1244 results about "Position error" patented technology

An apparatus and method for EUV light production is disclosed which may comprise a laser produced plasma (“LPP”) extreme ultraviolet (“EUV”) light source control system comprising a target delivery system adapted to deliver moving plasma initiation targets and an EUV light collection optic having a focus defining a desired plasma initiation site, comprising: a target tracking and feedback system comprising: at least one imaging device providing as an output an image of a target stream track, wherein the target stream track results from the imaging speed of the camera being too slow to image individual plasma formation targets forming the target stream imaged as the target stream track; a stream track error detector detecting an error in the position of the target stream track in at least one axis generally perpendicular to the target stream track from a desired stream track intersecting the desired plasma initiation site. At least one target crossing detector may be aimed at the target track and detecting the passage of a plasma formation target through a selected point in the target track. A drive laser triggering mechanism utilizing an output of the target crossing detector to determine the timing of a drive laser trigger in order for a drive laser output pulse to intersect the plasma initiation target at a selected plasma initiation site along the target track at generally its closest approach to the desired plasma initiation site. A plasma initiation detector may be aimed at the target track and detecting the location along the target track of a plasma initiation site for a respective target. An intermediate focus illuminator may illuminate an aperture formed at the intermediate focus to image the aperture in the at least one imaging device. The at least one imaging device may be at least two imaging devices each providing an error signal related to the separation of the target track from the vertical centerline axis of the image of the intermediate focus based upon an analysis of the image in the respective one of the at least two imaging devices. A target delivery feedback and control system may comprise a target delivery unit; a target delivery displacement control mechanism displacing the target delivery mechanism at least in an axis corresponding to a first displacement error signal derived from the analysis of the image in the first imaging device and at least in an axis corresponding to a second displacement error signal derived from the analysis of the image in the second imaging device.

A method of writing product servo bursts to a disk in a disk drive is disclosed. An external spiral servo writer comprising a head positioning pin and head positioning mechanics periodically writes a plurality of reference servo bursts in a plurality of spiral reference patterns to the disk. The reference servo bursts in the spiral reference patterns are processed to write product servo bursts to the disk. In one embodiment control circuitry within the disk drive processes the reference servo bursts to self-servo write the disk drive, and in another embodiment an external product servo writer processes the reference servo bursts to write the product servo bursts to the disk. In one embodiment, a slope of each spiral reference pattern is selected so that each spiral reference pattern is written over at least twenty revolutions of the disk to increase the accuracy of the head position error generated from the reference servo bursts.

A disk drive is disclosed comprising control circuitry for generating a control signal applied to a VCM in response to a position error signal (PES) generated from reading embedded servo sectors and a feed-forward compensation value that compensates for a repeatable runout (RRO) disturbance. The feed-forward compensation value is generated for each servo sector in response to an RRO estimate Ŝ computed recursively for each servo sector according to:

wherein: λ is a predetermined fraction;

• • PES_i is the position error signal generated for a selected servo sector during an ith revolution of the disk; and
  • n represents a number of disk revolutions.

Methods and apparatus for controlling a polyphase motor in implantable medical device applications are provided. In one embodiment, the polyphase motor is a brushless DC motor. The back emf of a selected phase of the motor is sampled while a drive voltage of the selected phase is substantially zero. Various embodiments utilize sinusoidal or trapezoidal drive voltages. The sampled back emf provides an error signal indicative of the positional error of the rotor. In one embodiment, the sampled back emf is normalized with respect to a commanded angular velocity of the rotor to provide an error signal proportional only to the positional error of the motor rotor. The error signal is provided as feedback to control a frequency of the drive voltage. A speed control generates a speed control signal corresponding to a difference between a commanded angular velocity and an angular velocity inferred from the frequency of the drive voltage. The speed control signal is provided as feedback to control an amplitude of the drive voltage. In one embodiment, an apparatus includes a brushless DC motor and a commutation control. The commutation control provides a commutation control signal for a selected phase of the motor in accordance with a sampled back electromotive force (emf) of that phase. The back emf of the phase is sampled only while the corresponding drive voltage for the selected phase is substantially zero, wherein a frequency of a drive voltage of the motor is varied in accordance with the commutation control signal.

