The strapdown dynamically tuned gyroscope (DTG) is a candidate for use as the angular motion sensor in s'trapdown inertial navigation systems and autopilots. However, the dynamic performance of the strapdown DTG is one of the limiting factors restricting usage of the instrument in these systems. This research project considers control strategies to enhance the strapdown DTG performance. The DTG equations of motion are derived, with damping terms, and angular speed components introduced about the spin axis. The DTG equations of motion are solved numerically using a 4th order Runge-Kutta method, and taking advantage of rotating reference frames to eliminate time varying elements in the system matrix. This approach reduces the number of computations per time step and improves numerical stability. The tuning conditions for a multigimbal DTG are derived. A modal analysis is carried out on the DTG system matrix for different tuning conditions. This work provides the basis for the reduction of the DTG equations of motion to a free rotor gyroscope form. A parameter estimation procedure is designed which reflects the sensitivity of the DTG dynamic characteristics to certain parameters. A comprehensive experimental programme is carried out to validate the DTG mathematical model and estimate the numerical value of critical DTG parameters. A control strategy which processes the torquer and demodulator signals of the strapdown DTG is formulated. This strategy, used on the strapdown DTG, improves the diagonal dominance of the system transfer function matrix. Throughout the bandwidth the amplitude of the nutation response is at least 20 dB down on the amplitude of the precession response, compared with only 6 dB down on an uncompensated strapdown DTG. The compensator-strap down DTG system bandwidth is extended, compared to the strapdown DTG. The increase in bandwidth and improvement in system diagonal dominance depends on the precise form of the compensator and the manner of implementation; analogue, digital or hybrid. The compensator is feed-forward and can therefore be integrated into a system without altering the strapdown loops. The flexibility of the strategy enables the system designer to balance conflicting requirements of performance allied with minimal, cost, hardware and processing increases. An analogue and hybrid version of the compensator has been added to a strapdown DTG with subsequent test results in close agreement with theoretical studies. The control strategy has potential applications wherever strapdown DTG's are used.

Gyroscopic stabilization can be used to maintain an otherwise unstable body in an upright position. Devices equipped with gyroscopes can balance upon a small area or point without falling over when the gyroscopic stabilizing force is greater than a rotational force or moment from an out-of-balance load that causes the device to tip. A new concept for a gyroscopically stabilized platform has been proposed in the form of a schematic diagram. The proposed system comprises of four interconnected gyroscopes that react to the tipping of an inherently unstable external body. The purpose of this research is to evolve a design for, and establish the feasibility of building the proposed stable platform using available materials and technology. If feasible, the gyroscopically stabilized platform will be made at the most practical and economic size. Louis Brennan developed a 37 tonne monorail that was maintained in the upright position with two 3 tonne counter rotating gyroscopes. The Brennan monorail is analysed to better understand the behaviour of a similar coupled gyroscopic stabilization system. The reactions between the components that maintain the monorail in the stable position are studied and comparisons are made between the proposed stable platform and the Brennan system. A mathematical analysis of the proposed system is presented. The equations of motion for the system are derived using the Lagrangian Formalism. The characteristic equation of the system is then determined and from this a set of stability conditions imposed on the design of the physical parameters of the stable platform. The general solutions to the equations of motion are then derived. Expressions that model the behaviour of two of the variables that describe the motion of the stable platform are determined. A systematic approach is adopted for establishing a new concept for the proposed system. Testing of the initial stable platform prototype (Prototype A) showed the system did not behave as intended. The platform was optimised further and this resulted in a second prototype, Prototype B. Prototype B exhibiting the desired oscillatory motion about the vertical of the platform. Predictions made using the mathematical model are compared with empirical results. The mathematical model was found to be an accurate method for predicting the response of the stable platform.