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339 results about "Active compensation" patented technology

Active compensation of streaks using spatial filtering and feedback control

What is disclosed is an image processing method to reduce streaking on a printed sheet. The method uses a negative feedback system to reduce streaking. The feedback system consists of a scanner that scans a printed sheet corrected with an error signal. The error signal is obtained from the scanned image of a previous print off the same printer and the desired output. There are a number of error signals in different positions across the process direction which adjust TRC values. The present invention makes use of a spatial filter representing the spatial frequency sensitivity of the human eye such that only differences (errors) of importance in need of correction are those which can be seen by the human eye. More specifically, a spatially distributed controller is utilized to improve sensitivity to measurement and printer noise. The printer adjusts the incoming bitmap so that each column in the image gives the same response for the same gray level. The printer sacrifices the uniformity of the responses at low and high frequencies where the eye is not responsive so that it can achieve better control at mid-frequencies where the eye is more responsive. At each iteration and for a fixed desired gray-level, the controller processes differences between desired output gray-levels and the values of the gray-levels obtained on the printed output image. A spatial filter is used to emphasize ranges of spatial frequencies critical for a human observer. Then, from these filtered differences (errors), TRC corrections to be applied to the output image are computed using simple scalar integral controllers. Advantageously, since the present invention compensates for defects introduced by lower quality components in a printer, printers can be less tightly specified.
Owner:XEROX CORP

Movable cold atom absolute gravitational acceleration sensor

ActiveCN106959473AHigh degree of freedom of light transmissionLight in massGravitational wave measurementAccelerometerAbsolute gravity
The invention discloses a movable cold atom absolute gravitational acceleration sensor, which belongs to the field of precise measurement of absolute gravitational acceleration. The sensor is composed of a vacuum unit, an optical path unit, a magnetic shielding unit, a passive vibration isolation platform, an accelerometer, an inclinometer and the like. Among them, the vacuum unit is mainly made of glass materials, and it is directly connected with the optical path unit in free space; the magnetic shielding unit is used to reduce the influence of the external magnetic field on the absolute gravity measurement; the passive vibration isolation platform is used to suppress Interference from ground vibration and noise; in addition, the accelerometer and inclinometer are mainly used for active compensation of random vibration and acquisition of vertical lines, and are assisted in absolute gravity measurement. The present invention is characterized in that the vacuum unit has a high degree of freedom for light transmission, is small in size and light in weight, and is directly connected with the optical path unit so that the measurement system is compact, stable and highly adaptable to the environment. The invention mainly solves key technical problems such as miniaturization, light weight and mobility of the cold atom absolute gravimeter.
Owner:杭州微伽量子科技有限公司

Marine dining table with six-DOF (degree of freedom) wave active compensation function and compensation method

The invention discloses a marine dining table with a six-DOF (degree of freedom) wave active compensation function and a compensation method. The marine dining table is characterized in that a rotary platform parallel to an upper platform is arranged right above the upper platform, and a table top is fixedly connected right above the rotary platform through table legs; the center of the rotary platform is connected with an upper end of a vertical transmission shaft, the lower end of the transmission shaft extends out of a center hole in the upper platform with clearance and is coaxially and fixedly connected with an output shaft of a hydraulic motor; an angle sensor is arranged the lower end of the transmission shaft, five servo cylinders are connected between the upper platform and a lower platform, one servo cylinder is vertically connected to centers of the upper platform and the lower platform, and the other four servo cylinders are uniformly arranged in the circumferential direction of the edges of the upper platform and the lower platform and are mounted in an inclined manner; the vertical servo cylinder compensates heaving motion, the four inclined servo cylinders compensate swaying motion, surging motion, heaving motion, rolling motion and pitching motion, and the hydraulic motor compensates yawing motion, therefore, one safe and stable dining table is provided when a ship is in a swinging state.
Owner:JIANGSU UNIV OF SCI & TECH

Winch heave compensation device for ocean floating drilling platform

The invention relates to a winch heave compensation device for an ocean floating drilling platform. The device comprises an active compensator and a passive compensator which are arranged on one side of a winch in parallel. The active compensator comprises a first single-rod piston cylinder with a piston rod stretching upwards and a force transducer, wherein two chambers of the first single-rod piston cylinder are connected to a hydraulic system through a three-position four-way magnetic exchange valve, and the force transducer is used for detecting force on a steel wire rope and electrically connected with a force feedback controller which controls exchange actions of the three-position four-way magnetic exchange valve. The passive compensator comprises a second single-rod piston cylinder with a piston rod stretching upwards. Tops of the piston rods of the first piston cylinder and the second piston cylinder are connected onto a movable pulley, a fixed pulley is further arranged on the drilling platform, and the steel wire rope on the winch is connected with a crown block and a traveling block after bypassing the movable pulley and the fixed pulley sequentially. According to the device, the compensation effect that active compensation and passive compensation are mutually synchronous and promoted can be achieved.
Owner:CHINA UNIV OF PETROLEUM (BEIJING)

Heave compensating control system of ocean exploration equipment and control method

