134results about How to "Avoid calibration" patented technology

A multi-tip extrusion method and apparatus for building a three-dimensional object deposits modeling materials from distinct supply sources, each in a layerwise predetermined pattern, from dispensers having co-planar dispensing tips. The tip spacing is controlled so that a road of material extruded by a leading one of the tips will cool and shrink from the plane of the tips before a trailing one of the tips passes over the road. In this manner, smearing of the road by a trailing one of the tips is avoided.

This invention relates to a method of performing eye gaze tracking of at least one eye of a user, by determining the position of the center of the eye, said method comprising the steps of:

• • detecting the position of at least three reflections on said eye,
  • transforming said positions to spanning a normalized coordinate system spanning a frame of reference, wherein said transformation is performed based on a bilinear transformation or a non linear transformation e.g. a möbius transformation or a homographic transformation,
  • detecting the position of said center of the eye relative to the position of said reflections and transforming this position to said normalized coordinate system,

tracking the eye gaze by tracking the movement of said eye in said normalized coordinate system.

Thereby calibration of a camera, such as knowledge of the exact position and zoom level of the camera, is avoided. Further, it is not necessary to know the position of light sources. This results in a much more flexible and user friendly system.

A baler comprises a baling chamber and a sensor arrangement. The sensor arrangement comprises at least one sensor arranged to provide information about a mechanical property of a bale built in the baling chamber and a control unit receiving signals from the sensor. The control unit is operable to automatically calibrate the signals from the sensor based upon at least one signal from the sensor received in at least one known state of the sensor.

The invention provides distance measuring and speed measuring methods and devices based on video images. On the premise that a movement track of a measured object is perpendicular to a camera optical axis and the movement track of the measured object is a straight line, when the measured object moves from point A to point B in the movement track, distance between point A' and point B' is measured, wherein the point A' and point B' are corresponding points of the point A and the point B in an image plane. The distance between the point A and the point B is measured, according to the measured distance between the point A' and the point B' and a mapping proportionality coefficient of the distance in the movement track to the corresponding distance in the image plane. By adopting of the methods and the devices, real-time performance and accuracy of the measurement can be improved.

An imaging sensor system images in two different spectral bands a light beam traveling on a light path from a target. The sensor system includes an imaging sensor operable to image light of the two different spectral bands, a common optics having at least one reflective or refractive optical element, and a wavelength-selective beamsplitter on the light path between the target and the imaging sensor. The wavelength-selective beamsplitter splits the light beam into two subbeams, one subbeam for each of the two different spectral bands, that are respectively incident upon two different locations of the imaging sensor. The imaging sensor may be used to detect buried explosive mines.

The invention discloses a spectral data calibration method based on black and white calibration plates. The method comprises the following steps of: firstly, collecting spectral data of a black calibration board and a white calibration board respectively; then collecting spectral data of a to-be-detected sample and carrying out data modeling, and recording the spectral data as spectral data X andthe model as a spectral model M; calculating actual spectral data Y of the to-be-detected sample by combining the spectral data of the black calibration plate and the spectral data X of the sample; calculating the actual reflectivity H of the to-be-detected sample by combining the spectral data of the white calibration plate and the actual spectral data Y of the sample; and finally, carrying out data modeling on the reflectivity H by adopting a modeling method which is the same as that of the spectral model M, and judging the quality of the spectral model through a model correlation coefficient and a root-mean-square error. According to the method, the spectral data can be effectively calibrated, the spectral model quality and the spectral prediction accuracy are further improved, meanwhile, the method is easy to implement, and the problem that the portable near infrared spectral data is difficult to calibrate is solved to a great extent.

A surrounding area monitoring apparatus for vehicle includes an infrared camera mounted on a vehicle for capturing images of surrounding area around the vehicle, a unit for generating and displaying images based on image data captured by the camera, and a controller for calibrating output of the camera with respect to a relation between pixels, based on image data produced by imaging a surface of a shutter that opens and closes an aperture introducing a light to the camera. The controller estimates whether a temperature of the camera is stable, based on an operation state of the vehicle, and determines a possibility that a driver is looking at the unit, based on a behavior of the vehicle. When the temperature of the camera is estimated stable and the possibility that the driver is looking at the unit is determined to be low, the means for calibrating executes the calibration.

The invention discloses a transmission detection device for a radio frequency terminal and a control method thereof. The device comprises a radio frequency feedback receiver and a calibration controller. The output end of the radio frequency feedback receiver is connected with the calibration controller. The radio frequency feedback receiver comprises a test signal generator, a gating switch and apreprocessing circuit. The input end of the preprocessing circuit is selectively connected with the test signal generator or a detection point of a radio frequency terminal through the gating switch.The preprocessing circuit is used for preprocessing an input signal. The output end of the preprocessing circuit is taken as the output end of the feedback receiver. The calibration controller comprises a digital signal processor. The digital signal processor is used for controlling the gating switch of the feedback receiver and calibrating the radio frequency feedback receiver or the radio frequency terminal according to an output signal of the radio frequency feedback receiver. The accuracy of the device and the control method are relatively high.

