the control data for a portion of the device actors is transferred by a master control to a memory within an associated individual device actor. During operation, device actors having control data within memory receive only a synchronization signal that indicates a location in a global timeline, a rate of progress through a global timeline, or both. 
     The specific embodiment described in  FIG. 5B  includes a camera robot, a follow focus, two lighting robots, a player robot that controls an object that is to appear in front of a camera, and two special effects actors. As described above, each actor has a path to follow through the scene from beginning at time a to end at time f In the specific embodiment of  FIG. 5B , each actor begins at a preset position. As described by the global timeline, only the player robot moves from time a to time b. This will be true whether b occurs 10 seconds after starting time a, or 20 seconds after time a due to modification of the rate at which the scene progresses by a master input, as is further detailed below. At time b, 1 st  special effects actor is activated with a single command, player robot continues moving, and follow focus and camera robot begin moving. 
     The chart of  FIG. 5B  is not meant to indicate that non-moving actors such as 1 st  lighting robot, 2 nd  lighting robot, and 2 nd  fx actor during time a to time b are not receiving input commands.  FIG. 5B  merely illustrates a global position timeline. In certain embodiments they may not be receiving input commands from a master control. In alternative embodiments, however, non-moving actors such as 1 st  lighting robot may periodically or continuously receive commands from a master control, even when not moving, where the command is an instruction not to move. Such a command may function to maintain synchronization, acting as a clock or a timing heartbeat to maintain synchronization. In some embodiments, real time adjustments are made to an actor during a scene. Such a clock or timing heartbeat further serves to provide synchronization data as the adjustments feed back to the master control to update and change the global timeline. 
     Referring back to  FIG. 5A , master input  524  includes a display interface  510 . Display interface  510  is a modular touch screen device that displays status information related to actors or the global timeline. For example, display interface  510  includes a scene time associated with the current position of the actors in the global timeline, or a frame number for a current scene associated with the current timeline. In such a display, time a, for example, or frame  1 , is displayed when the actors are in position for the beginning of the scene. In one potential embodiment, display interface  510  is a portable electronic device or a cellular telephone with an interface application that communicates with a master control. 
     Master input  524  additionally comprises an engage control  540 . Because of the size and force that many actors, particularly large industrial robot arms carrying heavy cameras moving at up to several meters per second, are capable of conveying in a collision, safety controls is extremely important for many embodiments of a motion controlled scene. Engage control  540  acts as an input regulator to prevent master input  524  from being operated by accident, such that engage control must be depressed at all times prior to any other input command being conveyed and acted upon from master input  524 . 
     As shown in  FIG. 5A , master input  524  also comprises a mode select  530  and an analog interface  520 . Analog interface  520  is any input device capable of defining a range of inputs by a user control. In one potential embodiment, analog interface  520  is a wheel with a spring action that returns the wheel to a central position in the absence of user manipulation. In other potential embodiments, analog interface is a lever, a sliding tab, or any other input control to enable a user to input a signal. Master input  524  may comprise multiple input modes. In one potential embodiment, master input  524  comprise a reset mode, a play mode, and a scan mode, with the mode selectable via mode select  530 . 
     In a reset mode, operation of engage control  540  and analog interface  520  operates to cause each actor within a scene to move to an initial position for the beginning of a global timeline. Additionally, a specific scene or frame number is selected by use of display interface  510 , and operation causes each actor to move to a position associated with that frame or time in the global timeline. Such a mode may allow device actors that are out of position for a particular time to be reset to a correct position. 
     In a play mode, operation of analog interface  520  may serve to speed up or slow down progress through a scene in a global timeline. For example, in a scene with actors set in position at global time a, selecting engage control  540  may serve to begin the action of all actors through the global timeline at a base rate, where each second of time is associated with one second of progress through the global timeline. Operation of analog interface  520  in a first direction then serves to slow down progress through the global timeline, such that 1 second of real time is associated with 0.5 seconds of progress through the global timeline. If the analog interface  520  is then set back to center, the progress through the global timeline will revert to a one to one ration with real time, but with the remaining actions being delayed from the initial start by the previous slowdown. Conversely, if analog interface  520  is operated in a second direction opposite from the first direction, progress through the global timeline is increased. If, for example, the nominal time from time a to time b is 10 seconds, increasing progress through the global timeline by 10% may reduce that actual time required for the motion controlled scene to progress from the positions of time a to the positions of time b by approximately 0.9 seconds and the actual time required the progress from time a to time b with analog interface set to increase playback being approximately 9.1 seconds. This may provide use when a human player being recorded by a camera as part of a motion controlled scene is delivering lines more slowly or more quickly than expected, and there is a desire to match the actions of the motion controlled scenes with the actions of human players that are not motion controlled. 
     In a scan mode, selecting the engage control  540  and then operating analog interface  520  may operate to shuttle or scan forwards or backwards through the global timeline in a continuous fashion. For example, if a motion controlled set currently has actors in positions associated with time c, selecting shuttle mode and operating analog interface  520  in a first direction may cause all actors to move continuously forward through the positions associated with the global timeline to reach time d. Moving analog interface  520  in a second direction may cause all actors to move continuously backwards through the positions associated with the global timeline to reach the positions associated with time b. In one potential embodiment, a particular time or frame is selected using display interface  510 . Operation of analog interface  520  may shuttle continuously through the positions of the global timeline until the particular time or frame is reached. Master input  524  may then cease to control device actors until a selection in display interface  510  is activated acknowledging that the previously selected point has been reached, or until analog interface  520  is returned to a central position. 
