NDT.net May 2004, Vol. 9 No.05

YXLON.MU231 - Structure of an In-Line X-Ray Wheel Inspection System
Andreas Beyer, Product Marketing
YXLON International X-Ray GmbH, Essener Str. 99, D-22419 Hamburg
Fon: 040/52729-405; Fax: 040/52729-272; E-mail: andreas.beyer@hbg.yxlon.com

The main components of an inspection system are:

  • Lead cabin (1) with shuttles (2) for the transport of wheels in/out the cabin
  • Decollators to get single wheels for transportation in the cabin
  • X-ray tube (3), Image Intensifier (4), High-voltage generator, X-ray control unit (5)
  • Industrial PC (6) (with mechanical positions and X-ray parameters for every wheel type)
  • Control cabinet with PLC (7)
  • Wheel manipulator (8) (Rotation and linear movement of wheels)
  • X-ray-manipulator (9) (tilt axis with X-ray tube and Image intensifier)
  • Vision System for wheel type recognition
  • Image-Processing Unit (Host PC with Slave PCs)
  • Output conveyor (10) e.g. with an alterable switch (for accepted wheels / rejects)

MU231 X-Ray inspection system for light cast wheels

Wheel handling


inner view of wheel and shuttles
Main task of the MU-231 x-ray inspection system is the 100% in-line inspection of lightweight alloy wheels. Depending on the test outcome determined either by a skilled operator or using YXLON's fully automatic defect recognition system, Y.AI/Rel.9, the tested wheels are precisely sorted according to the test result.

One of the fundamental new features of the YXLON.MU231 wheel inspection system is its robust and specially designed duplex chain manipulator (8). This method uses two chains to position the alloy wheels quickly and provides maximum flexibility for the x-ray inspection without having fixtures or parts of the cabinet in the field of view.

The wheel under inspection is gripped and positioned via two individually rotating chains. Translatory and rotatory movement of the wheel is done by the two chains that position the wheel between the x-ray source and image intensifier. By splitting the manipulation system into wheel manipulation (8) and x-ray/image intensifier manipulator (9), the time to position the wheel for x-ray inspection is decreased even further.

If equipped as a semiautomatic visual inspection system or as a fully automatic x-ray inspection system with YXLONs automatic defect recognition program, Y.AI/Rel.9, wheels can be tested randomly or in batches. The automatic wheel type recognition of individual, pre-set wheels ensures that only the type specific inspection program is selected.

X-ray image of a light cast wheel

X-ray image of a light cast wheel

X-ray image of a light cast wheel

Fully automatic defect recognition (ADR)

Fully automatic, 100% x-ray inspection of alloy wheels using YXLON's Y.AI/Rel.9 ADR program reaches a cycle time below 25 seconds per wheel.
Automatic monitoring of X-ray and imaging conditions ensures consistent boundary conditions for reliable inspection results. The unique region of interest (ROI) capability enables individual corrections and parameter settings for inspecting the different regions of the X-ray image. Thus any anomalies can be precisely surveyed and classified according to individual and pre-defined quality standards. In contrast to other methods, Y.AI/Rel.9 compensates for different local disruptive factors; e.g., image distortion or variances in magnification.

The result is a constantly objective, reproducible inspection decision that does not vary with the time of day. Individual program parameters can be set to comply with all major car manufacturers' quality specifications such as VW/Audi PV6601, BMW QV 36026, VW 501 22, ASTM E-155, or AK-LH08. The inspection data can be archived and the on-line statistics help to optimize the production process. Due to the simple, intuitive user interface, both the set up of new inspection programs and the adjustment of existing programs can be done quickly and easily.

More than half the 100 MU-231 inspection systems sold by YXLON are equipped with an ADR program. Its modular concept allows the system to be upgraded with the Y.AI/Rel.9 ADR program.

Modern X-ray technology

YXLON International is the leading producer of state-of-the-art industrial X-ray technology components. The unipolar 40kHz X-ray systems feature very high output stability, precise energy setting and extremely fast change over to any new value.

The x-ray tube (3) is especially high powered (1000 Watt) and has two identical focal spots of 0,4 x 0,4mm acc. IEC 336 for redundancy. The small sized focus spots provide a fine spatial resolution. Optionally a 9" or 12" image intensifier can be integrated.

YXLON International's industrial grade image intensifier systems are designed specifically for the high demands of the non-destructive testing environment. High resolution and excellent contrast latitude are realized in three different display formats that enable the operator to distinguish image information more clearly. Innovations like the use of non-browning output glass assure consistent results and prolonged operating life. All these factors combine to result in low-noise images of the highest quality.

System Controls

The system controls are based on a Siemens Slot-CPU that is integrated in an industrial rack mounted PC. Ergonomically positioned Joysticks and pushbuttons on the operators console let the operator handle the whole system intuitively. The system's MMI is a very user friendly, ergonomically designed graphical user interface which allows access to specific process controls and related information .

Position specific parameters or even statistical information can be accessed and controlled by a windows-like GUI. System operation is straightforward and can be learned in a short period of time.

Mechanical concept

The platform-based construction (control cabinet and lead shielded cabinet mounted on a common base) assures simple transport and quick installation of the whole system at the foundry. Even a move within or to another foundry is easily possible at a later date. The footprint of the cabinet is reduced to approx. 4.3 x 2.5m. The lead shielded cabinet is designed to meet the latest German X-ray law (RV) from 18.06.2002 and US Standard regulations 21CFR1020.40, 47CFR15 (FCC).

Due to the usage of two closed shuttle systems (2) at the entrance and exit of the lead cabinet, x-ray protection is guaranteed even during the loading and unloading sequence. Therefore the x-ray source can operate constantly. This detail of the MU231 system concept assures a high throughput and fast changeover time. Fewer moving parts contribute to reduced mechanical wear unlike when product doors need to open and the x-ray source needs to be shut down when changing the test parts. For maintenance and service purposes the lead shielded cabinet has large service doors to access relevant assemblies fast and safely.

The experience gained from selling 100 systems of this kind worldwide has made it possible to constantly and significantly reduce the number of wear parts. This leads to increased time between maintenance intervals, reduces the necessary spare parts stock, and saves money.


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