Search results for "Path following"
showing 9 items of 9 documents
Optimal Flight Path Determination in Turbulent Air: A Modified EKF Approach
2018
By using the Extended Kalman Filter an accurate path following in turbulent air is performed. The procedure employs simultaneously two dierent EKFs: the rst one estimates disturbances, the second one aords to determine the necessary controls displacements for rejecting those ones. To tune the EKFs an optimization algorithm has been designed to automatically determine Process Noise Covariance and Measurement Noise Covariance matrices. The rst lter, by using instrumental measurements gathered in turbulent air, estimates wind components. The second one obtains command laws able to follow the desired ight path. To perform this task aerodynamic coecients have been modied. Such a procedure leads …
Path Following in Non-Visual Conditions.
2018
Path-following tasks have been investigated mostly under visual conditions, that is when subjects are able to see both the path and the tool, or limb, used for navigation. Moreover, only basic path shapes are usually adopted. In the present experiment, participants must rely exclusively on continuous, non-speech, and ecological auditory and vibrotactile cues to follow a path on a flat surface. Two different, asymmetric path shapes were tested. Participants navigated by moving their index finger over a surface sensing position and force. Results show that the different non-visual feedback modes did not affect the task's accuracy, yet they affected its speed, with vibrotactile feedback causin…
Synergic algorithms for the planning and the intelligent following of a trajectory for non-holonomic vehicles
2008
Although there are many studies about two wheels non-holonomic vehicles, in order to simplify the problem the planning and the following of trajectories or paths are generally considered two different phases. In this paper, two algorithms for the synergic working of trajectory planning with intelligent trajectory following are presented. The "trajectory shape" characteristics obtained in the planning phase are used for the efficient trajectory following. From the shape, in order to follow the trajectory, an intelligent controller calculates, without further elaboration, the reference wheels velocity of the vehicle. The knowledge of trajectory shape characteristics and curvature constraints …
AUTOMATIC TAKE-OFF OR LANDING PATH FOLLOWING IN TURBULENT AIR FOR UAS - AN EKF BASED PROCEDURE
2015
By using the Extended Kalman Filter (EKF) an accurate take-off or landing flight path following in turbulent air is performed. The tuned up procedure employs simultaneously two different EKF: the first one estimates gust disturbances, the second one affords to determine the necessary controls displacements for rejecting those ones. In particular, the first filter, by using instrumental measurements gathered in turbulent air, estimates wind components. The second one obtains command laws able to follow the desired flight path. To perform this task aerodynamic coefficients have been modified by adding entirely new derivatives or synthetic increments to basic ones whose might the kind of chang…
Automatic EKF tuning for UAS path following in turbulent air
2018
By using two simultaneously working Extended Kalman Filters, a procedure is implemented in order to perform in a fully autonomous way the path following in turbulent air. To guarantee the robustness of the proposed algorithm, an automatic tuning procedure is proposed to determine optimal values of Process and Measurement Noise statistics. Such a procedure is based on both the characteristics of the disturbances and the desired flight path; in particular, a specific performance index is applied to tune filters. In this way control laws are adapted to the flight condition and these lead to an optimal path-following. This research represents an upload of previous papers. It allows eliminating …
Importance of force feedback for following uneven virtual paths with a stylus
2021
It is commonly known that a physical textured path can be followed by indirect touch through a probe also in absence of vision if sufficiently informative cues are delivered by the other sensory channels, but prior research indicates that the level of performance while following a virtual path on a touchscreen depends on the type and channel such cues belong to. The re-enactment of oriented forces, as they are induced by localized obstacles in probe-based exploration, may be important to equalize the performance between physical and virtual path following. Using a stylus attached to a force-feedback arm, an uneven path marked by virtual bars was traversed while time and positions were measu…
Generalizing LARS algorithm using differential geometry
2009
We propose a path following algorithm for generalized linear models that can be considered a differential geometric generalization of the LARS algorithm. In our approach we use differential geometry to generalize the equiangular condition on which is based the LARS algorithm and then we use a predictor-corrector method to compute the solution path of the coefficients.
AN EKF BASED PROCEDURE FOR AUTOMATIC PATH FOLLOWING IN TURBULENT AIR
2017
Aim of the present paper is to propose a procedure to afford an accurate automatic path following in turbulent air. The technique is based on the simultaneous employment of two different EKF. The first estimates disturbances, the second one estimates deflection that are necessary to reject the estimated disturbances. The first EKF uses measurements gathered in turbulent air. The second EKF obtains command laws able to follow the desired flight path rejecting disturbances. To purchase the objective, aerodynamic coefficients have been modified by adding entirely new derivatives or synthetic increments to basic ones. The modified aircraft parameters are determined by augmenting the aircraft’s …
Differential geometric least angle regression: a differential geometric approach to sparse generalized linear models
2013
Summary Sparsity is an essential feature of many contemporary data problems. Remote sensing, various forms of automated screening and other high throughput measurement devices collect a large amount of information, typically about few independent statistical subjects or units. In certain cases it is reasonable to assume that the underlying process generating the data is itself sparse, in the sense that only a few of the measured variables are involved in the process. We propose an explicit method of monotonically decreasing sparsity for outcomes that can be modelled by an exponential family. In our approach we generalize the equiangular condition in a generalized linear model. Although the …