Patent Publication Number: US-9846059-B2

Title: Nonvolatile rotation sensor with magnetic particle in serpentine track

Description:
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
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     CROSS REFERENCE TO RELATED APPLICATION 
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     BACKGROUND OF THE INVENTION 
     The present invention relates to rotation sensors and in particular to multi-turn rotation sensors that can output absolute angular position over a rotational range of greater than 360 degrees. 
     Rotation sensors including encoders, resolvers and the like, are electromechanical devices providing an electrical output indicating the position of a rotatable shaft. A common type of rotation sensor uses a disk-shaped rotor having an optically readable pattern marked on its surface, the pattern thrilling alternating opaque and transmissive frames. These frames are illuminated from one side by a lamp and light traveling from the lamp through the opaque and transmissive frames of the rotor and then through similar frames in a stationary stator, to be detected by one or more stationary photodetectors. Rotation of the shaft moves the rotor which in turn causes a fluctuation in the light transmitted through the rotor and stator thus producing a signal that may be decoded into a digital indication of shaft movement. 
     Rotation sensors may be classified as absolute rotation sensors or incremental rotation sensors. Incremental rotation sensors provide only an indication of the change in position of the sensor shaft. In incremental rotation sensors, the rotor normally contains a uniform periodic pattern whose movement past a photodetector creates an index signal indicative of the amount that the shaft has rotated. A separate track may also provide a zero signal for particular angular position. In some cases, one or more photodetectors arranged with an offset of 90 degrees (“quadrature”) provide an indication of the direction of rotation as well as the amount of rotation of the shaft, as is understood in the art. 
     Absolute rotation sensors, in contrast to incremental rotation sensors, produce a unique value (typically a digital code word) for each rotation sensor position. The rotor of an absolute rotation sensor may carry a series of concentric tracks whose opaque and transmissive segments, examined along a line of radius, reveal a binary or Grey code value indicative of shaft position. Each track provides the value of one bit and is read by a separate photodetector to produce an output digital word. 
     Often it is desired to have an absolute measure of rotary position over multiple turns (that is, a measurement that spans an angular range of greater than 360 degrees). This can be done using an absolute single-turn rotation sensor by adding an electronic counter that counts each time the value from the rotation sensor “rolls over” from its maximum value to zero. Precise angular position over multiple turns may be done by adding the output from the absolute single-turn rotation sensor to the value of the counter times 360 degrees. 
     The use of an electronic counter can cause the absolute angular position to be lost in the event of a power failure which causes the electronic counter to reset. In order to create a “non-volatile” multi-turn absolute rotational rotation sensor, a single-turn rotation sensor can be combined with a mechanical counter such as provided by a gear train. In one design, successive gears in the gear train are attached to simple, absolute rotation sensors that provide successive bits in a count value. For example, each gear in the gear train may provide a 2:1 reduction and may incorporate a single bit, absolute rotation sensor. Each rotation sensor then provides a separate binary digit of a count value. 
     Two alternative approaches use either a battery or electricity developed by Wiegand wires to write to a nonvolatile memory. 
     The addition of mechanical gear systems, multiple rotation sensors, batteries, or power generation systems to an absolute single-turn rotation sensor to provide multi-turn capability greatly increases the cost, complexity and potential for failure of the resulting rotation sensor. 
     SUMMARY OF THE INVENTION 
     The present invention provides a non-volatile, absolute rotation sensor that the problems of the above-described prior art systems by using a magnetic particle constrained in a serpentine path about the rotor shaft. Rotation of the shaft by 360 degrees exposes the magnetic particle to a reciprocating magnetic field that causes the magnetic particle to incrementally and predictably advance along the track. Sensors on the track can then be used to deduce the number of turns of the shaft based on the position of the magnetic particle in the track. In some embodiments, an angular resolution less than a full turn can be obtained in distinction from prior art systems. 
