Minimum-Time Eigenaxis Rotation Maneuvers for a Spacecraft With Three Axis Reaction Wheels

2015 ◽  
Vol 137 (11) ◽  
Author(s):  
Haoyu Wang ◽  
Guowei Zhao ◽  
Hai Huang
Keyword(s):  
Numerical Simulation ◽  
Momentum Conservation ◽  
Open Loop ◽  
Minimum Time ◽  
Control Law ◽  
Open Loop Control ◽  
Model Uncertainties ◽  
Loop Control ◽  
Control Scheme ◽  
And Control

This paper proposes a planning method of the theoretically fastest slew path, and correspondingly, an analytical open-loop control law for the minimum-time eigenaxis rotation of spacecraft with three reaction wheels. The path planning and the control law are based on the angular momentum conservation of the spacecraft system. Then, a control scheme is also proposed to correct the maneuver error caused by model uncertainties. The control law and control scheme are verified in numerical simulation cases. The results show that the control law would realize the fastest slew path for an eigenaxis rotation, and the control scheme is feasible in shortening the slew time.

scholarly journals Variational Calculus Approach to Optimal Interception Task of a Ballistic Missile in 1D and 2D Cases

Algorithms ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 148
Author(s):  
Dariusz Horla
Keyword(s):  
Parametric Analysis ◽  
Variational Calculus ◽  
Open Loop ◽  
Ballistic Missile ◽  
Control Law ◽  
Open Loop Control ◽  
Performance Indices ◽  
Lagrange Equations ◽  
Loop Control ◽  
Conservation Of Momentum

The paper presents the application of variational calculus to achieve the optimal design of the open-loop control law in the process of anti-ballistic missile interception task. It presents the analytical results in the form of appropriate Euler–Lagrange equations for three different performance indices, with a simple model of the rocket and the missile, based on the conservation of momentum principle. It also presents the software program enabling rapid simulation of the interception process with selected parameters, parametric analysis, as well as easy potential modification by other researchers, as it is written in open code as m-function of Matlab.

Modeling and Control of a Rotary Crane

1985 ◽  
Vol 107 (3) ◽  
pp. 200-206 ◽  
Author(s):  
Y. Sakawa ◽  
A. Nakazumi
Keyword(s):  
Feedback Control ◽  
Equilibrium State ◽  
Open Loop ◽  
The State ◽  
Control Input ◽  
Loop Control ◽  
Modeling And Control ◽  
Control Scheme ◽  
Rotary Crane ◽  
And Control

In this paper we first derive a dynamical model for the control of a rotary crane, which makes three kinds of motion (rotation, load hoisting, and boom hoisting) simultaneously. The goal is to transfer a load to a desired place in such a way that at the end of transfer the swing of the load decays as quickly as possible. We first apply an open-loop control input to the system such that the state of the system can be transferred to a neighborhood of the equilibrium state. Then we apply a feedback control signal so that the state of the system approaches the equilibrium state as quickly as possible. The results of computer simulation prove that the open-loop plus feedback control scheme works well.

Control of a Digital Micromirror Device Using Input Shaping

2007 ◽  
Author(s):  
H. Jammoussi ◽  
S. Choura ◽  
E. M. Abdel-Rahman ◽  
H. Arafat ◽  
A. Nayfeh ◽  
...  
Keyword(s):  
Electrostatic Field ◽  
Control Strategy ◽  
Nonlinear Function ◽  
Input Voltage ◽  
Open Loop ◽  
Input Shaping ◽  
Control Law ◽  
Digital Micromirror Device ◽  
Open Loop Control ◽  
Loop Control

In this paper, an open-loop control strategy is proposed for maneuvering the angular motion of a Digital Micromirror Device (DMD). The control law is based on a micromirror model that accounts for both bending and torsion motions. The model characterizes two DMD configurations: with and without contact with the substrate. The device is actuated using an electrostatic field which is a nonlinear function of the states and input voltage. The proposed control strategy is a Zero Vibration (ZV) shaper. It overshoots the DMD to its desired final angle by appropriately varying two independent input voltages. Actuating voltages and switching times are determined to maneuver the DMD from −10° to +10° tilt angles while reducing the residual vibrations.

