537results about How to "Small space size" patented technology

The invention relates to the technical field of unmanned aerial vehicles, and discloses a tandem double-duct type flight robot and a dynamics cooperative control method thereof. The invention provides a whole dynamics modeling and cooperative control strategy of an aerial vehicle and a mechanical arm based on the tandem double-duct type flight robot and the dynamics cooperative control method thereof. In a controlling process, an acting force of the mechanical arm is not considered as disturbance on the aerial vehicle, and the mechanical arm and the aerial vehicle are not controlled respectively; a whole flight robot platform is considered as a complete dynamic system; the aerial vehicle participates in adjustment of postures of a tail end of the mechanical arm through position control; the changes of a gravity center and a joint torque of the mechanical arm are caused by motions, and a corresponding moment is generated to assist the control on the postures of the aerial vehicle. The flight robot can realize automatic hovering and environment interaction, and has the advantages of small spatial size, large effective load, high passibility and accessibility, high control response sensitivity, great improvement of system stability and robustness, and the like.

The invention provides a hybrid type rapid direct current breaker, comprising: a main flow branch, a current transferring branch and an energy consumption branch. All are connected in parallel. The main flow branch comprises a rapid mechanical switch unit and a main branch sub-module unit. The two units are in series connection. The current transferring branch comprises valve module units in successive cascade connection with each valve module unit comprising a plurality of semiconductor modules in series connection. The energy consumption branch comprises energy consumption components in successive cascade connection. According to the invention, the design of the breaker structure is such a design featuring the electrical topology corresponding to modularization. This means that for the application requirement of different voltage grades, the structure can be expanded to do so. As the breaker adopts a single platform supporting structure, all functional units can be integrated onto the platform, therefore, making the equipment highly integrated, small in size, and strongly resistant to earthquakes. Highly reliable and flexible in structure, better electric compatibility can be achieved. With the breaker, it is possible to rapidly cut off the current in fault when the direct current system meets a fault.

Disclosed are a system, method, apparatus, and computer readable media containing instructions for displaying video files for rapid searching. In two different types of exemplary embodiments, a standalone video skimming system, and a video skimming system includes a server and a client system are disclosed, where the video file may be locally or remotely stored, or can be obtained from a live feed. The system displays many small windows simultaneously, in which different parts of the video chosen by the user are shown at the same time to shorten the skimming time. The video file is encoded using layered encoding to display smaller versions using lower layers, and without needing any processing to generate smaller versions of the video from the original full screen version. A video extractor is described for extracting the necessary bitstreams from a local video database containing layered encoded video files according to user specified window sizes, and distributing the signals over the electronic communications network channel. The system also includes a skimming control logic which can receive control commands from clients and invoke the video extractor to extract appropriate audio-visual signals there from for each command.

The invention belongs to electrical transmission equipment field, particularly a new type three degrees of freedom alternating current hybrid magnetic bearing. An annular permanent magnet is employed to provide axial and radial static offset magnetic flux simultaneously. The three degrees of freedom alternating current hybrid magnetic bearing is consisted of a rotation shaft, rotor outboard aluminum sheet, rotor inboard aluminum sheet, axial stator outboard aluminum sheet, axial stator inboard aluminum sheet, annular permanent magnet, thin-sheet shaped axial stator, radial stator, radial winding and a rotor with a thin-sheet shaped end. One end of the rotor is a thin-sheet shaped structure used as an axial bearing, the rotor outboard aluminum sheet and the rotor inboard aluminum sheet are used to increase strength and fatherly reduce length-diameter ratio. Tripolar structure AC excitation is employed in radial direction, which provides control current by employing a triphase inverter. Aluminum sheets are used to increase strength and reduce length-diameter ratio in the invention, passive suspension is realized based on lamellate electric motor principle, which improves passive suspension ability. Axial spacing dimension occupied by the magnetic bearing is greatly reduced for that no excitation winding is needed.