     In one embodiment, the invention provides a rotation sensor having a housing and a shaft supported by the housing to rotate about an axis. A magnetic particle is constrained within a track constraining the magnetic particle for movement therealong. The track is positioned about the axis and provides serpentine periodic variations in radius from the axis so that the magnetic particle moving through the track about the axis moves closer to and further from the axis with such movement. A permanent magnet is positioned adjacent to the track and the track and permanent magnet adapt to rotate relative to each other about the axis with rotation of the shaft to expose the magnetic particle to a magnetic field which has to radically oscillating component. The combined effect of the magnetic force and the constraint force from the track causes the magnetic particle to advance a predetermined amount along the track with each rotation of the shaft. A sensor system identifies a location of the magnetic particle along the track to output a number of turns of the shaft according to a position of the magnetic particle along the track. 
     It is thus a feature of at least one embodiment of the invention to provide a nonvolatile method of tracking the number of turns made by a shaft rotation sensor without using mechanical gearing or the like. 
     The permanent magnet may be a magnetic ring mounted eccentrically with respect to the track so that a portion of the magnetic ring passes from a radially outward position to a radially inward position with respect to a given location on the track as the shaft rotates. 
     It is thus a feature of at least one embodiment of the invention to provide a simple method of generating a radially oscillating magnetic field that may be easily dynamically balanced. 
     The permanent magnet may provide periodically extending radial teeth exerting a tangential force on the magnetic particle in the track when the teeth pass the magnetic particle with rotation of the shaft. The permanent magnet may also provide a spatial distribution of magnetization to exert a tangential force on the magnetic particle in the track when passing the magnetic particle with rotation of the shaft. 
     It is thus a feature of at least one embodiment of the invention to provide a mechanism to ensure the direction of the magnetic particle corresponds to the rotation of the shaft so as to provide a system that is bidirectional in operation. 
     The magnetic particle may be any of a ferromagnetic bead, a droplet of ferrofluid, and a droplet of ferrofluid surrounding a magnetized bead. 
     It is thus a feature of at least one embodiment of the invention to provide a magnetic particle that may be of arbitrary size and scale so that the present invention may be realized as a micro-electromechanical device. 
     The serpentine track may be a substantially sinusoidal path along a circle lying in a plane perpendicular to the axis. 
     It is thus a feature of at least one embodiment of the invention to provide a track reducing “jerk” on the magnetic particle being a derivative of acceleration such as may promote wear and vibration. 
     The sensors may be any of optical, resistive, capacitive, or inductive sensors. 
     It is thus a feature of at least one embodiment of the invention to provide a system that may work with a wide variety of well-established sensor types. 
     The sensor may be a noncontact electrical field sensor. 
     It is thus a feature of at least one embodiment of the invention to permit the magnetic particle to be fully isolated from other components for reduced risk of contamination. 
     The rotation sensor may include a second magnetic particle and a second track constraining the second magnetic particle and concentric with the track, the second track providing a serpentine periodic variation in radius from the axis so that the second magnetic particle moving to the second track about the axis moves closer to and further from the axis with such movement. The sensor system may identify a location of the second magnetic particle along the second track to reveal a number of turns of the shaft according to a position of the second magnetic particle along the second track. The system may further include more magnetic particles and serpentine tracks. 
     It is thus a feature of at least one embodiment of the invention to provide an extended range of rotational measurements by taking advantage of the large modulus available using two serpentine tracks that “roll-over” at different rotation numbers that are not factors of each other as will be discussed in more detail below. The sensor system may provide electrical output differentiating at least two angular positions of the shaft within the range of 360 degrees. 
     It is thus a feature of at least one embodiment of the invention to provide rotation sensor system that may also indicate different positions within a single-turn. 
     The sensor system may provide periodic sensor elements at locations associated with each periodic variation in the radius of the track to identify a location of the magnetic particle at any of such location. 
     It is thus a feature of at least one embodiment of the invention to permit instantaneous determination of shaft rotation counts, for example, from a power-up state, without the need to rotate the shaft. 
     The sensor may provide a continuous output indicating the position of the magnetic particle within one cycle of the serpentine periodicity. 
     It is thus a feature of at least one embodiment of the invention to provide discrimination between different angles within a single turn of the rotation sensor. 
     The track may be a channel constraining the magnetic particle to move along the channel. 
     It is thus a feature of at least one embodiment of the invention to provide a simple structure that can be implemented, for example, using MEMS and microfluidics fabrication technologies that are compatible to the semiconductor device fabrication process. 
     When the shaft is fixed in position, the magnetic particle may be stably held in a single location along the track by a magnetic field. 
