45results about How to "Ease of engineering" patented technology

The invention relates to a scissors type hexagonal-prism-shaped extensible unit and a space extensible mechanism formed by the same. The scissors type hexagonal-prism-shaped extensible unit being a single-freedom-degree over-constrained hexagonal-prism-shaped basic extensible unit comprises twelve floral discs, six groups of scissors type folding rods, and twelve groups of folding connecting rods. One group of folding connecting rods limits the extending degree of the basic extensible unit based on the connecting rod lengths and the rest of eleven groups of folding connecting rods are over-constrained folding connecting rod, so that the rigidity of the basic extensible unit is improved effectively. Multiple basic extensible unit are arranged closely and the adjacent basic extensible units can form a space extensible mechanism by sharing four floral discs, one group of scissors type folding rods and two groups of folding connecting rods; and the size of the pace extensible mechanism can be changed by changing the number of the space extensible units. The provided scissors type hexagonal-prism-shaped extensible unit has high structural symmetry; and different large-dimension space extensible mechanisms can be formed based on assembling of multiple extensible units. Therefore, the scissors type hexagonal-prism-shaped extensible unit and the space extensible mechanism are suitable for constructing a space solar battery array bracket and a satellite planar reflecting antenna.

The present invention provides a complete scissor-like double-layer annular truss extendible antenna mechanism. The mechanism comprises an inner layer annular truss component, an outer layer annular truss component and N inner and outer layer connection truss components; the inner layer annular truss component and the outer layer annular truss component both include N extending units; two common flower discs are connected between adjacent extending units; the inner and outer layer connection truss components are concentrically arranged; two upper and lower flower discs at each side of the inner layer extending units are connected with the corresponding two upper and lower outer layer flower discs at each side of the outer side layer extending units respectively through one inner and outer layer connection truss component to form a double-layer annular truss; and the distance between the length of the rod pieces at the same position of the inner and outer layer extending units and a flower disc rotation secondary axis and a center line satisfies a special proportional relation, and the ratio of the inner layer and the outer layer is (1-sin(180 / N)) / (1+sin(180 / N)). The complete scissor-like double-layer annular truss extendible antenna mechanism is high in rigidity, simple in structure and high in reliability, and can be applicable to a communication satellite, a space station and a space probe.

The invention discloses a 3R-3RSR single-degree-of-freedom tetrahedron expandable unit, which comprises a top face plate, three swing rods with equal lengths, six connecting rods, nine rotation pairs and three ball pairs, wherein the upper ends of the three swing rods are connected with the top face plate through three coplanar rotation pairs; the axis of each rotation pair is vertical to a plane which is determined by an intersection point of the upper ends of the three swing rods, a triangular circumcenter of the tetrahedron unit and the lower end point of the corresponding swing rod; the lower end of each swing rod is respectively connected with two folding rods through two rotation pairs; each folding rod comprises two connecting rods with equal lengths and one ball pair; the unit is in a completely expanded state; the axes of the rotation pairs at two ends of each folding rod are parallel to each other and are vertical to the connected line of the centers of two rotation pairs; and the unit can be folded or expanded by driving any rotation pair. The 3R-3RSR single-degree-of-freedom tetrahedron expandable unit has the advantages of being single in degree of freedom, few in hinges, simple in structure, small in folding volume and the like, and is suitable for a large-caliber truss-type expandable antenna.

The invention discloses a control method for a single-phase grid-connected inverter and a control parameter obtaining method therefor. The control method comprises the steps of collecting a power grid voltage value Ug, and inputting a phase-locked loop algorithm to obtain a phase angle <theta> of the power grid voltage; setting an amplitude value Im of a power grid reference current, and obtaining the power grid reference current Iref; enabling Iref and Ig to be subtracted obtain an error E, and enabling the obtained error E to pass through a proportional resonant controller and a harmonic compensation controller separately; enabling the output Upr of the proportional resonant controller to be added with the output Uhc of the harmonic compensation controller to obtain a sum Uab, and carrying out amplitude limiting on the obtained sum Uab to obtain a capacitive current reference value Icref of the filter; enabling the Ic and a feedback coefficient Kc to be multiplied to obtain a capacitive current feedback signal Ikc of the filter; enabling the difference value between the Ic and Ikc to be multiplied by a gain coefficient Kpwm of a PWM to form a modulation signal of a single-phase full-bridge inversion unit; and generating the driving pulse of the single-phase full-bridge inversion unit by the modulation signal. The control method is simple and feasible and capable of effectively restraining low-order harmonics.

