112results about How to "Guaranteed to be reliable" patented technology

The invention discloses an automatic charging system based on a snakelike-simulated mechanical arm. The automatic charging system comprises the snakelike-simulated mechanical arm, a charging device and a control system, and further comprises all control and execution modules, the control and execution modules are mutually matched, and whether to-be-charged vehicles exist or not can be automatically induced through a vehicle induction module; a charging-port pre-alignment module identifies charging ports through installed sensors, and general orientations of the charging ports are preliminarilycalculated; a main control module of a microcomputer is prepared, and is installed in a charging pile base, and the main control module controls the mechanical arm to clamp charging guns to move in the pre-alignment direction; an accurate alignment module of a snakehead-simulated joint accurately determines positions of the charging ports through the corresponding sensors and charges the to-be-charged vehicles. According to the automatic charging system based on the snakelike-simulated mechanical arm, vehicle using experiences of new-energy vehicles and automatic guide vehicles are greatly improved, the automatic charging requirements of automatic sites such as automatic-parking-place vehicles are met, a complete automatic parking and automatic inter-vehicle service system is formed, thelabor cost is greatly reduced, and the running efficiency is improved.

A satellite attitude and orbit control system based on satellite network is prepared for sending transfer order for obtaining information to certain assigned intelligent sensor with microprocessor through satellite network for making satellite affairs dispatch unit obtain relevant information, sending control command to certain assigned intelligent execution element by dispatch unit through satellite network after calculation, executing said control command by intelligent execution element with microprocessor in order to make satellite be moved for realizing control purpose after control command is received by said execution element.

The invention relates to a system and a method for human body movement identification of a combined sensor. The system comprises a power supply module, a data acquisition module, a signal processing module, a micro-controller module, a wireless communication module and a movement analysis machine, wherein the power supply module is used for supporting the normal working of the system, the data acquisition module is used for acquiring human body movement signals and is composed of an inertia sensor which is horizontally placed on the front portion of the waist of a human body and a flexible sensor which is placed on the elbow and the knee of the human body, the signal processing module is used for processing data signals and is respectively connected with the inertial sensor and the flexible sensor through leads, the micro-controller module is used for controlling and coordinating the entire system, the wireless communication module is used for transmitting data to the movement analysis machine, and the movement analysis machine is used for movement contrast and is a computer with a built-in movement identification model. The method is the identification of six kinds of daily human movement of walking, running, jumping, falling, standing and sitting with the system. The system and the method for the human body movement identification of the combined sensor are reliable to use, can be used for obtaining movement information of human torsos, and have the advantages of being simple and convenient.

The invention relates to an elevator safety precaution system comprising a landing door opening / closing detecting device, a lift car position detecting device, a car outer sensing device, a precaution device and a power device independent to the elevator. The landing door opening / closing detecting device is used for detecting whether the landing door is open or closed or not, the lift car position detecting device is used for detecting whether the lift car is near to the landing door or not, the car outer sensing device is used for detecting approaching condition of people outside the car, the precaution device is used for receiving detecting signals from the landing door opening / closing detecting device, the lift car position detecting device and the car outer sensing device, and judging whether to send precaution signals or not according to the detecting signals, and the power device independent to the elevator is used for supplying power to the precaution system. The elevator safety precaution system can precaution risks of early landing door unlocking and of entering unlocked landing door when monitoring elevator maintenance, so that life safety of passengers and maintenance staff can be guaranteed, and states of the car outer sensing device can be switched over intelligently, long and unnecessary power start is saved, and independent external power source is utilized to prevent losing monitoring capability due to power failure of the elevator.

The invention is concerned with a contact net system of high-speed electrical railroad made of some anchoring segments connecting with each other. Each anchoring segment relates to positioning device to wrist and arm, anchoring compensator, electric connecting equipment, suspension bowstring equipment and mid-point anchor equipment. The anchoring compensator sets at the two ends of each anchoring segment and the mid-point anchor equipment sets at the middle part of each anchoring segment. The connecting equipment of electricity sets at the inside of anchoring compensator and between the anchoring compensator and mid-point anchor equipment. Each anchoring segment has some positioning devices to wrist and arm and suspension bowstring equipments. It is fit to sustain, suspend, locate, machine, electric connecting and terminal anchoring to contact net system of electrical railroad with 200km / h, 50Hz single-phase and 25kV alternating current.