The invention discloses a space curve engagement and transmission mechanism, which is a novel transmission mechanism on the bases of the engagement principle of space curves. The transmission mechanism comprises a driving wheel, a driven wheel, a plurality of driving wheel hook levers and a plurality of driven wheel hook levers, wherein, the driving wheel hook levers are uniformly arranged on the end surface of the driving wheel; the driven wheel hook levers are uniformly arranged on the circumference of the driven wheel in a single row; the driving wheel hook levers and the driven wheel hook levers are in a conjugated spatial engaging curved shape; the driving wheel and the driven wheel which have mutually vertical axes form a transmission pair; and when the driving wheel is rotated, continuous stable engagement transmission is generated between the driving wheel hook levers and the driven wheel hook levers. The transmission mechanism has the advantages as follows: the mechanism is provided with only one transmission pair so that the number of transmission unit parts is minimized and the structure of the transmission unit is quite simple; transmission with high transmission ratio, such as the transmission of worm and gear, is achieved; and since two wheel axles are positioned on the same plane, the space dimension is smaller and the process is easy.

The invention relates to a tunneling mining and supporting machine for a coal roadway, in particular to a tunneling and bolting machine which is a tunneling and bolting integrated new machine type, solves the problems of time wasting caused by separation work of a tunneling machine and a roof-bolter, big labor intensity and low efficiency caused by a roof bolt artificially operated, etc., and realizes integration efficiency of the tunneling machine and the roof-bolter. The tunneling and bolting machine is an integrated installation structure of the tunneling machine and the roof-bolter, and the roof-bolter is arranged at both end of a cutting part of the tunneling machine. With utilizing one side of the cutting part of the tunneling machine as an installation platform of the roof-bolter, the invention realizes the integration of the roof-bolter and the cutting part of the tunneling machine. With utilizing lift and sway of the cutting part and the own function of the roof-bolter, the invention completes bolt installation work of a roadway bolt. The tunneling and bolting machine of the invention has the functions of stretching back and forth, vertical and horizontal regulation, self rotation of the roof-bolter, etc. When the tunneling machine works, the roof-bolter is shrunken for folding, and special dimension of the roof-bolter is lowered in great extend.

The invention discloses a powerful and mechanical automatic-locking hydraulic cylinder, and belongs to the technical field of hydraulic cylinders. The two ends of a cylinder barrel are sealed by a cylinder cover and a cylinder bottom respectively. A guiding column of the cylinder cover is sleeved with a spring. The spring is sleeved with a brake block. The two ends of the spring abut against the cylinder cover and the brake block respectively. The outer circumferential face of the large diameter of the brake block is in sealing fit with the inner circumferential face of the cylinder cover. The end face of the end, with a large-diameter hole, of a locking block abuts against the end face of the step of an inner hole of the cylinder barrel, and the other end face of the locking block abuts against the end face, located at the portion of the cylinder barrel, of the cylinder cover. After a steel ball is put into a steel ball installation hole of a piston, the steel ball installation hole of the piston is matched with an inner hole of the cylinder barrel, and an annular groove of the piston corresponds to a rodless cavity oil port in the cylinder barrel. One end of a piston rod is fixed to a piston rod installation hole of the piston, and the other end of the piston rod penetrates through the cylinder bottom to be located outside the cylinder barrel. According to the powerful and mechanical automatic-locking hydraulic cylinder, the requirement for automatic locking after the piston rod is completely retracted can be met, and the locking state can be kept for a long time under the situation that pressure relief of a hydraulic system is completed or leakage happens until unlocking is actively achieved.

The present invention discloses one kind of cascade cyclonic separator, and belongs to the field of liquid-solid and liquid-liquid separating apparatus. The cascade cyclonic separator consists of two serially connected cyclonic separator units, each of which consists of feeding cavity, guider, overflow pipe, barrel, cone, underflow pipe and other parts. The second cyclonic separator unit has its guider inlet connected directly to the underflow port of the first one, so that the under flow from the first cyclonic separator unit can enter the second one for secondary separation. The overflow of the second cyclonic separator unit is made to enter the cavity of the first one or led out through one additional pipe. The present invention has the advantages of high separating efficiency, compact structure, low cost, low power consumption and wide use.