       FIG. 6  describes a block diagram of a motion control system  600 . Motion control system  600  comprises a master control  610 , as well as details of one potential embodiment of input, feedback, and device actor sub-systems. In the embodiment disclosed by motion control system  600 , master control  610  comprises an operating system  614 , master control logic  612 , master clock  616 , network support  618 , control logic  696 , and feedback  698 . The elements of master control  610  are implemented in a computer system comprising a general function processor and memory hardware system. Alternatively, master control  610  is implemented in custom designed processing, memory, and networking hardware devices, or is implemented in an abstracted software layer of a general purpose computing system. Master clock  616  functions as a real time clock to coordinate movement of the actors in the system. Master control logic  612  functions to integrate the individual control signals into a master timeline, and to correctly route control signals to the correct device, both during operation of the entire motion control scene through the master timeline, and through individual modification and setting of device actor positioning and function using control logic  696 . Master control logic  612  also assists in coordination and routing of feedback  698 . Feedback  698  may include actual position and setting signals received from monitors attached to device actors. One potential example is a location device attached to a robot arm. The actual position of the arm is tracked via the location device to provide feedback and calibration in relation to an input position command sent to the arm from either database  622 , software control  657 , or another control input for the robot arm. Operating system  614  includes special libraries and functionality for interacting with device actors, and may further serve to manage basic hardware computing functionality such as memory storage and processor usage. Operating system  614  may further enable networking capability via OS network  654  to communicate with various related devices. 
     Network support  618  may also enable communications from master control  610  to related devices, actors, and input controls via network  620 . In one potential embodiment, network  620  may comprise an EtherCAT network operating according to IEEE 1588. In such an embodiment, packets are no longer received, then interpreted and copied as process data at every connection. Instead, the frame is processed on the fly using a field bus memory management unit in each slave node. Each network node reads the data addressed to it, while the telegram is forwarded to the next device. Similarly, input data is inserted while the telegram passes through. The telegrams are only delayed by a few nanoseconds. On the master side commercially available standard network interface cards or on board Ethernet controller can be as hardware interface. The common feature of these interfaces is data transfer to the master control via direct memory access with no CPU capacity is taken up for the network access. The EtherCAT protocol uses an officially assigned Ether Type inside the Ethernet Frame. The use of this Ether Type allows transport of control data directly within the Ethernet frame without redefining the standard Ethernet frame. The frame may consist of several sub-telegrams, each serving a particular memory area of the logical process images that can be up to 4 gigabytes in size. Addressing of the Ethernet terminals can be in any order because the data sequence is independent of the physical order. Broadcast, Multicast and communication between slaves are possible. Transfer directly in the Ethernet frame is used in cases where EtherCAT components are operated in the same subnet as the master controller and where the control software has direct access to the Ethernet controller. Wiring flexibility in EtherCAT is further maximized through the choice of different cables. Flexible and inexpensive standard Ethernet patch cables transfer the signals optionally in Ethernet mode (100BASE-TX) or in E-Bus (LVDS) signal representation. Plastic optical fiber (POF) can be used in special applications for longer distances. The complete bandwidth of the Ethernet network, such as different fiber optics and copper cables, can be used in combination with switches or media converters. Fast Ethernet (100BASE-FX) or E-Bus can be selected based on distance requirements. The Fast Ethernet physics enables a cable length of 100 m between devices while the E-Bus line is intended for modular devices. The size of the network is almost unlimited since up to 65535 devices can be connected. 
     Further, such an embodiment using EtherCAT supports an approach for synchronization with accurate alignment of distributed clocks, as described in the IEEE 1588 standard. In contrast to fully synchronous communication, where synchronization quality suffers immediately in the event of a communication fault, distributed aligned clocks have a high degree of tolerance from possible fault-related delays within the communication system. 
     Thus, data exchange is completely hardware based on “mother” and “daughter” clocks. Each clock can simply and accurately determine the other clocks run-time offset because the communication utilizes a logical and full-duplex Ethernet physical ring structure. The distributed clocks are adjusted based on this value, which means that a very precise network-wide time base with a jitter of significantly less than 1 microsecond is available. 
     However, high-resolution distributed clocks are not only used for synchronization, but can also provide accurate information about the local timing of the data acquisition. For example, controls frequently calculate velocities from sequentially measured positions. Particularly with very short sampling times, even a small temporal jitter in the displacement measurement leads to large step changes in velocity. In an embodiment comprising EtherCAT, the EtherCAT expanded data types (timestamp data type, oversampling data type) are introduced. The local time is linked to the measured value with a resolution of up to 10 ns, which is made possible by the large bandwidth offered by Ethernet. The accuracy of a velocity calculation then no longer depends on the jitter of the communication system. It is orders of magnitude better than that of measuring techniques based on jitter-free communication. 
