221 results about "Ultra-short baseline" patented technology

The invention belongs to the technical field of navigation and provides an integrated navigation and positioning system and method for a submarine oil and gas pipe detection robot. The integrated navigation and positioning system mainly comprises a differential GPS system, an ultra-short baseline positioning system (USBL), a strapdown inertial navigation system (SINS), a Doppler log (DVL) and thelike. The differential GPS system accurately positions geographic position coordinates of a surface vessel; the ultra-short baseline positioning system determines a three-dimensional vector position of the underwater unmanned aerial vehicle relative to the water surface unmanned ship; the strapdown inertial navigation system detects the real-time course and attitude of the underwater unmanned vehicle; and the Doppler log detects the absolute running speed of the underwater unmanned vehicle. The SINS and the DVL are combined to realize short-time high-precision positioning of the underwater unmanned vehicle, and the differential GPS and the USBL are combined to realize absolute positioning of the underwater unmanned vehicle; the long-endurance and long-voyage high-precision positioning of the underwater unmanned vehicle is realized, and the accurate position information is provided. The invention further provides a combined positioning method of various navigation instruments, and a solution is provided for underwater high-precision combined navigation.

The invention discloses an underwater cultural relic integrated detection device based on an ROV platform, which includes a deck device and an underwater integrated detection device, and belongs to the technical field of marine detection. Deck installations include the mother ship, GPS system, ultra-short baseline transceiver and ROV console. The underwater detection device integrates magnetometer, multi-beam sonar, side-scan sonar, high-definition camera, shallow stratum profiler (shallow profiler) and ultra-short baseline acoustic beacon on the ROV platform. The magnetometer is used to measure the magnetic anomalies in the detection area and roughly determine the location of the underwater cultural relics. The shallow profiler is used to describe the cross-sectional structure of the underwater strata, which is used to detect the location of cultural relics buried below the mud surface. Multi-beam sonar and side-scan sonar are used to provide high-resolution underwater acoustic images, combined with high-definition cameras to detect the location of cultural relics on mud surfaces. The device of the invention integrates and fuses various sensor information, realizes the visualized and refined real-time detection of underwater cultural relics, and improves the detection efficiency of underwater cultural relics archaeological operations.

The invention provides a hybrid derivative-free expansion Kalman filter-based USBL/SINS tight combined navigation positioning method particularly applicable to positioning of underwater equipment. Thehybrid derivative-free expansion Kalman filter-based USBL/SINS tight combined navigation positioning method involves a USBL acoustic positioning system and an SINS, and combined navigation is performed by a hybrid derivative-free expansion Kalman filter (HDEKF). The method comprises the steps of firstly, obtaining a slope distance measurement value between a transponder and a hydrophone by the USBL system through calculating one-way propagation time of an ultrasonic wave signal between the transponder and the hydrophone, and obtaining an observation equation by a coordinate conversion formula; secondly, building an error state equation according to an error transfer formula of the SINS; and finally, performing hybrid derivative-free expansion Kalman filtering, performing time updating bya standard linear Kalman filter, and performing measurement updating by a derivative-free expansion filter. By the method, the navigation accuracy and the stability of the USBL/INS combined navigationsystem can be effectively improved, and the real-time calculation quantity is reduced.

An inexpensive acoustic beacon-type system suitable for the self-localization of one or more submergable secondary vehicles such as AUVs. A single beacon in a primary system periodically transmits an acoustic signal to the secondary vehicle. The acoustic signal is passively received by at least two receivers such as an AUV-mounted ultra-short baseline (USBL) array, which enables multiple vehicles to localize using just a single beacon. A controller (i) maintains time-synchronization with the primary system, (ii) develops a range estimate signal from measurements of received signals from at least two receivers and (iii) develops an azimuth-inclination estimation of likeliest angle-of-arrival of the primary signals, wherein the controller utilizes a plurality of coordinate frames to provide an estimate of secondary system location.