The invention discloses a test turntable for an aircraft engine, and relates to continuously-rotating test equipment in the aviation field, in particular to the test turntable which is suitable for tests and rotor wings of engines of fixed models and other devices and used for dragging experiment. The test turntable comprises a turntable part, a sensor part, an electric conduction slip ring part, a clutch and brake device part, and a motor and bevel gear transmission case part; the motor and bevel gear transmission case part is fixed into a foundation through screws; the clutch and brake device part is fixed on the foundation through screws; the clutch and brake device part is connected with the motor and bevel gear transmission case part through a coupler; the electric conduction slip ring part is fixed on the clutch and brake device part through screws through screws and is adjusted horizontally through an adjusting shim; the sensor part is connected with the electric conduction slip ring part through screws and is horizontally adjusted through the adjusting shim; and the turntable part is connected with the sensor part through the screws and is horizontally adjusted through the adjusting shim.

The invention discloses a fast reflection mirror, comprising a base, a working mirror body, cross spring bearings and a driver; the working mirror body is assembled on a reflection mirror seat; two cross spring bearings constitute one group, there are totally two groups, wherein the axes of the two cross spring bearings in the first group of cross spring bearings coincide with a first straight line, and the axes of the two cross spring bearings in the second group of cross spring bearings coincide with a second straight line; the first straight line and the second straight line are perpendicular to each other and intersected at an origin; each cross spring bearing is connected to the reflection mirror seat and the base respectively; and the driver is used for driving the reflection mirrorseat to rotate within a preset angle range around the first straight line and / or the second straight line. According to the fast reflection mirror, the cross spring bearings support the reflection mirror seat, the cross spring bearings have the advantages of large deflection range and high rotating precision, and when the cross spring bearings are used with the driver, the deflection angle and therotating precision of the working mirror body can be improved, so that the fast reflection mirror is applicable in the fields of precision machinery, precision measuring instruments, medical equipment and the like.

The invention provides an optical lens, a lens module and a terminal. The lens module comprises the optical lens and a photosensitive assembly, wherein the optical lens is used for imaging a scene onan object side onto the photosensitive assembly; the optical lens comprises a lens barrel and a lens set accommodated in the lens barrel; the lens set sequentially comprises a first lens group, a second lens group and a third lens group from the object side to an image side; the first lens group comprises at least one first reflecting surface, and the first reflecting surface faces the image side;the second lens group comprises at least one second reflecting surface, and the second reflecting surface faces the object side, is opposite to the first reflecting surface and is used for reflectingreceived light to the first reflecting surface; and the lens module further comprises a motor, and the motor is connected with the first lens group or the second lens group so as to drive the first lens group or the second lens group to move in an optical axis direction. According to the optical lens, the lens module and the terminal, continuous zooming can be achieved under the condition of small optical thickness, and the structure is simple.

The invention relates to a liquid cooling and heating integrated power lithium battery pack and belongs to the technical field of power lithium battery pack. The invention mainly solves the problem that the space of a pack is insufficient due to the adoption of a heating device inside the pack. The invention is mainly characterized in that the liquid cooling and heating integrated power lithium battery pack comprises a lithium battery box, a battery management system, a liquid cooling plate, a lithium battery module, a pump, a triple valve, a fin radiator, a radiator fan and a heater; the battery management system, the liquid cooling plate and the lithium battery module are positioned inside the lithium battery box; the liquid cooling plate is in contact with the lithium battery module; the pump, the triple valve, the fin radiator, the radiator fan and the heater are positioned outside the lithium battery box; the triple valve is respectively connected to the pump, the fin radiator and the heater through water pipes; the other end of the pump is connected to one end of the liquid cooling plate through a water pipe; and the other ends of the fin radiator and the heater are connected to the other end of the liquid cooling plate through water pipes. By integrating liquid cooling and heating, internal space dimension of the pack is saved. The invention is mainly applicable to a vehicle-mounted power lithium battery pack.

