36 results about "Vertical stiffness" patented technology

The invention discloses a parameter optimization and reliability evaluation method for an active suspension control system of a high-speed train, and the method comprises the steps: combining a kinetic model with a multi-objective optimization algorithm; an active suspension secondary vertical stiffness parameter, an active suspension secondary transverse stiffness parameter, an active suspension primary radial stiffness parameter and an anti-snaking shock absorber stiffness parameter of the high-speed train are respectively used as design variables, and curve passing performance, a sperling index and a critical speed in the operation of the high-speed train are optimized; and when the optimization reaches the maximum iteration parameter and the obtained pareto optimal parameter combination meets the constraint condition, verifying the safety, stability and stability of the high-speed train until reaching the standard, thereby verifying the reliability of the active suspension control system, and finally evaluating the reliability of the active suspension control system of the high-speed train. Therefore, the running performance and the line adaptability of the train are improved.

The invention discloses a design method of an integral swing self-resetting structure for mounting a tension-compression energy-dissipation support, and relates to the technical field of civil engineering earthquake resistance, and the integral swing self-resetting structure comprises a tensile limiting device and a compression limiting device; the method specifically comprises the steps that a structural mechanical model is established, and the lateral stiffness of a traditional fixed foundation is calculated; setting a rigid body displacement ratio to determine the vertical and horizontal rigidity and strength of the support; carrying out finite element push-and-cover analysis to verify a rigid body displacement ratio; setting an additional damping ratio; carrying out seismic response spectrum analysis on the vertical seismic isolation structure; calculating the vertical natural vibration period of the structure and adjusting the rigidity according to the response spectrum; carrying out elastic-plastic time-history analysis to detect an interlayer displacement angle, acceleration and structural damage; checking the consistency of the additional damping ratio and the actual energy consumption; and finally, anti-overturning checking calculation under extremely rare earthquake is carried out to ensure that the support and the limiting device are in an elastic state. The energy dissipation capacity and anti-seismic safety of the structure can be effectively improved, and the structure is suitable for various building structures needing vertical and horizontal seismic isolation.

The application provides a method for determining the longitudinal wave velocity after fluid replacement in an anisotropic medium and related equipment. The method comprises the following steps: determining an average bulk modulus based on a matrix bulk modulus; determining a first bulk modulus when the medium contains fluid based on first property data; determining a second bulk modulus when the medium does not contain fluid based on the first property data, the matrix bulk modulus, the average bulk modulus and the first bulk modulus; determining a second vertical stiffness coefficient when the medium does not contain fluid based on the first property data, the average bulk modulus, the first bulk modulus and the second bulk modulus; obtaining second property data of each predetermined replacement fluid; and determining the longitudinal wave velocity after the fluid in the medium is replaced by the predetermined replacement fluid based on the first property data, the average bulk modulus, the second bulk modulus, the second vertical stiffness coefficient and the second property data. The technical problem that the longitudinal wave velocity determined after fluid replacement in an anisotropic medium is not accurate in the prior art is solved.

The present invention relates to the technical field of building vibration reduction technology, and discloses a design method for a limiter support vibration isolation structure, comprising the following steps: S1, designing the placement position of the vibration isolation layer; S2, determining the seismic performance targets of the upper and lower buildings, and determining the seismic performance levels of the lower building, the vibration isolation layer, and the upper building; S3, designing the limiting state of the limiter support under different earthquakes; S4, performing model envelope calculations on the horizontal stiffness and vertical stiffness combination of the overall structure according to different earthquakes, and obtaining the force data and relative displacement data of each structure; S5, performing structural design of the limiter support, and performing finite element analysis on the limiter support using the above data; S6, performing performance design on the upper and lower buildings. The present invention provides a design method for a limiter support vibration isolation structure, which can calculate the force data and relative displacement data of each structure under various special conditions, and ensure that the design results are reliable.

