213results about How to "Isolate interference" patented technology

The invention provides an embedded satellite configuration. The embedded satellite configuration comprises a platform cabin, a loading cabin, a docking locking-unlocking mechanism, a non-contact magnetic suspension direct force control mechanism and a solar cell array. The platform cabin is in a hollow annular structure; the loading cabin is arranged in the platform cabin; the docking locking-unlocking mechanism and the non-contact magnetic suspension direct force control mechanism are arranged between the platform cabin and the loading cabin respectively; the solar cell array is arranged on the side of the platform cabin. Ultrahigh-precision ultrahigh-stability control requirements of satellites are met, quality characteristics and agile mobility performances of the satellites are improved, a loading space environment is improved, and influences of platform disturbance and thermal cycling on satellite loading are reduced. According to a design conception of non-contact split design and centralized control, the embedded satellite configuration has advantages of structural configuration compactness, high control precision, high environmental adaptability, low development risk, short cycle and simplicity and feasibility in integration and final assembly.

The invention provides a vibration monitoring system and a signal processing method based on LFMCW (Linear Frequency Modulation Continuous Wave) radar. The vibration monitoring system comprises a radar transceiver, a tuned signal generator, a data collection module, a signal processing module, and a display and analysis module. The signal processing method comprises the following steps: step one,capturing effective baseband beat signals within each frequency sweep period, and generating composite beat signals; step two, estimating the beat frequency; step three, carrying out phase estimationthrough an algorithm similar to maximum likelihood estimate; step four, carrying out phase jump correction on an estimated initial phase time sequence; and step five, extracting vibration displacementtime domain information. The LFMCW radar is utilized to conduct non-contact type vibration movement sensing, vibration displacement time domain information is extracted by accurately estimating the initial phase of the beat signals within each frequency sweep period, and vibration monitoring requirements for target objects in an extreme environment and from a medium or short distance are satisfied.

The invention discloses an alternating current-direct current micro-grid system on the basis of an electricity energy collector. The alternating current-direct current micro-grid system comprises a power distribution network, a power distribution transformer, a distributed power source, distributed energy storage and loads which are sequentially connected with one another. The electricity energy collector is arranged among the loads, the distributed power source, the distributed energy storage and the transformer and is connected with an alternating-current 400V bus on a low-voltage side of the power distribution transformer by a point of common coupling (PCC) of a micro-grid. The alternating current-direct current micro-grid system has the advantages that the flexible all-controllable electricity energy collector is based on power electronic technologies, the micro-grid system on the basis of the power energy collector has electricity energy collector unified management and grid connection functions, direct-current and alternating-current circuits can be constructed in a unified manner, the quality of electric energy can be controlled in a unified manner, plug-and-play access of the distributed power source can be facilitated, and the alternating current-direct current micro-grid system brings convenience for unified coordination management and efficiency improvement.

The invention relates to a method for detecting abnormity of a zero line of an electric quantity metering device, which comprises the following steps: (1) measuring a phase-to-phase voltage included angle value and a voltage effective value of each phase of the electric quantity metering device; (b) calculating a voltage imbalance value of the electric quantity metering device according to the voltage effective value; and (c) generating abnormal signals existing in the electric quantity metering device when the phase-to-phase voltage included angle value is not within a normal range and the voltage imbalance value reaches a stated threshold value. The method and the device can accurately detect the electricity stealing behavior of applying interference to the electric quantity metering device, adopt the measures such as recording interference events or temporarily cutting off the zero line to sample and the like when the interference exists, and protect the legal interests of a power company.

