7 results about "Equivalent system" patented technology

The invention discloses a drag-free control ground verification method based on active control of two-stage torsional pendulum, which comprises the following steps of: suppressing the influence of ground vibration noise on free motion of a test mass in an inertial space to be below 10% of the original noise, and constructing a local inertial reference at the test mass; the problem that inertial space motion is difficult to simulate on the ground by a traditional method is effectively solved; secondly, a high-precision numerical model and a six-degree-of-freedom displacement platform are combined through a hybrid real-time simulation technology, and the high-fidelity on-orbit dynamics simulation capability is achieved. The experimental device has relatively high space-ground consistency, can realize ground high-precision representation of an on-orbit drag-free tracking process of a spacecraft, and provides a new solution thought for ground verification of a space drag-free task. In addition, compared with a complex dynamic equivalent system constructed on the ground, the solution provided by the invention has the characteristics of being easy to implement and low in complexity.

The invention belongs to the technical field of mechanical arm system tracking control, and discloses a mechanical arm system fixed time tracking control method and a mechanical arm system fixed time tracking control system under random interference. The model is expanded to a dynamic model of a multiple-input multiple-output random uncertain nonlinear system; then designing a time-dependent barrier function for processing output constraints, and designing nonlinear transformation for nonlinear control input of the actuator; and then establishing an equivalent system form, designing a non-singular self-adaptive fixed time tracking controller by using a backstepping method, and finally realizing fixed time tracking control on the mechanical arm system. According to the fixed time tracking control method for the mechanical arm system, the preset reference signal can be rapidly and accurately tracked under the condition that random disturbance, actuator nonlinearity and output constraint exist, and the robustness and the control performance of the system can be remarkably improved.

The invention relates to the technical field of turbine base dynamics calculation, and provides a turbine base equivalent damping ratio determination method and system.The turbine base equivalent damping ratio determination method comprises the steps that the structure size and the material attribute of a turbine base are obtained, and a mechanical model of the turbine base is established; based on the mechanical model, determining a mass matrix and a stiffness matrix of the structure so as to establish a free vibration differential equation composed of various materials and an equivalent free vibration differential equation of the overall structure; based on a free vibration differential equation composed of multiple materials and an equivalent free vibration differential equation of the overall structure, according to vibration mode orthogonality, strain energy of a system composed of the multiple materials and strain energy of an equivalent system in all orders of vibration modes are obtained; based on strain energy of a system composed of multiple materials and an equivalent system in each order of vibration mode, an equivalent complex damping coefficient of each order of vibration mode is solved, and the equivalent complex damping coefficient is converted into an equivalent damping ratio. The equivalent damping ratio of the turbine base can be quickly and accurately obtained, and powerful support is provided for engineering practice.

The present application relates to the technical field of mechanical structure fatigue test and durability verification, in particular to a non-equal amplitude interval random load equivalent system and method, the system comprises preprocessing, feature extraction, clustering classification, optimal classification number determination, initial equivalent spectrum construction, loading sequence correction and simulation verification module. The method is: first, the original load spectrum is preprocessed and the cycle characteristics are extracted, the optimal classification number is determined by hierarchical clustering and multi-objective weighted comprehensive evaluation index, the initial equivalent spectrum is constructed, and the reference fatigue life and damage of the initial equivalent spectrum are obtained through simulation. Based on the Corten-Dolan model, a correction factor sensitive to the loading sequence is constructed, the simulation result is corrected, the life deviation caused by the loading sequence is compensated, and finally the error is ensured to be less than 15%. The present application retains more than 99% of the pseudo-damage of the original spectrum, shortens the loading time by 80%, balances the efficiency and accuracy, and is suitable for bench verification of complex mechanical structures such as electric drive systems.

The application belongs to the technical field of mechanical arm system tracking control, and discloses a mechanical arm system fixed time tracking control method and system under random disturbance, which firstly establishes a mathematical model of the mechanical arm system under random disturbance affected by actuators and output constraints, and extends the mathematical model to a dynamic model of a multi-input multi-output random uncertain nonlinear system; then, a time-dependent barrier function is designed to process the output constraint, and a nonlinear transformation is designed for the nonlinear control input of the actuator; then, an equivalent system form is established, and a non-singular adaptive fixed time tracking controller is designed by using the backstepping method, so that the fixed time tracking control of the mechanical arm system is finally realized. The mechanical arm system fixed time tracking control method provided by the application can realize fast and accurate tracking of the preset reference signal under the conditions of random disturbance, actuator nonlinearity and output constraint, and can significantly improve the system robustness and control performance.

The application discloses an industrial robot control method, device and equipment and a storage medium, relates to the technical field of intelligent control, and comprises the following steps: acquiring physical characteristic data and a preset performance index of an industrial robot; constructing a constrained system model of the industrial robot according to the physical characteristic data and the preset performance index; performing equivalent system conversion on the constrained system model to obtain an unconstrained system model; constructing a Hamilton-Jacobi-Bellman equation according to the unconstrained system model and an optimal control strategy of the industrial robot; and solving the Hamilton-Jacobi-Bellman equation by using an adaptive dynamic programming method to obtain an optimal control law, so that the industrial robot is controlled according to the optimal control law. The application solves the problem that the existing industrial robot control method cannot realize optimal control while meeting the constraint of the preset performance index, and realizes high-precision control of the industrial robot.

The invention discloses a flight quality evaluation method and device based on time-domain low-order equivalent system fitting, equipment and a medium, relates to the technical field of aerospace system design and simulation analysis, and is used for processing flight test data of an aircraft. Discretizing the state equation, performing recursive calculation on the initial state and parameters of the aircraft by using a discretized matrix, and constructing a discrete equivalent system model; setting a value range for a to-be-identified parameter to generate an initial population, inputting a parameter vector in the initial population into the discrete equivalent system model, performing selection, crossover and mutation operation on the initial population based on the calculated fitness, introducing an elitism strategy until a convergence condition is met, and obtaining an optimal parameter; and processing the to-be-identified parameters by using a least square method to obtain fitting parameters so as to extract key parameters and evaluate the flight quality of the aircraft, so that the fitting precision and robustness of the low-order equivalent system are improved, and the robustness and fitting precision of the model are improved.