340 results about "System dynamics model" patented technology

The invention relates to a high-speed milling process parameter optimizing method based on a dynamic model. The optimizing method includes 1) inputting structure parameter and initial cutting condition of a spindle-cutter system; 2) building a dynamic model of the spindle-cutter system, calculating a frequency response function of the cutter nose position according to the model and determining cutting force coefficient; 3) building a high speed spindle-cutter dynamic characteristic and milling interaction process model to obtain the characteristic equation of a closed loop dynamic milling system; 4) calculating a high-speed milling machining shimmy stability leaf picture; 5) selecting lathe spindle rotating speed and cutting depth to achieve high-speed milling parameter optimization with the lower bound curve of the high-speed milling machining shimmy stability leaf picture as the constraint condition and with maximum material removing rate as the optimization target. The method considers centrifugal force and gyroscopic couple effect of the cutter-cutter system in the high-speed rotating state, approaches actual work condition, improves accuracy of stability prediction, and provides effective technology for optimization of high-speed milling process parameter optimization.

The invention discloses an active satellite attitude and tethered librational and vibrational combination control method based on a tethered dragging system, and the method comprises the following specific steps: 1, building a system dynamics model; 2, carrying out the designing of an adaptive sliding-mode controller; 3, carrying out the designing of a high-order sliding-mode observer; 4, carrying out MATLAB numerical simulation analysis. The analysis of a simulation result indicates that the method effectively inhibits the tether spatial swinging, eliminates the active satellite attitude coupling movement cause by the basis of a tethering point, is better in robustness of a control law, and is good in application prospect in this type of space tasks.

A method is disclosed for estimating clutch engagement characteristics of a friction clutch system in a vehicle powertrain. A dynamic model of the system is used under conditions that cause clutch slipping. Algebraic equations defining a functional relationship between clutch torque and an engagement angle have characteristic parameters that are estimated using a non-linear least squares technique. A non-linear least squares technique iteratively minimizes the difference between a measured output clutch disk speed and an output clutch disk speed from the system dynamic model for the same inputs until a small insignificant error is reached. Parameter estimates are used to compile an estimated clutch engagement characteristic.

The invention relates to a control method for predicting an air supply system model of a fuel cell and belongs to the technical field of control. The invention aims to provide the control method for predicting the air supply system model of the fuel cell to achieve steady operation of the system by adjusting the peroxy ratio of a proton exchange membrane fuel cell to avoid air hunger. The method comprises the following steps: S1, establishing an air supply system dynamic model of the fuel cell for high precision control; S2, determining a preoxy reference value of the proton exchange membranefuel cell system; S3, evaluating the internal pressure value of a cathode and system disturbance by adopting an expanding state observer; and S4, designing a peroxy ratio controller of the proton exchange membrane fuel cell system. By adjusting the output evaluation error in real time by using the expanding state observer and retraining the output error to zero within an infinite time, the pressure of a cathode pipeline which cannot be measured is evaluated accurately.

The invention discloses an adaptive terminal sliding-mode controller based mechanical arm trajectory tracking control method. The method includes the following steps: 1, establishing a rigid mechanical arm system dynamics model having n degrees of freedom rotating joints; 2, obtaining the measuring information of each joint angle q and angular velocity which is shown in the description of a mechanical arm through a photoelectric encoder, setting the expected angle q<d> and expected angular velocity which is shown in the description tracked by each joint, and calculating mechanical arm trajectory tracking errors [epsilon]1 = q - q<d> and the first derivative shown in the description of trajectory tracking error versus time; 3, establishing a novel non-singular terminal sliding-mode surface s according to the [epsilon]1 and [epsilon]2; and 4, designing the controlling moment tau of the driving motor of each joint of the mechanical arm according to the sliding-mode surface s, and establishing an adaptive rate which can adjust control gain to dynamically estimate system lumped disturbance upper bound. Under the circumstance that internal and external interference such as parameter perturbation and torque disturbance existing in the mechanical arm system, the method can perform real-time feedback so as to realize the accurate controlling of mechanical arm trajectory tracking based on the measuring information of each joint angle and angular velocity, and the controlling on the robustness of the whole course can be guaranteed.