The present application discloses a stiffening cable structure and design method for a suspension bridge, relating to the technical field of bridge structures. The suspension bridge comprises a main beam and two pylons, and the stiffening cable structure comprises two groups of stay cables and a plurality of slings. The two groups of stay cables are symmetrically arranged along the longitudinal direction of the main beam. Each group of stay cables is anchored transversely to a pylon, and one side of each group of stay cables is anchored to a side span pier or anchorage of the suspension bridge, and the other side is anchored to a quarter-span region of the main beam. The slings located at the same longitudinal position in the quarter-span region of the stay cables are cross-slings. The stay cables are fixed to the anchor points of the main beam and provided with weight blocks of a set weight. Under the action of the stay cables and weight blocks, the dead load cable force of the cross-sling does not exceed the dead load cable force of the non-cross-sling, and the vertical displacement extreme value of the main beam in the quarter-span region is not greater than the vertical displacement extreme value of the main beam in the mid-span. The stiffening cable structure and design method of the present application are intended to solve the technical problem of low vertical stiffness of suspension bridges in related technologies.

The present application relates to a kind of multi-foot coupling spoke and tire for non-pneumatic tire, spoke includes first leg structure, second leg structure and third leg structure, first leg structure and second leg structure are connected in V type, third leg structure is connected in V type with second leg structure, the end of third leg structure is equipped with first coupling surface, second coupling surface is equipped with in the opposite side surface of second leg structure with the side of third leg structure, first coupling surface can coincide with second coupling surface in translation process.The third leg structure of present application is arranged, and the third leg structure is coupled and connected with second leg structure, realizes circumferential coupling arrangement, substantially reduces the stress of originally bearing tension side, avoids interface and rubber body due to repeated tension and leads to the failure of adhesive surface, such as rubber fatigue tear phenomenon.The multi-foot coupling spoke improves the vertical stiffness of spoke, enhances the carrying capacity, further improves its carrying stability.

The invention discloses a vertical vibration reduction and isolation spherical steel support and a vibration reduction method, the vertical vibration reduction and isolation spherical steel support comprises an upper support plate, a spherical crown lining plate, a lower support plate, a vertical vibration reduction mechanism and a bottom basin, the spherical crown lining plate is arranged between the upper support plate and the lower support plate, the upper support plate covers the lower support plate, and the lower support plate is embedded in the bottom basin; the vertical vibration reduction mechanism is arranged between the lower seat plate and the bottom basin, the top of the vertical vibration reduction mechanism abuts against the bottom of the lower seat plate, the bottom of the vertical vibration reduction mechanism abuts against the bottom basin, and therefore the special-shaped metal springs conduct vertical vibration reduction on the upper seat plate, the spherical crown lining plate and the lower seat plate. The two special-shaped metal spring sets which are symmetrically stacked in groups are additionally arranged on the basis of a common spherical steel support, vertical elastic deformation generated when the support bears a vertical load is greatly increased, the vertical rigidity of the support can be effectively reduced, and therefore the inherent frequency of the support is reduced, and the service life of the support is prolonged. The dominant frequency generated by vibration of the upper structure of the support is isolated from the inherent frequency of the structure of the support, so that the vertical vibration reduction and isolation function of the whole support is achieved.

The application relates to a shock absorber and a shock absorbing system, and belongs to the technical field of precise shock absorbing. The shock absorber comprises a bottom plate and a top plate which are arranged in a relative interval, a shock absorbing cavity arranged between the bottom plate and the top plate, a horizontal positive stiffness component and a vertical positive stiffness component. The top plate is connected with the shock absorbing cavity in a movable mode along the depth direction of the shock absorbing cavity. The shock absorbing cavity is arranged in an interval with the bottom plate. The vertical positive stiffness component connects the shock absorbing cavity and the bottom plate together and is used for providing the vertical positive stiffness and horizontally damping the top plate. The horizontal positive stiffness component is located outside the shock absorbing cavity and is connected with the top plate and the bottom plate and is used for providing the horizontal positive stiffness, thereby realizing the decoupling of the horizontal stiffness and the vertical stiffness of the shock absorber, ensuring the stable positive stiffness in the horizontal direction, effectively isolating the interference of the vertical vibration on the horizontal damping performance, and greatly improving the overall performance of the shock absorber.