A system and method is provided for tracking and maintaining a highly accurate inventory of shipping containers that are stored within container storage facilities. The invention includes using multiple complementary real-time and post-processing positioning techniques associated with various positioning sensors that are associated with inventory pieces or equipment. Examples of such positioning techniques are DGPS, GPS with RTK, DGPS loosely-coupled with INS, DGPS tightly-coupled with INS, and DGPS deeply-coupled with INS. Data correction and fusion techniques are applied to these positioning stages to re-compute a calibrated position with an improved accuracy. An additional trajectory can be iteratively determined using the fusing technique until the position data becomes statistically trustworthy. Further, combinations of multiple real-time positioning techniques combined with past position error correction algorithms provide a high accuracy needed for inventory tracking.

The invention relates to a system and a method for addressing three problems:

• (A) generate a tollpath of consistent length by determining one of a possible set of paths which are all the same length in cell-count every time the same journey is taken,
• (B) determine a consistent price for each tollpath by setting pre-determined values on those cells such that every possible path variant of a specific journey produces the same toll, and
• (C) determine the correct price for each tollpath by adjusting prices in each cell to account for the exact distance actually represented (some roads pass through a cell parallel to the cell edges and some pass through at an angle) so that the toll calculated exactly matches the toll that would be calculated had the exact linear, analogue distance been measured on the actual road.

A method is disclosed for writing M spiral tracks (i=1 to M) to a disk of a disk drive. A head is positioned over a first radial location to write a concentric reference track comprising N concentric servo sectors. Prior to writing one of the spiral tracks, the concentric reference track is read and a position error signal first_PES_i(j) is generated for at least one of the servo sectors j in the concentric reference track, wherein the first_PES_i(j) represents an offset of the head from the first radial location, and the servo sector j corresponds to a circumferential location of the spiral track. At least one of a starting radial location and a velocity profile is adjusted in response to the first_PES_i(j), and the spiral track is written to the disk using the starting radial location and the velocity profile.

A method of writing spiral tracks for a disk drive is disclosed. A first concentric reference track is written at a first radial location near an outer diameter of a disk surface, a second concentric reference track is written at a second radial location near an inner diameter of the disk surface, and a third concentric reference track is written at a third radial location between the first and second radial locations. Prior to writing one of the spiral tracks, the concentric reference tracks are read to generate position error signals used to adjust a velocity profile for writing the spiral tracks. The velocity profile is adjusted to compensate for linear and non-linear disturbances due, for example, to thermal expansion.

A rotating media storage device (RMSD) includes a disk having at least one track with a plurality of servo wedges, a moveable head, and a microprocessor. The microprocessor receives a plurality of position error signal (PES) values during track following and sums PES values for a plurality of different sets of servo wedges of the track to generate a plurality of shifted summed position error signal (SSPES) values. The microprocessor shifts the plurality of generated SSPES values by a phase shift value to generate a plurality of corrected shifted summed position error signal (CSSPES) values, which correspond to the repeatable runout (RRO) of the disk.

A system and method in which a user and a mobile robot cooperate to create a plan for use by the robot in navigating a space. The robot may include a tracking unit that detects the distance traveled and direction from a starting or home location and orientation. The robot also includes a navigation module that controls the movement of the robot based on a navigation plan received from a robot control utility residing at a workstation operated by the user. The robot further includes a position error correction engine that is configured to correct for position errors that may occur as the robot traverses the space. The position error correction engine receives data from one or more robot sensors that detect structures disposed below the surface over which the robot travels. As the robot encounters obstacles in the space, it enters them on the floor plan. The user then reviews the information added by the robot to the floor plan and accepts, rejects or modifies that information in order to create the navigation plan.

Disclosed are an articulated hydraulic machine supporting, control system and control method for same. The articulated hydraulic machine has an end effector for performing useful work. The control system is capable of controlling the end effector for automated movement along a preselected trajectory. The control system has a position error correction system to correct discrepancies between an actual end effector trajectory and a desired end effector trajectory. The correction system can employ one or more absolute position signals provided by one or more acceleration sensors supported by one or more movable machine elements. Good trajectory positioning and repeatability can be obtained. A two-joystick controller system is enabled, which can in some cases facilitate the operator's task and enhance their work quality and productivity.

A method for processing data pixels in a holographic data storage system is disclosed. The method includes assigning predetermined reserved blocks throughout each data page, where each reserved block comprises known pixel patterns, determining position errors of the data page by computing the best match between regions of the data page and the predetermined reserved blocks, and compensating the data pixels at the detector in accordance with the corresponding position errors of the data page.

