Optimal Maneuver Research Articles

Multiobjective Optimal Parking Maneuver Planning of Autonomous Wheeled Vehicles

This article proposes a computational trajectory optimization framework for solving the problem of multiobjective automatic parking motion planning. Constrained automatic parking maneuver problem is usually difficult to solve because of some practical limitations and requirements. This problem becomes more challenging when multiple objectives are required to be optimized simultaneously. The designed approach employs a swarm intelligent algorithm to produce the tradeoff front along the objective space. In order to enhance the local search ability of the algorithm, a gradient operation is utilized to update the solution. In addition, since the evolutionary process tends to be sensitive with respect to the flight control parameters, a novel adaptive parameter controller is designed and incorporated in the algorithm framework such that the proposed method can dynamically balance the exploitation and exploration. The performance of using the designed multiobjective strategy is validated and analyzed by performing a number of simulation and experimental studies. The results indicate that the present approach can provide reliable solutions and it can outperform other existing approaches investigated in this article.

Closed-Form Optimal Impulsive Control of Spacecraft Formations Using Reachable Set Theory

This paper addresses the spacecraft relative orbit reconfiguration problem of minimizing the delta- cost of impulsive control actions while achieving a desired state in fixed time. The problem is posed in relative orbit element (ROE) space, which yields insight into relative motion geometry and allows for the straightforward inclusion of perturbations in linear time-variant form. Reachable set theory is used to translate the cost-minimization problem into a geometric path-planning problem and formulate the reachable delta- minimum, a new metric to assess optimality and quantify reachability of a maneuver scheme. Next, this paper presents a methodology to compute maneuver schemes that meet this new optimality criterion and achieve a prescribed reconfiguration. Though the methodology is applicable to any linear time-variant system, this paper uses a state representation in ROE to derive new globally optimal maneuver schemes in orbits of arbitrary eccentricity. The methodology is also used to generate quantifiably suboptimal solutions when the optimal solutions are unreachable. Further, this paper determines the mathematical impact of uncertainties on achieving the desired end state and provides a geometric visualization of those effects on the reachable set. The proposed algorithms are tested in realistic reconfiguration scenarios and validated in a high-fidelity computational simulation environment.

Gaining an insight into the importance of each inhalation manoeuvre parameter using altered patients’ inhalation profiles

The aerodynamic particle size distribution (APSD) and dose emission characteristics of indacaterol Breezhaler have been measured using ex-vivo methodology and altering original COPD inhalation manoeuvre profiles to investigate the influence of inspiratory parameters namely, the peak inhalation flow (PIF), inhalation acceleration rate (ACIM) and inhaled volume (Vin) by keeping two parameters fixed and varying the other one.All inhalation parameters had an impact on the dose emission, dose emptying from the capsule/device in the order of PIF > Vin > ACIM. ACIM and Vin have almost an equal effect on the delivered dose (DD) and the fine particle dose (FPD) but the impact of the PIF was the most pronounced. PIF also had the greatest impact on the mass median aerodynamic diameter (MMAD). Producing an optimal inhalation manoeuvre combining the highest PIF, ACIM and Vin in one single inhalation would improve both the quantity and the quality of the aerosol. Making two separate inhalation from each prepared dose would also be useful. This ex-vivo methodology replaying altered COPD profiles with the breath simulator allows an insight on the importance of each inhalation manoeuvre parameter which would have not been possible using conventional in-vitro Pharmacopoeial methodology.

Impact of government regulation of RPS on China’s power market under carbon abatement constraints

In a significant period of Chinese energy reformation to the point of expediting revolution in energy production and consumption, and promoting green low-carbon upgrading transformation of energy electricity, Chinese government has to implement the obligatory policy of renewable portfolio standards (RPS) with specific institutional provisions sternly. The renewable energy quotas in thermal power industry with carbon emission abatement constraints particularly have a latent impact on the behavior of thermal electricity producers, which is ineluctably involved in electricity connection of grid companies. To make clear the positive role in boosting investment in renewable energy generation in thermal power industry under mandatory quotas requirements, we will utilize evolutionary game based on system dynamics (SD) to tackle with the sophisticated nexus among the government, thermal power producers and grid companies. We begin analysis of general evolutionary strategy stability in scenario ll by dynamically adjusting values of external variables of SD model to uncover pivotal variables affecting evolutionary strategy stability. Then in scenario I, the dynamic punishment structure consisting of cost elements to spark off the emulation of optimal manoeuvre selections of tripartite game agents is amended based on the simulation of vital variables affecting evolutionary strategy stability in scenario II. The significant conclusions provide decision-making support and management enlightenment for Chinese government to edge renewable energy generation capacity of thermal power producers and constrained degree of dynamic penalty for grid companies.

