Gravity Powered Locomotion and Active Control of Three Mass System

2010 ◽  
Author(s):  
Ali Tavakoli ◽  
Yildirim Hurmuzlu
Keyword(s):  
Active Control ◽  
Research Effort ◽  
Robust Controller ◽  
Mass System ◽  
Gait Patterns ◽  
Hybrid Dynamics ◽  
Control Scheme ◽  
Parameter Variations ◽  
A Chain ◽  
Nonlinear Robust

This paper presents the latest results of our research effort to develop a family of energetically efficient robotic locomotors and introduce new gait patterns for them. We study a chain of mechanisms that span from the very simple to the progressively more complicated. These mechanisms can be as simple as a bouncing ball or as complex as a five link biped. This paper presents the results of our study for a three mass dynamical system. We show that this system can generate a rich set of passive gaits such as hopping, tapping, walking. We developed a nonlinear robust controller for the hybrid dynamics of three mass system that is insensitive to parameter variations of the system. The active control scheme generates the passive gaits on arbitrary ground slope angles.

A Study on μ-Synthesis Control for Four-Wheel Steering System to Enhance Vehicle Lateral Stability

2010 ◽  
Vol 133 (1) ◽  
Author(s):  
Guo-Dong Yin ◽  
Nan Chen ◽  
Jin-Xiang Wang ◽  
Ling-Yao Wu
Keyword(s):  
Control System ◽  
Experimental Tests ◽  
Steering System ◽  
Hardware In The Loop ◽  
Steering Control ◽  
Robust Controller ◽  
Control Scheme ◽  
Parameter Variations ◽  
Good Vehicle ◽  
Selection Of

This paper presents the design of μ-synthesis control for four-wheel steering (4WS) vehicle and an experimental study using a hardware-in-the-loop (Hil) setup. First, the robust controller is designed and the selection of weighting functions is discussed in the framework of μ-synthesis control scheme, considering the varying parameters induced by running vehicle condition. Second, in order to investigate the feasibility of the four-wheel steering control system, the 4WS vehicle control system is built using dSPACE DS1005 platform. The experimental tests are performed using the Hil setup which has been constructed using the devised rear steering actuating system. The dynamics performance is evaluated by experiment using the Hil setup under the condition of parameter variations. Finally, experimental results show that the μ-synthesis controller can enhance good vehicle lateral maneuverability.

Analysis and Design of a Nonlinear Robust Controller

1996 ◽  
Vol 118 (2) ◽  
pp. 339-341 ◽  
Author(s):  
Chyun-Chau Fuh ◽  
Pi-Cheng Tung
Keyword(s):  
Fuzzy Control ◽  
Pid Controller ◽  
Simple Structure ◽  
Design Method ◽  
Nonlinear Controller ◽  
Robust Controller ◽  
Analysis And Design ◽  
Parameter Variations ◽  
Digital Simulations ◽  
Nonlinear Robust

A nonlinear controller and its design method are proposed. The development of the controller is motivated by fuzzy control. The controller has the advantages of simple structure, rapid computation, zero steady error, few parameters to set, and robustness to structure uncertainties and to parameter variations. Comparing the new controller with the PID controller, we find the performance of the new controller to be better. Its sensitivity to variations of the system is smaller than that of the PID and it requires no prefilter to avoid large overshoot. Digital simulations are performed to verify the capability of the proposed new nonlinear controller.

Modeling and Active Control of Circular Electrostatic Torsional Micromirror

2012 ◽  
Vol 629 ◽  
pp. 649-654 ◽  
Author(s):  
Cheng Bai ◽  
Jin Huang
Keyword(s):  
Active Control ◽  
Trajectory Tracking ◽  
Pid Control ◽  
Model Uncertainty ◽  
System Model ◽  
Control Scheme ◽  
Parameter Variations ◽  
Mechanical Spring ◽  
Torsional Micromirror ◽  
Simulation Results

Three main obstacles in modeling electrostatic torsional micromirror are hard to calculate – damping coefficient, mechanical spring constant and electrostatic torsion accurately. Because that parameter variations and model uncertainty of the torsional micromirror resulting from fabrication imperfections are inevitable, it is another problem to seek a control scheme for achieving accurate positioning and trajectory tracking of an electrostatic torsional micromirror. In this paper, aimed at a real prototype of circular electrostatic torsional micromirrorr, both static and dynamic behaviors are modeled and studied. A novel nonlinear Proportional, Integral and Derivative (PID) control are proposed in succession. Simulation results show that the system model derived is more accurate to the micromirror and the nonlinear PID can eliminate the static deviation.

Cancelling of Self-Excited Vibrations by Means of Parametric Excitation

1999 ◽  
Author(s):  
Aleš Tondl ◽  
Horst Ecker
Keyword(s):  
Numerical Simulation ◽  
Harmonic Function ◽  
Parametric Excitation ◽  
Exciting Force ◽  
Mass System ◽  
Parameter Variations ◽  
Simulation Parameter ◽  
Top Mass ◽  
Theoretical Results ◽  
Good Agreement

Abstract The possibility of cancelling self-excited vibrations of a mechanical system using parametric excitation is discussed. A two-mass system is considered, with the top mass excited by a flow-generated self-exciting force. The parameter of the connecting stiffness between the base mass and the foundation is a harmonic function of time and represents a parametric excitation. For such a system general conditions for full vibration cancelling are derived and presented. By means of numerical simulation the system is investigated for several sets of parameters. The theoretical results are found to be in very good agreement with the results obtained by simulation. Parameter variations show the extent of the parameter space where significant vibration cancelling can be achieved and illustrate possible applications.

scholarly journals Improved Nonlinear Robust Controller for STATCOM Based on System Immersion and Manifold Invariant Methodology

2015 ◽  
Vol 7 (1) ◽  
pp. 747-756
Author(s):  
Chao Zhang ◽  
Aimin Zhang ◽  
Hang Zhang ◽  
Yunfei Bai ◽  
Yingsan Geng
Keyword(s):  
Robust Controller ◽  
Nonlinear Robust

Application of Robust Two Degree-of-Freedom Control Using μ-Synthesis to the Vibrations in Vehicle Engine-Body System

1999 ◽  
Author(s):  
J. Yang ◽  
Y. Suematsu ◽  
S. Shimizu ◽  
Y. Okumura
Keyword(s):  
Degree Of Freedom ◽  
Lms Algorithm ◽  
Body System ◽  
Engine Vibration ◽  
Vehicle Engine ◽  
Control Scheme ◽  
Parameter Variations ◽  
Active Vibration ◽  
Feedforward Controller ◽  
Two Degree Of Freedom

Abstract This paper presents a robust active control for the vehicle engine-body system. The robust two degree-of-freedom (2DOF) controller is formed by combining a feedback (FB) controller with a feedforward (FF) controller. The feedback controller is designed by μ-synthesis to attenuate the effect of engine vibration disturbance by modeling the vehicle engine-body system as a nominal four degree-of-freedom vibration system with the parameter variations and the unmodeled dynamics. Based on filtered-X LMS algorithm, an active vibration controller is used as a feedforward controller to improve control performance further. To demonstrate the effectiveness of the control scheme, we have made some experiments in an experimental device, which is designed to imitate real vehicle engine-body system.

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