The invention relates to ocean exploration equipment, which belongs to the field of ocean exploration. A heave compensating control system of the ocean exploration equipment comprises exploration equipment, a lifting truck, a guide pulley and a compensating oil cylinder, wherein the lifting truck and the exploration equipment are connected by steel wires, and the guide pulley and the compensating oil cylinder are arranged between the exploration equipment and the lifting truck, the steel wires connecting the exploration equipment and the lifting truck lead out from the lifting truck and are wound on the guide pulley and connected with the exploration equipment after being wound on the compensating oil cylinder, a steel wire tension sensor is mounted on the guide pulley, the compensating oil cylinder is connected with an energy storage device, the steel wire tension sensor transmits signals to a heave compensating controller, the heave compensating controller is connected with the lifting truck and controls the lifting truck to adjust the exploration equipment. By combining the oil cylinder and tension compensation and combining active compensation and passive compensation, the heave compensating control system is applicable to various wave conditions, energy-saving and high in efficiency, can be closer to field conditions and high in control speed due to real-time feedback.
Owner:FISHERY MACHINERY & INSTR RES INST CHINESE ACADEMY OF FISHERY SCI

Voltage control method in power system with non-effectively earthed neutral

The invention relates to a voltage control method in a power system with a non-effectively earthed neutral. Power current with adjustable amplitude value and phase position is injected in a system neutral, and three phases of voltage to earth and zero sequence voltage of the system are adjusted and controlled. The recovery degree and the recovery speed of the three phases of voltage and the zero sequence voltage can be delayed by the technology after the arc blowout of a small current grounding fault point, and enough time is provided for the insulation recovery of the fault point, so that the restriking probability is reduced, and the self-recovery (self-healing) probability of fault is improved. When the system is in normal operation, unbalanced voltage caused by the imbalance of the three phases of parameters to earth such as untransposition of circuits or incomplete transposition of the circuits is eliminated. The technology can be realized by an independent device, and also can be realized by an active compensation device platform for full electrical capacity compensation in a small current grounding fault. The voltage control method in the power system with the non-effectively earthed neutral disclosed by the invention is used as a main technical measure of a smart distribution grid, and the power quality and the self-healing level of the fault of a medium voltage distribution grid can be observably improved.
Owner:SHANDONG KEHUI POWER AUTOMATION

Intelligent power distribution network neutral point grounding active full-compensation control system

InactiveCN103715695AControl recovery speedFault self-healing in timeAc network voltage adjustmentControl powerElectric power system
The invention relates to the arc quenching and voltage stabilization technology of a power distribution network neutral point grounding fault point and particularly relates to an intelligent power distribution network neutral point grounding active full-compensation control system. The intelligent power distribution network neutral point grounding active full-compensation control system is characterized in structure by comprising a data acquisition system, a control circuit, a driving circuit, an inversion circuit, a filter circuit, an access circuit and a control power source, wherein a data acquisition end of the data acquisition system is connected with an electric power system, an output end of the data acquisition system is connected with the control circuit, a control output end of the control circuit is respectively connected with the driving circuit and the control power source, and the inversion circuit is connected with an input end of the electric power system respectively through the filter circuit and the access circuit. The system is advantaged in that a voltage recovery open loop and closed loop control method taking a dissonance degree, a damping rate, reactive compensation current and active compensation current as parameters is provided according to analysis, timely self-healing of a fault is guaranteed, moreover, the system voltage can recover to a normal state rapidly.
Owner:STATE GRID CORP OF CHINA +2

QKD system and method with improved signal-to-noise ratio

Systems and methods for performing quantum key distribution (QKD) that allow for an improved signal-to-noise ratio (SNR) when providing active compensation for differences that arise in the system's relative optical paths. The method includes generating at one QKD station (Alice) a train of quantum signals having a first wavelength and interspersing one or more strong control signals having a second wavelength in between the quantum signals. Only the quantum signals are modulated when the quantum and control signals travel over the first optical path at Alice. The quantum and control signals are sent to Bob, where only the quantum signals are modulated as both signal types travel over a second optical path at Bob. The control signals are directed to two different photodetectors by an optical splitter. The proportion of optical power detected by each photodetector represents the optical path difference between the first and second optical paths. This difference is then compensated for via a control signal sent to a path-length-adjusting element in one of the optical paths. The control signals provides a high SNR that allows for commercially viable QKD system that can operate with a high qubit rate and a small qubit error rate (QBER) in the face of real-world sources of noise.
Owner:MAGIQ TECH INC

Distributed energy grid connection and reactive compensation composite control method

The invention relates to a distributed energy grid connection and reactive compensation composite control method, which comprises the following processes of obtaining real-time grid voltage VS, system current IS and DC bus voltage Vdc through a collection module and then transmitting the real-time grid voltage VS, the system current IS and the DC bus voltage Vdc to a digital signal processor DSP; and obtaining reactive current and grid-connected current in a load through calculation, comparing the reactive current and the grid-connected current with a set adjustment target value, generating a fixed-frequency PWM pulse through a PI controller to drive an inverter power tube IGBT to be turned on and turned off, controlling output of each phase of grid-connected current and compensation current of a system, and outputting the maximum grid-connected power by the system in an active priority mode, firstly compensating the reactive current of the system in a regional reactive priority mode and providing the system with active compensation and reactive compensation in a regional balance mode. Through controlling output of each phase of grid-connected current and compensation current of the system, a distributed energy access device can be more intelligently used for a regional power grid and has the characteristic of high grid-connection efficiency.
Owner:SHANGHAI MUNICIPAL ELECTRIC POWER CO
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