New Cone-Rolling Principle and Its Application for the Underactuated Attitude Maneuver Optimization of a Rigid Body

AbstractThe global optimal solution for the underactuated attitude maneuver plays a significant role in the fields of spacecraft, robotics, and mechanics. This paper investigated the global optimal...

Optimal Energy Management for Microgrids Considering Uncertainties in Renewable Energy Generation and Load Demand

This paper proposes an efficient power management approach for the 24 h-ahead optimal maneuver of Mega–scale grid–connected microgrids containing a huge penetration of wind power, dispatchable distributed generation (diesel generator), energy storage system and local loads. The proposed energy management optimization objective aims to minimize the microgrid expenditure for fuel, operation and maintenance and main grid power import. It also aims to maximize the microgrid revenue by exporting energy to the upstream utility grid. The optimization model considers the uncertainties of the wind energy and power consumptions in the microgrids, and appropriate forecasting techniques are implemented to handle the uncertainties. The optimization model is formulated for a day-ahead optimization timeline with one-hour time steps, and it is solved using the ant colony optimization (ACO)-based metaheuristic approach. Actual data and parameters obtained from a practical microgrid platform in Atlanta, GA, USA are employed to formulate and validate the proposed energy management approach. Several simulations considering various operational scenarios are achieved to reveal the efficacy of the devised methodology. The obtained findings show the efficacy of the devised approach in various operational cases of the microgrids. To further confirm the efficacy of the devised approach, the achieved findings are compared to a pattern search (PS) optimization-based energy management approach and demonstrate outperformed performances with respect to solution optimality and computing time.

Design and ballistic analysis of the mission for long-term study of the asteroid Apophis by a nanosatellite with an electric rocket propulsion system

The paper considers non-spherical objects with low gravitational attraction, such as asteroids, satellites of the planet and comets. We considered possibility of a mission to small bodies of the solar system of irregular shape on the example of the asteroid Apophis. The authors of the article suggest using a nanoclass spacecraft with an electric rocket propulsion system for a long mission to study Apophis. The purpose of this work is to determine the necessary costs of the working body for all stages of the mission, which includes reaching the asteroid, forming and maintaining a given orbit relative to it. The gravity of the Earth, Sun, and asteroid is taken into account when modeling the controlled movement of the spacecraft. When a spacecraft is moving relative to an asteroid, its gravitational field is described as a superposition of the gravitational fields of two rotating massive points. In this paper, it is proposed to divide the mission into two sections for preliminary ballistic design. The first optimal speed heliocentric flight Earth-asteroid Apophis with the alignment of the speed of the spacecraft and the asteroid. The second is the movement in the vicinity of the asteroid, which includes the optimal speed maneuver for forming the working orbit and maintaining the working orbit for a given time.

Integrated fault‐tolerant control system design based on continuous model predictive control for longitudinal manoeuvre of hypersonic vehicle with actuator faults

In this study, an integrated fault-tolerant control (IFTC) approach with a two-layer structure is proposed for longitudinal manoeuvre of the hypersonic vehicle with elevator deflection faults. On the top, longitudinal manoeuvre trajectory optimisation problem being subjected to state and input constraints is formulated. The minimum oscillation is taken as the objective function, and the direct collocation method is introduced to calculate the optimal manoeuvre reference trajectory online. On the bottom, diverse elevator deflection faults of the hypersonic vehicle are considered. The faulty longitudinal model is reformulated by input–output feedback linearisation, and the faults are equivalently lumped into additional uncertainties. For the lumped uncertainties and high-order derivatives of velocity and altitude of manoeuvre feasible trajectory, an extended state observer is used for online estimation. The fault-tolerant control based on continuous model predictive control is designed, where predictive models are derived by Taylor expansion approximation. To guarantee that the control inputs do not violate constraints, the analytical control law is improved by the optimal-aim distance criterion. The stability of the closed-loop control system and boundedness of observation errors are proved. The simulations verify the effectiveness of the proposed IFTC approach.