The present invention discloses a bridge rescue and evacuation channel detection method based on transverse and vertical dynamic parameters, comprising: collecting the transverse dynamic characteristics of the high-speed railway bridge rescue and evacuation channel and establishing a first sub-model based on the transverse dynamic characteristics; testing the vertical dynamic stiffness of the bottom foundation of the high-speed railway bridge rescue and evacuation channel and establishing a second sub-model based on the vertical dynamic stiffness of the bottom foundation; establishing a transverse and vertical state evaluation system for the high-speed railway bridge rescue and evacuation channel, thereby detecting the bridge rescue and evacuation channel. A corresponding system is also disclosed, which analyzes the transverse stiffness state and the distribution of the transverse stiffness by testing the transverse vibration signals at different heights along the structure, and simultaneously obtains the vertical support bearing capacity of the foundation by testing the vertical dynamic stiffness of the bottom foundation, establishes an evaluation system that takes into account both the performance evaluation of the frame itself and the vertical support stiffness of the bottom foundation of the frame, and comprehensively evaluates the transverse and vertical stiffness states of the evacuation channel, thereby more comprehensively reflecting the actual state of the evacuation channel.

The application discloses a kind of measurement methods of tire lateral inclination working condition vertical stiffness, including the parameter setting of vertical stiffness test in tire static stiffness testing machine, the parameters include tire pressure, vertical load and displacement loading speed;When tire lateral inclination angle γ is 0, tire vertical stiffness test is carried out, and the radial force F r of tire is collected during measurement test process and the relationship curve of with subsidence amount ρ, and the radial force F r Of tire is collected during measurement test process and the relationship curve of with subsidence amount ρ;When tire lateral inclination angle γ is not 0, tire vertical stiffness test is carried out, and the test data of different lateral inclination angle during measurement test process are collected, and the test data include radial force F r , lateral force F s And subsidence amount ρ;According to the test data obtained in step S3, the tire model formula constructed is input, and the tire vertical stiffness under each lateral inclination angle is calculated.The application designs tire model, deduces tire vertical stiffness under lateral inclination working condition, to realize accurate measurement of tire vertical stiffness under lateral inclination working condition.

The application discloses a method and a structural system for improving three-way stress performance of a large-span three-tower cable-stayed bridge, and the method comprises the following steps: improving vertical stiffness of the three-tower cable-stayed bridge through auxiliary cables and longitudinal elastic cables on both sides of a middle tower; performing three-stage control on longitudinal static and dynamic responses of the three-tower cable-stayed bridge under temperature load, static force and most unfavorable load working conditions and earthquake working conditions through longitudinal elastic cables between the middle tower and a main beam and longitudinal viscous dampers on a first side tower and a second side tower; performing three-stage control on lateral static and dynamic responses of the large-span three-tower cable-stayed bridge through new damping and energy dissipation wind-resistant bearings between the middle tower, the first side tower, the second side tower and the main beam; and performing two-stage control on lateral static and dynamic responses of large-span three-tower cable-stayed bridge piers through friction pendulum seismic isolation bearings between first piers, second piers and the main beam.

The present invention discloses a method for improving the ultimate load stiffness of a marine vibration isolator. The vibration isolator includes an upper mounting seat, a lower mounting seat and a rubber body. The upper mounting seat includes an upper seat plate and a downwardly protruding conical circular boss arranged on the bottom surface of the upper seat plate. The lower mounting seat includes a lower seat plate and a conical sleeve arranged on the top surface of the lower seat plate. The conical circular boss is inserted into the conical sleeve and is vulcanized and bonded between the outer conical surface of the conical circular boss and the inner conical surface of the conical sleeve by using the rubber body. The bottom of the rubber body is set to be concave. The groove formed at the bottom of the concave rubber body is the bottom space A of the rubber body; a space B is formed between the top surface of the rubber body and the bottom surface of the upper seat plate. The method is to reduce the spatial volume of the bottom space A of the bottom of the rubber body so that when subjected to the ultimate load, the bottom of the rubber body expands, deforms and contacts in the reduced bottom space A, thereby improving the lateral stiffness and vertical stiffness of the vibration isolator, thereby improving the ultimate load stiffness of the vibration isolator.

The utility model discloses a 360-degree occlusion node equivalent spring vertical rigidity testing device considering a coupling effect, which comprises a bracket with a door-shaped structure, the lower ends of two supporting legs of the bracket are respectively provided with an extension plate, the two extension plates extend oppositely, and a gap is reserved between the close ends of the extension plates; a pressing plate is further arranged on the lower side of the extension plate in parallel, the pressing plate is connected with the extension plate through a bolt, and a gap is reserved between the pressing plate and the extension plate; a clamping end is arranged at the upper end of the support and used for being connected with loading equipment, and a base is arranged below the support. According to the utility model, through the clamping of the extension plate and the pressing plate, the transmission of force is ensured, the constraint effect on the panel of the occlusion node is improved, and the panel is prevented from horizontal displacement and rotation, so that the panel can only generate vertical displacement under the action of vertical tension, the vertical rigidity of the 360-degree occlusion node can be better tested, and the test precision is higher.

