scholarly journals Time optimal paths for high speed maneuvering

1993 ◽  
Author(s):  
D.B. Reister ◽  
S.M. Lenhart
1995 ◽  
Vol 14 (2) ◽  
pp. 184-194 ◽  
Author(s):  
David B. Reister ◽  
Suzanne M. Lenhart

2021 ◽  
pp. 027836492110333
Author(s):  
Gilhyun Ryou ◽  
Ezra Tal ◽  
Sertac Karaman

We consider the problem of generating a time-optimal quadrotor trajectory for highly maneuverable vehicles, such as quadrotor aircraft. The problem is challenging because the optimal trajectory is located on the boundary of the set of dynamically feasible trajectories. This boundary is hard to model as it involves limitations of the entire system, including complex aerodynamic and electromechanical phenomena, in agile high-speed flight. In this work, we propose a multi-fidelity Bayesian optimization framework that models the feasibility constraints based on analytical approximation, numerical simulation, and real-world flight experiments. By combining evaluations at different fidelities, trajectory time is optimized while the number of costly flight experiments is kept to a minimum. The algorithm is thoroughly evaluated for the trajectory generation problem in two different scenarios: (1) connecting predetermined waypoints; (2) planning in obstacle-rich environments. For each scenario, we conduct both simulation and real-world flight experiments at speeds up to 11 m/s. Resulting trajectories were found to be significantly faster than those obtained through minimum-snap trajectory planning.


2015 ◽  
Vol 789-790 ◽  
pp. 889-895
Author(s):  
Jahng Hyon Park ◽  
Jeseok Kim ◽  
Jin Han Jeong

In this paper, an actuation mechanism for high-speed aiming of a target is proposed. The mechanism is a 3DOF-SPS (spherical-prismatic-spherical) parallel manipulator and can be used for a missile defense system with a fast reaction time. This type of parallel mechanism has high rigidity against external disturbances and accordingly high stiffness and precision. The target aiming requires 2 degrees of freedom and this 3 DOF mechanism has one redundancy. For fast manipulation of the proposed mechanism, the redundancy can be exploited and an optimal solution can be found out of the infinite number of inverse kinematic solutions. For finding a near time-optimal solution, a cost function is formulated considering displacement of each parallel link and an optimization technique is used for solution of the inverse kinematic problem.


2017 ◽  
Vol 2017 ◽  
pp. 1-16 ◽  
Author(s):  
J. Xie ◽  
S. C. Wong ◽  
S. M. Lo

High-speed railways have been developing quickly in recent years and have become a main travel mode between cities in many countries, especially China. Studying passengers’ travel choices on high-speed railway networks can aid the design of efficient operations and schedule plans. The Tong and Richardson algorithm that is used in this model offers a promising method for finding the optimal path in a schedule-based transit network. However, three aspects of this algorithm limit its application to high-speed railway networks. First, these networks have more complicated common line problems than other transit networks. Without a proper treatment, the optimal paths cannot be found. Second, nonadditive fares are important factors in considering travel choices. Incorporating these factors increases the searching time; improvement in this area is desirable. Third, as high-speed railways have low-frequency running patterns, their passengers may prefer to wait at home or at the office instead of at the station. Thus, consideration of a waiting penalty is needed. This paper suggests three extensions to improve the treatments of these three aspects, and three examples are presented to illustrate the applications of these extensions. The improved algorithm can also be used for other transit systems.


SIMULATION ◽  
1970 ◽  
Vol 14 (1) ◽  
pp. 27-35 ◽  
Author(s):  
D.A. Mellichamp

This paper presents a method of interactive or real-time predictive control which can be implemented without a stored program computer. By restricting the process dy namic model to a second-order-plus-dead-time format, a configuration which is satisfactory for many chemical or petroleum processing systems, a time-optimal controller can be built entirely on a small analog/hybrid computer. For set-point changes, the controller utilizes an analog model of the process to search out the predicted optimum input switching sequence and continuously maintains the process on the time-optimal trajectory. Because of the predictive nature of the method there is no necessity to include the time-delay term in the high-speed model; the predicted switches in the process input are simply ad vanced in time by the amount of the time-delay.


1995 ◽  
Vol 117 (4) ◽  
pp. 503-512 ◽  
Author(s):  
Sudhendu Rai ◽  
Haruhiko Asada

This paper presents the integrated structure/control design of high speed single link robots based on time-optimal control and finite element analysis. First, the solutions of a time optimal control problem are analyzed with respect to the arm link inertia and its structural flexibility. A new technique is developed to further reduce the optimal traveling time by redesigning the arm structure through the trade-off analysis between the arm inertia and its natural frequency. In the latter half of the paper, the design criterion is extended to multiple indices by considering residual vibrations, load bearing capacity and other design constraints. For suppressing residual vibrations, a simple feedback control is designed and its dynamic performance with respect to pole-zero locations is improved along with other criteria through mechanical structure modification. The finite element method is used as a modeling tool and the shape of the arm geometry is modified as design parameters. An arm is designed which performs much better as compared to the design which is done without considering the interactions between physical structure and control. The newly designed arm is tested by constructing an experimental setup. The results show significantly improved performance.


2014 ◽  
Vol 687-691 ◽  
pp. 616-622
Author(s):  
Liang Liang Zhang ◽  
Yao Jiang ◽  
Tie Min Li

A time-optimal control of a 4RRR parallel manipulator with actuation redundancy is reported. A method using both redundant actuation and velocity planning is carried out to achieve the shortest moving time of the platform travelling through an assigned path without reducing precision caused by the backlashes in the actuators. The problem is simplified and an adaptive method of time-optimal control is designed based on the characteristics such as pre-coupling of time segments and decoupling of the redundant torques and time segments of this problem. The result demonstrates that this method can solve this problem with high speed. It serves as an example of both time-optimal control in robotics and multi-parameter optimization.


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