Peer Assessment of Operative Videos with Sleeve Gastrectomy to Determine Optimal Operative Technique

Global assessments of technical skill have been associated with surgical outcomes. More detailed understanding of which specific aspects of technique combine to make the "optimal" sleeve gastrectomy are necessary to help surgeons improve their practice. Practicing bariatric surgeons (n= 30) voluntarily submitted a de-identified video of a typical sleeve gastrectomy that was reviewed by a minimum of 10 peer surgeons on the technical quality of 9 operative maneuvers (ie mobilization of the fundus, stapler location, and sleeve width). An "optimal sleeve gastrectomy score" (OSGS) was calculated as a percentage of the total possible optimal maneuvers performed. Risk-adjusted 30-day complication rates and 1-year weight loss were compared between surgeons in the top and bottom quartile for OSGS for all patients who underwent sleeve gastrectomy during the time period. OSGS ranged from 49.1% to 82.9%. Surgeons in the top quartile for OSGS had lower rates of surgical complications (1.54% vs 2.75%; odds ratio 0.56; 95% CI 0.35 to 0.88; p= 0.013), hemorrhage (0.61% vs 1.48%; odds ratio 0.49; 95% CI 0.28 to 0.86; p= 0.013) and reoperation (0.37% vs 0.91%; odds ratio 0.4; 95% CI 0.20 to 0.81; p= 0.010) compared with surgeons in the bottom quartile. The median bougie size was 34F and the optimal location of the stapler near the pylorus and incisura was 5 cm and 2.25 cm, respectively. Sleeve gastrectomy videos thought to have "optimal" technique by peer surgeons were associated with lower complication rates. Understanding how to quantify and assess optimal vs suboptimal techniques can serve as a guide for surgeons to improve their practice.

Simulation and Optimization of Takeoff Maneuvers of Very Flexible Aircraft

A generic framework for the simulation of transient dynamics in nonlinear aeroelasticity is presented that is suitable for flexible aircraft maneuver optimization. Aircraft are modeled using a flexible multibody dynamics approach built on geometrically nonlinear composite beam elements, and the unsteady aerodynamics on their lifting surfaces is modeled using vortex lattices with free or prescribed wakes. The open loop response to commanded inputs and external constraints is then fed into a Bayesian optimization framework, which adaptively samples the configuration space to identify optimal maneuvers. As a representative example, the proposed approach is demonstrated on a catapult-assisted takeoff. The specific modeling challenges associated to that problem are first discussed, including the effect of aircraft flexibility. An optimality measure based on ground clearance and wing root loads is then defined. It is finally shown that the link that ramp-length constraints introduce between acceleration, release speed, and wing root loads is the main driver in the optimal solution.

Trajectory Planning of Quadrotor Systems for Various Objective Functions

SUMMARYQuadrotors are unmanned aerial vehicles with many potential applications ranging from mapping to supporting rescue operations. A key feature required for the use of these vehicles under complex conditions is a technique to analytically solve the problem of trajectory planning. Hence, this paper presents a heuristic approach for optimal path planning that the optimization strategy is based on the indirect solution of the open-loop optimal control problem. Firstly, an adequate dynamic system modeling is considered with respect to a configuration of a commercial quadrotor helicopter. The model predicts the effect of the thrust and torques induced by the four propellers on the quadrotor motion. Quadcopter dynamics is described by differential equations that have been derived by using the Newton–Euler method. Then, a path planning algorithm is developed to find the optimal trajectories that meet various objective functions, such as fuel efficiency, and guarantee the flight stability and high-speed operation. Typically, the necessary condition of optimality for a constrained optimal control problem is formulated as a standard form of a two-point boundary-value problem using Pontryagin’s minimum principle. One advantage of the proposed method can solve a wide range of optimal maneuvers for arbitrary initial and final states relevant to every considered cost function. In order to verify the effectiveness of the presented algorithm, several simulation and experiment studies are carried out for finding the optimal path between two points with different objective functions by using MATLAB software. The results clearly show the effect of the proposed approach on the quadrotor systems.

