By Xiang Linhao, CCS Science & Technology Innovation and Test Center

In order to meet the significantly increasing demand for remote ship survey from customers and to assure remote survey quality and efficiency, China classification society (CCS) utilized the 5G, Ad-Hoc Networks, wearable devices, UAVs (unmanned aerial vehicles) and other new technologies and new equipment to develop key technologies for real-time annual ship remote survey. CCS proposed a series of solutions, including the “5G + Ad-Hoc Networks” ship cabin network communication, the remote survey data acquisition based on multiple terminals including “smart phones/wearable devices/UAVs” and the scenario type remote survey platform based on ship-shore coordination. With the characteristic of “scenario type survey”, “one cloud, two terminals” were established to fulfill the survey coordination of ship and shore terminals and the 4 technologies, i.e. “network communications, acquisition terminal, interaction platform, and ship-shore coordination”. CCS organized and carried out the instructive document preparation and optimization upgrading for remote survey, and regulated the operation and execution of remote survey. It also carried out remote survey trials and demonstrations as well as application promotion for the industry, and has obtained favorable social benefits and economic efficiency.

I. Remote ship survey service system

1. Preparation and optimization of instructive documents for remote survey

Since 2018, based on the development needs of ship survey, CCS has begun to carry out remote survey and exploration, and issued the Guidelines for Remote Survey of Ships (2019) for ships engaged on international voyages in November 2019. The Guidelines was applicable for some temporary survey items for classification. In January 2022, on the basis of the practical application experience obtained in the real-time remote ship survey based on new technologies and new equipment, CCS issued the revised the Guidelines for Remote Survey of Ships (2022). The Guidelines specifies the principles, process and procedures of implementing remote ship survey, and defines the minimum requirements for adopting remote survey, so as to ensure that ship survey quality is not lowered due to the remote mode, and both the remote survey and on-board survey have the equal effectiveness.

For the remote survey of domestic ships and ocean-going fishing vessels, CCS issued the Interim Provisions on Remote Survey of Ships Operating in China and the Guidelines for Remote Survey of Ships (Trial).

2. Construct “3+1” remote ship survey service base

In January 2022, CCS officially put the remote ship survey service base into service. By establishing professional remote survey/approval teams, CCS provided more efficient centralized remote survey/review services to build the new pattern for “3+1” remote survey services. The remote survey service bases for classed ships were set up in CCS Zhejiang Branch, Shanghai Branch and Tianjin Branch each, which are responsible for the remote survey and review services of the ships classed by CCS. The remote survey service base for ocean-going trawlers was established in Qingdao Branch, and is responsible for the remote survey of CCS ocean-going fishing vessels. CCS further optimized and upgraded its survey service ability to provide customers with efficient and convenient survey services all the time.

II. Key technologies of 5G+ remote ship survey

1. Network communication technology for “5G + Ad-Hoc Networks” ship cabin

Considering the scenario and task characteristics, including a large quantity of cabins, the complex structure, the closed space, metal interference and convenient net laying, CCS proposed the “5G + Ad-Hoc Networks” communication technology scheme for the places such as ship cabins and cargo tanks to cover the whole ship survey area with 5G network signals through the technology of Ad-Hoc Networks. In this technical scheme, through the rapid deployment of portable Ad-Hoc Networks equipment, the flexible arrangement under complex ship environment can be realized. Leveraging the characteristics of 5G network data transmission, including high speed, low delay and large volume, the network communication conditions can meet the remote ship survey needs, i.e. a large bandwidth, high immunity and strong transmission stability.

2. Remote survey data acquisition technologies based on “smart phones/wearable devices/UAVs”

Through intelligent equipment, CCS fulfills the HD audio/video data acquisition, ensures the acquired image stability during real-time survey, reduces the effects of environmental noises, and assures voice connection quality. Additionally, CCS has made full use of the high-altitude accessibility and flexible mobility of UAVs. For inaccessible structures, CCS proposed the solutions of the real-time remote close-up survey using 5G+ UAVs. The ultra-HD images of hulls that are acquired by UAVs are transmitted to the remote survey center in a real-time manner for ship surveyors to master the entire structural status of the hull, which solves the problems in the scaffold, aerial cages and other traditional structure approaching measures, such as the high costs, low efficiency, high hazards and high limitation, and provides safe, efficient and economic fulfillment methods for ship survey.

Figure 1 Wearable devices (AR intelligent glasses)

Figure 2 UAV-acquired image of the hull structure at the cargo oil tank is transmitted to the onshore command center in real time.

3. Scenario type remote survey platform based on ship-shore coordination

In the remote survey mode, with the assistance of the crew, ship surveyors use the audio and video communication technologies to carry out survey by remote witness. In order to assure the implementation quality of remote survey, and improve the collaborative execution efficiency of both ship party and onshore party in the remote survey, CCS proposed the scenario type remote survey mode, and developed the scenario type remote ship survey platform supporting three survey modes, i.e. “on-line”, “off-line” and “ship/shore contactless” survey modes. Ship surveyors and the crew members can select proper modes based on survey item requirements to improve survey efficiency.

III. Promotion and application of 5G+ remote ship survey

Since 2021, CCS has implemented the promotion and application of 5G+ remote ship survey for international ships, ocean-going fishing vessels and ships engaged on domestic voyages. The survey types include damage, repair, extension, document verification and other additional survey as well as annual survey.

Figure 3 Working scenario of remote survey by ship surveyor

Figure 4 Remote ship survey implemented by ship surveyor

IV. Development of remote ship survey based on data driving

With the development of digital and intelligent technologies, remote survey will develop from the mode of “remote witness” implemented through audio and video to the mode of “remote ship survey based on data driving” implemented by ship status data, transform from the experience-driven survey to the data-driven digital survey, and change from the regular survey to condition-based survey.

For the remote ship survey based on data driving, the data acquisition range and assessment data quality shall be considered to establish the standards of verifying data security, reliability and accuracy and to establish the ship survey models based on data analysis and AI algorithm.

CCS is carrying out the technological study on the aided artificial intelligent decision-making represented by the image recognition technology, the mechanical ship equipment condition-based survey based on the digital twin as well as the digital ship survey based on data driving, so as to better help the industry realize digital transformation and upgrading.