499 results about "Kinetics equation" patented technology

The invention relates to a flexible satellite locus linearization attitude control method based on a disturbance observer. The invention aims at solving problems that a single locus linearization control method is poor in capability of inhibiting interference, is poorer in robustness, and does not consider external interference and the impact from flexible accessories. The method comprises the steps: employing Euler angles for describing attitudes of a spacecraft, employing an idea of equivalent disturbance, and building a flexible spacecraft dynamics and kinetics equation; solving the pseudo-inverse of a controlled object under the condition of neglecting equivalent disturbance, designing a quasi-differentiator of a specific type, and obtaining the nominal control of an expected locus; and designing a linear time varying adjuster through proportion-integration control. The method gives consideration to the influence of equivalent disturbance, designs the disturbance observer, and guarantees the asymptotic convergence of a tracking error of a flexible spacecraft. The method improves the anti-interference capability of a system, and improves the robustness of the system. The method is used in the attitude control field of flexible satellites.

The invention discloses a four-rotor aircraft control method based on PID neural network (PIDNN) control. First, dynamic equations of a four-rotor aircraft are established based on the Newton-Euler equations, and then, a nested controller is proposed. An inner loop decentralized controller is designed based on a PIDNN method to realize attitude control, and the outer loop adopts a classical PID control method. Next, online learning of a PIDNN controller is realized by an error back propagation method, the connection initial weight of PIDNN is determined based on the principle of PID control, and an appropriate learning step is selected according to the discrete Lyapunov theory to guarantee the convergence of the controller. Thus, the control problem of a four-rotor aircraft caused by high degree of nonlinearity, strong coupling and under-actuating capability, disturbance from the external environment in the process of flight and other factors can be effectively solved.

The invention provides an uncertain mechanical arm fixed time track following control method with input saturation, which can overcome influences of mechanical arm control input saturation effect anduncertainty, and improves robustness of a system. The method comprises the following steps: establishing a kinetic equation of an n-freedom rotary joint rigid mechanical arm system with a viscous friction item; according to the established kinetic equation and a mechanical arm track error following signal, establishing a following error kinetic equation which takes parameter uncertainty into consideration; establishing a state space model of mechanical arm track following errors; establishing a fixed time disturbance observer according to the established space model; establishing a fixed timenon-singular terminal sliding mode surface according to the mechanical arm track following error signal; preliminarily determining each joint drive motor control moment instruction of a mechanical arm, and integrating a moment output range of a performer, thereby obtaining each joint control moment of the mechanical arm. The invention relates to the field of mechanical arm control.

The invention discloses a self-adaptive starting control method for a four-wheel hub electric automobile. The self-adaptive starting control method for the four-wheel hub electric automobile comprises the following steps of estimating a vehicle running gradient through an Luenburg state observer in real time and obtaining a hill-holding torque, which is needed to keep the vehicle in a static at the gradient, according to vehicle kinetics equation; meanwhile, selecting a vehicle speed as a control target and outputting a compensating torque through PID feedback closed-loop control; and finally, overlaying the hill-holding torque and the compensating torque and inputting the overlaid torque into a motor after being amplitude-limited and filtered so as to drive the vehicle to be stably started on a ramp. According to the invention, drivers do not need to intervene in the starting process; the vehicle cannot slide in the uphill starting process through automatically calculated torque.

The invention provides a tracking method for a mechanical arm tail end trajectory of a robot, which comprises the following steps: the mechanical arm tail end moving track of a robot, which is defined by a user in advance, is expressed in a mathematic form; the moving track expressed in the mathematic form is positioned in a joint space; according to the kinetic equation of the robot, the application scene of the robot and the mechanical arm tail end moving trajectory of the robot, which is defined by the user in advance, a target function and a constraint equation are built; both the target function and the function in the constraint equation can be converted into convex functions; the target function and the function in the constraint function are both converted into the convex functions to form a convex programming optimization model; the convex programming optimization model is solved after being discretized to obtain the amount of exercise of each joint of the robot; and the robot is driven by the amount of exercise of each joint of the robot. The tracking method for a mechanical arm tail end track of a robot has the advantage of being high in calculation speed and easy to expand.

