Trajectory Control of a Tethered Underwater Robot System

2018 ◽  
Author(s):  
Jiaming Wu ◽  
Dongjun Chen ◽  
Ying Xu ◽  
Yuqing Chen ◽  
Lihua Lu
Keyword(s):  
Pid Control ◽  
Control Algorithm ◽  
Trajectory Control ◽  
Underwater Robot ◽  
Robot System ◽  
Feed Forward ◽  
Feed Forward Control ◽  
Robot Trajectory ◽  
Umbilical Cable ◽  
And Control

A three-dimensional hydrodynamic and control model to simulate tethered underwater robot system is proposed. The fluid motion around the moving robot main body with running control ducted propellers is governed by Navier-Stokes equations, and multiple sliding mesh technique is applied to solve the governing equations. The governing equation of umbilical cable connected to the robot is based on the Ablow and Schechter method. The six-degrees-of-freedom equations of motion for underwater vehicle simulations proposed by Gertler and Hargen are adopted to estimate the hydrodynamic performance of the underwater robot. In the model, the feed-forward control algorithm is applied to adjust the length of the umbilical cable according to the robot trajectory control target, the incremental PID control algorithm is adopt to regulate the rotating speeds of the ducted propellers producing appropriate thrusts for the robot control. With the proposed hydrodynamic and control model, hydrodynamic behaviors of the robot under definite trajectory control manipulations are observed numerically. The numerical results of robot trajectory control simulations indicate that the feed-forward control algorithm for adjusting the length of the umbilical cable, and the incremental PID control algorithm for regulating the rotating speeds of the propellers are feasible and effective, the adjusting the length of the umbilical cable with feed-forward control technique is largely responsible for the vertical trajectory control to the robot, while regulating the rotating speeds of the propellers by the PID control algorithm play a leading role in the horizontal trajectory manipulation, the deviation between the designated trajectory and the control one at each time step is acceptable.

Hydrodynamic Response of Tethered Underwater Robot by Feed-Forward and Incremental PID Control Techniques

2020 ◽  
Author(s):  
Jiaming Wu ◽  
Dongjun Chen ◽  
Jinhua Lin ◽  
Yan Chen ◽  
Yizhe Dou
Keyword(s):  
Hydrodynamic Model ◽  
Control Model ◽  
Control Mode ◽  
Control Technique ◽  
Underwater Robot ◽  
Robot System ◽  
Feed Forward ◽  
Trajectory Following ◽  
Umbilical Cable ◽  
And Control

Abstract The trajectory of tethered underwater robot is usually controlled by actuating the rotating speeds of control propellers attached to the robot and/or adjusting the length of umbilical cable. When the trajectory control problem of a tethered underwater robot is studied, it is necessary to couple the main body of underwater robot, umbilical cable and control propellers together forming an integrated hydrodynamic model so that the robot is in a comprehensive dynamic equilibrium condition, suitable control algorithms are then jointed into the hydrodynamic model constructing a hydrodynamic and control model for the tethered underwater robot system. Only in this way the hydrodynamic and control nature of a tethered underwater robot during different kinds of control manipulations can be numerically revealed objectively. In this paper, a hydrodynamic and control model to simulate the trajectory following control of a tethered underwater robot system is proposed, and the hydrodynamic performances of the robot and the umbilical cable are observed. To achieve this goal, three-dimensional hydrodynamic model of tethered underwater robot system is first introduced, feed-forward control technique for adjusting the length of umbilical cable and incremental PID algorithm for regulating the rotating speeds of propellers are then incorporated into the hydrodynamic model forming the hydrodynamic and control model. Based on the established hydrodynamic and control mode, relationships between the thrusts from the propellers and the rotating speeds of the propellers, and those among the trajectory following of the underwater robot and the control actions of adjusting the length of umbilical cable and governing the rotating speeds of the propellers are analyzed, and also the hydrodynamic performances of the tethered underwater robot system under the control manipulation are observed. In the research, the amplitude limit filtering method is applied in solving the governing equations of the umbilical cable, this technique is applied to avoid the chattering effect in the cable tension computation, so that a successive and stable computation process is maintained. The main factors affecting the singular nature of coefficient matrices during the numerical solutions of the proposed model are also investigated in the paper.

