scholarly journals Receding Horizon Trajectory Optimization with Terminal Impact Specifications

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Limin Zhang ◽  
Mingwei Sun ◽  
Zengqiang Chen ◽  
Zenghui Wang ◽  
Yongkun Wang
Keyword(s):  
Programming Language ◽  
Trajectory Optimization ◽  
Optimization Problem ◽  
Pseudospectral Method ◽  
Optimization Strategy ◽  
Receding Horizon ◽  
C Programming Language ◽  
Gauss Pseudospectral Method ◽  
C Programming ◽  
The Cost

The trajectory optimization problem subject to terminal impact time and angle specifications can be reformulated as a nonlinear programming problem using the Gauss pseudospectral method. The cost function of the trajectory optimization problem is modified to reduce the terminal control energy. A receding horizon optimization strategy is implemented to reject the errors caused by the motion of a surface target. Several simulations were performed to validate the proposed method via the C programming language. The simulation results demonstrate the effectiveness of the proposed algorithm and that the real-time requirement can be easily achieved if the C programming language is used to realize it.

WHEELED ROBOT WITH ARDUBLOCK PROGRAMMING FOR ELEMENTARY SCHOOL STUDENTS

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
FENDIK EKO PURNOMO ◽  
M A FIRMANSYAH
Keyword(s):  
Elementary School ◽  
Elementary School Students ◽  
Programming Language ◽  
Basic Assumption ◽  
School Curriculum ◽  
School Students ◽  
C Programming Language ◽  
C Programming ◽  
Wheeled Robot ◽  
The Cost

Robotics technology can be implemented into the elementary school curriculum with the presence of extracurricular robotics or better as robotics only. Robotics in students is taught to assemble and program simple robots packaged in robotics learning media. Robotics activities basically use wheelled robots but have different functions. With the basic assumption of the robot, we can reduce the cost of procurement by making a robot with one wheel but with various functions. The wheeled robot is portable, so it is easy to disassemble. Robotics activities in generaly uses an Arduino controller with the C programming language. Elementary school students have difficulty understanding the language. Ardublock as one of the easy and open-source solutions. This research focused on the working system of a wheeled robot with various features (line tracer, transporter, and wall tracking) as well as the success in using ardublock logic as the programming language of the robot. The results test show that the ardublock program can be used to program the Arduino controller on the robot. The wheeled robot with the line follower feature recorded a travel time of 6.0 seconds on a 200cm trajectory. The wheeled robot with a transporter feature on a 200 cm trajectory takes an average of 8.9 seconds with the success of lifting objects 7 times out of 10 attempts.

Reentry Trajectory Optimization and Simulation of Hypersonic Vehicle with Maximum Cross Range Based on GPM

2014 ◽  
Vol 635-637 ◽  
pp. 1431-1437
Author(s):  
Wu Jun Huo ◽  
Xu Liu ◽  
Li Wang ◽  
Chao Song
Keyword(s):  
Trajectory Optimization ◽  
Optimization Problem ◽  
Control Variable ◽  
Pseudospectral Method ◽  
Hypersonic Vehicle ◽  
State Variables ◽  
Hypersonic Aircraft ◽  
Gauss Pseudospectral Method ◽  
Reentry Trajectory ◽  
Reentry Trajectory Optimization

Abstract：The application of Gauss pseudospectral method (GPM) to hypersonic aircraft reentry trajectory optimization problem with maximum cross range was introduced. The Gauss pseudospectral method was used to solve the reentry trajectory of the hypersonic vehicle with the maximum cross range. Firstly, the model of hypersonic aircraft reentry trajectory optimization control problem was established. Taking no account of course constraint, the maximum cross range was chosen as optimal performance index, and angle of attack and bank was chosen as control variable. Terminal state was constrained by position and velocity. Then GPM was applied to change trajectory optimization problem into nonlinear programming problem (NLP), and the state variables and control variables were selected as optimal parameters at all Gauss nodes. At last, optimal reentry trajectory was solved by solving the NLP with the help of SNOPT. The simulation results indicate that GPM does not need to estimate the initial cost variable, and it is not sensitive to the initial states and effective to solve trajectory optimization problem.

scholarly journals The Earth-Mars Transfer Trajectory Optimization of Solar Sail Based on hp-Adaptive Pseudospectral Method

2018 ◽  
Vol 2018 ◽  
pp. 1-14
Author(s):  
Yufei Guo ◽  
Dongzhu Feng ◽  
Xin Wang ◽  
Cong Li ◽  
Yunzhao Liu
Keyword(s):  
Trajectory Optimization ◽  
Optimization Problem ◽  
Computational Cost ◽  
Pseudospectral Method ◽  
Solar Sail ◽  
Polar Coordinate System ◽  
Optimization Strategy ◽  
Solar Sails ◽  
Kinematic Equation ◽  
Transfer Trajectory