The invention belongs to the fields of antenna measuring technique and satellite navigation and positioning, and relates to a correction method for the absolute antenna phase center of an outdoor GNSS (Global Navigation Satellite System) receiver based on a precision mechanical arm. In view of the problem that conventional outdoor GNSS observation cannot obtain a high-precision correction model for the absolute antenna phase center of a receiver, a majority of common errors are eliminated through ultra-short baseline observation, the absolute phase center offset (PCO) of a receiver antenna and the separation of phase center variation (PCV) are realized through rapid rotation and inclination of the high-precision mechanical arm, finally the PCO is resolved through a least squares algorithm, and fitting calculation of the PCV is carried out for observation residual. According to the correction method, outdoor operation can be carried out, the correction precision of 1mm for the PCO and PCV can be reached, the correction method is suitable for accurate calibration of the PCO and PCV of the receiver capable of tracking the signals of satellite navigation systems such as a GPS (Global Positioning System), a BDS (Beidou Navigation System), a GLONASS (Global Navigation Satellite System) and Galileo, and thus the systematic measuring error caused by imprecision of the PCO and PCV of the receiver can be eliminated, and the user positioning precision is further improved.

This invention relates to a calibration method for ultra-short baseline acoustic positioning system, which comprises a main processor, a transceiver, a control unit, an ultra-short base line sound head, an underwater target transponder, a GPS system and IMU device both arranged on survey ship body above water surface. The calibration method comprises: a. stores GPS data, ship attitude data and the geometrical distance from sound head to the transponder; b. inputs to compute the transponder position and the position error from the sound head to GPS antenna; c. calls the computation to compute the navigation error for sound head; d. outputs new computer program for high-precise positioning.

A system for generating and utilizing a look-up mechanism consisting of one or more phase difference error maps, tables and/or mathematical models calculates the respective maps, tables and/or models by placing a short baseline or ultra-short baseline antenna array in a known location and known orientation, determining angles of incidence of incoming GNSS satellite signals with respect the antenna array and calculating expected carrier phase differences between respective pairs of antennas, calculating measured carrier phase differences between the respective pairs of antennas, and determining carrier phase difference errors using the expected and measured carrier phase differences. The carrier phase difference errors are then recorded in the look-up mechanism, with the maps and, as appropriate, look-up tables for the respective pairs of antennas being indexed by angles of incidence. Thereafter, the system utilizes the look-up mechanism when determining the unknown orientation of the antenna structure. For respective pairs of antennas, the system enters the look-up mechanism based on angles of incidence determined from a calculated orientation, and uses the retrieved values in the calculation of a corrected orientation, to compensate for phase distortion.

The invention discloses an underwater acoustic beacon with multiple work modes, which is underwater equipment used for positioning and navigating an underwater target, is an important component of a long baseline, a short baseline, a super-short baseline acoustic positioning and navigation system and an underwater GPS positioning system. The invention mainly comprises a signal processing board, a battery connected with the signal processing board, a transducer and a pressure sensor. The invention has multi work modes, such as an external synchronization mode, an internal synchronization mode, an inquire response mode and a test mode.

The present invention discloses an ultra short baseline extensometer, which relates to an extensometer. The present invention has the structure that one end of a baseline bar (130) is connected with a displacement sensor (110), which is connected with a first base rock (310) through a nulling device (120); the other end of the baseline bar (130) is connected with a calibrater (150) and then connected with a second base rock (320) through a fixed end (160); the displacement sensor (110) is respectively connected with a measurement and control system (200) through the calibrater (150); the displacement sensor (110) is a differential capacitance sensor (211) with an entire seal structure. The baseline of the present invention is not more than 100 cm, the resolving ability is superior to 1 is multiplied by 10 and then minus 10, the mechanical drive does not exist, the calibration is reliable; the extensometer can be arranged vertically; the volume is small, thus the extensometer is suitable for carrying, and adaptable to the flow of the forerunning effect of earthquake and the emergency monitoring; and the extensometer can be generalized to be used on a long baseline extensometer and other micro-displacement measuring devices.

A heading determination system comprises an inertial measurement unit (IMU) coupled with at least two GNSS receivers, each receiver paired with and receiving signals from a corresponding GNSS antenna, wherein the GNSS antennas are separated by an ultra-short baseline. The heading determination system receives signals broadcast by a plurality of GNSS satellites and calculates the phase difference in the signal seen among the separate GNSS antennas. Using this phase difference information, derived from comparing the signals received from a plurality of GNSS satellites, along with attitude data generated by the IMU, the heading determination system calculates a highly-accurate heading solution. A method is provided for determining a heading of a system including an IMU coupled with at least two GNSS receivers, with each receiver being paired with and receiving signals from a corresponding GNSS antenna and the antennas being separated by an ultra-short baseline.