DECAFF: Experimental Study on Human Haptic Perception

2000 ◽  
Author(s):  
Scott L. Springer ◽  
Nicola J. Ferrier
Keyword(s):  
Interface Design ◽  
Haptic Perception ◽  
Human Perception ◽  
Initial Contact ◽  
Haptic Interfaces ◽  
Feed Forward ◽  
Feed Forward Control ◽  
Contact Distance ◽  
Traditional Approaches ◽  
And Control

Abstract DECAFF is a method for design and control of haptic interfaces that utilizes a DE-Coupled Actuator and Feed-Forward control. In this paper results of an experimental investigation are presented that quantify improved human haptic perception while using the DECAFF system, compared to the traditional haptic interface design and control systems. Perception improvements include the increased stability for rigid surfaces and increased ability of subjects to accurately identify initial contact with virtual surface boundaries. Traditional haptic interfaces employ an actuator directly coupled to the human operator that provides a force proportional to wall penetration distance and velocity. The DECAFF paradigm for design and control of haptic displays utilizes a de-coupled actuator and pre-contact distance sensing as a feed forward control term to improve stability and response performance. A human perception experiment has been performed that compares the touch sensation of the subjects for both the DECAFF system and traditional approaches to haptic display. In the human factors study the quality of rigid body display is evaluated in addition to the sensitivity of touch experienced by the subjects while making initial contact with virtual surfaces.

scholarly journals Smooth Tracking Trajectory Generation of Large Antenna

2016 ◽  
Vol 53 (1) ◽  
pp. 24-33 ◽  
Author(s):  
S. Upnere ◽  
N. Jekabsons ◽  
U. Locans
Keyword(s):  
Pid Control ◽  
Control Algorithm ◽  
Case Analysis ◽  
Control Algorithms ◽  
Control Methods ◽  
Antenna Feed ◽  
Feed Forward Control ◽  
Order Polynomial ◽  
Smooth Tracking ◽  
Tracking Trajectory

Abstract The current paper presents an engineering approach for studies of the control algorithm designed for a mechanically robust large antenna. Feed-forward control methods with the 3rd-order polynomial tracking algorithm are supplemented to the original feed-back PID control system. Dynamical model of the existing servo system of 32m radio telescope has been developed to widen a case analysis of observation sessions and efficiency of the control algorithms due to limited access to an antenna. Algorithms along with the results from the system implemented on a real antenna as well as model results are presented.

Research on Vibration Isolation System Based on Disturbance Observer PID Control Algorithm

2017 ◽  
Vol 865 ◽  
pp. 480-485
Author(s):  
Jian Liang Li ◽  
Xiao Xi Liu ◽  
Shu Qing Li ◽  
Zhi Fei Tao ◽  
Lei Ma
Keyword(s):  
Pid Control ◽  
Disturbance Observer ◽  
Control Algorithm ◽  
Vibration Isolation ◽  
Low Frequency ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Virtual Test ◽  
Set Up ◽  
And Control

The research mainly focuses on the performance of the controllable hypocenter in the low frequency band. The hybrid vibration isolation method based on the disturbance observer PID control algorithm is used to improve the excitation signal quality. Based on the analysis of the structure and working principle of vibration isolator, the physical model and mathematical model are established, and the simulation test of ZK-5VIC virtual test vibration and control system is carried out. The experimental platform of hybrid vibration isolation system with low frequency interference is set up. The experiment of excitation and acquisition of low frequency signal is carried out, which provides the theoretical basis and guarantee for the vibration isolation technology in the low frequency range below 3Hz.

The Simulation of Robot Control Based on CMAC Neural Network PID Control Algorithm

2013 ◽  
Vol 336-338 ◽  
pp. 659-663
Author(s):  
Jian Li Yu ◽  
Ya Zhou Di ◽  
Lei Yin
Keyword(s):  
Neural Network ◽  
Pid Control ◽  
Robot Control ◽  
Control Algorithm ◽  
External Disturbance ◽  
System Model ◽  
Robot System ◽  
System Parameters ◽  
Cmac Neural Network ◽  
Neural Network Pid

According to the problem of nonlinear and uncertainty in robot control, this paper proposes a PID control algorithm based on CMAC neural network model, for the elimination of the influence of uncertainty caused by robot system parameters and external disturbance. The simulation results show that this algorithm can effectively overcome the uncertainties and external disturbance of robot system model, this algorithm has good robustness and stability, its performance is superior to the traditional PID control algorithm.