The invention discloses a suspension type monorail vehicle dynamic model and a vehicle-bridge coupling power simulation method, belongs to the technical field of rail traffic and aims to solve the technical problem that an existing suspension type monorail dynamics simulation device is large in simulation result errors during rail beam local vibration research. By providing the suspension type monorail vehicle system dynamic model, a rubber wheel-rail surface contact mechanical model, a rail beam bottom plate and web equivalent surface force application method and a vehicle and rail beam coupling dynamic model building method, a suspension type monorail vehicle-rail beam coupling dynamic simulation system is built. By the model, the system and the method, suspension type monorail vehicle system suspension mechanism decoupling and equivalent treatment are achieved, and the technical problems that the existing suspension type monorail dynamics simulation device is large in simulation result errors during the rail beam local vibration research, rail beam dynamic stress and strain results are hard to extract, rail beam local strength destroying cannot be evaluated accurately and the like are solved.

The invention discloses a spacecraft attitude stability control method by using a biasing tether. The method comprises: a system dynamics model is established; a nonaffine non-linear system model is converted into an affine non-linear system model; speed information is used as a virtual control value and a controller is designed; the designed virtual control value is used a control instruction and a speed/angular speed controlled is designed; and an anti-saturation module is added into the controller and an influence caused by movement limitation of a tether connecting point can be suppressed. According to the invention, on the basis of movement of a biasing tether point, an attitude of a capture mechanism is controlled, thereby substantially reducing fuel consumption of the capture mechanism during the operation task process. In addition, the nonaffine non-linear system model is converted into the affine non-linear system model by means of first-order taylor expansion and that the similarity and error meet the Lipschitz condition is demonstrated; and when the system design is controlled, an adaptive compensation item compensation module error is designed. The method is simple and the practicability is high.

The invention relates to a simulation analysis method of the vibratory response of a variable working condition single-stage heavy gear case containing a crackle fault, which comprises the following steps: establishing a gear pair 3D solid model containing a crackle fault on the basis of 3D design software SolidWorks; leading the model into finite element analysis software ansys, programming a program capable of calculating the gear meshing rigidity of any meshing positions by combining menu operations of the ansys and APDL languages and outputting a result data file of the meshing rigidity; establishing a damping gear case system kinetic model of 8 degrees-of-freedom and kinetic simultaneous differential equations considering factors of the rigidity and the damping of a shaft and the case, an input torque and a load torque of a motor, and the like and utilizing MATLAB to solve the equations so as to simulate the system vibratory response of the single-stage heavy gear case containing a crackle fault. The invention integrates the advantages of the SolidWorks, the ansys and the MATLAB and can quickly and accurately simulate the vibratory responses of variable working condition heavy single-stage heavy gear cases containing various different forms of crackle faults.

The invention discloses a VSG based photovoltaic microgrid dynamic frequency stability control method. The method includes the following steps: constructing a VSG based photovoltaic microgrid system dynamic model; performing adaptive control on the virtual inertia torque and virtual damping factors of the system model; configurating system key parameters, and selecting the optimal value of the parameters; and determining a calculation example, and adopting a simulation tool to perform simulation analysis on the calculation example. The method can establish the dynamic relation between the virtual inertia and virtual damping of a system and the frequency change of the system through the analysis on a frequency oscillation process, so that the two can be adaptively changed according to the frequency change, and therefore, frequency oscillation can be effectively inhibited, the system can better cope with transient disturbances, and the frequency stability of the system can be provided.

A reconfigurable mechanical arm decentralized control system and control method adopting position measuring belong to the field of robot control systems and control algorithms, and aim to solve the problems existing traditional reconfigurable mechanical arm control systems and methods thereof. The control method comprises the steps of initializing a system, detecting a reading of an incremental encoder to obtain position measuring information, and establishing a non-linear speed observer based on the information; according to the established non-linear speed observer, establishing a disturbance observation model; adopting an observation value obtaining a joint speed and a joint torque to establish a reconfigurable mechanical arm system dynamics model; by a given joint speed observer, a torque observer, expected dynamics information and the system dynamics model, adopting dynamics information of local joints to design a decentralized controller, compensating the modeling errors containing model determining items and friction and coupling items among joints, and inhibiting buffeting of the controller and enabling a mechanical arm joint to precisely trace an expected track.

