803 results about "Errors measurement" patented technology

According to one embodiment, a control device that controls operation of a system includes a first selecting module, a second selecting module, a control error measuring module, a determining module, and a control module. The first selecting module selects a first neural network from neural networks different in network configuration from each other. The second selecting module selects a second neural network different from the first neural network from the neural networks. The control error measuring module measures first control error in control by the first neural network and second control error in control by the second neural network. The determining module compares the first control error and the second control error measured by the control error measuring module, and determines a neural network with less control error. The control module controls the operation of the system by the neural network with less control error determined by the determining module.

A machine tool for machining and testing the non-spherical optical part features that its main body has the symmetrical gantry frame structure with X, Y, Z and C axises designed modularly, the milling head or polishing mechanism is installed to the Z-axis bench, and the floating platform equipped with the in-line measuring and error-measuring unit for plane and parallel to Y axis is arranged on main body. Its advantage is high machining precision.

The invention discloses propeller type surface contour error measurement instrument and method. The propeller type surface contour error measurement instrument is characterized in that a gantry structure is adopted, a left upright, a right upright and a top cross beam are arranged on a base, and a revolving spindle is arranged on a cross beam; the lower end of the revolving spindle is horizontally and fixedly connected with a measuring arm; a linear guiderail is arranged on the bottom surface of the measuring arm along the radial direction of the revolving plane of the measuring arm, a working platform capable of doing linear movement along the linear guiderail is arranged on the linear guiderail, and a displacement sensor is arranged on the working platform; and a Y-direction working platform and an X-direction working platform are arranged on the base in an overlapping, and the blade of a detected propeller is arranged in a positioning groove at the top surface of the X-direction working platform. The measuring device and the measuring method are established by adopting a cylindrical coordinate system according to the axial symmetry structure characteristics of the propeller blade. The measuring device and the measuring method are fast in data acquisition, have no objective errors of an operator, and are simple in follow-up error processing and analysis, and can be used for precision measurement on size parameters and geometric error parameters of large revolving parts.

A wireless broadband communications system that provides higher performance and increased spectral efficiency in point-to-point and point-to-multipoint applications. The wireless communications system includes a plurality of transceivers and a plurality of transmit and receive antennas. The system can be configured as a 1:n SIMO system that transmits and receives signals over a single channel of information flow, or an n:n MIMO system that transmits and receives signals over multiple channels of information flow, based upon channel state information and average vector error measurement values corresponding to the respective channels of information flow, which are determined by the system via an adaptive modulation technique.

A downlink time/frequency tracker for a receiver terminal, which may be mounted to a static platform on the earth, or to a dynamic platform, such as a ship. The tracker is operative to acquire and track time and frequency variations in time- and frequency-hopped synchronization signals from different data rate sources in a dynamic platform, such as a satellite. Characteristics of the Kalman filter are updated in accordance with data representative of timing error and frequency error measurements carried out on the synchronization signals, as well as data representative of local kinematic domain measurements carried out with respect to the receiver terminal. The Kalman filter outputs minimum mean square error estimates of timing and frequency errors in the receiver terminal's demodulator clock. These error estimates are used to synchronize the demodulator's clock with the clock embedded in the downlink signal, so as to enable demodulation and recovery of data.

A method, a system and a computer readable medium are provided. The method may include obtaining or receiving first area information representative of a first area of a first layer of an inspected object; wherein the inspected object further comprises a second layer that comprises a second area; wherein the second layer is buried under the first layer; directing electrons of a primary electron beam to interact with the first area; directing electrons of the primary electron beam to interact with the second area; generating detection signals responsive to electrons that were scattered or reflected from at least one of the first and second areas; and determining at least one spatial relationship between at least one feature of the first area and at least one feature of the second area based on the detection signals and on the first area information.