     Finally, in an embodiment where network  620  comprises EtherCAT, a hot connect function enables parts of the network to be linked and decoupled or reconfigured “on the fly”. Many applications require a change in I/O configuration during operation. The protocol structure of the EtherCAT system takes account of these changing configurations. 
     As described in  FIG. 6 , network  620  then interfaces with individual devices and actors via control data interface  650 . Control data interface is part of network  620 , or may comprise distributed components at the input of individual actors. Additionally, Input and feedback data interface is the same device as control data interface, acting as an opposite direction data flow of the same device interfacing with network  620 . The actors interfacing with network  620  comprise camera control  632 , secondary control  634 , audio  636 , digital output bank  648 , camera robot  670 , follow focus  672 , light  674 , master input  651 , and master safety control  690 . 
     In certain embodiments, some actors may communicate directly to network  620  via control data interface  650 . For example, in the embodiment described above where network  620  is an EtherCAT network, camera control  632 , secondary control  634 , audio  636 , and digital output bank  648  is able to communicate with no adapter through network  620 . In such an embodiment, adapter  662   a  is an EtherCAT-provibus adapter for communicating with camera robot  670 , adapter  662   b  is an EtherCAT-preston adapter for communicating with follow focus  672 , and adapter  662   c  is an EtherCAT-dmx adapter for controlling light  674 . 
     In addition to master control  610  and the devices communicating with master control  610  via network  620 , motion control system  600  may comprise a plurality of other input, feedback, and devices such as OS network  654 , database  622 , database interface  652 , MI display  656 , software control  657 , video output  658 , and adapters  655   a - c . In one potential embodiment, OS network  654  is an Ethernet network coupled to master control  610 . MI display  656  may function as a display for master input  651  in a manner similar to the display described for master input  524  of  FIG. 5A . Software control  657  may function as a software environment that may virtually create a global timeline for use with master control  610 , and may also function to create a global timeline in real-time with live control of device actors. In one embodiment, software control  657  is a software program such as MAYA™ with supporting software add-ons. Finally, video output  658  is a real time video output associated with a camera in motion control system  600 . As motion control system moves through a global timeline, video output may allow real time video review of a motion controlled set, such that individual device actors is modified, or a master input  651  controls is adjusted based on information from video output  658 . 
     Motion control system  600  of  FIG. 6  may then allow for function and creation of media in a variety of different ways, and described by  FIG. 10 . In an embodiment described by  FIG. 10 , a user may create control data using a software interface such as software control  657 . The control data may then be stored in database  622  for future use. Alternatively or concurrently, the control data is sent to master control  610 . The master control then manages control logic  696  and creates a global timeline, such that any data required by specific devices prior to function is communicated to those devices. For example, in one potential embodiment, camera robot  670  must have all position data prior to operation, with camera robot  670  functioning in synchronization with the global timeline by receiving a time or frame input and acting in response using previously received control information to move to the correct position for the current state of the global timeline. After the global timeline is prepared by master control  610 , and all device actors are prepared, a user may use a master input  651  or a software control  657  to send an operation signal to master control  610 . The master control then sends the appropriate control signals to individual device actors given the global timeline position and synchronization. The device actors then operate according to control signals, and send feedback signals via network  620  documenting actual operation, errors, and/or safety shutdown conditions. The feedback data can then be used to update the control signal managed by master control  610  to modify or match the original control data from the database  622  or software control  657 . 
     In one potential embodiment, motion control system  600  comprises master safety control  690 . Master safety control may comprise a hard wired shut down control connected directly to device actors identified as posing a safety risk. Such a shutdown control is attached to master input  651 . In another potential embodiment, master safety control  690  comprises a safety computing system or a safety PLC attached to safety sensors. Such safety sensors may comprise object proximity detectors attached to a device actor. When a scene is created in motion control system  600 , the scene will have data for expected device actors and for players appearing in the scene. Object proximity detectors is programmed or coupled to a computing system to filter expected objects with expected locations from unexpected objects and locations. If an object is detected by an object proximity detector in an unexpected and unsafe location, a signal is sent to shut down the entire motion controlled scene, or at a minimum, device actors determined to pose a potential danger to the unexpected object. In another potential embodiment, boundaries for a motion controlled scene are determined. Proximity detectors or motion detectors is configured to detect movement across a scene boundary or a device actor boundary during operation of the motion control system, and to halt operation when an unsafe motion or object is detected. In this fashion, master safety control may observes an area proximate to various device actors and transmit a safety shutdown signal. In one potential embodiment, an object detector comprises a light detection and ranging unit (LIDAR). In another potential embodiment, the object detector is a passive infrared sensor (PIR). 
       FIG. 7  shows a block diagram of an exemplary computer apparatus that can be used in some embodiments of the invention (e.g., in the components shown in the prior Figures). 
