INTELLIGENT MECHATRONIC SYSTEMS

Transducers, Sensors and Actuators for Intelligent Mechatronic Systems

Transducers, Sensors and Actuators for Intelligent Mechatronic Systems

Introduction

This paper integrates the principles of electrical and electronic engineering with Mechatronic system application in a simple manner, and is designed for both mechanical/industrial engineers. This paper enables one to design and select analog and digital circuits, microprocessor-based components, mechanical devices, sensors and actuators, and control devices to design modern mechatronic systems. The key aspect of mechatronic products is to add intelligent components and systems which combine an optimum use of multidisciplinary technologies to shorten the development cycle with reduced cost and increased quality. Recent advances in micro electromechanical systems (MEMS) have a profound impact in the field of sensors and actuators for intelligent mechatronic systems. Miniature sensors and actuators are fabricated using technologies from silicon integrated circuit industry. These micro machined sensors and actuators provide several advantages over the conventional counterparts, such as size reduction, new function, and integration with control circuitry, cost reduction, and sensor/actuator arrays. MEMS technology has dramatically increased the number of sensors and actuators implemented in mechatronic systems. Nowadays, micro sensors and actuators such as silicon pressure sensors, micro fabricated print heads, acceleration sensor, gyro sensor, and micro mechanical display devices have been used in a lot of mechatronic products. Table I shows some of examples of micro machined sensors and micro machined actuators PI.

Transducers, Sensors and Actuators for Intelligent Mechatronic Systems

Sensors are essential components of automotive electronic control systems. Sensors are defined as “devices that transform (or transduce) physical quantities such as pressure or acceleration (called measurands) into output signals (usually electrical) that serve as inputs for control systems.” It wasn't that long ago that the primary automotive sensors were discrete devices used to measure oil pressure, fuel level, coolant temperature, etc. Starting in the late 1970s, microprocessor-based automotive engine control modules were phased in to satisfy federal emissions regulations. These systems required new sensors such as MAP (manifold absolute pressure), air temperature, and exhaust-gas stoichiometric air-fuel-ratio operating point sensors. The need for sensors is evolving and is progressively growing. For example, in engine control applications, the number of sensors used will increase from approximately ten in 1995, to more than thirty in 2010, as predicted in . Automotive engineers are challenged by a multitude of stringent requirements. For example, automotive sensors typically must have combined/total error less than 3 % over their entire range of operating temperature and measurand change, including all measurement errors due to nonlinearity, Manuscript received September 8, 2000; revised November 2, 2001. This work was supported by Tom Vos, Director, Systems Technology, Occupant Safety Systems, Washington, MI. The associate editor coordinating the review of this paper and approving it for publication was Dr. Gerard L. Cote. W. J. Fleming is with Systems Technology, TRW Occupant Safety Systems, Washington, MI 48094 USA (e-mail: william.fleming@trw.com). Publisher Item Identifier S 1530-437X(01)11158-9. hysteresis, temperature sensitivity and repeatability. Moreover, even though hundreds of thousands of the sensors may be manufactured, calibrations of each sensor must be interchangeable ...