Currently, NB-IoT hot, get the three major carriers of high concern. However, at the same time, other Internet of Things standards such as eMTC and LoRa also showed rapid development. Which kind of Internet of Things technology is more mature? What kind of technology should operators focus on? These issues aroused much controversy from all sides. In response, the reporter recently interviewed Datang mobile mobile communications division chief engineer Chen Bo. It is reported that as a leading communications equipment manufacturers, Datang Mobile has the unique pipeline technology capabilities, developed from the core network to the access network, as well as matching the major chip manufacturers end-to-end pipeline network. Not only that, Datang Mobile also launched the Internet of Things security cloud platform, effectively protect the security of data transmission, to meet the security needs of private and general communication systems. In the IoT terminal layout, Datang Mobile introduced a variety of industry application terminals through cooperation and self research, and has a complete end-to-end IoT solution. Three major technologies are the mainstream, each has its advantages and disadvantages "All three technologies belong to the Internet of Things mainstream technology." Chen Bo said. The NB-IoT is based on the LTE band and has a bandwidth of only 200kHz, making it ideal for wide area networks, low-power, and low-speed connections. As a major evolutionary route for the Presence of the Internet of Things (IoT) in the cellular Internet of Things, mainstream carriers around the world and various vertical applications are more optimistic about this approach. eMTC, named Enhanced Machine Communication, is born with LTE descent and has a bandwidth of 1.4MHz, enabling direct software upgrades on LTE systems, as well as good mobility and voice capabilities. But its cost is higher than NB-IoT, can be considered as an important complement to the cellular Internet of things. LoRa belongs to the Internet of Things (IoT) technology in the unlicensed band and is more suitable for deployment in small-area networks. "Each of these three technologies has its own advantages and can bring its own advantages into full play by combining different applications." For example, applications in most scenarios are based on low-rate, wide coverage and low power consumption, such as environmental monitoring, intelligent parking, smart meter reading, etc., which can be solved by NB-IoT. In a small part, medium rate service Even voice service scenarios, such as smartwatch, vehicle mobility management, etc., need to be addressed by using eMTC. LoRa, which is mainly hosted in unlicensed bands and is limited by wireless coverage, has some short-range coverage and private network scenarios In the same farm, for example, data processing, operators can solve through LoRa. In terms of standard and trial commercial processes, how are each of the three technologies progressing and which ones will mature faster? In this regard, Chen Bo said that in 2017 already the first commercial year of NB-IoT technology. Although NB-IoT's industrial chain has advanced Commercial model has been clear, but limited by the industry chain and costs, the real boom is expected to take 1 to 2 years. However, once NB-IoT module prices due to mass production down to the expected level, NB-IoT technology will be greatly promoted. On the other hand, eMTC supports "VoLTE + Mobility + Positioning Capability" to flexibly meet the needs of various business scenarios; moreover, the cost and time for eMTC to operate in the 900 MHz band will be far less than NB-IoT. From the perspective of standards and industry chain, eMTC has the advantages of first mover advantage, but from the perspective of its development potential and the characteristics of the Internet of things, NB-IoT will have more space. While LoRa has been commercially available for many years without technical bottlenecks, it will still be one-third of the world in the short term. It was suggested that the current popular NB-IoT technology interoperability problems, LoRa will become the mainstream. This view is more popular abroad. In response, Chen Bo expressed different understandings. He mentioned that NB-IoT is suitable for a wide range of deployment of communications network applications, while LoRa is relatively more suitable for use in local scenarios. For example, in a car factory, LoRa technology can be used to track the production environment and production line of a car. However, once the car leaves the factory to become a shared car, LoRa can not get away with, but can use NB-IoT technology to transmit through the operator's wide area network data. In the future, NB-IoT and LoRa will have a large number of applications in different application scenarios and will coexist in the