Hybrid removal of end-of-life geosynchronous satellites using solar radiation pressure and impulsive thrusts

This paper proposes an analytical solution of removing end-of-life GEO satellites to the GEO graveyard region using solar radiation pressure (SRP) and impulsive thrusts. The dynamic model of a GEO satellite equipped with a solar sail is first built upon the magnitude comparisons of different accelerations exerted on the satellite. Then the dynamic system is constructed based on the Gauss’s Variation of Parameter (VOP) equations, and linearized along a nominal trajectory. Control angles of the sail and impulsive thrust vectors are generated using the proposed optimal hybrid disturbance-accommodation tracking maneuvers. Simulations indicate that, to remove a satellite in 360 days using only SRP with the proposed method, a minimal area-to-mass (A/M) ratio of 0.13 m2/kg is required. When the A/M ratio of spacecraft is smaller than the minimal value, impulsive thrusts are applied to assist the removal process. For a satellite with an A/M ratio of 0.1 m2/kg, a total impulse of 10.5 m/s is required.

Design and Implementation of An Improved Camera Mounted Remote Controlled Quadcopter

Aeronautics and other studies on the science of aircraft have advanced to the point where Unmanned Aerial Vehicles (UAVs) or drones are now being extensively designed. However, such aircrafts are large and not maneuverable in tight spots especially fixed wing aircraft, therefore, the design of multi-rotors are now being considered. It is inherent that small unmanned aircraft with optimal maneuverability and the ability to carry small payloads such as cameras should be designed for operations in places where a full-size aircraft are either too big or too expensive to be deployed. One of the types of Small Unmanned Aerial Vehicle (SUAV) is a Quadcopter, which can be implemented in different applications. Quadcopters are rapidly gaining interest due to their stability, low cost in building, handling capabilities and agility. Uses of such craft include aerial photography or surveillance, ground surveillance and mapping, package delivery, for rescue operations and as a research tool into ways of designing more advanced aircraft. This study therefore designed and implemented an improved industry-grade Small Unmanned Aerial Vehicle (SUAV) multi-rotor Quadcopter. Quadcopter structure model, basic components, hovering stability, dimensions, and description of basic principles of quadcopter were discussed. The study showed that SUAVs are useful across a broad range of applications. Keywords: Unmanned Aerial Vehicles, Aeronautics, Aircraft, Multi-rotors, Quadcopter, Surveillance, Aerial Photography, Small Unmanned Aerial Vehicle. DOI: 10.7176/CEIS/11-2-08 Publication date: April 30 th 2020

The Trajectory Generation of UCAV Evading Missiles Based on Neural Networks

In order to solve the problem of evading air-to-air missiles of UCAV in autonomous air combat, the flight dynamics model and 3-dimensional guidance trajectory model based on proportional guidance were established and performance constraint conditions of missiles were constructed. According to the definition of basic maneuver library, 72 kinds of avoidance maneuvers were constructed. All 72 avoidance maneuvers were simulated while UCAV was at different relative yaw angles and relative pitch angles, and the optimal avoidance maneuvers under the corresponding conditions were selected out. Training samples and test samples were constructed by utilizing the acquired data, and the neural network for generating control parameters was trained. Under different conditions, neural network method and random selection method were simulated. The results show that the success rate of escape of the proposed method is higher and the time cost of generating the control parameters is less, which meets the requirements of effectiveness and real-time.

Asymptotic behavior and control of a “guidance by repulsion” model

We model and analyze a guiding problem, where the drivers try to steer the evaders’ positions toward a target region while the evaders always try to escape from drivers. This problem is motivated by the guidance-by-repulsion model [R. Escobedo, A. Ibañez and E. Zuazua, Optimal strategies for driving a mobile agent in a “guidance by repulsion” model, Commun. Nonlinear Sci. Numer. Simul. 39 (2016) 58–72] where the authors answer how to control the evader’s position and what is the optimal maneuver of the driver. First, we analyze well posedness and behavior of the one-driver and one-evader model, assuming of the same friction coefficients. From the long-time behavior, the exact controllability is proved in a long enough time horizon. Then, we extend the model to the multi-driver and multi-evader case. We assumed three interaction rules in the context of collective behavior models: flocking between evaders, collision avoidance between drivers and repulsive forces between drivers and evaders. These interactions depend on the relative distances, and each agent is assumed to be undistinguishable and obtained an averaged effect from the other individuals. In this model, we develop numerical simulations to systematically explore the nature of controlled dynamics in various scenarios. The optimal strategies turn out to share a common pattern to the one-driver and one-evader case: the drivers rapidly occupy the position behind the target, and want to pursuit evaders in a straight line for most of the time. Inspired by this, we build a feedback strategy which stabilizes the direction of evaders.

