Showing papers by "Rogelio Lozano published in 2002"
TL;DR: In this paper, a model for the dynamics of a four rotor vertical take-off and landing (VTOL) vehicle known as an X4-flyer is proposed, which incorporates the airframe and motor dynamics as well as aerodynamic and gyroscopic effects due to the rotors for quasi-stationary flight conditions.
366 citations
TL;DR: In this paper, an energy-based control approach to control the Furuta pendulum is presented, where a controller is proposed for swinging the pendulum and raising it to its uppermost unstable equilibrium position.
Abstract: We present an energy based control approach to control the Furuta pendulum. A controller is proposed for swinging the pendulum and raise it to its uppermost unstable equilibrium position. The passivity properties of the system are used as a guideline in the control strategy. The stability analysis is carried out by using a Lyapunov technique.
82 citations
06 Oct 2002
TL;DR: A dynamic controller, based on backstepping techniques, is developed by neglecting the small body forces due to the mechanism used to obtain the torque control, and some simulation results are presented to illustrate the performance of such a controller.
Abstract: In this paper a simplified model and a nonlinear control algorithm for a coaxial helicopter are presented. The model of the helicopter dynamics is obtained in hover conditions. By neglecting the small body forces due to the mechanism used to obtain the torque control, a dynamic controller, based on backstepping techniques, is developed. Some simulation results are presented to illustrate the performance of such a controller.
33 citations
10 Dec 2002
TL;DR: A global stabilizing control design is proposed for the planar vertical takeoff and landing (PVTOL) aircraft based on the use of nonlinear combinations of saturation functions bounding the thrust input to arbitrary saturation limits.
Abstract: A global stabilizing control design is proposed for the planar vertical takeoff and landing (PVTOL) aircraft. The methodology is based on the use of nonlinear combinations of saturation functions bounding the thrust input to arbitrary saturation limits. The algorithm is simple and provides global convergence of the state to the origin.
32 citations
TL;DR: In this article, a simple stabilizing algorithm is presented for the planar vertical takeoff and landing (PVTOL) aircraft, which is proved by using very simple arguments and satisfactory behavior is shown in simulations.
24 citations
10 Dec 2002
TL;DR: In this paper, the authors focus on the closed-loop stability analysis of a teleoperation control scheme subject to delays in the communication channel and derive the stability conditions using a frequency-domain approach.
Abstract: This paper focuses on the closed-loop stability analysis of a teleoperation control scheme subject to delays in the communication channel. The stability conditions derived using a frequency-domain approach are analytical and easy to check. Delay-independent as well as various delay-intervals stability cases are treated. The novelty of the approach lies in its simplicity for characterizing the stability regions in terms of the systems' parameters. Physical interpretations are included and several examples are also presented.
17 citations
TL;DR: In this article, a Lyapunov control algorithm for a tandem rotor helicopter is obtained using backstepping techniques, and a simple model dynamics for a behavior of a helicopter close to hover is obtained.
15 citations
TL;DR: In this paper, the semiglobal stabilization of null-controllable linear systems with delayed inputs which are bounded is achieved and the robustness of the closed loop scheme with respect to uncertainty in the parameters, in the delay and input bounded disturbances is proved.
13 citations
TL;DR: In this paper, a modification of the Smith predictor control scheme is introduced, which consists in a periodical resetting of the initial condition of the predictor, which allows to extend the use of these control laws to unstable linear systems with delay.
10 citations
10 Dec 2002
TL;DR: In this paper, a simple control algorithm for the PVTOL aircraft is proposed, which takes into the account input constraints and does not have any singularities.
Abstract: In this paper, a simple control algorithm for the PVTOL aircraft is proposed. The control strategy takes into the account input constraints and does not have any singularities. The control design is such that the acceleration satisfies arbitrary bounds. The stability analysis is proved by using very simple arguments. Satisfactory behavior is shown in simulations.
9 citations
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TL;DR: The Furuta pendulum has a different structure, which has a direct-drive motor as its actuator source and its pendulum attached to the rotating shaft of the motor.