short term. eMTC has received the support of many foreign FDD operators. The FDD standard eMTC technology does not have bottlenecks in the network and industry. In China, eMTC has not been commercial. In this regard, Chen Bo explained that a technology is commercially available on the one hand, depending on its end-to-end maturity, Qualcomm and other foreign companies have launched support FDD eMTC chip, but TDD's eMTC chip business is relatively slow progress. Huawei is mainly focused on NB-IoT. On the other hand, chip cost and IoT application scenarios are also one of the important considerations in the deployment of vertical industries. The cost of eMTC is higher than that of NB-IoT at this stage, which is why its business is slow. Domestic NB-IoT technology is developing rapidly Recently, China Telecom held an Internet of Things conference to announce the NB-IoT and Cat1 module chip subsidy policies and built the largest NB-IoT commercial network in the world. China Unicom released in Shanghai NB-IoT commercial trial strategy, massive. Although China Mobile has not confirmed the key push NB-IoT or eMTC, but at this stage, China Mobile NB-IoT hottest in the country. From the perspective of equipment manufacturers, the current three major carriers of different Internet of Things technology support attitude and subsidies? What is the difference? Chen Bo said that China Telecom, China Unicom made it clear commercial first NB-IoT, after the commercial eMTC; China Mobile Then the two technologies for parallel testing, the first commercial NB-IoT or eMTC pending. Specifically, China Telecom is about to complete 800MHz LTE whole network tillage, when its 4G network coverage can achieve CDMA coverage standards. On May 17, 2017, China Telecom announced the completion of the commercial NB-IoT network. This is the world's most widely deployed narrowband Internet of Things with a synchronized upgrade of 310,000 base stations across the entire network. Not only has China led the global trend for the development of the Internet of Things, but it has also provided commercial experience for other operators worldwide to deploy NB-IoT. China Unicom to consider simultaneously promote NB-IoT and eMTC, NB-IoT frequency selection, China Unicom will promote dual-band 900MHz and 1800MHz networking approach. This decision is based on a number of considerations, including consideration of the pressure on the resumption of 900MHz frequency band of China Unicom and consideration of the support for the core industries in the current market. China Unicom is targeting business needs in the IoT coverage and strives for the early layout of cities with potential demand for the full coverage of first-tier cities, the provincial capitals and key cities with industry focus. On the core network, China Unicom will focus on building an independent NB-IoT virtualized core network to achieve smooth core network upgrade. From China Mobile's point of view, eMTC supports TDD access, which means that China Mobile can start eMTC-based commercialization before the 900MHz resumption permit is approved. It is undeniable
For retracting anchor and chain machinery on board. Using human, steam engine, electric motor and hydraulic motor as power. Usually installed on the first floor of the ship. The trend of its development is to achieve operation, anchor mooring, mooring and automatic mooring for a unit. According to the driving form can be divided into: manual, electric, hydraulic.
Photo of our Anchor Windlass:
Anchor windlass requirements
The windlass is the anchor and the anchor of the machinery, also used as mooring. There are some requirements for the anchor machine in our country:
1), the anchor should be independent of the original drive
2), the anchor rating should be not less than 41.68d2N (4.25d2kgf), when the d<25mm rating should not be less than 36.8d2N (3.75d2dgf), D for the chain diameter, the unit is mm. The average speed should be no less than 9m/min when the rated tension is used.
3) anchor machine under rated tension and speed should be continuous 30min, and should be continuous work in not less than 1.5 times of the rated tension overload tension under 2min; in addition to anchor machine should be equipped with overload protection device, overload can be transferred to the medium speed operation.
4), anchor chain sprocket on the brake should be reliable, 45 per cent of the brake chain fracture load pull (when freedom anchor at speeds of up to 5~7.5m/s can still stopped on the outskirts of falling chain); between the anchor machine chain wheel and axle load should be a clutch, brake and clutch manipulation is convenient and reliable; anchor machine operation should be along the reverse rotation and smoothly and rapidly.
5) anchor machine installation shall ensure the cable leads three eyes (hawsepipe, chain, sprocket and line).
