This article claims that the meaning of presence is closely linked to the concept we have of reality, i.e., to the ontology that we more or less explicitly adopt. Different ontological stances support different criteria for presence, telepresence, and virtual presence. We propose a cultural conception of presence that challenges the current idea that experiencing a real or simulated environment deals essentially with perceiving its “objective” physical features. We reject commonsense ingenuous realism and its dualism opposing external reality and internal ideas. In our perspective, presence in an environment, real or simulated, means that individuals can perceive themselves, objects, and other people not only as situated in an external space but also as immersed in a sociocultural web connecting objects, people, and their interactions. This cultural web---structured by artifacts both physical (e.g., the physical components of the computer networks) and ideal (e.g., the social norms that shape the organizational use of the computer networks)---makes possible communication and cooperation among different social actors by granting them a common reference grid. Environments, real and virtual, are not private recesses but public places for meaningful social interaction mediated by artifacts. Experiencing presence in a social environment such as a shared virtual office requires more than the reproduction of the physical features of external reality; it requires awareness of the cultural web that makes meaningful---and therefore visible---both people and objects populating the environment.

“Real” Presence: How Different Ontologies Generate Different Criteria for Presence, Telepresence, and Virtual Presence

Automatics and Robotics subjects are always greatly improved when classroom teaching is supported by adequate laboratory courses and experiments following the ''learning by doing'' paradigm, which provides students a deep understanding of theoretical lessons. However, expensive equipment and limited time prevent teachers having sufficient educational platforms, and several low cost and flexible solutions have been developed to permit an effective teaching in Automatics and Robotics at a reasonable cost. Virtual and remote laboratories are inside this group of solutions as Web-based experimentation tools which have demonstrated the importance and effectiveness of hand-on experiences. This paper presents an experience teaching based on a blended-learning method using as experimentation tool a virtual and remote robotic laboratory called RobUALab, which is also described in the paper, in Automatics and Robotics subjects of the Computer Science degree at the University of Alicante. Students experiment with a set of hand-on exercises about Automatics and Robotics using RobUALab, firstly in face-to-face classes where they experiment in-situ with the real plant and, afterwards, they access to the experimentation environment in order to finish remotely their practical exercises outside the laboratory. The results obtained in the evaluation of the educational methodology proposed attest its efficiency in terms of learning degree and performance of the students.

Hands-on experiences of undergraduate students in Automatics and Robotics using a virtual and remote laboratory

This paper presents a framework for rapid remote experiment implementation in the field of automatic control. The proposed solution is based on in-house developed embedded control hardware and two commercially available software packages. MATLAB/Simulink is used for rapid experiment control algorithm development, while LabVIEW is used for the user front-end and remote control. A combination of presented hardware and software solutions enables the rapid and easy creation of different interactive remote control experiments. Using this solution, a digital-signal-processor-based remote control laboratory for teaching purposes has been realized. This remote laboratory enables the remote users to easily interact with a set of physical control experiments through the Internet. In the friendly user interface, the remote user can change predefined system parameters and observe system response in textual, graphical, or video format. In addition, this remote laboratory includes a booking system, which enables remote users to book experiments in advance.

A DSP-Based Remote Control Laboratory

The so-called piezomechanics contain three parts: piezoelectric translator, carriage mechanism, and control system. It is well known that piezomechanics have three drawbacks: (1) it should only be loaded axially; (2) it contains a hysteresis feature; and (3) its expansion is dependent on temperature. The first drawback is tackled by the design of the carriage mechanism. This paper focuses on dealing with the second and third drawbacks by using an intelligent variable-structure control. First, a neural network is employed to learn the dynamics of the piezomechanism. Second, a novel forward control based on the learned model is employed to achieve an acceptable tracking result. Because the tracking performance by a forward control cannot be guaranteed as the system is subject to uncertainties, a discrete-time variable-structure control is synthesized to improve the performance. No state estimator is required for the proposed control. The stability of the overall system is verified via the Lyapunov analysis. Experiments are also presented to confirm the effectiveness of the proposed control.

Piezomechanics using intelligent variable-structure control

In networked control systems, random transmission delay significantly degrades the control performance and can cause system instability. To address this problem, the method of networked predictive control (NPC) has been proposed, which takes advantage of the feature of the network that a packet of data can be transferred simultaneously. At the controller side, future control sequences for every possible time delay are generated, which are then packed into a single packet and transmitted to the plant side. The plant side receives the packet and chooses the proper control signal based on the time delay measurement. However, this scheme needs an accurate plant mathematical model and the measurement of time delay. In this paper, a new event-driven NPC method is considered where the control signal is selected according to the plant output rather than the time delay measurement. The new method does not need any time delay measurement and can significantly improve the system performance in the presence of model uncertainty. The stability of the system when the method is used is analyzed. To illustrate the improved performance using the proposed method, the results from both simulations and real Internet-based networked experiments for a servo system are presented

Event-Driven Networked Predictive Control

Many enterprises experience difficulty in training people to work with expensive equipment, which is needed for carrying out profitable work tasks (e.g., production line robots). Similar problems are found when work is of a complex and safety-critical nature (e.g., nuclear environments, explosive placement, surgery). This paper describes a method of education and training involving offline usage of virtual environments for task planning. When tasks are developed to the satisfaction of the trainee, they are exported to remote physical hardware, via the Internet, for real-world execution. Development of the system and the training experiments is discussed, along with some of the issues raised for telerobotics and solutions to the problem of detecting collisions in the virtual world. The approach has been shown to be viable and increases the education and training possibilities for key workers while maintaining a low cost of ownership. The downtime of mission-critical equipment is minimized while the gaining of valuable experience is maximized.

Telerobotics experiments via Internet

This paper defines mechatronics, explains mechatronics philosophy, and describes characteristics of mechatronics products and systems. It reviews aspects of education and training for mechatronics and compares the two different approaches to engineering education: generalist engineering versus specialist engineering. It also examines the Japanese approach to product development strategies and mechatronics education and training. It also gives an overview of mechatronics education in higher education institutions across the world with a specific reference to a typical mechatronics engineering degree program. Finally it concludes that there will be an increasing need in the future for discipline-based mechatronics engineers.

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Engineering education for mechatronics

The concept of piezomechanics (piezoelectricity+mechanics+a control system) describing a complex interaction of dynamic effects and precision engineered devices is discussed. Piezomechanics is considered as part of the more broad philosophy of mechatronic devices. The object and structure of piezomechanics are presented as well as the primary linear and nonlinear effects, on which energy, motion and signal transformation processes are based. Novel applications are proposed to illustrate the potential benefits, including adaptive mechanical systems in addition to multifunctional and intelligent devices.

R.M. Parkin

Papers

Telerobotics experiments via Internet

Engineering education for mechatronics

Piezomechanics as a subsystem of mechatronics: present state of the art, problems, future developments