This invention provides a footwear product suitable for diabetic foot. The midsole is composed of multiple unit cell lattice structures arrayed simultaneously in the vertical, horizontal, and longitudinal directions. The vertical direction is consistent with the thickness direction of the midsole, while the horizontal and longitudinal directions are orthogonal to each other and parallel to the plane of the midsole. Each unit cell lattice structure consists of a cube structure, two rectangular structures, four rhombus structures, and five support rods. The two rectangular structures, four rhombus structures, and five support rods are all arranged within the cube structure. The long sides of the two rectangular structures form the diagonal sides of the vertical end face of the cube. A support rod coincides with the intersection line of the two rectangular structures to divide the two rectangular structures into four orthogonally intersecting rectangular faces. The midpoints of the four sides of each rectangular face form the four endpoints of the rhombus structure. The line connecting the two vertical endpoints of each rhombus structure coincides with a support rod, which allows the vertical stiffness of a local area of ​​the midsole to be adjusted by changing the diameter of the support rod.

The application discloses a primary suspension system and a railway vehicle, which comprises a framework, an axle box body arranged on the inner side of a side beam of the framework, a rubber node assembly connected between the top of the axle box body and the framework, used for providing longitudinal and transverse positioning stiffness and releasing vertical stiffness, two steel spring assemblies connected between the top of the axle box body and the framework, and the two steel spring assemblies are respectively arranged on the two sides of the rubber node assembly along the longitudinal direction, used for providing vertical stiffness, and a positioning pull rod connected between the bottom of the axle box body and the framework, used for providing longitudinal stiffness and releasing vertical stiffness and transverse stiffness. The vertical stiffness, the transverse stiffness and the longitudinal stiffness are decoupled, the stiffness in the vertical direction, the longitudinal direction and the transverse direction is respectively realized independently, the primary suspension system has sufficient wheelset axle box positioning stiffness and small vertical stiffness, the critical speed and the ride comfort of the vehicle are ensured, and the high-speed stability and the smoothness requirement of the vehicle are met.

The invention discloses a humanoid robot foot bearing structure which comprises a front foot bottom plate, a rear foot bottom plate, an imitated foot arch piece and an imitated foot sole fascia, the front foot bottom plate, the rear foot bottom plate and the imitated foot arch piece form a triangular arch support capable of being longitudinally deformed, the imitated foot sole fascia elastically deforms along with the imitated foot arch piece, a flexible rotating mechanism is arranged in the front arch section of the imitated foot arch piece, and the front arch section of the imitated foot arch piece is connected with the imitated foot sole fascia. Therefore, the foot arch imitating piece can transversely rotate, human foot tarsal transverse joint movement is simulated, and transverse disturbance is relieved. The device has the advantages that the front arch section and the rear arch section can rotate inwards and outwards around the rigid connecting shaft by utilizing the flexible rotating mechanism, so that the adaptability to complex terrains and the gait stability are improved; the triangular arch structure composed of the foot arch imitating pieces can be dynamically opened, closed and deformed, the impact force generated when the robot walks is dispersed, the vertical rigidity is reduced, and the buffering time is prolonged. The flexible foot sole imitating fascia simulates a human foot sole fascia mechanism, energy is stored when the foot arch imitating piece is compressed, restoring force is generated when the foot is lifted, and the gait efficiency and foot naturalness of the robot are improved.

This invention provides a design method, device, equipment, and medium for pile groups of unequal lengths on steep slopes, relating to the field of pile foundation design technology. The method includes: calculating the stiffness of the embedded pile section based on the vertical compressive stiffness of a single pile on flat ground, taking into account the parameters of the pile foundation structure and soil layer parameters on the slope; deriving a vertical stiffness model for a single pile on the slope based on the pile foundation structure, the length of the free section pile, and the stiffness of the embedded pile section; calculating the length of the free section pile based on the vertical stiffness model of the single pile on the slope and the slope topographic parameters, thus constructing a vertical stiffness model for the pile group on the slope; establishing the vertical stiffness model of the pile group on the slope and the expression for the design of the pile group with equal stiffness based on the spatial relationship between the slope and the pile foundation and the principle of equal stiffness, thus obtaining a basic model for the equal stiffness design method; calculating the length of the embedded pile section in the pile group based on the basic model of the equal stiffness design method, and constructing a pile group design scheme by combining the length of the embedded pile section and the length of the free section pile. This invention solves the problem of uneven stress and settlement in pile group foundations on slopes.

