Research Of Calibration Technology On Angular Displacement For Elevator, Aileron And Flap Of Airplane

We must calibrate sensor against angular displacement for airplanes'aileron , jaw rudder and elevator , and so on , when making airplanes and testing on their flying capabilities. All the methods reported aren't applicable because of its special working environment here . And the calibrating method being used nowadays can not meet the specific needs , because the operation is complex , and the calibration precision is low . So , inventing a new measuring method , which is simple while installing , convenient when operating , and of higher precision and adaptability , is very important to the making and testing departments of airplanes .The measuring methods based on the computer monocular vision has many advantages . But many present methods , which adopt several fixed points as characteristic mark , are hard to establish a simple and practical"resolving model"to calculate the relation between coordinates in object space and in image space . To overcome this , they use approximate calculating method , but the result is that the error is too big when doing close-range measurement , and it can not meet the needs of this research .Characteristic circle is adopted for characteristic mark; a new concept ,"characteristic diameter", is put forward ; the length and the position of the characteristic diameter's image is adopted for the basic"characteristic parameters"; and a new"resolving model"is established based on perspective projection principle and the speciality of"characteristic diameter"in this article , so that the normal direction of target plane can be got without calibrating camera parameters in real time . It only need basic mathematic tools .It has designed a special method for finding circular center image coordinates and a subpixel digital image process method , so that the precision of simulation for searching image point of circular center can reach to 0.01 pixel in grade of amount .It has designed amending method for errors , produced by improper installation position of the testing device .Computer simulation result shows that the error is mostly less than 0.1°, if using this method to calibrate against the angular displacement for airplane's rudders .