Shield Attitude Measurement Based On Data Fusion Of Several Measurement Methods

For the safety and efficiency of the shield tunnel construction, automatic guidancesystem can be used to measure the real-time position and attitude of the shield machine.Two prisms method、three prisms method and laser target method are the several mainautomatic guidance systems with different advantages and disadvantages. Funded by agrant from the Major State Basic Research Development Program of China (973Program),research and explore measuring principle of the several methods, improve the prismmethod and make fusion of the three measurement method. The main work and researchare as follows:First the position and attitude description of shield under the earth coordinate system arebuilt. Introduce the detail measuring principle of two prisms method, three prisms method,multi prisms method and laser target method. The detailed calculate processes of themethods above are present. The comparison between the several methods is also made inchapter2.Then further research about prism method is carried out in the chapter3. The layoutof three prisms would be a large factor to the measurement precision. Through thesimulation under MATLAB environment, a optimal layout is calculated. Synchronizationmeasurement problem is another problem to the measurement precision. Adaptive kalmanfilter is brought in to make forecast compensation of the prisms, which can improve themeasurement precision of the three prism method.At last the fusion of the measurement results is researched. Analyse the relationshipbetween the measurement precision and the optimal weighted average value. Under mostcases, the measurement precision of every method couldn’t be got easily so that a dynamicweighted average method is brought in.Both the simulation under MATLAB and the measurement experiment data processprove that the fusion measurement method can greatly increase the reliability and thecredibility of the measurement results.