The invention discloses an in-hole seismic probe, a surrounding rock detection device and a detection method. The in-hole seismic probe comprises a seismic source device and at least two signal receiving devices connected in sequence, wherein the seismic source device is located at the front end of the in-hole seismic probe; each signal receiving device comprises a carrier, at least one sensor core, at least one pinning coupling device, a seismic isolation device and at least one sound insulation device; all carriers of the signal receiving devices are lined up; the outer wall of each carrier is provided with at least one pinning coupling device; the adjacent two carriers are connected via the seismic isolation device; each carrier is internally provided with at least one sensor core; and the sensor cores in each carrier are covered with at least one sound insulation device. The in-hole seismic probe of the invention has the beneficial effect that portability is realized; multi-angle drilling self coupling is realized; the seismic wave data have a high signal-to-noise ratio; and a seismic exploration technique can be used for forming a wave velocity result, a frequency curve, a surface wave testing result, reflection and scattering profiles and the like.

The invention discloses a touch panel and a touch display device, and the touch panel comprises a first type of touch electrodes which are connected with a first signal line and a second signal line;between the first type of touch electrodes and the driving module, the second signal line comprises a first part and a second part which are insulated from each other; A first part of a second signalline is connected in parallel with a first signal line connected with a first type of touch electrodes, the abrupt change of the first signal lines connected with the two adjacent touch electrodes canbe effectively relieved, so that the problem of non-uniform display of each area of the touch panel can be relieved, and in addition, by floating the second parts of the second signal lines, interference between the adjacent first signal lines can be effectively isolated.

The invention discloses an anti-sliding texture detector for a highway surface. The detector comprises a box body, a traction apparatus, a traction hook, a shock absorber, detection components, a processor, a flat-panel display, a front guide wheel and a rear axle system, wherein the traction apparatus of the detector is hinged with the box body; the traction hook can be installed according to the traction requirements; the bottom of the box body of the detector is provided with the front guide wheel and the rear axle system; the rear axle system can be divided into a dual-wheel system and a multi-wheel system according to the quantity of the detection components. Vibration response generated by rigid universal rolling wheels of the detection components during rolling on the road surface is received by an electric vibration sensor which is connected with the detection components via bolts, and is transmitted to the processor through a signal line; the processor can convert a vibration spectrum in the vibration signal into a road-surface texture spectrum, calculates and stores the structure depth and structure density parameters; the friction coefficient is calculated by combining with the micro structure depth of coarse aggregate detected by an indoor test. Therefore, the anti-sliding texture detector is convenient to operate, stable in performance and low in construction cost, and a new choice is provided for highway engineering testing personnel.

The invention discloses a chip design method for a multi-chip module of a high-performance processor with an optical interface so as to solve the problems of the hybrid integration of the optical interface pin based on an MT locating pin with the pin of ball grid array (BGA) of a high-speed electrical interface of the high-performance processor, and the hybrid integration of a high-speed digital circuit with an analog circuit. The invention has the technical scheme that a photoelectric conversion chip substrate and a microprocessor chip substrate PCB are firstly made; a photoelectric conversion bare chip and the photoelectric conversion chip substrate PCB are integrated after testing; then multiple chips are assembled; the microprocessor chip substrate PCB with the multiple chips is encapsulated, thus obtaining an MCM chip; and at last the MCM chip is tested. The invention solves the problem of the hybrid integration of optical and electrical pins, devices and circuits. A chip for the multi-chip module of a high-performance processor can be designed and has high electromagnetic interference resistance and favorable signal transmission characteristic.

The invention discloses an electric power collector system for an alternating-current and direct-current microgrid. The system comprises a power electronic solid-state module, a monitoring module, an information processing module, an intelligent control module, a communication module, an energy storage module and an electric energy interface module. The communication module and the electric energy interface module are respectively connected with the power electronic solid-state module; the intelligent control module, the monitoring module and the information processing module are respectively connected with the communication module; the other end of the monitoring module is connected with the information processing module. By adoption of the technical scheme, a structure and a control process of distributed power source access equipment are greatly simplified, energy exchange and grid connection of the microgrid and a power distribution network are managed in a unified manner by the electric power collector system, integral control is realized, faults and interference between the microgrid and the power distribution network can be isolated completely, and unified control of power quality is realized.

