Robust steering control is used here for improving the yaw dynamics of a passenger car. A specific two degree of freedom control structure is adapted to the vehicle yaw dynamics problem and shown to robustly improve p...
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Robust steering control is used here for improving the yaw dynamics of a passenger car. A specific two degree of freedom control structure is adapted to the vehicle yaw dynamics problem and shown to robustly improve performance. The design study is based on six operating conditions for vehicle speed and the coefficient of friction between the tires and the road representing the operating domain of the vehicle. The relevant design specifications are formulated as attaining Hurwitz stability and a mixed sensitivity frequency domain bound. Simple, and therefore, easily implementable controller transfer functions with two design parameters are chosen for the two steering controller degrees of freedom. Using the parameter space method, the design specifications are mapped into the plane of controller parameters. The effectiveness of the final design is demonstrated using simulations.
It is shown how a passive multiple trailer system is designed and controlled for practical applications. The main focus is reducing the trajectory tracking error and the scope of the paper is limited to the passive sy...
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It is shown how a passive multiple trailer system is designed and controlled for practical applications. The main focus is reducing the trajectory tracking error and the scope of the paper is limited to the passive systems due to the cost and simplicity of the trailer mechanism. Three kinds of passive trailers are introduced, and then the analysis of path tracking performance is carried out, in order to show that the proposed off-hooked trailer is advantageous in a practical sense. Stability, issues are discussed with constant reference velocity. Numerical simulation results and experimental results are presented.
A method for suppressing residual vibrations in flexible systems is presented and experimentally demonstrated. The proposed method is based on the preconditioning of the inputs to the system using conventional low-pas...
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A method for suppressing residual vibrations in flexible systems is presented and experimentally demonstrated. The proposed method is based on the preconditioning of the inputs to the system using conventional low-pass FIR digital filters. Several classes of FIR filters such as: a) Parks-McClellan; b) window-based method (using Chebyshev window); and c) constrained least squares method, are shown to demonstrate excellent vibration suppression when they are properly designed while they introduce minimum possible delay. In order to ensure maximally robust behavior, the filter stop band is selected to cover all possible variations of the system dynamic parameters. The proposed method does not require modeling of the flexible system, can be used in a variety of systems exhibiting vibrations, is independent of the guidance function, is simple to implement in practical applications and robust to variations of the system dynamic parameters. The method is experimentally verified using a flexible aluminum beam attached at the end-effector of a robot manipulator. The beam is rotated, using one joint of the manipulator, from an initial to a final position. During this motion, vibrations of the beam are excited due to inertial forces. It is shown that the preconditioned inputs to the flexible system induce very little amount of residual vibrations compared to the inputs with no preconditioning.
In this paper, a method for suppressing residual vibrations in flexible mechatronic systems is proposed and experimentally demonstrated. The proposed method is based on the preconditioning of the arbitrary inputs to t...
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ISBN:
(纸本)0780367367
In this paper, a method for suppressing residual vibrations in flexible mechatronic systems is proposed and experimentally demonstrated. The proposed method is based on the preconditioning of the arbitrary inputs to the system using infinite impulse response (IIR) digital filters. To ensure robust behavior, the filter stop band is selected to cover all possible variations of the system dynamic parameters. It is shown that some of the IIR filters are capable of suppressing vibrations when they are properly designed.
This paper presents robust and optimal control methods to suppress vibrations of flexible payloads carried by robotic systems. A new improved estimator in discrete-time H2 optimal control design based on the Kalman Fi...
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This paper studies the geometric design of spatial two degrees of freedom, open loop robot manipulators with revolute joints that perform tasks, which require the positioning of the end-effector in three spatial locat...
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ISBN:
(纸本)9780791835173
This paper studies the geometric design of spatial two degrees of freedom, open loop robot manipulators with revolute joints that perform tasks, which require the positioning of the end-effector in three spatial locations. This research is important in situations where a robotic manipulator or mechanism with a small number of joint degrees of freedom is designed to perform higher degree of freedom end-effector tasks. The loop-closure geometric equations provide eighteen design equations in eighteen unknowns. Polynomial Elimination techniques are used to solve these equations and obtain the manipulator Denavit and Hartenberg parameters. A sixth order polynomial is obtained in one of the design parameters. Only two of the six roots of the polynomial are real and they correspond to two different robot manipulators that can reach the desired end-effector poses. Copyright (C) 2000 by ASME.
In this paper, the design and control of a novel shape memory alloy (SMA) actuator that possesses impressive payload lifting capabilities are presented. The actuator consists of 48 nickel-titanium SMA wires mechanical...
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In this paper, the application of Rapid Prototyping in the fabrication of a robotic hand is presented. Using the Selective Laser Sintering Sinterstation 2000 of DTM Corporation of Austin, TX, prototypes of mechanical ...
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The reaction of autonomous mobile robot to the dynamic, uncertain, and changeable environment is one of most difficult issue in the control of intelligent autonomous robot movement. Fuzzy control appears as a very use...
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In this paper, we consider hard contact transition such as hammering when the manipulator's approaching velocity is high or the environment is very stiff. In contact transition, phase transition can be divided int...
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In this paper, we consider hard contact transition such as hammering when the manipulator's approaching velocity is high or the environment is very stiff. In contact transition, phase transition can be divided into two definitely different phases, "pre-transition phase" and "transition phase". Here we define the "pre-transition phase" and we propose three control methods. First, we propose a novel controller named as "suppression controller" which is not only stable but also simple to implement. Second, we present passive damper named as "flexible-damped joint" which is a good solution to circumvent the pre-transition phase. Third, we suggest a stable and simple controller which can maximize joint damping and minimize recontact velocity in the flexible-damped joint. It is named as "joint damping controller". The effectiveness of these three approaches are verified via experiments using the POSTECH 1-DOF DD arm.
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