The present invention discloses a calibration method and system for high-intensity field sensors. The objective of the invention is to solve the problem that a standard field method is less likely to generate high field strength in a test area. The system of the invention comprises a transmitting antenna, a field strength meter, a reverberation chamber, a receiving antenna and a signal receiving system; the reverberation chamber comprises a horizontal agitator and a vertical agitator; the signal receiving system is used for measuring the field strength value of the receiving antenna. The method of the invention includes the following steps that: a calibrated field sensor is arranged in the field uniform area of the reverberation chamber, the transmitting antenna radiates electromagnetic waves into the reverberation chamber; the number of the times of the stepping of the horizontal agitator and the vertical agitator in one agitating cycle is set; when stepping occurs each time, the receiving field value of the field sensor and the aperture receiving power of the receiving antenna are measured; the average receiving field strength value of the field sensor and the average receiving field strength value of the receiving antenna in one agitating cycle are obtained; and the average receiving field strength value of the field sensor is compared with the average receiving field strength value of the receiving antenna, so that the field strength correction factor of the field strength sensor can be obtained. With the method and system of the invention adopted, the calibration of field strength sensors of which the field strength amplitude is above 200V/m can be realized.

The invention provides an ambient air monitoring sensor remote calibration method. The sensor remote calibration method is characterized in that a server, an ambient air monitoring mobile terminal andan air quality standard monitoring station are adopted to carry out remote calibration on a sensor of an ambient air quality monitoring device. The invention also provides the ambient air quality monitoring device for ambient air monitoring. The ambient air quality monitoring device comprises a shell and an air quality monitoring system located in the shell, wherein the air quality monitoring system is internally provided with the sensor, and the ambient air quality monitoring device is applied to the sensor remote calibration method to carry out remote calibration on the sensor. The sensor remote calibration method can solve problems of complex sensor calibration process, low efficiency and high cost of the existing ambient air quality monitoring device; and the ambient air quality monitoring device has the advantages of convenient carrying, easy calibration, accurate detection result and low cost, and can carry out remote calibration on the sensor through the sensor remote calibration method, thereby reducing the calibration cost.

The invention discloses a comprehensive ramp stopping and sliding control system applicable to an electric forklift. The system comprises control steps as follows: when a speed detection unit detectsthat the speed of the vehicle is zero, a torque evaluation unit calculates the current torque; when the torque is larger than a set threshold, a ramp staying control unit is triggered, and the vehicleis stopped on a ramp by electric brake of a motor; when the electric brake time of the vehicle exceeds ramp stopping time, the system actively switches to a ramp sliding control unit; the torque evaluation unit calculates the current torque, when the torque is smaller than the preset threshold, the vehicle is regarded to be located on the flat ground, the system actively quits the ramp sliding state, the vehicle is stopped on the flat ground, the torque is smaller than the preset threshold, and the normal working mode returns. The system enters the ramp stopping program by brake instead of anexternal trigger signal. A motor controller stops the motor through closed-loop control to automatically adapt to different ramps. Therefore, formulation of different PI tables for different ramps can be avoided. Stability and safety in the ramp sliding process are realized by adding ramp sliding speed setting items and speed closed loop.

An embodiment of the invention relates to a method for calibrating an optical path of a laser path. The method comprises the steps of forming a first image on an imaging device from a first light beam through a first lens, irradiating a to-be-measured object by a second light beam from a first light source through a reflector and a second lens, and forming a second image of the to-be-measured object on the imaging lens through the second lens and the first lens; and adjusting at least one in direction and pitch of the to-be-measured object until the first image is superposed with the second image at the imaging center of the imaging device.

The invention relates to a height sensor calibration method, device and equipment, an electric control air suspension and a vehicle, and the method comprises the steps: entering a calibration mode ifa height sensor calibration identification is not obtained; in the calibration mode, in the process of calibrating and adjusting the height of the detected object, acquiring coil charging data of theheight sensor; determining a working mode to which the height sensor belongs according to a preset association relationship between the coil charging data and the working mode of the height sensor; and calibrating the height sensor according to the working mode so as to carry out actual adjustment on the height of the detected object according to the working mode. By the adoption of the technicalscheme, the tedious degree of the installation and calibration process of the height sensor can be reduced, and the installation and calibration efficiency of the height sensor is improved.