9 results about "Trajectory method" patented technology

This invention provides a landing assistance decision system and method for manned aircraft, relating to the field of aviation technology. The method specifically includes: acquiring the aircraft's current state data in real time and planning the aircraft's landing trajectory using an exponentially flattened trajectory method to determine the optimal glide path; based on the aircraft's current state data and optimal glide path, calculating the aircraft's desired attitude angles and desired thrust changes using a command decision algorithm, and performing attitude control on the aircraft according to the desired attitude angles, generating flight decision suggestions; wherein the attitude control is divided into two parts: one part uses angle control to calculate the desired three-dimensional angles and three-axis attitude angular velocities; the other part uses angular velocity control to calculate the three-axis attitude angular accelerations; the pilot controls the aircraft's flight trajectory according to the generated flight decision suggestions to ensure the aircraft lands along the optimal glide path. This invention aims to solve the problem of inaccurate landing trajectories during aircraft landing.

The invention discloses a method for determining a stable area of a vehicle and an instability risk assessment method, and the method comprises the steps: firstly obtaining various state information of the vehicle at the current moment, and predicting the mass center position of the vehicle at the future moment through a vehicle state prediction model according to the historical data of the various state information of the vehicle; and then substituting the centroid position predicted by the vehicle state prediction model into a set dynamic model to construct a whole vehicle dynamic model of the vehicle. And finally, on the basis of the constructed vehicle dynamics model, determining a stable region corresponding to the current state of the vehicle by adopting an existing phase trajectory method or a Lyapunov function method. The mass center position of the vehicle at the future moment is estimated through the vehicle state prediction model, the change condition of the vehicle mass center position under different loads and limiting working conditions of the vehicle is fully considered, the modeling accuracy of the vehicle dynamic model is improved, an accurate vehicle model is provided for determining the vehicle stable area, and the vehicle stability is improved. And the accuracy of determining the stable area of the vehicle is improved.

This invention discloses a transmission trajectory method based on flow field smoothness. The method acquires wind field grid data of the target area, uses Gaussian smoothing to filter out high-frequency noise while preserving macroscopic flow characteristics, and improves the signal-to-noise ratio. Then, neighboring points are selected centered on the initial point, and a comprehensive weight is calculated using the inverse power of spatial distance and cosine similarity, thus doubly constraining the spatial proximity and wind direction consistency of neighboring points. The trajectory point position is dynamically predicted based on the weighted average wind speed vector of neighboring points, and spline interpolation is used to force the trajectory to be continuous and differentiable, eliminating abrupt changes at discrete points and generating a smooth and coherent transmission path. This method, through flow field smoothing, weight coupling, and dynamic iteration mechanisms, significantly improves the physical rationality and anti-interference capability of trajectory simulation, and is particularly suitable for the accurate prediction of large-scale cross-regional pollutant transport, providing reliable technical support for regional joint prevention and control and pollution control.

This invention proposes a method for inertial platform system rotation without activating gyroscopes. Based on the target frame position information and the acquired real-time frame position information, the inertial platform system rotates the four frames sequentially using a frame rotation trajectory method and a PID control algorithm designed for each frame, without activating the gyroscopes. The rotation is complete when the real-time positions of all four frames deviate from their corresponding target positions within (-3.5°, 3.5°). This invention solves the problem of relying solely on manual rotation for frame rotation in scenarios where gyroscopes cannot be activated. By using frame angle data instead of gyroscope data as the input for inertial platform system rotation, and through a well-designed frame rotation trajectory method and PID control algorithm, precise frame angle rotation can be achieved quickly and with high control accuracy.

The application provides an adaptive trajectory planning method based on amplitude-frequency cooperation, and relates to the fields of rehabilitation robots and intelligent control technologies.The method first constructs a super-helix torque estimator based on generalized momentum to realize human-robot interaction torque estimation without sensors;frequency adjustment factors and a fuzzy adaptive admittance controller are introduced to adaptively adjust the amplitude-frequency cooperative basic reference trajectory learned by a dynamic motion primitive;and finally, a position controller is used to realize trajectory tracking.Compared with existing trajectory methods based on fixed trajectories or only adjusting frequencies, the application can simultaneously adjust the frequency and amplitude of the trajectory, is more in line with human motion rules, and can effectively improve the compliance of rehabilitation training.

Method for controlling the curvature of a motor vehicle's trajectory by specifying a steering angle, which is based on the inversion of a first-order ordinary differential equation for the curvature of the trajectory as a function of the steering angle with respect to the steering angle, where several estimates of vehicle dynamics-dependent and / or vehicle-dependent parameters are used and the first derivative of the curvature of the trajectory is substituted by a weighted sum of (1) the inverse of an autonomous first-order differential equation for the deviation between the curvature of the trajectory and a target value for the curvature of the trajectory after the first derivative of the curvature of the trajectory and (2) a regression model.

The application discloses a tail-rotation type trajectory capturing test method, and aims to establish a trajectory capturing test capability of simulating a tail-rotation separation process of a separated body from a parent body in a wind tunnel, and belongs to the technical field of wind tunnel tests. The method comprises the following steps: a capturing trajectory technology that the separated body rotates around a tail fixed shaft, a technology that the separated body is switched from rotating around the fixed shaft to unconstrained rotation around the center of mass at a moment of unhooking, and a capturing trajectory technology that the separated body is in unconstrained free motion. The test is carried out by adopting the capturing trajectory method, and the trajectory and the attitude angle change of the separated body during the tail-rotation separation process from the parent body can be obtained, which is helpful to judging the safety and compatibility of the two-body separation. The method has the advantages of high simulation data precision and reliable data.

The invention discloses an inland water level monitoring method and system based on altimetry satellite altitude difference data, and the method comprises the steps: obtaining a target water remote sensing image and an altimetry satellite data set, and carrying out the superposition selection of altimetry data points completely falling into the surface of a water body; the height measurement data points are preprocessed, height difference data are obtained, and after preset conditions are supplemented, a water level change time sequence is obtained through least square adjustment calculation; the system correspondingly implements the method. The height difference data are obtained through the intersection point method or the overlapped trajectory method, the geoid model residual error is offset, the problem of height errors caused by the spatial position in a traditional method is solved, and the water level monitoring accuracy is improved.

Method (300) for determining a driving trajectory (145) of a motor vehicle (105), comprising the following steps: - Determining (305) positions (205) of the motor vehicle (105) by means of a receiver (120) of a satellite-based navigation system (125); - Determining (325) the travel trajectory (145) on the basis of the determined positions (205), characterized in that - each position (205) is weighted depending on a first number of other determined positions (205) that are located within a first predetermined spatial distance (210) from the position (205), - and depending on a second number of other specific positions (205) located within a second predetermined spatial distance (215) from the position (205), - where the first distance (210) is smaller than the second distance (215); - and the travel trajectory (145) is determined on the basis of weighted positions (205) (325).