     It is thus a feature of one embodiment of the invention to provide a system that resists vibration by locking the magnetic particle to the shaft through magnetic action. 
     These particular objects and advantages may apply to only some embodiments falling within the claims and thus do not define the scope of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a simplified perspective view of an rotation sensor according to one embodiment of the present invention also shown in exploded view with the housing removed to reveal a rotating magnet ring and fixed track and providing a detail of a track for holding a magnetic particle within the rotation sensor; 
         FIG. 2  is a simplified top plan view of the magnetic ring and rotary track at a relative angular position of zero degrees; 
         FIGS. 3 a -3 e    are fragmentary representations of the track of  FIG. 2  with the magnet ring at various angular locations showing interaction of the magnet ring and a magnetic particle in the track to move the magnetic particle at regular increments with each rotation of the shaft; 
         FIG. 4  is a schematic representation of a sensor system for sensing a location of the magnetic particle within the track; 
         FIGS. 5 a  and 5 b    are fragmentary views of alternative embodiments of the sensors of the sensor system of  FIG. 4 ; 
         FIG. 6  is a an exploded perspective view of the rotation sensor of  FIG. 1  linked to an absolute rotation sensor and showing relative signals from each and zones of uncertainty such as can be resolved with high-resolution sensing; 
         FIG. 7  is a schematic representation of two tracks providing two signals providing a greater range of rotation counting; 
         FIG. 8  is a figure similar to  FIG. 3  showing physical placement of the electrodes for sensing the position of a magnetic particle at any location along a serpentine track with a resolution that addresses the zones of uncertainty shown in  FIG. 6 ; and 
         FIG. 9  is a figure similar to  FIG. 8  showing the use of the resistive sensors that provide a continuous indication of movement of the magnetic particle along the serpentine track for higher resolution measurements. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to  FIG. 1 , a rotation sensor  10  per the present invention may provide a housing  12  through which a shaft  14  may project. The shaft  14  extends through the housing  12  and is supported by the housing  12  to rotate about an axis  16  with respect to the housing  12 . Electrical conductors  18  may extend from the housing  12  providing the electrical signals indicating an absolute rotary angle of the shaft  14  with respect to the housing  12 . 
     Within the housing  12 , the shaft  14  may attach to a first magnet disk  20  extending in a plane generally perpendicular to the axis  16  and supporting thereon a magnetic ring  22  of a magnetized permanent magnet material. As will be discussed further below, in one embodiment, the magnet ring  22  is circular and is mounted eccentrically so that its center is not aligned with the axis  16 . 
     Positioned adjacent to the magnet disk  20  is a track disk  24  also extending in a plane generally perpendicular to the axis  16  but fixed with respect to the housing  12 . The track disk  24  may hold a serpentine track  26  generally extending in a circle about the axis  16  but having radial perturbations  28 , for example, in the form of sinusoidal variations in the track radius so that the track moves radially outwardly and inwardly at regular periodic angular intervals  30  toward and away from the axis  16  as measured along lines of the radius perpendicular to axis  16 . 
     Positioned adjacent to the track disk  24 , on one or both sides of the track disk  24 , may be at least, one sensor disk  32 . The sensor disk  32  provides multiple sensors  34  associated with sensing locations  36  periodically spaced along the serpentine track  26 , for example, with one sensing location  36  for with each perturbation  28  of the serpentine track  26  at each interval  30 . As shown, and in one embodiment, each sensing location  36  spans one full cycle of perturbation  28  between peaks of maximum radius along the serpentine track  26 , although other regular locations may be chosen. Desirably, the sensor locations  36  fit against the adjacent sensor locations  36  without substantial gap so that the magnetic particle  48  (discussed below) may be sensed at any location. 
     Alternatively, the sensors may be placed directly on the track disk  24 , for example, to flank either side of the serpentine track  26  as will be discussed below with respect to  FIGS. 8 and 9 . 
     The shaft  14  may be supported at opposite ends by rotary bearings  40  as is generally understood in the art. 
