9 results about "Transverse velocity" patented technology

The invention discloses an obstacle cut-in intention prediction method and a vehicle, and the method comprises the steps: judging whether there is an obstacle meeting the initial condition of pre-cut-in in the current environment or not during the operation of the vehicle, and obtaining the historical track of the obstacle if there is the obstacle; according to the historical track, judging whether the obstacle has a lane line attaching trend or not; if yes, the transverse speed weight and the transverse position weight of the obstacle are obtained; and predicting a pre-cut-in intention of the obstacle according to the transverse position weight and the transverse speed weight. According to the method, the slow pre-cut-in intention of the obstacles around the vehicle can be accurately predicted.

The invention discloses a time migration method for a three-dimensional pre-stack wave equation in an imaging ray domain, which relates to the technical field of exploration geophysics and comprises the following steps of: deducing a bidirectional acoustic wave equation in an imaging ray coordinate system based on a Riemann wave field extrapolation theory in a three-dimensional semi-orthogonal coordinate system; an equation is directly solved by adopting a finite difference method, extrapolation of a seismic source and a receiving end wave field is achieved, and errors caused by Green function approximation in a traditional migration method are avoided; and generating a pre-stack time migration result by applying a zero-lag cross-correlation imaging condition. Through first-order linear disturbance approximation, an accurate three-dimensional time-depth conversion partial differential equation set is simplified into an optimized layer stripping algorithm, and a corresponding equation suitable for a weak transverse velocity change medium is deduced. According to the invention, the working process of three-dimensional wave equation time migration is realized in an imaging ray coordinate system, and an accurate seismic imaging result is generated; two-dimensional plane hypothesis limitation is avoided, and high-precision imaging technical guarantee is provided for seismic data processing of a complex structure area.

The present application relates to the technical field of ship motion, in particular to a ship maneuvering motion trajectory prediction method and system fusing shipborne radar wave measurement, the method comprising: acquiring multi-modal data, and preprocessing the acquired multi-modal data; performing multi-modal feature extraction on the preprocessed multi-modal data; performing cross-modal fusion based on the extracted multi-modal features to obtain a fusion feature vector; constructing a feedforward neural network with the fusion feature vector as input, and outputting a prediction value of a ship motion state; performing parameter optimization based on the constructed feedforward neural network, verifying the prediction result output by the feedforward neural network, and outputting a final prediction result; and the final output of the present application, the prediction value of the ship motion state, covers key parameters such as longitudinal velocity, transverse velocity, and yaw angle velocity, providing an accurate basis for ship maneuvering decision-making, and helping to improve the safety and precision of ship navigation.

The present invention provides a motion state estimation method and motion state estimation device that can improve the accuracy of estimating the motion state of an object moving in a direction intersecting the direction of travel of a vehicle. [Solution] From an image captured by the vehicle V1's imaging device 11, objects present around the vehicle V1 are detected. A first estimation model, in which the initial velocity is primarily composed of the vehicle V1's lateral velocity in the width direction, and a second estimation model, in which the initial velocity is primarily composed of the vehicle V1's longitudinal velocity in the direction of travel, are applied to the detected objects. The movement state of the objects is then estimated based on the first likelihood, which represents the movement state of the object, determined by the first estimation model, and the second likelihood, which represents the movement state of the object, determined by the second estimation model.

This invention relates to the field of unmanned vessel berthing and unberthing technology, specifically a fuzzy control method and system for the safe and autonomous berthing and unberthing of unmanned vessels, comprising the following steps: real-time scanning of the surrounding environment using a 3D lidar mounted on the unmanned vessel to generate point cloud data; and determining the desired longitudinal velocity u of the unmanned vessel's vector motion based on the relative pose. d Desired lateral velocity v d and desired turning angular velocity r d The system error and error change rate are input into a fuzzy controller for fuzzification. The control output is decomposed into thrust commands for each thruster of the unmanned surface vessel (USV), controlling the USV to achieve coordinated longitudinal, lateral, and bow-turning movements, enabling the USV to autonomously berth and unberth in an attitude parallel to the shore. This invention significantly improves the control accuracy and adaptability of USVs in autonomous berthing and unberthing under complex sea conditions by introducing a fuzzy adaptive PID control strategy combined with environmental perception and real-time pose calculation using 3D lidar.

The invention discloses an under-actuated ship trajectory tracking fixed time fault-tolerant control method under output constraint. The method comprises the following steps: constructing a fixed time sliding mode fault observer; constructing a virtual control law of preset time performance based on a fixed time preset performance function according to the under-actuated ship mathematical identification model; defining a transverse speed error and a longitudinal speed error according to the virtual control law in combination with a fixed time sliding mode fault observer so as to construct a saturation compensator for compensating dead zone saturation influence of an actuator, and constructing a fixed time integral sliding mode reaching law according to the saturation compensator so as to design a steering engine control law corresponding to a longitudinal propulsion and yawing channel of a ship, and according to the steering engine control law, realizing fault-tolerant control of the under-actuated ship trajectory tracking fixed time under the output constraint. According to the method, the problems that an existing method cannot process executor constraint and fault influence at the same time and cannot adapt to sudden disturbance change, uncertainty and the like are solved, and the safety and engineering realizability of the under-actuated ship under the complex working condition are reduced.

The invention discloses a method for realizing ship bow and stern vectors by a Beidou high-precision positioning technology, which comprises the following steps of: acquiring coordinates at the bow and stern ends of a ship in real time through a Beidou No.3 high-precision positioning module, calculating an included angle between the bow and stern directions and the true north, and decomposing the central point speed of the ship into forward and transverse speeds; and finally, bow and stern directions and velocity vectors are displayed on the electronic chart. According to the method, high-precision bow and stern azimuth measurement can be provided, the error range is + / -0.0015-0.006 degrees, the ship navigation situation is visually presented, the driving safety and efficiency are improved, and the method is suitable for berthing, narrow navigation channels and other scenes.

The invention relates to the technical field of geophysical exploration, and particularly discloses a one-way wave pre-stack depth migration method and system suitable for any variable-speed medium. According to the method, a Helmholtz operator is converted to a wavenumber domain, a square root of the Helmholtz operator is calculated by using a complex number transformation principle, and a propagation operator is efficiently solved in combination with complex number Pade approximation, so that a matrix decomposition operation with high cost in a traditional method is avoided; the system integrates the parallel computing capability of the GPU, realizes efficient processing of wave field extrapolation and imaging, and finally generates a depth migration imaging result. According to the method, the imaging precision and amplitude fidelity in a steep dip structure and a strong transverse velocity change medium are remarkably improved while high calculation efficiency is kept, and the method is suitable for seismic data imaging in a complex geological environment.

The invention provides a multi-control-surface hovercraft docking motion control and simulation method, a program, equipment and a storage medium. The method comprises the following steps: firstly, establishing a four-air-chamber hover dynamic model according to structural characteristics of a hover hover system, and constructing a complete six-degree-of-freedom motion model in combination with resistance change in a docking process; aiming at the problem of weak steering effect during low-speed docking, a method for controlling a heading angle through a screw pitch difference of a propeller is designed; and meanwhile, stability augmentation control is implemented in the sideslip direction, so that the expected transverse speed is zero in the hovercraft docking process. On the basis, a docking motion control simulation platform is built for verification. Simulation results show that according to the control method, the navigational speed error is not larger than one section, the heading error is not larger than 2 degrees, the transverse speed is effectively restrained, high control precision is achieved, and the docking working condition requirement is met. The research has an important guiding value for deeply developing a hovercraft docking driving control system and a docking control technology in a complex environment.