The invention discloses a motor servo system parameter identification method and anti-backlash control method. The purpose of rapid and accurate tracking of the motor can be achieved. According to thetechnical scheme, a kinetic equation of a motor servo system containing backlash is built, a backlash model is shown according to transmission torque obtained when a motor makes contact with load, linearization is conducted for the backlash model; aiming at the kinetic equation of the motor servo system containing the backlash, discretization is conducted, by means of the kinetic equation, obtained after discretization, of the motor servo system containing the backlash, the backlash model obtained after discretization is reconstructed to obtain a first compact type expression, the first compact type expression is identified through recursive least squares, and motor parameters are obtained; the identified result of the motor parameters is put in the backlash model obtained after linearization, a second compact type expression is built again, identification is conducted, and load parameters are obtained. Meanwhile, the anti-backlash control method is provided on the basis of the identified result.

The invention relates to a joint simulation method for a vehicle-road coupled vibration system. The method comprises the following steps of S1, building a vehicle dynamics model according to a dynamics equation; S2, building a pavement dynamics model according to a structural mechanics finite element equation; and S3, loading the vehicle dynamics model in the pavement dynamics model to generate a tire-pavement contact model, and finishing dynamics analysis of the vehicle-road coupled vibration system. According to the method, joint modeling of the vehicle-road coupled vibration system is realized by adopting efficient engineering software Matlab and Ansys; and by taking Matlab as control software and performing secondary development on Ansys, joint simulation of Matlab and Ansys is realized, and dynamics analysis of the vehicle-road coupled vibration system under complex road and vehicle conditions is finished.

The embodiment of the invention provides an impedance control method and device, an impedance controller and a robot. The method comprises the steps of acquiring joint motion information and joint stress information of a mechanical arm in a joint space and actual interaction force received by a tail end, and solving actual motion information of the tail end in a task space according to the joint motion information; calculating a corrected expected trajectory by using environmental information and tail end expected interaction force, carrying out calculation to obtain an impedance control moment according to the joint stress information, the actual interaction force, the actual motion information and the tail end expected information containing the corrected expected trajectory, determininga compensation moment according to a nonlinear term in a constructed dynamic equation, and therefore controlling the joint moment of the mechanical arm. According to the technical scheme, the impedance control law is corrected to realize directional decoupling impedance control, so that the interaction between the tail end and the environment is safer and more compliant, and the force control precision can be improved; and control complexity can be simplified through the nonlinear term in the compensation dynamic equation

The output of a nuclear reactor is increased by a predetermined magnitude, and the neutron beam is measured as time-series data. The temperature of the moderator in the reactor is acquired as time-series data. Time-series data on the reactivity is acquired from the time-series data on the neutron beam by the reverse dynamic characteristic method with respect to a one-point reactor kinetics equation. Time-series data on the fuel temperature of a predetermined average acquired by using the time-series data on the reactor output and a predetermined dynamic characteristic model is acquired. The reactivity feedback contribution component is determined by using the time-series data on the reactivity and the applied reactivity. The Doppler reactivity coefficient is determined by using the time-series data on the average temperature of the moderator in the reactor, the time-series data on the fuel temperature of the predetermined average, the isothermal temperature reactivity coefficient, and the reactivity feedback contribution component.