The invention discloses a horizontal rotating construction method for a steel truss beam bridge. The horizontal rotating construction method comprises the following steps: constructing a reinforced concrete pile foundation, a cushion cap, a slideway, a main pier and a cap beam in a rotating system by using a conventional construction technology, and mounting a rotating spherical hinge as a core part for rotating; mounting an upper rotating plate on the slideway for construction; constructing the main pier and the cap beam; mounting a permanent support saddle of the main pier; preparing safety measures before rotating; determining a weight scheme before rotating; preparing a jack; rechecking before rotating; performing rotating construction operation. Compared with other processes, the horizontal rotating construction method for the steel truss beam bridge, provided by the invention, has the advantages of high construction speed and low construction cost. The construction of a lower structure can be synchronously finished in the manufacturing process of a steel beam in a factory; the hoisting operation of symmetrical cantilevers can be performed when a spliced site is hardened to reach the traveling strength of cranes like crawler crane; main expenses are rental expenses of the cranes, so the cost is reduced.

The invention provides an NB-IOT (Narrow Band Internet of Things) equipment data acquisition system and method based on a block chain, and belongs to the field of embedded applications. The NB-IOT equipment data acquisition system consists of an NB-IOT terminal, an equipment base station and a block chain server. A block chain server network is established, and data acquired by the equipment are stored in a network database of block chain architecture by means of the non-tampering and non-counterfeiting characteristic of the block chain, thereby preventing truthful data from being tampered dueto tampering of a single node, and greatly enhancing the security of the NB-IOT network.

The invention relates to the technical field of cloud storage and in particular discloses a multi-cloud cooperative storage middleware system based on an existing cloud storage platform. The multi-cloud cooperative storage middleware system comprises a client terminal and a metadata server, wherein the client terminal is connected to a cloud platform through a network and is used for authenticating users, fragmenting and distributing files, operating and managing files, distributing data, restoring fault of data, encrypting and decrypting data; the metadata server is connected to the client terminal and is used for authenticating accounts and storing a file organization directory tree, a data encrypting key and a user operation log. The multi-cloud cooperative storage middleware system is used for cooperatively storing by using the existing multiple cloud storage platforms; through comprehensive consideration of multi-cloud storage resource and network service quality, a user data self-adaption distribution and integration algorithm is disclosed; an information security safeguard mechanism with separable data storage, data management and user visit is disclosed; a data fragmentation storage and key management method based on the metadata server is provided; the problem of leakage of the cloud storage data is solved.

The ivnention relates to a method for treating the synchronization of a clock output signal in a digit communication device. The method includes following procedures. (1) The output signal of clock is adjusted to the frequency that is the same frequency of the input signal of clock by use of a digit phase locked loop. (2) The value of target phase difference between the output signal of clock andthe input signal of clock is written to the memory of the filter controller in the digit loop circuit of the digitl phase lcoked loop. (3) After the output signal of clock and the input signal of clock have the same frequency, the value of control voltage Vd of the pressure-controlled oscillator in the digit phase locked loop is written to the memory of the filter controller in the digit loop circuit. (4) The output signal of clock is adjusted to the phase that is the same phase of the input signal of clock.

The invention relates to a bidirectional alignment laser centering adjustment device and a centering method, and belongs to the field of laser centering. A diameter measurement rear wing is fixedly connected with a fixed laser receiving cylinder, and a fixed leg support is fixed on the fixed laser receiving cylinder. A turnable laser macro-micro adjustment box is fixedly connected with the fixed laser receiving cylinder. The device is advantageous in that the device achieves the macro-micro adjustment of a laser, drives the laser to operate through the sticking-slipping inertia principle, obtains a laser linear equation through calculation, is used for a bidirectional centering shaft system, and enables the centering precision to be higher.

