A novel vectored thruster based on 3-RPS parallel manipulator for autonomous underwater vehicles

Liu, Tao; Hu, Yuli; Xu, Hui; Wang, Qiankun; Du, Weiqiang

doi:10.1016/j.mechmachtheory.2018.12.015

Cited by 24 publications

(8 citation statements)

References 40 publications

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“…31 Similarly, the issues related with the 3-RPS PM have also been explored in the literature such as its introduction, 32 velocity and acceleration analysis, 33,34 architecture and constraint singularities, 35 instantaneous motions, 36 kinematic synthesis, [37][38][39] position and workspace analysis, [40][41][42][43] dynamic parameters, 44 architecture optimization, 45 study kinematic mapping of the Euclidean group SE (3), 46,47 operation modes, 48 and its application in thrust-vectoring propulsion. 49 Since, both these manipulators have a common motion of 1T2R type and their planes are arranged such that they intersect at 120°in a common line that is, a plane arrangement of Y-pattern, they can be compared. A number of factors are there for the comparison such as link tolerances, input drive errors, parasitic motions, backlash, joint clearances, etc.…”

Section: Introductionmentioning

confidence: 99%

Comparison of 3-[PP]S-Y Spatial Parallel Manipulators based on link tolerances and parasitic motions

Jain,

Jawale

2023

Proceedings of the Institution of Mechanical Engineers, Part C:

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This paper strives to compare between two 3-Degree of Freedom (DoF) Spatial Parallel Manipulators (SPMs) belonging to the 3-[PP]S-Y family viz., 3-RRS and 3-RPS. The planes of the manipulators belong to this family are arranged in a Y-pattern such that they intersect at 120° in a common line. Both of these manipulators have a common motion of 1T2R (T: Translation, R: Rotation) type, and their comparison in this work is carried out by considering the effects of link tolerance and parasitic motions, for the same task space and End-Effector (EE) positions. Their respective position kinematic analysis is discussed initially. The comparison is then carried out by considering two different cases based on the sizes of the moving platform relative to the base platform. The errors are quantified and all the comparative results are represented with the aid of plots. The conclusions are summarized at the end that allow to know the better of the two manipulators for the given effects.

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Section: Introductionmentioning

confidence: 99%

Comparison of 3-[PP]S-Y Spatial Parallel Manipulators based on link tolerances and parasitic motions

Jain,

Jawale

2023

Proceedings of the Institution of Mechanical Engineers, Part C:

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“…Cavallo et al [15] first proposed the conceptual vectored thruster based on a 3-RRR spherical parallel mechanism. A 3SPS-S parallel mechanism [14] and a 3-RPS parallel mechanism [26] have also been employed as the thrust-vectoring device. However, due to the long distance between the base and the moving platform, the stiffness of these mechanisms still needs to be improved in practice.…”

Section: Introductionmentioning

confidence: 99%

Design and Analysis of a Stiffness-Enhanced 3-PPS Parallel Mechanism for Fault-Tolerant Underwater Vectored Thrusters

et al. 2022

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Vectored thrusters can significantly improve the maneuverability of underwater vehicles. However, due to the harsh underwater environment and severe working conditions, the thrust-vectoring device needs to be designed with high stiffness and high reliability. In this paper, a 3-degree-of-freedom (3-DOF) 3-PPS parallel mechanism is employed for the 2-DOF thrust-vectoring device, which has the advantages of high stiffness and a certain level of fault tolerance. The stiffness of the 3-PPS parallel mechanism is enhanced through employing additional passive prismatic joints. Based on the zero-torsion characteristics of the parallel mechanism, closed-form solutions are obtained for displacement analyses, and the orientation workspace of the moving platform under an actuation failure, i.e., one of the active prismatic joints is locked, is particularly investigated through an equi-volumetric partition method. To analyze the orientation workspace distribution under the actuation failure, the fault-tolerant workspace and the maximum inscribed workspace are defined. Furthermore, a new fault-tolerant index is proposed to evaluate the fault tolerance of the parallel mechanism. The proposed design analysis is validated through experiments on an engineering prototype of the parallel mechanism.

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“…Although the performance of AUVs has obtained a huge development, there are still a lot of challenging problems appealing to scientists and engineers immensely in this field. For example, the conventional AUVs are unable to perform detailed inspection missions at zero and low forward speed because the control surfaces become ineffective in this condition for control force depends on the forward speed [4][5][6][7]. ese disadvantages greatly limit the application of AUVs.…”

Section: Introductionmentioning

confidence: 99%

Deep Reinforcement Learning for Vectored Thruster Autonomous Underwater Vehicle Control

Liu

2021

Complexity

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Autonomous underwater vehicles (AUVs) are widely used to accomplish various missions in the complex marine environment; the design of a control system for AUVs is particularly difficult due to the high nonlinearity, variations in hydrodynamic coefficients, and external force from ocean currents. In this paper, we propose a controller based on deep reinforcement learning (DRL) in a simulation environment for studying the control performance of the vectored thruster AUV. RL is an important method of artificial intelligence that can learn behavior through trial-and-error interactions with the environment, so it does not need to provide an accurate AUV control model that is very hard to establish. The proposed RL algorithm only uses the information that can be measured by sensors inside the AUVs as the input parameters, and the outputs of the designed controller are the continuous control actions, which are the commands that are set to the vectored thruster. Moreover, a reward function is developed for deep RL controller considering different factors which actually affect the control accuracy of AUV navigation control. To confirm the algorithm’s effectiveness, a series of simulations are carried out in the designed simulation environment, which is a method to save time and improve efficiency. Simulation results prove the feasibility of the deep RL algorithm applied to the control system for AUV. Furthermore, our work also provides an optional method for robot control problems to deal with improving technology requirements and complicated application environments.

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A novel vectored thruster based on 3-RPS parallel manipulator for autonomous underwater vehicles

Cited by 24 publications

References 40 publications

Comparison of 3-[PP]S-Y Spatial Parallel Manipulators based on link tolerances and parasitic motions

Comparison of 3-[PP]S-Y Spatial Parallel Manipulators based on link tolerances and parasitic motions

Design and Analysis of a Stiffness-Enhanced 3-PPS Parallel Mechanism for Fault-Tolerant Underwater Vectored Thrusters

Deep Reinforcement Learning for Vectored Thruster Autonomous Underwater Vehicle Control

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