83 results about "Head measurements" patented technology

A navigation device includes: a map database 5 that holds map data; a location and heading measurement unit 4 that measures the current location and heading of a vehicle; a route calculation unit 12 that, based on the map data read from the map database, calculates a guidance route from the current location measured by the location and heading measurement unit to a destination; a camera 7 that captures video images ahead of the vehicle; a video image acquisition unit 8 that acquires the video images ahead of the vehicle captured by the camera; a side road acquisition unit 16 that acquires a side road connected at a location between the current location on the guidance route calculated by the route calculation unit and a guidance waypoint; a video image composition processing unit 14 that composes a picture representing the side road acquired by the side road acquisition unit onto the video images acquired by the video image acquisition unit; and a display unit 10 that displays the video image composed by the video image composition processing unit in a superimposing manner.

The invention relates to the technical field of gear measurement and especially relates to a gear measurement device based on a laser displacement sensor and a gear measurement method. The gear measurement device provided by the invention comprises a working table, wherein a work piece revolving table and a three-coordinate horizontal shifting device equipped with a rotatable measurement head are disposed on the working table; a zero marking spindle is disposed vertically on the work piece revolving table; the three-coordinate horizontal shifting device comprises an X-axis guide rail fixed on the working table; a Y-axis guide rail is disposed on the X-axis guide rail in a sliding manner; a Z-axis guide rail is disposed on the Y-axis guide rail in a sliding manner; a slide frame is disposed on the Z-axis guide rail in a sliding manner; and the rotatable laser displacement sensor is disposed on the slide frame. The gear measurement device provided by the invention is characterized in that the laser displacement sensor collects coordinate positions of each measurement point on a measured gear outline. In comparison with contact head measurement based on contact with a work piece, the device and the method provided by the invention have the advantages that measurement accuracy is high; a measurement head motion route does not need to be planned during the measurement; and measurement sources are simplified.

A method for generating a cephalometric analysis of an orthodontic patient is disclosed. A sequence of images that may each correspond to a specific anatomical plane of the patient is received. Then, a volumetric representation of the patient is derived from a combination of the sequence of the images. One or more markers associated with particular anatomical landmarks of the patient according to a predefined analysis method are received. The markers are defined by a set of coordinate values, and are designated via an interactive user interface to a two-dimensional representation derived from the volumetric representation. Connectors between one or more of the markers are generated in accordance with the predefined analysis method, and a visual representation of the markers and the connectors are overlaid on the volumetric representation.

An external index detection unit (105) receives an image sensed by a camera (100), and detects an external index set in a real scene. A tachometer (110) measures the rotational velocities of two rear wheels of a vehicle. A vehicle measurement unit (120) measures the position and azimuth of the vehicle on the basis of the image coordinate position of the external index and the rotational velocities of the two rear wheels of the vehicle. A head index detection unit (135) receives an image sensed by a camera (130), and detects a head index set on the head of a passenger (132). A head measurement unit (140) measures the position of the head on the basis of the image coordinate position of the head index. An image generation unit (150) generates a display image based on the position and azimuth of the vehicle and the position of the head, so that the passenger can observe predetermined navigation information superimposed at a predetermined position of the real scene, and controls a projector (160) to project the generated image.

A method and system for compensating for significant soft iron magnetic disturbances in a heading reference system, such as an aircraft heading reference system, such as an integrated standby unit; or a vehicle inertial system, provides a heading correction signal to the heading reference system when a detected difference in value between a gyro heading relative to magnetic north and a magnetometer reading during a defined measurement period exceeds a predetermined acceptable threshold value of change, such as one based on the expected gyro drift over that period. Upon receipt of the heading correction signal, the gyro heading is adjusted to maintain an accurate heading relative to true magnetic north. If this threshold value is not exceeded, then the magnetometer reading is used for the heading value. This method is iteratively repeated in order to continually maintain an accurate heading and may be employed for each heading measurement axis.

Disclosed herein is a combined panoramic, CT (Computed Tomography) and cephalometric photographing apparatus including: a base; a supporting pole; an elevation member; a panoramic and CT photographing part; and a cephalometric photographing part. The panoramic and CT photographing part includes: a rotary arm supporting member; a rotary arm arranging an X-ray source part and an X-ray sensor part in such a way that the X-ray source part and the X-ray sensor part are opposed to each other, the X-ray sensor part having a panoramic sensor and/or a CT sensor; and rotary arm driving means. A distance between the X-ray source part and the X-ray sensor part arranged opposed to each other with respect to the rotary arm is variable. The apparatus can conduct all of panoramic photographing, CT photographing and cephalometric photographing, and provide the optimum enlargement ratio according to whether the panoramic photographing or the CT photographing is conducted.

