Application of the hottest wireless communication

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The application of wireless communication technology in construction machinery

Abstract: This paper focuses on the analysis of several types of wireless communication technologies widely used in the field of construction machinery, and compares and summarizes the advantages and disadvantages of various types of communication technology through a large number of citations and combined with existing industrial application examples. According to the application of different projects and the corresponding hardware and software technology, the optimal combination of construction machinery and wireless communication products can be realized

0 introduction

in railway and port freight yards and construction and production sites, there are many cross operation of engineering machinery and equipment. Large outdoor engineering machinery is started frequently and the working environment is poor. The on-site control mode by operators has not met the needs of development. With the development of industrial production, based on the needs of the application of engineering machinery work information resources and production management, decision makers need to timely grasp the production status on site, conduct comprehensive analysis, make accurate, scientific and effective decisions, and command the production work on site. Today, almost all construction machinery and equipment can be remotely controlled through remote control transformation. Developing a general remote monitoring system platform can quickly and conveniently build a wireless data communication monitoring system that meets the needs of users, which will have a good application prospect

1 rapid development of wireless communication technology

lmds is a broadband wireless access technology gradually developed in recent years. It has the characteristics of large capacity, high bandwidth and two-way data transmission. Working in the 20GHz ~ 40GHz frequency band, it can realize the user access rate from thousands of bits per second to 25.6mbs, and has high reliability. Compared with the current common wired access methods ADSL, HFC and Ethernet access technologies, as well as common wireless access methods such as MMDS, satellite communication access technology and invisible optical fiber wireless system, LMDS is very suitable for user data intensive access environment and can fully meet various emerging broadband services. As a wireless access method, LMDS conforms to the development trend of high-speed network and broadband. Wire LMS sensor network (WSN) is the latest and most popular application in the field of wireless technology. Because of the new, there is no unified standard. At present, many research institutions and organizations around the world are developing technologies and specifications, and put forward different technical standards. ZigBee and Z wave are the most mature, basically forming two camps. ZigBee, which seeks to maximize its application field, is likely to fall into the information control and transmission fields such as industrial control and medical treatment due to its characteristics of short distance, low complexity, low power consumption, low data rate and low cost. The continuous emergence, maturity and application of similar cutting-edge technologies have led to a new pattern of construction machinery production and development. For example, the large-scale component hydraulic synchronous lifting technology in the construction and installation technology adopts flexible steel strand or rigid column load-bearing, elevator cluster, computer control, hydraulic synchronous lifting and other technologies combined with modern construction methods to lift tens of thousands of tons of components to a predetermined height after assembly on the ground. However, in most projects, the hydraulic lifter is located at a high altitude. If the local control has certain safety problems for the operators; Moreover, the high altitude environment and temperature climate conditions where the control system is located are not conducive to work, and it is very inconvenient to analyze and troubleshoot. The wireless remote control hydraulic synchronous lifting technology can smoothly lift the rigid legs and main beams of the gantry crane in place through the remote control of the central control room located 100m away, greatly improving the modern production quality

2 application of wireless communication technology in the field of construction machinery

2.1 Bluetooth technology in short-range wireless monitoring of road construction machinery

the current development direction of road construction machinery is to develop various intelligent road construction engineering equipment. Traditional condition monitoring, whether active or microcomputer automatic monitoring system, needs to transmit the measured signal value provided by each sensor to the microcomputer through the corresponding wired cable, Compare with the standard value of microprocessor memory. Due to the limitations of various working conditions, the airborne equipment should be as reliable and simple as possible, so that it can only simply process the signals monitored in the vibration compaction and paving leveling, and can not conduct a more comprehensive and systematic analysis, which may lead to false detection and missed detection of various potential failure hazards; On the other hand, the current operation management lacks a unified construction process mode. The quality of pavement and subgrade is completely determined by the proficiency of drivers. Without complete construction operation records, the construction progress and quality can not be well controlled. Bluetooth technology is based on low-cost short-range wireless connection, and the operating distance is usually 10cm ~ 10m. If the transmitting power is increased, the operating distance can reach 100m, which can fully meet the requirements of road construction machinery monitoring. Due to the unique anti-interference performance of Bluetooth technology, using a central control and monitoring unit in a work area can effectively monitor seven (point) devices to achieve the purpose of real-time monitoring. As an immature technology, Bluetooth has yet to be strictly tested in practice; Its communication rate is not very high, which may limit its promotion in other construction machinery. At present, the mainstream software and hardware platforms do not provide support for Bluetooth, which makes the application cost of Bluetooth higher and the popularization more difficult. A similar Z wave transmission rate is only 9.6kbps. Compared with ZigBee, even if we do not talk about 2.4G, it is undoubtedly a huge business opportunity. The 250kbps transmission rate in the Hz band is at least 40kbps in the 915MHz band (20kbps in the 868mhz band). Although WSN does not emphasize the transmission speed and transmission volume of data, it is not too low. Since Bluetooth chips have been mass produced for many years, and the volume and price of components have reached a high degree of maturity, ZigBee originally set to replace Bluetooth in the control field at a lower price, which makes it increasingly difficult to realize. Nowadays, ZigBee only grasps its own transmission distance and group advantages to seek the best use positioning