Abstract: The inverted pendulum is a very popular experiment used for educational purposes in modern control theory and this system can appear with different constructions. As we have seen in Chapter 3, the structure of the conventional inverted pendulum is the rail-cart type, which consists of a cart running on a rail and a pendulum attached to the cart. The inverted pendulum of this type has the movement limitation of its cart as a restriction of the control system. On the other hand, the Furuta pendulum has a different structure. It has a direct-drive motor as its actuator source and its pendulum attached to the rotating shaft of the motor. This inverted pendulum on the rotating arm was first developed by K. Furuta at Tokyo Institute of Technology. The product of the experiment was called the TITech pendulum (see [30, 43, 123]).
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TL;DR: The inverted pendulum is one of the most popular laboratory experiments used for illustrating non-linear control techniques and is motivated by applications such as the control of rockets and the antiseismic control of buildings.
Abstract: The inverted pendulum is one of the most popular laboratory experiments used for illustrating non-linear control techniques. This system is motivated by applications such as the control of rockets and the antiseismic control of buildings.
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TL;DR: This study focuses on the planar vertical take-off and landing (PVTOL) aircraft, which is a highly manoeuvrable jet aircraft.
Abstract: Flight control is an essential control problem that appears in many applications such as spacecraft, aircraft and helicopters. The complete dynamics of an aircraft, taking into account aeroelastic effects, flexibility of the wings, internal dynamics of the engine and the multitude of changing variables, are quite complex and somewhat unmanageable for the purposes of control. It is also particularly interesting to consider a simplified aircraft, which has a minimum number of states and inputs but retains the main features that must be considered when designing control laws for a real aircraft. Therefore, as considered by Hauser et al. [35], we focus our study on the planar vertical take-off and landing (PVTOL) aircraft, which is a highly manoeuvrable jet aircraft.
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TL;DR: The two-link underactuated robotic mechanism called the pendubot is used for research in non- linear control and for education in various concepts like non-linear dynamics, robotics and control system design.
Abstract: The two-link underactuated robotic mechanism called the pendubot is used for research in non-linear control and for education in various concepts like non-linear dynamics, robotics and control system design.
01 Jan 2002
TL;DR: In this paper, the authors proposed a control law for the ball and beam system acting on the ball instead of the beam, which is motivated by the control of small rotational oscillations of platforms and vehicle suspensions.
Abstract: Another interesting example of underactuated systems is the ball and beam system. In this chapter, we propose a control law for the ball and beam system acting on the ball instead of the beam. Such a mechanical system is outlined in Figure 10.1 and described in Section 10.2. The system in Figure 10.1 is motivated by the control of small rotational oscillations of platforms and vehicle suspensions. For simplicity, we assume that the center of the beam is connected to the pivot using a rotational spring and we neglect friction.
01 Jan 2002
TL;DR: In this chapter, a Lagrangian model of a VARIO scale model helicopter and a passivity-based control strategy are presented and it is noted that both cases represent underactuated systems.
Abstract: In this chapter, we present a Lagrangian model of a VARIO scale model helicopter and a passivity-based control strategy. Our global interest is a general model (7-DOF) to be used on the autonomous forward flight of helicopters. We present the basic idea of the 7-DOF modelling. However, in this chapter, we focus on the particular case of a reduced order model (3-DOF) representing the scale model helicopter mounted on an experimental platform. We note that both cases represent underactuated systems (υ € ℝ4 for the 7-DOF model and υ € ℝ2 for the 3-DOF model studied in this chapter).
01 Jan 2002
TL;DR: The reaction wheel pendulum as discussed by the authors is one of the simplest non-linear underactuated systems and is a pendulum with a rotating wheel at the end, which is free to spin about an axis parallel to the axis of rotation of the pendulum.
Abstract: The reaction wheel pendulum is one of the simplest non-linear underactuated systems. It is a pendulum with a rotating wheel at the end, which is free to spin about an axis parallel to the axis of rotation of the pendulum (see Figure 7.1). The wheel is actuated by a DC-motor, while the pendulum is unactuated. The coupling torque generated by the angular acceleration of the disk can be used to actively control the system. This mechanical system was introduced and studied in [108], where a partial feedback linearization control law was presented.
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TL;DR: Nowadays, control problems of underactuated vehicles motivate the development of new non-linear control design methodologies.
Abstract: Nowadays, control problems of underactuated vehicles motivate the development of new non-linear control design methodologies. Such systems are vehicles with fewer independent control inputs than degrees of freedom to be controlled.