34 results about "Stability loss" patented technology

The invention relates to a karst cave type foundation stability estimation method, in particular to a measurement method of karst cave type foundation collapse risks. The measurement method mainly solves the problem that because comprehensive prediction methods for the karst cave type foundation stability are immature in the prior art and judgment models are established on the basis of different angles, the reliability of influence factors is greatly lowered. According to the specific scheme, the relation between vertical stress of overlaying soil on karst caves and limit vertical stress of the overlaying soil on the karst caves is derived and established according to the karst collapse mechanism of karst cave type foundations, stability loss risk estimation parameters for determining karst cave type foundation collapse are proposed, and the one-to-one corresponding relation between the karst cave type foundation stability loss risk estimation parameters and stability factors is established. The measurement method has the advantages of having clear stability criteria, being simple and practical and having high practicality value for effective prediction, prevention and control of karst cave type foundation collapse.

The invention provides an aircraft aero-servo-elasticity (ASE) ground simulating test system which is applied to an aircraft capable of generating the ASE stability loss problem. The whole system comprises a test object aircraft (comprising a control and stability augmentation system), and a motion signal sensor, a central control computer, an aircraft pneumatic force number calculating model, a pneumatic force simulating loading device and the like which are arranged on the aircraft structure. The system carries out real-time measurement and processing on a motion signal of the aircraft, calculates the normal-stationary pneumatic force of the aircraft through a special algorithm on the basis of relevant theory, and realizes the pneumatic force simulating loading through a vibrator. The system is connected with the test aircraft to evaluate the ASE of the aircraft, and can be used for the improvement design of the control and stability augmentation system of the original aircraft and the verification research of the advanced control method.

The invention discloses a method of load shedding of a floating wind turbine generator system based on semi-active structure control of a magneto rheological damper. The method includes the following steps: (1) analyzing the structure of the magneto rheological damper, obtaining a force-displacement relationship of the magneto rheological damper; (2) establishing an equation of motion of a multi-degree of freedom system of an offshore floating wind turbine generator system which is configured with the magneto rheological damper, and establishing equations of motion of the wind turbine generator system and the magneto rheological damper; (3) controlling the magneto rheological damper through a LQR controller and a Fuzzy controller so as to reduce the pitch angle of the floating wind turbine generator system and the longitudinal displacement of a nacelle. According to the invention, the method overcomes the defects of passive control and active control in structural control of a damper, requires less extra energy, requires simple apparatus and is not less susceptible to stability loss, can effectively reduce total load of the floating wind turbine generator system, guarantees stability of a platform, and further increases service life and energy quality of output electricity of a wind turbine generator.

The invention discloses a scroll compressor. A floating disc is arranged between a movable scroll and an upper supporter of the compressor, the floating disc is a circular disc with two layers of steps, a crossed ring is positioned between the movable scroll and the upper surface of the second step of the circular disc of the floating disc, pressure guide passages are arranged on the upper supporter and the fixed scroll, and the pressure guide passages are communicated with a compression cavity of the compressor and the lower surface of the floating disc for forming a sealed cavity between pressure guide passages and the bottom surface of grooves formed on the upper supporter. The invention has the advantages that all sealing parts adopt static sealing, good and reliable sealing can be realized, the crossed ring moves flatly between the movable scroll and the step surface of the floating disc, the fit gap of the flat movement maintains unchanged, the problems of moving stability loss, vibration enhancement and the like of the crossed ring can not occur, the sealing effect of the sealing between the floating disc and the upper supporter can be ensured during large axial displacement, the movement gap of the crossed ring can not be changed after the floating of the movable scroll, the distance between the movable scroll and a fixed scroll can be longer, and the starting load can be reduced to the maximum degree.

The invention discloses a tube wall plane indentation residual thickness expanding device for a tube material mechanic performance test and a test method. The device comprises a pressure transmitter side plug, a liquid inlet side plug, a test tube section, a liquid inlet joint, a liquid inlet side sealing cushion, a pressure transmitter, a pressure transmitter side sealing cushion, a tube section support frame, a tube wall residual thickness expanding area, a linear displacement sensor, a displacement sensor locating frame, a pressurization liquid bath, a pressurization pump, a buffering tank, a data collecting system and a computer, wherein the tube residual thickness expanding area is in a rectangular plane indentation structure or a circular plane indentation structure. Through the tube wall plane indentation residual thickness expanding device, a maximum strain position is stabilized in the center of an indentation plane all the time from primary deformation to plastic drawing stability loss till breakage, so that the accurate location of measurement is facilitated; the measurement is easy, and a measurement strain range approximates to an overall range; the test device is simplified; the deformation is concentrated in a local area, so that only the shape and the position of a tube material and the displacement sensor are controlled; a complex clamping device is not needed; the test device is greatly simplified; the test is relatively safe.