The invention provides a strapdown inertial navigation system (SINS)/ultra short base line (USBL) phase difference tightly integrated navigation locating method based on double transponders. The SINS/USBL phase difference tightly integrated navigation locating method refers to a SINS and an USBL locating system which are mounted on an AUV; a hydrophone of the USBL system receives calibration of errors existing in fixed connection and mounting of a base array and the INS, the two transponders are laid on the seabed, and a slope distance phase observation model between the hydrophone of the USBLsystem and the transponders is built; the USBL locating system with the structure of the double transponders conducts differential processing on a slope distance phase equation on the hydrophone layer surface and the transponder layer surface; and then the slope distance phase difference equation subjected to double-layer differential processing is refined into an integrated navigation system observation equation to be filtered. The similarity errors in the USBL locating system can be effectively counteracted through a double-difference processing method, the USBL phase difference is adoptedas the observation quantity to be tightly integrated, the coordinate transformation error and the base array offset error which are caused by direct position computing of a USBL are avoided, and the precision of the AUV integrated navigation locating system can be effectively improved.

The invention belongs to the field of navigation and positioning technologies, and particularly relates to an integrated navigation device and a method for positioning an underwater towed body. The integrated navigation device comprises an ultra-short baseline acoustic positioning device, an inertial navigator and an above-water comprehensive processor; the ultra-short baseline acoustic positioning device comprises a GPS (global positioning system) device, an acoustic beacon and an ultra-short baseline primitive array; the navigation device is used on a mother ship and the underwater towed body, a perpendicular support is arranged on the mother ship, the acoustic beacon is mounted at the bottom of the support of the mother ship, the GPS device is mounted on the top of the support of the mother ship, the inertial navigator and the ultra-short baseline primitive array are mounted on the underwater towed body, the inertial navigator is connected with the ultra-short baseline primitive array, and the inertial navigator, the ultra-short baseline primitive array and the GPS device are connected with the above-water comprehensive processor. The integrated navigation device and the method have the advantages that the method cannot be affected by ambient sea noise, and the inertial navigator single can filter out acoustic positioning effects by the aid of a filter even if the single acoustic positioning effects are poor, so that the positioning stability can be kept.

The invention discloses a depth-information-based ultra-short baseline positioning system and method. The system is composed of an ultra-short baseline plane array, an underwater transponder, a strapdown inertial navigation system and a Doppler log. The ultra-short baseline plane array being a five-element cross array is installed at the bottom of a mother ship or the bottom of a surface buoy and is formed by four receiving hydrophones and one transmitting transducer. The underwater transponder is installed at an underwater mobile target carrier. The ultra-short baseline plane array and the underwater transponder are integrated with pressure sensors. According to the depth-information-based ultra-short baseline positioning system, the spatial position of the underwater transponder is calculated by using depth difference information to replace traditional slope distance information; and with combination of the Doppler compensation and fast correlation techniques of complicated wideband coding and the multi-source-information-fusion-based dynamic fast positioning technology, no time synchronization and inquiring are needed during the working process of the ultra-short baseline positioning system, so that the positioning process of the underwater mobile target is simplified greatly and requirements of low power consumption, miniaturization, and high updating rate of the positioning system are met.

The invention discloses a docking system of an unmanned ship and an AUV (Autonomous Underwater Vehicle). The docking system comprises the unmanned ship positioned on water surface and the AUV positioned under water and also comprises an ultrashort baseline positioning system for realizing positioning and preliminary docking between the unmanned ship and the AUV, and a wireless charging module forrealizing non-contact type charging between the unmanned ship and the AUV, wherein a manipulator for clamping the AUV and realizing multiple degrees of freedom of fine adjustment of the docking position is arranged at the bottom part of the unmanned ship. The docking system disclosed by the invention has the beneficial effects that by the ultrashort baseline positioning system, machine vision andthe manipulator, the docking between the unmanned ship and the AUV is realized, so that the reliability and the success ratio of docking is improved; charging endurance and data transmission are carried out after docking, so that the endurance of the AUV is improved.

