scholarly journals A simultaneous trajectory generation method for quadcopter intercepting ground mobile vehicle

2017 ◽  
Vol 14 (4) ◽  
pp. 172988141771770 ◽  
Author(s):  
Jiangcheng Zhu ◽  
Jun Zhu ◽  
Chao Xu

This article proposes a trajectory generator for quadcopter to intercept moving ground vehicle. For this air–ground interaction problem, we formulate the trajectory generation problem as quadratic dynamic programming in a moving-horizon scheme based on the quadcopter kinematics and observation to ground vehicle. The closed-form solution of quadratic dynamic programming in each iteration enables this algorithm a real-time replanning performance. Thereafter, segmented trajectory rule, inspired from commercial flight landing regular, is implemented to guarantee smoothness in approaching and interception to moving ground target from comparably far origin. Our established algorithm is verified through both simulations and experiments.

1976 ◽  
Vol 66 (1) ◽  
pp. 109-123
Author(s):  
J. E. Luco

abstract A study is made of the harmonic torsional response of an elastic structure placed on a rigid hemispherical foundation which is supported on an elastic medium and is subjected to the action of obliquely incident plane SH waves. As a basic step in the solution of the torsion interaction problem, a closed-form solution is obtained for the torsional response of a rigid hemispherical foundation excited externally by a harmonic torque and through the soil by an obliquely incident plane SH wave. Comparisons between the results for a hemispherical foundation with those for a circular plate allow the estimation of the effects that the embedment of the foundation has on the torsional response of the superstructure.


2016 ◽  
Vol 78 (11) ◽  
Author(s):  
Chessda Uttraphan ◽  
Nasir Shaikh-Husin ◽  
M. Khalil-Hani

Buffer insertion is a very effective technique to reduce propagation delay in nano-metre VLSI interconnects. There are two techniques for buffer insertion which are: (1) closed-form solution and (2) dynamic programming. Buffer insertion algorithm using dynamic programming is more useful than the closed-form solution as it allows the use of multiple buffer types and it can be used in tree structured interconnects. As design dimension shrinks, more buffers are needed to improve timing performance. However, the buffer itself consumes power and it has been shown that power dissipation of buffers is significant. Although there are many buffer insertion algorithms that were able to optimize propagation delay with power constraint, most of them used the closed-form solution. Hence, in this paper, we present a formulation to compute dynamic power dissipation of buffers for application in dynamic programming buffer insertion algorithm. The proposed formulation allows dynamic power dissipation of buffers to be computed incrementally. The technique is validated by comparing the formulation with the standard closed-form dynamic power equation. The advantage of the proposed formulation is demonstrated through a series of experiments where it is applied in van Ginneken’s algorithm. The results show that the output of the proposed formulation is consistent with the standard closed-form formulation. Furthermore, it also suggests that the proposed formulation is able to compute dynamic power dissipation for buffer insertion algorithm with multiple buffer types.  


2014 ◽  
Vol 58 (04) ◽  
pp. 185-200 ◽  
Author(s):  
M. G. Morabito

Recently there has been increasing interest in the fluid-structure interaction problem of planning hull bottom structure during slamming events. Significant work has been done in estimating the bottom pressures that occur during a slam and incorporating this into structural models of planing craft. In this article, empirical equations for the pressure distribution on prismatic planing hulls are developed, including both hydrostatic and hydrodynamic effects, deadrise variation, trim, and wetted length. The empirical method is based on relevant experimental measurements of planing hull bottom pressures that have been made over an 80-year period. This analysis may readily be extended to the impact problem by substitution of an equivalent planing velocity, which is discussed in the article. The end result is a closed form solution for bottom pressures on prismatic planing craft that can be rapidly calculated using a simple spreadsheet. The method is applicable for deadrise angles from 0 to 40, trim angles up to 30, and wetted lengths up to five beams. This wide range of parameters is significantly larger than most current models. The empirical method is modular, allowing for substitution of more accurate formulae as more data become available in the future.


2013 ◽  
Vol 40 (2) ◽  
pp. 106-114
Author(s):  
J. Venetis ◽  
Aimilios (Preferred name Emilios) Sideridis

1995 ◽  
Vol 23 (1) ◽  
pp. 2-10 ◽  
Author(s):  
J. K. Thompson

Abstract Vehicle interior noise is the result of numerous sources of excitation. One source involving tire pavement interaction is the tire air cavity resonance and the forcing it provides to the vehicle spindle: This paper applies fundamental principles combined with experimental verification to describe the tire cavity resonance. A closed form solution is developed to predict the resonance frequencies from geometric data. Tire test results are used to examine the accuracy of predictions of undeflected and deflected tire resonances. Errors in predicted and actual frequencies are shown to be less than 2%. The nature of the forcing this resonance as it applies to the vehicle spindle is also examined.


Author(s):  
Nguyen N. Tran ◽  
Ha X. Nguyen

A capacity analysis for generally correlated wireless multi-hop multi-input multi-output (MIMO) channels is presented in this paper. The channel at each hop is spatially correlated, the source symbols are mutually correlated, and the additive Gaussian noises are colored. First, by invoking Karush-Kuhn-Tucker condition for the optimality of convex programming, we derive the optimal source symbol covariance for the maximum mutual information between the channel input and the channel output when having the full knowledge of channel at the transmitter. Secondly, we formulate the average mutual information maximization problem when having only the channel statistics at the transmitter. Since this problem is almost impossible to be solved analytically, the numerical interior-point-method is employed to obtain the optimal solution. Furthermore, to reduce the computational complexity, an asymptotic closed-form solution is derived by maximizing an upper bound of the objective function. Simulation results show that the average mutual information obtained by the asymptotic design is very closed to that obtained by the optimal design, while saving a huge computational complexity.


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