The invention provides an electronic device containing a planar inverted F antenna with dual parasitic elements. The planar inverted F antenna comprises an antenna body, a grounding element, a low-frequency parasitic portion, and a high-frequency parasitic portion. The antenna body comprises a high-frequency radiation portion, a low-frequency radiation portion, and a connection portion. The high-frequency radiation portion and the low-frequency radiation portion are extended along opposite directions. The connection portion comprises a first end, a second end, and a feed-in point. The first end is coupled to a joint of the high-frequency radiation portion and the low-frequency radiation portion. The second end is coupled to the grounding element. The feed-in point is used for receiving a signal input. The grounding element is connected with the second end of the connection portion of the antenna body. The low-frequency parasitic portion is extended from the grounding element and is adjacent to the high-frequency radiation portion of the antenna body. The high-frequency parasitic portion extended from the grounding element is arranged between the antenna body and the low-frequency parasitic portion and is adjacent to the connection portion and the high-frequency radiation portion of the antenna body.

The invention discloses a thyristor breakover voltage drop measurement system and method. The thyristor breakover voltage drop measurement system comprises a constant current source auxiliary branch circuit, a main discharge circuit, a signal control unit and a measurement result displaying unit, wherein the constant current source auxiliary branch circuit is connected to the two ends of a thyristor to be measured in parallel, and the thyristor to be measured is both in a direct-current constant-current breakover state before or after pulse large current of the main discharge circuit flows across the thyristor to be measured. The measurement method is based on the measurement system, in order to solve the problem that the voltage of the thyristor can not be accurately measured when junction temperature is measured through a thermal sensitive parameter method, the direct-current constant current source auxiliary branch circuit is connected to the two ends of the thyristor to be measured in parallel, the thyristor to be measured is both in the direct-current constant-current breakover state before or after pulse large current of the main discharge circuit flows across the thyristor to be measured, the situation that breakover voltage drop of the thyristor to be measured is covered by blocking voltage of the two ends of the thyristor is avoided, and therefore accuracy of the breakover voltage drop measurement result of the thyristor is guaranteed.

The invention discloses a wheel speed sensing signal processing circuit and an automobile ABS (Anti-lock Braking System). The circuit comprises a resistor, a low pass filter, an amplitude limiting unit, a differential amplifier and a hysteresis shaping unit. One end of the resistor is connected with wheel speed sensing signals, and the other end of the resistor is grounded; the low pass filter receives the wheel speed sensing signals, filters out high frequency interference signals, and outputs first voltage signals; the amplitude limiting unit automatically adjusts the conduction slope according to the wheel speed sensing signals, so that high level signals of the wheel speed sensing signals are clamped on the preset direct current high level and low level signals of the wheel speed sensing signals are clamped on the preset direct current low level; the differential amplifier receives the wheel speed sensing signals and the first voltage signals passing the resistor, removes same-frequency interference signals and outputs second voltage signals; the hysteresis shaping unit receives the second voltage signals, performs hysteresis comparison with reference levels and outputs square wave signals. The circuit is novel in structure design, the anti-interference ability of the system can be effectively improved, and the wheel speed sensing signals can be processed more accurately.

The invention discloses a double-flame-retardant power cable for fire fighting, comprises a first cable and a second cable, one side of the first cable is provided with the second cable, the tail endsof the first cable and the second cable are provided with interfaces, and the outer parts of the first cable and the second cable are connected with a pull mechanism in a clamping manner, the insideof the first cable is provided with a sheath, and a mineral fire-insulation layer. The double-flame-retardant power cable has a good flame-retardant effect, when the first cable and the second cable are used in case of a fire-fighting fire danger, due to the functions of the mineral fire-insulation layer and a ceramic fiber refractory layer, The first cable and the second cable can be prevented from being burned, and the pulling mechanism is arranged for facilitating pulling the first cable and the second cable by a user, thereby realizing the pulling work of the first cable and the second cable at the same time, facilitating the use, and the shielding layer arranged, which can isolate the interference of external signals to the first cable and the second cable, thereby ensuring the normaloperation of the first cable and the second cable.