     Referring now to  FIG. 2 , as noted, the magnet ring  22  may have a center point  42  displaced with respect to the axis  16  so that the magnet ring  22  is eccentric with respect to the mounting of the track  26 . The eccentricity is chosen so that the magnet ring  22  with rotation of the shaft  14  moves between positions outside and inside a given location of the track  26 . Thus for example, at an arbitrarily chosen zero relative position of the magnet ring  22  with respect to the track  26 , the magnet ring  22  will be radially outward but adjacent to a given position  44  on the ring  22 . As the shaft  14  rotates and the ring  22  moves with it, the magnet ring  22  will pass inward over the given position  44  when the magnet ring moves to a 90-degree position relative to the track  26 . When the magnet ring  22  moves to 180 degrees with respect to the track  26 , the magnet ring  22  will be radially inward with respect to the given position  44 , that is, inside the track  26  with respect to the axis  16 . Finally, the magnet ring  22  will pass outward over the given position  44  when the magnet ring  22  moves to a 270 degree offset with respect to the track  26 . 
     In one embodiment, the magnet ring  22  includes two radially inwardly projecting teeth  46  positioned in 180-degree opposition along the magnet ring  22  to slightly overlap the given position  44  on the track  26  when the magnet ring is in the zero degree and 180-degree positions, respectively. 
     Referring now to  FIG. 3 a   , when the magnet ring  22  is in the zero degree position, as discussed above, a magnetic particle  48 , for example, of a solid ferrous material, a ferrofluid, or a solid permanent magnet coated with ferrofluid material, may be held against movement by vibration at a radially outward peak  27   a  of a given perturbation  28   a  attracted to the magnet ring  22  and the tooth  46  closely adjacent to the track  26 . As so held, the magnetic particle  48  is positioned within a sensing location  36 . The magnetic particle  48  is practically immobilized in the track  26  by the magnetic attraction of the ring  22  and the constraining effect of the track  26  to be resistant to movement by vibration. In this example, the track  26  may be a closed channel in which the magnetic particle  48  may move freely along the groove but is constrained by lateral groove walls and protected from external contamination. 
     Referring to  FIG. 3 b   , as the magnet ring  22  moves clockwise, for example, to a two-degree position with rotation of the shall  14 , the magnetic particle  48  is drawn from the radially outward peak  27   a  of the perturbation  28   a  rightward (as depicted) and downward along the track  26  toward a radially inward trough  27   b  closer to the axis  16 . 
     Referring to  FIG. 3 c   , further rotation clockwise of the ring  22 , for example, to the 90 degree position, moves the magnetic particle  48  further downward toward the trough  27   b  as the magnet ring  22  passes downward across the perturbations of the track  26  until (as shown in  FIG. 3 d   ) the magnetic particle  48  is pulled fully into the trough  27   b  held by the magnetic attraction of an opposite tooth  46   b.    
     Further clockwise rotation of the magnet ring  22 , as shown in  FIG. 3 e    causes the magnetic particle  48  to move upward toward a peak  27   a  of perturbation  28   b  again into a new sensing location  36 . 
     It will be appreciated that the magnetic particle  48  will arrive at the sensing location  36  of perturbation  28   b  after approximately 360 degrees of shaft rotation resulting in a movement rightward by one perturbation from a sensing location  36  of perturbation  28   a  to a sensing location  36  of perturbation  28   b . It will likewise be appreciated that counterclockwise rotation of the shaft  14  will cause the reverse direction motion of the magnetic particle  48 . In this way, it will be appreciated that the number of rotations of the shaft  14  in a given direction may be determined by monitoring movement of the magnetic particle  48  from one sensing location  36  to the next and that the number of rotations detectable is limited only by the number of perturbations within a full cycle of the track  26 . 
     Referring now to  FIG. 4 , a position of the magnetic particle  48  along the track  26  may be determined, for example, by placement of electrodes  50   a  and  50   b  on opposite sides of each sensing location  36  so as to flank the particle  48  when it is at the given sensing location  36 . In one embodiment, electrodes  50   a  and  50   b  may electrically contact the particle  48  to measure a change of resistance between the electrodes  50   a  and  50   b  with the presence and absence of the magnetic particle  48 . Noncontact electrical measurement, however, may be obtained by merely placing electrodes  50   a  and  50   b  in close proximity to the particle at each of the sensing locations  36  to measure change in electrical qualities of the circuit formed with electrodes  50   a  and  50   b  with the presence and absence of the particle  48 . For example, a sinusoidal voltage from a voltage source  52  may be imposed across the electrodes  50   a  and  50   b  and changes in an AC impedance (inductance or capacitance) in a circuit so formed may be detected such as will change according to the presence or absence of the magnetic particle  48  to determine the presence or absence of the particle  48 . Likewise, a magnetic hysteresis caused by the presence of the particle  48  in the environment of a changing magnetic field, for example, generated when electrodes  50   a  and  50   b  provide coil forms generating a magnetic field, may be detected. 