The invention relates to a scissors type hexagonal-prism-shaped extensible unit and a space extensible mechanism formed by the same. The scissors type hexagonal-prism-shaped extensible unit is a single-freedom-degree over-constrained hexagonal-prism-shaped basic extensible unit and comprises twelve faceplates, six groups of scissors type folding rods, and twelve groups of folding connecting rods. One group of folding connecting rods limits the extending degree of the basic extensible unit by the connecting rod lengths and the other eleven groups of folding connecting rods are over-constrained folding connecting rods, so that the rigidity of the basic extensible unit is improved effectively. Multiple basic extensible units are arranged closely and the adjacent basic extensible units can form a space extensible mechanism by sharing four faceplates, one group of scissors type folding rods and two groups of folding connecting rods; and the size of the pace extensible mechanism can be changed by changing the number of basic extensible units. The provided scissors type hexagonal-prism-shaped extensible unit has high structural symmetry; and different large-dimension space extensible mechanisms can be formed based on assembling of the multiple extensible units. Therefore, the scissors type hexagonal-prism-shaped extensible unit and the space extensible mechanism are suitable for constructing a space solar battery array bracket and a satellite planar reflecting antenna.

Provided is a torsional spring driven shear fork extending arm, wherein two terminal hexahedron unfolding elements are provided with several central hexahedron unfolding elements, and the terminal hexahedron unfolding elements together with the central hexahedron unfolding elements form a torsional spring driven shear fork extending arm. The folding and unfolding state of the torsional spring driven shear fork extending arm is in a shape of hexahedron frame, and every adjacent two central hexahedrons share one planar unfolding element, and are connected by four central disk chucks; meanwhile the terminal hexahedron unfolding elements also share one planar unfolding element with the adjacent central hexahedrons and are connected with the adjacent central hexahedrons through four central disk chucks. The torsional spring driven shear fork extending arm has the advantage of large folding proportion, high rigidity, good anti-seismic performance; and further has the advantages of simple structure, faster unfolding of overall mechanism, high reliability, which can respectively realize the corresponding functions of easy engineering manufacturing through movement, quick response, and application in the field of communication satellites, space stations and space probes.

The invention relates to an over-constrained shear fork-type double-layer annular truss deployable antenna mechanism. The over-constrained shear fork-type double-layer annular truss deployable antenna mechanism comprises an inner-layer annular truss assembly, an outer-layer annular truss assembly and 2N inner and outer-layer connection truss assemblies; the inner-layer annular truss assembly includes N inner-layer folding and unfolding units; adjacent inner-layer folding and unfolding units are connected with each other through two common inner-layer disc chucks, so that the inner-layer annular truss assembly can be formed; the outer-layer annular truss assembly includes N outer-layer folding and unfolding units; adjacent folding and unfolding units are connected with each other through two common outer-layer disc chucks, so that the outer-layer annular truss assembly can be formed; and two inner-layer disc chucks at the upper part and lower part of the same side of each of inner-layer folding and unfolding units are connected with four outer-layer disc chucks of a certain outer-layer folding and unfolding unit through two inner and outer-layer connection truss assemblies, so that the shear fork-type double-layer annular truss deployable antenna mechanism can be formed. The shear fork-type double-layer annular truss deployable antenna mechanism of the invention has good manufacturing process, high rigidity and large folding ratio.

A process for quickly growing the large-diameter monocrystal of potassium dihydrogen phosphate by solution temp lowering method features that the consumptions of potassium chloride and EDTA are respectively 1-5 M% and 0.01-0.02 Wt%, the initial over-saturation is 8 deg.C for maximum, and the temp lowering speed is 0.3-0.5 deg.C per day for initial growing stage and 2 deg.C per day for fast growing stage.

The invention discloses an expandable antenna mechanism of a torsion spring driven shears-fork annular truss. The mechanism comprises N folding and unfolding units with completely same structure, and the adjacent folding and unfolding units are connected by shared upper and lower flower discs to form a polygonal annular truss. Each folding and unfolding unit comprises two shears-fork rods, two groups of torsion spring driving assemblies, four connecting rods and four flower discs. All rotating pair axes on the shears-fork rods and the connecting rods in the same folding and unfolding unit are parallel. The mechanism has the characteristics of high rigidity, flexibility in motion and large folding ratio; and by adopting torsion spring driving, the whole mechanism is fast in unfolding and quick in response, and can be applied to communication satellites, space stations and space detectors.