Vibration and centrifugation composite-testing equipment is characterized by comprising a centrifuge and an air-cooling electric vibrating table, wherein the centrifuge comprises a base, a rotating arm and a driving device; both ends of the rotating arm extend outwards; one end of the rotating arm serves as a load end; the other end of the rotating arm is provided with a balance weight to serve as a balance end; an electric brush is arranged in the center of rotation of the rotating arm; the air-cooling electric vibrating table comprises a vibrating table main unit and a blower; the vibrating table main unit is arranged at the load end of the rotating arm; the blower is arranged at the middle section of the rotating arm and is connected with the vibrating table main unit through a hard pipe; the vibrating table main unit is connected with the electric brush through a conductor group fixed on the rotating arm so as to be connected with a power supply and input / output control signals through the electric brush. The vibration and centrifugation composite-testing equipment adopts a design of integration of the centrifuge and the air-cooling electric vibrating table and ensures that a test piece can receive the actions of vibration force and centrifugal force, thereby achieving the purpose of carrying out vibration and centrifugation composite testing and filling a gap in the field.

The invention provides a care bed intelligent management system applied to a care bed. The system comprises a care bed state detection and control module, a protocol conversion module, a control server, a database server, a web server, an App server, a remote monitoring client, a network camera and a video server. The care bed state detection and control module, a care bed posture sensor and a sign sensor are arranged on the care bed. Each movable joint of the care bed can be adjusted according to a control command. The control server, the database server, the web server and the App server are taken as TCP servers to receive connection of a remote care bed. The care bed accesses a network through the protocol conversion module and communicates with a video server, the control server, the database server, the web server and the App server. A remote monitoring client can access the network to communicate with the App server and / or the web server. According to the system, management demands of a hospital, an enterprise and a personal user for the care bed can be satisfied.

The invention belongs to the technical field of cloud storage, and discloses a cloud storage information processing system and method based on a dynamic encryption RBAC model, and a user side which isconnected with a cloud storage platform through a network and is used for user authentication, role authentication, file operation and management, file permission sharing and data online preview andediting. The safety management component is used for identity authentication and file access control; the cloud storage server is connected with the client and is used for data encryption and decryption, key management, file data storage and user operation logs; and the online collaboration server is used for providing online file preview and editing services. Based on the RBAC model of dynamic encryption, a reasonable and effective access control function can be provided, an access control strategy is dynamically encrypted, the reliability of data is practically and effectively ensured, and data privacy is protected; Meanwhile, a document online collaboration function is provided, so that difficulty in multi-version redundancy decentralized management of documents is avoided, and convenience is brought to enterprise organizations and individuals in private clouds.

The invention provides an autonomous electronic evidence obtaining method and system. The method includes the following steps: based on an evidence obtaining request, carrying out evidence obtaining operation and generating an evidence obtaining file. The system includes an acquiring module and an evidence obtaining module. According to the invention, a virtual space mode is used to establish a controllable evidence obtaining environment, such that a user can carry out evidence obtaining through the virtual space on a cloud rather than on individual terminal, which guarantees reliability of the environment. At the same time, the recording of whole process of the evidence obtaining guarantees controllability and audit of the evidence obtaining. Finally, the use of digital signature and time stamp guarantees authority and impossibility of tampering of electronic evidence, so that the contradiction between the evidence obtaining request and traditional evidence obtaining procedure is overcome.

The invention discloses an ATM special cashbox with an intelligent switch and a recording function, comprising a box body and a lock, further comprising: a control unit, a memory, a communication interface, a radio frequency card reading unit, a door lock control unit and an unlocking executing mechanism which are mounted on the box body; the control unit is connected with the memory, the communication interface, the radio frequency card reading unit and the door lock control unit; and the door lock control unit is connected with the unlocking executing mechanism. The cashbox guarantees the safety and reliability of the intelligent cashbox, and is convenient for data statistics and management as well as upgrading simultaneously.

The invention discloses a split crevice cover structure of a fire door. The structure comprises a door frame, a left door leaf and a right door leaf. Each of the left door leaf and the right door leaf is composed of a frame and an inorganic fireproof core plate arranged within the frame. A crevice cover plate is attached to each of the left door leaf and the right door leaf. The two crevice cover plates are disposed inside and outside the door leaves, respectively. When the door leaves are closed, the crevice cover plates can cover a crevice between the left door leaf and the right door leaf from inside and outside of the door leaves, respectively. Each crevice cover plate comprises a metal frame and an inorganic fireproof core plate filling the metal frame; the inorganic fireproof core plate is connected with the metal frame through high-temperature-resistant glue. The split fire door crevice cover structure has the effect of preventing fire spread and smoke spread.

