Magnetic and Electric Suspensions
The success of the Apollo moon flight program depended in no small part on the accuracy of the navigational and guidance systems developed at MIT's Charles Stark Draper Laboratory (formerly the Instrumentation Laboratory). The success of these systems in turn was partially dependent on the fact that they incorporated certain inertial sensors—accelerometers to sense changes in linear velocity, gyroscopic devices to sense changes in angular position—in which key moving elements float in magnetic or electric fields, eliminating the error-producing friction that would result from contact between solid parts. These devices have also been used in the guidance systems of submarines, airplanes, and unmanned missiles, and have potential applications in areas other than guidance. The authors of this monograph played a major role in the development of these suspension devices at the Draper Laboratory, and their book describes and analyzes the operating characteristics of both active and passive types of magnetic and electric suspensions.
Professor Draper writes in his Foreword that “The authors of this book have had the boldness to attack the problem of eliminating the last traces of rubbing friction in floated weight of the parts involved—but nevertheless basically essential for the achievement of substantially perfect results from sensors based on forces and torques produced by Newton's law reaction forces and gravitational fields. Fundamental principles and design details are the proper subject matter for the chapters that follow. Forces may be small, but performance improvements span orders of magnitude in providing advanced technology with the capabilities required by the progress of our modern societies. Readers should find the text coming from over two decades of imaginative conceptions, excellent engineering, and effective technology not only informative but also interesting as a saga of perseverance and achievement.”
Among the topics taken up are the following: ideal single-axis passive magnetic suspension, other tuned-circuit connections for single-axis magnetic suspensions, bridge-circuit connections for single-axis magnetic suspensions, comparison of performances for various operating conditions, ideal single-axis passive electric suspensions, ideal multiaxis suspensions, influence of materials, active and hybrid suspensions, testing and adjusting of suspensions, and developments and applications.
Magnetic and Electric Suspensions is included in the series Monographs in Modern Electrical Technology, edited by Alexander Kusko.