There are two kinds of horizontal and vertical anchor machine, the general use of the ship on the horizontal anchor. And vertical anchor machine also called anchor capstan (for) and part of its power in below deck, to save the deck area and warships on the vertical anchor machine. Recent large ships, because the anchor machine size is too large, the bow deck to accommodate and operation of adverse, therefore, using vertical anchor machine.
Classification of anchor machine
Type of anchor machine
Anchor machine is mainly by the base, a bracket, a chain wheel, brakes, sprocket, gear box, control system (manual windlasses except and other components, electric windlass motor and hydraulic windlass with hydraulic pump station.
The main specifications of the windlass include diameter of anchor chain, anchor nominal speed, rated load, support load, speed, power system etc..
Windlass in ship installation to ensure the chain and sprocket wrap angle is 117 - 120 degrees.
The type of anchor windlass can be divided into 12-- Phi Phi 120mm several kinds of specifications in accordance with the diameter of anchor chain.
According to the driving mechanism of energy points --- manual windlass, anchor steam machine, electric anchor machine (DC electric windlass, AC electric anchor machine) and hydraulic windlass (high pressure type anchor hydraulic machine, pressure type anchor hydraulic machine, pressure type anchor hydraulic machine.
- horizontal anchor machine, vertical anchor chain wheel machine according to the center line direction (winch)
According to the arrangement of the general (integral) type anchor machine, one side (independent) type anchor machine, the combined type of anchor machine
2, the characteristics of various types of anchor
A. manual anchor machine
The weight does not exceed 250kg of the anchor, according to the working conditions, if it can be suitable for use, you can configure the manual anchor. Manual anchor machine is only used in inland river small ship, it should prevent the handle from injuring people.
B. steam anchor machine
Steam windlass has been widely applied in the steam ship, currently used for large tankers. The firm structure, reliable work, no dangers caused by fire, but the steam engine efficiency low, huge structure, laying on the deck for a long pipeline heat loss, deck steam engine cylinder pressure is generally not more than 0.8MPa, operation management problems, in Yan Hanji day when the weather is cold, before use to fully warm engine, to discharge the residual water.
C. electric anchor machine
Electric anchor machine is currently the most widely used in the ship.
According to the power system of the ship, the electric anchor machine has DC motor and AC. DC motor speed control characteristics, high efficiency, but the high cost of the initial set, the brush should be regularly maintained.
AC motor speed adjustment performance is poor, usually only have a variable speed, depending on the pole or by the motor and the anchor of a set of speed reducer to get a number of speed grades. This set of gear reducer, due to the need of a large reduction ratio, and consider the transmission and the reliability of the work of the anchor and other issues, the structure is more complex, the weight and size of the area occupied by the larger deck.
Reducer transmission device often used spherical worm and worm gear transmission, spur gear transmission, planetary gear transmission and other transmission mode. Generally speaking, the planetary gear reduction gear transmission mechanism of light weight, small size, high transmission efficiency, maintenance is simple, so the current application more.
D. hydraulic anchor machine
Hydraulic anchor machine is mainly rely on hydraulic device to carry out and control the action of the anchor. Hydraulic anchor machine because of its hydraulic energy from the motor driven oil pump device, also known as electric hydraulic anchor. It has the following characteristics:
(1) with a good speed control performance of the DC motor.
(2) usually uses the low speed high torque hydraulic motor, low speed, large output torque, no longer need to set up a huge mechanical reducer, can directly drive a chain wheel.
(3) hydraulic drive with self made dynamic performance, work safety and reliability.
(4) compact structure, small weight and size of unit power. .
(5) easy to operate, maintenance is simple.
(6) easy to realize remote control and automation
Anchor Windlass Marine Anchor Windlass,Ship Anchor Windlass,High Quality Anchor Windlass,Electric Anchor Windlass Unisite Group Ltd. , https://www.shipsparts.nl
Three major technologies are the mainstream, each has its advantages and disadvantages