The invention discloses a high-precision friction compensation control method of a double-frame magnetic levitation CMG frame system. A double-frame servo system dynamics model is established at first, the coupling moment of the frame system is subjected to feedforward compensation control, the non-linear friction moment of the frame system is estimated by means of a time delay estimator (TDE), the feedback compensation of the non-linear friction moment is carried out by means of TDC, a two-degree freedom IMC is introduced to realize the independent control of the frame system tracking performance and disturbance suppression capability, and meanwhile, the robustness of the TDC is enhanced. The high-precision friction compensation control method enhances the robustness of the frame system to the non-linear friction moment and is suitable for the high-precision friction compensation control of the double-frame magnetic levitation CMG frame system.

The invention discloses a dispersed-learning optimal control method of a reconfigurable robot in contact with an uncertain environment, and belongs to the field of robot control algorithms. The methodaims at solving the problems of poor buffeting effect and stability and low control accuracy of robot joints in traditional reconfigurable robot control methods, and includes the steps of firstly, creating a reconfigurable robot system dynamics model, and constructing a cost function and an HJB equation according to the analysis of coupling moment crosslinking items among reconfigurable robot joint subsystems; by means of a learning algorithm based on strategy iteration, figuring out the solution to the HJB equation; adopting a neural network to conduct approximation on the cost function, andfinally verifying the validity of the presented control method through simulation; the method can make the robot system achieve great stability and control accuracy under the condition of uncertain environment-oriented contact, improve the control accuracy of the reconfigurable robot, and meanwhile reduce energy consumption of a system actuator and complexity of the robot system dynamics model.

The invention relates to a modal synthesis dynamic modeling and analysis method for an automobile driving axle system. The method is characterized by comprising the steps that 1, a finite element model of all components of a driving axle is established, boundary nodes are defined according to the connecting relation between the components, a modal synthesis model of all the components is established, and a modal synthesis rigidity matrix and a mass matrix of all the components are obtained; 2, a connecting relation model of all the components is established; 3, the modal synthesis rigidity matrix and the mass matrix of all the components are assembled according to the connecting relation, a complete modal synthesis dynamic model of the driving axle system is established, and a rigidity matrix and a mass matrix of the driving axle system are obtained; 4, natural vibration frequency and a regular vibration mode of the dynamic model of the driving axle system are calculated, and a mode superposition method is adopted to calculate the dynamic response of the driving axle system under excitation of dynamic engaging force of gears of a main reducing gear. In the whole modeling process, high universality and calculating efficiency are achieved, and the method can be widely applied to dynamic analysis of a gear transmission system.

The invention aims at an intermittent process with uncertainty, and proposes a constrained 2D tracking control method for the uncertainty intermittent process. The constrained 2D tracking control method comprises the steps of: firstly, designing an iterative learning control law for a given system dynamic model; secondly, converting the original system dynamic model into a 2D-FM closed-loop systemmodel expressed in the form of a predictive value according to a 2D system theory and the designed iterative learning control law through introducing state errors and output errors; and finally, giving a sufficient condition expressed in the form of a linear matrix inequality (LMI) for ensuring robust asymptotic stability of a closed-loop system and an expression form of the optimal control law according to a designed infinite time domain performance index and a Lyapunov stability theory. According to the constrained 2D tracking control method, numerical values of tracking errors under the control of the constrained 2D tracking control method are smaller, and the convergence is faster; more importantly, the control input does not drastically fluctuate and only require slight adjustment, thereby being conducive to resource conservation and reducing troubles caused by frequent operations.

The invention discloses a micro gyroscope adaptive control method based on model reference, and the method is applied to a controller comprising a gyroscope. The method comprises the following steps: establishing an ideal dynamics model; designing a reference model as two different frequency sine waves, wherein a state space form is X[m]=A[m]X[m]; establishing a micro gyroscope system dynamics model; controlling a micro gyroscope based on a Lyapunov method, wherein a design control law is u=K<T>X+K[f]e, K<T> is an on-line adaptive update controller parameter, and K[f] is a steady matrix, and selecting K[f] and allowing (A[m]+BK[f]) as a stabilization matrix. According to the invention, a model reference adaptive control method is applied to micro gyroscope control in order to compensate manufacture errors and environment interference, and estimate an angle rate correctly. By employing a designed self-adaptive algorithm based on the Lyapunov method, global progressive stability of a whole control system is ensured, and reliability and robustness to parameter change of the system are raised.

