Explorer AUV

Explorer (Tan Suo Zhe, 探索者) Autonomous underwater vehicle (AUV) is a Chinese AUV developed in the People's Republic of China (PRC), first entering service in November 1994, and it should not be confused with another two Anglo-American AUVs that share the same name: the American Autonomous Benthic Explorer AUV (ABE) built by Woods Hole Oceanographic Institution, and the British Columbia-based International Submarine Engineering built Canadian Explorer AUV, which is based on its earlier ARCS AUV. Explore AUV is the first member of a series of Chinese AUVs later developed, and all of which are based on Explorer AUV.

Explorer AUV is one of the projects of 863-512 subprogram of the 863 Program in PRC, developed by a joint team of research and educational establishments including the 702nd Research Institute(中国船舶重工集团公司第702研究所) of China Shipbuilding Industry Corporation (CSIC), Shenyang Institute of Automation(沈阳自动化所) of Chinese Academy of Science, Shipbuilding Engineering Institute(船舶工程学院) of Harbin Engineering University (HEU), Institute of Underwater Engineering (水下工程研究所) of Shanghai Jiao Tong University (SHJTU), and other establishments totaling over a dozen. Mr. Feng Xisheng (封锡盛), a professor of Shipbuilding Engineering Institute of HEU was named at the general designer of Explorer AUV, while Mr. Xu Huangnan (徐芑南), a professor of School of Naval Architecture, Ocean and Civil Engineering(船舶与海洋工程学院) of SHJTU and the general designer of 8A4 class ROUVs, was named as the deputy general designer of Explorer AUV. Explorer AUV is the first AUV of PRC.

The brain of Explorer AUV consists of three computers, central control computer, positioning computer, and imagery computer. In addition to controlling the interface tracing the traveling path and the interface controlling the surveillance of the system, the central control computer also controls the interface controlling remotely operated module so that in addition to being able to operate as an AUV, the Explorer AUV can also be operated as a remotely operated underwater vehicle (ROUV). To accurately provide the positional parameters of the Explore AUV in the water such as pitch, row, yaw, depth, distance and location, the navigational system of the Explorer AUV utilizes a number of methodologies, including GPS, Doppler Velocity Measurement, directional gyro, short baseline positioning, ultra short baseline positioning, visual tracking and fluxgate compass. Information provided by these subsystems are fed and processed by the navigational computer on board. The compressed underwater television images are handled by the imagery computer. These on board electronics are powered by the main propulsion system consisted of lead – acid batteries with 120 V direct current, which is converted to 220 V alternate current to power the electronic equipment.

Communication system of Explorer AUV consists of surface communication subsystem and underwater communication subsystem, and the two are linked via acoustic communication module, which passed the information received from underwater communication computer and pass it on the central computer. The central control computer analyzes this information, including sending the compressed television imagery signals to imagery computer, which in turn, convert the information to display the image on the screen. The communication between the central control computer and positioning computer is achieved via RS-232 interface, while GPS information is received from the positioning computer via EIA-422 interface. In addition to sending the information to control the AUV, the central computer is also designed to communicate and interface the operating console on the mother ship when needed. The underwater communication system of Explorer AUV consists of two major components, the sonar controlling module and communication computer (via CPU). The sonar controlling module is tasked to control acoustic communication module, Doppler sonar, side-looking sonar, and other sonars, while communication computer is tasked to act as an interface between various onboard subsystems. @ [http://ieeexplore.ieee.org/xpl/RecentCon.jsp?punumber=4054 OCEANS '95. MTS/IEEE. Challenges of Our Changing Global Environment. Conference]

The sonar control module is also tasked to process the imagery data, compress the data, and communicate with the communication computer. Numerous sensors were installed on board Explorer AUV to provide the necessary information for the AUV to operate, and these environmental subsystems consisted of underwater cameras and sonar. Information gathered is recorded on board the AUV while is also passed to the operator console on the mother ship at the same time, and the camera is capable of store 250 high resolution photos. The information gathered for navigation is also used to control the AUV, and extensive built-in-diagnostic system can automatically fix minor problems, and alert the mother ship of major mishaps that cannot be fixed automatically, while directing the AUV to ascend to surface at the same time. The success of Explorer AUV provide the foundation for Chinese cooperation with Russia to jointly develop the next Chinese AUV, the WZODA AUV.

Specifications:
 * Length: 4.4 meter
 * Width: 0.8 meter
 * Height: 1.5 meter
 * Weight: 2.2 ton
 * Speed: > 4 kt
 * Side-traveling speed: > 1 kt
 * Diving speed: > 0.5 kt
 * Maximum operating depth: 1 km
 * Propulsion: Electrically powered propellers
 * Power: lead – acid batteries

WZODA AUV
Just like its predecessor Explorer AUV, WZODA AUV is also part of the 863 Program, and it is jointly developed by Russia and several Chinese establishments including 702nd Research Institute (702nd Institute) and Shenyang Institute of Automation (SIoA), the developers of Explorer AUV. The general design follows that of earlier Explorer AUV, with many design changes to achieve the new depth requirement, which is 6000 meter. New technologies and design features adopted by 702nd Institute and agreed by Russian partners included the contra-rotating tunnel thrusters, which provides advantage for the AUV to climb underwater slopes. After a single unit was completed, the joint Sino-Russo team moved on the next design, CR-01 AUV.