The invention relates to a method for cooling peripheral frozen earth and preventing water catchment in an excavation pit for a permafrost region. The method is characterized in that a pit slot is excavated at a position which is 0.5-5 m far away from the rim of the designed pit; the slot depth is a depth being 0-100 cm below underground permafrost table; a cooling pipe is paved at the bottom of the pit slot; a waterproof film is paved on the cooling pipe, the bottom of the slot, and the wall of the pit to a ground surface, and refilled and punned with filled earth; and the cooling pipe injected with circular freezing liquid is connected with a refrigerator on the ground surface through a hose. Shown by practices, with the adoption of the method provided by the invention, the problems of melting and stability loss of the frozen earth and the frozen earth in the excavation pit in a warms-season construction process and water leakage and water collection of underground water can be solved through the effective combination of refrigeration and water insulation, so that the permafrost stability can be effectively protected, and the normal construction and the long-term stability of the Qinghai-Tibet direct-current networking engineering in the permafrost region can be ensured.

The invention relates to a prediction method for rapidly judging the power system transient stability. The technical characteristics of the prediction method comprise the following steps that the real-time measurement data of disturbed power angle trajectories are acquired by using a WAMS in each judgment period; a multicomputer system performs homological grouping on the measurement data; the power angle prediction trajectories in a period of time in the future are acquired by using an improved LS-SVR algorithm; the maximum value of the power angle is judged so as to perform stability judgment; the power angle prediction trajectories are split into two subsequences by using phase-space reconstruction and the standard deviation sigma and the standard deviation offset eta of each subsequence are calculated; and whether the standard deviation offset eta is less than 0 is judged so as to perform system stability judgment. Transient stability prediction is performed by using the phase-space reconstruction criterion so that the prediction time and the accuracy can be obviously enhanced in comparison with the conventional criterion, stability loss prediction time is improved to 1.1s from 1.4s, and thus the precious time is won for subsequent emergency control and the safety stability of the system can be enhanced.

The invention belongs to the technical field of bandwidth resource limited MIMO-NCSs (multiple-input multiple-output networked control systems) and relates to a two-input two-output networked control system delay compensation SPC (smith predictor control) and IMC (internal model control) method. In order to solve the problems that two-input two-output signals in a TITO-NCS (two-input two-output networked control system) have mutual effect, network delay due to the transmission of network data between nodes affects the stability of one closed-loop control circuit of the system and may also affect the stability of another closed-loop control circuit while even stability loss is caused to the TITO-NCS, it is presented that an inter-node network delay compensation model is replaced by network data transmission process between all true node s in the TITO-NCS, with dynamic feedforward as well as SPC and IMC applied to the two circuits; by using the method of the invention, it is possible to omit the measurement, estimation or identification of inter-node network delay, omit the requirement on node clock signal synchronization, reduce the effect of network delay upon TITO-NCS stability, and improve the control performance quality of the system.

The invention discloses a four wheel independent steering drive-by-wire vehicle-based emergency braking control method. The four wheel independent steering drive-by-wire vehicle-based emergency braking control method aims at making full use of the advantages of a four wheel independent steering/driving vehicle, and by exerting a small coaxial different-directional steering angle on two wheels on the same axle under emergency braking conditions, can improve the braking deceleration of the vehicle to the maximum degree to shorten the braking length and improve the vehicle safety. Besides, according to the four wheel independent steering drive-by-wire vehicle-based emergency braking control method, the additional steering angle is exerted onto the wheels, the wheels on both sides of the vehicle can produce lateral forces identical in size and opposite in direction, and the lateral forces can improve stability of the vehicle during a braking process; also, when the braking system of one wheel of the four wheel independent steering/driving vehicle breaks down or loses efficacy due to software failure or hardware failure, by exerting active control on the steering angle of the braking failed wheel and matching with active braking and steer angle control of the other three wheels, the vehicle can avoid stability loss such as sharp steering and achieve stable braking.

The invention aims to provide a technical method for testing physical and mechanical properties of rock-soil body in a dynamic/static coupled manner. The method can acquire the physical and mechanicalproperties of the rock-soil body after the rock-soil body is firstly subjected to earthquake load or mechanical vibration load and then is subjected to water induction or other static force load. Themethod provides a new theory for stability loss of the rock-soil body due to rainfall after earthquake or other external factors. In the method, a dynamic triaxial device and the like test equipmentis used for pre-applying an earthquake load or mechanical vibration load to a rock-soil body test sample; after the dynamic load works, the test sample, which is subjected to the dynamic load, is subjected to static characteristic test, water-physical property test and dynamic characteristic test of rock-soil body, etc.; if the dynamic characteristic test needs to carry out in later period, the rock-soil body test sample can be directly subjected to tests of dynamic strength, dynamic modulus and earthquake subsidence and the like after pre-vibration according to soil engineering test specification without removal of the test sample.