     The subsystems shown in  FIG. 7  are interconnected via a system bus  710 . Additional subsystems such as a keyboard  718 , fixed disk  720  (or other memory comprising computer readable media), monitor  714 , which is coupled to display adapter  712 , and others are shown. Peripherals and input/output (I/O) devices, which couple to I/O controller  702 , can be connected to the computer system by any number of means known in the art, such as through serial port  716 . For example, serial port  716  or external interface  722  can be used to connect the computer apparatus to a wide area network such as the Internet, a mouse input device, or a scanner. The interconnection via system bus  710  allows the central processor  706  to communicate with each subsystem and to control the execution of instructions from system memory  704  or the fixed disk  720 , as well as the exchange of information between subsystems. The system memory  704  and/or the fixed disk  720  may embody a computer readable medium. 
       FIG. 8  illustrates one potential embodiment of a user interface  800  in a software control for use with a motion control photography system. Such an interface may enable a number of functions, including modeling of individual device actors, software control of individual device actors, creation of control data for individual device actors, and recording control or operation data for individual device actors. Similarly multiple devices is modeled simultaneously to model, control, or record operation of an entire motion controlled set using an interface such as user interface  800 . 
     User interface  800  may include an actor panel with a plurality of interface buttons including an “actors” drop down menu to show a list of the current device actors is a scene, and “add actor” scene to bring up a prompt which allows selections of a name and/or type of device actor to be created or added to a scene, and a “delete actor” interface to allow deletion of an actor from a scene. 
     User interface  800  may also include a selection panel. A selection panel may include an interface for “Select End Effector” which selects a controller on the robot which allows the user to drive the robot via a wrist. This controller, when selected and viewed through channel box editor, may house additional attributes that the user can control. These attributes may include:
         Visibility—Toggles the visibility of the controller in a view port.   Disable Heads up Display (HUD) Updates—Disables all HUD updates in a view port.   A( 1 - 6 ) Angle—Displays the current angle of each respective robot axis.   Track Robot (TR) Position—Displays the position of robot on the track axis.   Show Axes—Toggles the visibility of a skeleton in a view port.   FK IK (A 1 -A 6 )—Allows the switching settings for of individual joints.       

     A selection panel may also include a “select base control” interface which may select a controller on the robot which allows the user to position the robot from the base. Such a controller may, when selected and viewed through the channel box editor, houses additional attributes that the user can manipulate such as: 
     Translate Z—Moves the base along the track system. 
     Rotate Y—Changes the orientation of the base. 
     Column Height—Changes the base height of the robot. 
     A selection panel may also include additional interface controls such as:
         Select Track Control—Selects a controller on the robot which allows the user to move and orient the track system to their liking. further describe the disconnect between the end effector and this node.   Select Worldspace Mount—Selects a controller for adding a mount.   Select World Controls—Selects a master controller which allows the user to move and orient the entire robot and track system together.       

     Additionally, user interface  800  may provide controls for adding and removing mounts to device actors within the software system, and for setting placement for mounts that are added to device actors. For example,  FIG. 8  shows three potential positions for mounting a camera to a robot arm that is a device actor in the current system. The user interface  800  may provide graphical or number input selections for choosing between various mounting options, and for adjusting the position variables associated with such a setting. 
     In one potential embodiment of a motion control photography system, user interface  800  is integrated through a software control to a camera robot such as software control  657  and camera robot  670  of  FIG. 6  to enable an automated system calibration. One potential such calibration comprises a lens node calculation for determining a calibrated lens position in a camera mounted to a robot arm. One potential embodiment of such a calibration comprises providing software control  657  with information regarding the location and dimensions of a base, wrist or joint elements, and camera mounts for camera robot  670 . A calibration player with known characteristics such as location and size is also provided. When a calibrate command is selected via software control  657 , camera robot  670  records a plurality of images of the calibration player from different camera angles or locations. The images in conjunction with known data regarding the calibration player and camera robot  670  allows the lense node of the currently mounted camera to be calculated and incorporated into the device actor modeled in software control  657 . 
     In an alternative embodiment of a calibration, software interface  800  may have a calibration command for altering size or location data in response to feedback from a temperature sensor. For example, software control  657  is receive data via digital output bank  658  from a temperature sensor attached to a rail that is part of camera robot  670 . Software control  657  is configured to adjust command signals due to known changes in rail characteristics over temperature, or is configured to signal a need to measure changes in device actor locations in response to temperature changes. 
     A software control such as software control  26  of  FIG. 1  or software control  657  of  FIG. 6  may also comprise an analysis interface such as analysis interface  900  of  FIG. 9 . Analysis interface  900  shows movement data for individual axis of a device actor. Data such as current velocity and current acceleration is displayed, along with graphs of these characteristics over time through a scene, maximum allowable limits for each characteristic, and maximum achieved value for each characteristic. The values presented in analysis interface  900  are modeled from a global timeline created within a software control or recorded in a database. The values may also be values recorded from the actual physical motion of device actors playing through a scene. Use of such analysis data may provide for modifications to be made to a scene while quickly verifying that safe limits of device actor function are not mistakenly exceeded. 