The invention discloses a digital controlled lathe thermal error measuring compensation system and method. The system comprises an eddy current displacement sensor, a platinum resistor temperature sensor, a laser interferometer, a displacement collecting and processing module, a thermal error compensation module and a PC. The platinum resistor temperature sensor measures the temperature of a lathe body heat sensitive point, the eddy current displacement sensor measures heat deformation of a spindle, the laser interferometer measures the locating error of a feeding system, and the spindle and a feeding shaft system are subjected to real-time thermal error comprehensive modeling. The thermal error compensation module compensates for axial heat expansion and radial heat inclination of a spindle workpiece in real time according to the temperature of the heat sensitive point and the coordinate value of a tool. The coupling problem of the digital controlled lathe spindle and the feeding shaft thermal error is solved, the thermal error can be compensated for in real time, and the machining precision of a digital controlled lathe is improved.

In the case where measurement/inspection of a wafer is performed in a measurement/inspection instrument before and after exposure is performed in an exposure apparatus, various kinds of conditions of the exposure apparatus and the measurement/inspection instrument such as environment in the apparatus/instrument, a measurement condition of an alignment system a measurement condition of an AF measurement device, a wafer grid, and image distortion are made to be matched. In particular, in accordance with a processing state of the exposure apparatus and a coater developer, a measurement result of a film, and the like, exclusion of a mark for overlay error measurement, adjustment of the measurement condition and correction of the measurement result, adjustment of the environment, correction of the measurement result according to the environment, and adjustment of pattern defect inspection are performed. Further, in calibration processing, aberration of a projection optical system of an exposure apparatus that transfers a pattern on a wafer for calibration, and the like are also taken into consideration. Accordingly, the yield of device production can be improved.

The invention discloses a non-cooperative target abutting measurement method based on additional sighting distance. The non-cooperative target abutting measurement method is combined by two measurement modes of different principles, i.e. a binocular vision measurement mode and a laser ranging mode, wherein the binocular vision measurement mode is a main measurement means for a six-degree-of-freedom parameter of a target relative position and a relative gesture; the laser ranging mode is mainly characterized in that a laser distance meter provides a laser light beam hot spot emitted on a target surface; and then, a Z coordinate of the hot spot to a laser distance meter coordinate system is obtained. Because measurement precision of the laser distance meter on a relatively long distance is far higher than that of the binocular vision measurement, the Z coordinate measured by a tiny fault of the laser distance meter can be used for correcting the Z coordinate obtained by the binocular vision measurement. X and Y coordinate correction can be carried out by relevance among three position coordinates in the binocular vision measurement, so that the three position coordinates of any characteristic point obtained by vision measurement can be corrected so as to improve binocular vision measurement precision, and especially measurement precision of a long-distance target characteristic point is improved.

Methods for improving the accuracy of characterizing unmonitored paths or virtual meters in a utility system. The hierarchical arrangement of IEDs in the utility system is determined. Measured quantities of a characteristic of the utility being monitored are received and error-adjusted using statistical or absolute methods. The statistical method accounts for the mean and standard deviation associated with error measurements of the subject IED, and the absolute method uses the absolute value of the error measurement, expressed as a percentage, to produce ranges of measured quantities within an error tolerance. The differences between the error-adjusted quantities are analyzed to determine whether an unmonitored path exists, and if so, whether the virtual meter is consuming or supplying the utility. The order in which IEDs are read is determined so that a parent and its children are read in sequence to increase synchronicity of the received data and the virtual meter evaluation.

The invention discloses a full working stroke thermal error compensation method of a numerically-controlled machine tool feeding system and an implementation system thereof. Reduction of whole machine machining accuracy is mainly caused by thermal errors of the numerically-controlled machine tool feeding system, and a whole set of the technical scheme for measuring, analyzing and compensating the feeding system is provided. Application techniques of thermal error measurement, thermal key point identification, thermal error compensation modeling and thermal error on-line compensation of the numerically-controlled machine tool feeding system under typical working conditions are surveyed. On that basis, a thermal error on-line compensation system of the numerically-controlled machine tool feeding system is constructed. Taking an X-direction high-speed feeding system of a Longmen numerical control machining center in a certain model as an example, measurement, analysis and modeling compensation of the thermal errors are carried out respectively, and compensation effects are obvious. The full working stroke thermal error compensation method can be used for solving the thermal error compensation problem of the numerically-controlled machine tool feeding system and provides technical supports for machining accuracy and stability of a numerically-controlled machine tool.