The invention relates to a thermal-shock-resistant oxide wave-transparent ceramic material and a preparation method thereof. The ceramic material comprises the following components in percentage by volume: 20-92% of an oxide ceramic matrix with a dielectric constant less than or equal to 10 and 8%-80% of silicon dioxide-coated calcium zirconium phosphate ceramic. The linear expansion coefficient of the material at a room temperature of -1000 DEG C ranges from 0*10<-6> / K to 0.3*10<-6> / K, and the material has excellent thermal shock resistance and good dielectric and mechanical properties. According to the invention, a certain proportion of nano-silica coated calcium zirconium phosphate ceramic particles are introduced into a low-dielectric oxide ceramic material, and the ceramic material with an expansion coefficient close to zero is obtained through air atmosphere high-temperature heat treatment. The method is based on a mature ceramic material preparation method, and is simple to operate, short in period, low in cost, low in process amplification difficulty and easy to realize engineering.

The invention discloses a single-degree-of-freedom overconstrained shear-type deployable unit and space deployable mechanisms composed of the same. The single-degree-of-freedom overconstrained shear-type deployable unit comprises eight disc chucks, four sets of shear fork folding rods and eight sets of folding connecting rods; one set of the folding connecting rods limit the deployable degree of the basic deployable units by depending on the length of the connecting rods, the other seven sets of the folding connecting rods are all overconstrained connecting rods, and the overconstrained connecting rods can effectively improve the rigidity of the basic deployable units. Accordingly, the basic deployable units can be sequentially arranged in order, every two adjacent deployable units can form the first space deployable mechanism and the second space deployable mechanism by sharing four of the disc chucks and one set of the shear fork folding rods, and the length of the first space deployable mechanism and the size of the second space deployable mechanism can be changed by changing the quantity of the basic deployable units. The single-degree-of-freedom overconstrained shear-type deployable unit is simple in structure, has the high structural symmetry and is suitable for constructing an extendable space mast, a solar battery array support and a satellite plane reflecting antenna.

The invention relates to a scissors fork linkage type double-layer circular truss unfoldable antenna mechanism. The scissors fork linkage type double-layer circular truss unfoldable antenna mechanism includes an inner-layer circular truss assembly, an outer-layer circular truss assembly and N inner and outer layer connection truss assemblies; each of the inner-layer circular truss assembly and the outer-layer circular truss assembly includes N folding and unfolding units, wherein adjacent folding and unfolding units are connected through two disk chucks; after being unfolded, each of the inner-layer circular truss assembly and the outer-layer circular truss assembly is a multi-faced circular truss structure; the inner-layer circular truss assembly and the outer-layer circular truss assembly are arranged concentrically; four disk chucks between the inner-layer circular truss assembly and the outer-layer circular truss assembly, which are located in a vertical plane, are connected together through one inner and outer layer connection truss assembly; the structure form and connection mode of the inner-layer folding and unfolding units are similar to the structure form and connection mode of the outer-layer folding and unfolding units; outer-layer rods are longer than inner-layer rods; and the length difference value of the outer-layer rods and the inner-layer rods can be designed according to the specific aperture and folding ratio of the unfoldable antenna. The scissors fork linkage type double-layer circular truss unfoldable antenna mechanism of the invention has the advantages of high rigidity, structural simplicity and high reliability. According to the scissors fork linkage type double-layer circular truss unfoldable antenna mechanism, the expansibility of modules is high, and the number of the modules can be changed randomly according to the requirements of the aperture of the antenna and the sizes of units. The scissors fork linkage type double-layer circular truss unfoldable antenna mechanism can be applied to communication satellites, space stations and space detectors.

The invention provides a construction method of a large-diameter steel-concrete combined cylindrical structure, which comprises the following steps: manufacturing a steel cylinder body and dowel bars: manufacturing the steel cylinder body and a plurality of dowel bars, and forming a notch in the lower end part of each dowel bar; the dowel bars and the steel cylinder are installed, specifically, the dowel bars are vertically inserted into the upper end of the cylinder wall of the steel cylinder at intervals through the notches to be fixed; the supporting structure comprises a plurality of transversely-arranged supporting rods, one end of each supporting rod is connected with one dowel bar, and the other ends of the supporting rods intersect and are fixed on the central axis of the steel cylinder; manufacturing and mounting of an annular driver: fixedly connecting the annular driver with the upper end part of the dowel bar; vibration sinking construction is conducted, specifically, a vibration sinking tool is installed for vibration sinking, and after vibration sinking construction is completed, the annular replacement hitting structure and the supporting structure are dismantled; prefabricating the concrete cylinder; and mounting the concrete cylinder. According to the construction method, the construction cost can be effectively reduced, engineering manufacturing is easy, and the obtained cylindrical structure is high in durability.