An offline bridge crane locus control method is a constrained under-actuated bridge crane acceleration locus control method. The method comprises the following steps: 1, locus programming scheme: adopting a smooth acceleration movement locus; 2, locus parameter determination: solving the kinetics equation of a crane system and analyzing a coupling relationship between trolley acceleration and load swing for any delivery process, and calculating an actual maximum acceleration amax, a uniform acceleration ta time and a uniform speed time tc in order to obtain an ideal acceleration locus meeting some core performance indexes; and 3, control method realization: realizing the crane control by calculating a deviation between x(t) and an acceleration single continuous integral signal xv(t) in real time by means of a trolley displacement signal x(t) and a speed signal and using a traditional PD controller to generate a corresponding drive motor control command in order to complete a transport task.

The invention relates to the field of advanced manufacturing, in particular to a milling stability predicting method based on a cubic polynomial. The milling stability predicting method has the advantages that a state term, a delay term and a cycle coefficient term of a dynamics equation are approximated by the cubic polynomial, the required term is fit by a plurality of known time points and corresponding responses, the local error of a calculating method is reduced, and the accuracy of the predicting method is improved; an H matrix is substituted into the stability lobe graph obtaining process, and is not directly substituted into an F matrix for calculating, so the number of iteration times in the F matrix calculating process can be reduced, the time of the calculating method is saved, and the calculating efficiency is improved.

The invention provides a dynamic sliding mode attitude tracking control method and system for a flexible spacecraft. The method comprises the steps of S1, establishing error posture quaternion-based kinematic equation and kinetic equation of the flexible spacecraft; and S2, by introducing a dynamic switching function, designing a dynamic sliding mode attitude tracking control law of the attitude tracking problem of the flexible spacecraft, and designing a finite time convergence-based robust differentiator to estimate a partial state of a flexible spacecraft system. The dynamic sliding mode attitude tracking control method and system has the beneficial effects that the problem of buffeting caused by a traditional sliding mode control law symbol function is effectively inhibited through thedesign of the switching function; and the dynamic sliding mode attitude tracking control method can enable the spacecraft system to carry out attitude tracking.

The invention relates to the field of advanced manufacturing, in particular to an orthogonal polynomial-based milling stability prediction method. The orthogonal polynomial-based milling stability prediction method adopts orthogonal polynomials to approach a state term, a delay term and a periodical coefficient term in a kinetic equation, and adopts a plurality of known time points and responses thereof to fit the needed terms, so that the local errors of the calculation method are reduced, and thereby the precision of the prediction method is increased; meanwhile, in the process of obtaining a stability lobe diagram, an H matrix is introduced instead of directly substituting an F matrix for calculation, so that the number of iterations in the F matrix calculation process is reduced, consequently, the time of the calculation method is saved, and the efficiency of calculation is increased.

The invention relates to a dynamic game theory-based multi-spacecraft chase control method. The dynamic game theory-based multi-spacecraft chase control method comprises the steps of ignoring all perturbative force according to space environments of spacecrafts and building a kinetic model, also known as a kinetic equation, for multiple spacecrafts in a gravitational field at the center of the earth, wherein the model comprises three roles, namely a target spacecraft, a defense spacecraft and an attack spacecraft; determining a payment function for the spacecrafts and a terminate target set ofchase games according to a role relationship among various spacecrafts in the kinetic model, thereby building a multi-spacecraft game model; processing the multi-spacecraft game model by using a dynamic game theory to obtain a two-point boundary value equation, wherein the two-point boundary value equation comprises a differential equation of a costate vector, and a new kinetic equation and a time cross-sectional equation represented by the costate vector; for the built two-point boundary value equation obtained in a two-point boundary value problem, obtaining a solution of the equation by using a method of combining a particle swarm algorithm with a nonlinear programming method, thereby obtaining an optimal control strategy and an optimal trajectory for spacecraft chase.