In-Hand Manipulation Primitives for a Minimal, Underactuated Gripper With Active Surfaces

2016 ◽  
Author(s):  
Raymond R. Ma ◽  
Aaron M. Dollar
Keyword(s):  
A Priori ◽  
Open Loop ◽  
Object Motion ◽  
A Priori Knowledge ◽  
Open Loop Control ◽  
Loop Control ◽  
Grasp Stability ◽  
Control Schemes ◽  
And Control ◽  
Underactuated Finger

Dexterous in-hand manipulation tasks have been difficult to execute, even with highly complex hands and control schemes, as the object grasp stability needs to be maintained while it is displaced in the hand workspace. Researchers have shown that underactuated, adaptive hand designs can effectively immobilize objects with simple, open-loop, but there have been few cases where underactuation has been leveraged to enhance in-hand manipulation. In this work, we investigate the performance of a gripper utilizing a thumb with an active, belt-driven, conveyor surface and an opposing, underactuated finger with passive rollers, for a variety of manipulation tasks and range of objects. We show that consistent, repeatable object motion can be obtained while ensuring a rigid grasp without a priori knowledge of the object geometry or contact locations, due to the adaptive qualities of underactuated design. Many dexterous in-hand manipulation examples with their anthropomorphic equivalents are examined, and simple, open-loop control schemes to optimize the repeatability of these tasks are proposed.

Minimum-time strategy to produce nonuniform emulsion copolymers. II. Open-loop control

1995 ◽  
Vol 57 (10) ◽  
pp. 1217-1226 ◽  
Author(s):  
Antonio Echevarria ◽  
Jose C. De La Cal ◽  
Jose M. Asua
Keyword(s):  
Open Loop ◽  
Minimum Time ◽  
Open Loop Control ◽  
Loop Control

An open-loop control scheme for minimization of residual vibrations of a flexible robot

2003 ◽  
Vol 43 (4) ◽  
pp. 387-395 ◽  
Author(s):  
W. S. Jang ◽  
K. S. Kim ◽  
S. K. Lee
Keyword(s):  
Open Loop ◽  
Open Loop Control ◽  
Flexible Robot ◽  
Loop Control ◽  
Control Scheme

Optimal Control of Restraint Forces in an Automobile Impact

2006 ◽  
Vol 129 (4) ◽  
pp. 415-424 ◽  
Author(s):  
Richard W. Kent ◽  
Dmitry V. Balandin ◽  
Nikolai N. Bolotnik ◽  
Walter D. Pilkey ◽  
Sergey V. Purtsezov
Keyword(s):  
Optimal Control ◽  
Seat Belt ◽  
Open Loop ◽  
Control Law ◽  
Continuous Control ◽  
Control Force ◽  
Restraint System ◽  
Open Loop Control ◽  
Loop Control ◽  
Linear Spring

This study concerns a concept for an optimal control of the force developed in an automotive restraint system during a frontal impact. The concept is close to that of “smart” restraint systems and involves continuous control of the restraint force by moving the point of attachment of the restraint system to the vehicle or retracting and releasing the seat belts. The analytical foundation for the control of the restraining force does not appear to have been formulated prior to this study. The control design involves the limiting performance analysis of the isolation of an occupant from the crash impact and the formation of a feedback to sustain the open-loop control law that provides the limiting performance. Initially, the problem is outlined using a single-degree-of-freedom system and solved for optimal isolator characteristics. This exercise shows that the optimal force is constant and that the performance of a restraint system behaving as a linear spring is half as effective as the optimal. The methodology is then applied to a published thoracic model having multiple degrees of freedom. A set of functionals is defined as constraints corresponding to injury criteria and the displacement of the occupant relative to the vehicle. The characteristics of the optimal isolator force are then determined. It is shown that this force has a short-duration period of high magnitude early in the profile, followed by an interval of nearly constant force. Next it is shown that a restraint behaving as a linear spring can generate the optimal control force if its attachment point in the vehicle is allowed to move. The design of the control law for this motion involves the determination of an optimal open-loop control and the formation of a feedback to sustain this control. Forms for both of these are presented. A substantial improvement in the behavior of an automobile occupant’s restraint systems can be anticipated from an active control of the seat belt retraction.

Sign in / Sign up

Export Citation Format

Share Document