106 results about "Damping matrix" patented technology

The invention provides an impedance control method for a flexibility joint mechanical arm based on a connection and damping configuration, and belongs to the technical field of robot controlling. The problem in a traditional mechanical arm control method that during the flexibility joint mechanical arm control process, due to the fact that the residual oscillation is large, the aim of stable control cannot be achieved is solved. The technical points are that according to a CAD three-dimensional model, a kinetic parameter and a kinematic parameter of the flexibility joint mechanical arm are obtained; according to the parameter identification, a key parameter of a flexibility joint is obtained; a kinetic equation of the flexibility joint mechanical arm is established; a gravity compensation algorithm and an external force compensation algorithm based on the motor position are established; a gravity compensation value and an external force compensation value of the mechanical arm are calculated and obtained; a minimum Hamiltonian function value on the expectation balance position of motor position information is calculated and obtained; an expectation connection matrix and a damping matrix in the impedance control are calculated; an impedance control rule of the flexibility joint based on the connection matrix and the damping matrix are obtained. The impedance control method for the flexibility joint mechanical arm based on the connection and the damping configuration can be used for controlling service robots, medical robots and space robots.

The invention discloses a nonlinear path planning method based on a hybrid pigeon population algorithm and belongs to the technical field of a single unmanned aerial vehicle. The method comprises determining a flight range and obstacles, initializing various parameters, producing a population initial state value through a random interval method, updating a population position and rate through an ego and social learning factor formula which has an inertia matrix and produces cosine transformation along with the inertia matrix according to the ideology of combination of particle swarm optimization algorithm self-learning and social learning in a map and a compass operator, after cycling upper limit, feeding the data into a landmark operator, sorting the pigeon populations according to adaptability values, recording a center position, calculating the iterative population quantity through a damping matrix producing cosine transformation, updating a position and a rate, and outputting the optimal path. The method improves the accuracy of the algorithm, can produce the optimal solution or the second-best solution very close to the optimal solution and can improve stability of the algorithm and the rate of the path planning.

The invention provides a rotor-rotor. The nonlinear dynamics analysis method for the bearing system comprises the following steps: inputting calculation parameters; Calculating a system overall mass matrix, a rigidity matrix, a damping matrix and a gyroscopic effect matrix; Calculating unbalanced excitation of the rotor; Calculating the thickness of the bearing oil film at the t moment; And calculating the bearing oil film pressure at the t moment. Judging whether the oil film pressure meets a convergence condition or not; Calculating a bearing friction force and an end leakage flow at a t moment; Calculating the effective temperature and effective viscosity of the lubricating oil at the t moment; And calculating the oil film bearing capacity at the t moment. Newmark-based And algorithm: calculating the vibration response of the rotor system at the t + t moment. And whether the break + t moment reaches a time upper limit is determined. According to the method, the bearing nonlinear oilfilm force solving process based on the finite difference method is embedded into calculation of the rotor vibration response, and influence factors such as lubricating oil rheological properties andbearing bush surface elastic deformation are considered when the oil film force is solved, so that the response calculation is more accurate.

A method is disclosed for analyzing the vibrational characteristics of rotating devices, such as hard disk drives and jet engines, that are coupled through bearings to flexible supports. In the method, the rotating device is discretized, for example, using a mesh suitable for finite element analysis. The support is also discretized. The natural frequency of elastic vibration modes for the rotating device is calculated and the natural frequency of vibration modes for the support is calculated. The mode shapes are then calculated and a set of modal basis corresponding to the mode shapes is utilized. Bearing stiffness and damping matrices are input, and the Lagrangian equations of motion are integrated numerically in the modal space, to calculate the vibrational response of the rotating device and support. The modal space results are then transformed into ordinary space. The vibrational analysis may be used to design devices having desired vibrational characteristics.

The invention relates to a damping injection control method for improving power angle oscillation of a water turbine generator set. An autocorrelation factor of the unit power angle is increased based on the structural analysis of a Hamilton model damping matrix of the water turbine generator set, namely the power angle damping is injected based on a dynamical mechanism associated inside the system, and the structural change is equivalent by designing a corresponding control law. Due to the applicability analysis of the equivalent control law, a variable structure control strategy by combining the algorithm and a traditional PID control algorithm is provided so as to control the machine set, and corresponding solutions are provided for the control of output phase step and other problems. The simulation proves that: the provided control algorithm can effectively improve the oscillating characteristics of the power angle of the machine set, even can keep the stability of the machine set under lower damping.

