Motion of a Tethered System Under Attitude Control With Large Deformation, Rotation and Translation

2003 ◽  
Author(s):  
Shoichiro Takehara ◽  
Yoshiaki Terumichi ◽  
Masahiro Nohmi ◽  
Kiyoshi Sogabe
Keyword(s):  
Large Deformation ◽  
Attitude Control ◽  
Rigid Bodies ◽  
Torque Control ◽  
Body Motion ◽  
Joint Torque ◽  
Control Technique ◽  
Flexible Body ◽  
First Eigenvalue ◽  
Reaction Wheel

In this paper, we discuss about the motion of a system consisting of a very flexible body and rigid bodies at its end under attitude control to the end body. A tethered subsatellite in space is known as an example of this system. We consider two mathematical models for flexible body. First, the flexible body motion in a plane is described by using Finite Element Method formulation. Second, the flexible body in planer motion is described by using Absolute Nodal Coordinate formulation. In this method, it is easy to describe the motion of the flexible body with large deformation, rotation and translation displacement. We can consider interaction between the deflection of the flexible body and the motion of the rigid bodies in these methods. Furthermore we attempt to control the attitude of the end body using a reaction wheel. The flexible body motion is influenced on the motion of the rigid bodies under attitude control of end body. The control technique consists of an attitude control by the reaction wheel and a control by the reaction wheel with the joint torque control to cancel accumulation of angular momentum. First, eigenvalue analysis is carried out where control gain changes. Second, the motion under controlled system is discussed under free vibration. We compared these results. Furthermore we treat large deformation problem. The end of flexible body moves horizontally. As a result, we confirm the interaction between flexible body and rigid body under the attitude control.

Numerical and Experimental Approaches on the Motion of a Tethered System With Large Deformation, Rotation and Translation

2005 ◽  
Author(s):  
Shoichiro Takehara ◽  
Yoshiaki Terumichi ◽  
Masahiro Nohmi ◽  
Kiyoshi Sogabe ◽  
Yoshihiro Suda
Keyword(s):  
Rigid Body ◽  
Large Deformation ◽  
Numerical Solutions ◽  
Rigid Bodies ◽  
Rigid Body Motion ◽  
Body Motion ◽  
Flexible Body ◽  
Numerical Formulation ◽  
Experimental Approaches ◽  
Good Agreement

In this paper, we discuss the motion of a tethered system. In general, a tether is a cable or wire rope, and a tethered system consists of a tether and attached equipment. A tethered subsatellite in space is an example of this system. We consider the tethered system consisting of a very flexible body (the tether) and rigid bodies at one end as our analytical model. A flexible body in planer motion is described using the Absolute Nodal Coordinate Formulation. Using this method, the motion of a flexible body with large deformation, rotation and translation can be expressed with the accuracy of rigid body motion. The combination of flexible body motion and rigid body motion is performed and the interaction between them is discussed. We also performed experiments to investigate the fundamental motion of the tethered system and to evaluate the validity of the numerical formulation. The first experiments were conducted using a steel tether and rubber tether in gravity space. We also conducted experiment of the motion of the tethered system with a rigid body in microgravity space. The numerical solutions using the proposed methods for the modeling and formulation for the tethered system are in good agreement with the experimental results.

Attitude Control of a String and Rigid Bodies System

2001 ◽  
Author(s):  
Masahiro Nohmi ◽  
Yoshiaki Terumichi ◽  
Kiyoshi Sogabe
Keyword(s):  
Attitude Control ◽  
Extreme Environment ◽  
Linear Interpolation ◽  
Rigid Bodies ◽  
Control Technique ◽  
Element Formulation ◽  
Controlled System ◽  
Control Approach ◽  
Natural Frequency Analysis ◽  
System Characteristics

Abstract Applications of mechanical systems of a string with a rigid bodies subsystem have various possibilities for the engineering in extreme environment conditions, for example, in space or in ocean. This rigid bodies subsystem can be used as a robot subsystem. This paper discusses about attitude control of the rigid bodies subsystem, especially around an equilibrium point of the whole system. The control technique is consists of attitude control with reaction wheels and angular momentum control with manipulation of the rigid bodies subsystem. In order to confirm the effectiveness of the control approach, numerical simulations have been done, under condition that the shape of the string is described by the finite-element formulation, selecting a linear interpolation Also, from the view point of natural frequency analysis of the controlled system, characteristics of the control approach have been examined.

scholarly journals Reaction Wheel Installation Deviation Compensation for Overactuated Spacecraft with Finite-Time Attitude Control

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Aihua Zhang ◽  
Jianfei Ni ◽  
Hamid Reza Karimi
Keyword(s):  
Finite Time ◽  
Attitude Control ◽  
Sliding Mode ◽  
External Disturbance ◽  
Control Technique ◽  
Adaptive Sliding Mode Control ◽  
Reaction Wheel ◽  
Compensation Control ◽  
Attitude Tracking ◽  
Attitude Tracking Control

A novel attitude tracking control scheme is presented for overactuated spacecraft to address the attitude stabilization problem in presence of reaction wheel installation deviation, external disturbance and uncertain mass of moment inertia. An adaptive sliding mode control technique is proposed to track the uncertainty. A Lyapunov-based analysis shows that the compensation control law can guarantee that the desired attitude trajectories are followed in finite-time. The key feature of the proposed control strategy is that it globally asymptotically stabilizes the system, even in the presence of reaction wheel installation deviation, external disturbances, and uncertain mass of moment inertia. The attitude track performance using the proposed finite-time compensation control is evaluated through a numerical example.