The invention provides a mixed preloaded bearing rigidity calculation method considering a main shaft-bearing coupling relation. The method comprises the steps as follows: firstly establishing iterative equations for a location preloaded bearing and a constant pressure preloaded bearing, and a main shaft kinetic equation; then coupling the main shaft and the bearing by using bearing rigidity and main shaft support node displacement (bearing inner race displacement) as coupling amount, and finally using Matlab to compile a calculation program to obtain the rigidity of the mixed preloaded bearing based on a finite iteration method. The method considers the influence of mixed preloaded and the main shaft-bearing coupling relation to the rigidity of the bearing, and could use different preloaded manners to perform accurate calculation to dynamic rigidity of the bearing under a working condition of bearing and high-speed cutting. The method provides guidance for designing and using an electric main shaft.

The invention discloses a morphing aircraft transition section tensor product interpolation modeling and control method. The morphing aircraft transition section tensor product interpolation modeling and control method comprises the following steps of, firstly, establishing a morphing aircraft transition section non-linear kinetic model, and establishing a morphing aircraft kinetic equation; secondly, through a linear parameter varying comprehensive modeling method integrating small-increment linearization and accurate linearization, establishing a morphing aircraft transition section linear parameter varying model, namely, an LPV model; thirdly, on the basis of the LPV model, establishing a tensor product interpolation model; fourthly, based on the tensor product interpolation model, designing a morphing aircraft transition section flight control method which is small in computational amount. On the basis of the new morphing aircraft transition section linear parameter varying modeling method, the tensor product interpolation model is established; on the basis of the tensor product interpolation model, the flight control method is designed and optimization of tensor product interpolation coefficients is performed, so that optimized control effects can be obtained.

The invention discloses a hybrid machine tool milling stability prediction method. The method comprises the steps of integrally dividing a hybrid machine tool system into a cutter, a cutter handle, amain shaft and a parallel/parallel hybrid mechanism, the cutter-cutter handle-main shaft serving as a first sub-structure, and the parallel/parallel hybrid mechanism serving as a second sub-structure;measuring to obtain frequency response functions of the first sub-structure and the second sub-structure, and obtaining a tool nose point frequency response function; establishing a milling kinetic equation under a physical coordinate system; converting the milling kinetic equation under the physical coordinate system into a milling kinetic equation under a modal coordinate system; solving a milling kinetic equation under the modal coordinate system to obtain a state transition matrix; judging the characteristic value of the state transition matrix, and drawing a stable lobe graph; and carrying out milling stability prediction on the parallel hybrid machine tool system according to the stability lobe graph. According to the method, the influences of the low-order dynamic characteristics and the medium-high-order dynamic characteristics of the parallel mechanism are comprehensively considered, and the milling stability of the parallel hybrid machine tool can be predicted more accurately.

The invention discloses a detection method of damage of one-way silicon carbide fiber toughening silicon carbide ceramic matrix composite in oxidation environment and aims to solve the technical problem that the prior detection method of damage of the one-way silicon carbide (SiC) / SiC composite is bad in accuracy. The technical scheme is that an oxidizing reaction kinetics equation is applied to calculate the thickness of oxidation loss of a carbon interface in the composite material microstructure oxidation process and acquire a geometric model under different oxidation times of the composite microstructure; a finite element model of the composite microstructure after being oxidized is built to conduct finite element calculation of microcosmic stress; and maximum stress strength criterions are adopted to detect damage conditions of materials. The detection method of damage of the one-way silicon carbide fiber toughening silicon carbide ceramic matrix composite in the oxidation environment is simple and high-efficiency from the molding process to the calculation process, overcomes the defects that the prior experimental method is high in cost and long in time consumption, acquires the microcosmic stress in the microstructure of the composite after being oxidized with the help of the strong finite element analysis function of ANSYS; improves accuracy of damage analysis of the one-way SiC / SiC composite and solves the problem that the mesomechanics model is low in accuracy.