Solar sails have many advantages over traditional chemical propulsion spacecraft, such as needlessness of fuel, high payload ratio, long service life, and great application potential in deep space exploration, interstellar voyage, and other aerospace application fields. However, the period of solar sail transfer from the initial orbit to the desired orbit is relatively long. Thus, it is necessary to optimize the transfer trajectory of solar sail according to specific tasks. The hp-adaptive pseudospectral method combines the global pseudospectral method with the finite element method, which adopts double layer optimization strategy to solve the optimal control problem and has higher computational efficiency and accuracy than the traditional global pseudospectral method. In this paper, the pressure of solar light acting on the solar sail is analyzed, and the kinematic equation of the solar sail is established in polar coordinate system first; then the basic principle of the hp-adaptive pseudospectral method is introduced, and the steps of solving the transfer trajectory optimization problem by hp-adaptive pseudospectral method are proposed; finally, the trajectory optimization of the solar sail from Earth orbit to Sun-centered Mars orbit is simulated as an example to demonstrate the effectiveness of hp-adaptive pseudospectral method in the orbit transfer optimization problem of solar sail. The simulation results show that the adopted method is not sensitive to the initial values and has more reasonable distribution and less computational cost than the Gauss pseudospectral method.

scholarly journals Onboard Trajectory Generation of Hypersonic Morphing Aircraft

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Chenxin Zhang ◽  
Yankun Zhang ◽  
Changzhu Wei
Keyword(s):  
Trajectory Optimization ◽  
Pseudospectral Method ◽  
Mean Value ◽  
Optimization Strategy ◽  
Initial State ◽  
Morphing Aircraft ◽  
Initial Errors ◽  
Aerodynamic Model ◽  
Gauss Pseudospectral Method ◽  
Trajectory Database

In this paper, a trajectory optimization strategy for the hypersonic morphing aircraft is proposed, and the AMPI method is used to generate the online trajectory with initial state errors. Firstly, the aerodynamic model and propulsion model of the hypersonic morphing aircraft were established considering the wingspan and the scramjet. Secondly, the optimization strategy was proposed via Gauss pseudospectral method considering the control variables including angle of attack (AOA) and wingspan. The optimized trajectory met the final constraints and path constraints with the objective to minimize the time of the ascent phase. Then, the AMPI method was used to generate online trajectory without solving OCP or NLP on the base of trajectory database calculated by the optimization strategy. The simulation results indicate high accuracy of AMPI method and the final errors corresponding to different initial errors were acceptable. The mean value of the CPU time of the method was about 0.1 second, which shows real-time capability.

scholarly journals Path Planning for Rapid Large-Angle Maneuver of Satellites Based on the Gauss Pseudospectral Method

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Wan Zhang ◽  
Yao Zhang ◽  
Wenbo Li ◽  
Youyi Wang
Keyword(s):  
Attitude Control ◽  
Trajectory Optimization ◽  
Optimal Trajectory ◽  
Optimization Problem ◽  
Large Angle ◽  
Pseudospectral Method ◽  
Performance Criteria ◽  
Planning Problem ◽  
Singularity Problem ◽  
Gauss Pseudospectral Method

A Gauss pseudospectral method is proposed in this study to solve the optimal trajectory-planning problem for satellite rapid large-angle maneuvers. In order to meet the requirement of rapid maneuver capability of agile small satellites, Single Gimbal Control Moment Gyros (SGCMGs) are adopted as the actuators for the attitude control systems (ACS). Because the singularity problem always exists for SGCMGs during the large-angle maneuvering of the satellites, a trajectory optimization method for the gimbal rates is developed based on the Gauss pseudospectral method. This method satisfies the control requirement of satellite rapid maneuvers and evades the singularity problem of SGCMGs. The method treats the large-angle maneuver problem as an optimization problem, which meets the boundary condition and a series of the physical constraints including the gimbal angle constraint, the gimbal rates constraint, the singularity index constraint, and some other performance criteria. This optimization problem is discretized as a nonlinear programming problem by the Gauss pseudospectral method. The optimal nonsingularity gimbal angle trajectory is obtained by the sequence of quadratic programming (SQP). This approach avoids the difficulties in solving the boundary value problem. The simulations reveal that the Gauss pseudospectral method effectively plans an optimal trajectory and satisfies all the constraints within a short time.

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