Two Wheel Differential Robot Kinematic Analysis and Control

2012 ◽  
Vol 548 ◽  
pp. 848-852
Author(s):  
Wei Xin Wang ◽  
Wei Zhang
Keyword(s):  
Motion Control ◽  
Pid Control ◽  
Control Algorithm ◽  
Control Model ◽  
System Response ◽  
Robot Motion ◽  
Input And Output ◽  
Fuzzy Control Strategy ◽  
And Control ◽  
The Membership Function

The paper analyse the two wheel differential robot motion control, and the membership function of affiliation between the amount of input and output was established.Then combine the incremental PID control algorithm with fuzzy control strategy, and it was used to the two wheel differential robot motion control model. By the MATLAB for simulation, get the control system response curve and achieve a satisfactory result.

scholarly journals Realization of active metamaterials with odd micropolar elasticity

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yangyang Chen ◽  
Xiaopeng Li ◽  
Colin Scheibner ◽  
Vincenzo Vitelli ◽  
Guoliang Huang
Keyword(s):  
Electrical Energy ◽  
Emergent Properties ◽  
Micropolar Elasticity ◽  
Feed Forward ◽  
Control Loops ◽  
Feed Forward Control ◽  
Bending Modulus ◽  
Active Metamaterials ◽  
Energy Conserving ◽  
And Control

AbstractMaterials made from active, living, or robotic components can display emergent properties arising from local sensing and computation. Here, we realize a freestanding active metabeam with piezoelectric elements and electronic feed-forward control that gives rise to an odd micropolar elasticity absent in energy-conserving media. The non-reciprocal odd modulus enables bending and shearing cycles that convert electrical energy into mechanical work, and vice versa. The sign of this elastic modulus is linked to a non-Hermitian topological index that determines the localization of vibrational modes to sample boundaries. At finite frequency, we can also tune the phase angle of the active modulus to produce a direction-dependent bending modulus and control non-Hermitian vibrational properties. Our continuum approach, built on symmetries and conservation laws, could be exploited to design others systems such as synthetic biofilaments and membranes with feed-forward control loops.

Research on Control Algorithm of Electric Loading System

2013 ◽  
Vol 579-580 ◽  
pp. 818-822
Author(s):  
Xiang Zhang ◽  
Guang Lin Wang ◽  
Xu Dong Pan ◽  
Hai Bing Xie
Keyword(s):  
Pid Control ◽  
Control Algorithm ◽  
Simulation Analysis ◽  
Feed Forward ◽  
Complex Control ◽  
Electric Loading ◽  
Loading System ◽  
Disturbance Torque

The disturbance torque which is caused by the interference of the motor position has observably impact on accuracy of the loading system. According to unstable loading channel and disturbance torque, this paper use a complex control algorithm of differential forward PID control and feed-forward compensation. At the end of this paper, the simulation analysis results show that the feed-forward compensation can observably eliminate the influence of the disturbance torque, and improve the accuracy of the loading system.

Feed-Forward Control of a Cracked Simply Supported Beam

2011 ◽  
Author(s):  
Sudhir Kaul
Keyword(s):  
Crack Propagation ◽  
Control Algorithm ◽  
Control Algorithms ◽  
Transverse Displacement ◽  
Control Force ◽  
Simply Supported Beam ◽  
Feed Forward ◽  
Simply Supported ◽  
Crack Location ◽  
Feed Forward Control

This paper demonstrates the use of two feed-forward control algorithms in order to mitigate crack propagation in a simply supported beam with a pre-existing crack. The main objective of the control algorithms is to minimize or reduce transverse deflection at the crack location so as to contain the damage resulting from the pre-existing crack and, thereby, reduce the rate of crack propagation. A point-load sinusoidal excitation, from a known disturbance, is used as the input load acting on the beam. Two control algorithms are used — the first control algorithm computes a control force to eliminate transverse displacement at the crack location resulting from the excitation force, and the second control algorithm minimizes the mean square transverse displacement over a section of the beam that contains the crack. Both the control algorithms are a-causal and assume that the excitation input is completely known a-priori. Simulation results for a simply supported beam are presented and discussed in detail. It is observed that the rate of crack propagation can be significantly reduced by implementing the proposed feed-forward control algorithms, increasing the useful life of the damaged beam. Also, it is found that the transverse displacement over a significant length of the beam can be substantially reduced when the beam response is dominated by a specific mode.

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