Method for forming a fixed geometric grid for a fluid dynamics system multi-cell computer model, the system having one or more surfaces, includes representing the system surfaces by an array of contiguous polygons. The method also includes creating a single model cell that encompasses the entire system and assigning all the surface polygons to the single model cell. The method further includes subdividing at least the portion of the single model cell encompassed by the surface polygon array, including subdividing all intersected assigned polygons, using one or more subdividing planes. The method still further includes reassigning the surface polygons to respective subdivided cells resulting from the subdividing step, identifying those subdivided cells having two or more surface polygons from a common system surface, and calculating effective common boundary areas and normal vectors for those cells. The method also includes treating “split” cells and “sliver” cells. Apparatus for automatically forming a fixed geometric grid includes a digital computer programmed with a CFD program having software to implement the disclosed method.

The invention provides a dynamics simulated analysis method on the basis of a multipoint positioning flexibility tool system. The dynamics simulated analysis method on the basis of the multipoint positioning flexibility tool system includes steps of firstly, preparing and mounting an ADAMS multi-body dynamics simulation software; secondly, establishing a model of a mechanical system; thirdly, rightly establishing various coordinate systems of the mechanical system; fourthly, building a dynamics model of the multipoint positioning flexibility tool system according to the various coordinate systems of the mechanical system set in the third step; fifthly, detecting the dynamics model set up in the fourth step by the ADAMS multi-body dynamics simulation software; sixthly, analyzing running results of the dynamics model; seventhly, optimizing the system to obtain the optimal solution according to the structural design scheme. The dynamics simulated analysis method basically solves the problem that an existing dynamics simulation analysis method is low in systematized degree, narrow in application range, poor in interference resistance and slow in simulation analysis.

The invention provides a model uncertainty mechanical arm motion control method based on a multi-layer neural network. Firstly, controller design is performed on mechanical arm system model uncertainty according to a nominal model; a mechanical arm system dynamic model with uncertainty is established; a mechanical arm system nominal model is established with an uncertain item caused by external interference factors being considered; a controller is designed for the model uncertain item according to the normal model; the multi-layer neural network is adopted to perform self-adaptive approach onthe model uncertain item; and a mechanical arm system controller is designed based on the multi-layer neural network. According to the model uncertainty mechanical arm motion control method based onthe multi-layer neural network, a good robustness effect on structural uncertainty such as parameters and non-structural uncertainty such as external interference is achieved simultaneously, and it can be guaranteed that the track of the tail end of a mechanical arm and the angles of all joints are well tracked.

The invention relates to an intelligent live fish cultivation water quality comprehensive forecasting method. The basic idea is that a radial base nerve network is used as pond water quality data forecasting base, a recurrence rolling type forecasting method is used as a nerve network forecasting strategy to express dynamic change characteristics of pond water quality environment, potential relation and feedback mechanism between key water quality factors and other water quality factors can be found by analyzing a systematic power model aiming at key factors, such as dissolved oxygen, ammonia nitrogen and nitrite nitrogen, of pond water quality, and different nerve network forecasting models of key water quality factors can be constructed. Values of all water quality factors and values of all key water quality factors can be obtained by building pond water quality comprehensive forecast and analyzing and calculating nerve network forecasting models of different key water quality factors. Key factors can be obtained through adjustment and comprehensive forecasting, values between key factors and key factors forecasted by the key factors can be obtained, and the final forecasting value can be obtained. Thus, water quality can be comprehensively and accurately forecasted so as to bring convenience to pond cultivation, greatly reduce cost and risk of pond cultivation and bring benefits to pond cultivation.

The invention relates to an automobile engine thermal management system modeling and control method, and belongs to the technical field of control. The aim is to provide an engine thermal management system dynamic modeling method and a water temperature control method. In the system dynamic modeling method, an accurate heating power model of an air cylinder to an inner wall, a heat exchange coefficient model of a water jacket and cooling liquid and a radiating power model of a radiator are built. The research method of the method comprises the following steps that according to the structure, the principle and measurable signals of an engine thermal management system, a system dynamic model is built; seen from the heat convection heat exchange and radiation heat exchange mechanisms, three intermediate variables in the dynamic model are derived; a system inverse dynamic model is derived according to the system dynamic model; a Smith predictor is designed according to the system dynamic model; and a PD feedback controller is designed. The dynamic model of the engine thermal management system is accurately built, and the control accuracy is improved.