scholarly journals Numerical approach to modeling flexible body motion with large deformation, displacement and time-varying length

2017 ◽  
Vol 4 (4) ◽  
pp. 17-00030-17-00030
Author(s):  
Masayuki FUJIWARA ◽  
Shoichiro TAKEHARA ◽  
Yoshiaki TERUMICHI
Keyword(s):  
Large Deformation ◽  
Numerical Approach ◽  
Body Motion ◽  
Flexible Body ◽  
Time Varying ◽  
Varying Length

Attitude control of inverted pendulums using reaction wheels: Comparison between using one and two actuators

2019 ◽  
Vol 234 (3) ◽  
pp. 420-429
Author(s):  
João Francisco Silva Trentin ◽  
Tiago Peghin Cenale ◽  
Samuel da Silva ◽  
Jean Marcos de Souza Ribeiro
Keyword(s):  
Attitude Control ◽  
Low Cost ◽  
Main Idea ◽  
Rigid Bodies ◽  
Rate Of Change ◽  
Reaction Wheel ◽  
External Disturbances ◽  
Inverted Position ◽  
And Control

The attitude control using reaction wheels as actuators has been one of the most popular ways to stabilize and repel external disturbances in aerospace devices. From the controlled change of the angular momentum rate of change using reaction wheels, it is possible to control the oscillation and direction rates of change of rigid bodies in space. Thus, the main idea of this article is to present a case study with different configurations of the well-known reaction wheel pendulum. The first is based on the classical configuration, and the second, a new one, a pendulum with two reaction wheels. For both configurations, proportional–integral–derivative controllers were designed and experimental devices were built to perform real-time controllers using low-cost hardware. The simulated and experimental results have shown that the pendulums were controlled using a simple controller in the inverted position and the results were satisfactory. Four performance indices were calculated to evaluate the results for each configuration. They showed that the pendulum with two reaction wheels worked better than the pendulum with one reaction wheel. Two actuators made it easier to move and control the pendulum in the inverted position.

A new neural network control technique for robot manipulators

Robotica ◽  
1995 ◽  
Vol 13 (5) ◽  
pp. 477-484 ◽  
Author(s):  
Seul Jung ◽  
T. C. Hsia
Keyword(s):  
Neural Network ◽  
Robot Manipulators ◽  
Tracking Error ◽  
Performance Degradation ◽  
Torque Control ◽  
Joint Torque ◽  
Control Technique ◽  
Training Algorithms ◽  
Control Approach ◽  
Computed Torque

SummaryA new neural network (NN) control technique for robot manipulators is introduced in this paper. The fundamental robot control technique is the model-based computed-torque control which is subjected to performance degradation due. to model uncertainty. NN controllers have been traditionally used to generate a compensating joint torque to account for the effects of the uncertainties. The proposed NN control approach is conceptually different in that it is aimed at prefiltering the desired joint trajectories before they are used to command the computed-torque-controlled robot system (the plant) to counteract performance degradation due to plant uncertainties. In this framework, the NN controller serves as the inverse model of the plant, which can be trained on-line using joint tracking error. Several variations of this basic technique is introduced; Back-propagation training algorithms for the NN controller have been developed. Simulation results have demonstrated the excellent tracking performance of the proposed control technique.

scholarly journals Design of Satellite Attitude Control Algorithm Based on the SDRE Method Using Gas Jets and Reaction Wheels

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Luiz C. G. de Souza ◽  
Victor M. R. Arena
Keyword(s):  
Attitude Control ◽  
Control Algorithm ◽  
Controller Design ◽  
Algorithm Design ◽  
Large Angle ◽  
Space Mission ◽  
Control Technique ◽  
Gas Jets ◽  
State Dependent ◽  
Highly Nonlinear

An experimental attitude control algorithm design using prototypes can minimize space mission costs by reducing the number of errors transmitted to the next phase of the project. The Space Mechanics and Control Division (DMC) of INPE is constructing a 3D simulator to supply the conditions for implementing and testing satellite control hardware and software. Satellite large angle maneuver makes the plant highly nonlinear and if the parameters of the system are not well determined, the plant can also present some level of uncertainty. As a result, controller designed by a linear control technique can have its performance and robustness degraded. In this paper the standard LQR linear controller and the SDRE controller associated with an SDRE filter are applied to design a controller for a nonlinear plant. The plant is similar to the DMC 3D satellite simulator where the unstructured uncertainties of the system are represented by process and measurements noise. In the sequel the State-Dependent Riccati Equation (SDRE) method is used to design and test an attitude control algorithm based on gas jets and reaction wheel torques to perform large angle maneuver in three axes. The SDRE controller design takes into account the effects of the plant nonlinearities and system noise which represents uncertainty. The SDRE controller performance and robustness are tested during the transition phase from angular velocity reductions to normal mode of operation with stringent pointing accuracy using a switching control algorithm based on minimum system energy. This work serves to validate the numerical simulator model and to verify the functionality of the control algorithm designed by the SDRE method.

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