The invention discloses an aero-engine rotor stack-assembling method and device and belongs to the technical field of mechanical assembly. The method comprises the steps of determining a rotary standard based on an air floatation rotary shaft system, determining angle location of a rotary table through an optical-electricity encoder, extracting the radial error of a rotor radial assembly surface and the oblique error of a rotor axial assembly surface through a four-measuring-head measurement device to obtain the influence weight of a rotor on the coaxiality of assembled rotors, measuring all the rotors needed by assembly to obtain the influence weight of each rotor on the coaxiality of the assembled rotors, and conducting vector optimization on the weight of each rotor to obtain the assembly angle of each rotor. The method and device can effectively solve the problem that coaxiality of aero-engine rotors is low after assembly and has the advantages that coaxiality of the rotors is high after assembly, vibration is reduced, installation is easy to achieve, flexibility is high, and the performance of an engine is improved.

Unlike customary vibrating mass gyros which operate by exciting a first fundamental mode of vibration of the vibrating mass and by detecting the effect of the Coriolis force on a second fundamental mode of vibration of the vibrating mass orthogonal to the first mode, this gyro operates by giving its suspended mass a circular motion alternately in the forward and reverse directions and by deducing the gyrometric effect from the difference between the apparent frequencies of the circular motion of the suspended mass in one direction and in the other. This allows a considerable reduction in the drafting of the heading measurement obtained with this type of gyro.

The invention discloses a portable device for soil surface in situ vertical permeability experiment. The device comprises a water supply unit and a measuring unit. The water supply unit comprises a water storage bucket, a lifting platform and a steady flow box; the storage bucket is in a Mariotte flash structure, and used to provide a constant head; the measuring unit comprises a measuring cylinder and pressure measuring lines; pressure measuring holes are arranged at the upper end of the measuring cylinder and below the water inlet of the measuring cylinder; a plurality of pressure measuring holes in spiral fan shape are distributed outside the measuring cylinder, and are internally provided with a Pitot tube plugs; a knife edge is arranged at the bottom of the measuring cylinder; the water inlet of the measuring cylinder is communicated with the water outlet at the bottom end of the steady flow box; and the Pitot tube plugs are communicated with the pressure measuring lines through PU tubes. The invention has experimental functions of fixed water head measurement and falling head measurement, can conduct layered determination on the permeability coefficient of the soil surface, effectively reduce the destruction of soil disturbance on the original structure and permeability characteristic, and is applicable to soil with different permeability characteristics, and convenient for carrying and operation, especially suitable for soil in situ permeability experiment in the field.

An automated cephalogram image analysis method is disclosed. In this method, a step is first performed for building a reference database in which a set of tracing feature curve models respectively representing a set of reference cephalometric patterns are established based on a set of tracing records. Then, a step of pattern comparison and analysis is performed. In this step, at least one cephalogram is first input, and then a step is performed for comparing the image of the cephalogram with the tracing feature curve models, thereby selecting at least one cephalometric pattern and at least one feature curve model belonging to the cephalometric pattern from the reference cephalometric patterns and the tracing feature curve models. Thereafter, the feature curve model is fitted to the image of the cephalogram so as to obtain at least one tracing of the at least one cephalogram.

A disclosed jig, for use in certifying accuracy of a vehicle wheel aligner, includes two axles of equal length having stub shafts at the ends of the axles and two adjustable side spacers for releasable connection to the stub shafts. Plates for mounting heads of the aligner system also are attached to the stub shafts. Stands support the corners of the rectangular jig formed by the connected axles and spacers. The aligner system measures parameters of the jig from the attached heads. A diagonal spacer of a predetermined length, may be used in setting the diagonals of the rectangular jig during assembly to be equal. In the example disclosed, the apparatus also includes a distance setting shaft for use in setting lengths of each of the two side spacers to be equal.

A method and system for compensating for soft iron magnetic disturbances in multiple heading reference systems, such as aircraft heading reference systems, integrated standby units; or vehicle inertial systems, detects and provides a heading correction signal to the error prone heading reference system when a detected difference in value between a gyro heading relative to magnetic north and a magnetometer reading during a defined measurement period exceeds a predetermined acceptable threshold value of change, such as one based on the expected gyro drift over that period. Upon receipt of the heading correction signal, the gyro heading is adjusted to maintain an accurate heading relative to true magnetic north. If this threshold value is not exceeded, then the magnetometer reading is used for the heading value. This method is periodically repeated in order to continually maintain an accurate heading and may be employed for each heading measurement axis.

A method for 3-D cephalometric analysis of a patient, executed at least in part on a computer processor, displays reconstructed volume image data from a computed tomographic scan of a patient's head from at least a first 2-D view and accepts an operator instruction that positions and displays at least one reference mark on the at least the first displayed 2-D view. One or more dentition elements within the mouth of the patient are segmented and one or more cephalometric parameters computed for the patient according to the at least one reference mark and the one or more segmented dentition elements. One or more results generated from analysis of the one or more computed cephalometric parameters are displayed.