Trajectory Planning of Quadrotor UAV with Maximum Payload and Minimum Oscillation of Suspended Load Using Optimal Control

This paper focuses on the problem of transporting a cable-suspended load by a quadrotor UAV for safer flight and more efficiency. The dynamic model of a quadrotor coupled to the suspended load is derived using the Euler-Lagrange formulation. The optimal trajectory for carrying the maximum payload and minimum oscillation of swinging load will be obtained. The optimal cable length to increase the maximum payload capacity and reduce the maximum oscillation angle of swinging load is obtained. Also, the effect of load mass on the maximum oscillation angle of swinging load is studied. In this paper, the optimization procedure is based on the solution of the optimal control problem from the class of open loop with an indirect method. The application Pontryagin’s Minimum Principle lead to deriving the optimality conditions and subsequently a two-point boundary value problem (TPBVP) which is solved by a numerical method. An appropriate algorithm is presented for calculating the maximum payload to move between two specified points. The main superiority of this method is that it can solve a wide range of optimal maneuvers for arbitrary initial and final configurations relevant to every considered cost function. Generating various optimal paths with different maximum payloads and oscillation angles by modifying the values of the penalty matrices. In order to verify the efficiency of the proposed method and the presented algorithm, a simulation study is performed for a quadrotor with a suspended load in maneuver between two specified points and various object function.

Orbital maneuver strategy design based on piecewise linear optimization for spacecraft soft landing on irregular asteroids

Recently, asteroid exploration becomes an important branch of human’s deep space activities. In this paper, a piecewise linear optimal orbital maneuver strategy is designed for a spacecraft soft landing on irregular-shaped asteroids. First, the space around an irregular asteroid is converted into several grid units, and the gravitational field of the asteroid is linearly fitted in each unit. Then, the soft-landing orbital maneuver strategy design problem is formulated as a piecewise linear optimal problem, and further transferred into a family of two-point boundary value problems, which can be solved using collocation method. Finally, a corresponding algorithm is developed to obtain the piecewise linear optimal maneuver strategy, which is proved to be able to achieve the soft-landing mission well. Simulation results show that the error of the model linearization is small enough, while the calculation efficiency is remarkably improved, and the robustness of maneuver strategy is also improved.

Optimal maneuver penetration strategy based on power series solution of miss distance

Optimal maneuver penetration strategy based on power series solution of miss distance

A Robust Coordinated Expansion Planning Model For Wind Farm-Integrated Power Systems With Flexibility Sources Using Affine Policies

This article presents a two-stage adaptive robust coordinated generation and transmission expansion planning model for a wind farm-integrated power system. Also, dynamic thermal rating (DTR) systems, energy storage systems, and optimal line switching maneuvers are considered as various flexible sources to enhance the flexibility of the power system in response to uncertain variations of net system demand. The proposed approach characterizes the uncertainty of demands, wind power, and DTRs in each representative day by a polyhedral uncertainty set. Additionally, the k-means clustering technique is used to obtain upward/downward variations of correlated uncertain parameters in each representative day and to construct the uncertainty set. The proposed model is inherently intractable as it includes infinite constraints modeling enforced techno-economic limitations for all realizations of uncertain parameters. To resolve this limitation, the proposed intractable model is recast as a tractable mixed-integer linear programming problem using affine policies. The proposed approach is implemented on the Garver 6-bus and IEEE 73-bus test systems. Simulation results illustrate its flexibility, practicality, and tractability.

Design of Satellite Maneuvers for Inertia Parameter Estimation

This paper addresses the design of satellite maneuvers for the inertia estimation. The experiment design is an important step in system identification, since the choice of the excitation signal has a great influence on the precision of the parameter estimates. In order to design an optimal maneuver, the proposed method uses a cubic B-spline representation of the trajectory. The optimized maneuver is obtained through minimization of a functional based on the Fisher information matrix. The optimization process considers the physical constraints due to the saturation of the actuators. The effectiveness of the generated trajectory is evaluated via Monte Carlo simulations using the model of a satellite-type platform. Moreover, the optimized maneuver has been also tested on a real platform in a zero-gravity experiment where, due to the limited duration of the tests, the achievement of the maximum excitation is of great importance.