{{unreferenced, date=April 2014 Closed-loop manufacturing (abbreviated CLM) is a closed-loop process of

manufacturing Manufacturing is the creation or production of goods with the help of equipment, labor, machines, tools, and chemical or biological processing or formulation. It is the essence of secondary sector of the economy. The term may refer to ...

and

measuring Measurement is the quantification of attributes of an object or event, which can be used to compare with other objects or events. In other words, measurement is a process of determining how large or small a physical quantity is as compared ...

(checking) in the manufacturing machine. The pre-stage to this is inspection in manufacturing. The idea is to reduce costs and improve the quality and accuracy of the produced parts.

General procedure

Closed-loop manufacturing can be done in different ways dependent on the manufacturing technique and on the

accuracy Accuracy and precision are two measures of ''observational error''. ''Accuracy'' is how close a given set of measurements ( observations or readings) are to their ''true value'', while ''precision'' is how close the measurements are to each oth ...

requirements. # Planning the sequence (iterations) # Producing nearly the target value on the part # Measuring the real value # Calculating the residual (stop if residual is smaller than needed accuracy) # Manufacturing the residual # Repeat from Step 3

Suitable manufacturing techniques

CLM is very suitable for

electrical discharge machining Electrical discharge machining (EDM), also known as spark machining, spark eroding, die sinking, wire burning or wire erosion, is a metal fabrication process whereby a desired shape is obtained by using electrical discharges (sparks). Material i ...

. Milling or

turning Turning is a machining process in which a cutting tool, typically a non-rotary tool bit, describes a helix toolpath by moving more or less linearly while the workpiece rotates. Usually the term "turning" is reserved for the generation ...

is also suitable for CLM.

Suitable measuring techniques

In machining measurement techniques have to fulfill special needs. In particular

optical Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behaviour of visible, ultravio ...

techniques have the advantage that they do not touch the part. The following parts are practically used: * Focus variation *

Tactile Tactile may refer to: * Tactile, related to the sense of touch * Haptics (disambiguation) * Tactile (device), a text-to-braille translation device See also * Tangibility, in law * Somatosensory system, where sensations are processed * CD96 CD ...

probes

Advantages / Disadvantages

The advantages are: * Reduce tool costs * Improving

* Quality control is done in the machine directly *

Measuring Measurement is the quantification of attributes of an object or event, which can be used to compare with other objects or events. In other words, measurement is a process of determining how large or small a physical quantity is as compared ...

can be more accurate because the part does not need to be unloaded * Better deployment of personnel * Integrated sensor eliminates clamping errors The disadvantages are: * Planning is needed * If planning is not done, machine time is increased

External links

EU EMRP project on traceable in-process dimensional measurement
Manufacturing