You may be familiar with systems that debit your account by reading the transponder on your vehicle as you pass through a toll gate. These systems use rfid.
What is Radio Frequency Technology?
RF technology is used in many different applications, such as television, radio, cellular phones, radar, and automatic identification systems. The term RFID (radio frequency identification) describes the use of radio frequency signals to provide automatic identification of items. RFID is used in applications such as:
· Electronic toll collection (ETC )
· Railway car identification and tracking
· Intermodal container identification
· Asset identification and tracking
· Item management for retail, health care, and logistics applications
· Access control
· Animal identification
· Fuel dispensing loyalty programs
- Automobile immobilizing (security)
Radio frequency (RF) refers to electromagnetic waves that have a wavelength suited for use in radio communication. Radio waves are classified by their frequencies, which are expressed in kilohertz, megahertz, or gigahertz. Radio frequencies range from very low frequency (VLF), which has a range of 10 to 30 kHz, to extremely high frequency (EHF), which has a range of 30 to 300 GHz.
RFID is a flexible technology that is convenient, easy to use, and well suited for automatic operation. It combines advantages not available with other identification technologies. RFID can be supplied as read-only or read/write, does not require contact or line-of-sight to operate, can function under a variety of environmental conditions, and provides a high level of data integrity. In addition, because the technology is difficult to counterfeit, RFID provides a high level of security.
RFID is similar in concept to bar coding. Bar code systems use a reader and coded labels that are attached to an item, whereas RFID uses a reader and special RFID devices that are attached to an item. Bar code uses optical signals to transfer information from the label to the reader; RFID uses RF signals to transfer information from the RFID device to the reader.
Radio waves transfer data between an item to which an RFID device is attached and an RFID reader. The device can contain data about the item, such as what the item is, what time the device traveled through a certain zone, perhaps even a parameter such as temperature. RFID devices, such as a tag or label, can be attached to virtually anything - from a vehicle to a pallet of merchandise.
RFID technology uses frequencies within the range of 50 kHz to 2.5 GHz. An RFID system typically includes the following components:
· An RFID device (transponder or tag) that contains data about an item
· An antenna used to transmit the RF signals between the reader and the RFID device
· An RF transceiver that generates the RF signals
- A reader that receives RF transmissions from an RFID device and passes the data to a host system for processing
In addition to this basic RFID equipment, an RFID system includes application-specific software.
Need of RF Technology
The demands on modern automobile production are high. The product must be accompanied by detailed data for quality assurance and documentation purposes in almost all production steps. Product processes of supplier parts, modules and subsystems must have maximum reproducibility, and be traceable throughout the process. The clear identification of the supplied modules is extremely important especially in the production of different types of vehicles on one line. Insensitivity to heat and soiling by dust, oil or water is a prerequisite for use of rewritable data memories in the harsh production environment of the automotive industry. Reusable information carrier installed directly on the workpiece or workpiece holder, which can be written and read without contact have proven excellent for these jobs.
Giant of a technology
Siemens provides identification and tracking systems, which are offered under the name of Moby. The robust radio frequency identification (RFID) systems are available in different versions for a range of tasks - from low-cost data media as a barcode replacement through ID systems for goods logistics to heat-resistant data media for the automotive industry.
Moby, with its writable/readable data memories, has decisive advantages over fixed code systems such as identification by barcode. With fixed code systems an object can merely be identified because all information above and beyond this is stored in a central database. The intelligent Moby identification system on the other hand saves the data on mobile data carriers directly on the object. The object can therefore continue being processed even when the network is overloaded; fails or the central server is unavailable. Another advantage is that subsystems can be started independently of the central data storage. Since setting parameters for processing machines or production controllers can also be saved in the mobile data memories, Moby also helps to minimise the tooling times in the process.
Safe and robust
Every Moby system is basically made up of three components: the mobile data memory (MDS), the write/read device (SLG), and the interface module (ASM). The mobile data memory is mounted directly on the object to be identified. Depending on the type of application, Moby provides different data media-from the simple, low-cost smart labels to the extremely robust memory media for industrial applications. Their strength lies not only in the high data security, but also in the excellent high degree of protection against ambient conditions such as soiling, temperature fluctuations, washing, or exposure to shock.
Up to 32 kb of data can be saved, read, and added to individually as required at the various workstations and production stations. High-temperature data memories are available specially for use in paint shops. The transmission frequency of 1.81 MHz, 13.56 MHz or 2.5 GHz makes Moby largely insensitive to electromagnetic faults. Even extreme ambient influences have no effect on the systems.
The information - apart from a few exceptions the energy - is transferred from the writer/reader, without contact by radio or inductively to the mobile data memory or read out of the memory. The data memory can move past the writer/reader at up to 20 metre per second. The transmission remains uninfluenced by dust and moisture, and non-metallic constructions such as Plexiglas panes or plastic covers. The write/read device can be connected directly to a PC or the interface module by a serial interface.
The interface module is the port to the world of automation and makes sure that the write/read device can communicate with Simatic and Sinumerik controllers and can be integrated in Profibus and some Moby systems in other networks such as Ethernet. The interface module only needs to be supplied with the appropriate parameters once and is then able to handle the data traffic with the mobile data memories independently. Since Moby has no moving parts and operates without contact, the system is free from wear, low maintenance and very robust.
Made for automotive…
Of the Moby product family, Moby I is used mainly in the automotive industry. Moby is distinguished by a very high immunity to interference from electromagnetic fields, resistance to soiling and temperature fluctuations. Up to 32 kb are transmitted at a net rate of 0.8 milliseconds per byte. Moby I has been equipped with a FRAM memory without batteries for a few years now. And data memories, which can easily be operated in temperatures up to 220 0C are available for this system especially for the identification of skids (body part carriers).
The new RF identification system Moby P is designed for use in small assembly lines and for production automation. It is suitable both for simple and complex applications and has a convincing price/performance ratio. A fast and reliable data transmission offers short cycle times with high data security. The low cost IQ-Sense interface technique via a two-wire line is available for communication with the Simatic. Apart from the system diagnostics, this allows individual write/read devices to be replaced during operation.
Nutrunners… on hand
A particularly fascinating solution was chosen in the section of production, in which the powertrain of the new Passat is assembled. Here the engine block and gear have to be fitted with the drive shafts and springs and all peripheral engine components so that a functional drivetrain is finally produced which is ready for installation in the body. Until now the individual components of the powertrain unit had to be mounted using various nutrunning systems - from handheld EC nutrunners to pneumatic nutrunners - which hung down from overhead rails and had to be pulled to the respective working position by the workers.
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|Posted : 10/26/2005|