8 results about "Eulerian method" patented technology

This invention provides a simulation method for test equivalent signals based on the Euler discrete model. It primarily solves the problem of equivalent generation of gyroscope angle signals in test equivalent converters, enabling high-precision reproduction of the complex dynamic angle changes of an aircraft during flight. This overcomes the difficulty of accurately simulating gyroscope angle signals during ground testing. First, using predetermined aircraft pitch channel altitude trajectory data, a fast differentiator is used to solve for the differential data of the altitude and horizontal trajectories, thereby solving for the aircraft pitch angle and pitch velocity data. Then, the Euler method is used to establish a discrete measurement model of the gyroscope, solving for the measured value of the pitch velocity. Considering the influence of error drift, integration is performed to obtain the gyroscope's measurement signal of the pitch angle. This outputs a high-precision result of the gyroscope angle changes during high-altitude flight. This method has the advantages of high simulation accuracy and good agreement with reality.

The application discloses a kind of gas-solid two-phase flow self-adapting simulation prediction method, system, medium and product, belong to the field of digital simulation of fluid dynamics, the method is: obtaining industrial equipment geometry, particle and fluid data, constructs gas-solid two-phase flow CMPPIC model;Wherein, continuous phase is with Euler method, discrete phase is with Lagrange particle bag representation;Perform time advance iteration to termination condition, output result, wherein each round of iteration includes mapping particle bag data to Euler cell, obtaining particle statistical information and marking fixed state particle according to rules;Freeze fixed cell particle volume fraction, calculate porous medium parameter, reconstruct its continuous phase momentum conservation equation;Based on reconstruction and unreconstructed equation, update flow field, while updating the particle motion of unmarked fixed state cell. By implementing the application, the problem that calculation efficiency and physical precision are difficult to consider in simulating fixed particle structure in the prior art can be solved.

The application discloses a nine-switch converter flexible interconnection system and a switching loss control method and device thereof. αβ The method comprises the following steps: firstly, 27 voltage space vectors are obtained by constructing a nine-switch converter mathematical model; secondly, a system Coordinate system mathematical model is established, a prediction model is obtained through forward Euler method discretization processing, and a weight coefficient value function is designed to accurately track the current; then, voltage vectors are selected and inserted into zero vectors, and a fixed switching frequency switching sequence is designed; finally, the action time of the voltage vector is determined through duty cycle modulation, and the optimal voltage vector is periodically and alternately selected. The application effectively solves the problems of the existing system, such as unfixed switching frequency, uneven loss, large current harmonic and heavy calculation burden, balances the power device loss, prolongs the service life of the device and improves the system stability. The application can realize the bidirectional power flexible interconnection between two three-phase power grids and guarantee the system operation stability and power quality.

The application discloses a multi-harmonic suppression method for a dual three-phase permanent magnet synchronous motor, and comprises the following steps: S1, a model of a dual three-phase permanent magnet synchronous motor driving system is established; a six-dimensional voltage vector is constructed through a switching state generated by a voltage source inverter, and a stator voltage vector is decomposed by adopting a vector space decomposition method to establish a voltage equation; S2, multi-source harmonic distortion characteristics are analyzed; current harmonic components caused by phase group asymmetry, non-sinusoidal distribution of counter electromotive force and nonlinearity of the inverter are respectively identified and analyzed; S3, a harmonic suppression controller based on an online neural network assisted linear extended state observer (ONN-assisted LESO) is designed; a super-local model is constructed to describe stator current dynamics; an auxiliary neural network compensator is introduced; a weight adaptive law is designed in combination with Lyapunov stability analysis, a forward Euler method is adopted to realize discretization control, and a voltage reference value is generated to realize real-time suppression of multi-harmonics. The application can effectively realize multi-harmonic suppression under different operating conditions, and meanwhile, fast dynamic response and robust current performance are maintained.

This invention discloses a flexible interconnection system with a nine-switch converter and its switching loss control method and device. The method first constructs a mathematical model of the nine-switch converter to obtain 27 voltage space vectors; secondly, it establishes the system... αβ A coordinate coefficient mathematical model is discretized using the forward Euler method to obtain a prediction model, and an unweighted coefficient value function is designed to accurately track the current. Then, a voltage vector is selected and a zero vector is inserted, and a fixed switching frequency switching sequence is designed. Finally, the voltage vector's action time is determined by duty cycle modulation, and the optimal voltage vector is periodically selected alternately. This invention effectively solves the problems of inconsistent switching frequencies, uneven losses, large current harmonics, and heavy computational burden in existing systems. By balancing power device losses, it extends device lifespan and improves system stability. It enables bidirectional flexible power interconnection between two three-phase power grids and ensures system operational stability and power quality.

The application discloses a cascaded large model robot motion planning method based on timing logic constraints, which comprises the following steps: a task planner receives user instructions and corresponding STL expressions, environment information, decomposes the user instructions and corresponding STL expressions, and obtains sub-tasks and corresponding STL expressions; whether the decomposed sub-tasks meet the logic constraints, time constraints and space constraints is detected by an STL checker; if yes, correct controllers are generated according to the sub-tasks; the generated correct controllers are integrated with a robot model, a Monte Carlo method is used to generate multiple groups of random parameters based on uncertainty factors, real environment disturbances are simulated, an Euler method is used to discretize and iteratively solve trajectories of the robot continuous kinematics equation, the trajectories are checked by the STL checker to make the trajectories meet the requirements of the user instructions, and finally correct trajectories are obtained. The application realizes user instructions containing space, time and kinematics constraints.

The application provides a robot dynamic error compensation method based on a capsule neural network, adopts Newton-Euler method to establish a robot dynamics model, and performs linearization and dynamics parameter identification; uses joint motion data as input to obtain predicted torque for model training by using the linearized dynamics model after the dynamics parameter identification, and calculates error between the predicted torque and actual torque; regards normalized parameters as vectors in a vector space, calculates inner products of the vectors to form a Gram matrix and converts the Gram matrix into a two-dimensional image; learns error between the predicted torque and the actual torque by using a capsule neural network, and obtains a trained capsule neural network; obtains real-time prediction error by using the trained capsule neural network, and compensates real-time predicted torque obtained by the linearized dynamics model after the parameter identification by using the real-time prediction error. The application realizes high-precision and adaptive dynamic error compensation.