4results about How to "Solving speed is fast" patented technology

This invention provides a method for predicting the hazard range of oil fires on the water surface based on interface tracking coupled combustion dynamics. The method includes: using a conserved two-dimensional shallow water equation to describe oil film diffusion; spatial discretization using the finite volume method; mitigating frictional rigidity using the Strang splitting method; calculating flux using the Roe scheme; suppressing spurious flow using the Well-Balanced scheme; controlling the time step using CFL conditions; and outputting the oil film thickness hourly. A mass evaporation rate conversion model based on energy balance is constructed to transform the oil film thickness field into a mass evaporation rate field per unit area. The mass evaporation rate field is used as the bottom boundary source term of the fire dynamics model and coupled to the three-dimensional low Mach number Navier-Stokes equations through a volume source term, achieving real-time coupled simulation of oil film transport and fire spread. The combustion dynamics control equations, including the conservation of mass, momentum, energy, and components, are solved. Combined with the radiative transfer equations, the spatiotemporal distributions of the temperature field, thermal radiation flux, and flue gas concentration are calculated to achieve dynamic prediction of the hazard range of oil fires on the water surface.

This invention provides a method for aerial refueling positioning using targets and dual cameras. A microcontroller controls a target system consisting of a liquid crystal light valve, a button battery, and a reflector to actively flash light. Three targets are fixed to the refueling hose, and two targets are fixed to the receiver aircraft's fuel tank. Two cameras are mounted on the refueling aircraft to continuously photograph the five targets. Based on the camera's intrinsic and extrinsic parameters, the pixel positions of the targets in the photographs, and the target distances, linear and nonlinear equations are constructed. Solving these equations yields the three-dimensional coordinates of the five targets. Averaging these coordinates yields the coordinates of the hose center and the fuel tank center, as well as their deviation vector. Finally, the vertical vector of the hose plane is calculated using the three targets on the hose. Through decomposition, the three-dimensional error vector required for hose control is obtained, completing the error measurement during the aerial refueling process.

The present disclosure provides a terminal initialization method, device, electronic equipment and storage medium. The terminal initialization method comprises: in response to an initialization event of a terminal, acquiring image data of the terminal from an initial time to an end time and inertial data measured in an inertial coordinate system, the inertial coordinate system being fixed relative to the position of the terminal; establishing a linear constraint equation of a feature point according to a constraint equation of the coordinates of the feature point in a normalized plane and the coordinates of the feature point in a camera coordinate system, and a representation of the coordinates of the feature point in the camera coordinate system converted into the inertial system at the same time in the form of inertial data; projecting the linear constraint equation to a left null space of the corresponding feature point for dimension reduction; superimposing the linear constraint equations of each feature point to obtain an integrated constraint equation; and solving an initialization parameter of the terminal at the initial time according to the integrated constraint equation. The method of the present disclosure can improve the solving speed compared with the existing tight coupling initialization method, and takes into account robustness and efficiency.

The present disclosure provides a terminal initialization method, device, electronic equipment and storage medium. The terminal initialization method comprises: obtaining initialization parameters, inertia constraints and visual constraints of a terminal; constructing an information matrix according to the initialization parameters, inertia constraints and visual constraints; performing Schur complement elimination on the information matrix to eliminate the feature points from the information matrix to obtain an eliminated information matrix; performing Cholesky decomposition on the eliminated information matrix to obtain an upper triangular matrix and a lower triangular matrix; inverting the image frame state quantity corresponding to the nearest preset time in the upper triangular matrix to obtain the square root of the covariance, and then determining the covariance; and determining the initialization state of the terminal according to the covariance and the initialization parameters. The method of the present disclosure can quickly solve the covariance and reduce the state quantity fluctuation amplitude.