A method for determining an error estimate concerning a target device's location. The target device moves and communicates in a wireless environment using signals having at least one measurable signal value. A probabilistic model of the wireless environment indicates a probability distribution for signal values at several sample points in the wireless environment. A set of observations of signal values is made and the target device's location is estimated based on the probabilistic model and the set of observations. The error estimate (43) is determined as a combination of products over several sample points (SP). Each product comprises a probability distribution (41) for the sample point in question being the target device's location and a distance function (43) between the sample point in question and the target device's estimated location.

A disk drive is disclosed comprising a disk and a head actuated over the disk, wherein the disk comprises a plurality of spiral tracks, each comprising a high frequency signal interrupted by a sync mark at a sync mark interval. The head is used to read a spiral track to generate a spiral track crossing signal g(x_n), where x_n is a time in a demodulation window. A position error signal (PES) is determined in response to g(x_n), and a deviation index is computed by correlating g(x_n) with a nominal track crossing signal shifted by the PES. When the deviation index is less than a threshold, the PES is used to servo the head over the disk.

A high-speed marker-free motion capture, which is capable of powerfully detecting a body's feature points corresponding to a body's end portions such as a head, hands, feet, trunk, arms and legs at a high speed in an illumination change or background or noises of cameras. The extracted feature points of the body can be directly tracked stably in a 3-dimensional space. The position errors of the feature points due to the change of the illumination conditions or a shadow can be automatically corrected and the feature points can be stably tracked with respect to overlapping and disappearance of the feature points. Further, when coordinates of the middle joints are estimated using 3-dimensional coordinates of the extracted feature points of the body, the present invention restores a human model by estimating the positions of the middle joints of the actor with high accuracy without using a motion database, thereby securing the stability and reality of the 3-dimensional motion data required in the motion capture.

A global navigation satellite sensor system (GNSS) and gyroscope control system for vehicle steering control comprising a GNSS receiver and antennas at a fixed spacing to determine a vehicle position, velocity and at least one of a heading angle, a pitch angle and a roll angle based on carrier phase position differences. The roll angle facilitates correction of the lateral motion induced position errors resultant from motion of the antennae as the vehicle moves based on an offset to ground and the roll angle. The system also includes a control system configured to receive the vehicle position, heading, and at least one of roll and pitch, and configured to generate a steering command to a vehicle steering system. The system includes gyroscopes for determining system attitude change with respect to multiple axes for integrating with GNSS-derived positioning information to determine vehicle position, velocity, rate-of-turn, attitude and other operating characteristics. A vehicle control method includes the steps of computing a position and a heading for the vehicle using GNSS positioning and a rate gyro for determining vehicle attitude, which is used for generating a steering command.

A method is disclosed for defining tracks on a rotating magnetic disk medium of a disk drive. Reference tracks are followed using a servo control loop while writing servo burst patterns defining a first target servo track. The servo control loop includes a two-dimensional digital state compensator having a first input that receives position error signals, a first output that generates control signals for positioning a transducer head, a second output that generates track-following state variables, and a second input that receives processed and stored track-following state variables. The first target track is followed using the servo control loop while servo burst patterns are written, and while the processed and stored track-following state variables corresponding to the servo burst patterns defining the first target track are applied to the second input.

A method is disclosed for efficiently determining and writing repeatable runout (RRO) compensation value sets for data tracks on a magnetic disk in a disk drive. The disk drive has a magnetoresistive (MR) head having a read element and a separate write element, and a secondary actuator coupled to the end of a primary actuator for adjusting a head skew angle. In the method, the head skew angle is set such that the read and write elements are substantially aligned along the first track. A position error signal for each servo sector is determined over a predetermined number of disk revolutions during track following along a first data track. An RRO compensation value set is calculated for the first data track based on the position error signals. The RRO compensation value set is written for the first data track. A seek operation is then performed to a second data track.

The invention relates to an industrial robot calibration method. The method comprises the following steps of : establishing a position and orientation transformational matrix of the coordinate system of a robot end effector relative to a base coordinate system; establishing a position coordinate vector P of the center of the gauge head of a laser tracker arranged on the end effector relative to the base coordinate system through the position and orientation transformational matrix; getting a linear relationship of position error with structural parameter error and joint variable error through a total differential of the position coordinate vector P; getting a compensation value of the structural parameter error and the joint variable error by substituting the position coordinate vector in the linear relationship; finally, getting the accurate position and orientation transformation matrix of the coordinate system of the robot end effector relative to the base coordinate system, thus completing the calibration of the positioning accuracy of the robot and eliminating the technical bias. The calibrated industrial robot can meet the requirements of various application occasions and running positions.

