193 results about "Length variation" patented technology

A Synchronous DRAM memory test assembly that converts a normal PC or Workstation with a synchronous bus into a memory tester. The test assembly may be split into two segments: a diagnostic card and an adapter card to limit mechanical load on the system socket as well as permit varying form factors. This test assembly architecture supports memory bus speeds of 66 MHz and above, and provides easy access for a logic analyzer. The test assembly supports Registered and Unbuffered Synchronous DRAM products. The test assembly permits good and questionable synchronous modules to be compared using an external logic analyzer. It permits resolution of in-system fails that occur uniquely in system environments and may be otherwise difficult or impossible to replicate. The test assembly re-drives the system clocks with a phase lock loop (PLL) buffer to a memory module socket on the test assembly to permit timing adjustments to minimize the degradation to the system's memory bus timings due to the additional wire length and loading. The test assembly is programmable to adjust to varying bus timings such as: CAS (column address strobe) Latencies and Burst Length variations. It is designed with Field Programmable Gate Arrays (FPGAs) to allow for changes internally without modifying the test assembly.

The invention discloses a fiber bragg grating array-based phase-sensitive optical time domain reflection device and method. The device includes a light source, a laser frequency adjustment module, a modulator, an optical fiber amplifier, a circulator, a sensing optical fiber, a light detector, a data acquisition module and a data processing module; the sensing optical fiber is provided with an optical fiber array formed by a plurality of FBGs (fiber bragg grating) which are arranged equidistantly; the laser frequency adjustment module is used for frequency adjustment of continuous light emitted by the light source; the continuous light is modulated by the modulator so as to form pulsed light; the optical fiber amplifier performs power amplification on the pulsed light; the sensing optical fiber is used for receiving and transmitting the pulsed light which has been subjected to power amplification; the light detector receives scattered light and reflected light; the scattered light and reflected light are acquired by the data acquisition module; and the data processing module generates interference signal frequency response spectrum and obtains the length variation quantity of the sensing optical fiber between two adjacent FBGs through processing. With the fiber bragg grating array-based phase-sensitive optical time domain reflection device and method of the invention adopted, strain quantitative detection can be realized, and high-spatial resolution measurement can be realized based on quantitative analysis.

A clipping cover for the assembling of a bicycle handle accessories that is disposed on the front stem of a bicycle, wherein the clamp mount crown has a clamp ring at both the left and right sides of its lower extremity and an elongate tab at both the left and right sides of its upper extremity. Thus, when the stem clamp mount and clamp mount crown are utilized to secure various shaped handlebars into position, the two elongate tabs and clamp rings of the clamp mount crown respectively enable the installation of two forearm support base connecting bar assemblies and two accessory handlebars such that the connecting bars below the accessory handlebars and forearm support base are movable forward and backward to effect adjustment. As such, the clamp mount crown provides for accessory installation as well as direction and length variations according to rider requirements to achieve the best grasping posture.

An optical imaging device includes a reference scanning unit offering a high signal-to-noise ratio and capable of scanning an object rapidly. An interference optical system can be realized inexpensively. In the optical imaging device, low coherent light passed through an optical coupler and another optical coupler, irradiated from an optical scanner probe, reflected from an observed point in a living tissue, returned to the optical coupler, propagated over a fourth SM optical fiber, and routed to another optical coupler shall be referred to as sample light. Light passed through an optical length variation optical system via the optical coupler and routed to the optical coupler shall be referred to as reference light. At this time, a difference between a delay time undergone by the sample light and a delay time undergone by the reference light is proportional to a difference between an optical length for the sample light and an optical length for the reference light. When the optical length difference falls within a coherence length, the sample light and reference light interfere with each other. An interfering signal is acquired into a computer through detectors, a differential amplifier, a demodulator, and an A/D converter.

The invention discloses an anti-shaking control method for a container shore bridge hanger. When the hanger is lifted, an anti-shaking controller acquires parameters of trolley speed, trolley position, hanger lifting speed, hanger swing length and hanger swing angle acquired by corresponding sensors and converted in real time, and the anti-shaking controller compares the swing angle of the hanger with a preset value and performs the following anti-shaking control when the swing angle is greater than the preset value: the anti-shaking controller selects a control model and a swing length representative value corresponding to a judgment interval according to the judgment interval of the hanger swing length or the swing length variation, and the anti-shaking controller calculates the trolley speed regulating parameter according to the swing length representative value and the real-time acquired hanger swing angle parameter under the selected control model and then provides a speed regulating signal for a trolley travelling controller to perform trolley acceleration so as to inhibit the swing angle of the hanger to realize anti-shaking control.