     In one embodiment each of the electrodes  50   a  be commonly driven and each of the electrodes  50   b  separately measured by being connected through a multiplexer  54  controlled by a microprocessor  58  to selectively connect one electrode  50   b  at a time to a sensing circuit  56 . The sensing circuit  56  may measure changes in voltage or current or the like and may provide an input to the microprocessor  58 , for example, via an analog-to-digital converter. Analysis of the signals from the sensing circuit  56  may thus be used to determine a location of the magnetic particle  48  along the track. This location, indicates the number of historical rotations of the shaft  14 , may be output from the microprocessor  58  as an angular output signal through conductors  18 . 
     Referring to  FIG. 5 a   , it will be appreciated that other sensing systems may be employed for detection of the position of the magnetic particle  48  including those having a photoemitter  60  that may project light upward into the sensing location  36  and reflected downward to a photodetector  62  when a magnetic particle  48  is in sensing location  36 . The photodetector  62  may be connected to multiplexer  54  to permit measurement of the reflected light such as indicates the presence or absence of the magnetic particle  48 . Similarly as shown in  FIG. 5 b   , the photoemitter  60  and photodetector  62  may be placed on opposite sides of the particle  48  when in the sensing location  36  so as to detect the particle  48  when it blocks transmitted light energy from the photoemitter  60 . 
     Referring now to  FIG. 6 , the multi-turn-counter rotation sensor of the present invention may be advantageously combined on a single shaft  14  with an absolute single-turn rotation sensor  64 . This combination is advantageous if a single-turn function of the magnetic particle in serpentine track is not implemented or the inherent single turn resolution is not adequate. As will be understood to those of ordinary skill in the art, the single-turn rotation sensor  64  may be adjusted to provide an output signal  66  having a value of zero when the magnet ring  22  is in the zero position with respect to the track  26  (for example, as shown in  FIG. 2 ) and to climb to a peak value after one full revolution of the shaft  14  before dropping back to the zero value again at a rollover angle  70  generally corresponding to the angular position of zero. The single-turn rotation sensor  64  may thus provide multiple output values that uniquely identify multiple angular positions within one rotation of the shaft  14  but may not indicate how many rotations of the shaft have occurred. 
     An output from the rotation sensor in this case can augment the signal from the single-turn rotation sensor  64  to provide an indication of how many rotations of the shaft have occurred. The rotation sensor provides for a generally rising turn-count signal  74  whose magnitude indicates total number of turns. The rising turn-count signal  74  will not have the exact period of the output signal  66 , which is 360 degrees. If the whole track consists of N serpentine perturbations, the period of the turn-count signal is 360 (N+1)/N degrees. Because the magnetic particle  48  moves generally around the track  26  with each successive rotation of the axis  16 , the angle of sensing of each next position of the magnetic particle  48  at a next sensing location  36  is delayed slightly after the rollover angle  70  by increasing amounts with increasing numbers of turns of the shaft  14 . When the turn-count reaches N, the accumulated delay is 360 degrees, after which, both the turn counts and the single turn angle starts from 0 again and the whole process cycles. 
     This mismatch in periods creates a narrow uncertainty region  72  where two different positions of the shaft  14  are associated with identical values of the output signal  66  and identical values of the of the turn-count signal  74 . Referring to  FIG. 8 , this ambiguity can be resolved by breaking each of the sensors  50   b  into two sensors, a first set of sensors  50   b  associated with an radial outer half of the track  26  and defining sensor locations  36   a  half the angular range of sensor location  36 , and a second set of sensors  50   b ′ associated with a radial inner half of the track  26  and defining sensor locations  36   b  also half angular range of sensor location  36 . This finer resolution of sensing allows one of each adjacent pair of uncertainty regions  72  to be segregated always into sensing regions  36   b  and thus to be uniquely identified relative to the corresponding part of the uncertainty regions  72  which is offset by 360 degrees and which will be in sensing regions  36   a.    