A global navigation satellite sensor system (GNSS) and gyroscope control system for vehicle steering control comprising a GNSS receiver and antennas at a fixed spacing to determine a vehicle position, velocity and at least one of a heading angle, a pitch angle and a roll angle based on carrier phase position differences. The roll angle facilitates correction of the lateral motion induced position errors resultant from motion of the antennae as the vehicle moves based on an offset to ground and the roll angle. The system also includes a control system configured to receive the vehicle position, heading, and at least one of roll and pitch, and configured to generate a steering command to a vehicle steering system. The system includes gyroscopes for determining system attitude change with respect to multiple axes for integrating with GNSS-derived positioning information to determine vehicle position, velocity, rate-of-turn, attitude and other operating characteristics. A vehicle control method includes the steps of computing a position and a heading for the vehicle using GNSS positioning and a rate gyro for determining vehicle attitude, which is used for generating a steering command. Alternative aspects include multiple-antenna GNSS guidance methods for high-dynamic roll compensation, real-time kinematic (RTK) using single-frequency (L1) receivers, fixed and moving baselines between antennas, multi-position GNSS tail guidance (“breadcrumb following”) for crosstrack error correction, articulated implements with multiple antennas on each implement section, video input and guiding multiple vehicles and pieces of equipment relative to each other.

A system and method for measuring a resistance or a resistance per square, R_sq, of a material having a surface using a multi-point probe including four or more collinear contact points placed in the interior of the sample, the method including: making a first measurement using a first set of probe electrodes for inducing a current and a second set of probe electrodes for measuring the voltage difference when the current is induced; making a second measurement using a set of probe electrodes different from the first set for inducing a current and a set of probe electrodes different from the second set for measuring the voltage difference when the current is induced; and using a known relationship among the currents induced, the voltages measured, the nominal probe positions and the resistance per square to determine the resistance per square such that measurement errors resulting from positioning of the probes are reduced.

A global navigation satellite sensor system (GNSS) and gyroscope control system for vehicle steering control comprising a GNSS receiver and antennas at a fixed spacing to determine a vehicle position, velocity and at least one of a heading angle, a pitch angle and a roll angle based on carrier phase position differences. The roll angle facilitates correction of the lateral motion induced position errors resultant from motion of the antennae as the vehicle moves based on an offset to ground and the roll angle. Alternative aspects include multiple-antenna GNSS guidance methods for high-dynamic roll compensation, real-time kinematic (RTK) using single-frequency (L1) receivers, fixed and moving baselines between antennas, multi-position GNSS tail guidance (“breadcrumb following”) for crosstrack error correction, guiding multiple vehicles and pieces of equipment relative to each other, and snow grooming equipment and method applications.

An opening-sealing apparatus for a honeycomb molded body comprising:

a paste filling device equipped with a paste filling unit having an opening-sealing mask in which a number of openings are formed at predetermined positions and a paste supplying unit;

an image pickup device for picking up an image of the end face of the honeycomb molded body; and

an image analyzing device for analyzing the image obtained by the image pickup device, wherein

the image analyzing device analyzes the positions of the cells based upon the image of the end face picked up by the image pickup device; the opening-sealing mask is made in contact with the end face of the honeycomb molded body in such a manner that the positional error between the openings of the opening-sealing mask and the cells of the honeycomb molded body is reduced to a minimal level; and the plug material paste, which has been supplied from the paste supplying unit to the paste filling unit, is injected through the opening-sealing mask and filled in the end portion of the cells.

A cellular phone is provided with a media scanning capability. Scanner optics, an optional light source and related scanning circuitry is integrated within a cellular phone to enable image or text scanning, facsimile, text-to-speech conversion, and language translation. Position sensors provide position data as the scanner is manually moved, in one or more passes across the scanned media, to enable a bit-mapped image of the strip to be created in a data buffer. Image data from the strips is processed to remove redundant overlap data and skew position errors, to give a bit-mapped final image of the entire scanned item. Image compression is provided to compress the image into standard JPEG format for storage or transmission, or into facsimile format for transmission of the document to any fax machine. Optical character recognition (OCR) is provided to convert image data to text which may be sent as email, locally displayed, stored for later use, or further processed. Further processing of text data includes language translation and text to speech conversion of either the original or translated text. The resulting speech audio can be heard locally or transmitted over the cellular network.