The invention relates to a broadband annular oscillator. Inverters of single end structure are currently used as the delay units of the broadband annular oscillator, wherein the delay units are subject to the interference of substrate coupling noise. The broadband annular oscillator of the invention comprises a voltage offset unit, a buffer unit, and four delay units connected in series. A phase shift of 180 degrees is realized from the input terminal of the first delay unit to the output terminal of the fourth delay unit. The input terminal of the voltage offset unit is connected to external input signals. The PMOS voltage offset terminals of the four delay units is connected to the PMOS voltage offset terminal of the voltage offset unit. The NMOS voltage offset terminals of the four delay units and the voltage offset terminal of the buffer unit are connected to the NMOS voltage offset terminal of the voltage offset unit. The in-phase output terminal of the buffer unit is used as an in-phase clock output pin, and the anti-phase output terminal of the buffer unit is used as an anti-phase clock output pin. According to the invention, the interference from a voltage offset circuit on the frequency of the oscillator is isolated, low-jitter clock signal outputting can be realized, and a multiprotocol multiterminal communication requirement can be satisfied.

The invention relates to an indoor agricultural unmanned aerial vehicle test platform. The indoor agricultural unmanned aerial vehicle test platform comprises an unmanned aerial vehicle, a parallel four-bar linkage, a movable trolley, a guide rail and a load-bearing platform; the unmanned aerial vehicle which flies horizontally is installed on the load-bearing platform; the load-bearing platform is installed on the parallel four-bar linkage; the parallel four-bar linkage is installed on the movable trolley; and the movable trolley is movably installed on the guide rail. The parallel four-bar linkage comprises an upper rotating rod, a lower rotating rod, a vertical fixed rod and a vertical lifting rod; the upper rotating rod is rotationally installed on the fixed rod and the lifting rod; one end of the lower rotating rod is rotationally installed on the fixed rod, and the other end of the lower rotating rod is rotationally installed on the lifting rod; and the fixed rod is installed on the movable trolley. The indoor agricultural unmanned aerial vehicle test platform can reliably and precisely test the unmanned aerial vehicle and belongs to the technical field of agricultural aviation.

The invention discloses a lithium battery cavity negative pressure formation method and an apparatus. The method comprises the following steps: 1) placing a battery core, for which liquid injection iscompleted, into a charging and discharging formation device; 2) turning on a vacuum valve, starting to vacuumize; 3) performing formation charging; 4) after completing formation charging, turning offthe vacuum valve, and breaking a vacuum state through inert gas; 5) taking out the battery from the charging and discharging device, namely, obtaining the needed lithium battery which is subjected tonegative pressure formation. The apparatus comprises a support apparatus, a needle plate component, a driving air cylinder, a tray and a control apparatus. The method and the apparatus provided by the invention have the following beneficial effects: negative pressure requirements of the lithium batteries of various forms can be guaranteed, alignment of battery liquid injection holes is not needed, moreover, a negative pressure pipeline is not directly contacted with the battery, and pollution to the battery caused by electrolyte of the previous batch is avoided. The cavity is sealed through aspecial seal groove design, tightness is better, negative pressure effect can be better, work time of a negative pressure pump is reduced, and an effect of saving energy and reducing emission is realized.

The invention discloses a phased array radar decoupling method. The method comprises the following steps: acquiring radar attitude information including a yaw angle psi n, an elevation angle and a roll angle gamma n in real time; acquiring a coordinate value of a target in an inertial rectangular coordinate system; carrying out coordinate transformation on the coordinate value of the target in theinertial rectangular coordinate system to obtain a coordinate value of the target in a rectangular coordinate system of an antenna array surface; and acquiring an antenna wave-control off-axis angletheta and a yaw angle phi according to the coordinate value of the target in the rectangular coordinate system of the antenna array surface. On the basis of the characteristics of beam pointing controllability of the phased array antenna, the external interference information is transformed in the phased-array antenna array coordinate system for open loop compensation; and the beam pointing angelof the phased array antenna is updated by using the compensated beam pointing angle.

