242results about How to "Accurate distance measurement" patented technology

A measuring device, comprising, (a) an ultrasonic acoustic transceiver unit capable of sending and receiving acoustic signals into the body of a patient; (b) frequency modulating circuitry which drives said transceiver unit with a signal whose frequency varies with time; and (c) processing circuitry which extracts an indication of a distance, from at least one signal detected by said transceiver unit, said signal being a reflection of a transmission of said transceiver unit driven by said time varying frequency signal. Optionally, the indication is a distance between walls of a bladder.

This invention describes the detection of atherosclerotic plaque or cancer cells by a light probe inside a blood vessel or internal to an elongate organ. In one embodiment, vessel wall is imaged by employing a scanning mechanism using one emitting and one receiving fiber, whereby light is directed at a spinning mirror, approximately normal to the vessel or elongate organ surface. The light is reflected circumferentially around the vessel or elongate organ surface as the mirror rotates and received by a low-numerical aperture (NA) fiber, which transmits it to a light detector, thereby generating a set of light amplitudes circumferentially around the vessel/elongate organ surface. Multiple rings are acquired by translating the probe within the vessel/elongate organ. In another embodiment, adding a piezoelectric transducer in proximity to the distal ends of the fibers permits simultaneous ultrasound and light images to be created.

An elongated substantially flat four-conductor moisture detection and location sensor is described. The sensor includes four parallel conductors laminated to a dielectric substrate. Two of the conductors are protected by a water pervious dielectric layer and form the water-sensing element. Two other conductors are covered by a water impervious dielectric layer and are used to loop-back one or more of the water-sensing conductors. Precise location of a water leak location is determined by connecting the four conductors to a resistance bridge. The design allows for the connection of a four-conductor cable to extend the monitoring and detection point to a convenient location without loss of location accuracy.

An apparatus comprises a test signal generator (401) which generates an ultrasonic test signal by modulating an audio band test signal on an ultrasonic signal. The ultrasonic test signal is radiated from a parametric loudspeaker (403) and is demodulated by non-linearities in the air. A reflected audio signal may arise from reflections of an object, such as a wall. An audio band sensor (405) generates an audio band captured signal which comprises the demodulated reflected audio band signal. A distance circuit (407) then generates a distance estimate for the distance from the parametric loudspeaker (403) to the object in response to a comparison of the audio band captured signal and the audio band test signal. Specifically two signals may be correlated to determine a delay corresponding to the full path length. Based on the distance estimates an audio environment may be estimated and a sound system may be adapted accordingly.

The invention discloses a dynamic positioning method and device based on UWB and laser ranging combination and belongs to dynamic positioning methods and devices. The dynamic positioning device comprises an ultra-wide band (UWB) wireless communication sensors, a UWB positioning label, laser ranging sensors, an upper computer and a POE interchanger. An ultra-wide band (UWB) wireless communication sensor station is arranged in an area to be detected, the laser ranging sensors are installed on and fixed to the ultra-wide band (UWB) wireless communication sensors, the UWB positioning label is fixed to a target to be detected, and the ultra-wide band (UWB) wireless communication sensors and the laser ranging sensors are connected with the upper computer through the POE interchanger. According to the dynamic positioning method and device based on the UWB and laser ranging combination, the laser ranging sensors are arranged on the ultra-wide band (UWB) wireless communication sensors respectively, so that the relative distance between every two adjacent ultra-wide band (UWB) wireless communication sensors is obtained, in this way, the coordinates of the ultra-wide band (UWB) wireless communication sensors can be re-determined or corrected after the ultra-wide band (UWB) wireless communication sensors are moved, and thus the requirement for dynamic positioning is met. The dynamic positioning method and device based on the UWB and laser ranging combination have the advantages that the dynamic positioning method based on the UWB and laser ranging combination is adopted, positioning is accurate, safety and reliability are guaranteed, installation is easy, and operation is convenient.

The invention belongs to navigation methods and particularly relates to a method for combined navigation of an inertia/visual odometer/laser radar. The method comprises (1) state model establishment, (2) visual odometer speed measurement based on characteristic information, (3) establishment of a measurement equation and obtaining of a measurement value, (4) Kalman filtering and (5) system error correction. The method has the advantages that a machine vision autonomous navigation technology is used, a monocular camera can measure a vector speed under the conditions of a known distance through the difference of a front frame image and a rear frame image, the laser radar can accurately measure the distance of an observation point and then measure a vector speed, navigation is performed by utilizing combination of the speed obtained through measurement and an inertial reference speed, and high-accuracy navigation is performed finally under the conditions of no outside reference information.

The application discloses a method for measuring distance of double-camera. The method comprises the following steps: simultaneously obtaining an image of a target object through the two cameras when a mobile apparatus is used for measuring distance, when receiving a target point on an input image obtained by a camera, determining a position of an imaging point of the target point on the image obtained by other camera so as to compute the distance from the target object to the mobile apparatus. Based on the same inventive concept, the application further provides a device for accurately measuring the distance from the mobile apparatus to the target object.

A method for detecting an intruder in a protected space that uses a microwave frequency sensor to determine an accurate distance measurement to the intruder. The accurate distance measurement reduces the false alarms typically associated with microwave frequency sensors due to motion outside the protected space and vibration within the protected space. The motion detector transmits three microwave frequency signals of different frequencies in order to eliminate an ambiguity problem when determining the accurate distance measurement. The accuracy of the intruder distance measurement may be determined with greater resolution by reiteratively transmitting and evaluating microwave frequency signals of different frequencies. The motion detector of the present invention may include a PIR sensor. The accurate distance measurement allows the motion detector to precisely set signal threshold levels for the microwave frequency detector and the passive infrared detector to reliably detect an intruder while discriminating against an animal or other moving object.

An echo-signal monitoring device having a plurality of transceiver units for transmitting signals and receiving the echoes reflected by an external object and an analyzer unit for estimating the distance from the monitoring device to the external object on the basis of the received echoes is characterized in that the device has an operating mode for calculating the relative position of the transceiver units from one another on the basis of the reflected echoes.

A cooperative adaptive lighting system for motor vehicles in which a vehicle transmits its geographic coordinates and receives similar coordinates from other vehicles, pedestrians, and stationary warning devices. Using the coordinates, the vehicle computes distances, and relative position more specifically, to those entities. When the distances become sufficiently small, indicating that the entities fall within headlight range, the vehicle alters its headlight beams to either (1) throw more light on an entity, (2) reduce light reaching the entity as appropriate, or (3) change a lighting pattern as appropriate.

A display apparatus is provided which, when projecting a video onto a curved surface of an object for display, can realize an undistorted display of the video. The measuring means outputs the distance information representing the distance to the object. Based on the distance information produced by the measuring means, the curved surface contour is detected with high precision. According to at least the detected curved surface contour distortions, pixels of the display image are unevenly rearranged to correct the video information before it is output. This arrangement realizes an undistorted display of video when the video is projected onto the curved surface of the object.