The emergence of smart instruments has greatly expanded the application of traditional instruments. By virtue of their small size, high functionality and low utility, smart instruments are rapidly being widely used in electrical, scientific and industrial establishments at home。
1. The working principles of smart instruments
The sensor picks up the information to be measured and converts it to a telecommunications number, removes the interference from the filter and sends it to a multi-road simulation switch; delivers the signal from each input channel to a flight control gain amplifier on a single-branded basis, which is converted from a/d converter to the corresponding pulsed signal into a single machine; calculates and processes the corresponding data (e. G., non-linear correction, etc.) according to the starting value set by the instrument; displays and prints the result of the calculation; and also compares the results of the operation with the parameters stored in the film in flasholm (slash-tracked storage) or e-m (e. G., e., e., eraseable to remove storage receptacles) by comparison with the resulting control signal (e. G., alarm trigger, relay touch points, etc.) based on the results and control requirements. In addition, smart instruments can form a distributed monitoring and control system with the pc machine, which collects a variety of measurement signals and data from the single machine as the lower machine, transmits information through serial communication to the upper machine, the pc machine, and is managed by the pc machine as a whole。
2. Functional characteristics of smart instruments
As microelectronics continue to develop, the formation of cpu, storage, timer/calculator, parallel and serial interfaces, doordogs, front amplifiers and even a/d, d/a converters, etc., have emerged on a large-scale integrated circuit chip (i. E. A single machine) on a chip. A single-piece machine, which combines computer technology with measurement control technology, forms the so-called “smart measurement control system”, i. E. A smart instrument。
Smart instruments have the following functional characteristics compared to traditional instruments:
1 operational automation. The entire measurement process of the instrument, such as keyboard scanning, range selection, switch activation closed, data collection, transmission and processing, and display printing, is controlled by single machine or microcontrollers, which achieves full automation of the measurement process。
2 has self-detective functions, including automatic zero, automatic failure and state tests, automatic calibration, self-diagnosis and automatic conversion of the quantum process. The smart instrument automatically detects the faulty parts or even the cause of the failure. Such self-testing can be performed at the time the instrument is activated, but also during the operation of the instrument, which greatly facilitates its maintenance。
Data processing functions are one of the main advantages of smart instruments. Intelligent instruments, through the use of single-formula or microcontrollers, make many of the problems that were previously difficult to resolve with hardware logic or simply impossible to resolve, which can now be addressed with great flexibility by software. For example, while the traditional one-size-fits-all tables can only measure electrical resistance, direct current voltage, currents, etc., the smart one-by-one tables not only allow such measurements, but also have complex data-processing functions such as zero-point offsets, averages, polarization, statistical analysis, which not only free users from heavy data processing, but also effectively improve instrument measurement accuracy。
4 a friendly human dialogue capability. Smart instruments use keyboards instead of switch switches in traditional instruments, and operators can perform some measurement function by simply using keyboard input commands. At the same time, smart instruments make their operation more intuitive by displaying screens that inform operators of their performance, working status and processing of measurements。
5 has programmable operational capability. General smart instruments are equipped with communication interfaces of gpib, rs232c, rs485 and can easily form, together with pcs and other instruments, an automated measurement system of multiple functions required by users to perform more complex test tasks。
Overview of the development of smart instruments
In the 1980s, microprocessors were used in the instrument, and the front panel of the instrument began to move in the direction of keyboardization, and the measurement system was often connected through the ieee-488 bus。
Personal instruments that differ from traditional independent models have been developed, for example。
In the 1990s, the intellectualization of instrument instruments was highlighted in the following ways: advances in microelectronics have more profoundly influenced the design of instrument instruments; the advent of the dsp chip has significantly enhanced the digital signal processing function of instrument instruments; the development of micromachines has made instrument instruments more capable of processing data; the increase in image processing functions is widespread; and the wide application of the vxi bus。
In recent years, the development of intelligent measurement control instruments has been particularly rapid. A wide variety of intelligent measurement control instruments have emerged in the domestic market, such as the smart flow meter that automatically compensates for differential pressure, the smart multi-temperature control that allows programme temperature control, the smart mode regulator that achieves digital ped and complex control patterns, and the smart chromatograph that allows for the analysis of spectrographs and data processing。
International smart gauges are more numerous, for example, the dstj-3000 series of smart transmitters produced by honeywell in the united states, capable of composite measurements of the state of the differential value, providing automatic compensation for the temperature, static pressure, etc. Of the carrier's core, with accuracy of up to > 0. 1 per cent fs; the 9303 ultra-high-altitude scales produced by raca-dana in the united states, using microprocessors to remove heat noise from currents through electrical resistance, measuring electrons up to -77db; the super multifunctional calibration made by fluke in the united states, 5520a, using three microprocessors with short-term stability of up to 1 ppm, linearly up to 0. 5 ppm; and the digital self-regulating adjusters produced by foxboro in the united states, using expert system techniques capable of rapid adjustment based on field parameters, as experienced control engineers. Such regulators are particularly suitable for control systems that are frequent or non-linear in object changes. As such regulators can automatically adjust their parameters, they can maintain the best quality throughout the production process。
