Numerical simulation based variable speed control strategy for bionic undulating fins
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摘要: 仿生波动鳍机器人具有独特的水动力性能。文中通过数值模拟的方式对波动鳍加、减速过程的水动力响应进行探究, 揭示了加、减速阶段推进力与控制频率的关系。结果表明, 在刚步入高频阶段时, 低频阶段产生的涡旋与新产生的涡旋融合在一起, 导致推力高于正常值, 可通过适当增大频率进行控制。而刚步入低频阶段时, 当频率降幅较小时, 涡旋来不及脱落, 产生长时间的不规则的较高推力, 可适当降低频率梯度以减小这种影响。当降幅过大时, 效果会明显减弱。这项研究将为波动鳍机器人的变速时的精确控制提供支持, 提高控制系统稳定性。Abstract: The bionic undulating fin robot has unique hydrodynamic properties. This paper investigates the hydrodynamics of the undulating fin during frequency change through numerical simulation, revealing the relationship between the propulsive force and the control frequency during the acceleration and deceleration phases. The results show that when just stepping into the high-frequency stage, the vortices generated in the low-frequency stage merge with the newly generated vortices, resulting in a higher-than-normal propulsive force, which can be controlled by appropriately increasing the frequency. When just stepping into the low-frequency phase, when the frequency drop is small, the vortices come off too late, producing a long period of irregular higher thrust, and the frequency gradient can be appropriately reduced to minimise this effect. This effect is significantly reduced when the drop is too large. This research will provide support for precise control of undulating fin robots when shifting speeds and improve control system stability.
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Key words:
- bionic undulating fins /
- numerical simulation /
- variable-speed propulsion /
- vortices
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表 1 波动鳍的关键参数
Table 1. Key parameters of fluctuating fins
参数 数值 长度/L 1000 mm宽度/B 200 mm 最大摆角/θmax 90° 厚度/b 10 mm 相位差/φ 90° 摆幅/H 100 mm 波数/Wn 2 波长/λ 500 mm 频率/f 0.25 Hz~1 Hz 表 2 网格无关性验证
Table 2. Verification of grid-independence
网格尺寸/mm 鳍面网格 内流域网格 外流域网格 精细网格 5 50 100 中等网格 10 50 100 粗大网格 15 50 100 表 3 方案分组情况
Table 3. Grouping of the programmes
组别 初始频率/Hz 目标频率/Hz 加速阶段A组 0.25 0.5 0.75 1.0 加速阶段B组 0.25 1.0 0.5 0.75 减速阶段 1.0 0.25 0.5 0.75 -
[1] 王文谦, 马鹏磊, 李广浩, 等. 仿生机器鱼步态控制及闭环运动控制方法综述[J]. 中国舰船研究, 2024, 19(1): 29-45.WANG W Q, MA P L, LI G H, et al. Review of gait control and closed-loop motion control methods for bionic robotic fish[J]. Chinese Journal of Ship Research, 2024, 19(1): 29-45. [2] DONG H, WU Z, ZHANG P, et al. Separate control strategy for a biomimetic gliding robotic fish[J]. IEEE/ASME Transactions on Mechatronics, 2021, 27(5): 2535-44. [3] SHAO H, DONG B, ZHENG C, et al. Thrust improvement of a biomimetic robotic fish by using a deformable caudal fin[J]. Biomimetics, 2022, 7(3): 12. [4] WANG M, WANG K, ZHAO Q, et al. LQR Control and Optimization for Trajectory Tracking of Biomimetic Robotic Fish Based on Unreal Engine[J]. Biomimetics, 2023, 8(2): 17. [5] CAO Y, XIE Y, HE Y, et al. Bioinspired central pattern generator and TS fuzzy neural network-based control of a robotic manta for depth and heading tracking[J]. Journal of Marine Science and Engineering, 2022, 10(6): 758. doi: 10.3390/jmse10060758 [6] HAO Y, CAO Y, CAO Y, et al. Course control of a manta robot based on amplitude and phase differences[J]. Journal of Marine Science and Engineering, 2022, 10(2): 285. doi: 10.3390/jmse10020285 [7] WANG M, ZHANG Y, YU J. An SNN-CPG hybrid locomotion control for biomimetic robotic fish[J]. Journal of Intelligent & Robotic Systems, 2022, 105(2): 45. [8] CHEN L, HU Q, ZHANG H, et al. Research on underwater motion modeling and closed-loop control of bionic undulating fin robot[J]. Ocean Engineering, 2024, 299: 117400. doi: 10.1016/j.oceaneng.2024.117400 [9] LE T-L, DAT P T. A Computational Fluid Dynamics Study of Modeling and Hydrodynamic Characteristics of a Bionic Undulating Fin[J]. International Journal of Mechanical Engineering, 2022, 7(4): 949 [10] HAN P, LAUDER G V, DONG H. Hydrodynamics of median-fin interactions in fish-like locomotion: Effects of fin shape and movement[J]. Physics of Fluids, 2020, 32(1): 011902. [11] CHEN L, BI S, CAI Y, et al. Design and hydrodynamic experiment research on novel biomimetic pectoral fins of a ray-inspired robotic fish[J]. Machines, 2022, 10(8): 606. doi: 10.3390/machines10080606 [12] HU Q-Q, YU Y-L. The hydrodynamic effects of undulating patterns on propulsion and braking performances of long-based fin[J]. AIP Advances, 2022, 12(3): 035319 doi: 10.1063/5.0083912 [13] REN K, YU J. Amplitude of undulating fin in the vicinity of a wall: Influence of unsteady wall effect on marine propulsion[J]. Ocean Engineering, 2022, 249: 110987. doi: 10.1016/j.oceaneng.2022.110987 [14] PANG S, QIN F, SHANG W, et al. Optimized design and investigation about propulsion of bionic Tandem undulating fins I: Effect of phase difference[J]. Ocean Engineering, 2021, 239: 109842. doi: 10.1016/j.oceaneng.2021.109842 [15] XIA M, WANG H, YIN Q, et al. Design and mechanics of a composite wave-driven soft robotic fin for biomimetic amphibious robot[J]. Journal of Bionic Engineering, 2023, 20(3): 934-952. doi: 10.1007/s42235-022-00328-4 [16] SHI X, CHEN Z, ZHANG T, et al. Hydrodynamic performance of a biomimetic undulating fin robot under different water conditions[J]. Ocean Engineering, 2023, 288: 116068. doi: 10.1016/j.oceaneng.2023.116068 [17] DAS A K, SINGH R K, GUPTA N, et al. Comparative study using renormalized group k-ɛ, realizable k-ɛ, and standard k-ɛ models for flow through S-shaped diffuser[J]. International Journal on Interactive Design and Manufacturing (IJIDeM), 2024, 18(5): 3397-3411. doi: 10.1007/s12008-023-01609-w -