The invention discloses an umbrella type wind power device which comprises an acting rope, a control cabinet, a sliding drum, an acting umbrella, a balancing device, a plurality of thin ropes and an umbrella control rope, wherein the acting rope forms a certain angle with the ground surface; the control cabinet, the sliding drum, the acting umbrella and the balancing device are connected on the acting rope in sequence from bottom to up, and the control cabinet is fixed on the acting rope and is wirelessly connected with a central controlling device; the plurality of thin ropes are connected between the umbrella type edge of the acting umbrella and the sliding drum; and the umbrella controlling rope is connected between the control cabinet and the sliding drum, and the extending length variation of the umbrella controlling rope is controlled by the control cabinet. The invention also discloses a wind power system which is realized by the umbrella type wind power device. In the invention, as the umbrella controlling rope and the acting rope are controlled separately, the control on the umbrella type wind power device is more easier, the folding and unfolding of the acting umbrella can not influence the stability of an aerial balancing system, the aerial part of the wind power system disclosed by the invention has good stability and control performance, and the stability of acting mechanical transferring power of a ground part is improved greatly.

The invention discloses digital steganography and digital extraction methods with compressed audio as a masking carrier. In a digital steganography method, the window shape of audio particle data is selected to be used as a steganography object and is switched to realize hiding of bits of secret information, and the code stream length of the compressed audio containing the secret information and the code stream length of the compressed audio containing no secret information are constant, thus the problems of code bit rate increment, document length variation and the like of the whole compressed audio due to steganography operation are avoided, and the safety of the secret information is effectively ensured; and in a digital extraction method, the window shape of the audio particle data corresponding to frame information obtained through decoding is determined, then the bits of the secret information are directly obtained according to the window shape, and because the window shape can be obtained through extraction from the frame information when the frame information of the audio particle data is decoded, the audio particle data does not require to be decoded, thus the real-time property of a secret information extraction process is effectively improved.

A deployable reflector of the invention includes connection members that bridge plural extendable structures constituting a deployable truss structure and connect portions corresponding to nodes of a buckling mode occurring in the extendable structures when a surface cable system is given tension, with portions corresponding to antinodes thereof. The surface cable system includes an internal surface cable system and a circumferential surface cable system connected to the outer circumference thereof. A cable used for the internal surface cable system is high in stiffness and small in ratio of length variation to tension variation. A cable used for the circumferential surface cable system is lower in stiffness and smaller in ratio of the tension variation to the length variation than that used for the internal surface cable system. Given tension by the deployable truss structure via the circumferential surface cable system, the internal surface cable system forms predetermined surface shape.

The invention relates to a fiber bragg grating strain sensitivity calibration device and a method. The device comprises two sensor clamping device, a gas floating guide rail, a laser interferometry system, a fiber bragg grating demodulator and the like. The fiber bragg grating sensor is fixed through the two sensor clamping devices, and is driven by a micrometric displacement drive device to be installed on the sensor clamping devices on the gas floating guide rail to enable the sensor to generate tensile or compressive strain. Sensor length variation is measured through the laser interferometry system, fiber bragg grating sensor wavelength variation read by the fiber bragg grating demodulator is compared with the compressive strain, and fiber bragg grating strain sensitivity calibration is achieved. The fiber bragg grating strain sensitivity calibration device and the method uses the gas floating guide rail to guide the stretching and compression process of the fiber bragg grating, uses the laser interferometry system to measure the length variation of the fiber bragg grating sensor, and the fiber bragg grating sensor can be calibrated accurately without damage.

A system for providing signal trigger pulses comprises an equivalent time sampling unit providing transmit and receive trigger pairs, and a control unit controlling the equivalent time sampling unit to provide pseudorandom delay length variations between the trigger pairs.

The invention provides a motion planning and control method of a parallel connection mechanical arm. The method comprises the following steps of 1, planning the expected motion track of a tail end executer of the parallel connection mechanical arm; 2, calculating a corresponding parallel mechanism arm speed layer kinematics relationship expression according to a concrete parallel connection mechanical arm parameter; 3, building an error function on the basis of the first step and the second step, and calculating the corresponding length variation rate of each driving rod through combining the kinematics; 4, transmitting the result solved in the third step to a lower computer to drive the mechanical arm to move. The method has the advantages that the problem that the parameter is difficult to determine in the prior art is solved; in addition, the tracks of the tail end executer can be effectively controlled; the operability is high; good application prospects are realized in the engineering field.

