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An integrated attitude-orbit controller based on extended state observer (ESO) is designed for spacecraft to settle down the unavailability of angular velocity and centroid velocity during on?orbit flight.First,the spacecraft’s integrated attitude?orbit kinematics and dynamics model is presented based on dual quaternion.Second,an extended state observer is designed for the case of velocity screw information missing,which takes the model parameter error and external disturbance into account,and the finite time convergence of the observation error is analyzed by using Lyapunov stability theorem.Then a fast terminal sliding mode controller for integrated attitude?orbit control is designed based on the above extended state observer,and its finite time convergence is analyzed.Finally,a numerical simulation is given to verify the effectiveness of the control system. [ABSTRACT FROM AUTHOR]

Aiming at hand-eye calibration problem in robotic hand-eye vision system, the hand-eye conversion relationship between end-effector and camera of manipulator was studied, the method of solving homogeneous matrix in hand-eye calibration was summarized, and a vision model based on motion posture was set up. The improved dual quaternion approach was used for solving separately the rotation parts and the translation of the hand-eye homogeneous transformation matrix. In order to obtain the optimum solution of the translation vector, the infinite norm minimization was introduced during the solving process of translation vector, the local optimal solution of translation vector was obtained by iteration. Simulations based on the considered optimal translation vector algorithm were performed in Matlab, and the classic; solving using dual quaternion and linear decoupling estimation algorithm were also implemented for comparison. The results indicate that the proposed method is better than traditional methods in the precision of calibration, robustness of noise and sensitivity and stability of motion posture numbers. It can meet the accuracy requirement of hand-eye calibration. [ABSTRACT FROM AUTHOR]

In order to improve the precision of the strapdown inertial navigation algorithm based on dual quaternion in the high dynamic environment, a trapezoid digital integral algorithm is applied to compen­sate the coning and sculling errors, which optimizes the attitude and velocity calculating algorithm and improves the calculating precision of the strapdown inertial navigation algorithm. During a sampling period of gyroscope and accelerometer, the angular rates of gyroscope outputs at previous and current times are both integrated by using the trapezoid digital integral algorithm, and the integral angle increment is used for the coning error compensation. The accelerometer outputs at previous and current times are integated by using the trapezoid digital integral algorithm, and the integral velocity increment and the integral angular increment are used for the sculling error compensation. Through the simulation of multi-group dynamic tracks, it is shown that the improved coning and sculling error compensation algorithms adopting the trapezoid digital integration have higher navigation precision than the traditional rectangular digital in­tegration method when the inputs are angular rate and acceleration. The dynamics of the track is higher, and the performance advantage of the improved algorithm is more obvious. The analysis and comparison of kinematic vehicle experimental results further verify the performance advantage of the proposed improved algorithm. [ABSTRACT FROM AUTHOR]

Aiming at the problem of unified coordinate system involved in the robot calibration with the help of laser tracker,the transformation relation between robot nominal base frame and the fitting base frame of spatial geometric method by laser tracker was researched,a calibration method of robot base frame using dual quaternion was proposed and applied.The 7-DOF serial robot kinematics model was established by the product-of-exponential formula,and calibration model for robot base frame using dual quaternion was derived.The results indicate that the calibration method can calculate the rotation and translation of the calibration equation at one time,overcome the error transfer in the traditional pose-step calculation process and improve the calibration accuracy directly.The calibration method is useful to other problem that formulates in the same mathematical form,such as robot hand-eye system calibration and multi-robot coordination. [ABSTRACT FROM AUTHOR]