CR-01 AUV
CR-01 AUV is the successor of WZODA AUV, which is also developed by the same developers, the joint Sino-Russo team that included the Chinese 702nd Institute and SIoA. CR-01 can dive to the same depth of its predecessor WZODA AUV, but with better positioning accuracy, thanks to GPS assisted navigation system incorporated. CR-01 has multiple microprocessors and reprogrammable, and in addition to be autonomous, it can also be remotely piloted via an eight-channel data link. The black box of CR-01 is based on that of aircraft, and in emergency situations such as lost of control, CR-01 would automatically surface and release markers, light and radio signals for easy salvage. Specifications:
 * Length: 4.374 m
 * Width: 0.8 m
 * Draft: 0.93 m
 * Weight: 1305.15 kg
 * Maximum depth: 6000 m
 * Maximum speed: 2 kt
 * Endurance: 10 hr
 * Positioning accuracy: 10 to 15 m

CR-01A AUV
CR-01A AUV is the development of CR-01 AUV. After successful deployments, it was recommended that CR-01 should be modified to solve the shortcomings exposed during its usage. After extensive refit that lasted more than one and half a year, it re-entered service as CR-01A. The external dimensions are general similar to that of its predecessor CR-01, but CR-02 can also perform salvage functions, with detection ability to penetrate mud layer up to 50 meters thick. Due to the success of CR-01 series AUV, its general designer Mr. Feng Xisheng (封锡盛, Dec 17, 1941——) was promoted to academician of Chinese Academy of Sciences in 1999.

CR-02 AUV
CR-02 is the development of CR-01A, and it has been deployed in oceanic mineral survey. In addition to the survey sonar, a total of eight miniature obstacle avoidance sonars are installed on CR-02 AUV. Specifications:
 * Length: 4.5 m
 * Diameter: 0.8 m
 * Weight: 1.5 t
 * Speed: 2.3 kt
 * Endurance: 25 hr
 * Depth: 6000 m
 * Power: silver-zinc battery
 * Photographic capability: 3000 photos
 * Recording capability: > 4 hr continuously
 * Obstacle avoidance sonar range: 60 m
 * Obstacle avoidance sonar accuracy: 1%
 * Survey sonar range: 12 km
 * Survey sonar accuracy: better than 20 m
 * Bottom penetration: 50 m (soft mud)

Submerged Dragon 1
Submerged Dragon 1 (Qian Long Yi Hao or Qianlong Yi Hao 潜龙一号 in Chinese) AUV is a development of CR-02 AUV, with SIoA as the primary contractor. The most significant improvement of Submerged Dragon 1 AUV over its predecessors is that all previous Chinese AUV could not be directly retrieved by the mother ship. All previous AUVs can only be released from their mother ships, but not be retrieved. To recover AUV of earlier designs, small boats carrying the crew must be first released from the mother ship to approach the surfaced AUV, and then crew had to connect the recovery attachment to the AUV, and only such operations are successful completed, then the AUV could be retrieved by the mother ship. Such requirement not only increased cost, but has also limited the efficiency because such recovery operation can only be performed under clam sea. Submerged Dragon 1 solved this problem by incorporating automated recovery system on the mother ship so that AUV can be directly retrieved. Submerged Dragon 1 AUV is equipped with obstacle avoidance sonar, high resolution side scan sonar, and other scientific equipment. Specifications:
 * Length: 4.6 m
 * Diameter: 0.8 m
 * Weight: 1.5 t
 * Max depth: 6000 m
 * Max speed: 2 kt
 * Endurance: 24 hr
 * Photographic capability: 3000 photos
 * Obstacle avoidance sonar range: 100 m
 * Side scan sonar range: 2 x 350 m
 * Bottom penetration: 50 m (soft mud)
 * Sea state: ≤ 4

Arctic ARV
Arctic (Bei Ji or Beiji 北极 in Chinese) ARV (Autonomous/Remotely operated Vehicle) is an AUV developed by SIoA, based on the experienced gained from other Chinese designs of AUV. Unlike previous Chinese AUVs that are fully autonomous, Arctic ARV can be operated in both fully autonomous or remotely piloted mode. The fully autonomous mode is used for large area scan, while remotely piloted mode is used for small area of a particular spot when needed. Remotely operated mode is achieved via fiber optic cable connection, and Arctic ARV can hover over particular spot if required. Arctic ARV (北极 ARV) has been deployed on Xuě Lóng and used in arctic explorations numerous times.

Unlike earlier Chinese AUVs all of which adopted a cylindrical body, Arctic ARV is box shaped, with draft greater than width, and there are tunnel thrusters at both ends of the ARV for better maneuverability. The main propulsion comes from a pair of ducted propeller thrusters with one mounted on each side. The composite buoyancy material is developed by Marine Chemical Research Institute (海洋化工研究院有限公司), of China Haohua Chemical Group Co. Ltd (中国昊华化工集团股份有限公司). Specifications:
 * Weight: 350 kg
 * Range: up to 3 km
 * Hovering depth: 100 m