The invention relates to a performance testing device for a sealing gasket under a high pressure and low temperature environment. The device comprises a test cavity, a liquid nitrogen refrigeration system, an electric heating temperature control system, a pressure adjustment system, a vacuum system, a data acquisition system and a visual observation system. The device provided by the invention cancontrol the temperature and pressure of a system in a wide range, and can realize the sealing performance test of the sealing gasket in the test pressure of 0 to 5 MPa and a temperature control rangeof -160 DEG C to +80 DEG C.

The invention discloses an adhesion-based bistable acceleration sensing micro-switch, which belongs to the field of micro-electronic components and mainly solves the problems of 'error off' and 'transient close' of the prior micro-switch. The micro-switch comprises a sensing mass block (34), a bearing beam (35) and a framework (32), wherein two ends of the bearing beam are fixed on the framework; the upper surface and the lower surface of the framework are fixed with an upper top cover (31) and a lower bottom cover (33) respectively; the distance between the mass block and the upper top cover is controlled to be between 0.1 and 1 mu m; the lower part of the mass block (34) is deposited with a gold film to form a movable pole plate (35); the inner side of the lower bottom cover is deposited with a gold film to form a fixed pole plate (38); and the movable pole plate is provided with two semi-spherical structural contacts (37). When the micro-switch is in an 'on' state, the mass block (34) is tightly adhered to the upper top cover (31), and when the micro-switch is in an 'off' state, the mass block (34) is tightly adhered to the lower bottom cover (33). The micro-switch has the advantages of strong anti-interference and stable conduction, and can be applied to the fields of vehicle safety air bags, anti-locking systems and household appliance triggering.

The invention discloses a full-closed type light trap sensing control unit and a manufacturing method therefor. The control unit comprises a cube micro-cavity for storing particles, a PDMS (polydimethylsiloxane) substrate with a common single-mode optical fiber channel, and a glass substrate for sealing. The glass substrate is provided with mark lines, and the mark lines are used for indicating the position of the center of a light trap and guaranteeing the relative position of the cube micro-cavity and the center of the light trap. The manufacturing method comprises the steps: the assembly of a square capillary tube, the preparation of the PDMS substrate, and the overall packaging. The control unit limits the movement range of particles through the micro-cavity, improves the capturing efficiency of particles, and isolates the external pollution and impact through the full-closed design.

The invention discloses a wireless monitoring terminal with a storage battery. The monitoring terminal comprises a micro-controller, a storage battery power supply module, a storage battery anti-reversal connection module, a data acquisition module and a wireless communication module. The storage battery power supply module provides power for the micro-controller, and the storage battery anti-reversal connection module, the data acquisition module and the wireless communication module are connected with the micro-controller respectively. The wireless monitoring terminal with the storage battery has the advantages that the structure is compact, the practicability is high, the application range is wide, and good promotion and usage values are provided.

The invention discloses a low-temperature air-cooled heat exchanger performance detection testbed. The testbed comprises a reverse flow type wind tunnel, a temperature and humidity adjusting assembly,a refrigeration unit and a control cabinet, wherein the temperature and humidity adjusting assembly and the refrigeration unit realize the high-precision adjustment of wind speed, temperature and humidity in the wind tunnel under the control of the control cabinet. The testbed has the advantages of being large in temperature, humidity and wind speed adjusting range and high in control precision,is suitable for the environment with low temperature, low humidity and large concentration, and is particularly suitable for researching the heat exchanger performance under frosting conditions.