     In addition to analysis of operation of individual device actors, software control is used for preventative safety in detecting potential collisions between device actors in modeling the motion of the actors through a global timeline. Further, such modeling of a scene through a global timeline is used to set safety parameters for a safety system such as master safety control  690  of  FIG. 6 . Modeling of locations and velocities of device actors through a global timeline may enable identification of unsafe zones and unsafe times in an area or set around a motion control system. Such an identification is used to set sensing triggers of object detectors that are part of the safety system described above. For example, if an area within 5 feet of a certain device actor is determined to be at risk of collision, and a buffer zone of 10 additional feet is required to insure safety during operation, a LIDAR detector is configured to detect unexpected objects and movement within a 15 foot area of the device actor during operation, and to automatically create a safety shutdown if an object is detected. In an alternative embodiment, the LIDAR detector is configured to create a warning signal if an object is detected in a periphery of the danger zone, and only to create a shutdown if the detected object is moving toward a potential impact zone. 
     In an alternate embodiment, a software control includes modeling of actors and models of defined safe zones. Analysis of the motion of the actors in software control allows a modeled safety check to see if any actor collides with a defined safe zone. Safe zones are defined by entry of fixed volumes of space into software control, by image capture of a set location. Safe zones may also be defined to be variable based on a detected motion, jerk, velocity, or acceleration of an object in a safe zone. In an alternate embodiment a safe zone is defined by input from transponder device data. For example, a transponder location device is attached to a player, and a safe zone defined by a distance from the transponder. The transponder feeds location data to software control, which may update safe zones within a software control or within a master safety control. In another embodiment, fixed safe zones are defined within software control, and published prior to a safety PLC within master safety control prior to operation of the motion controlled set. 
     A method  1100  is provided for causing a robotic device to move a robot tool along a motion path that corresponds to the motion path of a demonstration tool. In some examples, method  1100  may be carried out by a control system, such as master control  12  as described in reference to  FIG. 1 , in communication with one or more cameras that make up part of a motion capture system. In further examples, a robotic device may also receive instructions from the control system (e.g., a computer workstation with network connections to the robotic arm and the motion capture system). The robotic device may be operable with six degrees of freedom, or a different number of degrees of freedom. For instance, the robotic device may be a device actor within device actors  40  as described in reference to  FIG. 1 , device actor  242  as illustrated and described in reference to  FIG. 2 , device actor  342  as illustrated and described in reference to  FIGS. 3A, 3B , and/or  3 C, and/or device actor  442  as described in reference to  FIG. 4B . In other examples, part or all of method  1100  may be carried out by the robotic device itself. Additionally, while examples with a single robotic arm may be described, various alternative embodiments may include any number of robotic arms, or may include other automated systems integrated with at least one robotic arm. 
     Furthermore, it is noted that the functionality described in connection with the flowcharts described herein can be implemented as special-function and/or configured general-function hardware modules, portions of program code executed by a processor for achieving specific logical functions, determinations, and/or steps described in connection with the flowchart shown in  FIG. 11 . Where used, program code can be stored on any type of computer-readable medium, for example, such as a storage device including a disk or hard drive. 
     In addition, each block of the flowchart shown in  FIG. 11  may represent circuitry that is wired to perform the specific logical functions in the process. Unless specifically indicated, functions in the flowchart shown in  FIG. 11  may be executed out of order from that shown or discussed, including substantially concurrent execution of separately described functions, or even in reverse order in some examples, depending on the functionality involved, so long as the overall functionality of the described method is maintained. 
     As shown by block  1102  of  FIG. 11 , method  1100  may initially involve receiving data from one or more cameras indicative of position of a demonstration tool. The demonstration tool may be any object moving through space such that positions of the object may be determined based on sensor data received from a camera. In some examples, the demonstration tool may be a tool that is used by a human demonstrator. For instance, the tool may be a camera, a welding iron, a glue gun, a metal buffer, a pen, a paint brush, or a different type of manufacturing or design tool. Example methods may be particularly useful for types of activities that may benefit from nuanced human skill, such as the skill of an expert welder. 
     In order to capture data indicative of the position of the demonstration tool, a number of different types of motion capture systems may be used. In some embodiments, a motion capture system may employ a set of control markers on the demonstration tool that can be detected by one or more cameras. For instance, the motion capture system may use multiple linear detector based cameras that function in conjunction with active light emitting diode (LED) markers. Such LEDs may function in a variety of environments, including indoor and outdoor environments. They may additionally operate with minimal or no external light sources, since they provide a light source that may be detected by the cameras. Further, individual LEDs may have distinguishing characteristics, such as an output wavelength or a unique modulation pattern of output light that allows each marker to be distinguished from other markers. A camera may then distinguish movements of individual points on a demonstration tool, which may provide additional precision in determining positions of the demonstration tool and/or enable an individual LED to be identified by a single camera if some of the markers are occluded. 
     Other embodiments may use other computer vision systems, such as a computer vision system that detects passive markers which are not powered and are not implemented with electronics. Passive markers may be, for example, ink markings or colored objects attached to a surface. Unlike the active LED markers described above, the passive LEDs may require certain external lighting levels to be detectable by a camera. Further alternative embodiments may use a mixture of active and passive markers, and may use any number of cameras. 
