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Buoyancy System

The Experts below are selected from a list of 261 Experts worldwide ranked by ideXlab platform

R. Sharma – 1st expert on this subject based on the ideXlab platform

  • Design and Analysis of a Variable Buoyancy System for Efficient Hovering Control of Underwater Vehicles with State Feedback Controller
    Journal of Marine Science and Engineering, 2020
    Co-Authors: B K Tiwari, R. Sharma

    Abstract:

    The design process for Variable Buoyancy System (VBS) is not known in full, and existing approaches are not scalable. Furthermore, almost all the small size Autonomous Underwater Vehicles/Gliders (AUVs/G’s) use very low capacity of Buoyancy change (in the range of few milliliters) and the large size AUVs require large Buoyancy change. Especially for adverse weather conditions, emergency recovery or defense-related applications, higher rate of rising/sinking (heave velocity) is needed along with an ability to hover at certain depth of operation. Depth of UVs can be controlled either by changing the displaced volume or by changing the overall weight and, herein, our focus is on the later. This article presents the problem of design and analysis of VBS for efficient hovering control of underwater vehicles at desired depth using the state feedback controller. We formulate and analyze the design and analysis approach of VBS using the fundamental of mechanics, System dynamics integration and control theory. Buoyancy is controlled by changing the overall weight of the vehicle using the ballasting/de-ballasting of water in ballast tanks through the use of Positive Displacement Pump (PDP) for control in heave velocity and hovering depth. Furthermore, detailed mass metric analysis of scalable design of VBS for different Buoyancy capacities is performed to analyze the overall performance of the VBS. Also, the performances of AUVs integrated with VBS of different Buoyancy capacities are investigated in both the open loop and closed loop with the LQR state feedback controller. Hovering performance results are presented for three Design Examples (DEs) of AUVs with 2.8 m, 4.0 m and 5.0 m length and they are integrated with various Buoyancy capacities at 9 kg/min rate of change of Buoyancy. Results indicate that the AUVs achieve the desired depth with almost negligible steady state error and when they reach the desired hovering depth of 400 m the maximum pitch angle achieved of 16.5 degree for all the Des is observed. Maximum heave velocity achieved during sinking is 0.44 m/s and it reduces to zero when the vehicle reaches the desired depth of hovering. The presented computer simulation results indicate good performance and demonstrate that the designed VBS is effective and efficient in changing the Buoyancy, controlling and maintaining the depth, controlling the heave velocity and can be used in rescue/attack operations of both the civil and defense UVs.

  • A Computing Model for Design of Flexible Buoyancy System for Autonomous Underwater Vehicles and Gliders
    Defence Science Journal, 2018
    Co-Authors: Brajesh Tiwari, R. Sharma

    Abstract:

    Modern design approaches are conceived and utilised in an integrated loop covering System statics, dynamics, optimisation, and others. In this regard this paper presents a computing based integrated design approach for a flexible Buoyancy System (FBS) aimed towards the applications in autonomous underwater vehicles and gliders. The primary design alternatives for the FBS are: piston and pump driven and both are investigated. The primary design of autonomous underwater vehicles and gliders is computed from first principle of mechanics and defined in the computer aided design model and it is implemented in the Matlab*TM. Lastly, to show the application of the present approach, a design example is presented for a water depth of 6000 m.

  • A computing based design model of pneumatic driven variable buoayncy System for Autonomous Underwater Vehicles
    OCEANS 2016 MTS IEEE Monterey, 2016
    Co-Authors: Patitapaban Sahoo, R. Sharma, T Asokan

    Abstract:

    In the era of modern computing based environment, the process of design is conceptualized, implemented and tested in a close loop integrating different modules of design, manufacturing and usages. In this regard, this paper presents a computing based design model for the design of a ‘Pneumatic Driven Variable Buoyancy System (PDVBS)’ for ‘Autonomous Underwater Vehicles (AUVs)’. The presented design model is modular in architecture and integrates the design of PDVBS with design of AUV. The design approach is derived from the basic and advanced principles of mechanics and the approach is defined in the ‘Computer Aided Design (CAD)’ model in terms of different modules with implementation in Matlab*™. Finally, we present a design example of a PDVBS for depth rating up to 4200 m with application focused on a large AUV of length 7 m to show the efficiency and applicability of our proposed design model.

T Asokan – 2nd expert on this subject based on the ideXlab platform

  • A computing based design model of pneumatic driven variable buoayncy System for Autonomous Underwater Vehicles
    OCEANS 2016 MTS IEEE Monterey, 2016
    Co-Authors: Patitapaban Sahoo, R. Sharma, T Asokan

    Abstract:

    In the era of modern computing based environment, the process of design is conceptualized, implemented and tested in a close loop integrating different modules of design, manufacturing and usages. In this regard, this paper presents a computing based design model for the design of a ‘Pneumatic Driven Variable Buoyancy System (PDVBS)’ for ‘Autonomous Underwater Vehicles (AUVs)’. The presented design model is modular in architecture and integrates the design of PDVBS with design of AUV. The design approach is derived from the basic and advanced principles of mechanics and the approach is defined in the ‘Computer Aided Design (CAD)’ model in terms of different modules with implementation in Matlab*™. Finally, we present a design example of a PDVBS for depth rating up to 4200 m with application focused on a large AUV of length 7 m to show the efficiency and applicability of our proposed design model.