The invention provides an identification method of dynamic parameters of a machine tool fixed joint part. The method comprises the following steps: taking a structural damping matrix of a joint part unit and a stiffness matrix of the joint part unit as parametric variables, setting the difference between the product of a displacement impedance matrix and a displacement frequency response function and a unit matrix to be minimum as an optimum design objective, and obtaining parameter variable values (i.e., the identified parameters of the joint part) through multiple iteration. The identification method takes damping and stiffness of multiple key freedom directions and the intercoupling relation into account to avoid a secondary error produced by matrix inversion, has high precision, and more accurately characterizes richer dynamic characteristics of the joint part.

The invention provides a method for determining the critical rotating speed of a wet rotor of a multistage centrifugal pump. According to the method, an automatic node division module, a model creating module and a model calculation module are mainly utilized for determining the critical rotating speed, and the data processing is carried out among the modules in a sequence sequentially from the automatic node division module, the model creating module and the model calculation module. Firstly, the automatic node division module creates a geometrical model of a wet rotor system on the basis of an engineering drawing, and in addition, the automatic division of modes is carried out; secondly, the model creating module is utilized for inputting physical parameters of parts such as rotating shafts, impellers, bearings and sealing clearances, and a total mass matrix [M], a total rigidity matrix [K], a total damping matrix [C] and an overall calculation model of a multistage centrifugal pump shaft system are built; finally, the model calculation module is utilized for solving the overall calculation model of the multistage centrifugal pump shaft system, a Campbell chart is drawn, and the required first n step of critical rotating speed is obtained. The method has the advantages that the operation is simple, the engineering applicability is wide, the critical rotating speed of the wet rotor of the multistage centrifugal pump can be calculated under the condition of different structures, the engineering design and the application of the rotor of the multistage centrifugal pump are guided, the design period is shortened, and the production efficiency of the rotor of the multistage centrifugal pump is improved.

Disclosed is a deep-water pier seismic response evaluation method taking water-pier coupling effect into consideration. In the deep-water pier kinetic equation: P=-(M(1)ug(t)+M(2)us(t)), which takes water-pier coupling effect into consideration the M, the K and the C refer to quality matrix, rigidity matrix and damping matrix in the structure respectively, the ug(t) is the seismic oscillation acceleration time interval, the us (t) is the relative-movement displacement time interval of a pier, the u's (t) is the relative-movement speed time interval of the pier, the us(t) is the relative-movement acceleration time interval of the pier, the (M(1)) and the (M(2)) are the rigid-body associated mass matrix and the flexible associated mass matrix under water, and the P is the seismic oscillation water pressure load stressed on the pier. The deep-water pier seismic response evaluation method can be used for anti-seismic design and bearing force evaluation of a deep-water bridge structure under the action of earthquakes. Seismic response analysis of the pier of the deep-water bridge in finite element software can be conveniently performed, the factors, such as nonlinearity, interaction of soil-structural power and the like in materials can be considered during analysis, and the deep-water pier seismic response evaluation method is high in computing efficiency as compared with fluid-solid coupled numerical software and further provides the theoretical basis for the anti-seismic design of the deep-water bridge.

A method for analyzing a torsional vibration inherent characteristic of a planet gear transmission system comprises the following four steps: (1) carrying out mathematical modeling on pure torsional vibration of a single planet row with damping by using an Lagrangian equation; (2) analyzing the inherent characteristic of the transmission system; (3) verifying the influence of the damping on a fixed frequency through multigroup calculation; and (4) establishing a general matrix for the planet gear transmission system and carrying out modeling simulation verification through instance value calculation and simulation X. Through the adoption of the invention, an obtained damped natural vibration differential equation in the form of a parameterized matrix (a rigidity matrix, a damping matrix and a connecting matrix) in the planet transmission system is general; corresponding matrix forms are directly selected for corresponding parts according to different connecting structures and planet gear system parameters to construct an integral system matrix; and after parameters are brought in, the inherent characteristic of the transmission system is rapidly and accurately analyzed.