The invention discloses an airplane control plane deflection angle measuring system, and belongs to the technical field of engineering observation and control. The airplane control plane deflection angle measuring system is characterized by comprising an operation control unit [1], a horizontal stabilizer deflection angle measuring unit [2], an elevator deflection angle measuring unit [3], an aileron deflection angle measuring unit [4], a rudder deflection angle measuring unit [5], a spoiler deflection angle measuring unit [6], a flap deflection angle measuring unit [7], a slat deflection angle measuring unit [8], a field control bus [9], an operation application unit [10], a field power supply [11] and a field power line [12], wherein the operation control unit [1] executes the order of the operation application unit [10], and realizes transmission of control orders, state information and measurement data with the deflection angle measuring units through the field control bus [9]; the field power supply [11] supplies power to the various deflection angle measuring units through the power line [12]. The airplane control plane deflection angle measuring system disclosed by the invention is complete in functions, reasonable and compact in structure, reliable in working, convenient to use, and good in expandability and clipping modularity.

The invention discloses a drum brake cooled through heat pipes. The drum brake comprises a front brake shoe, a rear brake shoe, a friction plate, a brake shoe return spring, a brake cylinder, fan blades, the heat pipes and supporting pins. The multiple heat pipes are arranged on the front brake shoe, the rear brake shoe and the friction plate in a spaced mode. A brake drum body is mounted on the periphery of the friction plate and mounted on a wheel through brake drum mounting holes. The fan blades are mounted on the brake drum body which is provided with arc vent grooves. The heat pipe array is embedded between the brake shoes of the drum brake and the friction plate, the fan blades are arranged in the brake drum, and the role of a fan is played in the vehicle running process. Through the structural features, a large amount of heat generated in mutual friction of the friction plate and the brake drum in the vehicle braking process can be quickly conducted into a brake drum chamber through the heat pipes, the heat is taken into the external environment through air flowing into the brake drum chamber, and therefore the temperature of the brake drum and the temperature of the friction plate are reduced, and the braking performance of the brake is more stable.

The invention relates to an antenna device which comprises an antenna ground and also comprises a first feed port, a first antenna, a first regulation unit, a first switch unit, a second switch unit and a control unit, wherein the first feed port is used for connection with a radio frequency unit and signal transmission with the radio frequency unit; the first antenna is connected with the first feed port and the antenna ground respectively; one end of the first regulation unit is connected between the first feed port and the first antenna, and the other end is connected with the first switch unit; the first regulation unit is used for regulating the working frequency band of the first antenna; the other end of the first switch unit is connected with the antenna ground; one end of the second switch unit is connected with an antenna structure, far away from the antenna ground, on the first antenna, and the other end is connected with the antenna ground; and the control unit is used for respectively controlling the closing and opening of the first switch unit and the second switch so as to control the working condition of the first antenna. The antenna device has the characteristic of small space size, and meanwhile, multi-frequency band is achieved. The invention also relates to a mobile terminal.

The invention discloses a truss type erecting arm. The truss type erecting arm comprises a lower left main beam, a lower right main beam, an upper left main beam, an upper right main beam, an erecting cross beam, a rear main support, a front main support and a plurality of first assisting beams, wherein the lower right main beam and the upper right main beam are connected through vertical beams and inclined beams; the lower left main beam and the upper left main beam are connected through the vertical beams and the inclined beams; two ends of each first assisting beam are respectively and perpendicularly connected with the lower right main beam and the lower left main beam; the front main support, the erecting cross beam and the rear main support which are used for supporting a product are respectively sequentially fixedly connected from the front half parts to the tail ends of two lower main beams; the whole erecting arm is of a concave frame structure, and the longitudinal section of the concave shape is reversely trapezoidal. The erecting arm of the truss type double-layer main beam structure is simple and reliable in overall structure and can bear bending torque, erecting torque, and axial pulling force or pressure; the inclined beam is adopted, so that the material is saved, the dead weight is reduced, the rigidity is increased; the bending resisting section is high; large-ton reliable bearing is achieved.

