Abstract

Disclosed is a device for compensating for motor load variations, comprising: an angle pulsation analyzer for analyzing pulsation characteristics of a rotor angle of a motor on the basis of the detected value of the rotor angle; and a speed pulsation compensator, which generates a speed pulsation compensation value for reducing pulsation of the rotor speed on the basis of the pulsation characteristics of the rotor angle that are analyzed by means of the angle pulsation analyzer.

IPC Classes  ?

• H02P 6/10 - Arrangements for controlling torque ripple, e.g. providing reduced torque ripple
• H02P 23/14 - Estimation or adaptation of motor parameters, e.g. rotor time constant, flux, speed, current or voltage
• H02P 25/098 - Arrangements for reducing torque ripple

Abstract

Provided are an acoustic Luneburg meta lens including a lens structure on the substrate or a lens structure connected to each other by connecting rods, wherein the lens structure includes a plurality of unit structures, the volume of the unit structures decreases from the center of the lens structure toward an edge thereof, and positions of the unit structures are determined by direction components of a polar coordinate system or a spherical coordinate system, and a method for designing the acoustic Luneburg meta lens.

IPC Classes  ?

• G02B 1/00 - Optical elements characterised by the material of which they are madeOptical coatings for optical elements
• G10K 11/30 - Sound-focusing or directing, e.g. scanning using refraction, e.g. acoustic lenses

Abstract

The present invention relates to an eco-friendly insulating composition for a direct current power cable, and a direct current power cable manufactured using same, the composition being effectively mixed with polypropylene and elastomer so as to exhibit high insulation and be useable under the condition of a maximum use temperature of 110℃ or higher.

IPC Classes  ?

• H01B 3/44 - Insulators or insulating bodies characterised by the insulating materialsSelection of materials for their insulating or dielectric properties mainly consisting of organic substances plasticsInsulators or insulating bodies characterised by the insulating materialsSelection of materials for their insulating or dielectric properties mainly consisting of organic substances resinsInsulators or insulating bodies characterised by the insulating materialsSelection of materials for their insulating or dielectric properties mainly consisting of organic substances waxes vinyl resinsInsulators or insulating bodies characterised by the insulating materialsSelection of materials for their insulating or dielectric properties mainly consisting of organic substances plasticsInsulators or insulating bodies characterised by the insulating materialsSelection of materials for their insulating or dielectric properties mainly consisting of organic substances resinsInsulators or insulating bodies characterised by the insulating materialsSelection of materials for their insulating or dielectric properties mainly consisting of organic substances waxes acrylic resins
• H01B 7/02 - Disposition of insulation
• H01B 7/17 - Protection against damage caused by external factors, e.g. sheaths or armouring
• H01B 9/02 - Power cables with screens or conductive layers, e.g. for avoiding large potential gradients
• H01B 13/06 - Insulating conductors or cables
• C08L 23/10 - Homopolymers or copolymers of propene
• C08L 101/00 - Compositions of unspecified macromolecular compounds

Abstract

An interfacial pressure measuring device, according to the present invention, comprises: a cable part having a mounting groove part; a mounting bar part detachably mounted on the mounting groove part; an interfacial pressure measuring sensor module part detachably mounted on the mounting bar part; and a connection member provided on the cable part so as to be in close contact with the cable part, the mounting bar part, and the interfacial pressure measuring sensor module part, wherein the interfacial pressure measuring sensor module part measures interfacial pressure that is generated as the connection member comes into close contact with the cable part, the mounting bar part, and the interfacial pressure measuring sensor module part.

IPC Classes  ?

• G01L 5/00 - Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes
• G01L 1/26 - Auxiliary measures taken, or devices used, in connection with the measurement of force, e.g. for preventing influence of transverse components of force, for preventing overload
• G01L 7/00 - Measuring the steady or quasi-steady pressure of a fluid or a fluent solid material by mechanical or fluid pressure-sensitive elements
• H02G 1/02 - Methods or apparatus specially adapted for installing, maintaining, repairing, or dismantling electric cables or lines for overhead lines or cables

Abstract

The present invention provides a frictional resistance reducing device using external air, and a stepped boat having same, the device having a simple structure and mixing external air with seawater so as to implement an air-seawater mixture having uniform microbubbles, and spraying same to the bottom of the boat. To this end, the frictional resistance reducing device (200) using external air, of the present invention, comprises: an external air inflow pipe (210); a seawater inflow pipe (220) formed at the side surface of a hull (100) of the boat; an air suction device (260); a compressed air chamber (212); an air discharge pipe (213) formed at the lower end of the compressed air chamber (212); a seawater discharge pipe (223) formed so as to communicate with the seawater inflow pipe (220) and one side surface of the air discharge pipe (213); an air-seawater mixture moving pipe (240); a mixing chamber (250) connected to the lower end of the air-seawater mixture moving pipe (240) in an eccentric state; and a spray port (251) formed so as to be connected to the mixing chamber (250) and the outside of the hull (100).