The invention provides a high-speed train suspension parameter evaluation method which combines a particle Markov chain Monte Carlo model, a Kriging model and a particle swarm optimization algorithm. According to the method, firstly, based on a vehicle vertical six-degree-of-freedom dynamical model, a PMCMC algorithm is used for carrying out preliminary evaluation on suspension parameters; then, key suspension parameters, namely, the vertical stiffness of a primary spring and the vertical stiffness of an air spring, serve as design variables, the Pearson's correlation coefficient of the vertical acceleration power spectral density of the simulation and actual measurement vehicle body serves as output, and a Kriging proxy model is constructed; meanwhile, with the purpose of minimizing simulation and actually-measured vertical acceleration PSD errors of a vehicle body, key suspension parameters matched with the actual service state are obtained through a PSO algorithm. And taking the obtained key parameters as prior information of a PMCMC algorithm, and taking actually measured vibration data of the train as an observation value to complete posteriori estimation of the suspension parameters.

The application discloses a stiffness matching method of a frequency-variable stiffness rotary arm joint, which comprises adding different structures in the longitudinal and vertical directions of a liquid rubber composite joint shaft, so that different longitudinal, vertical and transverse stiffnesses and a lower longitudinal-transverse stiffness ratio are obtained, and relates to the technical field of locomotive component manufacturing. The application provides a stiffness matching method and structure of a frequency-variable stiffness rotary arm joint, different main body structures are formed by means of twice adding materials, longitudinal, transverse and vertical stiffnesses are quickly adjusted, and project research and development cost is saved and product development period is shortened.

The invention provides a cable-stayed bridge rubber elastic support vertical stiffness optimization method based on an influence matrix, and the method mainly comprises the steps: building a cable-stayed bridge finite element model, setting the vertical stiffness of all elastic supports to be 0, and applying all dead loads except for the tensioning force of a stay cable; unit cable force and unit support vertical counter force are sequentially applied to main beam nodes at all stay cables and supports, and a tower beam bending moment influence matrix, a support vertical compression amount influence matrix and an influence matrix of other structural responses needing to set boundary conditions are obtained; based on the bending moment influence matrix, establishing a matrix equation among the tower beam bending energy, the tension force and the support reaction force vector; the tower beam bending energy is minimized under the constraint of various boundary conditions, and the optimal tensioning force and support reaction vector are obtained; and finally, determining the vertical rigidity of the elastic support according to the linear relation between the support reaction force and the vertical compression amount of the support. According to the method, the step of optimizing the vertical rigidity of the elastic support of the cable-stayed bridge is integrated into the step of optimizing the cable force by adopting the influence matrix with the purpose of minimizing the bending energy of the tower beam, and a scientific basis is provided for designing the vertical rigidity of the elastic support of the cable-stayed bridge.

According to an embodiment of the present invention, an improved seismic isolation design method utilizing nonlinear time-history analysis based on vertical stiffness linked to horizontal displacement comprises a preliminary design stage and an analysis and review stage, wherein, in the analysis and review stage, vertical stiffness is calculated according to Equation 1 during nonlinear time-history analysis of a seismic isolation device–structure system with respect to horizontal and vertical vibrations, by considering a vertical load-resisting cross-sectional area that decreases according to horizontal displacement of a seismic isolation device, wherein, in Equation 1, Kv denotes vertical stiffness, Ec denotes a composite elastic modulus of rubber, A0 denotes the total cross-sectional area, nr denotes the number of rubber layers, tr denotes the thickness of one rubber layer, and Tr denotes the total thickness of the rubber layers.