The invention provides a positioning method based on a low-cost USBL-assisted SINS. The strapdown inertial navigation system (SINS) and an ultrashort base line system (USBL) are involved in the positioning method, and integrated navigation is completed through a Kalman filtering method. As an assistant navigation system, the USBL is composed of an array installed on an AUV and a single transponder arranged on the seabed. Generalized weighted quadratic correlation and position computation are sequentially carried out on signals received by the short base line array, Kalman filtering is carried out on a position computation result of the USBL and position output of the SINS, and feedback correction is carried out on the SINS according to output of a filter. By means of the positioning method, the problem of long-term error accumulation occurring when a low-cost SINS is adopted is solved; by adopting generalized weighted quadratic correlation for the USBL, time delay estimation precision and anti-noise performance are improved, the problems of complex array arrangement, correction and operation occurring when a long base line system is adopted are avoided, and meanwhile high-precision underwater positioning and navigation are guaranteed.

The invention relates to the technical field of ocean detection, in particular to a manned submersible ultra short baseline positioning system on-sea calibration test method. The manned submersible ultra short baseline positioning system on-sea calibration test method is used in the actual operation process. A mother ship is sailed to a sea area with the specific sea depth, and an instrument is started to record noise of the mother ship; then the steps including sound velocity section measurement, underwater subsurface buoy assembling and putting, transducer array installation error correction and the like are executed, and calibration parameters are reset to be initial values after an ultra short baseline positioning system is debugged to normally work; the mother ship sails in a track shaped like an Arabic numeral eight with a subsea beacon as a center, the diameter is 0.7 time of the depth, and it is required that the ship speed is smaller than 3 Kn in the sailing process; the subsea beacon is recovered. By means of the manned submersible ultra short baseline positioning system on-sea calibration test method, errors of the ultra short baseline system and all possibly-occurring conditions can be clearly recorded and analyzed, forceful guarantees are provided for sailing of a manned submersible, and hardware guarantees are provided for deep-sea detection.

The invention provides a three-measuring-point high-precision alignment calibration method for the absolute position of a submarine responder, which comprises the following steps: (1) using the single question and answer of the ultrashort baseline and the submarine responder to position the responder; (2) selecting three measuring points according to positioning result and the directional distribution property of positioning error, and positioning the submarine responder in the selected points under the guidance of the ultrashort baseline; (3) combing the coordinates of the three measuring points, listing a positioning equation based on the slope distance information measured at three times, and solving the absolute position of the submarine responder. The method can realize the high-precision calibration of the absolute position of the submarine responder. In addition, the method only requires respective single measurement at the three measuring points, thus avoiding the blindness of measuring point selection and improving working efficiency.

A GNSS receiver utilizes an antenna structure that two or more antennas that are spaced apart from their neighboring antennas by less than 1 wavelength of a GNSS satellite carrier signal of interest. The receiver calculates the orientation of the antennas directly from differences in the carrier phase angles measured at the two antennas, without resolving integer carrier cycle ambiguity.

The invention provides an underwater carrier positioning method which comprises the following specific steps: 1) equipping an inertial navigation system and an underwater acoustic ultra-short baseline positioning system to a carrier; 2) judging whether an underwater transponder exists within a range that underwater acoustic information of the underwater acoustic ultra-short baseline positioning system can reach, and if so, turning to the step 6), or otherwise, turning to the step 3); 3) the carrier releasing a buoy equipped with a GPS receiver; 4) the carrier receiving GPS signals of the buoy, and the underwater acoustic ultra-short baseline positioning system measuring position information of the buoy in an ultra-short baseline array coordinate system; 5) calculating position of the carrier in the navigation coordinate system according to the GPS signals and the position information, and carrying out calibration on the inertial navigation system; and 6) calculating the position of the carrier in the navigation coordinate system according to the position information of the underwater transponder in the navigation coordinate system and the position information thereof in the ultra-short baseline array coordinate system, and carrying out calibration on the inertial navigation system. The method realizes underwater positioning of the carrier.