Identifying pitching mode of aerial planting projectile by the use of image processing

Abstract

Aerial planting is a new and affordable method, which is used for purposes of reforestation and restoring pastures. In this study, flight dynamics of an aerial planting projectile has been simulated using data of the wind tunnel test. By creating the projectile graphical model and using the results of dynamic equations for this model, pitching angle has been simulated graphically by recording the pitch attitude of the graphical model and, by applying spectral filtration the rate of pitch angle at any point of the trajectory is calculated. Primary dynamic model parameters including the coefficients of regression equation of motion are estimated by applying the least squares estimator. Comparison of the estimated coefficients from image processing and coefficients given to the simulation program reveals high accuracy of the model resulting from the image processing data used in this method and approves wind tunnel test data by graphical model and calibration of camera measurement. Also, an experimental test setup has been created and the images of projectile falling down in the presence of fan flow have been captured with high-speed digital camera. By decreasing the ambient light intensity, the images and measurement noise of theta angle increases. By applying recursive least square algorithm, sensitivity of coefficients and robustness of this algorithm has been analyzed. The analysis results indicate that the estimation of coefficients using image processing data has great accuracy.

Magnetometer-Based Phase Shifting Ratio Method for High Spinning Projectile’s Attitude Measurement

“…The magnetic inclination and total field can be obtained by querying geomagnetic model IGRF11. But since the three equations are not independent of each other, we cannot solve Equation (5) to get the unique solution. For the above reason, the magnetometer cannot be used independently.…”

“…The above two formulas are both derived from the equation (5). For Crest and Trough method, the correction formula of yaw angle will introduce the errors of B b…”

“…The sensors currently used for high spinning projectiles' attitude measurement mainly include: MEMS IMU [2], magnetometer [3], GNSS [4], high speed camera [5], sun sensor [6], infrared sensor [7] and etc. Since high speed camera, photo sensor and infrared sensor suffer from the disturbance of environment and weather, their application scenarios are limited.…”

Online Correction Method for Ratio Methods by Using Geomagnetic Sensors Based on Kalman Filter

“…Assuming that the AD converter is ideal, the sampling process of the AD converter is simulated by using a function that rounds a number to the nearest integer. The data obtained after the AD converter is presented as follows: (16) where n ad is the bit number of an AD converter. Substituting (14) and (15) into (16), d ad can be represented as follows:…”

“…This method is only suitable for large carriers that are equipped with PTI equipment and is not suitable for small projectiles. In [16], by creating the projectile graphical model and using the results of dynamic equations for this model, pitching angle has been simulated graphically by recording the pitch attitude of the graphical model and by applying spectral filtration the rate of pitch angle at any point of the trajectory is calculated. However, determining the pitch angle of the projectile through the image requires higher experimental environment and is not widely used.…”