To realize stable supply and measurement of micro flow, the invention provides a micro flow supply measuring device. The device comprises a constant pressure unit, a supply unit and a measuring unit;the constant pressure unit comprises an automatic pressure regulating device and a constant pressure balancing container; the inlet of the constant pressure balance container is connected with an airsource through the automatic pressure regulating device, and the outlet of the constant pressure balance container is connected with the supply unit; the supply unit comprises a propellant supply container, an electronic scale, a first vibration damping assembly and a supply pipeline, wherein the inlet of the propellant supply container is connected with the outlet of the constant pressure balancecontainer, and the outlet of the propellant supply container is connected with the measuring unit through the supply pipeline; the electronic scale is arranged below the propellant supply container,and the first vibration damping assembly is arranged below the electronic scale; the measuring unit comprises a first capillary tube, a mass flow meter, a second capillary tube and a measuring pipeline, the first capillary tube, the mass flow meter, the second capillary tube and the measuring pipeline are connected in sequence, and a second filter, a second pneumatic control valve and a pneumaticdischarge valve are arranged on the measuring pipeline; and the inlet of the first capillary tube is connected to the supply pipeline.

The invention provides a device and a method for detecting the quality of a filter. A positioning block is connected to the lower part of a rotating shaft. The rotating shaft can be driven by a firstdriving mechanism to move up and down, and can be driven to rotate by a second driving mechanism. A tap is located below a first through hole, can be moved by the first driving mechanism, and enters the oil outlet hole of the filter after passing through the first through hole and a second through hole in sequence. A sliding block can move up and down synchronously along with the tap, and a pressure sensor is arranged right above the sliding block. The sliding block abuts against the pressure sensor when the tap completely enters the oil outlet hole of the filter; a gas hood is sleeved on theperiphery of the rotating shaft, and the air pressure sensor is connected to the inside of the gas hood; an air pump communicates with the first through hole through a gas supply pipe, and an air outlet of the air supply pipe is located above an electrically controllable valve; the gas hood abuts against a rotary table when a pressing block abuts against the filter on the rotary table. The devicecan perform the detection of the thread quality and the detection of the sealing performance on the filter, is low in the detection cost of the filter, and is accurate and reliable in the detection result.

The invention discloses a micro-dynamic accurate regulation control system which comprises a micro-dynamic device and a micro-dynamic control system. The micro-dynamic device comprises a magnetic circuit I composed of a giant magnetostrictive sheet, a permanent magnet, a static yoke I and a static yoke II, and a magnetic circuit II composed of a permanent magnet, a static yoke I, a static yoke II and a movable yoke. An air gap is formed in the magnetic circuit II. The magnetic circuit I and the magnetic circuit II are respectively provided with a magnetism regulation device. A piezoelectric ceramic sheet is arranged on the giant magnetostrictive sheet of the magnetic circuit I. The movable yoke of the magnetic circuit II is fixed through a ball screw lifting table driven by a stepping motor. The micro-dynamic control system comprises a sensor set, a signal amplifier, a signal comprehensive analysis controller, a computer, a signal generator, a power amplifier, a digital-to-analog converter and a driving power source, wherein the signal amplifier, the signal comprehensive analysis controller, the computer, the signal generator, the power amplifier, the digital-to-analog converter and the driving power source are sequentially in signal connection. The signal amplifier is connected with the sensor set. The driving power source is electrically connected with the piezoelectric ceramic sheet. The signal comprehensive analysis controller is connected with the stepping motor through a stepping motor driver.

The invention relates to a double-body type case electric connector, which consists of a plug and a socket, wherein the plug comprises a case A, a case B, an insulation base and a contact element, wherein the two cases are fixedly connected, a flange of the insulation base is clamped with grooves formed in the case A and the case B, the contact element is arranged in the insulation base, the socket comprises a case, a base and contact elements, a shielding base is arranged on the outer surface of the insulation base of the plug, the shielding base surrounds the insulation base for forming a Ferrari cage structure, all of the contact elements are staggered and arranged at both sides of the base, and an airflow passage is preserved in the middle. The connector of the invention has the advantages of simple structure, strong electromagnetic shielding effect, effective insulation of electric field and electromagnetic wave interference inside and outside the cage body and good heat radiation performance, is applicable to special connector fixing occasions, and has stronger practicability.

