Flexible integration of robotics, ultrasonics and metrology for the inspection of aerospace components

Abstract

The performance of modern robotic manipulators has allowed research in recent years, for the development of fast automated non-destructive testing (NDT) of complex geometries. Contemporary robots are well suited for their accuracy and flexibility when adapting to new tasks. Several robotic inspection prototype systems and a number of commercial products have been created around the world. This paper describes the latest progress of a new phase of the research applied to a composite aerospace component of size 1 by 3 metres. A multi robot flexible inspection cell was used to take the fundamental research and the feasibility studies to higher technology readiness levels, all set for future industrial exploitation. The robot cell was equipped with high accuracy and high payload robots, mounted on 7 metre tracks, and an external rotary axis.A robotically delivered photogrammetry technique was first used to assess the position of the components placed within the robot working envelope and their deviation to CAD. Offline programming was used to generate a scan path for phased array ultrasonics testing (PAUT) which was implemented using high data rate acquisition from a conformable wheel probe.Real-time robot path-correction, based on force-torque control (FTC), was deployed to achieve the optimum ultrasonic coupling and repeatable data quality. New communication software was developed that enabled the simultaneous control of the multiple robots performing different tasks and the reception of accurate positional feedback positions. All aspects of the system were controlled through a purposely developed graphic user interface that enabled the flexible use of the unique set of hardware resources, the data acquisition, visualisation and analysis.Acknowledgement:

Vision guided robotic inspection for parts in manufacturing and remanufacturing industry

“…Robots are equipped with sensors such as cameras [35], lasers [17], radars [16], and ultrasonic probes [26]. For example, in a factory setting, robots equipped with ultrasonic probes have been able to perform NDT inspection successfully [26,27,37].…”

“…Robotic inspection of components in the manufacturing and remanufacturing industry has been a growing research area [2,13]. Ultrasonic-based inspection techniques have been used in robotic systems to speed up the NDT inspection of critical components [26,27,34]. Although such robotic systems have increased inspection rates, these autonomous systems are based on robots that manipulate ultrasonic sensors through predefined tool paths.…”

Quantifying performance of ultrasonic immersion inspection using phased arrays for curvilinear disc forgings

“…Work on automating the delivery of ultrasonic phased array inspection has focused on optimising coverage speed [7], and flexible trajectory planning [8]. For a given complex geometry, it will be necessary to define the optimal probe positioning for coverage.…”

Compressive Sensing for Direct Time of Flight Estimation in Ultrasound-based NDT

“…In the latter case, there is physical contact between the couplant and the surface of the structure. This contact has to be maintained at an appropriate pressure, which is subject to variation depending on the control strategy being implemented [5]. The changing pressure introduces a variation in time of the first arrival, across different A and B frames.…”

“…The C-scan shown in Figure 1c was generated using this data set, using a maximum autocorrelation to estimate the TOF. Further details of this experimental technique have been published in [5], where the interested reader is referred to for further details.…”