仿海豹胡须阵列检测水中运动目标尾流特征

为检测水中运动目标的尾流特征，获取运动目标运动轨迹方向、几何尺寸等参数信息，通过模仿海豹使用胡须探测猎物的机理，提出了一种仿海豹胡须的尾流探测方法。首先，用3D打印技术制作了与海豹胡须形态相似的胡须模型，并结合压阻元件等材料制作了可感知水中运动目标尾流的传感器阵列。其次，设计尾流检测实验方案，并对0.5、1.0、1.5 m/s的均匀来流及具有微小波动的非均匀流场情况进行仿真分析，获取不同流场情况下的尾流速度场分布，分析S₁₁的升力系数及频谱分布，并与理论计算得到的尾流漩涡脱落频率进行对比，验证实验方案的有效性。最后，在实验室条件下，采用该传感器阵列实现了对被测目标尾流特征的测量，并分析了仿海豹胡须夹角对尾流检测的影响。结果表明：在不同来流情况下，胡须模型升力系数波动较明显，经快速傅里叶变换获得的主频与尾流漩涡脱落频率理论值一致性较好；在尾流区内传感器探测尾流信号的平均电压值是非尾流区的3倍以上，由此可准确识别出尾流区和非尾流区。在此基础上，对平均电压值衰减的梯度方向进行分析，实现了对被测目标运动轨迹方向的估算。该传感器阵列测得尾流信号的最大响应频率接近数值仿真的主...

Detecting wake characteristics of moving targets in water by bio-inspired seal whisker array

To detect the wake characteristics of a moving target in water and obtain the information of the target such as trajectory direction and geometric, we proposed a wake detection method by imitating the mechanism of seals using beards to detect prey. First, a whisker model similar to the shape of seal whisker was fabricated with 3D printing technology. Combined with piezoresistive elements and other materials, a sensor array that can sense the wake of a moving target in the water was fabricated. Then, the experimental scheme of wake detection was designed, and simulation analysis was performed under uniform incoming flow of 0.5,1.0,1.5 m/s and non-uniform flow with slight fluctuations to obtain the wake velocity field distribution in different conditions. The lift coefficient and spectral distribution of S₁₁ were analyzed. The wake vortex shedding frequency obtained by theoretical calculation was compared to verify the validity of the experimental scheme. Finally, under laboratory conditions, the sensor array was used to measure the wake characteristics of a target, and the influence of the imitation seal whisker angle on the wake detection was analyzed. Results show that the lift coefficient of the whisker model fluctuated significantly under different incoming flow conditions, and the main frequency obtained by the fast Fourier transform was consistent with the theoretical value of the wake vortex shedding frequency. The average voltage value of the wake signal detected in the wake area was more than 3 times the average voltage value of the non-wake area, so that the wake area and the non-wake area could be accurately identified. On this basis, the gradient direction of the average voltage value attenuation was analyzed to estimate the trajectory direction of the measured target. The maximum response frequency of the wake signal measured by the sensor array was close to the main frequency of the numerical simulation. By inverting the response frequency, the diameter size of the measured target could be estimated. The seal whisker angle could affect the vortex-induced vibration of the sensor and increase the disturbance signal, but it had no significant effect on the estimation of the direction of the motion track and the estimation of the measured target size.