The invention proposes an active vibration isolation system for an actuator test bench based on piezoelectric ceramics, and the system is used for the actuator test bench, and can effectively preventsvarious types of external vibration line spectrums from affecting a measurement result. The system comprises a piezoelectric ceramic actuator, a driver, a feedback sensor, a signal conditioner, and acontroller. The output force of the system is greater than 4000N through employing the piezoelectric ceramic actuator, and the displacement is small, so the system meets the control demands of smalldisplacement of an actuator measurement platform and the 4000N output force of the actuator. The system can be used for eliminating the external interference of more than eight line spectrums (20Hz-200Hz). The line spectrum vibration effect is greater than 15dB, and the precision can meet the requirement of the product quality verification of an electromagnetic actuator of an active vibration isolation device.

The invention relates to an AD7982 based single-battery voltage measuring device for a storage battery pack, and belongs to the technical field of batteries. 12 groups of difference converting single-end signal circuit measuring units, an A / D conversion unit and a display unit are included. Each difference converting single-end signal circuit measuring unit comprises a difference amplification circuit and a voltage follower, and the difference amplification circuits take AD7982 as a control chip. The display unit comprises a DAC and a display screen. The signal input ends of the difference amplification circuits of the difference measuring units are connected with the single battery, the signal output ends of the difference amplification circuits are connected with the voltage followers respectively, the voltage followers of the 12 groups of difference converting single-end signal circuit measuring units are connected to pins of the A / D converter, and the A / D converter is connected with the display unit. The single-battery voltage of the storage battery pack is measured by using a differential mode method, errors of voltage data do not accumulate, the measuring precision is high, the system uses the voltage followers, and external interference can be isolated.

The invention discloses an intelligent crib which comprises a bed body, a bed plate and light shielding devices arranged above the bed body, wherein guard bars are arranged on the two sides of the bed body; arc-shaped windows are respectively formed in the positions on the two sides of the bed body; the bed body comprises an outside bed frame and an inside bed frame which are connected with each other; the bed plate is arranged in an area formed by the inside bed frame; the guard bars are arranged between the outside bed frame and the inside bed frame; the light shielding devices are located on the outside bed frame on the outer side of the guard bars and are located in the arc-shaped windows; the light shielding devices after being unfolded are in closed connection with the two ends of the outside bed frame. According to the invention, the arc-shaped windows are respectively formed on the two sides of the bed body, the light shielding devices are arranged in the arc-shaped windows, and the light shielding devices after being unfolded are in arc-shaped connection with the two ends of the outside bed frame through light shielding cloth, so that the positions above and on the two sides of the bed body are kept out of light, blue light is prevented from entering the bed body from the two sides, the interference caused by the blue light can be effectively avoided when an infant is sleeping or playing and the healthy growth of the infant is benefited.

The invention discloses an integrated differential quartz vibrating beam accelerometer on the basis of a folding beam structure. A metal electrode is plated on a vibrating beam; one end of the vibrating beam is connected with a mass block; the other end of the vibrating beam is connected with a fixed frame; four corners of the mass block are respectively connected with the fixed frame by four folding beams; the fixed frame is connected with an isolation frame by one connecting arm; the isolation frame is connected with a mounting frame into one whole through the other connecting arm. The vibrating beam is separated from the mass block by two cavities; both the left and right sides of the mass block are separated from the fixed frame by cavities; the folding beams are separated from the upper and lower parts of the mass block and the fixed frame by cavities; and the fixed frame is separated from the isolation frame by a cavity. The accelerometer is obtained after the configuration cavities on a quartz substrate are removed by adopting a conventional wet corrosion machining process. The accelerometer designed by the invention solves the problem of the measurement blind zone caused by mechanical coupling between two differential sensing heads in the prior art.