The invention provides an overlay error measurement apparatus and a method. According to the present invention, a wide waveband light source is adopted, the emitted wide waveband measurement light beam turns through a beam splitting prism, then is subjected to normal incidence on an overlay measurement label through an object lens, and produces diffraction, the diffraction light is received by a first detector after passing through the object lens and the beam splitting prism so as to measure the diffraction light intensity, and the asymmetry of the high-order diffraction light spectral intensity is further calculated so as to obtain the overlay error; and the adopted wide waveband has the wide measurement range, the good process adaptability is provided, and the normally-incident light beam is adopted so as to provide large depth of focus and reduce the control difficulty of the focal plane position measurement, such that the feasibility during actual measurement is increased, and the high precision measurement result can be obtained.

A method and apparatus for matching compressed video data under a wireless fading environment are disclosed. The apparatus includes an encoder for encoding and outputting the video data as a compressed bit stream, a channel error measurement unit for measuring Signal-to-Noise Ratio (SNR) or Carrier-to-Noise Ratio (CNR) of a wireless channel, and an encoder optimization module for determining if the current fading is slow fading or fast fading. A control signal is output to reduce a frame transmission ratio or to change the quality of the vide data if it is determined that the current fading is slow fading. Another control signal is output to adjust the size of a data output buffer of the wireless channel if it is determined that the current fading is fast fading. The apparatus also includes a temporal Scalable Video Coding (SVC) selector 24 and an SNR SVC selector 22 for selecting the frame transmission ratio or the bit rate according to the control signal output from the encoder optimization module, to provide a frame selection signal or a bit rate selection signal to the encoder.

The invention discloses an electronic mutual inductor test system and a test method. The electronic mutual inductor test system comprises a standard device, a signal conversion device, an error measuring device, a test power supply, a merging unit and a tested electronic mutual inductor, wherein the standard device is used for providing a standard signal serving as a test reference; the signal conversion device is used for receiving the standard signal and converting the standard signal into an analog signal which can be acquired by the error measuring device; the test power supply is used for outputting a primary voltage and a primary current for test use; the merging unit is used for receiving a digital signal output by the tested electronic mutual inductor and processing the digital signal; and the error measuring device is used for receiving the standard signal output by the signal conversion device and the digital signal output by the merging unit, and acquiring the ratio difference and the phase difference of the tested electronic mutual inductor. The electronic mutual inductor test system is particularly suitable for a field error test of the electronic mutual inductor, andhas the advantages of convenient test work, high reliability, small equipment volume, light weight, high test result accuracy and the like.

The invention discloses a numerically-controlled machine tool error compensation system and method based on human-computer interface secondary development. The numerically-controlled machine tool error compensation system comprises a hardware portion and a software portion integrally arranged in the hardware portion. The hardware portion comprises a Siemens 840D numerical control system PCU, a temperature sensor, a temperature data acquisition card and an error measurement instrument. The software portion comprises a temperature acquisition module, a thermal error compensation module, a space error compensation mould and a state monitoring module. According to the numerically-controlled machine tool error compensation system and method based on the human-computer interface secondary development, the error compensation function of a Siemens 840D numerical control system is effectively used for compensating space errors; the numerically-controlled machine tool error compensation system and method based on the human-computer interface secondary development is convenient and effective to implement, external expansion of compensators is not required, machine tool parameters are read based on a human-computer interface and DDE, and good on-line state monitoring can be achieved without an external upper computer.

A method includes measuring a first overlay error between a first process layer and a second process layer using a first overlay target formed on the second process layer. A second overlay error between the first process layer and a third process layer is measured using a second overlay target formed on the third process layer. At least one parameter of an operating recipe for performing a photolithography process on the first process layer is determined based on the first and second overlay error measurements. A system includes a metrology tool and a controller. The metrology tool is configured to measure a first overlay error between a first process layer and a second process layer using a first overlay target formed on the second process layer and measure a second overlay error between the first process layer and a third process layer using a second overlay target formed on the third process layer. The controller is configured to determine at least one parameter of an operating recipe for performing a photolithography process on the first process layer based on the first and second overlay error measurements.