4. Trends in smart instruments
4. 1 minimation
Micro-intelligence instruments refer to a combination of microelectronics, micromechanical technologies, information technology, etc., which are used in their production, thus making them small and fully functional smart instruments. It can perform signal acquisition, linear processing, digital signal processing, control of signal output, magnification, interface with other instruments, interaction with people, etc. Micro-intelligence instruments will continue to expand their fields of application as they continue to develop their technological maturity and lower prices as micro-electronic machinery technologies develop. It not only functions as a traditional instrument but also plays a unique role in the fields of automation technology, space, military, biotechnology and medicine. For example, several different parameters for a patient are currently being measured simultaneously and some parameters are being controlled, usually with several tubes inserted into the patient's body, which increases the risk of infection in the patient, with micro-smart devices capable of measuring multiple parameters at the same time and small in size and implanting into the human body, thus addressing these problems。
4. 2 multifunctional
Multifunctionality is itself a feature of smart instrument meters. For example, in order to design faster and more complex digital systems, instrument producers have produced function generators with pulse generators, frequency synthesizers and any wave-form generators. This multifunctional composite product provides not only higher performance (e. G. Accuracy) than special pulse generators and frequency compositers, but also better solutions for various test functions。
4. 3 artificial intelligence
Artificial intelligence is a new field in computer applications, using computer simulators ' intelligence for robotics, medical diagnostics, expert systems, reasoning. The further development of smart instruments will include some artificial intelligence, i. E. A part of the intellectual work that replaces a human being, with a certain capacity in the areas of vision (figures and colour reading), hearing (voice recognition and language awareness), thinking (delineation, judgement, learning and association)。
In this way, smart instruments can perform detection or control functions autonomously without human intervention. It is clear that the application of artificial intelligence in modern instrumentation forms has allowed us not only to resolve a type of problem that is difficult to resolve by traditional methods, but also to be expected to solve problems that cannot be solved by traditional methods at all。
4. 4 integration of isp and emit technology to achieve internet access to instrumentation systems (networked)
With the rapid development of network technology, the internet technology is gradually penetrating into industrial control and the design of smart instrument systems, achieving internet-based communication capabilities for smart instrument systems and remote upgrading, functional replacement and system maintenance for designed smart instrument systems。
The system programming technology (in-systemprogramming, short isp technology) is the latest technology to modify, organize or reorganize software. It is the first technology proposed by the lattice semiconductor company that enables us to organize or reorganize at any time the logic and functions of its devices, circuit boards or the entire electronic system at every point in the product design, manufacture and even after the product has been sold to the end-user. Isp technology removes some of the limitations and connectivity deficiencies of traditional technologies and facilitates the design, manufacture and programming of panels. Isp hardware is flexible and easy to modify to facilitate design development. Since it can be processed on the printed circuit board (pcb) like any other device, programming is not required for special programming devices and more complex processes, as long as it is programmed via the pc, embedded system processor or even internet remote network。
Emit embedded micro-internet connectivity technology was introduced by emware when it created the eti (extendtheinternet) extension internet alliance. It is a technology that connects embedded devices such as single-piece machines to internet. Using this technology, it is possible to connect 8 and 16-bit monomechanical systems to internet and to perform remote data acquisition, smart control, upload/downloading of data files based on internet。
Software, solidware and hardware products based on intelnet-based devicenetworking are currently available from united states firms, emware, tasking and domestic p&s。
4. 5 virtual instruments are a new stage in the development of smart instruments
The main functions of the instrument are composed of three main components: data collection, data analysis and data. In the virtual reality system, data analysis and displays are done exclusively using software from the pc machine. As a result, additional hardware for data collection could be provided to form measurement instruments with the pc machine. This pc-based instrument is known as a virtual instrument. In virtual instruments, using the same hardware system, measurement instruments with completely different functionality can be obtained if different software programming is applied. The software system is thus at the heart of the virtual instrument, “software is the instrument”。
Traditional smart instruments use some kind of computer technology mainly in instrument technology, while virtual instruments emphasize the absorption of instrument technology in generic computer technologies. Software systems, which are at the core of virtual instruments, are universal, popular, visual, scalable and upgraded and can bring great benefits to users, and therefore traditional smart instruments cannot be compared to applications and markets。
Concluding remarks
Smart instruments are a combination of new and emerging technologies such as computer science, electronics, digital signal processing, artificial intelligence, vlsi and traditional instrumentation techniques. With the development of relevant technologies, such as specialized integrated circuits and personal instruments, the use of smart instruments will become wider. Single-form computer technology, which is the core component of smart instruments, is the driving force for the development of smart instruments in a miniaturized, multifunctional and more flexible direction. It is expected that smart instruments of various functions will be widely used in all spheres of society in the near future。
