Modeling and Control of Underwater Pan/Tilt Camera Tracking System: Geometry Modeling and Tracking Control

2009 ◽  
Author(s):  
Yingfeng Ji ◽  
Ronald A. Perez ◽  
Ryoichi S. Amano
Keyword(s):  
Tracking Control ◽  
Sliding Mode ◽  
Tracking System ◽  
Tracking Error ◽  
Variable Structure ◽  
Biological Behavior ◽  
Camera Tracking ◽  
Modeling And Control ◽  
Underwater Environment ◽  
External Forces

Biologists study on the biological behavior of various marine creatures in situ using underwater observation systems. The darkness in an underwater environment is always one of the most difficult problems to overcome in order to clearly monitor the life cycle of underwater creatures. This illumination would be solved employing the Master-Slave (camera-light platform) coordination tracking structure. The control of underwater platform is a challenging issue due to the complex external forces in the underwater environment. Comparing of tracking control between linear proportional-derivative (PD) and nonlinear PD for the Pan/Tilt camera platform were conducted. The variable structure control (VSC), i.e., sliding mode control (SMC), was employed to the tracking control of the underwater Pan/Tilt camera platform. The disadvantage of SMC is that the discontinuous control signal would excite the high frequency unmodeled dynamic which produces the chattering. One of the methods which eliminate the chattering is to use the boundary layer (BL). However, the width of BL can introduce a trade off between the tracking performance and chattering elimination. Large width of BL can much more eliminate the chattering, but lead to less accurate control results versa. A simple, easily implemented method to vary the width of BL according to the value of tracking error is illustrated and verified in this paper.

Modeling and Control of Underwater Pan/Tilt Camera Tracking System

2009 ◽  
Author(s):  
Yingfeng Ji ◽  
Ryoichi S. Amano ◽  
Ronald A. Perez
Keyword(s):  
Experimental Study ◽  
High Speed ◽  
Tracking System ◽  
Maximum Velocity ◽  
Turbulence Models ◽  
Hydrodynamic Forces ◽  
Biological Behavior ◽  
Camera Tracking ◽  
Geometry Model ◽  
Underwater Environment

Biologists study on the biological behavior of various marine creatures in situ using underwater observation systems. However, darkness in an underwater environment is always one of the most difficult problems to overcome in order to clearly monitor the life of underwater creatures. In this research, a light-following scheme is proposed with the lighting device installed on a separate Pan/Tilt platform as a slave while the main Pan/Tilt camera platform works as a master. A dynamic model of Pan/Tilt platform was developed using the Lagrange’s equation. In order to achieve high speed manipulation of the Pan/Tilt platforms in underwater environment, hydrodynamic forces have to be considered. Scientists had done a great deal of researches on the hydrodynamic forces of underwater motion bodies. Most of the researches employed the semi-empirical equation based on the experimental study. The coefficients (Cd Cm) of drag and added-mass which were solved by experimental study were the research point of hydrodynamic modeling in previous researches. However, these modeling methods can be employed for the underwater bodies with the simple geometry dimension. Two hydrodynamic torque models which represent the degree of freedoms (DOFs) of panning and tilting respectively had been developed employing CFD software. The selection of turbulence models, i.e., K-E, K-W, SST, RSM and LES, was firstly accomplished using the case of turbulence flow over flat plane. The hydrodynamic torque models are obtained with the simulations results for a certain range of position and velocity values for each of DOFs. The maximum velocity for simulation was set at 60 rpm for each axis. The geometry model which represents the space relationship between the master (camera) and slave (light) and the control algorithms would be elaborated in a separate paper.

Adaptive and sliding mode tracking control for wheeled mobile robots with unknown visual parameters

2016 ◽  
Vol 40 (1) ◽  
pp. 269-278 ◽  
Author(s):  
Fang Yang ◽  
Hongye Su ◽  
Chaoli Wang ◽  
Zhenxing Li
Keyword(s):  
Mobile Robots ◽  
Tracking Control ◽  
Visual Servoing ◽  
Sliding Mode ◽  
Tracking Error ◽  
Variable Structure ◽  
Wheeled Mobile Robots ◽  
Trajectory Tracking Control ◽  
Structure Control ◽  
Tracking Controller

The trajectory tracking control problem of dynamic nonholonomic wheeled mobile robots is considered via visual servoing feedback. A novel visual feedback tracking error model is proposed. Its tracking controller is independent of uncalibrated visual parameters by using new methods. This controller consists of two units: one is an adaptive control for compensation of the uncertainties of dynamic parameters, the other is a variable structure control for the interference suppression. In addition, the torque tracking controller is global and smooth, and the chattering phenomenon is eliminated. The asymptotic convergence of tracking errors to equilibrium point is rigorously proved by the Lyapunov method. Simulation and experiment results are provided to illustrate the performance of the control law.

