Research On Rb/dgps-network Based Integrated Navigation Technology

The integration of conventional radio beacon and satellite navigation system has shown a great many of advantages in cost-performance, and it represents a developing trend of navigation technology. In this thesis, the network schema of multi-station system, which includes radio beacons and GPS, is designed in details. This novel technology can be applied to many kinds of commercial and military projects, such as the GN&C system of controllable parachute/parafoil. Apparent performance improvement can be observed. The main work of this paper is: 1. The current status of navigation system is introduced as well as the principles and new features of radio beacon. While considering the precision guidance ability and attacking-defending strategies, some new requirements that modem warfare imposed on navigation system are generalized. 2. By comparing the structures, specifications and features of existing terrestrial navigation systems, a RB/DGPS network is framed and designed, which can achieve local area coverage and meet the requirements of modem warfare. Some key technologies are also investigated. 3. Current status of precision guided airdrop system in several countries is introduced briefly. Then aiming at controllable parachute and parafoil respectively, the GN&C subsystems are explored. With the emphases on guidance strategy, the schema is presented and some critical technologies are analyzed. 4. The feasibility of using Relative GPS and Differential GPS to achieve precision guidance and control is analyzed. Operating mode and signal structure are designed and some useful conclusion is drawn. The quantitative expressions of biases/errors in RGPS/DGPS mode are deduced. 5. By using rigid body-rigid body hypothesis, the equation of motion with eleven degrees of freedom is founded. According to the simplified model, stability criteria are given. 6. Other mathematical models are built, including the model of apparent mass, the model of parachute opening dynamic load, the model of flare landing control, the model of changing wind field, the model of Pneumatic Muscle Actuator and the model of radial homing gliding. All of them are absolutely necessary to the design of GN&C system. In particular, the pattern of position and velocity during flare landing are plotted with specific parameter variation.