The invention provides a method for making interconnected network transient stability emergency control strategies based on inter-region tie line measurement. The method comprises the following steps that 1, an off-line control strategy is made, tie lines among important regions are recorded, and the emergency control strategies for all regions of an interconnected network are made by means of fault setting; 2, relative power angles among the regions are calculated, in the actual operation process of the interconnected network, a PMU is used for collecting real-time voltage values of the tie lines of all the regions, and the relative power angle between every two regions is calculated; 3, the region where a unit disturbed most severely is located is judged, and according to real-time information of the relative power angles among the regions, contrastive analysis is carried out to determine the position where the unit disturbed most severely in the interconnected network is located; 4, emergency generator tripping control is implemented, and according to the area where the unit disturbed most severely is located, the specific off-line generator tripping control strategy is executed to prevent transient state stability loss of the system. The method has the advantages that the needed measurement amount is small, the calculation amount is small, and the method is suitable for the large region interconnected network and high in pertinence.

The invention discloses a high-speed train station concrete-filled steel tube column-steel reinforced concrete beam node structure. The high-speed train station concrete-filled steel tube column-steelreinforced concrete beam node structure comprises a concrete-filled steel tube column, a steel reinforced concrete beam and a ring beam and is characterized in that the concrete-filled steel tube column comprises an upper concrete-filled steel tube column, a lower concrete-filled steel tube column and a concrete-filled steel tube node column, and a cross plate and an eight-section plate are arranged in the bottom area of the upper concrete-filled steel tube column; an outer ring plate is arranged on the outer wall of the concrete-filled steel tube node column, and the upper flange and the lower flange of the steel reinforced concrete beam are in butt joint with the outer ring plate; the web of the steel reinforced concrete beam is connected with the concrete-filled steel tube node column;an inner ring plate, an inner partition and an inner rib plate are arranged in the concrete-filled steel tube node column. The node structure has the advantages that by the inner ring plate, the inner partition and the inner rib plate, axial force, transmitting to the upper column, in the column and shear force, transmitting to a frame girder, in the beam can be reduced effectively; after structural column stability loss, the inner ring plate, the inner partition and the inner rib plate can effectively transmit the axial force and bending moment in the beam, and structure collapse resistanceis increased effectively.

The invention discloses a tailing piling and storing system and method for reducing environment pollution. The tailing piling and storing system comprises a tailing concentration pool, a concentration tailing conveying pipeline and a tailing piling and storing yard, wherein the concentration tailing conveying pipeline comprises an ore feeding pipe, an overflow ore discharging pipe and a bottom flow ore discharging pipe; an ore feeding pipe of the tailing concentration pool is communicated with a tailing discharging pipe of a mine dressing plant; an overflow discharging pipe of the tailing concentration pool is communicated with a circulation water pipeline; a bottom flow ore discharging pipe of the tailing concentration pool is communicated with the tailing piling and storing yard; the bottom of the tailing piling and storing yard is provided with a waterproof compaction clay layer; a geotextile anti-seepage film is arranged on the compaction clay layer of the tailing piling and storing yard; a seeping and filtering water collecting system formed by a broken stone layer and a seepage discharging pattern pipe is arranged on the geotextile anti-seepage film; the lower side of the tailing piling and storing yard is provided with a water collecting pool. The system is reasonable, safe and reliable, the use is convenient, the zero discharge of tailing water is realized, the environment pollution of the tailing is reduced, and the stability loss or the dam breaking hidden danger of a tailing pond is reduced.

The invention belongs to the technical field of bandwidth resource limited MIMO-NCSs (multiple-input multiple-output networked control systems) and relates to a two-DOF (degree of freedom) IMC (internal model control) and SPC (smith predictor control) method for compensating uncertain delay in TITO-NCS (two-input two-output networked control system). In order to solve the problems that two-input two-output signals in a TITO-NCS (two-input two-output networked control system) have mutual effect, network delay due to the transmission of network data between nodes affects the stability of one closed-loop control circuit of the system and may also affect the stability of another closed-loop control circuit while even stability loss is caused to the TITO-NCS, it is presented that an inter-node network delay compensation model is replaced by network data transmission process between all true nodes in the TITO-NCS, with dynamic feedforward as well as two-DOF IMC and SPC applied to the two circuits; by using the method of the invention, it is possible to omit the measurement, estimation or identification of inter-node network delay, omit the requirement on node clock signal synchronization, reduce the effect of uncertain network delay upon TITO-NCS stability, and improve the control performance quality of the system.