       FIG. 12A  illustrates a motion capture system and a human actor with a demonstration tool, according to an example embodiment. As shown, a human actor  1202  may be controlling a demonstration tool, a camera  1204  in this example. A shoulder-mounted apparatus for controlling the camera  1204  is shown here, but any type of movable camera (e.g., a handheld camera) could be used as well. Additionally, the camera  1204  may contain one or more control markers  1206 , which may be any of the types of control markers described above in the context of a motion capture system. A camera  1208  may be used to capture data about the position of the demonstration tool and/or particular points on the demonstration tool corresponding to the markers  1206 . The camera  1208  is shown in this example as a free-standing camera on the floor, but cameras mounted in other ways and/or multiple cameras may be used in other examples as well. 
     Method  1100  may additionally involve determining a motion path of the demonstration tool, as shown by block  1104 . The motion path of the demonstration tool may include a sequence of positions (e.g., translations and orientations) of the demonstration tool as it moves through space. In some examples, the demonstration tool may be moved by a human actor while the sensor data indicative of the demonstration tool is received. In further examples, the position of the demonstration tool may be captured at a particular time interval (e.g., 100 times per second or 1,000 times per second). In additional examples, the motion path may include a sequence of cartesian coordinates and rotation angles indicating the position of the demonstration tool over time. 
       FIG. 12B  illustrates a motion path of a demonstration tool, according to an example embodiment. A human actor  1202  may control a camera  1204  by moving the camera  1204  within space (e.g., to film a scene of a movie). A camera  1208  operating as part of a motion capture system may capture movements of the camera  1204  as the camera  1204  moves through space. For instance, the position of the camera  1204  (and/or control markers  1206  on the camera  1204 ) may be recorded a certain number of times per second (e.g., 100 times per second), and the sequence of positions of the camera  1204  may define a motion path  1210  of the camera  1204  through space. The motion path  1210  is shown here as an arc through space, but could involve more complex and nuanced movements in multiple directions as well. For example, motions of a welding pen may be recorded that may involve nuanced movements in many different directions during a fabrication process to produce a manufactured output product. 
     In some examples, a user may view a visual simulation, or real-time preview, of the robotic arm achieving the same position as the demonstration tool with its end-effector-mounted tool during recording. In some examples, this preview can be viewed on a separate workstation. In other examples, the preview may be viewed on a screen attached to the demonstration tool itself. For instance, if the demonstration tool is a camera, a sub-window of a viewing window of the camera may show a preview of how the robot will move in order to replicate movements of the demonstration tool with its own robot tool. 
     In additional examples, the preview may include a real-time data stream of one or more numerical values associated with positions and/or movements of robotic device. The preview may also provide information about the robot&#39;s ability to replicate the motion path currently being demonstrated. For instance, the preview may send a warning signal when the motion path of the robot tool would approach or exceed a predefined constraint of the robotic device. Examples of displayed information may include the robot&#39;s joint positions, joint velocities, and joint accelerations relative to the robot&#39;s physical limits, as well as warnings about singularities and unreachable configurations. 
     In further examples, the user may be able to start and/or stop recording by pressing a button on the demonstration tool or at another location (e.g., on a workstation). For instance, data indicative of position of the demonstration tool may only be recorded or received when the button is depressed. Accordingly, a user may be able to use the demonstration tool to record a discrete motion sequence by holding down the button from the start of the motion sequence to the finish of the motion sequence. 
     By pressing buttons on a workstation and/or the demonstration tool itself, the user may also be able to adjust certain parameters of the recording and/or the preview of the robot movements. For example, one button may clear the current recording. Another button may switch the perspective used for the preview screen. Another button may enable or adjust a smoothing filter to apply to the demonstrated motion path during recording. For instance, motion curves within the motion path may be smoothed in order to prevent jerking movements or quick jumps between disconnected positions of the robot tool. 
     In additional embodiments, movements of the demonstration tool may result from physical forces, such as gravity, in addition to or instead of a human demonstrator. For instance, the demonstration tool may be a ball that is dropped, or thrown, or allowed to bounce on the ground. A robotic device may then be programmed to control an end-effector-mounted tool to move in much the same way as the ball to simulate the effect of physical forces on the ball. In another example, the demonstration tool may be a part of a car, and example systems may allow a robotic device to simulate certain effects of a car crash by recording and replicating movements of car part during a test crash. Other types of natural phenomena involving movements that are difficult to program directly may be captured and used to control robot movements in accordance with the systems and methods described herein as well. 
     Method  1100  may additionally include determining a replication control path for a robotic device, as shown by block  1106 . The replication control path may include robot movements that cause the robotic device to move a robot tool (e.g., an end-effector-mounted tool) through a motion path that corresponds to the motion path of the demonstration tool. Movements of the robot&#39;s joints may be determined for the robot device that place the robot tool at particular positions in space at particular points in times that correspond to positions of the demonstration tool within its motion path. In some examples, a motion control system, such as described above with respect to  FIG. 1  and/or  FIG. 6 , may be used to determine movements of the robotic device in order to position the robot tool at points in time along a timeline. 