The invention discloses a dynamic torque cooperative control method of a planetary series-parallel hybrid power system. The dynamic torque cooperative control method comprises two development parts ofan offline calculation method based on model prediction and an online cooperative control method. Firstly, a dynamic model of the planetary series-parallel hybrid power system is built, and an outputtorque observation model and a shock extent observation model of the planetary series-parallel hybrid power system are deduced based on the dynamic model of system; then, the output torque observation model and the shock extent observation model of the system are discretized, and thus a prediction model of the corresponding observed quantity is obtained; offline dynamic control models of a speed-regulating motor and a torque-regulating motor are deduced based on the prediction model; and offline simulating calculation is carried out, control rules of the two motors in the mode switching process are extracted based on the offline calculation result, the online torque cooperating method is obtained, and the online torque is cooperatively controlled.

The invention relates to a low rotating speed high precision control method of a control moment gyro gimbal servo system. The method solves the problems of friction interference and a disturbing moment caused by unbalanced rotor vibration of the control moment gyro gimbal servo system in a low speed operation process. The method comprises the steps of establishing a control moment gyro gimbal servo system kinetic model containing the friction interference and an unbalanced rotor vibration interference moment, performing control design on a frame servo system current loop via vector control andPI (proportional-integral) control methods, designing an interference observer to estimate equivalent interference formed by the friction interference and the disturbing moment caused by the unbalanced rotor vibration at a frame servo system speed loop, allowing the interference observer to offset an equivalent interference estimated value via a feedforward channel and designing a composite controller. The method has the advantages of high engineering practicability, high interference immunity and the like.

The present invention provides a control moment gyro gimbal system disturbance inhibition method based on a discrete non-linear cascading expansion state observer. The method comprises the steps of: establishing a double-frame servo system kinetic model, converting the double-frame servo system kinetic model to a system equation meeting an integration chain form of construction of a cascading expansion state observer (CESO) through conversion of coordinates, selecting an appropriate non-linear function to construct a discrete non-linear cascading expansion state observer (NCESO) to obtain theestimation of lumped disturbance, and combining an appropriate sliding mode controller to eliminate the influence of the lumped disturbance from the output channel of the system. The method solves theproblem that the parameters are difficult to be configured when a traditional expansion state observer is high in the number of orders, improves the estimation precision of the linear cascading expansion state observer, achieves the high-precision angular rate tracking control of a frame servo system and can be applied to the projects having uncertain interference.

The invention provides an integrated stabilization chaotic system based PID (Proportion Integration Differentiation) controller optimization control method. The analysis is performed on an integrated stabilization system dynamic model equation to obtain a chaotic system so as to solve the problem of ship stabilization. The chaotic behavior of the system under the certain conditions is verified by a phase diagram and Lyapunov exponent spectrum analysis method, controlled parameters are selected, and the chaotic behavior of the system can be effectively controlled by a nonlinear feedback control method. According to the integrated stabilization chaotic system based PID controller optimization control method, the chaotic dynamics behavior of the system is improved and the original dynamic characteristics of the system are reserved; a chaotic search algorithm is combined with an ant colony algorithm to implement the optimization of the PID control parameters and accordingly the global optimization capability of the ant colony algorithm is high, meanwhile the system convergence speed is improved, and accordingly the control system performance is significantly improved; the value of application to a controller device is high, wherein the ship rolling motion is effectively designed through the controller device.

The invention discloses a Kaplan turbine adjusting system dynamic model suitable for electric power system analysis, which comprises a speed governor model, a guide vane control system model, a blade control system model, a water turbine model and a water diversion system model, wherein the guide vane control system model and the blade control system model forms a Kaplan turbine dual adjusting system, the blade control system model takes a combined relationship existing between guide vane opening degrees and blade opening degrees into account, and the combined relationship is obtained by adopting a quintic polynomial curve fitting method; and the water turbine model takes the correction function of blade angles on water turbine efficiency into account on the basis of analyzing non-linear models, the mechanical power output of the water turbine model is affected by the guide vane opening degrees and blade opening degrees together, and the nonlinearity between the guide vane opening degrees and the mechanical power is metered and is described by adopting cubic polynomial fitting. The Kaplan turbine adjusting system dynamic model is exquisite and clear in structure, has distinct and easily-obtained model parameter meanings, is fast and efficient in modeling process, and has high practicability.