Gyroscopic Devices Research Articles

A programmable and portable NMES device for drop foot correction and blood flow assist applications

The Duo-STIM, a new, programmable and portable neuromuscular stimulation system for drop foot correction and blood flow assist applications is presented. The system consists of a programmer unit and a portable, programmable stimulator unit. The portable stimulator features fully programmable, sensor-controlled, constant-voltage, dual-channel stimulation and accommodates a range of customized stimulation profiles. Trapezoidal and free-form adaptive stimulation intensity envelope algorithms are provided for drop foot correction applications, while time dependent and activity dependent algorithms are provided for blood flow assist applications. A variety of sensor types can be used with the portable unit, including force sensitive resistor-based foot switches and MEMS-based accelerometer and gyroscope devices. The paper provides a detailed description of the hardware and block-level system design for both units. The programming and operating procedures for the system are also presented. Finally, functional bench test results for the system are presented.

Real-Time Assessment of Secondary Task Intrusiveness upon Real-World Driver Steering Performance using a Fiber-Optic Gyroscope

Lateral steering stability is a critical parameter of driving performance from both a theoretical as well as applied perspective. The measurement of lateral steering stability in a driving simulation environment is both straightforward and ubiquitous. However, the ability to measure this performance parameter in real-time during real-world driving has typically been fraught with technical challenges. The recent introduction of low cost fiber-optic gyroscope devices appears to have addressed many of the traditional difficulties associated with the real-time measurement of steering performance. State-of-the-art fiber-optic gyroscopes are capable of providing continuous data representing the rate of change in heading angle with a precision of 0.001 deg/sec. The current study evaluated the reliability and potential usefulness of real-time angular heading rate data collected from a instrumented research vehicle fitted with a KVH AutoGyro (fiber-optic laser gyroscope). Data from the fiber-optic gyroscope was collected and logged (at 10 Hz) via digital computer while volunteer participants performed a number of standard driving maneuvers and in-vehicle tasks involving interactions with instrument panel interfaces and controls.

From Chinese Chariots to Smart Cars: 2,000 Years of Vehicular Navigation

The odometer and differential odometer date back approximately 2,000 years, perhaps 1,000 years before the magnetic compass appeared. Gyroscopic devices were first described in the mid-1800s. Automatic mechanical route guides, which began appearing around 1910, introduced the concept of real-time turn-by-turn route guidance to early automobile drivers. The first vehicular navigation system to incorporate electronics was developed during World War II. A research project of the late 1960s established concepts for dynamic route guidance based on realtime traffic conditions. Satellite positioning and digitized road maps also originated in the 1960s. Map-matching software for reconciling measured vehicle paths with digitized road maps to remove position errors was invented in 1970. Thus the basic technologies were already in place when the microprocessor emerged in the 1970s to facilitate their integration in the sophisticated automobile navigation and route guidance systems that finally reached the market in the late 1980s. This paper reviews the historical background and then focuses on the last 25 years during which automobile navigation and route guidance systems achieved a degree of technological maturity and blossomed into the centerpiece of the worldwide intelligent transportation systems (ITS), known until recently as intelligent vehicle-highway systems (IVHS).

Determining conversion characteristics of gyroscopic devices by means of goniometers

Determining conversion characteristics of gyroscopic devices by means of goniometers

On the bifurcation and stability of the steady-state motions of complex mechanical systems: PMM vol. 37, n≗3, 1973, pp. 387–399

Many objects of modern technology (rockets, spaceships, airplanes, gyroscopic devices, centrifuges, etc.) can be modelled in a number of cases by mechanical systems comprised of absolutely rigid bodies and material points and of deformable (liquid and elastic) bodies connected with them. Mechanical systems containing among its parts both subsystems with a finite number of degrees of freedom as well as units with distributed parameters, i.e. continuous media, are called complex systems for brevity. We consider the steady-state motions of complex systems. Stationary values of the potential energy V or of the altered potential energy W of the system correspond to the steady-state motions. The stability problem for the steady-state motions leads to the investigation of the nature of the extremum of the potential energy V or W. The minimum of the potential energy corresponds to a stable motion. In a number of important cases the stability (instability) conditions can be obtained as conditions for the positive definiteness (for sign-alteration together with certain additional conditions) of the second variation δ 2 V or δ 2 W of the potential energy. These general results are applied to solving a number of concrete problems on the stability of the steady-state motions of complex systems. Stability conditions for the motion of a rigid body with liquid and elastic parts in various force fields are discussed.