     In further examples, a sequence of robot joint parameters, including joint angles, velocities, and/or accelerations, may be determined for the robot that locate the position and orientation of the robot&#39;s end effector over time in order to position the robot tool within space. In some examples, a direct mapping between joint parameters of the robot and positions of the robot tool at particular timestamps may be determined. In other examples, rather than a direct mapping, robot joint parameters may be determined in order to approximate the position of the robot tool. For instance, robot movements may be modified in order to smooth motion curves of the robot and/or of the robot tool in order to avoid jerking or disconnected movements while the robot is moving the robot tool. 
     In some examples, the motion path of the robot tool corresponding to the motion path of demonstration tool may contain positions of the robot tool that directly map to positions of the demonstration tool. In other examples, the motion path of the robot tool may be scaled up or down in size relative to the motion path of the demonstration tool. For instance, positions within the motion path of the robot tool may be scaled to account for differences in size between the demonstration tool and robot tool (and/or between a human demonstrator and a robotic device). 
     In further examples, the replication control path may be refined before the robot is controlled to replicate the movements of the demonstration tool. For instance, a review phase may be used during which the user may review the recorded motion path, validate it, and/or make adjustments. For instance, a user may be presented with a software environment that allows the user to visualize and control device actors, such as software control  657  described above with respect to  FIG. 6 . During a review phase, the user may have the ability to apply various filters to the motion path such as smoothing, interpolation, and speed adjustment. Data streams visible during the demonstration phase may also be visible during this phase, so that as the user makes adjustments, the user may see real-time feedback about the robot&#39;s ability to perform certain motions. In some examples, once the user has validated the motion, the user may enter a confirmation before moving on from the review phase. 
       FIG. 12C  illustrates a motion path of a demonstration tool and a corresponding motion path of a robot tool, according to an example embodiment. A human demonstrator  1202  may move a demonstration tool (camera  1204 ) through a motion path  1210 . A motion capture system may employ a camera  1208  to determine positions of the moving camera  1204  over time, possibly by detecting changes in positions of control markers  1206  attached to the camera  1204 . Additionally, a robotic device  1212  may be equipped with a robot tool (end-effector-mounted camera  1214 ). A motion path  1216  may be determined for the robot tool  1214  that contains positions of the robot tool  1214  that correspond to positions of the demonstration tool  1204  within motion path  1210 . A replication control path for the robotic device  1212  may then be determined, which includes movements of the robotic device  1212  that move the robot tool  1214  through the motion path  1216 . 
     Method  1100  may additionally involve causing the robotic device to move the robot tool based on the replication control path, as shown in block  1108 . In particular, the robotic device may follow the robot movements sequentially within the replication control path to control an end-effector-mounted tool to match the recorded motion of the demonstration tool. If the demonstration tool was a camera used to film a scene of a movie, the robot tool may then be used to film another iteration of the same scene. As another example, if the demonstration tool was a manufacturing tool used to fabricate an output product, robot tool may then be used to fabricate another copy of the output product. 
       FIG. 12D  illustrates a motion path of a robot tool, according to an example embodiment. In particular, the robotic device  1212  may be controlled to move the end-effector-mounted camera  1214  through motion path  1216 . Once the robotic device  1212  has been trained to control the camera  1214  with this motion, it may replicate the process multiple times. For instance, the robotic device  1212  may be used to film dozens or more takes of a single scene within a movie using the same motion path  1216  for camera  1214 . 
     Particular example applications may include manufacturing, where a user quickly teaches a welding or gluing path to the robot by demonstrating it with a hand-held demonstration tool. A user may thus use a pen, marker, or any other device to trace a path that is trackable by the motion control system. A robot may then be automatically programmed to replicate that movement. A review process may be used to adjust the pattern, or to change speed settings appropriate to a particular application. For example, if a glue system is applying excessive glue, the robot movement may be increased without adjusting the flow of glue to lessen the amount of glue at any given area. 
     Other examples involve cinema, where repeatable handheld camera moves can be achieved by demonstrating the move first with, for example, a handheld digital single-lens reflex camera, then replicating it with a film camera. In a real-time workflow, visual effects such as scaled camera moves can be achieved by slaving the robot&#39;s camera to the demonstration camera. Additional examples in design or architecture may involve fabrication of repeatable organic shapes by demonstrating the shape first with a handheld tool like a paintbrush. Yet further examples exist in ride programming, where a user can quickly program a motion base for an amusement park ride by demonstrating the motion first with a maquette of the ride. A number of different possible applications of the systems and methods described above will be apparent to a person of ordinary skill in the art. 
     While the robotic device moves the robot tool according to the replication control path, a user may use any of the tools of a motion control system as described above with respect to  FIG. 1  and  FIG. 6  to control playback of the recorded motion path. In some examples, a real-time workflow may be used to similar ends. In particular, the robot&#39;s end-effector-mounted tool may match the motion of the demonstration tool in real time or close to real time (with some offset in position, orientation, or time to avoid collision). Whether playback occurs in real time or at a later time, certain aspects of the system may need to be calibrated by find relative transformations between the coordinate frames of different components. 
     In some examples, the coordinate frame of a motion capture stage relative to the coordinate frames of one or more motion capture cameras may be determined. In other examples, the coordinate frame of the robotic arm relative to the coordinate frame of the motion capture stage may be determined. In further examples, the coordinate frame of the demonstration tool relative to the coordinate frame of the LED markers attached to it may be determined. In yet further examples, the coordinate frame of the robot&#39;s tool relative to the coordinate frame of the robot&#39;s end effector may be determined. 