The invention discloses a Buck-Boost converter variable damping passive control method based on a port controlled dissipation Hamiltonian model. The method comprises the following steps of 1, according to the system state averaging model and the state variables of a Buck-Boost converter, converting the system state averaging model of the Buck-Boost converter into a port controlled dissipation Hamiltonian model form, and verifying the passivity of the port controlled dissipation Hamiltonian model form; 2, according to the port controlled dissipation Hamiltonian model of the Buck-Boost converterand an interconnection and damping distribution passive control method, giving an expected interconnection and damping matrix and carrying out passive controller design; 3, designing a second-order differential tracker according to the influence of the damping coefficient change of the given damping matrix on the system performance, and realizing the real-time change of the injection damping; 4,designing a variable-damping passive controller according to the passive controller and the second-order differential tracker, and controlling the output voltage of the Buck-Boost converter. Accordingto the invention, by means of the control method, the output voltage of the Buck-Boost converter can be quickly converged to the expected output voltage. The steady-state error of the output voltageis reduced, and the overall performance of the system is improved.

The invention relates to the technical field of robots, in particular to a vibration suppression method of a flexible multi-joint robot. The vibration suppression method of the flexible multi-joint robot comprises the following steps that motion data of joints of the flexible robot are collected in time; according to the collected motion data of the joints, a dynamic equation of the rigid body andjoint deformation of the robot and a dynamic equation of an expected trajectory of the robot tail end are established, and a required joint moment value is obtained by solving the inverse dynamic calculation; according to a flexible expected damping matrix of a robot body, joint driving moment is optimized to obtain an optimized joint moment value; and according to the optimized joint driving moment value, joint moment control is carried out so as to suppress the flexible deformation vibration of the robot. The vibration suppression method of the flexible multi-joint robot has the beneficialeffects of suppressing the flexible vibration of the robot body and improving the trajectory tracking precision of the robot.

The invention provides a non-traditional damping system damping matrix identifying method which is based on unit matrix decomposition and can handle with three-dimensional space problem, aiming to solve the status quo that only low-order mode information is available in the traditional mode testing technology under environment excitation and overcome the problem that the relative high-order mode information is required at certain extent by the traditional damping matrix identifying method. The required practically tested vibration type can be the multiplex vibration type, the quality normalization is not required, and the method can be well suitable for the status quo that the damping matrix only can be accurately measured by the finite low-order mode; after being combined with the mode parameter identifying technology based on output response, the method can identify the non-traditional damping system damping matrix of the ocean platform under the environment excitation.

The invention relates to preparation of restraint damping fins, and mainly relates to an automobile graphene flame retardant restraint damping fin and a preparation method thereof. Brominated/chlorinated butyl rubber is used as a damping matrix material; by use of the intrinsic flame retardant property of a graphene microchip and extremely high synergetic flame retardant property of an added phosphorus based flame retardant, the brominated/chlorinated butyl rubber, the graphene microchip, a softening agent, a reinforcer and a vulcanizing agent are blended and mixed; after the materials are uniformly mixed, the mixture is extruded by a single-screw extruder to form a sheet; the sheet is combined with a restraint layer and a base plate at a die head, so that the automobile graphene flame retardant restraint damping fin is obtained.

The invention discloses a diesel engine shaft system torsional-vibration calculating method. The diesel engine shaft system torsional-vibration calculating method comprises the following steps that 1, equivalent simplification is conducted on a crank shaft system and a cam shaft system by utilizing a centralized parameter method, and an inertia matrix, a stiffness matrix and a damping matrix are calculated; 2, torsional-vibration excitation of the crank shaft system is calculated; 3, the load torque of a cam shaft is obtained according to a moment balance equilibrium principle; 4, forced vibration response is solved by using a Newmark-beta algorithm; 5, trend terms in response calculation are eliminated by using a least square method to obtain a real value of response calculation. The method gives full consideration to the coupling relation between the cam shaft system and the crank shaft system, and response calculation is more accurate. The application range of the shaft system torsional-vibration calculating method is widened, and the shaft system torsional-vibration calculation requirement of a high-power diesel engine can be met.