Sliding Mode Control of a Three Degrees of Freedom Anthropoid Robot by Driving the Controller Parameters to an Equivalent Regime

2000 ◽  
Vol 122 (4) ◽  
pp. 632-640 ◽  
Author(s):  
M. Onder Efe ◽  
Okyay Kaynak ◽  
Xinghuo Yu
Keyword(s):  
Degrees Of Freedom ◽  
Sliding Mode ◽  
Initial Conditions ◽  
Tracking Error ◽  
Variable Structure ◽  
Mathematical Representation ◽  
Dynamic Complexity ◽  
Variable Structure Systems ◽  
Sliding Motion ◽  
Three Degrees Of Freedom

Noise rejection, handling the difficulties coming from the mathematical representation of the system under investigation and alleviation of structural or unstructural uncertainties constitute prime challenges that are frequently encountered in the practice of systems and control engineering. Designing a controller has primarily the aim of achieving the tracking precision as well as a degree of robustness against the difficulties stated. From this point of view, variable structure systems theory offer well formulated solutions to such ill-posed problems containing uncertainty and imprecision. In this paper, a simple controller structure is discussed. The architecture is known as Adaptive Linear Element (ADALINE) in the framework of neural computing. The parameters of the controller evolve dynamically in time such that a sliding motion is obtained. The inner sliding motion concerns the establishment of a sliding mode in controller parameters, which aims to minimize the error on the controller outputs. The outer sliding motion is designed for the plant. The algorithm discussed drives the error on the output of the controller toward zero learning error level, and the state tracking error vector of the plant is driven toward the origin of the phase space simultaneously. The paper gives the analysis of the equivalence between the two sliding motions and demonstrates the performance of the algorithm on a three degrees of freedom, anthropoid robotic manipulator. In order to clarify the performance of the scheme, together with the dynamic complexity of the plant, the adverse effects of observation noise and nonzero initial conditions are studied. [S0022-0434(00)01704-4]

Design of Optimum Controller of APT Fine Tracking Control System

2013 ◽  
Vol 712-715 ◽  
pp. 2738-2741 ◽  
Author(s):  
Ming Qiu Li ◽  
Shu Hua Jiang
Keyword(s):  
Pid Control ◽  
Tracking Control ◽  
Control Algorithm ◽  
Tracking System ◽  
Dynamic Performance ◽  
Tracking Error ◽  
Stable State ◽  
Response Speed ◽  
Optimum Control ◽  
Performance Requirements

APT (Acquisition, Pointing, and Tracking) system of space laser communication adopts compound axis structure; it consists of coarse tracking and fine tracking system. Its response speed and tracking precision mainly rests with the fine tracking system. Traditional PID control algorithm often is used in APT fine tracking system. In order to improve the dynamic performance of the system and decrease the tracking error, optimum control technology was adopted in this paper. On the basis of considering the system dynamic performance requirements and tracking precision requirement, optimum controller was designed. The simulation result shows that the bandwidth of APT fine tracking system is up to 1310 Hz, and the stable state error is less than 0.002. Compared with PID control, optimum control can improve the tracking performance of system.

An Algorithm for Robust Tracking Control of Robots

Robotica ◽  
1991 ◽  
Vol 9 (1) ◽  
pp. 53-62 ◽  
Author(s):  
Zoran R. Novaković ◽  
Leon Z˘lajpah
Keyword(s):  
Tracking Control ◽  
Error Control ◽  
Sliding Mode ◽  
Tracking Error ◽  
Lyapunov Theory ◽  
Control Synthesis ◽  
Robust Tracking ◽  
Robust Tracking Control ◽  
Time Simulation ◽  
Inverse Kinematics Problem

SUMMARYBased on the Lyapunov theory, a new principle was developed for synthesizing robot tracking control in the presence of model uncertainties. First, a general Lyapunov-like robust tracking concept is presented. It is then used as a basis for the control algorithm derived via a quadratic Lyapunov function constructed using a sliding mode function (based on the output error). Control synthesis is made in task-space, without any need for solving the inverse kinematics problem, i.e. one does not need to inver the Jacobian matrix. It is also shown that the tracking error becomes close to zero in a settling time which is less than a prescribed finite time. Simulation results are incorporated.

scholarly journals Discrete-Time Sliding Mode Control Coupled with Asynchronous Sensor Fusion for Rigid-Link Flexible-Joint Manipulators

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Guangyue Xue ◽  
Xuemei Ren ◽  
Kexin Xing ◽  
Qiang Chen
Keyword(s):  
Sensor Fusion ◽  
Discrete Time ◽  
Tracking Control ◽  
Sliding Mode ◽  
Estimation Error ◽  
Tracking Error ◽  
Sampling Rate ◽  
Experimental Studies ◽  
Flexible Joint ◽  
Rigid Link

This paper proposes a novel discrete-time terminal sliding mode controller (DTSMC) coupled with an asynchronous multirate sensor fusion estimator for rigid-link flexible-joint (RLFJ) manipulator tracking control. A camera is employed as external sensors to observe the RLFJ manipulator’s state which cannot be directly obtained from the encoders since gear mechanisms or flexible joints exist. The extended Kalman filter- (EKF-) based asynchronous multirate sensor fusion method deals with the slow sampling rate and the latency of camera by using motor encoders to cover the missing information between two visual samples. In the proposed control scheme, a novel sliding mode surface is presented by taking advantage of both the estimation error and tracking error. It is proved that the proposed controller achieves convergence results for tracking control in the theoretical derivation. Simulation and experimental studies are included to validate the effectiveness of the proposed approach.

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