The invention discloses a whole bridge synchronized jacking support replacing system and a construction method. By adopting a PLC (Programmable Logic Controller) hydraulic synchronized jacking system,synchronization and accuracy of a jacking process can be accurately ensured, destruction caused by uneven stress of a bridge can be avoided, various parameters of a control system can be set and controlled on a touch screen, and unification of operation is ensured due to centralized operation; all data such as displacement, pressure, jacking height and error during running of the system can be displayed in real time, an abnormal situation during the running of the system can be subjected to automatic treatment and alarm displaying, the operation of the system becomes simpler and safer, and real-time monitoring of a whole process of support jacking and replacing is realized. The invention aims to provide the whole bridge synchronized jacking support replacing system which utilizes top space of a cover beam as counterforce support and realizes support replacement of the whole bridge in a synchronized and simultaneous jacking way, and the construction method.

The invention provides a two-dimensional code-based unmanned aerial vehicle device management system. The two-dimensional code-based unmanned aerial vehicle device management system includes two-dimension code tags, an inventory management module, a general assembly management module, a dispatching management module, a device operation management module, a data management center and a database; the two-dimension code tags are used for identifying each unmanned aerial vehicle device; the inventory management module is used for fast recording checkout and checkin information; the general assembly management module is used for recording relevant information of the installation or disassembly of the devices; the dispatching management module counts dispatching devices and generates a packing list; and the device operation management module downloads data in an unmanned aerial vehicle flight data recorder and is used for analyzing the operating states of the devices. All the above data are encrypted and uploaded to the database; the data management center calculates and analyzes the data, calculates the reliability of the devices and renders purchasing strategies and maintenance strategies. The two-dimensional code-based unmanned aerial vehicle device management system of the invention has high automation degree and can accurately, rapidly and scientifically manage the unmanned aerial vehicle devices, improve work efficiency and ensure reliable operation of the devices.

The invention relates to an air fryer stable in control. The air fryer comprises a base and a cover body hinged to the base. A fyer assembly is arranged in the machine base. The fryer assembly comprises an inner pot. A hot air assembly is arranged in the cover body, the hot air assembly comprises an air guide plate, a fan and a heating piece. The fan and the heating piece are positioned below theair guide plate; a transparent visual window is arranged on the cover body, the center of the hot air assembly deviates from the center of the fryer assembly, the distance between the center of the hot air assembly and the hinge center is smaller than the distance between the center of the fryer assembly and the hinge center, and the visual window surrounds the hot air assembly and is located above the inner pot. The hot air assembly is far away from a user relative to the fryer assembly, the area of the visual window located on one side of the user is enlarged, and therefore the user can visually observe the interior of the fryer assembly through the visual window. Meanwhile, the heights of the cover body and the whole air fryer can be effectively reduced, the gravity centers of the coverbody and the whole air fryer are reduced, and when the cover body is opened or closed, the whole air fryer is stably operated.

The invention discloses an industrial robot hand-eye calibration method based on a calibration ball, and the method comprises the following steps: fixing a 3D area-array camera at the tail end of a robot, fixing the calibration ball on the ground, and measuring the actual coordinates of the calibration ball; adjusting different poses of the robot in each working area, recording different pose dataof the robot, and acquiring 3D point cloud data of the calibration ball of the robot under the corresponding pose through the 3D area-array camera to obtain a pose-calibration ball 3D point cloud data set; processing the 3D point cloud data of the calibration ball under the corresponding pose, fitting the 3D point cloud data of the calibration ball under the corresponding pose, and calculating aball center coordinate; and calibrating the robot through the different pose data and sphere center measurement coordinates under the corresponding pose as well as the actual coordinates of the calibration ball. The method facilitates calibration of the robot, is simple and easy to implement, and is quick and accurate.

The invention discloses an overload protection clamp and belongs to the field of clamps. The overload protection clamp comprises a clamp base, a left fixed block, a left screw rod, a left clamping block, a right clamping, a right screw rod and a right fixed block, wherein the clamp base is provided with a dovetail groove; two ends of the dovetail groove are provided with the left fixed block and the right fixed block; the overload protection clamp further comprises a safety clutch mechanism, a fixed base, a regulating rod, an outer ring, a screw, a spring, a steel ball and a square shank; the regulating rod is assembled in a threaded hole of the fixed base; the square shank is connected with the regulating rod; the screw is assembled in a threaded hole of the outer ring; the steel ball is pressed on the surface of the square shank; the spring is arranged between the screw and the steel ball. The overload protection clamp can be used for solving the problems of difficulty in clamping force control and workpiece damage caused by high excessive clamping possibility of an existing clamp, and has the advantages of simple structure, reasonable design, and easiness for manufacturing.

