Dynamic Model and Motion Characteristics of an Underwater Glider with Manta-inspired Wings

Author(s):  
Yaqiang Zhu ◽  
Yuhong Liu ◽  
Lianhong Zhang ◽  
Yanhui Wang ◽  
Wendong Niu ◽  
...  
2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Yufei Liu ◽  
Wei Li ◽  
Xuefeng Yang ◽  
Mengbao Fan ◽  
Yuqiao Wang ◽  
...  

Flexible manipulator generally can be modeled as a coupling system with a flexible beam and a rigid moving base. This paper investigates the vibration responses and power flow of a flexible manipulator with a moving base (FMMB). Considering the motion characteristics of the rigid base, the moving base is modeled to have a motion with disturbances, and the dynamic model of the FMMB is established. With the dynamic model, vibration responses of the FMMB for the rigid base having disturbance velocities and accelerations are specifically presented. Subsequently, to investigate the effect of the disturbances on the vibration energy distributions of the FMMB, power flow of the FMMB is exhibited. To verify the dynamic model, an ADAMS physical model of the FMMB is constructed. It reveals that the motion characteristics of the rigid base have a noticeable effect on the vibration responses and power flow of the FMMB and should be considered. The results are significant and contribute to the vibration control of flexible manipulators.


2011 ◽  
Vol 66-68 ◽  
pp. 1748-1754
Author(s):  
Yu Liu ◽  
Yi Lin Wu

Based on the Kirchhoff equations, Newton-Euler laws, boundary layer theory and mass definition, the six degrees of freedom dynamic model of airship complete with aerodynamic forces, wind effect is presented. Then, the nonlinear dynamic model is divided into three group equations by restricting airship motion in different planes respectively. The motion characteristics of airship, including stability, the effect of ballast position and rotational damping, are studied using linearized model. The results of simulation verify the correctness of the theoretical analysis and airship design.


2021 ◽  
Vol 28 (2) ◽  
pp. 4-17
Author(s):  
Xiangcheng Wu ◽  
Pengyao Yu ◽  
Guangzhao Li ◽  
Fengkun Li

Abstract Underwater gliders are winged, autonomous underwater vehicles that are broadly applied in physical and biological oceanography. The position of the wing has an important effect on the movement performance of the underwater glider. In this paper, the dynamic motion of a series of underwater glider models with different longitudinal wing positions are simulated, which provides guidance for the design of underwater gliders. The results show that when the net buoyancy is constant, the wing position affects the gliding angle, but does not affect the relationship between the gliding angle and the gliding speed. In addition, the farther the wing position of the glider is from the buoyancy centre, the longer it takes for the attitude of a glider to change, whether the wing is in front of, or behind, the buoyancy centre.


Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4467
Author(s):  
Eva Reitbauer ◽  
Christoph Schmied

Nowadays, many precision farming applications rely on the use of GNSS-RTK. However, when it comes to autonomous agricultural vehicles, GNSS cannot be used as a stand-alone system for positioning. To ensure high availability and robustness of the positioning solution, GNSS-RTK must be fused with additional sensors. This paper presents a novel sensor fusion algorithm tailored to tracked agricultural vehicles. GNSS-RTK, an IMU and wheel speed sensors are fused in an error-state Kalman filter to estimate position and attitude of the vehicle. An odometry model for tracked vehicles is introduced which is used to propagate the filter state. By using both IMU and wheel speed sensors, specific motion characteristics of tracked vehicles such as slippage can be included in the dynamic model. The presented sensor fusion algorithm is tested at a composting site using a tracked compost turner. The sensor measurements are recorded using the Robot Operating System (ROS). To analyze the achievable accuracies for position and attitude of the vehicle, a precise reference trajectory is measured using two robotic total stations. The resulting trajectory of the error-state filter is then compared to the reference trajectory. To analyze how well the proposed error-state filter is suited to bridge GNSS outages, GNSS outages of 30 s are simulated in post-processing. During these outages, the vehicle’s state is propagated using the wheel speed sensors, IMU, and the dynamic model for tracked vehicles. The results show that after 30 s of GNSS outage, the estimated horizontal position of the vehicle still has a sub-decimetre accuracy.


2012 ◽  
Vol 457-458 ◽  
pp. 237-244
Author(s):  
Guo Chang Hu ◽  
Mei Ping Wu

Aiming at the requirements of autonomous control for stratospheric airships, based on description of the modeling plant and forces analysis in detail, the dynamic model is established by Newton Method. The motion characteristics of airships under control action are analyzed using simulation method. Simulation results indicate the correctness of dynamic model, and can make itself a theoretical basis for the overall design of the stratospheric airship.


Robotica ◽  
2021 ◽  
pp. 1-19
Author(s):  
Guoxing Zhang ◽  
Donghao Zheng ◽  
Jinwei Guo ◽  
Yulei Hou ◽  
Daxing Zeng

SUMMARY A novel 3-R(RRR)R+R (R as revolute joint) hybrid antenna mechanism (HAM) is proposed for noncircular polarized antenna. First, its mobility characteristic is analyzed. Besides, its kinematics is deduced, and the velocity and acceleration are obtained. Afterward, its dynamic model is established. The actuation torques of each actuation joint are obtained. Its actuation torques are verified by mathematical model analysis and dynamic simulation. Furthermore, its workspace is also presented. Finally, the motion characteristics experimental results show that the 3-R(RRR)R+R HAM can carry out the azimuth and pitch motion. This research work serves as a fundamental theoretical basis for its further application.


2012 ◽  
Vol 490-495 ◽  
pp. 1326-1331
Author(s):  
Bao Wei Song ◽  
Wen Long Tian ◽  
Zhao Yong Mao

Underwater gliders are a class of Autonomous Underwater Vehicles (AUVs) that offer many advantages over traditional AUVs. Previous research has mainly focused on underwater gliders with fixed wings. This paper studied a novel underwater glider whose wings can pitch independently about its installed shaft, called Movable-Winged Underwater Glider (MWUG). A 6-DOF model of dynamics for MWUG was developed based on Newton’s law and Euler’s equation, gravity, buoyancy, added mass forces and hydrodynamic forces considered. Longitudinal motion simulations were conducted to clarify the motion characteristics of MWUG. Results of the simulations indicated that compared to fix-winged gliders, MWUGs show a smaller glide angle and attack angle, higher glide speed and efficiency


2014 ◽  
Vol 48 (6) ◽  
pp. 112-124 ◽  
Author(s):  
Shilin Peng ◽  
Canjun Yang ◽  
Shuangshuang Fan ◽  
Shaoyong Zhang ◽  
Pinfu Wang ◽  
...  

AbstractThe development of a novel type of hybrid underwater glider that combines the advantages of buoyancy-driven gliders and propeller-driven autonomous underwater vehicles has recently received considerable interest. However, few studies have considered a hybrid glider with docking capability, which would expand the glider's applications. This study presents a hybrid glider with a rotatable thruster for realizing underwater docking. A tailored dynamic model of the hybrid glider is derived, and the motion performance is evaluated by simulations and experimental tests. A comparison between the experiments and simulations shows that results are in agreement, thus indicating the feasibility of the dynamic model and the accuracy of the hydrodynamic coefficients. In addition, the hybrid glider open-loop docking tests validate the feasibility of the mechanical docking system. Moreover, the experimental tests also validate the glider's different functions and indicate that the hybrid glider with rotatable thruster has high maneuverability even at low speeds. Thus, this type of hybrid glider can be used for underwater docking.


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