On Error Modulation For Strapdown Inertial Navigation System With Single-axis Rotation

It is possible to develop a low-cost rotating strapdown inertial system that can workcontinuously for a long time, because the fabrication technology of optic gyroscope hasmatured and perfected step by step. A rotating strapdown inertial navigation system isequivalent to a strapdown inertial navigation system which is mounted on a rotating assemblywith an angle measuring device, and the computer algorithm principle of the rotatingstrapdown inertial system is equal to the strapdown inertial system. The navigation error canbe compensated by rotating modulation to safeguard the navigation accuracy of vehicle in along term. Some crucial techniques in error modulation for strapdown inertial navigationsystem with single-axis rotation are studied in theoretical aspect in this paper. Meanwhile, inthe laboratory environment, the rotating assembly and the prototype of a fiber optic gyroscopestrapdown inertial navigation system which is developed in the lab are tested. The main worksare as follows:Firstly, the common coordinate and coordinate transformation relation is given. And thebasic principle and structure of strapdown inertial navigation system is analyzed. Then, theprinciple and structure of rotating of strapdown inertial navigation system is analyzed basedon it, and the error equation of strapdown inertial navigation system with single-axis rotationis deduced. Finally, the principle of error modulation for strapdown inertial navigation systemwith single-axis rotation is clarified.Secondly, main types and solution of error for strapdown inertial navigation system areintroduced. The various error effects of inertial measurement unit under single-axis rotation isanalyzed. And the basic crucial principles of simulation techniques for inertial navigation areexpounded.Thirdly, the selection of the rotating shaft, the modulation effect impact of rotational rateand the evaluation guidelines of rotation motion scheme are analyzed. Then the errormodulation principles of inertial measurement unit under different rotation motion schemeare analyzed based on them. After that, the error modulation effects of various rotationmotion schemes are simulated and analyzed comparatively.Lastly, the navigation test equipments are introduced. And the captive and single-axisrotation navigation tests which are based on the prototype of a fiber optic gyroscopestrapdown inertial navigation system that is developed independently in the lab are designed.The results of each test are compared and feasibility of the schemes is verified.