International Journal of Computer and Applications

Model predictive control of three-axis gimbal system mounted on UAV for real-time target tracking under external disturbances

where xt+1 is the position and orientation of the robot (with respect to a reference frame) at time t + 1, with (ξ, η) giving the x and y coordinates and θ the angle (with respect to the x-axis) that the robot is facing. The robot has two drive wheels, of radius r on an axle of length d. During time period t the right wheel is believed to rotate at a velocity of φRt and the left at a velocity of φLt. In this example, these velocities are fixed with φRt = 0.4 and φLt = 0.1. The state update function, F , calculates where the robot should be at each time point, given its previous position. However, in reality, there is some random fluctuation in the velocity of the wheels, for example, due to slippage. Therefore the actual position of the robot and the position given by equation F will differ. The magnitude of these random fluctuations is included in the model through Σx.

Unscented Kalman Filterの計測への応用に関する研究

In this paper, a size-dependent model for bending and free vibration of functionally graded Reddy plate is developed The present model accounts for both small scale and shear deformation effects in functionally graded microplates The small scale effects are captured using the modified couple stress theory, while the shear deformation effects are included using the third-order shear deformation theory The equations of motion and boundary conditions are derived from Hamilton’s principle Analytical solutions are obtained for a simply supported plate Numerical examples are presented to illustrate the effects of small scale on the responses of microplates The results reveal that the inclusion of small scale effects results in an increase in plate stiffness, and consequently, leads to a reduction of deflection and an increase in frequency Such small scale effects are significant when the plate thickness is small, but become negligible with increasing plate thickness

A size-dependent functionally graded Reddy plate model based on a modified couple stress theory

A study of a microstructure-dependent composite laminated Timoshenko beam using a modified couple stress theory and a meshless method

The application of inertial stabilization system is to stabilize the sensor's line of sight toward a target by isolating the sensor from the disturbances induced by the operating environment. The aim of this paper is to present two axes gimbal system. The gimbals torque relationships are derived using Lagrange equation considering the base angular motion and dynamic mass unbalance. The stabilization loops are constructed with cross coupling unit utilizing proposed fuzzy PID type controller. The overall control system is simulated and validated using MATLAB. Then, the performance of proposed controller is evaluated comparing with conventional PI controller in terms of transient response analysis and quantitative study of error analysis. The simulation results obtained in different conditions prove the efficiency of the proposed fuzzy controller which offers a better response than the classical one, and improves further the transient and steady-state performance.

Stabilization loop of a two axes gimbal system using self-tuning PID type fuzzy controller

In this paper, the size-dependent vibrational behavior of a microbeam conveying fluid was investigated using the Modified Couple Stress Theory. For cantilever and clamped-clamped microbeams, the small amplitude vibration equation of the micro-beams was solved using a Galerkin based reduced order model and the effects of material length-scale parameter on its natural frequencies were evaluated. It was found that for the both cantilever and clamped-clamped conditions, the critical fluid velocities predicted by the modified couple stress theory are higher than those predicted by the classical beam theory. In addition, the differences between the eigen-frequencies and the critical fluid velocities predicted by the modified couple stress theory and classical beam theory depends on the ratio of the material length-scale parameter to the beam height. In addition an unexpected result in the difference between the first eigen-frequency of the cantilever micro-beam obtained by the classical and the modified couple stress theory has been achieved.

On the stability of a microbeam conveying fluid considering modified couple stress theory

The aim of the gimballed stabilization system is to stabilize the sensor's line of sight towards a target by isolating the sensor from the disturbance induced by the operating environment, such as various disturbance torques and body motions. This paper presents a two axes gimbal assembly. The torque relationships are derived considering the angular motion of the base body and the dynamic unbalance. The stabilization loops for the two axes gimbal system are constructed and related to each other with a cross-coupling unit. Next, the overall model is simulated using two approaches and the obtained results are compared to show the correction of the model proposed. Finally, numerous tests are applied to evaluate the model's performance and investigate the effects of torque disturbance considered in this research.

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Research on the Cross-Coupling of a Two Axes Gimbal System with Dynamic Unbalance

One the most important problems in target tracking are state estimation. This paper deals on estimation of states from noisy sensor measurements. Due to important of exact estimation in tracking problems must evader position and Line Of Sight angles estimated with least error rather than actual position. In this paper extended Kalman filter (EKF) and unscented Kalman filter (UKF) and Cubature Kalman Filter (CKF) are presented for bearing only Tracking problem in 3D using bearing and elevation measurements from tows sensors. The algorithms and model of system simulated using MATLAB and many tests were carried out. Simulation experiments show that the efficiency of EKF due to least RMSE have better performance on compared with the UKF algorithm. Also, the performance of EKF algorithm has been dramatically decreased when initialization (initial state assumption) is not good, which in this condition CKF method provides a more accurate approximation. Numerical results from Monte Carlo simulations show that the CKF have the best state estimation accuracy among all nonlinear filters considered. The proposed approach is interesting for the design of optimization algorithms that can run on target tracking systems. General Terms Target tracking, Bearings-only tracking, Algorithms

/pdf/state-estimation-for-target-tracking-problems-with-nonlinear-4k971o1cp4.pdf

State Estimation for Target Tracking Problems with Nonlinear Kalman Filter Algorithms

One of the most important components constituting a homing guided missile is the seeker which basically consists of a detector with a servo-tracking loop. The performance of gimbal seeker is evaluated according to the line of sight (LOS) stability. The purpose of this paper is to present, investigate, and analyze the performance of two axes gimbal seeker which must strictly isolate the LOS from the torque disturbances and missile vibrations. The equations of gimbals motion are derived using Lagrange equation considering the missile angular motion and gimbals mass unbalance. The stabilization loop is constructed by identifying its components, then the traditional and cascade loops are defined. The overall control system is built considering the cross coupling unit and simulated in MATLAB for the traditional and cascade control loops. A comparison study is carried out to investigate the gimbal seeker performance under different operational conditions such as missile rates and accelerations. The simulation r...

Alireza Toloei

Papers

Stabilization loop of a two axes gimbal system using self-tuning PID type fuzzy controller

On the stability of a microbeam conveying fluid considering modified couple stress theory

Research on the Cross-Coupling of a Two Axes Gimbal System with Dynamic Unbalance

State Estimation for Target Tracking Problems with Nonlinear Kalman Filter Algorithms

Improving two axes gimbal seeker performance using cascade control approach