The invention discloses a railway fastener system rigidity optimization design method for reducing steel rail side abrasion. The method comprises the steps that a vehicle-rail coupling dynamic model is established, analogue simulation is conducted, and a plurality of wheeltrack transverse force time travel curves and railhead transverse movement time travel curves when a train passes under the condition of different rigidities are obtained; establishing a relation curve of the wheel rail transverse force and the fastener vertical rigidity and a relation curve of the rail head transverse movement and the fastener vertical rigidity; obtaining a changing curve of the transverse force of the outer steel rail and the wheel rail along with the vertical rigidity of the fastener and a changing curve of the gauge enlargement along with the vertical rigidity of the fastener; and normalizing to the same coordinate system, and taking the fastener vertical rigidity corresponding to the intersection point of the two change curves as the optimized elastic backing plate rigidity. The method is used for solving the problem that in the prior art, the development speed of steel rail head side grinding is high, and consequently the maintenance and repair workload is large, and the purposes that the occurrence and development speed of steel rail side grinding is reduced by optimizing the rigidity of the fastener system, and the maintenance and repair workload is reduced are achieved.

The application provides a design method and a support of a vibration isolation spherical steel support containing metal rubber, and the design method comprises the following steps: S1, determining the vertical design bearing capacity N of the vibration isolation spherical steel support S ; S2, determining the number n1 of metal rubber components according to the elastic load interval (N b , N c ); S3, calculating the vertical stiffness K1 of the metal rubber vibration isolation assembly according to the number n1 by using a formula; S4, calculating the vertical stiffness K and the basic frequency f of the vibration isolation spherical steel support; S5, judging whether the basic frequency f is less than or equal to f1 / (2^0.5), wherein f1 is the lower limit of the frequency of the dominant frequency band interval corresponding to the peak value of the reaction force of the vibration isolation spherical steel support caused by vehicle-induced vibration, if yes, the design is completed, and if no, the metal rubber component is redesigned, and the step S2 is returned until the condition of the step S5 is met. The application realizes the normal function of the support while making it have the vertical vibration isolation function, increases the bearing capacity by only changing the number of standard metal rubber components, and breaks through the design bottleneck of the bearing capacity.

This invention discloses a high-position lat pulldown strength trainer, relating to the technical field of strength training devices. It includes an adaptive mechanism mounted on top of a weight block support. The adaptive mechanism includes a fixed rod fixedly mounted on the top of the weight block support, with a movable pulley assembly at the end of the fixed rod away from the weight block support. By setting up the adaptive mechanism and a pair of movable pulley assemblies, each connected via a corresponding rotating shaft, the movable pulley assemblies can swing left and right according to the direction of force on the steel cable. This makes the user's pulldown trajectory no longer rigidly vertical, but rather an ergonomic arc movement centered on the shoulder. Furthermore, the split-motion design allows users to perform single-arm training or alternating training, correcting left-right muscle imbalances.

The invention discloses a vertical shear stiffness quantitative identification and safety monitoring evaluation method for a new and old widened bridge joint, and belongs to the field of bridge engineering safety detection and structural performance monitoring. The invention relates to a method for identifying the rigidity of an abutted seam of a widened bridge, which is characterized in that under the excitation of a low-speed vehicle load, the ratio of response time cumulants of quasi-static displacement generated in the midspan of a new bridge and an old bridge and the vertical rigidity of the abutted seam connecting the two have a clear and stable mathematical mapping relationship; and a stable and reliable dimensionless identification index which is directly associated with the abutted seam rigidity is constructed, so that quantitative evaluation of the health state of the abutted seam is realized. The invention discloses a new and old widened bridge joint safety assessment method. The method comprises the following steps: step 1, arranging a new and old widened bridge joint structure performance monitoring system; 2, deploying a signal processing module and a parameter calculation and state evaluation module in a background; and step 3, deploying a display and monitoring early warning module on a client, wherein a manager can see the content of the display and monitoring early warning module.

The present invention discloses a nano-pan-tilt platform with high static and low dynamic stiffness characteristics. The nano-pan-tilt platform includes a base frame, an output platform, an atomic force microscope probe, and a quasi-zero stiffness mechanism. The output platform is movably mounted on the base frame in the vertical direction. The atomic force microscope probe is mounted on the output platform. The quasi-zero stiffness mechanism includes a first mounting block, a second mounting block, and a quasi-zero stiffness unit. The quasi-zero stiffness unit is mounted between the first mounting block and the second mounting block. The first mounting block is used to connect to the base frame, and the second mounting block is used to connect to the output platform. The quasi-zero stiffness unit includes a positive stiffness mechanism and a negative stiffness mechanism. The positive stiffness mechanism is used to apply a supporting force to the output platform. The negative stiffness mechanism is arranged in the horizontal direction and is configured to offset the vertical stiffness of the positive stiffness mechanism when the positive stiffness mechanism applies a supporting force to the output platform. By introducing the quasi-zero stiffness structure into the nano-pan-tilt platform, the nano-pan-tilt platform achieves a lower system natural frequency.

