Desarrollo de sensores inalámbricos inteligentes de bajo coste y alta eficiencia energética

Abstract

In the last decade, the widespread use of systems of control and supervision of processes has led to the technological development of data acquisition systems. The special need to find flexible solutions, which allow the simple installation of sensors, avoiding complex wired networks, has led to the acquisition process being carried out wirelessly by devices powered locally by batteries. The boom in wireless technologies has been significant thanks to cost savings, both in terms of the installation itself and in the subsequent revision and maintenance. This thesis aims at the design, development and construction of sensor devices with low cost characteristics, reduced power consumption and small dimensions, always guaranteeing the requirements demanded in each application. This work deals with a practical way, through real implementations, the development of complete sensor systems, that is, that globally considers the integration of sensors, signal conditioning, processing and data monitoring, for the measurement of variables of interest. The development of this approach has been identified in three different areas: medical, domestic and industrial. In the medical field, a new method is developed to detect the respiratory rate (which is related to various diseases) using non-invasive, low-cost and highly sensitive detection technologies. The design and implementation of the same has been done in accordance with the principles of capacitive detection of LC oscillators, solving some disadvantages shown by the technological alternatives currently available. In the domestic and industrial fields, smoke detection devices and different types of gases are implemented, respectively. All of them have in common the optimization of power consumption through hardware and software strategies that guarantee a high degree of autonomy of the sensor nodes, given their wireless nature. The devices include control algorithms capable of avoiding false detection alarms. In addition, they are designed with small dimensions, with a versatile approach, so that they can be easily scaled and adapted to different environments.