The combination of electro-hydraulic control technology and wireless communication technology can be widely used in engineering machinery and other fields, not only improve the degree of automation and maneuverability of the construction machinery, but also improve the working environment angle straightener of the operator, reducing the Due to visual constraints caused by the misuse of the accident. In the construction machinery such as construction, mining and other industries have been widely used to speed up the process of national industrialization.
First, the basic principles of radio-electric control technology
First, the radio hydraulic control system operator or machine control instructions to digital processing (including the signal filtering, A / D conversion and other processing), into a simple digital signal processing; secondly, the radio frequency control system, , The digital instruction signal encoding process; again, the command signal in the digital modulation by the transmission system, through the transmitting antenna in the form of radio waves transmitted to the distant receiving system. Finally, the receiving system through the receiving antenna to control the command angle bender with the radio wave received down, after demodulation and decoding, converted to control instructions, to achieve the various types of valve control.
Because of its important position in the field of construction machinery, it has attracted more and more attention from all over the world. It has invested a lot of technical resources and funds for research and development. Although the infrared remote control can also achieve remote control of electro-hydraulic control technology, but because of the existence of infrared remote control on the background of high demand, high energy consumption, transmission distance is short (usually not more than 10 meters), and must be in the same line, There are any obstructions and susceptibility to industrial heat radiation and other shortcomings, making the radio and electric liquid control technology has become the main direction of the current study.
Second, the status and trends of the research on radio-electro-hydraulic control technology
(1) Research status of radio electro-hydraulic control technology
Initially, the remote control electro-hydraulic control system is the use of wired remote control manner. As early as the early 60s, people can use the streamer remote control device to control the hydraulic machinery manual, electro-hydraulic multi-valve, the operation of the cable through the remote control device on the bi-directional rocker output linear proportional signal to control the electro-hydraulic Proportional multi-way valve, wire box rocker signal can fully simulate the hydraulic multi-way valve manual rod action. Although this approach allows the operator to operate the machine outside of the operating area, the control signal is attenuated in the cable so that the distance of the remote control is limited and the flexibility of the cable is affected by the presence of the cable , And a few meters long cable is often the main source of accidents in the production.
With the maturation of radio technology, the radio technology into electro-hydraulic control system has become possible. As the radio-electric liquid control custom cnc machine technology is to pass radio waves to control the command, completely eliminating the streamer-type remote control devices brought about by hidden dangers. But the beginning of the radio hydraulic control system can only launch a simple command, such as: open / close and other instructions. Into the 1970s, with the large-scale integrated circuits and the emergence of special microprocessors, developed a more reliable handheld wireless remote control system. Later, with the rapid development of digital processing technology, wireless digital communication technology matures, the use of digital communication technology, anti-interference ability, easy to digital signal processing, and so the advantages of making remote control system anti-jamming performance At the same time, the rapid development of analog integrated circuit design, a variety of high-precision analog / digital converters (A / D) and digital / analog converter (D / A) of the successful development, and the development of high-performance, They can be applied to the radio-electro-hydraulic control system so that the radio-hydraulic control system can not only transmit the switching signal, but also can transmit the analog control quantity and have higher resolving power to the control command, that is, the radio-hydraulic control system not only can control the ordinary Electromagnetic switch valve, but also to control the proportional valve.
As the electro-hydraulic control technology has the advantages of electro-hydraulic control technology, but also the advantages of wireless technology, so it has a very wide range of applications, especially in the field of construction machinery. Typical applications of the radio-electro-hydraulic control system are industrial vehicles, truck cranes, lorry cranes, concrete pumps (jibs), shield-boring machines and the like.
The early 80s, the United States Kraft TeleRobtics and John Deere and other companies, have developed a wireless remote control system, and used in excavators, the successful launch of 3D CNC Drilling Machine remote excavator. Among them, the more typical is John Deere’s 690CR remote excavator.
In 1983, Japan’s Komatsu research and development of a variety of work devices of the micro-control and composite operation of the radio control, and successfully converted PC200-2 hydraulic excavator.
In 1987, the German HBC company successfully developed for engineering machinery in the field of industrial radio remote control devices. The remote control device uses advanced digital communication technology, transmission ratio control signal safe, reliable and practical, and has a high resolution of the transmitted instructions; use of analog technology at the receiving end can make the implementation of acceleration and deceleration movements And the radio remote control device is completely proportional to the action on the transmitter, in order to achieve the stepless control of the implementing agencies. Using it, combined with electro-hydraulic proportional servo drive mechanism, hydraulic proportional multi-way valve and electro-hydraulic proportional pressure reducing valve and the general electromagnetic control on-off valve, can realize the construction machinery wireless remote control. German HBC radio remote control system uses the proportional output signal (0-5V / 10V, 4-20mA, PWM0-2A) with a number of manufacturers of bevelling machine electro-hydraulic multi-valve signal matching, simulation can be achieved manually with the hydraulic control system to each other .
Compared with the research and application of radio-electro-hydraulic control technology in foreign countries, the domestic is relatively late, the technology is relatively lagging behind. Shanghai Baoshan Iron and Steel Company in 1997, the introduction of HBC wireless remote control system, Italy FABERCOM proportion of hydraulic servo module, the Yellow River Engineering Machinery Plant produced ZY65-type crawler loader remote control transformation, making it a remote control loader.
(2) Research trends of radio electro-hydraulic control technology
With the rapid development of digital communication technology and VLSI, the application of digital communication technology and high-performance, highly integrated integrated circuits to radio-electro-hydraulic control technology makes the performance of radio-electrohydraulic controller more perfect and reliability higher. . (1) the rapid development of VLSI to improve the reliability of the hardware circuit of the radio hydraulic controller, at the same time to provide a more powerful function for the realization of the (1) the development of ultra-large-scale integrated circuits, possibility;
(2) digital communication technology to improve the performance of the radio electro-hydraulic controller;
(3) error correction coding technology to improve the radio anti-jamming capability of liquid control.
Third, the conclusion
As the electro-hydraulic proportional technology has many advantages, in the field of construction machinery has been widely used. The application of this technology in engineering machinery will have important engineering application significance.