A system and method for recovery of phase information from recorded intensity values is disclosed. In one aspect, a phase filter is placed in a plane, which may be the back focal plane (BFP) of a lens used for observing an object. The phase filter changes the phase of a wave front distribution in the BFP in a known manner. Amplitude stops or combinations of phase and amplitude filtering patterns can also be used to capture N different sets of intensity data in a conjugate diffraction plane. The N intensity images are used to obtain an estimate of the wave front at the first plane. This wave front estimate is then used to generate N modified estimates of the wave front at the conjugate plane, each modified estimate corresponding to one of N filtering patterns. In one implementation, the N modified IP estimates are corrected by replacing the estimated amplitudes with the actually measured ones for that image. The process is repeated iteratively until an error measure between the measured values and the synthetically generated ones falls below a known threshold. The resulting phase estimates can be used to display wave front information similar in appearance to holograms, or to create lens-free microscopes.

A communications device includes a time/frequency error measurement circuit that receives a communications signal and measures its timing and frequency errors. A Kalman filter receives the communications signal from the time/frequency error measurement circuit and processes the signal using a multi-level state error covariance matrix P for controlling the Kalman gain in the Kalman filter. An on-line monitoring circuit is operative with the Kalman filter for monitoring the actual state errors in time and frequency and controlling the state error covariance matrix P based on a measured error threshold.

A test system is capable of performing parallel modulation error measurement of transceivers using a loop-back configuration. Each transceiver includes a transmitter and a receiver. A signal generator generates a first modulated signal for input to the receivers of the transceivers. A tester is operable to measure a first demodulation error produced by the receiver in response to the first modulated signal and to measure a modulation error of the transmitter based on the first demodulation error and a second demodulation error. The second demodulation error is produced by the receiver in response to a second modulated signal generated by the transmitter and coupled from the transmitter to the receiver.

The invention belongs to the field of geometric error measurement for machine tools and relates to a method for measuring dynamic space track errors of the machine tools by means of binocular vision, in particular to a dynamic error vision measurement method for a five-axis numerical control machine tool. The measurement method includes the steps that according to a three-dimension perceptive function of binocular vision measurement, multiple errors are measured and separated at a single time; and four types of spherical mark points are reasonably distributed at a machine tool cutter end and on the surface of a working table, and the position relation among a vision coordinate system, a machine tool reference coordinate system and a machine tool cutter principal axis coordinate system is calibrated by means of feature information of the spherical mark points. During measurement, a vision measurement system continuously, statically and dynamically collects images of the spherical mark points, then moving errors of all machine tool axes are solved, and the obtained theoretical value and actual machine tool moving amount are combined, so that the moving errors of each axis are solved. According to the dynamic error vision measurement method for the five-axis numerical control machine tool, the machine tool space track errors are measured by means of a binocular high-speed camera, so that the error measurement accuracy is improved, the measurement range of the machine tool moving track is widened, the measurement method is simple and reliable, and the measurement process is simplified.

The invention discloses a detection method for the synchronization error between a translational motion shaft and a rotating shaft of a five-axis numerically-controlled machine tool. The detection method comprises the following steps that (1) a measurement range is determined, and a measurement trajectory NC program is calculated; (2) an evaluation index of the synchronization error between the rotating shaft and the translational motion shaft is determined; (3) a ball bar meter is installed, a tool tip rotating follow function of the five-axis machine tool is started, the measurement program is operated, and measurement data of the ball bar meter are obtained; (4) the current synchronization error between the rotating shaft and the translational motion shaft is worked out; and (5) the servo position proportional gain and speed feed-forward gain servo parameters of the measured rotating shaft and servo position proportional gain and speed feed-forward gain servo parameters of the measured translational motion shaft are adjusted according to the measured synchronization error situation, and then error measurement is conducted till the error reaches the precision requirement level of the machine tool. According to the detection method for the synchronization error between the translational motion shaft and the rotating shaft of the five-axis numerically-controlled machine tool, measurement of the synchronization error between the rotating shaft and the translational motion shaft can be achieved by simply measuring the movement path, operation is easy, error separation is clear, and efficient adjustment of the synchronization error is convenient.