     Referring now to  FIG. 7  a second track  26 ′ and a second magnetic particle  48 ′, may be provided. A separate set of sensors may sense the position of the magnetic particle  48 ′ in track  26 ′. The multiple tracks  26  and  26 ′ can be used to substantially expand the number of rotations that the rotation sensor  10  may track to number far beyond the number of serpentine cycles of the tracks  26  and  26 ′ by giving each of the tracks a different number of cycles. Thus for example if track  26  can count up to 7 turns (in a greatly simplified example) before repeating, and track number  26 ′ can count up to nine turns. The combination of the two allows the rotation sensor  10  to count 7×9=63 turns. That is the magnetic particles  48  and  48 ′ will only return to the same positions every 63 turns. Of course if large prime numbers are used for the number of cycles (for example 89 and 97) this effect can be greatly increased (for example allowing 8633 rotations before the pattern repeats). In general, the least common multiple of the numbers of the serpentine units from all tracks provide the maximum turn-counts of the system. 
     Referring now to  FIG. 9 , intra-turn angular resolution can also be obtained, for example, by constraining an electrically conductive magnetic particle  48  between two resistive tracks  90   a  and  90   b  which provide walls of the tracks  26 . Current flowing from resistive track  90   a  from a voltage source  92  through the magnetic particle  48  to be received by resistive track  90   b  will experience a varying resistance depending on the position of the magnetic particle  48  along the track  26 . This resistance may be measured by sensing circuit  56  to provide a continuous measurement of rotational position with a finer resolution than single turns. 
     The further the magnetic particle  48  moves inward along the track  26 , the more resistance will be measured. This technique may be combined with discrete position sensors discussed above and it will be appreciated that there are other methods to provide continuous position measurement as well. 
     It is noted that there need only be relative rotation between the magnet ring  22  and the track  26  and therefore that either can be fixed with respect to the housing  12  or attached to the shaft  14 . The shape of the track  26  need not be sinusoidal and it will be appreciated that sawtooth or square tooth type perturbations may also be used. The shape of the magnetic ring may not be strictly circular, elliptical or other similar shape may also be used. The word “magnetic” may indicate either a ferromagnetic material that does not generate its own magnetic field or a material generating a magnetic field in the manner of a permanent magnet and should be interpreted according to context. 
     It will be understood that the present invention is applicable to a wide variety of applications and can replace conventional encoders, resolvers, eddy current sensors, and even operate in the context of sensorless motor to replace a two pole resolver over a limited angular range. 
     Certain terminology is used herein for purposes of reference only, and thus is not intended to be limiting. For example, terms such as “upper”, “lower”, “above”, “below”, “inside”, and “outside” refer to directions in the drawings to which reference is made. Terms such as “front”, “back”, “rear”, “bottom” and “side”, describe the orientation of portions of the component within a consistent but arbitrary frame of reference which is made clear by reference to the text and the associated drawings describing the component under discussion. Such terminology may include the words specifically mentioned above, derivatives thereof, and words of similar import. Similarly, the terms “first”, “second” and other such numerical terms referring to structures do not imply a sequence or order unless clearly indicated by the context. 
     When introducing elements or features of the present disclosure and the exemplary embodiments, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of such elements or features. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements or features other than those specifically noted. It is further to be understood that the method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed. 
     References to “a microprocessor” and “a processor” or “the microprocessor” and “the processor,” can be understood to include one or more microprocessors that can communicate in a stand-alone and/or a distributed environment(s), and can thus be configured to communicate via wired or wireless communications with other processors, where such one or more processor can be configured to operate on one or more processor-controlled devices that can be similar or different devices. Furthermore, references to memory, unless otherwise specified, can include one or more processor-readable and accessible memory elements and/or components that can be internal to the processor-controlled device, external to the processor-controlled device, and can be accessed via a wired or wireless network. It is understood that the processors described herein can hold programs holding data in non-transient medium for execution on the processors according to the steps described above 
     It is specifically intended that the present invention not be limited to the embodiments and illustrations contained herein and the claims should be understood to include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims. All of the publications described herein, including patents and non-patent publications, are hereby incorporated herein by reference in their entireties.