The invention relates to the technical field of railway tracks, in particular to a railway bridge track irregularity calculation method based on vehicle-mounted monitoring. The method comprises stepsof collecting and detecting vibration response of the vehicle when the vehicle runs on the line; calculating a stiffness matrix K, a damping matrix C, a mass matrix M and a load matrix p of the vehicle-bridge system at the current moment, and constructing a time-varying motion equation of the vehicle-bridge system; calculating coefficient matrixes phi k, theta k, omega k, Hk, lambda k and psi k ofthe observation equation at the current moment, and conducting discretization processing on a vehicle-bridge system state vector and a vehicle-mounted observation vector; calculating a weight matrixVk at the current moment based on calculation according to prediction and calculation; the bridge track irregularity state is monitored in real time by utilizing the vehicle-mounted vibration data ofthe operating vehicle on the basis of the axle coupling dynamic analysis theory and the Kalman filtering analysis method, so that the bridge track irregularity detection efficiency and detection precision are improved, and the detection cost is reduced.

The invention relates to a process damping modeling method suitable for a thin-walled part milling process, which considers vibration effects of two orthogonal directions at the same time. The processdamping modeling method suitable for the thin-walled part milling process comprises the following steps: firstly, calculating a dynamic cutting force matrix and a process damping matrix correspondingto each edge element considering the vibration effects of the two directions at the same time; then combining the dynamic cutting force matrix and the process damping matrix of each edge element to calculate the dynamic cutting force matrix and the process damping matrix applied on the whole tool-workpiece system; and then using the obtained dynamic cutting force matrix and process damping matrixto establish a milling dynamic control equation of the tool-workpiece system, so that a stability lobe diagram considering the damping effect of the milling process of the thin-walled part can be drawn by performing stabilized solving on the equation.

The invention discloses a noise pre-estimating system for pre-estimating noise of a single-phase oil-immersed transformer. The system includes a transformer component finite element unit for determining a solid unit stiffness matrix KS, a damping matrix CS and a mass matrix MS relevant to a solid; a fluid acoustic finite element unit which establishes a fluid acoustic finite element equation according to air parameters out of a box and a transformer internal fluid field; a solid and fluid coupling unit which establishes a solid and fluid coupling dynamic equation; a test unit which includes an optical fiber accelerometer, an acquisition instrument and a sound meter; an electromagnetic excitation analog input unit to which excitation vectors of a plurality of harmonic components of a solid structure are applied; and a data correction unit which takes the solid and fluid coupling dynamic equation as a pre-estimating model, and uses an acoustic model and a difference to calculate the coupling dynamic equation so as to obtain a sound pressure of a sensitive point.

The invention belongs to the technical field of construction and traffic bridges, and more particularly relates to a highway random traffic flow wind-vehicle-bridge coupling computation method. According to the method, traffic load of a typical road section is investigated by use of a traffic information acquisition system and dynamic bearing equipment; vehicle models in practical traffic load are classified according to an investigation result, a dynamic analysis model of each vehicle model is established, and motion equations of different vehicle models are deduced by use of different principles, so that a mass, rigidity and damping matrix is formed; a geometrical and mechanic coupling relation between the vehicle and the bridge system is established according to different beam unit analysis models, a vehicle bridge coupling random vibration analysis system is created, so that programmed vehicle bridge coupling computation is realized; and according to investigation of practical traffic load, a vehicle dynamic analysis model of each typical vehicle is established so as to form a complete analysis model bank, and the motion equation of each type of vehicle is established, so that vehicle bridge system dynamic response is computed and analyzed precisely.

The invention relates to a thin-wall piece milling vibration restraining method based on a movable support. The mass, rigidity and a damping matrix of a workpiece are obtained through the finite element; equivalent stiffness and damping provided through the movable support are calculated through the contact theory and assembled to rigidity and a damping matrix of an initial workpiece; and finally,dynamics parameters of the workpiece at different tool position points are rapidly obtained through a numerical calculation method, and stability prediction is conducted. The functions of efficient restraining of vibration and rapid prediction of vibration stability in the whole machining process are achieved, and the material removal rate in the milling process is improved by 67% to the maximumin the embodiment.