A system is provided for tracking and maintaining an inventory of location of containers that are stored on cargo ships or in a container yard. The system includes one or more sensors, such as GPS and INS sensors for obtaining real-time position information, as well as a processor configured to automatically provide post processing to recover lost data and to correct erroneous data, such as when real-time position signals are blocked or distorted, the post processing performed by estimating trajectories and correcting the location errors. Post-processed positioning techniques are continuously applied to the stored position data to iteratively determine calibrated position locations to provide calibrated second trajectory segments in a real-time fashion. The calibrated second trajectories are then used to identify the errors in the past real-time position data as soon as a segment of the second calibrated trajectory becomes statistically trustworthy. Corrections can be automatically made in inventory locations stored in a database to correct position errors for the containers.

A global navigation satellite sensor system (GNSS) and gyroscope control system for vehicle steering control comprising a GNSS receiver and antennas at a fixed spacing to determine a vehicle position, velocity and at least one of a heading angle, a pitch angle and a roll angle based on carrier phase position differences. The roll angle facilitates correction of the lateral motion induced position errors resultant from motion of the antennae as the vehicle moves based on an offset to ground and the roll angle. The system also includes a control system configured to receive the vehicle position, heading, and at least one of roll and pitch, and configured to generate a steering command to a vehicle steering system. The system includes gyroscopes for determining system attitude change with respect to multiple axes for integrating with GNSS-derived positioning information to determine vehicle position, velocity, rate-of-turn, attitude and other operating characteristics. A vehicle control method includes the steps of computing a position and a heading for the vehicle using GNSS positioning and a rate gyro for determining vehicle attitude, which is used for generating a steering command. Alternative aspects include multiple-antenna GNSS guidance methods for high-dynamic roll compensation, real-time kinematic (RTK) using single-frequency (L1) receivers, fixed and moving baselines between antennas, multi-position GNSS tail guidance (“breadcrumb following”) for crosstrack error correction, guiding multiple vehicles and pieces of equipment relative to each other and earth-moving equipment and method applications.

The invention discloses a calibration method of correlation between a single line laser radar and a CCD (Charge Coupled Device) camera, which is based on the condition that the CCD camera can carry out weak imaging on an infrared light source used by the single line laser radar. The calibration method comprises the steps of: firstly, extracting a virtual control point in a scanning plane under the assistance of a cubic calibration key; and then filtering visible light by using an infrared filter to image infrared light only, carrying out enhancement, binarization treatment and Hough transformation on an infrared image with scanning line information, and extracting two laser scanning lines, wherein the intersection point of the two scanning lines is the image coordinate of the virtual control point in the image. After acquiring multiple groups of corresponding points through the steps, a correlation parameter between the laser radar and the camera can be solved by adopting an optimization method for minimizing a reprojection error. Because the invention acquires the information of the corresponding points directly, the calibration process becomes simpler and the precision is greatly improved with a calibrated angle error smaller than 0.3 degree and a position error smaller than 0.5cm.

A sensor system for vehicle steering control comprising: a plurality of global navigation satellite sensor systems (GNSS) including receivers and antennas at a fixed spacing to determine a vehicle position, velocity and at least one of a heading angle, a pitch angle and a roll angle based on carrier phase corrected real time kinematic (RTK) position differences. The roll angle facilitates correction of the lateral motion induced position errors resultant from motion of the antennae as the vehicle moves based on an offset to ground and the roll angle. The system also includes a control system configured to receive the vehicle position, heading, and at least one of roll and pitch, and configured to generate a steering command to a vehicle steering system.

Embedded servo sectors within a data track of a hard disk drive including a rotating data storage disk and a closed loop rotary actuator structure for positioning a data transducer head relative to the data track are written by a method including the steps of positioning the rotary actuator structure relative to the data track with a laser-interferometer-based servo writer and writing a pattern of circumferentially sequential, radially offset fine position bursts within each servo sector with the data transducer head, this step including writing-in undetermined position errors within each pattern being written, moving the disk drive to a self scan environment away from the servo writer, operating the rotary actuator structure in closed loop for following the data track by reference to the servo burst pattern, extracting the undetermined position error from each pattern thereby to iteratively determine written-in position errors, generating burst correction values from the determined written-in position errors, and writing the burst correction values to the data track for later use by the closed loop rotary actuator structure during following of the data track to remove the written-in position errors.

A position keeping system, useable to maintain a position of a vehicle in a vehicle formation, to keep all formation members flying at a specified velocity and altitude, and to perform commanded maneuvers, determines guidance corrections based on a track state referenced to a leader or a virtual leader of the formation and on a formation position error indicating the error in the position of the vehicle in the formation. The guidance corrections are required so as to maintain the vehicles in the formation.