The invention relates to a dynamic positioning and dynamic tracking system of a drag suction dredger and a control method thereof, which belong to the technical field of engineering ship automation. The dynamic positioning and dynamic tracking system of the drag suction dredger comprises a control panel, a programmable logic controller, a heading measurement device, a position measurement device, a wind direction and wind speed measurement device, a ship motion attitude measurement device, a propeller and a steering engine, wherein the control panel is connected with and controls the programmable logic controller, the heading measurement device, the position measurement device, the wind direction and wind speed measurement device, the ship motion attitude measurement device, the propeller and the steering engine. The positioning and dynamic tracking control method aims to detect actual positions and target positions, actual motion directions and target directions of the drag suction dredger and a drag head, controls a thruster on the dredger so as to enable the dredger to be kept at required positions and headings, and accurately controls dredging operation. The dynamic positioning and dynamic tracking system and the control method thereof have the advantages of simple structure, convenience in operation, accurate control, multiple modes, high dredging efficiency and the like.

The invention relates to a three-redundant ship dynamic positioning heading measurement method based on an improved voting algorithm. The method comprises the following steps: 1, measuring a heading value: 2, adopting a variance self-learning weighting method to obtain respective weight values; 3, carrying out weighting on the measured mean, respectively subtracting a weighted mean from an input value of a sensor, calculating an absolute value, and comparing the absolute value with a threshold t1, wherein the absolute value less than the threshold t1 is considered that no failure exists so as to directly perform data fusion, and it is considered that the failure exists if the absolute value greater than t1 exists, such that failure redetermination is required to be performed; 4, obtaining difference between the current input value and the previous output value, and calculating an absolute value, wherein a normal state is determined when the absolute value is less than t2 and a heading change rate at the current time is similar to heading change rates of the current rudder angle and the ship speed, and otherwise a failure is determined; and 5, carrying out weighting on the remaining data reassignment weight values after excluding the failure data. With the present invention, a lot of failure determinations are achieved, such that the output result has high precision.

The invention discloses an attitude heading measurement system and a fusion method thereof, and a storage medium. The fusion method comprises the following steps of acquiring real attitude angles psi,gamma and theta of a car body by weighting of a three-antenna GNSS (Global Navigation Satellite System) and an accelerometer, wherein psi is a heading angle of the car body, gamma is a roll angle ofthe car body and theta is a pitch angle of the car body; acquiring zero offsets deltabx, deltaby, deltabz of a gyroscope; and performing fusion processing on the attitude angles psi, gamma and theta of the car body acquired by weighting of the three-antenna GNSS and the accelerometer and the zero offsets deltabx, deltaby, deltabz of the gyroscope through a Kalman filtering model to obtain an optimal estimation value of the attitude angles of the car body. According to the attitude heading measurement system and the fusion method thereof, and the storage medium, a weighted observation is performed on an output angle of the gyroscope by using the angles output by the accelerometer and a three-antenna GNSS receiver; the angles are fused on the basis of a Kalman filtering theory; the measurement precision is high; and the high requirement of the modern agricultural machinery navigation on the precision of the attitude angle can be satisfied.

The invention discloses a quasi morphological filtering method for extracting a two-dimensional contour in contact measuring head measurement and belongs to the field of precision measurement technology and instrument technology. According to the quasi morphological filtering method for extracting the two-dimensional contour in contact measuring head measurement, the envelope lines of measuring head contour lines of the positions corresponding to all direct measured data points serve as a final two-dimensional contour measurement result. According to the method, in the two-dimensional contour extracting process, the normal direction in the contact point position does not need to be estimated, and therefore the method is particularly applicable to the situation that in precise measurement, the curvature change of a measured contour is large and even the measured contour is unsmooth.

Systems and methods of calibrating and adjusting for deviations in a vehicle's heading system, such as the attitude heading and reference system of an aircraft or the heading system of a ship, positioned along the Earth's surface involve calibrating magnetometers for hard iron and misalignment errors using single heading measurements. This can be accomplished by obtaining both actual and theoretical readings for the magnetometer of the heading system, and comparing these values to obtain calibration values for the heading system. The vehicle may be repositioned, such as to North, South, East, and west magnetic headings, with the procedure repeated at each of these headings, and the calibration values averaged, further increasing the accuracy.

The invention relates to an asphalt mixture water seepage tester comprising a pedestal, a fixed frame and a lifting platform and also provided with a specimen lower fixing device, a sleeve cylinder, a specimen upper fixing device and a piston compression cylinder. The lower part of the piston compression cylinder is provided with an intelligent electronic water meter, the outside of the piston compression cylinder is sheevedly provided with a water tank, and the right upward side of the piston compression cylinder is correspondingly provided with a piston device; the piston device is driven through a motor and a wheel gear chain transmission device, and can perform up-and-down reciprocating motion in an inner cavity of the piston compression cylinder. By adopting the above structure, the asphalt mixture water seepage tester not only can achieve variable water head measurement and constant water head measurement under a hydrostatic pressure but also can achieve water seepage coefficient measurement under a hydrodynamic pressure, thereby greatly satisfying practical measurement requirements under different conditions, and having good economic benefits and wide application prospects.