Yang Weng

The use of autonomous underwater vehicles (AUVs) is highly desirable for collecting data from seafloor sensor platforms within a close range. With the recent innovations in underwater wireless optical communication (UWOC) for deep-sea exploration, UWOC could be used in conjunction with AUVs for high-speed data uploads near the surface. In addition to absorption and scattering effects, UWOC undergoes scintillation induced by temperature- and salinity-related turbulence. However, studies on scinti

With the developments in underwater wireless optical communication (UWOC) technology, UWOC can be used in conjunction with autonomous underwater vehicles (AUVs) for high-speed data sharing among the vehicle formation during underwater exploration. A beam alignment problem arises during communication due to the transmission range, external disturbances and noise, and uncertainties in the AUV dynamic model. In this article, we propose an acoustic navigation method to guide the alignment process wi

This letter discusses pointing errors in underwater optical communication caused by environmental disturbances and uncertainties that cannot be well measured and controlled in previous optical alignment methods. The bore-sight and jitter effects are identified in the motion model of the mobile platform. We propose to use the sensor suite that includes a pressure sensor, super short baseline (SSBL) acoustic system, Doppler velocity log (DVL), and fiber optic gyro (FOG) to observe and estimate poi

Mechanically flexible photonic devices are critical components of novel bio-integrated optoelectronic and high-end wearable systems, in which thermo-optic switches (TOSs) as optical signal control devices are crucial. In this paper, flexible titanium oxide (TiO₂) TOSs based on a Mach-Zehnder interferometer (MZI) structure were demonstrated around 1310 nm for, it is believed, the first time. The insertion loss of flexible passive TiO₂ 2 × 2 multi-mode interferometers (MMIs)

Time synchronization in autonomous underwater vehicle (AUV) formations is significant for joint underwater survey tasks. Maintaining a common time scale can improve the efficiency of cooperative localization, formation control, and data fusion. Instead of using atomic clocks to limit the offset and drift of time, we propose an acoustic and optical cooperative method to synchronize the clocks. Acoustic communication is used to guide the establishment of the optical link and to share the states of

• Using AUVs as commuter platforms to shuttle between seafloor stations and the surface for near-real-time data collection. • The proposed tracking method establishes underwater optical communication links in three-dimensional space. • A reinforcement learning-based controller to control the commuter AUV, reducing pointing errors and energy consumption. • This method maintains pointing error of distance within 1.10 m in actual machine experiments. • This near-real-time data retrieval solution al

Abstract High‐speed underwater wireless optical communication holds immense promise in ocean monitoring and surveys, providing crucial support for the real‐time sharing of observational data collected by autonomous underwater vehicles (AUVs). However, due to inaccurate target information and external interference in unknown environments, link alignment is challenging and needs to be addressed. In response to these challenges, we propose a reinforcement learning‐based alignment method to control

With the help of underwater wireless optical communication (UWOC) technology, autonomous underwater vehicles (AUVs) can share survey data at high speed during underwater exploration. Establishing a line-of-sight (LOS) link between AUVs and maintaining alignment is necessary for data transmission. We use acoustic navigation to guide two AUVs to maintain a specific relative position and direction for beam alignment. The relative motion and acoustic observation between two AUVs are modeled in this

As a kind of autonomous underwater vehicles (AUVs), underwater glider is gradually utilized in the long-term and large-scale observation. This paper considers underwater glider as a microstructure turbulence observation platform in terms of its low noise in the motion. On May 25th 2014, glider completed measurements in Thousand Island Lake. It proves that glider serves as a suitable observation platform based on the analysis of flight paths and sensors data of glider. Furthermore, the computed s

The underwater wireless optical communication (UWOC) technology provides a potential high data rate solution for information sharing between multiple autonomous underwater vehicles (AUVs). In order to deploy the UWOC system on mobile platforms, we propose to solve the optical beam alignment problem by maintaining the relative position and orientation of two AUVs. A reinforcement learning based alignment policy is transferred to the real world since it outperforms other baseline approaches and sh

Underwater wireless optical communication can be used between multiple autonomous underwater vehicles to enhance information sharing during ocean exploration. The quality of optical communication is affected by many marine environmental parameters, such as ocean currents, disturbances, and attenuation. This study proposes using a reinforcement learning algorithm and adding random parameters and thruster delay in the simulated environment to improve the stability of the link. The trained policy e

An AUV can be utilized to harvest data from sensor nodes on the seafloor by an optical link. This paper addresses issues that related the vehicle motion to the optical communication quality between the vehicle and the sensor node. Channel characterization of the optical communications is simulated by a Monte Carlo method. The Henyey-Greenstein model is used to compute the distribution of scattering angle of the node. After a large number of photons are tracked, an optical power map of light dist

Underwater laser communication has shown good performance in terms of rate, bandwidth and delay, and is a promising communication method for establishing internet of underwater things. In the past, all-optical pointing, acquisition and tracking (PAT) methods were used to establish laser links between underwater platforms. We propose a combined acousto-optical PAT method for link establishment in underwater laser communication to reduce the time consumed in the acquisition process and thus improv

Blood perfusion depends on blood flow and vessel in local tissue, which plays important role during hyperthermia. Laser speckle imaging technique was developed to obtain the regional blood flow distribution with high spatio-temporal resolution. Through LSI method, the velocity and diameter change of microvessels can be acquired simultaneously. In this paper, the spatiotemporal characteristics of local mesentery blood flow in anesthetized rats during thermal therapy (43°C, 45°C, 47°C, 49°C, 60min