Friction is a nonlinear phenomenon which has destructive effects on performance of control systems. To obviate these effects, friction compensation is an effectual solution. In this paper, an adaptive technique is proposed in order to eliminate limit cycles as one of the undesired behaviors due to presence of friction in control systems which happen frequently. The proposed approach works for n...

Many of the physical phenomena, like friction, backlash, drag, and etc., which appear in mechanical systems are inherently nonlinear and have destructive effects on the control systems behavior. Generally, they are modeled by hard nonlinearities. In this paper, two different methods are proposed to cope with the effects of hard nonlinearities which exist in friction various models. Simple inver...

The problem of stabilizing the double inverted pendulum has been solved using two different techniques which were the Pole Placement and Linear Quadratic Regulator techniques to design controls for the system. Copyright c ©2003 Yang’s Scientific Research Institute, LLC. All rights reserved.

In this note, we introduce cascade normal forms for underactuated mechanical systems that are convenient for control design. These normal forms include three classes of cascade systems, namely, nonlinear systems in strict feedback form, feedforward form, and nontriangular quadratic form (to be defined). In each case, the transformation to cascade systems is provided in closed-form. We apply our...

A technique to achieve output tracking for nonminimum phase nonlinear systems with nonhyperbolic internal dynamics is presented. The present paper integrates stable inversion techniques (that achieve exact-tra@ing) with approximation techniques (that modify the internal dynamics) to circumvent the nonhyperbolicity of the internal dynamics this nonhyperbolicity is an obstruction to applying pres...

In this paper, we introduce cascade normal forms for underactuated mechanical systems that are convenient for control design. These normal forms include three classes of cascade systems, namely, nonlinear systems in strict feedback form, feedforward form, and nontriangular quadratic form (to be defined). In each case, the transformation to cascade systems is provided in closed-form. We apply ou...

This paper deals with a recent design of event-driven observer-based smart sensors for output feedback control of linear systems. We re-design the triggering mechanism proposed in a previously reported system with the implementation of self-sampling data smart sensors; as a result, we improve its performance. Our approach is theoretically supported by using Lyapunov theory and numerically evide...

The problems of swinging up an inverted pendulum on a cart and controlling it around the upright position have been traditionally treated as two separate problems. This paper proposes a strategy that is globally asymptotically stabilizing under actuator saturation and, in addition, locally exponentially stabilizing. The proposed methodology performs swing up and control simultaneously and uses ...

In this project, we apply reinforcement learning techniques to control an inverted double pendulum on a cart. We successfully learn a controller for balancing in a simulation environment using Qlearning with a linear function approximator, without any prior knowledge of the system at hand. We do however fail to learn a controller for the swingup maneuver, which leads to a discussion on what mig...