2.2 micro power communication technology in wireless remote control system of tower crane

as a practical wireless communication technology, micro power short-range wireless communication technology generally uses a single RF transceiver chip, a microcontroller and a small number of peripheral devices to form a special or general wireless communication module. NRF905 is a monolithic RF transceiver launched by Nordic company in Norway, which operates on three ism channels of 433/868/915 MHz. NRF905 provides a powerful frequency hopping mechanism, which can be applied to many special occasions

in Germany, almost all mobile cranes over 20t are equipped with proportional radio control system. Generally, the remote control device is also equipped with data feedback equipment. The transmitter can be equipped with a large flat LCD display to continuously report load, boom length, load torque, oil temperature, pressure and other important operating parameters to the crane driver. At present, tower cranes used in domestic construction engineering and other industries are mostly in the form of control room. Factors such as control room restriction, unclear vision, poor environment or improper command and cooperation can form accident hidden dangers. A large number of small and medium-sized construction enterprises in China use many tower cranes. Therefore, based on the control of the existing tower crane control room, combined with microcomputer control technology, a low-power, high anti-interference ability and high reliability tower crane wireless remote control system has been developed: how can the MSP430 ultra-low-power 16 bit microcontroller and wireless transceiver chip nrf90 do the best for the ordinary protection of the experimental machine? 5 as the core, the anti-interference ability of the system is improved by means of software coding and hardware decoding. The system transmitter adopts timing scanning and the receiver adopts memoryless output control mode, which not only ensures the safe operation reliability but also greatly improves the production efficiency. It can be widely used in general industrial remote control systems such as tower cranes

2.3 wireless data transmission technology in the field of military construction machinery

traditional wireless data transmission radio is applied to large SCADA remote control and telemetry systems, and is applicable to various point-to-point and point-to-multipoint wireless data transmission, such as industrial automation systems such as power load monitoring, data acquisition, railway signal monitoring, etc. Compared with GSM mobile communication, short wave communication has the characteristics of low transmission power, long transmission distance, rapid station building and good mobility. Its communication range radius can reach more than ten kilometers to tens of kilometers. It is one of the main radio communication modes of military engineering machinery

the remote monitoring of construction machinery operation can be realized by establishing wireless communication between the military construction machinery on-board short wave radio and the radio base station of the monitoring center. The remote monitoring system for military construction machinery is mainly composed of on-board condition monitoring module, wireless self-organization (non civil channel communication network composed of on-board short wave radio and radio base station of monitoring center) and remote monitoring center. The on-board status monitoring module mainly completes the functions of signal acquisition, signal analysis, status display, fault alarm and human-computer interaction: first, the collected mechanical status information is analyzed and displayed, and then the information is transmitted to the monitoring center through wireless self-organization, and the mechanical status is analyzed accordingly; In case of operation failure or instruction, the monitoring center will transmit relevant command information to the on-board condition monitoring module of construction machinery through the wireless network, and then the module will instruct the operator to perform corresponding actions

the cost of professional wireless data transmission radio groups is high, and the communication distance is limited to a certain extent (the farthest distance in the plain is 50km), and the communication effect is greatly affected by buildings and mountains. The system needs professional maintenance and management, and the overall construction and maintenance costs are very high, which is not convenient for popularization and application in the field of construction machinery. Although SCADA system has developed rapidly in recent years, with the growing maturity of GPRS and CDMA networks, the market of data transmission radio has declined

2.4 modern GPRS Technology in engineering vehicles

gprs communication makes full use of existing network resources to realize high-speed and large-capacity data transmission. The maximum high-speed data transmission can reach 160kbps. The communication link established with the data center sends and receives data from the user data equipment at any time, and the traffic is billed according to the number of data packets received and sent. It is permanent and has high real-time performance. In the construction machinery system, GPS and GIS are often used to combine the chassis suspension of the space satellite system with the electronic map, wireless communication network and computer vehicle management information system to realize vehicle positioning Tracking and vehicle management

pavement construction machinery includes loaders, mixing stations, dump trucks, pavers, road rollers, etc. the remote monitoring system of modern intelligent construction machinery (National 863 project) is composed of construction machinery groups such as excavators, GPS global positioning system, GPRS Remote Communication Research and pointing system, Internet, client cluster monitoring center system, portable data acquisition system and remote enterprise monitoring system. It collects the running state parameters, fault information and position parameters of the equipment by relying on various sensors and controllers installed on the single machine of the construction machinery, converts them into can bus data and sends them to the fixed address, and displays them on the LCD screen after the processor calculation and processing. If the corresponding normal state parameters in the database are exceeded, the fault alarm program will be started to remind the operator; At the same time, the combined GPS positioning information and other information are wirelessly sent to the GPRS network by the GPRS module, and reach the remote enterprise service center system through GGSN and SGSN, so as to realize the communication between the client and the remote monitoring server

compared with professional wireless data transmission stations, GPRS has poor real-time performance, because the current public system is a voice priority system. Once the call connection rate is low, it can

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