A robust dynamic region-based control scheme for an autonomous underwater vehicle

Intelligent control of an autonomous underwater vehicle (AUV) requires a control scheme which is robust to external perturbations. These perturbations are highly uncertain and can prevent the AUV from accomplishing its mission. A well-known robust control called sliding mode control (SMC) and its development have been introduced. However, it produces a chattering effect which requires more energy. To overcome this problem, this paper presents a novel robust dynamic region-based control scheme. An AUV needs to be able not only to track a moving target as a region but also to position itself inside the region. The proposed controller is developed based on an adaptive sliding mode scheme. An adaptive element is useful for the AUV to attenuate the effect of external disturbances and also the chattering effect. Additionally, the application of the dynamic-region concept can reduce the energy demand. Simulations are performed to illustrate the effectiveness of the proposed controller. Furthermore, a Lyapunov-like function is presented for stability analysis. It is demonstrated that the proposed controller works better then an adaptive sliding mode without the region boundary scheme and a fuzzy sliding mode controller

Position Control of Pneumatic Actuator Using Self-Regulation Nonlinear PID

The enhancement of nonlinear PID (N-PID) controller for a pneumatic positioning system is proposed to improve the performance of this controller. This is executed by utilizing the characteristic of rate variation of the nonlinear gain that is readily available in N-PID controller. The proposed equation, namely, self-regulation nonlinear function (SNF), is used to reprocess the error signal with the purpose of generating the value of the rate variation, continuously. With the addition of this function, a new self-regulation nonlinear PID (SN-PID) controller is proposed. The proposed controller is then implemented to a variably loaded pneumatic actuator. Simulation and experimental tests are conducted with different inputs, namely, step, multistep, and random waveforms, to evaluate the performance of the proposed technique. The results obtained have been proven as a novel initiative at examining and identifying the characteristic based on a new proposal controller resulting from N-PID controller. The transient response is improved by a factor of 2.2 times greater than previous N-PID technique. Moreover, the performance of pneumatic positioning system is remarkably good under various loads

Efficient Detection of Robot Kidnapping in Range Finder-Based Indoor Localization Using Quasi-Standardized 2D Dynamic Time Warping

This paper proposes an augmented online approach to detect kidnapping events within range-finder-based indoor localization. The method is specifically designed for an Internet of Things (IoT)-Aided Robotics Platform that enables the system to detect kidnapping across all time instances of an indoor mobile robotic operation with high accuracy and maintain a high accuracy in the face of relocalization failures. The approach is based on similarity degree of geometry shape of the environment obtained from range scan data between two consecutive time instances. The proposed approach named Quasi-Standardized Two-Dimensional Dynamic Time Warping (QS-2DDTW) is based on the Multidimensional Dynamic Time Warping (MD-DTW) with homogeneity variance test imbued in it. A series of simulations are preformed against maximum current weight, measurement entropy, and the four metrics in metric based detector. The result shows that the proposed method yields high performance in terms of its ability to distinguish kidnapping condition from normal condition and that it has low dependency towards relocalization process, thus ensures the accuracy of detection is not disturbed by relocalization

Tracking Control Scheme for Multiple Autonomous Underwater Vehicles Subject to Union of Boundaries

AbstractThis paper presents a new region boundary-based tracking control for Multiple Autonomous Underwater Vehicles (MAUVs). The proposed controller enables MAUVs to track a moving target formed by the union of two or more boundaries. In this case, multiplicative potential energy function is used to unite the whole boundaries. Moreover, each underwater vehicle navigates into a specific position on the boundary lines or surfaces while the target itself is moving. A non-negative Lyapunov-like function is presented for stability analysis of the MAUVs. Simulation results on 6 degrees-of-freedom AUVs are presented to illustrate the performance of new tracking control scheme

Efficient detection of robot kidnapping in range finder-based indoor localization using quasi-standardized 2D dynamic time warping

This paper proposes an augmented online approach to detect kidnapping events within range-finder-based indoor localization. The method is specifically designed for an Internet of Things (IoT)-Aided Robotics Platform that enables the system to detect kidnapping across all time instances of an indoor mobile robotic operation with high accuracy and maintain a high accuracy in the face of relocalization failures. The approach is based on similarity degree of geometry shape of the environment obtained from range scan data between two consecutive time instances. The proposed approach named Quasi-Standardized Two-Dimensional Dynamic Time Warping (QS-2DDTW) is based on the Multidimensional Dynamic Time Warping (MD-DTW) with homogeneity variance test imbued in it. A series of simulations are preformed against maximum current weight, measurement entropy, and the four metrics in metric based detector. The result shows that the proposed method yields high performance in terms of its ability to distinguish kidnapping condition from normal condition and that it has low dependency towards relocalization process, thus ensures the accuracy of detection is not disturbed by relocalization

Robust-save energy controller on an autonomous underwater vehicle with obstacles avoidance

2572-2578This paper presents a robust-saved energy control and obstacles avoidance technique for an Autonomous Underwater Vehicle (AUV). A super twisting sliding mode which consists of discontinues and continuous function is engaged as a robust control. A discontinuous function is useful to switch between two different systems; thus, the disturbance's effect can be minimized. However, it is resulting a high-infinite frequency which degrades the robustness of an AUV, hence, a continuous function is useful to smoothness the switching movement. Instead of line trajectory, a region shape based on region-tracking control is included to save the energy usage, whilst, the calculation of repulsive force between an AUV and obstacles is used to avoid the collision. To observe the performance, some simulations on a 6-DOF-AUV are presented. During the obstacles avoidance, it is shown that the proposed control allows the AUV to produce 0.6 (m) less error without oscillation, obtain 80 (s) faster time of error convergence and save 9.3 % of energy consumption compared to modified Function-based Augmented Proposal Derivative (PFAPD). Overall, the proposed method contributes to a robust, energy saving and obstacles avoidances control for an AUV under disturbance’s effect

Dragonfly algorithm for multi-target search problem in swarm robotic with dynamic environment size

Target search elements are very important in real-world applications such as post-disaster search and rescue missions, and pollution detection. In such situations, there will be time limitations, especially under a dynamic environment size which makes multi-target search problems are more demanding and need a special approach and intention. To answer this need, a proposed multi-target search strategy, based on Dragonfly Algorithm (DA) has been presented in this paper for a Swarm Robotic application. The proposed strategy utilized the DA static swarm (food hunting process) and dynamic swarm (migration process) to achieve the optimized balance between the exploration and exploitation phases during the multi-target search process. For performance evaluation, numerical simulations have been done and the initial results of the proposed strategy show more stability and efficiency than the previous works