Shenzhen Reolink Technology Co., Ltd.

Huawei Technologies Co., Limited

Hon Hai Precision Industry Co., Ltd.

Tencent Technology (shenzhen) Company Limited

Hong-fu Jin Precision Industry (shenzhen) Co., Ltd.

Shenzhen Baichuan Security Technology Co., Ltd.

Rui Zhou

Xiaoyu Liu

Sheng Yong

Qiang Guo

Yulong Que

Lin Zhang

Zhiqun Yang

Ming-Fu Hsu

Tao Xu

Shuai Rao

Yongqi He

Jinglong Zhu

Juhao Li

Shengling Wu

Ruishan Chen

Yaping Liu

Embodiments of an optical amplification apparatus are disclosed which include a first optical amplifier, a second optical amplifier, and a mode exchanger. The first optical amplifier is connected to an input port of the mode exchanger, and the second optical amplifier is connected to an output port of the mode exchanger. The first optical amplifier is configured to amplify optical signals carried in a plurality of transmission modes of a few-mode fiber, the plurality of transmission modes of the few-mode fiber may be grouped into N groups, each group includes two transmission modes, and N is a positive integer greater than or equal to 1. The mode exchanger is configured to exchange the two transmission modes carrying optical signals in each group. The second optical amplifier is configured to amplify the optical signals that are carried in the two transmission modes in each group and whose modes are exchanged.

Optical amplification apparatus, and mode division multiplexing system including optical amplification apparatus

This application discloses a calibration method for navigation of an UAV including a vector sensor. The calibration method includes: collecting, during a flight of the UAV, a current correction value and current data during a current measurement performed by the vector sensor; acquiring previous data during a previous measurement performed by the vector sensor; acquiring an adjustment quantity according to the current data and the previous data; acquiring a next correction value according to the current correction value and the adjustment quantity; and acquiring next original data during a next measurement performed by the vector sensor, acquiring next valid data according to the next original data and the next correction value, and controlling headings and postures of the UAV according to the next valid data. With the calibration method of this application, the next valid data Vmore closely approximated to a true value can be obtained.

UAV navigation calibration method, non-transitory computer-readable storage medium and UAV implementing the same

This application discloses a calibration method for navigation of an unmanned aerial vehicle (UAV), a non-transitory computer-readable storage medium and a UAV implementing the same. The calibration method includes: collecting, during a flight of the UAV, reference data during two measurements of a reference vector performed by a vector sensor; acquiring a zero-point offset Mof the vector sensor according to the reference data; acquiring original data Rof any vector measured by the vector sensor; acquiring valid data Vaccording to the zero-point offset Mand the original data R; and control headings and postures of the UAV according to the valid data V. With the calibration method in this application, the valid data Vis defined as a vector data acquired after a zero-point error of the original data Ris eliminated, which is more closely approximated to an actual value of a to-be-measured vector.

A communication system is provided. The communication system may include few mode fibers of at least two spans and a mode converter. The few mode fiber is configured to transmit M received mode groups, where group delays of the M mode groups during transmission in the few mode fiber are symmetrically distributed about a center. The mode converter is configured to: receive the M mode groups from the few mode fiber, perform mode group exchange between a first mode group and a second mode group in the M mode groups to obtain M exchanged mode groups, where a group delay of the first mode group and a group delay of the second mode group are symmetric about the center.

Communication system

An optical fiber filter includes a fiber core, inner cladding, and outer cladding. A refractive index of the fiber core, a refractive index of the inner cladding, and a refractive index of the outer cladding progressively decrease in sequence. The fiber core is configured to transmit at least two mutually different first optical signal modes, the inner cladding is configured to transmit at least two mutually different second optical signal modes, and at least one fiber grating is etched on the fiber core. At least part of optical power of a target first optical signal mode is coupled to only a target second optical signal mode at the fiber grating. The target first optical signal mode is one of the at least two first optical signal modes, and the target second optical signal mode is one of the at least two second optical signal modes.

Optical fiber filter and optical fiber amplifier

A range-finding method, a apparatus, a terminal system, and a computer-readable storage medium are provided. The range-finding method includes: transmitting a first check code from a transmitting terminal to a receiving terminal by using a first communication technology; transmitting a modulated signal from the transmitting terminal to the receiving terminal by using a second communication technology different from the first communication technology, where the modulated signal carries a second check code; acquiring a first moment at which the modulated signal is transmitted and a second moment at which the modulated signal is received; demodulating the second check code in the modulated signal; acquiring a range-finding confidence according to the first check code and the demodulated second check code; and acquiring a measured distance between the transmitting terminal and the receiving terminal according to the first moment, the second moment, a transmission speed of the modulated signal, and the range-finding confidence.

Range-finding method, range-finding apparatus, terminal system, and computer-readable storage medium

A monocular visual simultaneous localization and mapping (SLAM) data processing method. The SLAM data processing method comprises: obtaining rotation angular velocities and accelerations of a camera cyclically; obtaining a plurality of feature point pairs in two frames of images acquired by the camera, and obtaining pixel coordinate values of feature points in the feature point pairs, where each of the feature point pairs includes two feature points that correspond to a same feature of a same object and that are respectively in the two frames of images; obtaining to-be-selected rotation matrices and to-be-selected displacement matrices according to the pixel coordinate values; obtaining a reference rotation matrix of the camera according to the rotation angular velocities, and obtaining a reference displacement matrix of the camera according to the accelerations; and filtering the to-be-selected rotation matrices and the to-be-selected displacement matrices according to the reference rotation matrix and the reference displacement matrix.

Monocular visual simultaneous localization and mapping data processing method apparatus, terminal, and readable storage medium

A method for automatic gain adjustment based on illuminance of video content and a camera are provided. The method includes arranging a first gain value for an image sensor according to a list of preset gain values; obtaining frequency domain data using frequency domain transformation on illuminance components of the image; setting a constant percentage value and summing up the percentage of the frequency domain data accumulated from the highest signal amplitude to obtain a first high frequency information cumulative value; repeating above steps according to a preset gain value arrangement order to obtain a number of high frequency information cumulative values; and using the gain value corresponding to a maximum high frequency information cumulative value in gain adjustment for the image sensor.

Method and camera for automatic gain adjustment based on illuminance of video content

Systems and methods are provided for repairing system files. For example, a list of system files including file information of one or more first repairable system files are updated in real time; file information of a target file sent from a terminal is received; whether the target file is in need of repair is detected based on at least information associated with the list of system files; in response to the target file being in need of repair, a first repair strategy for the target file is determined based on at least information associated with a predetermined database of repair strategies and a file type of the target file; and the target file is repaired based on at least information associated with the first repair strategy.

Systems and methods for repairing system files with remotely determined repair strategy

An exemplary liquid crystal display module includes a liquid crystal display panel, a backlight unit, a bottom frame, and an upper frame. The backlight unit is positioned on the bottom frame. The upper frame is assembled on the bottom frame to fix the backlight unit in position. The upper frame includes four sidewalls, a top flange extending from the four sidewalls towards a center of the upper frame, and a plurality of supporting members defined at the inner surfaces of the sidewalls adjacent to the top flange. At least one of the supporting members is resilient. The liquid crystal display panel is held in place between the top flange and the supporting members. A method for assembling the liquid crystal display module is also provided.

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Shenzhen, China

Rui Zhou