The invention provides a system for controlling the position of a lifting hook of a crane. The control system comprises a length variation detecting unit and a lifting hook lifting control unit, wherein the length variation detecting unit comprises a length judging unit and/or a command judging device; the length judging unit is used for detecting the real-time length of a telescopic arm and judging whether the acquired real-time lengths of the telescopic arm are the same or not, and confirming the length variation of the telescopic arm when the acquired real-time lengths of the telescopic arm are not the same; the command judging device is used for detecting whether the driving device receives a corresponding driving command or not, and confirming the length variation of the telescopic arm when the driving device receives the corresponding driving command; and the lifting hook lifting control unit is used for controlling the lifting of the lifting hook when the length of the telescopic arm changes, so that the lifting hook is in a pre-set safe height range. According to the other side of the invention, the invention further provides a method for controlling the position of the lifting hook of the crane as well as the crane. According to the technical scheme of the invention, the lifting hook can be adjusted intelligently according to the length of the telescopic arm, so as to improve the operation efficiency and reduce potential safety hazard during expansion and contraction processes.

A form, position and dimension measuring method of a blisk blade and a tool thereof are disclosed. The measuring method comprises the following steps: (1) taking an arc circumferential surface of blisk as a measuring reference surface, selecting any point on a blade top type surface as a measuring point, measuring a distance variation of the point relative to a normal direction of the measuring reference surface so as to obtain a position variation of a blade; (2) taking an arc end surface of the blisk as the measuring reference surface, selecting any point on the blade as the measuring point, measuring the distance variation of the point relative to an axial direction of the measuring reference surface so as to obtain a blade length variation. The invention provides the form, position and dimension measuring method of the blisk blade and the tool thereof. Intake and exhaust edge dimension change of the blade and a blade deformation situation can be real-timely monitored. Under the current condition, the real-time monitoring is performed inconveniently; a detection period is long; efficiency is low and cost is high. By using the method and the tool of the invention, the above problems can be solved.

A voltage detection terminal includes a bus bar connecting portion which is connected to a battery electrode and a bus bar by bolt-nut connection, a detector connecting portion connected to voltage detector, and an interconnecting portion interconnecting the bus bar connecting portion and the detector connecting portion. A gap for absorbing a length variation of a battery cell is formed between a plate body and the bus bar connecting portion, and a slanting portion for preventing the interconnecting portion from interference with the bus bar is formed at part of the interconnecting portion.

The invention is used in a communication system with at least two layers of retransmission control function. It comprises: deciding the length of PDU generated by an upper retransmission layer is changed; setting a length indication domain in lower retransmission control PDU; transmitting lower layer retransmission control PDU to the sending end. The invention also providing an apparatus thereof comprising: a comparison unit, a setting unit and a sending end.

The invention relates to a thermo-compensation current sensing head as well as an alternate current measurement method and a system thereof. A current sensing head is placed in a magnetic field generated by alternate current to be measured, and a fiber bragg grating FPI adhered on magnetostrictive material senses ambient temperature and magnetic induction. A light signal emitted by a monochromatic light source enters fiber bragg grating F-P cavity of a fiber bragg grating Fabry-Perot interferometer and forms a similar two beam light interference signal after interference to be output. Cavity length variation amount of the fiber bragg grating F-P cavity of the fiber bragg grating Fabry-Perot interferometer is obtained according to the two beam interference signal, and then alternate current measurement value is obtained according to the cavity length variation amount. And finally, compensation relation between current measurement value and actual value to be measured on temperature is utilized to obtain alternate current actual value. The performance of an original current sensor is improved, preparation technology is relatively simple, and simultaneous measurement of temperature and alternate current can be realized.

In sophisticated transistor elements, enhanced profile uniformity along the transistor width direction may be accomplished by using a gate material in an amorphous state, thereby reducing channeling effects and line edge roughness. In sophisticated high-k metal gate approaches, an appropriate sequence may be applied to avoid a change of the amorphous state prior to performing the critical implantation processes for forming drain and source extension regions and halo regions.