J.C. Soto

Suboptimal Regulation of a Class of Bilinear Interconnected Systems with Finite-Time Sliding Planning Horizons

This paper focuses on the suboptimization of a class of multivariable discrete-time bilinear systems consisting of interconnected bilinear subsystems with respect to a linear quadratic optimal regulation criterion which involves the use of state weighting terms only. Conditions which ensure the controllability of the overall system are given as a previous requirement for optimization. Three transformations of variables are made on the system equations in order to implement the scheme on an equivalent linear system. This leads to an equivalent representation of the used quadratic performance index that involves the appearance of quadratic weighting terms related to both transformed input and state variables. In this way, a Riccati-matrix sequence, allowing the synthesis of a standard feedback control law, is obtained. Finally, the proposed control scheme is tested on realistic examples.

Stability and Limit Oscillations of a Control Event-Based Sampling Criterion

This paper investigates the presence of limit oscillations in an adaptive sampling system. The basic sampling criterion operates in the sense that each next sampling occurs when the absolute difference of the signal amplitude with respect to its currently sampled signal equalizes a prescribed threshold amplitude. The sampling criterion is extended involving a prescribed set of amplitudes. The limit oscillations might be interpreted through the equivalence of the adaptive sampling and hold device with a nonlinear one consisting of a relay with multiple hysteresis whose parameterization is, in general, dependent on the initial conditions of the dynamic system. The performed study is performed on the time domain.

On the derivation and analysis of a non-linear model for describing a class of adaptive sampling laws

Abstract This paper deals with the non-linear oscillations arising from the use of a class of adaptive sampling laws. A method is proposed which diminishes the drawbacks related to the appearance of such oscillations.

Adaptive control for a d.c. motor controlled by a group of amplidynes using bilinear models

This paper presents a method for the application of adaptive control to a d.c. motor coupled with a group of amplidynes. The overall process is modelled as a bilinear system since no voltage or current is held constant. Standard adaptive control techniques are applied to compensate for undesirable deviations of the process parameters from their nominal values.

Control of robotic manipulators via supervision of the free-design parameters and sampling rate

An adaptive control scheme for mechanical manipulators is proposed. The control loop consists of a network for learning the robot¿s inverse dynamics and online generating the control signal. Some simulation results are provided to evaluate the design. A supervisor is used to improve the performances of the system during the adaptation transients. The supervisor exerts two actions. The first one consists of updating the free-design adaptive controller parameters so that the value of a quadratic loss function is maintained sufficiently small. The second action consists of an on-line adjustment of the sampling period within an interval centered at its nominal value.

On An Experience For Human-computer Interaction: A Relational Environment

The state-of-the-art in the field of Expert Systems (ES) focuses up till now two outlooks. On the one hand, a great deal of applications have been put into practice in recent years but they sometimes lackboth effective- ness and/or efficiency. However, they are quite promi- sing Artificial Intelligence (AI) programs. On the other hand, several attempts have begun to look for conventio nal conceptual modellings to set up appropriate forma lisms for ES. They are assumed to be deduced from a better comprenhention of ES intrinsic knowledge. This paper deals with some of the features that tipify an ES application to help chemistry research in a laboratory. In fact, the human-machine communication is emphasized, instead of paying attention to the overall ES structure. Interactivity is its most outstanding characteristic. Also, it is noticed the need of psychological support to solve some topics while implementing such interaction process.

On a sampling criterion -induced oscillatory behaviour

This paper investigates limit oscillations in an adaptive sampling system whose associated sampling instants are generated from a constant difference of amplitudes. The control law to the linear part is a piecewise - constant control generated from such an adaptive sampling rule. The limit oscillations which are generated are interpreted from the equivalence of the sampling and hold device with a nonlinear one consisting in a multiple relay with hysteresis.

Stable adaptive control of manipulators with improved transients via supervision of the free-design parameters and sampling period

An adaptive control scheme for mechanical manipulators is proposed. The control loop consists of a network for learning the robots inverse dynamics and online generating the control signal. Some simulation results are provided to evaluate the design. A supervisor is used to improve the performances of the system during the adaptation transients. The supervisory exerts two actions. The first one consists of updating the free-design adaptive controller parameters so that the value of a quadratic loss function is maintained sufficiently small. The second action consists of an on-line adjustment of the sampling period within an interval centered at its nominal value.

Time-sliding suboptimal regulation of bilinear interconnected systems

This paper focuses on the suboptimal regulation of multivariable discrete-time bilinear systems consisting of interconnected bilinear subsystems with respect to a linear quadratic optimal regulation criterion which involves the use of state weighting terms only. Three transformations are used in order to treat the scheme over an equivalent linear system. This leads to the appearance of quadratic weighting terms related to both transformed input and state variables. In this way, a Ricatti matrix-sequence allowing the synthesis of a standard feedback control law is obtained

Control of Hybrid Systems with Independent Continuous-Time and Discrete-Time Objectives

This paper deals with the control of a class of perfectly modelled linear hybrid systems which consist of two, in general coupled, subsystems one being continuous -time while the second one is digital. The discrete -time substate is jointly defined by the digital substate and the samples of the continuous substate while being driven by the sampled input. The control objective has a double nature and it consists of the achievement of separate continuous-time and discrete-time model-matching objectives with respect to two predefined stable reference models .