The invention discloses a parking brake module for a rail vehicle, a brake cylinder and a brake clamp unit. The parking brake module comprises a parking cylinder; a first parking piston is arranged in the parking cylinder; a hand brake mechanism is arranged in the parking cylinder, and comprises a parking rod, a rotating wheel and a parking pin; the first parking piston is fixedly connected with the parking rod; a chute is formed in the parking rod; a slide piece clamped on the parking rod is arranged on the inner wall of the rotating wheel corresponding to the chute; and the slide piece is matched with the chute to prevent the parking rod from moving in the radial direction. As the parking rod and the rotating wheel in the parking brake module adopt a buckling fixation mode, when the parking braking is performed, the rotating wheel and the parking pin cannot slide in the parking braking process to effectively prevent wear of the parking pin.

The invention discloses a motor direct-driven transmission device of a door lock and an intelligent door lock. The motor direct-driven transmission device mainly comprises an inner door panel, a bottom plate, a lock core, a shifting strip and components like an unlocking rotary knob, a driving bevel gear, a gear motor, a motor bevel gear, an optoelectronic switch, an optical grating coding disc, a buffer cushion and a locking cover. According to the motor direct-driven transmission device, the lock core is driven to rotate through the gear motor, automatic locking and unlocking functions of an electronic door lock are achieved through utilizing a traditional mechanical lock body, and the motor direct-driven transmission device has the advantages that the changing and mounting are easy, the cost is low, the operation is stable, reliable, safe and convenient, the device is abrasion resistant, the noise is low, and the service life is long, integrates convenience of an intelligent lock and safety and reliability of a mechanical lock, and has wide application prospect in the field of intelligent door locks.

The invention relates to an electromagnetically controlled gas-electric vertical welding (EMS-EGW) method, which is to set an external magnetic field above or / and near the side of the gas-electric vertical welding (EGW) molten pool (3), such as an excitation coil that provides an excitation current by an excitation power supply , produce time-varying or constant electromagnetic stirring and external magnetic field to produce electromagnetic stirring effect; the electromagnetic field promotes the forced movement of the metal fluid in the gas-electric vertical welding pool, and comprehensively controls the solidification process of the weld metal. With the cooperation of gas protection, the method of electromagnetically controlled gas-electric vertical welding (EMS-EGW) is realized on the workpiece. The electromagnetic control gas-electric vertical welding (EMS-EGW) device of the present invention adds excitation equipment on the existing basis, and the excitation equipment is composed of an excitation coil and an excitation power supply that provides excitation current for the excitation coil. The invention breaks through the traditional gas-electric vertical welding method, and provides a new idea for improving gas-electric vertical welding; reduces welding defects, reduces welding costs, improves welding quality and production efficiency, and ensures product reliability; The appearance is well formed; the equipment is simple and easy to popularize and apply.

The invention relates to an electronic meter and a meter reading instrument, which is mainly used in wireless infrared water meter systems and meter reading systems and can also be used in gas meter systems, heater meter systems and other systems. The motor is driven to rotate by an impeller, thereby obtaining the rotating information of the impeller and transmitting electric energy to batteries. The signal is input into a singlechip via a rectification circuit; the functions of analog-to-digital conversion, calculation, data storage and signal transmission of the singlechip are utilized to acquire and process the information of the motor, and store, transmit and display the data; and in addition, one meter head can be shared by multiple users, and the output pipe of each user is provided with an impeller and a motor. The meter reading instrument comprises a transmitting and receiving circuit, a singlechip system, a storage unit, a display screen, an alarm, a peripheral circuit and a minitype printer; the meter reading instrument can read and process the information transmitted by the meter, and display the information on the display screen; and the minitype printer can print payment notes.

