Objective
The evenness of geometric parameters of a textile like thickness, density of warp and weft define its final quality. Principally given by the primary construction these parameters are sometimes object to heavy changes due to processes in the finishing industry. A prime example is the heat-setting of a fabric in the stenter frame, where the effective thread density can be controlled by machine parameters. Although aimed at in close tolerances, the lack of on-line sensor and control systems results in machines set up by experience and trial and in varying thread densities within lengths of textile. As common method the final thread density is taken by off-line analysis from the finished product. Accordingly no real control of the geometry effects of the stenter process is possible today. The needed fast on-line measurement of the thread density has been made possible by a new sensing on the basis of optical profilometry. This measuring technique provides the tool for an integrated sensing and control system for pre-setting machine parameter of the stenter frame and other continuous processes.
It is the scope of the proposed project to set up a complex system of these low-cost sensors for thread density monitoring at various stages in the machine and to design an intelligent control circuit for automatic set up and on-line control of machine parameters.
A prototype intelligent multi-sensor system based on a low-cost, geometry sensitive type of sensor for the fast on-line measurement of the thread density of the textiles at industrial process speeds was designed as a precompetitive development.
On the reasons of cost, measuring speed and performance, optical profilometry was chosen as the measuring principle. Sensors (based on the triangulation priciple) were specially manufactured for the application. Fast and reliable evaluation of the time dependent signal train recorded by the sensors was achieved by means of a software-based, mathematical frequency analysis.
To achieve the various tasks of signal recording and analysis of the isolated sensors in continuous mode and in real time a hardware concept of modular architecture was developed in order to divide the sensing, controlling and analysing tasks to individual components, which can act simultaneously.
The actual performance of the multisensor design was tested under industrial conditions. The experimental system yielded a very high accuracy for geometry recordings in the region of +/- 2% under industrial conditions with machine speeds up to 140 meters per minute, with very fast analysing cycles appropriate for on-line measurements. No influence of fabric movement was detected at machine speeds. Samples with a rms-deviation in excess of 2 %, i.e. non-constant geometry with a danger not to meet tolerances, or too high or low mean values, i.e. failure to meet the customer specified set-value, could be identified.
In the frame of actual control experiments the controlling feedback was taken from a sensor placed at the machine's exit to the overfeed control. As could be clearly shown, arbitrary changes of the set values resulted in automatic reaction of the overfeed control. At all times the effective mean number of threads per cm equalled the set values.
Fields of science (EuroSciVoc)
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques.
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques.
- engineering and technologyelectrical engineering, electronic engineering, information engineeringelectronic engineeringcontrol systems
- engineering and technologymaterials engineeringtextiles
- engineering and technologyelectrical engineering, electronic engineering, information engineeringelectronic engineeringsensors
- natural sciencesmathematicspure mathematicsgeometry
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Topic(s)
Data not availableCall for proposal
Data not availableFunding Scheme
CSC - Cost-sharing contractsCoordinator
47803 Krefeld
Germany