Air levitation is the process by which an object is lifted without mechanical support in a stable position, by providing an upward force that counteracts the gravitational force exerted on the object. This work presents a low-cost lab implementation of an air levitation system, based on open solutions. The rapid dynamics makes it especially suitable for a control remote lab. Due to the system’s nature, the design can be optimized and, with some precision trade-off, kept affordable both in cost and construction effort. It was designed to be easily adopted to be used as both a remote lab and as a hands-on lab.

This paper presents the generalization of the shifting method for relay feedback identification of dynamic systems of any order. The original shifting method enables the fitting of a maximum of five parameters of a transfer function model from the information obtained from a short relay test and without prior knowledge of the process to identify. The generalization, known as n-shifting, allows the estimation of the parameters of transfer functions of any order by applying one short relay test to the process to identify. Without loss of generality, the n-shifting approach is applied to fit an n-order plus time delay (n-OPTD) model but the approach can be also developed to identify models with other structures (non-minimum phase, unstable, integrators). Some examples of estimations are presented.

The classical loop shaping is a design procedure that explicitly involves the shaping of the open loop transfer function L(s), within a desired frequency spectrum by manipulating the poles, zeros, and gain of the controller C(s). Interactive software tools have proven as, particularly, useful techniques with high impact on control education. This kind of interactive tools has demonstrated in the past that students learn in a much more active way. This paper presents the basic functionality of the linear control system design (LCSD), an interactive tool for analysis and design of linear control systems with special emphasis on the classical loop shaping design. The software tool is implemented in Sysquake, a MATLAB-like language with fast execution and excellent facilities for interactive graphics, and is delivered as a stand-alone executable that is readily accessible to students and instructors. Several design problems are used to illustrate the main features of the LCSD tool to perform classical loop shaping.

The advance in control engineering education needs well-designed studies that validate what methods and tools work best. This paper addresses the lack of empirical evidence supporting innovations in control engineering education by proposing a methodology that works at different abstraction levels. Hence, innovations' impact on students' performance can be statistically analyzed either globally or locally by examining competencies or fine-grained indicators, respectively. The article reports the application of the methodology for evaluating an interactive simulation tool, named LCSD, on 101 students at the Pontifical Catholic University of Valparaiso in Chile. According to the experimental results, LCSD is an effective free alternative to enhance the student's skills on control system analysis for our automatic control course. Also, some improvements have been identified for future LCSD versions.