The invention relates to a hook rod gear mechanism for parallel shaft transmission. The hook rod gear mechanism comprises a transmission pair composed of a driving wheel and a driven wheel. The axis of the driving wheel and the axis of the driven wheel are parallel to each other. The driving wheel is connected with an input shaft. The driven wheel is connected with an output shaft. Driving hook rods on the driving wheel are evenly distributed in the circumference of the cylindrical end face of the driving wheel. Driven hook rods on the driven wheel are also evenly distributed in the circumference of the cylindrical end face of the driven wheel. The driving hook rods and the driven hook rods are each in a cylindrical spiral linear shape. When the driving wheel and the driven wheel are installed, the driving hook rod and the driven hook rod in one pair are meshed, the driving wheel is driven by a driver to rotate, the continuous and stable meshing is completed through the meshed hook rods, and transmission between the two parallel shafts is achieved. The spiral linear shapes of the driving hook rods and the driven hook rods can be determined according to the installation spatial coordinate system, the transmission ratio and other parameters of the driving wheel and the driven wheel and according to the hook rod contact line equation. The hook rod gear mechanism is simple in structure, fewer in transmission mechanism part, small in size, light in weight, large in transmission ratio, stable in transmission and suitable for being applied to the fields of mini machines and micro machines.

The invention discloses a motor-transmission integrated transmission system for a blade electric vehicle. The motor-transmission integrated transmission system for the blade electric vehicle is a two-gear automatic transmission planet gear mechanism. The mechanism is composed of a single-row 2K-H planet gear mechanism, an electromagnetic clutch, an electromagnetic brake, a differential mechanism, a main speed reduction gear and a permanent magnet synchronous motor. A sun gear is directly and fixedly connected with a rotor base of the permanent magnet synchronous motor through a spline. A stator corresponding to a rotor is fixed to a motor shell. The differential mechanism is arranged in the rotor base of the permanent magnet synchronous motor. Power is transmitted to the sun gear through the motor, transmitted to a left half shaft and a right half shaft of the differential mechanism through a planet carrier, and finally output to wheels through the main speed reduction gear. A gear ring and the planet carrier are combined or separated through the clutch and the gear ring and a box body are fixed or separated through the brake. Through different combinations of the working condition or the non-working condition of the clutch and the working condition or the non-working condition of the brake, the switch between two gears is achieved. The motor-transmission integrated transmission system for the blade electric vehicle is simple in mode, compact in structure, small in size, low in weight and capable of meeting the principle that the vehicle is light in weight.

The invention relates to an aircraft control stick force and displacement measuring device and a measuring method thereof, belonging to the field of aeronautical engineering experiments and tests. The invention is characterized in that the measuring device consists of a control handle, a force signal detecting unit, a displacement signal detecting unit and a mounting and connecting unit; the controlling handle, the force signal detecting unit, the displacement signal detecting unit and the mounting and connecting unit are combined and integrated together into a 1-shaped structure in space; the force signal detecting unit and the displacement signal detecting unit are distributed at an upper side and a lower side of the mounting and connecting unit; the measuring device is connected with the control stick through the mounting and connecting unit; force is applied to the control stick by the controlling handle and the control stick is controlled to move; and the magnitudes of the controlling force and displacement are measured by the force signal detecting unit and the displacement signal detecting unit. The aircraft control stick force and displacement measuring device has the characteristics of compact and simple structure, small space dimension, low cost, reliability in work, high testing accuracy and convenience for mounting, using and adjusting, and is suitable for measurement of the controlling force and the displacements of various kinds of aircraft control sticks.

The invention discloses a high-performance magnetic liquid sealing structure, and belongs to magnetic liquid rotary sealing. The high-performance magnetic liquid sealing structure is suitable for conveying high-pressure medium gas at high speed. The sealing structure is composed of a magnetic conductive shaft, a first pole shoe, a second pole shoe, a third pole shoe, a permanent magnet, a sealing seat, an outer hexagonal bolt, a gland, a comb tooth sealing shell, a rolling bearing, a locking thread cover, an inner sleeve shell, an inner gland, a sealing ring and the like. When the pressure of sealed medium gas is high, a magnetic liquid seal needs to be set in multiple stages, thus the space structure is greatly limited, and the defect that the space size of the magnetic liquid seal is limited is overcome. A comb tooth seal is added to the rear end of the magnetic liquid seal, high-pressure air is introduced into a cavity of the comb tooth seal, air pressure balance between the cavity of the comb tooth seal and the interior of a medium end cavity is achieved, the sealing medium is fully sealed, and the sealing space size is saved.