The invention discloses a method for controlling diesel generating set parallel connection by using a computer, which comprises the following steps: selecting a machine set as a target machine and rendering the target machine set in a stable working condition; using other machine sets as adjusting machines; comparing the absolute values of the actual differences between the magnitude, frequency and phase of the output voltage of the adjusting machines and those of the output voltage of the target machine with standard differences; and accordingly and constantly adjusting the excitation and rotation speed of the adjusting machines, and executing parallel connection when all of the absolute values of the actual differences are smaller than the standard differences. As the parallel connection does not interfere the 'target machine', the method avoids changing the working condition of the target machine, ensures the stable operation of the machine sets and the safety and reliability of a main circuit after the parallel connection, and reduces the labor intensity of operating personnel and potential safety hazards.

The invention relates to the field of environmental monitoring equipment and particularly relates to a PM2.5 (Particulate Matter 2.5) source analyzing and sampling device based on carbon dioxide concentration control. The PM2.5 source analyzing and sampling device comprises a flue gas collecting assembly, a mixing residence chamber, a PM cutter and a sampling analysis unit, wherein the flue gas collecting assembly is connected to the mixing residence chamber, and the mixing residence chamber is connected to the sampling analysis unit through the PM cutter. The PM2.5 source analyzing and sampling device further comprises a second flowmeter, an air conveying unit, three carbon dioxide detecting units and a detecting air pump, wherein the flue gas collecting assembly, the air conveying unit and the mixing residence chamber are respectively connected to the carbon dioxide detecting units and then are connected to the detecting air pump. According to the PM2.5 source analyzing and sampling device, the traditional stationary pollution source sampling manner is adopted, the existing products can be subjected to improvement processing, the difficulty of manufacturing is lowered, the cost is relatively low, and thus, popularization is facilitated.

The invention relates to a low-temperature intracranial hematoma puncturing trocar, which comprises a low-temperature hematoma puncturing drill needle and a drainage sleeve. The upper end of the low-temperature hematoma puncturing drill needle is provided with a drill needle handle, the top part of the low-temperature hematoma puncturing drill needle is provided with a metal plug, a water injection tube is sleeved in the low-temperature hematoma puncturing drill needle, the diameter of the lower part of the water injection tube is smaller than the diameter of the upper part of the water injection tube, a plastic inner core is sleeved in the drainage sleeve, the top part of the drainage sleeve is provided with a cap, the upper part of the drainage sleeve is provided with a side tube, and the lower end of the drainage sleeve is provided with a round blunt opening. By adopting the technical scheme, the high speed of the electric drill can be maintained, the scalp can be prevented from being burnt, blood vessels and nerves can be effectively prevented from being damaged, and the safety and reliability of the micro puncturing treatment of hypertensive intracerebral hemorrhage can be ensured.

The invention discloses a worm self-locking anti-loose type overload protective clamp, and belongs to the field of clamps. The worm self-locking anti-loose type overload protective clamp comprises a clamp base, a left fixing block, a left screw, a left clamping block, a right clamping block, a right screw and a right fixing block, a dovetail groove is formed in the clamp base, and the left fixing block and the right fixing block are arranged at the two ends of the dovetail groove. The worm self-locking anti-loose type overload protective clamp further comprises a safe engaging and disengaging mechanism, a fixed base, an adjusting rod, an outer ring, a screw, a spring, a steel ball, a square shank and worm self-locking anti-loose devices, both the adjusting rod and the left screw are provided with the worm self-locking anti-loose devices, the adjusting rod is assembled in a threaded hole of the fixed base, the square shank is connected with the adjusting rod, the screw is assembled in a threaded hole of the outer ring, the steel ball is pressed on the surface of the square shank, and the spring is arranged between the screw and the steel ball. The worm self-locking anti-loose type overload protective clamp solves the problems that an existing clamp is not easy to control in clamping force and prone to loosening, and has the advantages of being simple in structure, reasonable in design and easy to manufacture.