The invention belongs to the technical field of short-pulse laser and particularly relates to a laser capable of directly generating two paths of coherent light. An existing multi-beam laser photoetching device has the defects of excessive devices, low light energy utilization rate, non-uniform interference fringe light intensity distribution and the like. The invention provides the laser capableof directly generating two paths of coherent light. The laser comprises a first laser oscillation assembly, an electro-optic Q-switching assembly and a second laser oscillation assembly which are arranged in sequence, the first laser oscillation assembly comprises a first Dammann transmission grating, a first laser crystal excitation component and a first Dammann reflection grating which are arranged in sequence; the second laser oscillation assembly comprises a second Dammann reflection grating, a second laser crystal excitation component and a second Dammann transmission grating; the first laser crystal excitation component comprises a first pump light source and a first laser crystal, and the second laser crystal excitation component comprises a second pump light source and a second laser crystal. The double-path light interference effect is good, the working efficiency is high, and the reliability is high.

The invention discloses a control method for a single-phase grid-connected inverter and a control parameter obtaining method therefor. The control method comprises the steps of collecting a power grid voltage value Ug, and inputting a phase-locked loop algorithm to obtain a phase angle <theta> of the power grid voltage; setting an amplitude value Im of a power grid reference current, and obtaining the power grid reference current Iref; enabling Iref and Ig to be subtracted obtain an error E, and enabling the obtained error E to pass through a proportional resonant controller and a harmonic compensation controller separately; enabling the output Upr of the proportional resonant controller to be added with the output Uhc of the harmonic compensation controller to obtain a sum Uab, and carrying out amplitude limiting on the obtained sum Uab to obtain a capacitive current reference value Icref of the filter; enabling the Ic and a feedback coefficient Kc to be multiplied to obtain a capacitive current feedback signal Ikc of the filter; enabling the difference value between the Ic and Ikc to be multiplied by a gain coefficient Kpwm of a PWM to form a modulation signal of a single-phase full-bridge inversion unit; and generating the driving pulse of the single-phase full-bridge inversion unit by the modulation signal. The control method is simple and feasible and capable of effectively restraining low-order harmonics.

Provided is a torsional spring driven shear fork extending arm, wherein two terminal hexahedron unfolding elements are provided with several central hexahedron unfolding elements, and the terminal hexahedron unfolding elements together with the central hexahedron unfolding elements form a torsional spring driven shear fork extending arm. The folding and unfolding state of the torsional spring driven shear fork extending arm is in a shape of hexahedron frame, and every adjacent two central hexahedrons share one planar unfolding element, and are connected by four central disk chucks; meanwhile the terminal hexahedron unfolding elements also share one planar unfolding element with the adjacent central hexahedrons and are connected with the adjacent central hexahedrons through four central disk chucks. The torsional spring driven shear fork extending arm has the advantage of large folding proportion, high rigidity, good anti-seismic performance; and further has the advantages of simple structure, faster unfolding of overall mechanism, high reliability, which can respectively realize the corresponding functions of easy engineering manufacturing through movement, quick response, and application in the field of communication satellites, space stations and space probes.

The invention proposes a construction method for a large-diameter steel-concrete composite cylindrical structure, comprising the following steps: making a steel cylinder and dowel bars: making a steel cylinder and a plurality of dowel bars, A gap is opened at the lower end of the steel cylinder; the installation of the dowel rod and the steel cylinder: the dowel rod is vertically inserted into the upper end of the steel cylinder through the gap to fix it; the installation of the support structure: the support structure includes A plurality of support rods arranged horizontally, one end of each support rod is respectively connected with a dowel rod, and the other end of the support rod intersects and is fixed on the central axis of the steel cylinder; the production and installation of the ring substitute: The ring-shaped substitute is fixedly connected with the upper end of the dowel bar; vibration and sinking construction: install the vibration-sinking tool for vibration-settling, and remove the ring-shaped substitute and supporting structure after the vibration-settling construction is completed; prefabrication of the concrete cylinder and installation of the concrete cylinder. The construction method can effectively reduce the construction cost, is easy to engineer and manufacture, and the obtained cylindrical structure has strong durability.