The invention relates to a processing technology for refining weld joint structures in a welding process, in particular to a method and a device for refining weld joint structures by using pulsed magnet fields in the welding process, and belongs to the technical field of welding. The method for refining weld joint structures by using pulsed magnet fields in the welding process includes that welding is performed by using an ordinary gas metal arc welding method, an applied magnetic field is added above a gas metal arc welding pool, mechanical movement and welding gun movement of the magnet fields are synchronous, electric arc and melt drip transition action is controlled by the magnet fields in a welding process, metal melt in the gas metal arc welding pool is forced to move, an electromagnetic stirring effect is produced, and weld joint structures are finally refined in the welding process. According to the method and the device, in the welding process, the weld joint structures are refined, welding defects are reduced, and further the cost is reduced, and the welding quality and the production efficiency are improved.

The invention discloses a linear-cavity active Q-switching all-fiber laser. The laser is characterized in that a linear cavity is provided, the output tail of a pumping semiconductor laser is connected with the pumping input port of a fiber beam combiner; the fiber output port of the fiber beam combiner is connected with a high-reflectivity fiber bragg grating; the other terminal of the high-reflectivity fiber bragg grating is welded with gain fibers together; the other terminal of the gain fibers is welded with a low-reflectivity fiber bragg grating formed on polarization-preserving fiber; an adjustable piezoelectric element signal drive circuit is used for driving a piezoelectric element to press fiber in the cavity periodically to modulate the polarization direction of light; the other terminal of the low-reflectivity fiber bragg grating is connected with the input terminal of a fiber isolator; and the output fiber is connected with the output terminal of the fiber isolator. The laser provided by the invention has the advantages of little insertion loss, simplified structure, high repeating frequency of laser pulses, low cost and easiness in industrialization. Large-diameter core double-cladding gain fibers can be used in the laser cavity, so that high-energy high-power laser pulses can be obtained conveniently.

The invention belongs to the technical field of an unmanned aerial vehicle, and discloses a novel composite rolling attitude control system and method. The control method integrates a principle for adjusting a flight attitude by utilizing a rudder surface and a conventional helicopter tipping tray periodically-pitch-variable principle; by utilizing a redundant control concept, an aerocraft rolling passage is controlled by a rudder system, the auxiliary compensation for the rolling passage is carried out by virtue of a rotary wing system, an airflow direction is limited by virtue of a duct, and the rudder system is controlled; and the control system comprises a controller, a rudder system, a rotary wing system and a duct. The novel composite rolling attitude control system is high in air passing capacity, compact in structure, reasonable in design and capable of realizing automatic hovering and precise attitude control and has advantages of small space size, large effective load, high control response sensitivity, high system stability, high robustness and the like.

The invention relates to a novel marked point pattern based on vision invariants and identification and tracking positioning algorithm thereof. The invention comprises a design of novel marked point pattern based on vision invariants and identification and tracking positioning algorithm based on the novel marked point. The novel marked point pattern based on vision invariants is a black pentagon with a round mark. The marked point can be a convex pentagon or a concave pentagon. The round mark is used for identifying a first vertex of the pentagon. The pattern is coded using the cross-ratio invariant of the pentagon and combining the concavity and convexity of the vertex. The marked point pattern based on vision invariants can conduct attitude calculation using self-characteristics and realize the coding of the marked point, thus saving the area needed by coding patterns, reducing the pattern size of the marked point and improving the registration precision in unit area. The tracking registration algorithm can be used for identifying the marked point, tracking the head posture of the user and calculating the accurate position and posture of virtual scenes in true environmental space.