  • a computer simulation model for design of variable Buoyancy System for autonomous underwater vehicles gliders
    OCEANS 2016 – Shanghai, 2016
    Co-Authors: B K Tiwari, R. Sharma, T Asokan

    Abstract:

    The efficient control of Buoyancy with low power is critically important in the design of new age ‘Autonomous Underwater Vehicles/Gliders (AUVs/Gs)’. This paper presents a ‘Computer Simulation Model (CSM)’ for the primary design of ‘Variable Buoyancy System (VBS)’ for AUVs/AUGs to efficient control Buoyancy and the simulation model is built in the environment of integration, modular architecture and specific range of applicability. The CSM for design of VBS is integrated in the overall design process of AUVs/AUGs. Finally, we present design example of the VBS for a AUVhaving two ballast tanks (each of a Buoyancy capacity of ± B = 10kg), maximum rate of change of Buoyancy = 9 kg/minute; and our presented results show that the proposed CSM for the design of VBS for AUVs/AUGs simulates the design process efficiently and leads to an efficient and economic design with the desired and specific range of applications.

  • A computer simulation model for design of variable Buoyancy System for autonomous underwater vehicles/gliders
    OCEANS 2016 – Shanghai, 2016
    Co-Authors: B K Tiwari, R. Sharma, T Asokan

    Abstract:

    The efficient control of Buoyancy with low power is critically important in the design of new age ‘Autonomous Underwater Vehicles/Gliders (AUVs/Gs)’. This paper presents a ‘Computer Simulation Model (CSM)’ for the primary design of ‘Variable Buoyancy System (VBS)’ for AUVs/AUGs to efficient control Buoyancy and the simulation model is built in the environment of integration, modular architecture and specific range of applicability. The CSM for design of VBS is integrated in the overall design process of AUVs/AUGs. Finally, we present design example of the VBS for a AUVhaving two ballast tanks (each of a Buoyancy capacity of ± B = 10kg), maximum rate of change of Buoyancy = 9 kg/minute; and our presented results show that the proposed CSM for the design of VBS for AUVs/AUGs simulates the design process efficiently and leads to an efficient and economic design with the desired and specific range of applications.

Rong Zheng – 3rd expert on this subject based on the ideXlab platform

  • the design and analysis of variable Buoyancy System of auv
    2017 2nd Asia-Pacific Conference on Intelligent Robot Systems (ACIRS), 2017
    Co-Authors: Rong Zheng, Mozhu Li, Hongguang Liang

    Abstract:

    The sailing posture of AUV in water will be affected by the density, depth of seawater and so on. The sailing posture of AUV will be changed when crossing the waters of different hydrological environment. For maintaining a good sailing posture of AUV, we designed a variable Buoyancy System. The variable Buoyancy System can change the Buoyancy of AUV by changing the oil of the outer oil sac to ensure that AUV can get a good posture. We can get a series of test data by the AMESim simulation of the no-load operation and loading operation of the hydraulic System and the test on the lake. Finally, the test data are compared with simulation data, and it can provide reliable reference for System optimization. The results showed that the flow of variable Buoyancy System is affected by the depth of water and the temperature of environment, and variable Buoyancy System can steadily operate and satisfy the engineering needs.

  • the resistance analysis of auv based on variable Buoyancy System
    Robotics and Biomimetics, 2016
    Co-Authors: Rong Zheng

    Abstract:

    With the development of autonomous underwater vehicle (AUV), the long distance and large depth is the main development direction of AUV. Using the equipment of Buoyancy adjusting instead of the motors of the bow and stern channel can save energy and increase endurance of AUV. Based on the oil capsules device of Buoyancy adjusting in this paper, designed two different schemes: one is that oil capsules are installed outside of the AUV; the other is that oil capsules are installed inside of the AUV. We calculate the resistance of two schemes based on CFD. By comparing the resistance under the same scheme at different speeds (3km, 4km, 5km) and in different schemes at the same speed, we can get the most optimal scheme.

  • ROBIO – The resistance analysis of AUV based on Variable Buoyancy System
    2016 IEEE International Conference on Robotics and Biomimetics (ROBIO), 2016
    Co-Authors: Rong Zheng

    Abstract:

    With the development of autonomous underwater vehicle (AUV), the long distance and large depth is the main development direction of AUV. Using the equipment of Buoyancy adjusting instead of the motors of the bow and stern channel can save energy and increase endurance of AUV. Based on the oil capsules device of Buoyancy adjusting in this paper, designed two different schemes: one is that oil capsules are installed outside of the AUV; the other is that oil capsules are installed inside of the AUV. We calculate the resistance of two schemes based on CFD. By comparing the resistance under the same scheme at different speeds (3km, 4km, 5km) and in different schemes at the same speed, we can get the most optimal scheme.