The invention discloses a hand-held high-precision GNSS positioning collector and a collection method. The collector includes an upper computer and a lower computer. The hardware platform of the upper computer takes the microprocessor as the core, and is equipped with a lithium battery, a resistive screen, a memory chip and a wireless data transmission module. The upper computer is based on the WinCE embedded operating system, which displays the location information and positioning quality information of the current sampling point in real time, and can lock and save the current location data through the touch screen buttons; the lower computer includes the sampling point support frame, GNSS antenna, and data transmission radio station Antenna and electric control box, the lower computer receives satellite and differential signals, obtains high-precision positioning information at the sampling point, and sends it to the upper computer through the wireless data transmission module. The invention can sample the boundary points of farmland plots off-line, and provide original GNSS positioning data with centimeter-level precision for system navigation operation route planning. It has the advantages of small size, matching with the handheld monitoring terminal, and high efficiency of point collection.

The invention discloses a data governance method based on a double message queue, includes the following steps: 1) inputting data from a user data source through a data access tool, 2) storing the accessed data resources in a message queue, 3) extracting data from that message queue for preprocessing operation such as cleaning, 4) re-storing the pre-processed data into a message queue, 5) variousdata governance program respectively extract data from that message queue for governance, and then store the governance result into the message queue again; 6) the last governance program extracting data from the message queue, and after the governance is completed, the governance result being stored into a result database for use by subsequent processes. The method inserts the message queue before and after the data governance, buffers the data before and after the governance, realizes the streaming processing of the data, and optimizes the whole data processing link from the aspects of reliability, availability, scalability, data security and performance.

The invention relates to the field of environmental monitoring equipment and particularly relates to a PM2.5 (Particulate Matter 2.5) source analyzing and sampling device based on multichannel parallel feedback control. The PM2.5 source analyzing and sampling device comprises a flue gas collecting assembly, a mixing residence chamber, a PM cutter, a sampling analysis unit, a second flowmeter and an air conveying unit, wherein the second flowmeter is connected between the flue gas collecting assembly and the mixing residence chamber, the air conveying unit comprises an air pump, an air filter, a buffer tank, a first proportional valve, an air conveying sensor unit and a first flowmeter, the air pump is connected to the buffer tank through the air filter, the buffer tank is connected to the first flowmeter through the first proportional valve and the air conveying sensor unit, the first flowmeter is connected to the mixing residence chamber, and the sampling analysis unit is a multichannel parallel sampling analysis unit and can be used for carrying out multichannel simultaneous sampling and controlling sampling flow. According to the PM2.5 source analyzing and sampling device, the traditional stationary pollution source sampling manner is adopted, the existing products can be subjected to improvement processing, the difficulty of manufacturing is lowered, the cost is relatively low, and thus, popularization is facilitated.

The invention relates to the field of application of radio frequency technology, and provides an outdoor advertizing supervisory system based on RFID (radio frequency identification), and the system comprises a background server, a PC (personal computer) terminal, a handheld terminal, a card dispenser and an RFID label. An outdoor advertisement database is arranged in the background server, the PC terminal can access the database of the background server and initialize the active RFID label via the card dispenser, the active RFID label is arranged on the outdoor advertisement, data reading-writing operation is carried out between the handheld terminal and the active RFID label via a radio frequency reading-writing module, and the handheld terminal can carry out synchronization via the PC terminal and the database of the background server. By virtue of the radio frequency manner, polling work can be completed quickly and effectively.

The invention relates to the technical field of deformation testing of sheet metal, in particular to a method for testing biaxial yield and hardening behaviors of the sheet metal. Novel cross-shaped specimen geometry is designed in the method, and biaxial initial yield stress and follow-up yield stress of the sheet metal are obtained directly by measuring biaxial load; the designed specimen is characterized by comprising grooves with slotted openings and thinned central deformation area, and yield moment of the sheet metal and strain corresponding to follow-up hardening are determined by measuring strain of a fixed central point of the thinned area in real time. According to the method, biaxial initial yield stress and follow-up yield stress (hardening) of the sheet metal are obtained directly by measuring the biaxial load under the condition of the fixed strain tracing point. By means of the strain of the fixed central trace point in a biaxial loading process of the novel cross-shapedspecimen, the biaxial initial yield stress and follow-up yield stress value can be obtained directly according to the measured biaxial load, and the testing method is simple and high in controllability.