IPC Classes  ?

• B63B 1/38 - Other means for varying the inherent hydrodynamic characteristics of hulls by reducing surface friction using air bubbles or air layers
• B63B 1/04 - Hydrodynamic or hydrostatic features of hulls or of hydrofoils deriving lift mainly from water displacement with single hull

Abstract

The present invention provides an apparatus and a method for detecting a piping alignment using image information and laser sensors capable of precisely and accurately measuring and aligning the alignment of the entire pipes. The apparatus includes: a fixed plate installed on a base stage and having a reference pipe located thereon; a movable plate installed on the base stage along three axes to face the reference pipe and has an aligning pipe located thereon; a circular stage installed between the reference and aligning pipes and is configured to rotate and move along three axes so as to detect levelness and deformations of the reference and aligning pipes; a laser sensor and an imaging device installed on an upper side of the circular stage; and a controller configured to control the laser sensor and the imaging device and determine an alignment of the aligning pipe.

IPC Classes  ?

• F16L 1/10 - Accessories therefor, e.g. anchors for aligning
• G01B 11/27 - Measuring arrangements characterised by the use of optical techniques for measuring angles or tapersMeasuring arrangements characterised by the use of optical techniques for testing the alignment of axes for testing the alignment of axes
• F16L 13/02 - Welded joints
• F16L 1/235 - Apparatus for controlling the pipe during laying
• E21B 19/16 - Connecting or disconnecting pipe couplings or joints
• B21D 19/00 - Flanging or other edge treatment, e.g. of tubes

Abstract

The present invention relates to a method and a device for compensating for errors, included in a measurement current, caused by offset and scale errors in a current sensor, and the device for compensating for an error current caused by an offset can comprise: an input unit for receiving a measurement current obtained by measuring, a current of two-phases, among three phases, coming from the current sensor and leading into an alternating current motor, and for generating the remaining one-phase current on the basis of the two-phase current according to Kirchhoff's Law; an abc-αβ conversion unit for converting a three-phase measurement current into a two-phase (α and β phases) current of an α-β coordinate system; an error compensation unit for calculating an error current caused by an offset on the basis of the compensated measurement current in a d-q coordinate system and a set target current, and for subtracting the calculated error current from the two-phase current of the α-β coordinate system so as to generate a compensated measurement current to be displayed on the α-β coordinate system; and an αβ conversion unit, which converts the compensated measurement current generated from the error compensation unit and displayed in the α-β coordinate system so as to generate a compensated measurement current in the d-q coordinate system.

IPC Classes  ?

• H02P 21/14 - Estimation or adaptation of machine parameters, e.g. flux, current or voltage
• H02P 21/22 - Current control, e.g. using a current control loop
• H02P 21/00 - Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation
• H02P 27/06 - Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using DC to AC converters or inverters

Abstract

Disclosed are a three-dimensional radio measurement method for extracting radio wave propagation parameter components, and a device therefor. The present invention relates to a three-dimensional radio measurement method for extracting radio wave propagation parameter components, and a device therefor, wherein, in order to move or rotate the radio wave reception direction of a reception antenna for receiving radio waves, predetermined rotation angles and movement distances are set, and at least one rotator and at least one mover connected to the reception antenna are rotated or moved according to the set rotation angles and movement distances.

IPC Classes  ?

• H04B 17/30 - MonitoringTesting of propagation channels
• H04B 17/00 - MonitoringTesting
• H01Q 1/12 - SupportsMounting means

Abstract

The present invention provides an apparatus and a method for detecting a piping alignment using image information and laser sensors capable of precisely and accurately measuring and aligning the alignment of the entire pipes. The apparatus includes: a fixed plate installed on a base stage and having a reference pipe located thereon; a movable plate installed on the base stage along three axes to face the reference pipe and has an aligning pipe located thereon; a circular stage installed between the reference and aligning pipes and is configured to rotate and move along three axes so as to detect levelness and deformations of the reference and aligning pipes; a laser sensor and an imaging device installed on an upper side of the circular stage; and a controller configured to control the laser sensor and the imaging device and determine an alignment of the aligning pipe.

IPC Classes  ?