The invention relates to an early warning method for pneumatic stability loss of turbines. The method comprises the following steps of: setting a dynamic pressure sensor at the wall surface of a case of a turbine to acquire wall surface static pressures generated by blades and record a dynamic pressure signal; carrying out real-time calculation through sapling points in the current rotor period and in the previous rotor period to obtain a periodic coefficient Rc of the current sampling point; obtaining a periodic coefficient Rc before the current sampling point through the sampling point in the previous rotor period and in the one before the previous rotor period, and doing the rest I the same manner to continuously obtain periodic coefficients Rc; setting a threshold value Rcth, and calculating the probability F (Rcth) that the periodic coefficient Rc in the previous statistical window before the current sampling point is less than or equal to Rctch; presetting an early warning value of a working margin, comparing the probability F (Rcth) with the early warning value, and when the probability F (Rcth) is greater than the early warning value, generating an early warning signal. The early warning method for pneumatic stability loss of turbines, stall early warning signals can be given earlier.

The invention relates to the field of petrochemical engineering equipment, and particularly provides a particulate matter bed layer support grid and a radial flow reactor. The particulate matter bed layer support grid is of a double-layer round tubular structure, and comprises a grid tube, a support rod, a distribution tube, and a connecting plate, wherein the grid tube, the support rod and the distribution tube are in radial arrangement; the connecting plate is arranged at the end part; the support rod is positioned between the grid tube and the distribution tube; the grid tube is a round tube formed by a V-shaped screen; the distributive tube is integrally in a round tube shape; the tube surface is of a wave-shaped structure and is provided with through holes. The particulate matter bedlayer support grid has the advantages that the flowing speed distribution of the inlet fluid can be more uniform; the impact of the fluid on the V-shaped screen can be reduced; the service life of theV-shaped screen can be prolonged; high bearing capability and external pressure stability loss resistant capability are realized; the particulate matter bed layer support grid is applicable to equipment for reaction, absorption, drying or purification and the like with high requirements on fluid distribution uniformity, great treatment quantity, great bed layer filling quantity, and strict bed layer pressure drop requirements.

The invention provides a method of deep foundation pit excavation. The method comprises the following steps that a standard safety factor of a to-be-dug soil slope is acquired, and an instability sliding curve is preset on the to-be-dug soil slope; the minimum safety factor is calculated according to the instability sliding curve; whether the minimum safety factor of the instability sliding curveis larger than the standard safety factor or not is judged; if so, excavation is conducted according to one side of the instability sliding curve; and if not, the instability sliding curve is preset again. The problems that the cost of a pit support structure needed to be formed is high, and collapsing occurs when excavation is conducted directly are solved. The minimum safety factor is calculatedaccording to the preset instability sliding curve of the dug soil slope due to the fact that stability loss of an average slope, and a sliding surface is a curve surface, the minimum safety factor ofthe instability sliding curve is larger than the standard safety factor, excavation is conducted according to the inner side of the instability sliding curve, the problem of collapsing on the soil slope does not occur, it is guaranteed that deep foundation pit construction excavation is safely and fast conducted, the working efficiency is high, and the economic cost is low.

The two-degree-of-freedom IMC method of two-input and two-output NDCS network delay belongs to the technical field of MIMO‑NDCS with limited bandwidth resources. For a kind of TITO-NDCS where two input and two output signals are influenced and coupled with each other, decoupling processing is required. The network delay caused by the transmission of network data between nodes not only affects the stability of the respective closed-loop control loops, but also Moreover, it will also affect the stability of the entire system, and even lead to the loss of stability of TITO-NDCS. It is proposed to replace the network delay compensation model with the network data transmission process between all real nodes in TITO-NDCS. The implementation of two-degree-of-freedom IMC can eliminate the need to measure, estimate or identify the network delay between nodes, reduce clock signal synchronization requirements, reduce the impact of network delay on the stability of TITO-NDCS, and improve the quality of system control.

The invention provides a processing process method of a reinforced installing pipe, and relates to the field of civil construction. The processing process method of the reinforced installing pipe comprises the following steps of firstly, finding a to-be-reinforced position on the outer pipe wall of the installing pipe, and forming a positioning hole in the found to-be-reinforced position of the outer pipe wall; passing a positioning strip into the positioning hole for temporary fixation; when an operator puts the reinforcing plate from one end of the installing pipe, pushing the reinforcing plate to the positioning strip to reach the proper position, so that the positioning on the reinforcing plate is realized; finally, welding and forming the reinforcing plate with the pipe wall of the installing pipe through hand holes formed in the opening end of the installing pipe or the pipe wall of the installing pipe, so that the economic performance and the durability of a whole truss structure can be realized. The local stability can be improved; too great welding steam stress due to local stability loss cannot occur; meanwhile, the reinforcing plate is arranged in the installing plate, so the attractiveness of the appearance of the whole truss structure is improved.