The present invention discloses a method, device, equipment and medium for checking the assembly line shape of steel truss girder segments, which relate to the field of bridge engineering technology. The method for checking the assembly line shape of steel truss girder segments comprises establishing a finite element model of a steel truss girder and calculating the equivalent vertical stiffness of the steel truss girder segment in the middle of the model, wherein the finite element model of the steel truss girder comprises a plurality of steel truss girder segments, and adjacent steel truss girder segments are spliced ​​by a main truss; the vertical stiffness of the elastic support is set based on the equivalent vertical stiffness, and the adjustable rigidity height of the elastic support is set based on the arch of the bridge design line shape; based on the steel truss girder segment elevation corresponding to the bridge design line shape, the rigidity height of the elastic support under each steel truss girder segment to be assembled is adjusted to obtain the line shape before assembly of the steel truss girder segment; the line shape after assembly of the steel truss girder segment to be assembled is obtained, and the manufacturing configuration deviation of the steel truss girder is determined according to the line shape before assembly and the line shape after assembly of the steel truss girder segment.

The invention discloses a stability control method for continuous reconstruction motion of a metamorphic robot based on nonlinear analysis, which comprises the following steps of: 1, establishing a continuous reconstruction kinematics model of the metamorphic robot by using a spinor theory so as to obtain homogeneous coordinates of centroids of all motion components; 2, establishing a pitch angle-vertical displacement two-degree-of-freedom nonlinear vibration model for continuous reconstruction of the metamorphic robot, and deducing an improved ZMP criterion containing foot wheel nonlinear vertical stiffness; and 4, converting the complex continuous reconstruction nonlinear dynamic model of the metamorphic robot into a simple linear system model for adjusting a centroid mechanism through a sliding block expected displacement deviation solver, and further converting the motion control of each leg joint with continuous reconstruction stability into the displacement control of a sliding block in the centroid mechanism. Therefore, stability control over the metamorphic robot in the continuous reconstruction process is achieved through the LQR controller optimized based on the artificial bee colony algorithm.

The utility model discloses an air spring with the ratio of transverse rigidity to vertical rigidity larger than 1, which comprises a bag skin, an upper cover and a piston which form a closed cavity, the closed cavity is filled with gas with set pressure so as to enable the bag skin to expand, the periphery of the upper cover is connected with an outer sleeve part, and the outer sleeve part extends vertically and wraps the outer side wall part of the bag skin. The air spring is provided with the outer sleeve piece, the air spring generates transverse rigidity through the interaction force between the outer sleeve piece and the expansion bag skin, the transverse rigidity of the air spring can be adjusted by adjusting the vertical height of the outer sleeve piece, and then the ratio of the transverse rigidity to the vertical rigidity of the air spring is larger than 1. The transverse stroke and the vertical stroke of the air spring are both large, rigidity sudden change does not exist in the operation process, and the overall stability is good. The air spring is simple in overall structure and low in production cost, the fatigue life of the bag skin of the air spring can be prolonged through shape optimization of the outer sleeve piece, and reliability is improved.

The invention discloses a method, system and equipment for testing the combination degree of a plate-truss combined beam and a storage medium, and relates to the technical field of bridge engineering, and the method specifically comprises the steps: constructing an experimental model and a theoretical model of a plate-truss combined cantilever beam, and determining the theoretical transverse stiffness of the plate-truss combined cantilever beam according to the theoretical model; carrying out a transverse loading test on the experimental model to obtain actual transverse rigidity; determining a second elastic modulus of the concrete in the experimental model based on the theoretical transverse stiffness, the actual transverse stiffness and the first elastic modulus of the concrete in the theoretical model; constructing a target influence curve based on the second elastic modulus, and determining the target vertical stiffness of the plate-truss combined cantilever beam in the theoretical model under the complete consolidation condition according to the target influence curve; performing a vertical loading test on the experimental model to obtain actual vertical rigidity; and determining a target combination degree based on the actual vertical stiffness and the target vertical stiffness. According to the invention, the precision of the combination degree test of the steel truss and the concrete bridge deck is improved.