The invention discloses a structural vibration control method based on reinforcement learning, a medium and equipment. The method comprises the following steps: establishing a kinetic equation and a reward function of a controlled system; establishing and initializing a strategy network, a target strategy network, a value network and a target value network; establishing a playback pool; data interaction is achieved. Meanwhile, the control signal, the feedback signal and the reward signal are stored in a playback pool, the control signal, the feedback signal and the reward signal are provided for a reinforcement learning algorithm in a random sampling mode to update parameters of a strategy network and a value network, and a soft update mechanism is adopted to update parameters of a target strategy network and a target value network; obtaining a final strategy neural network as a controller; and deploying a controller, taking the feedback signal acquired by the sensor as the input of the neural network, and outputting a control signal after the forward calculation of the neural network to complete the control operation of the structural vibration. The invention provides a more intelligent control method for vibration control of a complex structure, and has excellent control performance and engineering practicability.

A real-time simulation method of elastic materials based on an exemplar in a Laplace-Beltrami shape space includes the steps that by means of a Laplace-Beltrami operator and a linear finite element discretization method, characteristic functions and characteristic values of a simulation object and the exemplar on a three-dimensional tetrahedral mesh are calculated; the characteristic function of the exemplar and the characteristic function of the simulation object are subjected to registration; the position of the simulation object is projected in the Laplace-Beltrami shape space, and the shape of a target on an exemplar fashion is solved through non-linear shape interpolation; a final deformation result under an Euclidean space is obtained by building a local coordinate system on each vertex at current moment and adding shape details; a deformed object simulation kinetic equation under a non-inertial system is solved by means of a dimensionality reduction subspace built on a modal substrate, and displacement under a dimensionality reduction space at a new moment is obtained; the displacement under the dimensionality reduction space is projected to obtain global displacement by means of a projection matrix calculated in the preprocessing process under global and dimensionality reduction spaces, and a deformation result is drawn.

The invention provides a whole vehicle mass estimation method and a torque control method and device, which belong to the technical field of vehicle control. The whole vehicle mass estimation method comprises the steps that when a vehicle is in a neutral gear, a first acceleration is acquired; when the vehicle is in the gear, a second acceleration and a corresponding driving torque are obtained; avector sum of the first acceleration and the second acceleration is taken as an actual acceleration, and a longitudinal kinetic equation of the whole vehicle is constructed; and iterative computationis carried out on the longitudinal kinetic equation of the whole vehicle by using a recursive least square method, and the mass of the whole vehicle is obtained through estimation. When the method isused for estimating the mass of the whole vehicle, the influence of factors such as rolling resistance, air resistance, acceleration resistance and ramp resistance on the estimation of the mass of the whole vehicle is fully considered, the consideration is comprehensive, and the estimated mass of the whole vehicle is more accurate.

The invention discloses a multi-constraint robot milling attitude planning method and system based on a potential field method, and belongs to the field of milling manufacturing. According to the method, the geometric physical constraint is converted into a virtual potential field, so that the constrained quantity is far away from a constraint boundary under the action of repulsive torque generated by the virtual potential field, and a generated attitude trajectory meets the geometric physical constraint. According to the method, the redundant angle of a robot and the front heeling angle of an end effector are comprehensively considered, and the machining quality is further improved. After the factor is considered, a generated trajectory is applied to milling, and the machining precision is obviously improved. The invention provides a new potential field function, a virtual kinetic equation is calculated through numerical integration to solve the attitude trajectory, and the obtained solution is a numerical value in a continuous domain, so that the robot trajectory always ensures that the joint movement C3 is continuous in the movement process, and the fairness of the generated attitude trajectory is ensured.

The invention relates to a parameter optimization method based on Pareto optimality under a dual-mode configuration multi-target condition, and belongs to the field of new energy vehicles. The method comprises the following steps: S1, constructing a steady-state kinetic equation under different configuration modes of a dual-mode configuration and a mode switching strategy based on transmission efficiency maximization; S2, establishing a hybrid power transmission system transient kinetic equation considering the rotational inertia of components; S3, based on a dynamic programming algorithm, constructing economic evaluation indexes including working condition related economic cost and transmission system part cost and a dynamic property evaluation index quantified by hundred kilometers of acceleration time; and S4, constructing a multi-objective optimization function through a Chebyshev aggregation method, and obtaining the economic cost related to the dual-mode configuration related working condition, the power transmission system part cost and the optimal Pareto leading edge of the dynamic property taking the acceleration performance as an evaluation index based on a multi-objective evolutionary algorithm MOEA/D. According to the method, a wider design space is provided for configuration optimization.