• F16L 1/10 - Accessories therefor, e.g. anchors for aligning
• G01B 11/27 - Measuring arrangements characterised by the use of optical techniques for measuring angles or tapersMeasuring arrangements characterised by the use of optical techniques for testing the alignment of axes for testing the alignment of axes

Abstract

A ship according to an embodiment of the present invention comprises: a hull (100); water jets (600) formed at right and left sides of a ship stern (200) and having ejection openings protruding backward, respectively; openings (610) formed at right and left sides of a ship bottom (300) to allow a fluid to flow in inlets of the right and left water jets (600) therethrough; a fluid resistance reducing part (400) formed at the central part of the ship bottom (200) and comprising multiple corrugations (410, 420) formed in the transverse direction of the ship bottom (200) in order to reduce the frictional resistance of the fluid; and a bubble generation part (500) formed in front of the fluid resistance reducing part (400) to generate a bubble and supply the bubble to the fluid resistance reducing part (400).

IPC Classes  ?

• B63B 1/34 - Other means for varying the inherent hydrodynamic characteristics of hulls by reducing surface friction
• B63B 1/38 - Other means for varying the inherent hydrodynamic characteristics of hulls by reducing surface friction using air bubbles or air layers
• B63H 11/02 - Marine propulsion by water jets the propulsive medium being ambient water

Abstract

An apparatus and method for diagnosing the state of a power cable and measuring the remaining life thereof using VLF TD measurement data, and for determining a replacement time of a power cable using a 3D matrix exhibiting reproducibility of diagnosis of the state of the power cable. The apparatus and method for diagnosing the state of a power cable and measuring the remaining life thereof according to the present invention includes a Weibull modeling unit, a distance limiting unit, a data type classifying unit, a quantity representing unit, a normalization unit, a 3D constructing unit, a risk level calculating unit, and a remaining life measuring unit.

IPC Classes  ?

• G01R 31/02 - Testing of electric apparatus, lines, or components for short-circuits, discontinuities, leakage, or incorrect line connection
• G06F 17/18 - Complex mathematical operations for evaluating statistical data
• G01R 31/12 - Testing dielectric strength or breakdown voltage
• G01R 27/26 - Measuring inductance or capacitanceMeasuring quality factor, e.g. by using the resonance methodMeasuring loss factorMeasuring dielectric constants

Abstract

The present invention relates to an apparatus for diagnosing the condition and measuring the remaining life of a power cable by using very low frequency tan delta (TD) measured data, and a method therefor, which diagnose the condition of a power cable by using a very low frequency TD signal and determine a replacement time of the power cable by using a three-dimensional matrix for implementing the reproducibility of the condition diagnosis of the power cable. Provided are the apparatus for diagnosing the condition and measuring the remaining life of a power cable by using very low frequency TD measured data, and the method therefor, according to the present invention, the apparatus comprising: a weibull modeling unit; a distance limitation unit; a data type classification unit; a quantitative expression unit; a normalization unit; a three-dimensional composition unit; a risk level calculation unit; and a remaining life measurement unit.

IPC Classes  ?

• G01R 31/12 - Testing dielectric strength or breakdown voltage

Abstract

Disclosed is a mobile robot for detecting and repairing damages of a hull, including: a mobile robot unit which includes at least one frame to which motor-driven drive wheels are installed, frame connectors which flexibly connect the frames with each other, and at least one robot electromagnet and adsorption module mounted on each of the frames, and is configured to be attached to the hull through the robot electromagnet so as to move or stop on a surface of the hull by the drive wheels; a stage unit which includes a rechargeable battery mounted therein to supply power to the mobile robot unit, and a docking module provided to dock with or separate from the mobile robot unit; and a connection line configured to be wound or unwound while receiving tension controlled by the stage unit, and electrically connected between the mobile robot unit and the stage unit.

IPC Classes  ?

• B25J 5/00 - Manipulators mounted on wheels or on carriages
• B25J 19/00 - Accessories fitted to manipulators, e.g. for monitoring, for viewingSafety devices combined with or specially adapted for use in connection with manipulators
• B25J 19/02 - Sensing devices
• G05D 1/02 - Control of position or course in two dimensions

Abstract

The present invention relates to an earthquake-proof apparatus for protecting a building against an earthquake, and more particularly, to a seismic wave dustproof wall using a buried resonant cylinder, which decreases a seismic wave at the outside of a building, instead of having to install an earthquake-proof apparatus within the building. According to the seismic wave dustproof wall using the buried resonant cylinder of the present invention, respective buildings are not independently protected, but one region over the dustproof wall is protected to reduce the intensity of an earthquake to a degree desired by a user.

IPC Classes  ?

• E04H 9/02 - Buildings, groups of buildings or shelters adapted to withstand or provide protection against abnormal external influences, e.g. war-like action, earthquake or extreme climate withstanding earthquake or sinking of ground
• E04B 1/98 - Protection against other undesired influences or dangers against vibrations or shocksProtection against other undesired influences or dangers against mechanical destruction, e.g. by air-raids