     In examples where the demonstration tool or the robot tool is a camera, the system may also calibrate transformations from the 3D world to the 2D image plane of the camera. This may require calibrating various intrinsic parameters of the camera such as field-of-view and distortion parameters, as well as extrinsic parameters such as the camera&#39;s orientation relative to the end effector. 
     To calibrate the relative positions of the motion capture cameras, the system may use a built-in calibration routine that involves moving a calibration object around the stage. For calibration of the robotic arm relative to the motion capture stage, LED markers may be attached to the robot. The robot may then be commanded to move one or more of its joints or points of movement. For certain joints the movement may be along a circular path. For other joints the movement may be along a line or throughout a swept volume. The motion-capture coordinates of the markers may be recorded during the movement, and then the system may mathematically derive the position of the robot&#39;s base coordinate frame given the marker data. This may be done repeatedly to calibrate and identify the potential movement of all joints of the robot. 
     For calibration of camera tools, a user or automated system may move the camera to various positions on the stage and take images of a static checkerboard or background. Those images may then be combined with position information from the robot and motion capture system to derive the camera&#39;s intrinsic and/or extrinsic properties. 
     For calibration of non-camera tools a user or automated system may take direct physical measurements, touch the tool off to one static point in space from multiple angles and perform some calculations, or instrument it with LED markers and take position measurements with the motion capture system. 
     In alternative embodiments, other methods of calibration may be used, including methods that are a hybrid of automatic and manual calibration. Such methods of calibration will be apparent from the above methods of calibration and the description of systems included herein. 
     In further embodiments, an additional step may be used while the robotic device is moving its robot tool to replicate the positions of the demonstration tool. In such an optional step, movements of the robot tool may be recorded by a motion capture system (which could be the same motion capture system as described above or a different one) in order to determine how accurately the robot&#39;s tool is following the recorded motion path of the demonstration tool. Any variations from the expected motion path of the robot tool may be used as an input to a control system making “on-the-fly” adjustments to commanded robot movements in order to achieve better fidelity to the recorded path. This may be useful in the case where the robotic arm is not perfectly accurate. Depending on the application, this “closed-loop” control may function to achieve a desired fidelity to the recorded path during the replication phase. 
     The present disclosure is not to be limited in terms of the particular embodiments described in this application, which are intended as illustrations of various aspects. Many modifications and variations can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. Functionally equivalent methods and apparatuses within the scope of the disclosure, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the appended claims. 
     The above detailed description describes various features and functions of the disclosed systems, devices, and methods with reference to the accompanying figures. In the figures, similar symbols typically identify similar components, unless context dictates otherwise. The example embodiments described herein and in the figures are not meant to be limiting. Other embodiments can be utilized, and other changes can be made, without departing from the spirit or scope of the subject matter presented herein. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, separated, and designed in a wide variety of different configurations, all of which are explicitly contemplated herein. 
     With respect to any or all of the ladder diagrams, scenarios, and flow charts in the figures and as discussed herein, each block and/or communication may represent a processing of information and/or a transmission of information in accordance with example embodiments. Alternative embodiments are included within the scope of these example embodiments. In these alternative embodiments, for example, functions described as blocks, transmissions, communications, requests, responses, and/or messages may be executed out of order from that shown or discussed, including substantially concurrent or in reverse order, depending on the functionality involved. Further, more or fewer blocks and/or functions may be used with any of the ladder diagrams, scenarios, and flow charts discussed herein, and these ladder diagrams, scenarios, and flow charts may be combined with one another, in part or in whole. 
     A block that represents a processing of information, such as a block of method  1100  described above, may correspond to circuitry that can be configured to perform the specific logical functions of a herein-described method or technique. Alternatively or additionally, a block that represents a processing of information may correspond to a module, a segment, or a portion of program code (including related data). The program code may include one or more instructions executable by a processor for implementing specific logical functions or actions in the method or technique. The program code and/or related data may be stored on any type of computer readable medium such as a storage device including a disk or hard drive or other storage medium. 
     The computer readable medium may also include non-transitory computer readable media such as computer-readable media that stores data for short periods of time like register memory, processor cache, and random access memory (RAM). The computer readable media may also include non-transitory computer readable media that stores program code and/or data for longer periods of time, such as secondary or persistent long term storage, like read only memory (ROM), optical or magnetic disks, compact-disc read only memory (CD-ROM), for example. The computer readable media may also be any other volatile or non-volatile storage systems. A computer readable medium may be considered a computer readable storage medium, for example, or a tangible storage device. 
     Moreover, a block that represents one or more information transmissions may correspond to information transmissions between software and/or hardware modules in the same physical device. However, other information transmissions may be between software modules and/or hardware modules in different physical devices. 
     The particular arrangements shown in the figures should not be viewed as limiting. It should be understood that other embodiments can include more or less of each element shown in a given figure. Further, some of the illustrated elements can be combined or omitted. Yet further, an example embodiment can include elements that are not illustrated in the figures. 
     While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.