Gyrosystem Analysis by Signal Flow Graph Techniques

Equations for vector addition, vector cross products, and vector differentiation are represented in signal-flow-graph form, and are used to obtain signal flow graphs of the (tensor) equations of rotating rigid bodies. These signal flow graphs, in turn, are then applied to the analysis of several simple gyroscopic devices.

On the construction of periodic solutions of quasi-linear autonomous systems with several degrees of freedom

This paper attempts to explore the general rotatory 3D motion of a magnetic heavy solid body around one fixed point under the impact of a gyrostatic moment when the body awarded initially high angular velocity about one of its inertia principal axes. The asymptotic technique of Krylov-Bogoliubov-Mitropolski and its adjustment are applied to achieve new asymptotic periodic solutions of the controlling equations of motion. Discussion of these solutions is presented taking into consideration their graphs representations. The graphical depictions of such solutions and their corresponding phase planes are plotted to give an induction about its behaviour during the interval time of motion and to reveal the good effect of the different applied forces and moments on the body's motion. The application of the achieved results of the present work can be widely found in gyroscopic devices especially that used inertia reference systems like in satellites, airplanes, and missiles. Moreover, for devices that are responsible for the stability of motion for these applications.

Comparison of vibratory and rotating-wheel gyroscopic rate indicators

RECENT ADVANCES in atmospheric and space flight have increased the need for reliable and accurate instrumentation for sensing the angular motions of aircraft, missiles, and space ships. Such measurements are especially needed for guidance and control purposes. At the present time, the preferred devices for measuring angular motion are based on the rotating-wheel gyroscope. By the expenditure of much research and development effort these gyroscopic devices have been brought to a state of perfection which makes inertial navigation technically feasible but very expensive. The present reliance on the rotating wheel does not mean that other devices have not been considered. Over the years a number of alternatives to the rotating wheel have been devised and some of these have been developed to the point where practical limitations on performance were found. In general, however, the total research and development effort that has been devoted to these alternatives has been rather small compared with the effort that has been expended in the refinement of the rotating-wheel gyroscope.

Heading Definition in Commercial Aircraft

In this paper, methods of defining heading are enumerated and the limitations of magnetic and gyroscopic devices are analysed in detail. Particular attention is paid to the development of the rotated race principle which is likely to be responsible for a large improvement in the basic azimuth gyro. The gyro-magnetic combination is scrutinized and the errors inherent in this compass system are classified. The possibility and consequent effect of diminishing certain categories of error are presented. The current position is summarized and an attempt is made to suggest possible future trends. The authors are, respectively, with Smiths Aircraft Instruments and the Sperry Gyroscope Company.

A Route Direction-finder

The route direction-finder is a device giving an accurate directional reference. It uses two distant transmitters, A and B, radiating two continuous waves, the frequencies of which are different but very proximate. The paper was presented at the Paris convention on automatic navigation.Classical methods of navigation by dead reckoning have been considerably improved in recent years by the use of autonomous systems such as doppler and inertia which enable true speed to be measured. When using these systems, the principal cause of errors is the unreliability of the directional reference, which may be the meridian or any arc of a great circle, since it is with respect to this that the speed vector is obtained. The directional reference is given by the magnetic compass which often has an error of up to several degrees or is given by gyroscopic devices which can have considerable drift after several hours' operation. Errors in directional reference are especially marked in polar regions where magnetic or gyro compasses cannot be used.

On the motion of gyroscopic devices under the influence of random forces

The motion of gyroscopic devices under ship's rolling coniditions was usually considered assuming the roll sinusoidal. The works of Sveshnikov [1] showed that the rolling motion of a ship can be considered a stationary random process, and obtained the correlation function and spectral density for this process. The motion of some ship devices under these conditions was studied by Rivkin [2]. The present paper considers the motion of a powered gyrostabilizer, plane gyropendulum and a gyrocompass subject to irregular ship rolling; determines the dispersion of a stabilization angle for the powered gyrostabilizer; and derives an expression for intercardinal deviation of the gyrocompass.