Designation. A system is designed for automatic tracking of a center of weld reinforcing bead during automatic ultrasonic testing (AUT) of longitudinal pipe welds. SF-100 system is an independent weld tracking circuit for one mechano-acoustic block. Two or three tracking circuits can be installed depending on AUT unit type.
Structure and operation concept. Each SF-100 tracking system consists of laser-TV sensing block; communication controller; signal and power supply cables kit.
Function of the laser-TV sensors is based on a laser triangulation method. A narrow laser beam is projected on the object surface and registered with a video camera. Image of a light trace is a curve, nature of which corresponds to a surface geometry of the object being measured. Necessary parameters of the object, in this case a value of transverse displacement of the center of weld reinforcing bead, are determined as a result of TV images processing. The sensing blocks are set directly on mechano-acoustic blocks of the AUT units.
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A communication controller is designed as an interface between operator, sensors and peripheral devices such as main controller or/and electric drives of the devices for transverse adjustment of mechano-acoustic blocks. The digital signals are used for interaction with the peripheral devices. Indicator and function buttons are applied for communication with an operator. The communication controllers can be installed separately as well as in the cabinets together with electric equipment of AUT units.
The laser-TV sensor and commutation controller are microprocessor devices of commercial realization. A galvanic insulation of all power supply and signal cables is realized. The devices are fully interchangeable, i.e. there is no sensor-controller binding.
TV port of the sensing block is a standard analogue TV signal in PAL format that can be connected to any display of the Customer equipped with corresponding TV port.
A weld tracking takes place in the following way. The sensing block determines the value and sign of transverse displacement of the weld reinforcing bead and transfers acquired data to the communication controller. The latter, in turn, transforms received data into the digital driving signals for a mechanism of transverse adjustment of the mechano-acoustic block.
The interface tools of the communication controller are used for direct setting of the tracking system main parameters. Setting of the additional system parameters is carried out with special software of external computer, which can be connected to the communication controller using standard Ethernet interface.
SF-100 tracking systems are characterized by enhanced indices of noise immunity, reliability, fast response and sensitivity to weld height. They are equipped with TV signal output means. The signal can be used for visual monitoring of the tracking process.
Necessary functions of SF-100 tracking system, list of required digital signals and communication interfaces are additionally agreed between the Performer and the Customer at a stage of preparation of Technical Assignment.
Performance characteristics
| Accuracy of tracking for a center of weld reinforcing bead, mm | ±5 |
| Sensor operating area in transverse direction, mm | ±30 |
| Sensor operating area in vertical direction, mm | ±25 |
| Maximum length of communication line between laser sensor and communication controller, m | 50 |
| Standard of sensor output TV signal | PAL |
| Power supply | 24 В |
| Consumed power, W, not more than | 20 |
| Sensor IP protection | IP64 |
| Operating temperature range, °С | -10..+50 |