The invention discloses a pose control distribution method of an aircraft based on multiple execution mechanisms. The method comprises steps of S1, establishing a pose kinetics equation of the aircraft; S2, through a pose transmission matrix, determining a pose angle of the aircraft; S3, establishing a pose kinetics equation of the aircraft; S4, according a control principle, calculating an expected control torque of the aircraft; and S5, by use of a control distribution algorithm, acquiring a state combination of each execution mechanism of the aircraft at the present moment. According to theinvention, the method is suitable for rapid mechanical operaton and high-precision stable mechanical operation task requirements of large-angle poses of the aircraft.

The invention discloses an electromagnetic valve performance analysis method based on multi-physical-field optimization, and the method comprises the steps: building an electromagnetic differential equation and a valve element kinetic equation of a dynamic process of an electromagnetic valve through employing theoretical knowledge according to a plurality of physical fields related to the electromagnetic valve; according to the established mathematical physical model, calculating by utilizing finite element software to obtain part of physical field input parameters required in the equation; and then subjecting the mathematical model of the electromagnetic valve to joint simulation through mathematical calculation software, so that the performance law of the electromagnetic valve is furtherresearched, and meanwhile, electromagnetic valve design parameters in a joint simulation model are optimized by utilizing a genetic algorithm. According to the method, the response characteristic parameters of the electromagnetic valve can be accurately calculated, meanwhile, performance analysis and parameter optimization can be further conducted on the electromagnetic valve, a new method is provided for optimization design of the electromagnetic valve, the design efficiency and the design quality of the electromagnetic valve are improved, and the development cost is reduced. The invention relates to the technical field of electromagnetic valve optimization design.

The invention provides a double-rigid-body characteristic point saturation fixed time relative pose tracking control method. The method comprises the steps: establishing a pose kinetic equation of a tracker and a target device based on a Newton-Euler method; establishing a relative pose kinetic equation considering model uncertainty according to the established respective pose kinetic equations ofthe two rigid bodies and the relative pose and the relative speed between the two rigid body feature points; designing a fixed time disturbance observer according to the established relative pose kinetic equation; designing a non-linear saturation compensator according to the established fixed-time non-singular terminal sliding variable so as to solve the saturation effect of an actuator; and combining the established fixed-time disturbance observer and the nonlinear saturation compensator to obtain a model-based robust adaptive controller. The invention relates to the field of control of anautonomous moving body in a three-dimensional space and spacecrafts.

The invention discloses a method for calculating dynamic response characteristics of a captive balloon, which comprises the following steps of: establishing a rigid body motion equation of the tethered balloon, namely determining kinematics and dynamics equations of the captive balloon relative to a centroid in a stable coordinate system by taking a captive balloon system as a mass point and taking the motion of the captive balloon system as rigid body motion; carrying out stress analysis on the captive balloon, and establishing a kinetic model of the captive balloon; determining expressions of the external force and the moment, performing summing and arranging to obtain a six-degree-of-freedom motion equation around the center of mass of the balloon; modeling two external wind fields of discrete gust and atmospheric turbulence, and providing wind field environment input for six-degree-of-freedom simulation of the captive balloon; loading the established atmospheric wind field model into a motion equation of the captive balloon in a function form to obtain a state space function, so that the state space function becomes a known control parameter which influences the motion state of the captive balloon; and solving the state space function to obtain a dynamic response process of the captive balloon under the condition of atmospheric wind field disturbance.